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Message-ID: <174747616799.406.8189583184895348016.tip-bot2@tip-bot2>
Date: Sat, 17 May 2025 10:02:47 -0000
From: "tip-bot2 for James Morse" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: James Morse <james.morse@....com>, "Borislav Petkov (AMD)" <bp@...en8.de>,
Reinette Chatre <reinette.chatre@...el.com>, Fenghua Yu <fenghuay@...dia.com>,
Tony Luck <tony.luck@...el.com>, x86@...nel.org, linux-kernel@...r.kernel.org
Subject: [tip: x86/cache] x86,fs/resctrl: Move the resctrl filesystem code to
live in /fs/resctrl
The following commit has been merged into the x86/cache branch of tip:
Commit-ID: 7168ae330e8105296210b2b2d31d791d5c073345
Gitweb: https://git.kernel.org/tip/7168ae330e8105296210b2b2d31d791d5c073345
Author: James Morse <james.morse@....com>
AuthorDate: Thu, 15 May 2025 16:58:54
Committer: Borislav Petkov (AMD) <bp@...en8.de>
CommitterDate: Fri, 16 May 2025 14:36:09 +02:00
x86,fs/resctrl: Move the resctrl filesystem code to live in /fs/resctrl
Resctrl is a filesystem interface to hardware that provides cache
allocation policy and bandwidth control for groups of tasks or CPUs.
To support more than one architecture, resctrl needs to live in /fs/.
Move the code that is concerned with the filesystem interface to
/fs/resctrl.
Signed-off-by: James Morse <james.morse@....com>
Signed-off-by: Borislav Petkov (AMD) <bp@...en8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@...el.com>
Reviewed-by: Fenghua Yu <fenghuay@...dia.com>
Tested-by: Fenghua Yu <fenghuay@...dia.com>
Tested-by: Tony Luck <tony.luck@...el.com>
Link: https://lore.kernel.org/20250515165855.31452-25-james.morse@arm.com
---
Documentation/arch/x86/index.rst | 1 +-
Documentation/arch/x86/resctrl.rst | 1523 +-----
Documentation/filesystems/index.rst | 1 +-
Documentation/filesystems/resctrl.rst | 1523 +++++-
MAINTAINERS | 2 +-
arch/x86/kernel/cpu/resctrl/Makefile | 1 +-
arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 641 +--
arch/x86/kernel/cpu/resctrl/internal.h | 371 +-
arch/x86/kernel/cpu/resctrl/monitor.c | 909 +---
arch/x86/kernel/cpu/resctrl/monitor_trace.h | 31 +-
arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 1087 +---
arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h | 2 +-
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 4597 +--------------
fs/resctrl/Kconfig | 2 +-
fs/resctrl/ctrlmondata.c | 661 ++-
fs/resctrl/internal.h | 426 +-
fs/resctrl/monitor.c | 929 +++-
fs/resctrl/monitor_trace.h | 33 +-
fs/resctrl/pseudo_lock.c | 1105 +++-
fs/resctrl/pseudo_lock_trace.h | 0
fs/resctrl/rdtgroup.c | 4353 +++++++++++++-
21 files changed, 9186 insertions(+), 9012 deletions(-)
delete mode 100644 Documentation/arch/x86/resctrl.rst
create mode 100644 Documentation/filesystems/resctrl.rst
delete mode 100644 arch/x86/kernel/cpu/resctrl/monitor_trace.h
delete mode 100644 fs/resctrl/pseudo_lock_trace.h
diff --git a/Documentation/arch/x86/index.rst b/Documentation/arch/x86/index.rst
index 8ac64d7..00f9a99 100644
--- a/Documentation/arch/x86/index.rst
+++ b/Documentation/arch/x86/index.rst
@@ -31,7 +31,6 @@ x86-specific Documentation
pti
mds
microcode
- resctrl
tsx_async_abort
buslock
usb-legacy-support
diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
deleted file mode 100644
index c7949dd..0000000
--- a/Documentation/arch/x86/resctrl.rst
+++ /dev/null
@@ -1,1523 +0,0 @@
-.. SPDX-License-Identifier: GPL-2.0
-.. include:: <isonum.txt>
-
-=====================================================
-User Interface for Resource Control feature (resctrl)
-=====================================================
-
-:Copyright: |copy| 2016 Intel Corporation
-:Authors: - Fenghua Yu <fenghua.yu@...el.com>
- - Tony Luck <tony.luck@...el.com>
- - Vikas Shivappa <vikas.shivappa@...el.com>
-
-
-Intel refers to this feature as Intel Resource Director Technology(Intel(R) RDT).
-AMD refers to this feature as AMD Platform Quality of Service(AMD QoS).
-
-This feature is enabled by the CONFIG_X86_CPU_RESCTRL and the x86 /proc/cpuinfo
-flag bits:
-
-=============================================== ================================
-RDT (Resource Director Technology) Allocation "rdt_a"
-CAT (Cache Allocation Technology) "cat_l3", "cat_l2"
-CDP (Code and Data Prioritization) "cdp_l3", "cdp_l2"
-CQM (Cache QoS Monitoring) "cqm_llc", "cqm_occup_llc"
-MBM (Memory Bandwidth Monitoring) "cqm_mbm_total", "cqm_mbm_local"
-MBA (Memory Bandwidth Allocation) "mba"
-SMBA (Slow Memory Bandwidth Allocation) ""
-BMEC (Bandwidth Monitoring Event Configuration) ""
-=============================================== ================================
-
-Historically, new features were made visible by default in /proc/cpuinfo. This
-resulted in the feature flags becoming hard to parse by humans. Adding a new
-flag to /proc/cpuinfo should be avoided if user space can obtain information
-about the feature from resctrl's info directory.
-
-To use the feature mount the file system::
-
- # mount -t resctrl resctrl [-o cdp[,cdpl2][,mba_MBps][,debug]] /sys/fs/resctrl
-
-mount options are:
-
-"cdp":
- Enable code/data prioritization in L3 cache allocations.
-"cdpl2":
- Enable code/data prioritization in L2 cache allocations.
-"mba_MBps":
- Enable the MBA Software Controller(mba_sc) to specify MBA
- bandwidth in MiBps
-"debug":
- Make debug files accessible. Available debug files are annotated with
- "Available only with debug option".
-
-L2 and L3 CDP are controlled separately.
-
-RDT features are orthogonal. A particular system may support only
-monitoring, only control, or both monitoring and control. Cache
-pseudo-locking is a unique way of using cache control to "pin" or
-"lock" data in the cache. Details can be found in
-"Cache Pseudo-Locking".
-
-
-The mount succeeds if either of allocation or monitoring is present, but
-only those files and directories supported by the system will be created.
-For more details on the behavior of the interface during monitoring
-and allocation, see the "Resource alloc and monitor groups" section.
-
-Info directory
-==============
-
-The 'info' directory contains information about the enabled
-resources. Each resource has its own subdirectory. The subdirectory
-names reflect the resource names.
-
-Each subdirectory contains the following files with respect to
-allocation:
-
-Cache resource(L3/L2) subdirectory contains the following files
-related to allocation:
-
-"num_closids":
- The number of CLOSIDs which are valid for this
- resource. The kernel uses the smallest number of
- CLOSIDs of all enabled resources as limit.
-"cbm_mask":
- The bitmask which is valid for this resource.
- This mask is equivalent to 100%.
-"min_cbm_bits":
- The minimum number of consecutive bits which
- must be set when writing a mask.
-
-"shareable_bits":
- Bitmask of shareable resource with other executing
- entities (e.g. I/O). User can use this when
- setting up exclusive cache partitions. Note that
- some platforms support devices that have their
- own settings for cache use which can over-ride
- these bits.
-"bit_usage":
- Annotated capacity bitmasks showing how all
- instances of the resource are used. The legend is:
-
- "0":
- Corresponding region is unused. When the system's
- resources have been allocated and a "0" is found
- in "bit_usage" it is a sign that resources are
- wasted.
-
- "H":
- Corresponding region is used by hardware only
- but available for software use. If a resource
- has bits set in "shareable_bits" but not all
- of these bits appear in the resource groups'
- schematas then the bits appearing in
- "shareable_bits" but no resource group will
- be marked as "H".
- "X":
- Corresponding region is available for sharing and
- used by hardware and software. These are the
- bits that appear in "shareable_bits" as
- well as a resource group's allocation.
- "S":
- Corresponding region is used by software
- and available for sharing.
- "E":
- Corresponding region is used exclusively by
- one resource group. No sharing allowed.
- "P":
- Corresponding region is pseudo-locked. No
- sharing allowed.
-"sparse_masks":
- Indicates if non-contiguous 1s value in CBM is supported.
-
- "0":
- Only contiguous 1s value in CBM is supported.
- "1":
- Non-contiguous 1s value in CBM is supported.
-
-Memory bandwidth(MB) subdirectory contains the following files
-with respect to allocation:
-
-"min_bandwidth":
- The minimum memory bandwidth percentage which
- user can request.
-
-"bandwidth_gran":
- The granularity in which the memory bandwidth
- percentage is allocated. The allocated
- b/w percentage is rounded off to the next
- control step available on the hardware. The
- available bandwidth control steps are:
- min_bandwidth + N * bandwidth_gran.
-
-"delay_linear":
- Indicates if the delay scale is linear or
- non-linear. This field is purely informational
- only.
-
-"thread_throttle_mode":
- Indicator on Intel systems of how tasks running on threads
- of a physical core are throttled in cases where they
- request different memory bandwidth percentages:
-
- "max":
- the smallest percentage is applied
- to all threads
- "per-thread":
- bandwidth percentages are directly applied to
- the threads running on the core
-
-If RDT monitoring is available there will be an "L3_MON" directory
-with the following files:
-
-"num_rmids":
- The number of RMIDs available. This is the
- upper bound for how many "CTRL_MON" + "MON"
- groups can be created.
-
-"mon_features":
- Lists the monitoring events if
- monitoring is enabled for the resource.
- Example::
-
- # cat /sys/fs/resctrl/info/L3_MON/mon_features
- llc_occupancy
- mbm_total_bytes
- mbm_local_bytes
-
- If the system supports Bandwidth Monitoring Event
- Configuration (BMEC), then the bandwidth events will
- be configurable. The output will be::
-
- # cat /sys/fs/resctrl/info/L3_MON/mon_features
- llc_occupancy
- mbm_total_bytes
- mbm_total_bytes_config
- mbm_local_bytes
- mbm_local_bytes_config
-
-"mbm_total_bytes_config", "mbm_local_bytes_config":
- Read/write files containing the configuration for the mbm_total_bytes
- and mbm_local_bytes events, respectively, when the Bandwidth
- Monitoring Event Configuration (BMEC) feature is supported.
- The event configuration settings are domain specific and affect
- all the CPUs in the domain. When either event configuration is
- changed, the bandwidth counters for all RMIDs of both events
- (mbm_total_bytes as well as mbm_local_bytes) are cleared for that
- domain. The next read for every RMID will report "Unavailable"
- and subsequent reads will report the valid value.
-
- Following are the types of events supported:
-
- ==== ========================================================
- Bits Description
- ==== ========================================================
- 6 Dirty Victims from the QOS domain to all types of memory
- 5 Reads to slow memory in the non-local NUMA domain
- 4 Reads to slow memory in the local NUMA domain
- 3 Non-temporal writes to non-local NUMA domain
- 2 Non-temporal writes to local NUMA domain
- 1 Reads to memory in the non-local NUMA domain
- 0 Reads to memory in the local NUMA domain
- ==== ========================================================
-
- By default, the mbm_total_bytes configuration is set to 0x7f to count
- all the event types and the mbm_local_bytes configuration is set to
- 0x15 to count all the local memory events.
-
- Examples:
-
- * To view the current configuration::
- ::
-
- # cat /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config
- 0=0x7f;1=0x7f;2=0x7f;3=0x7f
-
- # cat /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
- 0=0x15;1=0x15;3=0x15;4=0x15
-
- * To change the mbm_total_bytes to count only reads on domain 0,
- the bits 0, 1, 4 and 5 needs to be set, which is 110011b in binary
- (in hexadecimal 0x33):
- ::
-
- # echo "0=0x33" > /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config
-
- # cat /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config
- 0=0x33;1=0x7f;2=0x7f;3=0x7f
-
- * To change the mbm_local_bytes to count all the slow memory reads on
- domain 0 and 1, the bits 4 and 5 needs to be set, which is 110000b
- in binary (in hexadecimal 0x30):
- ::
-
- # echo "0=0x30;1=0x30" > /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
-
- # cat /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
- 0=0x30;1=0x30;3=0x15;4=0x15
-
-"max_threshold_occupancy":
- Read/write file provides the largest value (in
- bytes) at which a previously used LLC_occupancy
- counter can be considered for re-use.
-
-Finally, in the top level of the "info" directory there is a file
-named "last_cmd_status". This is reset with every "command" issued
-via the file system (making new directories or writing to any of the
-control files). If the command was successful, it will read as "ok".
-If the command failed, it will provide more information that can be
-conveyed in the error returns from file operations. E.g.
-::
-
- # echo L3:0=f7 > schemata
- bash: echo: write error: Invalid argument
- # cat info/last_cmd_status
- mask f7 has non-consecutive 1-bits
-
-Resource alloc and monitor groups
-=================================
-
-Resource groups are represented as directories in the resctrl file
-system. The default group is the root directory which, immediately
-after mounting, owns all the tasks and cpus in the system and can make
-full use of all resources.
-
-On a system with RDT control features additional directories can be
-created in the root directory that specify different amounts of each
-resource (see "schemata" below). The root and these additional top level
-directories are referred to as "CTRL_MON" groups below.
-
-On a system with RDT monitoring the root directory and other top level
-directories contain a directory named "mon_groups" in which additional
-directories can be created to monitor subsets of tasks in the CTRL_MON
-group that is their ancestor. These are called "MON" groups in the rest
-of this document.
-
-Removing a directory will move all tasks and cpus owned by the group it
-represents to the parent. Removing one of the created CTRL_MON groups
-will automatically remove all MON groups below it.
-
-Moving MON group directories to a new parent CTRL_MON group is supported
-for the purpose of changing the resource allocations of a MON group
-without impacting its monitoring data or assigned tasks. This operation
-is not allowed for MON groups which monitor CPUs. No other move
-operation is currently allowed other than simply renaming a CTRL_MON or
-MON group.
-
-All groups contain the following files:
-
-"tasks":
- Reading this file shows the list of all tasks that belong to
- this group. Writing a task id to the file will add a task to the
- group. Multiple tasks can be added by separating the task ids
- with commas. Tasks will be assigned sequentially. Multiple
- failures are not supported. A single failure encountered while
- attempting to assign a task will cause the operation to abort and
- already added tasks before the failure will remain in the group.
- Failures will be logged to /sys/fs/resctrl/info/last_cmd_status.
-
- If the group is a CTRL_MON group the task is removed from
- whichever previous CTRL_MON group owned the task and also from
- any MON group that owned the task. If the group is a MON group,
- then the task must already belong to the CTRL_MON parent of this
- group. The task is removed from any previous MON group.
-
-
-"cpus":
- Reading this file shows a bitmask of the logical CPUs owned by
- this group. Writing a mask to this file will add and remove
- CPUs to/from this group. As with the tasks file a hierarchy is
- maintained where MON groups may only include CPUs owned by the
- parent CTRL_MON group.
- When the resource group is in pseudo-locked mode this file will
- only be readable, reflecting the CPUs associated with the
- pseudo-locked region.
-
-
-"cpus_list":
- Just like "cpus", only using ranges of CPUs instead of bitmasks.
-
-
-When control is enabled all CTRL_MON groups will also contain:
-
-"schemata":
- A list of all the resources available to this group.
- Each resource has its own line and format - see below for details.
-
-"size":
- Mirrors the display of the "schemata" file to display the size in
- bytes of each allocation instead of the bits representing the
- allocation.
-
-"mode":
- The "mode" of the resource group dictates the sharing of its
- allocations. A "shareable" resource group allows sharing of its
- allocations while an "exclusive" resource group does not. A
- cache pseudo-locked region is created by first writing
- "pseudo-locksetup" to the "mode" file before writing the cache
- pseudo-locked region's schemata to the resource group's "schemata"
- file. On successful pseudo-locked region creation the mode will
- automatically change to "pseudo-locked".
-
-"ctrl_hw_id":
- Available only with debug option. The identifier used by hardware
- for the control group. On x86 this is the CLOSID.
-
-When monitoring is enabled all MON groups will also contain:
-
-"mon_data":
- This contains a set of files organized by L3 domain and by
- RDT event. E.g. on a system with two L3 domains there will
- be subdirectories "mon_L3_00" and "mon_L3_01". Each of these
- directories have one file per event (e.g. "llc_occupancy",
- "mbm_total_bytes", and "mbm_local_bytes"). In a MON group these
- files provide a read out of the current value of the event for
- all tasks in the group. In CTRL_MON groups these files provide
- the sum for all tasks in the CTRL_MON group and all tasks in
- MON groups. Please see example section for more details on usage.
- On systems with Sub-NUMA Cluster (SNC) enabled there are extra
- directories for each node (located within the "mon_L3_XX" directory
- for the L3 cache they occupy). These are named "mon_sub_L3_YY"
- where "YY" is the node number.
-
-"mon_hw_id":
- Available only with debug option. The identifier used by hardware
- for the monitor group. On x86 this is the RMID.
-
-When the "mba_MBps" mount option is used all CTRL_MON groups will also contain:
-
-"mba_MBps_event":
- Reading this file shows which memory bandwidth event is used
- as input to the software feedback loop that keeps memory bandwidth
- below the value specified in the schemata file. Writing the
- name of one of the supported memory bandwidth events found in
- /sys/fs/resctrl/info/L3_MON/mon_features changes the input
- event.
-
-Resource allocation rules
--------------------------
-
-When a task is running the following rules define which resources are
-available to it:
-
-1) If the task is a member of a non-default group, then the schemata
- for that group is used.
-
-2) Else if the task belongs to the default group, but is running on a
- CPU that is assigned to some specific group, then the schemata for the
- CPU's group is used.
-
-3) Otherwise the schemata for the default group is used.
-
-Resource monitoring rules
--------------------------
-1) If a task is a member of a MON group, or non-default CTRL_MON group
- then RDT events for the task will be reported in that group.
-
-2) If a task is a member of the default CTRL_MON group, but is running
- on a CPU that is assigned to some specific group, then the RDT events
- for the task will be reported in that group.
-
-3) Otherwise RDT events for the task will be reported in the root level
- "mon_data" group.
-
-
-Notes on cache occupancy monitoring and control
-===============================================
-When moving a task from one group to another you should remember that
-this only affects *new* cache allocations by the task. E.g. you may have
-a task in a monitor group showing 3 MB of cache occupancy. If you move
-to a new group and immediately check the occupancy of the old and new
-groups you will likely see that the old group is still showing 3 MB and
-the new group zero. When the task accesses locations still in cache from
-before the move, the h/w does not update any counters. On a busy system
-you will likely see the occupancy in the old group go down as cache lines
-are evicted and re-used while the occupancy in the new group rises as
-the task accesses memory and loads into the cache are counted based on
-membership in the new group.
-
-The same applies to cache allocation control. Moving a task to a group
-with a smaller cache partition will not evict any cache lines. The
-process may continue to use them from the old partition.
-
-Hardware uses CLOSid(Class of service ID) and an RMID(Resource monitoring ID)
-to identify a control group and a monitoring group respectively. Each of
-the resource groups are mapped to these IDs based on the kind of group. The
-number of CLOSid and RMID are limited by the hardware and hence the creation of
-a "CTRL_MON" directory may fail if we run out of either CLOSID or RMID
-and creation of "MON" group may fail if we run out of RMIDs.
-
-max_threshold_occupancy - generic concepts
-------------------------------------------
-
-Note that an RMID once freed may not be immediately available for use as
-the RMID is still tagged the cache lines of the previous user of RMID.
-Hence such RMIDs are placed on limbo list and checked back if the cache
-occupancy has gone down. If there is a time when system has a lot of
-limbo RMIDs but which are not ready to be used, user may see an -EBUSY
-during mkdir.
-
-max_threshold_occupancy is a user configurable value to determine the
-occupancy at which an RMID can be freed.
-
-The mon_llc_occupancy_limbo tracepoint gives the precise occupancy in bytes
-for a subset of RMID that are not immediately available for allocation.
-This can't be relied on to produce output every second, it may be necessary
-to attempt to create an empty monitor group to force an update. Output may
-only be produced if creation of a control or monitor group fails.
-
-Schemata files - general concepts
----------------------------------
-Each line in the file describes one resource. The line starts with
-the name of the resource, followed by specific values to be applied
-in each of the instances of that resource on the system.
-
-Cache IDs
----------
-On current generation systems there is one L3 cache per socket and L2
-caches are generally just shared by the hyperthreads on a core, but this
-isn't an architectural requirement. We could have multiple separate L3
-caches on a socket, multiple cores could share an L2 cache. So instead
-of using "socket" or "core" to define the set of logical cpus sharing
-a resource we use a "Cache ID". At a given cache level this will be a
-unique number across the whole system (but it isn't guaranteed to be a
-contiguous sequence, there may be gaps). To find the ID for each logical
-CPU look in /sys/devices/system/cpu/cpu*/cache/index*/id
-
-Cache Bit Masks (CBM)
----------------------
-For cache resources we describe the portion of the cache that is available
-for allocation using a bitmask. The maximum value of the mask is defined
-by each cpu model (and may be different for different cache levels). It
-is found using CPUID, but is also provided in the "info" directory of
-the resctrl file system in "info/{resource}/cbm_mask". Some Intel hardware
-requires that these masks have all the '1' bits in a contiguous block. So
-0x3, 0x6 and 0xC are legal 4-bit masks with two bits set, but 0x5, 0x9
-and 0xA are not. Check /sys/fs/resctrl/info/{resource}/sparse_masks
-if non-contiguous 1s value is supported. On a system with a 20-bit mask
-each bit represents 5% of the capacity of the cache. You could partition
-the cache into four equal parts with masks: 0x1f, 0x3e0, 0x7c00, 0xf8000.
-
-Notes on Sub-NUMA Cluster mode
-==============================
-When SNC mode is enabled, Linux may load balance tasks between Sub-NUMA
-nodes much more readily than between regular NUMA nodes since the CPUs
-on Sub-NUMA nodes share the same L3 cache and the system may report
-the NUMA distance between Sub-NUMA nodes with a lower value than used
-for regular NUMA nodes.
-
-The top-level monitoring files in each "mon_L3_XX" directory provide
-the sum of data across all SNC nodes sharing an L3 cache instance.
-Users who bind tasks to the CPUs of a specific Sub-NUMA node can read
-the "llc_occupancy", "mbm_total_bytes", and "mbm_local_bytes" in the
-"mon_sub_L3_YY" directories to get node local data.
-
-Memory bandwidth allocation is still performed at the L3 cache
-level. I.e. throttling controls are applied to all SNC nodes.
-
-L3 cache allocation bitmaps also apply to all SNC nodes. But note that
-the amount of L3 cache represented by each bit is divided by the number
-of SNC nodes per L3 cache. E.g. with a 100MB cache on a system with 10-bit
-allocation masks each bit normally represents 10MB. With SNC mode enabled
-with two SNC nodes per L3 cache, each bit only represents 5MB.
-
-Memory bandwidth Allocation and monitoring
-==========================================
-
-For Memory bandwidth resource, by default the user controls the resource
-by indicating the percentage of total memory bandwidth.
-
-The minimum bandwidth percentage value for each cpu model is predefined
-and can be looked up through "info/MB/min_bandwidth". The bandwidth
-granularity that is allocated is also dependent on the cpu model and can
-be looked up at "info/MB/bandwidth_gran". The available bandwidth
-control steps are: min_bw + N * bw_gran. Intermediate values are rounded
-to the next control step available on the hardware.
-
-The bandwidth throttling is a core specific mechanism on some of Intel
-SKUs. Using a high bandwidth and a low bandwidth setting on two threads
-sharing a core may result in both threads being throttled to use the
-low bandwidth (see "thread_throttle_mode").
-
-The fact that Memory bandwidth allocation(MBA) may be a core
-specific mechanism where as memory bandwidth monitoring(MBM) is done at
-the package level may lead to confusion when users try to apply control
-via the MBA and then monitor the bandwidth to see if the controls are
-effective. Below are such scenarios:
-
-1. User may *not* see increase in actual bandwidth when percentage
- values are increased:
-
-This can occur when aggregate L2 external bandwidth is more than L3
-external bandwidth. Consider an SKL SKU with 24 cores on a package and
-where L2 external is 10GBps (hence aggregate L2 external bandwidth is
-240GBps) and L3 external bandwidth is 100GBps. Now a workload with '20
-threads, having 50% bandwidth, each consuming 5GBps' consumes the max L3
-bandwidth of 100GBps although the percentage value specified is only 50%
-<< 100%. Hence increasing the bandwidth percentage will not yield any
-more bandwidth. This is because although the L2 external bandwidth still
-has capacity, the L3 external bandwidth is fully used. Also note that
-this would be dependent on number of cores the benchmark is run on.
-
-2. Same bandwidth percentage may mean different actual bandwidth
- depending on # of threads:
-
-For the same SKU in #1, a 'single thread, with 10% bandwidth' and '4
-thread, with 10% bandwidth' can consume upto 10GBps and 40GBps although
-they have same percentage bandwidth of 10%. This is simply because as
-threads start using more cores in an rdtgroup, the actual bandwidth may
-increase or vary although user specified bandwidth percentage is same.
-
-In order to mitigate this and make the interface more user friendly,
-resctrl added support for specifying the bandwidth in MiBps as well. The
-kernel underneath would use a software feedback mechanism or a "Software
-Controller(mba_sc)" which reads the actual bandwidth using MBM counters
-and adjust the memory bandwidth percentages to ensure::
-
- "actual bandwidth < user specified bandwidth".
-
-By default, the schemata would take the bandwidth percentage values
-where as user can switch to the "MBA software controller" mode using
-a mount option 'mba_MBps'. The schemata format is specified in the below
-sections.
-
-L3 schemata file details (code and data prioritization disabled)
-----------------------------------------------------------------
-With CDP disabled the L3 schemata format is::
-
- L3:<cache_id0>=<cbm>;<cache_id1>=<cbm>;...
-
-L3 schemata file details (CDP enabled via mount option to resctrl)
-------------------------------------------------------------------
-When CDP is enabled L3 control is split into two separate resources
-so you can specify independent masks for code and data like this::
-
- L3DATA:<cache_id0>=<cbm>;<cache_id1>=<cbm>;...
- L3CODE:<cache_id0>=<cbm>;<cache_id1>=<cbm>;...
-
-L2 schemata file details
-------------------------
-CDP is supported at L2 using the 'cdpl2' mount option. The schemata
-format is either::
-
- L2:<cache_id0>=<cbm>;<cache_id1>=<cbm>;...
-
-or
-
- L2DATA:<cache_id0>=<cbm>;<cache_id1>=<cbm>;...
- L2CODE:<cache_id0>=<cbm>;<cache_id1>=<cbm>;...
-
-
-Memory bandwidth Allocation (default mode)
-------------------------------------------
-
-Memory b/w domain is L3 cache.
-::
-
- MB:<cache_id0>=bandwidth0;<cache_id1>=bandwidth1;...
-
-Memory bandwidth Allocation specified in MiBps
-----------------------------------------------
-
-Memory bandwidth domain is L3 cache.
-::
-
- MB:<cache_id0>=bw_MiBps0;<cache_id1>=bw_MiBps1;...
-
-Slow Memory Bandwidth Allocation (SMBA)
----------------------------------------
-AMD hardware supports Slow Memory Bandwidth Allocation (SMBA).
-CXL.memory is the only supported "slow" memory device. With the
-support of SMBA, the hardware enables bandwidth allocation on
-the slow memory devices. If there are multiple such devices in
-the system, the throttling logic groups all the slow sources
-together and applies the limit on them as a whole.
-
-The presence of SMBA (with CXL.memory) is independent of slow memory
-devices presence. If there are no such devices on the system, then
-configuring SMBA will have no impact on the performance of the system.
-
-The bandwidth domain for slow memory is L3 cache. Its schemata file
-is formatted as:
-::
-
- SMBA:<cache_id0>=bandwidth0;<cache_id1>=bandwidth1;...
-
-Reading/writing the schemata file
----------------------------------
-Reading the schemata file will show the state of all resources
-on all domains. When writing you only need to specify those values
-which you wish to change. E.g.
-::
-
- # cat schemata
- L3DATA:0=fffff;1=fffff;2=fffff;3=fffff
- L3CODE:0=fffff;1=fffff;2=fffff;3=fffff
- # echo "L3DATA:2=3c0;" > schemata
- # cat schemata
- L3DATA:0=fffff;1=fffff;2=3c0;3=fffff
- L3CODE:0=fffff;1=fffff;2=fffff;3=fffff
-
-Reading/writing the schemata file (on AMD systems)
---------------------------------------------------
-Reading the schemata file will show the current bandwidth limit on all
-domains. The allocated resources are in multiples of one eighth GB/s.
-When writing to the file, you need to specify what cache id you wish to
-configure the bandwidth limit.
-
-For example, to allocate 2GB/s limit on the first cache id:
-
-::
-
- # cat schemata
- MB:0=2048;1=2048;2=2048;3=2048
- L3:0=ffff;1=ffff;2=ffff;3=ffff
-
- # echo "MB:1=16" > schemata
- # cat schemata
- MB:0=2048;1= 16;2=2048;3=2048
- L3:0=ffff;1=ffff;2=ffff;3=ffff
-
-Reading/writing the schemata file (on AMD systems) with SMBA feature
---------------------------------------------------------------------
-Reading and writing the schemata file is the same as without SMBA in
-above section.
-
-For example, to allocate 8GB/s limit on the first cache id:
-
-::
-
- # cat schemata
- SMBA:0=2048;1=2048;2=2048;3=2048
- MB:0=2048;1=2048;2=2048;3=2048
- L3:0=ffff;1=ffff;2=ffff;3=ffff
-
- # echo "SMBA:1=64" > schemata
- # cat schemata
- SMBA:0=2048;1= 64;2=2048;3=2048
- MB:0=2048;1=2048;2=2048;3=2048
- L3:0=ffff;1=ffff;2=ffff;3=ffff
-
-Cache Pseudo-Locking
-====================
-CAT enables a user to specify the amount of cache space that an
-application can fill. Cache pseudo-locking builds on the fact that a
-CPU can still read and write data pre-allocated outside its current
-allocated area on a cache hit. With cache pseudo-locking, data can be
-preloaded into a reserved portion of cache that no application can
-fill, and from that point on will only serve cache hits. The cache
-pseudo-locked memory is made accessible to user space where an
-application can map it into its virtual address space and thus have
-a region of memory with reduced average read latency.
-
-The creation of a cache pseudo-locked region is triggered by a request
-from the user to do so that is accompanied by a schemata of the region
-to be pseudo-locked. The cache pseudo-locked region is created as follows:
-
-- Create a CAT allocation CLOSNEW with a CBM matching the schemata
- from the user of the cache region that will contain the pseudo-locked
- memory. This region must not overlap with any current CAT allocation/CLOS
- on the system and no future overlap with this cache region is allowed
- while the pseudo-locked region exists.
-- Create a contiguous region of memory of the same size as the cache
- region.
-- Flush the cache, disable hardware prefetchers, disable preemption.
-- Make CLOSNEW the active CLOS and touch the allocated memory to load
- it into the cache.
-- Set the previous CLOS as active.
-- At this point the closid CLOSNEW can be released - the cache
- pseudo-locked region is protected as long as its CBM does not appear in
- any CAT allocation. Even though the cache pseudo-locked region will from
- this point on not appear in any CBM of any CLOS an application running with
- any CLOS will be able to access the memory in the pseudo-locked region since
- the region continues to serve cache hits.
-- The contiguous region of memory loaded into the cache is exposed to
- user-space as a character device.
-
-Cache pseudo-locking increases the probability that data will remain
-in the cache via carefully configuring the CAT feature and controlling
-application behavior. There is no guarantee that data is placed in
-cache. Instructions like INVD, WBINVD, CLFLUSH, etc. can still evict
-“locked” data from cache. Power management C-states may shrink or
-power off cache. Deeper C-states will automatically be restricted on
-pseudo-locked region creation.
-
-It is required that an application using a pseudo-locked region runs
-with affinity to the cores (or a subset of the cores) associated
-with the cache on which the pseudo-locked region resides. A sanity check
-within the code will not allow an application to map pseudo-locked memory
-unless it runs with affinity to cores associated with the cache on which the
-pseudo-locked region resides. The sanity check is only done during the
-initial mmap() handling, there is no enforcement afterwards and the
-application self needs to ensure it remains affine to the correct cores.
-
-Pseudo-locking is accomplished in two stages:
-
-1) During the first stage the system administrator allocates a portion
- of cache that should be dedicated to pseudo-locking. At this time an
- equivalent portion of memory is allocated, loaded into allocated
- cache portion, and exposed as a character device.
-2) During the second stage a user-space application maps (mmap()) the
- pseudo-locked memory into its address space.
-
-Cache Pseudo-Locking Interface
-------------------------------
-A pseudo-locked region is created using the resctrl interface as follows:
-
-1) Create a new resource group by creating a new directory in /sys/fs/resctrl.
-2) Change the new resource group's mode to "pseudo-locksetup" by writing
- "pseudo-locksetup" to the "mode" file.
-3) Write the schemata of the pseudo-locked region to the "schemata" file. All
- bits within the schemata should be "unused" according to the "bit_usage"
- file.
-
-On successful pseudo-locked region creation the "mode" file will contain
-"pseudo-locked" and a new character device with the same name as the resource
-group will exist in /dev/pseudo_lock. This character device can be mmap()'ed
-by user space in order to obtain access to the pseudo-locked memory region.
-
-An example of cache pseudo-locked region creation and usage can be found below.
-
-Cache Pseudo-Locking Debugging Interface
-----------------------------------------
-The pseudo-locking debugging interface is enabled by default (if
-CONFIG_DEBUG_FS is enabled) and can be found in /sys/kernel/debug/resctrl.
-
-There is no explicit way for the kernel to test if a provided memory
-location is present in the cache. The pseudo-locking debugging interface uses
-the tracing infrastructure to provide two ways to measure cache residency of
-the pseudo-locked region:
-
-1) Memory access latency using the pseudo_lock_mem_latency tracepoint. Data
- from these measurements are best visualized using a hist trigger (see
- example below). In this test the pseudo-locked region is traversed at
- a stride of 32 bytes while hardware prefetchers and preemption
- are disabled. This also provides a substitute visualization of cache
- hits and misses.
-2) Cache hit and miss measurements using model specific precision counters if
- available. Depending on the levels of cache on the system the pseudo_lock_l2
- and pseudo_lock_l3 tracepoints are available.
-
-When a pseudo-locked region is created a new debugfs directory is created for
-it in debugfs as /sys/kernel/debug/resctrl/<newdir>. A single
-write-only file, pseudo_lock_measure, is present in this directory. The
-measurement of the pseudo-locked region depends on the number written to this
-debugfs file:
-
-1:
- writing "1" to the pseudo_lock_measure file will trigger the latency
- measurement captured in the pseudo_lock_mem_latency tracepoint. See
- example below.
-2:
- writing "2" to the pseudo_lock_measure file will trigger the L2 cache
- residency (cache hits and misses) measurement captured in the
- pseudo_lock_l2 tracepoint. See example below.
-3:
- writing "3" to the pseudo_lock_measure file will trigger the L3 cache
- residency (cache hits and misses) measurement captured in the
- pseudo_lock_l3 tracepoint.
-
-All measurements are recorded with the tracing infrastructure. This requires
-the relevant tracepoints to be enabled before the measurement is triggered.
-
-Example of latency debugging interface
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-In this example a pseudo-locked region named "newlock" was created. Here is
-how we can measure the latency in cycles of reading from this region and
-visualize this data with a histogram that is available if CONFIG_HIST_TRIGGERS
-is set::
-
- # :> /sys/kernel/tracing/trace
- # echo 'hist:keys=latency' > /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/trigger
- # echo 1 > /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/enable
- # echo 1 > /sys/kernel/debug/resctrl/newlock/pseudo_lock_measure
- # echo 0 > /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/enable
- # cat /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/hist
-
- # event histogram
- #
- # trigger info: hist:keys=latency:vals=hitcount:sort=hitcount:size=2048 [active]
- #
-
- { latency: 456 } hitcount: 1
- { latency: 50 } hitcount: 83
- { latency: 36 } hitcount: 96
- { latency: 44 } hitcount: 174
- { latency: 48 } hitcount: 195
- { latency: 46 } hitcount: 262
- { latency: 42 } hitcount: 693
- { latency: 40 } hitcount: 3204
- { latency: 38 } hitcount: 3484
-
- Totals:
- Hits: 8192
- Entries: 9
- Dropped: 0
-
-Example of cache hits/misses debugging
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-In this example a pseudo-locked region named "newlock" was created on the L2
-cache of a platform. Here is how we can obtain details of the cache hits
-and misses using the platform's precision counters.
-::
-
- # :> /sys/kernel/tracing/trace
- # echo 1 > /sys/kernel/tracing/events/resctrl/pseudo_lock_l2/enable
- # echo 2 > /sys/kernel/debug/resctrl/newlock/pseudo_lock_measure
- # echo 0 > /sys/kernel/tracing/events/resctrl/pseudo_lock_l2/enable
- # cat /sys/kernel/tracing/trace
-
- # tracer: nop
- #
- # _-----=> irqs-off
- # / _----=> need-resched
- # | / _---=> hardirq/softirq
- # || / _--=> preempt-depth
- # ||| / delay
- # TASK-PID CPU# |||| TIMESTAMP FUNCTION
- # | | | |||| | |
- pseudo_lock_mea-1672 [002] .... 3132.860500: pseudo_lock_l2: hits=4097 miss=0
-
-
-Examples for RDT allocation usage
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-1) Example 1
-
-On a two socket machine (one L3 cache per socket) with just four bits
-for cache bit masks, minimum b/w of 10% with a memory bandwidth
-granularity of 10%.
-::
-
- # mount -t resctrl resctrl /sys/fs/resctrl
- # cd /sys/fs/resctrl
- # mkdir p0 p1
- # echo "L3:0=3;1=c\nMB:0=50;1=50" > /sys/fs/resctrl/p0/schemata
- # echo "L3:0=3;1=3\nMB:0=50;1=50" > /sys/fs/resctrl/p1/schemata
-
-The default resource group is unmodified, so we have access to all parts
-of all caches (its schemata file reads "L3:0=f;1=f").
-
-Tasks that are under the control of group "p0" may only allocate from the
-"lower" 50% on cache ID 0, and the "upper" 50% of cache ID 1.
-Tasks in group "p1" use the "lower" 50% of cache on both sockets.
-
-Similarly, tasks that are under the control of group "p0" may use a
-maximum memory b/w of 50% on socket0 and 50% on socket 1.
-Tasks in group "p1" may also use 50% memory b/w on both sockets.
-Note that unlike cache masks, memory b/w cannot specify whether these
-allocations can overlap or not. The allocations specifies the maximum
-b/w that the group may be able to use and the system admin can configure
-the b/w accordingly.
-
-If resctrl is using the software controller (mba_sc) then user can enter the
-max b/w in MB rather than the percentage values.
-::
-
- # echo "L3:0=3;1=c\nMB:0=1024;1=500" > /sys/fs/resctrl/p0/schemata
- # echo "L3:0=3;1=3\nMB:0=1024;1=500" > /sys/fs/resctrl/p1/schemata
-
-In the above example the tasks in "p1" and "p0" on socket 0 would use a max b/w
-of 1024MB where as on socket 1 they would use 500MB.
-
-2) Example 2
-
-Again two sockets, but this time with a more realistic 20-bit mask.
-
-Two real time tasks pid=1234 running on processor 0 and pid=5678 running on
-processor 1 on socket 0 on a 2-socket and dual core machine. To avoid noisy
-neighbors, each of the two real-time tasks exclusively occupies one quarter
-of L3 cache on socket 0.
-::
-
- # mount -t resctrl resctrl /sys/fs/resctrl
- # cd /sys/fs/resctrl
-
-First we reset the schemata for the default group so that the "upper"
-50% of the L3 cache on socket 0 and 50% of memory b/w cannot be used by
-ordinary tasks::
-
- # echo "L3:0=3ff;1=fffff\nMB:0=50;1=100" > schemata
-
-Next we make a resource group for our first real time task and give
-it access to the "top" 25% of the cache on socket 0.
-::
-
- # mkdir p0
- # echo "L3:0=f8000;1=fffff" > p0/schemata
-
-Finally we move our first real time task into this resource group. We
-also use taskset(1) to ensure the task always runs on a dedicated CPU
-on socket 0. Most uses of resource groups will also constrain which
-processors tasks run on.
-::
-
- # echo 1234 > p0/tasks
- # taskset -cp 1 1234
-
-Ditto for the second real time task (with the remaining 25% of cache)::
-
- # mkdir p1
- # echo "L3:0=7c00;1=fffff" > p1/schemata
- # echo 5678 > p1/tasks
- # taskset -cp 2 5678
-
-For the same 2 socket system with memory b/w resource and CAT L3 the
-schemata would look like(Assume min_bandwidth 10 and bandwidth_gran is
-10):
-
-For our first real time task this would request 20% memory b/w on socket 0.
-::
-
- # echo -e "L3:0=f8000;1=fffff\nMB:0=20;1=100" > p0/schemata
-
-For our second real time task this would request an other 20% memory b/w
-on socket 0.
-::
-
- # echo -e "L3:0=f8000;1=fffff\nMB:0=20;1=100" > p0/schemata
-
-3) Example 3
-
-A single socket system which has real-time tasks running on core 4-7 and
-non real-time workload assigned to core 0-3. The real-time tasks share text
-and data, so a per task association is not required and due to interaction
-with the kernel it's desired that the kernel on these cores shares L3 with
-the tasks.
-::
-
- # mount -t resctrl resctrl /sys/fs/resctrl
- # cd /sys/fs/resctrl
-
-First we reset the schemata for the default group so that the "upper"
-50% of the L3 cache on socket 0, and 50% of memory bandwidth on socket 0
-cannot be used by ordinary tasks::
-
- # echo "L3:0=3ff\nMB:0=50" > schemata
-
-Next we make a resource group for our real time cores and give it access
-to the "top" 50% of the cache on socket 0 and 50% of memory bandwidth on
-socket 0.
-::
-
- # mkdir p0
- # echo "L3:0=ffc00\nMB:0=50" > p0/schemata
-
-Finally we move core 4-7 over to the new group and make sure that the
-kernel and the tasks running there get 50% of the cache. They should
-also get 50% of memory bandwidth assuming that the cores 4-7 are SMT
-siblings and only the real time threads are scheduled on the cores 4-7.
-::
-
- # echo F0 > p0/cpus
-
-4) Example 4
-
-The resource groups in previous examples were all in the default "shareable"
-mode allowing sharing of their cache allocations. If one resource group
-configures a cache allocation then nothing prevents another resource group
-to overlap with that allocation.
-
-In this example a new exclusive resource group will be created on a L2 CAT
-system with two L2 cache instances that can be configured with an 8-bit
-capacity bitmask. The new exclusive resource group will be configured to use
-25% of each cache instance.
-::
-
- # mount -t resctrl resctrl /sys/fs/resctrl/
- # cd /sys/fs/resctrl
-
-First, we observe that the default group is configured to allocate to all L2
-cache::
-
- # cat schemata
- L2:0=ff;1=ff
-
-We could attempt to create the new resource group at this point, but it will
-fail because of the overlap with the schemata of the default group::
-
- # mkdir p0
- # echo 'L2:0=0x3;1=0x3' > p0/schemata
- # cat p0/mode
- shareable
- # echo exclusive > p0/mode
- -sh: echo: write error: Invalid argument
- # cat info/last_cmd_status
- schemata overlaps
-
-To ensure that there is no overlap with another resource group the default
-resource group's schemata has to change, making it possible for the new
-resource group to become exclusive.
-::
-
- # echo 'L2:0=0xfc;1=0xfc' > schemata
- # echo exclusive > p0/mode
- # grep . p0/*
- p0/cpus:0
- p0/mode:exclusive
- p0/schemata:L2:0=03;1=03
- p0/size:L2:0=262144;1=262144
-
-A new resource group will on creation not overlap with an exclusive resource
-group::
-
- # mkdir p1
- # grep . p1/*
- p1/cpus:0
- p1/mode:shareable
- p1/schemata:L2:0=fc;1=fc
- p1/size:L2:0=786432;1=786432
-
-The bit_usage will reflect how the cache is used::
-
- # cat info/L2/bit_usage
- 0=SSSSSSEE;1=SSSSSSEE
-
-A resource group cannot be forced to overlap with an exclusive resource group::
-
- # echo 'L2:0=0x1;1=0x1' > p1/schemata
- -sh: echo: write error: Invalid argument
- # cat info/last_cmd_status
- overlaps with exclusive group
-
-Example of Cache Pseudo-Locking
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Lock portion of L2 cache from cache id 1 using CBM 0x3. Pseudo-locked
-region is exposed at /dev/pseudo_lock/newlock that can be provided to
-application for argument to mmap().
-::
-
- # mount -t resctrl resctrl /sys/fs/resctrl/
- # cd /sys/fs/resctrl
-
-Ensure that there are bits available that can be pseudo-locked, since only
-unused bits can be pseudo-locked the bits to be pseudo-locked needs to be
-removed from the default resource group's schemata::
-
- # cat info/L2/bit_usage
- 0=SSSSSSSS;1=SSSSSSSS
- # echo 'L2:1=0xfc' > schemata
- # cat info/L2/bit_usage
- 0=SSSSSSSS;1=SSSSSS00
-
-Create a new resource group that will be associated with the pseudo-locked
-region, indicate that it will be used for a pseudo-locked region, and
-configure the requested pseudo-locked region capacity bitmask::
-
- # mkdir newlock
- # echo pseudo-locksetup > newlock/mode
- # echo 'L2:1=0x3' > newlock/schemata
-
-On success the resource group's mode will change to pseudo-locked, the
-bit_usage will reflect the pseudo-locked region, and the character device
-exposing the pseudo-locked region will exist::
-
- # cat newlock/mode
- pseudo-locked
- # cat info/L2/bit_usage
- 0=SSSSSSSS;1=SSSSSSPP
- # ls -l /dev/pseudo_lock/newlock
- crw------- 1 root root 243, 0 Apr 3 05:01 /dev/pseudo_lock/newlock
-
-::
-
- /*
- * Example code to access one page of pseudo-locked cache region
- * from user space.
- */
- #define _GNU_SOURCE
- #include <fcntl.h>
- #include <sched.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <unistd.h>
- #include <sys/mman.h>
-
- /*
- * It is required that the application runs with affinity to only
- * cores associated with the pseudo-locked region. Here the cpu
- * is hardcoded for convenience of example.
- */
- static int cpuid = 2;
-
- int main(int argc, char *argv[])
- {
- cpu_set_t cpuset;
- long page_size;
- void *mapping;
- int dev_fd;
- int ret;
-
- page_size = sysconf(_SC_PAGESIZE);
-
- CPU_ZERO(&cpuset);
- CPU_SET(cpuid, &cpuset);
- ret = sched_setaffinity(0, sizeof(cpuset), &cpuset);
- if (ret < 0) {
- perror("sched_setaffinity");
- exit(EXIT_FAILURE);
- }
-
- dev_fd = open("/dev/pseudo_lock/newlock", O_RDWR);
- if (dev_fd < 0) {
- perror("open");
- exit(EXIT_FAILURE);
- }
-
- mapping = mmap(0, page_size, PROT_READ | PROT_WRITE, MAP_SHARED,
- dev_fd, 0);
- if (mapping == MAP_FAILED) {
- perror("mmap");
- close(dev_fd);
- exit(EXIT_FAILURE);
- }
-
- /* Application interacts with pseudo-locked memory @mapping */
-
- ret = munmap(mapping, page_size);
- if (ret < 0) {
- perror("munmap");
- close(dev_fd);
- exit(EXIT_FAILURE);
- }
-
- close(dev_fd);
- exit(EXIT_SUCCESS);
- }
-
-Locking between applications
-----------------------------
-
-Certain operations on the resctrl filesystem, composed of read/writes
-to/from multiple files, must be atomic.
-
-As an example, the allocation of an exclusive reservation of L3 cache
-involves:
-
- 1. Read the cbmmasks from each directory or the per-resource "bit_usage"
- 2. Find a contiguous set of bits in the global CBM bitmask that is clear
- in any of the directory cbmmasks
- 3. Create a new directory
- 4. Set the bits found in step 2 to the new directory "schemata" file
-
-If two applications attempt to allocate space concurrently then they can
-end up allocating the same bits so the reservations are shared instead of
-exclusive.
-
-To coordinate atomic operations on the resctrlfs and to avoid the problem
-above, the following locking procedure is recommended:
-
-Locking is based on flock, which is available in libc and also as a shell
-script command
-
-Write lock:
-
- A) Take flock(LOCK_EX) on /sys/fs/resctrl
- B) Read/write the directory structure.
- C) funlock
-
-Read lock:
-
- A) Take flock(LOCK_SH) on /sys/fs/resctrl
- B) If success read the directory structure.
- C) funlock
-
-Example with bash::
-
- # Atomically read directory structure
- $ flock -s /sys/fs/resctrl/ find /sys/fs/resctrl
-
- # Read directory contents and create new subdirectory
-
- $ cat create-dir.sh
- find /sys/fs/resctrl/ > output.txt
- mask = function-of(output.txt)
- mkdir /sys/fs/resctrl/newres/
- echo mask > /sys/fs/resctrl/newres/schemata
-
- $ flock /sys/fs/resctrl/ ./create-dir.sh
-
-Example with C::
-
- /*
- * Example code do take advisory locks
- * before accessing resctrl filesystem
- */
- #include <sys/file.h>
- #include <stdlib.h>
-
- void resctrl_take_shared_lock(int fd)
- {
- int ret;
-
- /* take shared lock on resctrl filesystem */
- ret = flock(fd, LOCK_SH);
- if (ret) {
- perror("flock");
- exit(-1);
- }
- }
-
- void resctrl_take_exclusive_lock(int fd)
- {
- int ret;
-
- /* release lock on resctrl filesystem */
- ret = flock(fd, LOCK_EX);
- if (ret) {
- perror("flock");
- exit(-1);
- }
- }
-
- void resctrl_release_lock(int fd)
- {
- int ret;
-
- /* take shared lock on resctrl filesystem */
- ret = flock(fd, LOCK_UN);
- if (ret) {
- perror("flock");
- exit(-1);
- }
- }
-
- void main(void)
- {
- int fd, ret;
-
- fd = open("/sys/fs/resctrl", O_DIRECTORY);
- if (fd == -1) {
- perror("open");
- exit(-1);
- }
- resctrl_take_shared_lock(fd);
- /* code to read directory contents */
- resctrl_release_lock(fd);
-
- resctrl_take_exclusive_lock(fd);
- /* code to read and write directory contents */
- resctrl_release_lock(fd);
- }
-
-Examples for RDT Monitoring along with allocation usage
-=======================================================
-Reading monitored data
-----------------------
-Reading an event file (for ex: mon_data/mon_L3_00/llc_occupancy) would
-show the current snapshot of LLC occupancy of the corresponding MON
-group or CTRL_MON group.
-
-
-Example 1 (Monitor CTRL_MON group and subset of tasks in CTRL_MON group)
-------------------------------------------------------------------------
-On a two socket machine (one L3 cache per socket) with just four bits
-for cache bit masks::
-
- # mount -t resctrl resctrl /sys/fs/resctrl
- # cd /sys/fs/resctrl
- # mkdir p0 p1
- # echo "L3:0=3;1=c" > /sys/fs/resctrl/p0/schemata
- # echo "L3:0=3;1=3" > /sys/fs/resctrl/p1/schemata
- # echo 5678 > p1/tasks
- # echo 5679 > p1/tasks
-
-The default resource group is unmodified, so we have access to all parts
-of all caches (its schemata file reads "L3:0=f;1=f").
-
-Tasks that are under the control of group "p0" may only allocate from the
-"lower" 50% on cache ID 0, and the "upper" 50% of cache ID 1.
-Tasks in group "p1" use the "lower" 50% of cache on both sockets.
-
-Create monitor groups and assign a subset of tasks to each monitor group.
-::
-
- # cd /sys/fs/resctrl/p1/mon_groups
- # mkdir m11 m12
- # echo 5678 > m11/tasks
- # echo 5679 > m12/tasks
-
-fetch data (data shown in bytes)
-::
-
- # cat m11/mon_data/mon_L3_00/llc_occupancy
- 16234000
- # cat m11/mon_data/mon_L3_01/llc_occupancy
- 14789000
- # cat m12/mon_data/mon_L3_00/llc_occupancy
- 16789000
-
-The parent ctrl_mon group shows the aggregated data.
-::
-
- # cat /sys/fs/resctrl/p1/mon_data/mon_l3_00/llc_occupancy
- 31234000
-
-Example 2 (Monitor a task from its creation)
---------------------------------------------
-On a two socket machine (one L3 cache per socket)::
-
- # mount -t resctrl resctrl /sys/fs/resctrl
- # cd /sys/fs/resctrl
- # mkdir p0 p1
-
-An RMID is allocated to the group once its created and hence the <cmd>
-below is monitored from its creation.
-::
-
- # echo $$ > /sys/fs/resctrl/p1/tasks
- # <cmd>
-
-Fetch the data::
-
- # cat /sys/fs/resctrl/p1/mon_data/mon_l3_00/llc_occupancy
- 31789000
-
-Example 3 (Monitor without CAT support or before creating CAT groups)
----------------------------------------------------------------------
-
-Assume a system like HSW has only CQM and no CAT support. In this case
-the resctrl will still mount but cannot create CTRL_MON directories.
-But user can create different MON groups within the root group thereby
-able to monitor all tasks including kernel threads.
-
-This can also be used to profile jobs cache size footprint before being
-able to allocate them to different allocation groups.
-::
-
- # mount -t resctrl resctrl /sys/fs/resctrl
- # cd /sys/fs/resctrl
- # mkdir mon_groups/m01
- # mkdir mon_groups/m02
-
- # echo 3478 > /sys/fs/resctrl/mon_groups/m01/tasks
- # echo 2467 > /sys/fs/resctrl/mon_groups/m02/tasks
-
-Monitor the groups separately and also get per domain data. From the
-below its apparent that the tasks are mostly doing work on
-domain(socket) 0.
-::
-
- # cat /sys/fs/resctrl/mon_groups/m01/mon_L3_00/llc_occupancy
- 31234000
- # cat /sys/fs/resctrl/mon_groups/m01/mon_L3_01/llc_occupancy
- 34555
- # cat /sys/fs/resctrl/mon_groups/m02/mon_L3_00/llc_occupancy
- 31234000
- # cat /sys/fs/resctrl/mon_groups/m02/mon_L3_01/llc_occupancy
- 32789
-
-
-Example 4 (Monitor real time tasks)
------------------------------------
-
-A single socket system which has real time tasks running on cores 4-7
-and non real time tasks on other cpus. We want to monitor the cache
-occupancy of the real time threads on these cores.
-::
-
- # mount -t resctrl resctrl /sys/fs/resctrl
- # cd /sys/fs/resctrl
- # mkdir p1
-
-Move the cpus 4-7 over to p1::
-
- # echo f0 > p1/cpus
-
-View the llc occupancy snapshot::
-
- # cat /sys/fs/resctrl/p1/mon_data/mon_L3_00/llc_occupancy
- 11234000
-
-Intel RDT Errata
-================
-
-Intel MBM Counters May Report System Memory Bandwidth Incorrectly
------------------------------------------------------------------
-
-Errata SKX99 for Skylake server and BDF102 for Broadwell server.
-
-Problem: Intel Memory Bandwidth Monitoring (MBM) counters track metrics
-according to the assigned Resource Monitor ID (RMID) for that logical
-core. The IA32_QM_CTR register (MSR 0xC8E), used to report these
-metrics, may report incorrect system bandwidth for certain RMID values.
-
-Implication: Due to the errata, system memory bandwidth may not match
-what is reported.
-
-Workaround: MBM total and local readings are corrected according to the
-following correction factor table:
-
-+---------------+---------------+---------------+-----------------+
-|core count |rmid count |rmid threshold |correction factor|
-+---------------+---------------+---------------+-----------------+
-|1 |8 |0 |1.000000 |
-+---------------+---------------+---------------+-----------------+
-|2 |16 |0 |1.000000 |
-+---------------+---------------+---------------+-----------------+
-|3 |24 |15 |0.969650 |
-+---------------+---------------+---------------+-----------------+
-|4 |32 |0 |1.000000 |
-+---------------+---------------+---------------+-----------------+
-|6 |48 |31 |0.969650 |
-+---------------+---------------+---------------+-----------------+
-|7 |56 |47 |1.142857 |
-+---------------+---------------+---------------+-----------------+
-|8 |64 |0 |1.000000 |
-+---------------+---------------+---------------+-----------------+
-|9 |72 |63 |1.185115 |
-+---------------+---------------+---------------+-----------------+
-|10 |80 |63 |1.066553 |
-+---------------+---------------+---------------+-----------------+
-|11 |88 |79 |1.454545 |
-+---------------+---------------+---------------+-----------------+
-|12 |96 |0 |1.000000 |
-+---------------+---------------+---------------+-----------------+
-|13 |104 |95 |1.230769 |
-+---------------+---------------+---------------+-----------------+
-|14 |112 |95 |1.142857 |
-+---------------+---------------+---------------+-----------------+
-|15 |120 |95 |1.066667 |
-+---------------+---------------+---------------+-----------------+
-|16 |128 |0 |1.000000 |
-+---------------+---------------+---------------+-----------------+
-|17 |136 |127 |1.254863 |
-+---------------+---------------+---------------+-----------------+
-|18 |144 |127 |1.185255 |
-+---------------+---------------+---------------+-----------------+
-|19 |152 |0 |1.000000 |
-+---------------+---------------+---------------+-----------------+
-|20 |160 |127 |1.066667 |
-+---------------+---------------+---------------+-----------------+
-|21 |168 |0 |1.000000 |
-+---------------+---------------+---------------+-----------------+
-|22 |176 |159 |1.454334 |
-+---------------+---------------+---------------+-----------------+
-|23 |184 |0 |1.000000 |
-+---------------+---------------+---------------+-----------------+
-|24 |192 |127 |0.969744 |
-+---------------+---------------+---------------+-----------------+
-|25 |200 |191 |1.280246 |
-+---------------+---------------+---------------+-----------------+
-|26 |208 |191 |1.230921 |
-+---------------+---------------+---------------+-----------------+
-|27 |216 |0 |1.000000 |
-+---------------+---------------+---------------+-----------------+
-|28 |224 |191 |1.143118 |
-+---------------+---------------+---------------+-----------------+
-
-If rmid > rmid threshold, MBM total and local values should be multiplied
-by the correction factor.
-
-See:
-
-1. Erratum SKX99 in Intel Xeon Processor Scalable Family Specification Update:
-http://web.archive.org/web/20200716124958/https://www.intel.com/content/www/us/en/processors/xeon/scalable/xeon-scalable-spec-update.html
-
-2. Erratum BDF102 in Intel Xeon E5-2600 v4 Processor Product Family Specification Update:
-http://web.archive.org/web/20191125200531/https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/xeon-e5-v4-spec-update.pdf
-
-3. The errata in Intel Resource Director Technology (Intel RDT) on 2nd Generation Intel Xeon Scalable Processors Reference Manual:
-https://software.intel.com/content/www/us/en/develop/articles/intel-resource-director-technology-rdt-reference-manual.html
-
-for further information.
diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst
index a9cf8e9..3261851 100644
--- a/Documentation/filesystems/index.rst
+++ b/Documentation/filesystems/index.rst
@@ -113,6 +113,7 @@ Documentation for filesystem implementations.
qnx6
ramfs-rootfs-initramfs
relay
+ resctrl
romfs
smb/index
spufs/index
diff --git a/Documentation/filesystems/resctrl.rst b/Documentation/filesystems/resctrl.rst
new file mode 100644
index 0000000..c7949dd
--- /dev/null
+++ b/Documentation/filesystems/resctrl.rst
@@ -0,0 +1,1523 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. include:: <isonum.txt>
+
+=====================================================
+User Interface for Resource Control feature (resctrl)
+=====================================================
+
+:Copyright: |copy| 2016 Intel Corporation
+:Authors: - Fenghua Yu <fenghua.yu@...el.com>
+ - Tony Luck <tony.luck@...el.com>
+ - Vikas Shivappa <vikas.shivappa@...el.com>
+
+
+Intel refers to this feature as Intel Resource Director Technology(Intel(R) RDT).
+AMD refers to this feature as AMD Platform Quality of Service(AMD QoS).
+
+This feature is enabled by the CONFIG_X86_CPU_RESCTRL and the x86 /proc/cpuinfo
+flag bits:
+
+=============================================== ================================
+RDT (Resource Director Technology) Allocation "rdt_a"
+CAT (Cache Allocation Technology) "cat_l3", "cat_l2"
+CDP (Code and Data Prioritization) "cdp_l3", "cdp_l2"
+CQM (Cache QoS Monitoring) "cqm_llc", "cqm_occup_llc"
+MBM (Memory Bandwidth Monitoring) "cqm_mbm_total", "cqm_mbm_local"
+MBA (Memory Bandwidth Allocation) "mba"
+SMBA (Slow Memory Bandwidth Allocation) ""
+BMEC (Bandwidth Monitoring Event Configuration) ""
+=============================================== ================================
+
+Historically, new features were made visible by default in /proc/cpuinfo. This
+resulted in the feature flags becoming hard to parse by humans. Adding a new
+flag to /proc/cpuinfo should be avoided if user space can obtain information
+about the feature from resctrl's info directory.
+
+To use the feature mount the file system::
+
+ # mount -t resctrl resctrl [-o cdp[,cdpl2][,mba_MBps][,debug]] /sys/fs/resctrl
+
+mount options are:
+
+"cdp":
+ Enable code/data prioritization in L3 cache allocations.
+"cdpl2":
+ Enable code/data prioritization in L2 cache allocations.
+"mba_MBps":
+ Enable the MBA Software Controller(mba_sc) to specify MBA
+ bandwidth in MiBps
+"debug":
+ Make debug files accessible. Available debug files are annotated with
+ "Available only with debug option".
+
+L2 and L3 CDP are controlled separately.
+
+RDT features are orthogonal. A particular system may support only
+monitoring, only control, or both monitoring and control. Cache
+pseudo-locking is a unique way of using cache control to "pin" or
+"lock" data in the cache. Details can be found in
+"Cache Pseudo-Locking".
+
+
+The mount succeeds if either of allocation or monitoring is present, but
+only those files and directories supported by the system will be created.
+For more details on the behavior of the interface during monitoring
+and allocation, see the "Resource alloc and monitor groups" section.
+
+Info directory
+==============
+
+The 'info' directory contains information about the enabled
+resources. Each resource has its own subdirectory. The subdirectory
+names reflect the resource names.
+
+Each subdirectory contains the following files with respect to
+allocation:
+
+Cache resource(L3/L2) subdirectory contains the following files
+related to allocation:
+
+"num_closids":
+ The number of CLOSIDs which are valid for this
+ resource. The kernel uses the smallest number of
+ CLOSIDs of all enabled resources as limit.
+"cbm_mask":
+ The bitmask which is valid for this resource.
+ This mask is equivalent to 100%.
+"min_cbm_bits":
+ The minimum number of consecutive bits which
+ must be set when writing a mask.
+
+"shareable_bits":
+ Bitmask of shareable resource with other executing
+ entities (e.g. I/O). User can use this when
+ setting up exclusive cache partitions. Note that
+ some platforms support devices that have their
+ own settings for cache use which can over-ride
+ these bits.
+"bit_usage":
+ Annotated capacity bitmasks showing how all
+ instances of the resource are used. The legend is:
+
+ "0":
+ Corresponding region is unused. When the system's
+ resources have been allocated and a "0" is found
+ in "bit_usage" it is a sign that resources are
+ wasted.
+
+ "H":
+ Corresponding region is used by hardware only
+ but available for software use. If a resource
+ has bits set in "shareable_bits" but not all
+ of these bits appear in the resource groups'
+ schematas then the bits appearing in
+ "shareable_bits" but no resource group will
+ be marked as "H".
+ "X":
+ Corresponding region is available for sharing and
+ used by hardware and software. These are the
+ bits that appear in "shareable_bits" as
+ well as a resource group's allocation.
+ "S":
+ Corresponding region is used by software
+ and available for sharing.
+ "E":
+ Corresponding region is used exclusively by
+ one resource group. No sharing allowed.
+ "P":
+ Corresponding region is pseudo-locked. No
+ sharing allowed.
+"sparse_masks":
+ Indicates if non-contiguous 1s value in CBM is supported.
+
+ "0":
+ Only contiguous 1s value in CBM is supported.
+ "1":
+ Non-contiguous 1s value in CBM is supported.
+
+Memory bandwidth(MB) subdirectory contains the following files
+with respect to allocation:
+
+"min_bandwidth":
+ The minimum memory bandwidth percentage which
+ user can request.
+
+"bandwidth_gran":
+ The granularity in which the memory bandwidth
+ percentage is allocated. The allocated
+ b/w percentage is rounded off to the next
+ control step available on the hardware. The
+ available bandwidth control steps are:
+ min_bandwidth + N * bandwidth_gran.
+
+"delay_linear":
+ Indicates if the delay scale is linear or
+ non-linear. This field is purely informational
+ only.
+
+"thread_throttle_mode":
+ Indicator on Intel systems of how tasks running on threads
+ of a physical core are throttled in cases where they
+ request different memory bandwidth percentages:
+
+ "max":
+ the smallest percentage is applied
+ to all threads
+ "per-thread":
+ bandwidth percentages are directly applied to
+ the threads running on the core
+
+If RDT monitoring is available there will be an "L3_MON" directory
+with the following files:
+
+"num_rmids":
+ The number of RMIDs available. This is the
+ upper bound for how many "CTRL_MON" + "MON"
+ groups can be created.
+
+"mon_features":
+ Lists the monitoring events if
+ monitoring is enabled for the resource.
+ Example::
+
+ # cat /sys/fs/resctrl/info/L3_MON/mon_features
+ llc_occupancy
+ mbm_total_bytes
+ mbm_local_bytes
+
+ If the system supports Bandwidth Monitoring Event
+ Configuration (BMEC), then the bandwidth events will
+ be configurable. The output will be::
+
+ # cat /sys/fs/resctrl/info/L3_MON/mon_features
+ llc_occupancy
+ mbm_total_bytes
+ mbm_total_bytes_config
+ mbm_local_bytes
+ mbm_local_bytes_config
+
+"mbm_total_bytes_config", "mbm_local_bytes_config":
+ Read/write files containing the configuration for the mbm_total_bytes
+ and mbm_local_bytes events, respectively, when the Bandwidth
+ Monitoring Event Configuration (BMEC) feature is supported.
+ The event configuration settings are domain specific and affect
+ all the CPUs in the domain. When either event configuration is
+ changed, the bandwidth counters for all RMIDs of both events
+ (mbm_total_bytes as well as mbm_local_bytes) are cleared for that
+ domain. The next read for every RMID will report "Unavailable"
+ and subsequent reads will report the valid value.
+
+ Following are the types of events supported:
+
+ ==== ========================================================
+ Bits Description
+ ==== ========================================================
+ 6 Dirty Victims from the QOS domain to all types of memory
+ 5 Reads to slow memory in the non-local NUMA domain
+ 4 Reads to slow memory in the local NUMA domain
+ 3 Non-temporal writes to non-local NUMA domain
+ 2 Non-temporal writes to local NUMA domain
+ 1 Reads to memory in the non-local NUMA domain
+ 0 Reads to memory in the local NUMA domain
+ ==== ========================================================
+
+ By default, the mbm_total_bytes configuration is set to 0x7f to count
+ all the event types and the mbm_local_bytes configuration is set to
+ 0x15 to count all the local memory events.
+
+ Examples:
+
+ * To view the current configuration::
+ ::
+
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config
+ 0=0x7f;1=0x7f;2=0x7f;3=0x7f
+
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
+ 0=0x15;1=0x15;3=0x15;4=0x15
+
+ * To change the mbm_total_bytes to count only reads on domain 0,
+ the bits 0, 1, 4 and 5 needs to be set, which is 110011b in binary
+ (in hexadecimal 0x33):
+ ::
+
+ # echo "0=0x33" > /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config
+
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config
+ 0=0x33;1=0x7f;2=0x7f;3=0x7f
+
+ * To change the mbm_local_bytes to count all the slow memory reads on
+ domain 0 and 1, the bits 4 and 5 needs to be set, which is 110000b
+ in binary (in hexadecimal 0x30):
+ ::
+
+ # echo "0=0x30;1=0x30" > /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
+
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
+ 0=0x30;1=0x30;3=0x15;4=0x15
+
+"max_threshold_occupancy":
+ Read/write file provides the largest value (in
+ bytes) at which a previously used LLC_occupancy
+ counter can be considered for re-use.
+
+Finally, in the top level of the "info" directory there is a file
+named "last_cmd_status". This is reset with every "command" issued
+via the file system (making new directories or writing to any of the
+control files). If the command was successful, it will read as "ok".
+If the command failed, it will provide more information that can be
+conveyed in the error returns from file operations. E.g.
+::
+
+ # echo L3:0=f7 > schemata
+ bash: echo: write error: Invalid argument
+ # cat info/last_cmd_status
+ mask f7 has non-consecutive 1-bits
+
+Resource alloc and monitor groups
+=================================
+
+Resource groups are represented as directories in the resctrl file
+system. The default group is the root directory which, immediately
+after mounting, owns all the tasks and cpus in the system and can make
+full use of all resources.
+
+On a system with RDT control features additional directories can be
+created in the root directory that specify different amounts of each
+resource (see "schemata" below). The root and these additional top level
+directories are referred to as "CTRL_MON" groups below.
+
+On a system with RDT monitoring the root directory and other top level
+directories contain a directory named "mon_groups" in which additional
+directories can be created to monitor subsets of tasks in the CTRL_MON
+group that is their ancestor. These are called "MON" groups in the rest
+of this document.
+
+Removing a directory will move all tasks and cpus owned by the group it
+represents to the parent. Removing one of the created CTRL_MON groups
+will automatically remove all MON groups below it.
+
+Moving MON group directories to a new parent CTRL_MON group is supported
+for the purpose of changing the resource allocations of a MON group
+without impacting its monitoring data or assigned tasks. This operation
+is not allowed for MON groups which monitor CPUs. No other move
+operation is currently allowed other than simply renaming a CTRL_MON or
+MON group.
+
+All groups contain the following files:
+
+"tasks":
+ Reading this file shows the list of all tasks that belong to
+ this group. Writing a task id to the file will add a task to the
+ group. Multiple tasks can be added by separating the task ids
+ with commas. Tasks will be assigned sequentially. Multiple
+ failures are not supported. A single failure encountered while
+ attempting to assign a task will cause the operation to abort and
+ already added tasks before the failure will remain in the group.
+ Failures will be logged to /sys/fs/resctrl/info/last_cmd_status.
+
+ If the group is a CTRL_MON group the task is removed from
+ whichever previous CTRL_MON group owned the task and also from
+ any MON group that owned the task. If the group is a MON group,
+ then the task must already belong to the CTRL_MON parent of this
+ group. The task is removed from any previous MON group.
+
+
+"cpus":
+ Reading this file shows a bitmask of the logical CPUs owned by
+ this group. Writing a mask to this file will add and remove
+ CPUs to/from this group. As with the tasks file a hierarchy is
+ maintained where MON groups may only include CPUs owned by the
+ parent CTRL_MON group.
+ When the resource group is in pseudo-locked mode this file will
+ only be readable, reflecting the CPUs associated with the
+ pseudo-locked region.
+
+
+"cpus_list":
+ Just like "cpus", only using ranges of CPUs instead of bitmasks.
+
+
+When control is enabled all CTRL_MON groups will also contain:
+
+"schemata":
+ A list of all the resources available to this group.
+ Each resource has its own line and format - see below for details.
+
+"size":
+ Mirrors the display of the "schemata" file to display the size in
+ bytes of each allocation instead of the bits representing the
+ allocation.
+
+"mode":
+ The "mode" of the resource group dictates the sharing of its
+ allocations. A "shareable" resource group allows sharing of its
+ allocations while an "exclusive" resource group does not. A
+ cache pseudo-locked region is created by first writing
+ "pseudo-locksetup" to the "mode" file before writing the cache
+ pseudo-locked region's schemata to the resource group's "schemata"
+ file. On successful pseudo-locked region creation the mode will
+ automatically change to "pseudo-locked".
+
+"ctrl_hw_id":
+ Available only with debug option. The identifier used by hardware
+ for the control group. On x86 this is the CLOSID.
+
+When monitoring is enabled all MON groups will also contain:
+
+"mon_data":
+ This contains a set of files organized by L3 domain and by
+ RDT event. E.g. on a system with two L3 domains there will
+ be subdirectories "mon_L3_00" and "mon_L3_01". Each of these
+ directories have one file per event (e.g. "llc_occupancy",
+ "mbm_total_bytes", and "mbm_local_bytes"). In a MON group these
+ files provide a read out of the current value of the event for
+ all tasks in the group. In CTRL_MON groups these files provide
+ the sum for all tasks in the CTRL_MON group and all tasks in
+ MON groups. Please see example section for more details on usage.
+ On systems with Sub-NUMA Cluster (SNC) enabled there are extra
+ directories for each node (located within the "mon_L3_XX" directory
+ for the L3 cache they occupy). These are named "mon_sub_L3_YY"
+ where "YY" is the node number.
+
+"mon_hw_id":
+ Available only with debug option. The identifier used by hardware
+ for the monitor group. On x86 this is the RMID.
+
+When the "mba_MBps" mount option is used all CTRL_MON groups will also contain:
+
+"mba_MBps_event":
+ Reading this file shows which memory bandwidth event is used
+ as input to the software feedback loop that keeps memory bandwidth
+ below the value specified in the schemata file. Writing the
+ name of one of the supported memory bandwidth events found in
+ /sys/fs/resctrl/info/L3_MON/mon_features changes the input
+ event.
+
+Resource allocation rules
+-------------------------
+
+When a task is running the following rules define which resources are
+available to it:
+
+1) If the task is a member of a non-default group, then the schemata
+ for that group is used.
+
+2) Else if the task belongs to the default group, but is running on a
+ CPU that is assigned to some specific group, then the schemata for the
+ CPU's group is used.
+
+3) Otherwise the schemata for the default group is used.
+
+Resource monitoring rules
+-------------------------
+1) If a task is a member of a MON group, or non-default CTRL_MON group
+ then RDT events for the task will be reported in that group.
+
+2) If a task is a member of the default CTRL_MON group, but is running
+ on a CPU that is assigned to some specific group, then the RDT events
+ for the task will be reported in that group.
+
+3) Otherwise RDT events for the task will be reported in the root level
+ "mon_data" group.
+
+
+Notes on cache occupancy monitoring and control
+===============================================
+When moving a task from one group to another you should remember that
+this only affects *new* cache allocations by the task. E.g. you may have
+a task in a monitor group showing 3 MB of cache occupancy. If you move
+to a new group and immediately check the occupancy of the old and new
+groups you will likely see that the old group is still showing 3 MB and
+the new group zero. When the task accesses locations still in cache from
+before the move, the h/w does not update any counters. On a busy system
+you will likely see the occupancy in the old group go down as cache lines
+are evicted and re-used while the occupancy in the new group rises as
+the task accesses memory and loads into the cache are counted based on
+membership in the new group.
+
+The same applies to cache allocation control. Moving a task to a group
+with a smaller cache partition will not evict any cache lines. The
+process may continue to use them from the old partition.
+
+Hardware uses CLOSid(Class of service ID) and an RMID(Resource monitoring ID)
+to identify a control group and a monitoring group respectively. Each of
+the resource groups are mapped to these IDs based on the kind of group. The
+number of CLOSid and RMID are limited by the hardware and hence the creation of
+a "CTRL_MON" directory may fail if we run out of either CLOSID or RMID
+and creation of "MON" group may fail if we run out of RMIDs.
+
+max_threshold_occupancy - generic concepts
+------------------------------------------
+
+Note that an RMID once freed may not be immediately available for use as
+the RMID is still tagged the cache lines of the previous user of RMID.
+Hence such RMIDs are placed on limbo list and checked back if the cache
+occupancy has gone down. If there is a time when system has a lot of
+limbo RMIDs but which are not ready to be used, user may see an -EBUSY
+during mkdir.
+
+max_threshold_occupancy is a user configurable value to determine the
+occupancy at which an RMID can be freed.
+
+The mon_llc_occupancy_limbo tracepoint gives the precise occupancy in bytes
+for a subset of RMID that are not immediately available for allocation.
+This can't be relied on to produce output every second, it may be necessary
+to attempt to create an empty monitor group to force an update. Output may
+only be produced if creation of a control or monitor group fails.
+
+Schemata files - general concepts
+---------------------------------
+Each line in the file describes one resource. The line starts with
+the name of the resource, followed by specific values to be applied
+in each of the instances of that resource on the system.
+
+Cache IDs
+---------
+On current generation systems there is one L3 cache per socket and L2
+caches are generally just shared by the hyperthreads on a core, but this
+isn't an architectural requirement. We could have multiple separate L3
+caches on a socket, multiple cores could share an L2 cache. So instead
+of using "socket" or "core" to define the set of logical cpus sharing
+a resource we use a "Cache ID". At a given cache level this will be a
+unique number across the whole system (but it isn't guaranteed to be a
+contiguous sequence, there may be gaps). To find the ID for each logical
+CPU look in /sys/devices/system/cpu/cpu*/cache/index*/id
+
+Cache Bit Masks (CBM)
+---------------------
+For cache resources we describe the portion of the cache that is available
+for allocation using a bitmask. The maximum value of the mask is defined
+by each cpu model (and may be different for different cache levels). It
+is found using CPUID, but is also provided in the "info" directory of
+the resctrl file system in "info/{resource}/cbm_mask". Some Intel hardware
+requires that these masks have all the '1' bits in a contiguous block. So
+0x3, 0x6 and 0xC are legal 4-bit masks with two bits set, but 0x5, 0x9
+and 0xA are not. Check /sys/fs/resctrl/info/{resource}/sparse_masks
+if non-contiguous 1s value is supported. On a system with a 20-bit mask
+each bit represents 5% of the capacity of the cache. You could partition
+the cache into four equal parts with masks: 0x1f, 0x3e0, 0x7c00, 0xf8000.
+
+Notes on Sub-NUMA Cluster mode
+==============================
+When SNC mode is enabled, Linux may load balance tasks between Sub-NUMA
+nodes much more readily than between regular NUMA nodes since the CPUs
+on Sub-NUMA nodes share the same L3 cache and the system may report
+the NUMA distance between Sub-NUMA nodes with a lower value than used
+for regular NUMA nodes.
+
+The top-level monitoring files in each "mon_L3_XX" directory provide
+the sum of data across all SNC nodes sharing an L3 cache instance.
+Users who bind tasks to the CPUs of a specific Sub-NUMA node can read
+the "llc_occupancy", "mbm_total_bytes", and "mbm_local_bytes" in the
+"mon_sub_L3_YY" directories to get node local data.
+
+Memory bandwidth allocation is still performed at the L3 cache
+level. I.e. throttling controls are applied to all SNC nodes.
+
+L3 cache allocation bitmaps also apply to all SNC nodes. But note that
+the amount of L3 cache represented by each bit is divided by the number
+of SNC nodes per L3 cache. E.g. with a 100MB cache on a system with 10-bit
+allocation masks each bit normally represents 10MB. With SNC mode enabled
+with two SNC nodes per L3 cache, each bit only represents 5MB.
+
+Memory bandwidth Allocation and monitoring
+==========================================
+
+For Memory bandwidth resource, by default the user controls the resource
+by indicating the percentage of total memory bandwidth.
+
+The minimum bandwidth percentage value for each cpu model is predefined
+and can be looked up through "info/MB/min_bandwidth". The bandwidth
+granularity that is allocated is also dependent on the cpu model and can
+be looked up at "info/MB/bandwidth_gran". The available bandwidth
+control steps are: min_bw + N * bw_gran. Intermediate values are rounded
+to the next control step available on the hardware.
+
+The bandwidth throttling is a core specific mechanism on some of Intel
+SKUs. Using a high bandwidth and a low bandwidth setting on two threads
+sharing a core may result in both threads being throttled to use the
+low bandwidth (see "thread_throttle_mode").
+
+The fact that Memory bandwidth allocation(MBA) may be a core
+specific mechanism where as memory bandwidth monitoring(MBM) is done at
+the package level may lead to confusion when users try to apply control
+via the MBA and then monitor the bandwidth to see if the controls are
+effective. Below are such scenarios:
+
+1. User may *not* see increase in actual bandwidth when percentage
+ values are increased:
+
+This can occur when aggregate L2 external bandwidth is more than L3
+external bandwidth. Consider an SKL SKU with 24 cores on a package and
+where L2 external is 10GBps (hence aggregate L2 external bandwidth is
+240GBps) and L3 external bandwidth is 100GBps. Now a workload with '20
+threads, having 50% bandwidth, each consuming 5GBps' consumes the max L3
+bandwidth of 100GBps although the percentage value specified is only 50%
+<< 100%. Hence increasing the bandwidth percentage will not yield any
+more bandwidth. This is because although the L2 external bandwidth still
+has capacity, the L3 external bandwidth is fully used. Also note that
+this would be dependent on number of cores the benchmark is run on.
+
+2. Same bandwidth percentage may mean different actual bandwidth
+ depending on # of threads:
+
+For the same SKU in #1, a 'single thread, with 10% bandwidth' and '4
+thread, with 10% bandwidth' can consume upto 10GBps and 40GBps although
+they have same percentage bandwidth of 10%. This is simply because as
+threads start using more cores in an rdtgroup, the actual bandwidth may
+increase or vary although user specified bandwidth percentage is same.
+
+In order to mitigate this and make the interface more user friendly,
+resctrl added support for specifying the bandwidth in MiBps as well. The
+kernel underneath would use a software feedback mechanism or a "Software
+Controller(mba_sc)" which reads the actual bandwidth using MBM counters
+and adjust the memory bandwidth percentages to ensure::
+
+ "actual bandwidth < user specified bandwidth".
+
+By default, the schemata would take the bandwidth percentage values
+where as user can switch to the "MBA software controller" mode using
+a mount option 'mba_MBps'. The schemata format is specified in the below
+sections.
+
+L3 schemata file details (code and data prioritization disabled)
+----------------------------------------------------------------
+With CDP disabled the L3 schemata format is::
+
+ L3:<cache_id0>=<cbm>;<cache_id1>=<cbm>;...
+
+L3 schemata file details (CDP enabled via mount option to resctrl)
+------------------------------------------------------------------
+When CDP is enabled L3 control is split into two separate resources
+so you can specify independent masks for code and data like this::
+
+ L3DATA:<cache_id0>=<cbm>;<cache_id1>=<cbm>;...
+ L3CODE:<cache_id0>=<cbm>;<cache_id1>=<cbm>;...
+
+L2 schemata file details
+------------------------
+CDP is supported at L2 using the 'cdpl2' mount option. The schemata
+format is either::
+
+ L2:<cache_id0>=<cbm>;<cache_id1>=<cbm>;...
+
+or
+
+ L2DATA:<cache_id0>=<cbm>;<cache_id1>=<cbm>;...
+ L2CODE:<cache_id0>=<cbm>;<cache_id1>=<cbm>;...
+
+
+Memory bandwidth Allocation (default mode)
+------------------------------------------
+
+Memory b/w domain is L3 cache.
+::
+
+ MB:<cache_id0>=bandwidth0;<cache_id1>=bandwidth1;...
+
+Memory bandwidth Allocation specified in MiBps
+----------------------------------------------
+
+Memory bandwidth domain is L3 cache.
+::
+
+ MB:<cache_id0>=bw_MiBps0;<cache_id1>=bw_MiBps1;...
+
+Slow Memory Bandwidth Allocation (SMBA)
+---------------------------------------
+AMD hardware supports Slow Memory Bandwidth Allocation (SMBA).
+CXL.memory is the only supported "slow" memory device. With the
+support of SMBA, the hardware enables bandwidth allocation on
+the slow memory devices. If there are multiple such devices in
+the system, the throttling logic groups all the slow sources
+together and applies the limit on them as a whole.
+
+The presence of SMBA (with CXL.memory) is independent of slow memory
+devices presence. If there are no such devices on the system, then
+configuring SMBA will have no impact on the performance of the system.
+
+The bandwidth domain for slow memory is L3 cache. Its schemata file
+is formatted as:
+::
+
+ SMBA:<cache_id0>=bandwidth0;<cache_id1>=bandwidth1;...
+
+Reading/writing the schemata file
+---------------------------------
+Reading the schemata file will show the state of all resources
+on all domains. When writing you only need to specify those values
+which you wish to change. E.g.
+::
+
+ # cat schemata
+ L3DATA:0=fffff;1=fffff;2=fffff;3=fffff
+ L3CODE:0=fffff;1=fffff;2=fffff;3=fffff
+ # echo "L3DATA:2=3c0;" > schemata
+ # cat schemata
+ L3DATA:0=fffff;1=fffff;2=3c0;3=fffff
+ L3CODE:0=fffff;1=fffff;2=fffff;3=fffff
+
+Reading/writing the schemata file (on AMD systems)
+--------------------------------------------------
+Reading the schemata file will show the current bandwidth limit on all
+domains. The allocated resources are in multiples of one eighth GB/s.
+When writing to the file, you need to specify what cache id you wish to
+configure the bandwidth limit.
+
+For example, to allocate 2GB/s limit on the first cache id:
+
+::
+
+ # cat schemata
+ MB:0=2048;1=2048;2=2048;3=2048
+ L3:0=ffff;1=ffff;2=ffff;3=ffff
+
+ # echo "MB:1=16" > schemata
+ # cat schemata
+ MB:0=2048;1= 16;2=2048;3=2048
+ L3:0=ffff;1=ffff;2=ffff;3=ffff
+
+Reading/writing the schemata file (on AMD systems) with SMBA feature
+--------------------------------------------------------------------
+Reading and writing the schemata file is the same as without SMBA in
+above section.
+
+For example, to allocate 8GB/s limit on the first cache id:
+
+::
+
+ # cat schemata
+ SMBA:0=2048;1=2048;2=2048;3=2048
+ MB:0=2048;1=2048;2=2048;3=2048
+ L3:0=ffff;1=ffff;2=ffff;3=ffff
+
+ # echo "SMBA:1=64" > schemata
+ # cat schemata
+ SMBA:0=2048;1= 64;2=2048;3=2048
+ MB:0=2048;1=2048;2=2048;3=2048
+ L3:0=ffff;1=ffff;2=ffff;3=ffff
+
+Cache Pseudo-Locking
+====================
+CAT enables a user to specify the amount of cache space that an
+application can fill. Cache pseudo-locking builds on the fact that a
+CPU can still read and write data pre-allocated outside its current
+allocated area on a cache hit. With cache pseudo-locking, data can be
+preloaded into a reserved portion of cache that no application can
+fill, and from that point on will only serve cache hits. The cache
+pseudo-locked memory is made accessible to user space where an
+application can map it into its virtual address space and thus have
+a region of memory with reduced average read latency.
+
+The creation of a cache pseudo-locked region is triggered by a request
+from the user to do so that is accompanied by a schemata of the region
+to be pseudo-locked. The cache pseudo-locked region is created as follows:
+
+- Create a CAT allocation CLOSNEW with a CBM matching the schemata
+ from the user of the cache region that will contain the pseudo-locked
+ memory. This region must not overlap with any current CAT allocation/CLOS
+ on the system and no future overlap with this cache region is allowed
+ while the pseudo-locked region exists.
+- Create a contiguous region of memory of the same size as the cache
+ region.
+- Flush the cache, disable hardware prefetchers, disable preemption.
+- Make CLOSNEW the active CLOS and touch the allocated memory to load
+ it into the cache.
+- Set the previous CLOS as active.
+- At this point the closid CLOSNEW can be released - the cache
+ pseudo-locked region is protected as long as its CBM does not appear in
+ any CAT allocation. Even though the cache pseudo-locked region will from
+ this point on not appear in any CBM of any CLOS an application running with
+ any CLOS will be able to access the memory in the pseudo-locked region since
+ the region continues to serve cache hits.
+- The contiguous region of memory loaded into the cache is exposed to
+ user-space as a character device.
+
+Cache pseudo-locking increases the probability that data will remain
+in the cache via carefully configuring the CAT feature and controlling
+application behavior. There is no guarantee that data is placed in
+cache. Instructions like INVD, WBINVD, CLFLUSH, etc. can still evict
+“locked” data from cache. Power management C-states may shrink or
+power off cache. Deeper C-states will automatically be restricted on
+pseudo-locked region creation.
+
+It is required that an application using a pseudo-locked region runs
+with affinity to the cores (or a subset of the cores) associated
+with the cache on which the pseudo-locked region resides. A sanity check
+within the code will not allow an application to map pseudo-locked memory
+unless it runs with affinity to cores associated with the cache on which the
+pseudo-locked region resides. The sanity check is only done during the
+initial mmap() handling, there is no enforcement afterwards and the
+application self needs to ensure it remains affine to the correct cores.
+
+Pseudo-locking is accomplished in two stages:
+
+1) During the first stage the system administrator allocates a portion
+ of cache that should be dedicated to pseudo-locking. At this time an
+ equivalent portion of memory is allocated, loaded into allocated
+ cache portion, and exposed as a character device.
+2) During the second stage a user-space application maps (mmap()) the
+ pseudo-locked memory into its address space.
+
+Cache Pseudo-Locking Interface
+------------------------------
+A pseudo-locked region is created using the resctrl interface as follows:
+
+1) Create a new resource group by creating a new directory in /sys/fs/resctrl.
+2) Change the new resource group's mode to "pseudo-locksetup" by writing
+ "pseudo-locksetup" to the "mode" file.
+3) Write the schemata of the pseudo-locked region to the "schemata" file. All
+ bits within the schemata should be "unused" according to the "bit_usage"
+ file.
+
+On successful pseudo-locked region creation the "mode" file will contain
+"pseudo-locked" and a new character device with the same name as the resource
+group will exist in /dev/pseudo_lock. This character device can be mmap()'ed
+by user space in order to obtain access to the pseudo-locked memory region.
+
+An example of cache pseudo-locked region creation and usage can be found below.
+
+Cache Pseudo-Locking Debugging Interface
+----------------------------------------
+The pseudo-locking debugging interface is enabled by default (if
+CONFIG_DEBUG_FS is enabled) and can be found in /sys/kernel/debug/resctrl.
+
+There is no explicit way for the kernel to test if a provided memory
+location is present in the cache. The pseudo-locking debugging interface uses
+the tracing infrastructure to provide two ways to measure cache residency of
+the pseudo-locked region:
+
+1) Memory access latency using the pseudo_lock_mem_latency tracepoint. Data
+ from these measurements are best visualized using a hist trigger (see
+ example below). In this test the pseudo-locked region is traversed at
+ a stride of 32 bytes while hardware prefetchers and preemption
+ are disabled. This also provides a substitute visualization of cache
+ hits and misses.
+2) Cache hit and miss measurements using model specific precision counters if
+ available. Depending on the levels of cache on the system the pseudo_lock_l2
+ and pseudo_lock_l3 tracepoints are available.
+
+When a pseudo-locked region is created a new debugfs directory is created for
+it in debugfs as /sys/kernel/debug/resctrl/<newdir>. A single
+write-only file, pseudo_lock_measure, is present in this directory. The
+measurement of the pseudo-locked region depends on the number written to this
+debugfs file:
+
+1:
+ writing "1" to the pseudo_lock_measure file will trigger the latency
+ measurement captured in the pseudo_lock_mem_latency tracepoint. See
+ example below.
+2:
+ writing "2" to the pseudo_lock_measure file will trigger the L2 cache
+ residency (cache hits and misses) measurement captured in the
+ pseudo_lock_l2 tracepoint. See example below.
+3:
+ writing "3" to the pseudo_lock_measure file will trigger the L3 cache
+ residency (cache hits and misses) measurement captured in the
+ pseudo_lock_l3 tracepoint.
+
+All measurements are recorded with the tracing infrastructure. This requires
+the relevant tracepoints to be enabled before the measurement is triggered.
+
+Example of latency debugging interface
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+In this example a pseudo-locked region named "newlock" was created. Here is
+how we can measure the latency in cycles of reading from this region and
+visualize this data with a histogram that is available if CONFIG_HIST_TRIGGERS
+is set::
+
+ # :> /sys/kernel/tracing/trace
+ # echo 'hist:keys=latency' > /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/trigger
+ # echo 1 > /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/enable
+ # echo 1 > /sys/kernel/debug/resctrl/newlock/pseudo_lock_measure
+ # echo 0 > /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/enable
+ # cat /sys/kernel/tracing/events/resctrl/pseudo_lock_mem_latency/hist
+
+ # event histogram
+ #
+ # trigger info: hist:keys=latency:vals=hitcount:sort=hitcount:size=2048 [active]
+ #
+
+ { latency: 456 } hitcount: 1
+ { latency: 50 } hitcount: 83
+ { latency: 36 } hitcount: 96
+ { latency: 44 } hitcount: 174
+ { latency: 48 } hitcount: 195
+ { latency: 46 } hitcount: 262
+ { latency: 42 } hitcount: 693
+ { latency: 40 } hitcount: 3204
+ { latency: 38 } hitcount: 3484
+
+ Totals:
+ Hits: 8192
+ Entries: 9
+ Dropped: 0
+
+Example of cache hits/misses debugging
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+In this example a pseudo-locked region named "newlock" was created on the L2
+cache of a platform. Here is how we can obtain details of the cache hits
+and misses using the platform's precision counters.
+::
+
+ # :> /sys/kernel/tracing/trace
+ # echo 1 > /sys/kernel/tracing/events/resctrl/pseudo_lock_l2/enable
+ # echo 2 > /sys/kernel/debug/resctrl/newlock/pseudo_lock_measure
+ # echo 0 > /sys/kernel/tracing/events/resctrl/pseudo_lock_l2/enable
+ # cat /sys/kernel/tracing/trace
+
+ # tracer: nop
+ #
+ # _-----=> irqs-off
+ # / _----=> need-resched
+ # | / _---=> hardirq/softirq
+ # || / _--=> preempt-depth
+ # ||| / delay
+ # TASK-PID CPU# |||| TIMESTAMP FUNCTION
+ # | | | |||| | |
+ pseudo_lock_mea-1672 [002] .... 3132.860500: pseudo_lock_l2: hits=4097 miss=0
+
+
+Examples for RDT allocation usage
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+1) Example 1
+
+On a two socket machine (one L3 cache per socket) with just four bits
+for cache bit masks, minimum b/w of 10% with a memory bandwidth
+granularity of 10%.
+::
+
+ # mount -t resctrl resctrl /sys/fs/resctrl
+ # cd /sys/fs/resctrl
+ # mkdir p0 p1
+ # echo "L3:0=3;1=c\nMB:0=50;1=50" > /sys/fs/resctrl/p0/schemata
+ # echo "L3:0=3;1=3\nMB:0=50;1=50" > /sys/fs/resctrl/p1/schemata
+
+The default resource group is unmodified, so we have access to all parts
+of all caches (its schemata file reads "L3:0=f;1=f").
+
+Tasks that are under the control of group "p0" may only allocate from the
+"lower" 50% on cache ID 0, and the "upper" 50% of cache ID 1.
+Tasks in group "p1" use the "lower" 50% of cache on both sockets.
+
+Similarly, tasks that are under the control of group "p0" may use a
+maximum memory b/w of 50% on socket0 and 50% on socket 1.
+Tasks in group "p1" may also use 50% memory b/w on both sockets.
+Note that unlike cache masks, memory b/w cannot specify whether these
+allocations can overlap or not. The allocations specifies the maximum
+b/w that the group may be able to use and the system admin can configure
+the b/w accordingly.
+
+If resctrl is using the software controller (mba_sc) then user can enter the
+max b/w in MB rather than the percentage values.
+::
+
+ # echo "L3:0=3;1=c\nMB:0=1024;1=500" > /sys/fs/resctrl/p0/schemata
+ # echo "L3:0=3;1=3\nMB:0=1024;1=500" > /sys/fs/resctrl/p1/schemata
+
+In the above example the tasks in "p1" and "p0" on socket 0 would use a max b/w
+of 1024MB where as on socket 1 they would use 500MB.
+
+2) Example 2
+
+Again two sockets, but this time with a more realistic 20-bit mask.
+
+Two real time tasks pid=1234 running on processor 0 and pid=5678 running on
+processor 1 on socket 0 on a 2-socket and dual core machine. To avoid noisy
+neighbors, each of the two real-time tasks exclusively occupies one quarter
+of L3 cache on socket 0.
+::
+
+ # mount -t resctrl resctrl /sys/fs/resctrl
+ # cd /sys/fs/resctrl
+
+First we reset the schemata for the default group so that the "upper"
+50% of the L3 cache on socket 0 and 50% of memory b/w cannot be used by
+ordinary tasks::
+
+ # echo "L3:0=3ff;1=fffff\nMB:0=50;1=100" > schemata
+
+Next we make a resource group for our first real time task and give
+it access to the "top" 25% of the cache on socket 0.
+::
+
+ # mkdir p0
+ # echo "L3:0=f8000;1=fffff" > p0/schemata
+
+Finally we move our first real time task into this resource group. We
+also use taskset(1) to ensure the task always runs on a dedicated CPU
+on socket 0. Most uses of resource groups will also constrain which
+processors tasks run on.
+::
+
+ # echo 1234 > p0/tasks
+ # taskset -cp 1 1234
+
+Ditto for the second real time task (with the remaining 25% of cache)::
+
+ # mkdir p1
+ # echo "L3:0=7c00;1=fffff" > p1/schemata
+ # echo 5678 > p1/tasks
+ # taskset -cp 2 5678
+
+For the same 2 socket system with memory b/w resource and CAT L3 the
+schemata would look like(Assume min_bandwidth 10 and bandwidth_gran is
+10):
+
+For our first real time task this would request 20% memory b/w on socket 0.
+::
+
+ # echo -e "L3:0=f8000;1=fffff\nMB:0=20;1=100" > p0/schemata
+
+For our second real time task this would request an other 20% memory b/w
+on socket 0.
+::
+
+ # echo -e "L3:0=f8000;1=fffff\nMB:0=20;1=100" > p0/schemata
+
+3) Example 3
+
+A single socket system which has real-time tasks running on core 4-7 and
+non real-time workload assigned to core 0-3. The real-time tasks share text
+and data, so a per task association is not required and due to interaction
+with the kernel it's desired that the kernel on these cores shares L3 with
+the tasks.
+::
+
+ # mount -t resctrl resctrl /sys/fs/resctrl
+ # cd /sys/fs/resctrl
+
+First we reset the schemata for the default group so that the "upper"
+50% of the L3 cache on socket 0, and 50% of memory bandwidth on socket 0
+cannot be used by ordinary tasks::
+
+ # echo "L3:0=3ff\nMB:0=50" > schemata
+
+Next we make a resource group for our real time cores and give it access
+to the "top" 50% of the cache on socket 0 and 50% of memory bandwidth on
+socket 0.
+::
+
+ # mkdir p0
+ # echo "L3:0=ffc00\nMB:0=50" > p0/schemata
+
+Finally we move core 4-7 over to the new group and make sure that the
+kernel and the tasks running there get 50% of the cache. They should
+also get 50% of memory bandwidth assuming that the cores 4-7 are SMT
+siblings and only the real time threads are scheduled on the cores 4-7.
+::
+
+ # echo F0 > p0/cpus
+
+4) Example 4
+
+The resource groups in previous examples were all in the default "shareable"
+mode allowing sharing of their cache allocations. If one resource group
+configures a cache allocation then nothing prevents another resource group
+to overlap with that allocation.
+
+In this example a new exclusive resource group will be created on a L2 CAT
+system with two L2 cache instances that can be configured with an 8-bit
+capacity bitmask. The new exclusive resource group will be configured to use
+25% of each cache instance.
+::
+
+ # mount -t resctrl resctrl /sys/fs/resctrl/
+ # cd /sys/fs/resctrl
+
+First, we observe that the default group is configured to allocate to all L2
+cache::
+
+ # cat schemata
+ L2:0=ff;1=ff
+
+We could attempt to create the new resource group at this point, but it will
+fail because of the overlap with the schemata of the default group::
+
+ # mkdir p0
+ # echo 'L2:0=0x3;1=0x3' > p0/schemata
+ # cat p0/mode
+ shareable
+ # echo exclusive > p0/mode
+ -sh: echo: write error: Invalid argument
+ # cat info/last_cmd_status
+ schemata overlaps
+
+To ensure that there is no overlap with another resource group the default
+resource group's schemata has to change, making it possible for the new
+resource group to become exclusive.
+::
+
+ # echo 'L2:0=0xfc;1=0xfc' > schemata
+ # echo exclusive > p0/mode
+ # grep . p0/*
+ p0/cpus:0
+ p0/mode:exclusive
+ p0/schemata:L2:0=03;1=03
+ p0/size:L2:0=262144;1=262144
+
+A new resource group will on creation not overlap with an exclusive resource
+group::
+
+ # mkdir p1
+ # grep . p1/*
+ p1/cpus:0
+ p1/mode:shareable
+ p1/schemata:L2:0=fc;1=fc
+ p1/size:L2:0=786432;1=786432
+
+The bit_usage will reflect how the cache is used::
+
+ # cat info/L2/bit_usage
+ 0=SSSSSSEE;1=SSSSSSEE
+
+A resource group cannot be forced to overlap with an exclusive resource group::
+
+ # echo 'L2:0=0x1;1=0x1' > p1/schemata
+ -sh: echo: write error: Invalid argument
+ # cat info/last_cmd_status
+ overlaps with exclusive group
+
+Example of Cache Pseudo-Locking
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Lock portion of L2 cache from cache id 1 using CBM 0x3. Pseudo-locked
+region is exposed at /dev/pseudo_lock/newlock that can be provided to
+application for argument to mmap().
+::
+
+ # mount -t resctrl resctrl /sys/fs/resctrl/
+ # cd /sys/fs/resctrl
+
+Ensure that there are bits available that can be pseudo-locked, since only
+unused bits can be pseudo-locked the bits to be pseudo-locked needs to be
+removed from the default resource group's schemata::
+
+ # cat info/L2/bit_usage
+ 0=SSSSSSSS;1=SSSSSSSS
+ # echo 'L2:1=0xfc' > schemata
+ # cat info/L2/bit_usage
+ 0=SSSSSSSS;1=SSSSSS00
+
+Create a new resource group that will be associated with the pseudo-locked
+region, indicate that it will be used for a pseudo-locked region, and
+configure the requested pseudo-locked region capacity bitmask::
+
+ # mkdir newlock
+ # echo pseudo-locksetup > newlock/mode
+ # echo 'L2:1=0x3' > newlock/schemata
+
+On success the resource group's mode will change to pseudo-locked, the
+bit_usage will reflect the pseudo-locked region, and the character device
+exposing the pseudo-locked region will exist::
+
+ # cat newlock/mode
+ pseudo-locked
+ # cat info/L2/bit_usage
+ 0=SSSSSSSS;1=SSSSSSPP
+ # ls -l /dev/pseudo_lock/newlock
+ crw------- 1 root root 243, 0 Apr 3 05:01 /dev/pseudo_lock/newlock
+
+::
+
+ /*
+ * Example code to access one page of pseudo-locked cache region
+ * from user space.
+ */
+ #define _GNU_SOURCE
+ #include <fcntl.h>
+ #include <sched.h>
+ #include <stdio.h>
+ #include <stdlib.h>
+ #include <unistd.h>
+ #include <sys/mman.h>
+
+ /*
+ * It is required that the application runs with affinity to only
+ * cores associated with the pseudo-locked region. Here the cpu
+ * is hardcoded for convenience of example.
+ */
+ static int cpuid = 2;
+
+ int main(int argc, char *argv[])
+ {
+ cpu_set_t cpuset;
+ long page_size;
+ void *mapping;
+ int dev_fd;
+ int ret;
+
+ page_size = sysconf(_SC_PAGESIZE);
+
+ CPU_ZERO(&cpuset);
+ CPU_SET(cpuid, &cpuset);
+ ret = sched_setaffinity(0, sizeof(cpuset), &cpuset);
+ if (ret < 0) {
+ perror("sched_setaffinity");
+ exit(EXIT_FAILURE);
+ }
+
+ dev_fd = open("/dev/pseudo_lock/newlock", O_RDWR);
+ if (dev_fd < 0) {
+ perror("open");
+ exit(EXIT_FAILURE);
+ }
+
+ mapping = mmap(0, page_size, PROT_READ | PROT_WRITE, MAP_SHARED,
+ dev_fd, 0);
+ if (mapping == MAP_FAILED) {
+ perror("mmap");
+ close(dev_fd);
+ exit(EXIT_FAILURE);
+ }
+
+ /* Application interacts with pseudo-locked memory @mapping */
+
+ ret = munmap(mapping, page_size);
+ if (ret < 0) {
+ perror("munmap");
+ close(dev_fd);
+ exit(EXIT_FAILURE);
+ }
+
+ close(dev_fd);
+ exit(EXIT_SUCCESS);
+ }
+
+Locking between applications
+----------------------------
+
+Certain operations on the resctrl filesystem, composed of read/writes
+to/from multiple files, must be atomic.
+
+As an example, the allocation of an exclusive reservation of L3 cache
+involves:
+
+ 1. Read the cbmmasks from each directory or the per-resource "bit_usage"
+ 2. Find a contiguous set of bits in the global CBM bitmask that is clear
+ in any of the directory cbmmasks
+ 3. Create a new directory
+ 4. Set the bits found in step 2 to the new directory "schemata" file
+
+If two applications attempt to allocate space concurrently then they can
+end up allocating the same bits so the reservations are shared instead of
+exclusive.
+
+To coordinate atomic operations on the resctrlfs and to avoid the problem
+above, the following locking procedure is recommended:
+
+Locking is based on flock, which is available in libc and also as a shell
+script command
+
+Write lock:
+
+ A) Take flock(LOCK_EX) on /sys/fs/resctrl
+ B) Read/write the directory structure.
+ C) funlock
+
+Read lock:
+
+ A) Take flock(LOCK_SH) on /sys/fs/resctrl
+ B) If success read the directory structure.
+ C) funlock
+
+Example with bash::
+
+ # Atomically read directory structure
+ $ flock -s /sys/fs/resctrl/ find /sys/fs/resctrl
+
+ # Read directory contents and create new subdirectory
+
+ $ cat create-dir.sh
+ find /sys/fs/resctrl/ > output.txt
+ mask = function-of(output.txt)
+ mkdir /sys/fs/resctrl/newres/
+ echo mask > /sys/fs/resctrl/newres/schemata
+
+ $ flock /sys/fs/resctrl/ ./create-dir.sh
+
+Example with C::
+
+ /*
+ * Example code do take advisory locks
+ * before accessing resctrl filesystem
+ */
+ #include <sys/file.h>
+ #include <stdlib.h>
+
+ void resctrl_take_shared_lock(int fd)
+ {
+ int ret;
+
+ /* take shared lock on resctrl filesystem */
+ ret = flock(fd, LOCK_SH);
+ if (ret) {
+ perror("flock");
+ exit(-1);
+ }
+ }
+
+ void resctrl_take_exclusive_lock(int fd)
+ {
+ int ret;
+
+ /* release lock on resctrl filesystem */
+ ret = flock(fd, LOCK_EX);
+ if (ret) {
+ perror("flock");
+ exit(-1);
+ }
+ }
+
+ void resctrl_release_lock(int fd)
+ {
+ int ret;
+
+ /* take shared lock on resctrl filesystem */
+ ret = flock(fd, LOCK_UN);
+ if (ret) {
+ perror("flock");
+ exit(-1);
+ }
+ }
+
+ void main(void)
+ {
+ int fd, ret;
+
+ fd = open("/sys/fs/resctrl", O_DIRECTORY);
+ if (fd == -1) {
+ perror("open");
+ exit(-1);
+ }
+ resctrl_take_shared_lock(fd);
+ /* code to read directory contents */
+ resctrl_release_lock(fd);
+
+ resctrl_take_exclusive_lock(fd);
+ /* code to read and write directory contents */
+ resctrl_release_lock(fd);
+ }
+
+Examples for RDT Monitoring along with allocation usage
+=======================================================
+Reading monitored data
+----------------------
+Reading an event file (for ex: mon_data/mon_L3_00/llc_occupancy) would
+show the current snapshot of LLC occupancy of the corresponding MON
+group or CTRL_MON group.
+
+
+Example 1 (Monitor CTRL_MON group and subset of tasks in CTRL_MON group)
+------------------------------------------------------------------------
+On a two socket machine (one L3 cache per socket) with just four bits
+for cache bit masks::
+
+ # mount -t resctrl resctrl /sys/fs/resctrl
+ # cd /sys/fs/resctrl
+ # mkdir p0 p1
+ # echo "L3:0=3;1=c" > /sys/fs/resctrl/p0/schemata
+ # echo "L3:0=3;1=3" > /sys/fs/resctrl/p1/schemata
+ # echo 5678 > p1/tasks
+ # echo 5679 > p1/tasks
+
+The default resource group is unmodified, so we have access to all parts
+of all caches (its schemata file reads "L3:0=f;1=f").
+
+Tasks that are under the control of group "p0" may only allocate from the
+"lower" 50% on cache ID 0, and the "upper" 50% of cache ID 1.
+Tasks in group "p1" use the "lower" 50% of cache on both sockets.
+
+Create monitor groups and assign a subset of tasks to each monitor group.
+::
+
+ # cd /sys/fs/resctrl/p1/mon_groups
+ # mkdir m11 m12
+ # echo 5678 > m11/tasks
+ # echo 5679 > m12/tasks
+
+fetch data (data shown in bytes)
+::
+
+ # cat m11/mon_data/mon_L3_00/llc_occupancy
+ 16234000
+ # cat m11/mon_data/mon_L3_01/llc_occupancy
+ 14789000
+ # cat m12/mon_data/mon_L3_00/llc_occupancy
+ 16789000
+
+The parent ctrl_mon group shows the aggregated data.
+::
+
+ # cat /sys/fs/resctrl/p1/mon_data/mon_l3_00/llc_occupancy
+ 31234000
+
+Example 2 (Monitor a task from its creation)
+--------------------------------------------
+On a two socket machine (one L3 cache per socket)::
+
+ # mount -t resctrl resctrl /sys/fs/resctrl
+ # cd /sys/fs/resctrl
+ # mkdir p0 p1
+
+An RMID is allocated to the group once its created and hence the <cmd>
+below is monitored from its creation.
+::
+
+ # echo $$ > /sys/fs/resctrl/p1/tasks
+ # <cmd>
+
+Fetch the data::
+
+ # cat /sys/fs/resctrl/p1/mon_data/mon_l3_00/llc_occupancy
+ 31789000
+
+Example 3 (Monitor without CAT support or before creating CAT groups)
+---------------------------------------------------------------------
+
+Assume a system like HSW has only CQM and no CAT support. In this case
+the resctrl will still mount but cannot create CTRL_MON directories.
+But user can create different MON groups within the root group thereby
+able to monitor all tasks including kernel threads.
+
+This can also be used to profile jobs cache size footprint before being
+able to allocate them to different allocation groups.
+::
+
+ # mount -t resctrl resctrl /sys/fs/resctrl
+ # cd /sys/fs/resctrl
+ # mkdir mon_groups/m01
+ # mkdir mon_groups/m02
+
+ # echo 3478 > /sys/fs/resctrl/mon_groups/m01/tasks
+ # echo 2467 > /sys/fs/resctrl/mon_groups/m02/tasks
+
+Monitor the groups separately and also get per domain data. From the
+below its apparent that the tasks are mostly doing work on
+domain(socket) 0.
+::
+
+ # cat /sys/fs/resctrl/mon_groups/m01/mon_L3_00/llc_occupancy
+ 31234000
+ # cat /sys/fs/resctrl/mon_groups/m01/mon_L3_01/llc_occupancy
+ 34555
+ # cat /sys/fs/resctrl/mon_groups/m02/mon_L3_00/llc_occupancy
+ 31234000
+ # cat /sys/fs/resctrl/mon_groups/m02/mon_L3_01/llc_occupancy
+ 32789
+
+
+Example 4 (Monitor real time tasks)
+-----------------------------------
+
+A single socket system which has real time tasks running on cores 4-7
+and non real time tasks on other cpus. We want to monitor the cache
+occupancy of the real time threads on these cores.
+::
+
+ # mount -t resctrl resctrl /sys/fs/resctrl
+ # cd /sys/fs/resctrl
+ # mkdir p1
+
+Move the cpus 4-7 over to p1::
+
+ # echo f0 > p1/cpus
+
+View the llc occupancy snapshot::
+
+ # cat /sys/fs/resctrl/p1/mon_data/mon_L3_00/llc_occupancy
+ 11234000
+
+Intel RDT Errata
+================
+
+Intel MBM Counters May Report System Memory Bandwidth Incorrectly
+-----------------------------------------------------------------
+
+Errata SKX99 for Skylake server and BDF102 for Broadwell server.
+
+Problem: Intel Memory Bandwidth Monitoring (MBM) counters track metrics
+according to the assigned Resource Monitor ID (RMID) for that logical
+core. The IA32_QM_CTR register (MSR 0xC8E), used to report these
+metrics, may report incorrect system bandwidth for certain RMID values.
+
+Implication: Due to the errata, system memory bandwidth may not match
+what is reported.
+
+Workaround: MBM total and local readings are corrected according to the
+following correction factor table:
+
++---------------+---------------+---------------+-----------------+
+|core count |rmid count |rmid threshold |correction factor|
++---------------+---------------+---------------+-----------------+
+|1 |8 |0 |1.000000 |
++---------------+---------------+---------------+-----------------+
+|2 |16 |0 |1.000000 |
++---------------+---------------+---------------+-----------------+
+|3 |24 |15 |0.969650 |
++---------------+---------------+---------------+-----------------+
+|4 |32 |0 |1.000000 |
++---------------+---------------+---------------+-----------------+
+|6 |48 |31 |0.969650 |
++---------------+---------------+---------------+-----------------+
+|7 |56 |47 |1.142857 |
++---------------+---------------+---------------+-----------------+
+|8 |64 |0 |1.000000 |
++---------------+---------------+---------------+-----------------+
+|9 |72 |63 |1.185115 |
++---------------+---------------+---------------+-----------------+
+|10 |80 |63 |1.066553 |
++---------------+---------------+---------------+-----------------+
+|11 |88 |79 |1.454545 |
++---------------+---------------+---------------+-----------------+
+|12 |96 |0 |1.000000 |
++---------------+---------------+---------------+-----------------+
+|13 |104 |95 |1.230769 |
++---------------+---------------+---------------+-----------------+
+|14 |112 |95 |1.142857 |
++---------------+---------------+---------------+-----------------+
+|15 |120 |95 |1.066667 |
++---------------+---------------+---------------+-----------------+
+|16 |128 |0 |1.000000 |
++---------------+---------------+---------------+-----------------+
+|17 |136 |127 |1.254863 |
++---------------+---------------+---------------+-----------------+
+|18 |144 |127 |1.185255 |
++---------------+---------------+---------------+-----------------+
+|19 |152 |0 |1.000000 |
++---------------+---------------+---------------+-----------------+
+|20 |160 |127 |1.066667 |
++---------------+---------------+---------------+-----------------+
+|21 |168 |0 |1.000000 |
++---------------+---------------+---------------+-----------------+
+|22 |176 |159 |1.454334 |
++---------------+---------------+---------------+-----------------+
+|23 |184 |0 |1.000000 |
++---------------+---------------+---------------+-----------------+
+|24 |192 |127 |0.969744 |
++---------------+---------------+---------------+-----------------+
+|25 |200 |191 |1.280246 |
++---------------+---------------+---------------+-----------------+
+|26 |208 |191 |1.230921 |
++---------------+---------------+---------------+-----------------+
+|27 |216 |0 |1.000000 |
++---------------+---------------+---------------+-----------------+
+|28 |224 |191 |1.143118 |
++---------------+---------------+---------------+-----------------+
+
+If rmid > rmid threshold, MBM total and local values should be multiplied
+by the correction factor.
+
+See:
+
+1. Erratum SKX99 in Intel Xeon Processor Scalable Family Specification Update:
+http://web.archive.org/web/20200716124958/https://www.intel.com/content/www/us/en/processors/xeon/scalable/xeon-scalable-spec-update.html
+
+2. Erratum BDF102 in Intel Xeon E5-2600 v4 Processor Product Family Specification Update:
+http://web.archive.org/web/20191125200531/https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/xeon-e5-v4-spec-update.pdf
+
+3. The errata in Intel Resource Director Technology (Intel RDT) on 2nd Generation Intel Xeon Scalable Processors Reference Manual:
+https://software.intel.com/content/www/us/en/develop/articles/intel-resource-director-technology-rdt-reference-manual.html
+
+for further information.
diff --git a/MAINTAINERS b/MAINTAINERS
index ed96cc7..c56ab7d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20424,7 +20424,7 @@ M: Tony Luck <tony.luck@...el.com>
M: Reinette Chatre <reinette.chatre@...el.com>
L: linux-kernel@...r.kernel.org
S: Supported
-F: Documentation/arch/x86/resctrl*
+F: Documentation/filesystems/resctrl.rst
F: arch/x86/include/asm/resctrl.h
F: arch/x86/kernel/cpu/resctrl/
F: fs/resctrl/
diff --git a/arch/x86/kernel/cpu/resctrl/Makefile b/arch/x86/kernel/cpu/resctrl/Makefile
index 909be78..d8a04b1 100644
--- a/arch/x86/kernel/cpu/resctrl/Makefile
+++ b/arch/x86/kernel/cpu/resctrl/Makefile
@@ -5,4 +5,3 @@ obj-$(CONFIG_RESCTRL_FS_PSEUDO_LOCK) += pseudo_lock.o
# To allow define_trace.h's recursive include:
CFLAGS_pseudo_lock.o = -I$(src)
-CFLAGS_monitor.o = -I$(src)
diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
index 110b534..1189c0d 100644
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -16,277 +16,9 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/cpu.h>
-#include <linux/kernfs.h>
-#include <linux/seq_file.h>
-#include <linux/slab.h>
-#include <linux/tick.h>
#include "internal.h"
-struct rdt_parse_data {
- struct rdtgroup *rdtgrp;
- char *buf;
-};
-
-typedef int (ctrlval_parser_t)(struct rdt_parse_data *data,
- struct resctrl_schema *s,
- struct rdt_ctrl_domain *d);
-
-/*
- * Check whether MBA bandwidth percentage value is correct. The value is
- * checked against the minimum and max bandwidth values specified by the
- * hardware. The allocated bandwidth percentage is rounded to the next
- * control step available on the hardware.
- */
-static bool bw_validate(char *buf, u32 *data, struct rdt_resource *r)
-{
- int ret;
- u32 bw;
-
- /*
- * Only linear delay values is supported for current Intel SKUs.
- */
- if (!r->membw.delay_linear && r->membw.arch_needs_linear) {
- rdt_last_cmd_puts("No support for non-linear MB domains\n");
- return false;
- }
-
- ret = kstrtou32(buf, 10, &bw);
- if (ret) {
- rdt_last_cmd_printf("Invalid MB value %s\n", buf);
- return false;
- }
-
- /* Nothing else to do if software controller is enabled. */
- if (is_mba_sc(r)) {
- *data = bw;
- return true;
- }
-
- if (bw < r->membw.min_bw || bw > r->membw.max_bw) {
- rdt_last_cmd_printf("MB value %u out of range [%d,%d]\n",
- bw, r->membw.min_bw, r->membw.max_bw);
- return false;
- }
-
- *data = roundup(bw, (unsigned long)r->membw.bw_gran);
- return true;
-}
-
-static int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s,
- struct rdt_ctrl_domain *d)
-{
- struct resctrl_staged_config *cfg;
- u32 closid = data->rdtgrp->closid;
- struct rdt_resource *r = s->res;
- u32 bw_val;
-
- cfg = &d->staged_config[s->conf_type];
- if (cfg->have_new_ctrl) {
- rdt_last_cmd_printf("Duplicate domain %d\n", d->hdr.id);
- return -EINVAL;
- }
-
- if (!bw_validate(data->buf, &bw_val, r))
- return -EINVAL;
-
- if (is_mba_sc(r)) {
- d->mbps_val[closid] = bw_val;
- return 0;
- }
-
- cfg->new_ctrl = bw_val;
- cfg->have_new_ctrl = true;
-
- return 0;
-}
-
-/*
- * Check whether a cache bit mask is valid.
- * On Intel CPUs, non-contiguous 1s value support is indicated by CPUID:
- * - CPUID.0x10.1:ECX[3]: L3 non-contiguous 1s value supported if 1
- * - CPUID.0x10.2:ECX[3]: L2 non-contiguous 1s value supported if 1
- *
- * Haswell does not support a non-contiguous 1s value and additionally
- * requires at least two bits set.
- * AMD allows non-contiguous bitmasks.
- */
-static bool cbm_validate(char *buf, u32 *data, struct rdt_resource *r)
-{
- u32 supported_bits = BIT_MASK(r->cache.cbm_len) - 1;
- unsigned int cbm_len = r->cache.cbm_len;
- unsigned long first_bit, zero_bit, val;
- int ret;
-
- ret = kstrtoul(buf, 16, &val);
- if (ret) {
- rdt_last_cmd_printf("Non-hex character in the mask %s\n", buf);
- return false;
- }
-
- if ((r->cache.min_cbm_bits > 0 && val == 0) || val > supported_bits) {
- rdt_last_cmd_puts("Mask out of range\n");
- return false;
- }
-
- first_bit = find_first_bit(&val, cbm_len);
- zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
-
- /* Are non-contiguous bitmasks allowed? */
- if (!r->cache.arch_has_sparse_bitmasks &&
- (find_next_bit(&val, cbm_len, zero_bit) < cbm_len)) {
- rdt_last_cmd_printf("The mask %lx has non-consecutive 1-bits\n", val);
- return false;
- }
-
- if ((zero_bit - first_bit) < r->cache.min_cbm_bits) {
- rdt_last_cmd_printf("Need at least %d bits in the mask\n",
- r->cache.min_cbm_bits);
- return false;
- }
-
- *data = val;
- return true;
-}
-
-/*
- * Read one cache bit mask (hex). Check that it is valid for the current
- * resource type.
- */
-static int parse_cbm(struct rdt_parse_data *data, struct resctrl_schema *s,
- struct rdt_ctrl_domain *d)
-{
- struct rdtgroup *rdtgrp = data->rdtgrp;
- struct resctrl_staged_config *cfg;
- struct rdt_resource *r = s->res;
- u32 cbm_val;
-
- cfg = &d->staged_config[s->conf_type];
- if (cfg->have_new_ctrl) {
- rdt_last_cmd_printf("Duplicate domain %d\n", d->hdr.id);
- return -EINVAL;
- }
-
- /*
- * Cannot set up more than one pseudo-locked region in a cache
- * hierarchy.
- */
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
- rdtgroup_pseudo_locked_in_hierarchy(d)) {
- rdt_last_cmd_puts("Pseudo-locked region in hierarchy\n");
- return -EINVAL;
- }
-
- if (!cbm_validate(data->buf, &cbm_val, r))
- return -EINVAL;
-
- if ((rdtgrp->mode == RDT_MODE_EXCLUSIVE ||
- rdtgrp->mode == RDT_MODE_SHAREABLE) &&
- rdtgroup_cbm_overlaps_pseudo_locked(d, cbm_val)) {
- rdt_last_cmd_puts("CBM overlaps with pseudo-locked region\n");
- return -EINVAL;
- }
-
- /*
- * The CBM may not overlap with the CBM of another closid if
- * either is exclusive.
- */
- if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, true)) {
- rdt_last_cmd_puts("Overlaps with exclusive group\n");
- return -EINVAL;
- }
-
- if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, false)) {
- if (rdtgrp->mode == RDT_MODE_EXCLUSIVE ||
- rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
- rdt_last_cmd_puts("Overlaps with other group\n");
- return -EINVAL;
- }
- }
-
- cfg->new_ctrl = cbm_val;
- cfg->have_new_ctrl = true;
-
- return 0;
-}
-
-/*
- * For each domain in this resource we expect to find a series of:
- * id=mask
- * separated by ";". The "id" is in decimal, and must match one of
- * the "id"s for this resource.
- */
-static int parse_line(char *line, struct resctrl_schema *s,
- struct rdtgroup *rdtgrp)
-{
- enum resctrl_conf_type t = s->conf_type;
- ctrlval_parser_t *parse_ctrlval = NULL;
- struct resctrl_staged_config *cfg;
- struct rdt_resource *r = s->res;
- struct rdt_parse_data data;
- struct rdt_ctrl_domain *d;
- char *dom = NULL, *id;
- unsigned long dom_id;
-
- /* Walking r->domains, ensure it can't race with cpuhp */
- lockdep_assert_cpus_held();
-
- switch (r->schema_fmt) {
- case RESCTRL_SCHEMA_BITMAP:
- parse_ctrlval = &parse_cbm;
- break;
- case RESCTRL_SCHEMA_RANGE:
- parse_ctrlval = &parse_bw;
- break;
- }
-
- if (WARN_ON_ONCE(!parse_ctrlval))
- return -EINVAL;
-
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
- (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA)) {
- rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n");
- return -EINVAL;
- }
-
-next:
- if (!line || line[0] == '\0')
- return 0;
- dom = strsep(&line, ";");
- id = strsep(&dom, "=");
- if (!dom || kstrtoul(id, 10, &dom_id)) {
- rdt_last_cmd_puts("Missing '=' or non-numeric domain\n");
- return -EINVAL;
- }
- dom = strim(dom);
- list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
- if (d->hdr.id == dom_id) {
- data.buf = dom;
- data.rdtgrp = rdtgrp;
- if (parse_ctrlval(&data, s, d))
- return -EINVAL;
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
- cfg = &d->staged_config[t];
- /*
- * In pseudo-locking setup mode and just
- * parsed a valid CBM that should be
- * pseudo-locked. Only one locked region per
- * resource group and domain so just do
- * the required initialization for single
- * region and return.
- */
- rdtgrp->plr->s = s;
- rdtgrp->plr->d = d;
- rdtgrp->plr->cbm = cfg->new_ctrl;
- d->plr = rdtgrp->plr;
- return 0;
- }
- goto next;
- }
- }
- return -EINVAL;
-}
-
int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_ctrl_domain *d,
u32 closid, enum resctrl_conf_type t, u32 cfg_val)
{
@@ -351,100 +83,6 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid)
return 0;
}
-static int rdtgroup_parse_resource(char *resname, char *tok,
- struct rdtgroup *rdtgrp)
-{
- struct resctrl_schema *s;
-
- list_for_each_entry(s, &resctrl_schema_all, list) {
- if (!strcmp(resname, s->name) && rdtgrp->closid < s->num_closid)
- return parse_line(tok, s, rdtgrp);
- }
- rdt_last_cmd_printf("Unknown or unsupported resource name '%s'\n", resname);
- return -EINVAL;
-}
-
-ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
-{
- struct resctrl_schema *s;
- struct rdtgroup *rdtgrp;
- struct rdt_resource *r;
- char *tok, *resname;
- int ret = 0;
-
- /* Valid input requires a trailing newline */
- if (nbytes == 0 || buf[nbytes - 1] != '\n')
- return -EINVAL;
- buf[nbytes - 1] = '\0';
-
- rdtgrp = rdtgroup_kn_lock_live(of->kn);
- if (!rdtgrp) {
- rdtgroup_kn_unlock(of->kn);
- return -ENOENT;
- }
- rdt_last_cmd_clear();
-
- /*
- * No changes to pseudo-locked region allowed. It has to be removed
- * and re-created instead.
- */
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
- ret = -EINVAL;
- rdt_last_cmd_puts("Resource group is pseudo-locked\n");
- goto out;
- }
-
- rdt_staged_configs_clear();
-
- while ((tok = strsep(&buf, "\n")) != NULL) {
- resname = strim(strsep(&tok, ":"));
- if (!tok) {
- rdt_last_cmd_puts("Missing ':'\n");
- ret = -EINVAL;
- goto out;
- }
- if (tok[0] == '\0') {
- rdt_last_cmd_printf("Missing '%s' value\n", resname);
- ret = -EINVAL;
- goto out;
- }
- ret = rdtgroup_parse_resource(resname, tok, rdtgrp);
- if (ret)
- goto out;
- }
-
- list_for_each_entry(s, &resctrl_schema_all, list) {
- r = s->res;
-
- /*
- * Writes to mba_sc resources update the software controller,
- * not the control MSR.
- */
- if (is_mba_sc(r))
- continue;
-
- ret = resctrl_arch_update_domains(r, rdtgrp->closid);
- if (ret)
- goto out;
- }
-
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
- /*
- * If pseudo-locking fails we keep the resource group in
- * mode RDT_MODE_PSEUDO_LOCKSETUP with its class of service
- * active and updated for just the domain the pseudo-locked
- * region was requested for.
- */
- ret = rdtgroup_pseudo_lock_create(rdtgrp);
- }
-
-out:
- rdt_staged_configs_clear();
- rdtgroup_kn_unlock(of->kn);
- return ret ?: nbytes;
-}
-
u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_ctrl_domain *d,
u32 closid, enum resctrl_conf_type type)
{
@@ -453,282 +91,3 @@ u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_ctrl_domain *d,
return hw_dom->ctrl_val[idx];
}
-
-static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int closid)
-{
- struct rdt_resource *r = schema->res;
- struct rdt_ctrl_domain *dom;
- bool sep = false;
- u32 ctrl_val;
-
- /* Walking r->domains, ensure it can't race with cpuhp */
- lockdep_assert_cpus_held();
-
- seq_printf(s, "%*s:", max_name_width, schema->name);
- list_for_each_entry(dom, &r->ctrl_domains, hdr.list) {
- if (sep)
- seq_puts(s, ";");
-
- if (is_mba_sc(r))
- ctrl_val = dom->mbps_val[closid];
- else
- ctrl_val = resctrl_arch_get_config(r, dom, closid,
- schema->conf_type);
-
- seq_printf(s, schema->fmt_str, dom->hdr.id, ctrl_val);
- sep = true;
- }
- seq_puts(s, "\n");
-}
-
-int rdtgroup_schemata_show(struct kernfs_open_file *of,
- struct seq_file *s, void *v)
-{
- struct resctrl_schema *schema;
- struct rdtgroup *rdtgrp;
- int ret = 0;
- u32 closid;
-
- rdtgrp = rdtgroup_kn_lock_live(of->kn);
- if (rdtgrp) {
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
- list_for_each_entry(schema, &resctrl_schema_all, list) {
- seq_printf(s, "%s:uninitialized\n", schema->name);
- }
- } else if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
- if (!rdtgrp->plr->d) {
- rdt_last_cmd_clear();
- rdt_last_cmd_puts("Cache domain offline\n");
- ret = -ENODEV;
- } else {
- seq_printf(s, "%s:%d=%x\n",
- rdtgrp->plr->s->res->name,
- rdtgrp->plr->d->hdr.id,
- rdtgrp->plr->cbm);
- }
- } else {
- closid = rdtgrp->closid;
- list_for_each_entry(schema, &resctrl_schema_all, list) {
- if (closid < schema->num_closid)
- show_doms(s, schema, closid);
- }
- }
- } else {
- ret = -ENOENT;
- }
- rdtgroup_kn_unlock(of->kn);
- return ret;
-}
-
-static int smp_mon_event_count(void *arg)
-{
- mon_event_count(arg);
-
- return 0;
-}
-
-ssize_t rdtgroup_mba_mbps_event_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
-{
- struct rdtgroup *rdtgrp;
- int ret = 0;
-
- /* Valid input requires a trailing newline */
- if (nbytes == 0 || buf[nbytes - 1] != '\n')
- return -EINVAL;
- buf[nbytes - 1] = '\0';
-
- rdtgrp = rdtgroup_kn_lock_live(of->kn);
- if (!rdtgrp) {
- rdtgroup_kn_unlock(of->kn);
- return -ENOENT;
- }
- rdt_last_cmd_clear();
-
- if (!strcmp(buf, "mbm_local_bytes")) {
- if (resctrl_arch_is_mbm_local_enabled())
- rdtgrp->mba_mbps_event = QOS_L3_MBM_LOCAL_EVENT_ID;
- else
- ret = -EINVAL;
- } else if (!strcmp(buf, "mbm_total_bytes")) {
- if (resctrl_arch_is_mbm_total_enabled())
- rdtgrp->mba_mbps_event = QOS_L3_MBM_TOTAL_EVENT_ID;
- else
- ret = -EINVAL;
- } else {
- ret = -EINVAL;
- }
-
- if (ret)
- rdt_last_cmd_printf("Unsupported event id '%s'\n", buf);
-
- rdtgroup_kn_unlock(of->kn);
-
- return ret ?: nbytes;
-}
-
-int rdtgroup_mba_mbps_event_show(struct kernfs_open_file *of,
- struct seq_file *s, void *v)
-{
- struct rdtgroup *rdtgrp;
- int ret = 0;
-
- rdtgrp = rdtgroup_kn_lock_live(of->kn);
-
- if (rdtgrp) {
- switch (rdtgrp->mba_mbps_event) {
- case QOS_L3_MBM_LOCAL_EVENT_ID:
- seq_puts(s, "mbm_local_bytes\n");
- break;
- case QOS_L3_MBM_TOTAL_EVENT_ID:
- seq_puts(s, "mbm_total_bytes\n");
- break;
- default:
- pr_warn_once("Bad event %d\n", rdtgrp->mba_mbps_event);
- ret = -EINVAL;
- break;
- }
- } else {
- ret = -ENOENT;
- }
-
- rdtgroup_kn_unlock(of->kn);
-
- return ret;
-}
-
-struct rdt_domain_hdr *resctrl_find_domain(struct list_head *h, int id,
- struct list_head **pos)
-{
- struct rdt_domain_hdr *d;
- struct list_head *l;
-
- list_for_each(l, h) {
- d = list_entry(l, struct rdt_domain_hdr, list);
- /* When id is found, return its domain. */
- if (id == d->id)
- return d;
- /* Stop searching when finding id's position in sorted list. */
- if (id < d->id)
- break;
- }
-
- if (pos)
- *pos = l;
-
- return NULL;
-}
-
-void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
- struct rdt_mon_domain *d, struct rdtgroup *rdtgrp,
- cpumask_t *cpumask, int evtid, int first)
-{
- int cpu;
-
- /* When picking a CPU from cpu_mask, ensure it can't race with cpuhp */
- lockdep_assert_cpus_held();
-
- /*
- * Setup the parameters to pass to mon_event_count() to read the data.
- */
- rr->rgrp = rdtgrp;
- rr->evtid = evtid;
- rr->r = r;
- rr->d = d;
- rr->first = first;
- rr->arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, evtid);
- if (IS_ERR(rr->arch_mon_ctx)) {
- rr->err = -EINVAL;
- return;
- }
-
- cpu = cpumask_any_housekeeping(cpumask, RESCTRL_PICK_ANY_CPU);
-
- /*
- * cpumask_any_housekeeping() prefers housekeeping CPUs, but
- * are all the CPUs nohz_full? If yes, pick a CPU to IPI.
- * MPAM's resctrl_arch_rmid_read() is unable to read the
- * counters on some platforms if its called in IRQ context.
- */
- if (tick_nohz_full_cpu(cpu))
- smp_call_function_any(cpumask, mon_event_count, rr, 1);
- else
- smp_call_on_cpu(cpu, smp_mon_event_count, rr, false);
-
- resctrl_arch_mon_ctx_free(r, evtid, rr->arch_mon_ctx);
-}
-
-int rdtgroup_mondata_show(struct seq_file *m, void *arg)
-{
- struct kernfs_open_file *of = m->private;
- enum resctrl_res_level resid;
- enum resctrl_event_id evtid;
- struct rdt_domain_hdr *hdr;
- struct rmid_read rr = {0};
- struct rdt_mon_domain *d;
- struct rdtgroup *rdtgrp;
- struct rdt_resource *r;
- struct mon_data *md;
- int domid, ret = 0;
-
- rdtgrp = rdtgroup_kn_lock_live(of->kn);
- if (!rdtgrp) {
- ret = -ENOENT;
- goto out;
- }
-
- md = of->kn->priv;
- if (WARN_ON_ONCE(!md)) {
- ret = -EIO;
- goto out;
- }
-
- resid = md->rid;
- domid = md->domid;
- evtid = md->evtid;
- r = resctrl_arch_get_resource(resid);
-
- if (md->sum) {
- /*
- * This file requires summing across all domains that share
- * the L3 cache id that was provided in the "domid" field of the
- * struct mon_data. Search all domains in the resource for
- * one that matches this cache id.
- */
- list_for_each_entry(d, &r->mon_domains, hdr.list) {
- if (d->ci->id == domid) {
- rr.ci = d->ci;
- mon_event_read(&rr, r, NULL, rdtgrp,
- &d->ci->shared_cpu_map, evtid, false);
- goto checkresult;
- }
- }
- ret = -ENOENT;
- goto out;
- } else {
- /*
- * This file provides data from a single domain. Search
- * the resource to find the domain with "domid".
- */
- hdr = resctrl_find_domain(&r->mon_domains, domid, NULL);
- if (!hdr || WARN_ON_ONCE(hdr->type != RESCTRL_MON_DOMAIN)) {
- ret = -ENOENT;
- goto out;
- }
- d = container_of(hdr, struct rdt_mon_domain, hdr);
- mon_event_read(&rr, r, d, rdtgrp, &d->hdr.cpu_mask, evtid, false);
- }
-
-checkresult:
-
- if (rr.err == -EIO)
- seq_puts(m, "Error\n");
- else if (rr.err == -EINVAL)
- seq_puts(m, "Unavailable\n");
- else
- seq_printf(m, "%llu\n", rr.val);
-
-out:
- rdtgroup_kn_unlock(of->kn);
- return ret;
-}
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index dc63ac5..5e3c41b 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -3,24 +3,21 @@
#define _ASM_X86_RESCTRL_INTERNAL_H
#include <linux/resctrl.h>
-#include <linux/sched.h>
-#include <linux/kernfs.h>
-#include <linux/fs_context.h>
-#include <linux/jump_label.h>
-#include <linux/tick.h>
#define L3_QOS_CDP_ENABLE 0x01ULL
#define L2_QOS_CDP_ENABLE 0x01ULL
-#define CQM_LIMBOCHECK_INTERVAL 1000
-
#define MBM_CNTR_WIDTH_BASE 24
+
#define MBA_IS_LINEAR 0x4
+
#define MBM_CNTR_WIDTH_OFFSET_AMD 20
#define RMID_VAL_ERROR BIT_ULL(63)
+
#define RMID_VAL_UNAVAIL BIT_ULL(62)
+
/*
* With the above fields in use 62 bits remain in MSR_IA32_QM_CTR for
* data to be returned. The counter width is discovered from the hardware
@@ -29,263 +26,6 @@
#define MBM_CNTR_WIDTH_OFFSET_MAX (62 - MBM_CNTR_WIDTH_BASE)
/**
- * cpumask_any_housekeeping() - Choose any CPU in @mask, preferring those that
- * aren't marked nohz_full
- * @mask: The mask to pick a CPU from.
- * @exclude_cpu:The CPU to avoid picking.
- *
- * Returns a CPU from @mask, but not @exclude_cpu. If there are housekeeping
- * CPUs that don't use nohz_full, these are preferred. Pass
- * RESCTRL_PICK_ANY_CPU to avoid excluding any CPUs.
- *
- * When a CPU is excluded, returns >= nr_cpu_ids if no CPUs are available.
- */
-static inline unsigned int
-cpumask_any_housekeeping(const struct cpumask *mask, int exclude_cpu)
-{
- unsigned int cpu;
-
- /* Try to find a CPU that isn't nohz_full to use in preference */
- if (tick_nohz_full_enabled()) {
- cpu = cpumask_any_andnot_but(mask, tick_nohz_full_mask, exclude_cpu);
- if (cpu < nr_cpu_ids)
- return cpu;
- }
-
- return cpumask_any_but(mask, exclude_cpu);
-}
-
-struct rdt_fs_context {
- struct kernfs_fs_context kfc;
- bool enable_cdpl2;
- bool enable_cdpl3;
- bool enable_mba_mbps;
- bool enable_debug;
-};
-
-static inline struct rdt_fs_context *rdt_fc2context(struct fs_context *fc)
-{
- struct kernfs_fs_context *kfc = fc->fs_private;
-
- return container_of(kfc, struct rdt_fs_context, kfc);
-}
-
-/**
- * struct mon_evt - Entry in the event list of a resource
- * @evtid: event id
- * @name: name of the event
- * @configurable: true if the event is configurable
- * @list: entry in &rdt_resource->evt_list
- */
-struct mon_evt {
- enum resctrl_event_id evtid;
- char *name;
- bool configurable;
- struct list_head list;
-};
-
-/**
- * struct mon_data - Monitoring details for each event file.
- * @list: Member of the global @mon_data_kn_priv_list list.
- * @rid: Resource id associated with the event file.
- * @evtid: Event id associated with the event file.
- * @sum: Set when event must be summed across multiple
- * domains.
- * @domid: When @sum is zero this is the domain to which
- * the event file belongs. When @sum is one this
- * is the id of the L3 cache that all domains to be
- * summed share.
- *
- * Pointed to by the kernfs kn->priv field of monitoring event files.
- * Readers and writers must hold rdtgroup_mutex.
- */
-struct mon_data {
- struct list_head list;
- enum resctrl_res_level rid;
- enum resctrl_event_id evtid;
- int domid;
- bool sum;
-};
-
-/**
- * struct rmid_read - Data passed across smp_call*() to read event count.
- * @rgrp: Resource group for which the counter is being read. If it is a parent
- * resource group then its event count is summed with the count from all
- * its child resource groups.
- * @r: Resource describing the properties of the event being read.
- * @d: Domain that the counter should be read from. If NULL then sum all
- * domains in @r sharing L3 @ci.id
- * @evtid: Which monitor event to read.
- * @first: Initialize MBM counter when true.
- * @ci: Cacheinfo for L3. Only set when @d is NULL. Used when summing domains.
- * @err: Error encountered when reading counter.
- * @val: Returned value of event counter. If @rgrp is a parent resource group,
- * @val includes the sum of event counts from its child resource groups.
- * If @d is NULL, @val includes the sum of all domains in @r sharing @ci.id,
- * (summed across child resource groups if @rgrp is a parent resource group).
- * @arch_mon_ctx: Hardware monitor allocated for this read request (MPAM only).
- */
-struct rmid_read {
- struct rdtgroup *rgrp;
- struct rdt_resource *r;
- struct rdt_mon_domain *d;
- enum resctrl_event_id evtid;
- bool first;
- struct cacheinfo *ci;
- int err;
- u64 val;
- void *arch_mon_ctx;
-};
-
-extern struct list_head resctrl_schema_all;
-extern bool resctrl_mounted;
-
-enum rdt_group_type {
- RDTCTRL_GROUP = 0,
- RDTMON_GROUP,
- RDT_NUM_GROUP,
-};
-
-/**
- * enum rdtgrp_mode - Mode of a RDT resource group
- * @RDT_MODE_SHAREABLE: This resource group allows sharing of its allocations
- * @RDT_MODE_EXCLUSIVE: No sharing of this resource group's allocations allowed
- * @RDT_MODE_PSEUDO_LOCKSETUP: Resource group will be used for Pseudo-Locking
- * @RDT_MODE_PSEUDO_LOCKED: No sharing of this resource group's allocations
- * allowed AND the allocations are Cache Pseudo-Locked
- * @RDT_NUM_MODES: Total number of modes
- *
- * The mode of a resource group enables control over the allowed overlap
- * between allocations associated with different resource groups (classes
- * of service). User is able to modify the mode of a resource group by
- * writing to the "mode" resctrl file associated with the resource group.
- *
- * The "shareable", "exclusive", and "pseudo-locksetup" modes are set by
- * writing the appropriate text to the "mode" file. A resource group enters
- * "pseudo-locked" mode after the schemata is written while the resource
- * group is in "pseudo-locksetup" mode.
- */
-enum rdtgrp_mode {
- RDT_MODE_SHAREABLE = 0,
- RDT_MODE_EXCLUSIVE,
- RDT_MODE_PSEUDO_LOCKSETUP,
- RDT_MODE_PSEUDO_LOCKED,
-
- /* Must be last */
- RDT_NUM_MODES,
-};
-
-/**
- * struct mongroup - store mon group's data in resctrl fs.
- * @mon_data_kn: kernfs node for the mon_data directory
- * @parent: parent rdtgrp
- * @crdtgrp_list: child rdtgroup node list
- * @rmid: rmid for this rdtgroup
- */
-struct mongroup {
- struct kernfs_node *mon_data_kn;
- struct rdtgroup *parent;
- struct list_head crdtgrp_list;
- u32 rmid;
-};
-
-/**
- * struct rdtgroup - store rdtgroup's data in resctrl file system.
- * @kn: kernfs node
- * @rdtgroup_list: linked list for all rdtgroups
- * @closid: closid for this rdtgroup
- * @cpu_mask: CPUs assigned to this rdtgroup
- * @flags: status bits
- * @waitcount: how many cpus expect to find this
- * group when they acquire rdtgroup_mutex
- * @type: indicates type of this rdtgroup - either
- * monitor only or ctrl_mon group
- * @mon: mongroup related data
- * @mode: mode of resource group
- * @mba_mbps_event: input monitoring event id when mba_sc is enabled
- * @plr: pseudo-locked region
- */
-struct rdtgroup {
- struct kernfs_node *kn;
- struct list_head rdtgroup_list;
- u32 closid;
- struct cpumask cpu_mask;
- int flags;
- atomic_t waitcount;
- enum rdt_group_type type;
- struct mongroup mon;
- enum rdtgrp_mode mode;
- enum resctrl_event_id mba_mbps_event;
- struct pseudo_lock_region *plr;
-};
-
-/* rdtgroup.flags */
-#define RDT_DELETED 1
-
-/* rftype.flags */
-#define RFTYPE_FLAGS_CPUS_LIST 1
-
-/*
- * Define the file type flags for base and info directories.
- */
-#define RFTYPE_INFO BIT(0)
-#define RFTYPE_BASE BIT(1)
-#define RFTYPE_CTRL BIT(4)
-#define RFTYPE_MON BIT(5)
-#define RFTYPE_TOP BIT(6)
-#define RFTYPE_RES_CACHE BIT(8)
-#define RFTYPE_RES_MB BIT(9)
-#define RFTYPE_DEBUG BIT(10)
-#define RFTYPE_CTRL_INFO (RFTYPE_INFO | RFTYPE_CTRL)
-#define RFTYPE_MON_INFO (RFTYPE_INFO | RFTYPE_MON)
-#define RFTYPE_TOP_INFO (RFTYPE_INFO | RFTYPE_TOP)
-#define RFTYPE_CTRL_BASE (RFTYPE_BASE | RFTYPE_CTRL)
-#define RFTYPE_MON_BASE (RFTYPE_BASE | RFTYPE_MON)
-
-/* List of all resource groups */
-extern struct list_head rdt_all_groups;
-
-extern int max_name_width;
-
-/**
- * struct rftype - describe each file in the resctrl file system
- * @name: File name
- * @mode: Access mode
- * @kf_ops: File operations
- * @flags: File specific RFTYPE_FLAGS_* flags
- * @fflags: File specific RFTYPE_* flags
- * @seq_show: Show content of the file
- * @write: Write to the file
- */
-struct rftype {
- char *name;
- umode_t mode;
- const struct kernfs_ops *kf_ops;
- unsigned long flags;
- unsigned long fflags;
-
- int (*seq_show)(struct kernfs_open_file *of,
- struct seq_file *sf, void *v);
- /*
- * write() is the generic write callback which maps directly to
- * kernfs write operation and overrides all other operations.
- * Maximum write size is determined by ->max_write_len.
- */
- ssize_t (*write)(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off);
-};
-
-/**
- * struct mbm_state - status for each MBM counter in each domain
- * @prev_bw_bytes: Previous bytes value read for bandwidth calculation
- * @prev_bw: The most recent bandwidth in MBps
- */
-struct mbm_state {
- u64 prev_bw_bytes;
- u32 prev_bw;
-};
-
-/**
* struct arch_mbm_state - values used to compute resctrl_arch_rmid_read()s
* return value.
* @chunks: Total data moved (multiply by rdt_group.mon_scale to get bytes)
@@ -382,17 +122,7 @@ static inline struct rdt_hw_resource *resctrl_to_arch_res(struct rdt_resource *r
return container_of(r, struct rdt_hw_resource, r_resctrl);
}
-extern struct mutex rdtgroup_mutex;
-
-static inline const char *rdt_kn_name(const struct kernfs_node *kn)
-{
- return rcu_dereference_check(kn->name, lockdep_is_held(&rdtgroup_mutex));
-}
-
extern struct rdt_hw_resource rdt_resources_all[];
-extern struct rdtgroup rdtgroup_default;
-extern struct dentry *debugfs_resctrl;
-extern enum resctrl_event_id mba_mbps_default_event;
void arch_mon_domain_online(struct rdt_resource *r, struct rdt_mon_domain *d);
@@ -429,99 +159,14 @@ union cpuid_0x10_x_edx {
unsigned int full;
};
-void rdt_last_cmd_clear(void);
-void rdt_last_cmd_puts(const char *s);
-__printf(1, 2)
-void rdt_last_cmd_printf(const char *fmt, ...);
-
void rdt_ctrl_update(void *arg);
-struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn);
-void rdtgroup_kn_unlock(struct kernfs_node *kn);
-int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name);
-int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name,
- umode_t mask);
-ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off);
-int rdtgroup_schemata_show(struct kernfs_open_file *of,
- struct seq_file *s, void *v);
-ssize_t rdtgroup_mba_mbps_event_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off);
-int rdtgroup_mba_mbps_event_show(struct kernfs_open_file *of,
- struct seq_file *s, void *v);
-bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_ctrl_domain *d,
- unsigned long cbm, int closid, bool exclusive);
-unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, struct rdt_ctrl_domain *d,
- unsigned long cbm);
-enum rdtgrp_mode rdtgroup_mode_by_closid(int closid);
-int rdtgroup_tasks_assigned(struct rdtgroup *r);
-int closids_supported(void);
-void closid_free(int closid);
-int alloc_rmid(u32 closid);
-void free_rmid(u32 closid, u32 rmid);
-int rdt_get_mon_l3_config(struct rdt_resource *r);
-void resctrl_mon_resource_exit(void);
-bool rdt_cpu_has(int flag);
-void mon_event_count(void *info);
-int rdtgroup_mondata_show(struct seq_file *m, void *arg);
-void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
- struct rdt_mon_domain *d, struct rdtgroup *rdtgrp,
- cpumask_t *cpumask, int evtid, int first);
-int resctrl_mon_resource_init(void);
-void mbm_setup_overflow_handler(struct rdt_mon_domain *dom,
- unsigned long delay_ms,
- int exclude_cpu);
-void mbm_handle_overflow(struct work_struct *work);
-void __init intel_rdt_mbm_apply_quirk(void);
-bool is_mba_sc(struct rdt_resource *r);
-void cqm_setup_limbo_handler(struct rdt_mon_domain *dom, unsigned long delay_ms,
- int exclude_cpu);
-void cqm_handle_limbo(struct work_struct *work);
-bool has_busy_rmid(struct rdt_mon_domain *d);
-void __check_limbo(struct rdt_mon_domain *d, bool force_free);
-void rdt_domain_reconfigure_cdp(struct rdt_resource *r);
-void resctrl_file_fflags_init(const char *config, unsigned long fflags);
-void rdt_staged_configs_clear(void);
-bool closid_allocated(unsigned int closid);
-int resctrl_find_cleanest_closid(void);
-
-#ifdef CONFIG_RESCTRL_FS_PSEUDO_LOCK
-int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp);
-int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp);
-bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_ctrl_domain *d, unsigned long cbm);
-bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d);
-int rdt_pseudo_lock_init(void);
-void rdt_pseudo_lock_release(void);
-int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp);
-void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp);
-#else
-static inline int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp)
-{
- return -EOPNOTSUPP;
-}
-static inline int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp)
-{
- return -EOPNOTSUPP;
-}
-
-static inline bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_ctrl_domain *d, unsigned long cbm)
-{
- return false;
-}
+int rdt_get_mon_l3_config(struct rdt_resource *r);
-static inline bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d)
-{
- return false;
-}
+bool rdt_cpu_has(int flag);
-static inline int rdt_pseudo_lock_init(void) { return 0; }
-static inline void rdt_pseudo_lock_release(void) { }
-static inline int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp)
-{
- return -EOPNOTSUPP;
-}
+void __init intel_rdt_mbm_apply_quirk(void);
-static inline void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp) { }
-#endif /* CONFIG_RESCTRL_FS_PSEUDO_LOCK */
+void rdt_domain_reconfigure_cdp(struct rdt_resource *r);
#endif /* _ASM_X86_RESCTRL_INTERNAL_H */
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 8847c23..3fc4d9f 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -18,65 +18,12 @@
#define pr_fmt(fmt) "resctrl: " fmt
#include <linux/cpu.h>
-#include <linux/module.h>
#include <linux/resctrl.h>
-#include <linux/sizes.h>
-#include <linux/slab.h>
#include <asm/cpu_device_id.h>
#include "internal.h"
-#define CREATE_TRACE_POINTS
-#include "monitor_trace.h"
-
-/**
- * struct rmid_entry - dirty tracking for all RMID.
- * @closid: The CLOSID for this entry.
- * @rmid: The RMID for this entry.
- * @busy: The number of domains with cached data using this RMID.
- * @list: Member of the rmid_free_lru list when busy == 0.
- *
- * Depending on the architecture the correct monitor is accessed using
- * both @closid and @rmid, or @rmid only.
- *
- * Take the rdtgroup_mutex when accessing.
- */
-struct rmid_entry {
- u32 closid;
- u32 rmid;
- int busy;
- struct list_head list;
-};
-
-/*
- * @rmid_free_lru - A least recently used list of free RMIDs
- * These RMIDs are guaranteed to have an occupancy less than the
- * threshold occupancy
- */
-static LIST_HEAD(rmid_free_lru);
-
-/*
- * @closid_num_dirty_rmid The number of dirty RMID each CLOSID has.
- * Only allocated when CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID is defined.
- * Indexed by CLOSID. Protected by rdtgroup_mutex.
- */
-static u32 *closid_num_dirty_rmid;
-
-/*
- * @rmid_limbo_count - count of currently unused but (potentially)
- * dirty RMIDs.
- * This counts RMIDs that no one is currently using but that
- * may have a occupancy value > resctrl_rmid_realloc_threshold. User can
- * change the threshold occupancy value.
- */
-static unsigned int rmid_limbo_count;
-
-/*
- * @rmid_entry - The entry in the limbo and free lists.
- */
-static struct rmid_entry *rmid_ptrs;
-
/*
* Global boolean for rdt_monitor which is true if any
* resource monitoring is enabled.
@@ -88,23 +35,12 @@ bool rdt_mon_capable;
*/
unsigned int rdt_mon_features;
-/*
- * This is the threshold cache occupancy in bytes at which we will consider an
- * RMID available for re-allocation.
- */
-unsigned int resctrl_rmid_realloc_threshold;
-
-/*
- * This is the maximum value for the reallocation threshold, in bytes.
- */
-unsigned int resctrl_rmid_realloc_limit;
-
#define CF(cf) ((unsigned long)(1048576 * (cf) + 0.5))
static int snc_nodes_per_l3_cache = 1;
/*
- * The correction factor table is documented in Documentation/arch/x86/resctrl.rst.
+ * The correction factor table is documented in Documentation/filesystems/resctrl.rst.
* If rmid > rmid threshold, MBM total and local values should be multiplied
* by the correction factor.
*
@@ -153,6 +89,7 @@ static const struct mbm_correction_factor_table {
};
static u32 mbm_cf_rmidthreshold __read_mostly = UINT_MAX;
+
static u64 mbm_cf __read_mostly;
static inline u64 get_corrected_mbm_count(u32 rmid, unsigned long val)
@@ -165,33 +102,6 @@ static inline u64 get_corrected_mbm_count(u32 rmid, unsigned long val)
}
/*
- * x86 and arm64 differ in their handling of monitoring.
- * x86's RMID are independent numbers, there is only one source of traffic
- * with an RMID value of '1'.
- * arm64's PMG extends the PARTID/CLOSID space, there are multiple sources of
- * traffic with a PMG value of '1', one for each CLOSID, meaning the RMID
- * value is no longer unique.
- * To account for this, resctrl uses an index. On x86 this is just the RMID,
- * on arm64 it encodes the CLOSID and RMID. This gives a unique number.
- *
- * The domain's rmid_busy_llc and rmid_ptrs[] are sized by index. The arch code
- * must accept an attempt to read every index.
- */
-static inline struct rmid_entry *__rmid_entry(u32 idx)
-{
- struct rmid_entry *entry;
- u32 closid, rmid;
-
- entry = &rmid_ptrs[idx];
- resctrl_arch_rmid_idx_decode(idx, &closid, &rmid);
-
- WARN_ON_ONCE(entry->closid != closid);
- WARN_ON_ONCE(entry->rmid != rmid);
-
- return entry;
-}
-
-/*
* When Sub-NUMA Cluster (SNC) mode is not enabled (as indicated by
* "snc_nodes_per_l3_cache == 1") no translation of the RMID value is
* needed. The physical RMID is the same as the logical RMID.
@@ -347,769 +257,6 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_mon_domain *d,
return 0;
}
-static void limbo_release_entry(struct rmid_entry *entry)
-{
- lockdep_assert_held(&rdtgroup_mutex);
-
- rmid_limbo_count--;
- list_add_tail(&entry->list, &rmid_free_lru);
-
- if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID))
- closid_num_dirty_rmid[entry->closid]--;
-}
-
-/*
- * Check the RMIDs that are marked as busy for this domain. If the
- * reported LLC occupancy is below the threshold clear the busy bit and
- * decrement the count. If the busy count gets to zero on an RMID, we
- * free the RMID
- */
-void __check_limbo(struct rdt_mon_domain *d, bool force_free)
-{
- struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
- u32 idx_limit = resctrl_arch_system_num_rmid_idx();
- struct rmid_entry *entry;
- u32 idx, cur_idx = 1;
- void *arch_mon_ctx;
- bool rmid_dirty;
- u64 val = 0;
-
- arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, QOS_L3_OCCUP_EVENT_ID);
- if (IS_ERR(arch_mon_ctx)) {
- pr_warn_ratelimited("Failed to allocate monitor context: %ld",
- PTR_ERR(arch_mon_ctx));
- return;
- }
-
- /*
- * Skip RMID 0 and start from RMID 1 and check all the RMIDs that
- * are marked as busy for occupancy < threshold. If the occupancy
- * is less than the threshold decrement the busy counter of the
- * RMID and move it to the free list when the counter reaches 0.
- */
- for (;;) {
- idx = find_next_bit(d->rmid_busy_llc, idx_limit, cur_idx);
- if (idx >= idx_limit)
- break;
-
- entry = __rmid_entry(idx);
- if (resctrl_arch_rmid_read(r, d, entry->closid, entry->rmid,
- QOS_L3_OCCUP_EVENT_ID, &val,
- arch_mon_ctx)) {
- rmid_dirty = true;
- } else {
- rmid_dirty = (val >= resctrl_rmid_realloc_threshold);
-
- /*
- * x86's CLOSID and RMID are independent numbers, so the entry's
- * CLOSID is an empty CLOSID (X86_RESCTRL_EMPTY_CLOSID). On Arm the
- * RMID (PMG) extends the CLOSID (PARTID) space with bits that aren't
- * used to select the configuration. It is thus necessary to track both
- * CLOSID and RMID because there may be dependencies between them
- * on some architectures.
- */
- trace_mon_llc_occupancy_limbo(entry->closid, entry->rmid, d->hdr.id, val);
- }
-
- if (force_free || !rmid_dirty) {
- clear_bit(idx, d->rmid_busy_llc);
- if (!--entry->busy)
- limbo_release_entry(entry);
- }
- cur_idx = idx + 1;
- }
-
- resctrl_arch_mon_ctx_free(r, QOS_L3_OCCUP_EVENT_ID, arch_mon_ctx);
-}
-
-bool has_busy_rmid(struct rdt_mon_domain *d)
-{
- u32 idx_limit = resctrl_arch_system_num_rmid_idx();
-
- return find_first_bit(d->rmid_busy_llc, idx_limit) != idx_limit;
-}
-
-static struct rmid_entry *resctrl_find_free_rmid(u32 closid)
-{
- struct rmid_entry *itr;
- u32 itr_idx, cmp_idx;
-
- if (list_empty(&rmid_free_lru))
- return rmid_limbo_count ? ERR_PTR(-EBUSY) : ERR_PTR(-ENOSPC);
-
- list_for_each_entry(itr, &rmid_free_lru, list) {
- /*
- * Get the index of this free RMID, and the index it would need
- * to be if it were used with this CLOSID.
- * If the CLOSID is irrelevant on this architecture, the two
- * index values are always the same on every entry and thus the
- * very first entry will be returned.
- */
- itr_idx = resctrl_arch_rmid_idx_encode(itr->closid, itr->rmid);
- cmp_idx = resctrl_arch_rmid_idx_encode(closid, itr->rmid);
-
- if (itr_idx == cmp_idx)
- return itr;
- }
-
- return ERR_PTR(-ENOSPC);
-}
-
-/**
- * resctrl_find_cleanest_closid() - Find a CLOSID where all the associated
- * RMID are clean, or the CLOSID that has
- * the most clean RMID.
- *
- * MPAM's equivalent of RMID are per-CLOSID, meaning a freshly allocated CLOSID
- * may not be able to allocate clean RMID. To avoid this the allocator will
- * choose the CLOSID with the most clean RMID.
- *
- * When the CLOSID and RMID are independent numbers, the first free CLOSID will
- * be returned.
- */
-int resctrl_find_cleanest_closid(void)
-{
- u32 cleanest_closid = ~0;
- int i = 0;
-
- lockdep_assert_held(&rdtgroup_mutex);
-
- if (!IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID))
- return -EIO;
-
- for (i = 0; i < closids_supported(); i++) {
- int num_dirty;
-
- if (closid_allocated(i))
- continue;
-
- num_dirty = closid_num_dirty_rmid[i];
- if (num_dirty == 0)
- return i;
-
- if (cleanest_closid == ~0)
- cleanest_closid = i;
-
- if (num_dirty < closid_num_dirty_rmid[cleanest_closid])
- cleanest_closid = i;
- }
-
- if (cleanest_closid == ~0)
- return -ENOSPC;
-
- return cleanest_closid;
-}
-
-/*
- * For MPAM the RMID value is not unique, and has to be considered with
- * the CLOSID. The (CLOSID, RMID) pair is allocated on all domains, which
- * allows all domains to be managed by a single free list.
- * Each domain also has a rmid_busy_llc to reduce the work of the limbo handler.
- */
-int alloc_rmid(u32 closid)
-{
- struct rmid_entry *entry;
-
- lockdep_assert_held(&rdtgroup_mutex);
-
- entry = resctrl_find_free_rmid(closid);
- if (IS_ERR(entry))
- return PTR_ERR(entry);
-
- list_del(&entry->list);
- return entry->rmid;
-}
-
-static void add_rmid_to_limbo(struct rmid_entry *entry)
-{
- struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
- struct rdt_mon_domain *d;
- u32 idx;
-
- lockdep_assert_held(&rdtgroup_mutex);
-
- /* Walking r->domains, ensure it can't race with cpuhp */
- lockdep_assert_cpus_held();
-
- idx = resctrl_arch_rmid_idx_encode(entry->closid, entry->rmid);
-
- entry->busy = 0;
- list_for_each_entry(d, &r->mon_domains, hdr.list) {
- /*
- * For the first limbo RMID in the domain,
- * setup up the limbo worker.
- */
- if (!has_busy_rmid(d))
- cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL,
- RESCTRL_PICK_ANY_CPU);
- set_bit(idx, d->rmid_busy_llc);
- entry->busy++;
- }
-
- rmid_limbo_count++;
- if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID))
- closid_num_dirty_rmid[entry->closid]++;
-}
-
-void free_rmid(u32 closid, u32 rmid)
-{
- u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid);
- struct rmid_entry *entry;
-
- lockdep_assert_held(&rdtgroup_mutex);
-
- /*
- * Do not allow the default rmid to be free'd. Comparing by index
- * allows architectures that ignore the closid parameter to avoid an
- * unnecessary check.
- */
- if (!resctrl_arch_mon_capable() ||
- idx == resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID,
- RESCTRL_RESERVED_RMID))
- return;
-
- entry = __rmid_entry(idx);
-
- if (resctrl_arch_is_llc_occupancy_enabled())
- add_rmid_to_limbo(entry);
- else
- list_add_tail(&entry->list, &rmid_free_lru);
-}
-
-static struct mbm_state *get_mbm_state(struct rdt_mon_domain *d, u32 closid,
- u32 rmid, enum resctrl_event_id evtid)
-{
- u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid);
-
- switch (evtid) {
- case QOS_L3_MBM_TOTAL_EVENT_ID:
- return &d->mbm_total[idx];
- case QOS_L3_MBM_LOCAL_EVENT_ID:
- return &d->mbm_local[idx];
- default:
- return NULL;
- }
-}
-
-static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr)
-{
- int cpu = smp_processor_id();
- struct rdt_mon_domain *d;
- struct mbm_state *m;
- int err, ret;
- u64 tval = 0;
-
- if (rr->first) {
- resctrl_arch_reset_rmid(rr->r, rr->d, closid, rmid, rr->evtid);
- m = get_mbm_state(rr->d, closid, rmid, rr->evtid);
- if (m)
- memset(m, 0, sizeof(struct mbm_state));
- return 0;
- }
-
- if (rr->d) {
- /* Reading a single domain, must be on a CPU in that domain. */
- if (!cpumask_test_cpu(cpu, &rr->d->hdr.cpu_mask))
- return -EINVAL;
- rr->err = resctrl_arch_rmid_read(rr->r, rr->d, closid, rmid,
- rr->evtid, &tval, rr->arch_mon_ctx);
- if (rr->err)
- return rr->err;
-
- rr->val += tval;
-
- return 0;
- }
-
- /* Summing domains that share a cache, must be on a CPU for that cache. */
- if (!cpumask_test_cpu(cpu, &rr->ci->shared_cpu_map))
- return -EINVAL;
-
- /*
- * Legacy files must report the sum of an event across all
- * domains that share the same L3 cache instance.
- * Report success if a read from any domain succeeds, -EINVAL
- * (translated to "Unavailable" for user space) if reading from
- * all domains fail for any reason.
- */
- ret = -EINVAL;
- list_for_each_entry(d, &rr->r->mon_domains, hdr.list) {
- if (d->ci->id != rr->ci->id)
- continue;
- err = resctrl_arch_rmid_read(rr->r, d, closid, rmid,
- rr->evtid, &tval, rr->arch_mon_ctx);
- if (!err) {
- rr->val += tval;
- ret = 0;
- }
- }
-
- if (ret)
- rr->err = ret;
-
- return ret;
-}
-
-/*
- * mbm_bw_count() - Update bw count from values previously read by
- * __mon_event_count().
- * @closid: The closid used to identify the cached mbm_state.
- * @rmid: The rmid used to identify the cached mbm_state.
- * @rr: The struct rmid_read populated by __mon_event_count().
- *
- * Supporting function to calculate the memory bandwidth
- * and delta bandwidth in MBps. The chunks value previously read by
- * __mon_event_count() is compared with the chunks value from the previous
- * invocation. This must be called once per second to maintain values in MBps.
- */
-static void mbm_bw_count(u32 closid, u32 rmid, struct rmid_read *rr)
-{
- u64 cur_bw, bytes, cur_bytes;
- struct mbm_state *m;
-
- m = get_mbm_state(rr->d, closid, rmid, rr->evtid);
- if (WARN_ON_ONCE(!m))
- return;
-
- cur_bytes = rr->val;
- bytes = cur_bytes - m->prev_bw_bytes;
- m->prev_bw_bytes = cur_bytes;
-
- cur_bw = bytes / SZ_1M;
-
- m->prev_bw = cur_bw;
-}
-
-/*
- * This is scheduled by mon_event_read() to read the CQM/MBM counters
- * on a domain.
- */
-void mon_event_count(void *info)
-{
- struct rdtgroup *rdtgrp, *entry;
- struct rmid_read *rr = info;
- struct list_head *head;
- int ret;
-
- rdtgrp = rr->rgrp;
-
- ret = __mon_event_count(rdtgrp->closid, rdtgrp->mon.rmid, rr);
-
- /*
- * For Ctrl groups read data from child monitor groups and
- * add them together. Count events which are read successfully.
- * Discard the rmid_read's reporting errors.
- */
- head = &rdtgrp->mon.crdtgrp_list;
-
- if (rdtgrp->type == RDTCTRL_GROUP) {
- list_for_each_entry(entry, head, mon.crdtgrp_list) {
- if (__mon_event_count(entry->closid, entry->mon.rmid,
- rr) == 0)
- ret = 0;
- }
- }
-
- /*
- * __mon_event_count() calls for newly created monitor groups may
- * report -EINVAL/Unavailable if the monitor hasn't seen any traffic.
- * Discard error if any of the monitor event reads succeeded.
- */
- if (ret == 0)
- rr->err = 0;
-}
-
-static struct rdt_ctrl_domain *get_ctrl_domain_from_cpu(int cpu,
- struct rdt_resource *r)
-{
- struct rdt_ctrl_domain *d;
-
- lockdep_assert_cpus_held();
-
- list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
- /* Find the domain that contains this CPU */
- if (cpumask_test_cpu(cpu, &d->hdr.cpu_mask))
- return d;
- }
-
- return NULL;
-}
-
-/*
- * Feedback loop for MBA software controller (mba_sc)
- *
- * mba_sc is a feedback loop where we periodically read MBM counters and
- * adjust the bandwidth percentage values via the IA32_MBA_THRTL_MSRs so
- * that:
- *
- * current bandwidth(cur_bw) < user specified bandwidth(user_bw)
- *
- * This uses the MBM counters to measure the bandwidth and MBA throttle
- * MSRs to control the bandwidth for a particular rdtgrp. It builds on the
- * fact that resctrl rdtgroups have both monitoring and control.
- *
- * The frequency of the checks is 1s and we just tag along the MBM overflow
- * timer. Having 1s interval makes the calculation of bandwidth simpler.
- *
- * Although MBA's goal is to restrict the bandwidth to a maximum, there may
- * be a need to increase the bandwidth to avoid unnecessarily restricting
- * the L2 <-> L3 traffic.
- *
- * Since MBA controls the L2 external bandwidth where as MBM measures the
- * L3 external bandwidth the following sequence could lead to such a
- * situation.
- *
- * Consider an rdtgroup which had high L3 <-> memory traffic in initial
- * phases -> mba_sc kicks in and reduced bandwidth percentage values -> but
- * after some time rdtgroup has mostly L2 <-> L3 traffic.
- *
- * In this case we may restrict the rdtgroup's L2 <-> L3 traffic as its
- * throttle MSRs already have low percentage values. To avoid
- * unnecessarily restricting such rdtgroups, we also increase the bandwidth.
- */
-static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_mon_domain *dom_mbm)
-{
- u32 closid, rmid, cur_msr_val, new_msr_val;
- struct mbm_state *pmbm_data, *cmbm_data;
- struct rdt_ctrl_domain *dom_mba;
- enum resctrl_event_id evt_id;
- struct rdt_resource *r_mba;
- struct list_head *head;
- struct rdtgroup *entry;
- u32 cur_bw, user_bw;
-
- r_mba = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
- evt_id = rgrp->mba_mbps_event;
-
- closid = rgrp->closid;
- rmid = rgrp->mon.rmid;
- pmbm_data = get_mbm_state(dom_mbm, closid, rmid, evt_id);
- if (WARN_ON_ONCE(!pmbm_data))
- return;
-
- dom_mba = get_ctrl_domain_from_cpu(smp_processor_id(), r_mba);
- if (!dom_mba) {
- pr_warn_once("Failure to get domain for MBA update\n");
- return;
- }
-
- cur_bw = pmbm_data->prev_bw;
- user_bw = dom_mba->mbps_val[closid];
-
- /* MBA resource doesn't support CDP */
- cur_msr_val = resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE);
-
- /*
- * For Ctrl groups read data from child monitor groups.
- */
- head = &rgrp->mon.crdtgrp_list;
- list_for_each_entry(entry, head, mon.crdtgrp_list) {
- cmbm_data = get_mbm_state(dom_mbm, entry->closid, entry->mon.rmid, evt_id);
- if (WARN_ON_ONCE(!cmbm_data))
- return;
- cur_bw += cmbm_data->prev_bw;
- }
-
- /*
- * Scale up/down the bandwidth linearly for the ctrl group. The
- * bandwidth step is the bandwidth granularity specified by the
- * hardware.
- * Always increase throttling if current bandwidth is above the
- * target set by user.
- * But avoid thrashing up and down on every poll by checking
- * whether a decrease in throttling is likely to push the group
- * back over target. E.g. if currently throttling to 30% of bandwidth
- * on a system with 10% granularity steps, check whether moving to
- * 40% would go past the limit by multiplying current bandwidth by
- * "(30 + 10) / 30".
- */
- if (cur_msr_val > r_mba->membw.min_bw && user_bw < cur_bw) {
- new_msr_val = cur_msr_val - r_mba->membw.bw_gran;
- } else if (cur_msr_val < MAX_MBA_BW &&
- (user_bw > (cur_bw * (cur_msr_val + r_mba->membw.min_bw) / cur_msr_val))) {
- new_msr_val = cur_msr_val + r_mba->membw.bw_gran;
- } else {
- return;
- }
-
- resctrl_arch_update_one(r_mba, dom_mba, closid, CDP_NONE, new_msr_val);
-}
-
-static void mbm_update_one_event(struct rdt_resource *r, struct rdt_mon_domain *d,
- u32 closid, u32 rmid, enum resctrl_event_id evtid)
-{
- struct rmid_read rr = {0};
-
- rr.r = r;
- rr.d = d;
- rr.evtid = evtid;
- rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
- if (IS_ERR(rr.arch_mon_ctx)) {
- pr_warn_ratelimited("Failed to allocate monitor context: %ld",
- PTR_ERR(rr.arch_mon_ctx));
- return;
- }
-
- __mon_event_count(closid, rmid, &rr);
-
- /*
- * If the software controller is enabled, compute the
- * bandwidth for this event id.
- */
- if (is_mba_sc(NULL))
- mbm_bw_count(closid, rmid, &rr);
-
- resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
-}
-
-static void mbm_update(struct rdt_resource *r, struct rdt_mon_domain *d,
- u32 closid, u32 rmid)
-{
- /*
- * This is protected from concurrent reads from user as both
- * the user and overflow handler hold the global mutex.
- */
- if (resctrl_arch_is_mbm_total_enabled())
- mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_TOTAL_EVENT_ID);
-
- if (resctrl_arch_is_mbm_local_enabled())
- mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_LOCAL_EVENT_ID);
-}
-
-/*
- * Handler to scan the limbo list and move the RMIDs
- * to free list whose occupancy < threshold_occupancy.
- */
-void cqm_handle_limbo(struct work_struct *work)
-{
- unsigned long delay = msecs_to_jiffies(CQM_LIMBOCHECK_INTERVAL);
- struct rdt_mon_domain *d;
-
- cpus_read_lock();
- mutex_lock(&rdtgroup_mutex);
-
- d = container_of(work, struct rdt_mon_domain, cqm_limbo.work);
-
- __check_limbo(d, false);
-
- if (has_busy_rmid(d)) {
- d->cqm_work_cpu = cpumask_any_housekeeping(&d->hdr.cpu_mask,
- RESCTRL_PICK_ANY_CPU);
- schedule_delayed_work_on(d->cqm_work_cpu, &d->cqm_limbo,
- delay);
- }
-
- mutex_unlock(&rdtgroup_mutex);
- cpus_read_unlock();
-}
-
-/**
- * cqm_setup_limbo_handler() - Schedule the limbo handler to run for this
- * domain.
- * @dom: The domain the limbo handler should run for.
- * @delay_ms: How far in the future the handler should run.
- * @exclude_cpu: Which CPU the handler should not run on,
- * RESCTRL_PICK_ANY_CPU to pick any CPU.
- */
-void cqm_setup_limbo_handler(struct rdt_mon_domain *dom, unsigned long delay_ms,
- int exclude_cpu)
-{
- unsigned long delay = msecs_to_jiffies(delay_ms);
- int cpu;
-
- cpu = cpumask_any_housekeeping(&dom->hdr.cpu_mask, exclude_cpu);
- dom->cqm_work_cpu = cpu;
-
- if (cpu < nr_cpu_ids)
- schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay);
-}
-
-void mbm_handle_overflow(struct work_struct *work)
-{
- unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL);
- struct rdtgroup *prgrp, *crgrp;
- struct rdt_mon_domain *d;
- struct list_head *head;
- struct rdt_resource *r;
-
- cpus_read_lock();
- mutex_lock(&rdtgroup_mutex);
-
- /*
- * If the filesystem has been unmounted this work no longer needs to
- * run.
- */
- if (!resctrl_mounted || !resctrl_arch_mon_capable())
- goto out_unlock;
-
- r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
- d = container_of(work, struct rdt_mon_domain, mbm_over.work);
-
- list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
- mbm_update(r, d, prgrp->closid, prgrp->mon.rmid);
-
- head = &prgrp->mon.crdtgrp_list;
- list_for_each_entry(crgrp, head, mon.crdtgrp_list)
- mbm_update(r, d, crgrp->closid, crgrp->mon.rmid);
-
- if (is_mba_sc(NULL))
- update_mba_bw(prgrp, d);
- }
-
- /*
- * Re-check for housekeeping CPUs. This allows the overflow handler to
- * move off a nohz_full CPU quickly.
- */
- d->mbm_work_cpu = cpumask_any_housekeeping(&d->hdr.cpu_mask,
- RESCTRL_PICK_ANY_CPU);
- schedule_delayed_work_on(d->mbm_work_cpu, &d->mbm_over, delay);
-
-out_unlock:
- mutex_unlock(&rdtgroup_mutex);
- cpus_read_unlock();
-}
-
-/**
- * mbm_setup_overflow_handler() - Schedule the overflow handler to run for this
- * domain.
- * @dom: The domain the overflow handler should run for.
- * @delay_ms: How far in the future the handler should run.
- * @exclude_cpu: Which CPU the handler should not run on,
- * RESCTRL_PICK_ANY_CPU to pick any CPU.
- */
-void mbm_setup_overflow_handler(struct rdt_mon_domain *dom, unsigned long delay_ms,
- int exclude_cpu)
-{
- unsigned long delay = msecs_to_jiffies(delay_ms);
- int cpu;
-
- /*
- * When a domain comes online there is no guarantee the filesystem is
- * mounted. If not, there is no need to catch counter overflow.
- */
- if (!resctrl_mounted || !resctrl_arch_mon_capable())
- return;
- cpu = cpumask_any_housekeeping(&dom->hdr.cpu_mask, exclude_cpu);
- dom->mbm_work_cpu = cpu;
-
- if (cpu < nr_cpu_ids)
- schedule_delayed_work_on(cpu, &dom->mbm_over, delay);
-}
-
-static int dom_data_init(struct rdt_resource *r)
-{
- u32 idx_limit = resctrl_arch_system_num_rmid_idx();
- u32 num_closid = resctrl_arch_get_num_closid(r);
- struct rmid_entry *entry = NULL;
- int err = 0, i;
- u32 idx;
-
- mutex_lock(&rdtgroup_mutex);
- if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
- u32 *tmp;
-
- /*
- * If the architecture hasn't provided a sanitised value here,
- * this may result in larger arrays than necessary. Resctrl will
- * use a smaller system wide value based on the resources in
- * use.
- */
- tmp = kcalloc(num_closid, sizeof(*tmp), GFP_KERNEL);
- if (!tmp) {
- err = -ENOMEM;
- goto out_unlock;
- }
-
- closid_num_dirty_rmid = tmp;
- }
-
- rmid_ptrs = kcalloc(idx_limit, sizeof(struct rmid_entry), GFP_KERNEL);
- if (!rmid_ptrs) {
- if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
- kfree(closid_num_dirty_rmid);
- closid_num_dirty_rmid = NULL;
- }
- err = -ENOMEM;
- goto out_unlock;
- }
-
- for (i = 0; i < idx_limit; i++) {
- entry = &rmid_ptrs[i];
- INIT_LIST_HEAD(&entry->list);
-
- resctrl_arch_rmid_idx_decode(i, &entry->closid, &entry->rmid);
- list_add_tail(&entry->list, &rmid_free_lru);
- }
-
- /*
- * RESCTRL_RESERVED_CLOSID and RESCTRL_RESERVED_RMID are special and
- * are always allocated. These are used for the rdtgroup_default
- * control group, which will be setup later in resctrl_init().
- */
- idx = resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID,
- RESCTRL_RESERVED_RMID);
- entry = __rmid_entry(idx);
- list_del(&entry->list);
-
-out_unlock:
- mutex_unlock(&rdtgroup_mutex);
-
- return err;
-}
-
-static void dom_data_exit(struct rdt_resource *r)
-{
- mutex_lock(&rdtgroup_mutex);
-
- if (!r->mon_capable)
- goto out_unlock;
-
- if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
- kfree(closid_num_dirty_rmid);
- closid_num_dirty_rmid = NULL;
- }
-
- kfree(rmid_ptrs);
- rmid_ptrs = NULL;
-
-out_unlock:
- mutex_unlock(&rdtgroup_mutex);
-}
-
-static struct mon_evt llc_occupancy_event = {
- .name = "llc_occupancy",
- .evtid = QOS_L3_OCCUP_EVENT_ID,
-};
-
-static struct mon_evt mbm_total_event = {
- .name = "mbm_total_bytes",
- .evtid = QOS_L3_MBM_TOTAL_EVENT_ID,
-};
-
-static struct mon_evt mbm_local_event = {
- .name = "mbm_local_bytes",
- .evtid = QOS_L3_MBM_LOCAL_EVENT_ID,
-};
-
-/*
- * Initialize the event list for the resource.
- *
- * Note that MBM events are also part of RDT_RESOURCE_L3 resource
- * because as per the SDM the total and local memory bandwidth
- * are enumerated as part of L3 monitoring.
- */
-static void l3_mon_evt_init(struct rdt_resource *r)
-{
- INIT_LIST_HEAD(&r->evt_list);
-
- if (resctrl_arch_is_llc_occupancy_enabled())
- list_add_tail(&llc_occupancy_event.list, &r->evt_list);
- if (resctrl_arch_is_mbm_total_enabled())
- list_add_tail(&mbm_total_event.list, &r->evt_list);
- if (resctrl_arch_is_mbm_local_enabled())
- list_add_tail(&mbm_local_event.list, &r->evt_list);
-}
-
/*
* The power-on reset value of MSR_RMID_SNC_CONFIG is 0x1
* which indicates that RMIDs are configured in legacy mode.
@@ -1193,51 +340,6 @@ static __init int snc_get_config(void)
return ret;
}
-/**
- * resctrl_mon_resource_init() - Initialise global monitoring structures.
- *
- * Allocate and initialise global monitor resources that do not belong to a
- * specific domain. i.e. the rmid_ptrs[] used for the limbo and free lists.
- * Called once during boot after the struct rdt_resource's have been configured
- * but before the filesystem is mounted.
- * Resctrl's cpuhp callbacks may be called before this point to bring a domain
- * online.
- *
- * Returns 0 for success, or -ENOMEM.
- */
-int resctrl_mon_resource_init(void)
-{
- struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
- int ret;
-
- if (!r->mon_capable)
- return 0;
-
- ret = dom_data_init(r);
- if (ret)
- return ret;
-
- l3_mon_evt_init(r);
-
- if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_TOTAL_EVENT_ID)) {
- mbm_total_event.configurable = true;
- resctrl_file_fflags_init("mbm_total_bytes_config",
- RFTYPE_MON_INFO | RFTYPE_RES_CACHE);
- }
- if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_LOCAL_EVENT_ID)) {
- mbm_local_event.configurable = true;
- resctrl_file_fflags_init("mbm_local_bytes_config",
- RFTYPE_MON_INFO | RFTYPE_RES_CACHE);
- }
-
- if (resctrl_arch_is_mbm_local_enabled())
- mba_mbps_default_event = QOS_L3_MBM_LOCAL_EVENT_ID;
- else if (resctrl_arch_is_mbm_total_enabled())
- mba_mbps_default_event = QOS_L3_MBM_TOTAL_EVENT_ID;
-
- return 0;
-}
-
int __init rdt_get_mon_l3_config(struct rdt_resource *r)
{
unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset;
@@ -1285,13 +387,6 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
return 0;
}
-void resctrl_mon_resource_exit(void)
-{
- struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
-
- dom_data_exit(r);
-}
-
void __init intel_rdt_mbm_apply_quirk(void)
{
int cf_index;
diff --git a/arch/x86/kernel/cpu/resctrl/monitor_trace.h b/arch/x86/kernel/cpu/resctrl/monitor_trace.h
deleted file mode 100644
index ade67da..0000000
--- a/arch/x86/kernel/cpu/resctrl/monitor_trace.h
+++ /dev/null
@@ -1,31 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#undef TRACE_SYSTEM
-#define TRACE_SYSTEM resctrl
-
-#if !defined(_FS_RESCTRL_MONITOR_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
-#define _FS_RESCTRL_MONITOR_TRACE_H
-
-#include <linux/tracepoint.h>
-
-TRACE_EVENT(mon_llc_occupancy_limbo,
- TP_PROTO(u32 ctrl_hw_id, u32 mon_hw_id, int domain_id, u64 llc_occupancy_bytes),
- TP_ARGS(ctrl_hw_id, mon_hw_id, domain_id, llc_occupancy_bytes),
- TP_STRUCT__entry(__field(u32, ctrl_hw_id)
- __field(u32, mon_hw_id)
- __field(int, domain_id)
- __field(u64, llc_occupancy_bytes)),
- TP_fast_assign(__entry->ctrl_hw_id = ctrl_hw_id;
- __entry->mon_hw_id = mon_hw_id;
- __entry->domain_id = domain_id;
- __entry->llc_occupancy_bytes = llc_occupancy_bytes;),
- TP_printk("ctrl_hw_id=%u mon_hw_id=%u domain_id=%d llc_occupancy_bytes=%llu",
- __entry->ctrl_hw_id, __entry->mon_hw_id, __entry->domain_id,
- __entry->llc_occupancy_bytes)
- );
-
-#endif /* _FS_RESCTRL_MONITOR_TRACE_H */
-
-#undef TRACE_INCLUDE_PATH
-#define TRACE_INCLUDE_PATH .
-#define TRACE_INCLUDE_FILE monitor_trace
-#include <trace/define_trace.h>
diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
index bb39ffd..241d0d7 100644
--- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
+++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
@@ -12,17 +12,10 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/cacheflush.h>
-#include <linux/cacheinfo.h>
#include <linux/cpu.h>
-#include <linux/cpumask.h>
-#include <linux/debugfs.h>
-#include <linux/kthread.h>
-#include <linux/mman.h>
#include <linux/perf_event.h>
#include <linux/pm_qos.h>
#include <linux/resctrl.h>
-#include <linux/slab.h>
-#include <linux/uaccess.h>
#include <asm/cpu_device_id.h>
#include <asm/perf_event.h>
@@ -31,6 +24,7 @@
#include "internal.h"
#define CREATE_TRACE_POINTS
+
#include "pseudo_lock_trace.h"
/*
@@ -39,29 +33,6 @@
*/
static u64 prefetch_disable_bits;
-/*
- * Major number assigned to and shared by all devices exposing
- * pseudo-locked regions.
- */
-static unsigned int pseudo_lock_major;
-static unsigned long pseudo_lock_minor_avail = GENMASK(MINORBITS, 0);
-
-static char *pseudo_lock_devnode(const struct device *dev, umode_t *mode)
-{
- const struct rdtgroup *rdtgrp;
-
- rdtgrp = dev_get_drvdata(dev);
- if (mode)
- *mode = 0600;
- guard(mutex)(&rdtgroup_mutex);
- return kasprintf(GFP_KERNEL, "pseudo_lock/%s", rdt_kn_name(rdtgrp->kn));
-}
-
-static const struct class pseudo_lock_class = {
- .name = "pseudo_lock",
- .devnode = pseudo_lock_devnode,
-};
-
/**
* resctrl_arch_get_prefetch_disable_bits - prefetch disable bits of supported
* platforms
@@ -123,298 +94,6 @@ u64 resctrl_arch_get_prefetch_disable_bits(void)
}
/**
- * pseudo_lock_minor_get - Obtain available minor number
- * @minor: Pointer to where new minor number will be stored
- *
- * A bitmask is used to track available minor numbers. Here the next free
- * minor number is marked as unavailable and returned.
- *
- * Return: 0 on success, <0 on failure.
- */
-static int pseudo_lock_minor_get(unsigned int *minor)
-{
- unsigned long first_bit;
-
- first_bit = find_first_bit(&pseudo_lock_minor_avail, MINORBITS);
-
- if (first_bit == MINORBITS)
- return -ENOSPC;
-
- __clear_bit(first_bit, &pseudo_lock_minor_avail);
- *minor = first_bit;
-
- return 0;
-}
-
-/**
- * pseudo_lock_minor_release - Return minor number to available
- * @minor: The minor number made available
- */
-static void pseudo_lock_minor_release(unsigned int minor)
-{
- __set_bit(minor, &pseudo_lock_minor_avail);
-}
-
-/**
- * region_find_by_minor - Locate a pseudo-lock region by inode minor number
- * @minor: The minor number of the device representing pseudo-locked region
- *
- * When the character device is accessed we need to determine which
- * pseudo-locked region it belongs to. This is done by matching the minor
- * number of the device to the pseudo-locked region it belongs.
- *
- * Minor numbers are assigned at the time a pseudo-locked region is associated
- * with a cache instance.
- *
- * Return: On success return pointer to resource group owning the pseudo-locked
- * region, NULL on failure.
- */
-static struct rdtgroup *region_find_by_minor(unsigned int minor)
-{
- struct rdtgroup *rdtgrp, *rdtgrp_match = NULL;
-
- list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
- if (rdtgrp->plr && rdtgrp->plr->minor == minor) {
- rdtgrp_match = rdtgrp;
- break;
- }
- }
- return rdtgrp_match;
-}
-
-/**
- * struct pseudo_lock_pm_req - A power management QoS request list entry
- * @list: Entry within the @pm_reqs list for a pseudo-locked region
- * @req: PM QoS request
- */
-struct pseudo_lock_pm_req {
- struct list_head list;
- struct dev_pm_qos_request req;
-};
-
-static void pseudo_lock_cstates_relax(struct pseudo_lock_region *plr)
-{
- struct pseudo_lock_pm_req *pm_req, *next;
-
- list_for_each_entry_safe(pm_req, next, &plr->pm_reqs, list) {
- dev_pm_qos_remove_request(&pm_req->req);
- list_del(&pm_req->list);
- kfree(pm_req);
- }
-}
-
-/**
- * pseudo_lock_cstates_constrain - Restrict cores from entering C6
- * @plr: Pseudo-locked region
- *
- * To prevent the cache from being affected by power management entering
- * C6 has to be avoided. This is accomplished by requesting a latency
- * requirement lower than lowest C6 exit latency of all supported
- * platforms as found in the cpuidle state tables in the intel_idle driver.
- * At this time it is possible to do so with a single latency requirement
- * for all supported platforms.
- *
- * Since Goldmont is supported, which is affected by X86_BUG_MONITOR,
- * the ACPI latencies need to be considered while keeping in mind that C2
- * may be set to map to deeper sleep states. In this case the latency
- * requirement needs to prevent entering C2 also.
- *
- * Return: 0 on success, <0 on failure
- */
-static int pseudo_lock_cstates_constrain(struct pseudo_lock_region *plr)
-{
- struct pseudo_lock_pm_req *pm_req;
- int cpu;
- int ret;
-
- for_each_cpu(cpu, &plr->d->hdr.cpu_mask) {
- pm_req = kzalloc(sizeof(*pm_req), GFP_KERNEL);
- if (!pm_req) {
- rdt_last_cmd_puts("Failure to allocate memory for PM QoS\n");
- ret = -ENOMEM;
- goto out_err;
- }
- ret = dev_pm_qos_add_request(get_cpu_device(cpu),
- &pm_req->req,
- DEV_PM_QOS_RESUME_LATENCY,
- 30);
- if (ret < 0) {
- rdt_last_cmd_printf("Failed to add latency req CPU%d\n",
- cpu);
- kfree(pm_req);
- ret = -1;
- goto out_err;
- }
- list_add(&pm_req->list, &plr->pm_reqs);
- }
-
- return 0;
-
-out_err:
- pseudo_lock_cstates_relax(plr);
- return ret;
-}
-
-/**
- * pseudo_lock_region_clear - Reset pseudo-lock region data
- * @plr: pseudo-lock region
- *
- * All content of the pseudo-locked region is reset - any memory allocated
- * freed.
- *
- * Return: void
- */
-static void pseudo_lock_region_clear(struct pseudo_lock_region *plr)
-{
- plr->size = 0;
- plr->line_size = 0;
- kfree(plr->kmem);
- plr->kmem = NULL;
- plr->s = NULL;
- if (plr->d)
- plr->d->plr = NULL;
- plr->d = NULL;
- plr->cbm = 0;
- plr->debugfs_dir = NULL;
-}
-
-/**
- * pseudo_lock_region_init - Initialize pseudo-lock region information
- * @plr: pseudo-lock region
- *
- * Called after user provided a schemata to be pseudo-locked. From the
- * schemata the &struct pseudo_lock_region is on entry already initialized
- * with the resource, domain, and capacity bitmask. Here the information
- * required for pseudo-locking is deduced from this data and &struct
- * pseudo_lock_region initialized further. This information includes:
- * - size in bytes of the region to be pseudo-locked
- * - cache line size to know the stride with which data needs to be accessed
- * to be pseudo-locked
- * - a cpu associated with the cache instance on which the pseudo-locking
- * flow can be executed
- *
- * Return: 0 on success, <0 on failure. Descriptive error will be written
- * to last_cmd_status buffer.
- */
-static int pseudo_lock_region_init(struct pseudo_lock_region *plr)
-{
- enum resctrl_scope scope = plr->s->res->ctrl_scope;
- struct cacheinfo *ci;
- int ret;
-
- if (WARN_ON_ONCE(scope != RESCTRL_L2_CACHE && scope != RESCTRL_L3_CACHE))
- return -ENODEV;
-
- /* Pick the first cpu we find that is associated with the cache. */
- plr->cpu = cpumask_first(&plr->d->hdr.cpu_mask);
-
- if (!cpu_online(plr->cpu)) {
- rdt_last_cmd_printf("CPU %u associated with cache not online\n",
- plr->cpu);
- ret = -ENODEV;
- goto out_region;
- }
-
- ci = get_cpu_cacheinfo_level(plr->cpu, scope);
- if (ci) {
- plr->line_size = ci->coherency_line_size;
- plr->size = rdtgroup_cbm_to_size(plr->s->res, plr->d, plr->cbm);
- return 0;
- }
-
- ret = -1;
- rdt_last_cmd_puts("Unable to determine cache line size\n");
-out_region:
- pseudo_lock_region_clear(plr);
- return ret;
-}
-
-/**
- * pseudo_lock_init - Initialize a pseudo-lock region
- * @rdtgrp: resource group to which new pseudo-locked region will belong
- *
- * A pseudo-locked region is associated with a resource group. When this
- * association is created the pseudo-locked region is initialized. The
- * details of the pseudo-locked region are not known at this time so only
- * allocation is done and association established.
- *
- * Return: 0 on success, <0 on failure
- */
-static int pseudo_lock_init(struct rdtgroup *rdtgrp)
-{
- struct pseudo_lock_region *plr;
-
- plr = kzalloc(sizeof(*plr), GFP_KERNEL);
- if (!plr)
- return -ENOMEM;
-
- init_waitqueue_head(&plr->lock_thread_wq);
- INIT_LIST_HEAD(&plr->pm_reqs);
- rdtgrp->plr = plr;
- return 0;
-}
-
-/**
- * pseudo_lock_region_alloc - Allocate kernel memory that will be pseudo-locked
- * @plr: pseudo-lock region
- *
- * Initialize the details required to set up the pseudo-locked region and
- * allocate the contiguous memory that will be pseudo-locked to the cache.
- *
- * Return: 0 on success, <0 on failure. Descriptive error will be written
- * to last_cmd_status buffer.
- */
-static int pseudo_lock_region_alloc(struct pseudo_lock_region *plr)
-{
- int ret;
-
- ret = pseudo_lock_region_init(plr);
- if (ret < 0)
- return ret;
-
- /*
- * We do not yet support contiguous regions larger than
- * KMALLOC_MAX_SIZE.
- */
- if (plr->size > KMALLOC_MAX_SIZE) {
- rdt_last_cmd_puts("Requested region exceeds maximum size\n");
- ret = -E2BIG;
- goto out_region;
- }
-
- plr->kmem = kzalloc(plr->size, GFP_KERNEL);
- if (!plr->kmem) {
- rdt_last_cmd_puts("Unable to allocate memory\n");
- ret = -ENOMEM;
- goto out_region;
- }
-
- ret = 0;
- goto out;
-out_region:
- pseudo_lock_region_clear(plr);
-out:
- return ret;
-}
-
-/**
- * pseudo_lock_free - Free a pseudo-locked region
- * @rdtgrp: resource group to which pseudo-locked region belonged
- *
- * The pseudo-locked region's resources have already been released, or not
- * yet created at this point. Now it can be freed and disassociated from the
- * resource group.
- *
- * Return: void
- */
-static void pseudo_lock_free(struct rdtgroup *rdtgrp)
-{
- pseudo_lock_region_clear(rdtgrp->plr);
- kfree(rdtgrp->plr);
- rdtgrp->plr = NULL;
-}
-
-/**
* resctrl_arch_pseudo_lock_fn - Load kernel memory into cache
* @_plr: the pseudo-lock region descriptor
*
@@ -544,340 +223,6 @@ int resctrl_arch_pseudo_lock_fn(void *_plr)
}
/**
- * rdtgroup_monitor_in_progress - Test if monitoring in progress
- * @rdtgrp: resource group being queried
- *
- * Return: 1 if monitor groups have been created for this resource
- * group, 0 otherwise.
- */
-static int rdtgroup_monitor_in_progress(struct rdtgroup *rdtgrp)
-{
- return !list_empty(&rdtgrp->mon.crdtgrp_list);
-}
-
-/**
- * rdtgroup_locksetup_user_restrict - Restrict user access to group
- * @rdtgrp: resource group needing access restricted
- *
- * A resource group used for cache pseudo-locking cannot have cpus or tasks
- * assigned to it. This is communicated to the user by restricting access
- * to all the files that can be used to make such changes.
- *
- * Permissions restored with rdtgroup_locksetup_user_restore()
- *
- * Return: 0 on success, <0 on failure. If a failure occurs during the
- * restriction of access an attempt will be made to restore permissions but
- * the state of the mode of these files will be uncertain when a failure
- * occurs.
- */
-static int rdtgroup_locksetup_user_restrict(struct rdtgroup *rdtgrp)
-{
- int ret;
-
- ret = rdtgroup_kn_mode_restrict(rdtgrp, "tasks");
- if (ret)
- return ret;
-
- ret = rdtgroup_kn_mode_restrict(rdtgrp, "cpus");
- if (ret)
- goto err_tasks;
-
- ret = rdtgroup_kn_mode_restrict(rdtgrp, "cpus_list");
- if (ret)
- goto err_cpus;
-
- if (resctrl_arch_mon_capable()) {
- ret = rdtgroup_kn_mode_restrict(rdtgrp, "mon_groups");
- if (ret)
- goto err_cpus_list;
- }
-
- ret = 0;
- goto out;
-
-err_cpus_list:
- rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0777);
-err_cpus:
- rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0777);
-err_tasks:
- rdtgroup_kn_mode_restore(rdtgrp, "tasks", 0777);
-out:
- return ret;
-}
-
-/**
- * rdtgroup_locksetup_user_restore - Restore user access to group
- * @rdtgrp: resource group needing access restored
- *
- * Restore all file access previously removed using
- * rdtgroup_locksetup_user_restrict()
- *
- * Return: 0 on success, <0 on failure. If a failure occurs during the
- * restoration of access an attempt will be made to restrict permissions
- * again but the state of the mode of these files will be uncertain when
- * a failure occurs.
- */
-static int rdtgroup_locksetup_user_restore(struct rdtgroup *rdtgrp)
-{
- int ret;
-
- ret = rdtgroup_kn_mode_restore(rdtgrp, "tasks", 0777);
- if (ret)
- return ret;
-
- ret = rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0777);
- if (ret)
- goto err_tasks;
-
- ret = rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0777);
- if (ret)
- goto err_cpus;
-
- if (resctrl_arch_mon_capable()) {
- ret = rdtgroup_kn_mode_restore(rdtgrp, "mon_groups", 0777);
- if (ret)
- goto err_cpus_list;
- }
-
- ret = 0;
- goto out;
-
-err_cpus_list:
- rdtgroup_kn_mode_restrict(rdtgrp, "cpus_list");
-err_cpus:
- rdtgroup_kn_mode_restrict(rdtgrp, "cpus");
-err_tasks:
- rdtgroup_kn_mode_restrict(rdtgrp, "tasks");
-out:
- return ret;
-}
-
-/**
- * rdtgroup_locksetup_enter - Resource group enters locksetup mode
- * @rdtgrp: resource group requested to enter locksetup mode
- *
- * A resource group enters locksetup mode to reflect that it would be used
- * to represent a pseudo-locked region and is in the process of being set
- * up to do so. A resource group used for a pseudo-locked region would
- * lose the closid associated with it so we cannot allow it to have any
- * tasks or cpus assigned nor permit tasks or cpus to be assigned in the
- * future. Monitoring of a pseudo-locked region is not allowed either.
- *
- * The above and more restrictions on a pseudo-locked region are checked
- * for and enforced before the resource group enters the locksetup mode.
- *
- * Returns: 0 if the resource group successfully entered locksetup mode, <0
- * on failure. On failure the last_cmd_status buffer is updated with text to
- * communicate details of failure to the user.
- */
-int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp)
-{
- int ret;
-
- /*
- * The default resource group can neither be removed nor lose the
- * default closid associated with it.
- */
- if (rdtgrp == &rdtgroup_default) {
- rdt_last_cmd_puts("Cannot pseudo-lock default group\n");
- return -EINVAL;
- }
-
- /*
- * Cache Pseudo-locking not supported when CDP is enabled.
- *
- * Some things to consider if you would like to enable this
- * support (using L3 CDP as example):
- * - When CDP is enabled two separate resources are exposed,
- * L3DATA and L3CODE, but they are actually on the same cache.
- * The implication for pseudo-locking is that if a
- * pseudo-locked region is created on a domain of one
- * resource (eg. L3CODE), then a pseudo-locked region cannot
- * be created on that same domain of the other resource
- * (eg. L3DATA). This is because the creation of a
- * pseudo-locked region involves a call to wbinvd that will
- * affect all cache allocations on particular domain.
- * - Considering the previous, it may be possible to only
- * expose one of the CDP resources to pseudo-locking and
- * hide the other. For example, we could consider to only
- * expose L3DATA and since the L3 cache is unified it is
- * still possible to place instructions there are execute it.
- * - If only one region is exposed to pseudo-locking we should
- * still keep in mind that availability of a portion of cache
- * for pseudo-locking should take into account both resources.
- * Similarly, if a pseudo-locked region is created in one
- * resource, the portion of cache used by it should be made
- * unavailable to all future allocations from both resources.
- */
- if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3) ||
- resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2)) {
- rdt_last_cmd_puts("CDP enabled\n");
- return -EINVAL;
- }
-
- /*
- * Not knowing the bits to disable prefetching implies that this
- * platform does not support Cache Pseudo-Locking.
- */
- if (resctrl_arch_get_prefetch_disable_bits() == 0) {
- rdt_last_cmd_puts("Pseudo-locking not supported\n");
- return -EINVAL;
- }
-
- if (rdtgroup_monitor_in_progress(rdtgrp)) {
- rdt_last_cmd_puts("Monitoring in progress\n");
- return -EINVAL;
- }
-
- if (rdtgroup_tasks_assigned(rdtgrp)) {
- rdt_last_cmd_puts("Tasks assigned to resource group\n");
- return -EINVAL;
- }
-
- if (!cpumask_empty(&rdtgrp->cpu_mask)) {
- rdt_last_cmd_puts("CPUs assigned to resource group\n");
- return -EINVAL;
- }
-
- if (rdtgroup_locksetup_user_restrict(rdtgrp)) {
- rdt_last_cmd_puts("Unable to modify resctrl permissions\n");
- return -EIO;
- }
-
- ret = pseudo_lock_init(rdtgrp);
- if (ret) {
- rdt_last_cmd_puts("Unable to init pseudo-lock region\n");
- goto out_release;
- }
-
- /*
- * If this system is capable of monitoring a rmid would have been
- * allocated when the control group was created. This is not needed
- * anymore when this group would be used for pseudo-locking. This
- * is safe to call on platforms not capable of monitoring.
- */
- free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
-
- ret = 0;
- goto out;
-
-out_release:
- rdtgroup_locksetup_user_restore(rdtgrp);
-out:
- return ret;
-}
-
-/**
- * rdtgroup_locksetup_exit - resource group exist locksetup mode
- * @rdtgrp: resource group
- *
- * When a resource group exits locksetup mode the earlier restrictions are
- * lifted.
- *
- * Return: 0 on success, <0 on failure
- */
-int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp)
-{
- int ret;
-
- if (resctrl_arch_mon_capable()) {
- ret = alloc_rmid(rdtgrp->closid);
- if (ret < 0) {
- rdt_last_cmd_puts("Out of RMIDs\n");
- return ret;
- }
- rdtgrp->mon.rmid = ret;
- }
-
- ret = rdtgroup_locksetup_user_restore(rdtgrp);
- if (ret) {
- free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
- return ret;
- }
-
- pseudo_lock_free(rdtgrp);
- return 0;
-}
-
-/**
- * rdtgroup_cbm_overlaps_pseudo_locked - Test if CBM or portion is pseudo-locked
- * @d: RDT domain
- * @cbm: CBM to test
- *
- * @d represents a cache instance and @cbm a capacity bitmask that is
- * considered for it. Determine if @cbm overlaps with any existing
- * pseudo-locked region on @d.
- *
- * @cbm is unsigned long, even if only 32 bits are used, to make the
- * bitmap functions work correctly.
- *
- * Return: true if @cbm overlaps with pseudo-locked region on @d, false
- * otherwise.
- */
-bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_ctrl_domain *d, unsigned long cbm)
-{
- unsigned int cbm_len;
- unsigned long cbm_b;
-
- if (d->plr) {
- cbm_len = d->plr->s->res->cache.cbm_len;
- cbm_b = d->plr->cbm;
- if (bitmap_intersects(&cbm, &cbm_b, cbm_len))
- return true;
- }
- return false;
-}
-
-/**
- * rdtgroup_pseudo_locked_in_hierarchy - Pseudo-locked region in cache hierarchy
- * @d: RDT domain under test
- *
- * The setup of a pseudo-locked region affects all cache instances within
- * the hierarchy of the region. It is thus essential to know if any
- * pseudo-locked regions exist within a cache hierarchy to prevent any
- * attempts to create new pseudo-locked regions in the same hierarchy.
- *
- * Return: true if a pseudo-locked region exists in the hierarchy of @d or
- * if it is not possible to test due to memory allocation issue,
- * false otherwise.
- */
-bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d)
-{
- struct rdt_ctrl_domain *d_i;
- cpumask_var_t cpu_with_psl;
- struct rdt_resource *r;
- bool ret = false;
-
- /* Walking r->domains, ensure it can't race with cpuhp */
- lockdep_assert_cpus_held();
-
- if (!zalloc_cpumask_var(&cpu_with_psl, GFP_KERNEL))
- return true;
-
- /*
- * First determine which cpus have pseudo-locked regions
- * associated with them.
- */
- for_each_alloc_capable_rdt_resource(r) {
- list_for_each_entry(d_i, &r->ctrl_domains, hdr.list) {
- if (d_i->plr)
- cpumask_or(cpu_with_psl, cpu_with_psl,
- &d_i->hdr.cpu_mask);
- }
- }
-
- /*
- * Next test if new pseudo-locked region would intersect with
- * existing region.
- */
- if (cpumask_intersects(&d->hdr.cpu_mask, cpu_with_psl))
- ret = true;
-
- free_cpumask_var(cpu_with_psl);
- return ret;
-}
-
-/**
* resctrl_arch_measure_cycles_lat_fn - Measure cycle latency to read
* pseudo-locked memory
* @_plr: pseudo-lock region to measure
@@ -1169,433 +514,3 @@ out:
wake_up_interruptible(&plr->lock_thread_wq);
return 0;
}
-
-/**
- * pseudo_lock_measure_cycles - Trigger latency measure to pseudo-locked region
- * @rdtgrp: Resource group to which the pseudo-locked region belongs.
- * @sel: Selector of which measurement to perform on a pseudo-locked region.
- *
- * The measurement of latency to access a pseudo-locked region should be
- * done from a cpu that is associated with that pseudo-locked region.
- * Determine which cpu is associated with this region and start a thread on
- * that cpu to perform the measurement, wait for that thread to complete.
- *
- * Return: 0 on success, <0 on failure
- */
-static int pseudo_lock_measure_cycles(struct rdtgroup *rdtgrp, int sel)
-{
- struct pseudo_lock_region *plr = rdtgrp->plr;
- struct task_struct *thread;
- unsigned int cpu;
- int ret = -1;
-
- cpus_read_lock();
- mutex_lock(&rdtgroup_mutex);
-
- if (rdtgrp->flags & RDT_DELETED) {
- ret = -ENODEV;
- goto out;
- }
-
- if (!plr->d) {
- ret = -ENODEV;
- goto out;
- }
-
- plr->thread_done = 0;
- cpu = cpumask_first(&plr->d->hdr.cpu_mask);
- if (!cpu_online(cpu)) {
- ret = -ENODEV;
- goto out;
- }
-
- plr->cpu = cpu;
-
- if (sel == 1)
- thread = kthread_run_on_cpu(resctrl_arch_measure_cycles_lat_fn,
- plr, cpu, "pseudo_lock_measure/%u");
- else if (sel == 2)
- thread = kthread_run_on_cpu(resctrl_arch_measure_l2_residency,
- plr, cpu, "pseudo_lock_measure/%u");
- else if (sel == 3)
- thread = kthread_run_on_cpu(resctrl_arch_measure_l3_residency,
- plr, cpu, "pseudo_lock_measure/%u");
- else
- goto out;
-
- if (IS_ERR(thread)) {
- ret = PTR_ERR(thread);
- goto out;
- }
-
- ret = wait_event_interruptible(plr->lock_thread_wq,
- plr->thread_done == 1);
- if (ret < 0)
- goto out;
-
- ret = 0;
-
-out:
- mutex_unlock(&rdtgroup_mutex);
- cpus_read_unlock();
- return ret;
-}
-
-static ssize_t pseudo_lock_measure_trigger(struct file *file,
- const char __user *user_buf,
- size_t count, loff_t *ppos)
-{
- struct rdtgroup *rdtgrp = file->private_data;
- size_t buf_size;
- char buf[32];
- int ret;
- int sel;
-
- buf_size = min(count, (sizeof(buf) - 1));
- if (copy_from_user(buf, user_buf, buf_size))
- return -EFAULT;
-
- buf[buf_size] = '\0';
- ret = kstrtoint(buf, 10, &sel);
- if (ret == 0) {
- if (sel != 1 && sel != 2 && sel != 3)
- return -EINVAL;
- ret = debugfs_file_get(file->f_path.dentry);
- if (ret)
- return ret;
- ret = pseudo_lock_measure_cycles(rdtgrp, sel);
- if (ret == 0)
- ret = count;
- debugfs_file_put(file->f_path.dentry);
- }
-
- return ret;
-}
-
-static const struct file_operations pseudo_measure_fops = {
- .write = pseudo_lock_measure_trigger,
- .open = simple_open,
- .llseek = default_llseek,
-};
-
-/**
- * rdtgroup_pseudo_lock_create - Create a pseudo-locked region
- * @rdtgrp: resource group to which pseudo-lock region belongs
- *
- * Called when a resource group in the pseudo-locksetup mode receives a
- * valid schemata that should be pseudo-locked. Since the resource group is
- * in pseudo-locksetup mode the &struct pseudo_lock_region has already been
- * allocated and initialized with the essential information. If a failure
- * occurs the resource group remains in the pseudo-locksetup mode with the
- * &struct pseudo_lock_region associated with it, but cleared from all
- * information and ready for the user to re-attempt pseudo-locking by
- * writing the schemata again.
- *
- * Return: 0 if the pseudo-locked region was successfully pseudo-locked, <0
- * on failure. Descriptive error will be written to last_cmd_status buffer.
- */
-int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp)
-{
- struct pseudo_lock_region *plr = rdtgrp->plr;
- struct task_struct *thread;
- unsigned int new_minor;
- struct device *dev;
- char *kn_name __free(kfree) = NULL;
- int ret;
-
- ret = pseudo_lock_region_alloc(plr);
- if (ret < 0)
- return ret;
-
- ret = pseudo_lock_cstates_constrain(plr);
- if (ret < 0) {
- ret = -EINVAL;
- goto out_region;
- }
- kn_name = kstrdup(rdt_kn_name(rdtgrp->kn), GFP_KERNEL);
- if (!kn_name) {
- ret = -ENOMEM;
- goto out_cstates;
- }
-
- plr->thread_done = 0;
-
- thread = kthread_run_on_cpu(resctrl_arch_pseudo_lock_fn, plr,
- plr->cpu, "pseudo_lock/%u");
- if (IS_ERR(thread)) {
- ret = PTR_ERR(thread);
- rdt_last_cmd_printf("Locking thread returned error %d\n", ret);
- goto out_cstates;
- }
-
- ret = wait_event_interruptible(plr->lock_thread_wq,
- plr->thread_done == 1);
- if (ret < 0) {
- /*
- * If the thread does not get on the CPU for whatever
- * reason and the process which sets up the region is
- * interrupted then this will leave the thread in runnable
- * state and once it gets on the CPU it will dereference
- * the cleared, but not freed, plr struct resulting in an
- * empty pseudo-locking loop.
- */
- rdt_last_cmd_puts("Locking thread interrupted\n");
- goto out_cstates;
- }
-
- ret = pseudo_lock_minor_get(&new_minor);
- if (ret < 0) {
- rdt_last_cmd_puts("Unable to obtain a new minor number\n");
- goto out_cstates;
- }
-
- /*
- * Unlock access but do not release the reference. The
- * pseudo-locked region will still be here on return.
- *
- * The mutex has to be released temporarily to avoid a potential
- * deadlock with the mm->mmap_lock which is obtained in the
- * device_create() and debugfs_create_dir() callpath below as well as
- * before the mmap() callback is called.
- */
- mutex_unlock(&rdtgroup_mutex);
-
- if (!IS_ERR_OR_NULL(debugfs_resctrl)) {
- plr->debugfs_dir = debugfs_create_dir(kn_name, debugfs_resctrl);
- if (!IS_ERR_OR_NULL(plr->debugfs_dir))
- debugfs_create_file("pseudo_lock_measure", 0200,
- plr->debugfs_dir, rdtgrp,
- &pseudo_measure_fops);
- }
-
- dev = device_create(&pseudo_lock_class, NULL,
- MKDEV(pseudo_lock_major, new_minor),
- rdtgrp, "%s", kn_name);
-
- mutex_lock(&rdtgroup_mutex);
-
- if (IS_ERR(dev)) {
- ret = PTR_ERR(dev);
- rdt_last_cmd_printf("Failed to create character device: %d\n",
- ret);
- goto out_debugfs;
- }
-
- /* We released the mutex - check if group was removed while we did so */
- if (rdtgrp->flags & RDT_DELETED) {
- ret = -ENODEV;
- goto out_device;
- }
-
- plr->minor = new_minor;
-
- rdtgrp->mode = RDT_MODE_PSEUDO_LOCKED;
- closid_free(rdtgrp->closid);
- rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0444);
- rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0444);
-
- ret = 0;
- goto out;
-
-out_device:
- device_destroy(&pseudo_lock_class, MKDEV(pseudo_lock_major, new_minor));
-out_debugfs:
- debugfs_remove_recursive(plr->debugfs_dir);
- pseudo_lock_minor_release(new_minor);
-out_cstates:
- pseudo_lock_cstates_relax(plr);
-out_region:
- pseudo_lock_region_clear(plr);
-out:
- return ret;
-}
-
-/**
- * rdtgroup_pseudo_lock_remove - Remove a pseudo-locked region
- * @rdtgrp: resource group to which the pseudo-locked region belongs
- *
- * The removal of a pseudo-locked region can be initiated when the resource
- * group is removed from user space via a "rmdir" from userspace or the
- * unmount of the resctrl filesystem. On removal the resource group does
- * not go back to pseudo-locksetup mode before it is removed, instead it is
- * removed directly. There is thus asymmetry with the creation where the
- * &struct pseudo_lock_region is removed here while it was not created in
- * rdtgroup_pseudo_lock_create().
- *
- * Return: void
- */
-void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp)
-{
- struct pseudo_lock_region *plr = rdtgrp->plr;
-
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
- /*
- * Default group cannot be a pseudo-locked region so we can
- * free closid here.
- */
- closid_free(rdtgrp->closid);
- goto free;
- }
-
- pseudo_lock_cstates_relax(plr);
- debugfs_remove_recursive(rdtgrp->plr->debugfs_dir);
- device_destroy(&pseudo_lock_class, MKDEV(pseudo_lock_major, plr->minor));
- pseudo_lock_minor_release(plr->minor);
-
-free:
- pseudo_lock_free(rdtgrp);
-}
-
-static int pseudo_lock_dev_open(struct inode *inode, struct file *filp)
-{
- struct rdtgroup *rdtgrp;
-
- mutex_lock(&rdtgroup_mutex);
-
- rdtgrp = region_find_by_minor(iminor(inode));
- if (!rdtgrp) {
- mutex_unlock(&rdtgroup_mutex);
- return -ENODEV;
- }
-
- filp->private_data = rdtgrp;
- atomic_inc(&rdtgrp->waitcount);
- /* Perform a non-seekable open - llseek is not supported */
- filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
-
- mutex_unlock(&rdtgroup_mutex);
-
- return 0;
-}
-
-static int pseudo_lock_dev_release(struct inode *inode, struct file *filp)
-{
- struct rdtgroup *rdtgrp;
-
- mutex_lock(&rdtgroup_mutex);
- rdtgrp = filp->private_data;
- WARN_ON(!rdtgrp);
- if (!rdtgrp) {
- mutex_unlock(&rdtgroup_mutex);
- return -ENODEV;
- }
- filp->private_data = NULL;
- atomic_dec(&rdtgrp->waitcount);
- mutex_unlock(&rdtgroup_mutex);
- return 0;
-}
-
-static int pseudo_lock_dev_mremap(struct vm_area_struct *area)
-{
- /* Not supported */
- return -EINVAL;
-}
-
-static const struct vm_operations_struct pseudo_mmap_ops = {
- .mremap = pseudo_lock_dev_mremap,
-};
-
-static int pseudo_lock_dev_mmap(struct file *filp, struct vm_area_struct *vma)
-{
- unsigned long vsize = vma->vm_end - vma->vm_start;
- unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
- struct pseudo_lock_region *plr;
- struct rdtgroup *rdtgrp;
- unsigned long physical;
- unsigned long psize;
-
- mutex_lock(&rdtgroup_mutex);
-
- rdtgrp = filp->private_data;
- WARN_ON(!rdtgrp);
- if (!rdtgrp) {
- mutex_unlock(&rdtgroup_mutex);
- return -ENODEV;
- }
-
- plr = rdtgrp->plr;
-
- if (!plr->d) {
- mutex_unlock(&rdtgroup_mutex);
- return -ENODEV;
- }
-
- /*
- * Task is required to run with affinity to the cpus associated
- * with the pseudo-locked region. If this is not the case the task
- * may be scheduled elsewhere and invalidate entries in the
- * pseudo-locked region.
- */
- if (!cpumask_subset(current->cpus_ptr, &plr->d->hdr.cpu_mask)) {
- mutex_unlock(&rdtgroup_mutex);
- return -EINVAL;
- }
-
- physical = __pa(plr->kmem) >> PAGE_SHIFT;
- psize = plr->size - off;
-
- if (off > plr->size) {
- mutex_unlock(&rdtgroup_mutex);
- return -ENOSPC;
- }
-
- /*
- * Ensure changes are carried directly to the memory being mapped,
- * do not allow copy-on-write mapping.
- */
- if (!(vma->vm_flags & VM_SHARED)) {
- mutex_unlock(&rdtgroup_mutex);
- return -EINVAL;
- }
-
- if (vsize > psize) {
- mutex_unlock(&rdtgroup_mutex);
- return -ENOSPC;
- }
-
- memset(plr->kmem + off, 0, vsize);
-
- if (remap_pfn_range(vma, vma->vm_start, physical + vma->vm_pgoff,
- vsize, vma->vm_page_prot)) {
- mutex_unlock(&rdtgroup_mutex);
- return -EAGAIN;
- }
- vma->vm_ops = &pseudo_mmap_ops;
- mutex_unlock(&rdtgroup_mutex);
- return 0;
-}
-
-static const struct file_operations pseudo_lock_dev_fops = {
- .owner = THIS_MODULE,
- .read = NULL,
- .write = NULL,
- .open = pseudo_lock_dev_open,
- .release = pseudo_lock_dev_release,
- .mmap = pseudo_lock_dev_mmap,
-};
-
-int rdt_pseudo_lock_init(void)
-{
- int ret;
-
- ret = register_chrdev(0, "pseudo_lock", &pseudo_lock_dev_fops);
- if (ret < 0)
- return ret;
-
- pseudo_lock_major = ret;
-
- ret = class_register(&pseudo_lock_class);
- if (ret) {
- unregister_chrdev(pseudo_lock_major, "pseudo_lock");
- return ret;
- }
-
- return 0;
-}
-
-void rdt_pseudo_lock_release(void)
-{
- class_unregister(&pseudo_lock_class);
- unregister_chrdev(pseudo_lock_major, "pseudo_lock");
- pseudo_lock_major = 0;
-}
diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h b/arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h
index 5a0fae6..7c8aef0 100644
--- a/arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h
+++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock_trace.h
@@ -39,5 +39,7 @@ TRACE_EVENT(pseudo_lock_l3,
#undef TRACE_INCLUDE_PATH
#define TRACE_INCLUDE_PATH .
+
#define TRACE_INCLUDE_FILE pseudo_lock_trace
+
#include <trace/define_trace.h>
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index ace86b6..c7a7f0a 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -32,4547 +32,230 @@
#include "internal.h"
DEFINE_STATIC_KEY_FALSE(rdt_enable_key);
-DEFINE_STATIC_KEY_FALSE(rdt_mon_enable_key);
-DEFINE_STATIC_KEY_FALSE(rdt_alloc_enable_key);
-
-/* Mutex to protect rdtgroup access. */
-DEFINE_MUTEX(rdtgroup_mutex);
-
-static struct kernfs_root *rdt_root;
-struct rdtgroup rdtgroup_default;
-LIST_HEAD(rdt_all_groups);
-
-/* list of entries for the schemata file */
-LIST_HEAD(resctrl_schema_all);
-
-/*
- * List of struct mon_data containing private data of event files for use by
- * rdtgroup_mondata_show(). Protected by rdtgroup_mutex.
- */
-static LIST_HEAD(mon_data_kn_priv_list);
-
-/* The filesystem can only be mounted once. */
-bool resctrl_mounted;
-
-/* Kernel fs node for "info" directory under root */
-static struct kernfs_node *kn_info;
-
-/* Kernel fs node for "mon_groups" directory under root */
-static struct kernfs_node *kn_mongrp;
-
-/* Kernel fs node for "mon_data" directory under root */
-static struct kernfs_node *kn_mondata;
-
-/*
- * Used to store the max resource name width to display the schemata names in
- * a tabular format.
- */
-int max_name_width;
-
-static struct seq_buf last_cmd_status;
-static char last_cmd_status_buf[512];
-static int rdtgroup_setup_root(struct rdt_fs_context *ctx);
-static void rdtgroup_destroy_root(void);
+DEFINE_STATIC_KEY_FALSE(rdt_mon_enable_key);
-struct dentry *debugfs_resctrl;
+DEFINE_STATIC_KEY_FALSE(rdt_alloc_enable_key);
/*
- * Memory bandwidth monitoring event to use for the default CTRL_MON group
- * and each new CTRL_MON group created by the user. Only relevant when
- * the filesystem is mounted with the "mba_MBps" option so it does not
- * matter that it remains uninitialized on systems that do not support
- * the "mba_MBps" option.
+ * This is safe against resctrl_arch_sched_in() called from __switch_to()
+ * because __switch_to() is executed with interrupts disabled. A local call
+ * from update_closid_rmid() is protected against __switch_to() because
+ * preemption is disabled.
*/
-enum resctrl_event_id mba_mbps_default_event;
-
-static bool resctrl_debug;
-
-void rdt_last_cmd_clear(void)
-{
- lockdep_assert_held(&rdtgroup_mutex);
- seq_buf_clear(&last_cmd_status);
-}
-
-void rdt_last_cmd_puts(const char *s)
-{
- lockdep_assert_held(&rdtgroup_mutex);
- seq_buf_puts(&last_cmd_status, s);
-}
-
-void rdt_last_cmd_printf(const char *fmt, ...)
-{
- va_list ap;
-
- va_start(ap, fmt);
- lockdep_assert_held(&rdtgroup_mutex);
- seq_buf_vprintf(&last_cmd_status, fmt, ap);
- va_end(ap);
-}
-
-void rdt_staged_configs_clear(void)
+void resctrl_arch_sync_cpu_closid_rmid(void *info)
{
- struct rdt_ctrl_domain *dom;
- struct rdt_resource *r;
-
- lockdep_assert_held(&rdtgroup_mutex);
+ struct resctrl_cpu_defaults *r = info;
- for_each_alloc_capable_rdt_resource(r) {
- list_for_each_entry(dom, &r->ctrl_domains, hdr.list)
- memset(dom->staged_config, 0, sizeof(dom->staged_config));
+ if (r) {
+ this_cpu_write(pqr_state.default_closid, r->closid);
+ this_cpu_write(pqr_state.default_rmid, r->rmid);
}
-}
-static bool resctrl_is_mbm_enabled(void)
-{
- return (resctrl_arch_is_mbm_total_enabled() ||
- resctrl_arch_is_mbm_local_enabled());
+ /*
+ * We cannot unconditionally write the MSR because the current
+ * executing task might have its own closid selected. Just reuse
+ * the context switch code.
+ */
+ resctrl_arch_sched_in(current);
}
-static bool resctrl_is_mbm_event(int e)
-{
- return (e >= QOS_L3_MBM_TOTAL_EVENT_ID &&
- e <= QOS_L3_MBM_LOCAL_EVENT_ID);
-}
+#define INVALID_CONFIG_INDEX UINT_MAX
-/*
- * Trivial allocator for CLOSIDs. Use BITMAP APIs to manipulate a bitmap
- * of free CLOSIDs.
+/**
+ * mon_event_config_index_get - get the hardware index for the
+ * configurable event
+ * @evtid: event id.
*
- * Using a global CLOSID across all resources has some advantages and
- * some drawbacks:
- * + We can simply set current's closid to assign a task to a resource
- * group.
- * + Context switch code can avoid extra memory references deciding which
- * CLOSID to load into the PQR_ASSOC MSR
- * - We give up some options in configuring resource groups across multi-socket
- * systems.
- * - Our choices on how to configure each resource become progressively more
- * limited as the number of resources grows.
+ * Return: 0 for evtid == QOS_L3_MBM_TOTAL_EVENT_ID
+ * 1 for evtid == QOS_L3_MBM_LOCAL_EVENT_ID
+ * INVALID_CONFIG_INDEX for invalid evtid
*/
-static unsigned long *closid_free_map;
-static int closid_free_map_len;
-
-int closids_supported(void)
-{
- return closid_free_map_len;
-}
-
-static int closid_init(void)
+static inline unsigned int mon_event_config_index_get(u32 evtid)
{
- struct resctrl_schema *s;
- u32 rdt_min_closid = ~0;
-
- /* Monitor only platforms still call closid_init() */
- if (list_empty(&resctrl_schema_all))
+ switch (evtid) {
+ case QOS_L3_MBM_TOTAL_EVENT_ID:
return 0;
-
- /* Compute rdt_min_closid across all resources */
- list_for_each_entry(s, &resctrl_schema_all, list)
- rdt_min_closid = min(rdt_min_closid, s->num_closid);
-
- closid_free_map = bitmap_alloc(rdt_min_closid, GFP_KERNEL);
- if (!closid_free_map)
- return -ENOMEM;
- bitmap_fill(closid_free_map, rdt_min_closid);
-
- /* RESCTRL_RESERVED_CLOSID is always reserved for the default group */
- __clear_bit(RESCTRL_RESERVED_CLOSID, closid_free_map);
- closid_free_map_len = rdt_min_closid;
-
- return 0;
-}
-
-static void closid_exit(void)
-{
- bitmap_free(closid_free_map);
- closid_free_map = NULL;
+ case QOS_L3_MBM_LOCAL_EVENT_ID:
+ return 1;
+ default:
+ /* Should never reach here */
+ return INVALID_CONFIG_INDEX;
+ }
}
-static int closid_alloc(void)
+void resctrl_arch_mon_event_config_read(void *_config_info)
{
- int cleanest_closid;
- u32 closid;
-
- lockdep_assert_held(&rdtgroup_mutex);
+ struct resctrl_mon_config_info *config_info = _config_info;
+ unsigned int index;
+ u64 msrval;
- if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID) &&
- resctrl_arch_is_llc_occupancy_enabled()) {
- cleanest_closid = resctrl_find_cleanest_closid();
- if (cleanest_closid < 0)
- return cleanest_closid;
- closid = cleanest_closid;
- } else {
- closid = find_first_bit(closid_free_map, closid_free_map_len);
- if (closid == closid_free_map_len)
- return -ENOSPC;
+ index = mon_event_config_index_get(config_info->evtid);
+ if (index == INVALID_CONFIG_INDEX) {
+ pr_warn_once("Invalid event id %d\n", config_info->evtid);
+ return;
}
- __clear_bit(closid, closid_free_map);
-
- return closid;
-}
-
-void closid_free(int closid)
-{
- lockdep_assert_held(&rdtgroup_mutex);
+ rdmsrl(MSR_IA32_EVT_CFG_BASE + index, msrval);
- __set_bit(closid, closid_free_map);
+ /* Report only the valid event configuration bits */
+ config_info->mon_config = msrval & MAX_EVT_CONFIG_BITS;
}
-/**
- * closid_allocated - test if provided closid is in use
- * @closid: closid to be tested
- *
- * Return: true if @closid is currently associated with a resource group,
- * false if @closid is free
- */
-bool closid_allocated(unsigned int closid)
+void resctrl_arch_mon_event_config_write(void *_config_info)
{
- lockdep_assert_held(&rdtgroup_mutex);
+ struct resctrl_mon_config_info *config_info = _config_info;
+ unsigned int index;
- return !test_bit(closid, closid_free_map);
+ index = mon_event_config_index_get(config_info->evtid);
+ if (index == INVALID_CONFIG_INDEX) {
+ pr_warn_once("Invalid event id %d\n", config_info->evtid);
+ return;
+ }
+ wrmsr(MSR_IA32_EVT_CFG_BASE + index, config_info->mon_config, 0);
}
-/**
- * rdtgroup_mode_by_closid - Return mode of resource group with closid
- * @closid: closid if the resource group
- *
- * Each resource group is associated with a @closid. Here the mode
- * of a resource group can be queried by searching for it using its closid.
- *
- * Return: mode as &enum rdtgrp_mode of resource group with closid @closid
- */
-enum rdtgrp_mode rdtgroup_mode_by_closid(int closid)
+static void l3_qos_cfg_update(void *arg)
{
- struct rdtgroup *rdtgrp;
-
- list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
- if (rdtgrp->closid == closid)
- return rdtgrp->mode;
- }
+ bool *enable = arg;
- return RDT_NUM_MODES;
+ wrmsrl(MSR_IA32_L3_QOS_CFG, *enable ? L3_QOS_CDP_ENABLE : 0ULL);
}
-static const char * const rdt_mode_str[] = {
- [RDT_MODE_SHAREABLE] = "shareable",
- [RDT_MODE_EXCLUSIVE] = "exclusive",
- [RDT_MODE_PSEUDO_LOCKSETUP] = "pseudo-locksetup",
- [RDT_MODE_PSEUDO_LOCKED] = "pseudo-locked",
-};
-
-/**
- * rdtgroup_mode_str - Return the string representation of mode
- * @mode: the resource group mode as &enum rdtgroup_mode
- *
- * Return: string representation of valid mode, "unknown" otherwise
- */
-static const char *rdtgroup_mode_str(enum rdtgrp_mode mode)
+static void l2_qos_cfg_update(void *arg)
{
- if (mode < RDT_MODE_SHAREABLE || mode >= RDT_NUM_MODES)
- return "unknown";
+ bool *enable = arg;
- return rdt_mode_str[mode];
+ wrmsrl(MSR_IA32_L2_QOS_CFG, *enable ? L2_QOS_CDP_ENABLE : 0ULL);
}
-/* set uid and gid of rdtgroup dirs and files to that of the creator */
-static int rdtgroup_kn_set_ugid(struct kernfs_node *kn)
+static int set_cache_qos_cfg(int level, bool enable)
{
- struct iattr iattr = { .ia_valid = ATTR_UID | ATTR_GID,
- .ia_uid = current_fsuid(),
- .ia_gid = current_fsgid(), };
-
- if (uid_eq(iattr.ia_uid, GLOBAL_ROOT_UID) &&
- gid_eq(iattr.ia_gid, GLOBAL_ROOT_GID))
- return 0;
+ void (*update)(void *arg);
+ struct rdt_ctrl_domain *d;
+ struct rdt_resource *r_l;
+ cpumask_var_t cpu_mask;
+ int cpu;
- return kernfs_setattr(kn, &iattr);
-}
+ /* Walking r->domains, ensure it can't race with cpuhp */
+ lockdep_assert_cpus_held();
-static int rdtgroup_add_file(struct kernfs_node *parent_kn, struct rftype *rft)
-{
- struct kernfs_node *kn;
- int ret;
+ if (level == RDT_RESOURCE_L3)
+ update = l3_qos_cfg_update;
+ else if (level == RDT_RESOURCE_L2)
+ update = l2_qos_cfg_update;
+ else
+ return -EINVAL;
- kn = __kernfs_create_file(parent_kn, rft->name, rft->mode,
- GLOBAL_ROOT_UID, GLOBAL_ROOT_GID,
- 0, rft->kf_ops, rft, NULL, NULL);
- if (IS_ERR(kn))
- return PTR_ERR(kn);
+ if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
+ return -ENOMEM;
- ret = rdtgroup_kn_set_ugid(kn);
- if (ret) {
- kernfs_remove(kn);
- return ret;
+ r_l = &rdt_resources_all[level].r_resctrl;
+ list_for_each_entry(d, &r_l->ctrl_domains, hdr.list) {
+ if (r_l->cache.arch_has_per_cpu_cfg)
+ /* Pick all the CPUs in the domain instance */
+ for_each_cpu(cpu, &d->hdr.cpu_mask)
+ cpumask_set_cpu(cpu, cpu_mask);
+ else
+ /* Pick one CPU from each domain instance to update MSR */
+ cpumask_set_cpu(cpumask_any(&d->hdr.cpu_mask), cpu_mask);
}
- return 0;
-}
+ /* Update QOS_CFG MSR on all the CPUs in cpu_mask */
+ on_each_cpu_mask(cpu_mask, update, &enable, 1);
-static int rdtgroup_seqfile_show(struct seq_file *m, void *arg)
-{
- struct kernfs_open_file *of = m->private;
- struct rftype *rft = of->kn->priv;
+ free_cpumask_var(cpu_mask);
- if (rft->seq_show)
- return rft->seq_show(of, m, arg);
return 0;
}
-static ssize_t rdtgroup_file_write(struct kernfs_open_file *of, char *buf,
- size_t nbytes, loff_t off)
+/* Restore the qos cfg state when a domain comes online */
+void rdt_domain_reconfigure_cdp(struct rdt_resource *r)
{
- struct rftype *rft = of->kn->priv;
-
- if (rft->write)
- return rft->write(of, buf, nbytes, off);
-
- return -EINVAL;
-}
-
-static const struct kernfs_ops rdtgroup_kf_single_ops = {
- .atomic_write_len = PAGE_SIZE,
- .write = rdtgroup_file_write,
- .seq_show = rdtgroup_seqfile_show,
-};
+ struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
-static const struct kernfs_ops kf_mondata_ops = {
- .atomic_write_len = PAGE_SIZE,
- .seq_show = rdtgroup_mondata_show,
-};
+ if (!r->cdp_capable)
+ return;
-static bool is_cpu_list(struct kernfs_open_file *of)
-{
- struct rftype *rft = of->kn->priv;
+ if (r->rid == RDT_RESOURCE_L2)
+ l2_qos_cfg_update(&hw_res->cdp_enabled);
- return rft->flags & RFTYPE_FLAGS_CPUS_LIST;
+ if (r->rid == RDT_RESOURCE_L3)
+ l3_qos_cfg_update(&hw_res->cdp_enabled);
}
-static int rdtgroup_cpus_show(struct kernfs_open_file *of,
- struct seq_file *s, void *v)
+static int cdp_enable(int level)
{
- struct rdtgroup *rdtgrp;
- struct cpumask *mask;
- int ret = 0;
+ struct rdt_resource *r_l = &rdt_resources_all[level].r_resctrl;
+ int ret;
- rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!r_l->alloc_capable)
+ return -EINVAL;
- if (rdtgrp) {
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
- if (!rdtgrp->plr->d) {
- rdt_last_cmd_clear();
- rdt_last_cmd_puts("Cache domain offline\n");
- ret = -ENODEV;
- } else {
- mask = &rdtgrp->plr->d->hdr.cpu_mask;
- seq_printf(s, is_cpu_list(of) ?
- "%*pbl\n" : "%*pb\n",
- cpumask_pr_args(mask));
- }
- } else {
- seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n",
- cpumask_pr_args(&rdtgrp->cpu_mask));
- }
- } else {
- ret = -ENOENT;
- }
- rdtgroup_kn_unlock(of->kn);
+ ret = set_cache_qos_cfg(level, true);
+ if (!ret)
+ rdt_resources_all[level].cdp_enabled = true;
return ret;
}
-/*
- * This is safe against resctrl_arch_sched_in() called from __switch_to()
- * because __switch_to() is executed with interrupts disabled. A local call
- * from update_closid_rmid() is protected against __switch_to() because
- * preemption is disabled.
- */
-void resctrl_arch_sync_cpu_closid_rmid(void *info)
-{
- struct resctrl_cpu_defaults *r = info;
-
- if (r) {
- this_cpu_write(pqr_state.default_closid, r->closid);
- this_cpu_write(pqr_state.default_rmid, r->rmid);
- }
-
- /*
- * We cannot unconditionally write the MSR because the current
- * executing task might have its own closid selected. Just reuse
- * the context switch code.
- */
- resctrl_arch_sched_in(current);
-}
-
-/*
- * Update the PGR_ASSOC MSR on all cpus in @cpu_mask,
- *
- * Per task closids/rmids must have been set up before calling this function.
- * @r may be NULL.
- */
-static void
-update_closid_rmid(const struct cpumask *cpu_mask, struct rdtgroup *r)
+static void cdp_disable(int level)
{
- struct resctrl_cpu_defaults defaults, *p = NULL;
+ struct rdt_hw_resource *r_hw = &rdt_resources_all[level];
- if (r) {
- defaults.closid = r->closid;
- defaults.rmid = r->mon.rmid;
- p = &defaults;
+ if (r_hw->cdp_enabled) {
+ set_cache_qos_cfg(level, false);
+ r_hw->cdp_enabled = false;
}
-
- on_each_cpu_mask(cpu_mask, resctrl_arch_sync_cpu_closid_rmid, p, 1);
}
-static int cpus_mon_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
- cpumask_var_t tmpmask)
+int resctrl_arch_set_cdp_enabled(enum resctrl_res_level l, bool enable)
{
- struct rdtgroup *prgrp = rdtgrp->mon.parent, *crgrp;
- struct list_head *head;
+ struct rdt_hw_resource *hw_res = &rdt_resources_all[l];
- /* Check whether cpus belong to parent ctrl group */
- cpumask_andnot(tmpmask, newmask, &prgrp->cpu_mask);
- if (!cpumask_empty(tmpmask)) {
- rdt_last_cmd_puts("Can only add CPUs to mongroup that belong to parent\n");
+ if (!hw_res->r_resctrl.cdp_capable)
return -EINVAL;
- }
-
- /* Check whether cpus are dropped from this group */
- cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
- if (!cpumask_empty(tmpmask)) {
- /* Give any dropped cpus to parent rdtgroup */
- cpumask_or(&prgrp->cpu_mask, &prgrp->cpu_mask, tmpmask);
- update_closid_rmid(tmpmask, prgrp);
- }
- /*
- * If we added cpus, remove them from previous group that owned them
- * and update per-cpu rmid
- */
- cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
- if (!cpumask_empty(tmpmask)) {
- head = &prgrp->mon.crdtgrp_list;
- list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
- if (crgrp == rdtgrp)
- continue;
- cpumask_andnot(&crgrp->cpu_mask, &crgrp->cpu_mask,
- tmpmask);
- }
- update_closid_rmid(tmpmask, rdtgrp);
- }
+ if (enable)
+ return cdp_enable(l);
- /* Done pushing/pulling - update this group with new mask */
- cpumask_copy(&rdtgrp->cpu_mask, newmask);
+ cdp_disable(l);
return 0;
}
-static void cpumask_rdtgrp_clear(struct rdtgroup *r, struct cpumask *m)
+bool resctrl_arch_get_cdp_enabled(enum resctrl_res_level l)
{
- struct rdtgroup *crgrp;
-
- cpumask_andnot(&r->cpu_mask, &r->cpu_mask, m);
- /* update the child mon group masks as well*/
- list_for_each_entry(crgrp, &r->mon.crdtgrp_list, mon.crdtgrp_list)
- cpumask_and(&crgrp->cpu_mask, &r->cpu_mask, &crgrp->cpu_mask);
+ return rdt_resources_all[l].cdp_enabled;
}
-static int cpus_ctrl_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
- cpumask_var_t tmpmask, cpumask_var_t tmpmask1)
+void resctrl_arch_reset_all_ctrls(struct rdt_resource *r)
{
- struct rdtgroup *r, *crgrp;
- struct list_head *head;
+ struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
+ struct rdt_hw_ctrl_domain *hw_dom;
+ struct msr_param msr_param;
+ struct rdt_ctrl_domain *d;
+ int i;
- /* Check whether cpus are dropped from this group */
- cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
- if (!cpumask_empty(tmpmask)) {
- /* Can't drop from default group */
- if (rdtgrp == &rdtgroup_default) {
- rdt_last_cmd_puts("Can't drop CPUs from default group\n");
- return -EINVAL;
- }
+ /* Walking r->domains, ensure it can't race with cpuhp */
+ lockdep_assert_cpus_held();
- /* Give any dropped cpus to rdtgroup_default */
- cpumask_or(&rdtgroup_default.cpu_mask,
- &rdtgroup_default.cpu_mask, tmpmask);
- update_closid_rmid(tmpmask, &rdtgroup_default);
- }
+ msr_param.res = r;
+ msr_param.low = 0;
+ msr_param.high = hw_res->num_closid;
/*
- * If we added cpus, remove them from previous group and
- * the prev group's child groups that owned them
- * and update per-cpu closid/rmid.
+ * Disable resource control for this resource by setting all
+ * CBMs in all ctrl_domains to the maximum mask value. Pick one CPU
+ * from each domain to update the MSRs below.
*/
- cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
- if (!cpumask_empty(tmpmask)) {
- list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) {
- if (r == rdtgrp)
- continue;
- cpumask_and(tmpmask1, &r->cpu_mask, tmpmask);
- if (!cpumask_empty(tmpmask1))
- cpumask_rdtgrp_clear(r, tmpmask1);
- }
- update_closid_rmid(tmpmask, rdtgrp);
- }
+ list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
+ hw_dom = resctrl_to_arch_ctrl_dom(d);
- /* Done pushing/pulling - update this group with new mask */
- cpumask_copy(&rdtgrp->cpu_mask, newmask);
+ for (i = 0; i < hw_res->num_closid; i++)
+ hw_dom->ctrl_val[i] = resctrl_get_default_ctrl(r);
+ msr_param.dom = d;
+ smp_call_function_any(&d->hdr.cpu_mask, rdt_ctrl_update, &msr_param, 1);
+ }
- /*
- * Clear child mon group masks since there is a new parent mask
- * now and update the rmid for the cpus the child lost.
- */
- head = &rdtgrp->mon.crdtgrp_list;
- list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
- cpumask_and(tmpmask, &rdtgrp->cpu_mask, &crgrp->cpu_mask);
- update_closid_rmid(tmpmask, rdtgrp);
- cpumask_clear(&crgrp->cpu_mask);
- }
-
- return 0;
-}
-
-static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
-{
- cpumask_var_t tmpmask, newmask, tmpmask1;
- struct rdtgroup *rdtgrp;
- int ret;
-
- if (!buf)
- return -EINVAL;
-
- if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
- return -ENOMEM;
- if (!zalloc_cpumask_var(&newmask, GFP_KERNEL)) {
- free_cpumask_var(tmpmask);
- return -ENOMEM;
- }
- if (!zalloc_cpumask_var(&tmpmask1, GFP_KERNEL)) {
- free_cpumask_var(tmpmask);
- free_cpumask_var(newmask);
- return -ENOMEM;
- }
-
- rdtgrp = rdtgroup_kn_lock_live(of->kn);
- if (!rdtgrp) {
- ret = -ENOENT;
- goto unlock;
- }
-
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
- rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
- ret = -EINVAL;
- rdt_last_cmd_puts("Pseudo-locking in progress\n");
- goto unlock;
- }
-
- if (is_cpu_list(of))
- ret = cpulist_parse(buf, newmask);
- else
- ret = cpumask_parse(buf, newmask);
-
- if (ret) {
- rdt_last_cmd_puts("Bad CPU list/mask\n");
- goto unlock;
- }
-
- /* check that user didn't specify any offline cpus */
- cpumask_andnot(tmpmask, newmask, cpu_online_mask);
- if (!cpumask_empty(tmpmask)) {
- ret = -EINVAL;
- rdt_last_cmd_puts("Can only assign online CPUs\n");
- goto unlock;
- }
-
- if (rdtgrp->type == RDTCTRL_GROUP)
- ret = cpus_ctrl_write(rdtgrp, newmask, tmpmask, tmpmask1);
- else if (rdtgrp->type == RDTMON_GROUP)
- ret = cpus_mon_write(rdtgrp, newmask, tmpmask);
- else
- ret = -EINVAL;
-
-unlock:
- rdtgroup_kn_unlock(of->kn);
- free_cpumask_var(tmpmask);
- free_cpumask_var(newmask);
- free_cpumask_var(tmpmask1);
-
- return ret ?: nbytes;
-}
-
-/**
- * rdtgroup_remove - the helper to remove resource group safely
- * @rdtgrp: resource group to remove
- *
- * On resource group creation via a mkdir, an extra kernfs_node reference is
- * taken to ensure that the rdtgroup structure remains accessible for the
- * rdtgroup_kn_unlock() calls where it is removed.
- *
- * Drop the extra reference here, then free the rdtgroup structure.
- *
- * Return: void
- */
-static void rdtgroup_remove(struct rdtgroup *rdtgrp)
-{
- kernfs_put(rdtgrp->kn);
- kfree(rdtgrp);
-}
-
-static void _update_task_closid_rmid(void *task)
-{
- /*
- * If the task is still current on this CPU, update PQR_ASSOC MSR.
- * Otherwise, the MSR is updated when the task is scheduled in.
- */
- if (task == current)
- resctrl_arch_sched_in(task);
-}
-
-static void update_task_closid_rmid(struct task_struct *t)
-{
- if (IS_ENABLED(CONFIG_SMP) && task_curr(t))
- smp_call_function_single(task_cpu(t), _update_task_closid_rmid, t, 1);
- else
- _update_task_closid_rmid(t);
-}
-
-static bool task_in_rdtgroup(struct task_struct *tsk, struct rdtgroup *rdtgrp)
-{
- u32 closid, rmid = rdtgrp->mon.rmid;
-
- if (rdtgrp->type == RDTCTRL_GROUP)
- closid = rdtgrp->closid;
- else if (rdtgrp->type == RDTMON_GROUP)
- closid = rdtgrp->mon.parent->closid;
- else
- return false;
-
- return resctrl_arch_match_closid(tsk, closid) &&
- resctrl_arch_match_rmid(tsk, closid, rmid);
-}
-
-static int __rdtgroup_move_task(struct task_struct *tsk,
- struct rdtgroup *rdtgrp)
-{
- /* If the task is already in rdtgrp, no need to move the task. */
- if (task_in_rdtgroup(tsk, rdtgrp))
- return 0;
-
- /*
- * Set the task's closid/rmid before the PQR_ASSOC MSR can be
- * updated by them.
- *
- * For ctrl_mon groups, move both closid and rmid.
- * For monitor groups, can move the tasks only from
- * their parent CTRL group.
- */
- if (rdtgrp->type == RDTMON_GROUP &&
- !resctrl_arch_match_closid(tsk, rdtgrp->mon.parent->closid)) {
- rdt_last_cmd_puts("Can't move task to different control group\n");
- return -EINVAL;
- }
-
- if (rdtgrp->type == RDTMON_GROUP)
- resctrl_arch_set_closid_rmid(tsk, rdtgrp->mon.parent->closid,
- rdtgrp->mon.rmid);
- else
- resctrl_arch_set_closid_rmid(tsk, rdtgrp->closid,
- rdtgrp->mon.rmid);
-
- /*
- * Ensure the task's closid and rmid are written before determining if
- * the task is current that will decide if it will be interrupted.
- * This pairs with the full barrier between the rq->curr update and
- * resctrl_arch_sched_in() during context switch.
- */
- smp_mb();
-
- /*
- * By now, the task's closid and rmid are set. If the task is current
- * on a CPU, the PQR_ASSOC MSR needs to be updated to make the resource
- * group go into effect. If the task is not current, the MSR will be
- * updated when the task is scheduled in.
- */
- update_task_closid_rmid(tsk);
-
- return 0;
-}
-
-static bool is_closid_match(struct task_struct *t, struct rdtgroup *r)
-{
- return (resctrl_arch_alloc_capable() && (r->type == RDTCTRL_GROUP) &&
- resctrl_arch_match_closid(t, r->closid));
-}
-
-static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r)
-{
- return (resctrl_arch_mon_capable() && (r->type == RDTMON_GROUP) &&
- resctrl_arch_match_rmid(t, r->mon.parent->closid,
- r->mon.rmid));
-}
-
-/**
- * rdtgroup_tasks_assigned - Test if tasks have been assigned to resource group
- * @r: Resource group
- *
- * Return: 1 if tasks have been assigned to @r, 0 otherwise
- */
-int rdtgroup_tasks_assigned(struct rdtgroup *r)
-{
- struct task_struct *p, *t;
- int ret = 0;
-
- lockdep_assert_held(&rdtgroup_mutex);
-
- rcu_read_lock();
- for_each_process_thread(p, t) {
- if (is_closid_match(t, r) || is_rmid_match(t, r)) {
- ret = 1;
- break;
- }
- }
- rcu_read_unlock();
-
- return ret;
-}
-
-static int rdtgroup_task_write_permission(struct task_struct *task,
- struct kernfs_open_file *of)
-{
- const struct cred *tcred = get_task_cred(task);
- const struct cred *cred = current_cred();
- int ret = 0;
-
- /*
- * Even if we're attaching all tasks in the thread group, we only
- * need to check permissions on one of them.
- */
- if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) &&
- !uid_eq(cred->euid, tcred->uid) &&
- !uid_eq(cred->euid, tcred->suid)) {
- rdt_last_cmd_printf("No permission to move task %d\n", task->pid);
- ret = -EPERM;
- }
-
- put_cred(tcred);
- return ret;
-}
-
-static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp,
- struct kernfs_open_file *of)
-{
- struct task_struct *tsk;
- int ret;
-
- rcu_read_lock();
- if (pid) {
- tsk = find_task_by_vpid(pid);
- if (!tsk) {
- rcu_read_unlock();
- rdt_last_cmd_printf("No task %d\n", pid);
- return -ESRCH;
- }
- } else {
- tsk = current;
- }
-
- get_task_struct(tsk);
- rcu_read_unlock();
-
- ret = rdtgroup_task_write_permission(tsk, of);
- if (!ret)
- ret = __rdtgroup_move_task(tsk, rdtgrp);
-
- put_task_struct(tsk);
- return ret;
-}
-
-static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
-{
- struct rdtgroup *rdtgrp;
- char *pid_str;
- int ret = 0;
- pid_t pid;
-
- rdtgrp = rdtgroup_kn_lock_live(of->kn);
- if (!rdtgrp) {
- rdtgroup_kn_unlock(of->kn);
- return -ENOENT;
- }
- rdt_last_cmd_clear();
-
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
- rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
- ret = -EINVAL;
- rdt_last_cmd_puts("Pseudo-locking in progress\n");
- goto unlock;
- }
-
- while (buf && buf[0] != '\0' && buf[0] != '\n') {
- pid_str = strim(strsep(&buf, ","));
-
- if (kstrtoint(pid_str, 0, &pid)) {
- rdt_last_cmd_printf("Task list parsing error pid %s\n", pid_str);
- ret = -EINVAL;
- break;
- }
-
- if (pid < 0) {
- rdt_last_cmd_printf("Invalid pid %d\n", pid);
- ret = -EINVAL;
- break;
- }
-
- ret = rdtgroup_move_task(pid, rdtgrp, of);
- if (ret) {
- rdt_last_cmd_printf("Error while processing task %d\n", pid);
- break;
- }
- }
-
-unlock:
- rdtgroup_kn_unlock(of->kn);
-
- return ret ?: nbytes;
-}
-
-static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s)
-{
- struct task_struct *p, *t;
- pid_t pid;
-
- rcu_read_lock();
- for_each_process_thread(p, t) {
- if (is_closid_match(t, r) || is_rmid_match(t, r)) {
- pid = task_pid_vnr(t);
- if (pid)
- seq_printf(s, "%d\n", pid);
- }
- }
- rcu_read_unlock();
-}
-
-static int rdtgroup_tasks_show(struct kernfs_open_file *of,
- struct seq_file *s, void *v)
-{
- struct rdtgroup *rdtgrp;
- int ret = 0;
-
- rdtgrp = rdtgroup_kn_lock_live(of->kn);
- if (rdtgrp)
- show_rdt_tasks(rdtgrp, s);
- else
- ret = -ENOENT;
- rdtgroup_kn_unlock(of->kn);
-
- return ret;
-}
-
-static int rdtgroup_closid_show(struct kernfs_open_file *of,
- struct seq_file *s, void *v)
-{
- struct rdtgroup *rdtgrp;
- int ret = 0;
-
- rdtgrp = rdtgroup_kn_lock_live(of->kn);
- if (rdtgrp)
- seq_printf(s, "%u\n", rdtgrp->closid);
- else
- ret = -ENOENT;
- rdtgroup_kn_unlock(of->kn);
-
- return ret;
-}
-
-static int rdtgroup_rmid_show(struct kernfs_open_file *of,
- struct seq_file *s, void *v)
-{
- struct rdtgroup *rdtgrp;
- int ret = 0;
-
- rdtgrp = rdtgroup_kn_lock_live(of->kn);
- if (rdtgrp)
- seq_printf(s, "%u\n", rdtgrp->mon.rmid);
- else
- ret = -ENOENT;
- rdtgroup_kn_unlock(of->kn);
-
- return ret;
-}
-
-#ifdef CONFIG_PROC_CPU_RESCTRL
-
-/*
- * A task can only be part of one resctrl control group and of one monitor
- * group which is associated to that control group.
- *
- * 1) res:
- * mon:
- *
- * resctrl is not available.
- *
- * 2) res:/
- * mon:
- *
- * Task is part of the root resctrl control group, and it is not associated
- * to any monitor group.
- *
- * 3) res:/
- * mon:mon0
- *
- * Task is part of the root resctrl control group and monitor group mon0.
- *
- * 4) res:group0
- * mon:
- *
- * Task is part of resctrl control group group0, and it is not associated
- * to any monitor group.
- *
- * 5) res:group0
- * mon:mon1
- *
- * Task is part of resctrl control group group0 and monitor group mon1.
- */
-int proc_resctrl_show(struct seq_file *s, struct pid_namespace *ns,
- struct pid *pid, struct task_struct *tsk)
-{
- struct rdtgroup *rdtg;
- int ret = 0;
-
- mutex_lock(&rdtgroup_mutex);
-
- /* Return empty if resctrl has not been mounted. */
- if (!resctrl_mounted) {
- seq_puts(s, "res:\nmon:\n");
- goto unlock;
- }
-
- list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) {
- struct rdtgroup *crg;
-
- /*
- * Task information is only relevant for shareable
- * and exclusive groups.
- */
- if (rdtg->mode != RDT_MODE_SHAREABLE &&
- rdtg->mode != RDT_MODE_EXCLUSIVE)
- continue;
-
- if (!resctrl_arch_match_closid(tsk, rdtg->closid))
- continue;
-
- seq_printf(s, "res:%s%s\n", (rdtg == &rdtgroup_default) ? "/" : "",
- rdt_kn_name(rdtg->kn));
- seq_puts(s, "mon:");
- list_for_each_entry(crg, &rdtg->mon.crdtgrp_list,
- mon.crdtgrp_list) {
- if (!resctrl_arch_match_rmid(tsk, crg->mon.parent->closid,
- crg->mon.rmid))
- continue;
- seq_printf(s, "%s", rdt_kn_name(crg->kn));
- break;
- }
- seq_putc(s, '\n');
- goto unlock;
- }
- /*
- * The above search should succeed. Otherwise return
- * with an error.
- */
- ret = -ENOENT;
-unlock:
- mutex_unlock(&rdtgroup_mutex);
-
- return ret;
-}
-#endif
-
-static int rdt_last_cmd_status_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- int len;
-
- mutex_lock(&rdtgroup_mutex);
- len = seq_buf_used(&last_cmd_status);
- if (len)
- seq_printf(seq, "%.*s", len, last_cmd_status_buf);
- else
- seq_puts(seq, "ok\n");
- mutex_unlock(&rdtgroup_mutex);
- return 0;
-}
-
-static void *rdt_kn_parent_priv(struct kernfs_node *kn)
-{
- /*
- * The parent pointer is only valid within RCU section since it can be
- * replaced.
- */
- guard(rcu)();
- return rcu_dereference(kn->__parent)->priv;
-}
-
-static int rdt_num_closids_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
-
- seq_printf(seq, "%u\n", s->num_closid);
- return 0;
-}
-
-static int rdt_default_ctrl_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
- struct rdt_resource *r = s->res;
-
- seq_printf(seq, "%x\n", resctrl_get_default_ctrl(r));
- return 0;
-}
-
-static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
- struct rdt_resource *r = s->res;
-
- seq_printf(seq, "%u\n", r->cache.min_cbm_bits);
- return 0;
-}
-
-static int rdt_shareable_bits_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
- struct rdt_resource *r = s->res;
-
- seq_printf(seq, "%x\n", r->cache.shareable_bits);
- return 0;
-}
-
-/*
- * rdt_bit_usage_show - Display current usage of resources
- *
- * A domain is a shared resource that can now be allocated differently. Here
- * we display the current regions of the domain as an annotated bitmask.
- * For each domain of this resource its allocation bitmask
- * is annotated as below to indicate the current usage of the corresponding bit:
- * 0 - currently unused
- * X - currently available for sharing and used by software and hardware
- * H - currently used by hardware only but available for software use
- * S - currently used and shareable by software only
- * E - currently used exclusively by one resource group
- * P - currently pseudo-locked by one resource group
- */
-static int rdt_bit_usage_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
- /*
- * Use unsigned long even though only 32 bits are used to ensure
- * test_bit() is used safely.
- */
- unsigned long sw_shareable = 0, hw_shareable = 0;
- unsigned long exclusive = 0, pseudo_locked = 0;
- struct rdt_resource *r = s->res;
- struct rdt_ctrl_domain *dom;
- int i, hwb, swb, excl, psl;
- enum rdtgrp_mode mode;
- bool sep = false;
- u32 ctrl_val;
-
- cpus_read_lock();
- mutex_lock(&rdtgroup_mutex);
- hw_shareable = r->cache.shareable_bits;
- list_for_each_entry(dom, &r->ctrl_domains, hdr.list) {
- if (sep)
- seq_putc(seq, ';');
- sw_shareable = 0;
- exclusive = 0;
- seq_printf(seq, "%d=", dom->hdr.id);
- for (i = 0; i < closids_supported(); i++) {
- if (!closid_allocated(i))
- continue;
- ctrl_val = resctrl_arch_get_config(r, dom, i,
- s->conf_type);
- mode = rdtgroup_mode_by_closid(i);
- switch (mode) {
- case RDT_MODE_SHAREABLE:
- sw_shareable |= ctrl_val;
- break;
- case RDT_MODE_EXCLUSIVE:
- exclusive |= ctrl_val;
- break;
- case RDT_MODE_PSEUDO_LOCKSETUP:
- /*
- * RDT_MODE_PSEUDO_LOCKSETUP is possible
- * here but not included since the CBM
- * associated with this CLOSID in this mode
- * is not initialized and no task or cpu can be
- * assigned this CLOSID.
- */
- break;
- case RDT_MODE_PSEUDO_LOCKED:
- case RDT_NUM_MODES:
- WARN(1,
- "invalid mode for closid %d\n", i);
- break;
- }
- }
- for (i = r->cache.cbm_len - 1; i >= 0; i--) {
- pseudo_locked = dom->plr ? dom->plr->cbm : 0;
- hwb = test_bit(i, &hw_shareable);
- swb = test_bit(i, &sw_shareable);
- excl = test_bit(i, &exclusive);
- psl = test_bit(i, &pseudo_locked);
- if (hwb && swb)
- seq_putc(seq, 'X');
- else if (hwb && !swb)
- seq_putc(seq, 'H');
- else if (!hwb && swb)
- seq_putc(seq, 'S');
- else if (excl)
- seq_putc(seq, 'E');
- else if (psl)
- seq_putc(seq, 'P');
- else /* Unused bits remain */
- seq_putc(seq, '0');
- }
- sep = true;
- }
- seq_putc(seq, '\n');
- mutex_unlock(&rdtgroup_mutex);
- cpus_read_unlock();
- return 0;
-}
-
-static int rdt_min_bw_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
- struct rdt_resource *r = s->res;
-
- seq_printf(seq, "%u\n", r->membw.min_bw);
- return 0;
-}
-
-static int rdt_num_rmids_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
-
- seq_printf(seq, "%d\n", r->num_rmid);
-
- return 0;
-}
-
-static int rdt_mon_features_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
- struct mon_evt *mevt;
-
- list_for_each_entry(mevt, &r->evt_list, list) {
- seq_printf(seq, "%s\n", mevt->name);
- if (mevt->configurable)
- seq_printf(seq, "%s_config\n", mevt->name);
- }
-
- return 0;
-}
-
-static int rdt_bw_gran_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
- struct rdt_resource *r = s->res;
-
- seq_printf(seq, "%u\n", r->membw.bw_gran);
- return 0;
-}
-
-static int rdt_delay_linear_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
- struct rdt_resource *r = s->res;
-
- seq_printf(seq, "%u\n", r->membw.delay_linear);
- return 0;
-}
-
-static int max_threshold_occ_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- seq_printf(seq, "%u\n", resctrl_rmid_realloc_threshold);
-
- return 0;
-}
-
-static int rdt_thread_throttle_mode_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
- struct rdt_resource *r = s->res;
-
- switch (r->membw.throttle_mode) {
- case THREAD_THROTTLE_PER_THREAD:
- seq_puts(seq, "per-thread\n");
- return 0;
- case THREAD_THROTTLE_MAX:
- seq_puts(seq, "max\n");
- return 0;
- case THREAD_THROTTLE_UNDEFINED:
- seq_puts(seq, "undefined\n");
- return 0;
- }
-
- WARN_ON_ONCE(1);
-
- return 0;
-}
-
-static ssize_t max_threshold_occ_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
-{
- unsigned int bytes;
- int ret;
-
- ret = kstrtouint(buf, 0, &bytes);
- if (ret)
- return ret;
-
- if (bytes > resctrl_rmid_realloc_limit)
- return -EINVAL;
-
- resctrl_rmid_realloc_threshold = resctrl_arch_round_mon_val(bytes);
-
- return nbytes;
-}
-
-/*
- * rdtgroup_mode_show - Display mode of this resource group
- */
-static int rdtgroup_mode_show(struct kernfs_open_file *of,
- struct seq_file *s, void *v)
-{
- struct rdtgroup *rdtgrp;
-
- rdtgrp = rdtgroup_kn_lock_live(of->kn);
- if (!rdtgrp) {
- rdtgroup_kn_unlock(of->kn);
- return -ENOENT;
- }
-
- seq_printf(s, "%s\n", rdtgroup_mode_str(rdtgrp->mode));
-
- rdtgroup_kn_unlock(of->kn);
- return 0;
-}
-
-static enum resctrl_conf_type resctrl_peer_type(enum resctrl_conf_type my_type)
-{
- switch (my_type) {
- case CDP_CODE:
- return CDP_DATA;
- case CDP_DATA:
- return CDP_CODE;
- default:
- case CDP_NONE:
- return CDP_NONE;
- }
-}
-
-static int rdt_has_sparse_bitmasks_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
- struct rdt_resource *r = s->res;
-
- seq_printf(seq, "%u\n", r->cache.arch_has_sparse_bitmasks);
-
- return 0;
-}
-
-/**
- * __rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other
- * @r: Resource to which domain instance @d belongs.
- * @d: The domain instance for which @closid is being tested.
- * @cbm: Capacity bitmask being tested.
- * @closid: Intended closid for @cbm.
- * @type: CDP type of @r.
- * @exclusive: Only check if overlaps with exclusive resource groups
- *
- * Checks if provided @cbm intended to be used for @closid on domain
- * @d overlaps with any other closids or other hardware usage associated
- * with this domain. If @exclusive is true then only overlaps with
- * resource groups in exclusive mode will be considered. If @exclusive
- * is false then overlaps with any resource group or hardware entities
- * will be considered.
- *
- * @cbm is unsigned long, even if only 32 bits are used, to make the
- * bitmap functions work correctly.
- *
- * Return: false if CBM does not overlap, true if it does.
- */
-static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_ctrl_domain *d,
- unsigned long cbm, int closid,
- enum resctrl_conf_type type, bool exclusive)
-{
- enum rdtgrp_mode mode;
- unsigned long ctrl_b;
- int i;
-
- /* Check for any overlap with regions used by hardware directly */
- if (!exclusive) {
- ctrl_b = r->cache.shareable_bits;
- if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len))
- return true;
- }
-
- /* Check for overlap with other resource groups */
- for (i = 0; i < closids_supported(); i++) {
- ctrl_b = resctrl_arch_get_config(r, d, i, type);
- mode = rdtgroup_mode_by_closid(i);
- if (closid_allocated(i) && i != closid &&
- mode != RDT_MODE_PSEUDO_LOCKSETUP) {
- if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) {
- if (exclusive) {
- if (mode == RDT_MODE_EXCLUSIVE)
- return true;
- continue;
- }
- return true;
- }
- }
- }
-
- return false;
-}
-
-/**
- * rdtgroup_cbm_overlaps - Does CBM overlap with other use of hardware
- * @s: Schema for the resource to which domain instance @d belongs.
- * @d: The domain instance for which @closid is being tested.
- * @cbm: Capacity bitmask being tested.
- * @closid: Intended closid for @cbm.
- * @exclusive: Only check if overlaps with exclusive resource groups
- *
- * Resources that can be allocated using a CBM can use the CBM to control
- * the overlap of these allocations. rdtgroup_cmb_overlaps() is the test
- * for overlap. Overlap test is not limited to the specific resource for
- * which the CBM is intended though - when dealing with CDP resources that
- * share the underlying hardware the overlap check should be performed on
- * the CDP resource sharing the hardware also.
- *
- * Refer to description of __rdtgroup_cbm_overlaps() for the details of the
- * overlap test.
- *
- * Return: true if CBM overlap detected, false if there is no overlap
- */
-bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_ctrl_domain *d,
- unsigned long cbm, int closid, bool exclusive)
-{
- enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type);
- struct rdt_resource *r = s->res;
-
- if (__rdtgroup_cbm_overlaps(r, d, cbm, closid, s->conf_type,
- exclusive))
- return true;
-
- if (!resctrl_arch_get_cdp_enabled(r->rid))
- return false;
- return __rdtgroup_cbm_overlaps(r, d, cbm, closid, peer_type, exclusive);
-}
-
-/**
- * rdtgroup_mode_test_exclusive - Test if this resource group can be exclusive
- * @rdtgrp: Resource group identified through its closid.
- *
- * An exclusive resource group implies that there should be no sharing of
- * its allocated resources. At the time this group is considered to be
- * exclusive this test can determine if its current schemata supports this
- * setting by testing for overlap with all other resource groups.
- *
- * Return: true if resource group can be exclusive, false if there is overlap
- * with allocations of other resource groups and thus this resource group
- * cannot be exclusive.
- */
-static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp)
-{
- int closid = rdtgrp->closid;
- struct rdt_ctrl_domain *d;
- struct resctrl_schema *s;
- struct rdt_resource *r;
- bool has_cache = false;
- u32 ctrl;
-
- /* Walking r->domains, ensure it can't race with cpuhp */
- lockdep_assert_cpus_held();
-
- list_for_each_entry(s, &resctrl_schema_all, list) {
- r = s->res;
- if (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA)
- continue;
- has_cache = true;
- list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
- ctrl = resctrl_arch_get_config(r, d, closid,
- s->conf_type);
- if (rdtgroup_cbm_overlaps(s, d, ctrl, closid, false)) {
- rdt_last_cmd_puts("Schemata overlaps\n");
- return false;
- }
- }
- }
-
- if (!has_cache) {
- rdt_last_cmd_puts("Cannot be exclusive without CAT/CDP\n");
- return false;
- }
-
- return true;
-}
-
-/*
- * rdtgroup_mode_write - Modify the resource group's mode
- */
-static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
-{
- struct rdtgroup *rdtgrp;
- enum rdtgrp_mode mode;
- int ret = 0;
-
- /* Valid input requires a trailing newline */
- if (nbytes == 0 || buf[nbytes - 1] != '\n')
- return -EINVAL;
- buf[nbytes - 1] = '\0';
-
- rdtgrp = rdtgroup_kn_lock_live(of->kn);
- if (!rdtgrp) {
- rdtgroup_kn_unlock(of->kn);
- return -ENOENT;
- }
-
- rdt_last_cmd_clear();
-
- mode = rdtgrp->mode;
-
- if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) ||
- (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE) ||
- (!strcmp(buf, "pseudo-locksetup") &&
- mode == RDT_MODE_PSEUDO_LOCKSETUP) ||
- (!strcmp(buf, "pseudo-locked") && mode == RDT_MODE_PSEUDO_LOCKED))
- goto out;
-
- if (mode == RDT_MODE_PSEUDO_LOCKED) {
- rdt_last_cmd_puts("Cannot change pseudo-locked group\n");
- ret = -EINVAL;
- goto out;
- }
-
- if (!strcmp(buf, "shareable")) {
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
- ret = rdtgroup_locksetup_exit(rdtgrp);
- if (ret)
- goto out;
- }
- rdtgrp->mode = RDT_MODE_SHAREABLE;
- } else if (!strcmp(buf, "exclusive")) {
- if (!rdtgroup_mode_test_exclusive(rdtgrp)) {
- ret = -EINVAL;
- goto out;
- }
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
- ret = rdtgroup_locksetup_exit(rdtgrp);
- if (ret)
- goto out;
- }
- rdtgrp->mode = RDT_MODE_EXCLUSIVE;
- } else if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK) &&
- !strcmp(buf, "pseudo-locksetup")) {
- ret = rdtgroup_locksetup_enter(rdtgrp);
- if (ret)
- goto out;
- rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP;
- } else {
- rdt_last_cmd_puts("Unknown or unsupported mode\n");
- ret = -EINVAL;
- }
-
-out:
- rdtgroup_kn_unlock(of->kn);
- return ret ?: nbytes;
-}
-
-/**
- * rdtgroup_cbm_to_size - Translate CBM to size in bytes
- * @r: RDT resource to which @d belongs.
- * @d: RDT domain instance.
- * @cbm: bitmask for which the size should be computed.
- *
- * The bitmask provided associated with the RDT domain instance @d will be
- * translated into how many bytes it represents. The size in bytes is
- * computed by first dividing the total cache size by the CBM length to
- * determine how many bytes each bit in the bitmask represents. The result
- * is multiplied with the number of bits set in the bitmask.
- *
- * @cbm is unsigned long, even if only 32 bits are used to make the
- * bitmap functions work correctly.
- */
-unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r,
- struct rdt_ctrl_domain *d, unsigned long cbm)
-{
- unsigned int size = 0;
- struct cacheinfo *ci;
- int num_b;
-
- if (WARN_ON_ONCE(r->ctrl_scope != RESCTRL_L2_CACHE && r->ctrl_scope != RESCTRL_L3_CACHE))
- return size;
-
- num_b = bitmap_weight(&cbm, r->cache.cbm_len);
- ci = get_cpu_cacheinfo_level(cpumask_any(&d->hdr.cpu_mask), r->ctrl_scope);
- if (ci)
- size = ci->size / r->cache.cbm_len * num_b;
-
- return size;
-}
-
-bool is_mba_sc(struct rdt_resource *r)
-{
- if (!r)
- r = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
-
- /*
- * The software controller support is only applicable to MBA resource.
- * Make sure to check for resource type.
- */
- if (r->rid != RDT_RESOURCE_MBA)
- return false;
-
- return r->membw.mba_sc;
-}
-
-/*
- * rdtgroup_size_show - Display size in bytes of allocated regions
- *
- * The "size" file mirrors the layout of the "schemata" file, printing the
- * size in bytes of each region instead of the capacity bitmask.
- */
-static int rdtgroup_size_show(struct kernfs_open_file *of,
- struct seq_file *s, void *v)
-{
- struct resctrl_schema *schema;
- enum resctrl_conf_type type;
- struct rdt_ctrl_domain *d;
- struct rdtgroup *rdtgrp;
- struct rdt_resource *r;
- unsigned int size;
- int ret = 0;
- u32 closid;
- bool sep;
- u32 ctrl;
-
- rdtgrp = rdtgroup_kn_lock_live(of->kn);
- if (!rdtgrp) {
- rdtgroup_kn_unlock(of->kn);
- return -ENOENT;
- }
-
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
- if (!rdtgrp->plr->d) {
- rdt_last_cmd_clear();
- rdt_last_cmd_puts("Cache domain offline\n");
- ret = -ENODEV;
- } else {
- seq_printf(s, "%*s:", max_name_width,
- rdtgrp->plr->s->name);
- size = rdtgroup_cbm_to_size(rdtgrp->plr->s->res,
- rdtgrp->plr->d,
- rdtgrp->plr->cbm);
- seq_printf(s, "%d=%u\n", rdtgrp->plr->d->hdr.id, size);
- }
- goto out;
- }
-
- closid = rdtgrp->closid;
-
- list_for_each_entry(schema, &resctrl_schema_all, list) {
- r = schema->res;
- type = schema->conf_type;
- sep = false;
- seq_printf(s, "%*s:", max_name_width, schema->name);
- list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
- if (sep)
- seq_putc(s, ';');
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
- size = 0;
- } else {
- if (is_mba_sc(r))
- ctrl = d->mbps_val[closid];
- else
- ctrl = resctrl_arch_get_config(r, d,
- closid,
- type);
- if (r->rid == RDT_RESOURCE_MBA ||
- r->rid == RDT_RESOURCE_SMBA)
- size = ctrl;
- else
- size = rdtgroup_cbm_to_size(r, d, ctrl);
- }
- seq_printf(s, "%d=%u", d->hdr.id, size);
- sep = true;
- }
- seq_putc(s, '\n');
- }
-
-out:
- rdtgroup_kn_unlock(of->kn);
-
- return ret;
-}
-
-#define INVALID_CONFIG_INDEX UINT_MAX
-
-/**
- * mon_event_config_index_get - get the hardware index for the
- * configurable event
- * @evtid: event id.
- *
- * Return: 0 for evtid == QOS_L3_MBM_TOTAL_EVENT_ID
- * 1 for evtid == QOS_L3_MBM_LOCAL_EVENT_ID
- * INVALID_CONFIG_INDEX for invalid evtid
- */
-static inline unsigned int mon_event_config_index_get(u32 evtid)
-{
- switch (evtid) {
- case QOS_L3_MBM_TOTAL_EVENT_ID:
- return 0;
- case QOS_L3_MBM_LOCAL_EVENT_ID:
- return 1;
- default:
- /* Should never reach here */
- return INVALID_CONFIG_INDEX;
- }
-}
-
-void resctrl_arch_mon_event_config_read(void *_config_info)
-{
- struct resctrl_mon_config_info *config_info = _config_info;
- unsigned int index;
- u64 msrval;
-
- index = mon_event_config_index_get(config_info->evtid);
- if (index == INVALID_CONFIG_INDEX) {
- pr_warn_once("Invalid event id %d\n", config_info->evtid);
- return;
- }
- rdmsrl(MSR_IA32_EVT_CFG_BASE + index, msrval);
-
- /* Report only the valid event configuration bits */
- config_info->mon_config = msrval & MAX_EVT_CONFIG_BITS;
-}
-
-static void mondata_config_read(struct resctrl_mon_config_info *mon_info)
-{
- smp_call_function_any(&mon_info->d->hdr.cpu_mask,
- resctrl_arch_mon_event_config_read, mon_info, 1);
-}
-
-static int mbm_config_show(struct seq_file *s, struct rdt_resource *r, u32 evtid)
-{
- struct resctrl_mon_config_info mon_info;
- struct rdt_mon_domain *dom;
- bool sep = false;
-
- cpus_read_lock();
- mutex_lock(&rdtgroup_mutex);
-
- list_for_each_entry(dom, &r->mon_domains, hdr.list) {
- if (sep)
- seq_puts(s, ";");
-
- memset(&mon_info, 0, sizeof(struct resctrl_mon_config_info));
- mon_info.r = r;
- mon_info.d = dom;
- mon_info.evtid = evtid;
- mondata_config_read(&mon_info);
-
- seq_printf(s, "%d=0x%02x", dom->hdr.id, mon_info.mon_config);
- sep = true;
- }
- seq_puts(s, "\n");
-
- mutex_unlock(&rdtgroup_mutex);
- cpus_read_unlock();
-
- return 0;
-}
-
-static int mbm_total_bytes_config_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
-
- mbm_config_show(seq, r, QOS_L3_MBM_TOTAL_EVENT_ID);
-
- return 0;
-}
-
-static int mbm_local_bytes_config_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
-{
- struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
-
- mbm_config_show(seq, r, QOS_L3_MBM_LOCAL_EVENT_ID);
-
- return 0;
-}
-
-void resctrl_arch_mon_event_config_write(void *_config_info)
-{
- struct resctrl_mon_config_info *config_info = _config_info;
- unsigned int index;
-
- index = mon_event_config_index_get(config_info->evtid);
- if (index == INVALID_CONFIG_INDEX) {
- pr_warn_once("Invalid event id %d\n", config_info->evtid);
- return;
- }
- wrmsr(MSR_IA32_EVT_CFG_BASE + index, config_info->mon_config, 0);
-}
-
-static void mbm_config_write_domain(struct rdt_resource *r,
- struct rdt_mon_domain *d, u32 evtid, u32 val)
-{
- struct resctrl_mon_config_info mon_info = {0};
-
- /*
- * Read the current config value first. If both are the same then
- * no need to write it again.
- */
- mon_info.r = r;
- mon_info.d = d;
- mon_info.evtid = evtid;
- mondata_config_read(&mon_info);
- if (mon_info.mon_config == val)
- return;
-
- mon_info.mon_config = val;
-
- /*
- * Update MSR_IA32_EVT_CFG_BASE MSR on one of the CPUs in the
- * domain. The MSRs offset from MSR MSR_IA32_EVT_CFG_BASE
- * are scoped at the domain level. Writing any of these MSRs
- * on one CPU is observed by all the CPUs in the domain.
- */
- smp_call_function_any(&d->hdr.cpu_mask, resctrl_arch_mon_event_config_write,
- &mon_info, 1);
-
- /*
- * When an Event Configuration is changed, the bandwidth counters
- * for all RMIDs and Events will be cleared by the hardware. The
- * hardware also sets MSR_IA32_QM_CTR.Unavailable (bit 62) for
- * every RMID on the next read to any event for every RMID.
- * Subsequent reads will have MSR_IA32_QM_CTR.Unavailable (bit 62)
- * cleared while it is tracked by the hardware. Clear the
- * mbm_local and mbm_total counts for all the RMIDs.
- */
- resctrl_arch_reset_rmid_all(r, d);
-}
-
-static int mon_config_write(struct rdt_resource *r, char *tok, u32 evtid)
-{
- char *dom_str = NULL, *id_str;
- unsigned long dom_id, val;
- struct rdt_mon_domain *d;
-
- /* Walking r->domains, ensure it can't race with cpuhp */
- lockdep_assert_cpus_held();
-
-next:
- if (!tok || tok[0] == '\0')
- return 0;
-
- /* Start processing the strings for each domain */
- dom_str = strim(strsep(&tok, ";"));
- id_str = strsep(&dom_str, "=");
-
- if (!id_str || kstrtoul(id_str, 10, &dom_id)) {
- rdt_last_cmd_puts("Missing '=' or non-numeric domain id\n");
- return -EINVAL;
- }
-
- if (!dom_str || kstrtoul(dom_str, 16, &val)) {
- rdt_last_cmd_puts("Non-numeric event configuration value\n");
- return -EINVAL;
- }
-
- /* Value from user cannot be more than the supported set of events */
- if ((val & r->mbm_cfg_mask) != val) {
- rdt_last_cmd_printf("Invalid event configuration: max valid mask is 0x%02x\n",
- r->mbm_cfg_mask);
- return -EINVAL;
- }
-
- list_for_each_entry(d, &r->mon_domains, hdr.list) {
- if (d->hdr.id == dom_id) {
- mbm_config_write_domain(r, d, evtid, val);
- goto next;
- }
- }
-
- return -EINVAL;
-}
-
-static ssize_t mbm_total_bytes_config_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes,
- loff_t off)
-{
- struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
- int ret;
-
- /* Valid input requires a trailing newline */
- if (nbytes == 0 || buf[nbytes - 1] != '\n')
- return -EINVAL;
-
- cpus_read_lock();
- mutex_lock(&rdtgroup_mutex);
-
- rdt_last_cmd_clear();
-
- buf[nbytes - 1] = '\0';
-
- ret = mon_config_write(r, buf, QOS_L3_MBM_TOTAL_EVENT_ID);
-
- mutex_unlock(&rdtgroup_mutex);
- cpus_read_unlock();
-
- return ret ?: nbytes;
-}
-
-static ssize_t mbm_local_bytes_config_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes,
- loff_t off)
-{
- struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
- int ret;
-
- /* Valid input requires a trailing newline */
- if (nbytes == 0 || buf[nbytes - 1] != '\n')
- return -EINVAL;
-
- cpus_read_lock();
- mutex_lock(&rdtgroup_mutex);
-
- rdt_last_cmd_clear();
-
- buf[nbytes - 1] = '\0';
-
- ret = mon_config_write(r, buf, QOS_L3_MBM_LOCAL_EVENT_ID);
-
- mutex_unlock(&rdtgroup_mutex);
- cpus_read_unlock();
-
- return ret ?: nbytes;
-}
-
-/* rdtgroup information files for one cache resource. */
-static struct rftype res_common_files[] = {
- {
- .name = "last_cmd_status",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdt_last_cmd_status_show,
- .fflags = RFTYPE_TOP_INFO,
- },
- {
- .name = "num_closids",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdt_num_closids_show,
- .fflags = RFTYPE_CTRL_INFO,
- },
- {
- .name = "mon_features",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdt_mon_features_show,
- .fflags = RFTYPE_MON_INFO,
- },
- {
- .name = "num_rmids",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdt_num_rmids_show,
- .fflags = RFTYPE_MON_INFO,
- },
- {
- .name = "cbm_mask",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdt_default_ctrl_show,
- .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
- },
- {
- .name = "min_cbm_bits",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdt_min_cbm_bits_show,
- .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
- },
- {
- .name = "shareable_bits",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdt_shareable_bits_show,
- .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
- },
- {
- .name = "bit_usage",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdt_bit_usage_show,
- .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
- },
- {
- .name = "min_bandwidth",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdt_min_bw_show,
- .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB,
- },
- {
- .name = "bandwidth_gran",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdt_bw_gran_show,
- .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB,
- },
- {
- .name = "delay_linear",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdt_delay_linear_show,
- .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB,
- },
- /*
- * Platform specific which (if any) capabilities are provided by
- * thread_throttle_mode. Defer "fflags" initialization to platform
- * discovery.
- */
- {
- .name = "thread_throttle_mode",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdt_thread_throttle_mode_show,
- },
- {
- .name = "max_threshold_occupancy",
- .mode = 0644,
- .kf_ops = &rdtgroup_kf_single_ops,
- .write = max_threshold_occ_write,
- .seq_show = max_threshold_occ_show,
- .fflags = RFTYPE_MON_INFO | RFTYPE_RES_CACHE,
- },
- {
- .name = "mbm_total_bytes_config",
- .mode = 0644,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = mbm_total_bytes_config_show,
- .write = mbm_total_bytes_config_write,
- },
- {
- .name = "mbm_local_bytes_config",
- .mode = 0644,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = mbm_local_bytes_config_show,
- .write = mbm_local_bytes_config_write,
- },
- {
- .name = "cpus",
- .mode = 0644,
- .kf_ops = &rdtgroup_kf_single_ops,
- .write = rdtgroup_cpus_write,
- .seq_show = rdtgroup_cpus_show,
- .fflags = RFTYPE_BASE,
- },
- {
- .name = "cpus_list",
- .mode = 0644,
- .kf_ops = &rdtgroup_kf_single_ops,
- .write = rdtgroup_cpus_write,
- .seq_show = rdtgroup_cpus_show,
- .flags = RFTYPE_FLAGS_CPUS_LIST,
- .fflags = RFTYPE_BASE,
- },
- {
- .name = "tasks",
- .mode = 0644,
- .kf_ops = &rdtgroup_kf_single_ops,
- .write = rdtgroup_tasks_write,
- .seq_show = rdtgroup_tasks_show,
- .fflags = RFTYPE_BASE,
- },
- {
- .name = "mon_hw_id",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdtgroup_rmid_show,
- .fflags = RFTYPE_MON_BASE | RFTYPE_DEBUG,
- },
- {
- .name = "schemata",
- .mode = 0644,
- .kf_ops = &rdtgroup_kf_single_ops,
- .write = rdtgroup_schemata_write,
- .seq_show = rdtgroup_schemata_show,
- .fflags = RFTYPE_CTRL_BASE,
- },
- {
- .name = "mba_MBps_event",
- .mode = 0644,
- .kf_ops = &rdtgroup_kf_single_ops,
- .write = rdtgroup_mba_mbps_event_write,
- .seq_show = rdtgroup_mba_mbps_event_show,
- },
- {
- .name = "mode",
- .mode = 0644,
- .kf_ops = &rdtgroup_kf_single_ops,
- .write = rdtgroup_mode_write,
- .seq_show = rdtgroup_mode_show,
- .fflags = RFTYPE_CTRL_BASE,
- },
- {
- .name = "size",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdtgroup_size_show,
- .fflags = RFTYPE_CTRL_BASE,
- },
- {
- .name = "sparse_masks",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdt_has_sparse_bitmasks_show,
- .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
- },
- {
- .name = "ctrl_hw_id",
- .mode = 0444,
- .kf_ops = &rdtgroup_kf_single_ops,
- .seq_show = rdtgroup_closid_show,
- .fflags = RFTYPE_CTRL_BASE | RFTYPE_DEBUG,
- },
-};
-
-static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags)
-{
- struct rftype *rfts, *rft;
- int ret, len;
-
- rfts = res_common_files;
- len = ARRAY_SIZE(res_common_files);
-
- lockdep_assert_held(&rdtgroup_mutex);
-
- if (resctrl_debug)
- fflags |= RFTYPE_DEBUG;
-
- for (rft = rfts; rft < rfts + len; rft++) {
- if (rft->fflags && ((fflags & rft->fflags) == rft->fflags)) {
- ret = rdtgroup_add_file(kn, rft);
- if (ret)
- goto error;
- }
- }
-
- return 0;
-error:
- pr_warn("Failed to add %s, err=%d\n", rft->name, ret);
- while (--rft >= rfts) {
- if ((fflags & rft->fflags) == rft->fflags)
- kernfs_remove_by_name(kn, rft->name);
- }
- return ret;
-}
-
-static struct rftype *rdtgroup_get_rftype_by_name(const char *name)
-{
- struct rftype *rfts, *rft;
- int len;
-
- rfts = res_common_files;
- len = ARRAY_SIZE(res_common_files);
-
- for (rft = rfts; rft < rfts + len; rft++) {
- if (!strcmp(rft->name, name))
- return rft;
- }
-
- return NULL;
-}
-
-static void thread_throttle_mode_init(void)
-{
- enum membw_throttle_mode throttle_mode = THREAD_THROTTLE_UNDEFINED;
- struct rdt_resource *r_mba, *r_smba;
-
- r_mba = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
- if (r_mba->alloc_capable &&
- r_mba->membw.throttle_mode != THREAD_THROTTLE_UNDEFINED)
- throttle_mode = r_mba->membw.throttle_mode;
-
- r_smba = resctrl_arch_get_resource(RDT_RESOURCE_SMBA);
- if (r_smba->alloc_capable &&
- r_smba->membw.throttle_mode != THREAD_THROTTLE_UNDEFINED)
- throttle_mode = r_smba->membw.throttle_mode;
-
- if (throttle_mode == THREAD_THROTTLE_UNDEFINED)
- return;
-
- resctrl_file_fflags_init("thread_throttle_mode",
- RFTYPE_CTRL_INFO | RFTYPE_RES_MB);
-}
-
-void resctrl_file_fflags_init(const char *config, unsigned long fflags)
-{
- struct rftype *rft;
-
- rft = rdtgroup_get_rftype_by_name(config);
- if (rft)
- rft->fflags = fflags;
-}
-
-/**
- * rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file
- * @r: The resource group with which the file is associated.
- * @name: Name of the file
- *
- * The permissions of named resctrl file, directory, or link are modified
- * to not allow read, write, or execute by any user.
- *
- * WARNING: This function is intended to communicate to the user that the
- * resctrl file has been locked down - that it is not relevant to the
- * particular state the system finds itself in. It should not be relied
- * on to protect from user access because after the file's permissions
- * are restricted the user can still change the permissions using chmod
- * from the command line.
- *
- * Return: 0 on success, <0 on failure.
- */
-int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name)
-{
- struct iattr iattr = {.ia_valid = ATTR_MODE,};
- struct kernfs_node *kn;
- int ret = 0;
-
- kn = kernfs_find_and_get_ns(r->kn, name, NULL);
- if (!kn)
- return -ENOENT;
-
- switch (kernfs_type(kn)) {
- case KERNFS_DIR:
- iattr.ia_mode = S_IFDIR;
- break;
- case KERNFS_FILE:
- iattr.ia_mode = S_IFREG;
- break;
- case KERNFS_LINK:
- iattr.ia_mode = S_IFLNK;
- break;
- }
-
- ret = kernfs_setattr(kn, &iattr);
- kernfs_put(kn);
- return ret;
-}
-
-/**
- * rdtgroup_kn_mode_restore - Restore user access to named resctrl file
- * @r: The resource group with which the file is associated.
- * @name: Name of the file
- * @mask: Mask of permissions that should be restored
- *
- * Restore the permissions of the named file. If @name is a directory the
- * permissions of its parent will be used.
- *
- * Return: 0 on success, <0 on failure.
- */
-int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name,
- umode_t mask)
-{
- struct iattr iattr = {.ia_valid = ATTR_MODE,};
- struct kernfs_node *kn, *parent;
- struct rftype *rfts, *rft;
- int ret, len;
-
- rfts = res_common_files;
- len = ARRAY_SIZE(res_common_files);
-
- for (rft = rfts; rft < rfts + len; rft++) {
- if (!strcmp(rft->name, name))
- iattr.ia_mode = rft->mode & mask;
- }
-
- kn = kernfs_find_and_get_ns(r->kn, name, NULL);
- if (!kn)
- return -ENOENT;
-
- switch (kernfs_type(kn)) {
- case KERNFS_DIR:
- parent = kernfs_get_parent(kn);
- if (parent) {
- iattr.ia_mode |= parent->mode;
- kernfs_put(parent);
- }
- iattr.ia_mode |= S_IFDIR;
- break;
- case KERNFS_FILE:
- iattr.ia_mode |= S_IFREG;
- break;
- case KERNFS_LINK:
- iattr.ia_mode |= S_IFLNK;
- break;
- }
-
- ret = kernfs_setattr(kn, &iattr);
- kernfs_put(kn);
- return ret;
-}
-
-static int rdtgroup_mkdir_info_resdir(void *priv, char *name,
- unsigned long fflags)
-{
- struct kernfs_node *kn_subdir;
- int ret;
-
- kn_subdir = kernfs_create_dir(kn_info, name,
- kn_info->mode, priv);
- if (IS_ERR(kn_subdir))
- return PTR_ERR(kn_subdir);
-
- ret = rdtgroup_kn_set_ugid(kn_subdir);
- if (ret)
- return ret;
-
- ret = rdtgroup_add_files(kn_subdir, fflags);
- if (!ret)
- kernfs_activate(kn_subdir);
-
- return ret;
-}
-
-static unsigned long fflags_from_resource(struct rdt_resource *r)
-{
- switch (r->rid) {
- case RDT_RESOURCE_L3:
- case RDT_RESOURCE_L2:
- return RFTYPE_RES_CACHE;
- case RDT_RESOURCE_MBA:
- case RDT_RESOURCE_SMBA:
- return RFTYPE_RES_MB;
- }
-
- return WARN_ON_ONCE(1);
-}
-
-static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
-{
- struct resctrl_schema *s;
- struct rdt_resource *r;
- unsigned long fflags;
- char name[32];
- int ret;
-
- /* create the directory */
- kn_info = kernfs_create_dir(parent_kn, "info", parent_kn->mode, NULL);
- if (IS_ERR(kn_info))
- return PTR_ERR(kn_info);
-
- ret = rdtgroup_add_files(kn_info, RFTYPE_TOP_INFO);
- if (ret)
- goto out_destroy;
-
- /* loop over enabled controls, these are all alloc_capable */
- list_for_each_entry(s, &resctrl_schema_all, list) {
- r = s->res;
- fflags = fflags_from_resource(r) | RFTYPE_CTRL_INFO;
- ret = rdtgroup_mkdir_info_resdir(s, s->name, fflags);
- if (ret)
- goto out_destroy;
- }
-
- for_each_mon_capable_rdt_resource(r) {
- fflags = fflags_from_resource(r) | RFTYPE_MON_INFO;
- sprintf(name, "%s_MON", r->name);
- ret = rdtgroup_mkdir_info_resdir(r, name, fflags);
- if (ret)
- goto out_destroy;
- }
-
- ret = rdtgroup_kn_set_ugid(kn_info);
- if (ret)
- goto out_destroy;
-
- kernfs_activate(kn_info);
-
- return 0;
-
-out_destroy:
- kernfs_remove(kn_info);
- return ret;
-}
-
-static int
-mongroup_create_dir(struct kernfs_node *parent_kn, struct rdtgroup *prgrp,
- char *name, struct kernfs_node **dest_kn)
-{
- struct kernfs_node *kn;
- int ret;
-
- /* create the directory */
- kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
- if (IS_ERR(kn))
- return PTR_ERR(kn);
-
- if (dest_kn)
- *dest_kn = kn;
-
- ret = rdtgroup_kn_set_ugid(kn);
- if (ret)
- goto out_destroy;
-
- kernfs_activate(kn);
-
- return 0;
-
-out_destroy:
- kernfs_remove(kn);
- return ret;
-}
-
-static void l3_qos_cfg_update(void *arg)
-{
- bool *enable = arg;
-
- wrmsrl(MSR_IA32_L3_QOS_CFG, *enable ? L3_QOS_CDP_ENABLE : 0ULL);
-}
-
-static void l2_qos_cfg_update(void *arg)
-{
- bool *enable = arg;
-
- wrmsrl(MSR_IA32_L2_QOS_CFG, *enable ? L2_QOS_CDP_ENABLE : 0ULL);
-}
-
-static inline bool is_mba_linear(void)
-{
- return resctrl_arch_get_resource(RDT_RESOURCE_MBA)->membw.delay_linear;
-}
-
-static int set_cache_qos_cfg(int level, bool enable)
-{
- void (*update)(void *arg);
- struct rdt_ctrl_domain *d;
- struct rdt_resource *r_l;
- cpumask_var_t cpu_mask;
- int cpu;
-
- /* Walking r->domains, ensure it can't race with cpuhp */
- lockdep_assert_cpus_held();
-
- if (level == RDT_RESOURCE_L3)
- update = l3_qos_cfg_update;
- else if (level == RDT_RESOURCE_L2)
- update = l2_qos_cfg_update;
- else
- return -EINVAL;
-
- if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
- return -ENOMEM;
-
- r_l = &rdt_resources_all[level].r_resctrl;
- list_for_each_entry(d, &r_l->ctrl_domains, hdr.list) {
- if (r_l->cache.arch_has_per_cpu_cfg)
- /* Pick all the CPUs in the domain instance */
- for_each_cpu(cpu, &d->hdr.cpu_mask)
- cpumask_set_cpu(cpu, cpu_mask);
- else
- /* Pick one CPU from each domain instance to update MSR */
- cpumask_set_cpu(cpumask_any(&d->hdr.cpu_mask), cpu_mask);
- }
-
- /* Update QOS_CFG MSR on all the CPUs in cpu_mask */
- on_each_cpu_mask(cpu_mask, update, &enable, 1);
-
- free_cpumask_var(cpu_mask);
-
- return 0;
-}
-
-/* Restore the qos cfg state when a domain comes online */
-void rdt_domain_reconfigure_cdp(struct rdt_resource *r)
-{
- struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
-
- if (!r->cdp_capable)
- return;
-
- if (r->rid == RDT_RESOURCE_L2)
- l2_qos_cfg_update(&hw_res->cdp_enabled);
-
- if (r->rid == RDT_RESOURCE_L3)
- l3_qos_cfg_update(&hw_res->cdp_enabled);
-}
-
-static int mba_sc_domain_allocate(struct rdt_resource *r, struct rdt_ctrl_domain *d)
-{
- u32 num_closid = resctrl_arch_get_num_closid(r);
- int cpu = cpumask_any(&d->hdr.cpu_mask);
- int i;
-
- d->mbps_val = kcalloc_node(num_closid, sizeof(*d->mbps_val),
- GFP_KERNEL, cpu_to_node(cpu));
- if (!d->mbps_val)
- return -ENOMEM;
-
- for (i = 0; i < num_closid; i++)
- d->mbps_val[i] = MBA_MAX_MBPS;
-
- return 0;
-}
-
-static void mba_sc_domain_destroy(struct rdt_resource *r,
- struct rdt_ctrl_domain *d)
-{
- kfree(d->mbps_val);
- d->mbps_val = NULL;
-}
-
-/*
- * MBA software controller is supported only if
- * MBM is supported and MBA is in linear scale,
- * and the MBM monitor scope is the same as MBA
- * control scope.
- */
-static bool supports_mba_mbps(void)
-{
- struct rdt_resource *rmbm = resctrl_arch_get_resource(RDT_RESOURCE_L3);
- struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
-
- return (resctrl_is_mbm_enabled() &&
- r->alloc_capable && is_mba_linear() &&
- r->ctrl_scope == rmbm->mon_scope);
-}
-
-/*
- * Enable or disable the MBA software controller
- * which helps user specify bandwidth in MBps.
- */
-static int set_mba_sc(bool mba_sc)
-{
- struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
- u32 num_closid = resctrl_arch_get_num_closid(r);
- struct rdt_ctrl_domain *d;
- unsigned long fflags;
- int i;
-
- if (!supports_mba_mbps() || mba_sc == is_mba_sc(r))
- return -EINVAL;
-
- r->membw.mba_sc = mba_sc;
-
- rdtgroup_default.mba_mbps_event = mba_mbps_default_event;
-
- list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
- for (i = 0; i < num_closid; i++)
- d->mbps_val[i] = MBA_MAX_MBPS;
- }
-
- fflags = mba_sc ? RFTYPE_CTRL_BASE | RFTYPE_MON_BASE : 0;
- resctrl_file_fflags_init("mba_MBps_event", fflags);
-
- return 0;
-}
-
-static int cdp_enable(int level)
-{
- struct rdt_resource *r_l = &rdt_resources_all[level].r_resctrl;
- int ret;
-
- if (!r_l->alloc_capable)
- return -EINVAL;
-
- ret = set_cache_qos_cfg(level, true);
- if (!ret)
- rdt_resources_all[level].cdp_enabled = true;
-
- return ret;
-}
-
-static void cdp_disable(int level)
-{
- struct rdt_hw_resource *r_hw = &rdt_resources_all[level];
-
- if (r_hw->cdp_enabled) {
- set_cache_qos_cfg(level, false);
- r_hw->cdp_enabled = false;
- }
-}
-
-int resctrl_arch_set_cdp_enabled(enum resctrl_res_level l, bool enable)
-{
- struct rdt_hw_resource *hw_res = &rdt_resources_all[l];
-
- if (!hw_res->r_resctrl.cdp_capable)
- return -EINVAL;
-
- if (enable)
- return cdp_enable(l);
-
- cdp_disable(l);
-
- return 0;
-}
-
-bool resctrl_arch_get_cdp_enabled(enum resctrl_res_level l)
-{
- return rdt_resources_all[l].cdp_enabled;
-}
-
-/*
- * We don't allow rdtgroup directories to be created anywhere
- * except the root directory. Thus when looking for the rdtgroup
- * structure for a kernfs node we are either looking at a directory,
- * in which case the rdtgroup structure is pointed at by the "priv"
- * field, otherwise we have a file, and need only look to the parent
- * to find the rdtgroup.
- */
-static struct rdtgroup *kernfs_to_rdtgroup(struct kernfs_node *kn)
-{
- if (kernfs_type(kn) == KERNFS_DIR) {
- /*
- * All the resource directories use "kn->priv"
- * to point to the "struct rdtgroup" for the
- * resource. "info" and its subdirectories don't
- * have rdtgroup structures, so return NULL here.
- */
- if (kn == kn_info ||
- rcu_access_pointer(kn->__parent) == kn_info)
- return NULL;
- else
- return kn->priv;
- } else {
- return rdt_kn_parent_priv(kn);
- }
-}
-
-static void rdtgroup_kn_get(struct rdtgroup *rdtgrp, struct kernfs_node *kn)
-{
- atomic_inc(&rdtgrp->waitcount);
- kernfs_break_active_protection(kn);
-}
-
-static void rdtgroup_kn_put(struct rdtgroup *rdtgrp, struct kernfs_node *kn)
-{
- if (atomic_dec_and_test(&rdtgrp->waitcount) &&
- (rdtgrp->flags & RDT_DELETED)) {
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
- rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
- rdtgroup_pseudo_lock_remove(rdtgrp);
- kernfs_unbreak_active_protection(kn);
- rdtgroup_remove(rdtgrp);
- } else {
- kernfs_unbreak_active_protection(kn);
- }
-}
-
-struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn)
-{
- struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn);
-
- if (!rdtgrp)
- return NULL;
-
- rdtgroup_kn_get(rdtgrp, kn);
-
- cpus_read_lock();
- mutex_lock(&rdtgroup_mutex);
-
- /* Was this group deleted while we waited? */
- if (rdtgrp->flags & RDT_DELETED)
- return NULL;
-
- return rdtgrp;
-}
-
-void rdtgroup_kn_unlock(struct kernfs_node *kn)
-{
- struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn);
-
- if (!rdtgrp)
- return;
-
- mutex_unlock(&rdtgroup_mutex);
- cpus_read_unlock();
-
- rdtgroup_kn_put(rdtgrp, kn);
-}
-
-static int mkdir_mondata_all(struct kernfs_node *parent_kn,
- struct rdtgroup *prgrp,
- struct kernfs_node **mon_data_kn);
-
-static void rdt_disable_ctx(void)
-{
- resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);
- resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);
- set_mba_sc(false);
-
- resctrl_debug = false;
-}
-
-static int rdt_enable_ctx(struct rdt_fs_context *ctx)
-{
- int ret = 0;
-
- if (ctx->enable_cdpl2) {
- ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, true);
- if (ret)
- goto out_done;
- }
-
- if (ctx->enable_cdpl3) {
- ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, true);
- if (ret)
- goto out_cdpl2;
- }
-
- if (ctx->enable_mba_mbps) {
- ret = set_mba_sc(true);
- if (ret)
- goto out_cdpl3;
- }
-
- if (ctx->enable_debug)
- resctrl_debug = true;
-
- return 0;
-
-out_cdpl3:
- resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);
-out_cdpl2:
- resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);
-out_done:
- return ret;
-}
-
-static int schemata_list_add(struct rdt_resource *r, enum resctrl_conf_type type)
-{
- struct resctrl_schema *s;
- const char *suffix = "";
- int ret, cl;
-
- s = kzalloc(sizeof(*s), GFP_KERNEL);
- if (!s)
- return -ENOMEM;
-
- s->res = r;
- s->num_closid = resctrl_arch_get_num_closid(r);
- if (resctrl_arch_get_cdp_enabled(r->rid))
- s->num_closid /= 2;
-
- s->conf_type = type;
- switch (type) {
- case CDP_CODE:
- suffix = "CODE";
- break;
- case CDP_DATA:
- suffix = "DATA";
- break;
- case CDP_NONE:
- suffix = "";
- break;
- }
-
- ret = snprintf(s->name, sizeof(s->name), "%s%s", r->name, suffix);
- if (ret >= sizeof(s->name)) {
- kfree(s);
- return -EINVAL;
- }
-
- cl = strlen(s->name);
-
- /*
- * If CDP is supported by this resource, but not enabled,
- * include the suffix. This ensures the tabular format of the
- * schemata file does not change between mounts of the filesystem.
- */
- if (r->cdp_capable && !resctrl_arch_get_cdp_enabled(r->rid))
- cl += 4;
-
- if (cl > max_name_width)
- max_name_width = cl;
-
- switch (r->schema_fmt) {
- case RESCTRL_SCHEMA_BITMAP:
- s->fmt_str = "%d=%x";
- break;
- case RESCTRL_SCHEMA_RANGE:
- s->fmt_str = "%d=%u";
- break;
- }
-
- if (WARN_ON_ONCE(!s->fmt_str)) {
- kfree(s);
- return -EINVAL;
- }
-
- INIT_LIST_HEAD(&s->list);
- list_add(&s->list, &resctrl_schema_all);
-
- return 0;
-}
-
-static int schemata_list_create(void)
-{
- struct rdt_resource *r;
- int ret = 0;
-
- for_each_alloc_capable_rdt_resource(r) {
- if (resctrl_arch_get_cdp_enabled(r->rid)) {
- ret = schemata_list_add(r, CDP_CODE);
- if (ret)
- break;
-
- ret = schemata_list_add(r, CDP_DATA);
- } else {
- ret = schemata_list_add(r, CDP_NONE);
- }
-
- if (ret)
- break;
- }
-
- return ret;
-}
-
-static void schemata_list_destroy(void)
-{
- struct resctrl_schema *s, *tmp;
-
- list_for_each_entry_safe(s, tmp, &resctrl_schema_all, list) {
- list_del(&s->list);
- kfree(s);
- }
-}
-
-static int rdt_get_tree(struct fs_context *fc)
-{
- struct rdt_fs_context *ctx = rdt_fc2context(fc);
- unsigned long flags = RFTYPE_CTRL_BASE;
- struct rdt_mon_domain *dom;
- struct rdt_resource *r;
- int ret;
-
- cpus_read_lock();
- mutex_lock(&rdtgroup_mutex);
- /*
- * resctrl file system can only be mounted once.
- */
- if (resctrl_mounted) {
- ret = -EBUSY;
- goto out;
- }
-
- ret = rdtgroup_setup_root(ctx);
- if (ret)
- goto out;
-
- ret = rdt_enable_ctx(ctx);
- if (ret)
- goto out_root;
-
- ret = schemata_list_create();
- if (ret) {
- schemata_list_destroy();
- goto out_ctx;
- }
-
- ret = closid_init();
- if (ret)
- goto out_schemata_free;
-
- if (resctrl_arch_mon_capable())
- flags |= RFTYPE_MON;
-
- ret = rdtgroup_add_files(rdtgroup_default.kn, flags);
- if (ret)
- goto out_closid_exit;
-
- kernfs_activate(rdtgroup_default.kn);
-
- ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
- if (ret < 0)
- goto out_closid_exit;
-
- if (resctrl_arch_mon_capable()) {
- ret = mongroup_create_dir(rdtgroup_default.kn,
- &rdtgroup_default, "mon_groups",
- &kn_mongrp);
- if (ret < 0)
- goto out_info;
-
- ret = mkdir_mondata_all(rdtgroup_default.kn,
- &rdtgroup_default, &kn_mondata);
- if (ret < 0)
- goto out_mongrp;
- rdtgroup_default.mon.mon_data_kn = kn_mondata;
- }
-
- ret = rdt_pseudo_lock_init();
- if (ret)
- goto out_mondata;
-
- ret = kernfs_get_tree(fc);
- if (ret < 0)
- goto out_psl;
-
- if (resctrl_arch_alloc_capable())
- resctrl_arch_enable_alloc();
- if (resctrl_arch_mon_capable())
- resctrl_arch_enable_mon();
-
- if (resctrl_arch_alloc_capable() || resctrl_arch_mon_capable())
- resctrl_mounted = true;
-
- if (resctrl_is_mbm_enabled()) {
- r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
- list_for_each_entry(dom, &r->mon_domains, hdr.list)
- mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL,
- RESCTRL_PICK_ANY_CPU);
- }
-
- goto out;
-
-out_psl:
- rdt_pseudo_lock_release();
-out_mondata:
- if (resctrl_arch_mon_capable())
- kernfs_remove(kn_mondata);
-out_mongrp:
- if (resctrl_arch_mon_capable())
- kernfs_remove(kn_mongrp);
-out_info:
- kernfs_remove(kn_info);
-out_closid_exit:
- closid_exit();
-out_schemata_free:
- schemata_list_destroy();
-out_ctx:
- rdt_disable_ctx();
-out_root:
- rdtgroup_destroy_root();
-out:
- rdt_last_cmd_clear();
- mutex_unlock(&rdtgroup_mutex);
- cpus_read_unlock();
- return ret;
-}
-
-enum rdt_param {
- Opt_cdp,
- Opt_cdpl2,
- Opt_mba_mbps,
- Opt_debug,
- nr__rdt_params
-};
-
-static const struct fs_parameter_spec rdt_fs_parameters[] = {
- fsparam_flag("cdp", Opt_cdp),
- fsparam_flag("cdpl2", Opt_cdpl2),
- fsparam_flag("mba_MBps", Opt_mba_mbps),
- fsparam_flag("debug", Opt_debug),
- {}
-};
-
-static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param)
-{
- struct rdt_fs_context *ctx = rdt_fc2context(fc);
- struct fs_parse_result result;
- const char *msg;
- int opt;
-
- opt = fs_parse(fc, rdt_fs_parameters, param, &result);
- if (opt < 0)
- return opt;
-
- switch (opt) {
- case Opt_cdp:
- ctx->enable_cdpl3 = true;
- return 0;
- case Opt_cdpl2:
- ctx->enable_cdpl2 = true;
- return 0;
- case Opt_mba_mbps:
- msg = "mba_MBps requires MBM and linear scale MBA at L3 scope";
- if (!supports_mba_mbps())
- return invalfc(fc, msg);
- ctx->enable_mba_mbps = true;
- return 0;
- case Opt_debug:
- ctx->enable_debug = true;
- return 0;
- }
-
- return -EINVAL;
-}
-
-static void rdt_fs_context_free(struct fs_context *fc)
-{
- struct rdt_fs_context *ctx = rdt_fc2context(fc);
-
- kernfs_free_fs_context(fc);
- kfree(ctx);
-}
-
-static const struct fs_context_operations rdt_fs_context_ops = {
- .free = rdt_fs_context_free,
- .parse_param = rdt_parse_param,
- .get_tree = rdt_get_tree,
-};
-
-static int rdt_init_fs_context(struct fs_context *fc)
-{
- struct rdt_fs_context *ctx;
-
- ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
- if (!ctx)
- return -ENOMEM;
-
- ctx->kfc.magic = RDTGROUP_SUPER_MAGIC;
- fc->fs_private = &ctx->kfc;
- fc->ops = &rdt_fs_context_ops;
- put_user_ns(fc->user_ns);
- fc->user_ns = get_user_ns(&init_user_ns);
- fc->global = true;
- return 0;
-}
-
-void resctrl_arch_reset_all_ctrls(struct rdt_resource *r)
-{
- struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
- struct rdt_hw_ctrl_domain *hw_dom;
- struct msr_param msr_param;
- struct rdt_ctrl_domain *d;
- int i;
-
- /* Walking r->domains, ensure it can't race with cpuhp */
- lockdep_assert_cpus_held();
-
- msr_param.res = r;
- msr_param.low = 0;
- msr_param.high = hw_res->num_closid;
-
- /*
- * Disable resource control for this resource by setting all
- * CBMs in all ctrl_domains to the maximum mask value. Pick one CPU
- * from each domain to update the MSRs below.
- */
- list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
- hw_dom = resctrl_to_arch_ctrl_dom(d);
-
- for (i = 0; i < hw_res->num_closid; i++)
- hw_dom->ctrl_val[i] = resctrl_get_default_ctrl(r);
- msr_param.dom = d;
- smp_call_function_any(&d->hdr.cpu_mask, rdt_ctrl_update, &msr_param, 1);
- }
-
- return;
-}
-
-/*
- * Move tasks from one to the other group. If @from is NULL, then all tasks
- * in the systems are moved unconditionally (used for teardown).
- *
- * If @mask is not NULL the cpus on which moved tasks are running are set
- * in that mask so the update smp function call is restricted to affected
- * cpus.
- */
-static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to,
- struct cpumask *mask)
-{
- struct task_struct *p, *t;
-
- read_lock(&tasklist_lock);
- for_each_process_thread(p, t) {
- if (!from || is_closid_match(t, from) ||
- is_rmid_match(t, from)) {
- resctrl_arch_set_closid_rmid(t, to->closid,
- to->mon.rmid);
-
- /*
- * Order the closid/rmid stores above before the loads
- * in task_curr(). This pairs with the full barrier
- * between the rq->curr update and
- * resctrl_arch_sched_in() during context switch.
- */
- smp_mb();
-
- /*
- * If the task is on a CPU, set the CPU in the mask.
- * The detection is inaccurate as tasks might move or
- * schedule before the smp function call takes place.
- * In such a case the function call is pointless, but
- * there is no other side effect.
- */
- if (IS_ENABLED(CONFIG_SMP) && mask && task_curr(t))
- cpumask_set_cpu(task_cpu(t), mask);
- }
- }
- read_unlock(&tasklist_lock);
-}
-
-static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp)
-{
- struct rdtgroup *sentry, *stmp;
- struct list_head *head;
-
- head = &rdtgrp->mon.crdtgrp_list;
- list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) {
- free_rmid(sentry->closid, sentry->mon.rmid);
- list_del(&sentry->mon.crdtgrp_list);
-
- if (atomic_read(&sentry->waitcount) != 0)
- sentry->flags = RDT_DELETED;
- else
- rdtgroup_remove(sentry);
- }
-}
-
-/*
- * Forcibly remove all of subdirectories under root.
- */
-static void rmdir_all_sub(void)
-{
- struct rdtgroup *rdtgrp, *tmp;
-
- /* Move all tasks to the default resource group */
- rdt_move_group_tasks(NULL, &rdtgroup_default, NULL);
-
- list_for_each_entry_safe(rdtgrp, tmp, &rdt_all_groups, rdtgroup_list) {
- /* Free any child rmids */
- free_all_child_rdtgrp(rdtgrp);
-
- /* Remove each rdtgroup other than root */
- if (rdtgrp == &rdtgroup_default)
- continue;
-
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
- rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
- rdtgroup_pseudo_lock_remove(rdtgrp);
-
- /*
- * Give any CPUs back to the default group. We cannot copy
- * cpu_online_mask because a CPU might have executed the
- * offline callback already, but is still marked online.
- */
- cpumask_or(&rdtgroup_default.cpu_mask,
- &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask);
-
- free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
-
- kernfs_remove(rdtgrp->kn);
- list_del(&rdtgrp->rdtgroup_list);
-
- if (atomic_read(&rdtgrp->waitcount) != 0)
- rdtgrp->flags = RDT_DELETED;
- else
- rdtgroup_remove(rdtgrp);
- }
- /* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */
- update_closid_rmid(cpu_online_mask, &rdtgroup_default);
-
- kernfs_remove(kn_info);
- kernfs_remove(kn_mongrp);
- kernfs_remove(kn_mondata);
-}
-
-/**
- * mon_get_kn_priv() - Get the mon_data priv data for this event.
- *
- * The same values are used across the mon_data directories of all control and
- * monitor groups for the same event in the same domain. Keep a list of
- * allocated structures and re-use an existing one with the same values for
- * @rid, @domid, etc.
- *
- * @rid: The resource id for the event file being created.
- * @domid: The domain id for the event file being created.
- * @mevt: The type of event file being created.
- * @do_sum: Whether SNC summing monitors are being created.
- */
-static struct mon_data *mon_get_kn_priv(enum resctrl_res_level rid, int domid,
- struct mon_evt *mevt,
- bool do_sum)
-{
- struct mon_data *priv;
-
- lockdep_assert_held(&rdtgroup_mutex);
-
- list_for_each_entry(priv, &mon_data_kn_priv_list, list) {
- if (priv->rid == rid && priv->domid == domid &&
- priv->sum == do_sum && priv->evtid == mevt->evtid)
- return priv;
- }
-
- priv = kzalloc(sizeof(*priv), GFP_KERNEL);
- if (!priv)
- return NULL;
-
- priv->rid = rid;
- priv->domid = domid;
- priv->sum = do_sum;
- priv->evtid = mevt->evtid;
- list_add_tail(&priv->list, &mon_data_kn_priv_list);
-
- return priv;
-}
-
-/**
- * mon_put_kn_priv() - Free all allocated mon_data structures.
- *
- * Called when resctrl file system is unmounted.
- */
-static void mon_put_kn_priv(void)
-{
- struct mon_data *priv, *tmp;
-
- lockdep_assert_held(&rdtgroup_mutex);
-
- list_for_each_entry_safe(priv, tmp, &mon_data_kn_priv_list, list) {
- list_del(&priv->list);
- kfree(priv);
- }
-}
-
-static void resctrl_fs_teardown(void)
-{
- lockdep_assert_held(&rdtgroup_mutex);
-
- /* Cleared by rdtgroup_destroy_root() */
- if (!rdtgroup_default.kn)
- return;
-
- rmdir_all_sub();
- mon_put_kn_priv();
- rdt_pseudo_lock_release();
- rdtgroup_default.mode = RDT_MODE_SHAREABLE;
- closid_exit();
- schemata_list_destroy();
- rdtgroup_destroy_root();
-}
-
-static void rdt_kill_sb(struct super_block *sb)
-{
- struct rdt_resource *r;
-
- cpus_read_lock();
- mutex_lock(&rdtgroup_mutex);
-
- rdt_disable_ctx();
-
- /* Put everything back to default values. */
- for_each_alloc_capable_rdt_resource(r)
- resctrl_arch_reset_all_ctrls(r);
-
- resctrl_fs_teardown();
- if (resctrl_arch_alloc_capable())
- resctrl_arch_disable_alloc();
- if (resctrl_arch_mon_capable())
- resctrl_arch_disable_mon();
- resctrl_mounted = false;
- kernfs_kill_sb(sb);
- mutex_unlock(&rdtgroup_mutex);
- cpus_read_unlock();
-}
-
-static struct file_system_type rdt_fs_type = {
- .name = "resctrl",
- .init_fs_context = rdt_init_fs_context,
- .parameters = rdt_fs_parameters,
- .kill_sb = rdt_kill_sb,
-};
-
-static int mon_addfile(struct kernfs_node *parent_kn, const char *name,
- void *priv)
-{
- struct kernfs_node *kn;
- int ret = 0;
-
- kn = __kernfs_create_file(parent_kn, name, 0444,
- GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 0,
- &kf_mondata_ops, priv, NULL, NULL);
- if (IS_ERR(kn))
- return PTR_ERR(kn);
-
- ret = rdtgroup_kn_set_ugid(kn);
- if (ret) {
- kernfs_remove(kn);
- return ret;
- }
-
- return ret;
-}
-
-static void mon_rmdir_one_subdir(struct kernfs_node *pkn, char *name, char *subname)
-{
- struct kernfs_node *kn;
-
- kn = kernfs_find_and_get(pkn, name);
- if (!kn)
- return;
- kernfs_put(kn);
-
- if (kn->dir.subdirs <= 1)
- kernfs_remove(kn);
- else
- kernfs_remove_by_name(kn, subname);
-}
-
-/*
- * Remove all subdirectories of mon_data of ctrl_mon groups
- * and monitor groups for the given domain.
- * Remove files and directories containing "sum" of domain data
- * when last domain being summed is removed.
- */
-static void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
- struct rdt_mon_domain *d)
-{
- struct rdtgroup *prgrp, *crgrp;
- char subname[32];
- bool snc_mode;
- char name[32];
-
- snc_mode = r->mon_scope == RESCTRL_L3_NODE;
- sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id);
- if (snc_mode)
- sprintf(subname, "mon_sub_%s_%02d", r->name, d->hdr.id);
-
- list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
- mon_rmdir_one_subdir(prgrp->mon.mon_data_kn, name, subname);
-
- list_for_each_entry(crgrp, &prgrp->mon.crdtgrp_list, mon.crdtgrp_list)
- mon_rmdir_one_subdir(crgrp->mon.mon_data_kn, name, subname);
- }
-}
-
-static int mon_add_all_files(struct kernfs_node *kn, struct rdt_mon_domain *d,
- struct rdt_resource *r, struct rdtgroup *prgrp,
- bool do_sum)
-{
- struct rmid_read rr = {0};
- struct mon_data *priv;
- struct mon_evt *mevt;
- int ret, domid;
-
- if (WARN_ON(list_empty(&r->evt_list)))
- return -EPERM;
-
- list_for_each_entry(mevt, &r->evt_list, list) {
- domid = do_sum ? d->ci->id : d->hdr.id;
- priv = mon_get_kn_priv(r->rid, domid, mevt, do_sum);
- if (WARN_ON_ONCE(!priv))
- return -EINVAL;
-
- ret = mon_addfile(kn, mevt->name, priv);
- if (ret)
- return ret;
-
- if (!do_sum && resctrl_is_mbm_event(mevt->evtid))
- mon_event_read(&rr, r, d, prgrp, &d->hdr.cpu_mask, mevt->evtid, true);
- }
-
- return 0;
-}
-
-static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
- struct rdt_mon_domain *d,
- struct rdt_resource *r, struct rdtgroup *prgrp)
-{
- struct kernfs_node *kn, *ckn;
- char name[32];
- bool snc_mode;
- int ret = 0;
-
- lockdep_assert_held(&rdtgroup_mutex);
-
- snc_mode = r->mon_scope == RESCTRL_L3_NODE;
- sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id);
- kn = kernfs_find_and_get(parent_kn, name);
- if (kn) {
- /*
- * rdtgroup_mutex will prevent this directory from being
- * removed. No need to keep this hold.
- */
- kernfs_put(kn);
- } else {
- kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
- if (IS_ERR(kn))
- return PTR_ERR(kn);
-
- ret = rdtgroup_kn_set_ugid(kn);
- if (ret)
- goto out_destroy;
- ret = mon_add_all_files(kn, d, r, prgrp, snc_mode);
- if (ret)
- goto out_destroy;
- }
-
- if (snc_mode) {
- sprintf(name, "mon_sub_%s_%02d", r->name, d->hdr.id);
- ckn = kernfs_create_dir(kn, name, parent_kn->mode, prgrp);
- if (IS_ERR(ckn)) {
- ret = -EINVAL;
- goto out_destroy;
- }
-
- ret = rdtgroup_kn_set_ugid(ckn);
- if (ret)
- goto out_destroy;
-
- ret = mon_add_all_files(ckn, d, r, prgrp, false);
- if (ret)
- goto out_destroy;
- }
-
- kernfs_activate(kn);
- return 0;
-
-out_destroy:
- kernfs_remove(kn);
- return ret;
-}
-
-/*
- * Add all subdirectories of mon_data for "ctrl_mon" groups
- * and "monitor" groups with given domain id.
- */
-static void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
- struct rdt_mon_domain *d)
-{
- struct kernfs_node *parent_kn;
- struct rdtgroup *prgrp, *crgrp;
- struct list_head *head;
-
- list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
- parent_kn = prgrp->mon.mon_data_kn;
- mkdir_mondata_subdir(parent_kn, d, r, prgrp);
-
- head = &prgrp->mon.crdtgrp_list;
- list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
- parent_kn = crgrp->mon.mon_data_kn;
- mkdir_mondata_subdir(parent_kn, d, r, crgrp);
- }
- }
-}
-
-static int mkdir_mondata_subdir_alldom(struct kernfs_node *parent_kn,
- struct rdt_resource *r,
- struct rdtgroup *prgrp)
-{
- struct rdt_mon_domain *dom;
- int ret;
-
- /* Walking r->domains, ensure it can't race with cpuhp */
- lockdep_assert_cpus_held();
-
- list_for_each_entry(dom, &r->mon_domains, hdr.list) {
- ret = mkdir_mondata_subdir(parent_kn, dom, r, prgrp);
- if (ret)
- return ret;
- }
-
- return 0;
-}
-
-/*
- * This creates a directory mon_data which contains the monitored data.
- *
- * mon_data has one directory for each domain which are named
- * in the format mon_<domain_name>_<domain_id>. For ex: A mon_data
- * with L3 domain looks as below:
- * ./mon_data:
- * mon_L3_00
- * mon_L3_01
- * mon_L3_02
- * ...
- *
- * Each domain directory has one file per event:
- * ./mon_L3_00/:
- * llc_occupancy
- *
- */
-static int mkdir_mondata_all(struct kernfs_node *parent_kn,
- struct rdtgroup *prgrp,
- struct kernfs_node **dest_kn)
-{
- struct rdt_resource *r;
- struct kernfs_node *kn;
- int ret;
-
- /*
- * Create the mon_data directory first.
- */
- ret = mongroup_create_dir(parent_kn, prgrp, "mon_data", &kn);
- if (ret)
- return ret;
-
- if (dest_kn)
- *dest_kn = kn;
-
- /*
- * Create the subdirectories for each domain. Note that all events
- * in a domain like L3 are grouped into a resource whose domain is L3
- */
- for_each_mon_capable_rdt_resource(r) {
- ret = mkdir_mondata_subdir_alldom(kn, r, prgrp);
- if (ret)
- goto out_destroy;
- }
-
- return 0;
-
-out_destroy:
- kernfs_remove(kn);
- return ret;
-}
-
-/**
- * cbm_ensure_valid - Enforce validity on provided CBM
- * @_val: Candidate CBM
- * @r: RDT resource to which the CBM belongs
- *
- * The provided CBM represents all cache portions available for use. This
- * may be represented by a bitmap that does not consist of contiguous ones
- * and thus be an invalid CBM.
- * Here the provided CBM is forced to be a valid CBM by only considering
- * the first set of contiguous bits as valid and clearing all bits.
- * The intention here is to provide a valid default CBM with which a new
- * resource group is initialized. The user can follow this with a
- * modification to the CBM if the default does not satisfy the
- * requirements.
- */
-static u32 cbm_ensure_valid(u32 _val, struct rdt_resource *r)
-{
- unsigned int cbm_len = r->cache.cbm_len;
- unsigned long first_bit, zero_bit;
- unsigned long val = _val;
-
- if (!val)
- return 0;
-
- first_bit = find_first_bit(&val, cbm_len);
- zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
-
- /* Clear any remaining bits to ensure contiguous region */
- bitmap_clear(&val, zero_bit, cbm_len - zero_bit);
- return (u32)val;
-}
-
-/*
- * Initialize cache resources per RDT domain
- *
- * Set the RDT domain up to start off with all usable allocations. That is,
- * all shareable and unused bits. All-zero CBM is invalid.
- */
-static int __init_one_rdt_domain(struct rdt_ctrl_domain *d, struct resctrl_schema *s,
- u32 closid)
-{
- enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type);
- enum resctrl_conf_type t = s->conf_type;
- struct resctrl_staged_config *cfg;
- struct rdt_resource *r = s->res;
- u32 used_b = 0, unused_b = 0;
- unsigned long tmp_cbm;
- enum rdtgrp_mode mode;
- u32 peer_ctl, ctrl_val;
- int i;
-
- cfg = &d->staged_config[t];
- cfg->have_new_ctrl = false;
- cfg->new_ctrl = r->cache.shareable_bits;
- used_b = r->cache.shareable_bits;
- for (i = 0; i < closids_supported(); i++) {
- if (closid_allocated(i) && i != closid) {
- mode = rdtgroup_mode_by_closid(i);
- if (mode == RDT_MODE_PSEUDO_LOCKSETUP)
- /*
- * ctrl values for locksetup aren't relevant
- * until the schemata is written, and the mode
- * becomes RDT_MODE_PSEUDO_LOCKED.
- */
- continue;
- /*
- * If CDP is active include peer domain's
- * usage to ensure there is no overlap
- * with an exclusive group.
- */
- if (resctrl_arch_get_cdp_enabled(r->rid))
- peer_ctl = resctrl_arch_get_config(r, d, i,
- peer_type);
- else
- peer_ctl = 0;
- ctrl_val = resctrl_arch_get_config(r, d, i,
- s->conf_type);
- used_b |= ctrl_val | peer_ctl;
- if (mode == RDT_MODE_SHAREABLE)
- cfg->new_ctrl |= ctrl_val | peer_ctl;
- }
- }
- if (d->plr && d->plr->cbm > 0)
- used_b |= d->plr->cbm;
- unused_b = used_b ^ (BIT_MASK(r->cache.cbm_len) - 1);
- unused_b &= BIT_MASK(r->cache.cbm_len) - 1;
- cfg->new_ctrl |= unused_b;
- /*
- * Force the initial CBM to be valid, user can
- * modify the CBM based on system availability.
- */
- cfg->new_ctrl = cbm_ensure_valid(cfg->new_ctrl, r);
- /*
- * Assign the u32 CBM to an unsigned long to ensure that
- * bitmap_weight() does not access out-of-bound memory.
- */
- tmp_cbm = cfg->new_ctrl;
- if (bitmap_weight(&tmp_cbm, r->cache.cbm_len) < r->cache.min_cbm_bits) {
- rdt_last_cmd_printf("No space on %s:%d\n", s->name, d->hdr.id);
- return -ENOSPC;
- }
- cfg->have_new_ctrl = true;
-
- return 0;
-}
-
-/*
- * Initialize cache resources with default values.
- *
- * A new RDT group is being created on an allocation capable (CAT)
- * supporting system. Set this group up to start off with all usable
- * allocations.
- *
- * If there are no more shareable bits available on any domain then
- * the entire allocation will fail.
- */
-static int rdtgroup_init_cat(struct resctrl_schema *s, u32 closid)
-{
- struct rdt_ctrl_domain *d;
- int ret;
-
- list_for_each_entry(d, &s->res->ctrl_domains, hdr.list) {
- ret = __init_one_rdt_domain(d, s, closid);
- if (ret < 0)
- return ret;
- }
-
- return 0;
-}
-
-/* Initialize MBA resource with default values. */
-static void rdtgroup_init_mba(struct rdt_resource *r, u32 closid)
-{
- struct resctrl_staged_config *cfg;
- struct rdt_ctrl_domain *d;
-
- list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
- if (is_mba_sc(r)) {
- d->mbps_val[closid] = MBA_MAX_MBPS;
- continue;
- }
-
- cfg = &d->staged_config[CDP_NONE];
- cfg->new_ctrl = resctrl_get_default_ctrl(r);
- cfg->have_new_ctrl = true;
- }
-}
-
-/* Initialize the RDT group's allocations. */
-static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
-{
- struct resctrl_schema *s;
- struct rdt_resource *r;
- int ret = 0;
-
- rdt_staged_configs_clear();
-
- list_for_each_entry(s, &resctrl_schema_all, list) {
- r = s->res;
- if (r->rid == RDT_RESOURCE_MBA ||
- r->rid == RDT_RESOURCE_SMBA) {
- rdtgroup_init_mba(r, rdtgrp->closid);
- if (is_mba_sc(r))
- continue;
- } else {
- ret = rdtgroup_init_cat(s, rdtgrp->closid);
- if (ret < 0)
- goto out;
- }
-
- ret = resctrl_arch_update_domains(r, rdtgrp->closid);
- if (ret < 0) {
- rdt_last_cmd_puts("Failed to initialize allocations\n");
- goto out;
- }
- }
-
- rdtgrp->mode = RDT_MODE_SHAREABLE;
-
-out:
- rdt_staged_configs_clear();
- return ret;
-}
-
-static int mkdir_rdt_prepare_rmid_alloc(struct rdtgroup *rdtgrp)
-{
- int ret;
-
- if (!resctrl_arch_mon_capable())
- return 0;
-
- ret = alloc_rmid(rdtgrp->closid);
- if (ret < 0) {
- rdt_last_cmd_puts("Out of RMIDs\n");
- return ret;
- }
- rdtgrp->mon.rmid = ret;
-
- ret = mkdir_mondata_all(rdtgrp->kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
- if (ret) {
- rdt_last_cmd_puts("kernfs subdir error\n");
- free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
- return ret;
- }
-
- return 0;
-}
-
-static void mkdir_rdt_prepare_rmid_free(struct rdtgroup *rgrp)
-{
- if (resctrl_arch_mon_capable())
- free_rmid(rgrp->closid, rgrp->mon.rmid);
-}
-
-/*
- * We allow creating mon groups only with in a directory called "mon_groups"
- * which is present in every ctrl_mon group. Check if this is a valid
- * "mon_groups" directory.
- *
- * 1. The directory should be named "mon_groups".
- * 2. The mon group itself should "not" be named "mon_groups".
- * This makes sure "mon_groups" directory always has a ctrl_mon group
- * as parent.
- */
-static bool is_mon_groups(struct kernfs_node *kn, const char *name)
-{
- return (!strcmp(rdt_kn_name(kn), "mon_groups") &&
- strcmp(name, "mon_groups"));
-}
-
-static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
- const char *name, umode_t mode,
- enum rdt_group_type rtype, struct rdtgroup **r)
-{
- struct rdtgroup *prdtgrp, *rdtgrp;
- unsigned long files = 0;
- struct kernfs_node *kn;
- int ret;
-
- prdtgrp = rdtgroup_kn_lock_live(parent_kn);
- if (!prdtgrp) {
- ret = -ENODEV;
- goto out_unlock;
- }
-
- /*
- * Check that the parent directory for a monitor group is a "mon_groups"
- * directory.
- */
- if (rtype == RDTMON_GROUP && !is_mon_groups(parent_kn, name)) {
- ret = -EPERM;
- goto out_unlock;
- }
-
- if (rtype == RDTMON_GROUP &&
- (prdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
- prdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)) {
- ret = -EINVAL;
- rdt_last_cmd_puts("Pseudo-locking in progress\n");
- goto out_unlock;
- }
-
- /* allocate the rdtgroup. */
- rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL);
- if (!rdtgrp) {
- ret = -ENOSPC;
- rdt_last_cmd_puts("Kernel out of memory\n");
- goto out_unlock;
- }
- *r = rdtgrp;
- rdtgrp->mon.parent = prdtgrp;
- rdtgrp->type = rtype;
- INIT_LIST_HEAD(&rdtgrp->mon.crdtgrp_list);
-
- /* kernfs creates the directory for rdtgrp */
- kn = kernfs_create_dir(parent_kn, name, mode, rdtgrp);
- if (IS_ERR(kn)) {
- ret = PTR_ERR(kn);
- rdt_last_cmd_puts("kernfs create error\n");
- goto out_free_rgrp;
- }
- rdtgrp->kn = kn;
-
- /*
- * kernfs_remove() will drop the reference count on "kn" which
- * will free it. But we still need it to stick around for the
- * rdtgroup_kn_unlock(kn) call. Take one extra reference here,
- * which will be dropped by kernfs_put() in rdtgroup_remove().
- */
- kernfs_get(kn);
-
- ret = rdtgroup_kn_set_ugid(kn);
- if (ret) {
- rdt_last_cmd_puts("kernfs perm error\n");
- goto out_destroy;
- }
-
- if (rtype == RDTCTRL_GROUP) {
- files = RFTYPE_BASE | RFTYPE_CTRL;
- if (resctrl_arch_mon_capable())
- files |= RFTYPE_MON;
- } else {
- files = RFTYPE_BASE | RFTYPE_MON;
- }
-
- ret = rdtgroup_add_files(kn, files);
- if (ret) {
- rdt_last_cmd_puts("kernfs fill error\n");
- goto out_destroy;
- }
-
- /*
- * The caller unlocks the parent_kn upon success.
- */
- return 0;
-
-out_destroy:
- kernfs_put(rdtgrp->kn);
- kernfs_remove(rdtgrp->kn);
-out_free_rgrp:
- kfree(rdtgrp);
-out_unlock:
- rdtgroup_kn_unlock(parent_kn);
- return ret;
-}
-
-static void mkdir_rdt_prepare_clean(struct rdtgroup *rgrp)
-{
- kernfs_remove(rgrp->kn);
- rdtgroup_remove(rgrp);
-}
-
-/*
- * Create a monitor group under "mon_groups" directory of a control
- * and monitor group(ctrl_mon). This is a resource group
- * to monitor a subset of tasks and cpus in its parent ctrl_mon group.
- */
-static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn,
- const char *name, umode_t mode)
-{
- struct rdtgroup *rdtgrp, *prgrp;
- int ret;
-
- ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTMON_GROUP, &rdtgrp);
- if (ret)
- return ret;
-
- prgrp = rdtgrp->mon.parent;
- rdtgrp->closid = prgrp->closid;
-
- ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp);
- if (ret) {
- mkdir_rdt_prepare_clean(rdtgrp);
- goto out_unlock;
- }
-
- kernfs_activate(rdtgrp->kn);
-
- /*
- * Add the rdtgrp to the list of rdtgrps the parent
- * ctrl_mon group has to track.
- */
- list_add_tail(&rdtgrp->mon.crdtgrp_list, &prgrp->mon.crdtgrp_list);
-
-out_unlock:
- rdtgroup_kn_unlock(parent_kn);
- return ret;
-}
-
-/*
- * These are rdtgroups created under the root directory. Can be used
- * to allocate and monitor resources.
- */
-static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
- const char *name, umode_t mode)
-{
- struct rdtgroup *rdtgrp;
- struct kernfs_node *kn;
- u32 closid;
- int ret;
-
- ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTCTRL_GROUP, &rdtgrp);
- if (ret)
- return ret;
-
- kn = rdtgrp->kn;
- ret = closid_alloc();
- if (ret < 0) {
- rdt_last_cmd_puts("Out of CLOSIDs\n");
- goto out_common_fail;
- }
- closid = ret;
- ret = 0;
-
- rdtgrp->closid = closid;
-
- ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp);
- if (ret)
- goto out_closid_free;
-
- kernfs_activate(rdtgrp->kn);
-
- ret = rdtgroup_init_alloc(rdtgrp);
- if (ret < 0)
- goto out_rmid_free;
-
- list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups);
-
- if (resctrl_arch_mon_capable()) {
- /*
- * Create an empty mon_groups directory to hold the subset
- * of tasks and cpus to monitor.
- */
- ret = mongroup_create_dir(kn, rdtgrp, "mon_groups", NULL);
- if (ret) {
- rdt_last_cmd_puts("kernfs subdir error\n");
- goto out_del_list;
- }
- if (is_mba_sc(NULL))
- rdtgrp->mba_mbps_event = mba_mbps_default_event;
- }
-
- goto out_unlock;
-
-out_del_list:
- list_del(&rdtgrp->rdtgroup_list);
-out_rmid_free:
- mkdir_rdt_prepare_rmid_free(rdtgrp);
-out_closid_free:
- closid_free(closid);
-out_common_fail:
- mkdir_rdt_prepare_clean(rdtgrp);
-out_unlock:
- rdtgroup_kn_unlock(parent_kn);
- return ret;
-}
-
-static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
- umode_t mode)
-{
- /* Do not accept '\n' to avoid unparsable situation. */
- if (strchr(name, '\n'))
- return -EINVAL;
-
- /*
- * If the parent directory is the root directory and RDT
- * allocation is supported, add a control and monitoring
- * subdirectory
- */
- if (resctrl_arch_alloc_capable() && parent_kn == rdtgroup_default.kn)
- return rdtgroup_mkdir_ctrl_mon(parent_kn, name, mode);
-
- /* Else, attempt to add a monitoring subdirectory. */
- if (resctrl_arch_mon_capable())
- return rdtgroup_mkdir_mon(parent_kn, name, mode);
-
- return -EPERM;
-}
-
-static int rdtgroup_rmdir_mon(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask)
-{
- struct rdtgroup *prdtgrp = rdtgrp->mon.parent;
- u32 closid, rmid;
- int cpu;
-
- /* Give any tasks back to the parent group */
- rdt_move_group_tasks(rdtgrp, prdtgrp, tmpmask);
-
- /*
- * Update per cpu closid/rmid of the moved CPUs first.
- * Note: the closid will not change, but the arch code still needs it.
- */
- closid = prdtgrp->closid;
- rmid = prdtgrp->mon.rmid;
- for_each_cpu(cpu, &rdtgrp->cpu_mask)
- resctrl_arch_set_cpu_default_closid_rmid(cpu, closid, rmid);
-
- /*
- * Update the MSR on moved CPUs and CPUs which have moved
- * task running on them.
- */
- cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
- update_closid_rmid(tmpmask, NULL);
-
- rdtgrp->flags = RDT_DELETED;
- free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
-
- /*
- * Remove the rdtgrp from the parent ctrl_mon group's list
- */
- WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list));
- list_del(&rdtgrp->mon.crdtgrp_list);
-
- kernfs_remove(rdtgrp->kn);
-
- return 0;
-}
-
-static int rdtgroup_ctrl_remove(struct rdtgroup *rdtgrp)
-{
- rdtgrp->flags = RDT_DELETED;
- list_del(&rdtgrp->rdtgroup_list);
-
- kernfs_remove(rdtgrp->kn);
- return 0;
-}
-
-static int rdtgroup_rmdir_ctrl(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask)
-{
- u32 closid, rmid;
- int cpu;
-
- /* Give any tasks back to the default group */
- rdt_move_group_tasks(rdtgrp, &rdtgroup_default, tmpmask);
-
- /* Give any CPUs back to the default group */
- cpumask_or(&rdtgroup_default.cpu_mask,
- &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask);
-
- /* Update per cpu closid and rmid of the moved CPUs first */
- closid = rdtgroup_default.closid;
- rmid = rdtgroup_default.mon.rmid;
- for_each_cpu(cpu, &rdtgrp->cpu_mask)
- resctrl_arch_set_cpu_default_closid_rmid(cpu, closid, rmid);
-
- /*
- * Update the MSR on moved CPUs and CPUs which have moved
- * task running on them.
- */
- cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
- update_closid_rmid(tmpmask, NULL);
-
- free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
- closid_free(rdtgrp->closid);
-
- rdtgroup_ctrl_remove(rdtgrp);
-
- /*
- * Free all the child monitor group rmids.
- */
- free_all_child_rdtgrp(rdtgrp);
-
- return 0;
-}
-
-static struct kernfs_node *rdt_kn_parent(struct kernfs_node *kn)
-{
- /*
- * Valid within the RCU section it was obtained or while rdtgroup_mutex
- * is held.
- */
- return rcu_dereference_check(kn->__parent, lockdep_is_held(&rdtgroup_mutex));
-}
-
-static int rdtgroup_rmdir(struct kernfs_node *kn)
-{
- struct kernfs_node *parent_kn;
- struct rdtgroup *rdtgrp;
- cpumask_var_t tmpmask;
- int ret = 0;
-
- if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
- return -ENOMEM;
-
- rdtgrp = rdtgroup_kn_lock_live(kn);
- if (!rdtgrp) {
- ret = -EPERM;
- goto out;
- }
- parent_kn = rdt_kn_parent(kn);
-
- /*
- * If the rdtgroup is a ctrl_mon group and parent directory
- * is the root directory, remove the ctrl_mon group.
- *
- * If the rdtgroup is a mon group and parent directory
- * is a valid "mon_groups" directory, remove the mon group.
- */
- if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn &&
- rdtgrp != &rdtgroup_default) {
- if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
- rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
- ret = rdtgroup_ctrl_remove(rdtgrp);
- } else {
- ret = rdtgroup_rmdir_ctrl(rdtgrp, tmpmask);
- }
- } else if (rdtgrp->type == RDTMON_GROUP &&
- is_mon_groups(parent_kn, rdt_kn_name(kn))) {
- ret = rdtgroup_rmdir_mon(rdtgrp, tmpmask);
- } else {
- ret = -EPERM;
- }
-
-out:
- rdtgroup_kn_unlock(kn);
- free_cpumask_var(tmpmask);
- return ret;
-}
-
-/**
- * mongrp_reparent() - replace parent CTRL_MON group of a MON group
- * @rdtgrp: the MON group whose parent should be replaced
- * @new_prdtgrp: replacement parent CTRL_MON group for @rdtgrp
- * @cpus: cpumask provided by the caller for use during this call
- *
- * Replaces the parent CTRL_MON group for a MON group, resulting in all member
- * tasks' CLOSID immediately changing to that of the new parent group.
- * Monitoring data for the group is unaffected by this operation.
- */
-static void mongrp_reparent(struct rdtgroup *rdtgrp,
- struct rdtgroup *new_prdtgrp,
- cpumask_var_t cpus)
-{
- struct rdtgroup *prdtgrp = rdtgrp->mon.parent;
-
- WARN_ON(rdtgrp->type != RDTMON_GROUP);
- WARN_ON(new_prdtgrp->type != RDTCTRL_GROUP);
-
- /* Nothing to do when simply renaming a MON group. */
- if (prdtgrp == new_prdtgrp)
- return;
-
- WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list));
- list_move_tail(&rdtgrp->mon.crdtgrp_list,
- &new_prdtgrp->mon.crdtgrp_list);
-
- rdtgrp->mon.parent = new_prdtgrp;
- rdtgrp->closid = new_prdtgrp->closid;
-
- /* Propagate updated closid to all tasks in this group. */
- rdt_move_group_tasks(rdtgrp, rdtgrp, cpus);
-
- update_closid_rmid(cpus, NULL);
-}
-
-static int rdtgroup_rename(struct kernfs_node *kn,
- struct kernfs_node *new_parent, const char *new_name)
-{
- struct kernfs_node *kn_parent;
- struct rdtgroup *new_prdtgrp;
- struct rdtgroup *rdtgrp;
- cpumask_var_t tmpmask;
- int ret;
-
- rdtgrp = kernfs_to_rdtgroup(kn);
- new_prdtgrp = kernfs_to_rdtgroup(new_parent);
- if (!rdtgrp || !new_prdtgrp)
- return -ENOENT;
-
- /* Release both kernfs active_refs before obtaining rdtgroup mutex. */
- rdtgroup_kn_get(rdtgrp, kn);
- rdtgroup_kn_get(new_prdtgrp, new_parent);
-
- mutex_lock(&rdtgroup_mutex);
-
- rdt_last_cmd_clear();
-
- /*
- * Don't allow kernfs_to_rdtgroup() to return a parent rdtgroup if
- * either kernfs_node is a file.
- */
- if (kernfs_type(kn) != KERNFS_DIR ||
- kernfs_type(new_parent) != KERNFS_DIR) {
- rdt_last_cmd_puts("Source and destination must be directories");
- ret = -EPERM;
- goto out;
- }
-
- if ((rdtgrp->flags & RDT_DELETED) || (new_prdtgrp->flags & RDT_DELETED)) {
- ret = -ENOENT;
- goto out;
- }
-
- kn_parent = rdt_kn_parent(kn);
- if (rdtgrp->type != RDTMON_GROUP || !kn_parent ||
- !is_mon_groups(kn_parent, rdt_kn_name(kn))) {
- rdt_last_cmd_puts("Source must be a MON group\n");
- ret = -EPERM;
- goto out;
- }
-
- if (!is_mon_groups(new_parent, new_name)) {
- rdt_last_cmd_puts("Destination must be a mon_groups subdirectory\n");
- ret = -EPERM;
- goto out;
- }
-
- /*
- * If the MON group is monitoring CPUs, the CPUs must be assigned to the
- * current parent CTRL_MON group and therefore cannot be assigned to
- * the new parent, making the move illegal.
- */
- if (!cpumask_empty(&rdtgrp->cpu_mask) &&
- rdtgrp->mon.parent != new_prdtgrp) {
- rdt_last_cmd_puts("Cannot move a MON group that monitors CPUs\n");
- ret = -EPERM;
- goto out;
- }
-
- /*
- * Allocate the cpumask for use in mongrp_reparent() to avoid the
- * possibility of failing to allocate it after kernfs_rename() has
- * succeeded.
- */
- if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) {
- ret = -ENOMEM;
- goto out;
- }
-
- /*
- * Perform all input validation and allocations needed to ensure
- * mongrp_reparent() will succeed before calling kernfs_rename(),
- * otherwise it would be necessary to revert this call if
- * mongrp_reparent() failed.
- */
- ret = kernfs_rename(kn, new_parent, new_name);
- if (!ret)
- mongrp_reparent(rdtgrp, new_prdtgrp, tmpmask);
-
- free_cpumask_var(tmpmask);
-
-out:
- mutex_unlock(&rdtgroup_mutex);
- rdtgroup_kn_put(rdtgrp, kn);
- rdtgroup_kn_put(new_prdtgrp, new_parent);
- return ret;
-}
-
-static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf)
-{
- if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3))
- seq_puts(seq, ",cdp");
-
- if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2))
- seq_puts(seq, ",cdpl2");
-
- if (is_mba_sc(resctrl_arch_get_resource(RDT_RESOURCE_MBA)))
- seq_puts(seq, ",mba_MBps");
-
- if (resctrl_debug)
- seq_puts(seq, ",debug");
-
- return 0;
-}
-
-static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = {
- .mkdir = rdtgroup_mkdir,
- .rmdir = rdtgroup_rmdir,
- .rename = rdtgroup_rename,
- .show_options = rdtgroup_show_options,
-};
-
-static int rdtgroup_setup_root(struct rdt_fs_context *ctx)
-{
- rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops,
- KERNFS_ROOT_CREATE_DEACTIVATED |
- KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK,
- &rdtgroup_default);
- if (IS_ERR(rdt_root))
- return PTR_ERR(rdt_root);
-
- ctx->kfc.root = rdt_root;
- rdtgroup_default.kn = kernfs_root_to_node(rdt_root);
-
- return 0;
-}
-
-static void rdtgroup_destroy_root(void)
-{
- lockdep_assert_held(&rdtgroup_mutex);
-
- kernfs_destroy_root(rdt_root);
- rdtgroup_default.kn = NULL;
-}
-
-static void rdtgroup_setup_default(void)
-{
- mutex_lock(&rdtgroup_mutex);
-
- rdtgroup_default.closid = RESCTRL_RESERVED_CLOSID;
- rdtgroup_default.mon.rmid = RESCTRL_RESERVED_RMID;
- rdtgroup_default.type = RDTCTRL_GROUP;
- INIT_LIST_HEAD(&rdtgroup_default.mon.crdtgrp_list);
-
- list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups);
-
- mutex_unlock(&rdtgroup_mutex);
-}
-
-static void domain_destroy_mon_state(struct rdt_mon_domain *d)
-{
- bitmap_free(d->rmid_busy_llc);
- kfree(d->mbm_total);
- kfree(d->mbm_local);
-}
-
-void resctrl_offline_ctrl_domain(struct rdt_resource *r, struct rdt_ctrl_domain *d)
-{
- mutex_lock(&rdtgroup_mutex);
-
- if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA)
- mba_sc_domain_destroy(r, d);
-
- mutex_unlock(&rdtgroup_mutex);
-}
-
-void resctrl_offline_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d)
-{
- mutex_lock(&rdtgroup_mutex);
-
- /*
- * If resctrl is mounted, remove all the
- * per domain monitor data directories.
- */
- if (resctrl_mounted && resctrl_arch_mon_capable())
- rmdir_mondata_subdir_allrdtgrp(r, d);
-
- if (resctrl_is_mbm_enabled())
- cancel_delayed_work(&d->mbm_over);
- if (resctrl_arch_is_llc_occupancy_enabled() && has_busy_rmid(d)) {
- /*
- * When a package is going down, forcefully
- * decrement rmid->ebusy. There is no way to know
- * that the L3 was flushed and hence may lead to
- * incorrect counts in rare scenarios, but leaving
- * the RMID as busy creates RMID leaks if the
- * package never comes back.
- */
- __check_limbo(d, true);
- cancel_delayed_work(&d->cqm_limbo);
- }
-
- domain_destroy_mon_state(d);
-
- mutex_unlock(&rdtgroup_mutex);
-}
-
-/**
- * domain_setup_mon_state() - Initialise domain monitoring structures.
- * @r: The resource for the newly online domain.
- * @d: The newly online domain.
- *
- * Allocate monitor resources that belong to this domain.
- * Called when the first CPU of a domain comes online, regardless of whether
- * the filesystem is mounted.
- * During boot this may be called before global allocations have been made by
- * resctrl_mon_resource_init().
- *
- * Returns 0 for success, or -ENOMEM.
- */
-static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_mon_domain *d)
-{
- u32 idx_limit = resctrl_arch_system_num_rmid_idx();
- size_t tsize;
-
- if (resctrl_arch_is_llc_occupancy_enabled()) {
- d->rmid_busy_llc = bitmap_zalloc(idx_limit, GFP_KERNEL);
- if (!d->rmid_busy_llc)
- return -ENOMEM;
- }
- if (resctrl_arch_is_mbm_total_enabled()) {
- tsize = sizeof(*d->mbm_total);
- d->mbm_total = kcalloc(idx_limit, tsize, GFP_KERNEL);
- if (!d->mbm_total) {
- bitmap_free(d->rmid_busy_llc);
- return -ENOMEM;
- }
- }
- if (resctrl_arch_is_mbm_local_enabled()) {
- tsize = sizeof(*d->mbm_local);
- d->mbm_local = kcalloc(idx_limit, tsize, GFP_KERNEL);
- if (!d->mbm_local) {
- bitmap_free(d->rmid_busy_llc);
- kfree(d->mbm_total);
- return -ENOMEM;
- }
- }
-
- return 0;
-}
-
-int resctrl_online_ctrl_domain(struct rdt_resource *r, struct rdt_ctrl_domain *d)
-{
- int err = 0;
-
- mutex_lock(&rdtgroup_mutex);
-
- if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA) {
- /* RDT_RESOURCE_MBA is never mon_capable */
- err = mba_sc_domain_allocate(r, d);
- }
-
- mutex_unlock(&rdtgroup_mutex);
-
- return err;
-}
-
-int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d)
-{
- int err;
-
- mutex_lock(&rdtgroup_mutex);
-
- err = domain_setup_mon_state(r, d);
- if (err)
- goto out_unlock;
-
- if (resctrl_is_mbm_enabled()) {
- INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow);
- mbm_setup_overflow_handler(d, MBM_OVERFLOW_INTERVAL,
- RESCTRL_PICK_ANY_CPU);
- }
-
- if (resctrl_arch_is_llc_occupancy_enabled())
- INIT_DELAYED_WORK(&d->cqm_limbo, cqm_handle_limbo);
-
- /*
- * If the filesystem is not mounted then only the default resource group
- * exists. Creation of its directories is deferred until mount time
- * by rdt_get_tree() calling mkdir_mondata_all().
- * If resctrl is mounted, add per domain monitor data directories.
- */
- if (resctrl_mounted && resctrl_arch_mon_capable())
- mkdir_mondata_subdir_allrdtgrp(r, d);
-
-out_unlock:
- mutex_unlock(&rdtgroup_mutex);
-
- return err;
-}
-
-void resctrl_online_cpu(unsigned int cpu)
-{
- mutex_lock(&rdtgroup_mutex);
- /* The CPU is set in default rdtgroup after online. */
- cpumask_set_cpu(cpu, &rdtgroup_default.cpu_mask);
- mutex_unlock(&rdtgroup_mutex);
-}
-
-static void clear_childcpus(struct rdtgroup *r, unsigned int cpu)
-{
- struct rdtgroup *cr;
-
- list_for_each_entry(cr, &r->mon.crdtgrp_list, mon.crdtgrp_list) {
- if (cpumask_test_and_clear_cpu(cpu, &cr->cpu_mask))
- break;
- }
-}
-
-static struct rdt_mon_domain *get_mon_domain_from_cpu(int cpu,
- struct rdt_resource *r)
-{
- struct rdt_mon_domain *d;
-
- lockdep_assert_cpus_held();
-
- list_for_each_entry(d, &r->mon_domains, hdr.list) {
- /* Find the domain that contains this CPU */
- if (cpumask_test_cpu(cpu, &d->hdr.cpu_mask))
- return d;
- }
-
- return NULL;
-}
-
-void resctrl_offline_cpu(unsigned int cpu)
-{
- struct rdt_resource *l3 = resctrl_arch_get_resource(RDT_RESOURCE_L3);
- struct rdt_mon_domain *d;
- struct rdtgroup *rdtgrp;
-
- mutex_lock(&rdtgroup_mutex);
- list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
- if (cpumask_test_and_clear_cpu(cpu, &rdtgrp->cpu_mask)) {
- clear_childcpus(rdtgrp, cpu);
- break;
- }
- }
-
- if (!l3->mon_capable)
- goto out_unlock;
-
- d = get_mon_domain_from_cpu(cpu, l3);
- if (d) {
- if (resctrl_is_mbm_enabled() && cpu == d->mbm_work_cpu) {
- cancel_delayed_work(&d->mbm_over);
- mbm_setup_overflow_handler(d, 0, cpu);
- }
- if (resctrl_arch_is_llc_occupancy_enabled() &&
- cpu == d->cqm_work_cpu && has_busy_rmid(d)) {
- cancel_delayed_work(&d->cqm_limbo);
- cqm_setup_limbo_handler(d, 0, cpu);
- }
- }
-
-out_unlock:
- mutex_unlock(&rdtgroup_mutex);
-}
-
-/*
- * resctrl_init - resctrl filesystem initialization
- *
- * Setup resctrl file system including set up root, create mount point,
- * register resctrl filesystem, and initialize files under root directory.
- *
- * Return: 0 on success or -errno
- */
-int resctrl_init(void)
-{
- int ret = 0;
-
- seq_buf_init(&last_cmd_status, last_cmd_status_buf,
- sizeof(last_cmd_status_buf));
-
- rdtgroup_setup_default();
-
- thread_throttle_mode_init();
-
- ret = resctrl_mon_resource_init();
- if (ret)
- return ret;
-
- ret = sysfs_create_mount_point(fs_kobj, "resctrl");
- if (ret) {
- resctrl_mon_resource_exit();
- return ret;
- }
-
- ret = register_filesystem(&rdt_fs_type);
- if (ret)
- goto cleanup_mountpoint;
-
- /*
- * Adding the resctrl debugfs directory here may not be ideal since
- * it would let the resctrl debugfs directory appear on the debugfs
- * filesystem before the resctrl filesystem is mounted.
- * It may also be ok since that would enable debugging of RDT before
- * resctrl is mounted.
- * The reason why the debugfs directory is created here and not in
- * rdt_get_tree() is because rdt_get_tree() takes rdtgroup_mutex and
- * during the debugfs directory creation also &sb->s_type->i_mutex_key
- * (the lockdep class of inode->i_rwsem). Other filesystem
- * interactions (eg. SyS_getdents) have the lock ordering:
- * &sb->s_type->i_mutex_key --> &mm->mmap_lock
- * During mmap(), called with &mm->mmap_lock, the rdtgroup_mutex
- * is taken, thus creating dependency:
- * &mm->mmap_lock --> rdtgroup_mutex for the latter that can cause
- * issues considering the other two lock dependencies.
- * By creating the debugfs directory here we avoid a dependency
- * that may cause deadlock (even though file operations cannot
- * occur until the filesystem is mounted, but I do not know how to
- * tell lockdep that).
- */
- debugfs_resctrl = debugfs_create_dir("resctrl", NULL);
-
- return 0;
-
-cleanup_mountpoint:
- sysfs_remove_mount_point(fs_kobj, "resctrl");
- resctrl_mon_resource_exit();
-
- return ret;
-}
-
-static bool resctrl_online_domains_exist(void)
-{
- struct rdt_resource *r;
-
- /*
- * Only walk capable resources to allow resctrl_arch_get_resource()
- * to return dummy 'not capable' resources.
- */
- for_each_alloc_capable_rdt_resource(r) {
- if (!list_empty(&r->ctrl_domains))
- return true;
- }
-
- for_each_mon_capable_rdt_resource(r) {
- if (!list_empty(&r->mon_domains))
- return true;
- }
-
- return false;
-}
-
-/**
- * resctrl_exit() - Remove the resctrl filesystem and free resources.
- *
- * Called by the architecture code in response to a fatal error.
- * Removes resctrl files and structures from kernfs to prevent further
- * configuration.
- *
- * When called by the architecture code, all CPUs and resctrl domains must be
- * offline. This ensures the limbo and overflow handlers are not scheduled to
- * run, meaning the data structures they access can be freed by
- * resctrl_mon_resource_exit().
- *
- * After resctrl_exit() returns, the architecture code should return an
- * error from all resctrl_arch_ functions that can do this.
- * resctrl_arch_get_resource() must continue to return struct rdt_resources
- * with the correct rid field to ensure the filesystem can be unmounted.
- */
-void resctrl_exit(void)
-{
- cpus_read_lock();
- WARN_ON_ONCE(resctrl_online_domains_exist());
-
- mutex_lock(&rdtgroup_mutex);
- resctrl_fs_teardown();
- mutex_unlock(&rdtgroup_mutex);
-
- cpus_read_unlock();
-
- debugfs_remove_recursive(debugfs_resctrl);
- debugfs_resctrl = NULL;
- unregister_filesystem(&rdt_fs_type);
-
- /*
- * Do not remove the sysfs mount point added by resctrl_init() so that
- * it can be used to umount resctrl.
- */
-
- resctrl_mon_resource_exit();
+ return;
}
diff --git a/fs/resctrl/Kconfig b/fs/resctrl/Kconfig
index 478a8e2..2167130 100644
--- a/fs/resctrl/Kconfig
+++ b/fs/resctrl/Kconfig
@@ -21,7 +21,7 @@ config RESCTRL_FS
On architectures where this can be disabled independently, it is
safe to say N.
- See <file:Documentation/arch/x86/resctrl.rst> for more information.
+ See <file:Documentation/filesystems/resctrl.rst> for more information.
config RESCTRL_FS_PSEUDO_LOCK
bool
diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c
index e69de29..6ed2dfd 100644
--- a/fs/resctrl/ctrlmondata.c
+++ b/fs/resctrl/ctrlmondata.c
@@ -0,0 +1,661 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Resource Director Technology(RDT)
+ * - Cache Allocation code.
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Authors:
+ * Fenghua Yu <fenghua.yu@...el.com>
+ * Tony Luck <tony.luck@...el.com>
+ *
+ * More information about RDT be found in the Intel (R) x86 Architecture
+ * Software Developer Manual June 2016, volume 3, section 17.17.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/cpu.h>
+#include <linux/kernfs.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/tick.h>
+
+#include "internal.h"
+
+struct rdt_parse_data {
+ struct rdtgroup *rdtgrp;
+ char *buf;
+};
+
+typedef int (ctrlval_parser_t)(struct rdt_parse_data *data,
+ struct resctrl_schema *s,
+ struct rdt_ctrl_domain *d);
+
+/*
+ * Check whether MBA bandwidth percentage value is correct. The value is
+ * checked against the minimum and max bandwidth values specified by the
+ * hardware. The allocated bandwidth percentage is rounded to the next
+ * control step available on the hardware.
+ */
+static bool bw_validate(char *buf, u32 *data, struct rdt_resource *r)
+{
+ int ret;
+ u32 bw;
+
+ /*
+ * Only linear delay values is supported for current Intel SKUs.
+ */
+ if (!r->membw.delay_linear && r->membw.arch_needs_linear) {
+ rdt_last_cmd_puts("No support for non-linear MB domains\n");
+ return false;
+ }
+
+ ret = kstrtou32(buf, 10, &bw);
+ if (ret) {
+ rdt_last_cmd_printf("Invalid MB value %s\n", buf);
+ return false;
+ }
+
+ /* Nothing else to do if software controller is enabled. */
+ if (is_mba_sc(r)) {
+ *data = bw;
+ return true;
+ }
+
+ if (bw < r->membw.min_bw || bw > r->membw.max_bw) {
+ rdt_last_cmd_printf("MB value %u out of range [%d,%d]\n",
+ bw, r->membw.min_bw, r->membw.max_bw);
+ return false;
+ }
+
+ *data = roundup(bw, (unsigned long)r->membw.bw_gran);
+ return true;
+}
+
+static int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s,
+ struct rdt_ctrl_domain *d)
+{
+ struct resctrl_staged_config *cfg;
+ u32 closid = data->rdtgrp->closid;
+ struct rdt_resource *r = s->res;
+ u32 bw_val;
+
+ cfg = &d->staged_config[s->conf_type];
+ if (cfg->have_new_ctrl) {
+ rdt_last_cmd_printf("Duplicate domain %d\n", d->hdr.id);
+ return -EINVAL;
+ }
+
+ if (!bw_validate(data->buf, &bw_val, r))
+ return -EINVAL;
+
+ if (is_mba_sc(r)) {
+ d->mbps_val[closid] = bw_val;
+ return 0;
+ }
+
+ cfg->new_ctrl = bw_val;
+ cfg->have_new_ctrl = true;
+
+ return 0;
+}
+
+/*
+ * Check whether a cache bit mask is valid.
+ * On Intel CPUs, non-contiguous 1s value support is indicated by CPUID:
+ * - CPUID.0x10.1:ECX[3]: L3 non-contiguous 1s value supported if 1
+ * - CPUID.0x10.2:ECX[3]: L2 non-contiguous 1s value supported if 1
+ *
+ * Haswell does not support a non-contiguous 1s value and additionally
+ * requires at least two bits set.
+ * AMD allows non-contiguous bitmasks.
+ */
+static bool cbm_validate(char *buf, u32 *data, struct rdt_resource *r)
+{
+ u32 supported_bits = BIT_MASK(r->cache.cbm_len) - 1;
+ unsigned int cbm_len = r->cache.cbm_len;
+ unsigned long first_bit, zero_bit, val;
+ int ret;
+
+ ret = kstrtoul(buf, 16, &val);
+ if (ret) {
+ rdt_last_cmd_printf("Non-hex character in the mask %s\n", buf);
+ return false;
+ }
+
+ if ((r->cache.min_cbm_bits > 0 && val == 0) || val > supported_bits) {
+ rdt_last_cmd_puts("Mask out of range\n");
+ return false;
+ }
+
+ first_bit = find_first_bit(&val, cbm_len);
+ zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
+
+ /* Are non-contiguous bitmasks allowed? */
+ if (!r->cache.arch_has_sparse_bitmasks &&
+ (find_next_bit(&val, cbm_len, zero_bit) < cbm_len)) {
+ rdt_last_cmd_printf("The mask %lx has non-consecutive 1-bits\n", val);
+ return false;
+ }
+
+ if ((zero_bit - first_bit) < r->cache.min_cbm_bits) {
+ rdt_last_cmd_printf("Need at least %d bits in the mask\n",
+ r->cache.min_cbm_bits);
+ return false;
+ }
+
+ *data = val;
+ return true;
+}
+
+/*
+ * Read one cache bit mask (hex). Check that it is valid for the current
+ * resource type.
+ */
+static int parse_cbm(struct rdt_parse_data *data, struct resctrl_schema *s,
+ struct rdt_ctrl_domain *d)
+{
+ struct rdtgroup *rdtgrp = data->rdtgrp;
+ struct resctrl_staged_config *cfg;
+ struct rdt_resource *r = s->res;
+ u32 cbm_val;
+
+ cfg = &d->staged_config[s->conf_type];
+ if (cfg->have_new_ctrl) {
+ rdt_last_cmd_printf("Duplicate domain %d\n", d->hdr.id);
+ return -EINVAL;
+ }
+
+ /*
+ * Cannot set up more than one pseudo-locked region in a cache
+ * hierarchy.
+ */
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
+ rdtgroup_pseudo_locked_in_hierarchy(d)) {
+ rdt_last_cmd_puts("Pseudo-locked region in hierarchy\n");
+ return -EINVAL;
+ }
+
+ if (!cbm_validate(data->buf, &cbm_val, r))
+ return -EINVAL;
+
+ if ((rdtgrp->mode == RDT_MODE_EXCLUSIVE ||
+ rdtgrp->mode == RDT_MODE_SHAREABLE) &&
+ rdtgroup_cbm_overlaps_pseudo_locked(d, cbm_val)) {
+ rdt_last_cmd_puts("CBM overlaps with pseudo-locked region\n");
+ return -EINVAL;
+ }
+
+ /*
+ * The CBM may not overlap with the CBM of another closid if
+ * either is exclusive.
+ */
+ if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, true)) {
+ rdt_last_cmd_puts("Overlaps with exclusive group\n");
+ return -EINVAL;
+ }
+
+ if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, false)) {
+ if (rdtgrp->mode == RDT_MODE_EXCLUSIVE ||
+ rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ rdt_last_cmd_puts("Overlaps with other group\n");
+ return -EINVAL;
+ }
+ }
+
+ cfg->new_ctrl = cbm_val;
+ cfg->have_new_ctrl = true;
+
+ return 0;
+}
+
+/*
+ * For each domain in this resource we expect to find a series of:
+ * id=mask
+ * separated by ";". The "id" is in decimal, and must match one of
+ * the "id"s for this resource.
+ */
+static int parse_line(char *line, struct resctrl_schema *s,
+ struct rdtgroup *rdtgrp)
+{
+ enum resctrl_conf_type t = s->conf_type;
+ ctrlval_parser_t *parse_ctrlval = NULL;
+ struct resctrl_staged_config *cfg;
+ struct rdt_resource *r = s->res;
+ struct rdt_parse_data data;
+ struct rdt_ctrl_domain *d;
+ char *dom = NULL, *id;
+ unsigned long dom_id;
+
+ /* Walking r->domains, ensure it can't race with cpuhp */
+ lockdep_assert_cpus_held();
+
+ switch (r->schema_fmt) {
+ case RESCTRL_SCHEMA_BITMAP:
+ parse_ctrlval = &parse_cbm;
+ break;
+ case RESCTRL_SCHEMA_RANGE:
+ parse_ctrlval = &parse_bw;
+ break;
+ }
+
+ if (WARN_ON_ONCE(!parse_ctrlval))
+ return -EINVAL;
+
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
+ (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA)) {
+ rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n");
+ return -EINVAL;
+ }
+
+next:
+ if (!line || line[0] == '\0')
+ return 0;
+ dom = strsep(&line, ";");
+ id = strsep(&dom, "=");
+ if (!dom || kstrtoul(id, 10, &dom_id)) {
+ rdt_last_cmd_puts("Missing '=' or non-numeric domain\n");
+ return -EINVAL;
+ }
+ dom = strim(dom);
+ list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
+ if (d->hdr.id == dom_id) {
+ data.buf = dom;
+ data.rdtgrp = rdtgrp;
+ if (parse_ctrlval(&data, s, d))
+ return -EINVAL;
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ cfg = &d->staged_config[t];
+ /*
+ * In pseudo-locking setup mode and just
+ * parsed a valid CBM that should be
+ * pseudo-locked. Only one locked region per
+ * resource group and domain so just do
+ * the required initialization for single
+ * region and return.
+ */
+ rdtgrp->plr->s = s;
+ rdtgrp->plr->d = d;
+ rdtgrp->plr->cbm = cfg->new_ctrl;
+ d->plr = rdtgrp->plr;
+ return 0;
+ }
+ goto next;
+ }
+ }
+ return -EINVAL;
+}
+
+static int rdtgroup_parse_resource(char *resname, char *tok,
+ struct rdtgroup *rdtgrp)
+{
+ struct resctrl_schema *s;
+
+ list_for_each_entry(s, &resctrl_schema_all, list) {
+ if (!strcmp(resname, s->name) && rdtgrp->closid < s->num_closid)
+ return parse_line(tok, s, rdtgrp);
+ }
+ rdt_last_cmd_printf("Unknown or unsupported resource name '%s'\n", resname);
+ return -EINVAL;
+}
+
+ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct resctrl_schema *s;
+ struct rdtgroup *rdtgrp;
+ struct rdt_resource *r;
+ char *tok, *resname;
+ int ret = 0;
+
+ /* Valid input requires a trailing newline */
+ if (nbytes == 0 || buf[nbytes - 1] != '\n')
+ return -EINVAL;
+ buf[nbytes - 1] = '\0';
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ rdtgroup_kn_unlock(of->kn);
+ return -ENOENT;
+ }
+ rdt_last_cmd_clear();
+
+ /*
+ * No changes to pseudo-locked region allowed. It has to be removed
+ * and re-created instead.
+ */
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
+ ret = -EINVAL;
+ rdt_last_cmd_puts("Resource group is pseudo-locked\n");
+ goto out;
+ }
+
+ rdt_staged_configs_clear();
+
+ while ((tok = strsep(&buf, "\n")) != NULL) {
+ resname = strim(strsep(&tok, ":"));
+ if (!tok) {
+ rdt_last_cmd_puts("Missing ':'\n");
+ ret = -EINVAL;
+ goto out;
+ }
+ if (tok[0] == '\0') {
+ rdt_last_cmd_printf("Missing '%s' value\n", resname);
+ ret = -EINVAL;
+ goto out;
+ }
+ ret = rdtgroup_parse_resource(resname, tok, rdtgrp);
+ if (ret)
+ goto out;
+ }
+
+ list_for_each_entry(s, &resctrl_schema_all, list) {
+ r = s->res;
+
+ /*
+ * Writes to mba_sc resources update the software controller,
+ * not the control MSR.
+ */
+ if (is_mba_sc(r))
+ continue;
+
+ ret = resctrl_arch_update_domains(r, rdtgrp->closid);
+ if (ret)
+ goto out;
+ }
+
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ /*
+ * If pseudo-locking fails we keep the resource group in
+ * mode RDT_MODE_PSEUDO_LOCKSETUP with its class of service
+ * active and updated for just the domain the pseudo-locked
+ * region was requested for.
+ */
+ ret = rdtgroup_pseudo_lock_create(rdtgrp);
+ }
+
+out:
+ rdt_staged_configs_clear();
+ rdtgroup_kn_unlock(of->kn);
+ return ret ?: nbytes;
+}
+
+static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int closid)
+{
+ struct rdt_resource *r = schema->res;
+ struct rdt_ctrl_domain *dom;
+ bool sep = false;
+ u32 ctrl_val;
+
+ /* Walking r->domains, ensure it can't race with cpuhp */
+ lockdep_assert_cpus_held();
+
+ seq_printf(s, "%*s:", max_name_width, schema->name);
+ list_for_each_entry(dom, &r->ctrl_domains, hdr.list) {
+ if (sep)
+ seq_puts(s, ";");
+
+ if (is_mba_sc(r))
+ ctrl_val = dom->mbps_val[closid];
+ else
+ ctrl_val = resctrl_arch_get_config(r, dom, closid,
+ schema->conf_type);
+
+ seq_printf(s, schema->fmt_str, dom->hdr.id, ctrl_val);
+ sep = true;
+ }
+ seq_puts(s, "\n");
+}
+
+int rdtgroup_schemata_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct resctrl_schema *schema;
+ struct rdtgroup *rdtgrp;
+ int ret = 0;
+ u32 closid;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (rdtgrp) {
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ list_for_each_entry(schema, &resctrl_schema_all, list) {
+ seq_printf(s, "%s:uninitialized\n", schema->name);
+ }
+ } else if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
+ if (!rdtgrp->plr->d) {
+ rdt_last_cmd_clear();
+ rdt_last_cmd_puts("Cache domain offline\n");
+ ret = -ENODEV;
+ } else {
+ seq_printf(s, "%s:%d=%x\n",
+ rdtgrp->plr->s->res->name,
+ rdtgrp->plr->d->hdr.id,
+ rdtgrp->plr->cbm);
+ }
+ } else {
+ closid = rdtgrp->closid;
+ list_for_each_entry(schema, &resctrl_schema_all, list) {
+ if (closid < schema->num_closid)
+ show_doms(s, schema, closid);
+ }
+ }
+ } else {
+ ret = -ENOENT;
+ }
+ rdtgroup_kn_unlock(of->kn);
+ return ret;
+}
+
+static int smp_mon_event_count(void *arg)
+{
+ mon_event_count(arg);
+
+ return 0;
+}
+
+ssize_t rdtgroup_mba_mbps_event_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct rdtgroup *rdtgrp;
+ int ret = 0;
+
+ /* Valid input requires a trailing newline */
+ if (nbytes == 0 || buf[nbytes - 1] != '\n')
+ return -EINVAL;
+ buf[nbytes - 1] = '\0';
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ rdtgroup_kn_unlock(of->kn);
+ return -ENOENT;
+ }
+ rdt_last_cmd_clear();
+
+ if (!strcmp(buf, "mbm_local_bytes")) {
+ if (resctrl_arch_is_mbm_local_enabled())
+ rdtgrp->mba_mbps_event = QOS_L3_MBM_LOCAL_EVENT_ID;
+ else
+ ret = -EINVAL;
+ } else if (!strcmp(buf, "mbm_total_bytes")) {
+ if (resctrl_arch_is_mbm_total_enabled())
+ rdtgrp->mba_mbps_event = QOS_L3_MBM_TOTAL_EVENT_ID;
+ else
+ ret = -EINVAL;
+ } else {
+ ret = -EINVAL;
+ }
+
+ if (ret)
+ rdt_last_cmd_printf("Unsupported event id '%s'\n", buf);
+
+ rdtgroup_kn_unlock(of->kn);
+
+ return ret ?: nbytes;
+}
+
+int rdtgroup_mba_mbps_event_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdtgroup *rdtgrp;
+ int ret = 0;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+
+ if (rdtgrp) {
+ switch (rdtgrp->mba_mbps_event) {
+ case QOS_L3_MBM_LOCAL_EVENT_ID:
+ seq_puts(s, "mbm_local_bytes\n");
+ break;
+ case QOS_L3_MBM_TOTAL_EVENT_ID:
+ seq_puts(s, "mbm_total_bytes\n");
+ break;
+ default:
+ pr_warn_once("Bad event %d\n", rdtgrp->mba_mbps_event);
+ ret = -EINVAL;
+ break;
+ }
+ } else {
+ ret = -ENOENT;
+ }
+
+ rdtgroup_kn_unlock(of->kn);
+
+ return ret;
+}
+
+struct rdt_domain_hdr *resctrl_find_domain(struct list_head *h, int id,
+ struct list_head **pos)
+{
+ struct rdt_domain_hdr *d;
+ struct list_head *l;
+
+ list_for_each(l, h) {
+ d = list_entry(l, struct rdt_domain_hdr, list);
+ /* When id is found, return its domain. */
+ if (id == d->id)
+ return d;
+ /* Stop searching when finding id's position in sorted list. */
+ if (id < d->id)
+ break;
+ }
+
+ if (pos)
+ *pos = l;
+
+ return NULL;
+}
+
+void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
+ struct rdt_mon_domain *d, struct rdtgroup *rdtgrp,
+ cpumask_t *cpumask, int evtid, int first)
+{
+ int cpu;
+
+ /* When picking a CPU from cpu_mask, ensure it can't race with cpuhp */
+ lockdep_assert_cpus_held();
+
+ /*
+ * Setup the parameters to pass to mon_event_count() to read the data.
+ */
+ rr->rgrp = rdtgrp;
+ rr->evtid = evtid;
+ rr->r = r;
+ rr->d = d;
+ rr->first = first;
+ rr->arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, evtid);
+ if (IS_ERR(rr->arch_mon_ctx)) {
+ rr->err = -EINVAL;
+ return;
+ }
+
+ cpu = cpumask_any_housekeeping(cpumask, RESCTRL_PICK_ANY_CPU);
+
+ /*
+ * cpumask_any_housekeeping() prefers housekeeping CPUs, but
+ * are all the CPUs nohz_full? If yes, pick a CPU to IPI.
+ * MPAM's resctrl_arch_rmid_read() is unable to read the
+ * counters on some platforms if its called in IRQ context.
+ */
+ if (tick_nohz_full_cpu(cpu))
+ smp_call_function_any(cpumask, mon_event_count, rr, 1);
+ else
+ smp_call_on_cpu(cpu, smp_mon_event_count, rr, false);
+
+ resctrl_arch_mon_ctx_free(r, evtid, rr->arch_mon_ctx);
+}
+
+int rdtgroup_mondata_show(struct seq_file *m, void *arg)
+{
+ struct kernfs_open_file *of = m->private;
+ enum resctrl_res_level resid;
+ enum resctrl_event_id evtid;
+ struct rdt_domain_hdr *hdr;
+ struct rmid_read rr = {0};
+ struct rdt_mon_domain *d;
+ struct rdtgroup *rdtgrp;
+ struct rdt_resource *r;
+ struct mon_data *md;
+ int domid, ret = 0;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ md = of->kn->priv;
+ if (WARN_ON_ONCE(!md)) {
+ ret = -EIO;
+ goto out;
+ }
+
+ resid = md->rid;
+ domid = md->domid;
+ evtid = md->evtid;
+ r = resctrl_arch_get_resource(resid);
+
+ if (md->sum) {
+ /*
+ * This file requires summing across all domains that share
+ * the L3 cache id that was provided in the "domid" field of the
+ * struct mon_data. Search all domains in the resource for
+ * one that matches this cache id.
+ */
+ list_for_each_entry(d, &r->mon_domains, hdr.list) {
+ if (d->ci->id == domid) {
+ rr.ci = d->ci;
+ mon_event_read(&rr, r, NULL, rdtgrp,
+ &d->ci->shared_cpu_map, evtid, false);
+ goto checkresult;
+ }
+ }
+ ret = -ENOENT;
+ goto out;
+ } else {
+ /*
+ * This file provides data from a single domain. Search
+ * the resource to find the domain with "domid".
+ */
+ hdr = resctrl_find_domain(&r->mon_domains, domid, NULL);
+ if (!hdr || WARN_ON_ONCE(hdr->type != RESCTRL_MON_DOMAIN)) {
+ ret = -ENOENT;
+ goto out;
+ }
+ d = container_of(hdr, struct rdt_mon_domain, hdr);
+ mon_event_read(&rr, r, d, rdtgrp, &d->hdr.cpu_mask, evtid, false);
+ }
+
+checkresult:
+
+ if (rr.err == -EIO)
+ seq_puts(m, "Error\n");
+ else if (rr.err == -EINVAL)
+ seq_puts(m, "Unavailable\n");
+ else
+ seq_printf(m, "%llu\n", rr.val);
+
+out:
+ rdtgroup_kn_unlock(of->kn);
+ return ret;
+}
diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h
index e69de29..9a8cf6f 100644
--- a/fs/resctrl/internal.h
+++ b/fs/resctrl/internal.h
@@ -0,0 +1,426 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _FS_RESCTRL_INTERNAL_H
+#define _FS_RESCTRL_INTERNAL_H
+
+#include <linux/resctrl.h>
+#include <linux/kernfs.h>
+#include <linux/fs_context.h>
+#include <linux/tick.h>
+
+#define CQM_LIMBOCHECK_INTERVAL 1000
+
+/**
+ * cpumask_any_housekeeping() - Choose any CPU in @mask, preferring those that
+ * aren't marked nohz_full
+ * @mask: The mask to pick a CPU from.
+ * @exclude_cpu:The CPU to avoid picking.
+ *
+ * Returns a CPU from @mask, but not @exclude_cpu. If there are housekeeping
+ * CPUs that don't use nohz_full, these are preferred. Pass
+ * RESCTRL_PICK_ANY_CPU to avoid excluding any CPUs.
+ *
+ * When a CPU is excluded, returns >= nr_cpu_ids if no CPUs are available.
+ */
+static inline unsigned int
+cpumask_any_housekeeping(const struct cpumask *mask, int exclude_cpu)
+{
+ unsigned int cpu;
+
+ /* Try to find a CPU that isn't nohz_full to use in preference */
+ if (tick_nohz_full_enabled()) {
+ cpu = cpumask_any_andnot_but(mask, tick_nohz_full_mask, exclude_cpu);
+ if (cpu < nr_cpu_ids)
+ return cpu;
+ }
+
+ return cpumask_any_but(mask, exclude_cpu);
+}
+
+struct rdt_fs_context {
+ struct kernfs_fs_context kfc;
+ bool enable_cdpl2;
+ bool enable_cdpl3;
+ bool enable_mba_mbps;
+ bool enable_debug;
+};
+
+static inline struct rdt_fs_context *rdt_fc2context(struct fs_context *fc)
+{
+ struct kernfs_fs_context *kfc = fc->fs_private;
+
+ return container_of(kfc, struct rdt_fs_context, kfc);
+}
+
+/**
+ * struct mon_evt - Entry in the event list of a resource
+ * @evtid: event id
+ * @name: name of the event
+ * @configurable: true if the event is configurable
+ * @list: entry in &rdt_resource->evt_list
+ */
+struct mon_evt {
+ enum resctrl_event_id evtid;
+ char *name;
+ bool configurable;
+ struct list_head list;
+};
+
+/**
+ * struct mon_data - Monitoring details for each event file.
+ * @list: Member of the global @mon_data_kn_priv_list list.
+ * @rid: Resource id associated with the event file.
+ * @evtid: Event id associated with the event file.
+ * @sum: Set when event must be summed across multiple
+ * domains.
+ * @domid: When @sum is zero this is the domain to which
+ * the event file belongs. When @sum is one this
+ * is the id of the L3 cache that all domains to be
+ * summed share.
+ *
+ * Pointed to by the kernfs kn->priv field of monitoring event files.
+ * Readers and writers must hold rdtgroup_mutex.
+ */
+struct mon_data {
+ struct list_head list;
+ enum resctrl_res_level rid;
+ enum resctrl_event_id evtid;
+ int domid;
+ bool sum;
+};
+
+/**
+ * struct rmid_read - Data passed across smp_call*() to read event count.
+ * @rgrp: Resource group for which the counter is being read. If it is a parent
+ * resource group then its event count is summed with the count from all
+ * its child resource groups.
+ * @r: Resource describing the properties of the event being read.
+ * @d: Domain that the counter should be read from. If NULL then sum all
+ * domains in @r sharing L3 @ci.id
+ * @evtid: Which monitor event to read.
+ * @first: Initialize MBM counter when true.
+ * @ci: Cacheinfo for L3. Only set when @d is NULL. Used when summing domains.
+ * @err: Error encountered when reading counter.
+ * @val: Returned value of event counter. If @rgrp is a parent resource group,
+ * @val includes the sum of event counts from its child resource groups.
+ * If @d is NULL, @val includes the sum of all domains in @r sharing @ci.id,
+ * (summed across child resource groups if @rgrp is a parent resource group).
+ * @arch_mon_ctx: Hardware monitor allocated for this read request (MPAM only).
+ */
+struct rmid_read {
+ struct rdtgroup *rgrp;
+ struct rdt_resource *r;
+ struct rdt_mon_domain *d;
+ enum resctrl_event_id evtid;
+ bool first;
+ struct cacheinfo *ci;
+ int err;
+ u64 val;
+ void *arch_mon_ctx;
+};
+
+extern struct list_head resctrl_schema_all;
+
+extern bool resctrl_mounted;
+
+enum rdt_group_type {
+ RDTCTRL_GROUP = 0,
+ RDTMON_GROUP,
+ RDT_NUM_GROUP,
+};
+
+/**
+ * enum rdtgrp_mode - Mode of a RDT resource group
+ * @RDT_MODE_SHAREABLE: This resource group allows sharing of its allocations
+ * @RDT_MODE_EXCLUSIVE: No sharing of this resource group's allocations allowed
+ * @RDT_MODE_PSEUDO_LOCKSETUP: Resource group will be used for Pseudo-Locking
+ * @RDT_MODE_PSEUDO_LOCKED: No sharing of this resource group's allocations
+ * allowed AND the allocations are Cache Pseudo-Locked
+ * @RDT_NUM_MODES: Total number of modes
+ *
+ * The mode of a resource group enables control over the allowed overlap
+ * between allocations associated with different resource groups (classes
+ * of service). User is able to modify the mode of a resource group by
+ * writing to the "mode" resctrl file associated with the resource group.
+ *
+ * The "shareable", "exclusive", and "pseudo-locksetup" modes are set by
+ * writing the appropriate text to the "mode" file. A resource group enters
+ * "pseudo-locked" mode after the schemata is written while the resource
+ * group is in "pseudo-locksetup" mode.
+ */
+enum rdtgrp_mode {
+ RDT_MODE_SHAREABLE = 0,
+ RDT_MODE_EXCLUSIVE,
+ RDT_MODE_PSEUDO_LOCKSETUP,
+ RDT_MODE_PSEUDO_LOCKED,
+
+ /* Must be last */
+ RDT_NUM_MODES,
+};
+
+/**
+ * struct mongroup - store mon group's data in resctrl fs.
+ * @mon_data_kn: kernfs node for the mon_data directory
+ * @parent: parent rdtgrp
+ * @crdtgrp_list: child rdtgroup node list
+ * @rmid: rmid for this rdtgroup
+ */
+struct mongroup {
+ struct kernfs_node *mon_data_kn;
+ struct rdtgroup *parent;
+ struct list_head crdtgrp_list;
+ u32 rmid;
+};
+
+/**
+ * struct rdtgroup - store rdtgroup's data in resctrl file system.
+ * @kn: kernfs node
+ * @rdtgroup_list: linked list for all rdtgroups
+ * @closid: closid for this rdtgroup
+ * @cpu_mask: CPUs assigned to this rdtgroup
+ * @flags: status bits
+ * @waitcount: how many cpus expect to find this
+ * group when they acquire rdtgroup_mutex
+ * @type: indicates type of this rdtgroup - either
+ * monitor only or ctrl_mon group
+ * @mon: mongroup related data
+ * @mode: mode of resource group
+ * @mba_mbps_event: input monitoring event id when mba_sc is enabled
+ * @plr: pseudo-locked region
+ */
+struct rdtgroup {
+ struct kernfs_node *kn;
+ struct list_head rdtgroup_list;
+ u32 closid;
+ struct cpumask cpu_mask;
+ int flags;
+ atomic_t waitcount;
+ enum rdt_group_type type;
+ struct mongroup mon;
+ enum rdtgrp_mode mode;
+ enum resctrl_event_id mba_mbps_event;
+ struct pseudo_lock_region *plr;
+};
+
+/* rdtgroup.flags */
+#define RDT_DELETED 1
+
+/* rftype.flags */
+#define RFTYPE_FLAGS_CPUS_LIST 1
+
+/*
+ * Define the file type flags for base and info directories.
+ */
+#define RFTYPE_INFO BIT(0)
+
+#define RFTYPE_BASE BIT(1)
+
+#define RFTYPE_CTRL BIT(4)
+
+#define RFTYPE_MON BIT(5)
+
+#define RFTYPE_TOP BIT(6)
+
+#define RFTYPE_RES_CACHE BIT(8)
+
+#define RFTYPE_RES_MB BIT(9)
+
+#define RFTYPE_DEBUG BIT(10)
+
+#define RFTYPE_CTRL_INFO (RFTYPE_INFO | RFTYPE_CTRL)
+
+#define RFTYPE_MON_INFO (RFTYPE_INFO | RFTYPE_MON)
+
+#define RFTYPE_TOP_INFO (RFTYPE_INFO | RFTYPE_TOP)
+
+#define RFTYPE_CTRL_BASE (RFTYPE_BASE | RFTYPE_CTRL)
+
+#define RFTYPE_MON_BASE (RFTYPE_BASE | RFTYPE_MON)
+
+/* List of all resource groups */
+extern struct list_head rdt_all_groups;
+
+extern int max_name_width;
+
+/**
+ * struct rftype - describe each file in the resctrl file system
+ * @name: File name
+ * @mode: Access mode
+ * @kf_ops: File operations
+ * @flags: File specific RFTYPE_FLAGS_* flags
+ * @fflags: File specific RFTYPE_* flags
+ * @seq_show: Show content of the file
+ * @write: Write to the file
+ */
+struct rftype {
+ char *name;
+ umode_t mode;
+ const struct kernfs_ops *kf_ops;
+ unsigned long flags;
+ unsigned long fflags;
+
+ int (*seq_show)(struct kernfs_open_file *of,
+ struct seq_file *sf, void *v);
+ /*
+ * write() is the generic write callback which maps directly to
+ * kernfs write operation and overrides all other operations.
+ * Maximum write size is determined by ->max_write_len.
+ */
+ ssize_t (*write)(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off);
+};
+
+/**
+ * struct mbm_state - status for each MBM counter in each domain
+ * @prev_bw_bytes: Previous bytes value read for bandwidth calculation
+ * @prev_bw: The most recent bandwidth in MBps
+ */
+struct mbm_state {
+ u64 prev_bw_bytes;
+ u32 prev_bw;
+};
+
+extern struct mutex rdtgroup_mutex;
+
+static inline const char *rdt_kn_name(const struct kernfs_node *kn)
+{
+ return rcu_dereference_check(kn->name, lockdep_is_held(&rdtgroup_mutex));
+}
+
+extern struct rdtgroup rdtgroup_default;
+
+extern struct dentry *debugfs_resctrl;
+
+extern enum resctrl_event_id mba_mbps_default_event;
+
+void rdt_last_cmd_clear(void);
+
+void rdt_last_cmd_puts(const char *s);
+
+__printf(1, 2)
+void rdt_last_cmd_printf(const char *fmt, ...);
+
+struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn);
+
+void rdtgroup_kn_unlock(struct kernfs_node *kn);
+
+int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name);
+
+int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name,
+ umode_t mask);
+
+ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off);
+
+int rdtgroup_schemata_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v);
+
+ssize_t rdtgroup_mba_mbps_event_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off);
+
+int rdtgroup_mba_mbps_event_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v);
+
+bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_ctrl_domain *d,
+ unsigned long cbm, int closid, bool exclusive);
+
+unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, struct rdt_ctrl_domain *d,
+ unsigned long cbm);
+
+enum rdtgrp_mode rdtgroup_mode_by_closid(int closid);
+
+int rdtgroup_tasks_assigned(struct rdtgroup *r);
+
+int closids_supported(void);
+
+void closid_free(int closid);
+
+int alloc_rmid(u32 closid);
+
+void free_rmid(u32 closid, u32 rmid);
+
+void resctrl_mon_resource_exit(void);
+
+void mon_event_count(void *info);
+
+int rdtgroup_mondata_show(struct seq_file *m, void *arg);
+
+void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
+ struct rdt_mon_domain *d, struct rdtgroup *rdtgrp,
+ cpumask_t *cpumask, int evtid, int first);
+
+int resctrl_mon_resource_init(void);
+
+void mbm_setup_overflow_handler(struct rdt_mon_domain *dom,
+ unsigned long delay_ms,
+ int exclude_cpu);
+
+void mbm_handle_overflow(struct work_struct *work);
+
+bool is_mba_sc(struct rdt_resource *r);
+
+void cqm_setup_limbo_handler(struct rdt_mon_domain *dom, unsigned long delay_ms,
+ int exclude_cpu);
+
+void cqm_handle_limbo(struct work_struct *work);
+
+bool has_busy_rmid(struct rdt_mon_domain *d);
+
+void __check_limbo(struct rdt_mon_domain *d, bool force_free);
+
+void resctrl_file_fflags_init(const char *config, unsigned long fflags);
+
+void rdt_staged_configs_clear(void);
+
+bool closid_allocated(unsigned int closid);
+
+int resctrl_find_cleanest_closid(void);
+
+#ifdef CONFIG_RESCTRL_FS_PSEUDO_LOCK
+int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp);
+
+int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp);
+
+bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_ctrl_domain *d, unsigned long cbm);
+
+bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d);
+
+int rdt_pseudo_lock_init(void);
+
+void rdt_pseudo_lock_release(void);
+
+int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp);
+
+void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp);
+
+#else
+static inline int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_ctrl_domain *d, unsigned long cbm)
+{
+ return false;
+}
+
+static inline bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d)
+{
+ return false;
+}
+
+static inline int rdt_pseudo_lock_init(void) { return 0; }
+static inline void rdt_pseudo_lock_release(void) { }
+static inline int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp) { }
+#endif /* CONFIG_RESCTRL_FS_PSEUDO_LOCK */
+
+#endif /* _FS_RESCTRL_INTERNAL_H */
diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c
index e69de29..bde2801 100644
--- a/fs/resctrl/monitor.c
+++ b/fs/resctrl/monitor.c
@@ -0,0 +1,929 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Resource Director Technology(RDT)
+ * - Monitoring code
+ *
+ * Copyright (C) 2017 Intel Corporation
+ *
+ * Author:
+ * Vikas Shivappa <vikas.shivappa@...el.com>
+ *
+ * This replaces the cqm.c based on perf but we reuse a lot of
+ * code and datastructures originally from Peter Zijlstra and Matt Fleming.
+ *
+ * More information about RDT be found in the Intel (R) x86 Architecture
+ * Software Developer Manual June 2016, volume 3, section 17.17.
+ */
+
+#define pr_fmt(fmt) "resctrl: " fmt
+
+#include <linux/cpu.h>
+#include <linux/resctrl.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+
+#include "internal.h"
+
+#define CREATE_TRACE_POINTS
+
+#include "monitor_trace.h"
+
+/**
+ * struct rmid_entry - dirty tracking for all RMID.
+ * @closid: The CLOSID for this entry.
+ * @rmid: The RMID for this entry.
+ * @busy: The number of domains with cached data using this RMID.
+ * @list: Member of the rmid_free_lru list when busy == 0.
+ *
+ * Depending on the architecture the correct monitor is accessed using
+ * both @closid and @rmid, or @rmid only.
+ *
+ * Take the rdtgroup_mutex when accessing.
+ */
+struct rmid_entry {
+ u32 closid;
+ u32 rmid;
+ int busy;
+ struct list_head list;
+};
+
+/*
+ * @rmid_free_lru - A least recently used list of free RMIDs
+ * These RMIDs are guaranteed to have an occupancy less than the
+ * threshold occupancy
+ */
+static LIST_HEAD(rmid_free_lru);
+
+/*
+ * @closid_num_dirty_rmid The number of dirty RMID each CLOSID has.
+ * Only allocated when CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID is defined.
+ * Indexed by CLOSID. Protected by rdtgroup_mutex.
+ */
+static u32 *closid_num_dirty_rmid;
+
+/*
+ * @rmid_limbo_count - count of currently unused but (potentially)
+ * dirty RMIDs.
+ * This counts RMIDs that no one is currently using but that
+ * may have a occupancy value > resctrl_rmid_realloc_threshold. User can
+ * change the threshold occupancy value.
+ */
+static unsigned int rmid_limbo_count;
+
+/*
+ * @rmid_entry - The entry in the limbo and free lists.
+ */
+static struct rmid_entry *rmid_ptrs;
+
+/*
+ * This is the threshold cache occupancy in bytes at which we will consider an
+ * RMID available for re-allocation.
+ */
+unsigned int resctrl_rmid_realloc_threshold;
+
+/*
+ * This is the maximum value for the reallocation threshold, in bytes.
+ */
+unsigned int resctrl_rmid_realloc_limit;
+
+/*
+ * x86 and arm64 differ in their handling of monitoring.
+ * x86's RMID are independent numbers, there is only one source of traffic
+ * with an RMID value of '1'.
+ * arm64's PMG extends the PARTID/CLOSID space, there are multiple sources of
+ * traffic with a PMG value of '1', one for each CLOSID, meaning the RMID
+ * value is no longer unique.
+ * To account for this, resctrl uses an index. On x86 this is just the RMID,
+ * on arm64 it encodes the CLOSID and RMID. This gives a unique number.
+ *
+ * The domain's rmid_busy_llc and rmid_ptrs[] are sized by index. The arch code
+ * must accept an attempt to read every index.
+ */
+static inline struct rmid_entry *__rmid_entry(u32 idx)
+{
+ struct rmid_entry *entry;
+ u32 closid, rmid;
+
+ entry = &rmid_ptrs[idx];
+ resctrl_arch_rmid_idx_decode(idx, &closid, &rmid);
+
+ WARN_ON_ONCE(entry->closid != closid);
+ WARN_ON_ONCE(entry->rmid != rmid);
+
+ return entry;
+}
+
+static void limbo_release_entry(struct rmid_entry *entry)
+{
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ rmid_limbo_count--;
+ list_add_tail(&entry->list, &rmid_free_lru);
+
+ if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID))
+ closid_num_dirty_rmid[entry->closid]--;
+}
+
+/*
+ * Check the RMIDs that are marked as busy for this domain. If the
+ * reported LLC occupancy is below the threshold clear the busy bit and
+ * decrement the count. If the busy count gets to zero on an RMID, we
+ * free the RMID
+ */
+void __check_limbo(struct rdt_mon_domain *d, bool force_free)
+{
+ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+ u32 idx_limit = resctrl_arch_system_num_rmid_idx();
+ struct rmid_entry *entry;
+ u32 idx, cur_idx = 1;
+ void *arch_mon_ctx;
+ bool rmid_dirty;
+ u64 val = 0;
+
+ arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, QOS_L3_OCCUP_EVENT_ID);
+ if (IS_ERR(arch_mon_ctx)) {
+ pr_warn_ratelimited("Failed to allocate monitor context: %ld",
+ PTR_ERR(arch_mon_ctx));
+ return;
+ }
+
+ /*
+ * Skip RMID 0 and start from RMID 1 and check all the RMIDs that
+ * are marked as busy for occupancy < threshold. If the occupancy
+ * is less than the threshold decrement the busy counter of the
+ * RMID and move it to the free list when the counter reaches 0.
+ */
+ for (;;) {
+ idx = find_next_bit(d->rmid_busy_llc, idx_limit, cur_idx);
+ if (idx >= idx_limit)
+ break;
+
+ entry = __rmid_entry(idx);
+ if (resctrl_arch_rmid_read(r, d, entry->closid, entry->rmid,
+ QOS_L3_OCCUP_EVENT_ID, &val,
+ arch_mon_ctx)) {
+ rmid_dirty = true;
+ } else {
+ rmid_dirty = (val >= resctrl_rmid_realloc_threshold);
+
+ /*
+ * x86's CLOSID and RMID are independent numbers, so the entry's
+ * CLOSID is an empty CLOSID (X86_RESCTRL_EMPTY_CLOSID). On Arm the
+ * RMID (PMG) extends the CLOSID (PARTID) space with bits that aren't
+ * used to select the configuration. It is thus necessary to track both
+ * CLOSID and RMID because there may be dependencies between them
+ * on some architectures.
+ */
+ trace_mon_llc_occupancy_limbo(entry->closid, entry->rmid, d->hdr.id, val);
+ }
+
+ if (force_free || !rmid_dirty) {
+ clear_bit(idx, d->rmid_busy_llc);
+ if (!--entry->busy)
+ limbo_release_entry(entry);
+ }
+ cur_idx = idx + 1;
+ }
+
+ resctrl_arch_mon_ctx_free(r, QOS_L3_OCCUP_EVENT_ID, arch_mon_ctx);
+}
+
+bool has_busy_rmid(struct rdt_mon_domain *d)
+{
+ u32 idx_limit = resctrl_arch_system_num_rmid_idx();
+
+ return find_first_bit(d->rmid_busy_llc, idx_limit) != idx_limit;
+}
+
+static struct rmid_entry *resctrl_find_free_rmid(u32 closid)
+{
+ struct rmid_entry *itr;
+ u32 itr_idx, cmp_idx;
+
+ if (list_empty(&rmid_free_lru))
+ return rmid_limbo_count ? ERR_PTR(-EBUSY) : ERR_PTR(-ENOSPC);
+
+ list_for_each_entry(itr, &rmid_free_lru, list) {
+ /*
+ * Get the index of this free RMID, and the index it would need
+ * to be if it were used with this CLOSID.
+ * If the CLOSID is irrelevant on this architecture, the two
+ * index values are always the same on every entry and thus the
+ * very first entry will be returned.
+ */
+ itr_idx = resctrl_arch_rmid_idx_encode(itr->closid, itr->rmid);
+ cmp_idx = resctrl_arch_rmid_idx_encode(closid, itr->rmid);
+
+ if (itr_idx == cmp_idx)
+ return itr;
+ }
+
+ return ERR_PTR(-ENOSPC);
+}
+
+/**
+ * resctrl_find_cleanest_closid() - Find a CLOSID where all the associated
+ * RMID are clean, or the CLOSID that has
+ * the most clean RMID.
+ *
+ * MPAM's equivalent of RMID are per-CLOSID, meaning a freshly allocated CLOSID
+ * may not be able to allocate clean RMID. To avoid this the allocator will
+ * choose the CLOSID with the most clean RMID.
+ *
+ * When the CLOSID and RMID are independent numbers, the first free CLOSID will
+ * be returned.
+ */
+int resctrl_find_cleanest_closid(void)
+{
+ u32 cleanest_closid = ~0;
+ int i = 0;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ if (!IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID))
+ return -EIO;
+
+ for (i = 0; i < closids_supported(); i++) {
+ int num_dirty;
+
+ if (closid_allocated(i))
+ continue;
+
+ num_dirty = closid_num_dirty_rmid[i];
+ if (num_dirty == 0)
+ return i;
+
+ if (cleanest_closid == ~0)
+ cleanest_closid = i;
+
+ if (num_dirty < closid_num_dirty_rmid[cleanest_closid])
+ cleanest_closid = i;
+ }
+
+ if (cleanest_closid == ~0)
+ return -ENOSPC;
+
+ return cleanest_closid;
+}
+
+/*
+ * For MPAM the RMID value is not unique, and has to be considered with
+ * the CLOSID. The (CLOSID, RMID) pair is allocated on all domains, which
+ * allows all domains to be managed by a single free list.
+ * Each domain also has a rmid_busy_llc to reduce the work of the limbo handler.
+ */
+int alloc_rmid(u32 closid)
+{
+ struct rmid_entry *entry;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ entry = resctrl_find_free_rmid(closid);
+ if (IS_ERR(entry))
+ return PTR_ERR(entry);
+
+ list_del(&entry->list);
+ return entry->rmid;
+}
+
+static void add_rmid_to_limbo(struct rmid_entry *entry)
+{
+ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+ struct rdt_mon_domain *d;
+ u32 idx;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ /* Walking r->domains, ensure it can't race with cpuhp */
+ lockdep_assert_cpus_held();
+
+ idx = resctrl_arch_rmid_idx_encode(entry->closid, entry->rmid);
+
+ entry->busy = 0;
+ list_for_each_entry(d, &r->mon_domains, hdr.list) {
+ /*
+ * For the first limbo RMID in the domain,
+ * setup up the limbo worker.
+ */
+ if (!has_busy_rmid(d))
+ cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL,
+ RESCTRL_PICK_ANY_CPU);
+ set_bit(idx, d->rmid_busy_llc);
+ entry->busy++;
+ }
+
+ rmid_limbo_count++;
+ if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID))
+ closid_num_dirty_rmid[entry->closid]++;
+}
+
+void free_rmid(u32 closid, u32 rmid)
+{
+ u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid);
+ struct rmid_entry *entry;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ /*
+ * Do not allow the default rmid to be free'd. Comparing by index
+ * allows architectures that ignore the closid parameter to avoid an
+ * unnecessary check.
+ */
+ if (!resctrl_arch_mon_capable() ||
+ idx == resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID,
+ RESCTRL_RESERVED_RMID))
+ return;
+
+ entry = __rmid_entry(idx);
+
+ if (resctrl_arch_is_llc_occupancy_enabled())
+ add_rmid_to_limbo(entry);
+ else
+ list_add_tail(&entry->list, &rmid_free_lru);
+}
+
+static struct mbm_state *get_mbm_state(struct rdt_mon_domain *d, u32 closid,
+ u32 rmid, enum resctrl_event_id evtid)
+{
+ u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid);
+
+ switch (evtid) {
+ case QOS_L3_MBM_TOTAL_EVENT_ID:
+ return &d->mbm_total[idx];
+ case QOS_L3_MBM_LOCAL_EVENT_ID:
+ return &d->mbm_local[idx];
+ default:
+ return NULL;
+ }
+}
+
+static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr)
+{
+ int cpu = smp_processor_id();
+ struct rdt_mon_domain *d;
+ struct mbm_state *m;
+ int err, ret;
+ u64 tval = 0;
+
+ if (rr->first) {
+ resctrl_arch_reset_rmid(rr->r, rr->d, closid, rmid, rr->evtid);
+ m = get_mbm_state(rr->d, closid, rmid, rr->evtid);
+ if (m)
+ memset(m, 0, sizeof(struct mbm_state));
+ return 0;
+ }
+
+ if (rr->d) {
+ /* Reading a single domain, must be on a CPU in that domain. */
+ if (!cpumask_test_cpu(cpu, &rr->d->hdr.cpu_mask))
+ return -EINVAL;
+ rr->err = resctrl_arch_rmid_read(rr->r, rr->d, closid, rmid,
+ rr->evtid, &tval, rr->arch_mon_ctx);
+ if (rr->err)
+ return rr->err;
+
+ rr->val += tval;
+
+ return 0;
+ }
+
+ /* Summing domains that share a cache, must be on a CPU for that cache. */
+ if (!cpumask_test_cpu(cpu, &rr->ci->shared_cpu_map))
+ return -EINVAL;
+
+ /*
+ * Legacy files must report the sum of an event across all
+ * domains that share the same L3 cache instance.
+ * Report success if a read from any domain succeeds, -EINVAL
+ * (translated to "Unavailable" for user space) if reading from
+ * all domains fail for any reason.
+ */
+ ret = -EINVAL;
+ list_for_each_entry(d, &rr->r->mon_domains, hdr.list) {
+ if (d->ci->id != rr->ci->id)
+ continue;
+ err = resctrl_arch_rmid_read(rr->r, d, closid, rmid,
+ rr->evtid, &tval, rr->arch_mon_ctx);
+ if (!err) {
+ rr->val += tval;
+ ret = 0;
+ }
+ }
+
+ if (ret)
+ rr->err = ret;
+
+ return ret;
+}
+
+/*
+ * mbm_bw_count() - Update bw count from values previously read by
+ * __mon_event_count().
+ * @closid: The closid used to identify the cached mbm_state.
+ * @rmid: The rmid used to identify the cached mbm_state.
+ * @rr: The struct rmid_read populated by __mon_event_count().
+ *
+ * Supporting function to calculate the memory bandwidth
+ * and delta bandwidth in MBps. The chunks value previously read by
+ * __mon_event_count() is compared with the chunks value from the previous
+ * invocation. This must be called once per second to maintain values in MBps.
+ */
+static void mbm_bw_count(u32 closid, u32 rmid, struct rmid_read *rr)
+{
+ u64 cur_bw, bytes, cur_bytes;
+ struct mbm_state *m;
+
+ m = get_mbm_state(rr->d, closid, rmid, rr->evtid);
+ if (WARN_ON_ONCE(!m))
+ return;
+
+ cur_bytes = rr->val;
+ bytes = cur_bytes - m->prev_bw_bytes;
+ m->prev_bw_bytes = cur_bytes;
+
+ cur_bw = bytes / SZ_1M;
+
+ m->prev_bw = cur_bw;
+}
+
+/*
+ * This is scheduled by mon_event_read() to read the CQM/MBM counters
+ * on a domain.
+ */
+void mon_event_count(void *info)
+{
+ struct rdtgroup *rdtgrp, *entry;
+ struct rmid_read *rr = info;
+ struct list_head *head;
+ int ret;
+
+ rdtgrp = rr->rgrp;
+
+ ret = __mon_event_count(rdtgrp->closid, rdtgrp->mon.rmid, rr);
+
+ /*
+ * For Ctrl groups read data from child monitor groups and
+ * add them together. Count events which are read successfully.
+ * Discard the rmid_read's reporting errors.
+ */
+ head = &rdtgrp->mon.crdtgrp_list;
+
+ if (rdtgrp->type == RDTCTRL_GROUP) {
+ list_for_each_entry(entry, head, mon.crdtgrp_list) {
+ if (__mon_event_count(entry->closid, entry->mon.rmid,
+ rr) == 0)
+ ret = 0;
+ }
+ }
+
+ /*
+ * __mon_event_count() calls for newly created monitor groups may
+ * report -EINVAL/Unavailable if the monitor hasn't seen any traffic.
+ * Discard error if any of the monitor event reads succeeded.
+ */
+ if (ret == 0)
+ rr->err = 0;
+}
+
+static struct rdt_ctrl_domain *get_ctrl_domain_from_cpu(int cpu,
+ struct rdt_resource *r)
+{
+ struct rdt_ctrl_domain *d;
+
+ lockdep_assert_cpus_held();
+
+ list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
+ /* Find the domain that contains this CPU */
+ if (cpumask_test_cpu(cpu, &d->hdr.cpu_mask))
+ return d;
+ }
+
+ return NULL;
+}
+
+/*
+ * Feedback loop for MBA software controller (mba_sc)
+ *
+ * mba_sc is a feedback loop where we periodically read MBM counters and
+ * adjust the bandwidth percentage values via the IA32_MBA_THRTL_MSRs so
+ * that:
+ *
+ * current bandwidth(cur_bw) < user specified bandwidth(user_bw)
+ *
+ * This uses the MBM counters to measure the bandwidth and MBA throttle
+ * MSRs to control the bandwidth for a particular rdtgrp. It builds on the
+ * fact that resctrl rdtgroups have both monitoring and control.
+ *
+ * The frequency of the checks is 1s and we just tag along the MBM overflow
+ * timer. Having 1s interval makes the calculation of bandwidth simpler.
+ *
+ * Although MBA's goal is to restrict the bandwidth to a maximum, there may
+ * be a need to increase the bandwidth to avoid unnecessarily restricting
+ * the L2 <-> L3 traffic.
+ *
+ * Since MBA controls the L2 external bandwidth where as MBM measures the
+ * L3 external bandwidth the following sequence could lead to such a
+ * situation.
+ *
+ * Consider an rdtgroup which had high L3 <-> memory traffic in initial
+ * phases -> mba_sc kicks in and reduced bandwidth percentage values -> but
+ * after some time rdtgroup has mostly L2 <-> L3 traffic.
+ *
+ * In this case we may restrict the rdtgroup's L2 <-> L3 traffic as its
+ * throttle MSRs already have low percentage values. To avoid
+ * unnecessarily restricting such rdtgroups, we also increase the bandwidth.
+ */
+static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_mon_domain *dom_mbm)
+{
+ u32 closid, rmid, cur_msr_val, new_msr_val;
+ struct mbm_state *pmbm_data, *cmbm_data;
+ struct rdt_ctrl_domain *dom_mba;
+ enum resctrl_event_id evt_id;
+ struct rdt_resource *r_mba;
+ struct list_head *head;
+ struct rdtgroup *entry;
+ u32 cur_bw, user_bw;
+
+ r_mba = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
+ evt_id = rgrp->mba_mbps_event;
+
+ closid = rgrp->closid;
+ rmid = rgrp->mon.rmid;
+ pmbm_data = get_mbm_state(dom_mbm, closid, rmid, evt_id);
+ if (WARN_ON_ONCE(!pmbm_data))
+ return;
+
+ dom_mba = get_ctrl_domain_from_cpu(smp_processor_id(), r_mba);
+ if (!dom_mba) {
+ pr_warn_once("Failure to get domain for MBA update\n");
+ return;
+ }
+
+ cur_bw = pmbm_data->prev_bw;
+ user_bw = dom_mba->mbps_val[closid];
+
+ /* MBA resource doesn't support CDP */
+ cur_msr_val = resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE);
+
+ /*
+ * For Ctrl groups read data from child monitor groups.
+ */
+ head = &rgrp->mon.crdtgrp_list;
+ list_for_each_entry(entry, head, mon.crdtgrp_list) {
+ cmbm_data = get_mbm_state(dom_mbm, entry->closid, entry->mon.rmid, evt_id);
+ if (WARN_ON_ONCE(!cmbm_data))
+ return;
+ cur_bw += cmbm_data->prev_bw;
+ }
+
+ /*
+ * Scale up/down the bandwidth linearly for the ctrl group. The
+ * bandwidth step is the bandwidth granularity specified by the
+ * hardware.
+ * Always increase throttling if current bandwidth is above the
+ * target set by user.
+ * But avoid thrashing up and down on every poll by checking
+ * whether a decrease in throttling is likely to push the group
+ * back over target. E.g. if currently throttling to 30% of bandwidth
+ * on a system with 10% granularity steps, check whether moving to
+ * 40% would go past the limit by multiplying current bandwidth by
+ * "(30 + 10) / 30".
+ */
+ if (cur_msr_val > r_mba->membw.min_bw && user_bw < cur_bw) {
+ new_msr_val = cur_msr_val - r_mba->membw.bw_gran;
+ } else if (cur_msr_val < MAX_MBA_BW &&
+ (user_bw > (cur_bw * (cur_msr_val + r_mba->membw.min_bw) / cur_msr_val))) {
+ new_msr_val = cur_msr_val + r_mba->membw.bw_gran;
+ } else {
+ return;
+ }
+
+ resctrl_arch_update_one(r_mba, dom_mba, closid, CDP_NONE, new_msr_val);
+}
+
+static void mbm_update_one_event(struct rdt_resource *r, struct rdt_mon_domain *d,
+ u32 closid, u32 rmid, enum resctrl_event_id evtid)
+{
+ struct rmid_read rr = {0};
+
+ rr.r = r;
+ rr.d = d;
+ rr.evtid = evtid;
+ rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
+ if (IS_ERR(rr.arch_mon_ctx)) {
+ pr_warn_ratelimited("Failed to allocate monitor context: %ld",
+ PTR_ERR(rr.arch_mon_ctx));
+ return;
+ }
+
+ __mon_event_count(closid, rmid, &rr);
+
+ /*
+ * If the software controller is enabled, compute the
+ * bandwidth for this event id.
+ */
+ if (is_mba_sc(NULL))
+ mbm_bw_count(closid, rmid, &rr);
+
+ resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
+}
+
+static void mbm_update(struct rdt_resource *r, struct rdt_mon_domain *d,
+ u32 closid, u32 rmid)
+{
+ /*
+ * This is protected from concurrent reads from user as both
+ * the user and overflow handler hold the global mutex.
+ */
+ if (resctrl_arch_is_mbm_total_enabled())
+ mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_TOTAL_EVENT_ID);
+
+ if (resctrl_arch_is_mbm_local_enabled())
+ mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_LOCAL_EVENT_ID);
+}
+
+/*
+ * Handler to scan the limbo list and move the RMIDs
+ * to free list whose occupancy < threshold_occupancy.
+ */
+void cqm_handle_limbo(struct work_struct *work)
+{
+ unsigned long delay = msecs_to_jiffies(CQM_LIMBOCHECK_INTERVAL);
+ struct rdt_mon_domain *d;
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+
+ d = container_of(work, struct rdt_mon_domain, cqm_limbo.work);
+
+ __check_limbo(d, false);
+
+ if (has_busy_rmid(d)) {
+ d->cqm_work_cpu = cpumask_any_housekeeping(&d->hdr.cpu_mask,
+ RESCTRL_PICK_ANY_CPU);
+ schedule_delayed_work_on(d->cqm_work_cpu, &d->cqm_limbo,
+ delay);
+ }
+
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+}
+
+/**
+ * cqm_setup_limbo_handler() - Schedule the limbo handler to run for this
+ * domain.
+ * @dom: The domain the limbo handler should run for.
+ * @delay_ms: How far in the future the handler should run.
+ * @exclude_cpu: Which CPU the handler should not run on,
+ * RESCTRL_PICK_ANY_CPU to pick any CPU.
+ */
+void cqm_setup_limbo_handler(struct rdt_mon_domain *dom, unsigned long delay_ms,
+ int exclude_cpu)
+{
+ unsigned long delay = msecs_to_jiffies(delay_ms);
+ int cpu;
+
+ cpu = cpumask_any_housekeeping(&dom->hdr.cpu_mask, exclude_cpu);
+ dom->cqm_work_cpu = cpu;
+
+ if (cpu < nr_cpu_ids)
+ schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay);
+}
+
+void mbm_handle_overflow(struct work_struct *work)
+{
+ unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL);
+ struct rdtgroup *prgrp, *crgrp;
+ struct rdt_mon_domain *d;
+ struct list_head *head;
+ struct rdt_resource *r;
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+
+ /*
+ * If the filesystem has been unmounted this work no longer needs to
+ * run.
+ */
+ if (!resctrl_mounted || !resctrl_arch_mon_capable())
+ goto out_unlock;
+
+ r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+ d = container_of(work, struct rdt_mon_domain, mbm_over.work);
+
+ list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
+ mbm_update(r, d, prgrp->closid, prgrp->mon.rmid);
+
+ head = &prgrp->mon.crdtgrp_list;
+ list_for_each_entry(crgrp, head, mon.crdtgrp_list)
+ mbm_update(r, d, crgrp->closid, crgrp->mon.rmid);
+
+ if (is_mba_sc(NULL))
+ update_mba_bw(prgrp, d);
+ }
+
+ /*
+ * Re-check for housekeeping CPUs. This allows the overflow handler to
+ * move off a nohz_full CPU quickly.
+ */
+ d->mbm_work_cpu = cpumask_any_housekeeping(&d->hdr.cpu_mask,
+ RESCTRL_PICK_ANY_CPU);
+ schedule_delayed_work_on(d->mbm_work_cpu, &d->mbm_over, delay);
+
+out_unlock:
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+}
+
+/**
+ * mbm_setup_overflow_handler() - Schedule the overflow handler to run for this
+ * domain.
+ * @dom: The domain the overflow handler should run for.
+ * @delay_ms: How far in the future the handler should run.
+ * @exclude_cpu: Which CPU the handler should not run on,
+ * RESCTRL_PICK_ANY_CPU to pick any CPU.
+ */
+void mbm_setup_overflow_handler(struct rdt_mon_domain *dom, unsigned long delay_ms,
+ int exclude_cpu)
+{
+ unsigned long delay = msecs_to_jiffies(delay_ms);
+ int cpu;
+
+ /*
+ * When a domain comes online there is no guarantee the filesystem is
+ * mounted. If not, there is no need to catch counter overflow.
+ */
+ if (!resctrl_mounted || !resctrl_arch_mon_capable())
+ return;
+ cpu = cpumask_any_housekeeping(&dom->hdr.cpu_mask, exclude_cpu);
+ dom->mbm_work_cpu = cpu;
+
+ if (cpu < nr_cpu_ids)
+ schedule_delayed_work_on(cpu, &dom->mbm_over, delay);
+}
+
+static int dom_data_init(struct rdt_resource *r)
+{
+ u32 idx_limit = resctrl_arch_system_num_rmid_idx();
+ u32 num_closid = resctrl_arch_get_num_closid(r);
+ struct rmid_entry *entry = NULL;
+ int err = 0, i;
+ u32 idx;
+
+ mutex_lock(&rdtgroup_mutex);
+ if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
+ u32 *tmp;
+
+ /*
+ * If the architecture hasn't provided a sanitised value here,
+ * this may result in larger arrays than necessary. Resctrl will
+ * use a smaller system wide value based on the resources in
+ * use.
+ */
+ tmp = kcalloc(num_closid, sizeof(*tmp), GFP_KERNEL);
+ if (!tmp) {
+ err = -ENOMEM;
+ goto out_unlock;
+ }
+
+ closid_num_dirty_rmid = tmp;
+ }
+
+ rmid_ptrs = kcalloc(idx_limit, sizeof(struct rmid_entry), GFP_KERNEL);
+ if (!rmid_ptrs) {
+ if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
+ kfree(closid_num_dirty_rmid);
+ closid_num_dirty_rmid = NULL;
+ }
+ err = -ENOMEM;
+ goto out_unlock;
+ }
+
+ for (i = 0; i < idx_limit; i++) {
+ entry = &rmid_ptrs[i];
+ INIT_LIST_HEAD(&entry->list);
+
+ resctrl_arch_rmid_idx_decode(i, &entry->closid, &entry->rmid);
+ list_add_tail(&entry->list, &rmid_free_lru);
+ }
+
+ /*
+ * RESCTRL_RESERVED_CLOSID and RESCTRL_RESERVED_RMID are special and
+ * are always allocated. These are used for the rdtgroup_default
+ * control group, which will be setup later in resctrl_init().
+ */
+ idx = resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID,
+ RESCTRL_RESERVED_RMID);
+ entry = __rmid_entry(idx);
+ list_del(&entry->list);
+
+out_unlock:
+ mutex_unlock(&rdtgroup_mutex);
+
+ return err;
+}
+
+static void dom_data_exit(struct rdt_resource *r)
+{
+ mutex_lock(&rdtgroup_mutex);
+
+ if (!r->mon_capable)
+ goto out_unlock;
+
+ if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
+ kfree(closid_num_dirty_rmid);
+ closid_num_dirty_rmid = NULL;
+ }
+
+ kfree(rmid_ptrs);
+ rmid_ptrs = NULL;
+
+out_unlock:
+ mutex_unlock(&rdtgroup_mutex);
+}
+
+static struct mon_evt llc_occupancy_event = {
+ .name = "llc_occupancy",
+ .evtid = QOS_L3_OCCUP_EVENT_ID,
+};
+
+static struct mon_evt mbm_total_event = {
+ .name = "mbm_total_bytes",
+ .evtid = QOS_L3_MBM_TOTAL_EVENT_ID,
+};
+
+static struct mon_evt mbm_local_event = {
+ .name = "mbm_local_bytes",
+ .evtid = QOS_L3_MBM_LOCAL_EVENT_ID,
+};
+
+/*
+ * Initialize the event list for the resource.
+ *
+ * Note that MBM events are also part of RDT_RESOURCE_L3 resource
+ * because as per the SDM the total and local memory bandwidth
+ * are enumerated as part of L3 monitoring.
+ */
+static void l3_mon_evt_init(struct rdt_resource *r)
+{
+ INIT_LIST_HEAD(&r->evt_list);
+
+ if (resctrl_arch_is_llc_occupancy_enabled())
+ list_add_tail(&llc_occupancy_event.list, &r->evt_list);
+ if (resctrl_arch_is_mbm_total_enabled())
+ list_add_tail(&mbm_total_event.list, &r->evt_list);
+ if (resctrl_arch_is_mbm_local_enabled())
+ list_add_tail(&mbm_local_event.list, &r->evt_list);
+}
+
+/**
+ * resctrl_mon_resource_init() - Initialise global monitoring structures.
+ *
+ * Allocate and initialise global monitor resources that do not belong to a
+ * specific domain. i.e. the rmid_ptrs[] used for the limbo and free lists.
+ * Called once during boot after the struct rdt_resource's have been configured
+ * but before the filesystem is mounted.
+ * Resctrl's cpuhp callbacks may be called before this point to bring a domain
+ * online.
+ *
+ * Returns 0 for success, or -ENOMEM.
+ */
+int resctrl_mon_resource_init(void)
+{
+ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+ int ret;
+
+ if (!r->mon_capable)
+ return 0;
+
+ ret = dom_data_init(r);
+ if (ret)
+ return ret;
+
+ l3_mon_evt_init(r);
+
+ if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_TOTAL_EVENT_ID)) {
+ mbm_total_event.configurable = true;
+ resctrl_file_fflags_init("mbm_total_bytes_config",
+ RFTYPE_MON_INFO | RFTYPE_RES_CACHE);
+ }
+ if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_LOCAL_EVENT_ID)) {
+ mbm_local_event.configurable = true;
+ resctrl_file_fflags_init("mbm_local_bytes_config",
+ RFTYPE_MON_INFO | RFTYPE_RES_CACHE);
+ }
+
+ if (resctrl_arch_is_mbm_local_enabled())
+ mba_mbps_default_event = QOS_L3_MBM_LOCAL_EVENT_ID;
+ else if (resctrl_arch_is_mbm_total_enabled())
+ mba_mbps_default_event = QOS_L3_MBM_TOTAL_EVENT_ID;
+
+ return 0;
+}
+
+void resctrl_mon_resource_exit(void)
+{
+ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+
+ dom_data_exit(r);
+}
diff --git a/fs/resctrl/monitor_trace.h b/fs/resctrl/monitor_trace.h
index e69de29..fdf49f2 100644
--- a/fs/resctrl/monitor_trace.h
+++ b/fs/resctrl/monitor_trace.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM resctrl
+
+#if !defined(_FS_RESCTRL_MONITOR_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _FS_RESCTRL_MONITOR_TRACE_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(mon_llc_occupancy_limbo,
+ TP_PROTO(u32 ctrl_hw_id, u32 mon_hw_id, int domain_id, u64 llc_occupancy_bytes),
+ TP_ARGS(ctrl_hw_id, mon_hw_id, domain_id, llc_occupancy_bytes),
+ TP_STRUCT__entry(__field(u32, ctrl_hw_id)
+ __field(u32, mon_hw_id)
+ __field(int, domain_id)
+ __field(u64, llc_occupancy_bytes)),
+ TP_fast_assign(__entry->ctrl_hw_id = ctrl_hw_id;
+ __entry->mon_hw_id = mon_hw_id;
+ __entry->domain_id = domain_id;
+ __entry->llc_occupancy_bytes = llc_occupancy_bytes;),
+ TP_printk("ctrl_hw_id=%u mon_hw_id=%u domain_id=%d llc_occupancy_bytes=%llu",
+ __entry->ctrl_hw_id, __entry->mon_hw_id, __entry->domain_id,
+ __entry->llc_occupancy_bytes)
+ );
+
+#endif /* _FS_RESCTRL_MONITOR_TRACE_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+
+#define TRACE_INCLUDE_FILE monitor_trace
+
+#include <trace/define_trace.h>
diff --git a/fs/resctrl/pseudo_lock.c b/fs/resctrl/pseudo_lock.c
index e69de29..ccc2f92 100644
--- a/fs/resctrl/pseudo_lock.c
+++ b/fs/resctrl/pseudo_lock.c
@@ -0,0 +1,1105 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Resource Director Technology (RDT)
+ *
+ * Pseudo-locking support built on top of Cache Allocation Technology (CAT)
+ *
+ * Copyright (C) 2018 Intel Corporation
+ *
+ * Author: Reinette Chatre <reinette.chatre@...el.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/cacheinfo.h>
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/debugfs.h>
+#include <linux/kthread.h>
+#include <linux/mman.h>
+#include <linux/pm_qos.h>
+#include <linux/resctrl.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include "internal.h"
+
+/*
+ * Major number assigned to and shared by all devices exposing
+ * pseudo-locked regions.
+ */
+static unsigned int pseudo_lock_major;
+
+static unsigned long pseudo_lock_minor_avail = GENMASK(MINORBITS, 0);
+
+static char *pseudo_lock_devnode(const struct device *dev, umode_t *mode)
+{
+ const struct rdtgroup *rdtgrp;
+
+ rdtgrp = dev_get_drvdata(dev);
+ if (mode)
+ *mode = 0600;
+ guard(mutex)(&rdtgroup_mutex);
+ return kasprintf(GFP_KERNEL, "pseudo_lock/%s", rdt_kn_name(rdtgrp->kn));
+}
+
+static const struct class pseudo_lock_class = {
+ .name = "pseudo_lock",
+ .devnode = pseudo_lock_devnode,
+};
+
+/**
+ * pseudo_lock_minor_get - Obtain available minor number
+ * @minor: Pointer to where new minor number will be stored
+ *
+ * A bitmask is used to track available minor numbers. Here the next free
+ * minor number is marked as unavailable and returned.
+ *
+ * Return: 0 on success, <0 on failure.
+ */
+static int pseudo_lock_minor_get(unsigned int *minor)
+{
+ unsigned long first_bit;
+
+ first_bit = find_first_bit(&pseudo_lock_minor_avail, MINORBITS);
+
+ if (first_bit == MINORBITS)
+ return -ENOSPC;
+
+ __clear_bit(first_bit, &pseudo_lock_minor_avail);
+ *minor = first_bit;
+
+ return 0;
+}
+
+/**
+ * pseudo_lock_minor_release - Return minor number to available
+ * @minor: The minor number made available
+ */
+static void pseudo_lock_minor_release(unsigned int minor)
+{
+ __set_bit(minor, &pseudo_lock_minor_avail);
+}
+
+/**
+ * region_find_by_minor - Locate a pseudo-lock region by inode minor number
+ * @minor: The minor number of the device representing pseudo-locked region
+ *
+ * When the character device is accessed we need to determine which
+ * pseudo-locked region it belongs to. This is done by matching the minor
+ * number of the device to the pseudo-locked region it belongs.
+ *
+ * Minor numbers are assigned at the time a pseudo-locked region is associated
+ * with a cache instance.
+ *
+ * Return: On success return pointer to resource group owning the pseudo-locked
+ * region, NULL on failure.
+ */
+static struct rdtgroup *region_find_by_minor(unsigned int minor)
+{
+ struct rdtgroup *rdtgrp, *rdtgrp_match = NULL;
+
+ list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
+ if (rdtgrp->plr && rdtgrp->plr->minor == minor) {
+ rdtgrp_match = rdtgrp;
+ break;
+ }
+ }
+ return rdtgrp_match;
+}
+
+/**
+ * struct pseudo_lock_pm_req - A power management QoS request list entry
+ * @list: Entry within the @pm_reqs list for a pseudo-locked region
+ * @req: PM QoS request
+ */
+struct pseudo_lock_pm_req {
+ struct list_head list;
+ struct dev_pm_qos_request req;
+};
+
+static void pseudo_lock_cstates_relax(struct pseudo_lock_region *plr)
+{
+ struct pseudo_lock_pm_req *pm_req, *next;
+
+ list_for_each_entry_safe(pm_req, next, &plr->pm_reqs, list) {
+ dev_pm_qos_remove_request(&pm_req->req);
+ list_del(&pm_req->list);
+ kfree(pm_req);
+ }
+}
+
+/**
+ * pseudo_lock_cstates_constrain - Restrict cores from entering C6
+ * @plr: Pseudo-locked region
+ *
+ * To prevent the cache from being affected by power management entering
+ * C6 has to be avoided. This is accomplished by requesting a latency
+ * requirement lower than lowest C6 exit latency of all supported
+ * platforms as found in the cpuidle state tables in the intel_idle driver.
+ * At this time it is possible to do so with a single latency requirement
+ * for all supported platforms.
+ *
+ * Since Goldmont is supported, which is affected by X86_BUG_MONITOR,
+ * the ACPI latencies need to be considered while keeping in mind that C2
+ * may be set to map to deeper sleep states. In this case the latency
+ * requirement needs to prevent entering C2 also.
+ *
+ * Return: 0 on success, <0 on failure
+ */
+static int pseudo_lock_cstates_constrain(struct pseudo_lock_region *plr)
+{
+ struct pseudo_lock_pm_req *pm_req;
+ int cpu;
+ int ret;
+
+ for_each_cpu(cpu, &plr->d->hdr.cpu_mask) {
+ pm_req = kzalloc(sizeof(*pm_req), GFP_KERNEL);
+ if (!pm_req) {
+ rdt_last_cmd_puts("Failure to allocate memory for PM QoS\n");
+ ret = -ENOMEM;
+ goto out_err;
+ }
+ ret = dev_pm_qos_add_request(get_cpu_device(cpu),
+ &pm_req->req,
+ DEV_PM_QOS_RESUME_LATENCY,
+ 30);
+ if (ret < 0) {
+ rdt_last_cmd_printf("Failed to add latency req CPU%d\n",
+ cpu);
+ kfree(pm_req);
+ ret = -1;
+ goto out_err;
+ }
+ list_add(&pm_req->list, &plr->pm_reqs);
+ }
+
+ return 0;
+
+out_err:
+ pseudo_lock_cstates_relax(plr);
+ return ret;
+}
+
+/**
+ * pseudo_lock_region_clear - Reset pseudo-lock region data
+ * @plr: pseudo-lock region
+ *
+ * All content of the pseudo-locked region is reset - any memory allocated
+ * freed.
+ *
+ * Return: void
+ */
+static void pseudo_lock_region_clear(struct pseudo_lock_region *plr)
+{
+ plr->size = 0;
+ plr->line_size = 0;
+ kfree(plr->kmem);
+ plr->kmem = NULL;
+ plr->s = NULL;
+ if (plr->d)
+ plr->d->plr = NULL;
+ plr->d = NULL;
+ plr->cbm = 0;
+ plr->debugfs_dir = NULL;
+}
+
+/**
+ * pseudo_lock_region_init - Initialize pseudo-lock region information
+ * @plr: pseudo-lock region
+ *
+ * Called after user provided a schemata to be pseudo-locked. From the
+ * schemata the &struct pseudo_lock_region is on entry already initialized
+ * with the resource, domain, and capacity bitmask. Here the information
+ * required for pseudo-locking is deduced from this data and &struct
+ * pseudo_lock_region initialized further. This information includes:
+ * - size in bytes of the region to be pseudo-locked
+ * - cache line size to know the stride with which data needs to be accessed
+ * to be pseudo-locked
+ * - a cpu associated with the cache instance on which the pseudo-locking
+ * flow can be executed
+ *
+ * Return: 0 on success, <0 on failure. Descriptive error will be written
+ * to last_cmd_status buffer.
+ */
+static int pseudo_lock_region_init(struct pseudo_lock_region *plr)
+{
+ enum resctrl_scope scope = plr->s->res->ctrl_scope;
+ struct cacheinfo *ci;
+ int ret;
+
+ if (WARN_ON_ONCE(scope != RESCTRL_L2_CACHE && scope != RESCTRL_L3_CACHE))
+ return -ENODEV;
+
+ /* Pick the first cpu we find that is associated with the cache. */
+ plr->cpu = cpumask_first(&plr->d->hdr.cpu_mask);
+
+ if (!cpu_online(plr->cpu)) {
+ rdt_last_cmd_printf("CPU %u associated with cache not online\n",
+ plr->cpu);
+ ret = -ENODEV;
+ goto out_region;
+ }
+
+ ci = get_cpu_cacheinfo_level(plr->cpu, scope);
+ if (ci) {
+ plr->line_size = ci->coherency_line_size;
+ plr->size = rdtgroup_cbm_to_size(plr->s->res, plr->d, plr->cbm);
+ return 0;
+ }
+
+ ret = -1;
+ rdt_last_cmd_puts("Unable to determine cache line size\n");
+out_region:
+ pseudo_lock_region_clear(plr);
+ return ret;
+}
+
+/**
+ * pseudo_lock_init - Initialize a pseudo-lock region
+ * @rdtgrp: resource group to which new pseudo-locked region will belong
+ *
+ * A pseudo-locked region is associated with a resource group. When this
+ * association is created the pseudo-locked region is initialized. The
+ * details of the pseudo-locked region are not known at this time so only
+ * allocation is done and association established.
+ *
+ * Return: 0 on success, <0 on failure
+ */
+static int pseudo_lock_init(struct rdtgroup *rdtgrp)
+{
+ struct pseudo_lock_region *plr;
+
+ plr = kzalloc(sizeof(*plr), GFP_KERNEL);
+ if (!plr)
+ return -ENOMEM;
+
+ init_waitqueue_head(&plr->lock_thread_wq);
+ INIT_LIST_HEAD(&plr->pm_reqs);
+ rdtgrp->plr = plr;
+ return 0;
+}
+
+/**
+ * pseudo_lock_region_alloc - Allocate kernel memory that will be pseudo-locked
+ * @plr: pseudo-lock region
+ *
+ * Initialize the details required to set up the pseudo-locked region and
+ * allocate the contiguous memory that will be pseudo-locked to the cache.
+ *
+ * Return: 0 on success, <0 on failure. Descriptive error will be written
+ * to last_cmd_status buffer.
+ */
+static int pseudo_lock_region_alloc(struct pseudo_lock_region *plr)
+{
+ int ret;
+
+ ret = pseudo_lock_region_init(plr);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * We do not yet support contiguous regions larger than
+ * KMALLOC_MAX_SIZE.
+ */
+ if (plr->size > KMALLOC_MAX_SIZE) {
+ rdt_last_cmd_puts("Requested region exceeds maximum size\n");
+ ret = -E2BIG;
+ goto out_region;
+ }
+
+ plr->kmem = kzalloc(plr->size, GFP_KERNEL);
+ if (!plr->kmem) {
+ rdt_last_cmd_puts("Unable to allocate memory\n");
+ ret = -ENOMEM;
+ goto out_region;
+ }
+
+ ret = 0;
+ goto out;
+out_region:
+ pseudo_lock_region_clear(plr);
+out:
+ return ret;
+}
+
+/**
+ * pseudo_lock_free - Free a pseudo-locked region
+ * @rdtgrp: resource group to which pseudo-locked region belonged
+ *
+ * The pseudo-locked region's resources have already been released, or not
+ * yet created at this point. Now it can be freed and disassociated from the
+ * resource group.
+ *
+ * Return: void
+ */
+static void pseudo_lock_free(struct rdtgroup *rdtgrp)
+{
+ pseudo_lock_region_clear(rdtgrp->plr);
+ kfree(rdtgrp->plr);
+ rdtgrp->plr = NULL;
+}
+
+/**
+ * rdtgroup_monitor_in_progress - Test if monitoring in progress
+ * @rdtgrp: resource group being queried
+ *
+ * Return: 1 if monitor groups have been created for this resource
+ * group, 0 otherwise.
+ */
+static int rdtgroup_monitor_in_progress(struct rdtgroup *rdtgrp)
+{
+ return !list_empty(&rdtgrp->mon.crdtgrp_list);
+}
+
+/**
+ * rdtgroup_locksetup_user_restrict - Restrict user access to group
+ * @rdtgrp: resource group needing access restricted
+ *
+ * A resource group used for cache pseudo-locking cannot have cpus or tasks
+ * assigned to it. This is communicated to the user by restricting access
+ * to all the files that can be used to make such changes.
+ *
+ * Permissions restored with rdtgroup_locksetup_user_restore()
+ *
+ * Return: 0 on success, <0 on failure. If a failure occurs during the
+ * restriction of access an attempt will be made to restore permissions but
+ * the state of the mode of these files will be uncertain when a failure
+ * occurs.
+ */
+static int rdtgroup_locksetup_user_restrict(struct rdtgroup *rdtgrp)
+{
+ int ret;
+
+ ret = rdtgroup_kn_mode_restrict(rdtgrp, "tasks");
+ if (ret)
+ return ret;
+
+ ret = rdtgroup_kn_mode_restrict(rdtgrp, "cpus");
+ if (ret)
+ goto err_tasks;
+
+ ret = rdtgroup_kn_mode_restrict(rdtgrp, "cpus_list");
+ if (ret)
+ goto err_cpus;
+
+ if (resctrl_arch_mon_capable()) {
+ ret = rdtgroup_kn_mode_restrict(rdtgrp, "mon_groups");
+ if (ret)
+ goto err_cpus_list;
+ }
+
+ ret = 0;
+ goto out;
+
+err_cpus_list:
+ rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0777);
+err_cpus:
+ rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0777);
+err_tasks:
+ rdtgroup_kn_mode_restore(rdtgrp, "tasks", 0777);
+out:
+ return ret;
+}
+
+/**
+ * rdtgroup_locksetup_user_restore - Restore user access to group
+ * @rdtgrp: resource group needing access restored
+ *
+ * Restore all file access previously removed using
+ * rdtgroup_locksetup_user_restrict()
+ *
+ * Return: 0 on success, <0 on failure. If a failure occurs during the
+ * restoration of access an attempt will be made to restrict permissions
+ * again but the state of the mode of these files will be uncertain when
+ * a failure occurs.
+ */
+static int rdtgroup_locksetup_user_restore(struct rdtgroup *rdtgrp)
+{
+ int ret;
+
+ ret = rdtgroup_kn_mode_restore(rdtgrp, "tasks", 0777);
+ if (ret)
+ return ret;
+
+ ret = rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0777);
+ if (ret)
+ goto err_tasks;
+
+ ret = rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0777);
+ if (ret)
+ goto err_cpus;
+
+ if (resctrl_arch_mon_capable()) {
+ ret = rdtgroup_kn_mode_restore(rdtgrp, "mon_groups", 0777);
+ if (ret)
+ goto err_cpus_list;
+ }
+
+ ret = 0;
+ goto out;
+
+err_cpus_list:
+ rdtgroup_kn_mode_restrict(rdtgrp, "cpus_list");
+err_cpus:
+ rdtgroup_kn_mode_restrict(rdtgrp, "cpus");
+err_tasks:
+ rdtgroup_kn_mode_restrict(rdtgrp, "tasks");
+out:
+ return ret;
+}
+
+/**
+ * rdtgroup_locksetup_enter - Resource group enters locksetup mode
+ * @rdtgrp: resource group requested to enter locksetup mode
+ *
+ * A resource group enters locksetup mode to reflect that it would be used
+ * to represent a pseudo-locked region and is in the process of being set
+ * up to do so. A resource group used for a pseudo-locked region would
+ * lose the closid associated with it so we cannot allow it to have any
+ * tasks or cpus assigned nor permit tasks or cpus to be assigned in the
+ * future. Monitoring of a pseudo-locked region is not allowed either.
+ *
+ * The above and more restrictions on a pseudo-locked region are checked
+ * for and enforced before the resource group enters the locksetup mode.
+ *
+ * Returns: 0 if the resource group successfully entered locksetup mode, <0
+ * on failure. On failure the last_cmd_status buffer is updated with text to
+ * communicate details of failure to the user.
+ */
+int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp)
+{
+ int ret;
+
+ /*
+ * The default resource group can neither be removed nor lose the
+ * default closid associated with it.
+ */
+ if (rdtgrp == &rdtgroup_default) {
+ rdt_last_cmd_puts("Cannot pseudo-lock default group\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Cache Pseudo-locking not supported when CDP is enabled.
+ *
+ * Some things to consider if you would like to enable this
+ * support (using L3 CDP as example):
+ * - When CDP is enabled two separate resources are exposed,
+ * L3DATA and L3CODE, but they are actually on the same cache.
+ * The implication for pseudo-locking is that if a
+ * pseudo-locked region is created on a domain of one
+ * resource (eg. L3CODE), then a pseudo-locked region cannot
+ * be created on that same domain of the other resource
+ * (eg. L3DATA). This is because the creation of a
+ * pseudo-locked region involves a call to wbinvd that will
+ * affect all cache allocations on particular domain.
+ * - Considering the previous, it may be possible to only
+ * expose one of the CDP resources to pseudo-locking and
+ * hide the other. For example, we could consider to only
+ * expose L3DATA and since the L3 cache is unified it is
+ * still possible to place instructions there are execute it.
+ * - If only one region is exposed to pseudo-locking we should
+ * still keep in mind that availability of a portion of cache
+ * for pseudo-locking should take into account both resources.
+ * Similarly, if a pseudo-locked region is created in one
+ * resource, the portion of cache used by it should be made
+ * unavailable to all future allocations from both resources.
+ */
+ if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3) ||
+ resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2)) {
+ rdt_last_cmd_puts("CDP enabled\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Not knowing the bits to disable prefetching implies that this
+ * platform does not support Cache Pseudo-Locking.
+ */
+ if (resctrl_arch_get_prefetch_disable_bits() == 0) {
+ rdt_last_cmd_puts("Pseudo-locking not supported\n");
+ return -EINVAL;
+ }
+
+ if (rdtgroup_monitor_in_progress(rdtgrp)) {
+ rdt_last_cmd_puts("Monitoring in progress\n");
+ return -EINVAL;
+ }
+
+ if (rdtgroup_tasks_assigned(rdtgrp)) {
+ rdt_last_cmd_puts("Tasks assigned to resource group\n");
+ return -EINVAL;
+ }
+
+ if (!cpumask_empty(&rdtgrp->cpu_mask)) {
+ rdt_last_cmd_puts("CPUs assigned to resource group\n");
+ return -EINVAL;
+ }
+
+ if (rdtgroup_locksetup_user_restrict(rdtgrp)) {
+ rdt_last_cmd_puts("Unable to modify resctrl permissions\n");
+ return -EIO;
+ }
+
+ ret = pseudo_lock_init(rdtgrp);
+ if (ret) {
+ rdt_last_cmd_puts("Unable to init pseudo-lock region\n");
+ goto out_release;
+ }
+
+ /*
+ * If this system is capable of monitoring a rmid would have been
+ * allocated when the control group was created. This is not needed
+ * anymore when this group would be used for pseudo-locking. This
+ * is safe to call on platforms not capable of monitoring.
+ */
+ free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
+
+ ret = 0;
+ goto out;
+
+out_release:
+ rdtgroup_locksetup_user_restore(rdtgrp);
+out:
+ return ret;
+}
+
+/**
+ * rdtgroup_locksetup_exit - resource group exist locksetup mode
+ * @rdtgrp: resource group
+ *
+ * When a resource group exits locksetup mode the earlier restrictions are
+ * lifted.
+ *
+ * Return: 0 on success, <0 on failure
+ */
+int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp)
+{
+ int ret;
+
+ if (resctrl_arch_mon_capable()) {
+ ret = alloc_rmid(rdtgrp->closid);
+ if (ret < 0) {
+ rdt_last_cmd_puts("Out of RMIDs\n");
+ return ret;
+ }
+ rdtgrp->mon.rmid = ret;
+ }
+
+ ret = rdtgroup_locksetup_user_restore(rdtgrp);
+ if (ret) {
+ free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
+ return ret;
+ }
+
+ pseudo_lock_free(rdtgrp);
+ return 0;
+}
+
+/**
+ * rdtgroup_cbm_overlaps_pseudo_locked - Test if CBM or portion is pseudo-locked
+ * @d: RDT domain
+ * @cbm: CBM to test
+ *
+ * @d represents a cache instance and @cbm a capacity bitmask that is
+ * considered for it. Determine if @cbm overlaps with any existing
+ * pseudo-locked region on @d.
+ *
+ * @cbm is unsigned long, even if only 32 bits are used, to make the
+ * bitmap functions work correctly.
+ *
+ * Return: true if @cbm overlaps with pseudo-locked region on @d, false
+ * otherwise.
+ */
+bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_ctrl_domain *d, unsigned long cbm)
+{
+ unsigned int cbm_len;
+ unsigned long cbm_b;
+
+ if (d->plr) {
+ cbm_len = d->plr->s->res->cache.cbm_len;
+ cbm_b = d->plr->cbm;
+ if (bitmap_intersects(&cbm, &cbm_b, cbm_len))
+ return true;
+ }
+ return false;
+}
+
+/**
+ * rdtgroup_pseudo_locked_in_hierarchy - Pseudo-locked region in cache hierarchy
+ * @d: RDT domain under test
+ *
+ * The setup of a pseudo-locked region affects all cache instances within
+ * the hierarchy of the region. It is thus essential to know if any
+ * pseudo-locked regions exist within a cache hierarchy to prevent any
+ * attempts to create new pseudo-locked regions in the same hierarchy.
+ *
+ * Return: true if a pseudo-locked region exists in the hierarchy of @d or
+ * if it is not possible to test due to memory allocation issue,
+ * false otherwise.
+ */
+bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d)
+{
+ struct rdt_ctrl_domain *d_i;
+ cpumask_var_t cpu_with_psl;
+ struct rdt_resource *r;
+ bool ret = false;
+
+ /* Walking r->domains, ensure it can't race with cpuhp */
+ lockdep_assert_cpus_held();
+
+ if (!zalloc_cpumask_var(&cpu_with_psl, GFP_KERNEL))
+ return true;
+
+ /*
+ * First determine which cpus have pseudo-locked regions
+ * associated with them.
+ */
+ for_each_alloc_capable_rdt_resource(r) {
+ list_for_each_entry(d_i, &r->ctrl_domains, hdr.list) {
+ if (d_i->plr)
+ cpumask_or(cpu_with_psl, cpu_with_psl,
+ &d_i->hdr.cpu_mask);
+ }
+ }
+
+ /*
+ * Next test if new pseudo-locked region would intersect with
+ * existing region.
+ */
+ if (cpumask_intersects(&d->hdr.cpu_mask, cpu_with_psl))
+ ret = true;
+
+ free_cpumask_var(cpu_with_psl);
+ return ret;
+}
+
+/**
+ * pseudo_lock_measure_cycles - Trigger latency measure to pseudo-locked region
+ * @rdtgrp: Resource group to which the pseudo-locked region belongs.
+ * @sel: Selector of which measurement to perform on a pseudo-locked region.
+ *
+ * The measurement of latency to access a pseudo-locked region should be
+ * done from a cpu that is associated with that pseudo-locked region.
+ * Determine which cpu is associated with this region and start a thread on
+ * that cpu to perform the measurement, wait for that thread to complete.
+ *
+ * Return: 0 on success, <0 on failure
+ */
+static int pseudo_lock_measure_cycles(struct rdtgroup *rdtgrp, int sel)
+{
+ struct pseudo_lock_region *plr = rdtgrp->plr;
+ struct task_struct *thread;
+ unsigned int cpu;
+ int ret = -1;
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+
+ if (rdtgrp->flags & RDT_DELETED) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ if (!plr->d) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ plr->thread_done = 0;
+ cpu = cpumask_first(&plr->d->hdr.cpu_mask);
+ if (!cpu_online(cpu)) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ plr->cpu = cpu;
+
+ if (sel == 1)
+ thread = kthread_run_on_cpu(resctrl_arch_measure_cycles_lat_fn,
+ plr, cpu, "pseudo_lock_measure/%u");
+ else if (sel == 2)
+ thread = kthread_run_on_cpu(resctrl_arch_measure_l2_residency,
+ plr, cpu, "pseudo_lock_measure/%u");
+ else if (sel == 3)
+ thread = kthread_run_on_cpu(resctrl_arch_measure_l3_residency,
+ plr, cpu, "pseudo_lock_measure/%u");
+ else
+ goto out;
+
+ if (IS_ERR(thread)) {
+ ret = PTR_ERR(thread);
+ goto out;
+ }
+
+ ret = wait_event_interruptible(plr->lock_thread_wq,
+ plr->thread_done == 1);
+ if (ret < 0)
+ goto out;
+
+ ret = 0;
+
+out:
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+ return ret;
+}
+
+static ssize_t pseudo_lock_measure_trigger(struct file *file,
+ const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct rdtgroup *rdtgrp = file->private_data;
+ size_t buf_size;
+ char buf[32];
+ int ret;
+ int sel;
+
+ buf_size = min(count, (sizeof(buf) - 1));
+ if (copy_from_user(buf, user_buf, buf_size))
+ return -EFAULT;
+
+ buf[buf_size] = '\0';
+ ret = kstrtoint(buf, 10, &sel);
+ if (ret == 0) {
+ if (sel != 1 && sel != 2 && sel != 3)
+ return -EINVAL;
+ ret = debugfs_file_get(file->f_path.dentry);
+ if (ret)
+ return ret;
+ ret = pseudo_lock_measure_cycles(rdtgrp, sel);
+ if (ret == 0)
+ ret = count;
+ debugfs_file_put(file->f_path.dentry);
+ }
+
+ return ret;
+}
+
+static const struct file_operations pseudo_measure_fops = {
+ .write = pseudo_lock_measure_trigger,
+ .open = simple_open,
+ .llseek = default_llseek,
+};
+
+/**
+ * rdtgroup_pseudo_lock_create - Create a pseudo-locked region
+ * @rdtgrp: resource group to which pseudo-lock region belongs
+ *
+ * Called when a resource group in the pseudo-locksetup mode receives a
+ * valid schemata that should be pseudo-locked. Since the resource group is
+ * in pseudo-locksetup mode the &struct pseudo_lock_region has already been
+ * allocated and initialized with the essential information. If a failure
+ * occurs the resource group remains in the pseudo-locksetup mode with the
+ * &struct pseudo_lock_region associated with it, but cleared from all
+ * information and ready for the user to re-attempt pseudo-locking by
+ * writing the schemata again.
+ *
+ * Return: 0 if the pseudo-locked region was successfully pseudo-locked, <0
+ * on failure. Descriptive error will be written to last_cmd_status buffer.
+ */
+int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp)
+{
+ struct pseudo_lock_region *plr = rdtgrp->plr;
+ struct task_struct *thread;
+ unsigned int new_minor;
+ struct device *dev;
+ char *kn_name __free(kfree) = NULL;
+ int ret;
+
+ ret = pseudo_lock_region_alloc(plr);
+ if (ret < 0)
+ return ret;
+
+ ret = pseudo_lock_cstates_constrain(plr);
+ if (ret < 0) {
+ ret = -EINVAL;
+ goto out_region;
+ }
+ kn_name = kstrdup(rdt_kn_name(rdtgrp->kn), GFP_KERNEL);
+ if (!kn_name) {
+ ret = -ENOMEM;
+ goto out_cstates;
+ }
+
+ plr->thread_done = 0;
+
+ thread = kthread_run_on_cpu(resctrl_arch_pseudo_lock_fn, plr,
+ plr->cpu, "pseudo_lock/%u");
+ if (IS_ERR(thread)) {
+ ret = PTR_ERR(thread);
+ rdt_last_cmd_printf("Locking thread returned error %d\n", ret);
+ goto out_cstates;
+ }
+
+ ret = wait_event_interruptible(plr->lock_thread_wq,
+ plr->thread_done == 1);
+ if (ret < 0) {
+ /*
+ * If the thread does not get on the CPU for whatever
+ * reason and the process which sets up the region is
+ * interrupted then this will leave the thread in runnable
+ * state and once it gets on the CPU it will dereference
+ * the cleared, but not freed, plr struct resulting in an
+ * empty pseudo-locking loop.
+ */
+ rdt_last_cmd_puts("Locking thread interrupted\n");
+ goto out_cstates;
+ }
+
+ ret = pseudo_lock_minor_get(&new_minor);
+ if (ret < 0) {
+ rdt_last_cmd_puts("Unable to obtain a new minor number\n");
+ goto out_cstates;
+ }
+
+ /*
+ * Unlock access but do not release the reference. The
+ * pseudo-locked region will still be here on return.
+ *
+ * The mutex has to be released temporarily to avoid a potential
+ * deadlock with the mm->mmap_lock which is obtained in the
+ * device_create() and debugfs_create_dir() callpath below as well as
+ * before the mmap() callback is called.
+ */
+ mutex_unlock(&rdtgroup_mutex);
+
+ if (!IS_ERR_OR_NULL(debugfs_resctrl)) {
+ plr->debugfs_dir = debugfs_create_dir(kn_name, debugfs_resctrl);
+ if (!IS_ERR_OR_NULL(plr->debugfs_dir))
+ debugfs_create_file("pseudo_lock_measure", 0200,
+ plr->debugfs_dir, rdtgrp,
+ &pseudo_measure_fops);
+ }
+
+ dev = device_create(&pseudo_lock_class, NULL,
+ MKDEV(pseudo_lock_major, new_minor),
+ rdtgrp, "%s", kn_name);
+
+ mutex_lock(&rdtgroup_mutex);
+
+ if (IS_ERR(dev)) {
+ ret = PTR_ERR(dev);
+ rdt_last_cmd_printf("Failed to create character device: %d\n",
+ ret);
+ goto out_debugfs;
+ }
+
+ /* We released the mutex - check if group was removed while we did so */
+ if (rdtgrp->flags & RDT_DELETED) {
+ ret = -ENODEV;
+ goto out_device;
+ }
+
+ plr->minor = new_minor;
+
+ rdtgrp->mode = RDT_MODE_PSEUDO_LOCKED;
+ closid_free(rdtgrp->closid);
+ rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0444);
+ rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0444);
+
+ ret = 0;
+ goto out;
+
+out_device:
+ device_destroy(&pseudo_lock_class, MKDEV(pseudo_lock_major, new_minor));
+out_debugfs:
+ debugfs_remove_recursive(plr->debugfs_dir);
+ pseudo_lock_minor_release(new_minor);
+out_cstates:
+ pseudo_lock_cstates_relax(plr);
+out_region:
+ pseudo_lock_region_clear(plr);
+out:
+ return ret;
+}
+
+/**
+ * rdtgroup_pseudo_lock_remove - Remove a pseudo-locked region
+ * @rdtgrp: resource group to which the pseudo-locked region belongs
+ *
+ * The removal of a pseudo-locked region can be initiated when the resource
+ * group is removed from user space via a "rmdir" from userspace or the
+ * unmount of the resctrl filesystem. On removal the resource group does
+ * not go back to pseudo-locksetup mode before it is removed, instead it is
+ * removed directly. There is thus asymmetry with the creation where the
+ * &struct pseudo_lock_region is removed here while it was not created in
+ * rdtgroup_pseudo_lock_create().
+ *
+ * Return: void
+ */
+void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp)
+{
+ struct pseudo_lock_region *plr = rdtgrp->plr;
+
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ /*
+ * Default group cannot be a pseudo-locked region so we can
+ * free closid here.
+ */
+ closid_free(rdtgrp->closid);
+ goto free;
+ }
+
+ pseudo_lock_cstates_relax(plr);
+ debugfs_remove_recursive(rdtgrp->plr->debugfs_dir);
+ device_destroy(&pseudo_lock_class, MKDEV(pseudo_lock_major, plr->minor));
+ pseudo_lock_minor_release(plr->minor);
+
+free:
+ pseudo_lock_free(rdtgrp);
+}
+
+static int pseudo_lock_dev_open(struct inode *inode, struct file *filp)
+{
+ struct rdtgroup *rdtgrp;
+
+ mutex_lock(&rdtgroup_mutex);
+
+ rdtgrp = region_find_by_minor(iminor(inode));
+ if (!rdtgrp) {
+ mutex_unlock(&rdtgroup_mutex);
+ return -ENODEV;
+ }
+
+ filp->private_data = rdtgrp;
+ atomic_inc(&rdtgrp->waitcount);
+ /* Perform a non-seekable open - llseek is not supported */
+ filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
+
+ mutex_unlock(&rdtgroup_mutex);
+
+ return 0;
+}
+
+static int pseudo_lock_dev_release(struct inode *inode, struct file *filp)
+{
+ struct rdtgroup *rdtgrp;
+
+ mutex_lock(&rdtgroup_mutex);
+ rdtgrp = filp->private_data;
+ WARN_ON(!rdtgrp);
+ if (!rdtgrp) {
+ mutex_unlock(&rdtgroup_mutex);
+ return -ENODEV;
+ }
+ filp->private_data = NULL;
+ atomic_dec(&rdtgrp->waitcount);
+ mutex_unlock(&rdtgroup_mutex);
+ return 0;
+}
+
+static int pseudo_lock_dev_mremap(struct vm_area_struct *area)
+{
+ /* Not supported */
+ return -EINVAL;
+}
+
+static const struct vm_operations_struct pseudo_mmap_ops = {
+ .mremap = pseudo_lock_dev_mremap,
+};
+
+static int pseudo_lock_dev_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+ unsigned long vsize = vma->vm_end - vma->vm_start;
+ unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
+ struct pseudo_lock_region *plr;
+ struct rdtgroup *rdtgrp;
+ unsigned long physical;
+ unsigned long psize;
+
+ mutex_lock(&rdtgroup_mutex);
+
+ rdtgrp = filp->private_data;
+ WARN_ON(!rdtgrp);
+ if (!rdtgrp) {
+ mutex_unlock(&rdtgroup_mutex);
+ return -ENODEV;
+ }
+
+ plr = rdtgrp->plr;
+
+ if (!plr->d) {
+ mutex_unlock(&rdtgroup_mutex);
+ return -ENODEV;
+ }
+
+ /*
+ * Task is required to run with affinity to the cpus associated
+ * with the pseudo-locked region. If this is not the case the task
+ * may be scheduled elsewhere and invalidate entries in the
+ * pseudo-locked region.
+ */
+ if (!cpumask_subset(current->cpus_ptr, &plr->d->hdr.cpu_mask)) {
+ mutex_unlock(&rdtgroup_mutex);
+ return -EINVAL;
+ }
+
+ physical = __pa(plr->kmem) >> PAGE_SHIFT;
+ psize = plr->size - off;
+
+ if (off > plr->size) {
+ mutex_unlock(&rdtgroup_mutex);
+ return -ENOSPC;
+ }
+
+ /*
+ * Ensure changes are carried directly to the memory being mapped,
+ * do not allow copy-on-write mapping.
+ */
+ if (!(vma->vm_flags & VM_SHARED)) {
+ mutex_unlock(&rdtgroup_mutex);
+ return -EINVAL;
+ }
+
+ if (vsize > psize) {
+ mutex_unlock(&rdtgroup_mutex);
+ return -ENOSPC;
+ }
+
+ memset(plr->kmem + off, 0, vsize);
+
+ if (remap_pfn_range(vma, vma->vm_start, physical + vma->vm_pgoff,
+ vsize, vma->vm_page_prot)) {
+ mutex_unlock(&rdtgroup_mutex);
+ return -EAGAIN;
+ }
+ vma->vm_ops = &pseudo_mmap_ops;
+ mutex_unlock(&rdtgroup_mutex);
+ return 0;
+}
+
+static const struct file_operations pseudo_lock_dev_fops = {
+ .owner = THIS_MODULE,
+ .read = NULL,
+ .write = NULL,
+ .open = pseudo_lock_dev_open,
+ .release = pseudo_lock_dev_release,
+ .mmap = pseudo_lock_dev_mmap,
+};
+
+int rdt_pseudo_lock_init(void)
+{
+ int ret;
+
+ ret = register_chrdev(0, "pseudo_lock", &pseudo_lock_dev_fops);
+ if (ret < 0)
+ return ret;
+
+ pseudo_lock_major = ret;
+
+ ret = class_register(&pseudo_lock_class);
+ if (ret) {
+ unregister_chrdev(pseudo_lock_major, "pseudo_lock");
+ return ret;
+ }
+
+ return 0;
+}
+
+void rdt_pseudo_lock_release(void)
+{
+ class_unregister(&pseudo_lock_class);
+ unregister_chrdev(pseudo_lock_major, "pseudo_lock");
+ pseudo_lock_major = 0;
+}
diff --git a/fs/resctrl/pseudo_lock_trace.h b/fs/resctrl/pseudo_lock_trace.h
deleted file mode 100644
index e69de29..0000000
--- a/fs/resctrl/pseudo_lock_trace.h
+++ /dev/null
diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index e69de29..cc37f58 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -0,0 +1,4353 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * User interface for Resource Allocation in Resource Director Technology(RDT)
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Author: Fenghua Yu <fenghua.yu@...el.com>
+ *
+ * More information about RDT be found in the Intel (R) x86 Architecture
+ * Software Developer Manual.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/cpu.h>
+#include <linux/debugfs.h>
+#include <linux/fs.h>
+#include <linux/fs_parser.h>
+#include <linux/sysfs.h>
+#include <linux/kernfs.h>
+#include <linux/resctrl.h>
+#include <linux/seq_buf.h>
+#include <linux/seq_file.h>
+#include <linux/sched/task.h>
+#include <linux/slab.h>
+#include <linux/user_namespace.h>
+
+#include <uapi/linux/magic.h>
+
+#include "internal.h"
+
+/* Mutex to protect rdtgroup access. */
+DEFINE_MUTEX(rdtgroup_mutex);
+
+static struct kernfs_root *rdt_root;
+
+struct rdtgroup rdtgroup_default;
+
+LIST_HEAD(rdt_all_groups);
+
+/* list of entries for the schemata file */
+LIST_HEAD(resctrl_schema_all);
+
+/*
+ * List of struct mon_data containing private data of event files for use by
+ * rdtgroup_mondata_show(). Protected by rdtgroup_mutex.
+ */
+static LIST_HEAD(mon_data_kn_priv_list);
+
+/* The filesystem can only be mounted once. */
+bool resctrl_mounted;
+
+/* Kernel fs node for "info" directory under root */
+static struct kernfs_node *kn_info;
+
+/* Kernel fs node for "mon_groups" directory under root */
+static struct kernfs_node *kn_mongrp;
+
+/* Kernel fs node for "mon_data" directory under root */
+static struct kernfs_node *kn_mondata;
+
+/*
+ * Used to store the max resource name width to display the schemata names in
+ * a tabular format.
+ */
+int max_name_width;
+
+static struct seq_buf last_cmd_status;
+
+static char last_cmd_status_buf[512];
+
+static int rdtgroup_setup_root(struct rdt_fs_context *ctx);
+
+static void rdtgroup_destroy_root(void);
+
+struct dentry *debugfs_resctrl;
+
+/*
+ * Memory bandwidth monitoring event to use for the default CTRL_MON group
+ * and each new CTRL_MON group created by the user. Only relevant when
+ * the filesystem is mounted with the "mba_MBps" option so it does not
+ * matter that it remains uninitialized on systems that do not support
+ * the "mba_MBps" option.
+ */
+enum resctrl_event_id mba_mbps_default_event;
+
+static bool resctrl_debug;
+
+void rdt_last_cmd_clear(void)
+{
+ lockdep_assert_held(&rdtgroup_mutex);
+ seq_buf_clear(&last_cmd_status);
+}
+
+void rdt_last_cmd_puts(const char *s)
+{
+ lockdep_assert_held(&rdtgroup_mutex);
+ seq_buf_puts(&last_cmd_status, s);
+}
+
+void rdt_last_cmd_printf(const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ lockdep_assert_held(&rdtgroup_mutex);
+ seq_buf_vprintf(&last_cmd_status, fmt, ap);
+ va_end(ap);
+}
+
+void rdt_staged_configs_clear(void)
+{
+ struct rdt_ctrl_domain *dom;
+ struct rdt_resource *r;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ for_each_alloc_capable_rdt_resource(r) {
+ list_for_each_entry(dom, &r->ctrl_domains, hdr.list)
+ memset(dom->staged_config, 0, sizeof(dom->staged_config));
+ }
+}
+
+static bool resctrl_is_mbm_enabled(void)
+{
+ return (resctrl_arch_is_mbm_total_enabled() ||
+ resctrl_arch_is_mbm_local_enabled());
+}
+
+static bool resctrl_is_mbm_event(int e)
+{
+ return (e >= QOS_L3_MBM_TOTAL_EVENT_ID &&
+ e <= QOS_L3_MBM_LOCAL_EVENT_ID);
+}
+
+/*
+ * Trivial allocator for CLOSIDs. Use BITMAP APIs to manipulate a bitmap
+ * of free CLOSIDs.
+ *
+ * Using a global CLOSID across all resources has some advantages and
+ * some drawbacks:
+ * + We can simply set current's closid to assign a task to a resource
+ * group.
+ * + Context switch code can avoid extra memory references deciding which
+ * CLOSID to load into the PQR_ASSOC MSR
+ * - We give up some options in configuring resource groups across multi-socket
+ * systems.
+ * - Our choices on how to configure each resource become progressively more
+ * limited as the number of resources grows.
+ */
+static unsigned long *closid_free_map;
+
+static int closid_free_map_len;
+
+int closids_supported(void)
+{
+ return closid_free_map_len;
+}
+
+static int closid_init(void)
+{
+ struct resctrl_schema *s;
+ u32 rdt_min_closid = ~0;
+
+ /* Monitor only platforms still call closid_init() */
+ if (list_empty(&resctrl_schema_all))
+ return 0;
+
+ /* Compute rdt_min_closid across all resources */
+ list_for_each_entry(s, &resctrl_schema_all, list)
+ rdt_min_closid = min(rdt_min_closid, s->num_closid);
+
+ closid_free_map = bitmap_alloc(rdt_min_closid, GFP_KERNEL);
+ if (!closid_free_map)
+ return -ENOMEM;
+ bitmap_fill(closid_free_map, rdt_min_closid);
+
+ /* RESCTRL_RESERVED_CLOSID is always reserved for the default group */
+ __clear_bit(RESCTRL_RESERVED_CLOSID, closid_free_map);
+ closid_free_map_len = rdt_min_closid;
+
+ return 0;
+}
+
+static void closid_exit(void)
+{
+ bitmap_free(closid_free_map);
+ closid_free_map = NULL;
+}
+
+static int closid_alloc(void)
+{
+ int cleanest_closid;
+ u32 closid;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID) &&
+ resctrl_arch_is_llc_occupancy_enabled()) {
+ cleanest_closid = resctrl_find_cleanest_closid();
+ if (cleanest_closid < 0)
+ return cleanest_closid;
+ closid = cleanest_closid;
+ } else {
+ closid = find_first_bit(closid_free_map, closid_free_map_len);
+ if (closid == closid_free_map_len)
+ return -ENOSPC;
+ }
+ __clear_bit(closid, closid_free_map);
+
+ return closid;
+}
+
+void closid_free(int closid)
+{
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ __set_bit(closid, closid_free_map);
+}
+
+/**
+ * closid_allocated - test if provided closid is in use
+ * @closid: closid to be tested
+ *
+ * Return: true if @closid is currently associated with a resource group,
+ * false if @closid is free
+ */
+bool closid_allocated(unsigned int closid)
+{
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ return !test_bit(closid, closid_free_map);
+}
+
+/**
+ * rdtgroup_mode_by_closid - Return mode of resource group with closid
+ * @closid: closid if the resource group
+ *
+ * Each resource group is associated with a @closid. Here the mode
+ * of a resource group can be queried by searching for it using its closid.
+ *
+ * Return: mode as &enum rdtgrp_mode of resource group with closid @closid
+ */
+enum rdtgrp_mode rdtgroup_mode_by_closid(int closid)
+{
+ struct rdtgroup *rdtgrp;
+
+ list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
+ if (rdtgrp->closid == closid)
+ return rdtgrp->mode;
+ }
+
+ return RDT_NUM_MODES;
+}
+
+static const char * const rdt_mode_str[] = {
+ [RDT_MODE_SHAREABLE] = "shareable",
+ [RDT_MODE_EXCLUSIVE] = "exclusive",
+ [RDT_MODE_PSEUDO_LOCKSETUP] = "pseudo-locksetup",
+ [RDT_MODE_PSEUDO_LOCKED] = "pseudo-locked",
+};
+
+/**
+ * rdtgroup_mode_str - Return the string representation of mode
+ * @mode: the resource group mode as &enum rdtgroup_mode
+ *
+ * Return: string representation of valid mode, "unknown" otherwise
+ */
+static const char *rdtgroup_mode_str(enum rdtgrp_mode mode)
+{
+ if (mode < RDT_MODE_SHAREABLE || mode >= RDT_NUM_MODES)
+ return "unknown";
+
+ return rdt_mode_str[mode];
+}
+
+/* set uid and gid of rdtgroup dirs and files to that of the creator */
+static int rdtgroup_kn_set_ugid(struct kernfs_node *kn)
+{
+ struct iattr iattr = { .ia_valid = ATTR_UID | ATTR_GID,
+ .ia_uid = current_fsuid(),
+ .ia_gid = current_fsgid(), };
+
+ if (uid_eq(iattr.ia_uid, GLOBAL_ROOT_UID) &&
+ gid_eq(iattr.ia_gid, GLOBAL_ROOT_GID))
+ return 0;
+
+ return kernfs_setattr(kn, &iattr);
+}
+
+static int rdtgroup_add_file(struct kernfs_node *parent_kn, struct rftype *rft)
+{
+ struct kernfs_node *kn;
+ int ret;
+
+ kn = __kernfs_create_file(parent_kn, rft->name, rft->mode,
+ GLOBAL_ROOT_UID, GLOBAL_ROOT_GID,
+ 0, rft->kf_ops, rft, NULL, NULL);
+ if (IS_ERR(kn))
+ return PTR_ERR(kn);
+
+ ret = rdtgroup_kn_set_ugid(kn);
+ if (ret) {
+ kernfs_remove(kn);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int rdtgroup_seqfile_show(struct seq_file *m, void *arg)
+{
+ struct kernfs_open_file *of = m->private;
+ struct rftype *rft = of->kn->priv;
+
+ if (rft->seq_show)
+ return rft->seq_show(of, m, arg);
+ return 0;
+}
+
+static ssize_t rdtgroup_file_write(struct kernfs_open_file *of, char *buf,
+ size_t nbytes, loff_t off)
+{
+ struct rftype *rft = of->kn->priv;
+
+ if (rft->write)
+ return rft->write(of, buf, nbytes, off);
+
+ return -EINVAL;
+}
+
+static const struct kernfs_ops rdtgroup_kf_single_ops = {
+ .atomic_write_len = PAGE_SIZE,
+ .write = rdtgroup_file_write,
+ .seq_show = rdtgroup_seqfile_show,
+};
+
+static const struct kernfs_ops kf_mondata_ops = {
+ .atomic_write_len = PAGE_SIZE,
+ .seq_show = rdtgroup_mondata_show,
+};
+
+static bool is_cpu_list(struct kernfs_open_file *of)
+{
+ struct rftype *rft = of->kn->priv;
+
+ return rft->flags & RFTYPE_FLAGS_CPUS_LIST;
+}
+
+static int rdtgroup_cpus_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdtgroup *rdtgrp;
+ struct cpumask *mask;
+ int ret = 0;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+
+ if (rdtgrp) {
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
+ if (!rdtgrp->plr->d) {
+ rdt_last_cmd_clear();
+ rdt_last_cmd_puts("Cache domain offline\n");
+ ret = -ENODEV;
+ } else {
+ mask = &rdtgrp->plr->d->hdr.cpu_mask;
+ seq_printf(s, is_cpu_list(of) ?
+ "%*pbl\n" : "%*pb\n",
+ cpumask_pr_args(mask));
+ }
+ } else {
+ seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n",
+ cpumask_pr_args(&rdtgrp->cpu_mask));
+ }
+ } else {
+ ret = -ENOENT;
+ }
+ rdtgroup_kn_unlock(of->kn);
+
+ return ret;
+}
+
+/*
+ * Update the PGR_ASSOC MSR on all cpus in @cpu_mask,
+ *
+ * Per task closids/rmids must have been set up before calling this function.
+ * @r may be NULL.
+ */
+static void
+update_closid_rmid(const struct cpumask *cpu_mask, struct rdtgroup *r)
+{
+ struct resctrl_cpu_defaults defaults, *p = NULL;
+
+ if (r) {
+ defaults.closid = r->closid;
+ defaults.rmid = r->mon.rmid;
+ p = &defaults;
+ }
+
+ on_each_cpu_mask(cpu_mask, resctrl_arch_sync_cpu_closid_rmid, p, 1);
+}
+
+static int cpus_mon_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
+ cpumask_var_t tmpmask)
+{
+ struct rdtgroup *prgrp = rdtgrp->mon.parent, *crgrp;
+ struct list_head *head;
+
+ /* Check whether cpus belong to parent ctrl group */
+ cpumask_andnot(tmpmask, newmask, &prgrp->cpu_mask);
+ if (!cpumask_empty(tmpmask)) {
+ rdt_last_cmd_puts("Can only add CPUs to mongroup that belong to parent\n");
+ return -EINVAL;
+ }
+
+ /* Check whether cpus are dropped from this group */
+ cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
+ if (!cpumask_empty(tmpmask)) {
+ /* Give any dropped cpus to parent rdtgroup */
+ cpumask_or(&prgrp->cpu_mask, &prgrp->cpu_mask, tmpmask);
+ update_closid_rmid(tmpmask, prgrp);
+ }
+
+ /*
+ * If we added cpus, remove them from previous group that owned them
+ * and update per-cpu rmid
+ */
+ cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
+ if (!cpumask_empty(tmpmask)) {
+ head = &prgrp->mon.crdtgrp_list;
+ list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
+ if (crgrp == rdtgrp)
+ continue;
+ cpumask_andnot(&crgrp->cpu_mask, &crgrp->cpu_mask,
+ tmpmask);
+ }
+ update_closid_rmid(tmpmask, rdtgrp);
+ }
+
+ /* Done pushing/pulling - update this group with new mask */
+ cpumask_copy(&rdtgrp->cpu_mask, newmask);
+
+ return 0;
+}
+
+static void cpumask_rdtgrp_clear(struct rdtgroup *r, struct cpumask *m)
+{
+ struct rdtgroup *crgrp;
+
+ cpumask_andnot(&r->cpu_mask, &r->cpu_mask, m);
+ /* update the child mon group masks as well*/
+ list_for_each_entry(crgrp, &r->mon.crdtgrp_list, mon.crdtgrp_list)
+ cpumask_and(&crgrp->cpu_mask, &r->cpu_mask, &crgrp->cpu_mask);
+}
+
+static int cpus_ctrl_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
+ cpumask_var_t tmpmask, cpumask_var_t tmpmask1)
+{
+ struct rdtgroup *r, *crgrp;
+ struct list_head *head;
+
+ /* Check whether cpus are dropped from this group */
+ cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
+ if (!cpumask_empty(tmpmask)) {
+ /* Can't drop from default group */
+ if (rdtgrp == &rdtgroup_default) {
+ rdt_last_cmd_puts("Can't drop CPUs from default group\n");
+ return -EINVAL;
+ }
+
+ /* Give any dropped cpus to rdtgroup_default */
+ cpumask_or(&rdtgroup_default.cpu_mask,
+ &rdtgroup_default.cpu_mask, tmpmask);
+ update_closid_rmid(tmpmask, &rdtgroup_default);
+ }
+
+ /*
+ * If we added cpus, remove them from previous group and
+ * the prev group's child groups that owned them
+ * and update per-cpu closid/rmid.
+ */
+ cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
+ if (!cpumask_empty(tmpmask)) {
+ list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) {
+ if (r == rdtgrp)
+ continue;
+ cpumask_and(tmpmask1, &r->cpu_mask, tmpmask);
+ if (!cpumask_empty(tmpmask1))
+ cpumask_rdtgrp_clear(r, tmpmask1);
+ }
+ update_closid_rmid(tmpmask, rdtgrp);
+ }
+
+ /* Done pushing/pulling - update this group with new mask */
+ cpumask_copy(&rdtgrp->cpu_mask, newmask);
+
+ /*
+ * Clear child mon group masks since there is a new parent mask
+ * now and update the rmid for the cpus the child lost.
+ */
+ head = &rdtgrp->mon.crdtgrp_list;
+ list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
+ cpumask_and(tmpmask, &rdtgrp->cpu_mask, &crgrp->cpu_mask);
+ update_closid_rmid(tmpmask, rdtgrp);
+ cpumask_clear(&crgrp->cpu_mask);
+ }
+
+ return 0;
+}
+
+static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ cpumask_var_t tmpmask, newmask, tmpmask1;
+ struct rdtgroup *rdtgrp;
+ int ret;
+
+ if (!buf)
+ return -EINVAL;
+
+ if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
+ return -ENOMEM;
+ if (!zalloc_cpumask_var(&newmask, GFP_KERNEL)) {
+ free_cpumask_var(tmpmask);
+ return -ENOMEM;
+ }
+ if (!zalloc_cpumask_var(&tmpmask1, GFP_KERNEL)) {
+ free_cpumask_var(tmpmask);
+ free_cpumask_var(newmask);
+ return -ENOMEM;
+ }
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ ret = -ENOENT;
+ goto unlock;
+ }
+
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
+ rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ ret = -EINVAL;
+ rdt_last_cmd_puts("Pseudo-locking in progress\n");
+ goto unlock;
+ }
+
+ if (is_cpu_list(of))
+ ret = cpulist_parse(buf, newmask);
+ else
+ ret = cpumask_parse(buf, newmask);
+
+ if (ret) {
+ rdt_last_cmd_puts("Bad CPU list/mask\n");
+ goto unlock;
+ }
+
+ /* check that user didn't specify any offline cpus */
+ cpumask_andnot(tmpmask, newmask, cpu_online_mask);
+ if (!cpumask_empty(tmpmask)) {
+ ret = -EINVAL;
+ rdt_last_cmd_puts("Can only assign online CPUs\n");
+ goto unlock;
+ }
+
+ if (rdtgrp->type == RDTCTRL_GROUP)
+ ret = cpus_ctrl_write(rdtgrp, newmask, tmpmask, tmpmask1);
+ else if (rdtgrp->type == RDTMON_GROUP)
+ ret = cpus_mon_write(rdtgrp, newmask, tmpmask);
+ else
+ ret = -EINVAL;
+
+unlock:
+ rdtgroup_kn_unlock(of->kn);
+ free_cpumask_var(tmpmask);
+ free_cpumask_var(newmask);
+ free_cpumask_var(tmpmask1);
+
+ return ret ?: nbytes;
+}
+
+/**
+ * rdtgroup_remove - the helper to remove resource group safely
+ * @rdtgrp: resource group to remove
+ *
+ * On resource group creation via a mkdir, an extra kernfs_node reference is
+ * taken to ensure that the rdtgroup structure remains accessible for the
+ * rdtgroup_kn_unlock() calls where it is removed.
+ *
+ * Drop the extra reference here, then free the rdtgroup structure.
+ *
+ * Return: void
+ */
+static void rdtgroup_remove(struct rdtgroup *rdtgrp)
+{
+ kernfs_put(rdtgrp->kn);
+ kfree(rdtgrp);
+}
+
+static void _update_task_closid_rmid(void *task)
+{
+ /*
+ * If the task is still current on this CPU, update PQR_ASSOC MSR.
+ * Otherwise, the MSR is updated when the task is scheduled in.
+ */
+ if (task == current)
+ resctrl_arch_sched_in(task);
+}
+
+static void update_task_closid_rmid(struct task_struct *t)
+{
+ if (IS_ENABLED(CONFIG_SMP) && task_curr(t))
+ smp_call_function_single(task_cpu(t), _update_task_closid_rmid, t, 1);
+ else
+ _update_task_closid_rmid(t);
+}
+
+static bool task_in_rdtgroup(struct task_struct *tsk, struct rdtgroup *rdtgrp)
+{
+ u32 closid, rmid = rdtgrp->mon.rmid;
+
+ if (rdtgrp->type == RDTCTRL_GROUP)
+ closid = rdtgrp->closid;
+ else if (rdtgrp->type == RDTMON_GROUP)
+ closid = rdtgrp->mon.parent->closid;
+ else
+ return false;
+
+ return resctrl_arch_match_closid(tsk, closid) &&
+ resctrl_arch_match_rmid(tsk, closid, rmid);
+}
+
+static int __rdtgroup_move_task(struct task_struct *tsk,
+ struct rdtgroup *rdtgrp)
+{
+ /* If the task is already in rdtgrp, no need to move the task. */
+ if (task_in_rdtgroup(tsk, rdtgrp))
+ return 0;
+
+ /*
+ * Set the task's closid/rmid before the PQR_ASSOC MSR can be
+ * updated by them.
+ *
+ * For ctrl_mon groups, move both closid and rmid.
+ * For monitor groups, can move the tasks only from
+ * their parent CTRL group.
+ */
+ if (rdtgrp->type == RDTMON_GROUP &&
+ !resctrl_arch_match_closid(tsk, rdtgrp->mon.parent->closid)) {
+ rdt_last_cmd_puts("Can't move task to different control group\n");
+ return -EINVAL;
+ }
+
+ if (rdtgrp->type == RDTMON_GROUP)
+ resctrl_arch_set_closid_rmid(tsk, rdtgrp->mon.parent->closid,
+ rdtgrp->mon.rmid);
+ else
+ resctrl_arch_set_closid_rmid(tsk, rdtgrp->closid,
+ rdtgrp->mon.rmid);
+
+ /*
+ * Ensure the task's closid and rmid are written before determining if
+ * the task is current that will decide if it will be interrupted.
+ * This pairs with the full barrier between the rq->curr update and
+ * resctrl_arch_sched_in() during context switch.
+ */
+ smp_mb();
+
+ /*
+ * By now, the task's closid and rmid are set. If the task is current
+ * on a CPU, the PQR_ASSOC MSR needs to be updated to make the resource
+ * group go into effect. If the task is not current, the MSR will be
+ * updated when the task is scheduled in.
+ */
+ update_task_closid_rmid(tsk);
+
+ return 0;
+}
+
+static bool is_closid_match(struct task_struct *t, struct rdtgroup *r)
+{
+ return (resctrl_arch_alloc_capable() && (r->type == RDTCTRL_GROUP) &&
+ resctrl_arch_match_closid(t, r->closid));
+}
+
+static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r)
+{
+ return (resctrl_arch_mon_capable() && (r->type == RDTMON_GROUP) &&
+ resctrl_arch_match_rmid(t, r->mon.parent->closid,
+ r->mon.rmid));
+}
+
+/**
+ * rdtgroup_tasks_assigned - Test if tasks have been assigned to resource group
+ * @r: Resource group
+ *
+ * Return: 1 if tasks have been assigned to @r, 0 otherwise
+ */
+int rdtgroup_tasks_assigned(struct rdtgroup *r)
+{
+ struct task_struct *p, *t;
+ int ret = 0;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ rcu_read_lock();
+ for_each_process_thread(p, t) {
+ if (is_closid_match(t, r) || is_rmid_match(t, r)) {
+ ret = 1;
+ break;
+ }
+ }
+ rcu_read_unlock();
+
+ return ret;
+}
+
+static int rdtgroup_task_write_permission(struct task_struct *task,
+ struct kernfs_open_file *of)
+{
+ const struct cred *tcred = get_task_cred(task);
+ const struct cred *cred = current_cred();
+ int ret = 0;
+
+ /*
+ * Even if we're attaching all tasks in the thread group, we only
+ * need to check permissions on one of them.
+ */
+ if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) &&
+ !uid_eq(cred->euid, tcred->uid) &&
+ !uid_eq(cred->euid, tcred->suid)) {
+ rdt_last_cmd_printf("No permission to move task %d\n", task->pid);
+ ret = -EPERM;
+ }
+
+ put_cred(tcred);
+ return ret;
+}
+
+static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp,
+ struct kernfs_open_file *of)
+{
+ struct task_struct *tsk;
+ int ret;
+
+ rcu_read_lock();
+ if (pid) {
+ tsk = find_task_by_vpid(pid);
+ if (!tsk) {
+ rcu_read_unlock();
+ rdt_last_cmd_printf("No task %d\n", pid);
+ return -ESRCH;
+ }
+ } else {
+ tsk = current;
+ }
+
+ get_task_struct(tsk);
+ rcu_read_unlock();
+
+ ret = rdtgroup_task_write_permission(tsk, of);
+ if (!ret)
+ ret = __rdtgroup_move_task(tsk, rdtgrp);
+
+ put_task_struct(tsk);
+ return ret;
+}
+
+static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct rdtgroup *rdtgrp;
+ char *pid_str;
+ int ret = 0;
+ pid_t pid;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ rdtgroup_kn_unlock(of->kn);
+ return -ENOENT;
+ }
+ rdt_last_cmd_clear();
+
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
+ rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ ret = -EINVAL;
+ rdt_last_cmd_puts("Pseudo-locking in progress\n");
+ goto unlock;
+ }
+
+ while (buf && buf[0] != '\0' && buf[0] != '\n') {
+ pid_str = strim(strsep(&buf, ","));
+
+ if (kstrtoint(pid_str, 0, &pid)) {
+ rdt_last_cmd_printf("Task list parsing error pid %s\n", pid_str);
+ ret = -EINVAL;
+ break;
+ }
+
+ if (pid < 0) {
+ rdt_last_cmd_printf("Invalid pid %d\n", pid);
+ ret = -EINVAL;
+ break;
+ }
+
+ ret = rdtgroup_move_task(pid, rdtgrp, of);
+ if (ret) {
+ rdt_last_cmd_printf("Error while processing task %d\n", pid);
+ break;
+ }
+ }
+
+unlock:
+ rdtgroup_kn_unlock(of->kn);
+
+ return ret ?: nbytes;
+}
+
+static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s)
+{
+ struct task_struct *p, *t;
+ pid_t pid;
+
+ rcu_read_lock();
+ for_each_process_thread(p, t) {
+ if (is_closid_match(t, r) || is_rmid_match(t, r)) {
+ pid = task_pid_vnr(t);
+ if (pid)
+ seq_printf(s, "%d\n", pid);
+ }
+ }
+ rcu_read_unlock();
+}
+
+static int rdtgroup_tasks_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdtgroup *rdtgrp;
+ int ret = 0;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (rdtgrp)
+ show_rdt_tasks(rdtgrp, s);
+ else
+ ret = -ENOENT;
+ rdtgroup_kn_unlock(of->kn);
+
+ return ret;
+}
+
+static int rdtgroup_closid_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdtgroup *rdtgrp;
+ int ret = 0;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (rdtgrp)
+ seq_printf(s, "%u\n", rdtgrp->closid);
+ else
+ ret = -ENOENT;
+ rdtgroup_kn_unlock(of->kn);
+
+ return ret;
+}
+
+static int rdtgroup_rmid_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdtgroup *rdtgrp;
+ int ret = 0;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (rdtgrp)
+ seq_printf(s, "%u\n", rdtgrp->mon.rmid);
+ else
+ ret = -ENOENT;
+ rdtgroup_kn_unlock(of->kn);
+
+ return ret;
+}
+
+#ifdef CONFIG_PROC_CPU_RESCTRL
+/*
+ * A task can only be part of one resctrl control group and of one monitor
+ * group which is associated to that control group.
+ *
+ * 1) res:
+ * mon:
+ *
+ * resctrl is not available.
+ *
+ * 2) res:/
+ * mon:
+ *
+ * Task is part of the root resctrl control group, and it is not associated
+ * to any monitor group.
+ *
+ * 3) res:/
+ * mon:mon0
+ *
+ * Task is part of the root resctrl control group and monitor group mon0.
+ *
+ * 4) res:group0
+ * mon:
+ *
+ * Task is part of resctrl control group group0, and it is not associated
+ * to any monitor group.
+ *
+ * 5) res:group0
+ * mon:mon1
+ *
+ * Task is part of resctrl control group group0 and monitor group mon1.
+ */
+int proc_resctrl_show(struct seq_file *s, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *tsk)
+{
+ struct rdtgroup *rdtg;
+ int ret = 0;
+
+ mutex_lock(&rdtgroup_mutex);
+
+ /* Return empty if resctrl has not been mounted. */
+ if (!resctrl_mounted) {
+ seq_puts(s, "res:\nmon:\n");
+ goto unlock;
+ }
+
+ list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) {
+ struct rdtgroup *crg;
+
+ /*
+ * Task information is only relevant for shareable
+ * and exclusive groups.
+ */
+ if (rdtg->mode != RDT_MODE_SHAREABLE &&
+ rdtg->mode != RDT_MODE_EXCLUSIVE)
+ continue;
+
+ if (!resctrl_arch_match_closid(tsk, rdtg->closid))
+ continue;
+
+ seq_printf(s, "res:%s%s\n", (rdtg == &rdtgroup_default) ? "/" : "",
+ rdt_kn_name(rdtg->kn));
+ seq_puts(s, "mon:");
+ list_for_each_entry(crg, &rdtg->mon.crdtgrp_list,
+ mon.crdtgrp_list) {
+ if (!resctrl_arch_match_rmid(tsk, crg->mon.parent->closid,
+ crg->mon.rmid))
+ continue;
+ seq_printf(s, "%s", rdt_kn_name(crg->kn));
+ break;
+ }
+ seq_putc(s, '\n');
+ goto unlock;
+ }
+ /*
+ * The above search should succeed. Otherwise return
+ * with an error.
+ */
+ ret = -ENOENT;
+unlock:
+ mutex_unlock(&rdtgroup_mutex);
+
+ return ret;
+}
+#endif
+
+static int rdt_last_cmd_status_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ int len;
+
+ mutex_lock(&rdtgroup_mutex);
+ len = seq_buf_used(&last_cmd_status);
+ if (len)
+ seq_printf(seq, "%.*s", len, last_cmd_status_buf);
+ else
+ seq_puts(seq, "ok\n");
+ mutex_unlock(&rdtgroup_mutex);
+ return 0;
+}
+
+static void *rdt_kn_parent_priv(struct kernfs_node *kn)
+{
+ /*
+ * The parent pointer is only valid within RCU section since it can be
+ * replaced.
+ */
+ guard(rcu)();
+ return rcu_dereference(kn->__parent)->priv;
+}
+
+static int rdt_num_closids_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+
+ seq_printf(seq, "%u\n", s->num_closid);
+ return 0;
+}
+
+static int rdt_default_ctrl_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+ struct rdt_resource *r = s->res;
+
+ seq_printf(seq, "%x\n", resctrl_get_default_ctrl(r));
+ return 0;
+}
+
+static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+ struct rdt_resource *r = s->res;
+
+ seq_printf(seq, "%u\n", r->cache.min_cbm_bits);
+ return 0;
+}
+
+static int rdt_shareable_bits_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+ struct rdt_resource *r = s->res;
+
+ seq_printf(seq, "%x\n", r->cache.shareable_bits);
+ return 0;
+}
+
+/*
+ * rdt_bit_usage_show - Display current usage of resources
+ *
+ * A domain is a shared resource that can now be allocated differently. Here
+ * we display the current regions of the domain as an annotated bitmask.
+ * For each domain of this resource its allocation bitmask
+ * is annotated as below to indicate the current usage of the corresponding bit:
+ * 0 - currently unused
+ * X - currently available for sharing and used by software and hardware
+ * H - currently used by hardware only but available for software use
+ * S - currently used and shareable by software only
+ * E - currently used exclusively by one resource group
+ * P - currently pseudo-locked by one resource group
+ */
+static int rdt_bit_usage_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+ /*
+ * Use unsigned long even though only 32 bits are used to ensure
+ * test_bit() is used safely.
+ */
+ unsigned long sw_shareable = 0, hw_shareable = 0;
+ unsigned long exclusive = 0, pseudo_locked = 0;
+ struct rdt_resource *r = s->res;
+ struct rdt_ctrl_domain *dom;
+ int i, hwb, swb, excl, psl;
+ enum rdtgrp_mode mode;
+ bool sep = false;
+ u32 ctrl_val;
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+ hw_shareable = r->cache.shareable_bits;
+ list_for_each_entry(dom, &r->ctrl_domains, hdr.list) {
+ if (sep)
+ seq_putc(seq, ';');
+ sw_shareable = 0;
+ exclusive = 0;
+ seq_printf(seq, "%d=", dom->hdr.id);
+ for (i = 0; i < closids_supported(); i++) {
+ if (!closid_allocated(i))
+ continue;
+ ctrl_val = resctrl_arch_get_config(r, dom, i,
+ s->conf_type);
+ mode = rdtgroup_mode_by_closid(i);
+ switch (mode) {
+ case RDT_MODE_SHAREABLE:
+ sw_shareable |= ctrl_val;
+ break;
+ case RDT_MODE_EXCLUSIVE:
+ exclusive |= ctrl_val;
+ break;
+ case RDT_MODE_PSEUDO_LOCKSETUP:
+ /*
+ * RDT_MODE_PSEUDO_LOCKSETUP is possible
+ * here but not included since the CBM
+ * associated with this CLOSID in this mode
+ * is not initialized and no task or cpu can be
+ * assigned this CLOSID.
+ */
+ break;
+ case RDT_MODE_PSEUDO_LOCKED:
+ case RDT_NUM_MODES:
+ WARN(1,
+ "invalid mode for closid %d\n", i);
+ break;
+ }
+ }
+ for (i = r->cache.cbm_len - 1; i >= 0; i--) {
+ pseudo_locked = dom->plr ? dom->plr->cbm : 0;
+ hwb = test_bit(i, &hw_shareable);
+ swb = test_bit(i, &sw_shareable);
+ excl = test_bit(i, &exclusive);
+ psl = test_bit(i, &pseudo_locked);
+ if (hwb && swb)
+ seq_putc(seq, 'X');
+ else if (hwb && !swb)
+ seq_putc(seq, 'H');
+ else if (!hwb && swb)
+ seq_putc(seq, 'S');
+ else if (excl)
+ seq_putc(seq, 'E');
+ else if (psl)
+ seq_putc(seq, 'P');
+ else /* Unused bits remain */
+ seq_putc(seq, '0');
+ }
+ sep = true;
+ }
+ seq_putc(seq, '\n');
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+ return 0;
+}
+
+static int rdt_min_bw_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+ struct rdt_resource *r = s->res;
+
+ seq_printf(seq, "%u\n", r->membw.min_bw);
+ return 0;
+}
+
+static int rdt_num_rmids_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+
+ seq_printf(seq, "%d\n", r->num_rmid);
+
+ return 0;
+}
+
+static int rdt_mon_features_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+ struct mon_evt *mevt;
+
+ list_for_each_entry(mevt, &r->evt_list, list) {
+ seq_printf(seq, "%s\n", mevt->name);
+ if (mevt->configurable)
+ seq_printf(seq, "%s_config\n", mevt->name);
+ }
+
+ return 0;
+}
+
+static int rdt_bw_gran_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+ struct rdt_resource *r = s->res;
+
+ seq_printf(seq, "%u\n", r->membw.bw_gran);
+ return 0;
+}
+
+static int rdt_delay_linear_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+ struct rdt_resource *r = s->res;
+
+ seq_printf(seq, "%u\n", r->membw.delay_linear);
+ return 0;
+}
+
+static int max_threshold_occ_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ seq_printf(seq, "%u\n", resctrl_rmid_realloc_threshold);
+
+ return 0;
+}
+
+static int rdt_thread_throttle_mode_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+ struct rdt_resource *r = s->res;
+
+ switch (r->membw.throttle_mode) {
+ case THREAD_THROTTLE_PER_THREAD:
+ seq_puts(seq, "per-thread\n");
+ return 0;
+ case THREAD_THROTTLE_MAX:
+ seq_puts(seq, "max\n");
+ return 0;
+ case THREAD_THROTTLE_UNDEFINED:
+ seq_puts(seq, "undefined\n");
+ return 0;
+ }
+
+ WARN_ON_ONCE(1);
+
+ return 0;
+}
+
+static ssize_t max_threshold_occ_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ unsigned int bytes;
+ int ret;
+
+ ret = kstrtouint(buf, 0, &bytes);
+ if (ret)
+ return ret;
+
+ if (bytes > resctrl_rmid_realloc_limit)
+ return -EINVAL;
+
+ resctrl_rmid_realloc_threshold = resctrl_arch_round_mon_val(bytes);
+
+ return nbytes;
+}
+
+/*
+ * rdtgroup_mode_show - Display mode of this resource group
+ */
+static int rdtgroup_mode_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdtgroup *rdtgrp;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ rdtgroup_kn_unlock(of->kn);
+ return -ENOENT;
+ }
+
+ seq_printf(s, "%s\n", rdtgroup_mode_str(rdtgrp->mode));
+
+ rdtgroup_kn_unlock(of->kn);
+ return 0;
+}
+
+static enum resctrl_conf_type resctrl_peer_type(enum resctrl_conf_type my_type)
+{
+ switch (my_type) {
+ case CDP_CODE:
+ return CDP_DATA;
+ case CDP_DATA:
+ return CDP_CODE;
+ default:
+ case CDP_NONE:
+ return CDP_NONE;
+ }
+}
+
+static int rdt_has_sparse_bitmasks_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+ struct rdt_resource *r = s->res;
+
+ seq_printf(seq, "%u\n", r->cache.arch_has_sparse_bitmasks);
+
+ return 0;
+}
+
+/**
+ * __rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other
+ * @r: Resource to which domain instance @d belongs.
+ * @d: The domain instance for which @closid is being tested.
+ * @cbm: Capacity bitmask being tested.
+ * @closid: Intended closid for @cbm.
+ * @type: CDP type of @r.
+ * @exclusive: Only check if overlaps with exclusive resource groups
+ *
+ * Checks if provided @cbm intended to be used for @closid on domain
+ * @d overlaps with any other closids or other hardware usage associated
+ * with this domain. If @exclusive is true then only overlaps with
+ * resource groups in exclusive mode will be considered. If @exclusive
+ * is false then overlaps with any resource group or hardware entities
+ * will be considered.
+ *
+ * @cbm is unsigned long, even if only 32 bits are used, to make the
+ * bitmap functions work correctly.
+ *
+ * Return: false if CBM does not overlap, true if it does.
+ */
+static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_ctrl_domain *d,
+ unsigned long cbm, int closid,
+ enum resctrl_conf_type type, bool exclusive)
+{
+ enum rdtgrp_mode mode;
+ unsigned long ctrl_b;
+ int i;
+
+ /* Check for any overlap with regions used by hardware directly */
+ if (!exclusive) {
+ ctrl_b = r->cache.shareable_bits;
+ if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len))
+ return true;
+ }
+
+ /* Check for overlap with other resource groups */
+ for (i = 0; i < closids_supported(); i++) {
+ ctrl_b = resctrl_arch_get_config(r, d, i, type);
+ mode = rdtgroup_mode_by_closid(i);
+ if (closid_allocated(i) && i != closid &&
+ mode != RDT_MODE_PSEUDO_LOCKSETUP) {
+ if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) {
+ if (exclusive) {
+ if (mode == RDT_MODE_EXCLUSIVE)
+ return true;
+ continue;
+ }
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
+
+/**
+ * rdtgroup_cbm_overlaps - Does CBM overlap with other use of hardware
+ * @s: Schema for the resource to which domain instance @d belongs.
+ * @d: The domain instance for which @closid is being tested.
+ * @cbm: Capacity bitmask being tested.
+ * @closid: Intended closid for @cbm.
+ * @exclusive: Only check if overlaps with exclusive resource groups
+ *
+ * Resources that can be allocated using a CBM can use the CBM to control
+ * the overlap of these allocations. rdtgroup_cmb_overlaps() is the test
+ * for overlap. Overlap test is not limited to the specific resource for
+ * which the CBM is intended though - when dealing with CDP resources that
+ * share the underlying hardware the overlap check should be performed on
+ * the CDP resource sharing the hardware also.
+ *
+ * Refer to description of __rdtgroup_cbm_overlaps() for the details of the
+ * overlap test.
+ *
+ * Return: true if CBM overlap detected, false if there is no overlap
+ */
+bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_ctrl_domain *d,
+ unsigned long cbm, int closid, bool exclusive)
+{
+ enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type);
+ struct rdt_resource *r = s->res;
+
+ if (__rdtgroup_cbm_overlaps(r, d, cbm, closid, s->conf_type,
+ exclusive))
+ return true;
+
+ if (!resctrl_arch_get_cdp_enabled(r->rid))
+ return false;
+ return __rdtgroup_cbm_overlaps(r, d, cbm, closid, peer_type, exclusive);
+}
+
+/**
+ * rdtgroup_mode_test_exclusive - Test if this resource group can be exclusive
+ * @rdtgrp: Resource group identified through its closid.
+ *
+ * An exclusive resource group implies that there should be no sharing of
+ * its allocated resources. At the time this group is considered to be
+ * exclusive this test can determine if its current schemata supports this
+ * setting by testing for overlap with all other resource groups.
+ *
+ * Return: true if resource group can be exclusive, false if there is overlap
+ * with allocations of other resource groups and thus this resource group
+ * cannot be exclusive.
+ */
+static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp)
+{
+ int closid = rdtgrp->closid;
+ struct rdt_ctrl_domain *d;
+ struct resctrl_schema *s;
+ struct rdt_resource *r;
+ bool has_cache = false;
+ u32 ctrl;
+
+ /* Walking r->domains, ensure it can't race with cpuhp */
+ lockdep_assert_cpus_held();
+
+ list_for_each_entry(s, &resctrl_schema_all, list) {
+ r = s->res;
+ if (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA)
+ continue;
+ has_cache = true;
+ list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
+ ctrl = resctrl_arch_get_config(r, d, closid,
+ s->conf_type);
+ if (rdtgroup_cbm_overlaps(s, d, ctrl, closid, false)) {
+ rdt_last_cmd_puts("Schemata overlaps\n");
+ return false;
+ }
+ }
+ }
+
+ if (!has_cache) {
+ rdt_last_cmd_puts("Cannot be exclusive without CAT/CDP\n");
+ return false;
+ }
+
+ return true;
+}
+
+/*
+ * rdtgroup_mode_write - Modify the resource group's mode
+ */
+static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct rdtgroup *rdtgrp;
+ enum rdtgrp_mode mode;
+ int ret = 0;
+
+ /* Valid input requires a trailing newline */
+ if (nbytes == 0 || buf[nbytes - 1] != '\n')
+ return -EINVAL;
+ buf[nbytes - 1] = '\0';
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ rdtgroup_kn_unlock(of->kn);
+ return -ENOENT;
+ }
+
+ rdt_last_cmd_clear();
+
+ mode = rdtgrp->mode;
+
+ if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) ||
+ (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE) ||
+ (!strcmp(buf, "pseudo-locksetup") &&
+ mode == RDT_MODE_PSEUDO_LOCKSETUP) ||
+ (!strcmp(buf, "pseudo-locked") && mode == RDT_MODE_PSEUDO_LOCKED))
+ goto out;
+
+ if (mode == RDT_MODE_PSEUDO_LOCKED) {
+ rdt_last_cmd_puts("Cannot change pseudo-locked group\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (!strcmp(buf, "shareable")) {
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ ret = rdtgroup_locksetup_exit(rdtgrp);
+ if (ret)
+ goto out;
+ }
+ rdtgrp->mode = RDT_MODE_SHAREABLE;
+ } else if (!strcmp(buf, "exclusive")) {
+ if (!rdtgroup_mode_test_exclusive(rdtgrp)) {
+ ret = -EINVAL;
+ goto out;
+ }
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ ret = rdtgroup_locksetup_exit(rdtgrp);
+ if (ret)
+ goto out;
+ }
+ rdtgrp->mode = RDT_MODE_EXCLUSIVE;
+ } else if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK) &&
+ !strcmp(buf, "pseudo-locksetup")) {
+ ret = rdtgroup_locksetup_enter(rdtgrp);
+ if (ret)
+ goto out;
+ rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP;
+ } else {
+ rdt_last_cmd_puts("Unknown or unsupported mode\n");
+ ret = -EINVAL;
+ }
+
+out:
+ rdtgroup_kn_unlock(of->kn);
+ return ret ?: nbytes;
+}
+
+/**
+ * rdtgroup_cbm_to_size - Translate CBM to size in bytes
+ * @r: RDT resource to which @d belongs.
+ * @d: RDT domain instance.
+ * @cbm: bitmask for which the size should be computed.
+ *
+ * The bitmask provided associated with the RDT domain instance @d will be
+ * translated into how many bytes it represents. The size in bytes is
+ * computed by first dividing the total cache size by the CBM length to
+ * determine how many bytes each bit in the bitmask represents. The result
+ * is multiplied with the number of bits set in the bitmask.
+ *
+ * @cbm is unsigned long, even if only 32 bits are used to make the
+ * bitmap functions work correctly.
+ */
+unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r,
+ struct rdt_ctrl_domain *d, unsigned long cbm)
+{
+ unsigned int size = 0;
+ struct cacheinfo *ci;
+ int num_b;
+
+ if (WARN_ON_ONCE(r->ctrl_scope != RESCTRL_L2_CACHE && r->ctrl_scope != RESCTRL_L3_CACHE))
+ return size;
+
+ num_b = bitmap_weight(&cbm, r->cache.cbm_len);
+ ci = get_cpu_cacheinfo_level(cpumask_any(&d->hdr.cpu_mask), r->ctrl_scope);
+ if (ci)
+ size = ci->size / r->cache.cbm_len * num_b;
+
+ return size;
+}
+
+bool is_mba_sc(struct rdt_resource *r)
+{
+ if (!r)
+ r = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
+
+ /*
+ * The software controller support is only applicable to MBA resource.
+ * Make sure to check for resource type.
+ */
+ if (r->rid != RDT_RESOURCE_MBA)
+ return false;
+
+ return r->membw.mba_sc;
+}
+
+/*
+ * rdtgroup_size_show - Display size in bytes of allocated regions
+ *
+ * The "size" file mirrors the layout of the "schemata" file, printing the
+ * size in bytes of each region instead of the capacity bitmask.
+ */
+static int rdtgroup_size_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct resctrl_schema *schema;
+ enum resctrl_conf_type type;
+ struct rdt_ctrl_domain *d;
+ struct rdtgroup *rdtgrp;
+ struct rdt_resource *r;
+ unsigned int size;
+ int ret = 0;
+ u32 closid;
+ bool sep;
+ u32 ctrl;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ rdtgroup_kn_unlock(of->kn);
+ return -ENOENT;
+ }
+
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
+ if (!rdtgrp->plr->d) {
+ rdt_last_cmd_clear();
+ rdt_last_cmd_puts("Cache domain offline\n");
+ ret = -ENODEV;
+ } else {
+ seq_printf(s, "%*s:", max_name_width,
+ rdtgrp->plr->s->name);
+ size = rdtgroup_cbm_to_size(rdtgrp->plr->s->res,
+ rdtgrp->plr->d,
+ rdtgrp->plr->cbm);
+ seq_printf(s, "%d=%u\n", rdtgrp->plr->d->hdr.id, size);
+ }
+ goto out;
+ }
+
+ closid = rdtgrp->closid;
+
+ list_for_each_entry(schema, &resctrl_schema_all, list) {
+ r = schema->res;
+ type = schema->conf_type;
+ sep = false;
+ seq_printf(s, "%*s:", max_name_width, schema->name);
+ list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
+ if (sep)
+ seq_putc(s, ';');
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+ size = 0;
+ } else {
+ if (is_mba_sc(r))
+ ctrl = d->mbps_val[closid];
+ else
+ ctrl = resctrl_arch_get_config(r, d,
+ closid,
+ type);
+ if (r->rid == RDT_RESOURCE_MBA ||
+ r->rid == RDT_RESOURCE_SMBA)
+ size = ctrl;
+ else
+ size = rdtgroup_cbm_to_size(r, d, ctrl);
+ }
+ seq_printf(s, "%d=%u", d->hdr.id, size);
+ sep = true;
+ }
+ seq_putc(s, '\n');
+ }
+
+out:
+ rdtgroup_kn_unlock(of->kn);
+
+ return ret;
+}
+
+static void mondata_config_read(struct resctrl_mon_config_info *mon_info)
+{
+ smp_call_function_any(&mon_info->d->hdr.cpu_mask,
+ resctrl_arch_mon_event_config_read, mon_info, 1);
+}
+
+static int mbm_config_show(struct seq_file *s, struct rdt_resource *r, u32 evtid)
+{
+ struct resctrl_mon_config_info mon_info;
+ struct rdt_mon_domain *dom;
+ bool sep = false;
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+
+ list_for_each_entry(dom, &r->mon_domains, hdr.list) {
+ if (sep)
+ seq_puts(s, ";");
+
+ memset(&mon_info, 0, sizeof(struct resctrl_mon_config_info));
+ mon_info.r = r;
+ mon_info.d = dom;
+ mon_info.evtid = evtid;
+ mondata_config_read(&mon_info);
+
+ seq_printf(s, "%d=0x%02x", dom->hdr.id, mon_info.mon_config);
+ sep = true;
+ }
+ seq_puts(s, "\n");
+
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+
+ return 0;
+}
+
+static int mbm_total_bytes_config_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+
+ mbm_config_show(seq, r, QOS_L3_MBM_TOTAL_EVENT_ID);
+
+ return 0;
+}
+
+static int mbm_local_bytes_config_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+
+ mbm_config_show(seq, r, QOS_L3_MBM_LOCAL_EVENT_ID);
+
+ return 0;
+}
+
+static void mbm_config_write_domain(struct rdt_resource *r,
+ struct rdt_mon_domain *d, u32 evtid, u32 val)
+{
+ struct resctrl_mon_config_info mon_info = {0};
+
+ /*
+ * Read the current config value first. If both are the same then
+ * no need to write it again.
+ */
+ mon_info.r = r;
+ mon_info.d = d;
+ mon_info.evtid = evtid;
+ mondata_config_read(&mon_info);
+ if (mon_info.mon_config == val)
+ return;
+
+ mon_info.mon_config = val;
+
+ /*
+ * Update MSR_IA32_EVT_CFG_BASE MSR on one of the CPUs in the
+ * domain. The MSRs offset from MSR MSR_IA32_EVT_CFG_BASE
+ * are scoped at the domain level. Writing any of these MSRs
+ * on one CPU is observed by all the CPUs in the domain.
+ */
+ smp_call_function_any(&d->hdr.cpu_mask, resctrl_arch_mon_event_config_write,
+ &mon_info, 1);
+
+ /*
+ * When an Event Configuration is changed, the bandwidth counters
+ * for all RMIDs and Events will be cleared by the hardware. The
+ * hardware also sets MSR_IA32_QM_CTR.Unavailable (bit 62) for
+ * every RMID on the next read to any event for every RMID.
+ * Subsequent reads will have MSR_IA32_QM_CTR.Unavailable (bit 62)
+ * cleared while it is tracked by the hardware. Clear the
+ * mbm_local and mbm_total counts for all the RMIDs.
+ */
+ resctrl_arch_reset_rmid_all(r, d);
+}
+
+static int mon_config_write(struct rdt_resource *r, char *tok, u32 evtid)
+{
+ char *dom_str = NULL, *id_str;
+ unsigned long dom_id, val;
+ struct rdt_mon_domain *d;
+
+ /* Walking r->domains, ensure it can't race with cpuhp */
+ lockdep_assert_cpus_held();
+
+next:
+ if (!tok || tok[0] == '\0')
+ return 0;
+
+ /* Start processing the strings for each domain */
+ dom_str = strim(strsep(&tok, ";"));
+ id_str = strsep(&dom_str, "=");
+
+ if (!id_str || kstrtoul(id_str, 10, &dom_id)) {
+ rdt_last_cmd_puts("Missing '=' or non-numeric domain id\n");
+ return -EINVAL;
+ }
+
+ if (!dom_str || kstrtoul(dom_str, 16, &val)) {
+ rdt_last_cmd_puts("Non-numeric event configuration value\n");
+ return -EINVAL;
+ }
+
+ /* Value from user cannot be more than the supported set of events */
+ if ((val & r->mbm_cfg_mask) != val) {
+ rdt_last_cmd_printf("Invalid event configuration: max valid mask is 0x%02x\n",
+ r->mbm_cfg_mask);
+ return -EINVAL;
+ }
+
+ list_for_each_entry(d, &r->mon_domains, hdr.list) {
+ if (d->hdr.id == dom_id) {
+ mbm_config_write_domain(r, d, evtid, val);
+ goto next;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static ssize_t mbm_total_bytes_config_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes,
+ loff_t off)
+{
+ struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+ int ret;
+
+ /* Valid input requires a trailing newline */
+ if (nbytes == 0 || buf[nbytes - 1] != '\n')
+ return -EINVAL;
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+
+ rdt_last_cmd_clear();
+
+ buf[nbytes - 1] = '\0';
+
+ ret = mon_config_write(r, buf, QOS_L3_MBM_TOTAL_EVENT_ID);
+
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+
+ return ret ?: nbytes;
+}
+
+static ssize_t mbm_local_bytes_config_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes,
+ loff_t off)
+{
+ struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+ int ret;
+
+ /* Valid input requires a trailing newline */
+ if (nbytes == 0 || buf[nbytes - 1] != '\n')
+ return -EINVAL;
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+
+ rdt_last_cmd_clear();
+
+ buf[nbytes - 1] = '\0';
+
+ ret = mon_config_write(r, buf, QOS_L3_MBM_LOCAL_EVENT_ID);
+
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+
+ return ret ?: nbytes;
+}
+
+/* rdtgroup information files for one cache resource. */
+static struct rftype res_common_files[] = {
+ {
+ .name = "last_cmd_status",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_last_cmd_status_show,
+ .fflags = RFTYPE_TOP_INFO,
+ },
+ {
+ .name = "num_closids",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_num_closids_show,
+ .fflags = RFTYPE_CTRL_INFO,
+ },
+ {
+ .name = "mon_features",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_mon_features_show,
+ .fflags = RFTYPE_MON_INFO,
+ },
+ {
+ .name = "num_rmids",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_num_rmids_show,
+ .fflags = RFTYPE_MON_INFO,
+ },
+ {
+ .name = "cbm_mask",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_default_ctrl_show,
+ .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
+ },
+ {
+ .name = "min_cbm_bits",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_min_cbm_bits_show,
+ .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
+ },
+ {
+ .name = "shareable_bits",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_shareable_bits_show,
+ .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
+ },
+ {
+ .name = "bit_usage",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_bit_usage_show,
+ .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
+ },
+ {
+ .name = "min_bandwidth",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_min_bw_show,
+ .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB,
+ },
+ {
+ .name = "bandwidth_gran",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_bw_gran_show,
+ .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB,
+ },
+ {
+ .name = "delay_linear",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_delay_linear_show,
+ .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB,
+ },
+ /*
+ * Platform specific which (if any) capabilities are provided by
+ * thread_throttle_mode. Defer "fflags" initialization to platform
+ * discovery.
+ */
+ {
+ .name = "thread_throttle_mode",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_thread_throttle_mode_show,
+ },
+ {
+ .name = "max_threshold_occupancy",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .write = max_threshold_occ_write,
+ .seq_show = max_threshold_occ_show,
+ .fflags = RFTYPE_MON_INFO | RFTYPE_RES_CACHE,
+ },
+ {
+ .name = "mbm_total_bytes_config",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = mbm_total_bytes_config_show,
+ .write = mbm_total_bytes_config_write,
+ },
+ {
+ .name = "mbm_local_bytes_config",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = mbm_local_bytes_config_show,
+ .write = mbm_local_bytes_config_write,
+ },
+ {
+ .name = "cpus",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .write = rdtgroup_cpus_write,
+ .seq_show = rdtgroup_cpus_show,
+ .fflags = RFTYPE_BASE,
+ },
+ {
+ .name = "cpus_list",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .write = rdtgroup_cpus_write,
+ .seq_show = rdtgroup_cpus_show,
+ .flags = RFTYPE_FLAGS_CPUS_LIST,
+ .fflags = RFTYPE_BASE,
+ },
+ {
+ .name = "tasks",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .write = rdtgroup_tasks_write,
+ .seq_show = rdtgroup_tasks_show,
+ .fflags = RFTYPE_BASE,
+ },
+ {
+ .name = "mon_hw_id",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdtgroup_rmid_show,
+ .fflags = RFTYPE_MON_BASE | RFTYPE_DEBUG,
+ },
+ {
+ .name = "schemata",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .write = rdtgroup_schemata_write,
+ .seq_show = rdtgroup_schemata_show,
+ .fflags = RFTYPE_CTRL_BASE,
+ },
+ {
+ .name = "mba_MBps_event",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .write = rdtgroup_mba_mbps_event_write,
+ .seq_show = rdtgroup_mba_mbps_event_show,
+ },
+ {
+ .name = "mode",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .write = rdtgroup_mode_write,
+ .seq_show = rdtgroup_mode_show,
+ .fflags = RFTYPE_CTRL_BASE,
+ },
+ {
+ .name = "size",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdtgroup_size_show,
+ .fflags = RFTYPE_CTRL_BASE,
+ },
+ {
+ .name = "sparse_masks",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_has_sparse_bitmasks_show,
+ .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
+ },
+ {
+ .name = "ctrl_hw_id",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdtgroup_closid_show,
+ .fflags = RFTYPE_CTRL_BASE | RFTYPE_DEBUG,
+ },
+};
+
+static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags)
+{
+ struct rftype *rfts, *rft;
+ int ret, len;
+
+ rfts = res_common_files;
+ len = ARRAY_SIZE(res_common_files);
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ if (resctrl_debug)
+ fflags |= RFTYPE_DEBUG;
+
+ for (rft = rfts; rft < rfts + len; rft++) {
+ if (rft->fflags && ((fflags & rft->fflags) == rft->fflags)) {
+ ret = rdtgroup_add_file(kn, rft);
+ if (ret)
+ goto error;
+ }
+ }
+
+ return 0;
+error:
+ pr_warn("Failed to add %s, err=%d\n", rft->name, ret);
+ while (--rft >= rfts) {
+ if ((fflags & rft->fflags) == rft->fflags)
+ kernfs_remove_by_name(kn, rft->name);
+ }
+ return ret;
+}
+
+static struct rftype *rdtgroup_get_rftype_by_name(const char *name)
+{
+ struct rftype *rfts, *rft;
+ int len;
+
+ rfts = res_common_files;
+ len = ARRAY_SIZE(res_common_files);
+
+ for (rft = rfts; rft < rfts + len; rft++) {
+ if (!strcmp(rft->name, name))
+ return rft;
+ }
+
+ return NULL;
+}
+
+static void thread_throttle_mode_init(void)
+{
+ enum membw_throttle_mode throttle_mode = THREAD_THROTTLE_UNDEFINED;
+ struct rdt_resource *r_mba, *r_smba;
+
+ r_mba = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
+ if (r_mba->alloc_capable &&
+ r_mba->membw.throttle_mode != THREAD_THROTTLE_UNDEFINED)
+ throttle_mode = r_mba->membw.throttle_mode;
+
+ r_smba = resctrl_arch_get_resource(RDT_RESOURCE_SMBA);
+ if (r_smba->alloc_capable &&
+ r_smba->membw.throttle_mode != THREAD_THROTTLE_UNDEFINED)
+ throttle_mode = r_smba->membw.throttle_mode;
+
+ if (throttle_mode == THREAD_THROTTLE_UNDEFINED)
+ return;
+
+ resctrl_file_fflags_init("thread_throttle_mode",
+ RFTYPE_CTRL_INFO | RFTYPE_RES_MB);
+}
+
+void resctrl_file_fflags_init(const char *config, unsigned long fflags)
+{
+ struct rftype *rft;
+
+ rft = rdtgroup_get_rftype_by_name(config);
+ if (rft)
+ rft->fflags = fflags;
+}
+
+/**
+ * rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file
+ * @r: The resource group with which the file is associated.
+ * @name: Name of the file
+ *
+ * The permissions of named resctrl file, directory, or link are modified
+ * to not allow read, write, or execute by any user.
+ *
+ * WARNING: This function is intended to communicate to the user that the
+ * resctrl file has been locked down - that it is not relevant to the
+ * particular state the system finds itself in. It should not be relied
+ * on to protect from user access because after the file's permissions
+ * are restricted the user can still change the permissions using chmod
+ * from the command line.
+ *
+ * Return: 0 on success, <0 on failure.
+ */
+int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name)
+{
+ struct iattr iattr = {.ia_valid = ATTR_MODE,};
+ struct kernfs_node *kn;
+ int ret = 0;
+
+ kn = kernfs_find_and_get_ns(r->kn, name, NULL);
+ if (!kn)
+ return -ENOENT;
+
+ switch (kernfs_type(kn)) {
+ case KERNFS_DIR:
+ iattr.ia_mode = S_IFDIR;
+ break;
+ case KERNFS_FILE:
+ iattr.ia_mode = S_IFREG;
+ break;
+ case KERNFS_LINK:
+ iattr.ia_mode = S_IFLNK;
+ break;
+ }
+
+ ret = kernfs_setattr(kn, &iattr);
+ kernfs_put(kn);
+ return ret;
+}
+
+/**
+ * rdtgroup_kn_mode_restore - Restore user access to named resctrl file
+ * @r: The resource group with which the file is associated.
+ * @name: Name of the file
+ * @mask: Mask of permissions that should be restored
+ *
+ * Restore the permissions of the named file. If @name is a directory the
+ * permissions of its parent will be used.
+ *
+ * Return: 0 on success, <0 on failure.
+ */
+int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name,
+ umode_t mask)
+{
+ struct iattr iattr = {.ia_valid = ATTR_MODE,};
+ struct kernfs_node *kn, *parent;
+ struct rftype *rfts, *rft;
+ int ret, len;
+
+ rfts = res_common_files;
+ len = ARRAY_SIZE(res_common_files);
+
+ for (rft = rfts; rft < rfts + len; rft++) {
+ if (!strcmp(rft->name, name))
+ iattr.ia_mode = rft->mode & mask;
+ }
+
+ kn = kernfs_find_and_get_ns(r->kn, name, NULL);
+ if (!kn)
+ return -ENOENT;
+
+ switch (kernfs_type(kn)) {
+ case KERNFS_DIR:
+ parent = kernfs_get_parent(kn);
+ if (parent) {
+ iattr.ia_mode |= parent->mode;
+ kernfs_put(parent);
+ }
+ iattr.ia_mode |= S_IFDIR;
+ break;
+ case KERNFS_FILE:
+ iattr.ia_mode |= S_IFREG;
+ break;
+ case KERNFS_LINK:
+ iattr.ia_mode |= S_IFLNK;
+ break;
+ }
+
+ ret = kernfs_setattr(kn, &iattr);
+ kernfs_put(kn);
+ return ret;
+}
+
+static int rdtgroup_mkdir_info_resdir(void *priv, char *name,
+ unsigned long fflags)
+{
+ struct kernfs_node *kn_subdir;
+ int ret;
+
+ kn_subdir = kernfs_create_dir(kn_info, name,
+ kn_info->mode, priv);
+ if (IS_ERR(kn_subdir))
+ return PTR_ERR(kn_subdir);
+
+ ret = rdtgroup_kn_set_ugid(kn_subdir);
+ if (ret)
+ return ret;
+
+ ret = rdtgroup_add_files(kn_subdir, fflags);
+ if (!ret)
+ kernfs_activate(kn_subdir);
+
+ return ret;
+}
+
+static unsigned long fflags_from_resource(struct rdt_resource *r)
+{
+ switch (r->rid) {
+ case RDT_RESOURCE_L3:
+ case RDT_RESOURCE_L2:
+ return RFTYPE_RES_CACHE;
+ case RDT_RESOURCE_MBA:
+ case RDT_RESOURCE_SMBA:
+ return RFTYPE_RES_MB;
+ }
+
+ return WARN_ON_ONCE(1);
+}
+
+static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
+{
+ struct resctrl_schema *s;
+ struct rdt_resource *r;
+ unsigned long fflags;
+ char name[32];
+ int ret;
+
+ /* create the directory */
+ kn_info = kernfs_create_dir(parent_kn, "info", parent_kn->mode, NULL);
+ if (IS_ERR(kn_info))
+ return PTR_ERR(kn_info);
+
+ ret = rdtgroup_add_files(kn_info, RFTYPE_TOP_INFO);
+ if (ret)
+ goto out_destroy;
+
+ /* loop over enabled controls, these are all alloc_capable */
+ list_for_each_entry(s, &resctrl_schema_all, list) {
+ r = s->res;
+ fflags = fflags_from_resource(r) | RFTYPE_CTRL_INFO;
+ ret = rdtgroup_mkdir_info_resdir(s, s->name, fflags);
+ if (ret)
+ goto out_destroy;
+ }
+
+ for_each_mon_capable_rdt_resource(r) {
+ fflags = fflags_from_resource(r) | RFTYPE_MON_INFO;
+ sprintf(name, "%s_MON", r->name);
+ ret = rdtgroup_mkdir_info_resdir(r, name, fflags);
+ if (ret)
+ goto out_destroy;
+ }
+
+ ret = rdtgroup_kn_set_ugid(kn_info);
+ if (ret)
+ goto out_destroy;
+
+ kernfs_activate(kn_info);
+
+ return 0;
+
+out_destroy:
+ kernfs_remove(kn_info);
+ return ret;
+}
+
+static int
+mongroup_create_dir(struct kernfs_node *parent_kn, struct rdtgroup *prgrp,
+ char *name, struct kernfs_node **dest_kn)
+{
+ struct kernfs_node *kn;
+ int ret;
+
+ /* create the directory */
+ kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
+ if (IS_ERR(kn))
+ return PTR_ERR(kn);
+
+ if (dest_kn)
+ *dest_kn = kn;
+
+ ret = rdtgroup_kn_set_ugid(kn);
+ if (ret)
+ goto out_destroy;
+
+ kernfs_activate(kn);
+
+ return 0;
+
+out_destroy:
+ kernfs_remove(kn);
+ return ret;
+}
+
+static inline bool is_mba_linear(void)
+{
+ return resctrl_arch_get_resource(RDT_RESOURCE_MBA)->membw.delay_linear;
+}
+
+static int mba_sc_domain_allocate(struct rdt_resource *r, struct rdt_ctrl_domain *d)
+{
+ u32 num_closid = resctrl_arch_get_num_closid(r);
+ int cpu = cpumask_any(&d->hdr.cpu_mask);
+ int i;
+
+ d->mbps_val = kcalloc_node(num_closid, sizeof(*d->mbps_val),
+ GFP_KERNEL, cpu_to_node(cpu));
+ if (!d->mbps_val)
+ return -ENOMEM;
+
+ for (i = 0; i < num_closid; i++)
+ d->mbps_val[i] = MBA_MAX_MBPS;
+
+ return 0;
+}
+
+static void mba_sc_domain_destroy(struct rdt_resource *r,
+ struct rdt_ctrl_domain *d)
+{
+ kfree(d->mbps_val);
+ d->mbps_val = NULL;
+}
+
+/*
+ * MBA software controller is supported only if
+ * MBM is supported and MBA is in linear scale,
+ * and the MBM monitor scope is the same as MBA
+ * control scope.
+ */
+static bool supports_mba_mbps(void)
+{
+ struct rdt_resource *rmbm = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
+
+ return (resctrl_is_mbm_enabled() &&
+ r->alloc_capable && is_mba_linear() &&
+ r->ctrl_scope == rmbm->mon_scope);
+}
+
+/*
+ * Enable or disable the MBA software controller
+ * which helps user specify bandwidth in MBps.
+ */
+static int set_mba_sc(bool mba_sc)
+{
+ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
+ u32 num_closid = resctrl_arch_get_num_closid(r);
+ struct rdt_ctrl_domain *d;
+ unsigned long fflags;
+ int i;
+
+ if (!supports_mba_mbps() || mba_sc == is_mba_sc(r))
+ return -EINVAL;
+
+ r->membw.mba_sc = mba_sc;
+
+ rdtgroup_default.mba_mbps_event = mba_mbps_default_event;
+
+ list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
+ for (i = 0; i < num_closid; i++)
+ d->mbps_val[i] = MBA_MAX_MBPS;
+ }
+
+ fflags = mba_sc ? RFTYPE_CTRL_BASE | RFTYPE_MON_BASE : 0;
+ resctrl_file_fflags_init("mba_MBps_event", fflags);
+
+ return 0;
+}
+
+/*
+ * We don't allow rdtgroup directories to be created anywhere
+ * except the root directory. Thus when looking for the rdtgroup
+ * structure for a kernfs node we are either looking at a directory,
+ * in which case the rdtgroup structure is pointed at by the "priv"
+ * field, otherwise we have a file, and need only look to the parent
+ * to find the rdtgroup.
+ */
+static struct rdtgroup *kernfs_to_rdtgroup(struct kernfs_node *kn)
+{
+ if (kernfs_type(kn) == KERNFS_DIR) {
+ /*
+ * All the resource directories use "kn->priv"
+ * to point to the "struct rdtgroup" for the
+ * resource. "info" and its subdirectories don't
+ * have rdtgroup structures, so return NULL here.
+ */
+ if (kn == kn_info ||
+ rcu_access_pointer(kn->__parent) == kn_info)
+ return NULL;
+ else
+ return kn->priv;
+ } else {
+ return rdt_kn_parent_priv(kn);
+ }
+}
+
+static void rdtgroup_kn_get(struct rdtgroup *rdtgrp, struct kernfs_node *kn)
+{
+ atomic_inc(&rdtgrp->waitcount);
+ kernfs_break_active_protection(kn);
+}
+
+static void rdtgroup_kn_put(struct rdtgroup *rdtgrp, struct kernfs_node *kn)
+{
+ if (atomic_dec_and_test(&rdtgrp->waitcount) &&
+ (rdtgrp->flags & RDT_DELETED)) {
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
+ rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
+ rdtgroup_pseudo_lock_remove(rdtgrp);
+ kernfs_unbreak_active_protection(kn);
+ rdtgroup_remove(rdtgrp);
+ } else {
+ kernfs_unbreak_active_protection(kn);
+ }
+}
+
+struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn)
+{
+ struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn);
+
+ if (!rdtgrp)
+ return NULL;
+
+ rdtgroup_kn_get(rdtgrp, kn);
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+
+ /* Was this group deleted while we waited? */
+ if (rdtgrp->flags & RDT_DELETED)
+ return NULL;
+
+ return rdtgrp;
+}
+
+void rdtgroup_kn_unlock(struct kernfs_node *kn)
+{
+ struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn);
+
+ if (!rdtgrp)
+ return;
+
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+
+ rdtgroup_kn_put(rdtgrp, kn);
+}
+
+static int mkdir_mondata_all(struct kernfs_node *parent_kn,
+ struct rdtgroup *prgrp,
+ struct kernfs_node **mon_data_kn);
+
+static void rdt_disable_ctx(void)
+{
+ resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);
+ resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);
+ set_mba_sc(false);
+
+ resctrl_debug = false;
+}
+
+static int rdt_enable_ctx(struct rdt_fs_context *ctx)
+{
+ int ret = 0;
+
+ if (ctx->enable_cdpl2) {
+ ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, true);
+ if (ret)
+ goto out_done;
+ }
+
+ if (ctx->enable_cdpl3) {
+ ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, true);
+ if (ret)
+ goto out_cdpl2;
+ }
+
+ if (ctx->enable_mba_mbps) {
+ ret = set_mba_sc(true);
+ if (ret)
+ goto out_cdpl3;
+ }
+
+ if (ctx->enable_debug)
+ resctrl_debug = true;
+
+ return 0;
+
+out_cdpl3:
+ resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);
+out_cdpl2:
+ resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);
+out_done:
+ return ret;
+}
+
+static int schemata_list_add(struct rdt_resource *r, enum resctrl_conf_type type)
+{
+ struct resctrl_schema *s;
+ const char *suffix = "";
+ int ret, cl;
+
+ s = kzalloc(sizeof(*s), GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ s->res = r;
+ s->num_closid = resctrl_arch_get_num_closid(r);
+ if (resctrl_arch_get_cdp_enabled(r->rid))
+ s->num_closid /= 2;
+
+ s->conf_type = type;
+ switch (type) {
+ case CDP_CODE:
+ suffix = "CODE";
+ break;
+ case CDP_DATA:
+ suffix = "DATA";
+ break;
+ case CDP_NONE:
+ suffix = "";
+ break;
+ }
+
+ ret = snprintf(s->name, sizeof(s->name), "%s%s", r->name, suffix);
+ if (ret >= sizeof(s->name)) {
+ kfree(s);
+ return -EINVAL;
+ }
+
+ cl = strlen(s->name);
+
+ /*
+ * If CDP is supported by this resource, but not enabled,
+ * include the suffix. This ensures the tabular format of the
+ * schemata file does not change between mounts of the filesystem.
+ */
+ if (r->cdp_capable && !resctrl_arch_get_cdp_enabled(r->rid))
+ cl += 4;
+
+ if (cl > max_name_width)
+ max_name_width = cl;
+
+ switch (r->schema_fmt) {
+ case RESCTRL_SCHEMA_BITMAP:
+ s->fmt_str = "%d=%x";
+ break;
+ case RESCTRL_SCHEMA_RANGE:
+ s->fmt_str = "%d=%u";
+ break;
+ }
+
+ if (WARN_ON_ONCE(!s->fmt_str)) {
+ kfree(s);
+ return -EINVAL;
+ }
+
+ INIT_LIST_HEAD(&s->list);
+ list_add(&s->list, &resctrl_schema_all);
+
+ return 0;
+}
+
+static int schemata_list_create(void)
+{
+ struct rdt_resource *r;
+ int ret = 0;
+
+ for_each_alloc_capable_rdt_resource(r) {
+ if (resctrl_arch_get_cdp_enabled(r->rid)) {
+ ret = schemata_list_add(r, CDP_CODE);
+ if (ret)
+ break;
+
+ ret = schemata_list_add(r, CDP_DATA);
+ } else {
+ ret = schemata_list_add(r, CDP_NONE);
+ }
+
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+
+static void schemata_list_destroy(void)
+{
+ struct resctrl_schema *s, *tmp;
+
+ list_for_each_entry_safe(s, tmp, &resctrl_schema_all, list) {
+ list_del(&s->list);
+ kfree(s);
+ }
+}
+
+static int rdt_get_tree(struct fs_context *fc)
+{
+ struct rdt_fs_context *ctx = rdt_fc2context(fc);
+ unsigned long flags = RFTYPE_CTRL_BASE;
+ struct rdt_mon_domain *dom;
+ struct rdt_resource *r;
+ int ret;
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+ /*
+ * resctrl file system can only be mounted once.
+ */
+ if (resctrl_mounted) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ ret = rdtgroup_setup_root(ctx);
+ if (ret)
+ goto out;
+
+ ret = rdt_enable_ctx(ctx);
+ if (ret)
+ goto out_root;
+
+ ret = schemata_list_create();
+ if (ret) {
+ schemata_list_destroy();
+ goto out_ctx;
+ }
+
+ ret = closid_init();
+ if (ret)
+ goto out_schemata_free;
+
+ if (resctrl_arch_mon_capable())
+ flags |= RFTYPE_MON;
+
+ ret = rdtgroup_add_files(rdtgroup_default.kn, flags);
+ if (ret)
+ goto out_closid_exit;
+
+ kernfs_activate(rdtgroup_default.kn);
+
+ ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
+ if (ret < 0)
+ goto out_closid_exit;
+
+ if (resctrl_arch_mon_capable()) {
+ ret = mongroup_create_dir(rdtgroup_default.kn,
+ &rdtgroup_default, "mon_groups",
+ &kn_mongrp);
+ if (ret < 0)
+ goto out_info;
+
+ ret = mkdir_mondata_all(rdtgroup_default.kn,
+ &rdtgroup_default, &kn_mondata);
+ if (ret < 0)
+ goto out_mongrp;
+ rdtgroup_default.mon.mon_data_kn = kn_mondata;
+ }
+
+ ret = rdt_pseudo_lock_init();
+ if (ret)
+ goto out_mondata;
+
+ ret = kernfs_get_tree(fc);
+ if (ret < 0)
+ goto out_psl;
+
+ if (resctrl_arch_alloc_capable())
+ resctrl_arch_enable_alloc();
+ if (resctrl_arch_mon_capable())
+ resctrl_arch_enable_mon();
+
+ if (resctrl_arch_alloc_capable() || resctrl_arch_mon_capable())
+ resctrl_mounted = true;
+
+ if (resctrl_is_mbm_enabled()) {
+ r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+ list_for_each_entry(dom, &r->mon_domains, hdr.list)
+ mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL,
+ RESCTRL_PICK_ANY_CPU);
+ }
+
+ goto out;
+
+out_psl:
+ rdt_pseudo_lock_release();
+out_mondata:
+ if (resctrl_arch_mon_capable())
+ kernfs_remove(kn_mondata);
+out_mongrp:
+ if (resctrl_arch_mon_capable())
+ kernfs_remove(kn_mongrp);
+out_info:
+ kernfs_remove(kn_info);
+out_closid_exit:
+ closid_exit();
+out_schemata_free:
+ schemata_list_destroy();
+out_ctx:
+ rdt_disable_ctx();
+out_root:
+ rdtgroup_destroy_root();
+out:
+ rdt_last_cmd_clear();
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+ return ret;
+}
+
+enum rdt_param {
+ Opt_cdp,
+ Opt_cdpl2,
+ Opt_mba_mbps,
+ Opt_debug,
+ nr__rdt_params
+};
+
+static const struct fs_parameter_spec rdt_fs_parameters[] = {
+ fsparam_flag("cdp", Opt_cdp),
+ fsparam_flag("cdpl2", Opt_cdpl2),
+ fsparam_flag("mba_MBps", Opt_mba_mbps),
+ fsparam_flag("debug", Opt_debug),
+ {}
+};
+
+static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+ struct rdt_fs_context *ctx = rdt_fc2context(fc);
+ struct fs_parse_result result;
+ const char *msg;
+ int opt;
+
+ opt = fs_parse(fc, rdt_fs_parameters, param, &result);
+ if (opt < 0)
+ return opt;
+
+ switch (opt) {
+ case Opt_cdp:
+ ctx->enable_cdpl3 = true;
+ return 0;
+ case Opt_cdpl2:
+ ctx->enable_cdpl2 = true;
+ return 0;
+ case Opt_mba_mbps:
+ msg = "mba_MBps requires MBM and linear scale MBA at L3 scope";
+ if (!supports_mba_mbps())
+ return invalfc(fc, msg);
+ ctx->enable_mba_mbps = true;
+ return 0;
+ case Opt_debug:
+ ctx->enable_debug = true;
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static void rdt_fs_context_free(struct fs_context *fc)
+{
+ struct rdt_fs_context *ctx = rdt_fc2context(fc);
+
+ kernfs_free_fs_context(fc);
+ kfree(ctx);
+}
+
+static const struct fs_context_operations rdt_fs_context_ops = {
+ .free = rdt_fs_context_free,
+ .parse_param = rdt_parse_param,
+ .get_tree = rdt_get_tree,
+};
+
+static int rdt_init_fs_context(struct fs_context *fc)
+{
+ struct rdt_fs_context *ctx;
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->kfc.magic = RDTGROUP_SUPER_MAGIC;
+ fc->fs_private = &ctx->kfc;
+ fc->ops = &rdt_fs_context_ops;
+ put_user_ns(fc->user_ns);
+ fc->user_ns = get_user_ns(&init_user_ns);
+ fc->global = true;
+ return 0;
+}
+
+/*
+ * Move tasks from one to the other group. If @from is NULL, then all tasks
+ * in the systems are moved unconditionally (used for teardown).
+ *
+ * If @mask is not NULL the cpus on which moved tasks are running are set
+ * in that mask so the update smp function call is restricted to affected
+ * cpus.
+ */
+static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to,
+ struct cpumask *mask)
+{
+ struct task_struct *p, *t;
+
+ read_lock(&tasklist_lock);
+ for_each_process_thread(p, t) {
+ if (!from || is_closid_match(t, from) ||
+ is_rmid_match(t, from)) {
+ resctrl_arch_set_closid_rmid(t, to->closid,
+ to->mon.rmid);
+
+ /*
+ * Order the closid/rmid stores above before the loads
+ * in task_curr(). This pairs with the full barrier
+ * between the rq->curr update and
+ * resctrl_arch_sched_in() during context switch.
+ */
+ smp_mb();
+
+ /*
+ * If the task is on a CPU, set the CPU in the mask.
+ * The detection is inaccurate as tasks might move or
+ * schedule before the smp function call takes place.
+ * In such a case the function call is pointless, but
+ * there is no other side effect.
+ */
+ if (IS_ENABLED(CONFIG_SMP) && mask && task_curr(t))
+ cpumask_set_cpu(task_cpu(t), mask);
+ }
+ }
+ read_unlock(&tasklist_lock);
+}
+
+static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp)
+{
+ struct rdtgroup *sentry, *stmp;
+ struct list_head *head;
+
+ head = &rdtgrp->mon.crdtgrp_list;
+ list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) {
+ free_rmid(sentry->closid, sentry->mon.rmid);
+ list_del(&sentry->mon.crdtgrp_list);
+
+ if (atomic_read(&sentry->waitcount) != 0)
+ sentry->flags = RDT_DELETED;
+ else
+ rdtgroup_remove(sentry);
+ }
+}
+
+/*
+ * Forcibly remove all of subdirectories under root.
+ */
+static void rmdir_all_sub(void)
+{
+ struct rdtgroup *rdtgrp, *tmp;
+
+ /* Move all tasks to the default resource group */
+ rdt_move_group_tasks(NULL, &rdtgroup_default, NULL);
+
+ list_for_each_entry_safe(rdtgrp, tmp, &rdt_all_groups, rdtgroup_list) {
+ /* Free any child rmids */
+ free_all_child_rdtgrp(rdtgrp);
+
+ /* Remove each rdtgroup other than root */
+ if (rdtgrp == &rdtgroup_default)
+ continue;
+
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
+ rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
+ rdtgroup_pseudo_lock_remove(rdtgrp);
+
+ /*
+ * Give any CPUs back to the default group. We cannot copy
+ * cpu_online_mask because a CPU might have executed the
+ * offline callback already, but is still marked online.
+ */
+ cpumask_or(&rdtgroup_default.cpu_mask,
+ &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask);
+
+ free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
+
+ kernfs_remove(rdtgrp->kn);
+ list_del(&rdtgrp->rdtgroup_list);
+
+ if (atomic_read(&rdtgrp->waitcount) != 0)
+ rdtgrp->flags = RDT_DELETED;
+ else
+ rdtgroup_remove(rdtgrp);
+ }
+ /* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */
+ update_closid_rmid(cpu_online_mask, &rdtgroup_default);
+
+ kernfs_remove(kn_info);
+ kernfs_remove(kn_mongrp);
+ kernfs_remove(kn_mondata);
+}
+
+/**
+ * mon_get_kn_priv() - Get the mon_data priv data for this event.
+ *
+ * The same values are used across the mon_data directories of all control and
+ * monitor groups for the same event in the same domain. Keep a list of
+ * allocated structures and re-use an existing one with the same values for
+ * @rid, @domid, etc.
+ *
+ * @rid: The resource id for the event file being created.
+ * @domid: The domain id for the event file being created.
+ * @mevt: The type of event file being created.
+ * @do_sum: Whether SNC summing monitors are being created.
+ */
+static struct mon_data *mon_get_kn_priv(enum resctrl_res_level rid, int domid,
+ struct mon_evt *mevt,
+ bool do_sum)
+{
+ struct mon_data *priv;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ list_for_each_entry(priv, &mon_data_kn_priv_list, list) {
+ if (priv->rid == rid && priv->domid == domid &&
+ priv->sum == do_sum && priv->evtid == mevt->evtid)
+ return priv;
+ }
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return NULL;
+
+ priv->rid = rid;
+ priv->domid = domid;
+ priv->sum = do_sum;
+ priv->evtid = mevt->evtid;
+ list_add_tail(&priv->list, &mon_data_kn_priv_list);
+
+ return priv;
+}
+
+/**
+ * mon_put_kn_priv() - Free all allocated mon_data structures.
+ *
+ * Called when resctrl file system is unmounted.
+ */
+static void mon_put_kn_priv(void)
+{
+ struct mon_data *priv, *tmp;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ list_for_each_entry_safe(priv, tmp, &mon_data_kn_priv_list, list) {
+ list_del(&priv->list);
+ kfree(priv);
+ }
+}
+
+static void resctrl_fs_teardown(void)
+{
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ /* Cleared by rdtgroup_destroy_root() */
+ if (!rdtgroup_default.kn)
+ return;
+
+ rmdir_all_sub();
+ mon_put_kn_priv();
+ rdt_pseudo_lock_release();
+ rdtgroup_default.mode = RDT_MODE_SHAREABLE;
+ closid_exit();
+ schemata_list_destroy();
+ rdtgroup_destroy_root();
+}
+
+static void rdt_kill_sb(struct super_block *sb)
+{
+ struct rdt_resource *r;
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+
+ rdt_disable_ctx();
+
+ /* Put everything back to default values. */
+ for_each_alloc_capable_rdt_resource(r)
+ resctrl_arch_reset_all_ctrls(r);
+
+ resctrl_fs_teardown();
+ if (resctrl_arch_alloc_capable())
+ resctrl_arch_disable_alloc();
+ if (resctrl_arch_mon_capable())
+ resctrl_arch_disable_mon();
+ resctrl_mounted = false;
+ kernfs_kill_sb(sb);
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+}
+
+static struct file_system_type rdt_fs_type = {
+ .name = "resctrl",
+ .init_fs_context = rdt_init_fs_context,
+ .parameters = rdt_fs_parameters,
+ .kill_sb = rdt_kill_sb,
+};
+
+static int mon_addfile(struct kernfs_node *parent_kn, const char *name,
+ void *priv)
+{
+ struct kernfs_node *kn;
+ int ret = 0;
+
+ kn = __kernfs_create_file(parent_kn, name, 0444,
+ GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 0,
+ &kf_mondata_ops, priv, NULL, NULL);
+ if (IS_ERR(kn))
+ return PTR_ERR(kn);
+
+ ret = rdtgroup_kn_set_ugid(kn);
+ if (ret) {
+ kernfs_remove(kn);
+ return ret;
+ }
+
+ return ret;
+}
+
+static void mon_rmdir_one_subdir(struct kernfs_node *pkn, char *name, char *subname)
+{
+ struct kernfs_node *kn;
+
+ kn = kernfs_find_and_get(pkn, name);
+ if (!kn)
+ return;
+ kernfs_put(kn);
+
+ if (kn->dir.subdirs <= 1)
+ kernfs_remove(kn);
+ else
+ kernfs_remove_by_name(kn, subname);
+}
+
+/*
+ * Remove all subdirectories of mon_data of ctrl_mon groups
+ * and monitor groups for the given domain.
+ * Remove files and directories containing "sum" of domain data
+ * when last domain being summed is removed.
+ */
+static void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
+ struct rdt_mon_domain *d)
+{
+ struct rdtgroup *prgrp, *crgrp;
+ char subname[32];
+ bool snc_mode;
+ char name[32];
+
+ snc_mode = r->mon_scope == RESCTRL_L3_NODE;
+ sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id);
+ if (snc_mode)
+ sprintf(subname, "mon_sub_%s_%02d", r->name, d->hdr.id);
+
+ list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
+ mon_rmdir_one_subdir(prgrp->mon.mon_data_kn, name, subname);
+
+ list_for_each_entry(crgrp, &prgrp->mon.crdtgrp_list, mon.crdtgrp_list)
+ mon_rmdir_one_subdir(crgrp->mon.mon_data_kn, name, subname);
+ }
+}
+
+static int mon_add_all_files(struct kernfs_node *kn, struct rdt_mon_domain *d,
+ struct rdt_resource *r, struct rdtgroup *prgrp,
+ bool do_sum)
+{
+ struct rmid_read rr = {0};
+ struct mon_data *priv;
+ struct mon_evt *mevt;
+ int ret, domid;
+
+ if (WARN_ON(list_empty(&r->evt_list)))
+ return -EPERM;
+
+ list_for_each_entry(mevt, &r->evt_list, list) {
+ domid = do_sum ? d->ci->id : d->hdr.id;
+ priv = mon_get_kn_priv(r->rid, domid, mevt, do_sum);
+ if (WARN_ON_ONCE(!priv))
+ return -EINVAL;
+
+ ret = mon_addfile(kn, mevt->name, priv);
+ if (ret)
+ return ret;
+
+ if (!do_sum && resctrl_is_mbm_event(mevt->evtid))
+ mon_event_read(&rr, r, d, prgrp, &d->hdr.cpu_mask, mevt->evtid, true);
+ }
+
+ return 0;
+}
+
+static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
+ struct rdt_mon_domain *d,
+ struct rdt_resource *r, struct rdtgroup *prgrp)
+{
+ struct kernfs_node *kn, *ckn;
+ char name[32];
+ bool snc_mode;
+ int ret = 0;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ snc_mode = r->mon_scope == RESCTRL_L3_NODE;
+ sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id);
+ kn = kernfs_find_and_get(parent_kn, name);
+ if (kn) {
+ /*
+ * rdtgroup_mutex will prevent this directory from being
+ * removed. No need to keep this hold.
+ */
+ kernfs_put(kn);
+ } else {
+ kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
+ if (IS_ERR(kn))
+ return PTR_ERR(kn);
+
+ ret = rdtgroup_kn_set_ugid(kn);
+ if (ret)
+ goto out_destroy;
+ ret = mon_add_all_files(kn, d, r, prgrp, snc_mode);
+ if (ret)
+ goto out_destroy;
+ }
+
+ if (snc_mode) {
+ sprintf(name, "mon_sub_%s_%02d", r->name, d->hdr.id);
+ ckn = kernfs_create_dir(kn, name, parent_kn->mode, prgrp);
+ if (IS_ERR(ckn)) {
+ ret = -EINVAL;
+ goto out_destroy;
+ }
+
+ ret = rdtgroup_kn_set_ugid(ckn);
+ if (ret)
+ goto out_destroy;
+
+ ret = mon_add_all_files(ckn, d, r, prgrp, false);
+ if (ret)
+ goto out_destroy;
+ }
+
+ kernfs_activate(kn);
+ return 0;
+
+out_destroy:
+ kernfs_remove(kn);
+ return ret;
+}
+
+/*
+ * Add all subdirectories of mon_data for "ctrl_mon" groups
+ * and "monitor" groups with given domain id.
+ */
+static void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
+ struct rdt_mon_domain *d)
+{
+ struct kernfs_node *parent_kn;
+ struct rdtgroup *prgrp, *crgrp;
+ struct list_head *head;
+
+ list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
+ parent_kn = prgrp->mon.mon_data_kn;
+ mkdir_mondata_subdir(parent_kn, d, r, prgrp);
+
+ head = &prgrp->mon.crdtgrp_list;
+ list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
+ parent_kn = crgrp->mon.mon_data_kn;
+ mkdir_mondata_subdir(parent_kn, d, r, crgrp);
+ }
+ }
+}
+
+static int mkdir_mondata_subdir_alldom(struct kernfs_node *parent_kn,
+ struct rdt_resource *r,
+ struct rdtgroup *prgrp)
+{
+ struct rdt_mon_domain *dom;
+ int ret;
+
+ /* Walking r->domains, ensure it can't race with cpuhp */
+ lockdep_assert_cpus_held();
+
+ list_for_each_entry(dom, &r->mon_domains, hdr.list) {
+ ret = mkdir_mondata_subdir(parent_kn, dom, r, prgrp);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * This creates a directory mon_data which contains the monitored data.
+ *
+ * mon_data has one directory for each domain which are named
+ * in the format mon_<domain_name>_<domain_id>. For ex: A mon_data
+ * with L3 domain looks as below:
+ * ./mon_data:
+ * mon_L3_00
+ * mon_L3_01
+ * mon_L3_02
+ * ...
+ *
+ * Each domain directory has one file per event:
+ * ./mon_L3_00/:
+ * llc_occupancy
+ *
+ */
+static int mkdir_mondata_all(struct kernfs_node *parent_kn,
+ struct rdtgroup *prgrp,
+ struct kernfs_node **dest_kn)
+{
+ struct rdt_resource *r;
+ struct kernfs_node *kn;
+ int ret;
+
+ /*
+ * Create the mon_data directory first.
+ */
+ ret = mongroup_create_dir(parent_kn, prgrp, "mon_data", &kn);
+ if (ret)
+ return ret;
+
+ if (dest_kn)
+ *dest_kn = kn;
+
+ /*
+ * Create the subdirectories for each domain. Note that all events
+ * in a domain like L3 are grouped into a resource whose domain is L3
+ */
+ for_each_mon_capable_rdt_resource(r) {
+ ret = mkdir_mondata_subdir_alldom(kn, r, prgrp);
+ if (ret)
+ goto out_destroy;
+ }
+
+ return 0;
+
+out_destroy:
+ kernfs_remove(kn);
+ return ret;
+}
+
+/**
+ * cbm_ensure_valid - Enforce validity on provided CBM
+ * @_val: Candidate CBM
+ * @r: RDT resource to which the CBM belongs
+ *
+ * The provided CBM represents all cache portions available for use. This
+ * may be represented by a bitmap that does not consist of contiguous ones
+ * and thus be an invalid CBM.
+ * Here the provided CBM is forced to be a valid CBM by only considering
+ * the first set of contiguous bits as valid and clearing all bits.
+ * The intention here is to provide a valid default CBM with which a new
+ * resource group is initialized. The user can follow this with a
+ * modification to the CBM if the default does not satisfy the
+ * requirements.
+ */
+static u32 cbm_ensure_valid(u32 _val, struct rdt_resource *r)
+{
+ unsigned int cbm_len = r->cache.cbm_len;
+ unsigned long first_bit, zero_bit;
+ unsigned long val = _val;
+
+ if (!val)
+ return 0;
+
+ first_bit = find_first_bit(&val, cbm_len);
+ zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
+
+ /* Clear any remaining bits to ensure contiguous region */
+ bitmap_clear(&val, zero_bit, cbm_len - zero_bit);
+ return (u32)val;
+}
+
+/*
+ * Initialize cache resources per RDT domain
+ *
+ * Set the RDT domain up to start off with all usable allocations. That is,
+ * all shareable and unused bits. All-zero CBM is invalid.
+ */
+static int __init_one_rdt_domain(struct rdt_ctrl_domain *d, struct resctrl_schema *s,
+ u32 closid)
+{
+ enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type);
+ enum resctrl_conf_type t = s->conf_type;
+ struct resctrl_staged_config *cfg;
+ struct rdt_resource *r = s->res;
+ u32 used_b = 0, unused_b = 0;
+ unsigned long tmp_cbm;
+ enum rdtgrp_mode mode;
+ u32 peer_ctl, ctrl_val;
+ int i;
+
+ cfg = &d->staged_config[t];
+ cfg->have_new_ctrl = false;
+ cfg->new_ctrl = r->cache.shareable_bits;
+ used_b = r->cache.shareable_bits;
+ for (i = 0; i < closids_supported(); i++) {
+ if (closid_allocated(i) && i != closid) {
+ mode = rdtgroup_mode_by_closid(i);
+ if (mode == RDT_MODE_PSEUDO_LOCKSETUP)
+ /*
+ * ctrl values for locksetup aren't relevant
+ * until the schemata is written, and the mode
+ * becomes RDT_MODE_PSEUDO_LOCKED.
+ */
+ continue;
+ /*
+ * If CDP is active include peer domain's
+ * usage to ensure there is no overlap
+ * with an exclusive group.
+ */
+ if (resctrl_arch_get_cdp_enabled(r->rid))
+ peer_ctl = resctrl_arch_get_config(r, d, i,
+ peer_type);
+ else
+ peer_ctl = 0;
+ ctrl_val = resctrl_arch_get_config(r, d, i,
+ s->conf_type);
+ used_b |= ctrl_val | peer_ctl;
+ if (mode == RDT_MODE_SHAREABLE)
+ cfg->new_ctrl |= ctrl_val | peer_ctl;
+ }
+ }
+ if (d->plr && d->plr->cbm > 0)
+ used_b |= d->plr->cbm;
+ unused_b = used_b ^ (BIT_MASK(r->cache.cbm_len) - 1);
+ unused_b &= BIT_MASK(r->cache.cbm_len) - 1;
+ cfg->new_ctrl |= unused_b;
+ /*
+ * Force the initial CBM to be valid, user can
+ * modify the CBM based on system availability.
+ */
+ cfg->new_ctrl = cbm_ensure_valid(cfg->new_ctrl, r);
+ /*
+ * Assign the u32 CBM to an unsigned long to ensure that
+ * bitmap_weight() does not access out-of-bound memory.
+ */
+ tmp_cbm = cfg->new_ctrl;
+ if (bitmap_weight(&tmp_cbm, r->cache.cbm_len) < r->cache.min_cbm_bits) {
+ rdt_last_cmd_printf("No space on %s:%d\n", s->name, d->hdr.id);
+ return -ENOSPC;
+ }
+ cfg->have_new_ctrl = true;
+
+ return 0;
+}
+
+/*
+ * Initialize cache resources with default values.
+ *
+ * A new RDT group is being created on an allocation capable (CAT)
+ * supporting system. Set this group up to start off with all usable
+ * allocations.
+ *
+ * If there are no more shareable bits available on any domain then
+ * the entire allocation will fail.
+ */
+static int rdtgroup_init_cat(struct resctrl_schema *s, u32 closid)
+{
+ struct rdt_ctrl_domain *d;
+ int ret;
+
+ list_for_each_entry(d, &s->res->ctrl_domains, hdr.list) {
+ ret = __init_one_rdt_domain(d, s, closid);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+/* Initialize MBA resource with default values. */
+static void rdtgroup_init_mba(struct rdt_resource *r, u32 closid)
+{
+ struct resctrl_staged_config *cfg;
+ struct rdt_ctrl_domain *d;
+
+ list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
+ if (is_mba_sc(r)) {
+ d->mbps_val[closid] = MBA_MAX_MBPS;
+ continue;
+ }
+
+ cfg = &d->staged_config[CDP_NONE];
+ cfg->new_ctrl = resctrl_get_default_ctrl(r);
+ cfg->have_new_ctrl = true;
+ }
+}
+
+/* Initialize the RDT group's allocations. */
+static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
+{
+ struct resctrl_schema *s;
+ struct rdt_resource *r;
+ int ret = 0;
+
+ rdt_staged_configs_clear();
+
+ list_for_each_entry(s, &resctrl_schema_all, list) {
+ r = s->res;
+ if (r->rid == RDT_RESOURCE_MBA ||
+ r->rid == RDT_RESOURCE_SMBA) {
+ rdtgroup_init_mba(r, rdtgrp->closid);
+ if (is_mba_sc(r))
+ continue;
+ } else {
+ ret = rdtgroup_init_cat(s, rdtgrp->closid);
+ if (ret < 0)
+ goto out;
+ }
+
+ ret = resctrl_arch_update_domains(r, rdtgrp->closid);
+ if (ret < 0) {
+ rdt_last_cmd_puts("Failed to initialize allocations\n");
+ goto out;
+ }
+ }
+
+ rdtgrp->mode = RDT_MODE_SHAREABLE;
+
+out:
+ rdt_staged_configs_clear();
+ return ret;
+}
+
+static int mkdir_rdt_prepare_rmid_alloc(struct rdtgroup *rdtgrp)
+{
+ int ret;
+
+ if (!resctrl_arch_mon_capable())
+ return 0;
+
+ ret = alloc_rmid(rdtgrp->closid);
+ if (ret < 0) {
+ rdt_last_cmd_puts("Out of RMIDs\n");
+ return ret;
+ }
+ rdtgrp->mon.rmid = ret;
+
+ ret = mkdir_mondata_all(rdtgrp->kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
+ if (ret) {
+ rdt_last_cmd_puts("kernfs subdir error\n");
+ free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void mkdir_rdt_prepare_rmid_free(struct rdtgroup *rgrp)
+{
+ if (resctrl_arch_mon_capable())
+ free_rmid(rgrp->closid, rgrp->mon.rmid);
+}
+
+/*
+ * We allow creating mon groups only with in a directory called "mon_groups"
+ * which is present in every ctrl_mon group. Check if this is a valid
+ * "mon_groups" directory.
+ *
+ * 1. The directory should be named "mon_groups".
+ * 2. The mon group itself should "not" be named "mon_groups".
+ * This makes sure "mon_groups" directory always has a ctrl_mon group
+ * as parent.
+ */
+static bool is_mon_groups(struct kernfs_node *kn, const char *name)
+{
+ return (!strcmp(rdt_kn_name(kn), "mon_groups") &&
+ strcmp(name, "mon_groups"));
+}
+
+static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
+ const char *name, umode_t mode,
+ enum rdt_group_type rtype, struct rdtgroup **r)
+{
+ struct rdtgroup *prdtgrp, *rdtgrp;
+ unsigned long files = 0;
+ struct kernfs_node *kn;
+ int ret;
+
+ prdtgrp = rdtgroup_kn_lock_live(parent_kn);
+ if (!prdtgrp) {
+ ret = -ENODEV;
+ goto out_unlock;
+ }
+
+ /*
+ * Check that the parent directory for a monitor group is a "mon_groups"
+ * directory.
+ */
+ if (rtype == RDTMON_GROUP && !is_mon_groups(parent_kn, name)) {
+ ret = -EPERM;
+ goto out_unlock;
+ }
+
+ if (rtype == RDTMON_GROUP &&
+ (prdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
+ prdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)) {
+ ret = -EINVAL;
+ rdt_last_cmd_puts("Pseudo-locking in progress\n");
+ goto out_unlock;
+ }
+
+ /* allocate the rdtgroup. */
+ rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL);
+ if (!rdtgrp) {
+ ret = -ENOSPC;
+ rdt_last_cmd_puts("Kernel out of memory\n");
+ goto out_unlock;
+ }
+ *r = rdtgrp;
+ rdtgrp->mon.parent = prdtgrp;
+ rdtgrp->type = rtype;
+ INIT_LIST_HEAD(&rdtgrp->mon.crdtgrp_list);
+
+ /* kernfs creates the directory for rdtgrp */
+ kn = kernfs_create_dir(parent_kn, name, mode, rdtgrp);
+ if (IS_ERR(kn)) {
+ ret = PTR_ERR(kn);
+ rdt_last_cmd_puts("kernfs create error\n");
+ goto out_free_rgrp;
+ }
+ rdtgrp->kn = kn;
+
+ /*
+ * kernfs_remove() will drop the reference count on "kn" which
+ * will free it. But we still need it to stick around for the
+ * rdtgroup_kn_unlock(kn) call. Take one extra reference here,
+ * which will be dropped by kernfs_put() in rdtgroup_remove().
+ */
+ kernfs_get(kn);
+
+ ret = rdtgroup_kn_set_ugid(kn);
+ if (ret) {
+ rdt_last_cmd_puts("kernfs perm error\n");
+ goto out_destroy;
+ }
+
+ if (rtype == RDTCTRL_GROUP) {
+ files = RFTYPE_BASE | RFTYPE_CTRL;
+ if (resctrl_arch_mon_capable())
+ files |= RFTYPE_MON;
+ } else {
+ files = RFTYPE_BASE | RFTYPE_MON;
+ }
+
+ ret = rdtgroup_add_files(kn, files);
+ if (ret) {
+ rdt_last_cmd_puts("kernfs fill error\n");
+ goto out_destroy;
+ }
+
+ /*
+ * The caller unlocks the parent_kn upon success.
+ */
+ return 0;
+
+out_destroy:
+ kernfs_put(rdtgrp->kn);
+ kernfs_remove(rdtgrp->kn);
+out_free_rgrp:
+ kfree(rdtgrp);
+out_unlock:
+ rdtgroup_kn_unlock(parent_kn);
+ return ret;
+}
+
+static void mkdir_rdt_prepare_clean(struct rdtgroup *rgrp)
+{
+ kernfs_remove(rgrp->kn);
+ rdtgroup_remove(rgrp);
+}
+
+/*
+ * Create a monitor group under "mon_groups" directory of a control
+ * and monitor group(ctrl_mon). This is a resource group
+ * to monitor a subset of tasks and cpus in its parent ctrl_mon group.
+ */
+static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn,
+ const char *name, umode_t mode)
+{
+ struct rdtgroup *rdtgrp, *prgrp;
+ int ret;
+
+ ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTMON_GROUP, &rdtgrp);
+ if (ret)
+ return ret;
+
+ prgrp = rdtgrp->mon.parent;
+ rdtgrp->closid = prgrp->closid;
+
+ ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp);
+ if (ret) {
+ mkdir_rdt_prepare_clean(rdtgrp);
+ goto out_unlock;
+ }
+
+ kernfs_activate(rdtgrp->kn);
+
+ /*
+ * Add the rdtgrp to the list of rdtgrps the parent
+ * ctrl_mon group has to track.
+ */
+ list_add_tail(&rdtgrp->mon.crdtgrp_list, &prgrp->mon.crdtgrp_list);
+
+out_unlock:
+ rdtgroup_kn_unlock(parent_kn);
+ return ret;
+}
+
+/*
+ * These are rdtgroups created under the root directory. Can be used
+ * to allocate and monitor resources.
+ */
+static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
+ const char *name, umode_t mode)
+{
+ struct rdtgroup *rdtgrp;
+ struct kernfs_node *kn;
+ u32 closid;
+ int ret;
+
+ ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTCTRL_GROUP, &rdtgrp);
+ if (ret)
+ return ret;
+
+ kn = rdtgrp->kn;
+ ret = closid_alloc();
+ if (ret < 0) {
+ rdt_last_cmd_puts("Out of CLOSIDs\n");
+ goto out_common_fail;
+ }
+ closid = ret;
+ ret = 0;
+
+ rdtgrp->closid = closid;
+
+ ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp);
+ if (ret)
+ goto out_closid_free;
+
+ kernfs_activate(rdtgrp->kn);
+
+ ret = rdtgroup_init_alloc(rdtgrp);
+ if (ret < 0)
+ goto out_rmid_free;
+
+ list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups);
+
+ if (resctrl_arch_mon_capable()) {
+ /*
+ * Create an empty mon_groups directory to hold the subset
+ * of tasks and cpus to monitor.
+ */
+ ret = mongroup_create_dir(kn, rdtgrp, "mon_groups", NULL);
+ if (ret) {
+ rdt_last_cmd_puts("kernfs subdir error\n");
+ goto out_del_list;
+ }
+ if (is_mba_sc(NULL))
+ rdtgrp->mba_mbps_event = mba_mbps_default_event;
+ }
+
+ goto out_unlock;
+
+out_del_list:
+ list_del(&rdtgrp->rdtgroup_list);
+out_rmid_free:
+ mkdir_rdt_prepare_rmid_free(rdtgrp);
+out_closid_free:
+ closid_free(closid);
+out_common_fail:
+ mkdir_rdt_prepare_clean(rdtgrp);
+out_unlock:
+ rdtgroup_kn_unlock(parent_kn);
+ return ret;
+}
+
+static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
+ umode_t mode)
+{
+ /* Do not accept '\n' to avoid unparsable situation. */
+ if (strchr(name, '\n'))
+ return -EINVAL;
+
+ /*
+ * If the parent directory is the root directory and RDT
+ * allocation is supported, add a control and monitoring
+ * subdirectory
+ */
+ if (resctrl_arch_alloc_capable() && parent_kn == rdtgroup_default.kn)
+ return rdtgroup_mkdir_ctrl_mon(parent_kn, name, mode);
+
+ /* Else, attempt to add a monitoring subdirectory. */
+ if (resctrl_arch_mon_capable())
+ return rdtgroup_mkdir_mon(parent_kn, name, mode);
+
+ return -EPERM;
+}
+
+static int rdtgroup_rmdir_mon(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask)
+{
+ struct rdtgroup *prdtgrp = rdtgrp->mon.parent;
+ u32 closid, rmid;
+ int cpu;
+
+ /* Give any tasks back to the parent group */
+ rdt_move_group_tasks(rdtgrp, prdtgrp, tmpmask);
+
+ /*
+ * Update per cpu closid/rmid of the moved CPUs first.
+ * Note: the closid will not change, but the arch code still needs it.
+ */
+ closid = prdtgrp->closid;
+ rmid = prdtgrp->mon.rmid;
+ for_each_cpu(cpu, &rdtgrp->cpu_mask)
+ resctrl_arch_set_cpu_default_closid_rmid(cpu, closid, rmid);
+
+ /*
+ * Update the MSR on moved CPUs and CPUs which have moved
+ * task running on them.
+ */
+ cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
+ update_closid_rmid(tmpmask, NULL);
+
+ rdtgrp->flags = RDT_DELETED;
+ free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
+
+ /*
+ * Remove the rdtgrp from the parent ctrl_mon group's list
+ */
+ WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list));
+ list_del(&rdtgrp->mon.crdtgrp_list);
+
+ kernfs_remove(rdtgrp->kn);
+
+ return 0;
+}
+
+static int rdtgroup_ctrl_remove(struct rdtgroup *rdtgrp)
+{
+ rdtgrp->flags = RDT_DELETED;
+ list_del(&rdtgrp->rdtgroup_list);
+
+ kernfs_remove(rdtgrp->kn);
+ return 0;
+}
+
+static int rdtgroup_rmdir_ctrl(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask)
+{
+ u32 closid, rmid;
+ int cpu;
+
+ /* Give any tasks back to the default group */
+ rdt_move_group_tasks(rdtgrp, &rdtgroup_default, tmpmask);
+
+ /* Give any CPUs back to the default group */
+ cpumask_or(&rdtgroup_default.cpu_mask,
+ &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask);
+
+ /* Update per cpu closid and rmid of the moved CPUs first */
+ closid = rdtgroup_default.closid;
+ rmid = rdtgroup_default.mon.rmid;
+ for_each_cpu(cpu, &rdtgrp->cpu_mask)
+ resctrl_arch_set_cpu_default_closid_rmid(cpu, closid, rmid);
+
+ /*
+ * Update the MSR on moved CPUs and CPUs which have moved
+ * task running on them.
+ */
+ cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
+ update_closid_rmid(tmpmask, NULL);
+
+ free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
+ closid_free(rdtgrp->closid);
+
+ rdtgroup_ctrl_remove(rdtgrp);
+
+ /*
+ * Free all the child monitor group rmids.
+ */
+ free_all_child_rdtgrp(rdtgrp);
+
+ return 0;
+}
+
+static struct kernfs_node *rdt_kn_parent(struct kernfs_node *kn)
+{
+ /*
+ * Valid within the RCU section it was obtained or while rdtgroup_mutex
+ * is held.
+ */
+ return rcu_dereference_check(kn->__parent, lockdep_is_held(&rdtgroup_mutex));
+}
+
+static int rdtgroup_rmdir(struct kernfs_node *kn)
+{
+ struct kernfs_node *parent_kn;
+ struct rdtgroup *rdtgrp;
+ cpumask_var_t tmpmask;
+ int ret = 0;
+
+ if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
+ return -ENOMEM;
+
+ rdtgrp = rdtgroup_kn_lock_live(kn);
+ if (!rdtgrp) {
+ ret = -EPERM;
+ goto out;
+ }
+ parent_kn = rdt_kn_parent(kn);
+
+ /*
+ * If the rdtgroup is a ctrl_mon group and parent directory
+ * is the root directory, remove the ctrl_mon group.
+ *
+ * If the rdtgroup is a mon group and parent directory
+ * is a valid "mon_groups" directory, remove the mon group.
+ */
+ if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn &&
+ rdtgrp != &rdtgroup_default) {
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
+ rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
+ ret = rdtgroup_ctrl_remove(rdtgrp);
+ } else {
+ ret = rdtgroup_rmdir_ctrl(rdtgrp, tmpmask);
+ }
+ } else if (rdtgrp->type == RDTMON_GROUP &&
+ is_mon_groups(parent_kn, rdt_kn_name(kn))) {
+ ret = rdtgroup_rmdir_mon(rdtgrp, tmpmask);
+ } else {
+ ret = -EPERM;
+ }
+
+out:
+ rdtgroup_kn_unlock(kn);
+ free_cpumask_var(tmpmask);
+ return ret;
+}
+
+/**
+ * mongrp_reparent() - replace parent CTRL_MON group of a MON group
+ * @rdtgrp: the MON group whose parent should be replaced
+ * @new_prdtgrp: replacement parent CTRL_MON group for @rdtgrp
+ * @cpus: cpumask provided by the caller for use during this call
+ *
+ * Replaces the parent CTRL_MON group for a MON group, resulting in all member
+ * tasks' CLOSID immediately changing to that of the new parent group.
+ * Monitoring data for the group is unaffected by this operation.
+ */
+static void mongrp_reparent(struct rdtgroup *rdtgrp,
+ struct rdtgroup *new_prdtgrp,
+ cpumask_var_t cpus)
+{
+ struct rdtgroup *prdtgrp = rdtgrp->mon.parent;
+
+ WARN_ON(rdtgrp->type != RDTMON_GROUP);
+ WARN_ON(new_prdtgrp->type != RDTCTRL_GROUP);
+
+ /* Nothing to do when simply renaming a MON group. */
+ if (prdtgrp == new_prdtgrp)
+ return;
+
+ WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list));
+ list_move_tail(&rdtgrp->mon.crdtgrp_list,
+ &new_prdtgrp->mon.crdtgrp_list);
+
+ rdtgrp->mon.parent = new_prdtgrp;
+ rdtgrp->closid = new_prdtgrp->closid;
+
+ /* Propagate updated closid to all tasks in this group. */
+ rdt_move_group_tasks(rdtgrp, rdtgrp, cpus);
+
+ update_closid_rmid(cpus, NULL);
+}
+
+static int rdtgroup_rename(struct kernfs_node *kn,
+ struct kernfs_node *new_parent, const char *new_name)
+{
+ struct kernfs_node *kn_parent;
+ struct rdtgroup *new_prdtgrp;
+ struct rdtgroup *rdtgrp;
+ cpumask_var_t tmpmask;
+ int ret;
+
+ rdtgrp = kernfs_to_rdtgroup(kn);
+ new_prdtgrp = kernfs_to_rdtgroup(new_parent);
+ if (!rdtgrp || !new_prdtgrp)
+ return -ENOENT;
+
+ /* Release both kernfs active_refs before obtaining rdtgroup mutex. */
+ rdtgroup_kn_get(rdtgrp, kn);
+ rdtgroup_kn_get(new_prdtgrp, new_parent);
+
+ mutex_lock(&rdtgroup_mutex);
+
+ rdt_last_cmd_clear();
+
+ /*
+ * Don't allow kernfs_to_rdtgroup() to return a parent rdtgroup if
+ * either kernfs_node is a file.
+ */
+ if (kernfs_type(kn) != KERNFS_DIR ||
+ kernfs_type(new_parent) != KERNFS_DIR) {
+ rdt_last_cmd_puts("Source and destination must be directories");
+ ret = -EPERM;
+ goto out;
+ }
+
+ if ((rdtgrp->flags & RDT_DELETED) || (new_prdtgrp->flags & RDT_DELETED)) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ kn_parent = rdt_kn_parent(kn);
+ if (rdtgrp->type != RDTMON_GROUP || !kn_parent ||
+ !is_mon_groups(kn_parent, rdt_kn_name(kn))) {
+ rdt_last_cmd_puts("Source must be a MON group\n");
+ ret = -EPERM;
+ goto out;
+ }
+
+ if (!is_mon_groups(new_parent, new_name)) {
+ rdt_last_cmd_puts("Destination must be a mon_groups subdirectory\n");
+ ret = -EPERM;
+ goto out;
+ }
+
+ /*
+ * If the MON group is monitoring CPUs, the CPUs must be assigned to the
+ * current parent CTRL_MON group and therefore cannot be assigned to
+ * the new parent, making the move illegal.
+ */
+ if (!cpumask_empty(&rdtgrp->cpu_mask) &&
+ rdtgrp->mon.parent != new_prdtgrp) {
+ rdt_last_cmd_puts("Cannot move a MON group that monitors CPUs\n");
+ ret = -EPERM;
+ goto out;
+ }
+
+ /*
+ * Allocate the cpumask for use in mongrp_reparent() to avoid the
+ * possibility of failing to allocate it after kernfs_rename() has
+ * succeeded.
+ */
+ if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /*
+ * Perform all input validation and allocations needed to ensure
+ * mongrp_reparent() will succeed before calling kernfs_rename(),
+ * otherwise it would be necessary to revert this call if
+ * mongrp_reparent() failed.
+ */
+ ret = kernfs_rename(kn, new_parent, new_name);
+ if (!ret)
+ mongrp_reparent(rdtgrp, new_prdtgrp, tmpmask);
+
+ free_cpumask_var(tmpmask);
+
+out:
+ mutex_unlock(&rdtgroup_mutex);
+ rdtgroup_kn_put(rdtgrp, kn);
+ rdtgroup_kn_put(new_prdtgrp, new_parent);
+ return ret;
+}
+
+static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf)
+{
+ if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3))
+ seq_puts(seq, ",cdp");
+
+ if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2))
+ seq_puts(seq, ",cdpl2");
+
+ if (is_mba_sc(resctrl_arch_get_resource(RDT_RESOURCE_MBA)))
+ seq_puts(seq, ",mba_MBps");
+
+ if (resctrl_debug)
+ seq_puts(seq, ",debug");
+
+ return 0;
+}
+
+static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = {
+ .mkdir = rdtgroup_mkdir,
+ .rmdir = rdtgroup_rmdir,
+ .rename = rdtgroup_rename,
+ .show_options = rdtgroup_show_options,
+};
+
+static int rdtgroup_setup_root(struct rdt_fs_context *ctx)
+{
+ rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops,
+ KERNFS_ROOT_CREATE_DEACTIVATED |
+ KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK,
+ &rdtgroup_default);
+ if (IS_ERR(rdt_root))
+ return PTR_ERR(rdt_root);
+
+ ctx->kfc.root = rdt_root;
+ rdtgroup_default.kn = kernfs_root_to_node(rdt_root);
+
+ return 0;
+}
+
+static void rdtgroup_destroy_root(void)
+{
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ kernfs_destroy_root(rdt_root);
+ rdtgroup_default.kn = NULL;
+}
+
+static void rdtgroup_setup_default(void)
+{
+ mutex_lock(&rdtgroup_mutex);
+
+ rdtgroup_default.closid = RESCTRL_RESERVED_CLOSID;
+ rdtgroup_default.mon.rmid = RESCTRL_RESERVED_RMID;
+ rdtgroup_default.type = RDTCTRL_GROUP;
+ INIT_LIST_HEAD(&rdtgroup_default.mon.crdtgrp_list);
+
+ list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups);
+
+ mutex_unlock(&rdtgroup_mutex);
+}
+
+static void domain_destroy_mon_state(struct rdt_mon_domain *d)
+{
+ bitmap_free(d->rmid_busy_llc);
+ kfree(d->mbm_total);
+ kfree(d->mbm_local);
+}
+
+void resctrl_offline_ctrl_domain(struct rdt_resource *r, struct rdt_ctrl_domain *d)
+{
+ mutex_lock(&rdtgroup_mutex);
+
+ if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA)
+ mba_sc_domain_destroy(r, d);
+
+ mutex_unlock(&rdtgroup_mutex);
+}
+
+void resctrl_offline_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d)
+{
+ mutex_lock(&rdtgroup_mutex);
+
+ /*
+ * If resctrl is mounted, remove all the
+ * per domain monitor data directories.
+ */
+ if (resctrl_mounted && resctrl_arch_mon_capable())
+ rmdir_mondata_subdir_allrdtgrp(r, d);
+
+ if (resctrl_is_mbm_enabled())
+ cancel_delayed_work(&d->mbm_over);
+ if (resctrl_arch_is_llc_occupancy_enabled() && has_busy_rmid(d)) {
+ /*
+ * When a package is going down, forcefully
+ * decrement rmid->ebusy. There is no way to know
+ * that the L3 was flushed and hence may lead to
+ * incorrect counts in rare scenarios, but leaving
+ * the RMID as busy creates RMID leaks if the
+ * package never comes back.
+ */
+ __check_limbo(d, true);
+ cancel_delayed_work(&d->cqm_limbo);
+ }
+
+ domain_destroy_mon_state(d);
+
+ mutex_unlock(&rdtgroup_mutex);
+}
+
+/**
+ * domain_setup_mon_state() - Initialise domain monitoring structures.
+ * @r: The resource for the newly online domain.
+ * @d: The newly online domain.
+ *
+ * Allocate monitor resources that belong to this domain.
+ * Called when the first CPU of a domain comes online, regardless of whether
+ * the filesystem is mounted.
+ * During boot this may be called before global allocations have been made by
+ * resctrl_mon_resource_init().
+ *
+ * Returns 0 for success, or -ENOMEM.
+ */
+static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_mon_domain *d)
+{
+ u32 idx_limit = resctrl_arch_system_num_rmid_idx();
+ size_t tsize;
+
+ if (resctrl_arch_is_llc_occupancy_enabled()) {
+ d->rmid_busy_llc = bitmap_zalloc(idx_limit, GFP_KERNEL);
+ if (!d->rmid_busy_llc)
+ return -ENOMEM;
+ }
+ if (resctrl_arch_is_mbm_total_enabled()) {
+ tsize = sizeof(*d->mbm_total);
+ d->mbm_total = kcalloc(idx_limit, tsize, GFP_KERNEL);
+ if (!d->mbm_total) {
+ bitmap_free(d->rmid_busy_llc);
+ return -ENOMEM;
+ }
+ }
+ if (resctrl_arch_is_mbm_local_enabled()) {
+ tsize = sizeof(*d->mbm_local);
+ d->mbm_local = kcalloc(idx_limit, tsize, GFP_KERNEL);
+ if (!d->mbm_local) {
+ bitmap_free(d->rmid_busy_llc);
+ kfree(d->mbm_total);
+ return -ENOMEM;
+ }
+ }
+
+ return 0;
+}
+
+int resctrl_online_ctrl_domain(struct rdt_resource *r, struct rdt_ctrl_domain *d)
+{
+ int err = 0;
+
+ mutex_lock(&rdtgroup_mutex);
+
+ if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA) {
+ /* RDT_RESOURCE_MBA is never mon_capable */
+ err = mba_sc_domain_allocate(r, d);
+ }
+
+ mutex_unlock(&rdtgroup_mutex);
+
+ return err;
+}
+
+int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d)
+{
+ int err;
+
+ mutex_lock(&rdtgroup_mutex);
+
+ err = domain_setup_mon_state(r, d);
+ if (err)
+ goto out_unlock;
+
+ if (resctrl_is_mbm_enabled()) {
+ INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow);
+ mbm_setup_overflow_handler(d, MBM_OVERFLOW_INTERVAL,
+ RESCTRL_PICK_ANY_CPU);
+ }
+
+ if (resctrl_arch_is_llc_occupancy_enabled())
+ INIT_DELAYED_WORK(&d->cqm_limbo, cqm_handle_limbo);
+
+ /*
+ * If the filesystem is not mounted then only the default resource group
+ * exists. Creation of its directories is deferred until mount time
+ * by rdt_get_tree() calling mkdir_mondata_all().
+ * If resctrl is mounted, add per domain monitor data directories.
+ */
+ if (resctrl_mounted && resctrl_arch_mon_capable())
+ mkdir_mondata_subdir_allrdtgrp(r, d);
+
+out_unlock:
+ mutex_unlock(&rdtgroup_mutex);
+
+ return err;
+}
+
+void resctrl_online_cpu(unsigned int cpu)
+{
+ mutex_lock(&rdtgroup_mutex);
+ /* The CPU is set in default rdtgroup after online. */
+ cpumask_set_cpu(cpu, &rdtgroup_default.cpu_mask);
+ mutex_unlock(&rdtgroup_mutex);
+}
+
+static void clear_childcpus(struct rdtgroup *r, unsigned int cpu)
+{
+ struct rdtgroup *cr;
+
+ list_for_each_entry(cr, &r->mon.crdtgrp_list, mon.crdtgrp_list) {
+ if (cpumask_test_and_clear_cpu(cpu, &cr->cpu_mask))
+ break;
+ }
+}
+
+static struct rdt_mon_domain *get_mon_domain_from_cpu(int cpu,
+ struct rdt_resource *r)
+{
+ struct rdt_mon_domain *d;
+
+ lockdep_assert_cpus_held();
+
+ list_for_each_entry(d, &r->mon_domains, hdr.list) {
+ /* Find the domain that contains this CPU */
+ if (cpumask_test_cpu(cpu, &d->hdr.cpu_mask))
+ return d;
+ }
+
+ return NULL;
+}
+
+void resctrl_offline_cpu(unsigned int cpu)
+{
+ struct rdt_resource *l3 = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+ struct rdt_mon_domain *d;
+ struct rdtgroup *rdtgrp;
+
+ mutex_lock(&rdtgroup_mutex);
+ list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
+ if (cpumask_test_and_clear_cpu(cpu, &rdtgrp->cpu_mask)) {
+ clear_childcpus(rdtgrp, cpu);
+ break;
+ }
+ }
+
+ if (!l3->mon_capable)
+ goto out_unlock;
+
+ d = get_mon_domain_from_cpu(cpu, l3);
+ if (d) {
+ if (resctrl_is_mbm_enabled() && cpu == d->mbm_work_cpu) {
+ cancel_delayed_work(&d->mbm_over);
+ mbm_setup_overflow_handler(d, 0, cpu);
+ }
+ if (resctrl_arch_is_llc_occupancy_enabled() &&
+ cpu == d->cqm_work_cpu && has_busy_rmid(d)) {
+ cancel_delayed_work(&d->cqm_limbo);
+ cqm_setup_limbo_handler(d, 0, cpu);
+ }
+ }
+
+out_unlock:
+ mutex_unlock(&rdtgroup_mutex);
+}
+
+/*
+ * resctrl_init - resctrl filesystem initialization
+ *
+ * Setup resctrl file system including set up root, create mount point,
+ * register resctrl filesystem, and initialize files under root directory.
+ *
+ * Return: 0 on success or -errno
+ */
+int resctrl_init(void)
+{
+ int ret = 0;
+
+ seq_buf_init(&last_cmd_status, last_cmd_status_buf,
+ sizeof(last_cmd_status_buf));
+
+ rdtgroup_setup_default();
+
+ thread_throttle_mode_init();
+
+ ret = resctrl_mon_resource_init();
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_mount_point(fs_kobj, "resctrl");
+ if (ret) {
+ resctrl_mon_resource_exit();
+ return ret;
+ }
+
+ ret = register_filesystem(&rdt_fs_type);
+ if (ret)
+ goto cleanup_mountpoint;
+
+ /*
+ * Adding the resctrl debugfs directory here may not be ideal since
+ * it would let the resctrl debugfs directory appear on the debugfs
+ * filesystem before the resctrl filesystem is mounted.
+ * It may also be ok since that would enable debugging of RDT before
+ * resctrl is mounted.
+ * The reason why the debugfs directory is created here and not in
+ * rdt_get_tree() is because rdt_get_tree() takes rdtgroup_mutex and
+ * during the debugfs directory creation also &sb->s_type->i_mutex_key
+ * (the lockdep class of inode->i_rwsem). Other filesystem
+ * interactions (eg. SyS_getdents) have the lock ordering:
+ * &sb->s_type->i_mutex_key --> &mm->mmap_lock
+ * During mmap(), called with &mm->mmap_lock, the rdtgroup_mutex
+ * is taken, thus creating dependency:
+ * &mm->mmap_lock --> rdtgroup_mutex for the latter that can cause
+ * issues considering the other two lock dependencies.
+ * By creating the debugfs directory here we avoid a dependency
+ * that may cause deadlock (even though file operations cannot
+ * occur until the filesystem is mounted, but I do not know how to
+ * tell lockdep that).
+ */
+ debugfs_resctrl = debugfs_create_dir("resctrl", NULL);
+
+ return 0;
+
+cleanup_mountpoint:
+ sysfs_remove_mount_point(fs_kobj, "resctrl");
+ resctrl_mon_resource_exit();
+
+ return ret;
+}
+
+static bool resctrl_online_domains_exist(void)
+{
+ struct rdt_resource *r;
+
+ /*
+ * Only walk capable resources to allow resctrl_arch_get_resource()
+ * to return dummy 'not capable' resources.
+ */
+ for_each_alloc_capable_rdt_resource(r) {
+ if (!list_empty(&r->ctrl_domains))
+ return true;
+ }
+
+ for_each_mon_capable_rdt_resource(r) {
+ if (!list_empty(&r->mon_domains))
+ return true;
+ }
+
+ return false;
+}
+
+/**
+ * resctrl_exit() - Remove the resctrl filesystem and free resources.
+ *
+ * Called by the architecture code in response to a fatal error.
+ * Removes resctrl files and structures from kernfs to prevent further
+ * configuration.
+ *
+ * When called by the architecture code, all CPUs and resctrl domains must be
+ * offline. This ensures the limbo and overflow handlers are not scheduled to
+ * run, meaning the data structures they access can be freed by
+ * resctrl_mon_resource_exit().
+ *
+ * After resctrl_exit() returns, the architecture code should return an
+ * error from all resctrl_arch_ functions that can do this.
+ * resctrl_arch_get_resource() must continue to return struct rdt_resources
+ * with the correct rid field to ensure the filesystem can be unmounted.
+ */
+void resctrl_exit(void)
+{
+ cpus_read_lock();
+ WARN_ON_ONCE(resctrl_online_domains_exist());
+
+ mutex_lock(&rdtgroup_mutex);
+ resctrl_fs_teardown();
+ mutex_unlock(&rdtgroup_mutex);
+
+ cpus_read_unlock();
+
+ debugfs_remove_recursive(debugfs_resctrl);
+ debugfs_resctrl = NULL;
+ unregister_filesystem(&rdt_fs_type);
+
+ /*
+ * Do not remove the sysfs mount point added by resctrl_init() so that
+ * it can be used to umount resctrl.
+ */
+
+ resctrl_mon_resource_exit();
+}
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