Message-ID: <10ed6cda-fb82-4663-0956-c7019ec49837@intel.com>
Date:   Wed, 28 Oct 2020 11:37:46 -0700
From:   Russ Weight <russell.h.weight@...el.com>
To:     "Wu, Hao" <hao.wu@...el.com>, "mdf@...nel.org" <mdf@...nel.org>,
        "linux-fpga@...r.kernel.org" <linux-fpga@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Cc:     "trix@...hat.com" <trix@...hat.com>,
        "lgoncalv@...hat.com" <lgoncalv@...hat.com>,
        "Xu, Yilun" <yilun.xu@...el.com>,
        "Gerlach, Matthew" <matthew.gerlach@...el.com>
Subject: Re: [PATCH v5 1/7] fpga: sec-mgr: intel fpga security manager class
 driver



On 10/27/20 7:41 PM, Wu, Hao wrote:
>> On 10/25/20 7:29 PM, Wu, Hao wrote:
>>>> Subject: [PATCH v5 1/7] fpga: sec-mgr: intel fpga security manager class
>>>> driver
>>>>
>>>> Create the FPGA Security Manager class driver. The security
>>>> manager provides interfaces to manage secure updates for the
>>>> FPGA and BMC images that are stored in FLASH. The driver can
>>>> also be used to update root entry hashes and to cancel code
>>>> signing keys.
>>>>
>>>> This patch creates the class driver and provides sysfs
>>>> interfaces for displaying root entry hashes, canceled code
>>>> signing keys and flash counts.
>>>>
>>>> Signed-off-by: Russ Weight <russell.h.weight@...el.com>
>>>> Signed-off-by: Xu Yilun <yilun.xu@...el.com>
>>>> Reviewed-by: Tom Rix <trix@...hat.com>
>>>> ---
>>>> v5:
>>>>   - Added the devm_fpga_sec_mgr_unregister() function, following recent
>>>>     changes to the fpga_manager() implementation.
>>>>   - Changed some *_show() functions to use sysfs_emit() instead of
>> sprintf(
>>>> v4:
>>>>   - Changed from "Intel FPGA Security Manager" to FPGA Security
>> Manager"
>>>>     and removed unnecessary references to "Intel".
>>>>   - Changed: iops -> sops, imgr -> smgr, IFPGA_ -> FPGA_, ifpga_ to fpga_
>>>> v3:
>>>>   - Modified sysfs handler check in check_sysfs_handler() to make
>>>>     it more readable.
>>>> v2:
>>>>   - Bumped documentation dates and versions
>>>>   - Added Documentation/fpga/ifpga-sec-mgr.rst
>>>>   - Removed references to bmc_flash_count & smbus_flash_count (not
>>>> supported)
>>>>   - Split ifpga_sec_mgr_register() into create() and register() functions
>>>>   - Added devm_ifpga_sec_mgr_create()
>>>>   - Removed typedefs for imgr ops
>>>> ---
>>>>  .../ABI/testing/sysfs-class-fpga-sec-mgr      |  67 +++
>>>>  Documentation/fpga/fpga-sec-mgr.rst           |  50 ++
>>>>  Documentation/fpga/index.rst                  |   1 +
>>>>  MAINTAINERS                                   |   9 +
>>>>  drivers/fpga/Kconfig                          |   9 +
>>>>  drivers/fpga/Makefile                         |   3 +
>>>>  drivers/fpga/fpga-sec-mgr.c                   | 487 ++++++++++++++++++
>>>>  include/linux/fpga/fpga-sec-mgr.h             |  83 +++
>>>>  8 files changed, 709 insertions(+)
>>>>  create mode 100644 Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
>>>>  create mode 100644 Documentation/fpga/fpga-sec-mgr.rst
>>>>  create mode 100644 drivers/fpga/fpga-sec-mgr.c
>>>>  create mode 100644 include/linux/fpga/fpga-sec-mgr.h
>>>>
>>>> diff --git a/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
>>>> b/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
>>>> new file mode 100644
>>>> index 000000000000..843f0b58f171
>>>> --- /dev/null
>>>> +++ b/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
>>>> @@ -0,0 +1,67 @@
>>>> +What: /sys/class/fpga_sec_mgr/fpga_secX/name
>>>> +Date:Oct 2020
>>>> +KernelVersion:  5.11
>>>> +Contact:Russ Weight <russell.h.weight@...el.com>
>>>> +Description:Name of low level fpga security manager driver.
>>>> +
>>>> +What:
>>>> /sys/class/fpga_sec_mgr/fpga_secX/security/sr_root_entry_hash
>>>> +Date:Oct 2020
>>>> +KernelVersion:  5.11
>>>> +Contact:Russ Weight <russell.h.weight@...el.com>
>>>> +Description:Read only. Returns the root entry hash for the static
>>>> +region if one is programmed, else it returns the
>>>> +string: "hash not programmed".  This file is only
>>>> +visible if the underlying device supports it.
>>>> +Format: "0x%x".
>>>> +
>>> If we plan to make this class driver a common one for everybody, then
>>> these sysfs defined here sounds a little device-specific? This is just my
>>> personal feeling, Moritz and Tom, how do you guys think about these ones?
>> Yes - this occurred to me as well. The data in the security subdirectory
>> could be different for different vendors. I'm not sure if this is a problem
>> or not. One thing to note is that these sysfs entries are only present if there
>> is a handler for them. Additional, optional, file types could be added by other
>> vendors.
> But if other vendors want to have their own ones, they follow the same method.
> that means every time we need to add more handlers and sysfs entries to this
> common class driver. This is not what we really want. If we consider this common
> class driver is one abstraction layer, we would like to have the real common items
> in such driver. Vendor specific items could be handled in drivers provided by
> the different vendors but not in the common file, at least we don't want to touch
> it every time. How do you think?
It isn't a generic interface if every vendor has to extend the number of sysfs
entries supported by the class device - but if the total number of vendors is
two, then maybe it isn't an issue? I'm really not sure what the number would be...

Looking through sysfs, I can also see a number stats files (e.g.
/sys/fs/xfs/stats/stats) that contain multiple lines of information. There are
also meminfo files (e.g. /sys/devices/system/node/node1/meminfo) that contain
multiple lines of information.

All of the information in the security/ directory is read-only information. Would
it be reasonable to replace the security directory with a single secinfo file that
contains name/value pairs that describe the data? For example:

bmc_canceled_csks:
bmc_root_entry_hash: 0x16609930bf6e65ee0d929a87884c37826a731bb317a11f4feb47b3cb328b9b0c
pr_canceled_csks:
pr_root_entry_hash: hash not programmed
sr_canceled_csks:
sr_root_entry_hash: 0xa74b1b31b6b010e94be4a3a043f9af3c5b81258893fbe40cd91d8441fb1cb827
user_flash_count: 113

If we did that, then the format could be enforced as an array of name/value string
pairs, which could vary by device/vendor. It would be human readable. Any parser
would have to know what device and format it was dealing with.

I think the options we have are:
(1) Extend the support sysfs entries as needed (the current implementation)
(2) Provide a single secinfo (or security_info) file that enforces name/value pairs
(3) Move the security information out of the class driver. The scope of the class
    driver would be the update only.

If (2) is acceptable, then I like that best. I think (3) is also OK. I am uncertain
about (1).

What are your thoughts? Any other proposals?

- Russ


>
> Thanks
> Hao
>
>> - Russ
>>> Hao
>>>
>>>> +What:
>>>> /sys/class/fpga_sec_mgr/fpga_secX/security/pr_root_entry_hash
>>>> +Date:Oct 2020
>>>> +KernelVersion:  5.11
>>>> +Contact:Russ Weight <russell.h.weight@...el.com>
>>>> +Description:Read only. Returns the root entry hash for the partial
>>>> +reconfiguration region if one is programmed, else it
>>>> +returns the string: "hash not programmed".  This file
>>>> +is only visible if the underlying device supports it.
>>>> +Format: "0x%x".
>>>> +
>>>> +What:
>>>> /sys/class/fpga_sec_mgr/fpga_secX/security/bmc_root_entry_hash
>>>> +Date:Oct 2020
>>>> +KernelVersion:  5.11
>>>> +Contact:Russ Weight <russell.h.weight@...el.com>
>>>> +Description:Read only. Returns the root entry hash for the BMC image
>>>> +if one is programmed, else it returns the string:
>>>> +"hash not programmed".  This file is only visible if the
>>>> +underlying device supports it.
>>>> +Format: "0x%x".
>>>> +
>>>> +What:
>>>> /sys/class/fpga_sec_mgr/fpga_secX/security/sr_canceled_csks
>>>> +Date:Oct 2020
>>>> +KernelVersion:  5.11
>>>> +Contact:Russ Weight <russell.h.weight@...el.com>
>>>> +Description:Read only. Returns a list of indices for canceled code
>>>> +signing keys for the static region. The standard bitmap
>>>> +list format is used (e.g. "1,2-6,9").
>>>> +
>>>> +What:
>>>> /sys/class/fpga_sec_mgr/fpga_secX/security/pr_canceled_csks
>>>> +Date:Oct 2020
>>>> +KernelVersion:  5.11
>>>> +Contact:Russ Weight <russell.h.weight@...el.com>
>>>> +Description:Read only. Returns a list of indices for canceled code
>>>> +signing keys for the partial reconfiguration region. The
>>>> +standard bitmap list format is used (e.g. "1,2-6,9").
>>>> +
>>>> +What:
>>>> /sys/class/fpga_sec_mgr/fpga_secX/security/bmc_canceled_csks
>>>> +Date:Oct 2020
>>>> +KernelVersion:  5.11
>>>> +Contact:Russ Weight <russell.h.weight@...el.com>
>>>> +Description:Read only. Returns a list of indices for canceled code
>>>> +signing keys for the BMC.  The standard bitmap list format
>>>> +is used (e.g. "1,2-6,9").
>>>> +
>>>> +What:
>>>> /sys/class/fpga_sec_mgr/fpga_secX/security/user_flash_count
>>>> +Date:Oct 2020
>>>> +KernelVersion:  5.11
>>>> +Contact:Russ Weight <russell.h.weight@...el.com>
>>>> +Description:Read only. Returns number of times the user image for the
>>>> +static region has been flashed.
>>>> +Format: "%u".
>>>> diff --git a/Documentation/fpga/fpga-sec-mgr.rst
>>>> b/Documentation/fpga/fpga-sec-mgr.rst
>>>> new file mode 100644
>>>> index 000000000000..4a1d6519b1d3
>>>> --- /dev/null
>>>> +++ b/Documentation/fpga/fpga-sec-mgr.rst
>>>> @@ -0,0 +1,50 @@
>>>> +.. SPDX-License-Identifier: GPL-2.0
>>>> +
>>>> +========================================
>>>> +FPGA Security Manager Class Driver
>>>> +========================================
>>>> +
>>>> +The FPGA Security Manager class driver provides a common
>>>> +API for user-space tools to manage updates for secure FPGA
>>>> +devices. Device drivers that instantiate the Security
>>>> +Manager class driver will interact with a HW secure update
>>>> +engine in order to transfer new FPGA and BMC images to FLASH so
>>>> +that they will be automatically loaded when the FPGA card reboots.
>>>> +
>>>> +A significant difference between the FPGA Manager and the FPGA
>>>> +Security Manager is that the FPGA Manager does a live update (Partial
>>>> +Reconfiguration) to a device, whereas the FPGA Security Manager
>>>> +updates the FLASH images for the Static Region and the BMC so that
>>>> +they will be loaded the next time the FPGA card boots. Security is
>>>> +enforced by hardware and firmware. The security manager interacts
>>>> +with the firmware to initiate an update, pass in the necessary data,
>>>> +and collect status on the update.
>>>> +
>>>> +In addition to managing secure updates of the FPGA and BMC images,
>>>> +the FPGA Security Manager update process may also used to
>>>> +program root entry hashes and cancellation keys for the FPGA static
>>>> +region, the FPGA partial reconfiguration region, and the BMC.
>>>> +
>>>> +Secure updates make use of the request_firmware framework, which
>>>> +requires that image files are accessible under /lib/firmware. A request
>>>> +for a secure update returns immediately, while the update itself
>>>> +proceeds in the context of a kernel worker thread. Sysfs files provide
>>>> +a means for monitoring the progress of a secure update and for
>>>> +retrieving error information in the event of a failure.
>>>> +
>>>> +Sysfs Attributes
>>>> +================
>>>> +
>>>> +The API consists of two groups of sysfs attributes as described below.
>>>> +
>>>> +1. Files in the *security* sub-directory can be used to read security
>>>> +   information including: Root Entry Hashes (REH), Cancelled Code
>>>> +   Signing Keys (CSK), and the flash update count for FPGA images.
>>>> +
>>>> +2. Files in the *update* sub-directory can be used to instantiate and
>>>> +   monitor a secure update.
>>>> +
>>>> +
>>>> +See `<../ABI/testing/sysfs-class-fpga-sec-mgr>`__ for a full
>>>> +description of the sysfs attributes for the FPGA Security
>>>> +Manager.
>>>> diff --git a/Documentation/fpga/index.rst
>> b/Documentation/fpga/index.rst
>>>> index f80f95667ca2..0b2f427042af 100644
>>>> --- a/Documentation/fpga/index.rst
>>>> +++ b/Documentation/fpga/index.rst
>>>> @@ -8,6 +8,7 @@ fpga
>>>>      :maxdepth: 1
>>>>
>>>>      dfl
>>>> +    fpga-sec-mgr
>>>>
>>>>  .. only::  subproject and html
>>>>
>>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>>> index 4538378de6f5..7997fff716a8 100644
>>>> --- a/MAINTAINERS
>>>> +++ b/MAINTAINERS
>>>> @@ -6901,6 +6901,15 @@ F:Documentation/fpga/
>>>>  F:drivers/fpga/
>>>>  F:include/linux/fpga/
>>>>
>>>> +FPGA SECURITY MANAGER DRIVERS
>>>> +M:Russ Weight <russell.h.weight@...el.com>
>>>> +L:linux-fpga@...r.kernel.org
>>>> +S:Maintained
>>>> +F:Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
>>>> +F:Documentation/fpga/fpga-sec-mgr.rst
>>>> +F:drivers/fpga/fpga-sec-mgr.c
>>>> +F:include/linux/fpga/fpga-sec-mgr.h
>>>> +
>>>>  FPU EMULATOR
>>>>  M:Bill Metzenthen <billm@...bpc.org.au>
>>>>  S:Maintained
>>>> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
>>>> index 7cd5a29fc437..6810b23b178d 100644
>>>> --- a/drivers/fpga/Kconfig
>>>> +++ b/drivers/fpga/Kconfig
>>>> @@ -215,4 +215,13 @@ config FPGA_MGR_ZYNQMP_FPGA
>>>>    to configure the programmable logic(PL) through PS
>>>>    on ZynqMP SoC.
>>>>
>>>> +config FPGA_SEC_MGR
>>>> +tristate "FPGA Security Manager"
>>>> +help
>>>> +  The Security Manager class driver presents a common
>>>> +  user API for managing secure updates for FPGA
>>>> +  devices, including flash images for the FPGA static
>>>> +  region and for the BMC. Select this option to enable
>>>> +  updates for secure FPGA devices.
>>>> +
>>>>  endif # FPGA
>>>> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
>>>> index d8e21dfc6778..0e357262faed 100644
>>>> --- a/drivers/fpga/Makefile
>>>> +++ b/drivers/fpga/Makefile
>>>> @@ -21,6 +21,9 @@ obj-$(CONFIG_FPGA_MGR_ZYNQMP_FPGA)+=
>>>> zynqmp-fpga.o
>>>>  obj-$(CONFIG_ALTERA_PR_IP_CORE)         += altera-pr-ip-core.o
>>>>  obj-$(CONFIG_ALTERA_PR_IP_CORE_PLAT)    += altera-pr-ip-core-plat.o
>>>>
>>>> +# FPGA Security Manager Framework
>>>> +obj-$(CONFIG_FPGA_SEC_MGR)+= fpga-sec-mgr.o
>>>> +
>>>>  # FPGA Bridge Drivers
>>>>  obj-$(CONFIG_FPGA_BRIDGE)+= fpga-bridge.o
>>>>  obj-$(CONFIG_SOCFPGA_FPGA_BRIDGE)+= altera-hps2fpga.o altera-
>>>> fpga2sdram.o
>>>> diff --git a/drivers/fpga/fpga-sec-mgr.c b/drivers/fpga/fpga-sec-mgr.c
>>>> new file mode 100644
>>>> index 000000000000..95b5a7ccbe44
>>>> --- /dev/null
>>>> +++ b/drivers/fpga/fpga-sec-mgr.c
>>>> @@ -0,0 +1,487 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +/*
>>>> + * FPGA Security Manager
>>>> + *
>>>> + * Copyright (C) 2019-2020 Intel Corporation, Inc.
>>>> + */
>>>> +
>>>> +#include <linux/fpga/fpga-sec-mgr.h>
>>>> +#include <linux/idr.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/slab.h>
>>>> +#include <linux/vmalloc.h>
>>>> +
>>>> +static DEFINE_IDA(fpga_sec_mgr_ida);
>>>> +static struct class *fpga_sec_mgr_class;
>>>> +
>>>> +struct fpga_sec_mgr_devres {
>>>> +struct fpga_sec_mgr *smgr;
>>>> +};
>>>> +
>>>> +#define to_sec_mgr(d) container_of(d, struct fpga_sec_mgr, dev)
>>>> +
>>>> +static ssize_t
>>>> +show_canceled_csk(struct fpga_sec_mgr *smgr,
>>>> +  int (*get_csk)(struct fpga_sec_mgr *smgr,
>>>> + unsigned long *csk_map, unsigned int nbits),
>>>> +  int (*get_csk_nbits)(struct fpga_sec_mgr *smgr),
>>>> +  char *buf)
>>>> +{
>>>> +unsigned long *csk_map = NULL;
>>>> +unsigned int nbits;
>>>> +int ret;
>>>> +
>>>> +ret = get_csk_nbits(smgr);
>>>> +if (ret < 0)
>>>> +return ret;
>>>> +
>>>> +nbits = (unsigned int)ret;
>>>> +csk_map = vmalloc(sizeof(unsigned long) * BITS_TO_LONGS(nbits));
>>>> +if (!csk_map)
>>>> +return -ENOMEM;
>>>> +
>>>> +ret = get_csk(smgr, csk_map, nbits);
>>>> +if (ret)
>>>> +goto vfree_exit;
>>>> +
>>>> +ret = bitmap_print_to_pagebuf(1, buf, csk_map, nbits);
>>>> +
>>>> +vfree_exit:
>>>> +vfree(csk_map);
>>>> +return ret;
>>>> +}
>>>> +
>>>> +static ssize_t
>>>> +show_root_entry_hash(struct fpga_sec_mgr *smgr,
>>>> +     int (*get_reh)(struct fpga_sec_mgr *smgr, u8 *hash,
>>>> +    unsigned int size),
>>>> +     int (*get_reh_size)(struct fpga_sec_mgr *smgr),
>>>> +     char *buf)
>>>> +{
>>>> +int size, i, cnt, ret;
>>>> +u8 *hash;
>>>> +
>>>> +ret = get_reh_size(smgr);
>>>> +if (ret < 0)
>>>> +return ret;
>>>> +else if (!ret)
>>>> +return sysfs_emit(buf, "hash not programmed\n");
>>>> +
>>>> +size = ret;
>>>> +hash = vmalloc(size);
>>>> +if (!hash)
>>>> +return -ENOMEM;
>>>> +
>>>> +ret = get_reh(smgr, hash, size);
>>>> +if (ret)
>>>> +goto vfree_exit;
>>>> +
>>>> +cnt = sprintf(buf, "0x");
>>>> +for (i = 0; i < size; i++)
>>>> +cnt += sprintf(buf + cnt, "%02x", hash[i]);
>>>> +cnt += sprintf(buf + cnt, "\n");
>>>> +
>>>> +vfree_exit:
>>>> +vfree(hash);
>>>> +return ret ? : cnt;
>>>> +}
>>>> +
>>>> +#define DEVICE_ATTR_SEC_CSK(_name) \
>>>> +static ssize_t _name##_canceled_csks_show(struct device *dev, \
>>>> +  struct device_attribute *attr, \
>>>> +  char *buf) \
>>>> +{ \
>>>> +struct fpga_sec_mgr *smgr = to_sec_mgr(dev); \
>>>> +return show_canceled_csk(smgr, \
>>>> +       smgr->sops->_name##_canceled_csks, \
>>>> +       smgr->sops->_name##_canceled_csk_nbits, buf); \
>>>> +} \
>>>> +static DEVICE_ATTR_RO(_name##_canceled_csks)
>>>> +
>>>> +#define DEVICE_ATTR_SEC_ROOT_ENTRY_HASH(_name) \
>>>> +static ssize_t _name##_root_entry_hash_show(struct device *dev, \
>>>> +     struct device_attribute *attr, \
>>>> +     char *buf) \
>>>> +{ \
>>>> +struct fpga_sec_mgr *smgr = to_sec_mgr(dev); \
>>>> +return show_root_entry_hash(smgr, \
>>>> +       smgr->sops->_name##_root_entry_hash, \
>>>> +       smgr->sops->_name##_reh_size, buf); \
>>>> +} \
>>>> +static DEVICE_ATTR_RO(_name##_root_entry_hash)
>>>> +
>>>> +static ssize_t user_flash_count_show(struct device *dev,
>>>> +     struct device_attribute *attr, char *buf)
>>>> +{
>>>> +struct fpga_sec_mgr *smgr = to_sec_mgr(dev);
>>>> +int cnt = smgr->sops->user_flash_count(smgr);
>>>> +
>>>> +return cnt < 0 ? cnt : sysfs_emit(buf, "%u\n", cnt);
>>>> +}
>>>> +static DEVICE_ATTR_RO(user_flash_count);
>>>> +
>>>> +DEVICE_ATTR_SEC_ROOT_ENTRY_HASH(sr);
>>>> +DEVICE_ATTR_SEC_ROOT_ENTRY_HASH(pr);
>>>> +DEVICE_ATTR_SEC_ROOT_ENTRY_HASH(bmc);
>>>> +DEVICE_ATTR_SEC_CSK(sr);
>>>> +DEVICE_ATTR_SEC_CSK(pr);
>>>> +DEVICE_ATTR_SEC_CSK(bmc);
>>>> +
>>>> +static struct attribute *sec_mgr_security_attrs[] = {
>>>> +&dev_attr_user_flash_count.attr,
>>>> +&dev_attr_bmc_root_entry_hash.attr,
>>>> +&dev_attr_sr_root_entry_hash.attr,
>>>> +&dev_attr_pr_root_entry_hash.attr,
>>>> +&dev_attr_sr_canceled_csks.attr,
>>>> +&dev_attr_pr_canceled_csks.attr,
>>>> +&dev_attr_bmc_canceled_csks.attr,
>>>> +NULL,
>>>> +};
>>>> +
>>>> +#define check_attr(attribute, _name) \
>>>> +((attribute) == &dev_attr_##_name.attr && smgr->sops->_name)
>>>> +
>>>> +static umode_t sec_mgr_visible(struct kobject *kobj,
>>>> +       struct attribute *attr, int n)
>>>> +{
>>>> +struct fpga_sec_mgr *smgr = to_sec_mgr(kobj_to_dev(kobj));
>>>> +
>>>> +/*
>>>> + * Only display optional sysfs attributes if a
>>>> + * corresponding handler is provided
>>>> + */
>>>> +if (check_attr(attr, user_flash_count) ||
>>>> +    check_attr(attr, bmc_root_entry_hash) ||
>>>> +    check_attr(attr, sr_root_entry_hash) ||
>>>> +    check_attr(attr, pr_root_entry_hash) ||
>>>> +    check_attr(attr, sr_canceled_csks) ||
>>>> +    check_attr(attr, pr_canceled_csks) ||
>>>> +    check_attr(attr, bmc_canceled_csks))
>>>> +return attr->mode;
>>>> +
>>>> +return 0;
>>>> +}
>>>> +
>>>> +static struct attribute_group sec_mgr_security_attr_group = {
>>>> +.name = "security",
>>>> +.attrs = sec_mgr_security_attrs,
>>>> +.is_visible = sec_mgr_visible,
>>>> +};
>>>> +
>>>> +static ssize_t name_show(struct device *dev,
>>>> + struct device_attribute *attr, char *buf)
>>>> +{
>>>> +struct fpga_sec_mgr *smgr = to_sec_mgr(dev);
>>>> +
>>>> +return sysfs_emit(buf, "%s\n", smgr->name);
>>>> +}
>>>> +static DEVICE_ATTR_RO(name);
>>>> +
>>>> +static struct attribute *sec_mgr_attrs[] = {
>>>> +&dev_attr_name.attr,
>>>> +NULL,
>>>> +};
>>>> +
>>>> +static struct attribute_group sec_mgr_attr_group = {
>>>> +.attrs = sec_mgr_attrs,
>>>> +};
>>>> +
>>>> +static const struct attribute_group *fpga_sec_mgr_attr_groups[] = {
>>>> +&sec_mgr_attr_group,
>>>> +&sec_mgr_security_attr_group,
>>>> +NULL,
>>>> +};
>>>> +
>>>> +static bool check_sysfs_handler(struct device *dev,
>>>> +void *sysfs_handler, void *size_handler,
>>>> +const char *sysfs_handler_name,
>>>> +const char *size_handler_name)
>>>> +{
>>>> +/*
>>>> + * sysfs_handler and size_handler must either both be
>>>> + * defined or both be NULL.
>>>> + */
>>>> +if (sysfs_handler && !size_handler) {
>>>> +dev_err(dev, "%s registered without %s\n",
>>>> +sysfs_handler_name, size_handler_name);
>>>> +return false;
>>>> +} else if (!sysfs_handler && size_handler) {
>>>> +dev_err(dev, "%s registered without %s\n",
>>>> +size_handler_name, sysfs_handler_name);
>>>> +return false;
>>>> +}
>>>> +return true;
>>>> +}
>>>> +
>>>> +#define check_reh_handler(_dev, _sops, _name) \
>>>> +check_sysfs_handler(_dev, (_sops)->_name##_root_entry_hash, \
>>>> +    (_sops)->_name##_reh_size, \
>>>> +    __stringify(_name##_root_entry_hash), \
>>>> +    __stringify(_name##_reh_size))
>>>> +
>>>> +#define check_csk_handler(_dev, _sops, _name) \
>>>> +check_sysfs_handler(_dev, (_sops)->_name##_canceled_csks, \
>>>> +    (_sops)->_name##_canceled_csk_nbits, \
>>>> +    __stringify(_name##_canceled_csks), \
>>>> +    __stringify(_name##_canceled_csk_nbits))
>>>> +
>>>> +/**
>>>> + * fpga_sec_mgr_create - create and initialize an FPGA
>>>> + *  security manager struct
>>>> + *
>>>> + * @dev:  fpga security manager device from pdev
>>>> + * @name: fpga security manager name
>>>> + * @sops: pointer to a structure of fpga callback functions
>>>> + * @priv: fpga security manager private data
>>>> + *
>>>> + * The caller of this function is responsible for freeing the struct
>>>> + * with ifpg_sec_mgr_free(). Using devm_fpga_sec_mgr_create() instead
>>>> + * is recommended.
>>>> + *
>>>> + * Return: pointer to struct fpga_sec_mgr or NULL
>>>> + */
>>>> +struct fpga_sec_mgr *
>>>> +fpga_sec_mgr_create(struct device *dev, const char *name,
>>>> +    const struct fpga_sec_mgr_ops *sops, void *priv)
>>>> +{
>>>> +struct fpga_sec_mgr *smgr;
>>>> +int id, ret;
>>>> +
>>>> +if (!check_reh_handler(dev, sops, bmc) ||
>>>> +    !check_reh_handler(dev, sops, sr) ||
>>>> +    !check_reh_handler(dev, sops, pr) ||
>>>> +    !check_csk_handler(dev, sops, bmc) ||
>>>> +    !check_csk_handler(dev, sops, sr) ||
>>>> +    !check_csk_handler(dev, sops, pr)) {
>>>> +return NULL;
>>>> +}
>>>> +
>>>> +if (!name || !strlen(name)) {
>>>> +dev_err(dev, "Attempt to register with no name!\n");
>>>> +return NULL;
>>>> +}
>>>> +
>>>> +smgr = kzalloc(sizeof(*smgr), GFP_KERNEL);
>>>> +if (!smgr)
>>>> +return NULL;
>>>> +
>>>> +id = ida_simple_get(&fpga_sec_mgr_ida, 0, 0, GFP_KERNEL);
>>>> +if (id < 0)
>>>> +goto error_kfree;
>>>> +
>>>> +mutex_init(&smgr->lock);
>>>> +
>>>> +smgr->name = name;
>>>> +smgr->priv = priv;
>>>> +smgr->sops = sops;
>>>> +
>>>> +device_initialize(&smgr->dev);
>>>> +smgr->dev.class = fpga_sec_mgr_class;
>>>> +smgr->dev.parent = dev;
>>>> +smgr->dev.id = id;
>>>> +
>>>> +ret = dev_set_name(&smgr->dev, "fpga_sec%d", id);
>>>> +if (ret) {
>>>> +dev_err(dev, "Failed to set device name: fpga_sec%d\n", id);
>>>> +goto error_device;
>>>> +}
>>>> +
>>>> +return smgr;
>>>> +
>>>> +error_device:
>>>> +ida_simple_remove(&fpga_sec_mgr_ida, id);
>>>> +
>>>> +error_kfree:
>>>> +kfree(smgr);
>>>> +
>>>> +return NULL;
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(fpga_sec_mgr_create);
>>>> +
>>>> +/**
>>>> + * fpga_sec_mgr_free - free an FPGA security manager created
>>>> + *with fpga_sec_mgr_create()
>>>> + *
>>>> + * @smgr:FPGA security manager structure
>>>> + */
>>>> +void fpga_sec_mgr_free(struct fpga_sec_mgr *smgr)
>>>> +{
>>>> +ida_simple_remove(&fpga_sec_mgr_ida, smgr->dev.id);
>>>> +kfree(smgr);
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(fpga_sec_mgr_free);
>>>> +
>>>> +static void devm_fpga_sec_mgr_release(struct device *dev, void *res)
>>>> +{
>>>> +struct fpga_sec_mgr_devres *dr = res;
>>>> +
>>>> +fpga_sec_mgr_free(dr->smgr);
>>>> +}
>>>> +
>>>> +/**
>>>> + * devm_fpga_sec_mgr_create - create and initialize an FPGA
>>>> + *       security manager struct
>>>> + *
>>>> + * @dev:  fpga security manager device from pdev
>>>> + * @name: fpga security manager name
>>>> + * @sops: pointer to a structure of fpga callback functions
>>>> + * @priv: fpga security manager private data
>>>> + *
>>>> + * This function is intended for use in a FPGA Security manager
>>>> + * driver's probe function.  After the security manager driver creates
>>>> + * the fpga_sec_mgr struct with devm_fpga_sec_mgr_create(), it should
>>>> + * register it with devm_fpga_sec_mgr_register().
>>>> + * The fpga_sec_mgr struct allocated with this function will be freed
>>>> + * automatically on driver detach.
>>>> + *
>>>> + * Return: pointer to struct fpga_sec_mgr or NULL
>>>> + */
>>>> +struct fpga_sec_mgr *
>>>> +devm_fpga_sec_mgr_create(struct device *dev, const char *name,
>>>> + const struct fpga_sec_mgr_ops *sops, void *priv)
>>>> +{
>>>> +struct fpga_sec_mgr_devres *dr;
>>>> +
>>>> +dr = devres_alloc(devm_fpga_sec_mgr_release, sizeof(*dr),
>>>> GFP_KERNEL);
>>>> +if (!dr)
>>>> +return NULL;
>>>> +
>>>> +dr->smgr = fpga_sec_mgr_create(dev, name, sops, priv);
>>>> +if (!dr->smgr) {
>>>> +devres_free(dr);
>>>> +return NULL;
>>>> +}
>>>> +
>>>> +devres_add(dev, dr);
>>>> +
>>>> +return dr->smgr;
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(devm_fpga_sec_mgr_create);
>>>> +
>>>> +/**
>>>> + * fpga_sec_mgr_register - register an FPGA security manager
>>>> + *
>>>> + * @smgr: fpga security manager struct
>>>> + *
>>>> + * Return: 0 on success, negative error code otherwise.
>>>> + */
>>>> +int fpga_sec_mgr_register(struct fpga_sec_mgr *smgr)
>>>> +{
>>>> +int ret;
>>>> +
>>>> +ret = device_add(&smgr->dev);
>>>> +if (ret)
>>>> +goto error_device;
>>>> +
>>>> +dev_info(&smgr->dev, "%s registered\n", smgr->name);
>>>> +
>>>> +return 0;
>>>> +
>>>> +error_device:
>>>> +ida_simple_remove(&fpga_sec_mgr_ida, smgr->dev.id);
>>>> +
>>>> +return ret;
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(fpga_sec_mgr_register);
>>>> +
>>>> +/**
>>>> + * fpga_sec_mgr_unregister - unregister an FPGA security manager
>>>> + *
>>>> + * @mgr: fpga manager struct
>>>> + *
>>>> + * This function is intended for use in an FPGA security manager
>>>> + * driver's remove() function.
>>>> + */
>>>> +void fpga_sec_mgr_unregister(struct fpga_sec_mgr *smgr)
>>>> +{
>>>> +dev_info(&smgr->dev, "%s %s\n", __func__, smgr->name);
>>>> +
>>>> +device_unregister(&smgr->dev);
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(fpga_sec_mgr_unregister);
>>>> +
>>>> +static int fpga_sec_mgr_devres_match(struct device *dev, void *res,
>>>> +     void *match_data)
>>>> +{
>>>> +struct fpga_sec_mgr_devres *dr = res;
>>>> +
>>>> +return match_data == dr->smgr;
>>>> +}
>>>> +
>>>> +static void devm_fpga_sec_mgr_unregister(struct device *dev, void *res)
>>>> +{
>>>> +struct fpga_sec_mgr_devres *dr = res;
>>>> +
>>>> +fpga_sec_mgr_unregister(dr->smgr);
>>>> +}
>>>> +
>>>> +/**
>>>> + * devm_fpga_sec_mgr_register - resource managed variant of
>>>> + *fpga_sec_mgr_register()
>>>> + *
>>>> + * @dev: managing device for this FPGA security manager
>>>> + * @smgr: fpga security manager struct
>>>> + *
>>>> + * This is the devres variant of fpga_sec_mgr_register() for which the
>>>> + * unregister function will be called automatically when the managing
>>>> + * device is detached.
>>>> + */
>>>> +int devm_fpga_sec_mgr_register(struct device *dev, struct fpga_sec_mgr
>>>> *smgr)
>>>> +{
>>>> +struct fpga_sec_mgr_devres *dr;
>>>> +int ret;
>>>> +
>>>> +/*
>>>> + * Make sure that the struct fpga_sec_mgr * that is passed in is
>>>> + * managed itself.
>>>> + */
>>>> +if (WARN_ON(!devres_find(dev, devm_fpga_sec_mgr_release,
>>>> + fpga_sec_mgr_devres_match, smgr)))
>>>> +return -EINVAL;
>>>> +
>>>> +dr = devres_alloc(devm_fpga_sec_mgr_unregister, sizeof(*dr),
>>>> GFP_KERNEL);
>>>> +if (!dr)
>>>> +return -ENOMEM;
>>>> +
>>>> +ret = fpga_sec_mgr_register(smgr);
>>>> +if (ret) {
>>>> +devres_free(dr);
>>>> +return ret;
>>>> +}
>>>> +
>>>> +dr->smgr = smgr;
>>>> +devres_add(dev, dr);
>>>> +
>>>> +return 0;
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(devm_fpga_sec_mgr_register);
>>>> +
>>>> +static void fpga_sec_mgr_dev_release(struct device *dev)
>>>> +{
>>>> +}
>>>> +
>>>> +static int __init fpga_sec_mgr_class_init(void)
>>>> +{
>>>> +pr_info("FPGA Security Manager\n");
>>>> +
>>>> +fpga_sec_mgr_class = class_create(THIS_MODULE, "fpga_sec_mgr");
>>>> +if (IS_ERR(fpga_sec_mgr_class))
>>>> +return PTR_ERR(fpga_sec_mgr_class);
>>>> +
>>>> +fpga_sec_mgr_class->dev_groups = fpga_sec_mgr_attr_groups;
>>>> +fpga_sec_mgr_class->dev_release = fpga_sec_mgr_dev_release;
>>>> +
>>>> +return 0;
>>>> +}
>>>> +
>>>> +static void __exit fpga_sec_mgr_class_exit(void)
>>>> +{
>>>> +class_destroy(fpga_sec_mgr_class);
>>>> +ida_destroy(&fpga_sec_mgr_ida);
>>>> +}
>>>> +
>>>> +MODULE_DESCRIPTION("FPGA Security Manager Driver");
>>>> +MODULE_LICENSE("GPL v2");
>>>> +
>>>> +subsys_initcall(fpga_sec_mgr_class_init);
>>>> +module_exit(fpga_sec_mgr_class_exit)
>>>> diff --git a/include/linux/fpga/fpga-sec-mgr.h b/include/linux/fpga/fpga-
>> sec-
>>>> mgr.h
>>>> new file mode 100644
>>>> index 000000000000..dd596c6c3748
>>>> --- /dev/null
>>>> +++ b/include/linux/fpga/fpga-sec-mgr.h
>>>> @@ -0,0 +1,83 @@
>>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>>> +/*
>>>> + * Header file for FPGA Security Manager
>>>> + *
>>>> + * Copyright (C) 2019-2020 Intel Corporation, Inc.
>>>> + */
>>>> +#ifndef _LINUX_FPGA_SEC_MGR_H
>>>> +#define _LINUX_FPGA_SEC_MGR_H
>>>> +
>>>> +#include <linux/device.h>
>>>> +#include <linux/mutex.h>
>>>> +#include <linux/types.h>
>>>> +
>>>> +struct fpga_sec_mgr;
>>>> +
>>>> +/**
>>>> + * struct fpga_sec_mgr_ops - device specific operations
>>>> + * @user_flash_count:    Optional: Return sysfs string output for
>>>> FPGA
>>>> + *    image flash count
>>>> + * @sr_root_entry_hash:    Optional: Return sysfs string output for
>>>> static
>>>> + *    region root entry hash
>>>> + * @pr_root_entry_hash:    Optional: Return sysfs string output for
>>>> partial
>>>> + *    reconfiguration root entry hash
>>>> + * @bmc_root_entry_hash:    Optional: Return sysfs string output for
>> BMC
>>>> + *    root entry hash
>>>> + * @sr_canceled_csks:    Optional: Return sysfs string output for static
>>>> + *    region canceled keys
>>>> + * @pr_canceled_csks:    Optional: Return sysfs string output for
>>>> partial
>>>> + *    reconfiguration canceled keys
>>>> + * @bmc_canceled_csks:    Optional: Return sysfs string output for
>>>> bmc
>>>> + *    canceled keys
>>>> + * @bmc_canceled_csk_nbits: Optional: Return BMC canceled csk vector
>> bit
>>>> count
>>>> + * @sr_canceled_csk_nbits:  Optional: Return SR canceled csk vector bit
>>>> count
>>>> + * @pr_canceled_csk_nbits:  Optional: Return PR canceled csk vector bit
>>>> count
>>>> + * @bmc_reh_size:    Optional: Return byte size for BMC root entry hash
>>>> + * @sr_reh_size:    Optional: Return byte size for SR root entry hash
>>>> + * @pr_reh_size:    Optional: Return byte size for PR root entry hash
>>>> + */
>>>> +struct fpga_sec_mgr_ops {
>>>> +int (*user_flash_count)(struct fpga_sec_mgr *smgr);
>>>> +int (*bmc_root_entry_hash)(struct fpga_sec_mgr *smgr, u8 *hash,
>>>> +   unsigned int size);
>>>> +int (*sr_root_entry_hash)(struct fpga_sec_mgr *smgr, u8 *hash,
>>>> +  unsigned int size);
>>>> +int (*pr_root_entry_hash)(struct fpga_sec_mgr *smgr, u8 *hash,
>>>> +  unsigned int size);
>>>> +int (*bmc_canceled_csks)(struct fpga_sec_mgr *smgr,
>>>> + unsigned long *csk_map, unsigned int nbits);
>>>> +int (*sr_canceled_csks)(struct fpga_sec_mgr *smgr,
>>>> +unsigned long *csk_map, unsigned int nbits);
>>>> +int (*pr_canceled_csks)(struct fpga_sec_mgr *smgr,
>>>> +unsigned long *csk_map, unsigned int nbits);
>>>> +int (*bmc_reh_size)(struct fpga_sec_mgr *smgr);
>>>> +int (*sr_reh_size)(struct fpga_sec_mgr *smgr);
>>>> +int (*pr_reh_size)(struct fpga_sec_mgr *smgr);
>>>> +int (*bmc_canceled_csk_nbits)(struct fpga_sec_mgr *smgr);
>>>> +int (*sr_canceled_csk_nbits)(struct fpga_sec_mgr *smgr);
>>>> +int (*pr_canceled_csk_nbits)(struct fpga_sec_mgr *smgr);
>>>> +};
>>>> +
>>>> +struct fpga_sec_mgr {
>>>> +const char *name;
>>>> +struct device dev;
>>>> +const struct fpga_sec_mgr_ops *sops;
>>>> +struct mutex lock;/* protect data structure contents */
>>>> +void *priv;
>>>> +};
>>>> +
>>>> +struct fpga_sec_mgr *
>>>> +fpga_sec_mgr_create(struct device *dev, const char *name,
>>>> +    const struct fpga_sec_mgr_ops *sops, void *priv);
>>>> +
>>>> +struct fpga_sec_mgr *
>>>> +devm_fpga_sec_mgr_create(struct device *dev, const char *name,
>>>> + const struct fpga_sec_mgr_ops *sops, void *priv);
>>>> +
>>>> +int fpga_sec_mgr_register(struct fpga_sec_mgr *smgr);
>>>> +int devm_fpga_sec_mgr_register(struct device *dev,
>>>> +       struct fpga_sec_mgr *smgr);
>>>> +void fpga_sec_mgr_unregister(struct fpga_sec_mgr *smgr);
>>>> +void fpga_sec_mgr_free(struct fpga_sec_mgr *smgr);
>>>> +
>>>> +#endif
>>>> --
>>>> 2.25.1

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