Message-Id: <20210105025839.23169-5-mike.ximing.chen@intel.com>
Date:   Mon,  4 Jan 2021 20:58:23 -0600
From:   Mike Ximing Chen <mike.ximing.chen@...el.com>
To:     linux-kernel@...r.kernel.org
Cc:     arnd@...db.de, gregkh@...uxfoundation.org,
        dan.j.williams@...el.com, pierre-louis.bossart@...ux.intel.com,
        Gage Eads <gage.eads@...el.com>
Subject: [PATCH v8 04/20] dlb: add device ioctl layer and first three ioctls

Introduce the dlb device ioctl layer and the first three ioctls: query
device version, query available resources, and create a scheduling domain.
Also introduce the user-space interface file dlb_user.h.

The device version query is designed to allow each DLB device version/type
to have its own unique ioctl API through the /dev/dlb%d node. Each such API
would share in common the device version command as its first command, and
all subsequent commands can be unique to the particular device.

The hardware operation for scheduling domain creation will be added in a
subsequent commit.

Signed-off-by: Gage Eads <gage.eads@...el.com>
Signed-off-by: Mike Ximing Chen <mike.ximing.chen@...el.com>
Reviewed-by: Magnus Karlsson <magnus.karlsson@...el.com>
Reviewed-by: Dan Williams <dan.j.williams@...el.com>
---
 .../userspace-api/ioctl/ioctl-number.rst      |   1 +
 drivers/misc/dlb/Makefile                     |   2 +-
 drivers/misc/dlb/dlb_bitmap.h                 |  32 ++++
 drivers/misc/dlb/dlb_ioctl.c                  | 119 +++++++++++++
 drivers/misc/dlb/dlb_ioctl.h                  |  11 ++
 drivers/misc/dlb/dlb_main.c                   |   3 +
 drivers/misc/dlb/dlb_main.h                   |   7 +
 drivers/misc/dlb/dlb_pf_ops.c                 |  21 +++
 drivers/misc/dlb/dlb_resource.c               |  63 +++++++
 drivers/misc/dlb/dlb_resource.h               |   5 +
 include/uapi/linux/dlb.h                      | 166 ++++++++++++++++++
 11 files changed, 429 insertions(+), 1 deletion(-)
 create mode 100644 drivers/misc/dlb/dlb_ioctl.c
 create mode 100644 drivers/misc/dlb/dlb_ioctl.h
 create mode 100644 include/uapi/linux/dlb.h

diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index 55a2d9b2ce33..afca043d59f8 100644
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -241,6 +241,7 @@ Code  Seq#    Include File                                           Comments
 'h'   00-7F                                                          conflict! Charon filesystem
                                                                      <mailto:zapman@...erlan.net>
 'h'   00-1F  linux/hpet.h                                            conflict!
+'h'   00-1F  uapi/linux/dlb.h                                        conflict!
 'h'   80-8F  fs/hfsplus/ioctl.c
 'i'   00-3F  linux/i2o-dev.h                                         conflict!
 'i'   0B-1F  linux/ipmi.h                                            conflict!
diff --git a/drivers/misc/dlb/Makefile b/drivers/misc/dlb/Makefile
index 8a49ea5fd752..aaafb3086d8d 100644
--- a/drivers/misc/dlb/Makefile
+++ b/drivers/misc/dlb/Makefile
@@ -7,4 +7,4 @@
 obj-$(CONFIG_INTEL_DLB) := dlb.o
 
 dlb-objs := dlb_main.o
-dlb-objs += dlb_pf_ops.o dlb_resource.o
+dlb-objs += dlb_pf_ops.o dlb_resource.o dlb_ioctl.o
diff --git a/drivers/misc/dlb/dlb_bitmap.h b/drivers/misc/dlb/dlb_bitmap.h
index fb3ef52a306d..3ea78b42c79f 100644
--- a/drivers/misc/dlb/dlb_bitmap.h
+++ b/drivers/misc/dlb/dlb_bitmap.h
@@ -73,4 +73,36 @@ static inline void dlb_bitmap_free(struct dlb_bitmap *bitmap)
 	kfree(bitmap);
 }
 
+/**
+ * dlb_bitmap_longest_set_range() - returns longest contiguous range of set
+ *				     bits
+ * @bitmap: pointer to dlb_bitmap structure.
+ *
+ * Return:
+ * Returns the bitmap's longest contiguous range of set bits upon success,
+ * <0 otherwise.
+ *
+ * Errors:
+ * EINVAL - bitmap is NULL or is uninitialized.
+ */
+static inline int dlb_bitmap_longest_set_range(struct dlb_bitmap *bitmap)
+{
+	int max_len, len;
+	int start, end;
+
+	if (!bitmap || !bitmap->map)
+		return -EINVAL;
+
+	if (bitmap_weight(bitmap->map, bitmap->len) == 0)
+		return 0;
+
+	max_len = 0;
+	bitmap_for_each_set_region(bitmap->map, start, end, 0, bitmap->len) {
+		len = end - start;
+		if (max_len < len)
+			max_len = len;
+	}
+	return max_len;
+}
+
 #endif /*  __DLB_OSDEP_BITMAP_H */
diff --git a/drivers/misc/dlb/dlb_ioctl.c b/drivers/misc/dlb/dlb_ioctl.c
new file mode 100644
index 000000000000..c072ed9b921c
--- /dev/null
+++ b/drivers/misc/dlb/dlb_ioctl.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(C) 2016-2020 Intel Corporation. All rights reserved. */
+
+#include <linux/uaccess.h>
+#include <linux/nospec.h>
+
+#include <uapi/linux/dlb.h>
+
+#include "dlb_ioctl.h"
+#include "dlb_main.h"
+
+/* [7:0]: device revision, [15:8]: device version */
+#define DLB_SET_DEVICE_VERSION(ver, rev) (((ver) << 8) | (rev))
+
+static int
+dlb_ioctl_get_device_version(struct dlb *dlb __attribute__((unused)),
+			     void *karg)
+{
+	struct dlb_get_device_version_args *arg = karg;
+
+	arg->response.status = 0;
+	arg->response.id = DLB_SET_DEVICE_VERSION(2, DLB_REV_A0);
+
+	return 0;
+}
+
+static int dlb_ioctl_create_sched_domain(struct dlb *dlb,
+					 void *karg)
+{
+	struct dlb_create_sched_domain_args *arg = karg;
+	struct dlb_cmd_response *resp;
+	int ret;
+
+	mutex_lock(&dlb->resource_mutex);
+
+	BUILD_BUG_ON(offsetof(typeof(*arg), response) != 0);
+	resp = &arg->response;
+
+	ret = dlb->ops->create_sched_domain(&dlb->hw, arg, resp);
+
+	mutex_unlock(&dlb->resource_mutex);
+
+	return ret;
+}
+
+static int dlb_ioctl_get_num_resources(struct dlb *dlb,
+				       void *karg)
+{
+	struct dlb_get_num_resources_args *arg = karg;
+	int ret;
+
+	mutex_lock(&dlb->resource_mutex);
+	ret = dlb->ops->get_num_resources(&dlb->hw, arg);
+	mutex_unlock(&dlb->resource_mutex);
+
+	return ret;
+}
+
+typedef int (*dlb_ioctl_fn_t)(struct dlb *dlb,
+			      void *karg);
+
+static dlb_ioctl_fn_t dlb_ioctl_fns[NUM_DLB_CMD] = {
+	dlb_ioctl_get_device_version,
+	dlb_ioctl_create_sched_domain,
+	dlb_ioctl_get_num_resources
+};
+
+static int dlb_ioctl_arg_size[NUM_DLB_CMD] = {
+	sizeof(struct dlb_get_device_version_args),
+	sizeof(struct dlb_create_sched_domain_args),
+	sizeof(struct dlb_get_num_resources_args)
+};
+
+long
+dlb_ioctl(struct file *f,
+	  unsigned int cmd,
+	  unsigned long user_arg)
+{
+	struct dlb *dlb;
+	dlb_ioctl_fn_t fn;
+	u32 cmd_nr;
+	void *karg;
+	int size;
+	int ret;
+
+	dlb = f->private_data;
+
+	if (!dlb) {
+		pr_err("dlb: [%s()] Invalid DLB data\n", __func__);
+		return -EFAULT;
+	}
+
+	if (_IOC_NR(cmd) >= NUM_DLB_CMD) {
+		dev_err(dlb->dev, "[%s()] Unexpected DLB command %d\n",
+			__func__, _IOC_NR(cmd));
+		return -EINVAL;
+	}
+
+	/* Block potential speculation on invalid command numbers.
+	 */
+	cmd_nr = array_index_nospec(_IOC_NR(cmd), NUM_DLB_CMD);
+
+	size = dlb_ioctl_arg_size[cmd_nr];
+	fn = dlb_ioctl_fns[cmd_nr];
+
+	karg = kzalloc(size, GFP_KERNEL);
+	if (!karg)
+		return -ENOMEM;
+
+	if (copy_from_user(karg, (void __user *)user_arg, size))
+		return -EFAULT;
+
+	ret = fn(dlb, karg);
+
+	if (copy_to_user((void __user *)user_arg, karg, size))
+		return -EFAULT;
+
+	return ret;
+}
diff --git a/drivers/misc/dlb/dlb_ioctl.h b/drivers/misc/dlb/dlb_ioctl.h
new file mode 100644
index 000000000000..0737676f4208
--- /dev/null
+++ b/drivers/misc/dlb/dlb_ioctl.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright(C) 2016-2020 Intel Corporation. All rights reserved. */
+
+#ifndef __DLB_IOCTL_H
+#define __DLB_IOCTL_H
+
+#include "dlb_main.h"
+
+long dlb_ioctl(struct file *f, unsigned int cmd, unsigned long user_arg);
+
+#endif /* __DLB_IOCTL_H */
diff --git a/drivers/misc/dlb/dlb_main.c b/drivers/misc/dlb/dlb_main.c
index daa5eb75380f..787610bf6b20 100644
--- a/drivers/misc/dlb/dlb_main.c
+++ b/drivers/misc/dlb/dlb_main.c
@@ -10,6 +10,7 @@
 #include <linux/pci.h>
 #include <linux/uaccess.h>
 
+#include "dlb_ioctl.h"
 #include "dlb_main.h"
 #include "dlb_resource.h"
 
@@ -68,6 +69,8 @@ static int dlb_device_create(struct dlb *dlb, struct pci_dev *pdev)
 
 static const struct file_operations dlb_fops = {
 	.owner   = THIS_MODULE,
+	.unlocked_ioctl = dlb_ioctl,
+	.compat_ioctl = compat_ptr_ioctl,
 };
 
 /**********************************/
diff --git a/drivers/misc/dlb/dlb_main.h b/drivers/misc/dlb/dlb_main.h
index aaa806be66af..b3be39397fa2 100644
--- a/drivers/misc/dlb/dlb_main.h
+++ b/drivers/misc/dlb/dlb_main.h
@@ -12,6 +12,8 @@
 #include <linux/pci.h>
 #include <linux/types.h>
 
+#include <uapi/linux/dlb.h>
+
 #include "dlb_hw_types.h"
 
 /*
@@ -37,6 +39,11 @@ struct dlb_device_ops {
 	int (*init_driver_state)(struct dlb *dlb);
 	void (*enable_pm)(struct dlb *dlb);
 	int (*wait_for_device_ready)(struct dlb *dlb, struct pci_dev *pdev);
+	int (*create_sched_domain)(struct dlb_hw *hw,
+				   struct dlb_create_sched_domain_args *args,
+				   struct dlb_cmd_response *resp);
+	int (*get_num_resources)(struct dlb_hw *hw,
+				 struct dlb_get_num_resources_args *args);
 };
 
 extern struct dlb_device_ops dlb_pf_ops;
diff --git a/drivers/misc/dlb/dlb_pf_ops.c b/drivers/misc/dlb/dlb_pf_ops.c
index a88f9519ac60..67d4300ca093 100644
--- a/drivers/misc/dlb/dlb_pf_ops.c
+++ b/drivers/misc/dlb/dlb_pf_ops.c
@@ -100,6 +100,25 @@ dlb_pf_wait_for_device_ready(struct dlb *dlb, struct pci_dev *pdev)
 	return 0;
 }
 
+/*****************************/
+/****** IOCTL callbacks ******/
+/*****************************/
+
+static int
+dlb_pf_create_sched_domain(struct dlb_hw *hw,
+			   struct dlb_create_sched_domain_args *args,
+			   struct dlb_cmd_response *resp)
+{
+	return 0;
+}
+
+static int
+dlb_pf_get_num_resources(struct dlb_hw *hw,
+			 struct dlb_get_num_resources_args *args)
+{
+	return dlb_hw_get_num_resources(hw, args, false, 0);
+}
+
 /********************************/
 /****** DLB PF Device Ops ******/
 /********************************/
@@ -110,4 +129,6 @@ struct dlb_device_ops dlb_pf_ops = {
 	.init_driver_state = dlb_pf_init_driver_state,
 	.enable_pm = dlb_pf_enable_pm,
 	.wait_for_device_ready = dlb_pf_wait_for_device_ready,
+	.create_sched_domain = dlb_pf_create_sched_domain,
+	.get_num_resources = dlb_pf_get_num_resources,
 };
diff --git a/drivers/misc/dlb/dlb_resource.c b/drivers/misc/dlb/dlb_resource.c
index 3c60b704f3d6..93936611027b 100644
--- a/drivers/misc/dlb/dlb_resource.c
+++ b/drivers/misc/dlb/dlb_resource.c
@@ -200,6 +200,69 @@ int dlb_resource_init(struct dlb_hw *hw)
 	return ret;
 }
 
+/**
+ * dlb_hw_get_num_resources() - query the PCI function's available resources
+ * @hw: dlb_hw handle for a particular device.
+ * @arg: pointer to resource counts.
+ * @vdev_req: indicates whether this request came from a vdev.
+ * @vdev_id: If vdev_req is true, this contains the vdev's ID.
+ *
+ * This function returns the number of available resources for the PF or for a
+ * VF.
+ *
+ * A vdev can be either an SR-IOV virtual function or a Scalable IOV virtual
+ * device.
+ *
+ * Return:
+ * Returns 0 upon success, -EINVAL if vdev_req is true and vdev_id is
+ * invalid.
+ */
+int dlb_hw_get_num_resources(struct dlb_hw *hw,
+			     struct dlb_get_num_resources_args *arg,
+			     bool vdev_req,
+			     unsigned int vdev_id)
+{
+	struct dlb_function_resources *rsrcs;
+	struct dlb_bitmap *map;
+	int i;
+
+	if (vdev_req && vdev_id >= DLB_MAX_NUM_VDEVS)
+		return -EINVAL;
+
+	if (vdev_req)
+		rsrcs = &hw->vdev[vdev_id];
+	else
+		rsrcs = &hw->pf;
+
+	arg->num_sched_domains = rsrcs->num_avail_domains;
+
+	arg->num_ldb_queues = rsrcs->num_avail_ldb_queues;
+
+	arg->num_ldb_ports = 0;
+	for (i = 0; i < DLB_NUM_COS_DOMAINS; i++)
+		arg->num_ldb_ports += rsrcs->num_avail_ldb_ports[i];
+
+	for (i = 0; i < DLB_NUM_COS_DOMAINS; i++)
+		arg->num_cos_ldb_ports[i] = rsrcs->num_avail_ldb_ports[i];
+
+	arg->num_dir_ports = rsrcs->num_avail_dir_pq_pairs;
+
+	arg->num_atomic_inflights = rsrcs->num_avail_aqed_entries;
+
+	map = rsrcs->avail_hist_list_entries;
+
+	arg->num_hist_list_entries = bitmap_weight(map->map, map->len);
+
+	arg->max_contiguous_hist_list_entries =
+		dlb_bitmap_longest_set_range(map);
+
+	arg->num_ldb_credits = rsrcs->num_avail_qed_entries;
+
+	arg->num_dir_credits = rsrcs->num_avail_dqed_entries;
+
+	return 0;
+}
+
 /**
  * dlb_clr_pmcsr_disable() - power on bulk of DLB 2.0 logic
  * @hw: dlb_hw handle for a particular device.
diff --git a/drivers/misc/dlb/dlb_resource.h b/drivers/misc/dlb/dlb_resource.h
index 2229813d9c45..752645900f34 100644
--- a/drivers/misc/dlb/dlb_resource.h
+++ b/drivers/misc/dlb/dlb_resource.h
@@ -12,6 +12,11 @@ int dlb_resource_init(struct dlb_hw *hw);
 
 void dlb_resource_free(struct dlb_hw *hw);
 
+int dlb_hw_get_num_resources(struct dlb_hw *hw,
+			     struct dlb_get_num_resources_args *arg,
+			     bool vdev_req,
+			     unsigned int vdev_id);
+
 void dlb_clr_pmcsr_disable(struct dlb_hw *hw);
 
 #endif /* __DLB_RESOURCE_H */
diff --git a/include/uapi/linux/dlb.h b/include/uapi/linux/dlb.h
new file mode 100644
index 000000000000..956d5e9d1ddc
--- /dev/null
+++ b/include/uapi/linux/dlb.h
@@ -0,0 +1,166 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
+ * Copyright(c) 2016-2020 Intel Corporation
+ */
+
+#ifndef __DLB_H
+#define __DLB_H
+
+#include <linux/types.h>
+
+struct dlb_cmd_response {
+	__u32 status; /* Interpret using enum dlb_error */
+	__u32 id;
+};
+
+/********************************/
+/* 'dlb' device file commands  */
+/********************************/
+
+#define DLB_DEVICE_VERSION(x) (((x) >> 8) & 0xFF)
+#define DLB_DEVICE_REVISION(x) ((x) & 0xFF)
+
+enum dlb_revisions {
+	DLB_REV_A0 = 0,
+};
+
+/*
+ * DLB_CMD_GET_DEVICE_VERSION: Query the DLB device version.
+ *
+ *	Each DLB device version has its own unique ioctl API, but all share
+ *	this as the first command in their interface, which tells user-space
+ *	which API to use. The device revision is provided in case of any
+ *	hardware errata.
+ *
+ * Output parameters:
+ * - response.status: Detailed error code. In certain cases, such as if the
+ *	ioctl request arg is invalid, the driver won't set status.
+ * - response.id[7:0]: Device revision.
+ * - response.id[15:8]: Device version.
+ */
+
+struct dlb_get_device_version_args {
+	/* Output parameters */
+	struct dlb_cmd_response response;
+};
+
+/*
+ * DLB_CMD_CREATE_SCHED_DOMAIN: Create a DLB 2.0 scheduling domain and reserve
+ *	its hardware resources. This command returns the newly created domain
+ *	ID and a file descriptor for accessing the domain.
+ *
+ * Input parameters:
+ * - num_ldb_queues: Number of load-balanced queues.
+ * - num_ldb_ports: Number of load-balanced ports that can be allocated from
+ *	any class-of-service with available ports.
+ * - num_cos_ldb_ports[4]: Number of load-balanced ports from
+ *	classes-of-service 0-3.
+ * - num_dir_ports: Number of directed ports. A directed port has one directed
+ *	queue, so no num_dir_queues argument is necessary.
+ * - num_atomic_inflights: This specifies the amount of temporary atomic QE
+ *	storage for the domain. This storage is divided among the domain's
+ *	load-balanced queues that are configured for atomic scheduling.
+ * - num_hist_list_entries: Amount of history list storage. This is divided
+ *	among the domain's CQs.
+ * - num_ldb_credits: Amount of load-balanced QE storage (QED). QEs occupy this
+ *	space until they are scheduled to a load-balanced CQ. One credit
+ *	represents the storage for one QE.
+ * - num_dir_credits: Amount of directed QE storage (DQED). QEs occupy this
+ *	space until they are scheduled to a directed CQ. One credit represents
+ *	the storage for one QE.
+ * - cos_strict: If set, return an error if there are insufficient ports in
+ *	class-of-service N to satisfy the num_ldb_ports_cosN argument. If
+ *	unset, attempt to fulfill num_ldb_ports_cosN arguments from other
+ *	classes-of-service if class N does not contain enough free ports.
+ * - padding1: Reserved for future use.
+ *
+ * Output parameters:
+ * - response.status: Detailed error code. In certain cases, such as if the
+ *	ioctl request arg is invalid, the driver won't set status.
+ * - response.id: domain ID.
+ * - domain_fd: file descriptor for performing the domain's ioctl operations
+ * - padding0: Reserved for future use.
+ */
+struct dlb_create_sched_domain_args {
+	/* Output parameters */
+	struct dlb_cmd_response response;
+	__u32 domain_fd;
+	__u32 padding0;
+	/* Input parameters */
+	__u32 num_ldb_queues;
+	__u32 num_ldb_ports;
+	__u32 num_cos_ldb_ports[4];
+	__u32 num_dir_ports;
+	__u32 num_atomic_inflights;
+	__u32 num_hist_list_entries;
+	__u32 num_ldb_credits;
+	__u32 num_dir_credits;
+	__u8 cos_strict;
+	__u8 padding1[3];
+};
+
+/*
+ * DLB_CMD_GET_NUM_RESOURCES: Return the number of available resources
+ *	(queues, ports, etc.) that this device owns.
+ *
+ * Output parameters:
+ * - num_domains: Number of available scheduling domains.
+ * - num_ldb_queues: Number of available load-balanced queues.
+ * - num_ldb_ports: Total number of available load-balanced ports.
+ * - num_cos_ldb_ports[4]: Number of available load-balanced ports from
+ *	classes-of-service 0-3.
+ * - num_dir_ports: Number of available directed ports. There is one directed
+ *	queue for every directed port.
+ * - num_atomic_inflights: Amount of available temporary atomic QE storage.
+ * - num_hist_list_entries: Amount of history list storage.
+ * - max_contiguous_hist_list_entries: History list storage is allocated in
+ *	a contiguous chunk, and this return value is the longest available
+ *	contiguous range of history list entries.
+ * - num_ldb_credits: Amount of available load-balanced QE storage.
+ * - num_dir_credits: Amount of available directed QE storage.
+ * - response.status: Detailed error code. In certain cases, such as if the
+ *	ioctl request arg is invalid, the driver won't set status.
+ */
+struct dlb_get_num_resources_args {
+	/* Output parameters */
+	struct dlb_cmd_response response;
+	__u32 num_sched_domains;
+	__u32 num_ldb_queues;
+	__u32 num_ldb_ports;
+	__u32 num_cos_ldb_ports[4];
+	__u32 num_dir_ports;
+	__u32 num_atomic_inflights;
+	__u32 num_hist_list_entries;
+	__u32 max_contiguous_hist_list_entries;
+	__u32 num_ldb_credits;
+	__u32 num_dir_credits;
+};
+
+enum dlb_user_interface_commands {
+	DLB_CMD_GET_DEVICE_VERSION,
+	DLB_CMD_CREATE_SCHED_DOMAIN,
+	DLB_CMD_GET_NUM_RESOURCES,
+
+	/* NUM_DLB_CMD must be last */
+	NUM_DLB_CMD,
+};
+
+/********************/
+/* dlb ioctl codes */
+/********************/
+
+#define DLB_IOC_MAGIC  'h'
+
+#define DLB_IOC_GET_DEVICE_VERSION				\
+		_IOR(DLB_IOC_MAGIC,				\
+		     DLB_CMD_GET_DEVICE_VERSION,		\
+		     struct dlb_get_device_version_args)
+#define DLB_IOC_CREATE_SCHED_DOMAIN				\
+		_IOWR(DLB_IOC_MAGIC,				\
+		      DLB_CMD_CREATE_SCHED_DOMAIN,		\
+		      struct dlb_create_sched_domain_args)
+#define DLB_IOC_GET_NUM_RESOURCES				\
+		_IOR(DLB_IOC_MAGIC,				\
+		     DLB_CMD_GET_NUM_RESOURCES,			\
+		     struct dlb_get_num_resources_args)
+
+#endif /* __DLB_H */
-- 
2.17.1

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