crypto: qat - add rate limiting sysfs interface

Add an interface for the rate limiting feature which allows to add,
remove and modify a QAT SLA (Service Level Agreement).

This adds a new sysfs attribute group, `qat_rl`, which can be accessed
from /sys/bus/pci/devices/<BUS:DEV:FUNCTION> with the following
hierarchy:
|-+ qat_rl
|---- id (RW) # SLA identifier
|---- cir (RW) # Committed Information Rate
|---- pir (RW) # Peak Information Rate
|---- srv (RW) # Service to be rate limited
|---- rp (RW) (HEX) # Ring pairs to be rate limited
|---- cap_rem (RW) # Remaining capability for a service
|---- sla_op (WO) # Allows to perform an operation on an SLA

The API works by setting the appropriate RW attributes and then
issuing a command through the `sla_op`. For example, to create an SLA, a
user needs to input the necessary data into the attributes cir, pir, srv
and rp and then write into `sla_op` the command `add` to execute the
operation.
The API also provides `cap_rem` attribute to get information about
the remaining device capability within a certain service which is
required when setting an SLA.

Signed-off-by: Ciunas Bennett <[e-mail]>
Reviewed-by: Giovanni Cabiddu <[e-mail]>
Reviewed-by: Damian Muszynski <[e-mail]>
Reviewed-by: Tero Kristo <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

Documentation/ABI/testing/sysfs-driver-qat_rl

···
+What:		/sys/bus/pci/devices/<BDF>/qat_rl/sla_op
+Date:		January 2024
+KernelVersion:	6.7
+Contact:	[e-mail]
+Description:
+		(WO) This attribute is used to perform an operation on an SLA.
+		The supported operations are: add, update, rm, rm_all, and get.
+
+		Input values must be filled through the associated attribute in
+		this group before a write to this file.
+		If the operation completes successfully, the associated
+		attributes will be updated.
+		The associated attributes are: cir, pir, srv, rp, and id.
+
+		Supported operations:
+
+		* add: Creates a new SLA with the provided inputs from user.
+			* Inputs: cir, pir, srv, and rp
+			* Output: id
+
+		* get: Returns the configuration of the specified SLA in id attribute
+			* Inputs: id
+			* Outputs: cir, pir, srv, and rp
+
+		* update: Updates the SLA with new values set in the following attributes
+			* Inputs: id, cir, and pir
+
+		* rm: Removes the specified SLA in the id attribute.
+			* Inputs: id
+
+		* rm_all: Removes all the configured SLAs.
+			* Inputs: None
+
+		This attribute is only available for qat_4xxx devices.
+
+What:		/sys/bus/pci/devices/<BDF>/qat_rl/rp
+Date:		January 2024
+KernelVersion:	6.7
+Contact:	[e-mail]
+Description:
+		(RW) When read, reports the current assigned ring pairs for the
+		queried SLA.
+		When wrote to, configures the ring pairs associated to a new SLA.
+
+		The value is a 64-bit bit mask and is written/displayed in hex.
+		Each bit of this mask represents a single ring pair i.e.,
+		bit 1 == ring pair id 0; bit 3 == ring pair id 2.
+
+		Selected ring pairs must to be assigned to a single service,
+		i.e. the one provided with the srv attribute. The service
+		assigned to a certain ring pair can be checked by querying
+		the attribute qat/rp2srv.
+
+		The maximum number of ring pairs is 4 per SLA.
+
+		Applicability in sla_op:
+
+		* WRITE: add operation
+		* READ: get operation
+
+		Example usage::
+
+			## Read
+			# echo 4 > /sys/bus/pci/devices/<BDF>/qat_rl/id
+			# cat /sys/bus/pci/devices/<BDF>/qat_rl/rp
+			0x5
+
+			## Write
+			# echo 0x5 > /sys/bus/pci/devices/<BDF>/qat_rl/rp
+
+		This attribute is only available for qat_4xxx devices.
+
+What:		/sys/bus/pci/devices/<BDF>/qat_rl/id
+Date:		January 2024
+KernelVersion:	6.7
+Contact:	[e-mail]
+Description:
+		(RW) If written to, the value is used to retrieve a particular
+		SLA and operate on it.
+		This is valid only for the following operations: update, rm,
+		and get.
+		A read of this attribute is only guaranteed to have correct data
+		after creation of an SLA.
+
+		Applicability in sla_op:
+
+		* WRITE: rm and update operations
+		* READ: add and get operations
+
+		Example usage::
+
+			## Read
+			## Set attributes e.g. cir, pir, srv, etc
+			# echo "add" > /sys/bus/pci/devices/<BDF>/qat_rl/sla_op
+			# cat /sys/bus/pci/devices/<BDF>/qat_rl/id
+			4
+
+			## Write
+			# echo 7 > /sys/bus/pci/devices/<BDF>/qat_rl/id
+			# echo "get" > /sys/bus/pci/devices/<BDF>/qat_rl/sla_op
+			# cat /sys/bus/pci/devices/<BDF>/qat_rl/rp
+			0x5  ## ring pair ID 0 and ring pair ID 2
+
+		This attribute is only available for qat_4xxx devices.
+
+What:		/sys/bus/pci/devices/<BDF>/qat_rl/cir
+Date:		January 2024
+KernelVersion:	6.7
+Contact:	[e-mail]
+Description:
+		(RW) Committed information rate (CIR). Rate guaranteed to be
+		achieved by a particular SLA. The value is expressed in
+		permille scale, i.e. 1000 refers to the maximum device
+		throughput for a selected service.
+
+		After sending a "get" to sla_op, this will be populated with the
+		CIR for that queried SLA.
+		Write to this file before sending an "add/update" sla_op, to set
+		the SLA to the specified value.
+
+		Applicability in sla_op:
+
+		* WRITE: add and update operations
+		* READ: get operation
+
+		Example usage::
+
+			## Write
+			# echo 500 > /sys/bus/pci/devices/<BDF>/qat_rl/cir
+			# echo "add" /sys/bus/pci/devices/<BDF>/qat_rl/sla_op
+
+			## Read
+			# echo 4 > /sys/bus/pci/devices/<BDF>/qat_rl/id
+			# echo "get" > /sys/bus/pci/devices/<BDF>/qat_rl/sla_op
+			# cat /sys/bus/pci/devices/<BDF>/qat_rl/cir
+			500
+
+		This attribute is only available for qat_4xxx devices.
+
+What:		/sys/bus/pci/devices/<BDF>/qat_rl/pir
+Date:		January 2024
+KernelVersion:	6.7
+Contact:	[e-mail]
+Description:
+		(RW) Peak information rate (PIR). The maximum rate that can be
+		achieved by that particular SLA. An SLA can reach a value
+		between CIR and PIR when the device is not fully utilized by
+		requests from other users (assigned to different SLAs).
+
+		After sending a "get" to sla_op, this will be populated with the
+		PIR for that queried SLA.
+		Write to this file before sending an "add/update" sla_op, to set
+		the SLA to the specified value.
+
+		Applicability in sla_op:
+
+		* WRITE: add and update operations
+		* READ: get operation
+
+		Example usage::
+
+			## Write
+			# echo 750 > /sys/bus/pci/devices/<BDF>/qat_rl/pir
+			# echo "add" > /sys/bus/pci/devices/<BDF>/qat_rl/sla_op
+
+			## Read
+			# echo 4 > /sys/bus/pci/devices/<BDF>/qat_rl/id
+			# echo "get" > /sys/bus/pci/devices/<BDF>/qat_rl/sla_op
+			# cat /sys/bus/pci/devices/<BDF>/qat_rl/pir
+			750
+
+		This attribute is only available for qat_4xxx devices.
+
+What:		/sys/bus/pci/devices/<BDF>/qat_rl/srv
+Date:		January 2024
+KernelVersion:	6.7
+Contact:	[e-mail]
+Description:
+		(RW) Service (SRV). Represents the service (sym, asym, dc)
+		associated to an SLA.
+		Can be written to or queried to set/show the SRV type for an SLA.
+		The SRV attribute is used to specify the SRV type before adding
+		an SLA. After an SLA is configured, reports the service
+		associated to that SLA.
+
+		Applicability in sla_op:
+
+		* WRITE: add and update operations
+		* READ: get operation
+
+		Example usage::
+
+			## Write
+			# echo "dc" > /sys/bus/pci/devices/<BDF>/qat_rl/srv
+			# echo "add" > /sys/bus/pci/devices/<BDF>/qat_rl/sla_op
+			# cat /sys/bus/pci/devices/<BDF>/qat_rl/id
+			4
+
+			## Read
+			# echo 4 > /sys/bus/pci/devices/<BDF>/qat_rl/id
+			# echo "get" > /sys/bus/pci/devices/<BDF>/qat_rl/sla_op
+			# cat /sys/bus/pci/devices/<BDF>/qat_rl/srv
+			dc
+
+		This attribute is only available for qat_4xxx devices.
+
+What:		/sys/bus/pci/devices/<BDF>/qat_rl/cap_rem
+Date:		January 2024
+KernelVersion:	6.7
+Contact:	[e-mail]
+Description:
+		(RW) This file will return the remaining capability for a
+		particular service/sla. This is the remaining value that a new
+		SLA can be set to or a current SLA can be increased with.
+
+		Example usage::
+
+			# echo "asym" > /sys/bus/pci/devices/<BDF>/qat_rl/cap_rem
+			# cat /sys/bus/pci/devices/<BDF>/qat_rl/cap_rem
+			250
+			# echo 250 > /sys/bus/pci/devices/<BDF>/qat_rl/cir
+			# echo "add" > /sys/bus/pci/devices/<BDF>/qat_rl/sla_op
+			# cat /sys/bus/pci/devices/<BDF>/qat_rl/cap_rem
+			0
+
+		This attribute is only available for qat_4xxx devices.

drivers/crypto/intel/qat/qat_common/Makefile

···
 	qat_algs_send.o \
 	adf_rl.o \
 	adf_rl_admin.o \
+	adf_sysfs_rl.o \
 	qat_uclo.o \
 	qat_hal.o \
 	qat_bl.o

drivers/crypto/intel/qat/qat_common/adf_rl.c

···
 #include "adf_common_drv.h"
 #include "adf_rl_admin.h"
 #include "adf_rl.h"
+#include "adf_sysfs_rl.h"
 
 #define RL_TOKEN_GRANULARITY_PCIEIN_BUCKET	0U
 #define RL_TOKEN_GRANULARITY_PCIEOUT_BUCKET	0U
···
 		goto ret_sla_rm;
 	}
 
+	ret = adf_sysfs_rl_add(accel_dev);
+	if (ret) {
+		dev_err(&GET_DEV(accel_dev), "failed to add sysfs interface\n");
+		goto ret_sysfs_rm;
+	}
+
 	return 0;
 
+ret_sysfs_rm:
+	adf_sysfs_rl_rm(accel_dev);
 ret_sla_rm:
 	adf_rl_remove_sla_all(accel_dev, true);
 ret_free:
···
 	if (!accel_dev->rate_limiting)
 		return;
 
+	adf_sysfs_rl_rm(accel_dev);
 	adf_rl_remove_sla_all(accel_dev, true);
 }
 

drivers/crypto/intel/qat/qat_common/adf_rl.h

···
 	u8 cph_cnt;
 };
 
+struct adf_rl_interface_data {
+	struct adf_rl_sla_input_data input;
+	enum adf_base_services cap_rem_srv;
+	struct rw_semaphore lock;
+};
+
 struct adf_rl_hw_data {
 	u32 scale_ref;
 	u32 scan_interval;
···
 	bool rp_in_use[RL_RP_CNT_MAX];
 	/* Mutex protecting writing to SLAs lists */
 	struct mutex rl_lock;
+	struct adf_rl_interface_data user_input;
 };
 
 /**

drivers/crypto/intel/qat/qat_common/adf_sysfs_rl.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2023 Intel Corporation */
+
+#define dev_fmt(fmt) "RateLimiting: " fmt
+
+#include <linux/dev_printk.h>
+#include <linux/pci.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#include "adf_common_drv.h"
+#include "adf_rl.h"
+#include "adf_sysfs_rl.h"
+
+#define GET_RL_STRUCT(accel_dev) ((accel_dev)->rate_limiting->user_input)
+
+enum rl_ops {
+	ADD,
+	UPDATE,
+	RM,
+	RM_ALL,
+	GET,
+};
+
+enum rl_params {
+	RP_MASK,
+	ID,
+	CIR,
+	PIR,
+	SRV,
+	CAP_REM_SRV,
+};
+
+static const char *const rl_services[] = {
+	[ADF_SVC_ASYM] = "asym",
+	[ADF_SVC_SYM] = "sym",
+	[ADF_SVC_DC] = "dc",
+};
+
+static const char *const rl_operations[] = {
+	[ADD] = "add",
+	[UPDATE] = "update",
+	[RM] = "rm",
+	[RM_ALL] = "rm_all",
+	[GET] = "get",
+};
+
+static int set_param_u(struct device *dev, enum rl_params param, u64 set)
+{
+	struct adf_rl_interface_data *data;
+	struct adf_accel_dev *accel_dev;
+	int ret = 0;
+
+	accel_dev = adf_devmgr_pci_to_accel_dev(to_pci_dev(dev));
+	if (!accel_dev)
+		return -EINVAL;
+
+	data = &GET_RL_STRUCT(accel_dev);
+
+	down_write(&data->lock);
+	switch (param) {
+	case RP_MASK:
+		data->input.rp_mask = set;
+		break;
+	case CIR:
+		data->input.cir = set;
+		break;
+	case PIR:
+		data->input.pir = set;
+		break;
+	case SRV:
+		data->input.srv = set;
+		break;
+	case CAP_REM_SRV:
+		data->cap_rem_srv = set;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	up_write(&data->lock);
+
+	return ret;
+}
+
+static int set_param_s(struct device *dev, enum rl_params param, int set)
+{
+	struct adf_rl_interface_data *data;
+	struct adf_accel_dev *accel_dev;
+
+	accel_dev = adf_devmgr_pci_to_accel_dev(to_pci_dev(dev));
+	if (!accel_dev || param != ID)
+		return -EINVAL;
+
+	data = &GET_RL_STRUCT(accel_dev);
+
+	down_write(&data->lock);
+	data->input.sla_id = set;
+	up_write(&data->lock);
+
+	return 0;
+}
+
+static int get_param_u(struct device *dev, enum rl_params param, u64 *get)
+{
+	struct adf_rl_interface_data *data;
+	struct adf_accel_dev *accel_dev;
+	int ret = 0;
+
+	accel_dev = adf_devmgr_pci_to_accel_dev(to_pci_dev(dev));
+	if (!accel_dev)
+		return -EINVAL;
+
+	data = &GET_RL_STRUCT(accel_dev);
+
+	down_read(&data->lock);
+	switch (param) {
+	case RP_MASK:
+		*get = data->input.rp_mask;
+		break;
+	case CIR:
+		*get = data->input.cir;
+		break;
+	case PIR:
+		*get = data->input.pir;
+		break;
+	case SRV:
+		*get = data->input.srv;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	up_read(&data->lock);
+
+	return ret;
+}
+
+static int get_param_s(struct device *dev, enum rl_params param)
+{
+	struct adf_rl_interface_data *data;
+	struct adf_accel_dev *accel_dev;
+	int ret = 0;
+
+	accel_dev = adf_devmgr_pci_to_accel_dev(to_pci_dev(dev));
+	if (!accel_dev)
+		return -EINVAL;
+
+	data = &GET_RL_STRUCT(accel_dev);
+
+	down_read(&data->lock);
+	if (param == ID)
+		ret = data->input.sla_id;
+	up_read(&data->lock);
+
+	return ret;
+}
+
+static ssize_t rp_show(struct device *dev, struct device_attribute *attr,
+		       char *buf)
+{
+	int ret;
+	u64 get;
+
+	ret = get_param_u(dev, RP_MASK, &get);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%#llx\n", get);
+}
+
+static ssize_t rp_store(struct device *dev, struct device_attribute *attr,
+			const char *buf, size_t count)
+{
+	int err;
+	u64 val;
+
+	err = kstrtou64(buf, 16, &val);
+	if (err)
+		return err;
+
+	err = set_param_u(dev, RP_MASK, val);
+	if (err)
+		return err;
+
+	return count;
+}
+static DEVICE_ATTR_RW(rp);
+
+static ssize_t id_show(struct device *dev, struct device_attribute *attr,
+		       char *buf)
+{
+	return sysfs_emit(buf, "%d\n", get_param_s(dev, ID));
+}
+
+static ssize_t id_store(struct device *dev, struct device_attribute *attr,
+			const char *buf, size_t count)
+{
+	int err;
+	int val;
+
+	err = kstrtoint(buf, 10, &val);
+	if (err)
+		return err;
+
+	err = set_param_s(dev, ID, val);
+	if (err)
+		return err;
+
+	return count;
+}
+static DEVICE_ATTR_RW(id);
+
+static ssize_t cir_show(struct device *dev, struct device_attribute *attr,
+			char *buf)
+{
+	int ret;
+	u64 get;
+
+	ret = get_param_u(dev, CIR, &get);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%llu\n", get);
+}
+
+static ssize_t cir_store(struct device *dev, struct device_attribute *attr,
+			 const char *buf, size_t count)
+{
+	unsigned int val;
+	int err;
+
+	err = kstrtouint(buf, 10, &val);
+	if (err)
+		return err;
+
+	err = set_param_u(dev, CIR, val);
+	if (err)
+		return err;
+
+	return count;
+}
+static DEVICE_ATTR_RW(cir);
+
+static ssize_t pir_show(struct device *dev, struct device_attribute *attr,
+			char *buf)
+{
+	int ret;
+	u64 get;
+
+	ret = get_param_u(dev, PIR, &get);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%llu\n", get);
+}
+
+static ssize_t pir_store(struct device *dev, struct device_attribute *attr,
+			 const char *buf, size_t count)
+{
+	unsigned int val;
+	int err;
+
+	err = kstrtouint(buf, 10, &val);
+	if (err)
+		return err;
+
+	err = set_param_u(dev, PIR, val);
+	if (err)
+		return err;
+
+	return count;
+}
+static DEVICE_ATTR_RW(pir);
+
+static ssize_t srv_show(struct device *dev, struct device_attribute *attr,
+			char *buf)
+{
+	int ret;
+	u64 get;
+
+	ret = get_param_u(dev, SRV, &get);
+	if (ret)
+		return ret;
+
+	if (get == ADF_SVC_NONE)
+		return -EINVAL;
+
+	return sysfs_emit(buf, "%s\n", rl_services[get]);
+}
+
+static ssize_t srv_store(struct device *dev, struct device_attribute *attr,
+			 const char *buf, size_t count)
+{
+	unsigned int val;
+	int ret;
+
+	ret = sysfs_match_string(rl_services, buf);
+	if (ret < 0)
+		return ret;
+
+	val = ret;
+	ret = set_param_u(dev, SRV, val);
+	if (ret)
+		return ret;
+
+	return count;
+}
+static DEVICE_ATTR_RW(srv);
+
+static ssize_t cap_rem_show(struct device *dev, struct device_attribute *attr,
+			    char *buf)
+{
+	struct adf_rl_interface_data *data;
+	struct adf_accel_dev *accel_dev;
+	int ret, rem_cap;
+
+	accel_dev = adf_devmgr_pci_to_accel_dev(to_pci_dev(dev));
+	if (!accel_dev)
+		return -EINVAL;
+
+	data = &GET_RL_STRUCT(accel_dev);
+
+	down_read(&data->lock);
+	rem_cap = adf_rl_get_capability_remaining(accel_dev, data->cap_rem_srv,
+						  RL_SLA_EMPTY_ID);
+	up_read(&data->lock);
+	if (rem_cap < 0)
+		return rem_cap;
+
+	ret = sysfs_emit(buf, "%u\n", rem_cap);
+
+	return ret;
+}
+
+static ssize_t cap_rem_store(struct device *dev, struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	unsigned int val;
+	int ret;
+
+	ret = sysfs_match_string(rl_services, buf);
+	if (ret < 0)
+		return ret;
+
+	val = ret;
+	ret = set_param_u(dev, CAP_REM_SRV, val);
+	if (ret)
+		return ret;
+
+	return count;
+}
+static DEVICE_ATTR_RW(cap_rem);
+
+static ssize_t sla_op_store(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct adf_rl_interface_data *data;
+	struct adf_accel_dev *accel_dev;
+	int ret;
+
+	accel_dev = adf_devmgr_pci_to_accel_dev(to_pci_dev(dev));
+	if (!accel_dev)
+		return -EINVAL;
+
+	data = &GET_RL_STRUCT(accel_dev);
+
+	ret = sysfs_match_string(rl_operations, buf);
+	if (ret < 0)
+		return ret;
+
+	down_write(&data->lock);
+	switch (ret) {
+	case ADD:
+		data->input.parent_id = RL_PARENT_DEFAULT_ID;
+		data->input.type = RL_LEAF;
+		data->input.sla_id = 0;
+		ret = adf_rl_add_sla(accel_dev, &data->input);
+		if (ret)
+			goto err_free_lock;
+		break;
+	case UPDATE:
+		ret = adf_rl_update_sla(accel_dev, &data->input);
+		if (ret)
+			goto err_free_lock;
+		break;
+	case RM:
+		ret = adf_rl_remove_sla(accel_dev, data->input.sla_id);
+		if (ret)
+			goto err_free_lock;
+		break;
+	case RM_ALL:
+		adf_rl_remove_sla_all(accel_dev, false);
+		break;
+	case GET:
+		ret = adf_rl_get_sla(accel_dev, &data->input);
+		if (ret)
+			goto err_free_lock;
+		break;
+	default:
+		ret = -EINVAL;
+		goto err_free_lock;
+	}
+	up_write(&data->lock);
+
+	return count;
+
+err_free_lock:
+	up_write(&data->lock);
+
+	return ret;
+}
+static DEVICE_ATTR_WO(sla_op);
+
+static struct attribute *qat_rl_attrs[] = {
+	&dev_attr_rp.attr,
+	&dev_attr_id.attr,
+	&dev_attr_cir.attr,
+	&dev_attr_pir.attr,
+	&dev_attr_srv.attr,
+	&dev_attr_cap_rem.attr,
+	&dev_attr_sla_op.attr,
+	NULL,
+};
+
+static struct attribute_group qat_rl_group = {
+	.attrs = qat_rl_attrs,
+	.name = "qat_rl",
+};
+
+int adf_sysfs_rl_add(struct adf_accel_dev *accel_dev)
+{
+	struct adf_rl_interface_data *data;
+	int ret;
+
+	data = &GET_RL_STRUCT(accel_dev);
+
+	ret = device_add_group(&GET_DEV(accel_dev), &qat_rl_group);
+	if (ret)
+		dev_err(&GET_DEV(accel_dev),
+			"Failed to create qat_rl attribute group\n");
+
+	data->cap_rem_srv = ADF_SVC_NONE;
+	data->input.srv = ADF_SVC_NONE;
+
+	return ret;
+}
+
+void adf_sysfs_rl_rm(struct adf_accel_dev *accel_dev)
+{
+	device_remove_group(&GET_DEV(accel_dev), &qat_rl_group);
+}

drivers/crypto/intel/qat/qat_common/adf_sysfs_rl.h

···
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright(c) 2023 Intel Corporation */
+#ifndef ADF_SYSFS_RL_H_
+#define ADF_SYSFS_RL_H_
+
+struct adf_accel_dev;
+
+int adf_sysfs_rl_add(struct adf_accel_dev *accel_dev);
+void adf_sysfs_rl_rm(struct adf_accel_dev *accel_dev);
+
+#endif /* ADF_SYSFS_RL_H_ */