linux/drivers/gpu/drm/xe/xe_gt_freq.c

// SPDX-License-Identifier: MIT
/*
 * Copyright © 2023 Intel Corporation
 */

#include "xe_gt_freq.h"

#include <linux/kobject.h>
#include <linux/sysfs.h>

#include <drm/drm_managed.h>
#include <drm/drm_print.h>

#include "xe_device_types.h"
#include "xe_gt_sysfs.h"
#include "xe_gt_throttle.h"
#include "xe_guc_pc.h"
#include "xe_pm.h"

/**
 * DOC: Xe GT Frequency Management
 *
 * This component is responsible for the raw GT frequency management, including
 * the sysfs API.
 *
 * Underneath, Xe enables GuC SLPC automated frequency management. GuC is then
 * allowed to request PCODE any frequency between the Minimum and the Maximum
 * selected by this component. Furthermore, it is important to highlight that
 * PCODE is the ultimate decision maker of the actual running frequency, based
 * on thermal and other running conditions.
 *
 * Xe's Freq provides a sysfs API for frequency management:
 *
 * device/tile#/gt#/freq0/<item>_freq *read-only* files:
 * - act_freq: The actual resolved frequency decided by PCODE.
 * - cur_freq: The current one requested by GuC PC to the PCODE.
 * - rpn_freq: The Render Performance (RP) N level, which is the minimal one.
 * - rpe_freq: The Render Performance (RP) E level, which is the efficient one.
 * - rp0_freq: The Render Performance (RP) 0 level, which is the maximum one.
 *
 * device/tile#/gt#/freq0/<item>_freq *read-write* files:
 * - min_freq: Min frequency request.
 * - max_freq: Max frequency request.
 *             If max <= min, then freq_min becomes a fixed frequency request.
 */

static struct xe_guc_pc *
dev_to_pc(struct device *dev)
{ … }

static struct xe_device *
dev_to_xe(struct device *dev)
{ … }

static ssize_t act_freq_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{ … }
static DEVICE_ATTR_RO(act_freq);

static ssize_t cur_freq_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{ … }
static DEVICE_ATTR_RO(cur_freq);

static ssize_t rp0_freq_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{ … }
static DEVICE_ATTR_RO(rp0_freq);

static ssize_t rpe_freq_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{ … }
static DEVICE_ATTR_RO(rpe_freq);

static ssize_t rpn_freq_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{ … }
static DEVICE_ATTR_RO(rpn_freq);

static ssize_t min_freq_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{ … }

static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
			      const char *buff, size_t count)
{ … }
static DEVICE_ATTR_RW(min_freq);

static ssize_t max_freq_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{ … }

static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
			      const char *buff, size_t count)
{ … }
static DEVICE_ATTR_RW(max_freq);

static const struct attribute *freq_attrs[] = …;

static void freq_fini(void *arg)
{ … }

/**
 * xe_gt_freq_init - Initialize Xe Freq component
 * @gt: Xe GT object
 *
 * It needs to be initialized after GT Sysfs and GuC PC components are ready.
 *
 * Returns: Returns error value for failure and 0 for success.
 */
int xe_gt_freq_init(struct xe_gt *gt)
{ … }