drivers/gpu/drm/xe/xe_vram_freq.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/xe/xe_vram_freq.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/xe/xe_vram_freq.c
Extension
.c
Size
3001 bytes
Lines
124
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: MIT
/*
 * Copyright © 2024 Intel Corporation
 */
#include <linux/sysfs.h>
#include <drm/drm_managed.h>

#include "xe_device_types.h"
#include "xe_pcode.h"
#include "xe_pcode_api.h"
#include "xe_tile_sysfs.h"
#include "xe_vram_freq.h"

/**
 * DOC: Xe VRAM freq
 *
 * Provides sysfs entries for vram frequency in tile
 *
 * device/tile#/memory/freq0/max_freq - This is maximum frequency. This value is read-only as it
 *					is the fixed fuse point P0. It is not the system
 *					configuration.
 * device/tile#/memory/freq0/min_freq - This is minimum frequency. This value is read-only as it
 *					is the fixed fuse point PN. It is not the system
 *					configuration.
 */

static struct xe_tile *dev_to_tile(struct device *dev)
{
	return kobj_to_tile(dev->kobj.parent);
}

static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct xe_tile *tile = dev_to_tile(dev);
	u32 val = 0, mbox;
	int err;

	mbox = REG_FIELD_PREP(PCODE_MB_COMMAND, PCODE_FREQUENCY_CONFIG)
		| REG_FIELD_PREP(PCODE_MB_PARAM1, PCODE_MBOX_FC_SC_READ_FUSED_P0)
		| REG_FIELD_PREP(PCODE_MB_PARAM2, PCODE_MBOX_DOMAIN_HBM);

	err = xe_pcode_read(tile, mbox, &val, NULL);
	if (err)
		return err;

	/* data_out - Fused P0 for domain ID in units of 50 MHz */
	val *= 50;

	return sysfs_emit(buf, "%u\n", val);
}
static DEVICE_ATTR_RO(max_freq);

static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct xe_tile *tile = dev_to_tile(dev);
	u32 val = 0, mbox;
	int err;

	mbox = REG_FIELD_PREP(PCODE_MB_COMMAND, PCODE_FREQUENCY_CONFIG)
		| REG_FIELD_PREP(PCODE_MB_PARAM1, PCODE_MBOX_FC_SC_READ_FUSED_PN)
		| REG_FIELD_PREP(PCODE_MB_PARAM2, PCODE_MBOX_DOMAIN_HBM);

	err = xe_pcode_read(tile, mbox, &val, NULL);
	if (err)
		return err;

	/* data_out - Fused Pn for domain ID in units of 50 MHz */
	val *= 50;

	return sysfs_emit(buf, "%u\n", val);
}
static DEVICE_ATTR_RO(min_freq);

static struct attribute *freq_attrs[] = {
	&dev_attr_max_freq.attr,
	&dev_attr_min_freq.attr,
	NULL
};

static const struct attribute_group freq_group_attrs = {
	.name = "freq0",
	.attrs = freq_attrs,
};

static void vram_freq_sysfs_fini(void *arg)
{
	struct kobject *kobj = arg;

Annotation

Implementation Notes