linux_dsm_epyc7002/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
Rob Herring 013b651013 drm/panfrost: Add madvise and shrinker support
Add support for madvise and a shrinker similar to other drivers. This
allows userspace to mark BOs which can be freed when there is memory
pressure.

Unlike other implementations, we don't depend on struct_mutex. The
driver maintains a list of BOs which can be freed when the shrinker
is called. Access to the list is serialized with the shrinker_lock.

Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190805143358.21245-2-robh@kernel.org
2019-08-08 15:57:36 -06:00

108 lines
2.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (C) 2019 Arm Ltd.
*
* Based on msm_gem_freedreno.c:
* Copyright (C) 2016 Red Hat
* Author: Rob Clark <robdclark@gmail.com>
*/
#include <linux/list.h>
#include <drm/drm_device.h>
#include <drm/drm_gem_shmem_helper.h>
#include "panfrost_device.h"
#include "panfrost_gem.h"
#include "panfrost_mmu.h"
static unsigned long
panfrost_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
{
struct panfrost_device *pfdev =
container_of(shrinker, struct panfrost_device, shrinker);
struct drm_gem_shmem_object *shmem;
unsigned long count = 0;
if (!mutex_trylock(&pfdev->shrinker_lock))
return 0;
list_for_each_entry(shmem, &pfdev->shrinker_list, madv_list) {
if (drm_gem_shmem_is_purgeable(shmem))
count += shmem->base.size >> PAGE_SHIFT;
}
mutex_unlock(&pfdev->shrinker_lock);
return count;
}
static void panfrost_gem_purge(struct drm_gem_object *obj)
{
struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
mutex_lock(&shmem->pages_lock);
panfrost_mmu_unmap(to_panfrost_bo(obj));
drm_gem_shmem_purge_locked(obj);
mutex_unlock(&shmem->pages_lock);
}
static unsigned long
panfrost_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
{
struct panfrost_device *pfdev =
container_of(shrinker, struct panfrost_device, shrinker);
struct drm_gem_shmem_object *shmem, *tmp;
unsigned long freed = 0;
if (!mutex_trylock(&pfdev->shrinker_lock))
return SHRINK_STOP;
list_for_each_entry_safe(shmem, tmp, &pfdev->shrinker_list, madv_list) {
if (freed >= sc->nr_to_scan)
break;
if (drm_gem_shmem_is_purgeable(shmem)) {
panfrost_gem_purge(&shmem->base);
freed += shmem->base.size >> PAGE_SHIFT;
list_del_init(&shmem->madv_list);
}
}
mutex_unlock(&pfdev->shrinker_lock);
if (freed > 0)
pr_info_ratelimited("Purging %lu bytes\n", freed << PAGE_SHIFT);
return freed;
}
/**
* panfrost_gem_shrinker_init - Initialize panfrost shrinker
* @dev: DRM device
*
* This function registers and sets up the panfrost shrinker.
*/
void panfrost_gem_shrinker_init(struct drm_device *dev)
{
struct panfrost_device *pfdev = dev->dev_private;
pfdev->shrinker.count_objects = panfrost_gem_shrinker_count;
pfdev->shrinker.scan_objects = panfrost_gem_shrinker_scan;
pfdev->shrinker.seeks = DEFAULT_SEEKS;
WARN_ON(register_shrinker(&pfdev->shrinker));
}
/**
* panfrost_gem_shrinker_cleanup - Clean up panfrost shrinker
* @dev: DRM device
*
* This function unregisters the panfrost shrinker.
*/
void panfrost_gem_shrinker_cleanup(struct drm_device *dev)
{
struct panfrost_device *pfdev = dev->dev_private;
if (pfdev->shrinker.nr_deferred) {
unregister_shrinker(&pfdev->shrinker);
}
}