// 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 <[email protected]>
*/
#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 = shrinker->private_data;
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 bool panfrost_gem_purge(struct drm_gem_object *obj)
{
struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
struct panfrost_gem_object *bo = to_panfrost_bo(obj);
bool ret = false;
if (atomic_read(&bo->gpu_usecount))
return false;
if (!mutex_trylock(&bo->mappings.lock))
return false;
if (!dma_resv_trylock(shmem->base.resv))
goto unlock_mappings;
panfrost_gem_teardown_mappings_locked(bo);
drm_gem_shmem_purge(&bo->base);
ret = true;
dma_resv_unlock(shmem->base.resv);
unlock_mappings:
mutex_unlock(&bo->mappings.lock);
return ret;
}
static unsigned long
panfrost_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
{
struct panfrost_device *pfdev = shrinker->private_data;
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.
*/
int panfrost_gem_shrinker_init(struct drm_device *dev)
{
struct panfrost_device *pfdev = dev->dev_private;
pfdev->shrinker = shrinker_alloc(0, "drm-panfrost");
if (!pfdev->shrinker)
return -ENOMEM;
pfdev->shrinker->count_objects = panfrost_gem_shrinker_count;
pfdev->shrinker->scan_objects = panfrost_gem_shrinker_scan;
pfdev->shrinker->private_data = pfdev;
shrinker_register(pfdev->shrinker);
return 0;
}
/**
* 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)
shrinker_free(pfdev->shrinker);
}