LXR linux/drivers/gpu/drm/panfrost/panfrost_gem

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/* Copyright (C) 2019 Arm Ltd.
   3 *
   4 * Based on msm_gem_freedreno.c:
   5 * Copyright (C) 2016 Red Hat
   6 * Author: Rob Clark <robdclark@gmail.com>
   7 */
   8
   9#include <linux/list.h>
  10
  11#include <drm/drm_device.h>
  12#include <drm/drm_gem_shmem_helper.h>
  13
  14#include "panfrost_device.h"
  15#include "panfrost_gem.h"
  16#include "panfrost_mmu.h"
  17
  18static unsigned long
  19panfrost_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
  20{
  21        struct panfrost_device *pfdev =
  22                container_of(shrinker, struct panfrost_device, shrinker);
  23        struct drm_gem_shmem_object *shmem;
  24        unsigned long count = 0;
  25
  26        if (!mutex_trylock(&pfdev->shrinker_lock))
  27                return 0;
  28
  29        list_for_each_entry(shmem, &pfdev->shrinker_list, madv_list) {
  30                if (drm_gem_shmem_is_purgeable(shmem))
  31                        count += shmem->base.size >> PAGE_SHIFT;
  32        }
  33
  34        mutex_unlock(&pfdev->shrinker_lock);
  35
  36        return count;
  37}
  38
  39static bool panfrost_gem_purge(struct drm_gem_object *obj)
  40{
  41        struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
  42        struct panfrost_gem_object *bo = to_panfrost_bo(obj);
  43
  44        if (atomic_read(&bo->gpu_usecount))
  45                return false;
  46
  47        if (!mutex_trylock(&shmem->pages_lock))
  48                return false;
  49
  50        panfrost_gem_teardown_mappings(bo);
  51        drm_gem_shmem_purge_locked(obj);
  52
  53        mutex_unlock(&shmem->pages_lock);
  54        return true;
  55}
  56
  57static unsigned long
  58panfrost_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
  59{
  60        struct panfrost_device *pfdev =
  61                container_of(shrinker, struct panfrost_device, shrinker);
  62        struct drm_gem_shmem_object *shmem, *tmp;
  63        unsigned long freed = 0;
  64
  65        if (!mutex_trylock(&pfdev->shrinker_lock))
  66                return SHRINK_STOP;
  67
  68        list_for_each_entry_safe(shmem, tmp, &pfdev->shrinker_list, madv_list) {
  69                if (freed >= sc->nr_to_scan)
  70                        break;
  71                if (drm_gem_shmem_is_purgeable(shmem) &&
  72                    panfrost_gem_purge(&shmem->base)) {
  73                        freed += shmem->base.size >> PAGE_SHIFT;
  74                        list_del_init(&shmem->madv_list);
  75                }
  76        }
  77
  78        mutex_unlock(&pfdev->shrinker_lock);
  79
  80        if (freed > 0)
  81                pr_info_ratelimited("Purging %lu bytes\n", freed << PAGE_SHIFT);
  82
  83        return freed;
  84}
  85
  86/**
  87 * panfrost_gem_shrinker_init - Initialize panfrost shrinker
  88 * @dev: DRM device
  89 *
  90 * This function registers and sets up the panfrost shrinker.
  91 */
  92void panfrost_gem_shrinker_init(struct drm_device *dev)
  93{
  94        struct panfrost_device *pfdev = dev->dev_private;
  95        pfdev->shrinker.count_objects = panfrost_gem_shrinker_count;
  96        pfdev->shrinker.scan_objects = panfrost_gem_shrinker_scan;
  97        pfdev->shrinker.seeks = DEFAULT_SEEKS;
  98        WARN_ON(register_shrinker(&pfdev->shrinker));
  99}
 100
 101/**
 102 * panfrost_gem_shrinker_cleanup - Clean up panfrost shrinker
 103 * @dev: DRM device
 104 *
 105 * This function unregisters the panfrost shrinker.
 106 */
 107void panfrost_gem_shrinker_cleanup(struct drm_device *dev)
 108{
 109        struct panfrost_device *pfdev = dev->dev_private;
 110
 111        if (pfdev->shrinker.nr_deferred) {
 112                unregister_shrinker(&pfdev->shrinker);
 113        }
 114}
 115