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 18 static unsigned long 19 panfrost_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 39 static 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 bool ret = false; 44 45 if (atomic_read(&bo->gpu_usecount)) 46 return false; 47 48 if (!mutex_trylock(&bo->mappings.lock)) 49 return false; 50 51 if (!mutex_trylock(&shmem->pages_lock)) 52 goto unlock_mappings; 53 54 panfrost_gem_teardown_mappings_locked(bo); 55 drm_gem_shmem_purge_locked(&bo->base); 56 ret = true; 57 58 mutex_unlock(&shmem->pages_lock); 59 60 unlock_mappings: 61 mutex_unlock(&bo->mappings.lock); 62 return ret; 63 } 64 65 static unsigned long 66 panfrost_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) 67 { 68 struct panfrost_device *pfdev = 69 container_of(shrinker, struct panfrost_device, shrinker); 70 struct drm_gem_shmem_object *shmem, *tmp; 71 unsigned long freed = 0; 72 73 if (!mutex_trylock(&pfdev->shrinker_lock)) 74 return SHRINK_STOP; 75 76 list_for_each_entry_safe(shmem, tmp, &pfdev->shrinker_list, madv_list) { 77 if (freed >= sc->nr_to_scan) 78 break; 79 if (drm_gem_shmem_is_purgeable(shmem) && 80 panfrost_gem_purge(&shmem->base)) { 81 freed += shmem->base.size >> PAGE_SHIFT; 82 list_del_init(&shmem->madv_list); 83 } 84 } 85 86 mutex_unlock(&pfdev->shrinker_lock); 87 88 if (freed > 0) 89 pr_info_ratelimited("Purging %lu bytes\n", freed << PAGE_SHIFT); 90 91 return freed; 92 } 93 94 /** 95 * panfrost_gem_shrinker_init - Initialize panfrost shrinker 96 * @dev: DRM device 97 * 98 * This function registers and sets up the panfrost shrinker. 99 */ 100 void panfrost_gem_shrinker_init(struct drm_device *dev) 101 { 102 struct panfrost_device *pfdev = dev->dev_private; 103 pfdev->shrinker.count_objects = panfrost_gem_shrinker_count; 104 pfdev->shrinker.scan_objects = panfrost_gem_shrinker_scan; 105 pfdev->shrinker.seeks = DEFAULT_SEEKS; 106 WARN_ON(register_shrinker(&pfdev->shrinker)); 107 } 108 109 /** 110 * panfrost_gem_shrinker_cleanup - Clean up panfrost shrinker 111 * @dev: DRM device 112 * 113 * This function unregisters the panfrost shrinker. 114 */ 115 void panfrost_gem_shrinker_cleanup(struct drm_device *dev) 116 { 117 struct panfrost_device *pfdev = dev->dev_private; 118 119 if (pfdev->shrinker.nr_deferred) { 120 unregister_shrinker(&pfdev->shrinker); 121 } 122 } 123