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 void panfrost_gem_purge(struct drm_gem_object *obj) 40 { 41 struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); 42 mutex_lock(&shmem->pages_lock); 43 44 panfrost_mmu_unmap(to_panfrost_bo(obj)); 45 drm_gem_shmem_purge_locked(obj); 46 47 mutex_unlock(&shmem->pages_lock); 48 } 49 50 static unsigned long 51 panfrost_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) 52 { 53 struct panfrost_device *pfdev = 54 container_of(shrinker, struct panfrost_device, shrinker); 55 struct drm_gem_shmem_object *shmem, *tmp; 56 unsigned long freed = 0; 57 58 if (!mutex_trylock(&pfdev->shrinker_lock)) 59 return SHRINK_STOP; 60 61 list_for_each_entry_safe(shmem, tmp, &pfdev->shrinker_list, madv_list) { 62 if (freed >= sc->nr_to_scan) 63 break; 64 if (drm_gem_shmem_is_purgeable(shmem)) { 65 panfrost_gem_purge(&shmem->base); 66 freed += shmem->base.size >> PAGE_SHIFT; 67 list_del_init(&shmem->madv_list); 68 } 69 } 70 71 mutex_unlock(&pfdev->shrinker_lock); 72 73 if (freed > 0) 74 pr_info_ratelimited("Purging %lu bytes\n", freed << PAGE_SHIFT); 75 76 return freed; 77 } 78 79 /** 80 * panfrost_gem_shrinker_init - Initialize panfrost shrinker 81 * @dev: DRM device 82 * 83 * This function registers and sets up the panfrost shrinker. 84 */ 85 void panfrost_gem_shrinker_init(struct drm_device *dev) 86 { 87 struct panfrost_device *pfdev = dev->dev_private; 88 pfdev->shrinker.count_objects = panfrost_gem_shrinker_count; 89 pfdev->shrinker.scan_objects = panfrost_gem_shrinker_scan; 90 pfdev->shrinker.seeks = DEFAULT_SEEKS; 91 WARN_ON(register_shrinker(&pfdev->shrinker)); 92 } 93 94 /** 95 * panfrost_gem_shrinker_cleanup - Clean up panfrost shrinker 96 * @dev: DRM device 97 * 98 * This function unregisters the panfrost shrinker. 99 */ 100 void panfrost_gem_shrinker_cleanup(struct drm_device *dev) 101 { 102 struct panfrost_device *pfdev = dev->dev_private; 103 104 if (pfdev->shrinker.nr_deferred) { 105 unregister_shrinker(&pfdev->shrinker); 106 } 107 } 108