1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2016 Red Hat 4 * Author: Rob Clark <robdclark@gmail.com> 5 */ 6 7 #include <linux/vmalloc.h> 8 #include <linux/sched/mm.h> 9 10 #include "msm_drv.h" 11 #include "msm_gem.h" 12 #include "msm_gpu.h" 13 #include "msm_gpu_trace.h" 14 15 /* Default disabled for now until it has some more testing on the different 16 * iommu combinations that can be paired with the driver: 17 */ 18 static bool enable_eviction = false; 19 MODULE_PARM_DESC(enable_eviction, "Enable swappable GEM buffers"); 20 module_param(enable_eviction, bool, 0600); 21 22 static bool can_swap(void) 23 { 24 return enable_eviction && get_nr_swap_pages() > 0; 25 } 26 27 static bool can_block(struct shrink_control *sc) 28 { 29 if (!(sc->gfp_mask & __GFP_DIRECT_RECLAIM)) 30 return false; 31 return current_is_kswapd() || (sc->gfp_mask & __GFP_RECLAIM); 32 } 33 34 static unsigned long 35 msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc) 36 { 37 struct msm_drm_private *priv = 38 container_of(shrinker, struct msm_drm_private, shrinker); 39 unsigned count = priv->lru.dontneed.count; 40 41 if (can_swap()) 42 count += priv->lru.willneed.count; 43 44 return count; 45 } 46 47 static bool 48 purge(struct drm_gem_object *obj) 49 { 50 if (!is_purgeable(to_msm_bo(obj))) 51 return false; 52 53 if (msm_gem_active(obj)) 54 return false; 55 56 msm_gem_purge(obj); 57 58 return true; 59 } 60 61 static bool 62 evict(struct drm_gem_object *obj) 63 { 64 if (is_unevictable(to_msm_bo(obj))) 65 return false; 66 67 if (msm_gem_active(obj)) 68 return false; 69 70 msm_gem_evict(obj); 71 72 return true; 73 } 74 75 static bool 76 wait_for_idle(struct drm_gem_object *obj) 77 { 78 enum dma_resv_usage usage = dma_resv_usage_rw(true); 79 return dma_resv_wait_timeout(obj->resv, usage, false, 1000) > 0; 80 } 81 82 static bool 83 active_purge(struct drm_gem_object *obj) 84 { 85 if (!wait_for_idle(obj)) 86 return false; 87 88 return purge(obj); 89 } 90 91 static bool 92 active_evict(struct drm_gem_object *obj) 93 { 94 if (!wait_for_idle(obj)) 95 return false; 96 97 return evict(obj); 98 } 99 100 static unsigned long 101 msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) 102 { 103 struct msm_drm_private *priv = 104 container_of(shrinker, struct msm_drm_private, shrinker); 105 struct { 106 struct drm_gem_lru *lru; 107 bool (*shrink)(struct drm_gem_object *obj); 108 bool cond; 109 unsigned long freed; 110 } stages[] = { 111 /* Stages of progressively more aggressive/expensive reclaim: */ 112 { &priv->lru.dontneed, purge, true }, 113 { &priv->lru.willneed, evict, can_swap() }, 114 { &priv->lru.dontneed, active_purge, can_block(sc) }, 115 { &priv->lru.willneed, active_evict, can_swap() && can_block(sc) }, 116 }; 117 long nr = sc->nr_to_scan; 118 unsigned long freed = 0; 119 120 for (unsigned i = 0; (nr > 0) && (i < ARRAY_SIZE(stages)); i++) { 121 if (!stages[i].cond) 122 continue; 123 stages[i].freed = 124 drm_gem_lru_scan(stages[i].lru, nr, stages[i].shrink); 125 nr -= stages[i].freed; 126 freed += stages[i].freed; 127 } 128 129 if (freed) { 130 trace_msm_gem_shrink(sc->nr_to_scan, stages[0].freed, 131 stages[1].freed, stages[2].freed, 132 stages[3].freed); 133 } 134 135 return (freed > 0) ? freed : SHRINK_STOP; 136 } 137 138 #ifdef CONFIG_DEBUG_FS 139 unsigned long 140 msm_gem_shrinker_shrink(struct drm_device *dev, unsigned long nr_to_scan) 141 { 142 struct msm_drm_private *priv = dev->dev_private; 143 struct shrink_control sc = { 144 .nr_to_scan = nr_to_scan, 145 }; 146 int ret; 147 148 fs_reclaim_acquire(GFP_KERNEL); 149 ret = msm_gem_shrinker_scan(&priv->shrinker, &sc); 150 fs_reclaim_release(GFP_KERNEL); 151 152 return ret; 153 } 154 #endif 155 156 /* since we don't know any better, lets bail after a few 157 * and if necessary the shrinker will be invoked again. 158 * Seems better than unmapping *everything* 159 */ 160 static const int vmap_shrink_limit = 15; 161 162 static bool 163 vmap_shrink(struct drm_gem_object *obj) 164 { 165 if (!is_vunmapable(to_msm_bo(obj))) 166 return false; 167 168 msm_gem_vunmap(obj); 169 170 return true; 171 } 172 173 static int 174 msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr) 175 { 176 struct msm_drm_private *priv = 177 container_of(nb, struct msm_drm_private, vmap_notifier); 178 struct drm_gem_lru *lrus[] = { 179 &priv->lru.dontneed, 180 &priv->lru.willneed, 181 &priv->lru.pinned, 182 NULL, 183 }; 184 unsigned idx, unmapped = 0; 185 186 for (idx = 0; lrus[idx] && unmapped < vmap_shrink_limit; idx++) { 187 unmapped += drm_gem_lru_scan(lrus[idx], 188 vmap_shrink_limit - unmapped, 189 vmap_shrink); 190 } 191 192 *(unsigned long *)ptr += unmapped; 193 194 if (unmapped > 0) 195 trace_msm_gem_purge_vmaps(unmapped); 196 197 return NOTIFY_DONE; 198 } 199 200 /** 201 * msm_gem_shrinker_init - Initialize msm shrinker 202 * @dev: drm device 203 * 204 * This function registers and sets up the msm shrinker. 205 */ 206 void msm_gem_shrinker_init(struct drm_device *dev) 207 { 208 struct msm_drm_private *priv = dev->dev_private; 209 priv->shrinker.count_objects = msm_gem_shrinker_count; 210 priv->shrinker.scan_objects = msm_gem_shrinker_scan; 211 priv->shrinker.seeks = DEFAULT_SEEKS; 212 WARN_ON(register_shrinker(&priv->shrinker, "drm-msm_gem")); 213 214 priv->vmap_notifier.notifier_call = msm_gem_shrinker_vmap; 215 WARN_ON(register_vmap_purge_notifier(&priv->vmap_notifier)); 216 } 217 218 /** 219 * msm_gem_shrinker_cleanup - Clean up msm shrinker 220 * @dev: drm device 221 * 222 * This function unregisters the msm shrinker. 223 */ 224 void msm_gem_shrinker_cleanup(struct drm_device *dev) 225 { 226 struct msm_drm_private *priv = dev->dev_private; 227 228 if (priv->shrinker.nr_deferred) { 229 WARN_ON(unregister_vmap_purge_notifier(&priv->vmap_notifier)); 230 unregister_shrinker(&priv->shrinker); 231 } 232 } 233