1 /* 2 * Copyright © 2008-2010 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 * 23 * Authors: 24 * Eric Anholt <eric@anholt.net> 25 * Chris Wilson <chris@chris-wilson.co.uuk> 26 * 27 */ 28 29 #include <drm/drmP.h> 30 #include <drm/i915_drm.h> 31 32 #include "i915_drv.h" 33 #include "intel_drv.h" 34 #include "i915_trace.h" 35 36 static bool ggtt_is_idle(struct drm_i915_private *dev_priv) 37 { 38 struct i915_ggtt *ggtt = &dev_priv->ggtt; 39 struct intel_engine_cs *engine; 40 enum intel_engine_id id; 41 42 for_each_engine(engine, dev_priv, id) { 43 struct intel_timeline *tl; 44 45 tl = &ggtt->base.timeline.engine[engine->id]; 46 if (i915_gem_active_isset(&tl->last_request)) 47 return false; 48 } 49 50 return true; 51 } 52 53 static bool 54 mark_free(struct drm_mm_scan *scan, 55 struct i915_vma *vma, 56 unsigned int flags, 57 struct list_head *unwind) 58 { 59 if (i915_vma_is_pinned(vma)) 60 return false; 61 62 if (WARN_ON(!list_empty(&vma->exec_list))) 63 return false; 64 65 if (flags & PIN_NONFAULT && !list_empty(&vma->obj->userfault_link)) 66 return false; 67 68 list_add(&vma->exec_list, unwind); 69 return drm_mm_scan_add_block(scan, &vma->node); 70 } 71 72 /** 73 * i915_gem_evict_something - Evict vmas to make room for binding a new one 74 * @vm: address space to evict from 75 * @min_size: size of the desired free space 76 * @alignment: alignment constraint of the desired free space 77 * @cache_level: cache_level for the desired space 78 * @start: start (inclusive) of the range from which to evict objects 79 * @end: end (exclusive) of the range from which to evict objects 80 * @flags: additional flags to control the eviction algorithm 81 * 82 * This function will try to evict vmas until a free space satisfying the 83 * requirements is found. Callers must check first whether any such hole exists 84 * already before calling this function. 85 * 86 * This function is used by the object/vma binding code. 87 * 88 * Since this function is only used to free up virtual address space it only 89 * ignores pinned vmas, and not object where the backing storage itself is 90 * pinned. Hence obj->pages_pin_count does not protect against eviction. 91 * 92 * To clarify: This is for freeing up virtual address space, not for freeing 93 * memory in e.g. the shrinker. 94 */ 95 int 96 i915_gem_evict_something(struct i915_address_space *vm, 97 u64 min_size, u64 alignment, 98 unsigned cache_level, 99 u64 start, u64 end, 100 unsigned flags) 101 { 102 struct drm_i915_private *dev_priv = vm->i915; 103 struct drm_mm_scan scan; 104 struct list_head eviction_list; 105 struct list_head *phases[] = { 106 &vm->inactive_list, 107 &vm->active_list, 108 NULL, 109 }, **phase; 110 struct i915_vma *vma, *next; 111 struct drm_mm_node *node; 112 enum drm_mm_insert_mode mode; 113 int ret; 114 115 lockdep_assert_held(&vm->i915->drm.struct_mutex); 116 trace_i915_gem_evict(vm, min_size, alignment, flags); 117 118 /* 119 * The goal is to evict objects and amalgamate space in LRU order. 120 * The oldest idle objects reside on the inactive list, which is in 121 * retirement order. The next objects to retire are those in flight, 122 * on the active list, again in retirement order. 123 * 124 * The retirement sequence is thus: 125 * 1. Inactive objects (already retired) 126 * 2. Active objects (will stall on unbinding) 127 * 128 * On each list, the oldest objects lie at the HEAD with the freshest 129 * object on the TAIL. 130 */ 131 mode = DRM_MM_INSERT_BEST; 132 if (flags & PIN_HIGH) 133 mode = DRM_MM_INSERT_HIGH; 134 if (flags & PIN_MAPPABLE) 135 mode = DRM_MM_INSERT_LOW; 136 drm_mm_scan_init_with_range(&scan, &vm->mm, 137 min_size, alignment, cache_level, 138 start, end, mode); 139 140 /* Retire before we search the active list. Although we have 141 * reasonable accuracy in our retirement lists, we may have 142 * a stray pin (preventing eviction) that can only be resolved by 143 * retiring. 144 */ 145 if (!(flags & PIN_NONBLOCK)) 146 i915_gem_retire_requests(dev_priv); 147 else 148 phases[1] = NULL; 149 150 search_again: 151 INIT_LIST_HEAD(&eviction_list); 152 phase = phases; 153 do { 154 list_for_each_entry(vma, *phase, vm_link) 155 if (mark_free(&scan, vma, flags, &eviction_list)) 156 goto found; 157 } while (*++phase); 158 159 /* Nothing found, clean up and bail out! */ 160 list_for_each_entry_safe(vma, next, &eviction_list, exec_list) { 161 ret = drm_mm_scan_remove_block(&scan, &vma->node); 162 BUG_ON(ret); 163 164 INIT_LIST_HEAD(&vma->exec_list); 165 } 166 167 /* Can we unpin some objects such as idle hw contents, 168 * or pending flips? But since only the GGTT has global entries 169 * such as scanouts, rinbuffers and contexts, we can skip the 170 * purge when inspecting per-process local address spaces. 171 */ 172 if (!i915_is_ggtt(vm) || flags & PIN_NONBLOCK) 173 return -ENOSPC; 174 175 if (ggtt_is_idle(dev_priv)) { 176 /* If we still have pending pageflip completions, drop 177 * back to userspace to give our workqueues time to 178 * acquire our locks and unpin the old scanouts. 179 */ 180 return intel_has_pending_fb_unpin(dev_priv) ? -EAGAIN : -ENOSPC; 181 } 182 183 /* Not everything in the GGTT is tracked via vma (otherwise we 184 * could evict as required with minimal stalling) so we are forced 185 * to idle the GPU and explicitly retire outstanding requests in 186 * the hopes that we can then remove contexts and the like only 187 * bound by their active reference. 188 */ 189 ret = i915_gem_switch_to_kernel_context(dev_priv); 190 if (ret) 191 return ret; 192 193 ret = i915_gem_wait_for_idle(dev_priv, 194 I915_WAIT_INTERRUPTIBLE | 195 I915_WAIT_LOCKED); 196 if (ret) 197 return ret; 198 199 goto search_again; 200 201 found: 202 /* drm_mm doesn't allow any other other operations while 203 * scanning, therefore store to-be-evicted objects on a 204 * temporary list and take a reference for all before 205 * calling unbind (which may remove the active reference 206 * of any of our objects, thus corrupting the list). 207 */ 208 list_for_each_entry_safe(vma, next, &eviction_list, exec_list) { 209 if (drm_mm_scan_remove_block(&scan, &vma->node)) 210 __i915_vma_pin(vma); 211 else 212 list_del_init(&vma->exec_list); 213 } 214 215 /* Unbinding will emit any required flushes */ 216 ret = 0; 217 while (!list_empty(&eviction_list)) { 218 vma = list_first_entry(&eviction_list, 219 struct i915_vma, 220 exec_list); 221 222 list_del_init(&vma->exec_list); 223 __i915_vma_unpin(vma); 224 if (ret == 0) 225 ret = i915_vma_unbind(vma); 226 } 227 228 while (ret == 0 && (node = drm_mm_scan_color_evict(&scan))) { 229 vma = container_of(node, struct i915_vma, node); 230 ret = i915_vma_unbind(vma); 231 } 232 233 return ret; 234 } 235 236 /** 237 * i915_gem_evict_for_vma - Evict vmas to make room for binding a new one 238 * @vm: address space to evict from 239 * @target: range (and color) to evict for 240 * @flags: additional flags to control the eviction algorithm 241 * 242 * This function will try to evict vmas that overlap the target node. 243 * 244 * To clarify: This is for freeing up virtual address space, not for freeing 245 * memory in e.g. the shrinker. 246 */ 247 int i915_gem_evict_for_node(struct i915_address_space *vm, 248 struct drm_mm_node *target, 249 unsigned int flags) 250 { 251 LIST_HEAD(eviction_list); 252 struct drm_mm_node *node; 253 u64 start = target->start; 254 u64 end = start + target->size; 255 struct i915_vma *vma, *next; 256 bool check_color; 257 int ret = 0; 258 259 lockdep_assert_held(&vm->i915->drm.struct_mutex); 260 GEM_BUG_ON(!IS_ALIGNED(start, I915_GTT_PAGE_SIZE)); 261 GEM_BUG_ON(!IS_ALIGNED(end, I915_GTT_PAGE_SIZE)); 262 263 trace_i915_gem_evict_node(vm, target, flags); 264 265 /* Retire before we search the active list. Although we have 266 * reasonable accuracy in our retirement lists, we may have 267 * a stray pin (preventing eviction) that can only be resolved by 268 * retiring. 269 */ 270 if (!(flags & PIN_NONBLOCK)) 271 i915_gem_retire_requests(vm->i915); 272 273 check_color = vm->mm.color_adjust; 274 if (check_color) { 275 /* Expand search to cover neighbouring guard pages (or lack!) */ 276 if (start) 277 start -= I915_GTT_PAGE_SIZE; 278 279 /* Always look at the page afterwards to avoid the end-of-GTT */ 280 end += I915_GTT_PAGE_SIZE; 281 } 282 GEM_BUG_ON(start >= end); 283 284 drm_mm_for_each_node_in_range(node, &vm->mm, start, end) { 285 /* If we find any non-objects (!vma), we cannot evict them */ 286 if (node->color == I915_COLOR_UNEVICTABLE) { 287 ret = -ENOSPC; 288 break; 289 } 290 291 GEM_BUG_ON(!node->allocated); 292 vma = container_of(node, typeof(*vma), node); 293 294 /* If we are using coloring to insert guard pages between 295 * different cache domains within the address space, we have 296 * to check whether the objects on either side of our range 297 * abutt and conflict. If they are in conflict, then we evict 298 * those as well to make room for our guard pages. 299 */ 300 if (check_color) { 301 if (node->start + node->size == target->start) { 302 if (node->color == target->color) 303 continue; 304 } 305 if (node->start == target->start + target->size) { 306 if (node->color == target->color) 307 continue; 308 } 309 } 310 311 if (flags & PIN_NONBLOCK && 312 (i915_vma_is_pinned(vma) || i915_vma_is_active(vma))) { 313 ret = -ENOSPC; 314 break; 315 } 316 317 /* Overlap of objects in the same batch? */ 318 if (i915_vma_is_pinned(vma) || !list_empty(&vma->exec_list)) { 319 ret = -ENOSPC; 320 if (vma->exec_entry && 321 vma->exec_entry->flags & EXEC_OBJECT_PINNED) 322 ret = -EINVAL; 323 break; 324 } 325 326 /* Never show fear in the face of dragons! 327 * 328 * We cannot directly remove this node from within this 329 * iterator and as with i915_gem_evict_something() we employ 330 * the vma pin_count in order to prevent the action of 331 * unbinding one vma from freeing (by dropping its active 332 * reference) another in our eviction list. 333 */ 334 __i915_vma_pin(vma); 335 list_add(&vma->exec_list, &eviction_list); 336 } 337 338 list_for_each_entry_safe(vma, next, &eviction_list, exec_list) { 339 list_del_init(&vma->exec_list); 340 __i915_vma_unpin(vma); 341 if (ret == 0) 342 ret = i915_vma_unbind(vma); 343 } 344 345 return ret; 346 } 347 348 /** 349 * i915_gem_evict_vm - Evict all idle vmas from a vm 350 * @vm: Address space to cleanse 351 * @do_idle: Boolean directing whether to idle first. 352 * 353 * This function evicts all idles vmas from a vm. If all unpinned vmas should be 354 * evicted the @do_idle needs to be set to true. 355 * 356 * This is used by the execbuf code as a last-ditch effort to defragment the 357 * address space. 358 * 359 * To clarify: This is for freeing up virtual address space, not for freeing 360 * memory in e.g. the shrinker. 361 */ 362 int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle) 363 { 364 struct i915_vma *vma, *next; 365 int ret; 366 367 lockdep_assert_held(&vm->i915->drm.struct_mutex); 368 trace_i915_gem_evict_vm(vm); 369 370 if (do_idle) { 371 struct drm_i915_private *dev_priv = vm->i915; 372 373 if (i915_is_ggtt(vm)) { 374 ret = i915_gem_switch_to_kernel_context(dev_priv); 375 if (ret) 376 return ret; 377 } 378 379 ret = i915_gem_wait_for_idle(dev_priv, 380 I915_WAIT_INTERRUPTIBLE | 381 I915_WAIT_LOCKED); 382 if (ret) 383 return ret; 384 385 WARN_ON(!list_empty(&vm->active_list)); 386 } 387 388 list_for_each_entry_safe(vma, next, &vm->inactive_list, vm_link) 389 if (!i915_vma_is_pinned(vma)) 390 WARN_ON(i915_vma_unbind(vma)); 391 392 return 0; 393 } 394 395 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) 396 #include "selftests/i915_gem_evict.c" 397 #endif 398