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 int ggtt_flush(struct drm_i915_private *i915) 54 { 55 int err; 56 57 /* Not everything in the GGTT is tracked via vma (otherwise we 58 * could evict as required with minimal stalling) so we are forced 59 * to idle the GPU and explicitly retire outstanding requests in 60 * the hopes that we can then remove contexts and the like only 61 * bound by their active reference. 62 */ 63 err = i915_gem_switch_to_kernel_context(i915); 64 if (err) 65 return err; 66 67 err = i915_gem_wait_for_idle(i915, 68 I915_WAIT_INTERRUPTIBLE | 69 I915_WAIT_LOCKED); 70 if (err) 71 return err; 72 73 return 0; 74 } 75 76 static bool 77 mark_free(struct drm_mm_scan *scan, 78 struct i915_vma *vma, 79 unsigned int flags, 80 struct list_head *unwind) 81 { 82 if (i915_vma_is_pinned(vma)) 83 return false; 84 85 if (flags & PIN_NONFAULT && !list_empty(&vma->obj->userfault_link)) 86 return false; 87 88 list_add(&vma->evict_link, unwind); 89 return drm_mm_scan_add_block(scan, &vma->node); 90 } 91 92 /** 93 * i915_gem_evict_something - Evict vmas to make room for binding a new one 94 * @vm: address space to evict from 95 * @min_size: size of the desired free space 96 * @alignment: alignment constraint of the desired free space 97 * @cache_level: cache_level for the desired space 98 * @start: start (inclusive) of the range from which to evict objects 99 * @end: end (exclusive) of the range from which to evict objects 100 * @flags: additional flags to control the eviction algorithm 101 * 102 * This function will try to evict vmas until a free space satisfying the 103 * requirements is found. Callers must check first whether any such hole exists 104 * already before calling this function. 105 * 106 * This function is used by the object/vma binding code. 107 * 108 * Since this function is only used to free up virtual address space it only 109 * ignores pinned vmas, and not object where the backing storage itself is 110 * pinned. Hence obj->pages_pin_count does not protect against eviction. 111 * 112 * To clarify: This is for freeing up virtual address space, not for freeing 113 * memory in e.g. the shrinker. 114 */ 115 int 116 i915_gem_evict_something(struct i915_address_space *vm, 117 u64 min_size, u64 alignment, 118 unsigned cache_level, 119 u64 start, u64 end, 120 unsigned flags) 121 { 122 struct drm_i915_private *dev_priv = vm->i915; 123 struct drm_mm_scan scan; 124 struct list_head eviction_list; 125 struct list_head *phases[] = { 126 &vm->inactive_list, 127 &vm->active_list, 128 NULL, 129 }, **phase; 130 struct i915_vma *vma, *next; 131 struct drm_mm_node *node; 132 enum drm_mm_insert_mode mode; 133 int ret; 134 135 lockdep_assert_held(&vm->i915->drm.struct_mutex); 136 trace_i915_gem_evict(vm, min_size, alignment, flags); 137 138 /* 139 * The goal is to evict objects and amalgamate space in LRU order. 140 * The oldest idle objects reside on the inactive list, which is in 141 * retirement order. The next objects to retire are those in flight, 142 * on the active list, again in retirement order. 143 * 144 * The retirement sequence is thus: 145 * 1. Inactive objects (already retired) 146 * 2. Active objects (will stall on unbinding) 147 * 148 * On each list, the oldest objects lie at the HEAD with the freshest 149 * object on the TAIL. 150 */ 151 mode = DRM_MM_INSERT_BEST; 152 if (flags & PIN_HIGH) 153 mode = DRM_MM_INSERT_HIGH; 154 if (flags & PIN_MAPPABLE) 155 mode = DRM_MM_INSERT_LOW; 156 drm_mm_scan_init_with_range(&scan, &vm->mm, 157 min_size, alignment, cache_level, 158 start, end, mode); 159 160 /* Retire before we search the active list. Although we have 161 * reasonable accuracy in our retirement lists, we may have 162 * a stray pin (preventing eviction) that can only be resolved by 163 * retiring. 164 */ 165 if (!(flags & PIN_NONBLOCK)) 166 i915_gem_retire_requests(dev_priv); 167 else 168 phases[1] = NULL; 169 170 search_again: 171 INIT_LIST_HEAD(&eviction_list); 172 phase = phases; 173 do { 174 list_for_each_entry(vma, *phase, vm_link) 175 if (mark_free(&scan, vma, flags, &eviction_list)) 176 goto found; 177 } while (*++phase); 178 179 /* Nothing found, clean up and bail out! */ 180 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) { 181 ret = drm_mm_scan_remove_block(&scan, &vma->node); 182 BUG_ON(ret); 183 } 184 185 /* Can we unpin some objects such as idle hw contents, 186 * or pending flips? But since only the GGTT has global entries 187 * such as scanouts, rinbuffers and contexts, we can skip the 188 * purge when inspecting per-process local address spaces. 189 */ 190 if (!i915_is_ggtt(vm) || flags & PIN_NONBLOCK) 191 return -ENOSPC; 192 193 if (ggtt_is_idle(dev_priv)) { 194 /* If we still have pending pageflip completions, drop 195 * back to userspace to give our workqueues time to 196 * acquire our locks and unpin the old scanouts. 197 */ 198 return intel_has_pending_fb_unpin(dev_priv) ? -EAGAIN : -ENOSPC; 199 } 200 201 ret = ggtt_flush(dev_priv); 202 if (ret) 203 return ret; 204 205 goto search_again; 206 207 found: 208 /* drm_mm doesn't allow any other other operations while 209 * scanning, therefore store to-be-evicted objects on a 210 * temporary list and take a reference for all before 211 * calling unbind (which may remove the active reference 212 * of any of our objects, thus corrupting the list). 213 */ 214 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) { 215 if (drm_mm_scan_remove_block(&scan, &vma->node)) 216 __i915_vma_pin(vma); 217 else 218 list_del(&vma->evict_link); 219 } 220 221 /* Unbinding will emit any required flushes */ 222 ret = 0; 223 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) { 224 __i915_vma_unpin(vma); 225 if (ret == 0) 226 ret = i915_vma_unbind(vma); 227 } 228 229 while (ret == 0 && (node = drm_mm_scan_color_evict(&scan))) { 230 vma = container_of(node, struct i915_vma, node); 231 ret = i915_vma_unbind(vma); 232 } 233 234 return ret; 235 } 236 237 /** 238 * i915_gem_evict_for_vma - Evict vmas to make room for binding a new one 239 * @vm: address space to evict from 240 * @target: range (and color) to evict for 241 * @flags: additional flags to control the eviction algorithm 242 * 243 * This function will try to evict vmas that overlap the target node. 244 * 245 * To clarify: This is for freeing up virtual address space, not for freeing 246 * memory in e.g. the shrinker. 247 */ 248 int i915_gem_evict_for_node(struct i915_address_space *vm, 249 struct drm_mm_node *target, 250 unsigned int flags) 251 { 252 LIST_HEAD(eviction_list); 253 struct drm_mm_node *node; 254 u64 start = target->start; 255 u64 end = start + target->size; 256 struct i915_vma *vma, *next; 257 bool check_color; 258 int ret = 0; 259 260 lockdep_assert_held(&vm->i915->drm.struct_mutex); 261 GEM_BUG_ON(!IS_ALIGNED(start, I915_GTT_PAGE_SIZE)); 262 GEM_BUG_ON(!IS_ALIGNED(end, I915_GTT_PAGE_SIZE)); 263 264 trace_i915_gem_evict_node(vm, target, flags); 265 266 /* Retire before we search the active list. Although we have 267 * reasonable accuracy in our retirement lists, we may have 268 * a stray pin (preventing eviction) that can only be resolved by 269 * retiring. 270 */ 271 if (!(flags & PIN_NONBLOCK)) 272 i915_gem_retire_requests(vm->i915); 273 274 check_color = vm->mm.color_adjust; 275 if (check_color) { 276 /* Expand search to cover neighbouring guard pages (or lack!) */ 277 if (start) 278 start -= I915_GTT_PAGE_SIZE; 279 280 /* Always look at the page afterwards to avoid the end-of-GTT */ 281 end += I915_GTT_PAGE_SIZE; 282 } 283 GEM_BUG_ON(start >= end); 284 285 drm_mm_for_each_node_in_range(node, &vm->mm, start, end) { 286 /* If we find any non-objects (!vma), we cannot evict them */ 287 if (node->color == I915_COLOR_UNEVICTABLE) { 288 ret = -ENOSPC; 289 break; 290 } 291 292 GEM_BUG_ON(!node->allocated); 293 vma = container_of(node, typeof(*vma), node); 294 295 /* If we are using coloring to insert guard pages between 296 * different cache domains within the address space, we have 297 * to check whether the objects on either side of our range 298 * abutt and conflict. If they are in conflict, then we evict 299 * those as well to make room for our guard pages. 300 */ 301 if (check_color) { 302 if (node->start + node->size == target->start) { 303 if (node->color == target->color) 304 continue; 305 } 306 if (node->start == target->start + target->size) { 307 if (node->color == target->color) 308 continue; 309 } 310 } 311 312 if (flags & PIN_NONBLOCK && 313 (i915_vma_is_pinned(vma) || i915_vma_is_active(vma))) { 314 ret = -ENOSPC; 315 break; 316 } 317 318 /* Overlap of objects in the same batch? */ 319 if (i915_vma_is_pinned(vma)) { 320 ret = -ENOSPC; 321 if (vma->exec_entry && 322 vma->exec_entry->flags & EXEC_OBJECT_PINNED) 323 ret = -EINVAL; 324 break; 325 } 326 327 /* Never show fear in the face of dragons! 328 * 329 * We cannot directly remove this node from within this 330 * iterator and as with i915_gem_evict_something() we employ 331 * the vma pin_count in order to prevent the action of 332 * unbinding one vma from freeing (by dropping its active 333 * reference) another in our eviction list. 334 */ 335 __i915_vma_pin(vma); 336 list_add(&vma->evict_link, &eviction_list); 337 } 338 339 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) { 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 * 352 * This function evicts all vmas from a vm. 353 * 354 * This is used by the execbuf code as a last-ditch effort to defragment the 355 * address space. 356 * 357 * To clarify: This is for freeing up virtual address space, not for freeing 358 * memory in e.g. the shrinker. 359 */ 360 int i915_gem_evict_vm(struct i915_address_space *vm) 361 { 362 struct list_head *phases[] = { 363 &vm->inactive_list, 364 &vm->active_list, 365 NULL 366 }, **phase; 367 struct list_head eviction_list; 368 struct i915_vma *vma, *next; 369 int ret; 370 371 lockdep_assert_held(&vm->i915->drm.struct_mutex); 372 trace_i915_gem_evict_vm(vm); 373 374 /* Switch back to the default context in order to unpin 375 * the existing context objects. However, such objects only 376 * pin themselves inside the global GTT and performing the 377 * switch otherwise is ineffective. 378 */ 379 if (i915_is_ggtt(vm)) { 380 ret = ggtt_flush(vm->i915); 381 if (ret) 382 return ret; 383 } 384 385 INIT_LIST_HEAD(&eviction_list); 386 phase = phases; 387 do { 388 list_for_each_entry(vma, *phase, vm_link) { 389 if (i915_vma_is_pinned(vma)) 390 continue; 391 392 __i915_vma_pin(vma); 393 list_add(&vma->evict_link, &eviction_list); 394 } 395 } while (*++phase); 396 397 ret = 0; 398 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) { 399 __i915_vma_unpin(vma); 400 if (ret == 0) 401 ret = i915_vma_unbind(vma); 402 } 403 return ret; 404 } 405 406 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) 407 #include "selftests/i915_gem_evict.c" 408 #endif 409