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 I915_SELFTEST_DECLARE(static struct igt_evict_ctl { 37 bool fail_if_busy:1; 38 } igt_evict_ctl;) 39 40 static bool ggtt_is_idle(struct drm_i915_private *i915) 41 { 42 struct intel_engine_cs *engine; 43 enum intel_engine_id id; 44 45 if (i915->gt.active_requests) 46 return false; 47 48 for_each_engine(engine, i915, id) { 49 if (engine->last_retired_context != i915->kernel_context) 50 return false; 51 } 52 53 return true; 54 } 55 56 static int ggtt_flush(struct drm_i915_private *i915) 57 { 58 int err; 59 60 /* Not everything in the GGTT is tracked via vma (otherwise we 61 * could evict as required with minimal stalling) so we are forced 62 * to idle the GPU and explicitly retire outstanding requests in 63 * the hopes that we can then remove contexts and the like only 64 * bound by their active reference. 65 */ 66 err = i915_gem_switch_to_kernel_context(i915); 67 if (err) 68 return err; 69 70 err = i915_gem_wait_for_idle(i915, 71 I915_WAIT_INTERRUPTIBLE | 72 I915_WAIT_LOCKED); 73 if (err) 74 return err; 75 76 return 0; 77 } 78 79 static bool 80 mark_free(struct drm_mm_scan *scan, 81 struct i915_vma *vma, 82 unsigned int flags, 83 struct list_head *unwind) 84 { 85 if (i915_vma_is_pinned(vma)) 86 return false; 87 88 if (flags & PIN_NONFAULT && i915_vma_has_userfault(vma)) 89 return false; 90 91 list_add(&vma->evict_link, unwind); 92 return drm_mm_scan_add_block(scan, &vma->node); 93 } 94 95 /** 96 * i915_gem_evict_something - Evict vmas to make room for binding a new one 97 * @vm: address space to evict from 98 * @min_size: size of the desired free space 99 * @alignment: alignment constraint of the desired free space 100 * @cache_level: cache_level for the desired space 101 * @start: start (inclusive) of the range from which to evict objects 102 * @end: end (exclusive) of the range from which to evict objects 103 * @flags: additional flags to control the eviction algorithm 104 * 105 * This function will try to evict vmas until a free space satisfying the 106 * requirements is found. Callers must check first whether any such hole exists 107 * already before calling this function. 108 * 109 * This function is used by the object/vma binding code. 110 * 111 * Since this function is only used to free up virtual address space it only 112 * ignores pinned vmas, and not object where the backing storage itself is 113 * pinned. Hence obj->pages_pin_count does not protect against eviction. 114 * 115 * To clarify: This is for freeing up virtual address space, not for freeing 116 * memory in e.g. the shrinker. 117 */ 118 int 119 i915_gem_evict_something(struct i915_address_space *vm, 120 u64 min_size, u64 alignment, 121 unsigned cache_level, 122 u64 start, u64 end, 123 unsigned flags) 124 { 125 struct drm_i915_private *dev_priv = vm->i915; 126 struct drm_mm_scan scan; 127 struct list_head eviction_list; 128 struct list_head *phases[] = { 129 &vm->inactive_list, 130 &vm->active_list, 131 NULL, 132 }, **phase; 133 struct i915_vma *vma, *next; 134 struct drm_mm_node *node; 135 enum drm_mm_insert_mode mode; 136 int ret; 137 138 lockdep_assert_held(&vm->i915->drm.struct_mutex); 139 trace_i915_gem_evict(vm, min_size, alignment, flags); 140 141 /* 142 * The goal is to evict objects and amalgamate space in LRU order. 143 * The oldest idle objects reside on the inactive list, which is in 144 * retirement order. The next objects to retire are those in flight, 145 * on the active list, again in retirement order. 146 * 147 * The retirement sequence is thus: 148 * 1. Inactive objects (already retired) 149 * 2. Active objects (will stall on unbinding) 150 * 151 * On each list, the oldest objects lie at the HEAD with the freshest 152 * object on the TAIL. 153 */ 154 kprintf("i915_gem_evict_something: %016llx-%016llx\n", start, end); 155 mode = DRM_MM_INSERT_BEST; 156 if (flags & PIN_HIGH) 157 mode = DRM_MM_INSERT_HIGH; 158 if (flags & PIN_MAPPABLE) 159 mode = DRM_MM_INSERT_LOW; 160 drm_mm_scan_init_with_range(&scan, &vm->mm, 161 min_size, alignment, cache_level, 162 start, end, mode); 163 164 /* 165 * Retire before we search the active list. Although we have 166 * reasonable accuracy in our retirement lists, we may have 167 * a stray pin (preventing eviction) that can only be resolved by 168 * retiring. 169 */ 170 if (!(flags & PIN_NONBLOCK)) 171 i915_gem_retire_requests(dev_priv); 172 else 173 phases[1] = NULL; 174 175 search_again: 176 INIT_LIST_HEAD(&eviction_list); 177 phase = phases; 178 do { 179 list_for_each_entry(vma, *phase, vm_link) 180 if (mark_free(&scan, vma, flags, &eviction_list)) 181 goto found; 182 } while (*++phase); 183 184 /* Nothing found, clean up and bail out! */ 185 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) { 186 ret = drm_mm_scan_remove_block(&scan, &vma->node); 187 BUG_ON(ret); 188 } 189 190 /* 191 * Can we unpin some objects such as idle hw contents, 192 * or pending flips? But since only the GGTT has global entries 193 * such as scanouts, rinbuffers and contexts, we can skip the 194 * purge when inspecting per-process local address spaces. 195 */ 196 if (!i915_is_ggtt(vm) || flags & PIN_NONBLOCK) { 197 return -ENOSPC; 198 } 199 kprintf("i915_gem_evict_something: Nothing found %d,%d\n", 200 ggtt_is_idle(dev_priv), 201 intel_has_pending_fb_unpin(dev_priv)); 202 203 /* 204 * Not everything in the GGTT is tracked via VMA using 205 * i915_vma_move_to_active(), otherwise we could evict as required 206 * with minimal stalling. Instead we are forced to idle the GPU and 207 * explicitly retire outstanding requests which will then remove 208 * the pinning for active objects such as contexts and ring, 209 * enabling us to evict them on the next iteration. 210 * 211 * To ensure that all user contexts are evictable, we perform 212 * a switch to the perma-pinned kernel context. This all also gives 213 * us a termination condition, when the last retired context is 214 * the kernel's there is no more we can evict. 215 */ 216 if (!ggtt_is_idle(dev_priv)) { 217 if (I915_SELFTEST_ONLY(igt_evict_ctl.fail_if_busy)) 218 return -EBUSY; 219 220 ret = ggtt_flush(dev_priv); 221 if (ret) 222 return ret; 223 224 goto search_again; 225 } 226 227 /* 228 * If we still have pending pageflip completions, drop 229 * back to userspace to give our workqueues time to 230 * acquire our locks and unpin the old scanouts. 231 */ 232 return intel_has_pending_fb_unpin(dev_priv) ? -EAGAIN : -ENOSPC; 233 234 found: 235 /* drm_mm doesn't allow any other other operations while 236 * scanning, therefore store to-be-evicted objects on a 237 * temporary list and take a reference for all before 238 * calling unbind (which may remove the active reference 239 * of any of our objects, thus corrupting the list). 240 */ 241 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) { 242 if (drm_mm_scan_remove_block(&scan, &vma->node)) 243 __i915_vma_pin(vma); 244 else 245 list_del(&vma->evict_link); 246 } 247 248 /* Unbinding will emit any required flushes */ 249 ret = 0; 250 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) { 251 __i915_vma_unpin(vma); 252 if (ret == 0) 253 ret = i915_vma_unbind(vma); 254 } 255 256 while (ret == 0 && (node = drm_mm_scan_color_evict(&scan))) { 257 vma = container_of(node, struct i915_vma, node); 258 ret = i915_vma_unbind(vma); 259 } 260 261 return ret; 262 } 263 264 /** 265 * i915_gem_evict_for_vma - Evict vmas to make room for binding a new one 266 * @vm: address space to evict from 267 * @target: range (and color) to evict for 268 * @flags: additional flags to control the eviction algorithm 269 * 270 * This function will try to evict vmas that overlap the target node. 271 * 272 * To clarify: This is for freeing up virtual address space, not for freeing 273 * memory in e.g. the shrinker. 274 */ 275 int i915_gem_evict_for_node(struct i915_address_space *vm, 276 struct drm_mm_node *target, 277 unsigned int flags) 278 { 279 LINUX_LIST_HEAD(eviction_list); 280 struct drm_mm_node *node; 281 u64 start = target->start; 282 u64 end = start + target->size; 283 struct i915_vma *vma, *next; 284 bool check_color; 285 int ret = 0; 286 287 lockdep_assert_held(&vm->i915->drm.struct_mutex); 288 GEM_BUG_ON(!IS_ALIGNED(start, I915_GTT_PAGE_SIZE)); 289 GEM_BUG_ON(!IS_ALIGNED(end, I915_GTT_PAGE_SIZE)); 290 291 trace_i915_gem_evict_node(vm, target, flags); 292 293 /* Retire before we search the active list. Although we have 294 * reasonable accuracy in our retirement lists, we may have 295 * a stray pin (preventing eviction) that can only be resolved by 296 * retiring. 297 */ 298 if (!(flags & PIN_NONBLOCK)) 299 i915_gem_retire_requests(vm->i915); 300 301 check_color = vm->mm.color_adjust; 302 if (check_color) { 303 /* Expand search to cover neighbouring guard pages (or lack!) */ 304 if (start) 305 start -= I915_GTT_PAGE_SIZE; 306 307 /* Always look at the page afterwards to avoid the end-of-GTT */ 308 end += I915_GTT_PAGE_SIZE; 309 } 310 GEM_BUG_ON(start >= end); 311 312 drm_mm_for_each_node_in_range(node, &vm->mm, start, end) { 313 /* If we find any non-objects (!vma), we cannot evict them */ 314 if (node->color == I915_COLOR_UNEVICTABLE) { 315 ret = -ENOSPC; 316 break; 317 } 318 319 GEM_BUG_ON(!node->allocated); 320 vma = container_of(node, typeof(*vma), node); 321 322 /* If we are using coloring to insert guard pages between 323 * different cache domains within the address space, we have 324 * to check whether the objects on either side of our range 325 * abutt and conflict. If they are in conflict, then we evict 326 * those as well to make room for our guard pages. 327 */ 328 if (check_color) { 329 if (node->start + node->size == target->start) { 330 if (node->color == target->color) 331 continue; 332 } 333 if (node->start == target->start + target->size) { 334 if (node->color == target->color) 335 continue; 336 } 337 } 338 339 if (flags & PIN_NONBLOCK && 340 (i915_vma_is_pinned(vma) || i915_vma_is_active(vma))) { 341 ret = -ENOSPC; 342 break; 343 } 344 345 if (flags & PIN_NONFAULT && i915_vma_has_userfault(vma)) { 346 ret = -ENOSPC; 347 break; 348 } 349 350 /* Overlap of objects in the same batch? */ 351 if (i915_vma_is_pinned(vma)) { 352 ret = -ENOSPC; 353 if (vma->exec_flags && 354 *vma->exec_flags & EXEC_OBJECT_PINNED) 355 ret = -EINVAL; 356 break; 357 } 358 359 /* Never show fear in the face of dragons! 360 * 361 * We cannot directly remove this node from within this 362 * iterator and as with i915_gem_evict_something() we employ 363 * the vma pin_count in order to prevent the action of 364 * unbinding one vma from freeing (by dropping its active 365 * reference) another in our eviction list. 366 */ 367 __i915_vma_pin(vma); 368 list_add(&vma->evict_link, &eviction_list); 369 } 370 371 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) { 372 __i915_vma_unpin(vma); 373 if (ret == 0) 374 ret = i915_vma_unbind(vma); 375 } 376 377 return ret; 378 } 379 380 /** 381 * i915_gem_evict_vm - Evict all idle vmas from a vm 382 * @vm: Address space to cleanse 383 * 384 * This function evicts all vmas from a vm. 385 * 386 * This is used by the execbuf code as a last-ditch effort to defragment the 387 * address space. 388 * 389 * To clarify: This is for freeing up virtual address space, not for freeing 390 * memory in e.g. the shrinker. 391 */ 392 int i915_gem_evict_vm(struct i915_address_space *vm) 393 { 394 struct list_head *phases[] = { 395 &vm->inactive_list, 396 &vm->active_list, 397 NULL 398 }, **phase; 399 struct list_head eviction_list; 400 struct i915_vma *vma, *next; 401 int ret; 402 403 lockdep_assert_held(&vm->i915->drm.struct_mutex); 404 trace_i915_gem_evict_vm(vm); 405 406 /* Switch back to the default context in order to unpin 407 * the existing context objects. However, such objects only 408 * pin themselves inside the global GTT and performing the 409 * switch otherwise is ineffective. 410 */ 411 if (i915_is_ggtt(vm)) { 412 ret = ggtt_flush(vm->i915); 413 if (ret) 414 return ret; 415 } 416 417 INIT_LIST_HEAD(&eviction_list); 418 phase = phases; 419 do { 420 list_for_each_entry(vma, *phase, vm_link) { 421 if (i915_vma_is_pinned(vma)) 422 continue; 423 424 __i915_vma_pin(vma); 425 list_add(&vma->evict_link, &eviction_list); 426 } 427 } while (*++phase); 428 429 ret = 0; 430 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) { 431 __i915_vma_unpin(vma); 432 if (ret == 0) 433 ret = i915_vma_unbind(vma); 434 } 435 return ret; 436 } 437 438 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) 439 #include "selftests/i915_gem_evict.c" 440 #endif 441