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