1 // SPDX-License-Identifier: MIT 2 /* 3 * Copyright © 2021 Intel Corporation 4 */ 5 6 #include <drm/ttm/ttm_bo_driver.h> 7 #include <drm/ttm/ttm_placement.h> 8 9 #include "i915_drv.h" 10 #include "intel_memory_region.h" 11 #include "intel_region_ttm.h" 12 13 #include "gem/i915_gem_object.h" 14 #include "gem/i915_gem_region.h" 15 #include "gem/i915_gem_ttm.h" 16 #include "gem/i915_gem_mman.h" 17 18 #include "gt/intel_migrate.h" 19 #include "gt/intel_engine_pm.h" 20 21 #define I915_PL_LMEM0 TTM_PL_PRIV 22 #define I915_PL_SYSTEM TTM_PL_SYSTEM 23 #define I915_PL_STOLEN TTM_PL_VRAM 24 #define I915_PL_GGTT TTM_PL_TT 25 26 #define I915_TTM_PRIO_PURGE 0 27 #define I915_TTM_PRIO_NO_PAGES 1 28 #define I915_TTM_PRIO_HAS_PAGES 2 29 30 /* 31 * Size of struct ttm_place vector in on-stack struct ttm_placement allocs 32 */ 33 #define I915_TTM_MAX_PLACEMENTS INTEL_REGION_UNKNOWN 34 35 /** 36 * struct i915_ttm_tt - TTM page vector with additional private information 37 * @ttm: The base TTM page vector. 38 * @dev: The struct device used for dma mapping and unmapping. 39 * @cached_st: The cached scatter-gather table. 40 * 41 * Note that DMA may be going on right up to the point where the page- 42 * vector is unpopulated in delayed destroy. Hence keep the 43 * scatter-gather table mapped and cached up to that point. This is 44 * different from the cached gem object io scatter-gather table which 45 * doesn't have an associated dma mapping. 46 */ 47 struct i915_ttm_tt { 48 struct ttm_tt ttm; 49 struct device *dev; 50 struct sg_table *cached_st; 51 }; 52 53 static const struct ttm_place sys_placement_flags = { 54 .fpfn = 0, 55 .lpfn = 0, 56 .mem_type = I915_PL_SYSTEM, 57 .flags = 0, 58 }; 59 60 static struct ttm_placement i915_sys_placement = { 61 .num_placement = 1, 62 .placement = &sys_placement_flags, 63 .num_busy_placement = 1, 64 .busy_placement = &sys_placement_flags, 65 }; 66 67 static int i915_ttm_err_to_gem(int err) 68 { 69 /* Fastpath */ 70 if (likely(!err)) 71 return 0; 72 73 switch (err) { 74 case -EBUSY: 75 /* 76 * TTM likes to convert -EDEADLK to -EBUSY, and wants us to 77 * restart the operation, since we don't record the contending 78 * lock. We use -EAGAIN to restart. 79 */ 80 return -EAGAIN; 81 case -ENOSPC: 82 /* 83 * Memory type / region is full, and we can't evict. 84 * Except possibly system, that returns -ENOMEM; 85 */ 86 return -ENXIO; 87 default: 88 break; 89 } 90 91 return err; 92 } 93 94 static bool gpu_binds_iomem(struct ttm_resource *mem) 95 { 96 return mem->mem_type != TTM_PL_SYSTEM; 97 } 98 99 static bool cpu_maps_iomem(struct ttm_resource *mem) 100 { 101 /* Once / if we support GGTT, this is also false for cached ttm_tts */ 102 return mem->mem_type != TTM_PL_SYSTEM; 103 } 104 105 static enum i915_cache_level 106 i915_ttm_cache_level(struct drm_i915_private *i915, struct ttm_resource *res, 107 struct ttm_tt *ttm) 108 { 109 return ((HAS_LLC(i915) || HAS_SNOOP(i915)) && !gpu_binds_iomem(res) && 110 ttm->caching == ttm_cached) ? I915_CACHE_LLC : 111 I915_CACHE_NONE; 112 } 113 114 static void i915_ttm_adjust_lru(struct drm_i915_gem_object *obj); 115 116 static enum ttm_caching 117 i915_ttm_select_tt_caching(const struct drm_i915_gem_object *obj) 118 { 119 /* 120 * Objects only allowed in system get cached cpu-mappings. 121 * Other objects get WC mapping for now. Even if in system. 122 */ 123 if (obj->mm.region->type == INTEL_MEMORY_SYSTEM && 124 obj->mm.n_placements <= 1) 125 return ttm_cached; 126 127 return ttm_write_combined; 128 } 129 130 static void 131 i915_ttm_place_from_region(const struct intel_memory_region *mr, 132 struct ttm_place *place, 133 unsigned int flags) 134 { 135 memset(place, 0, sizeof(*place)); 136 place->mem_type = intel_region_to_ttm_type(mr); 137 138 if (flags & I915_BO_ALLOC_CONTIGUOUS) 139 place->flags = TTM_PL_FLAG_CONTIGUOUS; 140 } 141 142 static void 143 i915_ttm_placement_from_obj(const struct drm_i915_gem_object *obj, 144 struct ttm_place *requested, 145 struct ttm_place *busy, 146 struct ttm_placement *placement) 147 { 148 unsigned int num_allowed = obj->mm.n_placements; 149 unsigned int flags = obj->flags; 150 unsigned int i; 151 152 placement->num_placement = 1; 153 i915_ttm_place_from_region(num_allowed ? obj->mm.placements[0] : 154 obj->mm.region, requested, flags); 155 156 /* Cache this on object? */ 157 placement->num_busy_placement = num_allowed; 158 for (i = 0; i < placement->num_busy_placement; ++i) 159 i915_ttm_place_from_region(obj->mm.placements[i], busy + i, flags); 160 161 if (num_allowed == 0) { 162 *busy = *requested; 163 placement->num_busy_placement = 1; 164 } 165 166 placement->placement = requested; 167 placement->busy_placement = busy; 168 } 169 170 static struct ttm_tt *i915_ttm_tt_create(struct ttm_buffer_object *bo, 171 uint32_t page_flags) 172 { 173 struct ttm_resource_manager *man = 174 ttm_manager_type(bo->bdev, bo->resource->mem_type); 175 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 176 struct i915_ttm_tt *i915_tt; 177 int ret; 178 179 i915_tt = kzalloc(sizeof(*i915_tt), GFP_KERNEL); 180 if (!i915_tt) 181 return NULL; 182 183 if (obj->flags & I915_BO_ALLOC_CPU_CLEAR && 184 man->use_tt) 185 page_flags |= TTM_PAGE_FLAG_ZERO_ALLOC; 186 187 ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags, 188 i915_ttm_select_tt_caching(obj)); 189 if (ret) { 190 kfree(i915_tt); 191 return NULL; 192 } 193 194 i915_tt->dev = obj->base.dev->dev; 195 196 return &i915_tt->ttm; 197 } 198 199 static void i915_ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm) 200 { 201 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 202 203 if (i915_tt->cached_st) { 204 dma_unmap_sgtable(i915_tt->dev, i915_tt->cached_st, 205 DMA_BIDIRECTIONAL, 0); 206 sg_free_table(i915_tt->cached_st); 207 kfree(i915_tt->cached_st); 208 i915_tt->cached_st = NULL; 209 } 210 ttm_pool_free(&bdev->pool, ttm); 211 } 212 213 static void i915_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm) 214 { 215 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 216 217 ttm_tt_fini(ttm); 218 kfree(i915_tt); 219 } 220 221 static bool i915_ttm_eviction_valuable(struct ttm_buffer_object *bo, 222 const struct ttm_place *place) 223 { 224 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 225 226 /* Will do for now. Our pinned objects are still on TTM's LRU lists */ 227 return i915_gem_object_evictable(obj); 228 } 229 230 static void i915_ttm_evict_flags(struct ttm_buffer_object *bo, 231 struct ttm_placement *placement) 232 { 233 *placement = i915_sys_placement; 234 } 235 236 static int i915_ttm_move_notify(struct ttm_buffer_object *bo) 237 { 238 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 239 int ret; 240 241 ret = i915_gem_object_unbind(obj, I915_GEM_OBJECT_UNBIND_ACTIVE); 242 if (ret) 243 return ret; 244 245 ret = __i915_gem_object_put_pages(obj); 246 if (ret) 247 return ret; 248 249 return 0; 250 } 251 252 static void i915_ttm_free_cached_io_st(struct drm_i915_gem_object *obj) 253 { 254 struct radix_tree_iter iter; 255 void __rcu **slot; 256 257 if (!obj->ttm.cached_io_st) 258 return; 259 260 rcu_read_lock(); 261 radix_tree_for_each_slot(slot, &obj->ttm.get_io_page.radix, &iter, 0) 262 radix_tree_delete(&obj->ttm.get_io_page.radix, iter.index); 263 rcu_read_unlock(); 264 265 sg_free_table(obj->ttm.cached_io_st); 266 kfree(obj->ttm.cached_io_st); 267 obj->ttm.cached_io_st = NULL; 268 } 269 270 static void 271 i915_ttm_adjust_domains_after_move(struct drm_i915_gem_object *obj) 272 { 273 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 274 275 if (cpu_maps_iomem(bo->resource) || bo->ttm->caching != ttm_cached) { 276 obj->write_domain = I915_GEM_DOMAIN_WC; 277 obj->read_domains = I915_GEM_DOMAIN_WC; 278 } else { 279 obj->write_domain = I915_GEM_DOMAIN_CPU; 280 obj->read_domains = I915_GEM_DOMAIN_CPU; 281 } 282 } 283 284 static void i915_ttm_adjust_gem_after_move(struct drm_i915_gem_object *obj) 285 { 286 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 287 unsigned int cache_level; 288 unsigned int i; 289 290 /* 291 * If object was moved to an allowable region, update the object 292 * region to consider it migrated. Note that if it's currently not 293 * in an allowable region, it's evicted and we don't update the 294 * object region. 295 */ 296 if (intel_region_to_ttm_type(obj->mm.region) != bo->resource->mem_type) { 297 for (i = 0; i < obj->mm.n_placements; ++i) { 298 struct intel_memory_region *mr = obj->mm.placements[i]; 299 300 if (intel_region_to_ttm_type(mr) == bo->resource->mem_type && 301 mr != obj->mm.region) { 302 i915_gem_object_release_memory_region(obj); 303 i915_gem_object_init_memory_region(obj, mr); 304 break; 305 } 306 } 307 } 308 309 obj->mem_flags &= ~(I915_BO_FLAG_STRUCT_PAGE | I915_BO_FLAG_IOMEM); 310 311 obj->mem_flags |= cpu_maps_iomem(bo->resource) ? I915_BO_FLAG_IOMEM : 312 I915_BO_FLAG_STRUCT_PAGE; 313 314 cache_level = i915_ttm_cache_level(to_i915(bo->base.dev), bo->resource, 315 bo->ttm); 316 i915_gem_object_set_cache_coherency(obj, cache_level); 317 } 318 319 static void i915_ttm_purge(struct drm_i915_gem_object *obj) 320 { 321 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 322 struct ttm_operation_ctx ctx = { 323 .interruptible = true, 324 .no_wait_gpu = false, 325 }; 326 struct ttm_placement place = {}; 327 int ret; 328 329 if (obj->mm.madv == __I915_MADV_PURGED) 330 return; 331 332 /* TTM's purge interface. Note that we might be reentering. */ 333 ret = ttm_bo_validate(bo, &place, &ctx); 334 if (!ret) { 335 obj->write_domain = 0; 336 obj->read_domains = 0; 337 i915_ttm_adjust_gem_after_move(obj); 338 i915_ttm_free_cached_io_st(obj); 339 obj->mm.madv = __I915_MADV_PURGED; 340 } 341 } 342 343 static void i915_ttm_swap_notify(struct ttm_buffer_object *bo) 344 { 345 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 346 int ret = i915_ttm_move_notify(bo); 347 348 GEM_WARN_ON(ret); 349 GEM_WARN_ON(obj->ttm.cached_io_st); 350 if (!ret && obj->mm.madv != I915_MADV_WILLNEED) 351 i915_ttm_purge(obj); 352 } 353 354 static void i915_ttm_delete_mem_notify(struct ttm_buffer_object *bo) 355 { 356 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 357 358 if (likely(obj)) { 359 /* This releases all gem object bindings to the backend. */ 360 i915_ttm_free_cached_io_st(obj); 361 __i915_gem_free_object(obj); 362 } 363 } 364 365 static struct intel_memory_region * 366 i915_ttm_region(struct ttm_device *bdev, int ttm_mem_type) 367 { 368 struct drm_i915_private *i915 = container_of(bdev, typeof(*i915), bdev); 369 370 /* There's some room for optimization here... */ 371 GEM_BUG_ON(ttm_mem_type != I915_PL_SYSTEM && 372 ttm_mem_type < I915_PL_LMEM0); 373 if (ttm_mem_type == I915_PL_SYSTEM) 374 return intel_memory_region_lookup(i915, INTEL_MEMORY_SYSTEM, 375 0); 376 377 return intel_memory_region_lookup(i915, INTEL_MEMORY_LOCAL, 378 ttm_mem_type - I915_PL_LMEM0); 379 } 380 381 static struct sg_table *i915_ttm_tt_get_st(struct ttm_tt *ttm) 382 { 383 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 384 struct sg_table *st; 385 int ret; 386 387 if (i915_tt->cached_st) 388 return i915_tt->cached_st; 389 390 st = kzalloc(sizeof(*st), GFP_KERNEL); 391 if (!st) 392 return ERR_PTR(-ENOMEM); 393 394 ret = sg_alloc_table_from_pages_segment(st, 395 ttm->pages, ttm->num_pages, 396 0, (unsigned long)ttm->num_pages << PAGE_SHIFT, 397 i915_sg_segment_size(), GFP_KERNEL); 398 if (ret) { 399 kfree(st); 400 return ERR_PTR(ret); 401 } 402 403 ret = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0); 404 if (ret) { 405 sg_free_table(st); 406 kfree(st); 407 return ERR_PTR(ret); 408 } 409 410 i915_tt->cached_st = st; 411 return st; 412 } 413 414 static struct sg_table * 415 i915_ttm_resource_get_st(struct drm_i915_gem_object *obj, 416 struct ttm_resource *res) 417 { 418 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 419 420 if (!gpu_binds_iomem(res)) 421 return i915_ttm_tt_get_st(bo->ttm); 422 423 /* 424 * If CPU mapping differs, we need to add the ttm_tt pages to 425 * the resulting st. Might make sense for GGTT. 426 */ 427 GEM_WARN_ON(!cpu_maps_iomem(res)); 428 return intel_region_ttm_resource_to_st(obj->mm.region, res); 429 } 430 431 static int i915_ttm_accel_move(struct ttm_buffer_object *bo, 432 struct ttm_resource *dst_mem, 433 struct sg_table *dst_st) 434 { 435 struct drm_i915_private *i915 = container_of(bo->bdev, typeof(*i915), 436 bdev); 437 struct ttm_resource_manager *src_man = 438 ttm_manager_type(bo->bdev, bo->resource->mem_type); 439 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 440 struct sg_table *src_st; 441 struct i915_request *rq; 442 struct ttm_tt *ttm = bo->ttm; 443 enum i915_cache_level src_level, dst_level; 444 int ret; 445 446 if (!i915->gt.migrate.context) 447 return -EINVAL; 448 449 dst_level = i915_ttm_cache_level(i915, dst_mem, ttm); 450 if (!ttm || !ttm_tt_is_populated(ttm)) { 451 if (bo->type == ttm_bo_type_kernel) 452 return -EINVAL; 453 454 if (ttm && !(ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)) 455 return 0; 456 457 intel_engine_pm_get(i915->gt.migrate.context->engine); 458 ret = intel_context_migrate_clear(i915->gt.migrate.context, NULL, 459 dst_st->sgl, dst_level, 460 gpu_binds_iomem(dst_mem), 461 0, &rq); 462 463 if (!ret && rq) { 464 i915_request_wait(rq, 0, MAX_SCHEDULE_TIMEOUT); 465 i915_request_put(rq); 466 } 467 intel_engine_pm_put(i915->gt.migrate.context->engine); 468 } else { 469 src_st = src_man->use_tt ? i915_ttm_tt_get_st(ttm) : 470 obj->ttm.cached_io_st; 471 472 src_level = i915_ttm_cache_level(i915, bo->resource, ttm); 473 intel_engine_pm_get(i915->gt.migrate.context->engine); 474 ret = intel_context_migrate_copy(i915->gt.migrate.context, 475 NULL, src_st->sgl, src_level, 476 gpu_binds_iomem(bo->resource), 477 dst_st->sgl, dst_level, 478 gpu_binds_iomem(dst_mem), 479 &rq); 480 if (!ret && rq) { 481 i915_request_wait(rq, 0, MAX_SCHEDULE_TIMEOUT); 482 i915_request_put(rq); 483 } 484 intel_engine_pm_put(i915->gt.migrate.context->engine); 485 } 486 487 return ret; 488 } 489 490 static int i915_ttm_move(struct ttm_buffer_object *bo, bool evict, 491 struct ttm_operation_ctx *ctx, 492 struct ttm_resource *dst_mem, 493 struct ttm_place *hop) 494 { 495 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 496 struct ttm_resource_manager *dst_man = 497 ttm_manager_type(bo->bdev, dst_mem->mem_type); 498 struct intel_memory_region *dst_reg, *src_reg; 499 union { 500 struct ttm_kmap_iter_tt tt; 501 struct ttm_kmap_iter_iomap io; 502 } _dst_iter, _src_iter; 503 struct ttm_kmap_iter *dst_iter, *src_iter; 504 struct sg_table *dst_st; 505 int ret; 506 507 dst_reg = i915_ttm_region(bo->bdev, dst_mem->mem_type); 508 src_reg = i915_ttm_region(bo->bdev, bo->resource->mem_type); 509 GEM_BUG_ON(!dst_reg || !src_reg); 510 511 /* Sync for now. We could do the actual copy async. */ 512 ret = ttm_bo_wait_ctx(bo, ctx); 513 if (ret) 514 return ret; 515 516 ret = i915_ttm_move_notify(bo); 517 if (ret) 518 return ret; 519 520 if (obj->mm.madv != I915_MADV_WILLNEED) { 521 i915_ttm_purge(obj); 522 ttm_resource_free(bo, &dst_mem); 523 return 0; 524 } 525 526 /* Populate ttm with pages if needed. Typically system memory. */ 527 if (bo->ttm && (dst_man->use_tt || 528 (bo->ttm->page_flags & TTM_PAGE_FLAG_SWAPPED))) { 529 ret = ttm_tt_populate(bo->bdev, bo->ttm, ctx); 530 if (ret) 531 return ret; 532 } 533 534 dst_st = i915_ttm_resource_get_st(obj, dst_mem); 535 if (IS_ERR(dst_st)) 536 return PTR_ERR(dst_st); 537 538 ret = i915_ttm_accel_move(bo, dst_mem, dst_st); 539 if (ret) { 540 /* If we start mapping GGTT, we can no longer use man::use_tt here. */ 541 dst_iter = !cpu_maps_iomem(dst_mem) ? 542 ttm_kmap_iter_tt_init(&_dst_iter.tt, bo->ttm) : 543 ttm_kmap_iter_iomap_init(&_dst_iter.io, &dst_reg->iomap, 544 dst_st, dst_reg->region.start); 545 546 src_iter = !cpu_maps_iomem(bo->resource) ? 547 ttm_kmap_iter_tt_init(&_src_iter.tt, bo->ttm) : 548 ttm_kmap_iter_iomap_init(&_src_iter.io, &src_reg->iomap, 549 obj->ttm.cached_io_st, 550 src_reg->region.start); 551 552 ttm_move_memcpy(bo, dst_mem->num_pages, dst_iter, src_iter); 553 } 554 /* Below dst_mem becomes bo->resource. */ 555 ttm_bo_move_sync_cleanup(bo, dst_mem); 556 i915_ttm_adjust_domains_after_move(obj); 557 i915_ttm_free_cached_io_st(obj); 558 559 if (gpu_binds_iomem(dst_mem) || cpu_maps_iomem(dst_mem)) { 560 obj->ttm.cached_io_st = dst_st; 561 obj->ttm.get_io_page.sg_pos = dst_st->sgl; 562 obj->ttm.get_io_page.sg_idx = 0; 563 } 564 565 i915_ttm_adjust_gem_after_move(obj); 566 return 0; 567 } 568 569 static int i915_ttm_io_mem_reserve(struct ttm_device *bdev, struct ttm_resource *mem) 570 { 571 if (!cpu_maps_iomem(mem)) 572 return 0; 573 574 mem->bus.caching = ttm_write_combined; 575 mem->bus.is_iomem = true; 576 577 return 0; 578 } 579 580 static unsigned long i915_ttm_io_mem_pfn(struct ttm_buffer_object *bo, 581 unsigned long page_offset) 582 { 583 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 584 unsigned long base = obj->mm.region->iomap.base - obj->mm.region->region.start; 585 struct scatterlist *sg; 586 unsigned int ofs; 587 588 GEM_WARN_ON(bo->ttm); 589 590 sg = __i915_gem_object_get_sg(obj, &obj->ttm.get_io_page, page_offset, &ofs, true); 591 592 return ((base + sg_dma_address(sg)) >> PAGE_SHIFT) + ofs; 593 } 594 595 static struct ttm_device_funcs i915_ttm_bo_driver = { 596 .ttm_tt_create = i915_ttm_tt_create, 597 .ttm_tt_unpopulate = i915_ttm_tt_unpopulate, 598 .ttm_tt_destroy = i915_ttm_tt_destroy, 599 .eviction_valuable = i915_ttm_eviction_valuable, 600 .evict_flags = i915_ttm_evict_flags, 601 .move = i915_ttm_move, 602 .swap_notify = i915_ttm_swap_notify, 603 .delete_mem_notify = i915_ttm_delete_mem_notify, 604 .io_mem_reserve = i915_ttm_io_mem_reserve, 605 .io_mem_pfn = i915_ttm_io_mem_pfn, 606 }; 607 608 /** 609 * i915_ttm_driver - Return a pointer to the TTM device funcs 610 * 611 * Return: Pointer to statically allocated TTM device funcs. 612 */ 613 struct ttm_device_funcs *i915_ttm_driver(void) 614 { 615 return &i915_ttm_bo_driver; 616 } 617 618 static int __i915_ttm_get_pages(struct drm_i915_gem_object *obj, 619 struct ttm_placement *placement) 620 { 621 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 622 struct ttm_operation_ctx ctx = { 623 .interruptible = true, 624 .no_wait_gpu = false, 625 }; 626 struct sg_table *st; 627 int real_num_busy; 628 int ret; 629 630 /* First try only the requested placement. No eviction. */ 631 real_num_busy = fetch_and_zero(&placement->num_busy_placement); 632 ret = ttm_bo_validate(bo, placement, &ctx); 633 if (ret) { 634 ret = i915_ttm_err_to_gem(ret); 635 /* 636 * Anything that wants to restart the operation gets to 637 * do that. 638 */ 639 if (ret == -EDEADLK || ret == -EINTR || ret == -ERESTARTSYS || 640 ret == -EAGAIN) 641 return ret; 642 643 /* 644 * If the initial attempt fails, allow all accepted placements, 645 * evicting if necessary. 646 */ 647 placement->num_busy_placement = real_num_busy; 648 ret = ttm_bo_validate(bo, placement, &ctx); 649 if (ret) 650 return i915_ttm_err_to_gem(ret); 651 } 652 653 i915_ttm_adjust_lru(obj); 654 if (bo->ttm && !ttm_tt_is_populated(bo->ttm)) { 655 ret = ttm_tt_populate(bo->bdev, bo->ttm, &ctx); 656 if (ret) 657 return ret; 658 659 i915_ttm_adjust_domains_after_move(obj); 660 i915_ttm_adjust_gem_after_move(obj); 661 } 662 663 if (!i915_gem_object_has_pages(obj)) { 664 /* Object either has a page vector or is an iomem object */ 665 st = bo->ttm ? i915_ttm_tt_get_st(bo->ttm) : obj->ttm.cached_io_st; 666 if (IS_ERR(st)) 667 return PTR_ERR(st); 668 669 __i915_gem_object_set_pages(obj, st, i915_sg_dma_sizes(st->sgl)); 670 } 671 672 return ret; 673 } 674 675 static int i915_ttm_get_pages(struct drm_i915_gem_object *obj) 676 { 677 struct ttm_place requested, busy[I915_TTM_MAX_PLACEMENTS]; 678 struct ttm_placement placement; 679 680 GEM_BUG_ON(obj->mm.n_placements > I915_TTM_MAX_PLACEMENTS); 681 682 /* Move to the requested placement. */ 683 i915_ttm_placement_from_obj(obj, &requested, busy, &placement); 684 685 return __i915_ttm_get_pages(obj, &placement); 686 } 687 688 /** 689 * DOC: Migration vs eviction 690 * 691 * GEM migration may not be the same as TTM migration / eviction. If 692 * the TTM core decides to evict an object it may be evicted to a 693 * TTM memory type that is not in the object's allowable GEM regions, or 694 * in fact theoretically to a TTM memory type that doesn't correspond to 695 * a GEM memory region. In that case the object's GEM region is not 696 * updated, and the data is migrated back to the GEM region at 697 * get_pages time. TTM may however set up CPU ptes to the object even 698 * when it is evicted. 699 * Gem forced migration using the i915_ttm_migrate() op, is allowed even 700 * to regions that are not in the object's list of allowable placements. 701 */ 702 static int i915_ttm_migrate(struct drm_i915_gem_object *obj, 703 struct intel_memory_region *mr) 704 { 705 struct ttm_place requested; 706 struct ttm_placement placement; 707 int ret; 708 709 i915_ttm_place_from_region(mr, &requested, obj->flags); 710 placement.num_placement = 1; 711 placement.num_busy_placement = 1; 712 placement.placement = &requested; 713 placement.busy_placement = &requested; 714 715 ret = __i915_ttm_get_pages(obj, &placement); 716 if (ret) 717 return ret; 718 719 /* 720 * Reinitialize the region bindings. This is primarily 721 * required for objects where the new region is not in 722 * its allowable placements. 723 */ 724 if (obj->mm.region != mr) { 725 i915_gem_object_release_memory_region(obj); 726 i915_gem_object_init_memory_region(obj, mr); 727 } 728 729 return 0; 730 } 731 732 static void i915_ttm_put_pages(struct drm_i915_gem_object *obj, 733 struct sg_table *st) 734 { 735 /* 736 * We're currently not called from a shrinker, so put_pages() 737 * typically means the object is about to destroyed, or called 738 * from move_notify(). So just avoid doing much for now. 739 * If the object is not destroyed next, The TTM eviction logic 740 * and shrinkers will move it out if needed. 741 */ 742 743 i915_ttm_adjust_lru(obj); 744 } 745 746 static void i915_ttm_adjust_lru(struct drm_i915_gem_object *obj) 747 { 748 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 749 750 /* 751 * Don't manipulate the TTM LRUs while in TTM bo destruction. 752 * We're called through i915_ttm_delete_mem_notify(). 753 */ 754 if (!kref_read(&bo->kref)) 755 return; 756 757 /* 758 * Put on the correct LRU list depending on the MADV status 759 */ 760 spin_lock(&bo->bdev->lru_lock); 761 if (obj->mm.madv != I915_MADV_WILLNEED) { 762 bo->priority = I915_TTM_PRIO_PURGE; 763 } else if (!i915_gem_object_has_pages(obj)) { 764 if (bo->priority < I915_TTM_PRIO_HAS_PAGES) 765 bo->priority = I915_TTM_PRIO_HAS_PAGES; 766 } else { 767 if (bo->priority > I915_TTM_PRIO_NO_PAGES) 768 bo->priority = I915_TTM_PRIO_NO_PAGES; 769 } 770 771 ttm_bo_move_to_lru_tail(bo, bo->resource, NULL); 772 spin_unlock(&bo->bdev->lru_lock); 773 } 774 775 /* 776 * TTM-backed gem object destruction requires some clarification. 777 * Basically we have two possibilities here. We can either rely on the 778 * i915 delayed destruction and put the TTM object when the object 779 * is idle. This would be detected by TTM which would bypass the 780 * TTM delayed destroy handling. The other approach is to put the TTM 781 * object early and rely on the TTM destroyed handling, and then free 782 * the leftover parts of the GEM object once TTM's destroyed list handling is 783 * complete. For now, we rely on the latter for two reasons: 784 * a) TTM can evict an object even when it's on the delayed destroy list, 785 * which in theory allows for complete eviction. 786 * b) There is work going on in TTM to allow freeing an object even when 787 * it's not idle, and using the TTM destroyed list handling could help us 788 * benefit from that. 789 */ 790 static void i915_ttm_delayed_free(struct drm_i915_gem_object *obj) 791 { 792 if (obj->ttm.created) { 793 ttm_bo_put(i915_gem_to_ttm(obj)); 794 } else { 795 __i915_gem_free_object(obj); 796 call_rcu(&obj->rcu, __i915_gem_free_object_rcu); 797 } 798 } 799 800 static vm_fault_t vm_fault_ttm(struct vm_fault *vmf) 801 { 802 struct vm_area_struct *area = vmf->vma; 803 struct drm_i915_gem_object *obj = 804 i915_ttm_to_gem(area->vm_private_data); 805 806 /* Sanity check that we allow writing into this object */ 807 if (unlikely(i915_gem_object_is_readonly(obj) && 808 area->vm_flags & VM_WRITE)) 809 return VM_FAULT_SIGBUS; 810 811 return ttm_bo_vm_fault(vmf); 812 } 813 814 static int 815 vm_access_ttm(struct vm_area_struct *area, unsigned long addr, 816 void *buf, int len, int write) 817 { 818 struct drm_i915_gem_object *obj = 819 i915_ttm_to_gem(area->vm_private_data); 820 821 if (i915_gem_object_is_readonly(obj) && write) 822 return -EACCES; 823 824 return ttm_bo_vm_access(area, addr, buf, len, write); 825 } 826 827 static void ttm_vm_open(struct vm_area_struct *vma) 828 { 829 struct drm_i915_gem_object *obj = 830 i915_ttm_to_gem(vma->vm_private_data); 831 832 GEM_BUG_ON(!obj); 833 i915_gem_object_get(obj); 834 } 835 836 static void ttm_vm_close(struct vm_area_struct *vma) 837 { 838 struct drm_i915_gem_object *obj = 839 i915_ttm_to_gem(vma->vm_private_data); 840 841 GEM_BUG_ON(!obj); 842 i915_gem_object_put(obj); 843 } 844 845 static const struct vm_operations_struct vm_ops_ttm = { 846 .fault = vm_fault_ttm, 847 .access = vm_access_ttm, 848 .open = ttm_vm_open, 849 .close = ttm_vm_close, 850 }; 851 852 static u64 i915_ttm_mmap_offset(struct drm_i915_gem_object *obj) 853 { 854 /* The ttm_bo must be allocated with I915_BO_ALLOC_USER */ 855 GEM_BUG_ON(!drm_mm_node_allocated(&obj->base.vma_node.vm_node)); 856 857 return drm_vma_node_offset_addr(&obj->base.vma_node); 858 } 859 860 static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = { 861 .name = "i915_gem_object_ttm", 862 863 .get_pages = i915_ttm_get_pages, 864 .put_pages = i915_ttm_put_pages, 865 .truncate = i915_ttm_purge, 866 .adjust_lru = i915_ttm_adjust_lru, 867 .delayed_free = i915_ttm_delayed_free, 868 .migrate = i915_ttm_migrate, 869 .mmap_offset = i915_ttm_mmap_offset, 870 .mmap_ops = &vm_ops_ttm, 871 }; 872 873 void i915_ttm_bo_destroy(struct ttm_buffer_object *bo) 874 { 875 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 876 877 i915_gem_object_release_memory_region(obj); 878 mutex_destroy(&obj->ttm.get_io_page.lock); 879 if (obj->ttm.created) 880 call_rcu(&obj->rcu, __i915_gem_free_object_rcu); 881 } 882 883 /** 884 * __i915_gem_ttm_object_init - Initialize a ttm-backed i915 gem object 885 * @mem: The initial memory region for the object. 886 * @obj: The gem object. 887 * @size: Object size in bytes. 888 * @flags: gem object flags. 889 * 890 * Return: 0 on success, negative error code on failure. 891 */ 892 int __i915_gem_ttm_object_init(struct intel_memory_region *mem, 893 struct drm_i915_gem_object *obj, 894 resource_size_t size, 895 resource_size_t page_size, 896 unsigned int flags) 897 { 898 static struct lock_class_key lock_class; 899 struct drm_i915_private *i915 = mem->i915; 900 struct ttm_operation_ctx ctx = { 901 .interruptible = true, 902 .no_wait_gpu = false, 903 }; 904 enum ttm_bo_type bo_type; 905 int ret; 906 907 drm_gem_private_object_init(&i915->drm, &obj->base, size); 908 i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class, flags); 909 i915_gem_object_init_memory_region(obj, mem); 910 i915_gem_object_make_unshrinkable(obj); 911 INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL | __GFP_NOWARN); 912 mutex_init(&obj->ttm.get_io_page.lock); 913 bo_type = (obj->flags & I915_BO_ALLOC_USER) ? ttm_bo_type_device : 914 ttm_bo_type_kernel; 915 916 obj->base.vma_node.driver_private = i915_gem_to_ttm(obj); 917 918 /* Forcing the page size is kernel internal only */ 919 GEM_BUG_ON(page_size && obj->mm.n_placements); 920 921 /* 922 * If this function fails, it will call the destructor, but 923 * our caller still owns the object. So no freeing in the 924 * destructor until obj->ttm.created is true. 925 * Similarly, in delayed_destroy, we can't call ttm_bo_put() 926 * until successful initialization. 927 */ 928 ret = ttm_bo_init_reserved(&i915->bdev, i915_gem_to_ttm(obj), size, 929 bo_type, &i915_sys_placement, 930 page_size >> PAGE_SHIFT, 931 &ctx, NULL, NULL, i915_ttm_bo_destroy); 932 if (ret) 933 return i915_ttm_err_to_gem(ret); 934 935 obj->ttm.created = true; 936 i915_ttm_adjust_domains_after_move(obj); 937 i915_ttm_adjust_gem_after_move(obj); 938 i915_gem_object_unlock(obj); 939 940 return 0; 941 } 942 943 static const struct intel_memory_region_ops ttm_system_region_ops = { 944 .init_object = __i915_gem_ttm_object_init, 945 }; 946 947 struct intel_memory_region * 948 i915_gem_ttm_system_setup(struct drm_i915_private *i915, 949 u16 type, u16 instance) 950 { 951 struct intel_memory_region *mr; 952 953 mr = intel_memory_region_create(i915, 0, 954 totalram_pages() << PAGE_SHIFT, 955 PAGE_SIZE, 0, 956 type, instance, 957 &ttm_system_region_ops); 958 if (IS_ERR(mr)) 959 return mr; 960 961 intel_memory_region_set_name(mr, "system-ttm"); 962 return mr; 963 } 964