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_mman.h" 14 #include "gem/i915_gem_object.h" 15 #include "gem/i915_gem_region.h" 16 #include "gem/i915_gem_ttm.h" 17 #include "gem/i915_gem_ttm_move.h" 18 #include "gem/i915_gem_ttm_pm.h" 19 20 #define I915_TTM_PRIO_PURGE 0 21 #define I915_TTM_PRIO_NO_PAGES 1 22 #define I915_TTM_PRIO_HAS_PAGES 2 23 24 /* 25 * Size of struct ttm_place vector in on-stack struct ttm_placement allocs 26 */ 27 #define I915_TTM_MAX_PLACEMENTS INTEL_REGION_UNKNOWN 28 29 /** 30 * struct i915_ttm_tt - TTM page vector with additional private information 31 * @ttm: The base TTM page vector. 32 * @dev: The struct device used for dma mapping and unmapping. 33 * @cached_rsgt: The cached scatter-gather table. 34 * @is_shmem: Set if using shmem. 35 * @filp: The shmem file, if using shmem backend. 36 * 37 * Note that DMA may be going on right up to the point where the page- 38 * vector is unpopulated in delayed destroy. Hence keep the 39 * scatter-gather table mapped and cached up to that point. This is 40 * different from the cached gem object io scatter-gather table which 41 * doesn't have an associated dma mapping. 42 */ 43 struct i915_ttm_tt { 44 struct ttm_tt ttm; 45 struct device *dev; 46 struct i915_refct_sgt cached_rsgt; 47 48 bool is_shmem; 49 struct file *filp; 50 }; 51 52 static const struct ttm_place sys_placement_flags = { 53 .fpfn = 0, 54 .lpfn = 0, 55 .mem_type = I915_PL_SYSTEM, 56 .flags = 0, 57 }; 58 59 static struct ttm_placement i915_sys_placement = { 60 .num_placement = 1, 61 .placement = &sys_placement_flags, 62 .num_busy_placement = 1, 63 .busy_placement = &sys_placement_flags, 64 }; 65 66 /** 67 * i915_ttm_sys_placement - Return the struct ttm_placement to be 68 * used for an object in system memory. 69 * 70 * Rather than making the struct extern, use this 71 * function. 72 * 73 * Return: A pointer to a static variable for sys placement. 74 */ 75 struct ttm_placement *i915_ttm_sys_placement(void) 76 { 77 return &i915_sys_placement; 78 } 79 80 static int i915_ttm_err_to_gem(int err) 81 { 82 /* Fastpath */ 83 if (likely(!err)) 84 return 0; 85 86 switch (err) { 87 case -EBUSY: 88 /* 89 * TTM likes to convert -EDEADLK to -EBUSY, and wants us to 90 * restart the operation, since we don't record the contending 91 * lock. We use -EAGAIN to restart. 92 */ 93 return -EAGAIN; 94 case -ENOSPC: 95 /* 96 * Memory type / region is full, and we can't evict. 97 * Except possibly system, that returns -ENOMEM; 98 */ 99 return -ENXIO; 100 default: 101 break; 102 } 103 104 return err; 105 } 106 107 static enum ttm_caching 108 i915_ttm_select_tt_caching(const struct drm_i915_gem_object *obj) 109 { 110 /* 111 * Objects only allowed in system get cached cpu-mappings, or when 112 * evicting lmem-only buffers to system for swapping. Other objects get 113 * WC mapping for now. Even if in system. 114 */ 115 if (obj->mm.n_placements <= 1) 116 return ttm_cached; 117 118 return ttm_write_combined; 119 } 120 121 static void 122 i915_ttm_place_from_region(const struct intel_memory_region *mr, 123 struct ttm_place *place, 124 unsigned int flags) 125 { 126 memset(place, 0, sizeof(*place)); 127 place->mem_type = intel_region_to_ttm_type(mr); 128 129 if (flags & I915_BO_ALLOC_CONTIGUOUS) 130 place->flags = TTM_PL_FLAG_CONTIGUOUS; 131 } 132 133 static void 134 i915_ttm_placement_from_obj(const struct drm_i915_gem_object *obj, 135 struct ttm_place *requested, 136 struct ttm_place *busy, 137 struct ttm_placement *placement) 138 { 139 unsigned int num_allowed = obj->mm.n_placements; 140 unsigned int flags = obj->flags; 141 unsigned int i; 142 143 placement->num_placement = 1; 144 i915_ttm_place_from_region(num_allowed ? obj->mm.placements[0] : 145 obj->mm.region, requested, flags); 146 147 /* Cache this on object? */ 148 placement->num_busy_placement = num_allowed; 149 for (i = 0; i < placement->num_busy_placement; ++i) 150 i915_ttm_place_from_region(obj->mm.placements[i], busy + i, flags); 151 152 if (num_allowed == 0) { 153 *busy = *requested; 154 placement->num_busy_placement = 1; 155 } 156 157 placement->placement = requested; 158 placement->busy_placement = busy; 159 } 160 161 static int i915_ttm_tt_shmem_populate(struct ttm_device *bdev, 162 struct ttm_tt *ttm, 163 struct ttm_operation_ctx *ctx) 164 { 165 struct drm_i915_private *i915 = container_of(bdev, typeof(*i915), bdev); 166 struct intel_memory_region *mr = i915->mm.regions[INTEL_MEMORY_SYSTEM]; 167 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 168 const unsigned int max_segment = i915_sg_segment_size(); 169 const size_t size = (size_t)ttm->num_pages << PAGE_SHIFT; 170 struct file *filp = i915_tt->filp; 171 struct sgt_iter sgt_iter; 172 struct sg_table *st; 173 struct page *page; 174 unsigned long i; 175 int err; 176 177 if (!filp) { 178 struct address_space *mapping; 179 gfp_t mask; 180 181 filp = shmem_file_setup("i915-shmem-tt", size, VM_NORESERVE); 182 if (IS_ERR(filp)) 183 return PTR_ERR(filp); 184 185 mask = GFP_HIGHUSER | __GFP_RECLAIMABLE; 186 187 mapping = filp->f_mapping; 188 mapping_set_gfp_mask(mapping, mask); 189 GEM_BUG_ON(!(mapping_gfp_mask(mapping) & __GFP_RECLAIM)); 190 191 i915_tt->filp = filp; 192 } 193 194 st = &i915_tt->cached_rsgt.table; 195 err = shmem_sg_alloc_table(i915, st, size, mr, filp->f_mapping, 196 max_segment); 197 if (err) 198 return err; 199 200 err = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 201 DMA_ATTR_SKIP_CPU_SYNC); 202 if (err) 203 goto err_free_st; 204 205 i = 0; 206 for_each_sgt_page(page, sgt_iter, st) 207 ttm->pages[i++] = page; 208 209 if (ttm->page_flags & TTM_TT_FLAG_SWAPPED) 210 ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED; 211 212 return 0; 213 214 err_free_st: 215 shmem_sg_free_table(st, filp->f_mapping, false, false); 216 217 return err; 218 } 219 220 static void i915_ttm_tt_shmem_unpopulate(struct ttm_tt *ttm) 221 { 222 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 223 bool backup = ttm->page_flags & TTM_TT_FLAG_SWAPPED; 224 struct sg_table *st = &i915_tt->cached_rsgt.table; 225 226 shmem_sg_free_table(st, file_inode(i915_tt->filp)->i_mapping, 227 backup, backup); 228 } 229 230 static void i915_ttm_tt_release(struct kref *ref) 231 { 232 struct i915_ttm_tt *i915_tt = 233 container_of(ref, typeof(*i915_tt), cached_rsgt.kref); 234 struct sg_table *st = &i915_tt->cached_rsgt.table; 235 236 GEM_WARN_ON(st->sgl); 237 238 kfree(i915_tt); 239 } 240 241 static const struct i915_refct_sgt_ops tt_rsgt_ops = { 242 .release = i915_ttm_tt_release 243 }; 244 245 static struct ttm_tt *i915_ttm_tt_create(struct ttm_buffer_object *bo, 246 uint32_t page_flags) 247 { 248 struct ttm_resource_manager *man = 249 ttm_manager_type(bo->bdev, bo->resource->mem_type); 250 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 251 enum ttm_caching caching; 252 struct i915_ttm_tt *i915_tt; 253 int ret; 254 255 if (!obj) 256 return NULL; 257 258 i915_tt = kzalloc(sizeof(*i915_tt), GFP_KERNEL); 259 if (!i915_tt) 260 return NULL; 261 262 if (obj->flags & I915_BO_ALLOC_CPU_CLEAR && 263 man->use_tt) 264 page_flags |= TTM_TT_FLAG_ZERO_ALLOC; 265 266 caching = i915_ttm_select_tt_caching(obj); 267 if (i915_gem_object_is_shrinkable(obj) && caching == ttm_cached) { 268 page_flags |= TTM_TT_FLAG_EXTERNAL | 269 TTM_TT_FLAG_EXTERNAL_MAPPABLE; 270 i915_tt->is_shmem = true; 271 } 272 273 ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags, caching); 274 if (ret) 275 goto err_free; 276 277 __i915_refct_sgt_init(&i915_tt->cached_rsgt, bo->base.size, 278 &tt_rsgt_ops); 279 280 i915_tt->dev = obj->base.dev->dev; 281 282 return &i915_tt->ttm; 283 284 err_free: 285 kfree(i915_tt); 286 return NULL; 287 } 288 289 static int i915_ttm_tt_populate(struct ttm_device *bdev, 290 struct ttm_tt *ttm, 291 struct ttm_operation_ctx *ctx) 292 { 293 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 294 295 if (i915_tt->is_shmem) 296 return i915_ttm_tt_shmem_populate(bdev, ttm, ctx); 297 298 return ttm_pool_alloc(&bdev->pool, ttm, ctx); 299 } 300 301 static void i915_ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm) 302 { 303 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 304 struct sg_table *st = &i915_tt->cached_rsgt.table; 305 306 if (st->sgl) 307 dma_unmap_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0); 308 309 if (i915_tt->is_shmem) { 310 i915_ttm_tt_shmem_unpopulate(ttm); 311 } else { 312 sg_free_table(st); 313 ttm_pool_free(&bdev->pool, ttm); 314 } 315 } 316 317 static void i915_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm) 318 { 319 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 320 321 if (i915_tt->filp) 322 fput(i915_tt->filp); 323 324 ttm_tt_fini(ttm); 325 i915_refct_sgt_put(&i915_tt->cached_rsgt); 326 } 327 328 static bool i915_ttm_eviction_valuable(struct ttm_buffer_object *bo, 329 const struct ttm_place *place) 330 { 331 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 332 333 if (!obj) 334 return false; 335 336 /* 337 * EXTERNAL objects should never be swapped out by TTM, instead we need 338 * to handle that ourselves. TTM will already skip such objects for us, 339 * but we would like to avoid grabbing locks for no good reason. 340 */ 341 if (bo->ttm && bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL) 342 return false; 343 344 /* Will do for now. Our pinned objects are still on TTM's LRU lists */ 345 return i915_gem_object_evictable(obj); 346 } 347 348 static void i915_ttm_evict_flags(struct ttm_buffer_object *bo, 349 struct ttm_placement *placement) 350 { 351 *placement = i915_sys_placement; 352 } 353 354 /** 355 * i915_ttm_free_cached_io_rsgt - Free object cached LMEM information 356 * @obj: The GEM object 357 * This function frees any LMEM-related information that is cached on 358 * the object. For example the radix tree for fast page lookup and the 359 * cached refcounted sg-table 360 */ 361 void i915_ttm_free_cached_io_rsgt(struct drm_i915_gem_object *obj) 362 { 363 struct radix_tree_iter iter; 364 void __rcu **slot; 365 366 if (!obj->ttm.cached_io_rsgt) 367 return; 368 369 rcu_read_lock(); 370 radix_tree_for_each_slot(slot, &obj->ttm.get_io_page.radix, &iter, 0) 371 radix_tree_delete(&obj->ttm.get_io_page.radix, iter.index); 372 rcu_read_unlock(); 373 374 i915_refct_sgt_put(obj->ttm.cached_io_rsgt); 375 obj->ttm.cached_io_rsgt = NULL; 376 } 377 378 /** 379 * i915_ttm_purge - Clear an object of its memory 380 * @obj: The object 381 * 382 * This function is called to clear an object of it's memory when it is 383 * marked as not needed anymore. 384 * 385 * Return: 0 on success, negative error code on failure. 386 */ 387 int i915_ttm_purge(struct drm_i915_gem_object *obj) 388 { 389 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 390 struct i915_ttm_tt *i915_tt = 391 container_of(bo->ttm, typeof(*i915_tt), ttm); 392 struct ttm_operation_ctx ctx = { 393 .interruptible = true, 394 .no_wait_gpu = false, 395 }; 396 struct ttm_placement place = {}; 397 int ret; 398 399 if (obj->mm.madv == __I915_MADV_PURGED) 400 return 0; 401 402 ret = ttm_bo_validate(bo, &place, &ctx); 403 if (ret) 404 return ret; 405 406 if (bo->ttm && i915_tt->filp) { 407 /* 408 * The below fput(which eventually calls shmem_truncate) might 409 * be delayed by worker, so when directly called to purge the 410 * pages(like by the shrinker) we should try to be more 411 * aggressive and release the pages immediately. 412 */ 413 shmem_truncate_range(file_inode(i915_tt->filp), 414 0, (loff_t)-1); 415 fput(fetch_and_zero(&i915_tt->filp)); 416 } 417 418 obj->write_domain = 0; 419 obj->read_domains = 0; 420 i915_ttm_adjust_gem_after_move(obj); 421 i915_ttm_free_cached_io_rsgt(obj); 422 obj->mm.madv = __I915_MADV_PURGED; 423 424 return 0; 425 } 426 427 static int i915_ttm_shrinker_release_pages(struct drm_i915_gem_object *obj, 428 bool no_wait_gpu, 429 bool should_writeback) 430 { 431 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 432 struct i915_ttm_tt *i915_tt = 433 container_of(bo->ttm, typeof(*i915_tt), ttm); 434 struct ttm_operation_ctx ctx = { 435 .interruptible = true, 436 .no_wait_gpu = no_wait_gpu, 437 }; 438 struct ttm_placement place = {}; 439 int ret; 440 441 if (!bo->ttm || bo->resource->mem_type != TTM_PL_SYSTEM) 442 return 0; 443 444 GEM_BUG_ON(!i915_tt->is_shmem); 445 446 if (!i915_tt->filp) 447 return 0; 448 449 ret = ttm_bo_wait_ctx(bo, &ctx); 450 if (ret) 451 return ret; 452 453 switch (obj->mm.madv) { 454 case I915_MADV_DONTNEED: 455 return i915_ttm_purge(obj); 456 case __I915_MADV_PURGED: 457 return 0; 458 } 459 460 if (bo->ttm->page_flags & TTM_TT_FLAG_SWAPPED) 461 return 0; 462 463 bo->ttm->page_flags |= TTM_TT_FLAG_SWAPPED; 464 ret = ttm_bo_validate(bo, &place, &ctx); 465 if (ret) { 466 bo->ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED; 467 return ret; 468 } 469 470 if (should_writeback) 471 __shmem_writeback(obj->base.size, i915_tt->filp->f_mapping); 472 473 return 0; 474 } 475 476 static void i915_ttm_delete_mem_notify(struct ttm_buffer_object *bo) 477 { 478 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 479 480 if (likely(obj)) { 481 __i915_gem_object_pages_fini(obj); 482 i915_ttm_free_cached_io_rsgt(obj); 483 } 484 } 485 486 static struct i915_refct_sgt *i915_ttm_tt_get_st(struct ttm_tt *ttm) 487 { 488 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 489 struct sg_table *st; 490 int ret; 491 492 if (i915_tt->cached_rsgt.table.sgl) 493 return i915_refct_sgt_get(&i915_tt->cached_rsgt); 494 495 st = &i915_tt->cached_rsgt.table; 496 ret = sg_alloc_table_from_pages_segment(st, 497 ttm->pages, ttm->num_pages, 498 0, (unsigned long)ttm->num_pages << PAGE_SHIFT, 499 i915_sg_segment_size(), GFP_KERNEL); 500 if (ret) { 501 st->sgl = NULL; 502 return ERR_PTR(ret); 503 } 504 505 ret = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0); 506 if (ret) { 507 sg_free_table(st); 508 return ERR_PTR(ret); 509 } 510 511 return i915_refct_sgt_get(&i915_tt->cached_rsgt); 512 } 513 514 /** 515 * i915_ttm_resource_get_st - Get a refcounted sg-table pointing to the 516 * resource memory 517 * @obj: The GEM object used for sg-table caching 518 * @res: The struct ttm_resource for which an sg-table is requested. 519 * 520 * This function returns a refcounted sg-table representing the memory 521 * pointed to by @res. If @res is the object's current resource it may also 522 * cache the sg_table on the object or attempt to access an already cached 523 * sg-table. The refcounted sg-table needs to be put when no-longer in use. 524 * 525 * Return: A valid pointer to a struct i915_refct_sgt or error pointer on 526 * failure. 527 */ 528 struct i915_refct_sgt * 529 i915_ttm_resource_get_st(struct drm_i915_gem_object *obj, 530 struct ttm_resource *res) 531 { 532 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 533 534 if (!i915_ttm_gtt_binds_lmem(res)) 535 return i915_ttm_tt_get_st(bo->ttm); 536 537 /* 538 * If CPU mapping differs, we need to add the ttm_tt pages to 539 * the resulting st. Might make sense for GGTT. 540 */ 541 GEM_WARN_ON(!i915_ttm_cpu_maps_iomem(res)); 542 if (bo->resource == res) { 543 if (!obj->ttm.cached_io_rsgt) { 544 struct i915_refct_sgt *rsgt; 545 546 rsgt = intel_region_ttm_resource_to_rsgt(obj->mm.region, 547 res); 548 if (IS_ERR(rsgt)) 549 return rsgt; 550 551 obj->ttm.cached_io_rsgt = rsgt; 552 } 553 return i915_refct_sgt_get(obj->ttm.cached_io_rsgt); 554 } 555 556 return intel_region_ttm_resource_to_rsgt(obj->mm.region, res); 557 } 558 559 static int i915_ttm_truncate(struct drm_i915_gem_object *obj) 560 { 561 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 562 int err; 563 564 WARN_ON_ONCE(obj->mm.madv == I915_MADV_WILLNEED); 565 566 err = i915_ttm_move_notify(bo); 567 if (err) 568 return err; 569 570 return i915_ttm_purge(obj); 571 } 572 573 static void i915_ttm_swap_notify(struct ttm_buffer_object *bo) 574 { 575 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 576 int ret; 577 578 if (!obj) 579 return; 580 581 ret = i915_ttm_move_notify(bo); 582 GEM_WARN_ON(ret); 583 GEM_WARN_ON(obj->ttm.cached_io_rsgt); 584 if (!ret && obj->mm.madv != I915_MADV_WILLNEED) 585 i915_ttm_purge(obj); 586 } 587 588 static int i915_ttm_io_mem_reserve(struct ttm_device *bdev, struct ttm_resource *mem) 589 { 590 if (!i915_ttm_cpu_maps_iomem(mem)) 591 return 0; 592 593 mem->bus.caching = ttm_write_combined; 594 mem->bus.is_iomem = true; 595 596 return 0; 597 } 598 599 static unsigned long i915_ttm_io_mem_pfn(struct ttm_buffer_object *bo, 600 unsigned long page_offset) 601 { 602 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 603 struct scatterlist *sg; 604 unsigned long base; 605 unsigned int ofs; 606 607 GEM_BUG_ON(!obj); 608 GEM_WARN_ON(bo->ttm); 609 610 base = obj->mm.region->iomap.base - obj->mm.region->region.start; 611 sg = __i915_gem_object_get_sg(obj, &obj->ttm.get_io_page, page_offset, &ofs, true); 612 613 return ((base + sg_dma_address(sg)) >> PAGE_SHIFT) + ofs; 614 } 615 616 /* 617 * All callbacks need to take care not to downcast a struct ttm_buffer_object 618 * without checking its subclass, since it might be a TTM ghost object. 619 */ 620 static struct ttm_device_funcs i915_ttm_bo_driver = { 621 .ttm_tt_create = i915_ttm_tt_create, 622 .ttm_tt_populate = i915_ttm_tt_populate, 623 .ttm_tt_unpopulate = i915_ttm_tt_unpopulate, 624 .ttm_tt_destroy = i915_ttm_tt_destroy, 625 .eviction_valuable = i915_ttm_eviction_valuable, 626 .evict_flags = i915_ttm_evict_flags, 627 .move = i915_ttm_move, 628 .swap_notify = i915_ttm_swap_notify, 629 .delete_mem_notify = i915_ttm_delete_mem_notify, 630 .io_mem_reserve = i915_ttm_io_mem_reserve, 631 .io_mem_pfn = i915_ttm_io_mem_pfn, 632 }; 633 634 /** 635 * i915_ttm_driver - Return a pointer to the TTM device funcs 636 * 637 * Return: Pointer to statically allocated TTM device funcs. 638 */ 639 struct ttm_device_funcs *i915_ttm_driver(void) 640 { 641 return &i915_ttm_bo_driver; 642 } 643 644 static int __i915_ttm_get_pages(struct drm_i915_gem_object *obj, 645 struct ttm_placement *placement) 646 { 647 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 648 struct ttm_operation_ctx ctx = { 649 .interruptible = true, 650 .no_wait_gpu = false, 651 }; 652 int real_num_busy; 653 int ret; 654 655 /* First try only the requested placement. No eviction. */ 656 real_num_busy = fetch_and_zero(&placement->num_busy_placement); 657 ret = ttm_bo_validate(bo, placement, &ctx); 658 if (ret) { 659 ret = i915_ttm_err_to_gem(ret); 660 /* 661 * Anything that wants to restart the operation gets to 662 * do that. 663 */ 664 if (ret == -EDEADLK || ret == -EINTR || ret == -ERESTARTSYS || 665 ret == -EAGAIN) 666 return ret; 667 668 /* 669 * If the initial attempt fails, allow all accepted placements, 670 * evicting if necessary. 671 */ 672 placement->num_busy_placement = real_num_busy; 673 ret = ttm_bo_validate(bo, placement, &ctx); 674 if (ret) 675 return i915_ttm_err_to_gem(ret); 676 } 677 678 if (bo->ttm && !ttm_tt_is_populated(bo->ttm)) { 679 ret = ttm_tt_populate(bo->bdev, bo->ttm, &ctx); 680 if (ret) 681 return ret; 682 683 i915_ttm_adjust_domains_after_move(obj); 684 i915_ttm_adjust_gem_after_move(obj); 685 } 686 687 if (!i915_gem_object_has_pages(obj)) { 688 struct i915_refct_sgt *rsgt = 689 i915_ttm_resource_get_st(obj, bo->resource); 690 691 if (IS_ERR(rsgt)) 692 return PTR_ERR(rsgt); 693 694 GEM_BUG_ON(obj->mm.rsgt); 695 obj->mm.rsgt = rsgt; 696 __i915_gem_object_set_pages(obj, &rsgt->table, 697 i915_sg_dma_sizes(rsgt->table.sgl)); 698 } 699 700 i915_ttm_adjust_lru(obj); 701 return ret; 702 } 703 704 static int i915_ttm_get_pages(struct drm_i915_gem_object *obj) 705 { 706 struct ttm_place requested, busy[I915_TTM_MAX_PLACEMENTS]; 707 struct ttm_placement placement; 708 709 GEM_BUG_ON(obj->mm.n_placements > I915_TTM_MAX_PLACEMENTS); 710 711 /* Move to the requested placement. */ 712 i915_ttm_placement_from_obj(obj, &requested, busy, &placement); 713 714 return __i915_ttm_get_pages(obj, &placement); 715 } 716 717 /** 718 * DOC: Migration vs eviction 719 * 720 * GEM migration may not be the same as TTM migration / eviction. If 721 * the TTM core decides to evict an object it may be evicted to a 722 * TTM memory type that is not in the object's allowable GEM regions, or 723 * in fact theoretically to a TTM memory type that doesn't correspond to 724 * a GEM memory region. In that case the object's GEM region is not 725 * updated, and the data is migrated back to the GEM region at 726 * get_pages time. TTM may however set up CPU ptes to the object even 727 * when it is evicted. 728 * Gem forced migration using the i915_ttm_migrate() op, is allowed even 729 * to regions that are not in the object's list of allowable placements. 730 */ 731 static int i915_ttm_migrate(struct drm_i915_gem_object *obj, 732 struct intel_memory_region *mr) 733 { 734 struct ttm_place requested; 735 struct ttm_placement placement; 736 int ret; 737 738 i915_ttm_place_from_region(mr, &requested, obj->flags); 739 placement.num_placement = 1; 740 placement.num_busy_placement = 1; 741 placement.placement = &requested; 742 placement.busy_placement = &requested; 743 744 ret = __i915_ttm_get_pages(obj, &placement); 745 if (ret) 746 return ret; 747 748 /* 749 * Reinitialize the region bindings. This is primarily 750 * required for objects where the new region is not in 751 * its allowable placements. 752 */ 753 if (obj->mm.region != mr) { 754 i915_gem_object_release_memory_region(obj); 755 i915_gem_object_init_memory_region(obj, mr); 756 } 757 758 return 0; 759 } 760 761 static void i915_ttm_put_pages(struct drm_i915_gem_object *obj, 762 struct sg_table *st) 763 { 764 /* 765 * We're currently not called from a shrinker, so put_pages() 766 * typically means the object is about to destroyed, or called 767 * from move_notify(). So just avoid doing much for now. 768 * If the object is not destroyed next, The TTM eviction logic 769 * and shrinkers will move it out if needed. 770 */ 771 772 if (obj->mm.rsgt) 773 i915_refct_sgt_put(fetch_and_zero(&obj->mm.rsgt)); 774 } 775 776 /** 777 * i915_ttm_adjust_lru - Adjust an object's position on relevant LRU lists. 778 * @obj: The object 779 */ 780 void i915_ttm_adjust_lru(struct drm_i915_gem_object *obj) 781 { 782 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 783 struct i915_ttm_tt *i915_tt = 784 container_of(bo->ttm, typeof(*i915_tt), ttm); 785 bool shrinkable = 786 bo->ttm && i915_tt->filp && ttm_tt_is_populated(bo->ttm); 787 788 /* 789 * Don't manipulate the TTM LRUs while in TTM bo destruction. 790 * We're called through i915_ttm_delete_mem_notify(). 791 */ 792 if (!kref_read(&bo->kref)) 793 return; 794 795 /* 796 * We skip managing the shrinker LRU in set_pages() and just manage 797 * everything here. This does at least solve the issue with having 798 * temporary shmem mappings(like with evicted lmem) not being visible to 799 * the shrinker. Only our shmem objects are shrinkable, everything else 800 * we keep as unshrinkable. 801 * 802 * To make sure everything plays nice we keep an extra shrink pin in TTM 803 * if the underlying pages are not currently shrinkable. Once we release 804 * our pin, like when the pages are moved to shmem, the pages will then 805 * be added to the shrinker LRU, assuming the caller isn't also holding 806 * a pin. 807 * 808 * TODO: consider maybe also bumping the shrinker list here when we have 809 * already unpinned it, which should give us something more like an LRU. 810 * 811 * TODO: There is a small window of opportunity for this function to 812 * get called from eviction after we've dropped the last GEM refcount, 813 * but before the TTM deleted flag is set on the object. Avoid 814 * adjusting the shrinker list in such cases, since the object is 815 * not available to the shrinker anyway due to its zero refcount. 816 * To fix this properly we should move to a TTM shrinker LRU list for 817 * these objects. 818 */ 819 if (kref_get_unless_zero(&obj->base.refcount)) { 820 if (shrinkable != obj->mm.ttm_shrinkable) { 821 if (shrinkable) { 822 if (obj->mm.madv == I915_MADV_WILLNEED) 823 __i915_gem_object_make_shrinkable(obj); 824 else 825 __i915_gem_object_make_purgeable(obj); 826 } else { 827 i915_gem_object_make_unshrinkable(obj); 828 } 829 830 obj->mm.ttm_shrinkable = shrinkable; 831 } 832 i915_gem_object_put(obj); 833 } 834 835 /* 836 * Put on the correct LRU list depending on the MADV status 837 */ 838 spin_lock(&bo->bdev->lru_lock); 839 if (shrinkable) { 840 /* Try to keep shmem_tt from being considered for shrinking. */ 841 bo->priority = TTM_MAX_BO_PRIORITY - 1; 842 } else if (obj->mm.madv != I915_MADV_WILLNEED) { 843 bo->priority = I915_TTM_PRIO_PURGE; 844 } else if (!i915_gem_object_has_pages(obj)) { 845 bo->priority = I915_TTM_PRIO_NO_PAGES; 846 } else { 847 bo->priority = I915_TTM_PRIO_HAS_PAGES; 848 } 849 850 ttm_bo_move_to_lru_tail(bo, bo->resource, NULL); 851 spin_unlock(&bo->bdev->lru_lock); 852 } 853 854 /* 855 * TTM-backed gem object destruction requires some clarification. 856 * Basically we have two possibilities here. We can either rely on the 857 * i915 delayed destruction and put the TTM object when the object 858 * is idle. This would be detected by TTM which would bypass the 859 * TTM delayed destroy handling. The other approach is to put the TTM 860 * object early and rely on the TTM destroyed handling, and then free 861 * the leftover parts of the GEM object once TTM's destroyed list handling is 862 * complete. For now, we rely on the latter for two reasons: 863 * a) TTM can evict an object even when it's on the delayed destroy list, 864 * which in theory allows for complete eviction. 865 * b) There is work going on in TTM to allow freeing an object even when 866 * it's not idle, and using the TTM destroyed list handling could help us 867 * benefit from that. 868 */ 869 static void i915_ttm_delayed_free(struct drm_i915_gem_object *obj) 870 { 871 GEM_BUG_ON(!obj->ttm.created); 872 873 ttm_bo_put(i915_gem_to_ttm(obj)); 874 } 875 876 static vm_fault_t vm_fault_ttm(struct vm_fault *vmf) 877 { 878 struct vm_area_struct *area = vmf->vma; 879 struct ttm_buffer_object *bo = area->vm_private_data; 880 struct drm_device *dev = bo->base.dev; 881 struct drm_i915_gem_object *obj; 882 vm_fault_t ret; 883 int idx; 884 885 obj = i915_ttm_to_gem(bo); 886 if (!obj) 887 return VM_FAULT_SIGBUS; 888 889 /* Sanity check that we allow writing into this object */ 890 if (unlikely(i915_gem_object_is_readonly(obj) && 891 area->vm_flags & VM_WRITE)) 892 return VM_FAULT_SIGBUS; 893 894 ret = ttm_bo_vm_reserve(bo, vmf); 895 if (ret) 896 return ret; 897 898 if (obj->mm.madv != I915_MADV_WILLNEED) { 899 dma_resv_unlock(bo->base.resv); 900 return VM_FAULT_SIGBUS; 901 } 902 903 if (drm_dev_enter(dev, &idx)) { 904 ret = ttm_bo_vm_fault_reserved(vmf, vmf->vma->vm_page_prot, 905 TTM_BO_VM_NUM_PREFAULT); 906 drm_dev_exit(idx); 907 } else { 908 ret = ttm_bo_vm_dummy_page(vmf, vmf->vma->vm_page_prot); 909 } 910 if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) 911 return ret; 912 913 i915_ttm_adjust_lru(obj); 914 915 dma_resv_unlock(bo->base.resv); 916 return ret; 917 } 918 919 static int 920 vm_access_ttm(struct vm_area_struct *area, unsigned long addr, 921 void *buf, int len, int write) 922 { 923 struct drm_i915_gem_object *obj = 924 i915_ttm_to_gem(area->vm_private_data); 925 926 if (i915_gem_object_is_readonly(obj) && write) 927 return -EACCES; 928 929 return ttm_bo_vm_access(area, addr, buf, len, write); 930 } 931 932 static void ttm_vm_open(struct vm_area_struct *vma) 933 { 934 struct drm_i915_gem_object *obj = 935 i915_ttm_to_gem(vma->vm_private_data); 936 937 GEM_BUG_ON(!obj); 938 i915_gem_object_get(obj); 939 } 940 941 static void ttm_vm_close(struct vm_area_struct *vma) 942 { 943 struct drm_i915_gem_object *obj = 944 i915_ttm_to_gem(vma->vm_private_data); 945 946 GEM_BUG_ON(!obj); 947 i915_gem_object_put(obj); 948 } 949 950 static const struct vm_operations_struct vm_ops_ttm = { 951 .fault = vm_fault_ttm, 952 .access = vm_access_ttm, 953 .open = ttm_vm_open, 954 .close = ttm_vm_close, 955 }; 956 957 static u64 i915_ttm_mmap_offset(struct drm_i915_gem_object *obj) 958 { 959 /* The ttm_bo must be allocated with I915_BO_ALLOC_USER */ 960 GEM_BUG_ON(!drm_mm_node_allocated(&obj->base.vma_node.vm_node)); 961 962 return drm_vma_node_offset_addr(&obj->base.vma_node); 963 } 964 965 static void i915_ttm_unmap_virtual(struct drm_i915_gem_object *obj) 966 { 967 ttm_bo_unmap_virtual(i915_gem_to_ttm(obj)); 968 } 969 970 static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = { 971 .name = "i915_gem_object_ttm", 972 .flags = I915_GEM_OBJECT_IS_SHRINKABLE | 973 I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST, 974 975 .get_pages = i915_ttm_get_pages, 976 .put_pages = i915_ttm_put_pages, 977 .truncate = i915_ttm_truncate, 978 .shrinker_release_pages = i915_ttm_shrinker_release_pages, 979 980 .adjust_lru = i915_ttm_adjust_lru, 981 .delayed_free = i915_ttm_delayed_free, 982 .migrate = i915_ttm_migrate, 983 984 .mmap_offset = i915_ttm_mmap_offset, 985 .unmap_virtual = i915_ttm_unmap_virtual, 986 .mmap_ops = &vm_ops_ttm, 987 }; 988 989 void i915_ttm_bo_destroy(struct ttm_buffer_object *bo) 990 { 991 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 992 993 i915_gem_object_release_memory_region(obj); 994 mutex_destroy(&obj->ttm.get_io_page.lock); 995 996 if (obj->ttm.created) { 997 /* 998 * We freely manage the shrinker LRU outide of the mm.pages life 999 * cycle. As a result when destroying the object we should be 1000 * extra paranoid and ensure we remove it from the LRU, before 1001 * we free the object. 1002 * 1003 * Touching the ttm_shrinkable outside of the object lock here 1004 * should be safe now that the last GEM object ref was dropped. 1005 */ 1006 if (obj->mm.ttm_shrinkable) 1007 i915_gem_object_make_unshrinkable(obj); 1008 1009 i915_ttm_backup_free(obj); 1010 1011 /* This releases all gem object bindings to the backend. */ 1012 __i915_gem_free_object(obj); 1013 1014 call_rcu(&obj->rcu, __i915_gem_free_object_rcu); 1015 } else { 1016 __i915_gem_object_fini(obj); 1017 } 1018 } 1019 1020 /** 1021 * __i915_gem_ttm_object_init - Initialize a ttm-backed i915 gem object 1022 * @mem: The initial memory region for the object. 1023 * @obj: The gem object. 1024 * @size: Object size in bytes. 1025 * @flags: gem object flags. 1026 * 1027 * Return: 0 on success, negative error code on failure. 1028 */ 1029 int __i915_gem_ttm_object_init(struct intel_memory_region *mem, 1030 struct drm_i915_gem_object *obj, 1031 resource_size_t size, 1032 resource_size_t page_size, 1033 unsigned int flags) 1034 { 1035 static struct lock_class_key lock_class; 1036 struct drm_i915_private *i915 = mem->i915; 1037 struct ttm_operation_ctx ctx = { 1038 .interruptible = true, 1039 .no_wait_gpu = false, 1040 }; 1041 enum ttm_bo_type bo_type; 1042 int ret; 1043 1044 drm_gem_private_object_init(&i915->drm, &obj->base, size); 1045 i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class, flags); 1046 1047 /* Don't put on a region list until we're either locked or fully initialized. */ 1048 obj->mm.region = mem; 1049 INIT_LIST_HEAD(&obj->mm.region_link); 1050 1051 INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL | __GFP_NOWARN); 1052 mutex_init(&obj->ttm.get_io_page.lock); 1053 bo_type = (obj->flags & I915_BO_ALLOC_USER) ? ttm_bo_type_device : 1054 ttm_bo_type_kernel; 1055 1056 obj->base.vma_node.driver_private = i915_gem_to_ttm(obj); 1057 1058 /* Forcing the page size is kernel internal only */ 1059 GEM_BUG_ON(page_size && obj->mm.n_placements); 1060 1061 /* 1062 * Keep an extra shrink pin to prevent the object from being made 1063 * shrinkable too early. If the ttm_tt is ever allocated in shmem, we 1064 * drop the pin. The TTM backend manages the shrinker LRU itself, 1065 * outside of the normal mm.pages life cycle. 1066 */ 1067 i915_gem_object_make_unshrinkable(obj); 1068 1069 /* 1070 * If this function fails, it will call the destructor, but 1071 * our caller still owns the object. So no freeing in the 1072 * destructor until obj->ttm.created is true. 1073 * Similarly, in delayed_destroy, we can't call ttm_bo_put() 1074 * until successful initialization. 1075 */ 1076 ret = ttm_bo_init_reserved(&i915->bdev, i915_gem_to_ttm(obj), size, 1077 bo_type, &i915_sys_placement, 1078 page_size >> PAGE_SHIFT, 1079 &ctx, NULL, NULL, i915_ttm_bo_destroy); 1080 if (ret) 1081 return i915_ttm_err_to_gem(ret); 1082 1083 obj->ttm.created = true; 1084 i915_gem_object_release_memory_region(obj); 1085 i915_gem_object_init_memory_region(obj, mem); 1086 i915_ttm_adjust_domains_after_move(obj); 1087 i915_ttm_adjust_gem_after_move(obj); 1088 i915_gem_object_unlock(obj); 1089 1090 return 0; 1091 } 1092 1093 static const struct intel_memory_region_ops ttm_system_region_ops = { 1094 .init_object = __i915_gem_ttm_object_init, 1095 .release = intel_region_ttm_fini, 1096 }; 1097 1098 struct intel_memory_region * 1099 i915_gem_ttm_system_setup(struct drm_i915_private *i915, 1100 u16 type, u16 instance) 1101 { 1102 struct intel_memory_region *mr; 1103 1104 mr = intel_memory_region_create(i915, 0, 1105 totalram_pages() << PAGE_SHIFT, 1106 PAGE_SIZE, 0, 1107 type, instance, 1108 &ttm_system_region_ops); 1109 if (IS_ERR(mr)) 1110 return mr; 1111 1112 intel_memory_region_set_name(mr, "system-ttm"); 1113 return mr; 1114 } 1115