1 // SPDX-License-Identifier: MIT 2 /* 3 * Copyright © 2021 Intel Corporation 4 */ 5 6 #include <linux/shmem_fs.h> 7 8 #include <drm/ttm/ttm_bo_driver.h> 9 #include <drm/ttm/ttm_placement.h> 10 #include <drm/drm_buddy.h> 11 12 #include "i915_drv.h" 13 #include "i915_ttm_buddy_manager.h" 14 #include "intel_memory_region.h" 15 #include "intel_region_ttm.h" 16 17 #include "gem/i915_gem_mman.h" 18 #include "gem/i915_gem_object.h" 19 #include "gem/i915_gem_region.h" 20 #include "gem/i915_gem_ttm.h" 21 #include "gem/i915_gem_ttm_move.h" 22 #include "gem/i915_gem_ttm_pm.h" 23 24 #define I915_TTM_PRIO_PURGE 0 25 #define I915_TTM_PRIO_NO_PAGES 1 26 #define I915_TTM_PRIO_HAS_PAGES 2 27 #define I915_TTM_PRIO_NEEDS_CPU_ACCESS 3 28 29 /* 30 * Size of struct ttm_place vector in on-stack struct ttm_placement allocs 31 */ 32 #define I915_TTM_MAX_PLACEMENTS INTEL_REGION_UNKNOWN 33 34 /** 35 * struct i915_ttm_tt - TTM page vector with additional private information 36 * @ttm: The base TTM page vector. 37 * @dev: The struct device used for dma mapping and unmapping. 38 * @cached_rsgt: The cached scatter-gather table. 39 * @is_shmem: Set if using shmem. 40 * @filp: The shmem file, if using shmem backend. 41 * 42 * Note that DMA may be going on right up to the point where the page- 43 * vector is unpopulated in delayed destroy. Hence keep the 44 * scatter-gather table mapped and cached up to that point. This is 45 * different from the cached gem object io scatter-gather table which 46 * doesn't have an associated dma mapping. 47 */ 48 struct i915_ttm_tt { 49 struct ttm_tt ttm; 50 struct device *dev; 51 struct i915_refct_sgt cached_rsgt; 52 53 bool is_shmem; 54 struct file *filp; 55 }; 56 57 static const struct ttm_place sys_placement_flags = { 58 .fpfn = 0, 59 .lpfn = 0, 60 .mem_type = I915_PL_SYSTEM, 61 .flags = 0, 62 }; 63 64 static struct ttm_placement i915_sys_placement = { 65 .num_placement = 1, 66 .placement = &sys_placement_flags, 67 .num_busy_placement = 1, 68 .busy_placement = &sys_placement_flags, 69 }; 70 71 /** 72 * i915_ttm_sys_placement - Return the struct ttm_placement to be 73 * used for an object in system memory. 74 * 75 * Rather than making the struct extern, use this 76 * function. 77 * 78 * Return: A pointer to a static variable for sys placement. 79 */ 80 struct ttm_placement *i915_ttm_sys_placement(void) 81 { 82 return &i915_sys_placement; 83 } 84 85 static int i915_ttm_err_to_gem(int err) 86 { 87 /* Fastpath */ 88 if (likely(!err)) 89 return 0; 90 91 switch (err) { 92 case -EBUSY: 93 /* 94 * TTM likes to convert -EDEADLK to -EBUSY, and wants us to 95 * restart the operation, since we don't record the contending 96 * lock. We use -EAGAIN to restart. 97 */ 98 return -EAGAIN; 99 case -ENOSPC: 100 /* 101 * Memory type / region is full, and we can't evict. 102 * Except possibly system, that returns -ENOMEM; 103 */ 104 return -ENXIO; 105 default: 106 break; 107 } 108 109 return err; 110 } 111 112 static enum ttm_caching 113 i915_ttm_select_tt_caching(const struct drm_i915_gem_object *obj) 114 { 115 /* 116 * Objects only allowed in system get cached cpu-mappings, or when 117 * evicting lmem-only buffers to system for swapping. Other objects get 118 * WC mapping for now. Even if in system. 119 */ 120 if (obj->mm.n_placements <= 1) 121 return ttm_cached; 122 123 return ttm_write_combined; 124 } 125 126 static void 127 i915_ttm_place_from_region(const struct intel_memory_region *mr, 128 struct ttm_place *place, 129 unsigned int flags) 130 { 131 memset(place, 0, sizeof(*place)); 132 place->mem_type = intel_region_to_ttm_type(mr); 133 134 if (flags & I915_BO_ALLOC_CONTIGUOUS) 135 place->flags |= TTM_PL_FLAG_CONTIGUOUS; 136 if (mr->io_size && mr->io_size < mr->total) { 137 if (flags & I915_BO_ALLOC_GPU_ONLY) { 138 place->flags |= TTM_PL_FLAG_TOPDOWN; 139 } else { 140 place->fpfn = 0; 141 place->lpfn = mr->io_size >> PAGE_SHIFT; 142 } 143 } 144 } 145 146 static void 147 i915_ttm_placement_from_obj(const struct drm_i915_gem_object *obj, 148 struct ttm_place *requested, 149 struct ttm_place *busy, 150 struct ttm_placement *placement) 151 { 152 unsigned int num_allowed = obj->mm.n_placements; 153 unsigned int flags = obj->flags; 154 unsigned int i; 155 156 placement->num_placement = 1; 157 i915_ttm_place_from_region(num_allowed ? obj->mm.placements[0] : 158 obj->mm.region, requested, flags); 159 160 /* Cache this on object? */ 161 placement->num_busy_placement = num_allowed; 162 for (i = 0; i < placement->num_busy_placement; ++i) 163 i915_ttm_place_from_region(obj->mm.placements[i], busy + i, flags); 164 165 if (num_allowed == 0) { 166 *busy = *requested; 167 placement->num_busy_placement = 1; 168 } 169 170 placement->placement = requested; 171 placement->busy_placement = busy; 172 } 173 174 static int i915_ttm_tt_shmem_populate(struct ttm_device *bdev, 175 struct ttm_tt *ttm, 176 struct ttm_operation_ctx *ctx) 177 { 178 struct drm_i915_private *i915 = container_of(bdev, typeof(*i915), bdev); 179 struct intel_memory_region *mr = i915->mm.regions[INTEL_MEMORY_SYSTEM]; 180 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 181 const unsigned int max_segment = i915_sg_segment_size(); 182 const size_t size = (size_t)ttm->num_pages << PAGE_SHIFT; 183 struct file *filp = i915_tt->filp; 184 struct sgt_iter sgt_iter; 185 struct sg_table *st; 186 struct page *page; 187 unsigned long i; 188 int err; 189 190 if (!filp) { 191 struct address_space *mapping; 192 gfp_t mask; 193 194 filp = shmem_file_setup("i915-shmem-tt", size, VM_NORESERVE); 195 if (IS_ERR(filp)) 196 return PTR_ERR(filp); 197 198 mask = GFP_HIGHUSER | __GFP_RECLAIMABLE; 199 200 mapping = filp->f_mapping; 201 mapping_set_gfp_mask(mapping, mask); 202 GEM_BUG_ON(!(mapping_gfp_mask(mapping) & __GFP_RECLAIM)); 203 204 i915_tt->filp = filp; 205 } 206 207 st = &i915_tt->cached_rsgt.table; 208 err = shmem_sg_alloc_table(i915, st, size, mr, filp->f_mapping, 209 max_segment); 210 if (err) 211 return err; 212 213 err = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 214 DMA_ATTR_SKIP_CPU_SYNC); 215 if (err) 216 goto err_free_st; 217 218 i = 0; 219 for_each_sgt_page(page, sgt_iter, st) 220 ttm->pages[i++] = page; 221 222 if (ttm->page_flags & TTM_TT_FLAG_SWAPPED) 223 ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED; 224 225 return 0; 226 227 err_free_st: 228 shmem_sg_free_table(st, filp->f_mapping, false, false); 229 230 return err; 231 } 232 233 static void i915_ttm_tt_shmem_unpopulate(struct ttm_tt *ttm) 234 { 235 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 236 bool backup = ttm->page_flags & TTM_TT_FLAG_SWAPPED; 237 struct sg_table *st = &i915_tt->cached_rsgt.table; 238 239 shmem_sg_free_table(st, file_inode(i915_tt->filp)->i_mapping, 240 backup, backup); 241 } 242 243 static void i915_ttm_tt_release(struct kref *ref) 244 { 245 struct i915_ttm_tt *i915_tt = 246 container_of(ref, typeof(*i915_tt), cached_rsgt.kref); 247 struct sg_table *st = &i915_tt->cached_rsgt.table; 248 249 GEM_WARN_ON(st->sgl); 250 251 kfree(i915_tt); 252 } 253 254 static const struct i915_refct_sgt_ops tt_rsgt_ops = { 255 .release = i915_ttm_tt_release 256 }; 257 258 static struct ttm_tt *i915_ttm_tt_create(struct ttm_buffer_object *bo, 259 uint32_t page_flags) 260 { 261 struct ttm_resource_manager *man = 262 ttm_manager_type(bo->bdev, bo->resource->mem_type); 263 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 264 enum ttm_caching caching; 265 struct i915_ttm_tt *i915_tt; 266 int ret; 267 268 if (!obj) 269 return NULL; 270 271 i915_tt = kzalloc(sizeof(*i915_tt), GFP_KERNEL); 272 if (!i915_tt) 273 return NULL; 274 275 if (obj->flags & I915_BO_ALLOC_CPU_CLEAR && 276 man->use_tt) 277 page_flags |= TTM_TT_FLAG_ZERO_ALLOC; 278 279 caching = i915_ttm_select_tt_caching(obj); 280 if (i915_gem_object_is_shrinkable(obj) && caching == ttm_cached) { 281 page_flags |= TTM_TT_FLAG_EXTERNAL | 282 TTM_TT_FLAG_EXTERNAL_MAPPABLE; 283 i915_tt->is_shmem = true; 284 } 285 286 ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags, caching); 287 if (ret) 288 goto err_free; 289 290 __i915_refct_sgt_init(&i915_tt->cached_rsgt, bo->base.size, 291 &tt_rsgt_ops); 292 293 i915_tt->dev = obj->base.dev->dev; 294 295 return &i915_tt->ttm; 296 297 err_free: 298 kfree(i915_tt); 299 return NULL; 300 } 301 302 static int i915_ttm_tt_populate(struct ttm_device *bdev, 303 struct ttm_tt *ttm, 304 struct ttm_operation_ctx *ctx) 305 { 306 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 307 308 if (i915_tt->is_shmem) 309 return i915_ttm_tt_shmem_populate(bdev, ttm, ctx); 310 311 return ttm_pool_alloc(&bdev->pool, ttm, ctx); 312 } 313 314 static void i915_ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm) 315 { 316 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 317 struct sg_table *st = &i915_tt->cached_rsgt.table; 318 319 if (st->sgl) 320 dma_unmap_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0); 321 322 if (i915_tt->is_shmem) { 323 i915_ttm_tt_shmem_unpopulate(ttm); 324 } else { 325 sg_free_table(st); 326 ttm_pool_free(&bdev->pool, ttm); 327 } 328 } 329 330 static void i915_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm) 331 { 332 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 333 334 if (i915_tt->filp) 335 fput(i915_tt->filp); 336 337 ttm_tt_fini(ttm); 338 i915_refct_sgt_put(&i915_tt->cached_rsgt); 339 } 340 341 static bool i915_ttm_eviction_valuable(struct ttm_buffer_object *bo, 342 const struct ttm_place *place) 343 { 344 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 345 struct ttm_resource *res = bo->resource; 346 347 if (!obj) 348 return false; 349 350 /* 351 * EXTERNAL objects should never be swapped out by TTM, instead we need 352 * to handle that ourselves. TTM will already skip such objects for us, 353 * but we would like to avoid grabbing locks for no good reason. 354 */ 355 if (bo->ttm && bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL) 356 return false; 357 358 /* Will do for now. Our pinned objects are still on TTM's LRU lists */ 359 if (!i915_gem_object_evictable(obj)) 360 return false; 361 362 switch (res->mem_type) { 363 case I915_PL_LMEM0: { 364 struct ttm_resource_manager *man = 365 ttm_manager_type(bo->bdev, res->mem_type); 366 struct i915_ttm_buddy_resource *bman_res = 367 to_ttm_buddy_resource(res); 368 struct drm_buddy *mm = bman_res->mm; 369 struct drm_buddy_block *block; 370 371 if (!place->fpfn && !place->lpfn) 372 return true; 373 374 GEM_BUG_ON(!place->lpfn); 375 376 /* 377 * If we just want something mappable then we can quickly check 378 * if the current victim resource is using any of the CPU 379 * visible portion. 380 */ 381 if (!place->fpfn && 382 place->lpfn == i915_ttm_buddy_man_visible_size(man)) 383 return bman_res->used_visible_size > 0; 384 385 /* Real range allocation */ 386 list_for_each_entry(block, &bman_res->blocks, link) { 387 unsigned long fpfn = 388 drm_buddy_block_offset(block) >> PAGE_SHIFT; 389 unsigned long lpfn = fpfn + 390 (drm_buddy_block_size(mm, block) >> PAGE_SHIFT); 391 392 if (place->fpfn < lpfn && place->lpfn > fpfn) 393 return true; 394 } 395 return false; 396 } default: 397 break; 398 } 399 400 return true; 401 } 402 403 static void i915_ttm_evict_flags(struct ttm_buffer_object *bo, 404 struct ttm_placement *placement) 405 { 406 *placement = i915_sys_placement; 407 } 408 409 /** 410 * i915_ttm_free_cached_io_rsgt - Free object cached LMEM information 411 * @obj: The GEM object 412 * This function frees any LMEM-related information that is cached on 413 * the object. For example the radix tree for fast page lookup and the 414 * cached refcounted sg-table 415 */ 416 void i915_ttm_free_cached_io_rsgt(struct drm_i915_gem_object *obj) 417 { 418 struct radix_tree_iter iter; 419 void __rcu **slot; 420 421 if (!obj->ttm.cached_io_rsgt) 422 return; 423 424 rcu_read_lock(); 425 radix_tree_for_each_slot(slot, &obj->ttm.get_io_page.radix, &iter, 0) 426 radix_tree_delete(&obj->ttm.get_io_page.radix, iter.index); 427 rcu_read_unlock(); 428 429 i915_refct_sgt_put(obj->ttm.cached_io_rsgt); 430 obj->ttm.cached_io_rsgt = NULL; 431 } 432 433 /** 434 * i915_ttm_purge - Clear an object of its memory 435 * @obj: The object 436 * 437 * This function is called to clear an object of it's memory when it is 438 * marked as not needed anymore. 439 * 440 * Return: 0 on success, negative error code on failure. 441 */ 442 int i915_ttm_purge(struct drm_i915_gem_object *obj) 443 { 444 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 445 struct i915_ttm_tt *i915_tt = 446 container_of(bo->ttm, typeof(*i915_tt), ttm); 447 struct ttm_operation_ctx ctx = { 448 .interruptible = true, 449 .no_wait_gpu = false, 450 }; 451 struct ttm_placement place = {}; 452 int ret; 453 454 if (obj->mm.madv == __I915_MADV_PURGED) 455 return 0; 456 457 ret = ttm_bo_validate(bo, &place, &ctx); 458 if (ret) 459 return ret; 460 461 if (bo->ttm && i915_tt->filp) { 462 /* 463 * The below fput(which eventually calls shmem_truncate) might 464 * be delayed by worker, so when directly called to purge the 465 * pages(like by the shrinker) we should try to be more 466 * aggressive and release the pages immediately. 467 */ 468 shmem_truncate_range(file_inode(i915_tt->filp), 469 0, (loff_t)-1); 470 fput(fetch_and_zero(&i915_tt->filp)); 471 } 472 473 obj->write_domain = 0; 474 obj->read_domains = 0; 475 i915_ttm_adjust_gem_after_move(obj); 476 i915_ttm_free_cached_io_rsgt(obj); 477 obj->mm.madv = __I915_MADV_PURGED; 478 479 return 0; 480 } 481 482 static int i915_ttm_shrink(struct drm_i915_gem_object *obj, unsigned int flags) 483 { 484 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 485 struct i915_ttm_tt *i915_tt = 486 container_of(bo->ttm, typeof(*i915_tt), ttm); 487 struct ttm_operation_ctx ctx = { 488 .interruptible = true, 489 .no_wait_gpu = flags & I915_GEM_OBJECT_SHRINK_NO_GPU_WAIT, 490 }; 491 struct ttm_placement place = {}; 492 int ret; 493 494 if (!bo->ttm || bo->resource->mem_type != TTM_PL_SYSTEM) 495 return 0; 496 497 GEM_BUG_ON(!i915_tt->is_shmem); 498 499 if (!i915_tt->filp) 500 return 0; 501 502 ret = ttm_bo_wait_ctx(bo, &ctx); 503 if (ret) 504 return ret; 505 506 switch (obj->mm.madv) { 507 case I915_MADV_DONTNEED: 508 return i915_ttm_purge(obj); 509 case __I915_MADV_PURGED: 510 return 0; 511 } 512 513 if (bo->ttm->page_flags & TTM_TT_FLAG_SWAPPED) 514 return 0; 515 516 bo->ttm->page_flags |= TTM_TT_FLAG_SWAPPED; 517 ret = ttm_bo_validate(bo, &place, &ctx); 518 if (ret) { 519 bo->ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED; 520 return ret; 521 } 522 523 if (flags & I915_GEM_OBJECT_SHRINK_WRITEBACK) 524 __shmem_writeback(obj->base.size, i915_tt->filp->f_mapping); 525 526 return 0; 527 } 528 529 static void i915_ttm_delete_mem_notify(struct ttm_buffer_object *bo) 530 { 531 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 532 533 if (likely(obj)) { 534 __i915_gem_object_pages_fini(obj); 535 i915_ttm_free_cached_io_rsgt(obj); 536 } 537 } 538 539 static struct i915_refct_sgt *i915_ttm_tt_get_st(struct ttm_tt *ttm) 540 { 541 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 542 struct sg_table *st; 543 int ret; 544 545 if (i915_tt->cached_rsgt.table.sgl) 546 return i915_refct_sgt_get(&i915_tt->cached_rsgt); 547 548 st = &i915_tt->cached_rsgt.table; 549 ret = sg_alloc_table_from_pages_segment(st, 550 ttm->pages, ttm->num_pages, 551 0, (unsigned long)ttm->num_pages << PAGE_SHIFT, 552 i915_sg_segment_size(), GFP_KERNEL); 553 if (ret) { 554 st->sgl = NULL; 555 return ERR_PTR(ret); 556 } 557 558 ret = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0); 559 if (ret) { 560 sg_free_table(st); 561 return ERR_PTR(ret); 562 } 563 564 return i915_refct_sgt_get(&i915_tt->cached_rsgt); 565 } 566 567 /** 568 * i915_ttm_resource_get_st - Get a refcounted sg-table pointing to the 569 * resource memory 570 * @obj: The GEM object used for sg-table caching 571 * @res: The struct ttm_resource for which an sg-table is requested. 572 * 573 * This function returns a refcounted sg-table representing the memory 574 * pointed to by @res. If @res is the object's current resource it may also 575 * cache the sg_table on the object or attempt to access an already cached 576 * sg-table. The refcounted sg-table needs to be put when no-longer in use. 577 * 578 * Return: A valid pointer to a struct i915_refct_sgt or error pointer on 579 * failure. 580 */ 581 struct i915_refct_sgt * 582 i915_ttm_resource_get_st(struct drm_i915_gem_object *obj, 583 struct ttm_resource *res) 584 { 585 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 586 587 if (!i915_ttm_gtt_binds_lmem(res)) 588 return i915_ttm_tt_get_st(bo->ttm); 589 590 /* 591 * If CPU mapping differs, we need to add the ttm_tt pages to 592 * the resulting st. Might make sense for GGTT. 593 */ 594 GEM_WARN_ON(!i915_ttm_cpu_maps_iomem(res)); 595 if (bo->resource == res) { 596 if (!obj->ttm.cached_io_rsgt) { 597 struct i915_refct_sgt *rsgt; 598 599 rsgt = intel_region_ttm_resource_to_rsgt(obj->mm.region, 600 res); 601 if (IS_ERR(rsgt)) 602 return rsgt; 603 604 obj->ttm.cached_io_rsgt = rsgt; 605 } 606 return i915_refct_sgt_get(obj->ttm.cached_io_rsgt); 607 } 608 609 return intel_region_ttm_resource_to_rsgt(obj->mm.region, res); 610 } 611 612 static int i915_ttm_truncate(struct drm_i915_gem_object *obj) 613 { 614 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 615 int err; 616 617 WARN_ON_ONCE(obj->mm.madv == I915_MADV_WILLNEED); 618 619 err = i915_ttm_move_notify(bo); 620 if (err) 621 return err; 622 623 return i915_ttm_purge(obj); 624 } 625 626 static void i915_ttm_swap_notify(struct ttm_buffer_object *bo) 627 { 628 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 629 int ret; 630 631 if (!obj) 632 return; 633 634 ret = i915_ttm_move_notify(bo); 635 GEM_WARN_ON(ret); 636 GEM_WARN_ON(obj->ttm.cached_io_rsgt); 637 if (!ret && obj->mm.madv != I915_MADV_WILLNEED) 638 i915_ttm_purge(obj); 639 } 640 641 static bool i915_ttm_resource_mappable(struct ttm_resource *res) 642 { 643 struct i915_ttm_buddy_resource *bman_res = to_ttm_buddy_resource(res); 644 645 if (!i915_ttm_cpu_maps_iomem(res)) 646 return true; 647 648 return bman_res->used_visible_size == bman_res->base.num_pages; 649 } 650 651 static int i915_ttm_io_mem_reserve(struct ttm_device *bdev, struct ttm_resource *mem) 652 { 653 if (!i915_ttm_cpu_maps_iomem(mem)) 654 return 0; 655 656 if (!i915_ttm_resource_mappable(mem)) 657 return -EINVAL; 658 659 mem->bus.caching = ttm_write_combined; 660 mem->bus.is_iomem = true; 661 662 return 0; 663 } 664 665 static unsigned long i915_ttm_io_mem_pfn(struct ttm_buffer_object *bo, 666 unsigned long page_offset) 667 { 668 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 669 struct scatterlist *sg; 670 unsigned long base; 671 unsigned int ofs; 672 673 GEM_BUG_ON(!obj); 674 GEM_WARN_ON(bo->ttm); 675 676 base = obj->mm.region->iomap.base - obj->mm.region->region.start; 677 sg = __i915_gem_object_get_sg(obj, &obj->ttm.get_io_page, page_offset, &ofs, true); 678 679 return ((base + sg_dma_address(sg)) >> PAGE_SHIFT) + ofs; 680 } 681 682 /* 683 * All callbacks need to take care not to downcast a struct ttm_buffer_object 684 * without checking its subclass, since it might be a TTM ghost object. 685 */ 686 static struct ttm_device_funcs i915_ttm_bo_driver = { 687 .ttm_tt_create = i915_ttm_tt_create, 688 .ttm_tt_populate = i915_ttm_tt_populate, 689 .ttm_tt_unpopulate = i915_ttm_tt_unpopulate, 690 .ttm_tt_destroy = i915_ttm_tt_destroy, 691 .eviction_valuable = i915_ttm_eviction_valuable, 692 .evict_flags = i915_ttm_evict_flags, 693 .move = i915_ttm_move, 694 .swap_notify = i915_ttm_swap_notify, 695 .delete_mem_notify = i915_ttm_delete_mem_notify, 696 .io_mem_reserve = i915_ttm_io_mem_reserve, 697 .io_mem_pfn = i915_ttm_io_mem_pfn, 698 }; 699 700 /** 701 * i915_ttm_driver - Return a pointer to the TTM device funcs 702 * 703 * Return: Pointer to statically allocated TTM device funcs. 704 */ 705 struct ttm_device_funcs *i915_ttm_driver(void) 706 { 707 return &i915_ttm_bo_driver; 708 } 709 710 static int __i915_ttm_get_pages(struct drm_i915_gem_object *obj, 711 struct ttm_placement *placement) 712 { 713 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 714 struct ttm_operation_ctx ctx = { 715 .interruptible = true, 716 .no_wait_gpu = false, 717 }; 718 int real_num_busy; 719 int ret; 720 721 /* First try only the requested placement. No eviction. */ 722 real_num_busy = fetch_and_zero(&placement->num_busy_placement); 723 ret = ttm_bo_validate(bo, placement, &ctx); 724 if (ret) { 725 ret = i915_ttm_err_to_gem(ret); 726 /* 727 * Anything that wants to restart the operation gets to 728 * do that. 729 */ 730 if (ret == -EDEADLK || ret == -EINTR || ret == -ERESTARTSYS || 731 ret == -EAGAIN) 732 return ret; 733 734 /* 735 * If the initial attempt fails, allow all accepted placements, 736 * evicting if necessary. 737 */ 738 placement->num_busy_placement = real_num_busy; 739 ret = ttm_bo_validate(bo, placement, &ctx); 740 if (ret) 741 return i915_ttm_err_to_gem(ret); 742 } 743 744 if (bo->ttm && !ttm_tt_is_populated(bo->ttm)) { 745 ret = ttm_tt_populate(bo->bdev, bo->ttm, &ctx); 746 if (ret) 747 return ret; 748 749 i915_ttm_adjust_domains_after_move(obj); 750 i915_ttm_adjust_gem_after_move(obj); 751 } 752 753 if (!i915_gem_object_has_pages(obj)) { 754 struct i915_refct_sgt *rsgt = 755 i915_ttm_resource_get_st(obj, bo->resource); 756 757 if (IS_ERR(rsgt)) 758 return PTR_ERR(rsgt); 759 760 GEM_BUG_ON(obj->mm.rsgt); 761 obj->mm.rsgt = rsgt; 762 __i915_gem_object_set_pages(obj, &rsgt->table, 763 i915_sg_dma_sizes(rsgt->table.sgl)); 764 } 765 766 i915_ttm_adjust_lru(obj); 767 return ret; 768 } 769 770 static int i915_ttm_get_pages(struct drm_i915_gem_object *obj) 771 { 772 struct ttm_place requested, busy[I915_TTM_MAX_PLACEMENTS]; 773 struct ttm_placement placement; 774 775 GEM_BUG_ON(obj->mm.n_placements > I915_TTM_MAX_PLACEMENTS); 776 777 /* Move to the requested placement. */ 778 i915_ttm_placement_from_obj(obj, &requested, busy, &placement); 779 780 return __i915_ttm_get_pages(obj, &placement); 781 } 782 783 /** 784 * DOC: Migration vs eviction 785 * 786 * GEM migration may not be the same as TTM migration / eviction. If 787 * the TTM core decides to evict an object it may be evicted to a 788 * TTM memory type that is not in the object's allowable GEM regions, or 789 * in fact theoretically to a TTM memory type that doesn't correspond to 790 * a GEM memory region. In that case the object's GEM region is not 791 * updated, and the data is migrated back to the GEM region at 792 * get_pages time. TTM may however set up CPU ptes to the object even 793 * when it is evicted. 794 * Gem forced migration using the i915_ttm_migrate() op, is allowed even 795 * to regions that are not in the object's list of allowable placements. 796 */ 797 static int __i915_ttm_migrate(struct drm_i915_gem_object *obj, 798 struct intel_memory_region *mr, 799 unsigned int flags) 800 { 801 struct ttm_place requested; 802 struct ttm_placement placement; 803 int ret; 804 805 i915_ttm_place_from_region(mr, &requested, flags); 806 placement.num_placement = 1; 807 placement.num_busy_placement = 1; 808 placement.placement = &requested; 809 placement.busy_placement = &requested; 810 811 ret = __i915_ttm_get_pages(obj, &placement); 812 if (ret) 813 return ret; 814 815 /* 816 * Reinitialize the region bindings. This is primarily 817 * required for objects where the new region is not in 818 * its allowable placements. 819 */ 820 if (obj->mm.region != mr) { 821 i915_gem_object_release_memory_region(obj); 822 i915_gem_object_init_memory_region(obj, mr); 823 } 824 825 return 0; 826 } 827 828 static int i915_ttm_migrate(struct drm_i915_gem_object *obj, 829 struct intel_memory_region *mr) 830 { 831 return __i915_ttm_migrate(obj, mr, obj->flags); 832 } 833 834 static void i915_ttm_put_pages(struct drm_i915_gem_object *obj, 835 struct sg_table *st) 836 { 837 /* 838 * We're currently not called from a shrinker, so put_pages() 839 * typically means the object is about to destroyed, or called 840 * from move_notify(). So just avoid doing much for now. 841 * If the object is not destroyed next, The TTM eviction logic 842 * and shrinkers will move it out if needed. 843 */ 844 845 if (obj->mm.rsgt) 846 i915_refct_sgt_put(fetch_and_zero(&obj->mm.rsgt)); 847 } 848 849 /** 850 * i915_ttm_adjust_lru - Adjust an object's position on relevant LRU lists. 851 * @obj: The object 852 */ 853 void i915_ttm_adjust_lru(struct drm_i915_gem_object *obj) 854 { 855 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 856 struct i915_ttm_tt *i915_tt = 857 container_of(bo->ttm, typeof(*i915_tt), ttm); 858 bool shrinkable = 859 bo->ttm && i915_tt->filp && ttm_tt_is_populated(bo->ttm); 860 861 /* 862 * Don't manipulate the TTM LRUs while in TTM bo destruction. 863 * We're called through i915_ttm_delete_mem_notify(). 864 */ 865 if (!kref_read(&bo->kref)) 866 return; 867 868 /* 869 * We skip managing the shrinker LRU in set_pages() and just manage 870 * everything here. This does at least solve the issue with having 871 * temporary shmem mappings(like with evicted lmem) not being visible to 872 * the shrinker. Only our shmem objects are shrinkable, everything else 873 * we keep as unshrinkable. 874 * 875 * To make sure everything plays nice we keep an extra shrink pin in TTM 876 * if the underlying pages are not currently shrinkable. Once we release 877 * our pin, like when the pages are moved to shmem, the pages will then 878 * be added to the shrinker LRU, assuming the caller isn't also holding 879 * a pin. 880 * 881 * TODO: consider maybe also bumping the shrinker list here when we have 882 * already unpinned it, which should give us something more like an LRU. 883 * 884 * TODO: There is a small window of opportunity for this function to 885 * get called from eviction after we've dropped the last GEM refcount, 886 * but before the TTM deleted flag is set on the object. Avoid 887 * adjusting the shrinker list in such cases, since the object is 888 * not available to the shrinker anyway due to its zero refcount. 889 * To fix this properly we should move to a TTM shrinker LRU list for 890 * these objects. 891 */ 892 if (kref_get_unless_zero(&obj->base.refcount)) { 893 if (shrinkable != obj->mm.ttm_shrinkable) { 894 if (shrinkable) { 895 if (obj->mm.madv == I915_MADV_WILLNEED) 896 __i915_gem_object_make_shrinkable(obj); 897 else 898 __i915_gem_object_make_purgeable(obj); 899 } else { 900 i915_gem_object_make_unshrinkable(obj); 901 } 902 903 obj->mm.ttm_shrinkable = shrinkable; 904 } 905 i915_gem_object_put(obj); 906 } 907 908 /* 909 * Put on the correct LRU list depending on the MADV status 910 */ 911 spin_lock(&bo->bdev->lru_lock); 912 if (shrinkable) { 913 /* Try to keep shmem_tt from being considered for shrinking. */ 914 bo->priority = TTM_MAX_BO_PRIORITY - 1; 915 } else if (obj->mm.madv != I915_MADV_WILLNEED) { 916 bo->priority = I915_TTM_PRIO_PURGE; 917 } else if (!i915_gem_object_has_pages(obj)) { 918 bo->priority = I915_TTM_PRIO_NO_PAGES; 919 } else { 920 struct ttm_resource_manager *man = 921 ttm_manager_type(bo->bdev, bo->resource->mem_type); 922 923 /* 924 * If we need to place an LMEM resource which doesn't need CPU 925 * access then we should try not to victimize mappable objects 926 * first, since we likely end up stealing more of the mappable 927 * portion. And likewise when we try to find space for a mappble 928 * object, we know not to ever victimize objects that don't 929 * occupy any mappable pages. 930 */ 931 if (i915_ttm_cpu_maps_iomem(bo->resource) && 932 i915_ttm_buddy_man_visible_size(man) < man->size && 933 !(obj->flags & I915_BO_ALLOC_GPU_ONLY)) 934 bo->priority = I915_TTM_PRIO_NEEDS_CPU_ACCESS; 935 else 936 bo->priority = I915_TTM_PRIO_HAS_PAGES; 937 } 938 939 ttm_bo_move_to_lru_tail(bo, bo->resource, NULL); 940 spin_unlock(&bo->bdev->lru_lock); 941 } 942 943 /* 944 * TTM-backed gem object destruction requires some clarification. 945 * Basically we have two possibilities here. We can either rely on the 946 * i915 delayed destruction and put the TTM object when the object 947 * is idle. This would be detected by TTM which would bypass the 948 * TTM delayed destroy handling. The other approach is to put the TTM 949 * object early and rely on the TTM destroyed handling, and then free 950 * the leftover parts of the GEM object once TTM's destroyed list handling is 951 * complete. For now, we rely on the latter for two reasons: 952 * a) TTM can evict an object even when it's on the delayed destroy list, 953 * which in theory allows for complete eviction. 954 * b) There is work going on in TTM to allow freeing an object even when 955 * it's not idle, and using the TTM destroyed list handling could help us 956 * benefit from that. 957 */ 958 static void i915_ttm_delayed_free(struct drm_i915_gem_object *obj) 959 { 960 GEM_BUG_ON(!obj->ttm.created); 961 962 ttm_bo_put(i915_gem_to_ttm(obj)); 963 } 964 965 static vm_fault_t vm_fault_ttm(struct vm_fault *vmf) 966 { 967 struct vm_area_struct *area = vmf->vma; 968 struct ttm_buffer_object *bo = area->vm_private_data; 969 struct drm_device *dev = bo->base.dev; 970 struct drm_i915_gem_object *obj; 971 vm_fault_t ret; 972 int idx; 973 974 obj = i915_ttm_to_gem(bo); 975 if (!obj) 976 return VM_FAULT_SIGBUS; 977 978 /* Sanity check that we allow writing into this object */ 979 if (unlikely(i915_gem_object_is_readonly(obj) && 980 area->vm_flags & VM_WRITE)) 981 return VM_FAULT_SIGBUS; 982 983 ret = ttm_bo_vm_reserve(bo, vmf); 984 if (ret) 985 return ret; 986 987 if (obj->mm.madv != I915_MADV_WILLNEED) { 988 dma_resv_unlock(bo->base.resv); 989 return VM_FAULT_SIGBUS; 990 } 991 992 if (!i915_ttm_resource_mappable(bo->resource)) { 993 int err = -ENODEV; 994 int i; 995 996 for (i = 0; i < obj->mm.n_placements; i++) { 997 struct intel_memory_region *mr = obj->mm.placements[i]; 998 unsigned int flags; 999 1000 if (!mr->io_size && mr->type != INTEL_MEMORY_SYSTEM) 1001 continue; 1002 1003 flags = obj->flags; 1004 flags &= ~I915_BO_ALLOC_GPU_ONLY; 1005 err = __i915_ttm_migrate(obj, mr, flags); 1006 if (!err) 1007 break; 1008 } 1009 1010 if (err) { 1011 drm_dbg(dev, "Unable to make resource CPU accessible\n"); 1012 dma_resv_unlock(bo->base.resv); 1013 return VM_FAULT_SIGBUS; 1014 } 1015 } 1016 1017 if (drm_dev_enter(dev, &idx)) { 1018 ret = ttm_bo_vm_fault_reserved(vmf, vmf->vma->vm_page_prot, 1019 TTM_BO_VM_NUM_PREFAULT); 1020 drm_dev_exit(idx); 1021 } else { 1022 ret = ttm_bo_vm_dummy_page(vmf, vmf->vma->vm_page_prot); 1023 } 1024 if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) 1025 return ret; 1026 1027 i915_ttm_adjust_lru(obj); 1028 1029 dma_resv_unlock(bo->base.resv); 1030 return ret; 1031 } 1032 1033 static int 1034 vm_access_ttm(struct vm_area_struct *area, unsigned long addr, 1035 void *buf, int len, int write) 1036 { 1037 struct drm_i915_gem_object *obj = 1038 i915_ttm_to_gem(area->vm_private_data); 1039 1040 if (i915_gem_object_is_readonly(obj) && write) 1041 return -EACCES; 1042 1043 return ttm_bo_vm_access(area, addr, buf, len, write); 1044 } 1045 1046 static void ttm_vm_open(struct vm_area_struct *vma) 1047 { 1048 struct drm_i915_gem_object *obj = 1049 i915_ttm_to_gem(vma->vm_private_data); 1050 1051 GEM_BUG_ON(!obj); 1052 i915_gem_object_get(obj); 1053 } 1054 1055 static void ttm_vm_close(struct vm_area_struct *vma) 1056 { 1057 struct drm_i915_gem_object *obj = 1058 i915_ttm_to_gem(vma->vm_private_data); 1059 1060 GEM_BUG_ON(!obj); 1061 i915_gem_object_put(obj); 1062 } 1063 1064 static const struct vm_operations_struct vm_ops_ttm = { 1065 .fault = vm_fault_ttm, 1066 .access = vm_access_ttm, 1067 .open = ttm_vm_open, 1068 .close = ttm_vm_close, 1069 }; 1070 1071 static u64 i915_ttm_mmap_offset(struct drm_i915_gem_object *obj) 1072 { 1073 /* The ttm_bo must be allocated with I915_BO_ALLOC_USER */ 1074 GEM_BUG_ON(!drm_mm_node_allocated(&obj->base.vma_node.vm_node)); 1075 1076 return drm_vma_node_offset_addr(&obj->base.vma_node); 1077 } 1078 1079 static void i915_ttm_unmap_virtual(struct drm_i915_gem_object *obj) 1080 { 1081 ttm_bo_unmap_virtual(i915_gem_to_ttm(obj)); 1082 } 1083 1084 static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = { 1085 .name = "i915_gem_object_ttm", 1086 .flags = I915_GEM_OBJECT_IS_SHRINKABLE | 1087 I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST, 1088 1089 .get_pages = i915_ttm_get_pages, 1090 .put_pages = i915_ttm_put_pages, 1091 .truncate = i915_ttm_truncate, 1092 .shrink = i915_ttm_shrink, 1093 1094 .adjust_lru = i915_ttm_adjust_lru, 1095 .delayed_free = i915_ttm_delayed_free, 1096 .migrate = i915_ttm_migrate, 1097 1098 .mmap_offset = i915_ttm_mmap_offset, 1099 .unmap_virtual = i915_ttm_unmap_virtual, 1100 .mmap_ops = &vm_ops_ttm, 1101 }; 1102 1103 void i915_ttm_bo_destroy(struct ttm_buffer_object *bo) 1104 { 1105 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 1106 1107 i915_gem_object_release_memory_region(obj); 1108 mutex_destroy(&obj->ttm.get_io_page.lock); 1109 1110 if (obj->ttm.created) { 1111 /* 1112 * We freely manage the shrinker LRU outide of the mm.pages life 1113 * cycle. As a result when destroying the object we should be 1114 * extra paranoid and ensure we remove it from the LRU, before 1115 * we free the object. 1116 * 1117 * Touching the ttm_shrinkable outside of the object lock here 1118 * should be safe now that the last GEM object ref was dropped. 1119 */ 1120 if (obj->mm.ttm_shrinkable) 1121 i915_gem_object_make_unshrinkable(obj); 1122 1123 i915_ttm_backup_free(obj); 1124 1125 /* This releases all gem object bindings to the backend. */ 1126 __i915_gem_free_object(obj); 1127 1128 call_rcu(&obj->rcu, __i915_gem_free_object_rcu); 1129 } else { 1130 __i915_gem_object_fini(obj); 1131 } 1132 } 1133 1134 /** 1135 * __i915_gem_ttm_object_init - Initialize a ttm-backed i915 gem object 1136 * @mem: The initial memory region for the object. 1137 * @obj: The gem object. 1138 * @size: Object size in bytes. 1139 * @flags: gem object flags. 1140 * 1141 * Return: 0 on success, negative error code on failure. 1142 */ 1143 int __i915_gem_ttm_object_init(struct intel_memory_region *mem, 1144 struct drm_i915_gem_object *obj, 1145 resource_size_t size, 1146 resource_size_t page_size, 1147 unsigned int flags) 1148 { 1149 static struct lock_class_key lock_class; 1150 struct drm_i915_private *i915 = mem->i915; 1151 struct ttm_operation_ctx ctx = { 1152 .interruptible = true, 1153 .no_wait_gpu = false, 1154 }; 1155 enum ttm_bo_type bo_type; 1156 int ret; 1157 1158 drm_gem_private_object_init(&i915->drm, &obj->base, size); 1159 i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class, flags); 1160 1161 /* Don't put on a region list until we're either locked or fully initialized. */ 1162 obj->mm.region = mem; 1163 INIT_LIST_HEAD(&obj->mm.region_link); 1164 1165 INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL | __GFP_NOWARN); 1166 mutex_init(&obj->ttm.get_io_page.lock); 1167 bo_type = (obj->flags & I915_BO_ALLOC_USER) ? ttm_bo_type_device : 1168 ttm_bo_type_kernel; 1169 1170 obj->base.vma_node.driver_private = i915_gem_to_ttm(obj); 1171 1172 /* Forcing the page size is kernel internal only */ 1173 GEM_BUG_ON(page_size && obj->mm.n_placements); 1174 1175 /* 1176 * Keep an extra shrink pin to prevent the object from being made 1177 * shrinkable too early. If the ttm_tt is ever allocated in shmem, we 1178 * drop the pin. The TTM backend manages the shrinker LRU itself, 1179 * outside of the normal mm.pages life cycle. 1180 */ 1181 i915_gem_object_make_unshrinkable(obj); 1182 1183 /* 1184 * If this function fails, it will call the destructor, but 1185 * our caller still owns the object. So no freeing in the 1186 * destructor until obj->ttm.created is true. 1187 * Similarly, in delayed_destroy, we can't call ttm_bo_put() 1188 * until successful initialization. 1189 */ 1190 ret = ttm_bo_init_reserved(&i915->bdev, i915_gem_to_ttm(obj), size, 1191 bo_type, &i915_sys_placement, 1192 page_size >> PAGE_SHIFT, 1193 &ctx, NULL, NULL, i915_ttm_bo_destroy); 1194 if (ret) 1195 return i915_ttm_err_to_gem(ret); 1196 1197 obj->ttm.created = true; 1198 i915_gem_object_release_memory_region(obj); 1199 i915_gem_object_init_memory_region(obj, mem); 1200 i915_ttm_adjust_domains_after_move(obj); 1201 i915_ttm_adjust_gem_after_move(obj); 1202 i915_gem_object_unlock(obj); 1203 1204 return 0; 1205 } 1206 1207 static const struct intel_memory_region_ops ttm_system_region_ops = { 1208 .init_object = __i915_gem_ttm_object_init, 1209 .release = intel_region_ttm_fini, 1210 }; 1211 1212 struct intel_memory_region * 1213 i915_gem_ttm_system_setup(struct drm_i915_private *i915, 1214 u16 type, u16 instance) 1215 { 1216 struct intel_memory_region *mr; 1217 1218 mr = intel_memory_region_create(i915, 0, 1219 totalram_pages() << PAGE_SHIFT, 1220 PAGE_SIZE, 0, 0, 1221 type, instance, 1222 &ttm_system_region_ops); 1223 if (IS_ERR(mr)) 1224 return mr; 1225 1226 intel_memory_region_set_name(mr, "system-ttm"); 1227 return mr; 1228 } 1229