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 #include "gt/intel_gpu_commands.h" 24 25 #define I915_TTM_PRIO_PURGE 0 26 #define I915_TTM_PRIO_NO_PAGES 1 27 #define I915_TTM_PRIO_HAS_PAGES 2 28 #define I915_TTM_PRIO_NEEDS_CPU_ACCESS 3 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_rsgt: The cached scatter-gather table. 40 * @is_shmem: Set if using shmem. 41 * @filp: The shmem file, if using shmem backend. 42 * 43 * Note that DMA may be going on right up to the point where the page- 44 * vector is unpopulated in delayed destroy. Hence keep the 45 * scatter-gather table mapped and cached up to that point. This is 46 * different from the cached gem object io scatter-gather table which 47 * doesn't have an associated dma mapping. 48 */ 49 struct i915_ttm_tt { 50 struct ttm_tt ttm; 51 struct device *dev; 52 struct i915_refct_sgt cached_rsgt; 53 54 bool is_shmem; 55 struct file *filp; 56 }; 57 58 static const struct ttm_place sys_placement_flags = { 59 .fpfn = 0, 60 .lpfn = 0, 61 .mem_type = I915_PL_SYSTEM, 62 .flags = 0, 63 }; 64 65 static struct ttm_placement i915_sys_placement = { 66 .num_placement = 1, 67 .placement = &sys_placement_flags, 68 .num_busy_placement = 1, 69 .busy_placement = &sys_placement_flags, 70 }; 71 72 /** 73 * i915_ttm_sys_placement - Return the struct ttm_placement to be 74 * used for an object in system memory. 75 * 76 * Rather than making the struct extern, use this 77 * function. 78 * 79 * Return: A pointer to a static variable for sys placement. 80 */ 81 struct ttm_placement *i915_ttm_sys_placement(void) 82 { 83 return &i915_sys_placement; 84 } 85 86 static int i915_ttm_err_to_gem(int err) 87 { 88 /* Fastpath */ 89 if (likely(!err)) 90 return 0; 91 92 switch (err) { 93 case -EBUSY: 94 /* 95 * TTM likes to convert -EDEADLK to -EBUSY, and wants us to 96 * restart the operation, since we don't record the contending 97 * lock. We use -EAGAIN to restart. 98 */ 99 return -EAGAIN; 100 case -ENOSPC: 101 /* 102 * Memory type / region is full, and we can't evict. 103 * Except possibly system, that returns -ENOMEM; 104 */ 105 return -ENXIO; 106 default: 107 break; 108 } 109 110 return err; 111 } 112 113 static enum ttm_caching 114 i915_ttm_select_tt_caching(const struct drm_i915_gem_object *obj) 115 { 116 /* 117 * Objects only allowed in system get cached cpu-mappings, or when 118 * evicting lmem-only buffers to system for swapping. Other objects get 119 * WC mapping for now. Even if in system. 120 */ 121 if (obj->mm.n_placements <= 1) 122 return ttm_cached; 123 124 return ttm_write_combined; 125 } 126 127 static void 128 i915_ttm_place_from_region(const struct intel_memory_region *mr, 129 struct ttm_place *place, 130 resource_size_t offset, 131 resource_size_t size, 132 unsigned int flags) 133 { 134 memset(place, 0, sizeof(*place)); 135 place->mem_type = intel_region_to_ttm_type(mr); 136 137 if (mr->type == INTEL_MEMORY_SYSTEM) 138 return; 139 140 if (flags & I915_BO_ALLOC_CONTIGUOUS) 141 place->flags |= TTM_PL_FLAG_CONTIGUOUS; 142 if (offset != I915_BO_INVALID_OFFSET) { 143 place->fpfn = offset >> PAGE_SHIFT; 144 place->lpfn = place->fpfn + (size >> PAGE_SHIFT); 145 } else if (mr->io_size && mr->io_size < mr->total) { 146 if (flags & I915_BO_ALLOC_GPU_ONLY) { 147 place->flags |= TTM_PL_FLAG_TOPDOWN; 148 } else { 149 place->fpfn = 0; 150 place->lpfn = mr->io_size >> PAGE_SHIFT; 151 } 152 } 153 } 154 155 static void 156 i915_ttm_placement_from_obj(const struct drm_i915_gem_object *obj, 157 struct ttm_place *requested, 158 struct ttm_place *busy, 159 struct ttm_placement *placement) 160 { 161 unsigned int num_allowed = obj->mm.n_placements; 162 unsigned int flags = obj->flags; 163 unsigned int i; 164 165 placement->num_placement = 1; 166 i915_ttm_place_from_region(num_allowed ? obj->mm.placements[0] : 167 obj->mm.region, requested, obj->bo_offset, 168 obj->base.size, flags); 169 170 /* Cache this on object? */ 171 placement->num_busy_placement = num_allowed; 172 for (i = 0; i < placement->num_busy_placement; ++i) 173 i915_ttm_place_from_region(obj->mm.placements[i], busy + i, 174 obj->bo_offset, obj->base.size, flags); 175 176 if (num_allowed == 0) { 177 *busy = *requested; 178 placement->num_busy_placement = 1; 179 } 180 181 placement->placement = requested; 182 placement->busy_placement = busy; 183 } 184 185 static int i915_ttm_tt_shmem_populate(struct ttm_device *bdev, 186 struct ttm_tt *ttm, 187 struct ttm_operation_ctx *ctx) 188 { 189 struct drm_i915_private *i915 = container_of(bdev, typeof(*i915), bdev); 190 struct intel_memory_region *mr = i915->mm.regions[INTEL_MEMORY_SYSTEM]; 191 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 192 const unsigned int max_segment = i915_sg_segment_size(); 193 const size_t size = (size_t)ttm->num_pages << PAGE_SHIFT; 194 struct file *filp = i915_tt->filp; 195 struct sgt_iter sgt_iter; 196 struct sg_table *st; 197 struct page *page; 198 unsigned long i; 199 int err; 200 201 if (!filp) { 202 struct address_space *mapping; 203 gfp_t mask; 204 205 filp = shmem_file_setup("i915-shmem-tt", size, VM_NORESERVE); 206 if (IS_ERR(filp)) 207 return PTR_ERR(filp); 208 209 mask = GFP_HIGHUSER | __GFP_RECLAIMABLE; 210 211 mapping = filp->f_mapping; 212 mapping_set_gfp_mask(mapping, mask); 213 GEM_BUG_ON(!(mapping_gfp_mask(mapping) & __GFP_RECLAIM)); 214 215 i915_tt->filp = filp; 216 } 217 218 st = &i915_tt->cached_rsgt.table; 219 err = shmem_sg_alloc_table(i915, st, size, mr, filp->f_mapping, 220 max_segment); 221 if (err) 222 return err; 223 224 err = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 225 DMA_ATTR_SKIP_CPU_SYNC); 226 if (err) 227 goto err_free_st; 228 229 i = 0; 230 for_each_sgt_page(page, sgt_iter, st) 231 ttm->pages[i++] = page; 232 233 if (ttm->page_flags & TTM_TT_FLAG_SWAPPED) 234 ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED; 235 236 return 0; 237 238 err_free_st: 239 shmem_sg_free_table(st, filp->f_mapping, false, false); 240 241 return err; 242 } 243 244 static void i915_ttm_tt_shmem_unpopulate(struct ttm_tt *ttm) 245 { 246 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 247 bool backup = ttm->page_flags & TTM_TT_FLAG_SWAPPED; 248 struct sg_table *st = &i915_tt->cached_rsgt.table; 249 250 shmem_sg_free_table(st, file_inode(i915_tt->filp)->i_mapping, 251 backup, backup); 252 } 253 254 static void i915_ttm_tt_release(struct kref *ref) 255 { 256 struct i915_ttm_tt *i915_tt = 257 container_of(ref, typeof(*i915_tt), cached_rsgt.kref); 258 struct sg_table *st = &i915_tt->cached_rsgt.table; 259 260 GEM_WARN_ON(st->sgl); 261 262 kfree(i915_tt); 263 } 264 265 static const struct i915_refct_sgt_ops tt_rsgt_ops = { 266 .release = i915_ttm_tt_release 267 }; 268 269 static struct ttm_tt *i915_ttm_tt_create(struct ttm_buffer_object *bo, 270 uint32_t page_flags) 271 { 272 struct drm_i915_private *i915 = container_of(bo->bdev, typeof(*i915), 273 bdev); 274 struct ttm_resource_manager *man = 275 ttm_manager_type(bo->bdev, bo->resource->mem_type); 276 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 277 unsigned long ccs_pages = 0; 278 enum ttm_caching caching; 279 struct i915_ttm_tt *i915_tt; 280 int ret; 281 282 if (!obj) 283 return NULL; 284 285 i915_tt = kzalloc(sizeof(*i915_tt), GFP_KERNEL); 286 if (!i915_tt) 287 return NULL; 288 289 if (obj->flags & I915_BO_ALLOC_CPU_CLEAR && 290 man->use_tt) 291 page_flags |= TTM_TT_FLAG_ZERO_ALLOC; 292 293 caching = i915_ttm_select_tt_caching(obj); 294 if (i915_gem_object_is_shrinkable(obj) && caching == ttm_cached) { 295 page_flags |= TTM_TT_FLAG_EXTERNAL | 296 TTM_TT_FLAG_EXTERNAL_MAPPABLE; 297 i915_tt->is_shmem = true; 298 } 299 300 if (i915_gem_object_needs_ccs_pages(obj)) 301 ccs_pages = DIV_ROUND_UP(DIV_ROUND_UP(bo->base.size, 302 NUM_BYTES_PER_CCS_BYTE), 303 PAGE_SIZE); 304 305 ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags, caching, ccs_pages); 306 if (ret) 307 goto err_free; 308 309 __i915_refct_sgt_init(&i915_tt->cached_rsgt, bo->base.size, 310 &tt_rsgt_ops); 311 312 i915_tt->dev = obj->base.dev->dev; 313 314 return &i915_tt->ttm; 315 316 err_free: 317 kfree(i915_tt); 318 return NULL; 319 } 320 321 static int i915_ttm_tt_populate(struct ttm_device *bdev, 322 struct ttm_tt *ttm, 323 struct ttm_operation_ctx *ctx) 324 { 325 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 326 327 if (i915_tt->is_shmem) 328 return i915_ttm_tt_shmem_populate(bdev, ttm, ctx); 329 330 return ttm_pool_alloc(&bdev->pool, ttm, ctx); 331 } 332 333 static void i915_ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm) 334 { 335 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 336 struct sg_table *st = &i915_tt->cached_rsgt.table; 337 338 if (st->sgl) 339 dma_unmap_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0); 340 341 if (i915_tt->is_shmem) { 342 i915_ttm_tt_shmem_unpopulate(ttm); 343 } else { 344 sg_free_table(st); 345 ttm_pool_free(&bdev->pool, ttm); 346 } 347 } 348 349 static void i915_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm) 350 { 351 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 352 353 if (i915_tt->filp) 354 fput(i915_tt->filp); 355 356 ttm_tt_fini(ttm); 357 i915_refct_sgt_put(&i915_tt->cached_rsgt); 358 } 359 360 static bool i915_ttm_eviction_valuable(struct ttm_buffer_object *bo, 361 const struct ttm_place *place) 362 { 363 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 364 365 if (!obj) 366 return false; 367 368 /* 369 * EXTERNAL objects should never be swapped out by TTM, instead we need 370 * to handle that ourselves. TTM will already skip such objects for us, 371 * but we would like to avoid grabbing locks for no good reason. 372 */ 373 if (bo->ttm && bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL) 374 return false; 375 376 /* Will do for now. Our pinned objects are still on TTM's LRU lists */ 377 if (!i915_gem_object_evictable(obj)) 378 return false; 379 380 return ttm_bo_eviction_valuable(bo, place); 381 } 382 383 static void i915_ttm_evict_flags(struct ttm_buffer_object *bo, 384 struct ttm_placement *placement) 385 { 386 *placement = i915_sys_placement; 387 } 388 389 /** 390 * i915_ttm_free_cached_io_rsgt - Free object cached LMEM information 391 * @obj: The GEM object 392 * This function frees any LMEM-related information that is cached on 393 * the object. For example the radix tree for fast page lookup and the 394 * cached refcounted sg-table 395 */ 396 void i915_ttm_free_cached_io_rsgt(struct drm_i915_gem_object *obj) 397 { 398 struct radix_tree_iter iter; 399 void __rcu **slot; 400 401 if (!obj->ttm.cached_io_rsgt) 402 return; 403 404 rcu_read_lock(); 405 radix_tree_for_each_slot(slot, &obj->ttm.get_io_page.radix, &iter, 0) 406 radix_tree_delete(&obj->ttm.get_io_page.radix, iter.index); 407 rcu_read_unlock(); 408 409 i915_refct_sgt_put(obj->ttm.cached_io_rsgt); 410 obj->ttm.cached_io_rsgt = NULL; 411 } 412 413 /** 414 * i915_ttm_purge - Clear an object of its memory 415 * @obj: The object 416 * 417 * This function is called to clear an object of it's memory when it is 418 * marked as not needed anymore. 419 * 420 * Return: 0 on success, negative error code on failure. 421 */ 422 int i915_ttm_purge(struct drm_i915_gem_object *obj) 423 { 424 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 425 struct i915_ttm_tt *i915_tt = 426 container_of(bo->ttm, typeof(*i915_tt), ttm); 427 struct ttm_operation_ctx ctx = { 428 .interruptible = true, 429 .no_wait_gpu = false, 430 }; 431 struct ttm_placement place = {}; 432 int ret; 433 434 if (obj->mm.madv == __I915_MADV_PURGED) 435 return 0; 436 437 ret = ttm_bo_validate(bo, &place, &ctx); 438 if (ret) 439 return ret; 440 441 if (bo->ttm && i915_tt->filp) { 442 /* 443 * The below fput(which eventually calls shmem_truncate) might 444 * be delayed by worker, so when directly called to purge the 445 * pages(like by the shrinker) we should try to be more 446 * aggressive and release the pages immediately. 447 */ 448 shmem_truncate_range(file_inode(i915_tt->filp), 449 0, (loff_t)-1); 450 fput(fetch_and_zero(&i915_tt->filp)); 451 } 452 453 obj->write_domain = 0; 454 obj->read_domains = 0; 455 i915_ttm_adjust_gem_after_move(obj); 456 i915_ttm_free_cached_io_rsgt(obj); 457 obj->mm.madv = __I915_MADV_PURGED; 458 459 return 0; 460 } 461 462 static int i915_ttm_shrink(struct drm_i915_gem_object *obj, unsigned int flags) 463 { 464 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 465 struct i915_ttm_tt *i915_tt = 466 container_of(bo->ttm, typeof(*i915_tt), ttm); 467 struct ttm_operation_ctx ctx = { 468 .interruptible = true, 469 .no_wait_gpu = flags & I915_GEM_OBJECT_SHRINK_NO_GPU_WAIT, 470 }; 471 struct ttm_placement place = {}; 472 int ret; 473 474 if (!bo->ttm || bo->resource->mem_type != TTM_PL_SYSTEM) 475 return 0; 476 477 GEM_BUG_ON(!i915_tt->is_shmem); 478 479 if (!i915_tt->filp) 480 return 0; 481 482 ret = ttm_bo_wait_ctx(bo, &ctx); 483 if (ret) 484 return ret; 485 486 switch (obj->mm.madv) { 487 case I915_MADV_DONTNEED: 488 return i915_ttm_purge(obj); 489 case __I915_MADV_PURGED: 490 return 0; 491 } 492 493 if (bo->ttm->page_flags & TTM_TT_FLAG_SWAPPED) 494 return 0; 495 496 bo->ttm->page_flags |= TTM_TT_FLAG_SWAPPED; 497 ret = ttm_bo_validate(bo, &place, &ctx); 498 if (ret) { 499 bo->ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED; 500 return ret; 501 } 502 503 if (flags & I915_GEM_OBJECT_SHRINK_WRITEBACK) 504 __shmem_writeback(obj->base.size, i915_tt->filp->f_mapping); 505 506 return 0; 507 } 508 509 static void i915_ttm_delete_mem_notify(struct ttm_buffer_object *bo) 510 { 511 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 512 intel_wakeref_t wakeref = 0; 513 514 if (bo->resource && likely(obj)) { 515 /* ttm_bo_release() already has dma_resv_lock */ 516 if (i915_ttm_cpu_maps_iomem(bo->resource)) 517 wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm); 518 519 __i915_gem_object_pages_fini(obj); 520 521 if (wakeref) 522 intel_runtime_pm_put(&to_i915(obj->base.dev)->runtime_pm, wakeref); 523 524 i915_ttm_free_cached_io_rsgt(obj); 525 } 526 } 527 528 static struct i915_refct_sgt *i915_ttm_tt_get_st(struct ttm_tt *ttm) 529 { 530 struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm); 531 struct sg_table *st; 532 int ret; 533 534 if (i915_tt->cached_rsgt.table.sgl) 535 return i915_refct_sgt_get(&i915_tt->cached_rsgt); 536 537 st = &i915_tt->cached_rsgt.table; 538 ret = sg_alloc_table_from_pages_segment(st, 539 ttm->pages, ttm->num_pages, 540 0, (unsigned long)ttm->num_pages << PAGE_SHIFT, 541 i915_sg_segment_size(), GFP_KERNEL); 542 if (ret) { 543 st->sgl = NULL; 544 return ERR_PTR(ret); 545 } 546 547 ret = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0); 548 if (ret) { 549 sg_free_table(st); 550 return ERR_PTR(ret); 551 } 552 553 return i915_refct_sgt_get(&i915_tt->cached_rsgt); 554 } 555 556 /** 557 * i915_ttm_resource_get_st - Get a refcounted sg-table pointing to the 558 * resource memory 559 * @obj: The GEM object used for sg-table caching 560 * @res: The struct ttm_resource for which an sg-table is requested. 561 * 562 * This function returns a refcounted sg-table representing the memory 563 * pointed to by @res. If @res is the object's current resource it may also 564 * cache the sg_table on the object or attempt to access an already cached 565 * sg-table. The refcounted sg-table needs to be put when no-longer in use. 566 * 567 * Return: A valid pointer to a struct i915_refct_sgt or error pointer on 568 * failure. 569 */ 570 struct i915_refct_sgt * 571 i915_ttm_resource_get_st(struct drm_i915_gem_object *obj, 572 struct ttm_resource *res) 573 { 574 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 575 u32 page_alignment; 576 577 if (!i915_ttm_gtt_binds_lmem(res)) 578 return i915_ttm_tt_get_st(bo->ttm); 579 580 page_alignment = bo->page_alignment << PAGE_SHIFT; 581 if (!page_alignment) 582 page_alignment = obj->mm.region->min_page_size; 583 584 /* 585 * If CPU mapping differs, we need to add the ttm_tt pages to 586 * the resulting st. Might make sense for GGTT. 587 */ 588 GEM_WARN_ON(!i915_ttm_cpu_maps_iomem(res)); 589 if (bo->resource == res) { 590 if (!obj->ttm.cached_io_rsgt) { 591 struct i915_refct_sgt *rsgt; 592 593 rsgt = intel_region_ttm_resource_to_rsgt(obj->mm.region, 594 res, 595 page_alignment); 596 if (IS_ERR(rsgt)) 597 return rsgt; 598 599 obj->ttm.cached_io_rsgt = rsgt; 600 } 601 return i915_refct_sgt_get(obj->ttm.cached_io_rsgt); 602 } 603 604 return intel_region_ttm_resource_to_rsgt(obj->mm.region, res, 605 page_alignment); 606 } 607 608 static int i915_ttm_truncate(struct drm_i915_gem_object *obj) 609 { 610 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 611 int err; 612 613 WARN_ON_ONCE(obj->mm.madv == I915_MADV_WILLNEED); 614 615 err = i915_ttm_move_notify(bo); 616 if (err) 617 return err; 618 619 return i915_ttm_purge(obj); 620 } 621 622 static void i915_ttm_swap_notify(struct ttm_buffer_object *bo) 623 { 624 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 625 int ret; 626 627 if (!obj) 628 return; 629 630 ret = i915_ttm_move_notify(bo); 631 GEM_WARN_ON(ret); 632 GEM_WARN_ON(obj->ttm.cached_io_rsgt); 633 if (!ret && obj->mm.madv != I915_MADV_WILLNEED) 634 i915_ttm_purge(obj); 635 } 636 637 /** 638 * i915_ttm_resource_mappable - Return true if the ttm resource is CPU 639 * accessible. 640 * @res: The TTM resource to check. 641 * 642 * This is interesting on small-BAR systems where we may encounter lmem objects 643 * that can't be accessed via the CPU. 644 */ 645 bool i915_ttm_resource_mappable(struct ttm_resource *res) 646 { 647 struct i915_ttm_buddy_resource *bman_res = to_ttm_buddy_resource(res); 648 649 if (!i915_ttm_cpu_maps_iomem(res)) 650 return true; 651 652 return bman_res->used_visible_size == bman_res->base.num_pages; 653 } 654 655 static int i915_ttm_io_mem_reserve(struct ttm_device *bdev, struct ttm_resource *mem) 656 { 657 struct drm_i915_gem_object *obj = i915_ttm_to_gem(mem->bo); 658 bool unknown_state; 659 660 if (!obj) 661 return -EINVAL; 662 663 if (!kref_get_unless_zero(&obj->base.refcount)) 664 return -EINVAL; 665 666 assert_object_held(obj); 667 668 unknown_state = i915_gem_object_has_unknown_state(obj); 669 i915_gem_object_put(obj); 670 if (unknown_state) 671 return -EINVAL; 672 673 if (!i915_ttm_cpu_maps_iomem(mem)) 674 return 0; 675 676 if (!i915_ttm_resource_mappable(mem)) 677 return -EINVAL; 678 679 mem->bus.caching = ttm_write_combined; 680 mem->bus.is_iomem = true; 681 682 return 0; 683 } 684 685 static unsigned long i915_ttm_io_mem_pfn(struct ttm_buffer_object *bo, 686 unsigned long page_offset) 687 { 688 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 689 struct scatterlist *sg; 690 unsigned long base; 691 unsigned int ofs; 692 693 GEM_BUG_ON(!obj); 694 GEM_WARN_ON(bo->ttm); 695 696 base = obj->mm.region->iomap.base - obj->mm.region->region.start; 697 sg = __i915_gem_object_get_sg(obj, &obj->ttm.get_io_page, page_offset, &ofs, true); 698 699 return ((base + sg_dma_address(sg)) >> PAGE_SHIFT) + ofs; 700 } 701 702 /* 703 * All callbacks need to take care not to downcast a struct ttm_buffer_object 704 * without checking its subclass, since it might be a TTM ghost object. 705 */ 706 static struct ttm_device_funcs i915_ttm_bo_driver = { 707 .ttm_tt_create = i915_ttm_tt_create, 708 .ttm_tt_populate = i915_ttm_tt_populate, 709 .ttm_tt_unpopulate = i915_ttm_tt_unpopulate, 710 .ttm_tt_destroy = i915_ttm_tt_destroy, 711 .eviction_valuable = i915_ttm_eviction_valuable, 712 .evict_flags = i915_ttm_evict_flags, 713 .move = i915_ttm_move, 714 .swap_notify = i915_ttm_swap_notify, 715 .delete_mem_notify = i915_ttm_delete_mem_notify, 716 .io_mem_reserve = i915_ttm_io_mem_reserve, 717 .io_mem_pfn = i915_ttm_io_mem_pfn, 718 }; 719 720 /** 721 * i915_ttm_driver - Return a pointer to the TTM device funcs 722 * 723 * Return: Pointer to statically allocated TTM device funcs. 724 */ 725 struct ttm_device_funcs *i915_ttm_driver(void) 726 { 727 return &i915_ttm_bo_driver; 728 } 729 730 static int __i915_ttm_get_pages(struct drm_i915_gem_object *obj, 731 struct ttm_placement *placement) 732 { 733 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 734 struct ttm_operation_ctx ctx = { 735 .interruptible = true, 736 .no_wait_gpu = false, 737 }; 738 int real_num_busy; 739 int ret; 740 741 /* First try only the requested placement. No eviction. */ 742 real_num_busy = fetch_and_zero(&placement->num_busy_placement); 743 ret = ttm_bo_validate(bo, placement, &ctx); 744 if (ret) { 745 ret = i915_ttm_err_to_gem(ret); 746 /* 747 * Anything that wants to restart the operation gets to 748 * do that. 749 */ 750 if (ret == -EDEADLK || ret == -EINTR || ret == -ERESTARTSYS || 751 ret == -EAGAIN) 752 return ret; 753 754 /* 755 * If the initial attempt fails, allow all accepted placements, 756 * evicting if necessary. 757 */ 758 placement->num_busy_placement = real_num_busy; 759 ret = ttm_bo_validate(bo, placement, &ctx); 760 if (ret) 761 return i915_ttm_err_to_gem(ret); 762 } 763 764 if (bo->ttm && !ttm_tt_is_populated(bo->ttm)) { 765 ret = ttm_tt_populate(bo->bdev, bo->ttm, &ctx); 766 if (ret) 767 return ret; 768 769 i915_ttm_adjust_domains_after_move(obj); 770 i915_ttm_adjust_gem_after_move(obj); 771 } 772 773 if (!i915_gem_object_has_pages(obj)) { 774 struct i915_refct_sgt *rsgt = 775 i915_ttm_resource_get_st(obj, bo->resource); 776 777 if (IS_ERR(rsgt)) 778 return PTR_ERR(rsgt); 779 780 GEM_BUG_ON(obj->mm.rsgt); 781 obj->mm.rsgt = rsgt; 782 __i915_gem_object_set_pages(obj, &rsgt->table, 783 i915_sg_dma_sizes(rsgt->table.sgl)); 784 } 785 786 GEM_BUG_ON(bo->ttm && ((obj->base.size >> PAGE_SHIFT) < bo->ttm->num_pages)); 787 i915_ttm_adjust_lru(obj); 788 return ret; 789 } 790 791 static int i915_ttm_get_pages(struct drm_i915_gem_object *obj) 792 { 793 struct ttm_place requested, busy[I915_TTM_MAX_PLACEMENTS]; 794 struct ttm_placement placement; 795 796 GEM_BUG_ON(obj->mm.n_placements > I915_TTM_MAX_PLACEMENTS); 797 798 /* Move to the requested placement. */ 799 i915_ttm_placement_from_obj(obj, &requested, busy, &placement); 800 801 return __i915_ttm_get_pages(obj, &placement); 802 } 803 804 /** 805 * DOC: Migration vs eviction 806 * 807 * GEM migration may not be the same as TTM migration / eviction. If 808 * the TTM core decides to evict an object it may be evicted to a 809 * TTM memory type that is not in the object's allowable GEM regions, or 810 * in fact theoretically to a TTM memory type that doesn't correspond to 811 * a GEM memory region. In that case the object's GEM region is not 812 * updated, and the data is migrated back to the GEM region at 813 * get_pages time. TTM may however set up CPU ptes to the object even 814 * when it is evicted. 815 * Gem forced migration using the i915_ttm_migrate() op, is allowed even 816 * to regions that are not in the object's list of allowable placements. 817 */ 818 static int __i915_ttm_migrate(struct drm_i915_gem_object *obj, 819 struct intel_memory_region *mr, 820 unsigned int flags) 821 { 822 struct ttm_place requested; 823 struct ttm_placement placement; 824 int ret; 825 826 i915_ttm_place_from_region(mr, &requested, obj->bo_offset, 827 obj->base.size, flags); 828 placement.num_placement = 1; 829 placement.num_busy_placement = 1; 830 placement.placement = &requested; 831 placement.busy_placement = &requested; 832 833 ret = __i915_ttm_get_pages(obj, &placement); 834 if (ret) 835 return ret; 836 837 /* 838 * Reinitialize the region bindings. This is primarily 839 * required for objects where the new region is not in 840 * its allowable placements. 841 */ 842 if (obj->mm.region != mr) { 843 i915_gem_object_release_memory_region(obj); 844 i915_gem_object_init_memory_region(obj, mr); 845 } 846 847 return 0; 848 } 849 850 static int i915_ttm_migrate(struct drm_i915_gem_object *obj, 851 struct intel_memory_region *mr, 852 unsigned int flags) 853 { 854 return __i915_ttm_migrate(obj, mr, flags); 855 } 856 857 static void i915_ttm_put_pages(struct drm_i915_gem_object *obj, 858 struct sg_table *st) 859 { 860 /* 861 * We're currently not called from a shrinker, so put_pages() 862 * typically means the object is about to destroyed, or called 863 * from move_notify(). So just avoid doing much for now. 864 * If the object is not destroyed next, The TTM eviction logic 865 * and shrinkers will move it out if needed. 866 */ 867 868 if (obj->mm.rsgt) 869 i915_refct_sgt_put(fetch_and_zero(&obj->mm.rsgt)); 870 } 871 872 /** 873 * i915_ttm_adjust_lru - Adjust an object's position on relevant LRU lists. 874 * @obj: The object 875 */ 876 void i915_ttm_adjust_lru(struct drm_i915_gem_object *obj) 877 { 878 struct ttm_buffer_object *bo = i915_gem_to_ttm(obj); 879 struct i915_ttm_tt *i915_tt = 880 container_of(bo->ttm, typeof(*i915_tt), ttm); 881 bool shrinkable = 882 bo->ttm && i915_tt->filp && ttm_tt_is_populated(bo->ttm); 883 884 /* 885 * Don't manipulate the TTM LRUs while in TTM bo destruction. 886 * We're called through i915_ttm_delete_mem_notify(). 887 */ 888 if (!kref_read(&bo->kref)) 889 return; 890 891 /* 892 * We skip managing the shrinker LRU in set_pages() and just manage 893 * everything here. This does at least solve the issue with having 894 * temporary shmem mappings(like with evicted lmem) not being visible to 895 * the shrinker. Only our shmem objects are shrinkable, everything else 896 * we keep as unshrinkable. 897 * 898 * To make sure everything plays nice we keep an extra shrink pin in TTM 899 * if the underlying pages are not currently shrinkable. Once we release 900 * our pin, like when the pages are moved to shmem, the pages will then 901 * be added to the shrinker LRU, assuming the caller isn't also holding 902 * a pin. 903 * 904 * TODO: consider maybe also bumping the shrinker list here when we have 905 * already unpinned it, which should give us something more like an LRU. 906 * 907 * TODO: There is a small window of opportunity for this function to 908 * get called from eviction after we've dropped the last GEM refcount, 909 * but before the TTM deleted flag is set on the object. Avoid 910 * adjusting the shrinker list in such cases, since the object is 911 * not available to the shrinker anyway due to its zero refcount. 912 * To fix this properly we should move to a TTM shrinker LRU list for 913 * these objects. 914 */ 915 if (kref_get_unless_zero(&obj->base.refcount)) { 916 if (shrinkable != obj->mm.ttm_shrinkable) { 917 if (shrinkable) { 918 if (obj->mm.madv == I915_MADV_WILLNEED) 919 __i915_gem_object_make_shrinkable(obj); 920 else 921 __i915_gem_object_make_purgeable(obj); 922 } else { 923 i915_gem_object_make_unshrinkable(obj); 924 } 925 926 obj->mm.ttm_shrinkable = shrinkable; 927 } 928 i915_gem_object_put(obj); 929 } 930 931 /* 932 * Put on the correct LRU list depending on the MADV status 933 */ 934 spin_lock(&bo->bdev->lru_lock); 935 if (shrinkable) { 936 /* Try to keep shmem_tt from being considered for shrinking. */ 937 bo->priority = TTM_MAX_BO_PRIORITY - 1; 938 } else if (obj->mm.madv != I915_MADV_WILLNEED) { 939 bo->priority = I915_TTM_PRIO_PURGE; 940 } else if (!i915_gem_object_has_pages(obj)) { 941 bo->priority = I915_TTM_PRIO_NO_PAGES; 942 } else { 943 struct ttm_resource_manager *man = 944 ttm_manager_type(bo->bdev, bo->resource->mem_type); 945 946 /* 947 * If we need to place an LMEM resource which doesn't need CPU 948 * access then we should try not to victimize mappable objects 949 * first, since we likely end up stealing more of the mappable 950 * portion. And likewise when we try to find space for a mappble 951 * object, we know not to ever victimize objects that don't 952 * occupy any mappable pages. 953 */ 954 if (i915_ttm_cpu_maps_iomem(bo->resource) && 955 i915_ttm_buddy_man_visible_size(man) < man->size && 956 !(obj->flags & I915_BO_ALLOC_GPU_ONLY)) 957 bo->priority = I915_TTM_PRIO_NEEDS_CPU_ACCESS; 958 else 959 bo->priority = I915_TTM_PRIO_HAS_PAGES; 960 } 961 962 ttm_bo_move_to_lru_tail(bo); 963 spin_unlock(&bo->bdev->lru_lock); 964 } 965 966 /* 967 * TTM-backed gem object destruction requires some clarification. 968 * Basically we have two possibilities here. We can either rely on the 969 * i915 delayed destruction and put the TTM object when the object 970 * is idle. This would be detected by TTM which would bypass the 971 * TTM delayed destroy handling. The other approach is to put the TTM 972 * object early and rely on the TTM destroyed handling, and then free 973 * the leftover parts of the GEM object once TTM's destroyed list handling is 974 * complete. For now, we rely on the latter for two reasons: 975 * a) TTM can evict an object even when it's on the delayed destroy list, 976 * which in theory allows for complete eviction. 977 * b) There is work going on in TTM to allow freeing an object even when 978 * it's not idle, and using the TTM destroyed list handling could help us 979 * benefit from that. 980 */ 981 static void i915_ttm_delayed_free(struct drm_i915_gem_object *obj) 982 { 983 GEM_BUG_ON(!obj->ttm.created); 984 985 ttm_bo_put(i915_gem_to_ttm(obj)); 986 } 987 988 static vm_fault_t vm_fault_ttm(struct vm_fault *vmf) 989 { 990 struct vm_area_struct *area = vmf->vma; 991 struct ttm_buffer_object *bo = area->vm_private_data; 992 struct drm_device *dev = bo->base.dev; 993 struct drm_i915_gem_object *obj; 994 intel_wakeref_t wakeref = 0; 995 vm_fault_t ret; 996 int idx; 997 998 obj = i915_ttm_to_gem(bo); 999 if (!obj) 1000 return VM_FAULT_SIGBUS; 1001 1002 /* Sanity check that we allow writing into this object */ 1003 if (unlikely(i915_gem_object_is_readonly(obj) && 1004 area->vm_flags & VM_WRITE)) 1005 return VM_FAULT_SIGBUS; 1006 1007 ret = ttm_bo_vm_reserve(bo, vmf); 1008 if (ret) 1009 return ret; 1010 1011 if (obj->mm.madv != I915_MADV_WILLNEED) { 1012 dma_resv_unlock(bo->base.resv); 1013 return VM_FAULT_SIGBUS; 1014 } 1015 1016 if (i915_ttm_cpu_maps_iomem(bo->resource)) 1017 wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm); 1018 1019 if (!i915_ttm_resource_mappable(bo->resource)) { 1020 int err = -ENODEV; 1021 int i; 1022 1023 for (i = 0; i < obj->mm.n_placements; i++) { 1024 struct intel_memory_region *mr = obj->mm.placements[i]; 1025 unsigned int flags; 1026 1027 if (!mr->io_size && mr->type != INTEL_MEMORY_SYSTEM) 1028 continue; 1029 1030 flags = obj->flags; 1031 flags &= ~I915_BO_ALLOC_GPU_ONLY; 1032 err = __i915_ttm_migrate(obj, mr, flags); 1033 if (!err) 1034 break; 1035 } 1036 1037 if (err) { 1038 drm_dbg(dev, "Unable to make resource CPU accessible\n"); 1039 dma_resv_unlock(bo->base.resv); 1040 ret = VM_FAULT_SIGBUS; 1041 goto out_rpm; 1042 } 1043 } 1044 1045 if (drm_dev_enter(dev, &idx)) { 1046 ret = ttm_bo_vm_fault_reserved(vmf, vmf->vma->vm_page_prot, 1047 TTM_BO_VM_NUM_PREFAULT); 1048 drm_dev_exit(idx); 1049 } else { 1050 ret = ttm_bo_vm_dummy_page(vmf, vmf->vma->vm_page_prot); 1051 } 1052 1053 if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) 1054 goto out_rpm; 1055 1056 /* ttm_bo_vm_reserve() already has dma_resv_lock */ 1057 if (ret == VM_FAULT_NOPAGE && wakeref && !obj->userfault_count) { 1058 obj->userfault_count = 1; 1059 mutex_lock(&to_gt(to_i915(obj->base.dev))->lmem_userfault_lock); 1060 list_add(&obj->userfault_link, &to_gt(to_i915(obj->base.dev))->lmem_userfault_list); 1061 mutex_unlock(&to_gt(to_i915(obj->base.dev))->lmem_userfault_lock); 1062 } 1063 1064 if (wakeref & CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND) 1065 intel_wakeref_auto(&to_gt(to_i915(obj->base.dev))->userfault_wakeref, 1066 msecs_to_jiffies_timeout(CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND)); 1067 1068 i915_ttm_adjust_lru(obj); 1069 1070 dma_resv_unlock(bo->base.resv); 1071 1072 out_rpm: 1073 if (wakeref) 1074 intel_runtime_pm_put(&to_i915(obj->base.dev)->runtime_pm, wakeref); 1075 1076 return ret; 1077 } 1078 1079 static int 1080 vm_access_ttm(struct vm_area_struct *area, unsigned long addr, 1081 void *buf, int len, int write) 1082 { 1083 struct drm_i915_gem_object *obj = 1084 i915_ttm_to_gem(area->vm_private_data); 1085 1086 if (i915_gem_object_is_readonly(obj) && write) 1087 return -EACCES; 1088 1089 return ttm_bo_vm_access(area, addr, buf, len, write); 1090 } 1091 1092 static void ttm_vm_open(struct vm_area_struct *vma) 1093 { 1094 struct drm_i915_gem_object *obj = 1095 i915_ttm_to_gem(vma->vm_private_data); 1096 1097 GEM_BUG_ON(!obj); 1098 i915_gem_object_get(obj); 1099 } 1100 1101 static void ttm_vm_close(struct vm_area_struct *vma) 1102 { 1103 struct drm_i915_gem_object *obj = 1104 i915_ttm_to_gem(vma->vm_private_data); 1105 1106 GEM_BUG_ON(!obj); 1107 i915_gem_object_put(obj); 1108 } 1109 1110 static const struct vm_operations_struct vm_ops_ttm = { 1111 .fault = vm_fault_ttm, 1112 .access = vm_access_ttm, 1113 .open = ttm_vm_open, 1114 .close = ttm_vm_close, 1115 }; 1116 1117 static u64 i915_ttm_mmap_offset(struct drm_i915_gem_object *obj) 1118 { 1119 /* The ttm_bo must be allocated with I915_BO_ALLOC_USER */ 1120 GEM_BUG_ON(!drm_mm_node_allocated(&obj->base.vma_node.vm_node)); 1121 1122 return drm_vma_node_offset_addr(&obj->base.vma_node); 1123 } 1124 1125 static void i915_ttm_unmap_virtual(struct drm_i915_gem_object *obj) 1126 { 1127 ttm_bo_unmap_virtual(i915_gem_to_ttm(obj)); 1128 } 1129 1130 static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = { 1131 .name = "i915_gem_object_ttm", 1132 .flags = I915_GEM_OBJECT_IS_SHRINKABLE | 1133 I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST, 1134 1135 .get_pages = i915_ttm_get_pages, 1136 .put_pages = i915_ttm_put_pages, 1137 .truncate = i915_ttm_truncate, 1138 .shrink = i915_ttm_shrink, 1139 1140 .adjust_lru = i915_ttm_adjust_lru, 1141 .delayed_free = i915_ttm_delayed_free, 1142 .migrate = i915_ttm_migrate, 1143 1144 .mmap_offset = i915_ttm_mmap_offset, 1145 .unmap_virtual = i915_ttm_unmap_virtual, 1146 .mmap_ops = &vm_ops_ttm, 1147 }; 1148 1149 void i915_ttm_bo_destroy(struct ttm_buffer_object *bo) 1150 { 1151 struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo); 1152 1153 i915_gem_object_release_memory_region(obj); 1154 mutex_destroy(&obj->ttm.get_io_page.lock); 1155 1156 if (obj->ttm.created) { 1157 /* 1158 * We freely manage the shrinker LRU outide of the mm.pages life 1159 * cycle. As a result when destroying the object we should be 1160 * extra paranoid and ensure we remove it from the LRU, before 1161 * we free the object. 1162 * 1163 * Touching the ttm_shrinkable outside of the object lock here 1164 * should be safe now that the last GEM object ref was dropped. 1165 */ 1166 if (obj->mm.ttm_shrinkable) 1167 i915_gem_object_make_unshrinkable(obj); 1168 1169 i915_ttm_backup_free(obj); 1170 1171 /* This releases all gem object bindings to the backend. */ 1172 __i915_gem_free_object(obj); 1173 1174 call_rcu(&obj->rcu, __i915_gem_free_object_rcu); 1175 } else { 1176 __i915_gem_object_fini(obj); 1177 } 1178 } 1179 1180 /** 1181 * __i915_gem_ttm_object_init - Initialize a ttm-backed i915 gem object 1182 * @mem: The initial memory region for the object. 1183 * @obj: The gem object. 1184 * @size: Object size in bytes. 1185 * @flags: gem object flags. 1186 * 1187 * Return: 0 on success, negative error code on failure. 1188 */ 1189 int __i915_gem_ttm_object_init(struct intel_memory_region *mem, 1190 struct drm_i915_gem_object *obj, 1191 resource_size_t offset, 1192 resource_size_t size, 1193 resource_size_t page_size, 1194 unsigned int flags) 1195 { 1196 static struct lock_class_key lock_class; 1197 struct drm_i915_private *i915 = mem->i915; 1198 struct ttm_operation_ctx ctx = { 1199 .interruptible = true, 1200 .no_wait_gpu = false, 1201 }; 1202 enum ttm_bo_type bo_type; 1203 int ret; 1204 1205 drm_gem_private_object_init(&i915->drm, &obj->base, size); 1206 i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class, flags); 1207 1208 obj->bo_offset = offset; 1209 1210 /* Don't put on a region list until we're either locked or fully initialized. */ 1211 obj->mm.region = mem; 1212 INIT_LIST_HEAD(&obj->mm.region_link); 1213 1214 INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL | __GFP_NOWARN); 1215 mutex_init(&obj->ttm.get_io_page.lock); 1216 bo_type = (obj->flags & I915_BO_ALLOC_USER) ? ttm_bo_type_device : 1217 ttm_bo_type_kernel; 1218 1219 obj->base.vma_node.driver_private = i915_gem_to_ttm(obj); 1220 1221 /* Forcing the page size is kernel internal only */ 1222 GEM_BUG_ON(page_size && obj->mm.n_placements); 1223 1224 /* 1225 * Keep an extra shrink pin to prevent the object from being made 1226 * shrinkable too early. If the ttm_tt is ever allocated in shmem, we 1227 * drop the pin. The TTM backend manages the shrinker LRU itself, 1228 * outside of the normal mm.pages life cycle. 1229 */ 1230 i915_gem_object_make_unshrinkable(obj); 1231 1232 /* 1233 * If this function fails, it will call the destructor, but 1234 * our caller still owns the object. So no freeing in the 1235 * destructor until obj->ttm.created is true. 1236 * Similarly, in delayed_destroy, we can't call ttm_bo_put() 1237 * until successful initialization. 1238 */ 1239 ret = ttm_bo_init_reserved(&i915->bdev, i915_gem_to_ttm(obj), bo_type, 1240 &i915_sys_placement, page_size >> PAGE_SHIFT, 1241 &ctx, NULL, NULL, i915_ttm_bo_destroy); 1242 if (ret) 1243 return i915_ttm_err_to_gem(ret); 1244 1245 obj->ttm.created = true; 1246 i915_gem_object_release_memory_region(obj); 1247 i915_gem_object_init_memory_region(obj, mem); 1248 i915_ttm_adjust_domains_after_move(obj); 1249 i915_ttm_adjust_gem_after_move(obj); 1250 i915_gem_object_unlock(obj); 1251 1252 return 0; 1253 } 1254 1255 static const struct intel_memory_region_ops ttm_system_region_ops = { 1256 .init_object = __i915_gem_ttm_object_init, 1257 .release = intel_region_ttm_fini, 1258 }; 1259 1260 struct intel_memory_region * 1261 i915_gem_ttm_system_setup(struct drm_i915_private *i915, 1262 u16 type, u16 instance) 1263 { 1264 struct intel_memory_region *mr; 1265 1266 mr = intel_memory_region_create(i915, 0, 1267 totalram_pages() << PAGE_SHIFT, 1268 PAGE_SIZE, 0, 0, 1269 type, instance, 1270 &ttm_system_region_ops); 1271 if (IS_ERR(mr)) 1272 return mr; 1273 1274 intel_memory_region_set_name(mr, "system-ttm"); 1275 return mr; 1276 } 1277