drivers/gpu/drm/i915/gem/i915_gem_ttm.c

   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                            resource_size_t offset,
 130                            resource_size_t size,
 131                            unsigned int flags)
 132 {
 133         memset(place, 0, sizeof(*place));
 134         place->mem_type = intel_region_to_ttm_type(mr);
 135
 136         if (mr->type == INTEL_MEMORY_SYSTEM)
 137                 return;
 138
 139         if (flags & I915_BO_ALLOC_CONTIGUOUS)
 140                 place->flags |= TTM_PL_FLAG_CONTIGUOUS;
 141         if (offset != I915_BO_INVALID_OFFSET) {
 142                 place->fpfn = offset >> PAGE_SHIFT;
 143                 place->lpfn = place->fpfn + (size >> PAGE_SHIFT);
 144         } else if (mr->io_size && mr->io_size < mr->total) {
 145                 if (flags & I915_BO_ALLOC_GPU_ONLY) {
 146                         place->flags |= TTM_PL_FLAG_TOPDOWN;
 147                 } else {
 148                         place->fpfn = 0;
 149                         place->lpfn = mr->io_size >> PAGE_SHIFT;
 150                 }
 151         }
 152 }
 153
 154 static void
 155 i915_ttm_placement_from_obj(const struct drm_i915_gem_object *obj,
 156                             struct ttm_place *requested,
 157                             struct ttm_place *busy,
 158                             struct ttm_placement *placement)
 159 {
 160         unsigned int num_allowed = obj->mm.n_placements;
 161         unsigned int flags = obj->flags;
 162         unsigned int i;
 163
 164         placement->num_placement = 1;
 165         i915_ttm_place_from_region(num_allowed ? obj->mm.placements[0] :
 166                                    obj->mm.region, requested, obj->bo_offset,
 167                                    obj->base.size, flags);
 168
 169         /* Cache this on object? */
 170         placement->num_busy_placement = num_allowed;
 171         for (i = 0; i < placement->num_busy_placement; ++i)
 172                 i915_ttm_place_from_region(obj->mm.placements[i], busy + i,
 173                                            obj->bo_offset, obj->base.size, flags);
 174
 175         if (num_allowed == 0) {
 176                 *busy = *requested;
 177                 placement->num_busy_placement = 1;
 178         }
 179
 180         placement->placement = requested;
 181         placement->busy_placement = busy;
 182 }
 183
 184 static int i915_ttm_tt_shmem_populate(struct ttm_device *bdev,
 185                                       struct ttm_tt *ttm,
 186                                       struct ttm_operation_ctx *ctx)
 187 {
 188         struct drm_i915_private *i915 = container_of(bdev, typeof(*i915), bdev);
 189         struct intel_memory_region *mr = i915->mm.regions[INTEL_MEMORY_SYSTEM];
 190         struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 191         const unsigned int max_segment = i915_sg_segment_size();
 192         const size_t size = (size_t)ttm->num_pages << PAGE_SHIFT;
 193         struct file *filp = i915_tt->filp;
 194         struct sgt_iter sgt_iter;
 195         struct sg_table *st;
 196         struct page *page;
 197         unsigned long i;
 198         int err;
 199
 200         if (!filp) {
 201                 struct address_space *mapping;
 202                 gfp_t mask;
 203
 204                 filp = shmem_file_setup("i915-shmem-tt", size, VM_NORESERVE);
 205                 if (IS_ERR(filp))
 206                         return PTR_ERR(filp);
 207
 208                 mask = GFP_HIGHUSER | __GFP_RECLAIMABLE;
 209
 210                 mapping = filp->f_mapping;
 211                 mapping_set_gfp_mask(mapping, mask);
 212                 GEM_BUG_ON(!(mapping_gfp_mask(mapping) & __GFP_RECLAIM));
 213
 214                 i915_tt->filp = filp;
 215         }
 216
 217         st = &i915_tt->cached_rsgt.table;
 218         err = shmem_sg_alloc_table(i915, st, size, mr, filp->f_mapping,
 219                                    max_segment);
 220         if (err)
 221                 return err;
 222
 223         err = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL,
 224                               DMA_ATTR_SKIP_CPU_SYNC);
 225         if (err)
 226                 goto err_free_st;
 227
 228         i = 0;
 229         for_each_sgt_page(page, sgt_iter, st)
 230                 ttm->pages[i++] = page;
 231
 232         if (ttm->page_flags & TTM_TT_FLAG_SWAPPED)
 233                 ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
 234
 235         return 0;
 236
 237 err_free_st:
 238         shmem_sg_free_table(st, filp->f_mapping, false, false);
 239
 240         return err;
 241 }
 242
 243 static void i915_ttm_tt_shmem_unpopulate(struct ttm_tt *ttm)
 244 {
 245         struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 246         bool backup = ttm->page_flags & TTM_TT_FLAG_SWAPPED;
 247         struct sg_table *st = &i915_tt->cached_rsgt.table;
 248
 249         shmem_sg_free_table(st, file_inode(i915_tt->filp)->i_mapping,
 250                             backup, backup);
 251 }
 252
 253 static void i915_ttm_tt_release(struct kref *ref)
 254 {
 255         struct i915_ttm_tt *i915_tt =
 256                 container_of(ref, typeof(*i915_tt), cached_rsgt.kref);
 257         struct sg_table *st = &i915_tt->cached_rsgt.table;
 258
 259         GEM_WARN_ON(st->sgl);
 260
 261         kfree(i915_tt);
 262 }
 263
 264 static const struct i915_refct_sgt_ops tt_rsgt_ops = {
 265         .release = i915_ttm_tt_release
 266 };
 267
 268 static struct ttm_tt *i915_ttm_tt_create(struct ttm_buffer_object *bo,
 269                                          uint32_t page_flags)
 270 {
 271         struct ttm_resource_manager *man =
 272                 ttm_manager_type(bo->bdev, bo->resource->mem_type);
 273         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 274         enum ttm_caching caching;
 275         struct i915_ttm_tt *i915_tt;
 276         int ret;
 277
 278         if (!obj)
 279                 return NULL;
 280
 281         i915_tt = kzalloc(sizeof(*i915_tt), GFP_KERNEL);
 282         if (!i915_tt)
 283                 return NULL;
 284
 285         if (obj->flags & I915_BO_ALLOC_CPU_CLEAR &&
 286             man->use_tt)
 287                 page_flags |= TTM_TT_FLAG_ZERO_ALLOC;
 288
 289         caching = i915_ttm_select_tt_caching(obj);
 290         if (i915_gem_object_is_shrinkable(obj) && caching == ttm_cached) {
 291                 page_flags |= TTM_TT_FLAG_EXTERNAL |
 292                               TTM_TT_FLAG_EXTERNAL_MAPPABLE;
 293                 i915_tt->is_shmem = true;
 294         }
 295
 296         ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags, caching, 0);
 297         if (ret)
 298                 goto err_free;
 299
 300         __i915_refct_sgt_init(&i915_tt->cached_rsgt, bo->base.size,
 301                               &tt_rsgt_ops);
 302
 303         i915_tt->dev = obj->base.dev->dev;
 304
 305         return &i915_tt->ttm;
 306
 307 err_free:
 308         kfree(i915_tt);
 309         return NULL;
 310 }
 311
 312 static int i915_ttm_tt_populate(struct ttm_device *bdev,
 313                                 struct ttm_tt *ttm,
 314                                 struct ttm_operation_ctx *ctx)
 315 {
 316         struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 317
 318         if (i915_tt->is_shmem)
 319                 return i915_ttm_tt_shmem_populate(bdev, ttm, ctx);
 320
 321         return ttm_pool_alloc(&bdev->pool, ttm, ctx);
 322 }
 323
 324 static void i915_ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
 325 {
 326         struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 327         struct sg_table *st = &i915_tt->cached_rsgt.table;
 328
 329         if (st->sgl)
 330                 dma_unmap_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0);
 331
 332         if (i915_tt->is_shmem) {
 333                 i915_ttm_tt_shmem_unpopulate(ttm);
 334         } else {
 335                 sg_free_table(st);
 336                 ttm_pool_free(&bdev->pool, ttm);
 337         }
 338 }
 339
 340 static void i915_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
 341 {
 342         struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 343
 344         if (i915_tt->filp)
 345                 fput(i915_tt->filp);
 346
 347         ttm_tt_fini(ttm);
 348         i915_refct_sgt_put(&i915_tt->cached_rsgt);
 349 }
 350
 351 static bool i915_ttm_eviction_valuable(struct ttm_buffer_object *bo,
 352                                        const struct ttm_place *place)
 353 {
 354         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 355         struct ttm_resource *res = bo->resource;
 356
 357         if (!obj)
 358                 return false;
 359
 360         /*
 361          * EXTERNAL objects should never be swapped out by TTM, instead we need
 362          * to handle that ourselves. TTM will already skip such objects for us,
 363          * but we would like to avoid grabbing locks for no good reason.
 364          */
 365         if (bo->ttm && bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL)
 366                 return false;
 367
 368         /* Will do for now. Our pinned objects are still on TTM's LRU lists */
 369         if (!i915_gem_object_evictable(obj))
 370                 return false;
 371
 372         switch (res->mem_type) {
 373         case I915_PL_LMEM0: {
 374                 struct ttm_resource_manager *man =
 375                         ttm_manager_type(bo->bdev, res->mem_type);
 376                 struct i915_ttm_buddy_resource *bman_res =
 377                         to_ttm_buddy_resource(res);
 378                 struct drm_buddy *mm = bman_res->mm;
 379                 struct drm_buddy_block *block;
 380
 381                 if (!place->fpfn && !place->lpfn)
 382                         return true;
 383
 384                 GEM_BUG_ON(!place->lpfn);
 385
 386                 /*
 387                  * If we just want something mappable then we can quickly check
 388                  * if the current victim resource is using any of the CPU
 389                  * visible portion.
 390                  */
 391                 if (!place->fpfn &&
 392                     place->lpfn == i915_ttm_buddy_man_visible_size(man))
 393                         return bman_res->used_visible_size > 0;
 394
 395                 /* Real range allocation */
 396                 list_for_each_entry(block, &bman_res->blocks, link) {
 397                         unsigned long fpfn =
 398                                 drm_buddy_block_offset(block) >> PAGE_SHIFT;
 399                         unsigned long lpfn = fpfn +
 400                                 (drm_buddy_block_size(mm, block) >> PAGE_SHIFT);
 401
 402                         if (place->fpfn < lpfn && place->lpfn > fpfn)
 403                                 return true;
 404                 }
 405                 return false;
 406         } default:
 407                 break;
 408         }
 409
 410         return true;
 411 }
 412
 413 static void i915_ttm_evict_flags(struct ttm_buffer_object *bo,
 414                                  struct ttm_placement *placement)
 415 {
 416         *placement = i915_sys_placement;
 417 }
 418
 419 /**
 420  * i915_ttm_free_cached_io_rsgt - Free object cached LMEM information
 421  * @obj: The GEM object
 422  * This function frees any LMEM-related information that is cached on
 423  * the object. For example the radix tree for fast page lookup and the
 424  * cached refcounted sg-table
 425  */
 426 void i915_ttm_free_cached_io_rsgt(struct drm_i915_gem_object *obj)
 427 {
 428         struct radix_tree_iter iter;
 429         void __rcu **slot;
 430
 431         if (!obj->ttm.cached_io_rsgt)
 432                 return;
 433
 434         rcu_read_lock();
 435         radix_tree_for_each_slot(slot, &obj->ttm.get_io_page.radix, &iter, 0)
 436                 radix_tree_delete(&obj->ttm.get_io_page.radix, iter.index);
 437         rcu_read_unlock();
 438
 439         i915_refct_sgt_put(obj->ttm.cached_io_rsgt);
 440         obj->ttm.cached_io_rsgt = NULL;
 441 }
 442
 443 /**
 444  * i915_ttm_purge - Clear an object of its memory
 445  * @obj: The object
 446  *
 447  * This function is called to clear an object of it's memory when it is
 448  * marked as not needed anymore.
 449  *
 450  * Return: 0 on success, negative error code on failure.
 451  */
 452 int i915_ttm_purge(struct drm_i915_gem_object *obj)
 453 {
 454         struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 455         struct i915_ttm_tt *i915_tt =
 456                 container_of(bo->ttm, typeof(*i915_tt), ttm);
 457         struct ttm_operation_ctx ctx = {
 458                 .interruptible = true,
 459                 .no_wait_gpu = false,
 460         };
 461         struct ttm_placement place = {};
 462         int ret;
 463
 464         if (obj->mm.madv == __I915_MADV_PURGED)
 465                 return 0;
 466
 467         ret = ttm_bo_validate(bo, &place, &ctx);
 468         if (ret)
 469                 return ret;
 470
 471         if (bo->ttm && i915_tt->filp) {
 472                 /*
 473                  * The below fput(which eventually calls shmem_truncate) might
 474                  * be delayed by worker, so when directly called to purge the
 475                  * pages(like by the shrinker) we should try to be more
 476                  * aggressive and release the pages immediately.
 477                  */
 478                 shmem_truncate_range(file_inode(i915_tt->filp),
 479                                      0, (loff_t)-1);
 480                 fput(fetch_and_zero(&i915_tt->filp));
 481         }
 482
 483         obj->write_domain = 0;
 484         obj->read_domains = 0;
 485         i915_ttm_adjust_gem_after_move(obj);
 486         i915_ttm_free_cached_io_rsgt(obj);
 487         obj->mm.madv = __I915_MADV_PURGED;
 488
 489         return 0;
 490 }
 491
 492 static int i915_ttm_shrink(struct drm_i915_gem_object *obj, unsigned int flags)
 493 {
 494         struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 495         struct i915_ttm_tt *i915_tt =
 496                 container_of(bo->ttm, typeof(*i915_tt), ttm);
 497         struct ttm_operation_ctx ctx = {
 498                 .interruptible = true,
 499                 .no_wait_gpu = flags & I915_GEM_OBJECT_SHRINK_NO_GPU_WAIT,
 500         };
 501         struct ttm_placement place = {};
 502         int ret;
 503
 504         if (!bo->ttm || bo->resource->mem_type != TTM_PL_SYSTEM)
 505                 return 0;
 506
 507         GEM_BUG_ON(!i915_tt->is_shmem);
 508
 509         if (!i915_tt->filp)
 510                 return 0;
 511
 512         ret = ttm_bo_wait_ctx(bo, &ctx);
 513         if (ret)
 514                 return ret;
 515
 516         switch (obj->mm.madv) {
 517         case I915_MADV_DONTNEED:
 518                 return i915_ttm_purge(obj);
 519         case __I915_MADV_PURGED:
 520                 return 0;
 521         }
 522
 523         if (bo->ttm->page_flags & TTM_TT_FLAG_SWAPPED)
 524                 return 0;
 525
 526         bo->ttm->page_flags |= TTM_TT_FLAG_SWAPPED;
 527         ret = ttm_bo_validate(bo, &place, &ctx);
 528         if (ret) {
 529                 bo->ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
 530                 return ret;
 531         }
 532
 533         if (flags & I915_GEM_OBJECT_SHRINK_WRITEBACK)
 534                 __shmem_writeback(obj->base.size, i915_tt->filp->f_mapping);
 535
 536         return 0;
 537 }
 538
 539 static void i915_ttm_delete_mem_notify(struct ttm_buffer_object *bo)
 540 {
 541         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 542
 543         if (likely(obj)) {
 544                 __i915_gem_object_pages_fini(obj);
 545                 i915_ttm_free_cached_io_rsgt(obj);
 546         }
 547 }
 548
 549 static struct i915_refct_sgt *i915_ttm_tt_get_st(struct ttm_tt *ttm)
 550 {
 551         struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 552         struct sg_table *st;
 553         int ret;
 554
 555         if (i915_tt->cached_rsgt.table.sgl)
 556                 return i915_refct_sgt_get(&i915_tt->cached_rsgt);
 557
 558         st = &i915_tt->cached_rsgt.table;
 559         ret = sg_alloc_table_from_pages_segment(st,
 560                         ttm->pages, ttm->num_pages,
 561                         0, (unsigned long)ttm->num_pages << PAGE_SHIFT,
 562                         i915_sg_segment_size(), GFP_KERNEL);
 563         if (ret) {
 564                 st->sgl = NULL;
 565                 return ERR_PTR(ret);
 566         }
 567
 568         ret = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0);
 569         if (ret) {
 570                 sg_free_table(st);
 571                 return ERR_PTR(ret);
 572         }
 573
 574         return i915_refct_sgt_get(&i915_tt->cached_rsgt);
 575 }
 576
 577 /**
 578  * i915_ttm_resource_get_st - Get a refcounted sg-table pointing to the
 579  * resource memory
 580  * @obj: The GEM object used for sg-table caching
 581  * @res: The struct ttm_resource for which an sg-table is requested.
 582  *
 583  * This function returns a refcounted sg-table representing the memory
 584  * pointed to by @res. If @res is the object's current resource it may also
 585  * cache the sg_table on the object or attempt to access an already cached
 586  * sg-table. The refcounted sg-table needs to be put when no-longer in use.
 587  *
 588  * Return: A valid pointer to a struct i915_refct_sgt or error pointer on
 589  * failure.
 590  */
 591 struct i915_refct_sgt *
 592 i915_ttm_resource_get_st(struct drm_i915_gem_object *obj,
 593                          struct ttm_resource *res)
 594 {
 595         struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 596
 597         if (!i915_ttm_gtt_binds_lmem(res))
 598                 return i915_ttm_tt_get_st(bo->ttm);
 599
 600         /*
 601          * If CPU mapping differs, we need to add the ttm_tt pages to
 602          * the resulting st. Might make sense for GGTT.
 603          */
 604         GEM_WARN_ON(!i915_ttm_cpu_maps_iomem(res));
 605         if (bo->resource == res) {
 606                 if (!obj->ttm.cached_io_rsgt) {
 607                         struct i915_refct_sgt *rsgt;
 608
 609                         rsgt = intel_region_ttm_resource_to_rsgt(obj->mm.region,
 610                                                                  res);
 611                         if (IS_ERR(rsgt))
 612                                 return rsgt;
 613
 614                         obj->ttm.cached_io_rsgt = rsgt;
 615                 }
 616                 return i915_refct_sgt_get(obj->ttm.cached_io_rsgt);
 617         }
 618
 619         return intel_region_ttm_resource_to_rsgt(obj->mm.region, res);
 620 }
 621
 622 static int i915_ttm_truncate(struct drm_i915_gem_object *obj)
 623 {
 624         struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 625         int err;
 626
 627         WARN_ON_ONCE(obj->mm.madv == I915_MADV_WILLNEED);
 628
 629         err = i915_ttm_move_notify(bo);
 630         if (err)
 631                 return err;
 632
 633         return i915_ttm_purge(obj);
 634 }
 635
 636 static void i915_ttm_swap_notify(struct ttm_buffer_object *bo)
 637 {
 638         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 639         int ret;
 640
 641         if (!obj)
 642                 return;
 643
 644         ret = i915_ttm_move_notify(bo);
 645         GEM_WARN_ON(ret);
 646         GEM_WARN_ON(obj->ttm.cached_io_rsgt);
 647         if (!ret && obj->mm.madv != I915_MADV_WILLNEED)
 648                 i915_ttm_purge(obj);
 649 }
 650
 651 static bool i915_ttm_resource_mappable(struct ttm_resource *res)
 652 {
 653         struct i915_ttm_buddy_resource *bman_res = to_ttm_buddy_resource(res);
 654
 655         if (!i915_ttm_cpu_maps_iomem(res))
 656                 return true;
 657
 658         return bman_res->used_visible_size == bman_res->base.num_pages;
 659 }
 660
 661 static int i915_ttm_io_mem_reserve(struct ttm_device *bdev, struct ttm_resource *mem)
 662 {
 663         if (!i915_ttm_cpu_maps_iomem(mem))
 664                 return 0;
 665
 666         if (!i915_ttm_resource_mappable(mem))
 667                 return -EINVAL;
 668
 669         mem->bus.caching = ttm_write_combined;
 670         mem->bus.is_iomem = true;
 671
 672         return 0;
 673 }
 674
 675 static unsigned long i915_ttm_io_mem_pfn(struct ttm_buffer_object *bo,
 676                                          unsigned long page_offset)
 677 {
 678         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 679         struct scatterlist *sg;
 680         unsigned long base;
 681         unsigned int ofs;
 682
 683         GEM_BUG_ON(!obj);
 684         GEM_WARN_ON(bo->ttm);
 685
 686         base = obj->mm.region->iomap.base - obj->mm.region->region.start;
 687         sg = __i915_gem_object_get_sg(obj, &obj->ttm.get_io_page, page_offset, &ofs, true);
 688
 689         return ((base + sg_dma_address(sg)) >> PAGE_SHIFT) + ofs;
 690 }
 691
 692 /*
 693  * All callbacks need to take care not to downcast a struct ttm_buffer_object
 694  * without checking its subclass, since it might be a TTM ghost object.
 695  */
 696 static struct ttm_device_funcs i915_ttm_bo_driver = {
 697         .ttm_tt_create = i915_ttm_tt_create,
 698         .ttm_tt_populate = i915_ttm_tt_populate,
 699         .ttm_tt_unpopulate = i915_ttm_tt_unpopulate,
 700         .ttm_tt_destroy = i915_ttm_tt_destroy,
 701         .eviction_valuable = i915_ttm_eviction_valuable,
 702         .evict_flags = i915_ttm_evict_flags,
 703         .move = i915_ttm_move,
 704         .swap_notify = i915_ttm_swap_notify,
 705         .delete_mem_notify = i915_ttm_delete_mem_notify,
 706         .io_mem_reserve = i915_ttm_io_mem_reserve,
 707         .io_mem_pfn = i915_ttm_io_mem_pfn,
 708 };
 709
 710 /**
 711  * i915_ttm_driver - Return a pointer to the TTM device funcs
 712  *
 713  * Return: Pointer to statically allocated TTM device funcs.
 714  */
 715 struct ttm_device_funcs *i915_ttm_driver(void)
 716 {
 717         return &i915_ttm_bo_driver;
 718 }
 719
 720 static int __i915_ttm_get_pages(struct drm_i915_gem_object *obj,
 721                                 struct ttm_placement *placement)
 722 {
 723         struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 724         struct ttm_operation_ctx ctx = {
 725                 .interruptible = true,
 726                 .no_wait_gpu = false,
 727         };
 728         int real_num_busy;
 729         int ret;
 730
 731         /* First try only the requested placement. No eviction. */
 732         real_num_busy = fetch_and_zero(&placement->num_busy_placement);
 733         ret = ttm_bo_validate(bo, placement, &ctx);
 734         if (ret) {
 735                 ret = i915_ttm_err_to_gem(ret);
 736                 /*
 737                  * Anything that wants to restart the operation gets to
 738                  * do that.
 739                  */
 740                 if (ret == -EDEADLK || ret == -EINTR || ret == -ERESTARTSYS ||
 741                     ret == -EAGAIN)
 742                         return ret;
 743
 744                 /*
 745                  * If the initial attempt fails, allow all accepted placements,
 746                  * evicting if necessary.
 747                  */
 748                 placement->num_busy_placement = real_num_busy;
 749                 ret = ttm_bo_validate(bo, placement, &ctx);
 750                 if (ret)
 751                         return i915_ttm_err_to_gem(ret);
 752         }
 753
 754         if (bo->ttm && !ttm_tt_is_populated(bo->ttm)) {
 755                 ret = ttm_tt_populate(bo->bdev, bo->ttm, &ctx);
 756                 if (ret)
 757                         return ret;
 758
 759                 i915_ttm_adjust_domains_after_move(obj);
 760                 i915_ttm_adjust_gem_after_move(obj);
 761         }
 762
 763         if (!i915_gem_object_has_pages(obj)) {
 764                 struct i915_refct_sgt *rsgt =
 765                         i915_ttm_resource_get_st(obj, bo->resource);
 766
 767                 if (IS_ERR(rsgt))
 768                         return PTR_ERR(rsgt);
 769
 770                 GEM_BUG_ON(obj->mm.rsgt);
 771                 obj->mm.rsgt = rsgt;
 772                 __i915_gem_object_set_pages(obj, &rsgt->table,
 773                                             i915_sg_dma_sizes(rsgt->table.sgl));
 774         }
 775
 776         i915_ttm_adjust_lru(obj);
 777         return ret;
 778 }
 779
 780 static int i915_ttm_get_pages(struct drm_i915_gem_object *obj)
 781 {
 782         struct ttm_place requested, busy[I915_TTM_MAX_PLACEMENTS];
 783         struct ttm_placement placement;
 784
 785         GEM_BUG_ON(obj->mm.n_placements > I915_TTM_MAX_PLACEMENTS);
 786
 787         /* Move to the requested placement. */
 788         i915_ttm_placement_from_obj(obj, &requested, busy, &placement);
 789
 790         return __i915_ttm_get_pages(obj, &placement);
 791 }
 792
 793 /**
 794  * DOC: Migration vs eviction
 795  *
 796  * GEM migration may not be the same as TTM migration / eviction. If
 797  * the TTM core decides to evict an object it may be evicted to a
 798  * TTM memory type that is not in the object's allowable GEM regions, or
 799  * in fact theoretically to a TTM memory type that doesn't correspond to
 800  * a GEM memory region. In that case the object's GEM region is not
 801  * updated, and the data is migrated back to the GEM region at
 802  * get_pages time. TTM may however set up CPU ptes to the object even
 803  * when it is evicted.
 804  * Gem forced migration using the i915_ttm_migrate() op, is allowed even
 805  * to regions that are not in the object's list of allowable placements.
 806  */
 807 static int __i915_ttm_migrate(struct drm_i915_gem_object *obj,
 808                               struct intel_memory_region *mr,
 809                               unsigned int flags)
 810 {
 811         struct ttm_place requested;
 812         struct ttm_placement placement;
 813         int ret;
 814
 815         i915_ttm_place_from_region(mr, &requested, obj->bo_offset,
 816                                    obj->base.size, flags);
 817         placement.num_placement = 1;
 818         placement.num_busy_placement = 1;
 819         placement.placement = &requested;
 820         placement.busy_placement = &requested;
 821
 822         ret = __i915_ttm_get_pages(obj, &placement);
 823         if (ret)
 824                 return ret;
 825
 826         /*
 827          * Reinitialize the region bindings. This is primarily
 828          * required for objects where the new region is not in
 829          * its allowable placements.
 830          */
 831         if (obj->mm.region != mr) {
 832                 i915_gem_object_release_memory_region(obj);
 833                 i915_gem_object_init_memory_region(obj, mr);
 834         }
 835
 836         return 0;
 837 }
 838
 839 static int i915_ttm_migrate(struct drm_i915_gem_object *obj,
 840                             struct intel_memory_region *mr)
 841 {
 842         return __i915_ttm_migrate(obj, mr, obj->flags);
 843 }
 844
 845 static void i915_ttm_put_pages(struct drm_i915_gem_object *obj,
 846                                struct sg_table *st)
 847 {
 848         /*
 849          * We're currently not called from a shrinker, so put_pages()
 850          * typically means the object is about to destroyed, or called
 851          * from move_notify(). So just avoid doing much for now.
 852          * If the object is not destroyed next, The TTM eviction logic
 853          * and shrinkers will move it out if needed.
 854          */
 855
 856         if (obj->mm.rsgt)
 857                 i915_refct_sgt_put(fetch_and_zero(&obj->mm.rsgt));
 858 }
 859
 860 /**
 861  * i915_ttm_adjust_lru - Adjust an object's position on relevant LRU lists.
 862  * @obj: The object
 863  */
 864 void i915_ttm_adjust_lru(struct drm_i915_gem_object *obj)
 865 {
 866         struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 867         struct i915_ttm_tt *i915_tt =
 868                 container_of(bo->ttm, typeof(*i915_tt), ttm);
 869         bool shrinkable =
 870                 bo->ttm && i915_tt->filp && ttm_tt_is_populated(bo->ttm);
 871
 872         /*
 873          * Don't manipulate the TTM LRUs while in TTM bo destruction.
 874          * We're called through i915_ttm_delete_mem_notify().
 875          */
 876         if (!kref_read(&bo->kref))
 877                 return;
 878
 879         /*
 880          * We skip managing the shrinker LRU in set_pages() and just manage
 881          * everything here. This does at least solve the issue with having
 882          * temporary shmem mappings(like with evicted lmem) not being visible to
 883          * the shrinker. Only our shmem objects are shrinkable, everything else
 884          * we keep as unshrinkable.
 885          *
 886          * To make sure everything plays nice we keep an extra shrink pin in TTM
 887          * if the underlying pages are not currently shrinkable. Once we release
 888          * our pin, like when the pages are moved to shmem, the pages will then
 889          * be added to the shrinker LRU, assuming the caller isn't also holding
 890          * a pin.
 891          *
 892          * TODO: consider maybe also bumping the shrinker list here when we have
 893          * already unpinned it, which should give us something more like an LRU.
 894          *
 895          * TODO: There is a small window of opportunity for this function to
 896          * get called from eviction after we've dropped the last GEM refcount,
 897          * but before the TTM deleted flag is set on the object. Avoid
 898          * adjusting the shrinker list in such cases, since the object is
 899          * not available to the shrinker anyway due to its zero refcount.
 900          * To fix this properly we should move to a TTM shrinker LRU list for
 901          * these objects.
 902          */
 903         if (kref_get_unless_zero(&obj->base.refcount)) {
 904                 if (shrinkable != obj->mm.ttm_shrinkable) {
 905                         if (shrinkable) {
 906                                 if (obj->mm.madv == I915_MADV_WILLNEED)
 907                                         __i915_gem_object_make_shrinkable(obj);
 908                                 else
 909                                         __i915_gem_object_make_purgeable(obj);
 910                         } else {
 911                                 i915_gem_object_make_unshrinkable(obj);
 912                         }
 913
 914                         obj->mm.ttm_shrinkable = shrinkable;
 915                 }
 916                 i915_gem_object_put(obj);
 917         }
 918
 919         /*
 920          * Put on the correct LRU list depending on the MADV status
 921          */
 922         spin_lock(&bo->bdev->lru_lock);
 923         if (shrinkable) {
 924                 /* Try to keep shmem_tt from being considered for shrinking. */
 925                 bo->priority = TTM_MAX_BO_PRIORITY - 1;
 926         } else if (obj->mm.madv != I915_MADV_WILLNEED) {
 927                 bo->priority = I915_TTM_PRIO_PURGE;
 928         } else if (!i915_gem_object_has_pages(obj)) {
 929                 bo->priority = I915_TTM_PRIO_NO_PAGES;
 930         } else {
 931                 struct ttm_resource_manager *man =
 932                         ttm_manager_type(bo->bdev, bo->resource->mem_type);
 933
 934                 /*
 935                  * If we need to place an LMEM resource which doesn't need CPU
 936                  * access then we should try not to victimize mappable objects
 937                  * first, since we likely end up stealing more of the mappable
 938                  * portion. And likewise when we try to find space for a mappble
 939                  * object, we know not to ever victimize objects that don't
 940                  * occupy any mappable pages.
 941                  */
 942                 if (i915_ttm_cpu_maps_iomem(bo->resource) &&
 943                     i915_ttm_buddy_man_visible_size(man) < man->size &&
 944                     !(obj->flags & I915_BO_ALLOC_GPU_ONLY))
 945                         bo->priority = I915_TTM_PRIO_NEEDS_CPU_ACCESS;
 946                 else
 947                         bo->priority = I915_TTM_PRIO_HAS_PAGES;
 948         }
 949
 950         ttm_bo_move_to_lru_tail(bo);
 951         spin_unlock(&bo->bdev->lru_lock);
 952 }
 953
 954 /*
 955  * TTM-backed gem object destruction requires some clarification.
 956  * Basically we have two possibilities here. We can either rely on the
 957  * i915 delayed destruction and put the TTM object when the object
 958  * is idle. This would be detected by TTM which would bypass the
 959  * TTM delayed destroy handling. The other approach is to put the TTM
 960  * object early and rely on the TTM destroyed handling, and then free
 961  * the leftover parts of the GEM object once TTM's destroyed list handling is
 962  * complete. For now, we rely on the latter for two reasons:
 963  * a) TTM can evict an object even when it's on the delayed destroy list,
 964  * which in theory allows for complete eviction.
 965  * b) There is work going on in TTM to allow freeing an object even when
 966  * it's not idle, and using the TTM destroyed list handling could help us
 967  * benefit from that.
 968  */
 969 static void i915_ttm_delayed_free(struct drm_i915_gem_object *obj)
 970 {
 971         GEM_BUG_ON(!obj->ttm.created);
 972
 973         ttm_bo_put(i915_gem_to_ttm(obj));
 974 }
 975
 976 static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
 977 {
 978         struct vm_area_struct *area = vmf->vma;
 979         struct ttm_buffer_object *bo = area->vm_private_data;
 980         struct drm_device *dev = bo->base.dev;
 981         struct drm_i915_gem_object *obj;
 982         vm_fault_t ret;
 983         int idx;
 984
 985         obj = i915_ttm_to_gem(bo);
 986         if (!obj)
 987                 return VM_FAULT_SIGBUS;
 988
 989         /* Sanity check that we allow writing into this object */
 990         if (unlikely(i915_gem_object_is_readonly(obj) &&
 991                      area->vm_flags & VM_WRITE))
 992                 return VM_FAULT_SIGBUS;
 993
 994         ret = ttm_bo_vm_reserve(bo, vmf);
 995         if (ret)
 996                 return ret;
 997
 998         if (obj->mm.madv != I915_MADV_WILLNEED) {
 999                 dma_resv_unlock(bo->base.resv);
1000                 return VM_FAULT_SIGBUS;
1001         }
1002
1003         if (!i915_ttm_resource_mappable(bo->resource)) {
1004                 int err = -ENODEV;
1005                 int i;
1006
1007                 for (i = 0; i < obj->mm.n_placements; i++) {
1008                         struct intel_memory_region *mr = obj->mm.placements[i];
1009                         unsigned int flags;
1010
1011                         if (!mr->io_size && mr->type != INTEL_MEMORY_SYSTEM)
1012                                 continue;
1013
1014                         flags = obj->flags;
1015                         flags &= ~I915_BO_ALLOC_GPU_ONLY;
1016                         err = __i915_ttm_migrate(obj, mr, flags);
1017                         if (!err)
1018                                 break;
1019                 }
1020
1021                 if (err) {
1022                         drm_dbg(dev, "Unable to make resource CPU accessible\n");
1023                         dma_resv_unlock(bo->base.resv);
1024                         return VM_FAULT_SIGBUS;
1025                 }
1026         }
1027
1028         if (drm_dev_enter(dev, &idx)) {
1029                 ret = ttm_bo_vm_fault_reserved(vmf, vmf->vma->vm_page_prot,
1030                                                TTM_BO_VM_NUM_PREFAULT);
1031                 drm_dev_exit(idx);
1032         } else {
1033                 ret = ttm_bo_vm_dummy_page(vmf, vmf->vma->vm_page_prot);
1034         }
1035         if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
1036                 return ret;
1037
1038         i915_ttm_adjust_lru(obj);
1039
1040         dma_resv_unlock(bo->base.resv);
1041         return ret;
1042 }
1043
1044 static int
1045 vm_access_ttm(struct vm_area_struct *area, unsigned long addr,
1046               void *buf, int len, int write)
1047 {
1048         struct drm_i915_gem_object *obj =
1049                 i915_ttm_to_gem(area->vm_private_data);
1050
1051         if (i915_gem_object_is_readonly(obj) && write)
1052                 return -EACCES;
1053
1054         return ttm_bo_vm_access(area, addr, buf, len, write);
1055 }
1056
1057 static void ttm_vm_open(struct vm_area_struct *vma)
1058 {
1059         struct drm_i915_gem_object *obj =
1060                 i915_ttm_to_gem(vma->vm_private_data);
1061
1062         GEM_BUG_ON(!obj);
1063         i915_gem_object_get(obj);
1064 }
1065
1066 static void ttm_vm_close(struct vm_area_struct *vma)
1067 {
1068         struct drm_i915_gem_object *obj =
1069                 i915_ttm_to_gem(vma->vm_private_data);
1070
1071         GEM_BUG_ON(!obj);
1072         i915_gem_object_put(obj);
1073 }
1074
1075 static const struct vm_operations_struct vm_ops_ttm = {
1076         .fault = vm_fault_ttm,
1077         .access = vm_access_ttm,
1078         .open = ttm_vm_open,
1079         .close = ttm_vm_close,
1080 };
1081
1082 static u64 i915_ttm_mmap_offset(struct drm_i915_gem_object *obj)
1083 {
1084         /* The ttm_bo must be allocated with I915_BO_ALLOC_USER */
1085         GEM_BUG_ON(!drm_mm_node_allocated(&obj->base.vma_node.vm_node));
1086
1087         return drm_vma_node_offset_addr(&obj->base.vma_node);
1088 }
1089
1090 static void i915_ttm_unmap_virtual(struct drm_i915_gem_object *obj)
1091 {
1092         ttm_bo_unmap_virtual(i915_gem_to_ttm(obj));
1093 }
1094
1095 static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = {
1096         .name = "i915_gem_object_ttm",
1097         .flags = I915_GEM_OBJECT_IS_SHRINKABLE |
1098                  I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST,
1099
1100         .get_pages = i915_ttm_get_pages,
1101         .put_pages = i915_ttm_put_pages,
1102         .truncate = i915_ttm_truncate,
1103         .shrink = i915_ttm_shrink,
1104
1105         .adjust_lru = i915_ttm_adjust_lru,
1106         .delayed_free = i915_ttm_delayed_free,
1107         .migrate = i915_ttm_migrate,
1108
1109         .mmap_offset = i915_ttm_mmap_offset,
1110         .unmap_virtual = i915_ttm_unmap_virtual,
1111         .mmap_ops = &vm_ops_ttm,
1112 };
1113
1114 void i915_ttm_bo_destroy(struct ttm_buffer_object *bo)
1115 {
1116         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
1117
1118         i915_gem_object_release_memory_region(obj);
1119         mutex_destroy(&obj->ttm.get_io_page.lock);
1120
1121         if (obj->ttm.created) {
1122                 /*
1123                  * We freely manage the shrinker LRU outide of the mm.pages life
1124                  * cycle. As a result when destroying the object we should be
1125                  * extra paranoid and ensure we remove it from the LRU, before
1126                  * we free the object.
1127                  *
1128                  * Touching the ttm_shrinkable outside of the object lock here
1129                  * should be safe now that the last GEM object ref was dropped.
1130                  */
1131                 if (obj->mm.ttm_shrinkable)
1132                         i915_gem_object_make_unshrinkable(obj);
1133
1134                 i915_ttm_backup_free(obj);
1135
1136                 /* This releases all gem object bindings to the backend. */
1137                 __i915_gem_free_object(obj);
1138
1139                 call_rcu(&obj->rcu, __i915_gem_free_object_rcu);
1140         } else {
1141                 __i915_gem_object_fini(obj);
1142         }
1143 }
1144
1145 /**
1146  * __i915_gem_ttm_object_init - Initialize a ttm-backed i915 gem object
1147  * @mem: The initial memory region for the object.
1148  * @obj: The gem object.
1149  * @size: Object size in bytes.
1150  * @flags: gem object flags.
1151  *
1152  * Return: 0 on success, negative error code on failure.
1153  */
1154 int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
1155                                struct drm_i915_gem_object *obj,
1156                                resource_size_t offset,
1157                                resource_size_t size,
1158                                resource_size_t page_size,
1159                                unsigned int flags)
1160 {
1161         static struct lock_class_key lock_class;
1162         struct drm_i915_private *i915 = mem->i915;
1163         struct ttm_operation_ctx ctx = {
1164                 .interruptible = true,
1165                 .no_wait_gpu = false,
1166         };
1167         enum ttm_bo_type bo_type;
1168         int ret;
1169
1170         drm_gem_private_object_init(&i915->drm, &obj->base, size);
1171         i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class, flags);
1172
1173         obj->bo_offset = offset;
1174
1175         /* Don't put on a region list until we're either locked or fully initialized. */
1176         obj->mm.region = mem;
1177         INIT_LIST_HEAD(&obj->mm.region_link);
1178
1179         INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL | __GFP_NOWARN);
1180         mutex_init(&obj->ttm.get_io_page.lock);
1181         bo_type = (obj->flags & I915_BO_ALLOC_USER) ? ttm_bo_type_device :
1182                 ttm_bo_type_kernel;
1183
1184         obj->base.vma_node.driver_private = i915_gem_to_ttm(obj);
1185
1186         /* Forcing the page size is kernel internal only */
1187         GEM_BUG_ON(page_size && obj->mm.n_placements);
1188
1189         /*
1190          * Keep an extra shrink pin to prevent the object from being made
1191          * shrinkable too early. If the ttm_tt is ever allocated in shmem, we
1192          * drop the pin. The TTM backend manages the shrinker LRU itself,
1193          * outside of the normal mm.pages life cycle.
1194          */
1195         i915_gem_object_make_unshrinkable(obj);
1196
1197         /*
1198          * If this function fails, it will call the destructor, but
1199          * our caller still owns the object. So no freeing in the
1200          * destructor until obj->ttm.created is true.
1201          * Similarly, in delayed_destroy, we can't call ttm_bo_put()
1202          * until successful initialization.
1203          */
1204         ret = ttm_bo_init_reserved(&i915->bdev, i915_gem_to_ttm(obj), size,
1205                                    bo_type, &i915_sys_placement,
1206                                    page_size >> PAGE_SHIFT,
1207                                    &ctx, NULL, NULL, i915_ttm_bo_destroy);
1208         if (ret)
1209                 return i915_ttm_err_to_gem(ret);
1210
1211         obj->ttm.created = true;
1212         i915_gem_object_release_memory_region(obj);
1213         i915_gem_object_init_memory_region(obj, mem);
1214         i915_ttm_adjust_domains_after_move(obj);
1215         i915_ttm_adjust_gem_after_move(obj);
1216         i915_gem_object_unlock(obj);
1217
1218         return 0;
1219 }
1220
1221 static const struct intel_memory_region_ops ttm_system_region_ops = {
1222         .init_object = __i915_gem_ttm_object_init,
1223         .release = intel_region_ttm_fini,
1224 };
1225
1226 struct intel_memory_region *
1227 i915_gem_ttm_system_setup(struct drm_i915_private *i915,
1228                           u16 type, u16 instance)
1229 {
1230         struct intel_memory_region *mr;
1231
1232         mr = intel_memory_region_create(i915, 0,
1233                                         totalram_pages() << PAGE_SHIFT,
1234                                         PAGE_SIZE, 0, 0,
1235                                         type, instance,
1236                                         &ttm_system_region_ops);
1237         if (IS_ERR(mr))
1238                 return mr;
1239
1240         intel_memory_region_set_name(mr, "system-ttm");
1241         return mr;
1242 }