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_placement.h>
   9 #include <drm/ttm/ttm_tt.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                 WARN_ON(overflows_type(offset >> PAGE_SHIFT, place->fpfn));
 144                 place->fpfn = offset >> PAGE_SHIFT;
 145                 WARN_ON(overflows_type(place->fpfn + (size >> PAGE_SHIFT), place->lpfn));
 146                 place->lpfn = place->fpfn + (size >> PAGE_SHIFT);
 147         } else if (mr->io_size && mr->io_size < mr->total) {
 148                 if (flags & I915_BO_ALLOC_GPU_ONLY) {
 149                         place->flags |= TTM_PL_FLAG_TOPDOWN;
 150                 } else {
 151                         place->fpfn = 0;
 152                         WARN_ON(overflows_type(mr->io_size >> PAGE_SHIFT, place->lpfn));
 153                         place->lpfn = mr->io_size >> PAGE_SHIFT;
 154                 }
 155         }
 156 }
 157
 158 static void
 159 i915_ttm_placement_from_obj(const struct drm_i915_gem_object *obj,
 160                             struct ttm_place *requested,
 161                             struct ttm_place *busy,
 162                             struct ttm_placement *placement)
 163 {
 164         unsigned int num_allowed = obj->mm.n_placements;
 165         unsigned int flags = obj->flags;
 166         unsigned int i;
 167
 168         placement->num_placement = 1;
 169         i915_ttm_place_from_region(num_allowed ? obj->mm.placements[0] :
 170                                    obj->mm.region, requested, obj->bo_offset,
 171                                    obj->base.size, flags);
 172
 173         /* Cache this on object? */
 174         placement->num_busy_placement = num_allowed;
 175         for (i = 0; i < placement->num_busy_placement; ++i)
 176                 i915_ttm_place_from_region(obj->mm.placements[i], busy + i,
 177                                            obj->bo_offset, obj->base.size, flags);
 178
 179         if (num_allowed == 0) {
 180                 *busy = *requested;
 181                 placement->num_busy_placement = 1;
 182         }
 183
 184         placement->placement = requested;
 185         placement->busy_placement = busy;
 186 }
 187
 188 static int i915_ttm_tt_shmem_populate(struct ttm_device *bdev,
 189                                       struct ttm_tt *ttm,
 190                                       struct ttm_operation_ctx *ctx)
 191 {
 192         struct drm_i915_private *i915 = container_of(bdev, typeof(*i915), bdev);
 193         struct intel_memory_region *mr = i915->mm.regions[INTEL_MEMORY_SYSTEM];
 194         struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 195         const unsigned int max_segment = i915_sg_segment_size(i915->drm.dev);
 196         const size_t size = (size_t)ttm->num_pages << PAGE_SHIFT;
 197         struct file *filp = i915_tt->filp;
 198         struct sgt_iter sgt_iter;
 199         struct sg_table *st;
 200         struct page *page;
 201         unsigned long i;
 202         int err;
 203
 204         if (!filp) {
 205                 struct address_space *mapping;
 206                 gfp_t mask;
 207
 208                 filp = shmem_file_setup("i915-shmem-tt", size, VM_NORESERVE);
 209                 if (IS_ERR(filp))
 210                         return PTR_ERR(filp);
 211
 212                 mask = GFP_HIGHUSER | __GFP_RECLAIMABLE;
 213
 214                 mapping = filp->f_mapping;
 215                 mapping_set_gfp_mask(mapping, mask);
 216                 GEM_BUG_ON(!(mapping_gfp_mask(mapping) & __GFP_RECLAIM));
 217
 218                 i915_tt->filp = filp;
 219         }
 220
 221         st = &i915_tt->cached_rsgt.table;
 222         err = shmem_sg_alloc_table(i915, st, size, mr, filp->f_mapping,
 223                                    max_segment);
 224         if (err)
 225                 return err;
 226
 227         err = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL,
 228                               DMA_ATTR_SKIP_CPU_SYNC);
 229         if (err)
 230                 goto err_free_st;
 231
 232         i = 0;
 233         for_each_sgt_page(page, sgt_iter, st)
 234                 ttm->pages[i++] = page;
 235
 236         if (ttm->page_flags & TTM_TT_FLAG_SWAPPED)
 237                 ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
 238
 239         return 0;
 240
 241 err_free_st:
 242         shmem_sg_free_table(st, filp->f_mapping, false, false);
 243
 244         return err;
 245 }
 246
 247 static void i915_ttm_tt_shmem_unpopulate(struct ttm_tt *ttm)
 248 {
 249         struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 250         bool backup = ttm->page_flags & TTM_TT_FLAG_SWAPPED;
 251         struct sg_table *st = &i915_tt->cached_rsgt.table;
 252
 253         shmem_sg_free_table(st, file_inode(i915_tt->filp)->i_mapping,
 254                             backup, backup);
 255 }
 256
 257 static void i915_ttm_tt_release(struct kref *ref)
 258 {
 259         struct i915_ttm_tt *i915_tt =
 260                 container_of(ref, typeof(*i915_tt), cached_rsgt.kref);
 261         struct sg_table *st = &i915_tt->cached_rsgt.table;
 262
 263         GEM_WARN_ON(st->sgl);
 264
 265         kfree(i915_tt);
 266 }
 267
 268 static const struct i915_refct_sgt_ops tt_rsgt_ops = {
 269         .release = i915_ttm_tt_release
 270 };
 271
 272 static struct ttm_tt *i915_ttm_tt_create(struct ttm_buffer_object *bo,
 273                                          uint32_t page_flags)
 274 {
 275         struct drm_i915_private *i915 = container_of(bo->bdev, typeof(*i915),
 276                                                      bdev);
 277         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 278         unsigned long ccs_pages = 0;
 279         enum ttm_caching caching;
 280         struct i915_ttm_tt *i915_tt;
 281         int ret;
 282
 283         if (i915_ttm_is_ghost_object(bo))
 284                 return NULL;
 285
 286         i915_tt = kzalloc(sizeof(*i915_tt), GFP_KERNEL);
 287         if (!i915_tt)
 288                 return NULL;
 289
 290         if (obj->flags & I915_BO_ALLOC_CPU_CLEAR && (!bo->resource ||
 291             ttm_manager_type(bo->bdev, bo->resource->mem_type)->use_tt))
 292                 page_flags |= TTM_TT_FLAG_ZERO_ALLOC;
 293
 294         caching = i915_ttm_select_tt_caching(obj);
 295         if (i915_gem_object_is_shrinkable(obj) && caching == ttm_cached) {
 296                 page_flags |= TTM_TT_FLAG_EXTERNAL |
 297                               TTM_TT_FLAG_EXTERNAL_MAPPABLE;
 298                 i915_tt->is_shmem = true;
 299         }
 300
 301         if (i915_gem_object_needs_ccs_pages(obj))
 302                 ccs_pages = DIV_ROUND_UP(DIV_ROUND_UP(bo->base.size,
 303                                                       NUM_BYTES_PER_CCS_BYTE),
 304                                          PAGE_SIZE);
 305
 306         ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags, caching, ccs_pages);
 307         if (ret)
 308                 goto err_free;
 309
 310         __i915_refct_sgt_init(&i915_tt->cached_rsgt, bo->base.size,
 311                               &tt_rsgt_ops);
 312
 313         i915_tt->dev = obj->base.dev->dev;
 314
 315         return &i915_tt->ttm;
 316
 317 err_free:
 318         kfree(i915_tt);
 319         return NULL;
 320 }
 321
 322 static int i915_ttm_tt_populate(struct ttm_device *bdev,
 323                                 struct ttm_tt *ttm,
 324                                 struct ttm_operation_ctx *ctx)
 325 {
 326         struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 327
 328         if (i915_tt->is_shmem)
 329                 return i915_ttm_tt_shmem_populate(bdev, ttm, ctx);
 330
 331         return ttm_pool_alloc(&bdev->pool, ttm, ctx);
 332 }
 333
 334 static void i915_ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
 335 {
 336         struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 337         struct sg_table *st = &i915_tt->cached_rsgt.table;
 338
 339         if (st->sgl)
 340                 dma_unmap_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0);
 341
 342         if (i915_tt->is_shmem) {
 343                 i915_ttm_tt_shmem_unpopulate(ttm);
 344         } else {
 345                 sg_free_table(st);
 346                 ttm_pool_free(&bdev->pool, ttm);
 347         }
 348 }
 349
 350 static void i915_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
 351 {
 352         struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 353
 354         if (i915_tt->filp)
 355                 fput(i915_tt->filp);
 356
 357         ttm_tt_fini(ttm);
 358         i915_refct_sgt_put(&i915_tt->cached_rsgt);
 359 }
 360
 361 static bool i915_ttm_eviction_valuable(struct ttm_buffer_object *bo,
 362                                        const struct ttm_place *place)
 363 {
 364         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 365
 366         if (i915_ttm_is_ghost_object(bo))
 367                 return false;
 368
 369         /*
 370          * EXTERNAL objects should never be swapped out by TTM, instead we need
 371          * to handle that ourselves. TTM will already skip such objects for us,
 372          * but we would like to avoid grabbing locks for no good reason.
 373          */
 374         if (bo->ttm && bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL)
 375                 return false;
 376
 377         /* Will do for now. Our pinned objects are still on TTM's LRU lists */
 378         if (!i915_gem_object_evictable(obj))
 379                 return false;
 380
 381         return ttm_bo_eviction_valuable(bo, place);
 382 }
 383
 384 static void i915_ttm_evict_flags(struct ttm_buffer_object *bo,
 385                                  struct ttm_placement *placement)
 386 {
 387         *placement = i915_sys_placement;
 388 }
 389
 390 /**
 391  * i915_ttm_free_cached_io_rsgt - Free object cached LMEM information
 392  * @obj: The GEM object
 393  * This function frees any LMEM-related information that is cached on
 394  * the object. For example the radix tree for fast page lookup and the
 395  * cached refcounted sg-table
 396  */
 397 void i915_ttm_free_cached_io_rsgt(struct drm_i915_gem_object *obj)
 398 {
 399         struct radix_tree_iter iter;
 400         void __rcu **slot;
 401
 402         if (!obj->ttm.cached_io_rsgt)
 403                 return;
 404
 405         rcu_read_lock();
 406         radix_tree_for_each_slot(slot, &obj->ttm.get_io_page.radix, &iter, 0)
 407                 radix_tree_delete(&obj->ttm.get_io_page.radix, iter.index);
 408         rcu_read_unlock();
 409
 410         i915_refct_sgt_put(obj->ttm.cached_io_rsgt);
 411         obj->ttm.cached_io_rsgt = NULL;
 412 }
 413
 414 /**
 415  * i915_ttm_purge - Clear an object of its memory
 416  * @obj: The object
 417  *
 418  * This function is called to clear an object of it's memory when it is
 419  * marked as not needed anymore.
 420  *
 421  * Return: 0 on success, negative error code on failure.
 422  */
 423 int i915_ttm_purge(struct drm_i915_gem_object *obj)
 424 {
 425         struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 426         struct i915_ttm_tt *i915_tt =
 427                 container_of(bo->ttm, typeof(*i915_tt), ttm);
 428         struct ttm_operation_ctx ctx = {
 429                 .interruptible = true,
 430                 .no_wait_gpu = false,
 431         };
 432         struct ttm_placement place = {};
 433         int ret;
 434
 435         if (obj->mm.madv == __I915_MADV_PURGED)
 436                 return 0;
 437
 438         ret = ttm_bo_validate(bo, &place, &ctx);
 439         if (ret)
 440                 return ret;
 441
 442         if (bo->ttm && i915_tt->filp) {
 443                 /*
 444                  * The below fput(which eventually calls shmem_truncate) might
 445                  * be delayed by worker, so when directly called to purge the
 446                  * pages(like by the shrinker) we should try to be more
 447                  * aggressive and release the pages immediately.
 448                  */
 449                 shmem_truncate_range(file_inode(i915_tt->filp),
 450                                      0, (loff_t)-1);
 451                 fput(fetch_and_zero(&i915_tt->filp));
 452         }
 453
 454         obj->write_domain = 0;
 455         obj->read_domains = 0;
 456         i915_ttm_adjust_gem_after_move(obj);
 457         i915_ttm_free_cached_io_rsgt(obj);
 458         obj->mm.madv = __I915_MADV_PURGED;
 459
 460         return 0;
 461 }
 462
 463 static int i915_ttm_shrink(struct drm_i915_gem_object *obj, unsigned int flags)
 464 {
 465         struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 466         struct i915_ttm_tt *i915_tt =
 467                 container_of(bo->ttm, typeof(*i915_tt), ttm);
 468         struct ttm_operation_ctx ctx = {
 469                 .interruptible = true,
 470                 .no_wait_gpu = flags & I915_GEM_OBJECT_SHRINK_NO_GPU_WAIT,
 471         };
 472         struct ttm_placement place = {};
 473         int ret;
 474
 475         if (!bo->ttm || i915_ttm_cpu_maps_iomem(bo->resource))
 476                 return 0;
 477
 478         GEM_BUG_ON(!i915_tt->is_shmem);
 479
 480         if (!i915_tt->filp)
 481                 return 0;
 482
 483         ret = ttm_bo_wait_ctx(bo, &ctx);
 484         if (ret)
 485                 return ret;
 486
 487         switch (obj->mm.madv) {
 488         case I915_MADV_DONTNEED:
 489                 return i915_ttm_purge(obj);
 490         case __I915_MADV_PURGED:
 491                 return 0;
 492         }
 493
 494         if (bo->ttm->page_flags & TTM_TT_FLAG_SWAPPED)
 495                 return 0;
 496
 497         bo->ttm->page_flags |= TTM_TT_FLAG_SWAPPED;
 498         ret = ttm_bo_validate(bo, &place, &ctx);
 499         if (ret) {
 500                 bo->ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
 501                 return ret;
 502         }
 503
 504         if (flags & I915_GEM_OBJECT_SHRINK_WRITEBACK)
 505                 __shmem_writeback(obj->base.size, i915_tt->filp->f_mapping);
 506
 507         return 0;
 508 }
 509
 510 static void i915_ttm_delete_mem_notify(struct ttm_buffer_object *bo)
 511 {
 512         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 513
 514         /*
 515          * This gets called twice by ttm, so long as we have a ttm resource or
 516          * ttm_tt then we can still safely call this. Due to pipeline-gutting,
 517          * we maybe have NULL bo->resource, but in that case we should always
 518          * have a ttm alive (like if the pages are swapped out).
 519          */
 520         if ((bo->resource || bo->ttm) && !i915_ttm_is_ghost_object(bo)) {
 521                 __i915_gem_object_pages_fini(obj);
 522                 i915_ttm_free_cached_io_rsgt(obj);
 523         }
 524 }
 525
 526 static struct i915_refct_sgt *i915_ttm_tt_get_st(struct ttm_tt *ttm)
 527 {
 528         struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 529         struct sg_table *st;
 530         int ret;
 531
 532         if (i915_tt->cached_rsgt.table.sgl)
 533                 return i915_refct_sgt_get(&i915_tt->cached_rsgt);
 534
 535         st = &i915_tt->cached_rsgt.table;
 536         ret = sg_alloc_table_from_pages_segment(st,
 537                         ttm->pages, ttm->num_pages,
 538                         0, (unsigned long)ttm->num_pages << PAGE_SHIFT,
 539                         i915_sg_segment_size(i915_tt->dev), GFP_KERNEL);
 540         if (ret) {
 541                 st->sgl = NULL;
 542                 return ERR_PTR(ret);
 543         }
 544
 545         ret = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0);
 546         if (ret) {
 547                 sg_free_table(st);
 548                 return ERR_PTR(ret);
 549         }
 550
 551         return i915_refct_sgt_get(&i915_tt->cached_rsgt);
 552 }
 553
 554 /**
 555  * i915_ttm_resource_get_st - Get a refcounted sg-table pointing to the
 556  * resource memory
 557  * @obj: The GEM object used for sg-table caching
 558  * @res: The struct ttm_resource for which an sg-table is requested.
 559  *
 560  * This function returns a refcounted sg-table representing the memory
 561  * pointed to by @res. If @res is the object's current resource it may also
 562  * cache the sg_table on the object or attempt to access an already cached
 563  * sg-table. The refcounted sg-table needs to be put when no-longer in use.
 564  *
 565  * Return: A valid pointer to a struct i915_refct_sgt or error pointer on
 566  * failure.
 567  */
 568 struct i915_refct_sgt *
 569 i915_ttm_resource_get_st(struct drm_i915_gem_object *obj,
 570                          struct ttm_resource *res)
 571 {
 572         struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 573         u32 page_alignment;
 574
 575         if (!i915_ttm_gtt_binds_lmem(res))
 576                 return i915_ttm_tt_get_st(bo->ttm);
 577
 578         page_alignment = bo->page_alignment << PAGE_SHIFT;
 579         if (!page_alignment)
 580                 page_alignment = obj->mm.region->min_page_size;
 581
 582         /*
 583          * If CPU mapping differs, we need to add the ttm_tt pages to
 584          * the resulting st. Might make sense for GGTT.
 585          */
 586         GEM_WARN_ON(!i915_ttm_cpu_maps_iomem(res));
 587         if (bo->resource == res) {
 588                 if (!obj->ttm.cached_io_rsgt) {
 589                         struct i915_refct_sgt *rsgt;
 590
 591                         rsgt = intel_region_ttm_resource_to_rsgt(obj->mm.region,
 592                                                                  res,
 593                                                                  page_alignment);
 594                         if (IS_ERR(rsgt))
 595                                 return rsgt;
 596
 597                         obj->ttm.cached_io_rsgt = rsgt;
 598                 }
 599                 return i915_refct_sgt_get(obj->ttm.cached_io_rsgt);
 600         }
 601
 602         return intel_region_ttm_resource_to_rsgt(obj->mm.region, res,
 603                                                  page_alignment);
 604 }
 605
 606 static int i915_ttm_truncate(struct drm_i915_gem_object *obj)
 607 {
 608         struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 609         long err;
 610
 611         WARN_ON_ONCE(obj->mm.madv == I915_MADV_WILLNEED);
 612
 613         err = dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_BOOKKEEP,
 614                                     true, 15 * HZ);
 615         if (err < 0)
 616                 return err;
 617         if (err == 0)
 618                 return -EBUSY;
 619
 620         err = i915_ttm_move_notify(bo);
 621         if (err)
 622                 return err;
 623
 624         return i915_ttm_purge(obj);
 625 }
 626
 627 static void i915_ttm_swap_notify(struct ttm_buffer_object *bo)
 628 {
 629         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 630         int ret;
 631
 632         if (i915_ttm_is_ghost_object(bo))
 633                 return;
 634
 635         ret = i915_ttm_move_notify(bo);
 636         GEM_WARN_ON(ret);
 637         GEM_WARN_ON(obj->ttm.cached_io_rsgt);
 638         if (!ret && obj->mm.madv != I915_MADV_WILLNEED)
 639                 i915_ttm_purge(obj);
 640 }
 641
 642 /**
 643  * i915_ttm_resource_mappable - Return true if the ttm resource is CPU
 644  * accessible.
 645  * @res: The TTM resource to check.
 646  *
 647  * This is interesting on small-BAR systems where we may encounter lmem objects
 648  * that can't be accessed via the CPU.
 649  */
 650 bool i915_ttm_resource_mappable(struct ttm_resource *res)
 651 {
 652         struct i915_ttm_buddy_resource *bman_res = to_ttm_buddy_resource(res);
 653
 654         if (!i915_ttm_cpu_maps_iomem(res))
 655                 return true;
 656
 657         return bman_res->used_visible_size == PFN_UP(bman_res->base.size);
 658 }
 659
 660 static int i915_ttm_io_mem_reserve(struct ttm_device *bdev, struct ttm_resource *mem)
 661 {
 662         struct drm_i915_gem_object *obj = i915_ttm_to_gem(mem->bo);
 663         bool unknown_state;
 664
 665         if (i915_ttm_is_ghost_object(mem->bo))
 666                 return -EINVAL;
 667
 668         if (!kref_get_unless_zero(&obj->base.refcount))
 669                 return -EINVAL;
 670
 671         assert_object_held(obj);
 672
 673         unknown_state = i915_gem_object_has_unknown_state(obj);
 674         i915_gem_object_put(obj);
 675         if (unknown_state)
 676                 return -EINVAL;
 677
 678         if (!i915_ttm_cpu_maps_iomem(mem))
 679                 return 0;
 680
 681         if (!i915_ttm_resource_mappable(mem))
 682                 return -EINVAL;
 683
 684         mem->bus.caching = ttm_write_combined;
 685         mem->bus.is_iomem = true;
 686
 687         return 0;
 688 }
 689
 690 static unsigned long i915_ttm_io_mem_pfn(struct ttm_buffer_object *bo,
 691                                          unsigned long page_offset)
 692 {
 693         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 694         struct scatterlist *sg;
 695         unsigned long base;
 696         unsigned int ofs;
 697
 698         GEM_BUG_ON(i915_ttm_is_ghost_object(bo));
 699         GEM_WARN_ON(bo->ttm);
 700
 701         base = obj->mm.region->iomap.base - obj->mm.region->region.start;
 702         sg = i915_gem_object_page_iter_get_sg(obj, &obj->ttm.get_io_page, page_offset, &ofs);
 703
 704         return ((base + sg_dma_address(sg)) >> PAGE_SHIFT) + ofs;
 705 }
 706
 707 static int i915_ttm_access_memory(struct ttm_buffer_object *bo,
 708                                   unsigned long offset, void *buf,
 709                                   int len, int write)
 710 {
 711         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 712         resource_size_t iomap = obj->mm.region->iomap.base -
 713                 obj->mm.region->region.start;
 714         unsigned long page = offset >> PAGE_SHIFT;
 715         unsigned long bytes_left = len;
 716
 717         /*
 718          * TODO: For now just let it fail if the resource is non-mappable,
 719          * otherwise we need to perform the memcpy from the gpu here, without
 720          * interfering with the object (like moving the entire thing).
 721          */
 722         if (!i915_ttm_resource_mappable(bo->resource))
 723                 return -EIO;
 724
 725         offset -= page << PAGE_SHIFT;
 726         do {
 727                 unsigned long bytes = min(bytes_left, PAGE_SIZE - offset);
 728                 void __iomem *ptr;
 729                 dma_addr_t daddr;
 730
 731                 daddr = i915_gem_object_get_dma_address(obj, page);
 732                 ptr = ioremap_wc(iomap + daddr + offset, bytes);
 733                 if (!ptr)
 734                         return -EIO;
 735
 736                 if (write)
 737                         memcpy_toio(ptr, buf, bytes);
 738                 else
 739                         memcpy_fromio(buf, ptr, bytes);
 740                 iounmap(ptr);
 741
 742                 page++;
 743                 buf += bytes;
 744                 bytes_left -= bytes;
 745                 offset = 0;
 746         } while (bytes_left);
 747
 748         return len;
 749 }
 750
 751 /*
 752  * All callbacks need to take care not to downcast a struct ttm_buffer_object
 753  * without checking its subclass, since it might be a TTM ghost object.
 754  */
 755 static struct ttm_device_funcs i915_ttm_bo_driver = {
 756         .ttm_tt_create = i915_ttm_tt_create,
 757         .ttm_tt_populate = i915_ttm_tt_populate,
 758         .ttm_tt_unpopulate = i915_ttm_tt_unpopulate,
 759         .ttm_tt_destroy = i915_ttm_tt_destroy,
 760         .eviction_valuable = i915_ttm_eviction_valuable,
 761         .evict_flags = i915_ttm_evict_flags,
 762         .move = i915_ttm_move,
 763         .swap_notify = i915_ttm_swap_notify,
 764         .delete_mem_notify = i915_ttm_delete_mem_notify,
 765         .io_mem_reserve = i915_ttm_io_mem_reserve,
 766         .io_mem_pfn = i915_ttm_io_mem_pfn,
 767         .access_memory = i915_ttm_access_memory,
 768 };
 769
 770 /**
 771  * i915_ttm_driver - Return a pointer to the TTM device funcs
 772  *
 773  * Return: Pointer to statically allocated TTM device funcs.
 774  */
 775 struct ttm_device_funcs *i915_ttm_driver(void)
 776 {
 777         return &i915_ttm_bo_driver;
 778 }
 779
 780 static int __i915_ttm_get_pages(struct drm_i915_gem_object *obj,
 781                                 struct ttm_placement *placement)
 782 {
 783         struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 784         struct ttm_operation_ctx ctx = {
 785                 .interruptible = true,
 786                 .no_wait_gpu = false,
 787         };
 788         int real_num_busy;
 789         int ret;
 790
 791         /* First try only the requested placement. No eviction. */
 792         real_num_busy = fetch_and_zero(&placement->num_busy_placement);
 793         ret = ttm_bo_validate(bo, placement, &ctx);
 794         if (ret) {
 795                 ret = i915_ttm_err_to_gem(ret);
 796                 /*
 797                  * Anything that wants to restart the operation gets to
 798                  * do that.
 799                  */
 800                 if (ret == -EDEADLK || ret == -EINTR || ret == -ERESTARTSYS ||
 801                     ret == -EAGAIN)
 802                         return ret;
 803
 804                 /*
 805                  * If the initial attempt fails, allow all accepted placements,
 806                  * evicting if necessary.
 807                  */
 808                 placement->num_busy_placement = real_num_busy;
 809                 ret = ttm_bo_validate(bo, placement, &ctx);
 810                 if (ret)
 811                         return i915_ttm_err_to_gem(ret);
 812         }
 813
 814         if (bo->ttm && !ttm_tt_is_populated(bo->ttm)) {
 815                 ret = ttm_tt_populate(bo->bdev, bo->ttm, &ctx);
 816                 if (ret)
 817                         return ret;
 818
 819                 i915_ttm_adjust_domains_after_move(obj);
 820                 i915_ttm_adjust_gem_after_move(obj);
 821         }
 822
 823         if (!i915_gem_object_has_pages(obj)) {
 824                 struct i915_refct_sgt *rsgt =
 825                         i915_ttm_resource_get_st(obj, bo->resource);
 826
 827                 if (IS_ERR(rsgt))
 828                         return PTR_ERR(rsgt);
 829
 830                 GEM_BUG_ON(obj->mm.rsgt);
 831                 obj->mm.rsgt = rsgt;
 832                 __i915_gem_object_set_pages(obj, &rsgt->table);
 833         }
 834
 835         GEM_BUG_ON(bo->ttm && ((obj->base.size >> PAGE_SHIFT) < bo->ttm->num_pages));
 836         i915_ttm_adjust_lru(obj);
 837         return ret;
 838 }
 839
 840 static int i915_ttm_get_pages(struct drm_i915_gem_object *obj)
 841 {
 842         struct ttm_place requested, busy[I915_TTM_MAX_PLACEMENTS];
 843         struct ttm_placement placement;
 844
 845         /* restricted by sg_alloc_table */
 846         if (overflows_type(obj->base.size >> PAGE_SHIFT, unsigned int))
 847                 return -E2BIG;
 848
 849         GEM_BUG_ON(obj->mm.n_placements > I915_TTM_MAX_PLACEMENTS);
 850
 851         /* Move to the requested placement. */
 852         i915_ttm_placement_from_obj(obj, &requested, busy, &placement);
 853
 854         return __i915_ttm_get_pages(obj, &placement);
 855 }
 856
 857 /**
 858  * DOC: Migration vs eviction
 859  *
 860  * GEM migration may not be the same as TTM migration / eviction. If
 861  * the TTM core decides to evict an object it may be evicted to a
 862  * TTM memory type that is not in the object's allowable GEM regions, or
 863  * in fact theoretically to a TTM memory type that doesn't correspond to
 864  * a GEM memory region. In that case the object's GEM region is not
 865  * updated, and the data is migrated back to the GEM region at
 866  * get_pages time. TTM may however set up CPU ptes to the object even
 867  * when it is evicted.
 868  * Gem forced migration using the i915_ttm_migrate() op, is allowed even
 869  * to regions that are not in the object's list of allowable placements.
 870  */
 871 static int __i915_ttm_migrate(struct drm_i915_gem_object *obj,
 872                               struct intel_memory_region *mr,
 873                               unsigned int flags)
 874 {
 875         struct ttm_place requested;
 876         struct ttm_placement placement;
 877         int ret;
 878
 879         i915_ttm_place_from_region(mr, &requested, obj->bo_offset,
 880                                    obj->base.size, flags);
 881         placement.num_placement = 1;
 882         placement.num_busy_placement = 1;
 883         placement.placement = &requested;
 884         placement.busy_placement = &requested;
 885
 886         ret = __i915_ttm_get_pages(obj, &placement);
 887         if (ret)
 888                 return ret;
 889
 890         /*
 891          * Reinitialize the region bindings. This is primarily
 892          * required for objects where the new region is not in
 893          * its allowable placements.
 894          */
 895         if (obj->mm.region != mr) {
 896                 i915_gem_object_release_memory_region(obj);
 897                 i915_gem_object_init_memory_region(obj, mr);
 898         }
 899
 900         return 0;
 901 }
 902
 903 static int i915_ttm_migrate(struct drm_i915_gem_object *obj,
 904                             struct intel_memory_region *mr,
 905                             unsigned int flags)
 906 {
 907         return __i915_ttm_migrate(obj, mr, flags);
 908 }
 909
 910 static void i915_ttm_put_pages(struct drm_i915_gem_object *obj,
 911                                struct sg_table *st)
 912 {
 913         /*
 914          * We're currently not called from a shrinker, so put_pages()
 915          * typically means the object is about to destroyed, or called
 916          * from move_notify(). So just avoid doing much for now.
 917          * If the object is not destroyed next, The TTM eviction logic
 918          * and shrinkers will move it out if needed.
 919          */
 920
 921         if (obj->mm.rsgt)
 922                 i915_refct_sgt_put(fetch_and_zero(&obj->mm.rsgt));
 923 }
 924
 925 /**
 926  * i915_ttm_adjust_lru - Adjust an object's position on relevant LRU lists.
 927  * @obj: The object
 928  */
 929 void i915_ttm_adjust_lru(struct drm_i915_gem_object *obj)
 930 {
 931         struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 932         struct i915_ttm_tt *i915_tt =
 933                 container_of(bo->ttm, typeof(*i915_tt), ttm);
 934         bool shrinkable =
 935                 bo->ttm && i915_tt->filp && ttm_tt_is_populated(bo->ttm);
 936
 937         /*
 938          * Don't manipulate the TTM LRUs while in TTM bo destruction.
 939          * We're called through i915_ttm_delete_mem_notify().
 940          */
 941         if (!kref_read(&bo->kref))
 942                 return;
 943
 944         /*
 945          * We skip managing the shrinker LRU in set_pages() and just manage
 946          * everything here. This does at least solve the issue with having
 947          * temporary shmem mappings(like with evicted lmem) not being visible to
 948          * the shrinker. Only our shmem objects are shrinkable, everything else
 949          * we keep as unshrinkable.
 950          *
 951          * To make sure everything plays nice we keep an extra shrink pin in TTM
 952          * if the underlying pages are not currently shrinkable. Once we release
 953          * our pin, like when the pages are moved to shmem, the pages will then
 954          * be added to the shrinker LRU, assuming the caller isn't also holding
 955          * a pin.
 956          *
 957          * TODO: consider maybe also bumping the shrinker list here when we have
 958          * already unpinned it, which should give us something more like an LRU.
 959          *
 960          * TODO: There is a small window of opportunity for this function to
 961          * get called from eviction after we've dropped the last GEM refcount,
 962          * but before the TTM deleted flag is set on the object. Avoid
 963          * adjusting the shrinker list in such cases, since the object is
 964          * not available to the shrinker anyway due to its zero refcount.
 965          * To fix this properly we should move to a TTM shrinker LRU list for
 966          * these objects.
 967          */
 968         if (kref_get_unless_zero(&obj->base.refcount)) {
 969                 if (shrinkable != obj->mm.ttm_shrinkable) {
 970                         if (shrinkable) {
 971                                 if (obj->mm.madv == I915_MADV_WILLNEED)
 972                                         __i915_gem_object_make_shrinkable(obj);
 973                                 else
 974                                         __i915_gem_object_make_purgeable(obj);
 975                         } else {
 976                                 i915_gem_object_make_unshrinkable(obj);
 977                         }
 978
 979                         obj->mm.ttm_shrinkable = shrinkable;
 980                 }
 981                 i915_gem_object_put(obj);
 982         }
 983
 984         /*
 985          * Put on the correct LRU list depending on the MADV status
 986          */
 987         spin_lock(&bo->bdev->lru_lock);
 988         if (shrinkable) {
 989                 /* Try to keep shmem_tt from being considered for shrinking. */
 990                 bo->priority = TTM_MAX_BO_PRIORITY - 1;
 991         } else if (obj->mm.madv != I915_MADV_WILLNEED) {
 992                 bo->priority = I915_TTM_PRIO_PURGE;
 993         } else if (!i915_gem_object_has_pages(obj)) {
 994                 bo->priority = I915_TTM_PRIO_NO_PAGES;
 995         } else {
 996                 struct ttm_resource_manager *man =
 997                         ttm_manager_type(bo->bdev, bo->resource->mem_type);
 998
 999                 /*
1000                  * If we need to place an LMEM resource which doesn't need CPU
1001                  * access then we should try not to victimize mappable objects
1002                  * first, since we likely end up stealing more of the mappable
1003                  * portion. And likewise when we try to find space for a mappble
1004                  * object, we know not to ever victimize objects that don't
1005                  * occupy any mappable pages.
1006                  */
1007                 if (i915_ttm_cpu_maps_iomem(bo->resource) &&
1008                     i915_ttm_buddy_man_visible_size(man) < man->size &&
1009                     !(obj->flags & I915_BO_ALLOC_GPU_ONLY))
1010                         bo->priority = I915_TTM_PRIO_NEEDS_CPU_ACCESS;
1011                 else
1012                         bo->priority = I915_TTM_PRIO_HAS_PAGES;
1013         }
1014
1015         ttm_bo_move_to_lru_tail(bo);
1016         spin_unlock(&bo->bdev->lru_lock);
1017 }
1018
1019 /*
1020  * TTM-backed gem object destruction requires some clarification.
1021  * Basically we have two possibilities here. We can either rely on the
1022  * i915 delayed destruction and put the TTM object when the object
1023  * is idle. This would be detected by TTM which would bypass the
1024  * TTM delayed destroy handling. The other approach is to put the TTM
1025  * object early and rely on the TTM destroyed handling, and then free
1026  * the leftover parts of the GEM object once TTM's destroyed list handling is
1027  * complete. For now, we rely on the latter for two reasons:
1028  * a) TTM can evict an object even when it's on the delayed destroy list,
1029  * which in theory allows for complete eviction.
1030  * b) There is work going on in TTM to allow freeing an object even when
1031  * it's not idle, and using the TTM destroyed list handling could help us
1032  * benefit from that.
1033  */
1034 static void i915_ttm_delayed_free(struct drm_i915_gem_object *obj)
1035 {
1036         GEM_BUG_ON(!obj->ttm.created);
1037
1038         ttm_bo_put(i915_gem_to_ttm(obj));
1039 }
1040
1041 static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
1042 {
1043         struct vm_area_struct *area = vmf->vma;
1044         struct ttm_buffer_object *bo = area->vm_private_data;
1045         struct drm_device *dev = bo->base.dev;
1046         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
1047         intel_wakeref_t wakeref = 0;
1048         vm_fault_t ret;
1049         int idx;
1050
1051         /* Sanity check that we allow writing into this object */
1052         if (unlikely(i915_gem_object_is_readonly(obj) &&
1053                      area->vm_flags & VM_WRITE))
1054                 return VM_FAULT_SIGBUS;
1055
1056         ret = ttm_bo_vm_reserve(bo, vmf);
1057         if (ret)
1058                 return ret;
1059
1060         if (obj->mm.madv != I915_MADV_WILLNEED) {
1061                 dma_resv_unlock(bo->base.resv);
1062                 return VM_FAULT_SIGBUS;
1063         }
1064
1065         /*
1066          * This must be swapped out with shmem ttm_tt (pipeline-gutting).
1067          * Calling ttm_bo_validate() here with TTM_PL_SYSTEM should only go as
1068          * far as far doing a ttm_bo_move_null(), which should skip all the
1069          * other junk.
1070          */
1071         if (!bo->resource) {
1072                 struct ttm_operation_ctx ctx = {
1073                         .interruptible = true,
1074                         .no_wait_gpu = true, /* should be idle already */
1075                 };
1076                 int err;
1077
1078                 GEM_BUG_ON(!bo->ttm || !(bo->ttm->page_flags & TTM_TT_FLAG_SWAPPED));
1079
1080                 err = ttm_bo_validate(bo, i915_ttm_sys_placement(), &ctx);
1081                 if (err) {
1082                         dma_resv_unlock(bo->base.resv);
1083                         return VM_FAULT_SIGBUS;
1084                 }
1085         } else if (!i915_ttm_resource_mappable(bo->resource)) {
1086                 int err = -ENODEV;
1087                 int i;
1088
1089                 for (i = 0; i < obj->mm.n_placements; i++) {
1090                         struct intel_memory_region *mr = obj->mm.placements[i];
1091                         unsigned int flags;
1092
1093                         if (!mr->io_size && mr->type != INTEL_MEMORY_SYSTEM)
1094                                 continue;
1095
1096                         flags = obj->flags;
1097                         flags &= ~I915_BO_ALLOC_GPU_ONLY;
1098                         err = __i915_ttm_migrate(obj, mr, flags);
1099                         if (!err)
1100                                 break;
1101                 }
1102
1103                 if (err) {
1104                         drm_dbg(dev, "Unable to make resource CPU accessible(err = %pe)\n",
1105                                 ERR_PTR(err));
1106                         dma_resv_unlock(bo->base.resv);
1107                         ret = VM_FAULT_SIGBUS;
1108                         goto out_rpm;
1109                 }
1110         }
1111
1112         if (i915_ttm_cpu_maps_iomem(bo->resource))
1113                 wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm);
1114
1115         if (drm_dev_enter(dev, &idx)) {
1116                 ret = ttm_bo_vm_fault_reserved(vmf, vmf->vma->vm_page_prot,
1117                                                TTM_BO_VM_NUM_PREFAULT);
1118                 drm_dev_exit(idx);
1119         } else {
1120                 ret = ttm_bo_vm_dummy_page(vmf, vmf->vma->vm_page_prot);
1121         }
1122
1123         if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
1124                 goto out_rpm;
1125
1126         /*
1127          * ttm_bo_vm_reserve() already has dma_resv_lock.
1128          * userfault_count is protected by dma_resv lock and rpm wakeref.
1129          */
1130         if (ret == VM_FAULT_NOPAGE && wakeref && !obj->userfault_count) {
1131                 obj->userfault_count = 1;
1132                 spin_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
1133                 list_add(&obj->userfault_link, &to_i915(obj->base.dev)->runtime_pm.lmem_userfault_list);
1134                 spin_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
1135
1136                 GEM_WARN_ON(!i915_ttm_cpu_maps_iomem(bo->resource));
1137         }
1138
1139         if (wakeref & CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND)
1140                 intel_wakeref_auto(&to_i915(obj->base.dev)->runtime_pm.userfault_wakeref,
1141                                    msecs_to_jiffies_timeout(CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND));
1142
1143         i915_ttm_adjust_lru(obj);
1144
1145         dma_resv_unlock(bo->base.resv);
1146
1147 out_rpm:
1148         if (wakeref)
1149                 intel_runtime_pm_put(&to_i915(obj->base.dev)->runtime_pm, wakeref);
1150
1151         return ret;
1152 }
1153
1154 static int
1155 vm_access_ttm(struct vm_area_struct *area, unsigned long addr,
1156               void *buf, int len, int write)
1157 {
1158         struct drm_i915_gem_object *obj =
1159                 i915_ttm_to_gem(area->vm_private_data);
1160
1161         if (i915_gem_object_is_readonly(obj) && write)
1162                 return -EACCES;
1163
1164         return ttm_bo_vm_access(area, addr, buf, len, write);
1165 }
1166
1167 static void ttm_vm_open(struct vm_area_struct *vma)
1168 {
1169         struct drm_i915_gem_object *obj =
1170                 i915_ttm_to_gem(vma->vm_private_data);
1171
1172         GEM_BUG_ON(i915_ttm_is_ghost_object(vma->vm_private_data));
1173         i915_gem_object_get(obj);
1174 }
1175
1176 static void ttm_vm_close(struct vm_area_struct *vma)
1177 {
1178         struct drm_i915_gem_object *obj =
1179                 i915_ttm_to_gem(vma->vm_private_data);
1180
1181         GEM_BUG_ON(i915_ttm_is_ghost_object(vma->vm_private_data));
1182         i915_gem_object_put(obj);
1183 }
1184
1185 static const struct vm_operations_struct vm_ops_ttm = {
1186         .fault = vm_fault_ttm,
1187         .access = vm_access_ttm,
1188         .open = ttm_vm_open,
1189         .close = ttm_vm_close,
1190 };
1191
1192 static u64 i915_ttm_mmap_offset(struct drm_i915_gem_object *obj)
1193 {
1194         /* The ttm_bo must be allocated with I915_BO_ALLOC_USER */
1195         GEM_BUG_ON(!drm_mm_node_allocated(&obj->base.vma_node.vm_node));
1196
1197         return drm_vma_node_offset_addr(&obj->base.vma_node);
1198 }
1199
1200 static void i915_ttm_unmap_virtual(struct drm_i915_gem_object *obj)
1201 {
1202         struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
1203         intel_wakeref_t wakeref = 0;
1204
1205         assert_object_held_shared(obj);
1206
1207         if (i915_ttm_cpu_maps_iomem(bo->resource)) {
1208                 wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm);
1209
1210                 /* userfault_count is protected by obj lock and rpm wakeref. */
1211                 if (obj->userfault_count) {
1212                         spin_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
1213                         list_del(&obj->userfault_link);
1214                         spin_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
1215                         obj->userfault_count = 0;
1216                 }
1217         }
1218
1219         GEM_WARN_ON(obj->userfault_count);
1220
1221         ttm_bo_unmap_virtual(i915_gem_to_ttm(obj));
1222
1223         if (wakeref)
1224                 intel_runtime_pm_put(&to_i915(obj->base.dev)->runtime_pm, wakeref);
1225 }
1226
1227 static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = {
1228         .name = "i915_gem_object_ttm",
1229         .flags = I915_GEM_OBJECT_IS_SHRINKABLE |
1230                  I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST,
1231
1232         .get_pages = i915_ttm_get_pages,
1233         .put_pages = i915_ttm_put_pages,
1234         .truncate = i915_ttm_truncate,
1235         .shrink = i915_ttm_shrink,
1236
1237         .adjust_lru = i915_ttm_adjust_lru,
1238         .delayed_free = i915_ttm_delayed_free,
1239         .migrate = i915_ttm_migrate,
1240
1241         .mmap_offset = i915_ttm_mmap_offset,
1242         .unmap_virtual = i915_ttm_unmap_virtual,
1243         .mmap_ops = &vm_ops_ttm,
1244 };
1245
1246 void i915_ttm_bo_destroy(struct ttm_buffer_object *bo)
1247 {
1248         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
1249
1250         i915_gem_object_release_memory_region(obj);
1251         mutex_destroy(&obj->ttm.get_io_page.lock);
1252
1253         if (obj->ttm.created) {
1254                 /*
1255                  * We freely manage the shrinker LRU outide of the mm.pages life
1256                  * cycle. As a result when destroying the object we should be
1257                  * extra paranoid and ensure we remove it from the LRU, before
1258                  * we free the object.
1259                  *
1260                  * Touching the ttm_shrinkable outside of the object lock here
1261                  * should be safe now that the last GEM object ref was dropped.
1262                  */
1263                 if (obj->mm.ttm_shrinkable)
1264                         i915_gem_object_make_unshrinkable(obj);
1265
1266                 i915_ttm_backup_free(obj);
1267
1268                 /* This releases all gem object bindings to the backend. */
1269                 __i915_gem_free_object(obj);
1270
1271                 call_rcu(&obj->rcu, __i915_gem_free_object_rcu);
1272         } else {
1273                 __i915_gem_object_fini(obj);
1274         }
1275 }
1276
1277 /*
1278  * __i915_gem_ttm_object_init - Initialize a ttm-backed i915 gem object
1279  * @mem: The initial memory region for the object.
1280  * @obj: The gem object.
1281  * @size: Object size in bytes.
1282  * @flags: gem object flags.
1283  *
1284  * Return: 0 on success, negative error code on failure.
1285  */
1286 int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
1287                                struct drm_i915_gem_object *obj,
1288                                resource_size_t offset,
1289                                resource_size_t size,
1290                                resource_size_t page_size,
1291                                unsigned int flags)
1292 {
1293         static struct lock_class_key lock_class;
1294         struct drm_i915_private *i915 = mem->i915;
1295         struct ttm_operation_ctx ctx = {
1296                 .interruptible = true,
1297                 .no_wait_gpu = false,
1298         };
1299         enum ttm_bo_type bo_type;
1300         int ret;
1301
1302         drm_gem_private_object_init(&i915->drm, &obj->base, size);
1303         i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class, flags);
1304
1305         obj->bo_offset = offset;
1306
1307         /* Don't put on a region list until we're either locked or fully initialized. */
1308         obj->mm.region = mem;
1309         INIT_LIST_HEAD(&obj->mm.region_link);
1310
1311         INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL | __GFP_NOWARN);
1312         mutex_init(&obj->ttm.get_io_page.lock);
1313         bo_type = (obj->flags & I915_BO_ALLOC_USER) ? ttm_bo_type_device :
1314                 ttm_bo_type_kernel;
1315
1316         obj->base.vma_node.driver_private = i915_gem_to_ttm(obj);
1317
1318         /* Forcing the page size is kernel internal only */
1319         GEM_BUG_ON(page_size && obj->mm.n_placements);
1320
1321         /*
1322          * Keep an extra shrink pin to prevent the object from being made
1323          * shrinkable too early. If the ttm_tt is ever allocated in shmem, we
1324          * drop the pin. The TTM backend manages the shrinker LRU itself,
1325          * outside of the normal mm.pages life cycle.
1326          */
1327         i915_gem_object_make_unshrinkable(obj);
1328
1329         /*
1330          * If this function fails, it will call the destructor, but
1331          * our caller still owns the object. So no freeing in the
1332          * destructor until obj->ttm.created is true.
1333          * Similarly, in delayed_destroy, we can't call ttm_bo_put()
1334          * until successful initialization.
1335          */
1336         ret = ttm_bo_init_reserved(&i915->bdev, i915_gem_to_ttm(obj), bo_type,
1337                                    &i915_sys_placement, page_size >> PAGE_SHIFT,
1338                                    &ctx, NULL, NULL, i915_ttm_bo_destroy);
1339
1340         /*
1341          * XXX: The ttm_bo_init_reserved() functions returns -ENOSPC if the size
1342          * is too big to add vma. The direct function that returns -ENOSPC is
1343          * drm_mm_insert_node_in_range(). To handle the same error as other code
1344          * that returns -E2BIG when the size is too large, it converts -ENOSPC to
1345          * -E2BIG.
1346          */
1347         if (size >> PAGE_SHIFT > INT_MAX && ret == -ENOSPC)
1348                 ret = -E2BIG;
1349
1350         if (ret)
1351                 return i915_ttm_err_to_gem(ret);
1352
1353         obj->ttm.created = true;
1354         i915_gem_object_release_memory_region(obj);
1355         i915_gem_object_init_memory_region(obj, mem);
1356         i915_ttm_adjust_domains_after_move(obj);
1357         i915_ttm_adjust_gem_after_move(obj);
1358         i915_gem_object_unlock(obj);
1359
1360         return 0;
1361 }
1362
1363 static const struct intel_memory_region_ops ttm_system_region_ops = {
1364         .init_object = __i915_gem_ttm_object_init,
1365         .release = intel_region_ttm_fini,
1366 };
1367
1368 struct intel_memory_region *
1369 i915_gem_ttm_system_setup(struct drm_i915_private *i915,
1370                           u16 type, u16 instance)
1371 {
1372         struct intel_memory_region *mr;
1373
1374         mr = intel_memory_region_create(i915, 0,
1375                                         totalram_pages() << PAGE_SHIFT,
1376                                         PAGE_SIZE, 0, 0,
1377                                         type, instance,
1378                                         &ttm_system_region_ops);
1379         if (IS_ERR(mr))
1380                 return mr;
1381
1382         intel_memory_region_set_name(mr, "system-ttm");
1383         return mr;
1384 }