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   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 */
  49struct 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
  58static const struct ttm_place sys_placement_flags = {
  59	.fpfn = 0,
  60	.lpfn = 0,
  61	.mem_type = I915_PL_SYSTEM,
  62	.flags = 0,
  63};
  64
  65static struct ttm_placement i915_sys_placement = {
  66	.num_placement = 1,
  67	.placement = &sys_placement_flags,
  68};
  69
  70/**
  71 * i915_ttm_sys_placement - Return the struct ttm_placement to be
  72 * used for an object in system memory.
  73 *
  74 * Rather than making the struct extern, use this
  75 * function.
  76 *
  77 * Return: A pointer to a static variable for sys placement.
  78 */
  79struct ttm_placement *i915_ttm_sys_placement(void)
  80{
  81	return &i915_sys_placement;
  82}
  83
  84static int i915_ttm_err_to_gem(int err)
  85{
  86	/* Fastpath */
  87	if (likely(!err))
  88		return 0;
  89
  90	switch (err) {
  91	case -EBUSY:
  92		/*
  93		 * TTM likes to convert -EDEADLK to -EBUSY, and wants us to
  94		 * restart the operation, since we don't record the contending
  95		 * lock. We use -EAGAIN to restart.
  96		 */
  97		return -EAGAIN;
  98	case -ENOSPC:
  99		/*
 100		 * Memory type / region is full, and we can't evict.
 101		 * Except possibly system, that returns -ENOMEM;
 102		 */
 103		return -ENXIO;
 104	default:
 105		break;
 106	}
 107
 108	return err;
 109}
 110
 111static enum ttm_caching
 112i915_ttm_select_tt_caching(const struct drm_i915_gem_object *obj)
 113{
 114	/*
 115	 * Objects only allowed in system get cached cpu-mappings, or when
 116	 * evicting lmem-only buffers to system for swapping. Other objects get
 117	 * WC mapping for now. Even if in system.
 118	 */
 119	if (obj->mm.n_placements <= 1)
 120		return ttm_cached;
 121
 122	return ttm_write_combined;
 123}
 124
 125static void
 126i915_ttm_place_from_region(const struct intel_memory_region *mr,
 127			   struct ttm_place *place,
 128			   resource_size_t offset,
 129			   resource_size_t size,
 130			   unsigned int flags)
 131{
 132	memset(place, 0, sizeof(*place));
 133	place->mem_type = intel_region_to_ttm_type(mr);
 134
 135	if (mr->type == INTEL_MEMORY_SYSTEM)
 136		return;
 137
 138	if (flags & I915_BO_ALLOC_CONTIGUOUS)
 139		place->flags |= TTM_PL_FLAG_CONTIGUOUS;
 140	if (offset != I915_BO_INVALID_OFFSET) {
 141		WARN_ON(overflows_type(offset >> PAGE_SHIFT, place->fpfn));
 142		place->fpfn = offset >> PAGE_SHIFT;
 143		WARN_ON(overflows_type(place->fpfn + (size >> PAGE_SHIFT), place->lpfn));
 144		place->lpfn = place->fpfn + (size >> PAGE_SHIFT);
 145	} else if (resource_size(&mr->io) && resource_size(&mr->io) < mr->total) {
 146		if (flags & I915_BO_ALLOC_GPU_ONLY) {
 147			place->flags |= TTM_PL_FLAG_TOPDOWN;
 148		} else {
 149			place->fpfn = 0;
 150			WARN_ON(overflows_type(resource_size(&mr->io) >> PAGE_SHIFT, place->lpfn));
 151			place->lpfn = resource_size(&mr->io) >> PAGE_SHIFT;
 152		}
 153	}
 154}
 155
 156static void
 157i915_ttm_placement_from_obj(const struct drm_i915_gem_object *obj,
 158			    struct ttm_place *places,
 159			    struct ttm_placement *placement)
 160{
 161	unsigned int num_allowed = obj->mm.n_placements;
 162	unsigned int flags = obj->flags;
 163	unsigned int i;
 164
 165	i915_ttm_place_from_region(num_allowed ? obj->mm.placements[0] :
 166				   obj->mm.region, &places[0], obj->bo_offset,
 167				   obj->base.size, flags);
 168
 169	/* Cache this on object? */
 170	for (i = 0; i < num_allowed; ++i) {
 171		i915_ttm_place_from_region(obj->mm.placements[i],
 172					   &places[i + 1], obj->bo_offset,
 173					   obj->base.size, flags);
 174		places[i + 1].flags |= TTM_PL_FLAG_FALLBACK;
 175	}
 176
 177	placement->num_placement = num_allowed + 1;
 178	placement->placement = places;
 179}
 180
 181static int i915_ttm_tt_shmem_populate(struct ttm_device *bdev,
 182				      struct ttm_tt *ttm,
 183				      struct ttm_operation_ctx *ctx)
 184{
 185	struct drm_i915_private *i915 = container_of(bdev, typeof(*i915), bdev);
 186	struct intel_memory_region *mr = i915->mm.regions[INTEL_MEMORY_SYSTEM];
 187	struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 188	const unsigned int max_segment = i915_sg_segment_size(i915->drm.dev);
 189	const size_t size = (size_t)ttm->num_pages << PAGE_SHIFT;
 190	struct file *filp = i915_tt->filp;
 191	struct sgt_iter sgt_iter;
 192	struct sg_table *st;
 193	struct page *page;
 194	unsigned long i;
 195	int err;
 196
 197	if (!filp) {
 198		struct address_space *mapping;
 199		gfp_t mask;
 200
 201		filp = shmem_file_setup("i915-shmem-tt", size, VM_NORESERVE);
 202		if (IS_ERR(filp))
 203			return PTR_ERR(filp);
 204
 205		mask = GFP_HIGHUSER | __GFP_RECLAIMABLE;
 206
 207		mapping = filp->f_mapping;
 208		mapping_set_gfp_mask(mapping, mask);
 209		GEM_BUG_ON(!(mapping_gfp_mask(mapping) & __GFP_RECLAIM));
 210
 211		i915_tt->filp = filp;
 212	}
 213
 214	st = &i915_tt->cached_rsgt.table;
 215	err = shmem_sg_alloc_table(i915, st, size, mr, filp->f_mapping,
 216				   max_segment);
 217	if (err)
 218		return err;
 219
 220	err = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL,
 221			      DMA_ATTR_SKIP_CPU_SYNC);
 222	if (err)
 223		goto err_free_st;
 224
 225	i = 0;
 226	for_each_sgt_page(page, sgt_iter, st)
 227		ttm->pages[i++] = page;
 228
 229	if (ttm->page_flags & TTM_TT_FLAG_SWAPPED)
 230		ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
 231
 232	return 0;
 233
 234err_free_st:
 235	shmem_sg_free_table(st, filp->f_mapping, false, false);
 236
 237	return err;
 238}
 239
 240static void i915_ttm_tt_shmem_unpopulate(struct ttm_tt *ttm)
 241{
 242	struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 243	bool backup = ttm->page_flags & TTM_TT_FLAG_SWAPPED;
 244	struct sg_table *st = &i915_tt->cached_rsgt.table;
 245
 246	shmem_sg_free_table(st, file_inode(i915_tt->filp)->i_mapping,
 247			    backup, backup);
 248}
 249
 250static void i915_ttm_tt_release(struct kref *ref)
 251{
 252	struct i915_ttm_tt *i915_tt =
 253		container_of(ref, typeof(*i915_tt), cached_rsgt.kref);
 254	struct sg_table *st = &i915_tt->cached_rsgt.table;
 255
 256	GEM_WARN_ON(st->sgl);
 257
 258	kfree(i915_tt);
 259}
 260
 261static const struct i915_refct_sgt_ops tt_rsgt_ops = {
 262	.release = i915_ttm_tt_release
 263};
 264
 265static struct ttm_tt *i915_ttm_tt_create(struct ttm_buffer_object *bo,
 266					 uint32_t page_flags)
 267{
 268	struct drm_i915_private *i915 = container_of(bo->bdev, typeof(*i915),
 269						     bdev);
 270	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 271	unsigned long ccs_pages = 0;
 272	enum ttm_caching caching;
 273	struct i915_ttm_tt *i915_tt;
 274	int ret;
 275
 276	if (i915_ttm_is_ghost_object(bo))
 277		return NULL;
 278
 279	i915_tt = kzalloc(sizeof(*i915_tt), GFP_KERNEL);
 280	if (!i915_tt)
 281		return NULL;
 282
 283	if (obj->flags & I915_BO_ALLOC_CPU_CLEAR && (!bo->resource ||
 284	    ttm_manager_type(bo->bdev, bo->resource->mem_type)->use_tt))
 285		page_flags |= TTM_TT_FLAG_ZERO_ALLOC;
 286
 287	caching = i915_ttm_select_tt_caching(obj);
 288	if (i915_gem_object_is_shrinkable(obj) && caching == ttm_cached) {
 289		page_flags |= TTM_TT_FLAG_EXTERNAL |
 290			      TTM_TT_FLAG_EXTERNAL_MAPPABLE;
 291		i915_tt->is_shmem = true;
 292	}
 293
 294	if (i915_gem_object_needs_ccs_pages(obj))
 295		ccs_pages = DIV_ROUND_UP(DIV_ROUND_UP(bo->base.size,
 296						      NUM_BYTES_PER_CCS_BYTE),
 297					 PAGE_SIZE);
 298
 299	ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags, caching, ccs_pages);
 300	if (ret)
 301		goto err_free;
 302
 303	__i915_refct_sgt_init(&i915_tt->cached_rsgt, bo->base.size,
 304			      &tt_rsgt_ops);
 305
 306	i915_tt->dev = obj->base.dev->dev;
 307
 308	return &i915_tt->ttm;
 309
 310err_free:
 311	kfree(i915_tt);
 312	return NULL;
 313}
 314
 315static int i915_ttm_tt_populate(struct ttm_device *bdev,
 316				struct ttm_tt *ttm,
 317				struct ttm_operation_ctx *ctx)
 318{
 319	struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 320
 321	if (i915_tt->is_shmem)
 322		return i915_ttm_tt_shmem_populate(bdev, ttm, ctx);
 323
 324	return ttm_pool_alloc(&bdev->pool, ttm, ctx);
 325}
 326
 327static void i915_ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
 328{
 329	struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 330	struct sg_table *st = &i915_tt->cached_rsgt.table;
 331
 332	if (st->sgl)
 333		dma_unmap_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0);
 334
 335	if (i915_tt->is_shmem) {
 336		i915_ttm_tt_shmem_unpopulate(ttm);
 337	} else {
 338		sg_free_table(st);
 339		ttm_pool_free(&bdev->pool, ttm);
 340	}
 341}
 342
 343static void i915_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
 344{
 345	struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 346
 347	if (i915_tt->filp)
 348		fput(i915_tt->filp);
 349
 350	ttm_tt_fini(ttm);
 351	i915_refct_sgt_put(&i915_tt->cached_rsgt);
 352}
 353
 354static bool i915_ttm_eviction_valuable(struct ttm_buffer_object *bo,
 355				       const struct ttm_place *place)
 356{
 357	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 358
 359	if (i915_ttm_is_ghost_object(bo))
 360		return false;
 361
 362	/*
 363	 * EXTERNAL objects should never be swapped out by TTM, instead we need
 364	 * to handle that ourselves. TTM will already skip such objects for us,
 365	 * but we would like to avoid grabbing locks for no good reason.
 366	 */
 367	if (bo->ttm && bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL)
 368		return false;
 369
 370	/* Will do for now. Our pinned objects are still on TTM's LRU lists */
 371	if (!i915_gem_object_evictable(obj))
 372		return false;
 373
 374	return ttm_bo_eviction_valuable(bo, place);
 375}
 376
 377static void i915_ttm_evict_flags(struct ttm_buffer_object *bo,
 378				 struct ttm_placement *placement)
 379{
 380	*placement = i915_sys_placement;
 381}
 382
 383/**
 384 * i915_ttm_free_cached_io_rsgt - Free object cached LMEM information
 385 * @obj: The GEM object
 386 * This function frees any LMEM-related information that is cached on
 387 * the object. For example the radix tree for fast page lookup and the
 388 * cached refcounted sg-table
 389 */
 390void i915_ttm_free_cached_io_rsgt(struct drm_i915_gem_object *obj)
 391{
 392	struct radix_tree_iter iter;
 393	void __rcu **slot;
 394
 395	if (!obj->ttm.cached_io_rsgt)
 396		return;
 397
 398	rcu_read_lock();
 399	radix_tree_for_each_slot(slot, &obj->ttm.get_io_page.radix, &iter, 0)
 400		radix_tree_delete(&obj->ttm.get_io_page.radix, iter.index);
 401	rcu_read_unlock();
 402
 403	i915_refct_sgt_put(obj->ttm.cached_io_rsgt);
 404	obj->ttm.cached_io_rsgt = NULL;
 405}
 406
 407/**
 408 * i915_ttm_purge - Clear an object of its memory
 409 * @obj: The object
 410 *
 411 * This function is called to clear an object of it's memory when it is
 412 * marked as not needed anymore.
 413 *
 414 * Return: 0 on success, negative error code on failure.
 415 */
 416int i915_ttm_purge(struct drm_i915_gem_object *obj)
 417{
 418	struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 419	struct i915_ttm_tt *i915_tt =
 420		container_of(bo->ttm, typeof(*i915_tt), ttm);
 421	struct ttm_operation_ctx ctx = {
 422		.interruptible = true,
 423		.no_wait_gpu = false,
 424	};
 425	struct ttm_placement place = {};
 426	int ret;
 427
 428	if (obj->mm.madv == __I915_MADV_PURGED)
 429		return 0;
 430
 431	ret = ttm_bo_validate(bo, &place, &ctx);
 432	if (ret)
 433		return ret;
 434
 435	if (bo->ttm && i915_tt->filp) {
 436		/*
 437		 * The below fput(which eventually calls shmem_truncate) might
 438		 * be delayed by worker, so when directly called to purge the
 439		 * pages(like by the shrinker) we should try to be more
 440		 * aggressive and release the pages immediately.
 441		 */
 442		shmem_truncate_range(file_inode(i915_tt->filp),
 443				     0, (loff_t)-1);
 444		fput(fetch_and_zero(&i915_tt->filp));
 445	}
 446
 447	obj->write_domain = 0;
 448	obj->read_domains = 0;
 449	i915_ttm_adjust_gem_after_move(obj);
 450	i915_ttm_free_cached_io_rsgt(obj);
 451	obj->mm.madv = __I915_MADV_PURGED;
 452
 453	return 0;
 454}
 455
 456static int i915_ttm_shrink(struct drm_i915_gem_object *obj, unsigned int flags)
 457{
 458	struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 459	struct i915_ttm_tt *i915_tt =
 460		container_of(bo->ttm, typeof(*i915_tt), ttm);
 461	struct ttm_operation_ctx ctx = {
 462		.interruptible = true,
 463		.no_wait_gpu = flags & I915_GEM_OBJECT_SHRINK_NO_GPU_WAIT,
 464	};
 465	struct ttm_placement place = {};
 466	int ret;
 467
 468	if (!bo->ttm || i915_ttm_cpu_maps_iomem(bo->resource))
 469		return 0;
 470
 471	GEM_BUG_ON(!i915_tt->is_shmem);
 472
 473	if (!i915_tt->filp)
 474		return 0;
 475
 476	ret = ttm_bo_wait_ctx(bo, &ctx);
 477	if (ret)
 478		return ret;
 479
 480	switch (obj->mm.madv) {
 481	case I915_MADV_DONTNEED:
 482		return i915_ttm_purge(obj);
 483	case __I915_MADV_PURGED:
 484		return 0;
 485	}
 486
 487	if (bo->ttm->page_flags & TTM_TT_FLAG_SWAPPED)
 488		return 0;
 489
 490	bo->ttm->page_flags |= TTM_TT_FLAG_SWAPPED;
 491	ret = ttm_bo_validate(bo, &place, &ctx);
 492	if (ret) {
 493		bo->ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
 494		return ret;
 495	}
 496
 497	if (flags & I915_GEM_OBJECT_SHRINK_WRITEBACK)
 498		__shmem_writeback(obj->base.size, i915_tt->filp->f_mapping);
 499
 500	return 0;
 501}
 502
 503static void i915_ttm_delete_mem_notify(struct ttm_buffer_object *bo)
 504{
 505	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 506
 507	/*
 508	 * This gets called twice by ttm, so long as we have a ttm resource or
 509	 * ttm_tt then we can still safely call this. Due to pipeline-gutting,
 510	 * we maybe have NULL bo->resource, but in that case we should always
 511	 * have a ttm alive (like if the pages are swapped out).
 512	 */
 513	if ((bo->resource || bo->ttm) && !i915_ttm_is_ghost_object(bo)) {
 514		__i915_gem_object_pages_fini(obj);
 515		i915_ttm_free_cached_io_rsgt(obj);
 516	}
 517}
 518
 519static struct i915_refct_sgt *i915_ttm_tt_get_st(struct ttm_tt *ttm)
 520{
 521	struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 522	struct sg_table *st;
 523	int ret;
 524
 525	if (i915_tt->cached_rsgt.table.sgl)
 526		return i915_refct_sgt_get(&i915_tt->cached_rsgt);
 527
 528	st = &i915_tt->cached_rsgt.table;
 529	ret = sg_alloc_table_from_pages_segment(st,
 530			ttm->pages, ttm->num_pages,
 531			0, (unsigned long)ttm->num_pages << PAGE_SHIFT,
 532			i915_sg_segment_size(i915_tt->dev), GFP_KERNEL);
 533	if (ret) {
 534		st->sgl = NULL;
 535		return ERR_PTR(ret);
 536	}
 537
 538	ret = dma_map_sgtable(i915_tt->dev, st, DMA_BIDIRECTIONAL, 0);
 539	if (ret) {
 540		sg_free_table(st);
 541		return ERR_PTR(ret);
 542	}
 543
 544	return i915_refct_sgt_get(&i915_tt->cached_rsgt);
 545}
 546
 547/**
 548 * i915_ttm_resource_get_st - Get a refcounted sg-table pointing to the
 549 * resource memory
 550 * @obj: The GEM object used for sg-table caching
 551 * @res: The struct ttm_resource for which an sg-table is requested.
 552 *
 553 * This function returns a refcounted sg-table representing the memory
 554 * pointed to by @res. If @res is the object's current resource it may also
 555 * cache the sg_table on the object or attempt to access an already cached
 556 * sg-table. The refcounted sg-table needs to be put when no-longer in use.
 557 *
 558 * Return: A valid pointer to a struct i915_refct_sgt or error pointer on
 559 * failure.
 560 */
 561struct i915_refct_sgt *
 562i915_ttm_resource_get_st(struct drm_i915_gem_object *obj,
 563			 struct ttm_resource *res)
 564{
 565	struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 566	u32 page_alignment;
 567
 568	if (!i915_ttm_gtt_binds_lmem(res))
 569		return i915_ttm_tt_get_st(bo->ttm);
 570
 571	page_alignment = bo->page_alignment << PAGE_SHIFT;
 572	if (!page_alignment)
 573		page_alignment = obj->mm.region->min_page_size;
 574
 575	/*
 576	 * If CPU mapping differs, we need to add the ttm_tt pages to
 577	 * the resulting st. Might make sense for GGTT.
 578	 */
 579	GEM_WARN_ON(!i915_ttm_cpu_maps_iomem(res));
 580	if (bo->resource == res) {
 581		if (!obj->ttm.cached_io_rsgt) {
 582			struct i915_refct_sgt *rsgt;
 583
 584			rsgt = intel_region_ttm_resource_to_rsgt(obj->mm.region,
 585								 res,
 586								 page_alignment);
 587			if (IS_ERR(rsgt))
 588				return rsgt;
 589
 590			obj->ttm.cached_io_rsgt = rsgt;
 591		}
 592		return i915_refct_sgt_get(obj->ttm.cached_io_rsgt);
 593	}
 594
 595	return intel_region_ttm_resource_to_rsgt(obj->mm.region, res,
 596						 page_alignment);
 597}
 598
 599static int i915_ttm_truncate(struct drm_i915_gem_object *obj)
 600{
 601	struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 602	long err;
 603
 604	WARN_ON_ONCE(obj->mm.madv == I915_MADV_WILLNEED);
 605
 606	err = dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_BOOKKEEP,
 607				    true, 15 * HZ);
 608	if (err < 0)
 609		return err;
 610	if (err == 0)
 611		return -EBUSY;
 612
 613	err = i915_ttm_move_notify(bo);
 614	if (err)
 615		return err;
 616
 617	return i915_ttm_purge(obj);
 618}
 619
 620static void i915_ttm_swap_notify(struct ttm_buffer_object *bo)
 621{
 622	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 623	int ret;
 624
 625	if (i915_ttm_is_ghost_object(bo))
 626		return;
 627
 628	ret = i915_ttm_move_notify(bo);
 629	GEM_WARN_ON(ret);
 630	GEM_WARN_ON(obj->ttm.cached_io_rsgt);
 631	if (!ret && obj->mm.madv != I915_MADV_WILLNEED)
 632		i915_ttm_purge(obj);
 633}
 634
 635/**
 636 * i915_ttm_resource_mappable - Return true if the ttm resource is CPU
 637 * accessible.
 638 * @res: The TTM resource to check.
 639 *
 640 * This is interesting on small-BAR systems where we may encounter lmem objects
 641 * that can't be accessed via the CPU.
 642 */
 643bool i915_ttm_resource_mappable(struct ttm_resource *res)
 644{
 645	struct i915_ttm_buddy_resource *bman_res = to_ttm_buddy_resource(res);
 646
 647	if (!i915_ttm_cpu_maps_iomem(res))
 648		return true;
 649
 650	return bman_res->used_visible_size == PFN_UP(bman_res->base.size);
 651}
 652
 653static int i915_ttm_io_mem_reserve(struct ttm_device *bdev, struct ttm_resource *mem)
 654{
 655	struct drm_i915_gem_object *obj = i915_ttm_to_gem(mem->bo);
 656	bool unknown_state;
 657
 658	if (i915_ttm_is_ghost_object(mem->bo))
 659		return -EINVAL;
 660
 661	if (!kref_get_unless_zero(&obj->base.refcount))
 662		return -EINVAL;
 663
 664	assert_object_held(obj);
 665
 666	unknown_state = i915_gem_object_has_unknown_state(obj);
 667	i915_gem_object_put(obj);
 668	if (unknown_state)
 669		return -EINVAL;
 670
 671	if (!i915_ttm_cpu_maps_iomem(mem))
 672		return 0;
 673
 674	if (!i915_ttm_resource_mappable(mem))
 675		return -EINVAL;
 676
 677	mem->bus.caching = ttm_write_combined;
 678	mem->bus.is_iomem = true;
 679
 680	return 0;
 681}
 682
 683static unsigned long i915_ttm_io_mem_pfn(struct ttm_buffer_object *bo,
 684					 unsigned long page_offset)
 685{
 686	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 687	struct scatterlist *sg;
 688	unsigned long base;
 689	unsigned int ofs;
 690
 691	GEM_BUG_ON(i915_ttm_is_ghost_object(bo));
 692	GEM_WARN_ON(bo->ttm);
 693
 694	base = obj->mm.region->iomap.base - obj->mm.region->region.start;
 695	sg = i915_gem_object_page_iter_get_sg(obj, &obj->ttm.get_io_page, page_offset, &ofs);
 696
 697	return ((base + sg_dma_address(sg)) >> PAGE_SHIFT) + ofs;
 698}
 699
 700static int i915_ttm_access_memory(struct ttm_buffer_object *bo,
 701				  unsigned long offset, void *buf,
 702				  int len, int write)
 703{
 704	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
 705	resource_size_t iomap = obj->mm.region->iomap.base -
 706		obj->mm.region->region.start;
 707	unsigned long page = offset >> PAGE_SHIFT;
 708	unsigned long bytes_left = len;
 709
 710	/*
 711	 * TODO: For now just let it fail if the resource is non-mappable,
 712	 * otherwise we need to perform the memcpy from the gpu here, without
 713	 * interfering with the object (like moving the entire thing).
 714	 */
 715	if (!i915_ttm_resource_mappable(bo->resource))
 716		return -EIO;
 717
 718	offset -= page << PAGE_SHIFT;
 719	do {
 720		unsigned long bytes = min(bytes_left, PAGE_SIZE - offset);
 721		void __iomem *ptr;
 722		dma_addr_t daddr;
 723
 724		daddr = i915_gem_object_get_dma_address(obj, page);
 725		ptr = ioremap_wc(iomap + daddr + offset, bytes);
 726		if (!ptr)
 727			return -EIO;
 728
 729		if (write)
 730			memcpy_toio(ptr, buf, bytes);
 731		else
 732			memcpy_fromio(buf, ptr, bytes);
 733		iounmap(ptr);
 734
 735		page++;
 736		buf += bytes;
 737		bytes_left -= bytes;
 738		offset = 0;
 739	} while (bytes_left);
 740
 741	return len;
 742}
 743
 744/*
 745 * All callbacks need to take care not to downcast a struct ttm_buffer_object
 746 * without checking its subclass, since it might be a TTM ghost object.
 747 */
 748static struct ttm_device_funcs i915_ttm_bo_driver = {
 749	.ttm_tt_create = i915_ttm_tt_create,
 750	.ttm_tt_populate = i915_ttm_tt_populate,
 751	.ttm_tt_unpopulate = i915_ttm_tt_unpopulate,
 752	.ttm_tt_destroy = i915_ttm_tt_destroy,
 753	.eviction_valuable = i915_ttm_eviction_valuable,
 754	.evict_flags = i915_ttm_evict_flags,
 755	.move = i915_ttm_move,
 756	.swap_notify = i915_ttm_swap_notify,
 757	.delete_mem_notify = i915_ttm_delete_mem_notify,
 758	.io_mem_reserve = i915_ttm_io_mem_reserve,
 759	.io_mem_pfn = i915_ttm_io_mem_pfn,
 760	.access_memory = i915_ttm_access_memory,
 761};
 762
 763/**
 764 * i915_ttm_driver - Return a pointer to the TTM device funcs
 765 *
 766 * Return: Pointer to statically allocated TTM device funcs.
 767 */
 768struct ttm_device_funcs *i915_ttm_driver(void)
 769{
 770	return &i915_ttm_bo_driver;
 771}
 772
 773static int __i915_ttm_get_pages(struct drm_i915_gem_object *obj,
 774				struct ttm_placement *placement)
 775{
 776	struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 777	struct ttm_operation_ctx ctx = {
 778		.interruptible = true,
 779		.no_wait_gpu = false,
 780	};
 781	struct ttm_placement initial_placement;
 782	struct ttm_place initial_place;
 783	int ret;
 784
 785	/* First try only the requested placement. No eviction. */
 786	initial_placement.num_placement = 1;
 787	memcpy(&initial_place, placement->placement, sizeof(struct ttm_place));
 788	initial_place.flags |= TTM_PL_FLAG_DESIRED;
 789	initial_placement.placement = &initial_place;
 790	ret = ttm_bo_validate(bo, &initial_placement, &ctx);
 791	if (ret) {
 792		ret = i915_ttm_err_to_gem(ret);
 793		/*
 794		 * Anything that wants to restart the operation gets to
 795		 * do that.
 796		 */
 797		if (ret == -EDEADLK || ret == -EINTR || ret == -ERESTARTSYS ||
 798		    ret == -EAGAIN)
 799			return ret;
 800
 801		/*
 802		 * If the initial attempt fails, allow all accepted placements,
 803		 * evicting if necessary.
 804		 */
 805		ret = ttm_bo_validate(bo, placement, &ctx);
 806		if (ret)
 807			return i915_ttm_err_to_gem(ret);
 808	}
 809
 810	if (bo->ttm && !ttm_tt_is_populated(bo->ttm)) {
 811		ret = ttm_bo_populate(bo, &ctx);
 812		if (ret)
 813			return ret;
 814
 815		i915_ttm_adjust_domains_after_move(obj);
 816		i915_ttm_adjust_gem_after_move(obj);
 817	}
 818
 819	if (!i915_gem_object_has_pages(obj)) {
 820		struct i915_refct_sgt *rsgt =
 821			i915_ttm_resource_get_st(obj, bo->resource);
 822
 823		if (IS_ERR(rsgt))
 824			return PTR_ERR(rsgt);
 825
 826		GEM_BUG_ON(obj->mm.rsgt);
 827		obj->mm.rsgt = rsgt;
 828		__i915_gem_object_set_pages(obj, &rsgt->table);
 829	}
 830
 831	GEM_BUG_ON(bo->ttm && ((obj->base.size >> PAGE_SHIFT) < bo->ttm->num_pages));
 832	i915_ttm_adjust_lru(obj);
 833	return ret;
 834}
 835
 836static int i915_ttm_get_pages(struct drm_i915_gem_object *obj)
 837{
 838	struct ttm_place places[I915_TTM_MAX_PLACEMENTS + 1];
 839	struct ttm_placement placement;
 840
 841	/* restricted by sg_alloc_table */
 842	if (overflows_type(obj->base.size >> PAGE_SHIFT, unsigned int))
 843		return -E2BIG;
 844
 845	GEM_BUG_ON(obj->mm.n_placements > I915_TTM_MAX_PLACEMENTS);
 846
 847	/* Move to the requested placement. */
 848	i915_ttm_placement_from_obj(obj, places, &placement);
 849
 850	return __i915_ttm_get_pages(obj, &placement);
 851}
 852
 853/**
 854 * DOC: Migration vs eviction
 855 *
 856 * GEM migration may not be the same as TTM migration / eviction. If
 857 * the TTM core decides to evict an object it may be evicted to a
 858 * TTM memory type that is not in the object's allowable GEM regions, or
 859 * in fact theoretically to a TTM memory type that doesn't correspond to
 860 * a GEM memory region. In that case the object's GEM region is not
 861 * updated, and the data is migrated back to the GEM region at
 862 * get_pages time. TTM may however set up CPU ptes to the object even
 863 * when it is evicted.
 864 * Gem forced migration using the i915_ttm_migrate() op, is allowed even
 865 * to regions that are not in the object's list of allowable placements.
 866 */
 867static int __i915_ttm_migrate(struct drm_i915_gem_object *obj,
 868			      struct intel_memory_region *mr,
 869			      unsigned int flags)
 870{
 871	struct ttm_place requested;
 872	struct ttm_placement placement;
 873	int ret;
 874
 875	i915_ttm_place_from_region(mr, &requested, obj->bo_offset,
 876				   obj->base.size, flags);
 877	placement.num_placement = 1;
 878	placement.placement = &requested;
 879
 880	ret = __i915_ttm_get_pages(obj, &placement);
 881	if (ret)
 882		return ret;
 883
 884	/*
 885	 * Reinitialize the region bindings. This is primarily
 886	 * required for objects where the new region is not in
 887	 * its allowable placements.
 888	 */
 889	if (obj->mm.region != mr) {
 890		i915_gem_object_release_memory_region(obj);
 891		i915_gem_object_init_memory_region(obj, mr);
 892	}
 893
 894	return 0;
 895}
 896
 897static int i915_ttm_migrate(struct drm_i915_gem_object *obj,
 898			    struct intel_memory_region *mr,
 899			    unsigned int flags)
 900{
 901	return __i915_ttm_migrate(obj, mr, flags);
 902}
 903
 904static void i915_ttm_put_pages(struct drm_i915_gem_object *obj,
 905			       struct sg_table *st)
 906{
 907	/*
 908	 * We're currently not called from a shrinker, so put_pages()
 909	 * typically means the object is about to destroyed, or called
 910	 * from move_notify(). So just avoid doing much for now.
 911	 * If the object is not destroyed next, The TTM eviction logic
 912	 * and shrinkers will move it out if needed.
 913	 */
 914
 915	if (obj->mm.rsgt)
 916		i915_refct_sgt_put(fetch_and_zero(&obj->mm.rsgt));
 917}
 918
 919/**
 920 * i915_ttm_adjust_lru - Adjust an object's position on relevant LRU lists.
 921 * @obj: The object
 922 */
 923void i915_ttm_adjust_lru(struct drm_i915_gem_object *obj)
 924{
 925	struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
 926	struct i915_ttm_tt *i915_tt =
 927		container_of(bo->ttm, typeof(*i915_tt), ttm);
 928	bool shrinkable =
 929		bo->ttm && i915_tt->filp && ttm_tt_is_populated(bo->ttm);
 930
 931	/*
 932	 * Don't manipulate the TTM LRUs while in TTM bo destruction.
 933	 * We're called through i915_ttm_delete_mem_notify().
 934	 */
 935	if (!kref_read(&bo->kref))
 936		return;
 937
 938	/*
 939	 * We skip managing the shrinker LRU in set_pages() and just manage
 940	 * everything here. This does at least solve the issue with having
 941	 * temporary shmem mappings(like with evicted lmem) not being visible to
 942	 * the shrinker. Only our shmem objects are shrinkable, everything else
 943	 * we keep as unshrinkable.
 944	 *
 945	 * To make sure everything plays nice we keep an extra shrink pin in TTM
 946	 * if the underlying pages are not currently shrinkable. Once we release
 947	 * our pin, like when the pages are moved to shmem, the pages will then
 948	 * be added to the shrinker LRU, assuming the caller isn't also holding
 949	 * a pin.
 950	 *
 951	 * TODO: consider maybe also bumping the shrinker list here when we have
 952	 * already unpinned it, which should give us something more like an LRU.
 953	 *
 954	 * TODO: There is a small window of opportunity for this function to
 955	 * get called from eviction after we've dropped the last GEM refcount,
 956	 * but before the TTM deleted flag is set on the object. Avoid
 957	 * adjusting the shrinker list in such cases, since the object is
 958	 * not available to the shrinker anyway due to its zero refcount.
 959	 * To fix this properly we should move to a TTM shrinker LRU list for
 960	 * these objects.
 961	 */
 962	if (kref_get_unless_zero(&obj->base.refcount)) {
 963		if (shrinkable != obj->mm.ttm_shrinkable) {
 964			if (shrinkable) {
 965				if (obj->mm.madv == I915_MADV_WILLNEED)
 966					__i915_gem_object_make_shrinkable(obj);
 967				else
 968					__i915_gem_object_make_purgeable(obj);
 969			} else {
 970				i915_gem_object_make_unshrinkable(obj);
 971			}
 972
 973			obj->mm.ttm_shrinkable = shrinkable;
 974		}
 975		i915_gem_object_put(obj);
 976	}
 977
 978	/*
 979	 * Put on the correct LRU list depending on the MADV status
 980	 */
 981	spin_lock(&bo->bdev->lru_lock);
 982	if (shrinkable) {
 983		/* Try to keep shmem_tt from being considered for shrinking. */
 984		bo->priority = TTM_MAX_BO_PRIORITY - 1;
 985	} else if (obj->mm.madv != I915_MADV_WILLNEED) {
 986		bo->priority = I915_TTM_PRIO_PURGE;
 987	} else if (!i915_gem_object_has_pages(obj)) {
 988		bo->priority = I915_TTM_PRIO_NO_PAGES;
 989	} else {
 990		struct ttm_resource_manager *man =
 991			ttm_manager_type(bo->bdev, bo->resource->mem_type);
 992
 993		/*
 994		 * If we need to place an LMEM resource which doesn't need CPU
 995		 * access then we should try not to victimize mappable objects
 996		 * first, since we likely end up stealing more of the mappable
 997		 * portion. And likewise when we try to find space for a mappble
 998		 * object, we know not to ever victimize objects that don't
 999		 * occupy any mappable pages.
1000		 */
1001		if (i915_ttm_cpu_maps_iomem(bo->resource) &&
1002		    i915_ttm_buddy_man_visible_size(man) < man->size &&
1003		    !(obj->flags & I915_BO_ALLOC_GPU_ONLY))
1004			bo->priority = I915_TTM_PRIO_NEEDS_CPU_ACCESS;
1005		else
1006			bo->priority = I915_TTM_PRIO_HAS_PAGES;
1007	}
1008
1009	ttm_bo_move_to_lru_tail(bo);
1010	spin_unlock(&bo->bdev->lru_lock);
1011}
1012
1013/*
1014 * TTM-backed gem object destruction requires some clarification.
1015 * Basically we have two possibilities here. We can either rely on the
1016 * i915 delayed destruction and put the TTM object when the object
1017 * is idle. This would be detected by TTM which would bypass the
1018 * TTM delayed destroy handling. The other approach is to put the TTM
1019 * object early and rely on the TTM destroyed handling, and then free
1020 * the leftover parts of the GEM object once TTM's destroyed list handling is
1021 * complete. For now, we rely on the latter for two reasons:
1022 * a) TTM can evict an object even when it's on the delayed destroy list,
1023 * which in theory allows for complete eviction.
1024 * b) There is work going on in TTM to allow freeing an object even when
1025 * it's not idle, and using the TTM destroyed list handling could help us
1026 * benefit from that.
1027 */
1028static void i915_ttm_delayed_free(struct drm_i915_gem_object *obj)
1029{
1030	GEM_BUG_ON(!obj->ttm.created);
1031
1032	ttm_bo_put(i915_gem_to_ttm(obj));
1033}
1034
1035static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
1036{
1037	struct vm_area_struct *area = vmf->vma;
1038	struct ttm_buffer_object *bo = area->vm_private_data;
1039	struct drm_device *dev = bo->base.dev;
1040	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
1041	intel_wakeref_t wakeref = NULL;
1042	vm_fault_t ret;
1043	int idx;
1044
1045	/* Sanity check that we allow writing into this object */
1046	if (unlikely(i915_gem_object_is_readonly(obj) &&
1047		     area->vm_flags & VM_WRITE))
1048		return VM_FAULT_SIGBUS;
1049
1050	ret = ttm_bo_vm_reserve(bo, vmf);
1051	if (ret)
1052		return ret;
1053
1054	if (obj->mm.madv != I915_MADV_WILLNEED) {
1055		dma_resv_unlock(bo->base.resv);
1056		return VM_FAULT_SIGBUS;
1057	}
1058
1059	/*
1060	 * This must be swapped out with shmem ttm_tt (pipeline-gutting).
1061	 * Calling ttm_bo_validate() here with TTM_PL_SYSTEM should only go as
1062	 * far as far doing a ttm_bo_move_null(), which should skip all the
1063	 * other junk.
1064	 */
1065	if (!bo->resource) {
1066		struct ttm_operation_ctx ctx = {
1067			.interruptible = true,
1068			.no_wait_gpu = true, /* should be idle already */
1069		};
1070		int err;
1071
1072		GEM_BUG_ON(!bo->ttm || !(bo->ttm->page_flags & TTM_TT_FLAG_SWAPPED));
1073
1074		err = ttm_bo_validate(bo, i915_ttm_sys_placement(), &ctx);
1075		if (err) {
1076			dma_resv_unlock(bo->base.resv);
1077			return VM_FAULT_SIGBUS;
1078		}
1079	} else if (!i915_ttm_resource_mappable(bo->resource)) {
1080		int err = -ENODEV;
1081		int i;
1082
1083		for (i = 0; i < obj->mm.n_placements; i++) {
1084			struct intel_memory_region *mr = obj->mm.placements[i];
1085			unsigned int flags;
1086
1087			if (!resource_size(&mr->io) && mr->type != INTEL_MEMORY_SYSTEM)
1088				continue;
1089
1090			flags = obj->flags;
1091			flags &= ~I915_BO_ALLOC_GPU_ONLY;
1092			err = __i915_ttm_migrate(obj, mr, flags);
1093			if (!err)
1094				break;
1095		}
1096
1097		if (err) {
1098			drm_dbg_ratelimited(dev,
1099					    "Unable to make resource CPU accessible(err = %pe)\n",
1100					    ERR_PTR(err));
1101			dma_resv_unlock(bo->base.resv);
1102			ret = VM_FAULT_SIGBUS;
1103			goto out_rpm;
1104		}
1105	}
1106
1107	if (i915_ttm_cpu_maps_iomem(bo->resource))
1108		wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm);
1109
1110	if (drm_dev_enter(dev, &idx)) {
1111		ret = ttm_bo_vm_fault_reserved(vmf, vmf->vma->vm_page_prot,
1112					       TTM_BO_VM_NUM_PREFAULT);
1113		drm_dev_exit(idx);
1114	} else {
1115		ret = ttm_bo_vm_dummy_page(vmf, vmf->vma->vm_page_prot);
1116	}
1117
1118	if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
1119		goto out_rpm;
1120
1121	/*
1122	 * ttm_bo_vm_reserve() already has dma_resv_lock.
1123	 * userfault_count is protected by dma_resv lock and rpm wakeref.
1124	 */
1125	if (ret == VM_FAULT_NOPAGE && wakeref && !obj->userfault_count) {
1126		obj->userfault_count = 1;
1127		spin_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
1128		list_add(&obj->userfault_link, &to_i915(obj->base.dev)->runtime_pm.lmem_userfault_list);
1129		spin_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
1130
1131		GEM_WARN_ON(!i915_ttm_cpu_maps_iomem(bo->resource));
1132	}
1133
1134	if (wakeref && CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND != 0)
1135		intel_wakeref_auto(&to_i915(obj->base.dev)->runtime_pm.userfault_wakeref,
1136				   msecs_to_jiffies_timeout(CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND));
1137
1138	i915_ttm_adjust_lru(obj);
1139
1140	dma_resv_unlock(bo->base.resv);
1141
1142out_rpm:
1143	if (wakeref)
1144		intel_runtime_pm_put(&to_i915(obj->base.dev)->runtime_pm, wakeref);
1145
1146	return ret;
1147}
1148
1149static int
1150vm_access_ttm(struct vm_area_struct *area, unsigned long addr,
1151	      void *buf, int len, int write)
1152{
1153	struct drm_i915_gem_object *obj =
1154		i915_ttm_to_gem(area->vm_private_data);
1155
1156	if (i915_gem_object_is_readonly(obj) && write)
1157		return -EACCES;
1158
1159	return ttm_bo_vm_access(area, addr, buf, len, write);
1160}
1161
1162static void ttm_vm_open(struct vm_area_struct *vma)
1163{
1164	struct drm_i915_gem_object *obj =
1165		i915_ttm_to_gem(vma->vm_private_data);
1166
1167	GEM_BUG_ON(i915_ttm_is_ghost_object(vma->vm_private_data));
1168	i915_gem_object_get(obj);
1169}
1170
1171static void ttm_vm_close(struct vm_area_struct *vma)
1172{
1173	struct drm_i915_gem_object *obj =
1174		i915_ttm_to_gem(vma->vm_private_data);
1175
1176	GEM_BUG_ON(i915_ttm_is_ghost_object(vma->vm_private_data));
1177	i915_gem_object_put(obj);
1178}
1179
1180static const struct vm_operations_struct vm_ops_ttm = {
1181	.fault = vm_fault_ttm,
1182	.access = vm_access_ttm,
1183	.open = ttm_vm_open,
1184	.close = ttm_vm_close,
1185};
1186
1187static u64 i915_ttm_mmap_offset(struct drm_i915_gem_object *obj)
1188{
1189	/* The ttm_bo must be allocated with I915_BO_ALLOC_USER */
1190	GEM_BUG_ON(!drm_mm_node_allocated(&obj->base.vma_node.vm_node));
1191
1192	return drm_vma_node_offset_addr(&obj->base.vma_node);
1193}
1194
1195static void i915_ttm_unmap_virtual(struct drm_i915_gem_object *obj)
1196{
1197	struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
1198	intel_wakeref_t wakeref = NULL;
1199
1200	assert_object_held_shared(obj);
1201
1202	if (i915_ttm_cpu_maps_iomem(bo->resource)) {
1203		wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm);
1204
1205		/* userfault_count is protected by obj lock and rpm wakeref. */
1206		if (obj->userfault_count) {
1207			spin_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
1208			list_del(&obj->userfault_link);
1209			spin_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
1210			obj->userfault_count = 0;
1211		}
1212	}
1213
1214	GEM_WARN_ON(obj->userfault_count);
1215
1216	ttm_bo_unmap_virtual(i915_gem_to_ttm(obj));
1217
1218	if (wakeref)
1219		intel_runtime_pm_put(&to_i915(obj->base.dev)->runtime_pm, wakeref);
1220}
1221
1222static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = {
1223	.name = "i915_gem_object_ttm",
1224	.flags = I915_GEM_OBJECT_IS_SHRINKABLE |
1225		 I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST,
1226
1227	.get_pages = i915_ttm_get_pages,
1228	.put_pages = i915_ttm_put_pages,
1229	.truncate = i915_ttm_truncate,
1230	.shrink = i915_ttm_shrink,
1231
1232	.adjust_lru = i915_ttm_adjust_lru,
1233	.delayed_free = i915_ttm_delayed_free,
1234	.migrate = i915_ttm_migrate,
1235
1236	.mmap_offset = i915_ttm_mmap_offset,
1237	.unmap_virtual = i915_ttm_unmap_virtual,
1238	.mmap_ops = &vm_ops_ttm,
1239};
1240
1241void i915_ttm_bo_destroy(struct ttm_buffer_object *bo)
1242{
1243	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
1244
1245	i915_gem_object_release_memory_region(obj);
1246	mutex_destroy(&obj->ttm.get_io_page.lock);
1247
1248	if (obj->ttm.created) {
1249		/*
1250		 * We freely manage the shrinker LRU outide of the mm.pages life
1251		 * cycle. As a result when destroying the object we should be
1252		 * extra paranoid and ensure we remove it from the LRU, before
1253		 * we free the object.
1254		 *
1255		 * Touching the ttm_shrinkable outside of the object lock here
1256		 * should be safe now that the last GEM object ref was dropped.
1257		 */
1258		if (obj->mm.ttm_shrinkable)
1259			i915_gem_object_make_unshrinkable(obj);
1260
1261		i915_ttm_backup_free(obj);
1262
1263		/* This releases all gem object bindings to the backend. */
1264		__i915_gem_free_object(obj);
1265
1266		call_rcu(&obj->rcu, __i915_gem_free_object_rcu);
1267	} else {
1268		__i915_gem_object_fini(obj);
1269	}
1270}
1271
1272/*
1273 * __i915_gem_ttm_object_init - Initialize a ttm-backed i915 gem object
1274 * @mem: The initial memory region for the object.
1275 * @obj: The gem object.
1276 * @size: Object size in bytes.
1277 * @flags: gem object flags.
1278 *
1279 * Return: 0 on success, negative error code on failure.
1280 */
1281int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
1282			       struct drm_i915_gem_object *obj,
1283			       resource_size_t offset,
1284			       resource_size_t size,
1285			       resource_size_t page_size,
1286			       unsigned int flags)
1287{
1288	static struct lock_class_key lock_class;
1289	struct drm_i915_private *i915 = mem->i915;
1290	struct ttm_operation_ctx ctx = {
1291		.interruptible = true,
1292		.no_wait_gpu = false,
1293	};
1294	enum ttm_bo_type bo_type;
1295	int ret;
1296
1297	drm_gem_private_object_init(&i915->drm, &obj->base, size);
1298	i915_gem_object_init(obj, &i915_gem_ttm_obj_ops, &lock_class, flags);
1299
1300	obj->bo_offset = offset;
1301
1302	/* Don't put on a region list until we're either locked or fully initialized. */
1303	obj->mm.region = mem;
1304	INIT_LIST_HEAD(&obj->mm.region_link);
1305
1306	INIT_RADIX_TREE(&obj->ttm.get_io_page.radix, GFP_KERNEL | __GFP_NOWARN);
1307	mutex_init(&obj->ttm.get_io_page.lock);
1308	bo_type = (obj->flags & I915_BO_ALLOC_USER) ? ttm_bo_type_device :
1309		ttm_bo_type_kernel;
1310
1311	obj->base.vma_node.driver_private = i915_gem_to_ttm(obj);
1312
1313	/* Forcing the page size is kernel internal only */
1314	GEM_BUG_ON(page_size && obj->mm.n_placements);
1315
1316	/*
1317	 * Keep an extra shrink pin to prevent the object from being made
1318	 * shrinkable too early. If the ttm_tt is ever allocated in shmem, we
1319	 * drop the pin. The TTM backend manages the shrinker LRU itself,
1320	 * outside of the normal mm.pages life cycle.
1321	 */
1322	i915_gem_object_make_unshrinkable(obj);
1323
1324	/*
1325	 * If this function fails, it will call the destructor, but
1326	 * our caller still owns the object. So no freeing in the
1327	 * destructor until obj->ttm.created is true.
1328	 * Similarly, in delayed_destroy, we can't call ttm_bo_put()
1329	 * until successful initialization.
1330	 */
1331	ret = ttm_bo_init_reserved(&i915->bdev, i915_gem_to_ttm(obj), bo_type,
1332				   &i915_sys_placement, page_size >> PAGE_SHIFT,
1333				   &ctx, NULL, NULL, i915_ttm_bo_destroy);
1334
1335	/*
1336	 * XXX: The ttm_bo_init_reserved() functions returns -ENOSPC if the size
1337	 * is too big to add vma. The direct function that returns -ENOSPC is
1338	 * drm_mm_insert_node_in_range(). To handle the same error as other code
1339	 * that returns -E2BIG when the size is too large, it converts -ENOSPC to
1340	 * -E2BIG.
1341	 */
1342	if (size >> PAGE_SHIFT > INT_MAX && ret == -ENOSPC)
1343		ret = -E2BIG;
1344
1345	if (ret)
1346		return i915_ttm_err_to_gem(ret);
1347
1348	obj->ttm.created = true;
1349	i915_gem_object_release_memory_region(obj);
1350	i915_gem_object_init_memory_region(obj, mem);
1351	i915_ttm_adjust_domains_after_move(obj);
1352	i915_ttm_adjust_gem_after_move(obj);
1353	i915_gem_object_unlock(obj);
1354
1355	return 0;
1356}
1357
1358static const struct intel_memory_region_ops ttm_system_region_ops = {
1359	.init_object = __i915_gem_ttm_object_init,
1360	.release = intel_region_ttm_fini,
1361};
1362
1363struct intel_memory_region *
1364i915_gem_ttm_system_setup(struct drm_i915_private *i915,
1365			  u16 type, u16 instance)
1366{
1367	struct intel_memory_region *mr;
1368
1369	mr = intel_memory_region_create(i915, 0,
1370					totalram_pages() << PAGE_SHIFT,
1371					PAGE_SIZE, 0, 0,
1372					type, instance,
1373					&ttm_system_region_ops);
1374	if (IS_ERR(mr))
1375		return mr;
1376
1377	intel_memory_region_set_name(mr, "system-ttm");
1378	return mr;
1379}