i915_gem_object.c

   1// SPDX-License-Identifier: MIT
   2/*
   3 * Copyright © 2017 Intel Corporation
   4 *
   5 * Permission is hereby granted, free of charge, to any person obtaining a
   6 * copy of this software and associated documentation files (the "Software"),
   7 * to deal in the Software without restriction, including without limitation
   8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9 * and/or sell copies of the Software, and to permit persons to whom the
  10 * Software is furnished to do so, subject to the following conditions:
  11 *
  12 * The above copyright notice and this permission notice (including the next
  13 * paragraph) shall be included in all copies or substantial portions of the
  14 * Software.
  15 *
  16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  22 * IN THE SOFTWARE.
  23 *
  24 */
  25
  26#include <linux/highmem.h>
  27#include <linux/sched/mm.h>
  28
  29#include <drm/drm_cache.h>
  30#include <drm/drm_print.h>
  31
  32#include "display/intel_frontbuffer.h"
  33#include "pxp/intel_pxp.h"
  34
  35#include "i915_drv.h"
  36#include "i915_file_private.h"
  37#include "i915_gem_clflush.h"
  38#include "i915_gem_context.h"
  39#include "i915_gem_dmabuf.h"
  40#include "i915_gem_mman.h"
  41#include "i915_gem_object.h"
  42#include "i915_gem_object_frontbuffer.h"
  43#include "i915_gem_ttm.h"
  44#include "i915_memcpy.h"
  45#include "i915_trace.h"
  46
  47static struct kmem_cache *slab_objects;
  48
  49static const struct drm_gem_object_funcs i915_gem_object_funcs;
  50
  51unsigned int i915_gem_get_pat_index(struct drm_i915_private *i915,
  52				    enum i915_cache_level level)
  53{
  54	if (drm_WARN_ON(&i915->drm, level >= I915_MAX_CACHE_LEVEL))
  55		return 0;
  56
  57	return INTEL_INFO(i915)->cachelevel_to_pat[level];
  58}
  59
  60bool i915_gem_object_has_cache_level(const struct drm_i915_gem_object *obj,
  61				     enum i915_cache_level lvl)
  62{
  63	/*
  64	 * In case the pat_index is set by user space, this kernel mode
  65	 * driver should leave the coherency to be managed by user space,
  66	 * simply return true here.
  67	 */
  68	if (obj->pat_set_by_user)
  69		return true;
  70
  71	/*
  72	 * Otherwise the pat_index should have been converted from cache_level
  73	 * so that the following comparison is valid.
  74	 */
  75	return obj->pat_index == i915_gem_get_pat_index(obj_to_i915(obj), lvl);
  76}
  77
  78struct drm_i915_gem_object *i915_gem_object_alloc(void)
  79{
  80	struct drm_i915_gem_object *obj;
  81
  82	obj = kmem_cache_zalloc(slab_objects, GFP_KERNEL);
  83	if (!obj)
  84		return NULL;
  85	obj->base.funcs = &i915_gem_object_funcs;
  86
  87	return obj;
  88}
  89
  90void i915_gem_object_free(struct drm_i915_gem_object *obj)
  91{
  92	return kmem_cache_free(slab_objects, obj);
  93}
  94
  95void i915_gem_object_init(struct drm_i915_gem_object *obj,
  96			  const struct drm_i915_gem_object_ops *ops,
  97			  struct lock_class_key *key, unsigned flags)
  98{
  99	/*
 100	 * A gem object is embedded both in a struct ttm_buffer_object :/ and
 101	 * in a drm_i915_gem_object. Make sure they are aliased.
 102	 */
 103	BUILD_BUG_ON(offsetof(typeof(*obj), base) !=
 104		     offsetof(typeof(*obj), __do_not_access.base));
 105
 106	spin_lock_init(&obj->vma.lock);
 107	INIT_LIST_HEAD(&obj->vma.list);
 108
 109	INIT_LIST_HEAD(&obj->mm.link);
 110
 111#ifdef CONFIG_PROC_FS
 112	INIT_LIST_HEAD(&obj->client_link);
 113#endif
 114
 115	INIT_LIST_HEAD(&obj->lut_list);
 116	spin_lock_init(&obj->lut_lock);
 117
 118	spin_lock_init(&obj->mmo.lock);
 119	obj->mmo.offsets = RB_ROOT;
 120
 121	init_rcu_head(&obj->rcu);
 122
 123	obj->ops = ops;
 124	GEM_BUG_ON(flags & ~I915_BO_ALLOC_FLAGS);
 125	obj->flags = flags;
 126
 127	obj->mm.madv = I915_MADV_WILLNEED;
 128	INIT_RADIX_TREE(&obj->mm.get_page.radix, GFP_KERNEL | __GFP_NOWARN);
 129	mutex_init(&obj->mm.get_page.lock);
 130	INIT_RADIX_TREE(&obj->mm.get_dma_page.radix, GFP_KERNEL | __GFP_NOWARN);
 131	mutex_init(&obj->mm.get_dma_page.lock);
 132}
 133
 134/**
 135 * __i915_gem_object_fini - Clean up a GEM object initialization
 136 * @obj: The gem object to cleanup
 137 *
 138 * This function cleans up gem object fields that are set up by
 139 * drm_gem_private_object_init() and i915_gem_object_init().
 140 * It's primarily intended as a helper for backends that need to
 141 * clean up the gem object in separate steps.
 142 */
 143void __i915_gem_object_fini(struct drm_i915_gem_object *obj)
 144{
 145	mutex_destroy(&obj->mm.get_page.lock);
 146	mutex_destroy(&obj->mm.get_dma_page.lock);
 147	dma_resv_fini(&obj->base._resv);
 148}
 149
 150/**
 151 * i915_gem_object_set_cache_coherency - Mark up the object's coherency levels
 152 * for a given cache_level
 153 * @obj: #drm_i915_gem_object
 154 * @cache_level: cache level
 155 */
 156void i915_gem_object_set_cache_coherency(struct drm_i915_gem_object *obj,
 157					 unsigned int cache_level)
 158{
 159	struct drm_i915_private *i915 = to_i915(obj->base.dev);
 160
 161	obj->pat_index = i915_gem_get_pat_index(i915, cache_level);
 162
 163	if (cache_level != I915_CACHE_NONE)
 164		obj->cache_coherent = (I915_BO_CACHE_COHERENT_FOR_READ |
 165				       I915_BO_CACHE_COHERENT_FOR_WRITE);
 166	else if (HAS_LLC(i915))
 167		obj->cache_coherent = I915_BO_CACHE_COHERENT_FOR_READ;
 168	else
 169		obj->cache_coherent = 0;
 170
 171	obj->cache_dirty =
 172		!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE) &&
 173		!IS_DGFX(i915);
 174}
 175
 176/**
 177 * i915_gem_object_set_pat_index - set PAT index to be used in PTE encode
 178 * @obj: #drm_i915_gem_object
 179 * @pat_index: PAT index
 180 *
 181 * This is a clone of i915_gem_object_set_cache_coherency taking pat index
 182 * instead of cache_level as its second argument.
 183 */
 184void i915_gem_object_set_pat_index(struct drm_i915_gem_object *obj,
 185				   unsigned int pat_index)
 186{
 187	struct drm_i915_private *i915 = to_i915(obj->base.dev);
 188
 189	if (obj->pat_index == pat_index)
 190		return;
 191
 192	obj->pat_index = pat_index;
 193
 194	if (pat_index != i915_gem_get_pat_index(i915, I915_CACHE_NONE))
 195		obj->cache_coherent = (I915_BO_CACHE_COHERENT_FOR_READ |
 196				       I915_BO_CACHE_COHERENT_FOR_WRITE);
 197	else if (HAS_LLC(i915))
 198		obj->cache_coherent = I915_BO_CACHE_COHERENT_FOR_READ;
 199	else
 200		obj->cache_coherent = 0;
 201
 202	obj->cache_dirty =
 203		!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE) &&
 204		!IS_DGFX(i915);
 205}
 206
 207bool i915_gem_object_can_bypass_llc(struct drm_i915_gem_object *obj)
 208{
 209	struct drm_i915_private *i915 = to_i915(obj->base.dev);
 210
 211	/*
 212	 * This is purely from a security perspective, so we simply don't care
 213	 * about non-userspace objects being able to bypass the LLC.
 214	 */
 215	if (!(obj->flags & I915_BO_ALLOC_USER))
 216		return false;
 217
 218	/*
 219	 * Always flush cache for UMD objects at creation time.
 220	 */
 221	if (obj->pat_set_by_user)
 222		return true;
 223
 224	/*
 225	 * EHL and JSL add the 'Bypass LLC' MOCS entry, which should make it
 226	 * possible for userspace to bypass the GTT caching bits set by the
 227	 * kernel, as per the given object cache_level. This is troublesome
 228	 * since the heavy flush we apply when first gathering the pages is
 229	 * skipped if the kernel thinks the object is coherent with the GPU. As
 230	 * a result it might be possible to bypass the cache and read the
 231	 * contents of the page directly, which could be stale data. If it's
 232	 * just a case of userspace shooting themselves in the foot then so be
 233	 * it, but since i915 takes the stance of always zeroing memory before
 234	 * handing it to userspace, we need to prevent this.
 235	 */
 236	return (IS_JASPERLAKE(i915) || IS_ELKHARTLAKE(i915));
 237}
 238
 239static void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file)
 240{
 241	struct drm_i915_gem_object *obj = to_intel_bo(gem);
 242	struct drm_i915_file_private *fpriv = file->driver_priv;
 243	struct i915_lut_handle bookmark = {};
 244	struct i915_mmap_offset *mmo, *mn;
 245	struct i915_lut_handle *lut, *ln;
 246	LIST_HEAD(close);
 247
 248	spin_lock(&obj->lut_lock);
 249	list_for_each_entry_safe(lut, ln, &obj->lut_list, obj_link) {
 250		struct i915_gem_context *ctx = lut->ctx;
 251
 252		if (ctx && ctx->file_priv == fpriv) {
 253			i915_gem_context_get(ctx);
 254			list_move(&lut->obj_link, &close);
 255		}
 256
 257		/* Break long locks, and carefully continue on from this spot */
 258		if (&ln->obj_link != &obj->lut_list) {
 259			list_add_tail(&bookmark.obj_link, &ln->obj_link);
 260			if (cond_resched_lock(&obj->lut_lock))
 261				list_safe_reset_next(&bookmark, ln, obj_link);
 262			__list_del_entry(&bookmark.obj_link);
 263		}
 264	}
 265	spin_unlock(&obj->lut_lock);
 266
 267	spin_lock(&obj->mmo.lock);
 268	rbtree_postorder_for_each_entry_safe(mmo, mn, &obj->mmo.offsets, offset)
 269		drm_vma_node_revoke(&mmo->vma_node, file);
 270	spin_unlock(&obj->mmo.lock);
 271
 272	list_for_each_entry_safe(lut, ln, &close, obj_link) {
 273		struct i915_gem_context *ctx = lut->ctx;
 274		struct i915_vma *vma;
 275
 276		/*
 277		 * We allow the process to have multiple handles to the same
 278		 * vma, in the same fd namespace, by virtue of flink/open.
 279		 */
 280
 281		mutex_lock(&ctx->lut_mutex);
 282		vma = radix_tree_delete(&ctx->handles_vma, lut->handle);
 283		if (vma) {
 284			GEM_BUG_ON(vma->obj != obj);
 285			GEM_BUG_ON(!atomic_read(&vma->open_count));
 286			i915_vma_close(vma);
 287		}
 288		mutex_unlock(&ctx->lut_mutex);
 289
 290		i915_gem_context_put(lut->ctx);
 291		i915_lut_handle_free(lut);
 292		i915_gem_object_put(obj);
 293	}
 294}
 295
 296void __i915_gem_free_object_rcu(struct rcu_head *head)
 297{
 298	struct drm_i915_gem_object *obj =
 299		container_of(head, typeof(*obj), rcu);
 300	struct drm_i915_private *i915 = to_i915(obj->base.dev);
 301
 302	/* We need to keep this alive for RCU read access from fdinfo. */
 303	if (obj->mm.n_placements > 1)
 304		kfree(obj->mm.placements);
 305
 306	i915_gem_object_free(obj);
 307
 308	GEM_BUG_ON(!atomic_read(&i915->mm.free_count));
 309	atomic_dec(&i915->mm.free_count);
 310}
 311
 312static void __i915_gem_object_free_mmaps(struct drm_i915_gem_object *obj)
 313{
 314	/* Skip serialisation and waking the device if known to be not used. */
 315
 316	if (obj->userfault_count && !IS_DGFX(to_i915(obj->base.dev)))
 317		i915_gem_object_release_mmap_gtt(obj);
 318
 319	if (!RB_EMPTY_ROOT(&obj->mmo.offsets)) {
 320		struct i915_mmap_offset *mmo, *mn;
 321
 322		i915_gem_object_release_mmap_offset(obj);
 323
 324		rbtree_postorder_for_each_entry_safe(mmo, mn,
 325						     &obj->mmo.offsets,
 326						     offset) {
 327			drm_vma_offset_remove(obj->base.dev->vma_offset_manager,
 328					      &mmo->vma_node);
 329			kfree(mmo);
 330		}
 331		obj->mmo.offsets = RB_ROOT;
 332	}
 333}
 334
 335/**
 336 * __i915_gem_object_pages_fini - Clean up pages use of a gem object
 337 * @obj: The gem object to clean up
 338 *
 339 * This function cleans up usage of the object mm.pages member. It
 340 * is intended for backends that need to clean up a gem object in
 341 * separate steps and needs to be called when the object is idle before
 342 * the object's backing memory is freed.
 343 */
 344void __i915_gem_object_pages_fini(struct drm_i915_gem_object *obj)
 345{
 346	assert_object_held_shared(obj);
 347
 348	if (!list_empty(&obj->vma.list)) {
 349		struct i915_vma *vma;
 350
 351		spin_lock(&obj->vma.lock);
 352		while ((vma = list_first_entry_or_null(&obj->vma.list,
 353						       struct i915_vma,
 354						       obj_link))) {
 355			GEM_BUG_ON(vma->obj != obj);
 356			spin_unlock(&obj->vma.lock);
 357
 358			i915_vma_destroy(vma);
 359
 360			spin_lock(&obj->vma.lock);
 361		}
 362		spin_unlock(&obj->vma.lock);
 363	}
 364
 365	__i915_gem_object_free_mmaps(obj);
 366
 367	atomic_set(&obj->mm.pages_pin_count, 0);
 368
 369	/*
 370	 * dma_buf_unmap_attachment() requires reservation to be
 371	 * locked. The imported GEM shouldn't share reservation lock
 372	 * and ttm_bo_cleanup_memtype_use() shouldn't be invoked for
 373	 * dma-buf, so it's safe to take the lock.
 374	 */
 375	if (obj->base.import_attach)
 376		i915_gem_object_lock(obj, NULL);
 377
 378	__i915_gem_object_put_pages(obj);
 379
 380	if (obj->base.import_attach)
 381		i915_gem_object_unlock(obj);
 382
 383	GEM_BUG_ON(i915_gem_object_has_pages(obj));
 384}
 385
 386void __i915_gem_free_object(struct drm_i915_gem_object *obj)
 387{
 388	trace_i915_gem_object_destroy(obj);
 389
 390	GEM_BUG_ON(!list_empty(&obj->lut_list));
 391
 392	bitmap_free(obj->bit_17);
 393
 394	if (obj->base.import_attach)
 395		drm_prime_gem_destroy(&obj->base, NULL);
 396
 397	drm_gem_free_mmap_offset(&obj->base);
 398
 399	if (obj->ops->release)
 400		obj->ops->release(obj);
 401
 402	if (obj->shares_resv_from)
 403		i915_vm_resv_put(obj->shares_resv_from);
 404
 405	__i915_gem_object_fini(obj);
 406}
 407
 408static void __i915_gem_free_objects(struct drm_i915_private *i915,
 409				    struct llist_node *freed)
 410{
 411	struct drm_i915_gem_object *obj, *on;
 412
 413	llist_for_each_entry_safe(obj, on, freed, freed) {
 414		might_sleep();
 415		if (obj->ops->delayed_free) {
 416			obj->ops->delayed_free(obj);
 417			continue;
 418		}
 419
 420		__i915_gem_object_pages_fini(obj);
 421		__i915_gem_free_object(obj);
 422
 423		/* But keep the pointer alive for RCU-protected lookups */
 424		call_rcu(&obj->rcu, __i915_gem_free_object_rcu);
 425		cond_resched();
 426	}
 427}
 428
 429void i915_gem_flush_free_objects(struct drm_i915_private *i915)
 430{
 431	struct llist_node *freed = llist_del_all(&i915->mm.free_list);
 432
 433	if (unlikely(freed))
 434		__i915_gem_free_objects(i915, freed);
 435}
 436
 437static void __i915_gem_free_work(struct work_struct *work)
 438{
 439	struct drm_i915_private *i915 =
 440		container_of(work, struct drm_i915_private, mm.free_work);
 441
 442	i915_gem_flush_free_objects(i915);
 443}
 444
 445static void i915_gem_free_object(struct drm_gem_object *gem_obj)
 446{
 447	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 448	struct drm_i915_private *i915 = to_i915(obj->base.dev);
 449
 450	GEM_BUG_ON(i915_gem_object_is_framebuffer(obj));
 451
 452	i915_drm_client_remove_object(obj);
 453
 454	/*
 455	 * Before we free the object, make sure any pure RCU-only
 456	 * read-side critical sections are complete, e.g.
 457	 * i915_gem_busy_ioctl(). For the corresponding synchronized
 458	 * lookup see i915_gem_object_lookup_rcu().
 459	 */
 460	atomic_inc(&i915->mm.free_count);
 461
 462	/*
 463	 * Since we require blocking on drm_i915_gem_object->vma.lock to unbind
 464	 * the freed object from the GPU before releasing resources back to the
 465	 * system, we can not do that directly from the RCU callback (which may
 466	 * be a softirq context), but must instead then defer that work onto a
 467	 * kthread. We use the RCU callback rather than move the freed object
 468	 * directly onto the work queue so that we can mix between using the
 469	 * worker and performing frees directly from subsequent allocations for
 470	 * crude but effective memory throttling.
 471	 */
 472
 473	if (llist_add(&obj->freed, &i915->mm.free_list))
 474		queue_work(i915->wq, &i915->mm.free_work);
 475}
 476
 477void __i915_gem_object_flush_frontbuffer(struct drm_i915_gem_object *obj,
 478					 enum fb_op_origin origin)
 479{
 480	struct i915_frontbuffer *front;
 481
 482	front = i915_gem_object_frontbuffer_lookup(obj);
 483	if (front) {
 484		intel_frontbuffer_flush(&front->base, origin);
 485		i915_gem_object_frontbuffer_put(front);
 486	}
 487}
 488
 489void __i915_gem_object_invalidate_frontbuffer(struct drm_i915_gem_object *obj,
 490					      enum fb_op_origin origin)
 491{
 492	struct i915_frontbuffer *front;
 493
 494	front = i915_gem_object_frontbuffer_lookup(obj);
 495	if (front) {
 496		intel_frontbuffer_invalidate(&front->base, origin);
 497		i915_gem_object_frontbuffer_put(front);
 498	}
 499}
 500
 501static void
 502i915_gem_object_read_from_page_kmap(struct drm_i915_gem_object *obj, u64 offset, void *dst, int size)
 503{
 504	pgoff_t idx = offset >> PAGE_SHIFT;
 505	void *src_ptr;
 506
 507	src_ptr = kmap_local_page(i915_gem_object_get_page(obj, idx))
 508	          + offset_in_page(offset);
 509	if (!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_READ))
 510		drm_clflush_virt_range(src_ptr, size);
 511	memcpy(dst, src_ptr, size);
 512
 513	kunmap_local(src_ptr);
 514}
 515
 516static void
 517i915_gem_object_read_from_page_iomap(struct drm_i915_gem_object *obj, u64 offset, void *dst, int size)
 518{
 519	pgoff_t idx = offset >> PAGE_SHIFT;
 520	dma_addr_t dma = i915_gem_object_get_dma_address(obj, idx);
 521	void __iomem *src_map;
 522	void __iomem *src_ptr;
 523
 524	src_map = io_mapping_map_wc(&obj->mm.region->iomap,
 525				    dma - obj->mm.region->region.start,
 526				    PAGE_SIZE);
 527
 528	src_ptr = src_map + offset_in_page(offset);
 529	if (!i915_memcpy_from_wc(dst, (void __force *)src_ptr, size))
 530		memcpy_fromio(dst, src_ptr, size);
 531
 532	io_mapping_unmap(src_map);
 533}
 534
 535static bool object_has_mappable_iomem(struct drm_i915_gem_object *obj)
 536{
 537	GEM_BUG_ON(!i915_gem_object_has_iomem(obj));
 538
 539	if (IS_DGFX(to_i915(obj->base.dev)))
 540		return i915_ttm_resource_mappable(i915_gem_to_ttm(obj)->resource);
 541
 542	return true;
 543}
 544
 545/**
 546 * i915_gem_object_read_from_page - read data from the page of a GEM object
 547 * @obj: GEM object to read from
 548 * @offset: offset within the object
 549 * @dst: buffer to store the read data
 550 * @size: size to read
 551 *
 552 * Reads data from @obj at the specified offset. The requested region to read
 553 * from can't cross a page boundary. The caller must ensure that @obj pages
 554 * are pinned and that @obj is synced wrt. any related writes.
 555 *
 556 * Return: %0 on success or -ENODEV if the type of @obj's backing store is
 557 * unsupported.
 558 */
 559int i915_gem_object_read_from_page(struct drm_i915_gem_object *obj, u64 offset, void *dst, int size)
 560{
 561	GEM_BUG_ON(overflows_type(offset >> PAGE_SHIFT, pgoff_t));
 562	GEM_BUG_ON(offset >= obj->base.size);
 563	GEM_BUG_ON(offset_in_page(offset) > PAGE_SIZE - size);
 564	GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));
 565
 566	if (i915_gem_object_has_struct_page(obj))
 567		i915_gem_object_read_from_page_kmap(obj, offset, dst, size);
 568	else if (i915_gem_object_has_iomem(obj) && object_has_mappable_iomem(obj))
 569		i915_gem_object_read_from_page_iomap(obj, offset, dst, size);
 570	else
 571		return -ENODEV;
 572
 573	return 0;
 574}
 575
 576/**
 577 * i915_gem_object_evictable - Whether object is likely evictable after unbind.
 578 * @obj: The object to check
 579 *
 580 * This function checks whether the object is likely unvictable after unbind.
 581 * If the object is not locked when checking, the result is only advisory.
 582 * If the object is locked when checking, and the function returns true,
 583 * then an eviction should indeed be possible. But since unlocked vma
 584 * unpinning and unbinding is currently possible, the object can actually
 585 * become evictable even if this function returns false.
 586 *
 587 * Return: true if the object may be evictable. False otherwise.
 588 */
 589bool i915_gem_object_evictable(struct drm_i915_gem_object *obj)
 590{
 591	struct i915_vma *vma;
 592	int pin_count = atomic_read(&obj->mm.pages_pin_count);
 593
 594	if (!pin_count)
 595		return true;
 596
 597	spin_lock(&obj->vma.lock);
 598	list_for_each_entry(vma, &obj->vma.list, obj_link) {
 599		if (i915_vma_is_pinned(vma)) {
 600			spin_unlock(&obj->vma.lock);
 601			return false;
 602		}
 603		if (atomic_read(&vma->pages_count))
 604			pin_count--;
 605	}
 606	spin_unlock(&obj->vma.lock);
 607	GEM_WARN_ON(pin_count < 0);
 608
 609	return pin_count == 0;
 610}
 611
 612/**
 613 * i915_gem_object_migratable - Whether the object is migratable out of the
 614 * current region.
 615 * @obj: Pointer to the object.
 616 *
 617 * Return: Whether the object is allowed to be resident in other
 618 * regions than the current while pages are present.
 619 */
 620bool i915_gem_object_migratable(struct drm_i915_gem_object *obj)
 621{
 622	struct intel_memory_region *mr = READ_ONCE(obj->mm.region);
 623
 624	if (!mr)
 625		return false;
 626
 627	return obj->mm.n_placements > 1;
 628}
 629
 630/**
 631 * i915_gem_object_has_struct_page - Whether the object is page-backed
 632 * @obj: The object to query.
 633 *
 634 * This function should only be called while the object is locked or pinned,
 635 * otherwise the page backing may change under the caller.
 636 *
 637 * Return: True if page-backed, false otherwise.
 638 */
 639bool i915_gem_object_has_struct_page(const struct drm_i915_gem_object *obj)
 640{
 641#ifdef CONFIG_LOCKDEP
 642	if (IS_DGFX(to_i915(obj->base.dev)) &&
 643	    i915_gem_object_evictable((void __force *)obj))
 644		assert_object_held_shared(obj);
 645#endif
 646	return obj->mem_flags & I915_BO_FLAG_STRUCT_PAGE;
 647}
 648
 649/**
 650 * i915_gem_object_has_iomem - Whether the object is iomem-backed
 651 * @obj: The object to query.
 652 *
 653 * This function should only be called while the object is locked or pinned,
 654 * otherwise the iomem backing may change under the caller.
 655 *
 656 * Return: True if iomem-backed, false otherwise.
 657 */
 658bool i915_gem_object_has_iomem(const struct drm_i915_gem_object *obj)
 659{
 660#ifdef CONFIG_LOCKDEP
 661	if (IS_DGFX(to_i915(obj->base.dev)) &&
 662	    i915_gem_object_evictable((void __force *)obj))
 663		assert_object_held_shared(obj);
 664#endif
 665	return obj->mem_flags & I915_BO_FLAG_IOMEM;
 666}
 667
 668/**
 669 * i915_gem_object_can_migrate - Whether an object likely can be migrated
 670 *
 671 * @obj: The object to migrate
 672 * @id: The region intended to migrate to
 673 *
 674 * Check whether the object backend supports migration to the
 675 * given region. Note that pinning may affect the ability to migrate as
 676 * returned by this function.
 677 *
 678 * This function is primarily intended as a helper for checking the
 679 * possibility to migrate objects and might be slightly less permissive
 680 * than i915_gem_object_migrate() when it comes to objects with the
 681 * I915_BO_ALLOC_USER flag set.
 682 *
 683 * Return: true if migration is possible, false otherwise.
 684 */
 685bool i915_gem_object_can_migrate(struct drm_i915_gem_object *obj,
 686				 enum intel_region_id id)
 687{
 688	struct drm_i915_private *i915 = to_i915(obj->base.dev);
 689	unsigned int num_allowed = obj->mm.n_placements;
 690	struct intel_memory_region *mr;
 691	unsigned int i;
 692
 693	GEM_BUG_ON(id >= INTEL_REGION_UNKNOWN);
 694	GEM_BUG_ON(obj->mm.madv != I915_MADV_WILLNEED);
 695
 696	mr = i915->mm.regions[id];
 697	if (!mr)
 698		return false;
 699
 700	if (!IS_ALIGNED(obj->base.size, mr->min_page_size))
 701		return false;
 702
 703	if (obj->mm.region == mr)
 704		return true;
 705
 706	if (!i915_gem_object_evictable(obj))
 707		return false;
 708
 709	if (!obj->ops->migrate)
 710		return false;
 711
 712	if (!(obj->flags & I915_BO_ALLOC_USER))
 713		return true;
 714
 715	if (num_allowed == 0)
 716		return false;
 717
 718	for (i = 0; i < num_allowed; ++i) {
 719		if (mr == obj->mm.placements[i])
 720			return true;
 721	}
 722
 723	return false;
 724}
 725
 726/**
 727 * i915_gem_object_migrate - Migrate an object to the desired region id
 728 * @obj: The object to migrate.
 729 * @ww: An optional struct i915_gem_ww_ctx. If NULL, the backend may
 730 * not be successful in evicting other objects to make room for this object.
 731 * @id: The region id to migrate to.
 732 *
 733 * Attempt to migrate the object to the desired memory region. The
 734 * object backend must support migration and the object may not be
 735 * pinned, (explicitly pinned pages or pinned vmas). The object must
 736 * be locked.
 737 * On successful completion, the object will have pages pointing to
 738 * memory in the new region, but an async migration task may not have
 739 * completed yet, and to accomplish that, i915_gem_object_wait_migration()
 740 * must be called.
 741 *
 742 * Note: the @ww parameter is not used yet, but included to make sure
 743 * callers put some effort into obtaining a valid ww ctx if one is
 744 * available.
 745 *
 746 * Return: 0 on success. Negative error code on failure. In particular may
 747 * return -ENXIO on lack of region space, -EDEADLK for deadlock avoidance
 748 * if @ww is set, -EINTR or -ERESTARTSYS if signal pending, and
 749 * -EBUSY if the object is pinned.
 750 */
 751int i915_gem_object_migrate(struct drm_i915_gem_object *obj,
 752			    struct i915_gem_ww_ctx *ww,
 753			    enum intel_region_id id)
 754{
 755	return __i915_gem_object_migrate(obj, ww, id, obj->flags);
 756}
 757
 758/**
 759 * __i915_gem_object_migrate - Migrate an object to the desired region id, with
 760 * control of the extra flags
 761 * @obj: The object to migrate.
 762 * @ww: An optional struct i915_gem_ww_ctx. If NULL, the backend may
 763 * not be successful in evicting other objects to make room for this object.
 764 * @id: The region id to migrate to.
 765 * @flags: The object flags. Normally just obj->flags.
 766 *
 767 * Attempt to migrate the object to the desired memory region. The
 768 * object backend must support migration and the object may not be
 769 * pinned, (explicitly pinned pages or pinned vmas). The object must
 770 * be locked.
 771 * On successful completion, the object will have pages pointing to
 772 * memory in the new region, but an async migration task may not have
 773 * completed yet, and to accomplish that, i915_gem_object_wait_migration()
 774 * must be called.
 775 *
 776 * Note: the @ww parameter is not used yet, but included to make sure
 777 * callers put some effort into obtaining a valid ww ctx if one is
 778 * available.
 779 *
 780 * Return: 0 on success. Negative error code on failure. In particular may
 781 * return -ENXIO on lack of region space, -EDEADLK for deadlock avoidance
 782 * if @ww is set, -EINTR or -ERESTARTSYS if signal pending, and
 783 * -EBUSY if the object is pinned.
 784 */
 785int __i915_gem_object_migrate(struct drm_i915_gem_object *obj,
 786			      struct i915_gem_ww_ctx *ww,
 787			      enum intel_region_id id,
 788			      unsigned int flags)
 789{
 790	struct drm_i915_private *i915 = to_i915(obj->base.dev);
 791	struct intel_memory_region *mr;
 792
 793	GEM_BUG_ON(id >= INTEL_REGION_UNKNOWN);
 794	GEM_BUG_ON(obj->mm.madv != I915_MADV_WILLNEED);
 795	assert_object_held(obj);
 796
 797	mr = i915->mm.regions[id];
 798	GEM_BUG_ON(!mr);
 799
 800	if (!i915_gem_object_can_migrate(obj, id))
 801		return -EINVAL;
 802
 803	if (!obj->ops->migrate) {
 804		if (GEM_WARN_ON(obj->mm.region != mr))
 805			return -EINVAL;
 806		return 0;
 807	}
 808
 809	return obj->ops->migrate(obj, mr, flags);
 810}
 811
 812/**
 813 * i915_gem_object_placement_possible - Check whether the object can be
 814 * placed at certain memory type
 815 * @obj: Pointer to the object
 816 * @type: The memory type to check
 817 *
 818 * Return: True if the object can be placed in @type. False otherwise.
 819 */
 820bool i915_gem_object_placement_possible(struct drm_i915_gem_object *obj,
 821					enum intel_memory_type type)
 822{
 823	unsigned int i;
 824
 825	if (!obj->mm.n_placements) {
 826		switch (type) {
 827		case INTEL_MEMORY_LOCAL:
 828			return i915_gem_object_has_iomem(obj);
 829		case INTEL_MEMORY_SYSTEM:
 830			return i915_gem_object_has_pages(obj);
 831		default:
 832			/* Ignore stolen for now */
 833			GEM_BUG_ON(1);
 834			return false;
 835		}
 836	}
 837
 838	for (i = 0; i < obj->mm.n_placements; i++) {
 839		if (obj->mm.placements[i]->type == type)
 840			return true;
 841	}
 842
 843	return false;
 844}
 845
 846/**
 847 * i915_gem_object_needs_ccs_pages - Check whether the object requires extra
 848 * pages when placed in system-memory, in order to save and later restore the
 849 * flat-CCS aux state when the object is moved between local-memory and
 850 * system-memory
 851 * @obj: Pointer to the object
 852 *
 853 * Return: True if the object needs extra ccs pages. False otherwise.
 854 */
 855bool i915_gem_object_needs_ccs_pages(struct drm_i915_gem_object *obj)
 856{
 857	bool lmem_placement = false;
 858	int i;
 859
 860	if (!HAS_FLAT_CCS(to_i915(obj->base.dev)))
 861		return false;
 862
 863	if (obj->flags & I915_BO_ALLOC_CCS_AUX)
 864		return true;
 865
 866	for (i = 0; i < obj->mm.n_placements; i++) {
 867		/* Compression is not allowed for the objects with smem placement */
 868		if (obj->mm.placements[i]->type == INTEL_MEMORY_SYSTEM)
 869			return false;
 870		if (!lmem_placement &&
 871		    obj->mm.placements[i]->type == INTEL_MEMORY_LOCAL)
 872			lmem_placement = true;
 873	}
 874
 875	return lmem_placement;
 876}
 877
 878static int i915_gem_vmap_object(struct drm_gem_object *gem_obj,
 879				struct iosys_map *map)
 880{
 881	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 882	void *vaddr;
 883
 884	vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
 885	if (IS_ERR(vaddr))
 886		return PTR_ERR(vaddr);
 887
 888	iosys_map_set_vaddr(map, vaddr);
 889
 890	return 0;
 891}
 892
 893static void i915_gem_vunmap_object(struct drm_gem_object *gem_obj,
 894				   struct iosys_map *map)
 895{
 896	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 897
 898	i915_gem_object_flush_map(obj);
 899	i915_gem_object_unpin_map(obj);
 900}
 901
 902void i915_gem_init__objects(struct drm_i915_private *i915)
 903{
 904	INIT_WORK(&i915->mm.free_work, __i915_gem_free_work);
 905}
 906
 907void i915_objects_module_exit(void)
 908{
 909	kmem_cache_destroy(slab_objects);
 910}
 911
 912int __init i915_objects_module_init(void)
 913{
 914	slab_objects = KMEM_CACHE(drm_i915_gem_object, SLAB_HWCACHE_ALIGN);
 915	if (!slab_objects)
 916		return -ENOMEM;
 917
 918	return 0;
 919}
 920
 921static const struct drm_gem_object_funcs i915_gem_object_funcs = {
 922	.free = i915_gem_free_object,
 923	.close = i915_gem_close_object,
 924	.export = i915_gem_prime_export,
 925	.vmap = i915_gem_vmap_object,
 926	.vunmap = i915_gem_vunmap_object,
 927};
 928
 929/**
 930 * i915_gem_object_get_moving_fence - Get the object's moving fence if any
 931 * @obj: The object whose moving fence to get.
 932 * @fence: The resulting fence
 933 *
 934 * A non-signaled moving fence means that there is an async operation
 935 * pending on the object that needs to be waited on before setting up
 936 * any GPU- or CPU PTEs to the object's pages.
 937 *
 938 * Return: Negative error code or 0 for success.
 939 */
 940int i915_gem_object_get_moving_fence(struct drm_i915_gem_object *obj,
 941				     struct dma_fence **fence)
 942{
 943	return dma_resv_get_singleton(obj->base.resv, DMA_RESV_USAGE_KERNEL,
 944				      fence);
 945}
 946
 947/**
 948 * i915_gem_object_wait_moving_fence - Wait for the object's moving fence if any
 949 * @obj: The object whose moving fence to wait for.
 950 * @intr: Whether to wait interruptible.
 951 *
 952 * If the moving fence signaled without an error, it is detached from the
 953 * object and put.
 954 *
 955 * Return: 0 if successful, -ERESTARTSYS if the wait was interrupted,
 956 * negative error code if the async operation represented by the
 957 * moving fence failed.
 958 */
 959int i915_gem_object_wait_moving_fence(struct drm_i915_gem_object *obj,
 960				      bool intr)
 961{
 962	long ret;
 963
 964	assert_object_held(obj);
 965
 966	ret = dma_resv_wait_timeout(obj->base. resv, DMA_RESV_USAGE_KERNEL,
 967				    intr, MAX_SCHEDULE_TIMEOUT);
 968	if (!ret)
 969		ret = -ETIME;
 970	else if (ret > 0 && i915_gem_object_has_unknown_state(obj))
 971		ret = -EIO;
 972
 973	return ret < 0 ? ret : 0;
 974}
 975
 976/*
 977 * i915_gem_object_has_unknown_state - Return true if the object backing pages are
 978 * in an unknown_state. This means that userspace must NEVER be allowed to touch
 979 * the pages, with either the GPU or CPU.
 980 *
 981 * ONLY valid to be called after ensuring that all kernel fences have signalled
 982 * (in particular the fence for moving/clearing the object).
 983 */
 984bool i915_gem_object_has_unknown_state(struct drm_i915_gem_object *obj)
 985{
 986	/*
 987	 * The below barrier pairs with the dma_fence_signal() in
 988	 * __memcpy_work(). We should only sample the unknown_state after all
 989	 * the kernel fences have signalled.
 990	 */
 991	smp_rmb();
 992	return obj->mm.unknown_state;
 993}
 994
 995#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
 996#include "selftests/huge_gem_object.c"
 997#include "selftests/huge_pages.c"
 998#include "selftests/i915_gem_migrate.c"
 999#include "selftests/i915_gem_object.c"
1000#include "selftests/i915_gem_coherency.c"
1001#endif