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