Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 967 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
new file mode 100644
index 000000000..ef9346ed6
--- /dev/null
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
@@ -0,0 +1,967 @@
+/*
+ * Copyright © 2017 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <linux/highmem.h>
+#include <linux/sched/mm.h>
+
+#include <drm/drm_cache.h>
+
+#include "display/intel_frontbuffer.h"
+#include "pxp/intel_pxp.h"
+
+#include "i915_drv.h"
+#include "i915_file_private.h"
+#include "i915_gem_clflush.h"
+#include "i915_gem_context.h"
+#include "i915_gem_dmabuf.h"
+#include "i915_gem_mman.h"
+#include "i915_gem_object.h"
+#include "i915_gem_ttm.h"
+#include "i915_memcpy.h"
+#include "i915_trace.h"
+
+static struct kmem_cache *slab_objects;
+
+static const struct drm_gem_object_funcs i915_gem_object_funcs;
+
+unsigned int i915_gem_get_pat_index(struct drm_i915_private *i915,
+				    enum i915_cache_level level)
+{
+	if (drm_WARN_ON(&i915->drm, level >= I915_MAX_CACHE_LEVEL))
+		return 0;
+
+	return INTEL_INFO(i915)->cachelevel_to_pat[level];
+}
+
+bool i915_gem_object_has_cache_level(const struct drm_i915_gem_object *obj,
+				     enum i915_cache_level lvl)
+{
+	/*
+	 * In case the pat_index is set by user space, this kernel mode
+	 * driver should leave the coherency to be managed by user space,
+	 * simply return true here.
+	 */
+	if (obj->pat_set_by_user)
+		return true;
+
+	/*
+	 * Otherwise the pat_index should have been converted from cache_level
+	 * so that the following comparison is valid.
+	 */
+	return obj->pat_index == i915_gem_get_pat_index(obj_to_i915(obj), lvl);
+}
+
+struct drm_i915_gem_object *i915_gem_object_alloc(void)
+{
+	struct drm_i915_gem_object *obj;
+
+	obj = kmem_cache_zalloc(slab_objects, GFP_KERNEL);
+	if (!obj)
+		return NULL;
+	obj->base.funcs = &i915_gem_object_funcs;
+
+	return obj;
+}
+
+void i915_gem_object_free(struct drm_i915_gem_object *obj)
+{
+	return kmem_cache_free(slab_objects, obj);
+}
+
+void i915_gem_object_init(struct drm_i915_gem_object *obj,
+			  const struct drm_i915_gem_object_ops *ops,
+			  struct lock_class_key *key, unsigned flags)
+{
+	/*
+	 * A gem object is embedded both in a struct ttm_buffer_object :/ and
+	 * in a drm_i915_gem_object. Make sure they are aliased.
+	 */
+	BUILD_BUG_ON(offsetof(typeof(*obj), base) !=
+		     offsetof(typeof(*obj), __do_not_access.base));
+
+	spin_lock_init(&obj->vma.lock);
+	INIT_LIST_HEAD(&obj->vma.list);
+
+	INIT_LIST_HEAD(&obj->mm.link);
+
+	INIT_LIST_HEAD(&obj->lut_list);
+	spin_lock_init(&obj->lut_lock);
+
+	spin_lock_init(&obj->mmo.lock);
+	obj->mmo.offsets = RB_ROOT;
+
+	init_rcu_head(&obj->rcu);
+
+	obj->ops = ops;
+	GEM_BUG_ON(flags & ~I915_BO_ALLOC_FLAGS);
+	obj->flags = flags;
+
+	obj->mm.madv = I915_MADV_WILLNEED;
+	INIT_RADIX_TREE(&obj->mm.get_page.radix, GFP_KERNEL | __GFP_NOWARN);
+	mutex_init(&obj->mm.get_page.lock);
+	INIT_RADIX_TREE(&obj->mm.get_dma_page.radix, GFP_KERNEL | __GFP_NOWARN);
+	mutex_init(&obj->mm.get_dma_page.lock);
+}
+
+/**
+ * __i915_gem_object_fini - Clean up a GEM object initialization
+ * @obj: The gem object to cleanup
+ *
+ * This function cleans up gem object fields that are set up by
+ * drm_gem_private_object_init() and i915_gem_object_init().
+ * It's primarily intended as a helper for backends that need to
+ * clean up the gem object in separate steps.
+ */
+void __i915_gem_object_fini(struct drm_i915_gem_object *obj)
+{
+	mutex_destroy(&obj->mm.get_page.lock);
+	mutex_destroy(&obj->mm.get_dma_page.lock);
+	dma_resv_fini(&obj->base._resv);
+}
+
+/**
+ * i915_gem_object_set_cache_coherency - Mark up the object's coherency levels
+ * for a given cache_level
+ * @obj: #drm_i915_gem_object
+ * @cache_level: cache level
+ */
+void i915_gem_object_set_cache_coherency(struct drm_i915_gem_object *obj,
+					 unsigned int cache_level)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+
+	obj->pat_index = i915_gem_get_pat_index(i915, cache_level);
+
+	if (cache_level != I915_CACHE_NONE)
+		obj->cache_coherent = (I915_BO_CACHE_COHERENT_FOR_READ |
+				       I915_BO_CACHE_COHERENT_FOR_WRITE);
+	else if (HAS_LLC(i915))
+		obj->cache_coherent = I915_BO_CACHE_COHERENT_FOR_READ;
+	else
+		obj->cache_coherent = 0;
+
+	obj->cache_dirty =
+		!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE) &&
+		!IS_DGFX(i915);
+}
+
+/**
+ * i915_gem_object_set_pat_index - set PAT index to be used in PTE encode
+ * @obj: #drm_i915_gem_object
+ * @pat_index: PAT index
+ *
+ * This is a clone of i915_gem_object_set_cache_coherency taking pat index
+ * instead of cache_level as its second argument.
+ */
+void i915_gem_object_set_pat_index(struct drm_i915_gem_object *obj,
+				   unsigned int pat_index)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+
+	if (obj->pat_index == pat_index)
+		return;
+
+	obj->pat_index = pat_index;
+
+	if (pat_index != i915_gem_get_pat_index(i915, I915_CACHE_NONE))
+		obj->cache_coherent = (I915_BO_CACHE_COHERENT_FOR_READ |
+				       I915_BO_CACHE_COHERENT_FOR_WRITE);
+	else if (HAS_LLC(i915))
+		obj->cache_coherent = I915_BO_CACHE_COHERENT_FOR_READ;
+	else
+		obj->cache_coherent = 0;
+
+	obj->cache_dirty =
+		!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE) &&
+		!IS_DGFX(i915);
+}
+
+bool i915_gem_object_can_bypass_llc(struct drm_i915_gem_object *obj)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+
+	/*
+	 * This is purely from a security perspective, so we simply don't care
+	 * about non-userspace objects being able to bypass the LLC.
+	 */
+	if (!(obj->flags & I915_BO_ALLOC_USER))
+		return false;
+
+	/*
+	 * Always flush cache for UMD objects at creation time.
+	 */
+	if (obj->pat_set_by_user)
+		return true;
+
+	/*
+	 * EHL and JSL add the 'Bypass LLC' MOCS entry, which should make it
+	 * possible for userspace to bypass the GTT caching bits set by the
+	 * kernel, as per the given object cache_level. This is troublesome
+	 * since the heavy flush we apply when first gathering the pages is
+	 * skipped if the kernel thinks the object is coherent with the GPU. As
+	 * a result it might be possible to bypass the cache and read the
+	 * contents of the page directly, which could be stale data. If it's
+	 * just a case of userspace shooting themselves in the foot then so be
+	 * it, but since i915 takes the stance of always zeroing memory before
+	 * handing it to userspace, we need to prevent this.
+	 */
+	return (IS_JASPERLAKE(i915) || IS_ELKHARTLAKE(i915));
+}
+
+static void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file)
+{
+	struct drm_i915_gem_object *obj = to_intel_bo(gem);
+	struct drm_i915_file_private *fpriv = file->driver_priv;
+	struct i915_lut_handle bookmark = {};
+	struct i915_mmap_offset *mmo, *mn;
+	struct i915_lut_handle *lut, *ln;
+	LIST_HEAD(close);
+
+	spin_lock(&obj->lut_lock);
+	list_for_each_entry_safe(lut, ln, &obj->lut_list, obj_link) {
+		struct i915_gem_context *ctx = lut->ctx;
+
+		if (ctx && ctx->file_priv == fpriv) {
+			i915_gem_context_get(ctx);
+			list_move(&lut->obj_link, &close);
+		}
+
+		/* Break long locks, and carefully continue on from this spot */
+		if (&ln->obj_link != &obj->lut_list) {
+			list_add_tail(&bookmark.obj_link, &ln->obj_link);
+			if (cond_resched_lock(&obj->lut_lock))
+				list_safe_reset_next(&bookmark, ln, obj_link);
+			__list_del_entry(&bookmark.obj_link);
+		}
+	}
+	spin_unlock(&obj->lut_lock);
+
+	spin_lock(&obj->mmo.lock);
+	rbtree_postorder_for_each_entry_safe(mmo, mn, &obj->mmo.offsets, offset)
+		drm_vma_node_revoke(&mmo->vma_node, file);
+	spin_unlock(&obj->mmo.lock);
+
+	list_for_each_entry_safe(lut, ln, &close, obj_link) {
+		struct i915_gem_context *ctx = lut->ctx;
+		struct i915_vma *vma;
+
+		/*
+		 * We allow the process to have multiple handles to the same
+		 * vma, in the same fd namespace, by virtue of flink/open.
+		 */
+
+		mutex_lock(&ctx->lut_mutex);
+		vma = radix_tree_delete(&ctx->handles_vma, lut->handle);
+		if (vma) {
+			GEM_BUG_ON(vma->obj != obj);
+			GEM_BUG_ON(!atomic_read(&vma->open_count));
+			i915_vma_close(vma);
+		}
+		mutex_unlock(&ctx->lut_mutex);
+
+		i915_gem_context_put(lut->ctx);
+		i915_lut_handle_free(lut);
+		i915_gem_object_put(obj);
+	}
+}
+
+void __i915_gem_free_object_rcu(struct rcu_head *head)
+{
+	struct drm_i915_gem_object *obj =
+		container_of(head, typeof(*obj), rcu);
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+
+	i915_gem_object_free(obj);
+
+	GEM_BUG_ON(!atomic_read(&i915->mm.free_count));
+	atomic_dec(&i915->mm.free_count);
+}
+
+static void __i915_gem_object_free_mmaps(struct drm_i915_gem_object *obj)
+{
+	/* Skip serialisation and waking the device if known to be not used. */
+
+	if (obj->userfault_count && !IS_DGFX(to_i915(obj->base.dev)))
+		i915_gem_object_release_mmap_gtt(obj);
+
+	if (!RB_EMPTY_ROOT(&obj->mmo.offsets)) {
+		struct i915_mmap_offset *mmo, *mn;
+
+		i915_gem_object_release_mmap_offset(obj);
+
+		rbtree_postorder_for_each_entry_safe(mmo, mn,
+						     &obj->mmo.offsets,
+						     offset) {
+			drm_vma_offset_remove(obj->base.dev->vma_offset_manager,
+					      &mmo->vma_node);
+			kfree(mmo);
+		}
+		obj->mmo.offsets = RB_ROOT;
+	}
+}
+
+/**
+ * __i915_gem_object_pages_fini - Clean up pages use of a gem object
+ * @obj: The gem object to clean up
+ *
+ * This function cleans up usage of the object mm.pages member. It
+ * is intended for backends that need to clean up a gem object in
+ * separate steps and needs to be called when the object is idle before
+ * the object's backing memory is freed.
+ */
+void __i915_gem_object_pages_fini(struct drm_i915_gem_object *obj)
+{
+	assert_object_held_shared(obj);
+
+	if (!list_empty(&obj->vma.list)) {
+		struct i915_vma *vma;
+
+		spin_lock(&obj->vma.lock);
+		while ((vma = list_first_entry_or_null(&obj->vma.list,
+						       struct i915_vma,
+						       obj_link))) {
+			GEM_BUG_ON(vma->obj != obj);
+			spin_unlock(&obj->vma.lock);
+
+			i915_vma_destroy(vma);
+
+			spin_lock(&obj->vma.lock);
+		}
+		spin_unlock(&obj->vma.lock);
+	}
+
+	__i915_gem_object_free_mmaps(obj);
+
+	atomic_set(&obj->mm.pages_pin_count, 0);
+
+	/*
+	 * dma_buf_unmap_attachment() requires reservation to be
+	 * locked. The imported GEM shouldn't share reservation lock
+	 * and ttm_bo_cleanup_memtype_use() shouldn't be invoked for
+	 * dma-buf, so it's safe to take the lock.
+	 */
+	if (obj->base.import_attach)
+		i915_gem_object_lock(obj, NULL);
+
+	__i915_gem_object_put_pages(obj);
+
+	if (obj->base.import_attach)
+		i915_gem_object_unlock(obj);
+
+	GEM_BUG_ON(i915_gem_object_has_pages(obj));
+}
+
+void __i915_gem_free_object(struct drm_i915_gem_object *obj)
+{
+	trace_i915_gem_object_destroy(obj);
+
+	GEM_BUG_ON(!list_empty(&obj->lut_list));
+
+	bitmap_free(obj->bit_17);
+
+	if (obj->base.import_attach)
+		drm_prime_gem_destroy(&obj->base, NULL);
+
+	drm_gem_free_mmap_offset(&obj->base);
+
+	if (obj->ops->release)
+		obj->ops->release(obj);
+
+	if (obj->mm.n_placements > 1)
+		kfree(obj->mm.placements);
+
+	if (obj->shares_resv_from)
+		i915_vm_resv_put(obj->shares_resv_from);
+
+	__i915_gem_object_fini(obj);
+}
+
+static void __i915_gem_free_objects(struct drm_i915_private *i915,
+				    struct llist_node *freed)
+{
+	struct drm_i915_gem_object *obj, *on;
+
+	llist_for_each_entry_safe(obj, on, freed, freed) {
+		might_sleep();
+		if (obj->ops->delayed_free) {
+			obj->ops->delayed_free(obj);
+			continue;
+		}
+
+		__i915_gem_object_pages_fini(obj);
+		__i915_gem_free_object(obj);
+
+		/* But keep the pointer alive for RCU-protected lookups */
+		call_rcu(&obj->rcu, __i915_gem_free_object_rcu);
+		cond_resched();
+	}
+}
+
+void i915_gem_flush_free_objects(struct drm_i915_private *i915)
+{
+	struct llist_node *freed = llist_del_all(&i915->mm.free_list);
+
+	if (unlikely(freed))
+		__i915_gem_free_objects(i915, freed);
+}
+
+static void __i915_gem_free_work(struct work_struct *work)
+{
+	struct drm_i915_private *i915 =
+		container_of(work, struct drm_i915_private, mm.free_work);
+
+	i915_gem_flush_free_objects(i915);
+}
+
+static void i915_gem_free_object(struct drm_gem_object *gem_obj)
+{
+	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+
+	GEM_BUG_ON(i915_gem_object_is_framebuffer(obj));
+
+	/*
+	 * Before we free the object, make sure any pure RCU-only
+	 * read-side critical sections are complete, e.g.
+	 * i915_gem_busy_ioctl(). For the corresponding synchronized
+	 * lookup see i915_gem_object_lookup_rcu().
+	 */
+	atomic_inc(&i915->mm.free_count);
+
+	/*
+	 * Since we require blocking on struct_mutex to unbind the freed
+	 * object from the GPU before releasing resources back to the
+	 * system, we can not do that directly from the RCU callback (which may
+	 * be a softirq context), but must instead then defer that work onto a
+	 * kthread. We use the RCU callback rather than move the freed object
+	 * directly onto the work queue so that we can mix between using the
+	 * worker and performing frees directly from subsequent allocations for
+	 * crude but effective memory throttling.
+	 */
+
+	if (llist_add(&obj->freed, &i915->mm.free_list))
+		queue_work(i915->wq, &i915->mm.free_work);
+}
+
+void __i915_gem_object_flush_frontbuffer(struct drm_i915_gem_object *obj,
+					 enum fb_op_origin origin)
+{
+	struct intel_frontbuffer *front;
+
+	front = i915_gem_object_get_frontbuffer(obj);
+	if (front) {
+		intel_frontbuffer_flush(front, origin);
+		intel_frontbuffer_put(front);
+	}
+}
+
+void __i915_gem_object_invalidate_frontbuffer(struct drm_i915_gem_object *obj,
+					      enum fb_op_origin origin)
+{
+	struct intel_frontbuffer *front;
+
+	front = i915_gem_object_get_frontbuffer(obj);
+	if (front) {
+		intel_frontbuffer_invalidate(front, origin);
+		intel_frontbuffer_put(front);
+	}
+}
+
+static void
+i915_gem_object_read_from_page_kmap(struct drm_i915_gem_object *obj, u64 offset, void *dst, int size)
+{
+	pgoff_t idx = offset >> PAGE_SHIFT;
+	void *src_map;
+	void *src_ptr;
+
+	src_map = kmap_atomic(i915_gem_object_get_page(obj, idx));
+
+	src_ptr = src_map + offset_in_page(offset);
+	if (!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_READ))
+		drm_clflush_virt_range(src_ptr, size);
+	memcpy(dst, src_ptr, size);
+
+	kunmap_atomic(src_map);
+}
+
+static void
+i915_gem_object_read_from_page_iomap(struct drm_i915_gem_object *obj, u64 offset, void *dst, int size)
+{
+	pgoff_t idx = offset >> PAGE_SHIFT;
+	dma_addr_t dma = i915_gem_object_get_dma_address(obj, idx);
+	void __iomem *src_map;
+	void __iomem *src_ptr;
+
+	src_map = io_mapping_map_wc(&obj->mm.region->iomap,
+				    dma - obj->mm.region->region.start,
+				    PAGE_SIZE);
+
+	src_ptr = src_map + offset_in_page(offset);
+	if (!i915_memcpy_from_wc(dst, (void __force *)src_ptr, size))
+		memcpy_fromio(dst, src_ptr, size);
+
+	io_mapping_unmap(src_map);
+}
+
+static bool object_has_mappable_iomem(struct drm_i915_gem_object *obj)
+{
+	GEM_BUG_ON(!i915_gem_object_has_iomem(obj));
+
+	if (IS_DGFX(to_i915(obj->base.dev)))
+		return i915_ttm_resource_mappable(i915_gem_to_ttm(obj)->resource);
+
+	return true;
+}
+
+/**
+ * i915_gem_object_read_from_page - read data from the page of a GEM object
+ * @obj: GEM object to read from
+ * @offset: offset within the object
+ * @dst: buffer to store the read data
+ * @size: size to read
+ *
+ * Reads data from @obj at the specified offset. The requested region to read
+ * from can't cross a page boundary. The caller must ensure that @obj pages
+ * are pinned and that @obj is synced wrt. any related writes.
+ *
+ * Return: %0 on success or -ENODEV if the type of @obj's backing store is
+ * unsupported.
+ */
+int i915_gem_object_read_from_page(struct drm_i915_gem_object *obj, u64 offset, void *dst, int size)
+{
+	GEM_BUG_ON(overflows_type(offset >> PAGE_SHIFT, pgoff_t));
+	GEM_BUG_ON(offset >= obj->base.size);
+	GEM_BUG_ON(offset_in_page(offset) > PAGE_SIZE - size);
+	GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));
+
+	if (i915_gem_object_has_struct_page(obj))
+		i915_gem_object_read_from_page_kmap(obj, offset, dst, size);
+	else if (i915_gem_object_has_iomem(obj) && object_has_mappable_iomem(obj))
+		i915_gem_object_read_from_page_iomap(obj, offset, dst, size);
+	else
+		return -ENODEV;
+
+	return 0;
+}
+
+/**
+ * i915_gem_object_evictable - Whether object is likely evictable after unbind.
+ * @obj: The object to check
+ *
+ * This function checks whether the object is likely unvictable after unbind.
+ * If the object is not locked when checking, the result is only advisory.
+ * If the object is locked when checking, and the function returns true,
+ * then an eviction should indeed be possible. But since unlocked vma
+ * unpinning and unbinding is currently possible, the object can actually
+ * become evictable even if this function returns false.
+ *
+ * Return: true if the object may be evictable. False otherwise.
+ */
+bool i915_gem_object_evictable(struct drm_i915_gem_object *obj)
+{
+	struct i915_vma *vma;
+	int pin_count = atomic_read(&obj->mm.pages_pin_count);
+
+	if (!pin_count)
+		return true;
+
+	spin_lock(&obj->vma.lock);
+	list_for_each_entry(vma, &obj->vma.list, obj_link) {
+		if (i915_vma_is_pinned(vma)) {
+			spin_unlock(&obj->vma.lock);
+			return false;
+		}
+		if (atomic_read(&vma->pages_count))
+			pin_count--;
+	}
+	spin_unlock(&obj->vma.lock);
+	GEM_WARN_ON(pin_count < 0);
+
+	return pin_count == 0;
+}
+
+/**
+ * i915_gem_object_migratable - Whether the object is migratable out of the
+ * current region.
+ * @obj: Pointer to the object.
+ *
+ * Return: Whether the object is allowed to be resident in other
+ * regions than the current while pages are present.
+ */
+bool i915_gem_object_migratable(struct drm_i915_gem_object *obj)
+{
+	struct intel_memory_region *mr = READ_ONCE(obj->mm.region);
+
+	if (!mr)
+		return false;
+
+	return obj->mm.n_placements > 1;
+}
+
+/**
+ * i915_gem_object_has_struct_page - Whether the object is page-backed
+ * @obj: The object to query.
+ *
+ * This function should only be called while the object is locked or pinned,
+ * otherwise the page backing may change under the caller.
+ *
+ * Return: True if page-backed, false otherwise.
+ */
+bool i915_gem_object_has_struct_page(const struct drm_i915_gem_object *obj)
+{
+#ifdef CONFIG_LOCKDEP
+	if (IS_DGFX(to_i915(obj->base.dev)) &&
+	    i915_gem_object_evictable((void __force *)obj))
+		assert_object_held_shared(obj);
+#endif
+	return obj->mem_flags & I915_BO_FLAG_STRUCT_PAGE;
+}
+
+/**
+ * i915_gem_object_has_iomem - Whether the object is iomem-backed
+ * @obj: The object to query.
+ *
+ * This function should only be called while the object is locked or pinned,
+ * otherwise the iomem backing may change under the caller.
+ *
+ * Return: True if iomem-backed, false otherwise.
+ */
+bool i915_gem_object_has_iomem(const struct drm_i915_gem_object *obj)
+{
+#ifdef CONFIG_LOCKDEP
+	if (IS_DGFX(to_i915(obj->base.dev)) &&
+	    i915_gem_object_evictable((void __force *)obj))
+		assert_object_held_shared(obj);
+#endif
+	return obj->mem_flags & I915_BO_FLAG_IOMEM;
+}
+
+/**
+ * i915_gem_object_can_migrate - Whether an object likely can be migrated
+ *
+ * @obj: The object to migrate
+ * @id: The region intended to migrate to
+ *
+ * Check whether the object backend supports migration to the
+ * given region. Note that pinning may affect the ability to migrate as
+ * returned by this function.
+ *
+ * This function is primarily intended as a helper for checking the
+ * possibility to migrate objects and might be slightly less permissive
+ * than i915_gem_object_migrate() when it comes to objects with the
+ * I915_BO_ALLOC_USER flag set.
+ *
+ * Return: true if migration is possible, false otherwise.
+ */
+bool i915_gem_object_can_migrate(struct drm_i915_gem_object *obj,
+				 enum intel_region_id id)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	unsigned int num_allowed = obj->mm.n_placements;
+	struct intel_memory_region *mr;
+	unsigned int i;
+
+	GEM_BUG_ON(id >= INTEL_REGION_UNKNOWN);
+	GEM_BUG_ON(obj->mm.madv != I915_MADV_WILLNEED);
+
+	mr = i915->mm.regions[id];
+	if (!mr)
+		return false;
+
+	if (!IS_ALIGNED(obj->base.size, mr->min_page_size))
+		return false;
+
+	if (obj->mm.region == mr)
+		return true;
+
+	if (!i915_gem_object_evictable(obj))
+		return false;
+
+	if (!obj->ops->migrate)
+		return false;
+
+	if (!(obj->flags & I915_BO_ALLOC_USER))
+		return true;
+
+	if (num_allowed == 0)
+		return false;
+
+	for (i = 0; i < num_allowed; ++i) {
+		if (mr == obj->mm.placements[i])
+			return true;
+	}
+
+	return false;
+}
+
+/**
+ * i915_gem_object_migrate - Migrate an object to the desired region id
+ * @obj: The object to migrate.
+ * @ww: An optional struct i915_gem_ww_ctx. If NULL, the backend may
+ * not be successful in evicting other objects to make room for this object.
+ * @id: The region id to migrate to.
+ *
+ * Attempt to migrate the object to the desired memory region. The
+ * object backend must support migration and the object may not be
+ * pinned, (explicitly pinned pages or pinned vmas). The object must
+ * be locked.
+ * On successful completion, the object will have pages pointing to
+ * memory in the new region, but an async migration task may not have
+ * completed yet, and to accomplish that, i915_gem_object_wait_migration()
+ * must be called.
+ *
+ * Note: the @ww parameter is not used yet, but included to make sure
+ * callers put some effort into obtaining a valid ww ctx if one is
+ * available.
+ *
+ * Return: 0 on success. Negative error code on failure. In particular may
+ * return -ENXIO on lack of region space, -EDEADLK for deadlock avoidance
+ * if @ww is set, -EINTR or -ERESTARTSYS if signal pending, and
+ * -EBUSY if the object is pinned.
+ */
+int i915_gem_object_migrate(struct drm_i915_gem_object *obj,
+			    struct i915_gem_ww_ctx *ww,
+			    enum intel_region_id id)
+{
+	return __i915_gem_object_migrate(obj, ww, id, obj->flags);
+}
+
+/**
+ * __i915_gem_object_migrate - Migrate an object to the desired region id, with
+ * control of the extra flags
+ * @obj: The object to migrate.
+ * @ww: An optional struct i915_gem_ww_ctx. If NULL, the backend may
+ * not be successful in evicting other objects to make room for this object.
+ * @id: The region id to migrate to.
+ * @flags: The object flags. Normally just obj->flags.
+ *
+ * Attempt to migrate the object to the desired memory region. The
+ * object backend must support migration and the object may not be
+ * pinned, (explicitly pinned pages or pinned vmas). The object must
+ * be locked.
+ * On successful completion, the object will have pages pointing to
+ * memory in the new region, but an async migration task may not have
+ * completed yet, and to accomplish that, i915_gem_object_wait_migration()
+ * must be called.
+ *
+ * Note: the @ww parameter is not used yet, but included to make sure
+ * callers put some effort into obtaining a valid ww ctx if one is
+ * available.
+ *
+ * Return: 0 on success. Negative error code on failure. In particular may
+ * return -ENXIO on lack of region space, -EDEADLK for deadlock avoidance
+ * if @ww is set, -EINTR or -ERESTARTSYS if signal pending, and
+ * -EBUSY if the object is pinned.
+ */
+int __i915_gem_object_migrate(struct drm_i915_gem_object *obj,
+			      struct i915_gem_ww_ctx *ww,
+			      enum intel_region_id id,
+			      unsigned int flags)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	struct intel_memory_region *mr;
+
+	GEM_BUG_ON(id >= INTEL_REGION_UNKNOWN);
+	GEM_BUG_ON(obj->mm.madv != I915_MADV_WILLNEED);
+	assert_object_held(obj);
+
+	mr = i915->mm.regions[id];
+	GEM_BUG_ON(!mr);
+
+	if (!i915_gem_object_can_migrate(obj, id))
+		return -EINVAL;
+
+	if (!obj->ops->migrate) {
+		if (GEM_WARN_ON(obj->mm.region != mr))
+			return -EINVAL;
+		return 0;
+	}
+
+	return obj->ops->migrate(obj, mr, flags);
+}
+
+/**
+ * i915_gem_object_placement_possible - Check whether the object can be
+ * placed at certain memory type
+ * @obj: Pointer to the object
+ * @type: The memory type to check
+ *
+ * Return: True if the object can be placed in @type. False otherwise.
+ */
+bool i915_gem_object_placement_possible(struct drm_i915_gem_object *obj,
+					enum intel_memory_type type)
+{
+	unsigned int i;
+
+	if (!obj->mm.n_placements) {
+		switch (type) {
+		case INTEL_MEMORY_LOCAL:
+			return i915_gem_object_has_iomem(obj);
+		case INTEL_MEMORY_SYSTEM:
+			return i915_gem_object_has_pages(obj);
+		default:
+			/* Ignore stolen for now */
+			GEM_BUG_ON(1);
+			return false;
+		}
+	}
+
+	for (i = 0; i < obj->mm.n_placements; i++) {
+		if (obj->mm.placements[i]->type == type)
+			return true;
+	}
+
+	return false;
+}
+
+/**
+ * i915_gem_object_needs_ccs_pages - Check whether the object requires extra
+ * pages when placed in system-memory, in order to save and later restore the
+ * flat-CCS aux state when the object is moved between local-memory and
+ * system-memory
+ * @obj: Pointer to the object
+ *
+ * Return: True if the object needs extra ccs pages. False otherwise.
+ */
+bool i915_gem_object_needs_ccs_pages(struct drm_i915_gem_object *obj)
+{
+	bool lmem_placement = false;
+	int i;
+
+	if (!HAS_FLAT_CCS(to_i915(obj->base.dev)))
+		return false;
+
+	if (obj->flags & I915_BO_ALLOC_CCS_AUX)
+		return true;
+
+	for (i = 0; i < obj->mm.n_placements; i++) {
+		/* Compression is not allowed for the objects with smem placement */
+		if (obj->mm.placements[i]->type == INTEL_MEMORY_SYSTEM)
+			return false;
+		if (!lmem_placement &&
+		    obj->mm.placements[i]->type == INTEL_MEMORY_LOCAL)
+			lmem_placement = true;
+	}
+
+	return lmem_placement;
+}
+
+void i915_gem_init__objects(struct drm_i915_private *i915)
+{
+	INIT_WORK(&i915->mm.free_work, __i915_gem_free_work);
+}
+
+void i915_objects_module_exit(void)
+{
+	kmem_cache_destroy(slab_objects);
+}
+
+int __init i915_objects_module_init(void)
+{
+	slab_objects = KMEM_CACHE(drm_i915_gem_object, SLAB_HWCACHE_ALIGN);
+	if (!slab_objects)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static const struct drm_gem_object_funcs i915_gem_object_funcs = {
+	.free = i915_gem_free_object,
+	.close = i915_gem_close_object,
+	.export = i915_gem_prime_export,
+};
+
+/**
+ * i915_gem_object_get_moving_fence - Get the object's moving fence if any
+ * @obj: The object whose moving fence to get.
+ * @fence: The resulting fence
+ *
+ * A non-signaled moving fence means that there is an async operation
+ * pending on the object that needs to be waited on before setting up
+ * any GPU- or CPU PTEs to the object's pages.
+ *
+ * Return: Negative error code or 0 for success.
+ */
+int i915_gem_object_get_moving_fence(struct drm_i915_gem_object *obj,
+				     struct dma_fence **fence)
+{
+	return dma_resv_get_singleton(obj->base.resv, DMA_RESV_USAGE_KERNEL,
+				      fence);
+}
+
+/**
+ * i915_gem_object_wait_moving_fence - Wait for the object's moving fence if any
+ * @obj: The object whose moving fence to wait for.
+ * @intr: Whether to wait interruptible.
+ *
+ * If the moving fence signaled without an error, it is detached from the
+ * object and put.
+ *
+ * Return: 0 if successful, -ERESTARTSYS if the wait was interrupted,
+ * negative error code if the async operation represented by the
+ * moving fence failed.
+ */
+int i915_gem_object_wait_moving_fence(struct drm_i915_gem_object *obj,
+				      bool intr)
+{
+	long ret;
+
+	assert_object_held(obj);
+
+	ret = dma_resv_wait_timeout(obj->base. resv, DMA_RESV_USAGE_KERNEL,
+				    intr, MAX_SCHEDULE_TIMEOUT);
+	if (!ret)
+		ret = -ETIME;
+	else if (ret > 0 && i915_gem_object_has_unknown_state(obj))
+		ret = -EIO;
+
+	return ret < 0 ? ret : 0;
+}
+
+/*
+ * i915_gem_object_has_unknown_state - Return true if the object backing pages are
+ * in an unknown_state. This means that userspace must NEVER be allowed to touch
+ * the pages, with either the GPU or CPU.
+ *
+ * ONLY valid to be called after ensuring that all kernel fences have signalled
+ * (in particular the fence for moving/clearing the object).
+ */
+bool i915_gem_object_has_unknown_state(struct drm_i915_gem_object *obj)
+{
+	/*
+	 * The below barrier pairs with the dma_fence_signal() in
+	 * __memcpy_work(). We should only sample the unknown_state after all
+	 * the kernel fences have signalled.
+	 */
+	smp_rmb();
+	return obj->mm.unknown_state;
+}
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftests/huge_gem_object.c"
+#include "selftests/huge_pages.c"
+#include "selftests/i915_gem_migrate.c"
+#include "selftests/i915_gem_object.c"
+#include "selftests/i915_gem_coherency.c"
+#endif