drm/i915: Remove pages_mutex and intel_gtt->vma_ops.set/clear_pages members, v3.

Big delta, but boils down to moving set_pages to i915_vma.c, and removing
the special handling, all callers use the defaults anyway. We only remap
in ggtt, so default case will fall through.

Because we still don't require locking in i915_vma_unpin(), handle this by
using xchg in get_pages(), as it's locked with obj->mutex, and cmpxchg in
unpin, which only fails if we race a against a new pin.

Changes since v1:
- aliasing gtt sets ZERO_SIZE_PTR, not -ENODEV, remove special case
  from __i915_vma_get_pages(). (Matt)
Changes since v2:
- Free correct old pages in __i915_vma_get_pages(). (Matt)
  Remove race of clearing vma->pages accidentally from put,
  free it but leave it set, as only get has the lock.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211216142749.1966107-4-maarten.lankhorst@linux.intel.com
Reviewed-by: Matthew Auld <matthew.auld@intel.com>

11 files changed, 374 insertions, 439 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_dpt.c b/drivers/gpu/drm/i915/display/intel_dpt.c
index 53449de5f744..6fcf08c7ac66 100644
--- a/drivers/gpu/drm/i915/display/intel_dpt.c
+++ b/drivers/gpu/drm/i915/display/intel_dpt.c
@@ -221,8 +221,6 @@ intel_dpt_create(struct intel_framebuffer *fb)
 
 	vm->vma_ops.bind_vma    = dpt_bind_vma;
 	vm->vma_ops.unbind_vma  = dpt_unbind_vma;
-	vm->vma_ops.set_pages   = ggtt_set_pages;
-	vm->vma_ops.clear_pages = clear_pages;
 
 	vm->pte_encode = gen8_ggtt_pte_encode;
 
diff --git a/drivers/gpu/drm/i915/gt/gen6_ppgtt.c b/drivers/gpu/drm/i915/gt/gen6_ppgtt.c
index c0d149f04949..6e9292918bfc 100644
--- a/drivers/gpu/drm/i915/gt/gen6_ppgtt.c
+++ b/drivers/gpu/drm/i915/gt/gen6_ppgtt.c
@@ -269,19 +269,6 @@ static void gen6_ppgtt_cleanup(struct i915_address_space *vm)
 	free_pd(&ppgtt->base.vm, ppgtt->base.pd);
 }
 
-static int pd_vma_set_pages(struct i915_vma *vma)
-{
-	vma->pages = ERR_PTR(-ENODEV);
-	return 0;
-}
-
-static void pd_vma_clear_pages(struct i915_vma *vma)
-{
-	GEM_BUG_ON(!vma->pages);
-
-	vma->pages = NULL;
-}
-
 static void pd_vma_bind(struct i915_address_space *vm,
 			struct i915_vm_pt_stash *stash,
 			struct i915_vma *vma,
@@ -321,8 +308,6 @@ static void pd_vma_unbind(struct i915_address_space *vm, struct i915_vma *vma)
 }
 
 static const struct i915_vma_ops pd_vma_ops = {
-	.set_pages = pd_vma_set_pages,
-	.clear_pages = pd_vma_clear_pages,
 	.bind_vma = pd_vma_bind,
 	.unbind_vma = pd_vma_unbind,
 };
diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
index b1bb3c9f08ce..b6dbd12af74e 100644
--- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
@@ -20,9 +20,6 @@
 #include "intel_gtt.h"
 #include "gen8_ppgtt.h"
 
-static int
-i915_get_ggtt_vma_pages(struct i915_vma *vma);
-
 static void i915_ggtt_color_adjust(const struct drm_mm_node *node,
 				   unsigned long color,
 				   u64 *start,
@@ -875,21 +872,6 @@ static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size)
 	return 0;
 }
 
-int ggtt_set_pages(struct i915_vma *vma)
-{
-	int ret;
-
-	GEM_BUG_ON(vma->pages);
-
-	ret = i915_get_ggtt_vma_pages(vma);
-	if (ret)
-		return ret;
-
-	vma->page_sizes = vma->obj->mm.page_sizes;
-
-	return 0;
-}
-
 static void gen6_gmch_remove(struct i915_address_space *vm)
 {
 	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
@@ -951,8 +933,6 @@ static int gen8_gmch_probe(struct i915_ggtt *ggtt)
 
 	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
 	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
-	ggtt->vm.vma_ops.set_pages   = ggtt_set_pages;
-	ggtt->vm.vma_ops.clear_pages = clear_pages;
 
 	ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
 
@@ -1102,8 +1082,6 @@ static int gen6_gmch_probe(struct i915_ggtt *ggtt)
 
 	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
 	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
-	ggtt->vm.vma_ops.set_pages   = ggtt_set_pages;
-	ggtt->vm.vma_ops.clear_pages = clear_pages;
 
 	return ggtt_probe_common(ggtt, size);
 }
@@ -1148,8 +1126,6 @@ static int i915_gmch_probe(struct i915_ggtt *ggtt)
 
 	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
 	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
-	ggtt->vm.vma_ops.set_pages   = ggtt_set_pages;
-	ggtt->vm.vma_ops.clear_pages = clear_pages;
 
 	if (unlikely(ggtt->do_idle_maps))
 		drm_notice(&i915->drm,
@@ -1297,327 +1273,3 @@ void i915_ggtt_resume(struct i915_ggtt *ggtt)
 
 	intel_ggtt_restore_fences(ggtt);
 }
-
-static struct scatterlist *
-rotate_pages(struct drm_i915_gem_object *obj, unsigned int offset,
-	     unsigned int width, unsigned int height,
-	     unsigned int src_stride, unsigned int dst_stride,
-	     struct sg_table *st, struct scatterlist *sg)
-{
-	unsigned int column, row;
-	unsigned int src_idx;
-
-	for (column = 0; column < width; column++) {
-		unsigned int left;
-
-		src_idx = src_stride * (height - 1) + column + offset;
-		for (row = 0; row < height; row++) {
-			st->nents++;
-			/*
-			 * We don't need the pages, but need to initialize
-			 * the entries so the sg list can be happily traversed.
-			 * The only thing we need are DMA addresses.
-			 */
-			sg_set_page(sg, NULL, I915_GTT_PAGE_SIZE, 0);
-			sg_dma_address(sg) =
-				i915_gem_object_get_dma_address(obj, src_idx);
-			sg_dma_len(sg) = I915_GTT_PAGE_SIZE;
-			sg = sg_next(sg);
-			src_idx -= src_stride;
-		}
-
-		left = (dst_stride - height) * I915_GTT_PAGE_SIZE;
-
-		if (!left)
-			continue;
-
-		st->nents++;
-
-		/*
-		 * The DE ignores the PTEs for the padding tiles, the sg entry
-		 * here is just a conenience to indicate how many padding PTEs
-		 * to insert at this spot.
-		 */
-		sg_set_page(sg, NULL, left, 0);
-		sg_dma_address(sg) = 0;
-		sg_dma_len(sg) = left;
-		sg = sg_next(sg);
-	}
-
-	return sg;
-}
-
-static noinline struct sg_table *
-intel_rotate_pages(struct intel_rotation_info *rot_info,
-		   struct drm_i915_gem_object *obj)
-{
-	unsigned int size = intel_rotation_info_size(rot_info);
-	struct drm_i915_private *i915 = to_i915(obj->base.dev);
-	struct sg_table *st;
-	struct scatterlist *sg;
-	int ret = -ENOMEM;
-	int i;
-
-	/* Allocate target SG list. */
-	st = kmalloc(sizeof(*st), GFP_KERNEL);
-	if (!st)
-		goto err_st_alloc;
-
-	ret = sg_alloc_table(st, size, GFP_KERNEL);
-	if (ret)
-		goto err_sg_alloc;
-
-	st->nents = 0;
-	sg = st->sgl;
-
-	for (i = 0 ; i < ARRAY_SIZE(rot_info->plane); i++)
-		sg = rotate_pages(obj, rot_info->plane[i].offset,
-				  rot_info->plane[i].width, rot_info->plane[i].height,
-				  rot_info->plane[i].src_stride,
-				  rot_info->plane[i].dst_stride,
-				  st, sg);
-
-	return st;
-
-err_sg_alloc:
-	kfree(st);
-err_st_alloc:
-
-	drm_dbg(&i915->drm, "Failed to create rotated mapping for object size %zu! (%ux%u tiles, %u pages)\n",
-		obj->base.size, rot_info->plane[0].width,
-		rot_info->plane[0].height, size);
-
-	return ERR_PTR(ret);
-}
-
-static struct scatterlist *
-remap_pages(struct drm_i915_gem_object *obj,
-	    unsigned int offset, unsigned int alignment_pad,
-	    unsigned int width, unsigned int height,
-	    unsigned int src_stride, unsigned int dst_stride,
-	    struct sg_table *st, struct scatterlist *sg)
-{
-	unsigned int row;
-
-	if (!width || !height)
-		return sg;
-
-	if (alignment_pad) {
-		st->nents++;
-
-		/*
-		 * The DE ignores the PTEs for the padding tiles, the sg entry
-		 * here is just a convenience to indicate how many padding PTEs
-		 * to insert at this spot.
-		 */
-		sg_set_page(sg, NULL, alignment_pad * 4096, 0);
-		sg_dma_address(sg) = 0;
-		sg_dma_len(sg) = alignment_pad * 4096;
-		sg = sg_next(sg);
-	}
-
-	for (row = 0; row < height; row++) {
-		unsigned int left = width * I915_GTT_PAGE_SIZE;
-
-		while (left) {
-			dma_addr_t addr;
-			unsigned int length;
-
-			/*
-			 * We don't need the pages, but need to initialize
-			 * the entries so the sg list can be happily traversed.
-			 * The only thing we need are DMA addresses.
-			 */
-
-			addr = i915_gem_object_get_dma_address_len(obj, offset, &length);
-
-			length = min(left, length);
-
-			st->nents++;
-
-			sg_set_page(sg, NULL, length, 0);
-			sg_dma_address(sg) = addr;
-			sg_dma_len(sg) = length;
-			sg = sg_next(sg);
-
-			offset += length / I915_GTT_PAGE_SIZE;
-			left -= length;
-		}
-
-		offset += src_stride - width;
-
-		left = (dst_stride - width) * I915_GTT_PAGE_SIZE;
-
-		if (!left)
-			continue;
-
-		st->nents++;
-
-		/*
-		 * The DE ignores the PTEs for the padding tiles, the sg entry
-		 * here is just a conenience to indicate how many padding PTEs
-		 * to insert at this spot.
-		 */
-		sg_set_page(sg, NULL, left, 0);
-		sg_dma_address(sg) = 0;
-		sg_dma_len(sg) = left;
-		sg = sg_next(sg);
-	}
-
-	return sg;
-}
-
-static noinline struct sg_table *
-intel_remap_pages(struct intel_remapped_info *rem_info,
-		  struct drm_i915_gem_object *obj)
-{
-	unsigned int size = intel_remapped_info_size(rem_info);
-	struct drm_i915_private *i915 = to_i915(obj->base.dev);
-	struct sg_table *st;
-	struct scatterlist *sg;
-	unsigned int gtt_offset = 0;
-	int ret = -ENOMEM;
-	int i;
-
-	/* Allocate target SG list. */
-	st = kmalloc(sizeof(*st), GFP_KERNEL);
-	if (!st)
-		goto err_st_alloc;
-
-	ret = sg_alloc_table(st, size, GFP_KERNEL);
-	if (ret)
-		goto err_sg_alloc;
-
-	st->nents = 0;
-	sg = st->sgl;
-
-	for (i = 0 ; i < ARRAY_SIZE(rem_info->plane); i++) {
-		unsigned int alignment_pad = 0;
-
-		if (rem_info->plane_alignment)
-			alignment_pad = ALIGN(gtt_offset, rem_info->plane_alignment) - gtt_offset;
-
-		sg = remap_pages(obj,
-				 rem_info->plane[i].offset, alignment_pad,
-				 rem_info->plane[i].width, rem_info->plane[i].height,
-				 rem_info->plane[i].src_stride, rem_info->plane[i].dst_stride,
-				 st, sg);
-
-		gtt_offset += alignment_pad +
-			      rem_info->plane[i].dst_stride * rem_info->plane[i].height;
-	}
-
-	i915_sg_trim(st);
-
-	return st;
-
-err_sg_alloc:
-	kfree(st);
-err_st_alloc:
-
-	drm_dbg(&i915->drm, "Failed to create remapped mapping for object size %zu! (%ux%u tiles, %u pages)\n",
-		obj->base.size, rem_info->plane[0].width,
-		rem_info->plane[0].height, size);
-
-	return ERR_PTR(ret);
-}
-
-static noinline struct sg_table *
-intel_partial_pages(const struct i915_ggtt_view *view,
-		    struct drm_i915_gem_object *obj)
-{
-	struct sg_table *st;
-	struct scatterlist *sg, *iter;
-	unsigned int count = view->partial.size;
-	unsigned int offset;
-	int ret = -ENOMEM;
-
-	st = kmalloc(sizeof(*st), GFP_KERNEL);
-	if (!st)
-		goto err_st_alloc;
-
-	ret = sg_alloc_table(st, count, GFP_KERNEL);
-	if (ret)
-		goto err_sg_alloc;
-
-	iter = i915_gem_object_get_sg_dma(obj, view->partial.offset, &offset);
-	GEM_BUG_ON(!iter);
-
-	sg = st->sgl;
-	st->nents = 0;
-	do {
-		unsigned int len;
-
-		len = min(sg_dma_len(iter) - (offset << PAGE_SHIFT),
-			  count << PAGE_SHIFT);
-		sg_set_page(sg, NULL, len, 0);
-		sg_dma_address(sg) =
-			sg_dma_address(iter) + (offset << PAGE_SHIFT);
-		sg_dma_len(sg) = len;
-
-		st->nents++;
-		count -= len >> PAGE_SHIFT;
-		if (count == 0) {
-			sg_mark_end(sg);
-			i915_sg_trim(st); /* Drop any unused tail entries. */
-
-			return st;
-		}
-
-		sg = __sg_next(sg);
-		iter = __sg_next(iter);
-		offset = 0;
-	} while (1);
-
-err_sg_alloc:
-	kfree(st);
-err_st_alloc:
-	return ERR_PTR(ret);
-}
-
-static int
-i915_get_ggtt_vma_pages(struct i915_vma *vma)
-{
-	int ret;
-
-	/*
-	 * The vma->pages are only valid within the lifespan of the borrowed
-	 * obj->mm.pages. When the obj->mm.pages sg_table is regenerated, so
-	 * must be the vma->pages. A simple rule is that vma->pages must only
-	 * be accessed when the obj->mm.pages are pinned.
-	 */
-	GEM_BUG_ON(!i915_gem_object_has_pinned_pages(vma->obj));
-
-	switch (vma->ggtt_view.type) {
-	default:
-		GEM_BUG_ON(vma->ggtt_view.type);
-		fallthrough;
-	case I915_GGTT_VIEW_NORMAL:
-		vma->pages = vma->obj->mm.pages;
-		return 0;
-
-	case I915_GGTT_VIEW_ROTATED:
-		vma->pages =
-			intel_rotate_pages(&vma->ggtt_view.rotated, vma->obj);
-		break;
-
-	case I915_GGTT_VIEW_REMAPPED:
-		vma->pages =
-			intel_remap_pages(&vma->ggtt_view.remapped, vma->obj);
-		break;
-
-	case I915_GGTT_VIEW_PARTIAL:
-		vma->pages = intel_partial_pages(&vma->ggtt_view, vma->obj);
-		break;
-	}
-
-	ret = 0;
-	if (IS_ERR(vma->pages)) {
-		ret = PTR_ERR(vma->pages);
-		vma->pages = NULL;
-		drm_err(&vma->vm->i915->drm,
-			"Failed to get pages for VMA view type %u (%d)!\n",
-			vma->ggtt_view.type, ret);
-	}
-	return ret;
-}
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
index b30e4478f098..c3846ff33118 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
@@ -223,19 +223,6 @@ void i915_address_space_init(struct i915_address_space *vm, int subclass)
 	INIT_LIST_HEAD(&vm->bound_list);
 }
 
-void clear_pages(struct i915_vma *vma)
-{
-	GEM_BUG_ON(!vma->pages);
-
-	if (vma->pages != vma->obj->mm.pages) {
-		sg_free_table(vma->pages);
-		kfree(vma->pages);
-	}
-	vma->pages = NULL;
-
-	memset(&vma->page_sizes, 0, sizeof(vma->page_sizes));
-}
-
 void *__px_vaddr(struct drm_i915_gem_object *p)
 {
 	enum i915_map_type type;
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
index a27d57e1c7eb..fa1bdec2473c 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.h
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
@@ -209,9 +209,6 @@ struct i915_vma_ops {
 	 */
 	void (*unbind_vma)(struct i915_address_space *vm,
 			   struct i915_vma *vma);
-
-	int (*set_pages)(struct i915_vma *vma);
-	void (*clear_pages)(struct i915_vma *vma);
 };
 
 struct i915_address_space {
@@ -599,10 +596,6 @@ release_pd_entry(struct i915_page_directory * const pd,
 		 const struct drm_i915_gem_object * const scratch);
 void gen6_ggtt_invalidate(struct i915_ggtt *ggtt);
 
-int ggtt_set_pages(struct i915_vma *vma);
-int ppgtt_set_pages(struct i915_vma *vma);
-void clear_pages(struct i915_vma *vma);
-
 void ppgtt_bind_vma(struct i915_address_space *vm,
 		    struct i915_vm_pt_stash *stash,
 		    struct i915_vma *vma,
diff --git a/drivers/gpu/drm/i915/gt/intel_ppgtt.c b/drivers/gpu/drm/i915/gt/intel_ppgtt.c
index 4396bfd630d8..083b3090c69c 100644
--- a/drivers/gpu/drm/i915/gt/intel_ppgtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_ppgtt.c
@@ -289,16 +289,6 @@ void i915_vm_free_pt_stash(struct i915_address_space *vm,
 	}
 }
 
-int ppgtt_set_pages(struct i915_vma *vma)
-{
-	GEM_BUG_ON(vma->pages);
-
-	vma->pages = vma->obj->mm.pages;
-	vma->page_sizes = vma->obj->mm.page_sizes;
-
-	return 0;
-}
-
 void ppgtt_init(struct i915_ppgtt *ppgtt, struct intel_gt *gt,
 		unsigned long lmem_pt_obj_flags)
 {
@@ -315,6 +305,4 @@ void ppgtt_init(struct i915_ppgtt *ppgtt, struct intel_gt *gt,
 
 	ppgtt->vm.vma_ops.bind_vma    = ppgtt_bind_vma;
 	ppgtt->vm.vma_ops.unbind_vma  = ppgtt_unbind_vma;
-	ppgtt->vm.vma_ops.set_pages   = ppgtt_set_pages;
-	ppgtt->vm.vma_ops.clear_pages = clear_pages;
 }
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 921d5b946c32..4a73bf045e62 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -109,7 +109,6 @@ vma_create(struct drm_i915_gem_object *obj,
 		return ERR_PTR(-ENOMEM);
 
 	kref_init(&vma->ref);
-	mutex_init(&vma->pages_mutex);
 	vma->vm = i915_vm_get(vm);
 	vma->ops = &vm->vma_ops;
 	vma->obj = obj;
@@ -415,7 +414,7 @@ int i915_vma_bind(struct i915_vma *vma,
 	if (bind_flags == 0)
 		return 0;
 
-	GEM_BUG_ON(!vma->pages);
+	GEM_BUG_ON(!atomic_read(&vma->pages_count));
 
 	trace_i915_vma_bind(vma, bind_flags);
 	if (work && bind_flags & vma->vm->bind_async_flags) {
@@ -816,10 +815,337 @@ unpinned:
 	return pinned;
 }
 
-static int vma_get_pages(struct i915_vma *vma)
+static struct scatterlist *
+rotate_pages(struct drm_i915_gem_object *obj, unsigned int offset,
+	     unsigned int width, unsigned int height,
+	     unsigned int src_stride, unsigned int dst_stride,
+	     struct sg_table *st, struct scatterlist *sg)
 {
-	int err = 0;
-	bool pinned_pages = true;
+	unsigned int column, row;
+	unsigned int src_idx;
+
+	for (column = 0; column < width; column++) {
+		unsigned int left;
+
+		src_idx = src_stride * (height - 1) + column + offset;
+		for (row = 0; row < height; row++) {
+			st->nents++;
+			/*
+			 * We don't need the pages, but need to initialize
+			 * the entries so the sg list can be happily traversed.
+			 * The only thing we need are DMA addresses.
+			 */
+			sg_set_page(sg, NULL, I915_GTT_PAGE_SIZE, 0);
+			sg_dma_address(sg) =
+				i915_gem_object_get_dma_address(obj, src_idx);
+			sg_dma_len(sg) = I915_GTT_PAGE_SIZE;
+			sg = sg_next(sg);
+			src_idx -= src_stride;
+		}
+
+		left = (dst_stride - height) * I915_GTT_PAGE_SIZE;
+
+		if (!left)
+			continue;
+
+		st->nents++;
+
+		/*
+		 * The DE ignores the PTEs for the padding tiles, the sg entry
+		 * here is just a conenience to indicate how many padding PTEs
+		 * to insert at this spot.
+		 */
+		sg_set_page(sg, NULL, left, 0);
+		sg_dma_address(sg) = 0;
+		sg_dma_len(sg) = left;
+		sg = sg_next(sg);
+	}
+
+	return sg;
+}
+
+static noinline struct sg_table *
+intel_rotate_pages(struct intel_rotation_info *rot_info,
+		   struct drm_i915_gem_object *obj)
+{
+	unsigned int size = intel_rotation_info_size(rot_info);
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	struct sg_table *st;
+	struct scatterlist *sg;
+	int ret = -ENOMEM;
+	int i;
+
+	/* Allocate target SG list. */
+	st = kmalloc(sizeof(*st), GFP_KERNEL);
+	if (!st)
+		goto err_st_alloc;
+
+	ret = sg_alloc_table(st, size, GFP_KERNEL);
+	if (ret)
+		goto err_sg_alloc;
+
+	st->nents = 0;
+	sg = st->sgl;
+
+	for (i = 0 ; i < ARRAY_SIZE(rot_info->plane); i++)
+		sg = rotate_pages(obj, rot_info->plane[i].offset,
+				  rot_info->plane[i].width, rot_info->plane[i].height,
+				  rot_info->plane[i].src_stride,
+				  rot_info->plane[i].dst_stride,
+				  st, sg);
+
+	return st;
+
+err_sg_alloc:
+	kfree(st);
+err_st_alloc:
+
+	drm_dbg(&i915->drm, "Failed to create rotated mapping for object size %zu! (%ux%u tiles, %u pages)\n",
+		obj->base.size, rot_info->plane[0].width,
+		rot_info->plane[0].height, size);
+
+	return ERR_PTR(ret);
+}
+
+static struct scatterlist *
+remap_pages(struct drm_i915_gem_object *obj,
+	    unsigned int offset, unsigned int alignment_pad,
+	    unsigned int width, unsigned int height,
+	    unsigned int src_stride, unsigned int dst_stride,
+	    struct sg_table *st, struct scatterlist *sg)
+{
+	unsigned int row;
+
+	if (!width || !height)
+		return sg;
+
+	if (alignment_pad) {
+		st->nents++;
+
+		/*
+		 * The DE ignores the PTEs for the padding tiles, the sg entry
+		 * here is just a convenience to indicate how many padding PTEs
+		 * to insert at this spot.
+		 */
+		sg_set_page(sg, NULL, alignment_pad * 4096, 0);
+		sg_dma_address(sg) = 0;
+		sg_dma_len(sg) = alignment_pad * 4096;
+		sg = sg_next(sg);
+	}
+
+	for (row = 0; row < height; row++) {
+		unsigned int left = width * I915_GTT_PAGE_SIZE;
+
+		while (left) {
+			dma_addr_t addr;
+			unsigned int length;
+
+			/*
+			 * We don't need the pages, but need to initialize
+			 * the entries so the sg list can be happily traversed.
+			 * The only thing we need are DMA addresses.
+			 */
+
+			addr = i915_gem_object_get_dma_address_len(obj, offset, &length);
+
+			length = min(left, length);
+
+			st->nents++;
+
+			sg_set_page(sg, NULL, length, 0);
+			sg_dma_address(sg) = addr;
+			sg_dma_len(sg) = length;
+			sg = sg_next(sg);
+
+			offset += length / I915_GTT_PAGE_SIZE;
+			left -= length;
+		}
+
+		offset += src_stride - width;
+
+		left = (dst_stride - width) * I915_GTT_PAGE_SIZE;
+
+		if (!left)
+			continue;
+
+		st->nents++;
+
+		/*
+		 * The DE ignores the PTEs for the padding tiles, the sg entry
+		 * here is just a conenience to indicate how many padding PTEs
+		 * to insert at this spot.
+		 */
+		sg_set_page(sg, NULL, left, 0);
+		sg_dma_address(sg) = 0;
+		sg_dma_len(sg) = left;
+		sg = sg_next(sg);
+	}
+
+	return sg;
+}
+
+static noinline struct sg_table *
+intel_remap_pages(struct intel_remapped_info *rem_info,
+		  struct drm_i915_gem_object *obj)
+{
+	unsigned int size = intel_remapped_info_size(rem_info);
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	struct sg_table *st;
+	struct scatterlist *sg;
+	unsigned int gtt_offset = 0;
+	int ret = -ENOMEM;
+	int i;
+
+	/* Allocate target SG list. */
+	st = kmalloc(sizeof(*st), GFP_KERNEL);
+	if (!st)
+		goto err_st_alloc;
+
+	ret = sg_alloc_table(st, size, GFP_KERNEL);
+	if (ret)
+		goto err_sg_alloc;
+
+	st->nents = 0;
+	sg = st->sgl;
+
+	for (i = 0 ; i < ARRAY_SIZE(rem_info->plane); i++) {
+		unsigned int alignment_pad = 0;
+
+		if (rem_info->plane_alignment)
+			alignment_pad = ALIGN(gtt_offset, rem_info->plane_alignment) - gtt_offset;
+
+		sg = remap_pages(obj,
+				 rem_info->plane[i].offset, alignment_pad,
+				 rem_info->plane[i].width, rem_info->plane[i].height,
+				 rem_info->plane[i].src_stride, rem_info->plane[i].dst_stride,
+				 st, sg);
+
+		gtt_offset += alignment_pad +
+			      rem_info->plane[i].dst_stride * rem_info->plane[i].height;
+	}
+
+	i915_sg_trim(st);
+
+	return st;
+
+err_sg_alloc:
+	kfree(st);
+err_st_alloc:
+
+	drm_dbg(&i915->drm, "Failed to create remapped mapping for object size %zu! (%ux%u tiles, %u pages)\n",
+		obj->base.size, rem_info->plane[0].width,
+		rem_info->plane[0].height, size);
+
+	return ERR_PTR(ret);
+}
+
+static noinline struct sg_table *
+intel_partial_pages(const struct i915_ggtt_view *view,
+		    struct drm_i915_gem_object *obj)
+{
+	struct sg_table *st;
+	struct scatterlist *sg, *iter;
+	unsigned int count = view->partial.size;
+	unsigned int offset;
+	int ret = -ENOMEM;
+
+	st = kmalloc(sizeof(*st), GFP_KERNEL);
+	if (!st)
+		goto err_st_alloc;
+
+	ret = sg_alloc_table(st, count, GFP_KERNEL);
+	if (ret)
+		goto err_sg_alloc;
+
+	iter = i915_gem_object_get_sg_dma(obj, view->partial.offset, &offset);
+	GEM_BUG_ON(!iter);
+
+	sg = st->sgl;
+	st->nents = 0;
+	do {
+		unsigned int len;
+
+		len = min(sg_dma_len(iter) - (offset << PAGE_SHIFT),
+			  count << PAGE_SHIFT);
+		sg_set_page(sg, NULL, len, 0);
+		sg_dma_address(sg) =
+			sg_dma_address(iter) + (offset << PAGE_SHIFT);
+		sg_dma_len(sg) = len;
+
+		st->nents++;
+		count -= len >> PAGE_SHIFT;
+		if (count == 0) {
+			sg_mark_end(sg);
+			i915_sg_trim(st); /* Drop any unused tail entries. */
+
+			return st;
+		}
+
+		sg = __sg_next(sg);
+		iter = __sg_next(iter);
+		offset = 0;
+	} while (1);
+
+err_sg_alloc:
+	kfree(st);
+err_st_alloc:
+	return ERR_PTR(ret);
+}
+
+static int
+__i915_vma_get_pages(struct i915_vma *vma)
+{
+	struct sg_table *pages;
+	int ret;
+
+	/*
+	 * The vma->pages are only valid within the lifespan of the borrowed
+	 * obj->mm.pages. When the obj->mm.pages sg_table is regenerated, so
+	 * must be the vma->pages. A simple rule is that vma->pages must only
+	 * be accessed when the obj->mm.pages are pinned.
+	 */
+	GEM_BUG_ON(!i915_gem_object_has_pinned_pages(vma->obj));
+
+	switch (vma->ggtt_view.type) {
+	default:
+		GEM_BUG_ON(vma->ggtt_view.type);
+		fallthrough;
+	case I915_GGTT_VIEW_NORMAL:
+		pages = vma->obj->mm.pages;
+		break;
+
+	case I915_GGTT_VIEW_ROTATED:
+		pages =
+			intel_rotate_pages(&vma->ggtt_view.rotated, vma->obj);
+		break;
+
+	case I915_GGTT_VIEW_REMAPPED:
+		pages =
+			intel_remap_pages(&vma->ggtt_view.remapped, vma->obj);
+		break;
+
+	case I915_GGTT_VIEW_PARTIAL:
+		pages = intel_partial_pages(&vma->ggtt_view, vma->obj);
+		break;
+	}
+
+	ret = 0;
+	if (IS_ERR(pages)) {
+		ret = PTR_ERR(pages);
+		pages = NULL;
+		drm_err(&vma->vm->i915->drm,
+			"Failed to get pages for VMA view type %u (%d)!\n",
+			vma->ggtt_view.type, ret);
+	}
+
+	vma->pages = pages;
+
+	return ret;
+}
+
+I915_SELFTEST_EXPORT int i915_vma_get_pages(struct i915_vma *vma)
+{
+	int err;
 
 	if (atomic_add_unless(&vma->pages_count, 1, 0))
 		return 0;
@@ -828,25 +1154,17 @@ static int vma_get_pages(struct i915_vma *vma)
 	if (err)
 		return err;
 
-	/* Allocations ahoy! */
-	if (mutex_lock_interruptible(&vma->pages_mutex)) {
-		err = -EINTR;
-		goto unpin;
-	}
+	err = __i915_vma_get_pages(vma);
+	if (err)
+		goto err_unpin;
 
-	if (!atomic_read(&vma->pages_count)) {
-		err = vma->ops->set_pages(vma);
-		if (err)
-			goto unlock;
-		pinned_pages = false;
-	}
+	vma->page_sizes = vma->obj->mm.page_sizes;
 	atomic_inc(&vma->pages_count);
 
-unlock:
-	mutex_unlock(&vma->pages_mutex);
-unpin:
-	if (pinned_pages)
-		__i915_gem_object_unpin_pages(vma->obj);
+	return 0;
+
+err_unpin:
+	__i915_gem_object_unpin_pages(vma->obj);
 
 	return err;
 }
@@ -854,18 +1172,31 @@ unpin:
 static void __vma_put_pages(struct i915_vma *vma, unsigned int count)
 {
 	/* We allocate under vma_get_pages, so beware the shrinker */
-	mutex_lock_nested(&vma->pages_mutex, SINGLE_DEPTH_NESTING);
+	struct sg_table *pages = READ_ONCE(vma->pages);
+
 	GEM_BUG_ON(atomic_read(&vma->pages_count) < count);
+
 	if (atomic_sub_return(count, &vma->pages_count) == 0) {
-		vma->ops->clear_pages(vma);
-		GEM_BUG_ON(vma->pages);
+		/*
+		 * The atomic_sub_return is a read barrier for the READ_ONCE of
+		 * vma->pages above.
+		 *
+		 * READ_ONCE is safe because this is either called from the same
+		 * function (i915_vma_pin_ww), or guarded by vma->vm->mutex.
+		 *
+		 * TODO: We're leaving vma->pages dangling, until vma->obj->resv
+		 * lock is required.
+		 */
+		if (pages != vma->obj->mm.pages) {
+			sg_free_table(pages);
+			kfree(pages);
+		}
 
 		i915_gem_object_unpin_pages(vma->obj);
 	}
-	mutex_unlock(&vma->pages_mutex);
 }
 
-static void vma_put_pages(struct i915_vma *vma)
+I915_SELFTEST_EXPORT void i915_vma_put_pages(struct i915_vma *vma)
 {
 	if (atomic_add_unless(&vma->pages_count, -1, 1))
 		return;
@@ -896,10 +1227,8 @@ int i915_vma_pin_ww(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,
 	unsigned int bound;
 	int err;
 
-#ifdef CONFIG_PROVE_LOCKING
-	if (debug_locks && !WARN_ON(!ww))
-		assert_vma_held(vma);
-#endif
+	assert_vma_held(vma);
+	GEM_BUG_ON(!ww);
 
 	BUILD_BUG_ON(PIN_GLOBAL != I915_VMA_GLOBAL_BIND);
 	BUILD_BUG_ON(PIN_USER != I915_VMA_LOCAL_BIND);
@@ -910,7 +1239,7 @@ int i915_vma_pin_ww(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,
 	if (try_qad_pin(vma, flags & I915_VMA_BIND_MASK))
 		return 0;
 
-	err = vma_get_pages(vma);
+	err = i915_vma_get_pages(vma);
 	if (err)
 		return err;
 
@@ -1038,10 +1367,11 @@ err_fence:
 err_rpm:
 	if (wakeref)
 		intel_runtime_pm_put(&vma->vm->i915->runtime_pm, wakeref);
+
 	if (moving)
 		dma_fence_put(moving);
-	vma_put_pages(vma);
 
+	i915_vma_put_pages(vma);
 	return err;
 }
 
diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
index 9a931ecb09e5..32719431b3df 100644
--- a/drivers/gpu/drm/i915/i915_vma.h
+++ b/drivers/gpu/drm/i915/i915_vma.h
@@ -431,4 +431,7 @@ static inline int i915_vma_sync(struct i915_vma *vma)
 void i915_vma_module_exit(void);
 int i915_vma_module_init(void);
 
+I915_SELFTEST_DECLARE(int i915_vma_get_pages(struct i915_vma *vma));
+I915_SELFTEST_DECLARE(void i915_vma_put_pages(struct i915_vma *vma));
+
 #endif
diff --git a/drivers/gpu/drm/i915/i915_vma_types.h b/drivers/gpu/drm/i915/i915_vma_types.h
index 8a0decb19bcc..412d3e78a30d 100644
--- a/drivers/gpu/drm/i915/i915_vma_types.h
+++ b/drivers/gpu/drm/i915/i915_vma_types.h
@@ -261,7 +261,6 @@ struct i915_vma {
 #define I915_VMA_PAGES_BIAS 24
 #define I915_VMA_PAGES_ACTIVE (BIT(24) | 1)
 	atomic_t pages_count; /* number of active binds to the pages */
-	struct mutex pages_mutex; /* protect acquire/release of backing pages */
 
 	/**
 	 * Support different GGTT views into the same object.
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
index 48123c3e1ff0..575705c3bce9 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -1275,7 +1275,7 @@ static void track_vma_bind(struct i915_vma *vma)
 
 	__i915_gem_object_pin_pages(obj);
 
-	GEM_BUG_ON(vma->pages);
+	GEM_BUG_ON(atomic_read(&vma->pages_count));
 	atomic_set(&vma->pages_count, I915_VMA_PAGES_ACTIVE);
 	__i915_gem_object_pin_pages(obj);
 	vma->pages = obj->mm.pages;
@@ -1953,7 +1953,9 @@ static int igt_cs_tlb(void *arg)
 				goto end;
 			}
 
-			err = vma->ops->set_pages(vma);
+			i915_gem_object_lock(bbe, NULL);
+			err = i915_vma_get_pages(vma);
+			i915_gem_object_unlock(bbe);
 			if (err)
 				goto end;
 
@@ -1994,7 +1996,7 @@ end_ww:
 				i915_request_put(rq);
 			}
 
-			vma->ops->clear_pages(vma);
+			i915_vma_put_pages(vma);
 
 			err = context_sync(ce);
 			if (err) {
@@ -2009,7 +2011,9 @@ end_ww:
 				goto end;
 			}
 
-			err = vma->ops->set_pages(vma);
+			i915_gem_object_lock(act, NULL);
+			err = i915_vma_get_pages(vma);
+			i915_gem_object_unlock(act);
 			if (err)
 				goto end;
 
@@ -2047,7 +2051,7 @@ end_ww:
 			}
 			end_spin(batch, count - 1);
 
-			vma->ops->clear_pages(vma);
+			i915_vma_put_pages(vma);
 
 			err = context_sync(ce);
 			if (err) {
diff --git a/drivers/gpu/drm/i915/selftests/mock_gtt.c b/drivers/gpu/drm/i915/selftests/mock_gtt.c
index 13bb0c3c3f0d..1802baf80a17 100644
--- a/drivers/gpu/drm/i915/selftests/mock_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/mock_gtt.c
@@ -87,8 +87,6 @@ struct i915_ppgtt *mock_ppgtt(struct drm_i915_private *i915, const char *name)
 
 	ppgtt->vm.vma_ops.bind_vma    = mock_bind_ppgtt;
 	ppgtt->vm.vma_ops.unbind_vma  = mock_unbind_ppgtt;
-	ppgtt->vm.vma_ops.set_pages   = ppgtt_set_pages;
-	ppgtt->vm.vma_ops.clear_pages = clear_pages;
 
 	return ppgtt;
 }
@@ -128,8 +126,6 @@ void mock_init_ggtt(struct drm_i915_private *i915, struct i915_ggtt *ggtt)
 
 	ggtt->vm.vma_ops.bind_vma    = mock_bind_ggtt;
 	ggtt->vm.vma_ops.unbind_vma  = mock_unbind_ggtt;
-	ggtt->vm.vma_ops.set_pages   = ggtt_set_pages;
-	ggtt->vm.vma_ops.clear_pages = clear_pages;
 
 	i915_address_space_init(&ggtt->vm, VM_CLASS_GGTT);
 	to_gt(i915)->ggtt = ggtt;