drm/i915: Use struct vma_resource instead of struct vma_snapshot

There is always a struct vma_resource guaranteed to be alive when we
access a corresponding struct vma_snapshot.

So ditch the latter and instead of allocating vma_snapshots, reference
the already existning vma_resource.

This requires a couple of extra members in struct vma_resource but that's
a small price to pay for the simplification.

v2:
- Fix a missing include and declaration (kernel test robot <lkp@intel.com>)

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220110172219.107131-7-thomas.hellstrom@linux.intel.com

1 files changed, 4 insertions, 12 deletions

diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index b86666f653ca..9d859b0a3fbe 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -288,7 +288,6 @@ struct i915_vma_work {
 	struct i915_vma_resource *vma_res;
 	struct drm_i915_gem_object *pinned;
 	struct i915_sw_dma_fence_cb cb;
-	struct i915_refct_sgt *rsgt;
 	enum i915_cache_level cache_level;
 	unsigned int flags;
 };
@@ -314,8 +313,6 @@ static void __vma_release(struct dma_fence_work *work)
 	i915_vm_put(vw->vm);
 	if (vw->vma_res)
 		i915_vma_resource_put(vw->vma_res);
-	if (vw->rsgt)
-		i915_refct_sgt_put(vw->rsgt);
 }
 
 static const struct dma_fence_work_ops bind_ops = {
@@ -386,8 +383,8 @@ i915_vma_resource_init_from_vma(struct i915_vma_resource *vma_res,
 	struct drm_i915_gem_object *obj = vma->obj;
 
 	i915_vma_resource_init(vma_res, vma->vm, vma->pages, &vma->page_sizes,
-			       i915_gem_object_is_readonly(obj),
-			       i915_gem_object_is_lmem(obj),
+			       obj->mm.rsgt, i915_gem_object_is_readonly(obj),
+			       i915_gem_object_is_lmem(obj), obj->mm.region,
 			       vma->ops, vma->private, vma->node.start,
 			       vma->node.size, vma->size);
 }
@@ -478,8 +475,6 @@ int i915_vma_bind(struct i915_vma *vma,
 		work->vma_res = i915_vma_resource_get(vma->resource);
 		work->cache_level = cache_level;
 		work->flags = bind_flags;
-		if (vma->obj->mm.rsgt)
-			work->rsgt = i915_refct_sgt_get(vma->obj->mm.rsgt);
 
 		/*
 		 * Note we only want to chain up to the migration fence on
@@ -505,7 +500,7 @@ int i915_vma_bind(struct i915_vma *vma,
 		 * on the object to avoid waiting for the async bind to
 		 * complete in the object destruction path.
 		 */
-		if (!work->rsgt)
+		if (!work->vma_res->bi.pages_rsgt)
 			work->pinned = i915_gem_object_get(vma->obj);
 	} else {
 		if (vma->obj) {
@@ -1771,7 +1766,7 @@ struct dma_fence *__i915_vma_evict(struct i915_vma *vma, bool async)
 	GEM_BUG_ON(i915_vma_has_userfault(vma));
 
 	/* Object backend must be async capable. */
-	GEM_WARN_ON(async && !vma->obj->mm.rsgt);
+	GEM_WARN_ON(async && !vma->resource->bi.pages_rsgt);
 
 	/* If vm is not open, unbind is a nop. */
 	vma_res->needs_wakeref = i915_vma_is_bound(vma, I915_VMA_GLOBAL_BIND) &&
@@ -1784,9 +1779,6 @@ struct dma_fence *__i915_vma_evict(struct i915_vma *vma, bool async)
 	atomic_and(~(I915_VMA_BIND_MASK | I915_VMA_ERROR | I915_VMA_GGTT_WRITE),
 		   &vma->flags);
 
-	/* Object backend must be async capable. */
-	GEM_WARN_ON(async && !vma->obj->mm.rsgt);
-
 	i915_vma_detach(vma);
 
 	if (!async && unbind_fence) {