drm/i915: Embed drm_mm_node in i915 gem obj

Embedding the node in the obj is more natural in the transition to VMAs
which will also have embedded nodes. This change also helps transition
away from put_block to remove node.

Though it's quite an uncommon occurrence, it's somewhat convenient to not
fail at bind time because we cannot allocate the node. Though in
practice there are other allocations (like the request structure) which
would probably make this point not terribly useful.

Quoting Daniel:
Note that the only difference between put_block and remove_node is
that the former fills up the preallocation cache. Which we don't need
anyway and hence is just wasted space.

v2: Clean up the stolen preallocation code.
Rebased on the reserve_node patches
renames ggtt_ stuff to gtt_ stuff
WARN_ON if the object is already bound (which doesn't mean it's in the
bound list, tricky)

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 11 insertions, 20 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 3ea54c8eec24..339404937ab9 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2632,8 +2632,7 @@ i915_gem_object_unbind(struct drm_i915_gem_object *obj)
 	/* Avoid an unnecessary call to unbind on rebind. */
 	obj->map_and_fenceable = true;
 
-	drm_mm_put_block(obj->gtt_space);
-	obj->gtt_space = NULL;
+	drm_mm_remove_node(&obj->gtt_space);
 
 	return 0;
 }
@@ -3011,7 +3010,7 @@ static bool i915_gem_valid_gtt_space(struct drm_device *dev,
 	if (HAS_LLC(dev))
 		return true;
 
-	if (gtt_space == NULL)
+	if (!drm_mm_node_allocated(gtt_space))
 		return true;
 
 	if (list_empty(&gtt_space->node_list))
@@ -3079,7 +3078,6 @@ i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
 {
 	struct drm_device *dev = obj->base.dev;
 	drm_i915_private_t *dev_priv = dev->dev_private;
-	struct drm_mm_node *node;
 	u32 size, fence_size, fence_alignment, unfenced_alignment;
 	bool mappable, fenceable;
 	size_t gtt_max = map_and_fenceable ?
@@ -3124,14 +3122,9 @@ i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
 
 	i915_gem_object_pin_pages(obj);
 
-	node = kzalloc(sizeof(*node), GFP_KERNEL);
-	if (node == NULL) {
-		i915_gem_object_unpin_pages(obj);
-		return -ENOMEM;
-	}
-
 search_free:
-	ret = drm_mm_insert_node_in_range_generic(&dev_priv->mm.gtt_space, node,
+	ret = drm_mm_insert_node_in_range_generic(&dev_priv->mm.gtt_space,
+						  &obj->gtt_space,
 						  size, alignment,
 						  obj->cache_level, 0, gtt_max);
 	if (ret) {
@@ -3143,30 +3136,28 @@ search_free:
 			goto search_free;
 
 		i915_gem_object_unpin_pages(obj);
-		kfree(node);
 		return ret;
 	}
-	if (WARN_ON(!i915_gem_valid_gtt_space(dev, node, obj->cache_level))) {
+	if (WARN_ON(!i915_gem_valid_gtt_space(dev, &obj->gtt_space,
+					      obj->cache_level))) {
 		i915_gem_object_unpin_pages(obj);
-		drm_mm_put_block(node);
+		drm_mm_remove_node(&obj->gtt_space);
 		return -EINVAL;
 	}
 
 	ret = i915_gem_gtt_prepare_object(obj);
 	if (ret) {
 		i915_gem_object_unpin_pages(obj);
-		drm_mm_put_block(node);
+		drm_mm_remove_node(&obj->gtt_space);
 		return ret;
 	}
 
 	list_move_tail(&obj->global_list, &dev_priv->mm.bound_list);
 	list_add_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
 
-	obj->gtt_space = node;
-
 	fenceable =
-		node->size == fence_size &&
-		(node->start & (fence_alignment - 1)) == 0;
+		i915_gem_obj_ggtt_size(obj) == fence_size &&
+		(i915_gem_obj_ggtt_offset(obj) & (fence_alignment - 1)) == 0;
 
 	mappable = i915_gem_obj_ggtt_offset(obj) + obj->base.size <=
 		dev_priv->gtt.mappable_end;
@@ -3330,7 +3321,7 @@ int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj,
 		return -EBUSY;
 	}
 
-	if (!i915_gem_valid_gtt_space(dev, obj->gtt_space, cache_level)) {
+	if (!i915_gem_valid_gtt_space(dev, &obj->gtt_space, cache_level)) {
 		ret = i915_gem_object_unbind(obj);
 		if (ret)
 			return ret;