drm: Convert drm_vma_manager to embedded interval-tree in drm_mm

Having added an interval-tree to struct drm_mm, we can replace the
auxiliary rb-tree inside the drm_vma_manager with it.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1470236651-678-2-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/drm_vma_manager.c

@@ -86,7 +86,6 @@ void drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr,
 				 unsigned long page_offset, unsigned long size)
 {
 	rwlock_init(&mgr->vm_lock);
-	mgr->vm_addr_space_rb = RB_ROOT;
 	drm_mm_init(&mgr->vm_addr_space_mm, page_offset, size);
 }
 EXPORT_SYMBOL(drm_vma_offset_manager_init);
@@ -145,16 +144,16 @@ struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_m
 							 unsigned long start,
 							 unsigned long pages)
 {
-	struct drm_vma_offset_node *node, *best;
+	struct drm_mm_node *node, *best;
 	struct rb_node *iter;
 	unsigned long offset;
 
-	iter = mgr->vm_addr_space_rb.rb_node;
+	iter = mgr->vm_addr_space_mm.interval_tree.rb_node;
 	best = NULL;
 
 	while (likely(iter)) {
-		node = rb_entry(iter, struct drm_vma_offset_node, vm_rb);
-		offset = node->vm_node.start;
+		node = rb_entry(iter, struct drm_mm_node, rb);
+		offset = node->start;
 		if (start >= offset) {
 			iter = iter->rb_right;
 			best = node;
@@ -167,38 +166,17 @@ struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_m
 
 	/* verify that the node spans the requested area */
 	if (best) {
-		offset = best->vm_node.start + best->vm_node.size;
+		offset = best->start + best->size;
 		if (offset < start + pages)
 			best = NULL;
 	}
 
-	return best;
-}
-EXPORT_SYMBOL(drm_vma_offset_lookup_locked);
-
-/* internal helper to link @node into the rb-tree */
-static void _drm_vma_offset_add_rb(struct drm_vma_offset_manager *mgr,
-				   struct drm_vma_offset_node *node)
-{
-	struct rb_node **iter = &mgr->vm_addr_space_rb.rb_node;
-	struct rb_node *parent = NULL;
-	struct drm_vma_offset_node *iter_node;
-
-	while (likely(*iter)) {
-		parent = *iter;
-		iter_node = rb_entry(*iter, struct drm_vma_offset_node, vm_rb);
-
-		if (node->vm_node.start < iter_node->vm_node.start)
-			iter = &(*iter)->rb_left;
-		else if (node->vm_node.start > iter_node->vm_node.start)
-			iter = &(*iter)->rb_right;
-		else
-			BUG();
-	}
+	if (!best)
+		return NULL;
 
-	rb_link_node(&node->vm_rb, parent, iter);
-	rb_insert_color(&node->vm_rb, &mgr->vm_addr_space_rb);
+	return container_of(best, struct drm_vma_offset_node, vm_node);
 }
+EXPORT_SYMBOL(drm_vma_offset_lookup_locked);
 
 /**
  * drm_vma_offset_add() - Add offset node to manager
@@ -240,8 +218,6 @@ int drm_vma_offset_add(struct drm_vma_offset_manager *mgr,
 	if (ret)
 		goto out_unlock;
 
-	_drm_vma_offset_add_rb(mgr, node);
-
 out_unlock:
 	write_unlock(&mgr->vm_lock);
 	return ret;
@@ -265,7 +241,6 @@ void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr,
 	write_lock(&mgr->vm_lock);
 
 	if (drm_mm_node_allocated(&node->vm_node)) {
-		rb_erase(&node->vm_rb, &mgr->vm_addr_space_rb);
 		drm_mm_remove_node(&node->vm_node);
 		memset(&node->vm_node, 0, sizeof(node->vm_node));
 	}

include/drm/drm_vma_manager.h

@@ -40,13 +40,11 @@ struct drm_vma_offset_file {
 struct drm_vma_offset_node {
 	rwlock_t vm_lock;
 	struct drm_mm_node vm_node;
-	struct rb_node vm_rb;
 	struct rb_root vm_files;
 };
 
 struct drm_vma_offset_manager {
 	rwlock_t vm_lock;
-	struct rb_root vm_addr_space_rb;
 	struct drm_mm vm_addr_space_mm;
 };