1 files changed, 25 insertions, 5 deletions

diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
index 4b7cc4fe366..8d5382e62c0 100644
--- a/include/linux/rbtree.h
+++ b/include/linux/rbtree.h
@@ -99,22 +99,43 @@ static inline struct page * rb_insert_page_cache(struct inode * inode,
 
 struct rb_node
 {
-	struct rb_node *rb_parent;
-	int rb_color;
+	unsigned long  rb_parent_color;
 #define	RB_RED		0
 #define	RB_BLACK	1
 	struct rb_node *rb_right;
 	struct rb_node *rb_left;
-};
+} __attribute__((aligned(sizeof(long))));
+    /* The alignment might seem pointless, but allegedly CRIS needs it */
 
 struct rb_root
 {
 	struct rb_node *rb_node;
 };
 
+
+#define rb_parent(r)   ((struct rb_node *)((r)->rb_parent_color & ~3))
+#define rb_color(r)   ((r)->rb_parent_color & 1)
+#define rb_is_red(r)   (!rb_color(r))
+#define rb_is_black(r) rb_color(r)
+#define rb_set_red(r)  do { (r)->rb_parent_color &= ~1; } while (0)
+#define rb_set_black(r)  do { (r)->rb_parent_color |= 1; } while (0)
+
+static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
+{
+	rb->rb_parent_color = (rb->rb_parent_color & 3) | (unsigned long)p;
+}
+static inline void rb_set_color(struct rb_node *rb, int color)
+{
+	rb->rb_parent_color = (rb->rb_parent_color & ~1) | color;
+}
+
 #define RB_ROOT	(struct rb_root) { NULL, }
 #define	rb_entry(ptr, type, member) container_of(ptr, type, member)
 
+#define RB_EMPTY_ROOT(root)	((root)->rb_node == NULL)
+#define RB_EMPTY_NODE(node)	(rb_parent(node) != node)
+#define RB_CLEAR_NODE(node)	(rb_set_parent(node, node))
+
 extern void rb_insert_color(struct rb_node *, struct rb_root *);
 extern void rb_erase(struct rb_node *, struct rb_root *);
 
@@ -131,8 +152,7 @@ extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,
 static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
 				struct rb_node ** rb_link)
 {
-	node->rb_parent = parent;
-	node->rb_color = RB_RED;
+	node->rb_parent_color = (unsigned long )parent;
 	node->rb_left = node->rb_right = NULL;
 
 	*rb_link = node;