[RBTREE] Add accessor macros for colour and parent fields of rb_node
This is in preparation for merging those fields into a single
'unsigned long', because using a whole machine-word for a single bit
of colour information is wasteful.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
index 4b7cc4f..ffee81c 100644
--- a/include/linux/rbtree.h
+++ b/include/linux/rbtree.h
@@ -107,6 +107,15 @@
struct rb_node *rb_left;
};
+#define rb_parent(r) ((r)->rb_parent)
+#define rb_set_parent(r,p) do { (r)->rb_parent = p; } while (0)
+#define rb_colour(r) ((r)->rb_colour)
+#define rb_is_red(r) ((r)->colour == RB_RED)
+#define rb_is_black(r) ((r)->colour == RB_BLACK)
+#define rb_set_red(r) do { (r)->colour = RB_RED; } while (0)
+#define rb_set_black(r) do { (r)->colour = RB_BLACK; } while (0)
+#define rb_set_colour(r,c) do { (r)->colour = (c); } while (0)
+
struct rb_root
{
struct rb_node *rb_node;