From: Jack Leigh <jack.leigh@collabora.com>
Date: Thu, 2 Oct 2014 12:22:58 +0100
Subject: Import interval_tree for i915_gem_userptr.c

---
 drivers/gpu/drm/i915/i915_gem_userptr.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
index 5d9a801..5b14b7e 100644
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -36,6 +36,15 @@
 
 #if defined(CONFIG_MMU_NOTIFIER)
 #include <linux/interval_tree.h>
+#include <linux/interval_tree_generic.h>
+
+/* from lib/interval_tree.c */
+#define START(node) ((node)->start)
+#define LAST(node)  ((node)->last)
+
+INTERVAL_TREE_DEFINE(struct interval_tree_node, rb,
+		     unsigned long, __subtree_last,
+		     START, LAST,, interval_tree)
 
 struct i915_mmu_notifier {
 	spinlock_t lock;
