1 files changed, 22 insertions, 4 deletions

diff --git a/drivers/pci/iova.c b/drivers/pci/iova.c
index 2287116e982..46dd440e231 100644
--- a/drivers/pci/iova.c
+++ b/drivers/pci/iova.c
@@ -1,9 +1,19 @@
 /*
- * Copyright (c) 2006, Intel Corporation.
+ * Copyright © 2006-2009, Intel Corporation.
  *
- * This file is released under the GPLv2.
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
  *
- * Copyright (C) 2006-2008 Intel Corporation
  * Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
  */
 
@@ -123,7 +133,15 @@ move_left:
         /* Insert the new_iova into domain rbtree by holding writer lock */
         /* Add new node and rebalance tree. */
         {
-                struct rb_node **entry = &((prev)), *parent = NULL;
+                struct rb_node **entry, *parent = NULL;
+
+                /* If we have 'prev', it's a valid place to start the
+                   insertion. Otherwise, start from the root. */
+                if (prev)
+                        entry = &prev;
+                else
+                        entry = &iovad->rbroot.rb_node;
+
                 /* Figure out where to put new node */
                 while (*entry) {
                         struct iova *this = container_of(*entry,