cfg80211: add assert_cfg80211_lock() to ensure proper protection

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/wireless/core.h b/net/wireless/core.h
index f3ab00c..982cc6b 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -10,6 +10,7 @@
 #include <linux/netdevice.h>
 #include <linux/kref.h>
 #include <linux/rbtree.h>
+#include <linux/mutex.h>
 #include <net/genetlink.h>
 #include <net/wireless.h>
 #include <net/cfg80211.h>
@@ -73,6 +74,11 @@
 extern struct mutex cfg80211_mutex;
 extern struct list_head cfg80211_drv_list;
 
+static inline void assert_cfg80211_lock(void)
+{
+	BUG_ON(!mutex_is_locked(&cfg80211_mutex));
+}
+
 struct cfg80211_internal_bss {
 	struct list_head list;
 	struct rb_node rbn;