Merge tag 'v3.13-rc1' into asoc-arizona

Linux 3.13-rc1

1 files changed, 12 insertions, 1 deletions

diff --git a/include/linux/lockref.h b/include/linux/lockref.h
index f279ed9a9163..c8929c3832db 100644
--- a/include/linux/lockref.h
+++ b/include/linux/lockref.h
@@ -15,10 +15,15 @@
  */
 
 #include <linux/spinlock.h>
+#include <generated/bounds.h>
+
+#define USE_CMPXCHG_LOCKREF \
+        (IS_ENABLED(CONFIG_ARCH_USE_CMPXCHG_LOCKREF) && \
+         IS_ENABLED(CONFIG_SMP) && !BLOATED_SPINLOCKS)
 
 struct lockref {
         union {
-#ifdef CONFIG_CMPXCHG_LOCKREF
+#if USE_CMPXCHG_LOCKREF
                 aligned_u64 lock_count;
 #endif
                 struct {
@@ -36,4 +41,10 @@ extern int lockref_put_or_lock(struct lockref *);
 extern void lockref_mark_dead(struct lockref *);
 extern int lockref_get_not_dead(struct lockref *);
 
+/* Must be called under spinlock for reliable results */
+static inline int __lockref_is_dead(const struct lockref *l)
+{
+        return ((int)l->count < 0);
+}
+
 #endif /* __LINUX_LOCKREF_H */