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authorMark Brown <broonie@opensource.wolfsonmicro.com>2012-09-05 13:04:34 +0800
committerMark Brown <broonie@opensource.wolfsonmicro.com>2012-09-05 13:04:34 +0800
commitfc600432cd23e35c85de2ff4468d816d6938a112 (patch)
treec191c51e4458ec31c1d8254f01e23b2e1574b6f4 /include/linux/kref.h
parentdb61550931957ee6c7dba751662919424b4344f3 (diff)
parent4cbe5a555fa58a79b6ecbb6c531b8bab0650778d (diff)
Merge tag 'v3.6-rc4' into asoc-omap
Linux 3.6-rc4
Diffstat (limited to 'include/linux/kref.h')
-rw-r--r--include/linux/kref.h18
1 files changed, 18 insertions, 0 deletions
diff --git a/include/linux/kref.h b/include/linux/kref.h
index 9c07dcebded..65af6887872 100644
--- a/include/linux/kref.h
+++ b/include/linux/kref.h
@@ -18,6 +18,7 @@
#include <linux/bug.h>
#include <linux/atomic.h>
#include <linux/kernel.h>
+#include <linux/mutex.h>
struct kref {
atomic_t refcount;
@@ -93,4 +94,21 @@ static inline int kref_put(struct kref *kref, void (*release)(struct kref *kref)
{
return kref_sub(kref, 1, release);
}
+
+static inline int kref_put_mutex(struct kref *kref,
+ void (*release)(struct kref *kref),
+ struct mutex *lock)
+{
+ WARN_ON(release == NULL);
+ if (unlikely(!atomic_add_unless(&kref->refcount, -1, 1))) {
+ mutex_lock(lock);
+ if (unlikely(!atomic_dec_and_test(&kref->refcount))) {
+ mutex_unlock(lock);
+ return 0;
+ }
+ release(kref);
+ return 1;
+ }
+ return 0;
+}
#endif /* _KREF_H_ */