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authorOlof Johansson <olof@lixom.net>2012-09-05 15:35:48 -0700
committerOlof Johansson <olof@lixom.net>2012-09-05 15:35:48 -0700
commit1875962377574b4edb7b164001e3e341c25290d5 (patch)
tree374a5299403ec21e2d9a66a6548ce876a388b589 /include/linux/kref.h
parent5cbee140a28c2746449ae31e85738043ae4da927 (diff)
parentc88a79a7789b2909ad1cf69ea2c9142030bbd6f4 (diff)
downloadolio-linux-3.10-1875962377574b4edb7b164001e3e341c25290d5.tar.xz
olio-linux-3.10-1875962377574b4edb7b164001e3e341c25290d5.zip
Merge branch 'soc-core' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into next/dt
* 'soc-core' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas: ARM: mach-shmobile: Add compilation support for dtbs using 'make dtbs' + sync to 3.6-rc3
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_ */