svn commit: r300497 - head/sys/compat/linuxkpi/common/include/linux

[Hans Petter Selasky]

Author: hselasky
Date: Mon May 23 12:06:34 2016
New Revision: 300497
URL: https://svnweb.freebsd.org/changeset/base/300497

Log:
  Implement "kref_put_mutex()" for the LinuxKPI.
  
  Obtained from:	kmacy @
  MFC after:	1 week
  Sponsored by:	Mellanox Technologies

Modified:
  head/sys/compat/linuxkpi/common/include/linux/kref.h

Modified: head/sys/compat/linuxkpi/common/include/linux/kref.h
==============================================================================
--- head/sys/compat/linuxkpi/common/include/linux/kref.h	Mon May 23 12:03:40 2016	(r300496)
+++ head/sys/compat/linuxkpi/common/include/linux/kref.h	Mon May 23 12:06:34 2016	(r300497)
@@ -36,6 +36,9 @@
 #include <sys/refcount.h>
 
 #include <linux/compiler.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+
 #include <asm/atomic.h>
 
 struct kref {
@@ -88,4 +91,20 @@ kref_get_unless_zero(struct kref *kref)
 	return atomic_add_unless(&kref->refcount, 1, 0);
 }
 
+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 /* _LINUX_KREF_H_ */