2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013-2015 Mellanox Technologies, Ltd.
6 * Copyright (c) 2013 François Tigeot
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice unmodified, this list of conditions, and the following
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 #ifndef _LINUX_KREF_H_
33 #define _LINUX_KREF_H_
35 #include <sys/types.h>
36 #include <sys/refcount.h>
38 #include <linux/compiler.h>
39 #include <linux/kernel.h>
40 #include <linux/mutex.h>
42 #include <asm/atomic.h>
49 kref_init(struct kref *kref)
52 refcount_init(&kref->refcount.counter, 1);
56 kref_get(struct kref *kref)
59 refcount_acquire(&kref->refcount.counter);
63 kref_put(struct kref *kref, void (*rel)(struct kref *kref))
66 if (refcount_release(&kref->refcount.counter)) {
74 kref_sub(struct kref *kref, unsigned int count,
75 void (*rel)(struct kref *kref))
79 if (refcount_release(&kref->refcount.counter)) {
87 static inline int __must_check
88 kref_get_unless_zero(struct kref *kref)
91 return atomic_add_unless(&kref->refcount, 1, 0);
94 static inline int kref_put_mutex(struct kref *kref,
95 void (*release)(struct kref *kref), struct mutex *lock)
97 WARN_ON(release == NULL);
98 if (unlikely(!atomic_add_unless(&kref->refcount, -1, 1))) {
100 if (unlikely(!atomic_dec_and_test(&kref->refcount))) {
110 #endif /* _LINUX_KREF_H_ */