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/*-
* Copyright (c) 2010 Isilon Systems, Inc.
* Copyright (c) 2010 iX Systems, Inc.
* Copyright (c) 2010 Panasas, Inc.
* Copyright (c) 2013-2015 Mellanox Technologies, Ltd.
* Copyright (c) 2013 François Tigeot
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _LINUX_KREF_H_
#define _LINUX_KREF_H_
#include <sys/types.h>
#include <sys/refcount.h>
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/mutex.h>
#include <asm/atomic.h>
struct kref {
atomic_t refcount;
};
static inline void
kref_init(struct kref *kref)
{
refcount_init(&kref->refcount.counter, 1);
}
static inline void
kref_get(struct kref *kref)
{
refcount_acquire(&kref->refcount.counter);
}
static inline int
kref_put(struct kref *kref, void (*rel)(struct kref *kref))
{
if (refcount_release(&kref->refcount.counter)) {
rel(kref);
return 1;
}
return 0;
}
static inline int
kref_sub(struct kref *kref, unsigned int count,
void (*rel)(struct kref *kref))
{
while (count--) {
if (refcount_release(&kref->refcount.counter)) {
rel(kref);
return 1;
}
}
return 0;
}
static inline int __must_check
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_ */
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