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/*-
* Copyright (c) 2010 Isilon Systems, Inc.
* Copyright (c) 2010 iX Systems, Inc.
* Copyright (c) 2010 Panasas, Inc.
* Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
* 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 _ASM_ATOMIC_H_
#define _ASM_ATOMIC_H_
#include <sys/cdefs.h>
#include <sys/types.h>
#include <machine/atomic.h>
typedef struct {
volatile u_int counter;
} atomic_t;
#define ATOMIC_INIT(v) { (v) }
#define atomic_add(i, v) atomic_add_return((i), (v))
#define atomic_sub(i, v) atomic_sub_return((i), (v))
#define atomic_inc_return(v) atomic_add_return(1, (v))
#define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0)
#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
#define atomic_dec_return(v) atomic_sub_return(1, (v))
static inline int
atomic_add_return(int i, atomic_t *v)
{
return i + atomic_fetchadd_int(&v->counter, i);
}
static inline int
atomic_sub_return(int i, atomic_t *v)
{
return atomic_fetchadd_int(&v->counter, -i) - i;
}
static inline void
atomic_set(atomic_t *v, int i)
{
atomic_store_rel_int(&v->counter, i);
}
static inline int
atomic_read(atomic_t *v)
{
return atomic_load_acq_int(&v->counter);
}
static inline int
atomic_inc(atomic_t *v)
{
return atomic_fetchadd_int(&v->counter, 1) + 1;
}
static inline int
atomic_dec(atomic_t *v)
{
return atomic_fetchadd_int(&v->counter, -1) - 1;
}
static inline int atomic_add_unless(atomic_t *v, int a, int u)
{
int c, old;
c = atomic_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic_cmpset_int(&v->counter, c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c != (u);
}
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
#endif /* _ASM_ATOMIC_H_ */
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