zfs-builds-mm/zfs-2.0.0/module/os/freebsd/spl/spl_atomic.c
2020-12-02 17:25:31 +01:00

123 lines
3 KiB
C

/*
* Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
* 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, 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 AUTHORS AND CONTRIBUTORS ``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 AUTHORS OR CONTRIBUTORS 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/atomic.h>
#if !defined(__LP64__) && !defined(__mips_n32) && \
!defined(ARM_HAVE_ATOMIC64) && !defined(I386_HAVE_ATOMIC64) && \
!defined(HAS_EMULATED_ATOMIC64)
#ifdef _KERNEL
#include <sys/kernel.h>
struct mtx atomic_mtx;
MTX_SYSINIT(atomic, &atomic_mtx, "atomic", MTX_DEF);
#else
#include <pthread.h>
#define mtx_lock(lock) pthread_mutex_lock(lock)
#define mtx_unlock(lock) pthread_mutex_unlock(lock)
static pthread_mutex_t atomic_mtx;
static __attribute__((constructor)) void
atomic_init(void)
{
pthread_mutex_init(&atomic_mtx, NULL);
}
#endif
void
atomic_add_64(volatile uint64_t *target, int64_t delta)
{
mtx_lock(&atomic_mtx);
*target += delta;
mtx_unlock(&atomic_mtx);
}
void
atomic_dec_64(volatile uint64_t *target)
{
mtx_lock(&atomic_mtx);
*target -= 1;
mtx_unlock(&atomic_mtx);
}
uint64_t
atomic_swap_64(volatile uint64_t *a, uint64_t value)
{
uint64_t ret;
mtx_lock(&atomic_mtx);
ret = *a;
*a = value;
mtx_unlock(&atomic_mtx);
return (ret);
}
uint64_t
atomic_load_64(volatile uint64_t *a)
{
uint64_t ret;
mtx_lock(&atomic_mtx);
ret = *a;
mtx_unlock(&atomic_mtx);
return (ret);
}
uint64_t
atomic_add_64_nv(volatile uint64_t *target, int64_t delta)
{
uint64_t newval;
mtx_lock(&atomic_mtx);
newval = (*target += delta);
mtx_unlock(&atomic_mtx);
return (newval);
}
uint64_t
atomic_cas_64(volatile uint64_t *target, uint64_t cmp, uint64_t newval)
{
uint64_t oldval;
mtx_lock(&atomic_mtx);
oldval = *target;
if (oldval == cmp)
*target = newval;
mtx_unlock(&atomic_mtx);
return (oldval);
}
#endif