freebsd-dev/lib/libkse/arch/arm/include/atomic_ops.h
2004-05-14 12:21:29 +00:00

52 lines
1.9 KiB
C

/*-
* Copyright (c) 2001 Daniel Eischen <deischen@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. Neither the name of the author nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#ifndef _ATOMIC_OPS_H_
#define _ATOMIC_OPS_H_
/*
* Atomic swap:
* Atomic (tmp = *dst, *dst = val), then *res = tmp
*
* void atomic_swap32(intptr_t *dst, intptr_t val, intptr_t *res);
*/
static inline void
atomic_swap32(intptr_t *dst, intptr_t val, intptr_t *res)
{
__asm __volatile(
"swp %2, %2, [%1]; mov %2, %0"
: "=r" (*res) : "r" (dst), "r" (val) : "cc");
}
#define atomic_swap_ptr(d, v, r) \
atomic_swap32((intptr_t *)d, (intptr_t)v, (intptr_t *)r)
#define atomic_swap_int(d, v, r) \
atomic_swap32((intptr_t *)d, (intptr_t)v, (intptr_t *)r)
#endif