freebsd-dev/lib/libkse/arch/amd64/include/atomic_ops.h
Daniel Eischen 850108c0b4 Don't assume sizeof(long) = sizeof(int) on x86; use int
instead of long types for low-level locks.

Add prototypes for some internal libc functions that are
wrapped by the library as cancellation points.

Add memory barriers to alpha atomic swap functions (submitted
by davidxu).

Requested by:	bde
2003-09-03 17:56:26 +00:00

58 lines
2.0 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_swap64(intptr_t *dst, intptr_t val, intptr_t *res);
*/
static inline void
atomic_swap64(intptr_t *dst, intptr_t val, intptr_t *res)
{
__asm __volatile(
"xchgq %2, %1; movq %2, %0"
: "=m" (*res) : "m" (*dst), "r" (val) : "memory");
}
static inline void
atomic_swap_int(int *dst, int val, int *res)
{
__asm __volatile(
"xchgl %2, %1; movl %2, %0"
: "=m" (*res) : "m" (*dst), "r" (val) : "memory");
}
#define atomic_swap_ptr(d, v, r) \
atomic_swap64((intptr_t *)(d), (intptr_t)(v), (intptr_t *)(r))
#endif