1/*- 2 * Copyright (c) 2001 Daniel Eischen <deischen@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Neither the name of the author nor the names of its contributors 11 * may be used to endorse or promote products derived from this software 12 * without specific prior written permission. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29#ifndef _ATOMIC_OPS_H_ 30#define _ATOMIC_OPS_H_ 31 32/* 33 * Atomic swap: 34 * Atomic (tmp = *dst, *dst = val), then *res = tmp 35 * 36 * void atomic_swap64(intptr_t *dst, intptr_t val, intptr_t *res); 37 */ 38static inline void 39atomic_swap64(volatile intptr_t *dst, intptr_t val, intptr_t *res) 40{ 41 __asm __volatile( 42 "xchgq %2, %1; movq %2, %0" 43 : "=m" (*res) : "m" (*dst), "r" (val) : "memory"); 44} 45 46static inline void 47atomic_swap_int(volatile int *dst, int val, int *res) 48{ 49 __asm __volatile( 50 "xchgl %2, %1; movl %2, %0" 51 : "=m" (*res) : "m" (*dst), "r" (val) : "memory"); 52} 53 54#define atomic_swap_ptr(d, v, r) \ 55 atomic_swap64((volatile intptr_t *)(d), (intptr_t)(v), (intptr_t *)(r)) 56 57#endif 58