atomic_ops.h revision 132400
1132400Sgrehan/* 2132400Sgrehan * Copyright 2004 by Peter Grehan. All rights reserved. 3132400Sgrehan * 4132400Sgrehan * Redistribution and use in source and binary forms, with or without 5132400Sgrehan * modification, are permitted provided that the following conditions 6132400Sgrehan * are met: 7132400Sgrehan * 1. Redistributions of source code must retain the above copyright 8132400Sgrehan * notice, this list of conditions and the following disclaimer. 9132400Sgrehan * 2. Redistributions in binary form must reproduce the above copyright 10132400Sgrehan * notice, this list of conditions and the following disclaimer in the 11132400Sgrehan * documentation and/or other materials provided with the distribution. 12132400Sgrehan * 3. The name of the author may not be used to endorse or promote products 13132400Sgrehan * derived from this software without specific prior written permission. 14132400Sgrehan * 15132400Sgrehan * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16132400Sgrehan * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17132400Sgrehan * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18132400Sgrehan * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19132400Sgrehan * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 20132400Sgrehan * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 21132400Sgrehan * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 22132400Sgrehan * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 23132400Sgrehan * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24132400Sgrehan * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25132400Sgrehan * SUCH DAMAGE. 26132400Sgrehan * 27132400Sgrehan * $FreeBSD: head/lib/libkse/arch/powerpc/include/atomic_ops.h 132400 2004-07-19 12:19:04Z grehan $ 28132400Sgrehan */ 29132400Sgrehan 30132400Sgrehan#ifndef _ATOMIC_OPS_H_ 31132400Sgrehan#define _ATOMIC_OPS_H_ 32132400Sgrehan 33132400Sgrehan/* 34132400Sgrehan * Atomic swap: 35132400Sgrehan * Atomic (tmp = *dst, *dst = val), then *res = tmp 36132400Sgrehan * 37132400Sgrehan * void atomic_swap32(intptr_t *dst, intptr_t val, intptr_t *res); 38132400Sgrehan */ 39132400Sgrehanstatic inline void 40132400Sgrehanatomic_swap32(intptr_t *dst, intptr_t val, intptr_t *res) 41132400Sgrehan{ 42132400Sgrehan int tmp; 43132400Sgrehan 44132400Sgrehan tmp = 0; /* should be a better way to quieten cc1... */ 45132400Sgrehan#ifdef __GNUC__ 46132400Sgrehan __asm __volatile( 47132400Sgrehan "1: lwarx %0, 0, %4\n" /* load with reservation */ 48132400Sgrehan " stwcx. %3, 0, %4\n" /* attempt to store val */ 49132400Sgrehan " bne- 1b\n" /* interrupted? retry */ 50132400Sgrehan " stw %0, %1\n" /* else, *dst -> *res */ 51132400Sgrehan : "=&r" (tmp), "=m" (*res), "+m" (*dst) 52132400Sgrehan : "r" (val), "r" (dst) 53132400Sgrehan : "cc", "memory"); 54132400Sgrehan#endif 55132400Sgrehan} 56132400Sgrehan 57132400Sgrehan#define atomic_swap_ptr(d, v, r) \ 58132400Sgrehan atomic_swap32((intptr_t *)d, (intptr_t)v, (intptr_t *)r) 59132400Sgrehan 60132400Sgrehan#define atomic_swap_int(d, v, r) \ 61132400Sgrehan atomic_swap32((intptr_t *)d, (intptr_t)v, (intptr_t *)r) 62132400Sgrehan#endif 63