1103840Sjulian/*- 2103840Sjulian * Copyright (c) 2002 David Xu (davidxu@freebsd.org). 3103840Sjulian * All rights reserved. 4103840Sjulian * 5103840Sjulian * Redistribution and use in source and binary forms, with or without 6103840Sjulian * modification, are permitted provided that the following conditions 7103840Sjulian * are met: 8103840Sjulian * 1. Redistributions of source code must retain the above copyright 9103840Sjulian * notice, this list of conditions and the following disclaimer. 10103840Sjulian * 2. Redistributions in binary form must reproduce the above copyright 11103840Sjulian * notice, this list of conditions and the following disclaimer in the 12103840Sjulian * documentation and/or other materials provided with the distribution. 13103840Sjulian * 14103840Sjulian * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15103840Sjulian * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16103840Sjulian * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17103840Sjulian * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18103840Sjulian * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19103840Sjulian * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20103840Sjulian * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21103840Sjulian * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22103840Sjulian * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23103840Sjulian * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24103840Sjulian * SUCH DAMAGE. 25103840Sjulian * 26103840Sjulian * $FreeBSD$ 27103840Sjulian */ 28103840Sjulian 29103840Sjulian#ifndef _SIMPLELOCK_H 30103840Sjulian#define _SIMPLELOCK_H 31103840Sjulian 32103840Sjulian#include <machine/asmacros.h> 33103840Sjulian#include <machine/atomic.h> 34103840Sjulian 35103840Sjulianstruct simplelock { 36103840Sjulian int s_lock; 37103840Sjulian}; 38103840Sjulian 39103840Sjulianstatic inline void 40103840Sjuliansimplelock_init(struct simplelock *lock) 41103840Sjulian{ 42103840Sjulian lock->s_lock = 0; 43103840Sjulian} 44103840Sjulian 45103840Sjulianstatic inline void 46103840Sjuliansimplelock_lock(struct simplelock *lock) 47103840Sjulian{ 48106336Sdavidxu while (!atomic_cmpset_int(&lock->s_lock, 0, 1)) 49103840Sjulian ; 50103840Sjulian} 51103840Sjulian 52110535Sdavidxustatic inline void 53110535Sdavidxusimplelock_unlock(struct simplelock *lock) 54103840Sjulian{ 55103840Sjulian atomic_store_rel_int(&lock->s_lock, 0); 56103840Sjulian} 57103840Sjulian 58103840Sjulian#endif 59103840Sjulian 60