1*7f2d47d8SEvgeniy Ivanov /* $NetBSD: rwlock.h,v 1.5 2008/04/28 20:23:40 martin Exp $ */ 2*7f2d47d8SEvgeniy Ivanov 3*7f2d47d8SEvgeniy Ivanov /*- 4*7f2d47d8SEvgeniy Ivanov * Copyright (c) 2002, 2006 The NetBSD Foundation, Inc. 5*7f2d47d8SEvgeniy Ivanov * All rights reserved. 6*7f2d47d8SEvgeniy Ivanov * 7*7f2d47d8SEvgeniy Ivanov * This code is derived from software contributed to The NetBSD Foundation 8*7f2d47d8SEvgeniy Ivanov * by Jason R. Thorpe and Andrew Doran. 9*7f2d47d8SEvgeniy Ivanov * 10*7f2d47d8SEvgeniy Ivanov * Redistribution and use in source and binary forms, with or without 11*7f2d47d8SEvgeniy Ivanov * modification, are permitted provided that the following conditions 12*7f2d47d8SEvgeniy Ivanov * are met: 13*7f2d47d8SEvgeniy Ivanov * 1. Redistributions of source code must retain the above copyright 14*7f2d47d8SEvgeniy Ivanov * notice, this list of conditions and the following disclaimer. 15*7f2d47d8SEvgeniy Ivanov * 2. Redistributions in binary form must reproduce the above copyright 16*7f2d47d8SEvgeniy Ivanov * notice, this list of conditions and the following disclaimer in the 17*7f2d47d8SEvgeniy Ivanov * documentation and/or other materials provided with the distribution. 18*7f2d47d8SEvgeniy Ivanov * 19*7f2d47d8SEvgeniy Ivanov * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20*7f2d47d8SEvgeniy Ivanov * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21*7f2d47d8SEvgeniy Ivanov * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22*7f2d47d8SEvgeniy Ivanov * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23*7f2d47d8SEvgeniy Ivanov * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24*7f2d47d8SEvgeniy Ivanov * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25*7f2d47d8SEvgeniy Ivanov * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26*7f2d47d8SEvgeniy Ivanov * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27*7f2d47d8SEvgeniy Ivanov * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28*7f2d47d8SEvgeniy Ivanov * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29*7f2d47d8SEvgeniy Ivanov * POSSIBILITY OF SUCH DAMAGE. 30*7f2d47d8SEvgeniy Ivanov */ 31*7f2d47d8SEvgeniy Ivanov 32*7f2d47d8SEvgeniy Ivanov #ifndef _X86_RWLOCK_H_ 33*7f2d47d8SEvgeniy Ivanov #define _X86_RWLOCK_H_ 34*7f2d47d8SEvgeniy Ivanov 35*7f2d47d8SEvgeniy Ivanov struct krwlock { 36*7f2d47d8SEvgeniy Ivanov volatile uintptr_t rw_owner; 37*7f2d47d8SEvgeniy Ivanov }; 38*7f2d47d8SEvgeniy Ivanov 39*7f2d47d8SEvgeniy Ivanov #ifdef __RWLOCK_PRIVATE 40*7f2d47d8SEvgeniy Ivanov 41*7f2d47d8SEvgeniy Ivanov #define __HAVE_SIMPLE_RW_LOCKS 1 42*7f2d47d8SEvgeniy Ivanov #define __HAVE_RW_STUBS 1 43*7f2d47d8SEvgeniy Ivanov 44*7f2d47d8SEvgeniy Ivanov /* 45*7f2d47d8SEvgeniy Ivanov * RW_RECEIVE: no memory barrier required, as 'ret' implies a load fence. 46*7f2d47d8SEvgeniy Ivanov */ 47*7f2d47d8SEvgeniy Ivanov #define RW_RECEIVE(rw) /* nothing */ 48*7f2d47d8SEvgeniy Ivanov 49*7f2d47d8SEvgeniy Ivanov /* 50*7f2d47d8SEvgeniy Ivanov * RW_GIVE: no memory barrier required, as _lock_cas() will take care of it. 51*7f2d47d8SEvgeniy Ivanov */ 52*7f2d47d8SEvgeniy Ivanov #define RW_GIVE(rw) /* nothing */ 53*7f2d47d8SEvgeniy Ivanov 54*7f2d47d8SEvgeniy Ivanov #define RW_CAS(p, o, n) \ 55*7f2d47d8SEvgeniy Ivanov (_atomic_cas_ulong((volatile unsigned long *)(p), (o), (n)) == (o)) 56*7f2d47d8SEvgeniy Ivanov 57*7f2d47d8SEvgeniy Ivanov unsigned long _atomic_cas_ulong(volatile unsigned long *, 58*7f2d47d8SEvgeniy Ivanov unsigned long, unsigned long); 59*7f2d47d8SEvgeniy Ivanov 60*7f2d47d8SEvgeniy Ivanov #endif /* __RWLOCK_PRIVATE */ 61*7f2d47d8SEvgeniy Ivanov 62*7f2d47d8SEvgeniy Ivanov #endif /* _X86_RWLOCK_H_ */ 63