1*71ee315fSriastradh /* $NetBSD: compiler.h,v 1.2 2021/12/19 00:48:23 riastradh Exp $ */ 2704dac09Sriastradh 3704dac09Sriastradh /*- 4704dac09Sriastradh * Copyright (c) 2018 The NetBSD Foundation, Inc. 5704dac09Sriastradh * All rights reserved. 6704dac09Sriastradh * 7704dac09Sriastradh * This code is derived from software contributed to The NetBSD Foundation 8704dac09Sriastradh * by Taylor R. Campbell. 9704dac09Sriastradh * 10704dac09Sriastradh * Redistribution and use in source and binary forms, with or without 11704dac09Sriastradh * modification, are permitted provided that the following conditions 12704dac09Sriastradh * are met: 13704dac09Sriastradh * 1. Redistributions of source code must retain the above copyright 14704dac09Sriastradh * notice, this list of conditions and the following disclaimer. 15704dac09Sriastradh * 2. Redistributions in binary form must reproduce the above copyright 16704dac09Sriastradh * notice, this list of conditions and the following disclaimer in the 17704dac09Sriastradh * documentation and/or other materials provided with the distribution. 18704dac09Sriastradh * 19704dac09Sriastradh * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20704dac09Sriastradh * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21704dac09Sriastradh * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22704dac09Sriastradh * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23704dac09Sriastradh * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24704dac09Sriastradh * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25704dac09Sriastradh * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26704dac09Sriastradh * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27704dac09Sriastradh * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28704dac09Sriastradh * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29704dac09Sriastradh * POSSIBILITY OF SUCH DAMAGE. 30704dac09Sriastradh */ 31704dac09Sriastradh 32704dac09Sriastradh #ifndef _LINUX_COMPILER_H_ 33704dac09Sriastradh #define _LINUX_COMPILER_H_ 34704dac09Sriastradh 35*71ee315fSriastradh #include <sys/atomic.h> 36*71ee315fSriastradh 37*71ee315fSriastradh #define READ_ONCE(X) ({ \ 38*71ee315fSriastradh typeof(X) __read_once_tmp = (X); \ 39*71ee315fSriastradh membar_datadep_consumer(); \ 40*71ee315fSriastradh __read_once_tmp; \ 41*71ee315fSriastradh }) 42*71ee315fSriastradh 43*71ee315fSriastradh #define WRITE_ONCE(X, V) ({ \ 44*71ee315fSriastradh typeof(X) __write_once_tmp = (V); \ 45*71ee315fSriastradh (X) = __write_once_tmp; \ 46*71ee315fSriastradh __write_once_tmp; \ 47*71ee315fSriastradh }) 48*71ee315fSriastradh 49704dac09Sriastradh #endif /* _LINUX_COMPILER_H_ */ 50