/* $NetBSD: barrier.h,v 1.4 2018/08/28 15:04:58 riastradh Exp $ */ /*- * Copyright (c) 2013 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Taylor R. Campbell. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #ifndef _ASM_BARRIER_H_ #define _ASM_BARRIER_H_ #include <sys/atomic.h> #ifdef _KERNEL_OPT #include "opt_multiprocessor.h" #else #define MULTIPROCESSOR 1 /* safer to assume multiprocessor */ #endif #define mb membar_sync #define wmb membar_producer #define rmb membar_consumer #ifdef __alpha__ /* XXX As if... */ # define read_barrier_depends membar_sync #else # define read_barrier_depends() do {} while (0) #endif #ifdef MULTIPROCESSOR # define smp_mb mb # define smp_wmb wmb # define smp_rmb rmb # define smp_read_barrier_depends read_barrier_depends #else # define smp_mb() do {} while (0) # define smp_wmb() do {} while (0) # define smp_rmb() do {} while (0) # define smp_read_barrier_depends() do {} while (0) #endif #endif /* _ASM_BARRIER_H_ */ |