xref: /src/sys/external/bsd/common/include/linux/compiler.h

/*	$NetBSD: compiler.h,v 1.3 2021/12/19 01:24:36 riastradh Exp $	*/

/*-
 * Copyright (c) 2018 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	_LINUX_COMPILER_H_
#define	_LINUX_COMPILER_H_

#include <sys/atomic.h>

#include <asm/barrier.h>

#define	READ_ONCE(X)	({						      \
	typeof(X) __read_once_tmp = (X);				      \
	membar_datadep_consumer();					      \
	__read_once_tmp;						      \
})

#define	WRITE_ONCE(X, V)	({					      \
	typeof(X) __write_once_tmp = (V);				      \
	(X) = __write_once_tmp;						      \
	__write_once_tmp;						      \
})

#define	smp_store_mb(X, V)	do {					      \
	WRITE_ONCE(X, V);						      \
	smp_mb();							      \
} while (0)

#define	smp_store_release(X, V)	do {					      \
	typeof(X) __smp_store_release_tmp = (V);			      \
	membar_exit();							      \
	(X) = __write_once_tmp;						      \
} while (0)

#endif	/* _LINUX_COMPILER_H_ */