barrier.h

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/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2001  Hiroyuki Kondo, Hirokazu Takata, and Hitoshi Yamamoto
 * Copyright (C) 2004, 2006  Hirokazu Takata <takata at linux-m32r.org>
 */
#ifndef _ASM_M32R_BARRIER_H
#define _ASM_M32R_BARRIER_H

#define nop()  __asm__ __volatile__ ("nop" : : )

/*
 * Memory barrier.
 *
 * mb() prevents loads and stores being reordered across this point.
 * rmb() prevents loads being reordered across this point.
 * wmb() prevents stores being reordered across this point.
 */
#define mb()   barrier()
#define rmb()  mb()
#define wmb()  mb()

#define read_barrier_depends()  do { } while (0)

#ifdef CONFIG_SMP
#define smp_mb()    mb()
#define smp_rmb()   rmb()
#define smp_wmb()   wmb()
#define smp_read_barrier_depends()  read_barrier_depends()
#define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
#else
#define smp_mb()    barrier()
#define smp_rmb()   barrier()
#define smp_wmb()   barrier()
#define smp_read_barrier_depends()  do { } while (0)
#define set_mb(var, value) do { var = value; barrier(); } while (0)
#endif

#endif /* _ASM_M32R_BARRIER_H */