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Diffstat (limited to 'include/asm-generic/barrier.h')
| -rw-r--r-- | include/asm-generic/barrier.h | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h new file mode 100644 index 000000000000..639d7a4d033b --- /dev/null +++ b/include/asm-generic/barrier.h @@ -0,0 +1,50 @@ +/* Generic barrier definitions, based on MN10300 definitions. + * + * It should be possible to use these on really simple architectures, + * but it serves more as a starting point for new ports. + * + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#ifndef __ASM_GENERIC_BARRIER_H +#define __ASM_GENERIC_BARRIER_H + +#ifndef __ASSEMBLY__ + +#define nop() asm volatile ("nop") + +/* + * Force strict CPU ordering. + * And yes, this is required on UP too when we're talking + * to devices. + * + * This implementation only contains a compiler barrier. + */ + +#define mb() asm volatile ("": : :"memory") +#define rmb() mb() +#define wmb() asm volatile ("": : :"memory") + +#ifdef CONFIG_SMP +#define smp_mb() mb() +#define smp_rmb() rmb() +#define smp_wmb() wmb() +#else +#define smp_mb() barrier() +#define smp_rmb() barrier() +#define smp_wmb() barrier() +#endif + +#define set_mb(var, value) do { var = value; mb(); } while (0) +#define set_wmb(var, value) do { var = value; wmb(); } while (0) + +#define read_barrier_depends() do {} while (0) +#define smp_read_barrier_depends() do {} while (0) + +#endif /* !__ASSEMBLY__ */ +#endif /* __ASM_GENERIC_BARRIER_H */ |