| David Howells | 885df91 | 2012-03-28 18:30:03 +0100 | [diff] [blame] | 1 | /* Generic barrier definitions, based on MN10300 definitions. |
| 2 | * |
| 3 | * It should be possible to use these on really simple architectures, |
| 4 | * but it serves more as a starting point for new ports. |
| 5 | * |
| 6 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. |
| 7 | * Written by David Howells (dhowells@redhat.com) |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or |
| 10 | * modify it under the terms of the GNU General Public Licence |
| 11 | * as published by the Free Software Foundation; either version |
| 12 | * 2 of the Licence, or (at your option) any later version. |
| 13 | */ |
| 14 | #ifndef __ASM_GENERIC_BARRIER_H |
| 15 | #define __ASM_GENERIC_BARRIER_H |
| 16 | |
| 17 | #ifndef __ASSEMBLY__ |
| 18 | |
| 19 | #define nop() asm volatile ("nop") |
| 20 | |
| 21 | /* |
| 22 | * Force strict CPU ordering. |
| 23 | * And yes, this is required on UP too when we're talking |
| 24 | * to devices. |
| 25 | * |
| 26 | * This implementation only contains a compiler barrier. |
| 27 | */ |
| 28 | |
| 29 | #define mb() asm volatile ("": : :"memory") |
| 30 | #define rmb() mb() |
| 31 | #define wmb() asm volatile ("": : :"memory") |
| 32 | |
| 33 | #ifdef CONFIG_SMP |
| 34 | #define smp_mb() mb() |
| 35 | #define smp_rmb() rmb() |
| 36 | #define smp_wmb() wmb() |
| 37 | #else |
| 38 | #define smp_mb() barrier() |
| 39 | #define smp_rmb() barrier() |
| 40 | #define smp_wmb() barrier() |
| 41 | #endif |
| 42 | |
| 43 | #define set_mb(var, value) do { var = value; mb(); } while (0) |
| 44 | #define set_wmb(var, value) do { var = value; wmb(); } while (0) |
| 45 | |
| 46 | #define read_barrier_depends() do {} while (0) |
| 47 | #define smp_read_barrier_depends() do {} while (0) |
| 48 | |
| 49 | #endif /* !__ASSEMBLY__ */ |
| 50 | #endif /* __ASM_GENERIC_BARRIER_H */ |