| /* 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 */ |