/* 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 */