From 9623b3732d11b0a18d9af3419f680d27ea24b014 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Wed, 28 Feb 2007 12:30:38 +0100 Subject: [PATCH] [ARM] 4241/1: Define mb() as compiler barrier on a uniprocessor system Currently, the mb() is defined as a DMB operation on ARMv6, even for UP systems. This patch defines mb() as a compiler barrier only. For the SMP case, the smp_* variants should be used anyway and the patch defines them as DMB. Signed-off-by: Catalin Marinas Signed-off-by: Russell King --- include/asm-arm/system.h | 40 +++++++++++++++++++--------------------- 1 file changed, 19 insertions(+), 21 deletions(-) diff --git a/include/asm-arm/system.h b/include/asm-arm/system.h index f4386906b2..f06d8a43fd 100644 --- a/include/asm-arm/system.h +++ b/include/asm-arm/system.h @@ -167,11 +167,25 @@ extern unsigned int user_debug; : : "r" (0) : "memory") #define dmb() __asm__ __volatile__ ("" : : : "memory") #endif -#define mb() dmb() -#define rmb() mb() -#define wmb() mb() -#define read_barrier_depends() do { } while(0) -#define set_mb(var, value) do { var = value; mb(); } while (0) + +#define mb() barrier() +#define rmb() barrier() +#define wmb() barrier() +#define read_barrier_depends() do { } while(0) + +#ifdef CONFIG_SMP +#define smp_mb() dmb() +#define smp_rmb() dmb() +#define smp_wmb() dmb() +#define smp_read_barrier_depends() read_barrier_depends() +#else +#define smp_mb() barrier() +#define smp_rmb() barrier() +#define smp_wmb() barrier() +#define smp_read_barrier_depends() read_barrier_depends() +#endif /* CONFIG_SMP */ + +#define set_mb(var, value) do { var = value; smp_mb(); } while (0) #define nop() __asm__ __volatile__("mov\tr0,r0\t@ nop\n\t"); extern unsigned long cr_no_alignment; /* defined in entry-armv.S */ @@ -243,22 +257,6 @@ static inline void sched_cacheflush(void) { } -#ifdef CONFIG_SMP - -#define smp_mb() mb() -#define smp_rmb() rmb() -#define smp_wmb() wmb() -#define smp_read_barrier_depends() read_barrier_depends() - -#else - -#define smp_mb() barrier() -#define smp_rmb() barrier() -#define smp_wmb() barrier() -#define smp_read_barrier_depends() do { } while(0) - -#endif /* CONFIG_SMP */ - #if defined(CONFIG_CPU_SA1100) || defined(CONFIG_CPU_SA110) /* * On the StrongARM, "swp" is terminally broken since it bypasses the -- 2.39.5