From 053a7b5b7617a72d7c61b6f84196d1c0f79b9849 Mon Sep 17 00:00:00 2001 From: Russell King Date: Tue, 28 Jun 2005 19:22:25 +0100 Subject: [PATCH] [PATCH] ARM SMP: __xchg support This enables the existing __xchg implementation to be used on SMP. Signed-off-by: Russell King --- include/asm-arm/system.h | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/include/asm-arm/system.h b/include/asm-arm/system.h index 3d0d2860b6db..cdf49f442fd2 100644 --- a/include/asm-arm/system.h +++ b/include/asm-arm/system.h @@ -290,7 +290,6 @@ do { \ }) #ifdef CONFIG_SMP -#error SMP not supported #define smp_mb() mb() #define smp_rmb() rmb() @@ -304,6 +303,8 @@ do { \ #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 @@ -316,9 +317,16 @@ do { \ * * We choose (1) since its the "easiest" to achieve here and is not * dependent on the processor type. + * + * NOTE that this solution won't work on an SMP system, so explcitly + * forbid it here. */ +#ifdef CONFIG_SMP +#error SMP is not supported on SA1100/SA110 +#else #define swp_is_buggy #endif +#endif static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size) { @@ -361,8 +369,6 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size return ret; } -#endif /* CONFIG_SMP */ - #endif /* __ASSEMBLY__ */ #define arch_align_stack(x) (x) -- 2.20.1