From 10b8827068377a11ed0e396248f7d02751fe5f17 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Thu, 7 Feb 2008 00:16:13 -0800 Subject: Add cmpxchg_local to blackfin, replace __cmpxchg by generic cmpxchg Use the new generic cmpxchg_local (disables interrupt). Also use the generic cmpxchg as fallback if SMP is not set since nobody seems to know why __cmpxchg has been implemented in assembly in the first place thather than in plain C. Signed-off-by: Mathieu Desnoyers Cc: Bryan Wu Cc: Michael Frysinger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-blackfin/system.h | 57 +++++++++---------------------------------- 1 file changed, 11 insertions(+), 46 deletions(-) (limited to 'include') diff --git a/include/asm-blackfin/system.h b/include/asm-blackfin/system.h index 4a927379ee1c..51494ef5bb41 100644 --- a/include/asm-blackfin/system.h +++ b/include/asm-blackfin/system.h @@ -183,55 +183,20 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, return tmp; } +#include + /* - * Atomic compare and exchange. Compare OLD with MEM, if identical, - * store NEW in MEM. Return the initial value in MEM. Success is - * indicated by comparing RETURN with OLD. + * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make + * them available. */ -static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, - unsigned long new, int size) -{ - unsigned long tmp = 0; - unsigned long flags = 0; - - local_irq_save(flags); - - switch (size) { - case 1: - __asm__ __volatile__ - ("%0 = b%3 (z);\n\t" - "CC = %1 == %0;\n\t" - "IF !CC JUMP 1f;\n\t" - "b%3 = %2;\n\t" - "1:\n\t" - : "=&d" (tmp) : "d" (old), "d" (new), "m" (*__xg(ptr)) : "memory"); - break; - case 2: - __asm__ __volatile__ - ("%0 = w%3 (z);\n\t" - "CC = %1 == %0;\n\t" - "IF !CC JUMP 1f;\n\t" - "w%3 = %2;\n\t" - "1:\n\t" - : "=&d" (tmp) : "d" (old), "d" (new), "m" (*__xg(ptr)) : "memory"); - break; - case 4: - __asm__ __volatile__ - ("%0 = %3;\n\t" - "CC = %1 == %0;\n\t" - "IF !CC JUMP 1f;\n\t" - "%3 = %2;\n\t" - "1:\n\t" - : "=&d" (tmp) : "d" (old), "d" (new), "m" (*__xg(ptr)) : "memory"); - break; - } - local_irq_restore(flags); - return tmp; -} +#define cmpxchg_local(ptr, o, n) \ + ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\ + (unsigned long)(n), sizeof(*(ptr)))) +#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) -#define cmpxchg(ptr,o,n)\ - ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\ - (unsigned long)(n),sizeof(*(ptr)))) +#ifndef CONFIG_SMP +#include +#endif #define prepare_to_switch() do { } while(0) -- cgit v1.2.3