Add a local processor version of cmpxchg for ppc. Implements __cmpxchg_u32_local and uses it for 32 bits cmpxchg_local. It uses the non NMI safe cmpxchg_local_generic for 1, 2 and 8 bytes cmpxchg_local. From: Gunnar Larisch From: Mathieu Desnoyers Signed-off-by: Gunnar Larisch Signed-off-by: Mathieu Desnoyers CC: clameter@sgi.com CC: benh@kernel.crashing.org --- include/asm-ppc/system.h | 49 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 48 insertions(+), 1 deletion(-) Index: linux-2.6-lttng/include/asm-ppc/system.h =================================================================== --- linux-2.6-lttng.orig/include/asm-ppc/system.h 2007-08-07 14:31:51.000000000 -0400 +++ linux-2.6-lttng/include/asm-ppc/system.h 2007-08-07 15:03:51.000000000 -0400 @@ -208,12 +208,34 @@ __cmpxchg_u32(volatile unsigned int *p, return prev; } +static __inline__ unsigned long +__cmpxchg_u32_local(volatile unsigned int *p, unsigned int old, + unsigned int new) +{ + unsigned int prev; + + __asm__ __volatile__ ("\n\ +1: lwarx %0,0,%2 \n\ + cmpw 0,%0,%3 \n\ + bne 2f \n" + PPC405_ERR77(0,%2) +" stwcx. %4,0,%2 \n\ + bne- 1b\n" +"2:" + : "=&r" (prev), "=m" (*p) + : "r" (p), "r" (old), "r" (new), "m" (*p) + : "cc", "memory"); + + return prev; +} + /* This function doesn't exist, so you'll get a linker error if something tries to do an invalid cmpxchg(). */ extern void __cmpxchg_called_with_bad_pointer(void); static __inline__ unsigned long -__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size) +__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, + unsigned int size) { switch (size) { case 4: @@ -235,6 +257,31 @@ __cmpxchg(volatile void *ptr, unsigned l (unsigned long)_n_, sizeof(*(ptr))); \ }) +#include + +static inline unsigned long __cmpxchg_local(volatile void *ptr, + unsigned long old, + unsigned long new, int size) +{ + switch (size) { + case 4: + return __cmpxchg_u32_local(ptr, old, new); + default: + return __cmpxchg_local_generic(ptr, old, new, size); + } + + return old; +} + +/* + * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make + * them available. + */ +#define cmpxchg_local(ptr,o,n) \ + (__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \ + (unsigned long)(n), sizeof(*(ptr))) +#define cmpxchg64_local(ptr,o,n) __cmpxchg64_local_generic((ptr), (o), (n)) + #define arch_align_stack(x) (x) #endif /* __KERNEL__ */ -- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/