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authorGunnar Larisch <gl@denx.de>2008-02-07 00:16:22 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-07 08:42:32 -0800
commit85fdbe1b4b33b797321bfadf706b355e7cca6165 (patch)
treebb24d49bb9cc2167742af843718587b408ad71e2
parentdf80c8c5679c4e6c72e694525d76a9f26d5f33dc (diff)
Add cmpxchg_local to ppc
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. Signed-off-by: Gunnar Larisch <gl@denx.de> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Kumar Gala <galak@gate.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/asm-ppc/system.h51
1 files changed, 49 insertions, 2 deletions
diff --git a/include/asm-ppc/system.h b/include/asm-ppc/system.h
index 51df94c73846..0593cb889d45 100644
--- a/include/asm-ppc/system.h
+++ b/include/asm-ppc/system.h
@@ -209,12 +209,34 @@ __cmpxchg_u32(volatile unsigned int *p, unsigned int old, unsigned int new)
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:
@@ -228,7 +250,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
return old;
}
-#define cmpxchg(ptr,o,n) \
+#define cmpxchg(ptr, o, n) \
({ \
__typeof__(*(ptr)) _o_ = (o); \
__typeof__(*(ptr)) _n_ = (n); \
@@ -236,6 +258,31 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
(unsigned long)_n_, sizeof(*(ptr))); \
})
+#include <asm-generic/cmpxchg-local.h>
+
+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__ */