[patch 23/28] Add cmpxchg_local to sh, use generic cmpxchg() instead of cmpxchg_u32

Mathieu Desnoyers
2007-10-31T22:47:17Z

[-- Attachment #1: add-cmpxchg-local-to-sh.patch --]
[-- Type: text/plain, Size: 2785 bytes --]

Use the new generic cmpxchg_local (disables interrupt). Also use the generic
cmpxchg as fallback if SMP is not set.

Since cmpxchg_u32 is _exactly_ the cmpxchg_local generic implementation, remove
it and use the generic version instead.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: clameter@sgi.com
CC: lethal@linux-sh.org
---
include/asm-sh/system.h | 52 ++++++++++++------------------------------------
1 file changed, 14 insertions(+), 38 deletions(-)

Index: linux-2.6-lttng/include/asm-sh/system.h
===================================================================
--- linux-2.6-lttng.orig/include/asm-sh/system.h 2007-10-31 17:32:43.000000000 -0400
+++ linux-2.6-lttng/include/asm-sh/system.h 2007-10-31 18:27:24.000000000 -0400
@@ -199,47 +199,23 @@ extern void __xchg_called_with_bad_point
__xchg__res; \
})

-#define xchg(ptr,x) \
- ((__typeof__(*(ptr)))__xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
+#define xchg(ptr, x) \
+ ((__typeof__(*(ptr)))__xchg((ptr), (unsigned long)(x), sizeof(*(ptr))))

-static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old,
- unsigned long new)
-{
- __u32 retval;
- unsigned long flags;
-
- local_irq_save(flags);
- retval = *m;
- if (retval == old)
- *m = new;
- local_irq_restore(flags); /* implies memory barrier */
- return retval;
-}
-
-/* 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);
-
-#define __HAVE_ARCH_CMPXCHG 1
+#include <asm-generic/cmpxchg-local.h>

-static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
- unsigned long new, int size)
-{
- switch (size) {
- case 4:
- return __cmpxchg_u32(ptr, old, new);
- }
- __cmpxchg_called_with_bad_pointer();
- 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_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)) _o_ = (o); \
- __typeof__(*(ptr)) _n_ = (n); \
- (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
- (unsigned long)_n_, sizeof(*(ptr))); \
- })
+#ifndef CONFIG_SMP
+#include <asm-generic/cmpxchg.h>
+#endif

extern void die(const char *str, struct pt_regs *regs, long err) __attribute__ ((noreturn));