Add cmpxchg_local to avr32

Use the new generic cmpxchg_local (disables interrupt) for 8, 16 and 64 bits
cmpxchg_local. Use the __cmpxchg_u32 primitive for 32 bits cmpxchg_local.

Note that cmpxchg only uses the __cmpxchg_u32 or __cmpxchg_u64 and will cause
a linker error if called with 8 or 16 bits argument.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/asm-avr32/system.h

@@ -145,6 +145,29 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
 				   (unsigned long)(new),	\
 				   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(ptr, old, new);
+	default:
+		return __cmpxchg_local_generic(ptr, old, new, size);
+	}
+
+	return old;
+}
+
+#define cmpxchg_local(ptr, old, new)					\
+	((typeof(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(old),	\
+				   (unsigned long)(new),		\
+				   sizeof(*(ptr))))
+
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+
 struct pt_regs;
 void NORET_TYPE die(const char *str, struct pt_regs *regs, long err);
 void _exception(long signr, struct pt_regs *regs, int code,