Add cmpxchg_local to m68knommu

Use the new generic cmpxchg_local (disables interrupt). Also use the generic
cmpxchg as fallback if SMP is not set.
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/asm-m68knommu/system.h

@@ -186,26 +186,20 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz
 }
 #endif
 
+#include <asm-generic/cmpxchg-local.h>
+
 /*
- * 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.
  */
-#define __HAVE_ARCH_CMPXCHG	1
-
-static __inline__ unsigned long
-cmpxchg(volatile int *p, int old, int new)
-{
-	unsigned long flags;
-	int prev;
-
-	local_irq_save(flags);
-	if ((prev = *p) == old)
-		*p = new;
-	local_irq_restore(flags);
-	return(prev);
-}
+#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))
 
+#ifndef CONFIG_SMP
+#include <asm-generic/cmpxchg.h>
+#endif
 
 #if defined( CONFIG_M68328 ) || defined( CONFIG_M68EZ328 ) || \
 	defined (CONFIG_M68360) || defined( CONFIG_M68VZ328 )