alpha: fix build failures from system.h dismemberment

commit ec2212088c42ff7d1362629ec26dda4f3e8bdad3

    "Disintegrate asm/system.h for Alpha"

combined with commit b4816afa3986704d1404fc48e931da5135820472

    "Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h"

introduced the concept of asm/cmpxchg.h but the alpha arch
never got one.  Fork the cmpxchg content out of the asm/atomic.h
file to create one.

Some minor whitespace fixups were done on the block of code that
created the new file.

Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Acked-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h
index f62251e..3bb7ffe 100644
--- a/arch/alpha/include/asm/atomic.h
+++ b/arch/alpha/include/asm/atomic.h
@@ -3,6 +3,7 @@
 
 #include <linux/types.h>
 #include <asm/barrier.h>
+#include <asm/cmpxchg.h>
 
 /*
  * Atomic operations that C can't guarantee us.  Useful for
@@ -168,73 +169,6 @@
 	return result;
 }
 
-/*
- * Atomic exchange routines.
- */
-
-#define __ASM__MB
-#define ____xchg(type, args...)		__xchg ## type ## _local(args)
-#define ____cmpxchg(type, args...)	__cmpxchg ## type ## _local(args)
-#include <asm/xchg.h>
-
-#define xchg_local(ptr,x)						\
-  ({									\
-     __typeof__(*(ptr)) _x_ = (x);					\
-     (__typeof__(*(ptr))) __xchg_local((ptr), (unsigned long)_x_,	\
-				       sizeof(*(ptr)));			\
-  })
-
-#define cmpxchg_local(ptr, o, n)					\
-  ({									\
-     __typeof__(*(ptr)) _o_ = (o);					\
-     __typeof__(*(ptr)) _n_ = (n);					\
-     (__typeof__(*(ptr))) __cmpxchg_local((ptr), (unsigned long)_o_,	\
-					  (unsigned long)_n_,		\
-					  sizeof(*(ptr)));		\
-  })
-
-#define cmpxchg64_local(ptr, o, n)					\
-  ({									\
-	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
-	cmpxchg_local((ptr), (o), (n));					\
-  })
-
-#ifdef CONFIG_SMP
-#undef __ASM__MB
-#define __ASM__MB	"\tmb\n"
-#endif
-#undef ____xchg
-#undef ____cmpxchg
-#define ____xchg(type, args...)		__xchg ##type(args)
-#define ____cmpxchg(type, args...)	__cmpxchg ##type(args)
-#include <asm/xchg.h>
-
-#define xchg(ptr,x)							\
-  ({									\
-     __typeof__(*(ptr)) _x_ = (x);					\
-     (__typeof__(*(ptr))) __xchg((ptr), (unsigned long)_x_,		\
-				 sizeof(*(ptr)));			\
-  })
-
-#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)));\
-  })
-
-#define cmpxchg64(ptr, o, n)						\
-  ({									\
-	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
-	cmpxchg((ptr), (o), (n));					\
-  })
-
-#undef __ASM__MB
-#undef ____cmpxchg
-
-#define __HAVE_ARCH_CMPXCHG 1
-
 #define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))