ia64: reuse asm-generic/barrier.h

On ia64 smp_rmb, smp_wmb, read_barrier_depends, smp_read_barrier_depends
and smp_store_mb() match the asm-generic variants exactly. Drop the
local definitions and pull in asm-generic/barrier.h instead.

This is in preparation to refactoring this code area.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

arch/ia64/include/asm/barrier.h

@@ -48,12 +48,6 @@
 # define smp_mb()	barrier()
 #endif
 
-#define smp_rmb()	smp_mb()
-#define smp_wmb()	smp_mb()
-
-#define read_barrier_depends()		do { } while (0)
-#define smp_read_barrier_depends()	do { } while (0)
-
 #define smp_mb__before_atomic()	barrier()
 #define smp_mb__after_atomic()	barrier()
 
@@ -77,12 +71,12 @@ do {									\
 	___p1;								\
 })
 
-#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0)
-
 /*
  * The group barrier in front of the rsm & ssm are necessary to ensure
  * that none of the previous instructions in the same group are
  * affected by the rsm/ssm.
  */
 
+#include <asm-generic/barrier.h>
+
 #endif /* _ASM_IA64_BARRIER_H */