metag: define __smp_xxx

This defines __smp_xxx barriers for metag,
for use by virtualization.

smp_xxx barriers are removed as they are
defined correctly by asm-generic/barriers.h

Note: as __smp_XX macros should not depend on CONFIG_SMP, they can not
use the existing fence() macro since that is defined differently between
SMP and !SMP.  For this reason, this patch introduces a wrapper
metag_fence() that doesn't depend on CONFIG_SMP.
fence() is then defined using that, depending on CONFIG_SMP.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

arch/metag/include/asm/barrier.h

@@ -44,13 +44,6 @@ static inline void wr_fence(void)
 #define rmb()		barrier()
 #define wmb()		mb()
 
-#ifndef CONFIG_SMP
-#define fence()		do { } while (0)
-#define smp_mb()        barrier()
-#define smp_rmb()       barrier()
-#define smp_wmb()       barrier()
-#else
-
 #ifdef CONFIG_METAG_SMP_WRITE_REORDERING
 /*
  * Write to the atomic memory unlock system event register (command 0). This is
@@ -60,26 +53,31 @@ static inline void wr_fence(void)
  * incoherence). It is therefore ineffective if used after and on the same
  * thread as a write.
  */
-static inline void fence(void)
+static inline void metag_fence(void)
 {
 	volatile int *flushptr = (volatile int *) LINSYSEVENT_WR_ATOMIC_UNLOCK;
 	barrier();
 	*flushptr = 0;
 	barrier();
 }
-#define smp_mb()        fence()
-#define smp_rmb()       fence()
-#define smp_wmb()       barrier()
+#define __smp_mb()	metag_fence()
+#define __smp_rmb()	metag_fence()
+#define __smp_wmb()	barrier()
 #else
-#define fence()		do { } while (0)
-#define smp_mb()        barrier()
-#define smp_rmb()       barrier()
-#define smp_wmb()       barrier()
-#endif
+#define metag_fence()	do { } while (0)
+#define __smp_mb()	barrier()
+#define __smp_rmb()	barrier()
+#define __smp_wmb()	barrier()
 #endif
 
-#define smp_mb__before_atomic()	barrier()
-#define smp_mb__after_atomic()	barrier()
+#ifdef CONFIG_SMP
+#define fence()		metag_fence()
+#else
+#define fence()		do { } while (0)
+#endif
+
+#define __smp_mb__before_atomic()	barrier()
+#define __smp_mb__after_atomic()	barrier()
 
 #include <asm-generic/barrier.h>