[PATCH 21/34] metag: define __smp_xxx

Michael S. Tsirkin
2015-12-30T21:55:05Z

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>
---
arch/metag/include/asm/barrier.h | 32 +++++++++++++++-----------------
1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/arch/metag/include/asm/barrier.h b/arch/metag/include/asm/barrier.h
index b5b778b..84880c9 100644
--- a/arch/metag/include/asm/barrier.h
+++ b/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()
+#define metag_fence() do { } while (0)
+#define __smp_mb() barrier()
+#define __smp_rmb() barrier()
+#define __smp_wmb() barrier()
#endif
+
+#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()
+#define __smp_mb__before_atomic() barrier()
+#define __smp_mb__after_atomic() barrier()

#include <asm-generic/barrier.h>

--
MST