[PATCH 5/5] FRV: Don't make smp_{r, w,}mb() interpolate MEMBAR when CONFIG_SMP=n [try #2]

From: David Howells
Date: Thu Apr 10 2008 - 11:12:32 EST


From: David Howells <dhowells@xxxxxxxxxx>

Don't make smp_{r,w,}mb() interpolate a MEMBAR instruction when CONFIG_SMP=n as
SMP memory barries on UP systems should interpolate a compiler barrier only.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

include/asm-frv/system.h | 21 +++++++++++++++------
1 files changed, 15 insertions(+), 6 deletions(-)


diff --git a/include/asm-frv/system.h b/include/asm-frv/system.h
index 2c57f47..30a67a9 100644
--- a/include/asm-frv/system.h
+++ b/include/asm-frv/system.h
@@ -179,14 +179,23 @@ do { \
#define mb() asm volatile ("membar" : : :"memory")
#define rmb() asm volatile ("membar" : : :"memory")
#define wmb() asm volatile ("membar" : : :"memory")
-#define set_mb(var, value) do { var = value; mb(); } while (0)
+#define read_barrier_depends() barrier()

-#define smp_mb() mb()
-#define smp_rmb() rmb()
-#define smp_wmb() wmb()
-
-#define read_barrier_depends() do {} while(0)
+#ifdef CONFIG_SMP
+#define smp_mb() mb()
+#define smp_rmb() rmb()
+#define smp_wmb() wmb()
#define smp_read_barrier_depends() read_barrier_depends()
+#define set_mb(var, value) \
+ do { xchg(&var, (value)); } while (0)
+#else
+#define smp_mb() barrier()
+#define smp_rmb() barrier()
+#define smp_wmb() barrier()
+#define smp_read_barrier_depends() do {} while(0)
+#define set_mb(var, value) \
+ do { var = (value); barrier(); } while (0)
+#endif

#define HARD_RESET_NOW() \
do { \

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