* [PATCH 24/34] sh: define __smp_xxx, fix smp_store_mb for !SMP
[not found] <1451473761-30019-1-git-send-email-mst@redhat.com>
@ 2015-12-30 13:25 ` Michael S. Tsirkin
0 siblings, 0 replies; only message in thread
From: Michael S. Tsirkin @ 2015-12-30 13:25 UTC (permalink / raw)
To: linux-kernel
Cc: linux-arch, Arnd Bergmann, Stefano Stabellini, Peter Zijlstra,
Andrew Cooper, linux-sh, virtualization, Ingo Molnar
sh variant of smp_store_mb() calls xchg() on !SMP which is stronger than
implied by both the name and the documentation.
define __smp_store_mb instead: code in asm-generic/barrier.h
will then define smp_store_mb correctly depending on
CONFIG_SMP.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
arch/sh/include/asm/barrier.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/sh/include/asm/barrier.h b/arch/sh/include/asm/barrier.h
index bf91037..f887c64 100644
--- a/arch/sh/include/asm/barrier.h
+++ b/arch/sh/include/asm/barrier.h
@@ -32,7 +32,8 @@
#define ctrl_barrier() __asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop")
#endif
-#define smp_store_mb(var, value) do { (void)xchg(&var, value); } while (0)
+#define __smp_store_mb(var, value) do { (void)xchg(&var, value); } while (0)
+#define smp_store_mb(var, value) __smp_store_mb(var, value)
#include <asm-generic/barrier.h>
--
MST
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2015-12-30 13:25 ` [PATCH 24/34] sh: define __smp_xxx, fix smp_store_mb for !SMP Michael S. Tsirkin
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