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From: "Michael S. Tsirkin" <mst@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	linux-sh@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	Ingo Molnar <mingo@kernel.org>
Subject: [PATCH 24/34] sh: define __smp_xxx, fix smp_store_mb for !SMP
Date: Wed, 30 Dec 2015 13:25:57 +0000	[thread overview]
Message-ID: <1451473761-30019-25-git-send-email-mst@redhat.com> (raw)
In-Reply-To: <1451473761-30019-1-git-send-email-mst@redhat.com>

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


           reply	other threads:[~2015-12-30 13:25 UTC|newest]

Thread overview: expand[flat|nested]  mbox.gz  Atom feed
 [parent not found: <1451473761-30019-1-git-send-email-mst@redhat.com>]

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