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From: Sinan Kaya <okaya@codeaurora.org>
To: linux-mips@vger.kernel.org, timur@codeaurora.org, sulrich@codeaurora.org
Cc: arnd@arndb.de, linux-arm-msm@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Sinan Kaya <okaya@codeaurora.org>,
	Ralf Baechle <ralf@linux-mips.org>,
	James Hogan <jhogan@kernel.org>,
	Paul Burton <paul.burton@mips.com>,
	linux-mips@linux-mips.org, linux-kernel@vger.kernel.org
Subject: [PATCH] MIPS: io: add a barrier after readX()
Date: Mon,  2 Apr 2018 14:10:32 -0400	[thread overview]
Message-ID: <1522692633-24304-1-git-send-email-okaya@codeaurora.org> (raw)

While a barrier is present in writeX() function before the register write,
a similar barrier is missing in the readX() function after the register
read. This could allow register accesses following readX() to observe
stale data.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Reported-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/mips/include/asm/io.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index 0cbf3af..7f9068d 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -377,6 +377,7 @@ static inline type pfx##read##bwlq(const volatile void __iomem *mem)	\
 		BUG();							\
 	}								\
 									\
+	war_io_reorder_wmb();						\
 	return pfx##ioswab##bwlq(__mem, __val);				\
 }
 
-- 
2.7.4

                 reply	other threads:[~2018-04-02 18:10 UTC|newest]

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