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Subject[PATCH v2] MIPS: io: add a barrier after register read in readX()
Date
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 memory 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
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