2018-04-02 18:12:19

by Sinan Kaya

[permalink] [raw]
Subject: [PATCH] MIPS: io: add a barrier after readX()

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 <[email protected]>
Reported-by: Arnd Bergmann <[email protected]>
---
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