lkml.org 
[lkml]   [2018]   [Jul]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.17 123/220] MIPS: io: Add barrier after register read in inX()
Date
4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Huacai Chen <chenhc@lemote.com>

commit 18f3e95b90b28318ef35910d21c39908de672331 upstream.

While a barrier is present in the outX() functions before the register
write, a similar barrier is missing in the inX() functions after the
register read. This could allow memory accesses following inX() to
observe stale data.

This patch is very similar to commit a1cc7034e33d12dc1 ("MIPS: io: Add
barrier after register read in readX()"). Because war_io_reorder_wmb()
is both used by writeX() and outX(), if readX() need a barrier then so
does inX().

Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Patchwork: https://patchwork.linux-mips.org/patch/19516/
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <james.hogan@mips.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhuacai@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/mips/include/asm/io.h | 2 ++
1 file changed, 2 insertions(+)

--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -414,6 +414,8 @@ static inline type pfx##in##bwlq##p(unsi
__val = *__addr; \
slow; \
\
+ /* prevent prefetching of coherent DMA data prematurely */ \
+ rmb(); \
return pfx##ioswab##bwlq(__addr, __val); \
}


\
 
 \ /
  Last update: 2018-07-01 19:07    [W:0.623 / U:0.612 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site