MIPS: io: Add barrier after register read in readX()
authorSinan Kaya <okaya@codeaurora.org>
Fri, 13 Apr 2018 02:30:44 +0000 (22:30 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 20 Jun 2018 19:02:41 +0000 (04:02 +0900)
commite7b720ef94d8582a1346e6aebf03f8a59e682b17
treecbba7c31567262769df79f415ad80499f07730b5
parentdc94ac5fc41054c16824b01683fade1b77a07c7a
MIPS: io: Add barrier after register read in readX()

[ Upstream commit a1cc7034e33d12dc17d13fbcd7d597d552889097 ]

While a barrier is present in the writeX() functions before the register
write, a similar barrier is missing in the readX() functions 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>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/19069/
[jhogan@kernel.org: Tidy commit message]
Signed-off-by: James Hogan <jhogan@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/mips/include/asm/io.h