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)
committerJames Hogan <jhogan@kernel.org>
Fri, 13 Apr 2018 23:46:53 +0000 (00:46 +0100)
commita1cc7034e33d12dc17d13fbcd7d597d552889097
treeb95a0cd926555f26ec83f127b2c3e76b7f0e86a8
parentf6b7aeee8f167409195fbf1364d02988fecad1d0
MIPS: io: Add barrier after register read in readX()

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>
arch/mips/include/asm/io.h