Re: [PATCH 0/3] io.h, logic_pio: Allow barriers for inX() and outX() be overridden
From: Arnd Bergmann <arnd@arndb.de>
Date: 2020-03-18 16:21:24
Also in:
linux-arch, lkml
On Wed, Mar 18, 2020 at 4:59 PM John Garry [off-list ref] wrote:
Since commits a7851aa54c0c ("io: change outX() to have their own IO
barrier overrides") and 87fe2d543f81 ("io: change inX() to have their own
IO barrier overrides"), the outX() and inX() functions have memory
barriers which can be overridden per-arch.
However, under CONFIG_INDIRECT_PIO, logic_pio defines its own version of
inX() and outX(), which still use readb et al. For these, the barrier
after a raw read is weaker than it otherwise would be.
This series generates consistent behaviour for logic_pio, by defining
generic _inX() and _outX() in asm-generic/io.h, and using those in
logic_pio. Generic _inX() and _outX() have per-arch overrideable
barriers.
The topic was discussed there originally:
https://lore.kernel.org/lkml/2e80d7bc-32a0-cc40-00a9-8a383a1966c2@huawei.com/ (local)
A small tidy-up patch is included.
I hope that series can go through the arm-soc tree, as with other recent
logic_pio changes.Looks good to me, thanks for the cleanup! Reviewed-by: Arnd Bergmann <arnd@arndb.de> _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel