| Message ID | 1584546935-75393-1-git-send-email-john.garry@huawei.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | io.h, logic_pio: Allow barriers for inX() and outX() be overridden | expand |
On Wed, Mar 18, 2020 at 4:59 PM John Garry <john.garry@huawei.com> 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/ > > 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>
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/ 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. John Garry (3): io: Provide _inX() and _outX() logic_pio: Improve macro argument name logic_pio: Use _inX() and _outX() include/asm-generic/io.h | 64 +++++++++++++++++++++++++++++++++--------------- lib/logic_pio.c | 22 ++++++++--------- 2 files changed, 55 insertions(+), 31 deletions(-)