[PATCH v2 00/10] Allow opal-async waiters to get interrupted

Cyril Bur
2017-07-10T01:33:11Z

Hello,

Version one of this series ignored that OPAL may continue to use
buffers passed to it after Linux kfree()s the buffer. This version
addresses this, not in a particularly nice way - future work could
make this better. This version also includes a few cleanups and fixups
to powernv_flash driver one along the course of this work that I
thought I would just send.

The problem we're trying to solve here is that currently all users of
the opal-async calls must use wait_event(), this may be undesirable
when there is a userspace process behind the request for the opal
call, if OPAL takes too long to complete the call then hung task
warnings will appear.

In order to solve the problem callers should use
wait_event_interruptible(), due to the interruptible nature of this
call the opal-async infrastructure needs to track extra state
associated with each async token, this is prepared for in patch 6/10.

While I was working on the opal-async infrastructure improvements
Stewart fixed another problem and he relies on the corrected behaviour
of opal-async so I've sent it here.

Hello MTD folk, traditionally Michael Ellerman takes powernv_flash
driver patches through the powerpc tree, as always your feedback is
very welcome.

Thanks,

Cyril

Cyril Bur (9):
mtd: powernv_flash: Use WARN_ON_ONCE() rather than BUG_ON()
mtd: powernv_flash: Lock around concurrent access to OPAL
mtd: powernv_flash: Don't treat OPAL_SUCCESS as an error
mtd: powernv_flash: Remove pointless goto in driver init
powerpc/opal: Make __opal_async_{get,release}_token() static
powerpc/opal: Rework the opal-async interface
powerpc/opal: Add opal_async_wait_response_interruptible() to
opal-async
powerpc/powernv: Add OPAL_BUSY to opal_error_code()
mtd: powernv_flash: Use opal_async_wait_response_interruptible()

Stewart Smith (1):
powernv/opal-sensor: remove not needed lock

arch/powerpc/include/asm/opal.h | 4 +-
arch/powerpc/platforms/powernv/opal-async.c | 188 +++++++++++++++++++--------
arch/powerpc/platforms/powernv/opal-sensor.c | 17 +--
arch/powerpc/platforms/powernv/opal.c | 1 +
drivers/mtd/devices/powernv_flash.c | 66 +++++++---
5 files changed, 190 insertions(+), 86 deletions(-)

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2.13.2