dmaengine: idxd: drain ATS translations when disabling WQ

dmaengine: idxd: drain ATS translations when disabling WQ

There's an errata[1], for the Disable WQ command that it
does not guaranteee that address translations are drained. If WQ
configuration is updated, pending address translations can use an
updated WQ configuration, resulting an invalid translation response
that is cached in the device translation cache.

Replace the Disable WQ command with a Drain WQ command followed by a
Reset WQ command, this guarantees that all ATS translations are
drained from the device before changing WQ configuration.

[1] https://cdrdv2.intel.com/v1/dl/getcontent/843306 ("Intel DSA May
Cause Invalid Translation Caching")

Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>