[PATCH v4 11/15] iommu/arm-smmu-v3: Discard partial PRI faults on PRIQ overflow

[Jonathan Cameron]

> On PRIQ overflow, partial requests stored via report_partial_fault() whose
> LAST-page entry was lost stay in iopf_param->partial. Drop them by calling
> iopf_queue_discard_partial(), matching intel-iommu's handling.
> 
> Do it only after the queue is fully drained, since the visible entries all
> precede the loss point: a group whose LAST-page entry is still in the queue
> gets assembled before the discard, rather than losing its stored partials
> to it.
> 
> Nothing can arrive in between, as an active overflow inhibits new entries
> from being written to the PRI queue until a final CONS write acknowledges
> it (IHI0070 8.1).
> 
> Suggested-by: Harsha Vardhan V <harsha.v at oss.qualcomm.com>
> Assisted-by: Claude:claude-sonnet-5
> Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>

Reviewed-by: Jonathan Cameron <jonathan.cameron at oss.qualcomm.com>

-- 
Jonathan Cameron <jonathan.cameron at oss.qualcomm.com>