Re: [PATCH v4 06/15] iommu/arm-smmu-v3: Allocate IOPF queue without FEAT_SVA

[sashiko-bot@kernel.org]

> arm_smmu_init_queues() allocates the IOPF queue only for FEAT_SVA together
> with FEAT_STALLS. This queue has no SVA dependency, and FEAT_STALLS alone
> can produce events that need IOPF.
> 
> On HW with FEAT_STALLS but no FEAT_SVA, a master with the "dma-can-stall"
> device-tree property has master->stall_enabled set at probe. Then also with
> CONFIG_ARM_SMMU_V3_SVA=y, arm_smmu_enable_iopf() sees stall_enabled, calls
> iopf_queue_add_device(NULL, ...) at fault-handling domain attach, which can
> oops on mutex_lock(&queue->lock).
> 
> Allocate the queue whenever FEAT_STALLS is present. Also select IOMMU_IOPF
> so iopf_queue_alloc() is always available without CONFIG_ARM_SMMU_V3_SVA.
> Since IOPF does not depend on SVA, drop the SVA guards from its enable and
> disable paths.
> 
> Fixes: 395ad89d11fd9 ("iommu/arm-smmu-v3: Add stall support for platform devices")
> Cc: stable@vger.kernel.org # v5.14
> Assisted-by: Claude:claude-opus-4-8
> Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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