[PATCH v10 03/13] iommu/arm-smmu-v3: Add ARM_SMMU_FEAT_EVTQ for the event queue

Jason Gunthorpe jgg at nvidia.com
Wed Sep 23 09:39:16 PDT 2026


On Sun, 30 Aug 2026 16:18:04 -0700, Nicolin Chen <nicolinc at nvidia.com> wrote:
> The driver programs and enables the event queue unconditionally, while the
> PRI queue has an ARM_SMMU_FEAT_PRI gating each of its touch points. Yet a
> kdump kernel wants to leave both of the queues alone, which would take an
> is_kdump_kernel() test at every one of those places.
> 
> Add an ARM_SMMU_FEAT_EVTQ that the probe always sets, as the event queue is
> architecturally mandatory, and gate the queue's allocation, its interrupt
> and its CR0 and IRQ_CTRL enables on it, so that a later change can turn the
> queue off in a single place.
> 
> [...]

Reviewed-by: Jason Gunthorpe <jgg at nvidia.com>

-- 
Jason



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