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Also, we cannot serve page requests. > > Skip the IRQ setup for EVTQ/PRIQ in arm_smmu_setup_irqs(), and guard the > thread functions against being entered via a combined-IRQ delivery while > the queue is disabled. > > Fixes: b63b3439b856 ("iommu/arm-smmu-v3: Abort all transactions if SMMU is enabled in kdump kernel") > Cc: stable@vger.kernel.org # v6.12+ > Reviewed-by: Kevin Tian > Signed-off-by: Nicolin Chen > --- > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 23 +++++++++++++++++++-- > 1 file changed, 21 insertions(+), 2 deletions(-) > > diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > index 579c8af82d6b6..ebb0826d74541 100644 > --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > @@ -2364,6 +2364,14 @@ static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev) > static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, > DEFAULT_RATELIMIT_BURST); > > + /* > + * A combined IRQ might call into this function with the queue disabled. > + * E.g. kdump, where stale HW PROD vs SW CONS would drive a bogus drain > + * and a CONS write to a disabled queue. > + */ > + if (!(readl_relaxed(smmu->base + ARM_SMMU_CR0) & CR0_EVTQEN)) > + return IRQ_NONE; I don't think we should be doing register reads on these paths. Why not load a different irq function instead? Jason