Threaded IRQ handlers run in a less critical context compared to normal IRQs, so they can perform more complex and time-consuming operations without causing significant delays in other parts of the kernel. During a context fault, it might be needed to do more processing and gather debug information from TBUs in the handler. These operations may sleep, so add an option to use a threaded IRQ handler in these cases. Signed-off-by: Georgi Djakov <quic_c_gdjako@xxxxxxxxxxx> --- drivers/iommu/arm/arm-smmu/arm-smmu.c | 12 ++++++++++-- drivers/iommu/arm/arm-smmu/arm-smmu.h | 1 + 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index c572d877b0e1..dcf0479363c3 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -806,8 +806,16 @@ static int arm_smmu_init_domain_context(struct arm_smmu_domain *smmu_domain, else context_fault = arm_smmu_context_fault; - ret = devm_request_irq(smmu->dev, irq, context_fault, IRQF_SHARED, - "arm-smmu-context-fault", smmu_domain); + if (smmu->impl && smmu->impl->context_fault_needs_threaded_irq) + ret = devm_request_threaded_irq(smmu->dev, irq, NULL, + context_fault, + IRQF_ONESHOT | IRQF_SHARED, + "arm-smmu-context-fault", + smmu_domain); + else + ret = devm_request_irq(smmu->dev, irq, context_fault, IRQF_SHARED, + "arm-smmu-context-fault", smmu_domain); + if (ret < 0) { dev_err(smmu->dev, "failed to request context IRQ %d (%u)\n", cfg->irptndx, irq); diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.h b/drivers/iommu/arm/arm-smmu/arm-smmu.h index 1670e95c4637..4765c6945c34 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.h +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.h @@ -438,6 +438,7 @@ struct arm_smmu_impl { int (*def_domain_type)(struct device *dev); irqreturn_t (*global_fault)(int irq, void *dev); irqreturn_t (*context_fault)(int irq, void *dev); + bool context_fault_needs_threaded_irq; int (*alloc_context_bank)(struct arm_smmu_domain *smmu_domain, struct arm_smmu_device *smmu, struct device *dev, int start);