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 68b6bc5e7c71..978ef8ab042c 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 17f704920190..54cb9dfcec76 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);
