[RFC PATCH v1 1/3] iommu/arm-smmu: Add support for driver IOMMU fault handlers
From: Jordan Crouse <hidden>
Date: 2020-11-09 22:23:35
Also in:
linux-arm-msm, linux-iommu, lkml
Subsystem:
arm smmu drivers, iommu subsystem, the rest · Maintainers:
Will Deacon, Joerg Roedel, Linus Torvalds
Call report_iommu_fault() to allow upper-level drivers to register their own fault handlers. Signed-off-by: Jordan Crouse <redacted> --- drivers/iommu/arm/arm-smmu/arm-smmu.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 0f28a8614da3..7fd18bbda8f5 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c@@ -427,6 +427,7 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev) struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); struct arm_smmu_device *smmu = smmu_domain->smmu; int idx = smmu_domain->cfg.cbndx; + int ret; fsr = arm_smmu_cb_read(smmu, idx, ARM_SMMU_CB_FSR); if (!(fsr & ARM_SMMU_FSR_FAULT))
@@ -436,11 +437,20 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev) iova = arm_smmu_cb_readq(smmu, idx, ARM_SMMU_CB_FAR); cbfrsynra = arm_smmu_gr1_read(smmu, ARM_SMMU_GR1_CBFRSYNRA(idx)); - dev_err_ratelimited(smmu->dev, - "Unhandled context fault: fsr=0x%x, iova=0x%08lx, fsynr=0x%x, cbfrsynra=0x%x, cb=%d\n", + ret = report_iommu_fault(domain, dev, iova, + fsynr & ARM_SMMU_FSYNR0_WNR ? IOMMU_FAULT_WRITE : IOMMU_FAULT_READ); + + if (ret == -ENOSYS) + dev_err_ratelimited(smmu->dev, + "Unhandled context fault: fsr=0x%x, iova=0x%08lx, fsynr=0x%x, cbfrsynra=0x%x, cb=%d\n", fsr, iova, fsynr, cbfrsynra, idx); - arm_smmu_cb_write(smmu, idx, ARM_SMMU_CB_FSR, fsr); + /* + * If the iommu fault returns an error (except -ENOSYS) then assume that + * they will handle resuming on their own + */ + if (!ret || ret == -ENOSYS) + arm_smmu_cb_write(smmu, idx, ARM_SMMU_CB_FSR, fsr); return IRQ_HANDLED; }
--
2.25.1
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