[PATCH v5 1/5] iommu/arm-smmu: Add support for driver IOMMU fault handlers

Rob Clark
2021-06-10T21:44:08Z

From: Jordan Crouse <jcrouse@codeaurora.org>

Call report_iommu_fault() to allow upper-level drivers to register their
own fault handlers.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Acked-by: Will Deacon <will@kernel.org>
---
drivers/iommu/arm/arm-smmu/arm-smmu.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 6f72c4d208ca..b4b32d31fc06 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -408,6 +408,7 @@ 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))
@@ -417,8 +418,12 @@ 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, NULL, 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);
--
2.31.1