Hi Rob, On Tue, Jun 4, 2024 at 8:32 PM Rob Clark <robdclark@xxxxxxxxx> wrote: > > From: Rob Clark <robdclark@xxxxxxxxxxxx> > > Parse out the bitfields for easier-to-read fault messages. > > Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx> > --- > Stephen was wanting easier to read fault messages.. so I typed this up. > > Resend with the new iommu list address > > drivers/iommu/arm/arm-smmu/arm-smmu.c | 53 +++++++++++++++++++++++++-- > drivers/iommu/arm/arm-smmu/arm-smmu.h | 5 +++ > 2 files changed, 54 insertions(+), 4 deletions(-) > > diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c > index c572d877b0e1..06712d73519c 100644 > --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c > +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c > @@ -411,6 +411,8 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev) > unsigned long iova; > struct arm_smmu_domain *smmu_domain = dev; > struct arm_smmu_device *smmu = smmu_domain->smmu; > + static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, > + DEFAULT_RATELIMIT_BURST); > int idx = smmu_domain->cfg.cbndx; > int ret; > > @@ -425,10 +427,53 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev) > ret = report_iommu_fault(&smmu_domain->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); > + if (ret == -ENOSYS && __ratelimit(&rs)) { > + static const struct { > + u32 mask; const char *name; > + } fsr_bits[] = { > + { ARM_SMMU_FSR_MULTI, "MULTI" }, > + { ARM_SMMU_FSR_SS, "SS" }, > + { ARM_SMMU_FSR_UUT, "UUT" }, > + { ARM_SMMU_FSR_ASF, "ASF" }, > + { ARM_SMMU_FSR_TLBLKF, "TLBLKF" }, > + { ARM_SMMU_FSR_TLBMCF, "TLBMCF" }, > + { ARM_SMMU_FSR_EF, "EF" }, > + { ARM_SMMU_FSR_PF, "PF" }, > + { ARM_SMMU_FSR_AFF, "AFF" }, > + { ARM_SMMU_FSR_TF, "TF" }, I think we are missing to log the translation scheme i.e. `Format bits[10:9]` field of this register as per the SMMUv2 spec. Maybe add that too? > + }, fsynr0_bits[] = { > + { ARM_SMMU_FSYNR0_WNR, "WNR" }, > + { ARM_SMMU_FSYNR0_PNU, "PNU" }, > + { ARM_SMMU_FSYNR0_IND, "IND" }, > + { ARM_SMMU_FSYNR0_NSATTR, "NSATTR" }, > + { ARM_SMMU_FSYNR0_PTWF, "PTWF" }, > + { ARM_SMMU_FSYNR0_AFR, "AFR" }, > + }; > + > + pr_err("%s %s: Unhandled context fault: fsr=0x%x (", > + dev_driver_string(smmu->dev), dev_name(smmu->dev), fsr); > + > + for (int i = 0, n = 0; i < ARRAY_SIZE(fsr_bits); i++) { > + if (fsr & fsr_bits[i].mask) { > + pr_cont("%s%s", (n > 0) ? "|" : "", fsr_bits[i].name); > + n++; > + } > + } Nit: Maybe add a line-wrap here after logging the iova? Not trying to sound like a terminal geek, but a full log with pr_cont could get very long (> 80 characters). So, let's log fsr & iova in one line, fsynr and others in the next. > + > + pr_cont("), iova=0x%08lx, fsynr=0x%x (S1CBNDX=%u", iova, fsynr, > + (fsynr >> 16) & 0xff); > + > + for (int i = 0; i < ARRAY_SIZE(fsynr0_bits); i++) { > + if (fsynr & fsynr0_bits[i].mask) { > + pr_cont("|%s", fsynr0_bits[i].name); > + } > + } > + > + pr_cont("|PLVL=%u), cbfrsynra=0x%x, cb=%d\n", > + fsynr & 0x3, /* FSYNR0.PLV */ > + cbfrsynra, idx); > + > + } > > arm_smmu_cb_write(smmu, idx, ARM_SMMU_CB_FSR, fsr); > return IRQ_HANDLED; > diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.h b/drivers/iommu/arm/arm-smmu/arm-smmu.h > index 836ed6799a80..3b051273718b 100644 > --- a/drivers/iommu/arm/arm-smmu/arm-smmu.h > +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.h > @@ -223,6 +223,11 @@ enum arm_smmu_cbar_type { > > #define ARM_SMMU_CB_FSYNR0 0x68 > #define ARM_SMMU_FSYNR0_WNR BIT(4) > +#define ARM_SMMU_FSYNR0_PNU BIT(5) > +#define ARM_SMMU_FSYNR0_IND BIT(6) > +#define ARM_SMMU_FSYNR0_NSATTR BIT(8) > +#define ARM_SMMU_FSYNR0_PTWF BIT(10) > +#define ARM_SMMU_FSYNR0_AFR BIT(11) > Nit: Worth prefixing these with "CB_" i.e. "ARM_SMMU_CB_FSYNR0_* " to avoid confusion with "GFSYNR0". > #define ARM_SMMU_CB_FSYNR1 0x6c > > -- > 2.45.1 > > Thanks, Pranjal