On Tue, Nov 03, 2020 at 10:28:13AM -0700, Jordan Crouse wrote: > On Mon, Nov 02, 2020 at 06:18:45PM +0000, Robin Murphy wrote: > > On 2020-11-02 17:14, Jordan Crouse wrote: > > >From: Rob Clark <robdclark@xxxxxxxxxxxx> > > > > > >For the Adreno GPU's SMMU, we want SCTLR.HUPCF set to ensure that > > >pending translations are not terminated on iova fault. Otherwise > > >a terminated CP read could hang the GPU by returning invalid > > >command-stream data. > > > > > >Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx> > > >Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> > > >Signed-off-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx> > > >--- > > > > > > drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 6 ++++++ > > > drivers/iommu/arm/arm-smmu/arm-smmu.c | 3 +++ > > > drivers/iommu/arm/arm-smmu/arm-smmu.h | 3 +++ > > > 3 files changed, 12 insertions(+) > > > > > >diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c > > >index 1e942eed2dfc..0663d7d26908 100644 > > >--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c > > >+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c > > >@@ -129,6 +129,12 @@ static int qcom_adreno_smmu_init_context(struct arm_smmu_domain *smmu_domain, > > > (smmu_domain->cfg.fmt == ARM_SMMU_CTX_FMT_AARCH64)) > > > pgtbl_cfg->quirks |= IO_PGTABLE_QUIRK_ARM_TTBR1; > > >+ /* > > >+ * On the GPU device we want to process subsequent transactions after a > > >+ * fault to keep the GPU from hanging > > >+ */ > > >+ smmu_domain->cfg.sctlr_set |= ARM_SMMU_SCTLR_HUPCF; > > >+ > > > /* > > > * Initialize private interface with GPU: > > > */ > > >diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c > > >index dad7fa86fbd4..1f06ab219819 100644 > > >--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c > > >+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c > > >@@ -617,6 +617,9 @@ void arm_smmu_write_context_bank(struct arm_smmu_device *smmu, int idx) > > > if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) > > > reg |= ARM_SMMU_SCTLR_E; > > >+ reg |= cfg->sctlr_set; > > >+ reg &= ~cfg->sctlr_clr; > > > > Since we now have a write_s2cr hook, I'm inclined to think that the > > consistency of a write_sctlr hook that could similarly apply its own > > arbitrary tweaks would make sense for this. Does anyone have any strong > > opinions? > > None from me. That would make an eventual stall-on-fault implementation easier > too. Sounds like people like this idea, so please can you spin a new version with that so that I can queue the first three patches for 5.11? Cheers, Will
