From: Bjorn Andersson Date: Mon, 19 Oct 2020 18:23:21 +0000 (-0700) Subject: iommu/arm-smmu: Allow implementation specific write_s2cr X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=56b75b51ed6d5e7bffda59440404409bca2dff00;p=linux.git iommu/arm-smmu: Allow implementation specific write_s2cr The firmware found in some Qualcomm platforms intercepts writes to the S2CR register in order to replace the BYPASS type with FAULT. Further more it treats faults at this level as catastrophic and restarts the device. Add support for providing implementation specific versions of the S2CR write function, to allow the Qualcomm driver to work around this behavior. Cc: Signed-off-by: Bjorn Andersson Tested-by: Steev Klimaszewski Reviewed-by: Robin Murphy Link: https://lore.kernel.org/r/20201019182323.3162386-2-bjorn.andersson@linaro.org Signed-off-by: Will Deacon --- diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index dad7fa86fbd4c..bcbacf22331d6 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -929,9 +929,16 @@ static void arm_smmu_write_smr(struct arm_smmu_device *smmu, int idx) static void arm_smmu_write_s2cr(struct arm_smmu_device *smmu, int idx) { struct arm_smmu_s2cr *s2cr = smmu->s2crs + idx; - u32 reg = FIELD_PREP(ARM_SMMU_S2CR_TYPE, s2cr->type) | - FIELD_PREP(ARM_SMMU_S2CR_CBNDX, s2cr->cbndx) | - FIELD_PREP(ARM_SMMU_S2CR_PRIVCFG, s2cr->privcfg); + u32 reg; + + if (smmu->impl && smmu->impl->write_s2cr) { + smmu->impl->write_s2cr(smmu, idx); + return; + } + + reg = FIELD_PREP(ARM_SMMU_S2CR_TYPE, s2cr->type) | + FIELD_PREP(ARM_SMMU_S2CR_CBNDX, s2cr->cbndx) | + FIELD_PREP(ARM_SMMU_S2CR_PRIVCFG, s2cr->privcfg); if (smmu->features & ARM_SMMU_FEAT_EXIDS && smmu->smrs && smmu->smrs[idx].valid) diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.h b/drivers/iommu/arm/arm-smmu/arm-smmu.h index 1a746476927c9..b71647eaa319b 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.h +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.h @@ -436,6 +436,7 @@ struct arm_smmu_impl { int (*alloc_context_bank)(struct arm_smmu_domain *smmu_domain, struct arm_smmu_device *smmu, struct device *dev, int start); + void (*write_s2cr)(struct arm_smmu_device *smmu, int idx); }; #define INVALID_SMENDX -1