This adds the downstream property required to support SMMUs on SDM630 and other platforms (the need for it most likely depends on firmware configuration).
Signed-off-by: Konrad Dybcio <[email protected]> --- .../devicetree/bindings/iommu/arm,smmu.yaml | 10 ++++++++++ drivers/iommu/arm-smmu.c | 15 +++++++++------ 2 files changed, 19 insertions(+), 6 deletions(-) diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.yaml b/Documentation/devicetree/bindings/iommu/arm,smmu.yaml index d7ceb4c34423..9abd6d41a32c 100644 --- a/Documentation/devicetree/bindings/iommu/arm,smmu.yaml +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.yaml @@ -102,6 +102,16 @@ properties: access to SMMU configuration registers. In this case non-secure aliases of secure registers have to be used during SMMU configuration. + qcom,skip-init: + description: | + Disable resetting configuration for all context banks + during device reset. This is useful for targets where + some context banks are dedicated to other execution + environments outside of Linux and those other EEs are + programming their own stream match tables, SCTLR, etc. + Without setting this option we will trample on their + configuration. + stream-match-mask: $ref: /schemas/types.yaml#/definitions/uint32 description: | diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 243bc4cb2705..a5c623d4caf9 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -1655,13 +1655,16 @@ static void arm_smmu_device_reset(struct arm_smmu_device *smmu) * Reset stream mapping groups: Initial values mark all SMRn as * invalid and all S2CRn as bypass unless overridden. */ - for (i = 0; i < smmu->num_mapping_groups; ++i) - arm_smmu_write_sme(smmu, i); - /* Make sure all context banks are disabled and clear CB_FSR */ - for (i = 0; i < smmu->num_context_banks; ++i) { - arm_smmu_write_context_bank(smmu, i); - arm_smmu_cb_write(smmu, i, ARM_SMMU_CB_FSR, ARM_SMMU_FSR_FAULT); + if (!of_find_property(smmu->dev->of_node, "qcom,skip-init", NULL)) { + for (i = 0; i < smmu->num_mapping_groups; ++i) + arm_smmu_write_sme(smmu, i); + + /* Make sure all context banks are disabled and clear CB_FSR */ + for (i = 0; i < smmu->num_context_banks; ++i) { + arm_smmu_write_context_bank(smmu, i); + arm_smmu_cb_write(smmu, i, ARM_SMMU_CB_FSR, ARM_SMMU_FSR_FAULT); + } } /* Invalidate the TLB, just in case */ -- 2.27.0
