The Q6 modem sub-system has direct access to DDR through memnoc and an indirect access routed through a SMMU which MSS CE (crypto engine sub-component of MSS) uses during out of reset sequence. Request direct mapping for the modem device since smmu is not expected to provide access control/translation for these SIDs (sandboxing of the modem is achieved through XPUs engaged using SMC calls). This is done on platforms which don't have TrustZone (which programs the modem SIDs) to prevent the following global faults seen on Cheza/Trogdor: Cheza: arm-smmu 15000000.iommu: Unexpected global fault, this could be serious arm-smmu 15000000.iommu: GFSR 0x80000002, GFSYNR0 0x00000000, GFSYNR1 0x00000781, GFSYNR2 0x00000000 Trogdor: arm-smmu 15000000.iommu: Unexpected global fault, this could be serious arm-smmu 15000000.iommu: GFSR 0x80000002, GFSYNR0 0x00000000, GFSYNR1 0x00000461, GFSYNR2 0x00000000 V2: * Request direct mapping from SoC-specific corner of the SMMU driver [Robin] * Add iommu property to remoteproc modem node on Cheza Depends on: https://lore.kernel.org/patchwork/cover/1183528/ Sibi Sankar (3): dt-bindings: remoteproc: qcom: Add iommus property remoteproc: qcom_q6v5_mss: Request direct mapping for modem device arm64: dts: qcom: sdm845-cheza: Add iommus property Documentation/devicetree/bindings/remoteproc/qcom,q6v5.txt | 3 +++ arch/arm64/boot/dts/qcom/sdm845-cheza.dtsi | 4 ++++ drivers/iommu/arm-smmu-qcom.c | 6 ++++++ 3 files changed, 13 insertions(+) -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
