[PATCH v4 2/3] iommu/arm-smmu-qcom: Read back stream mappings
From: Bjorn Andersson <hidden>
Date: 2020-10-17 05:54:44
Also in:
linux-arm-msm, linux-iommu, lkml
Subsystem:
arm smmu drivers, iommu subsystem, qualcomm iommu, the rest · Maintainers:
Will Deacon, Joerg Roedel, Rob Clark, Linus Torvalds
The Qualcomm boot loader configures stream mapping for the peripherals that it accesses and in particular it sets up the stream mapping for the display controller to be allowed to scan out a splash screen or EFI framebuffer. Read back the stream mappings during initialization and make the arm-smmu driver maintain the streams in bypass mode. Signed-off-by: Bjorn Andersson <redacted> --- Changes since v3: - Extracted from different patch in v3. - Now configures the stream as BYPASS, rather than translate, which should work for platforms with working S2CR handling as well. drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 24 ++++++++++++++++++++++ 1 file changed, 24 insertions(+)
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
index be4318044f96..0089048342dd 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c@@ -23,6 +23,29 @@ static const struct of_device_id qcom_smmu_client_of_match[] __maybe_unused = { { } }; +static int qcom_smmu_cfg_probe(struct arm_smmu_device *smmu) +{ + u32 smr; + int i; + + for (i = 0; i < smmu->num_mapping_groups; i++) { + smr = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_SMR(i)); + + if (FIELD_GET(ARM_SMMU_SMR_VALID, smr)) { + smmu->smrs[i].id = FIELD_GET(ARM_SMMU_SMR_ID, smr); + smmu->smrs[i].mask = FIELD_GET(ARM_SMMU_SMR_MASK, smr); + smmu->smrs[i].valid = true; + + smmu->s2crs[i].type = S2CR_TYPE_BYPASS; + smmu->s2crs[i].privcfg = S2CR_PRIVCFG_DEFAULT; + smmu->s2crs[i].cbndx = 0xff; + smmu->s2crs[i].count++; + } + } + + return 0; +} + static int qcom_smmu_def_domain_type(struct device *dev) { const struct of_device_id *match =
@@ -61,6 +84,7 @@ static int qcom_smmu500_reset(struct arm_smmu_device *smmu) } static const struct arm_smmu_impl qcom_smmu_impl = { + .cfg_probe = qcom_smmu_cfg_probe, .def_domain_type = qcom_smmu_def_domain_type, .reset = qcom_smmu500_reset, };
--
2.28.0
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