Re: [PATCH v12 05/13] iommu/arm-smmu-qcom: Add implementation for the adreno GPU SMMU
From: Will Deacon <will@kernel.org>
Date: 2020-08-13 13:23:48
Also in:
linux-arm-msm, linux-iommu, lkml
On Mon, Aug 10, 2020 at 04:26:49PM -0600, Jordan Crouse wrote:
quoted hunk ↗ jump to hunk
Add a special implementation for the SMMU attached to most Adreno GPU target triggered from the qcom,adreno-smmu compatible string. The new Adreno SMMU implementation will enable split pagetables (TTBR1) for the domain attached to the GPU device (SID 0) and hard code it context bank 0 so the GPU hardware can implement per-instance pagetables. Signed-off-by: Jordan Crouse <redacted> --- drivers/iommu/arm/arm-smmu/arm-smmu-impl.c | 3 + drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 156 ++++++++++++++++++++- 2 files changed, 157 insertions(+), 2 deletions(-)diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c b/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c index 88f17cc33023..d199b4bff15d 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c@@ -223,6 +223,9 @@ struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu) of_device_is_compatible(np, "qcom,sm8250-smmu-500")) return qcom_smmu_impl_init(smmu); + if (of_device_is_compatible(smmu->dev->of_node, "qcom,adreno-smmu")) + return qcom_adreno_smmu_impl_init(smmu); + if (of_device_is_compatible(np, "marvell,ap806-smmu-500")) smmu->impl = &mrvl_mmu500_impl;diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c index be4318044f96..3be10145bf57 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c@@ -12,6 +12,138 @@ struct qcom_smmu { struct arm_smmu_device smmu; }; +#define QCOM_ADRENO_SMMU_GPU_SID 0 + +static bool qcom_adreno_smmu_is_gpu_device(struct device *dev) +{ + struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); + struct arm_smmu_master_cfg *cfg = dev_iommu_priv_get(dev); + int idx, i; + + /* + * The GPU will always use SID 0 so that is a handy way to uniquely + * identify it and configure it for per-instance pagetables + */ + for_each_cfg_sme(cfg, fwspec, i, idx) { + u16 sid = FIELD_GET(ARM_SMMU_SMR_ID, fwspec->ids[i]); + + if (sid == QCOM_ADRENO_SMMU_GPU_SID) + return true; + }
Is for_each_cfg_sme() really what you want here? You're not using idx for anything, so I guess it should really be a loop over the sids (e.g. a bog standard for loop from 0 to fw->num_ids - 1)? Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel