Thread (59 messages) 59 messages, 5 authors, 2020-09-01

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
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help