[PATCH 1/7] iommu/arm-smmu-qcom: apply num_context_bank fixes for SDM630 / SDM660

[Dmitry Baryshkov]

The Qualcomm SDM630 / SDM660 platform requires the same kind of
workaround as MSM8998: some IOMMUs have context banks reserved by
firmware / TZ, touching those banks resets the board.

Apply the num_context_bank workaround to those two SMMU devices in order
to allow them to be used by Linux.

Fixes: b812834b5329 ("iommu: arm-smmu-qcom: Add sdm630/msm8998 compatibles for qcom quirks")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
 drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
index 087fb4f6f4d3..13a3e3585c89 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
@@ -288,6 +288,12 @@ static int qcom_smmu_cfg_probe(struct arm_smmu_device *smmu)
 	 */
 	if (of_device_is_compatible(smmu->dev->of_node, "qcom,msm8998-smmu-v2") && smmu->num_context_banks == 13)
 		smmu->num_context_banks = 12;
+	else if (of_device_is_compatible(smmu->dev->of_node, "qcom,sdm630-smmu-v2")) {
+		if (smmu->num_context_banks == 21) /* SDM630 / SDM660 A2NOC SMMU */
+			smmu->num_context_banks = 7;
+		else if (smmu->num_context_banks == 14) /* SDM630 / SDM660 LPASS SMMU */
+			smmu->num_context_banks = 13;
+	}
 
 	/*
 	 * Some platforms support more than the Arm SMMU architected maximum of
@@ -350,6 +356,11 @@ static int qcom_adreno_smmuv2_cfg_probe(struct arm_smmu_device *smmu)
 	/* Support for 16K pages is advertised on some SoCs, but it doesn't seem to work */
 	smmu->features &= ~ARM_SMMU_FEAT_FMT_AARCH64_16K;
 
+	/* TZ protects several last context banks, hide them from Linux */
+	if (of_device_is_compatible(smmu->dev->of_node, "qcom,sdm630-smmu-v2") &&
+	    smmu->num_context_banks == 5)
+		smmu->num_context_banks = 2;
+
 	return 0;
 }
 

-- 
2.39.2