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Subject: [PATCH 5/8] iommu/arm-smmu-qcom: Add test_smr_masks detail to QCOM SMMUv2
Date:   Sat, 26 Sep 2020 15:00:01 +0200
Message-Id: <20200926130004.13528-6-kholk11@gmail.com>
In-Reply-To: <20200926130004.13528-1-kholk11@gmail.com>
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From: AngeloGioacchino Del Regno <kholk11@gmail.com>

On some Qualcomm SoCs with certain hypervisor configurations,
writing the streamid masks to the SMRs will trigger a hyp-fault
and crash the system.

This is seen on at least Qualcomm SDM630, SDM636 and SDM660.

Signed-off-by: AngeloGioacchino Del Regno <kholk11@gmail.com>
---
 drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
index f5bbfe86ef30..b18e70bddf29 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
@@ -85,8 +85,21 @@ static int qcom_smmuv2_cfg_probe(struct arm_smmu_device *smmu)
 	return 0;
 }
 
+static void qcom_smmuv2_test_smr_masks(struct arm_smmu_device *smmu)
+{
+	/*
+	 * Broken firmware quirk:
+	 * On some Qualcomm SoCs with certain hypervisor configurations,
+	 * writing the streamid masks to the SMRs will trigger a hyp-fault
+	 * and crash the system.
+	 */
+	smmu->streamid_mask = 0x7FFF;
+	smmu->smr_mask_mask = 0x7FFF;
+}
+
 static const struct arm_smmu_impl qcom_smmuv2_impl = {
 	.cfg_probe = qcom_smmuv2_cfg_probe,
+	.test_smr_masks = qcom_smmuv2_test_smr_masks,
 };
 
 struct arm_smmu_device *qcom_smmu_impl_init(struct arm_smmu_device *smmu)
-- 
2.28.0