[PATCH 5/8] iommu/arm-smmu-qcom: Add test_smr_masks detail to QCOM SMMUv2

From: kholk11
Date: Sat Sep 26 2020 - 09:00:36 EST


From: AngeloGioacchino Del Regno <kholk11@xxxxxxxxx>

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@xxxxxxxxx>
---
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