Merging upstream version 6.1.82.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 15 insertions, 1 deletions

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
index d80065c81..f15dcb9e4 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
@@ -267,13 +267,27 @@ static int qcom_smmu_init_context(struct arm_smmu_domain *smmu_domain,
 
 static int qcom_smmu_cfg_probe(struct arm_smmu_device *smmu)
 {
-	unsigned int last_s2cr = ARM_SMMU_GR0_S2CR(smmu->num_mapping_groups - 1);
 	struct qcom_smmu *qsmmu = to_qcom_smmu(smmu);
+	unsigned int last_s2cr;
 	u32 reg;
 	u32 smr;
 	int i;
 
 	/*
+	 * Some platforms support more than the Arm SMMU architected maximum of
+	 * 128 stream matching groups. For unknown reasons, the additional
+	 * groups don't exhibit the same behavior as the architected registers,
+	 * so limit the groups to 128 until the behavior is fixed for the other
+	 * groups.
+	 */
+	if (smmu->num_mapping_groups > 128) {
+		dev_notice(smmu->dev, "\tLimiting the stream matching groups to 128\n");
+		smmu->num_mapping_groups = 128;
+	}
+
+	last_s2cr = ARM_SMMU_GR0_S2CR(smmu->num_mapping_groups - 1);
+
+	/*
 	 * With some firmware versions writes to S2CR of type FAULT are
 	 * ignored, and writing BYPASS will end up written as FAULT in the
 	 * register. Perform a write to S2CR to detect if this is the case and