[PATCH 5.10 601/717] iommu/arm-smmu-qcom: Read back stream mappings

[Greg Kroah-Hartman]

From: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>

commit 07a7f2caaa5a2619934491bab3c47b261c554fb0 upstream.

The Qualcomm boot loader configures stream mapping for the peripherals
that it accesses and in particular it sets up the stream mapping for the
display controller to be allowed to scan out a splash screen or EFI
framebuffer.

Read back the stream mappings during initialization and make the
arm-smmu driver maintain the streams in bypass mode.

Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Tested-by: Steev Klimaszewski <steev@xxxxxxxx>
Acked-by: Robin Murphy <robin.murphy@xxxxxxx>
Link: https://lore.kernel.org/r/20201019182323.3162386-3-bjorn.andersson@xxxxxxxxxx
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c |   23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
@@ -23,6 +23,28 @@ static const struct of_device_id qcom_sm
 	{ }
 };
 
+static int qcom_smmu_cfg_probe(struct arm_smmu_device *smmu)
+{
+	u32 smr;
+	int i;
+
+	for (i = 0; i < smmu->num_mapping_groups; i++) {
+		smr = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_SMR(i));
+
+		if (FIELD_GET(ARM_SMMU_SMR_VALID, smr)) {
+			smmu->smrs[i].id = FIELD_GET(ARM_SMMU_SMR_ID, smr);
+			smmu->smrs[i].mask = FIELD_GET(ARM_SMMU_SMR_MASK, smr);
+			smmu->smrs[i].valid = true;
+
+			smmu->s2crs[i].type = S2CR_TYPE_BYPASS;
+			smmu->s2crs[i].privcfg = S2CR_PRIVCFG_DEFAULT;
+			smmu->s2crs[i].cbndx = 0xff;
+		}
+	}
+
+	return 0;
+}
+
 static int qcom_smmu_def_domain_type(struct device *dev)
 {
 	const struct of_device_id *match =
@@ -61,6 +83,7 @@ static int qcom_smmu500_reset(struct arm
 }
 
 static const struct arm_smmu_impl qcom_smmu_impl = {
+	.cfg_probe = qcom_smmu_cfg_probe,
 	.def_domain_type = qcom_smmu_def_domain_type,
 	.reset = qcom_smmu500_reset,
 };