Merge remote-tracking branch 'iommu/tracking-qcomlt-iommu' into integration-linux-qcomlt

3 files changed, 101 insertions, 3 deletions

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
index be4318044f96..66ba4870659f 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
@@ -10,8 +10,15 @@
 
 struct qcom_smmu {
 	struct arm_smmu_device smmu;
+	bool bypass_quirk;
+	u8 bypass_cbndx;
 };
 
+static struct qcom_smmu *to_qcom_smmu(struct arm_smmu_device *smmu)
+{
+	return container_of(smmu, struct qcom_smmu, smmu);
+}
+
 static const struct of_device_id qcom_smmu_client_of_match[] __maybe_unused = {
 	{ .compatible = "qcom,adreno" },
 	{ .compatible = "qcom,mdp4" },
@@ -23,6 +30,87 @@ static const struct of_device_id qcom_smmu_client_of_match[] __maybe_unused = {
 	{ }
 };
 
+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);
+	u32 reg;
+	u32 smr;
+	int i;
+
+	/*
+	 * 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
+	 * if so reserve a context bank to emulate bypass streams.
+	 */
+	reg = FIELD_PREP(ARM_SMMU_S2CR_TYPE, S2CR_TYPE_BYPASS) |
+	      FIELD_PREP(ARM_SMMU_S2CR_CBNDX, 0xff) |
+	      FIELD_PREP(ARM_SMMU_S2CR_PRIVCFG, S2CR_PRIVCFG_DEFAULT);
+	arm_smmu_gr0_write(smmu, last_s2cr, reg);
+	reg = arm_smmu_gr0_read(smmu, last_s2cr);
+	if (FIELD_GET(ARM_SMMU_S2CR_TYPE, reg) != S2CR_TYPE_BYPASS) {
+		qsmmu->bypass_quirk = true;
+		qsmmu->bypass_cbndx = smmu->num_context_banks - 1;
+
+		set_bit(qsmmu->bypass_cbndx, smmu->context_map);
+
+		reg = FIELD_PREP(ARM_SMMU_CBAR_TYPE, CBAR_TYPE_S1_TRANS_S2_BYPASS);
+		arm_smmu_gr1_write(smmu, ARM_SMMU_GR1_CBAR(qsmmu->bypass_cbndx), reg);
+	}
+
+	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 void qcom_smmu_write_s2cr(struct arm_smmu_device *smmu, int idx)
+{
+	struct arm_smmu_s2cr *s2cr = smmu->s2crs + idx;
+	struct qcom_smmu *qsmmu = to_qcom_smmu(smmu);
+	u32 cbndx = s2cr->cbndx;
+	u32 type = s2cr->type;
+	u32 reg;
+
+	if (qsmmu->bypass_quirk) {
+		if (type == S2CR_TYPE_BYPASS) {
+			/*
+			 * Firmware with quirky S2CR handling will substitute
+			 * BYPASS writes with FAULT, so point the stream to the
+			 * reserved context bank and ask for translation on the
+			 * stream
+			 */
+			type = S2CR_TYPE_TRANS;
+			cbndx = qsmmu->bypass_cbndx;
+		} else if (type == S2CR_TYPE_FAULT) {
+			/*
+			 * Firmware with quirky S2CR handling will ignore FAULT
+			 * writes, so trick it to write FAULT by asking for a
+			 * BYPASS.
+			 */
+			type = S2CR_TYPE_BYPASS;
+			cbndx = 0xff;
+		}
+	}
+
+	reg = FIELD_PREP(ARM_SMMU_S2CR_TYPE, type) |
+	      FIELD_PREP(ARM_SMMU_S2CR_CBNDX, cbndx) |
+	      FIELD_PREP(ARM_SMMU_S2CR_PRIVCFG, s2cr->privcfg);
+	arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_S2CR(idx), reg);
+}
+
 static int qcom_smmu_def_domain_type(struct device *dev)
 {
 	const struct of_device_id *match =
@@ -61,8 +149,10 @@ static int qcom_smmu500_reset(struct arm_smmu_device *smmu)
 }
 
 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,
+	.write_s2cr = qcom_smmu_write_s2cr,
 };
 
 struct arm_smmu_device *qcom_smmu_impl_init(struct arm_smmu_device *smmu)
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index dad7fa86fbd4..bcbacf22331d 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -929,9 +929,16 @@ static void arm_smmu_write_smr(struct arm_smmu_device *smmu, int idx)
 static void arm_smmu_write_s2cr(struct arm_smmu_device *smmu, int idx)
 {
 	struct arm_smmu_s2cr *s2cr = smmu->s2crs + idx;
-	u32 reg = FIELD_PREP(ARM_SMMU_S2CR_TYPE, s2cr->type) |
-		  FIELD_PREP(ARM_SMMU_S2CR_CBNDX, s2cr->cbndx) |
-		  FIELD_PREP(ARM_SMMU_S2CR_PRIVCFG, s2cr->privcfg);
+	u32 reg;
+
+	if (smmu->impl && smmu->impl->write_s2cr) {
+		smmu->impl->write_s2cr(smmu, idx);
+		return;
+	}
+
+	reg = FIELD_PREP(ARM_SMMU_S2CR_TYPE, s2cr->type) |
+	      FIELD_PREP(ARM_SMMU_S2CR_CBNDX, s2cr->cbndx) |
+	      FIELD_PREP(ARM_SMMU_S2CR_PRIVCFG, s2cr->privcfg);
 
 	if (smmu->features & ARM_SMMU_FEAT_EXIDS && smmu->smrs &&
 	    smmu->smrs[idx].valid)
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.h b/drivers/iommu/arm/arm-smmu/arm-smmu.h
index 1a746476927c..b71647eaa319 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.h
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.h
@@ -436,6 +436,7 @@ struct arm_smmu_impl {
 	int (*alloc_context_bank)(struct arm_smmu_domain *smmu_domain,
 				  struct arm_smmu_device *smmu,
 				  struct device *dev, int start);
+	void (*write_s2cr)(struct arm_smmu_device *smmu, int idx);
 };
 
 #define INVALID_SMENDX			-1