3 files changed, 38 insertions, 14 deletions

diff --git a/drivers/iommu/arm-smmu-impl.c b/drivers/iommu/arm-smmu-impl.c
index 0657c85580cb..696417908793 100644
--- a/drivers/iommu/arm-smmu-impl.c
+++ b/drivers/iommu/arm-smmu-impl.c
@@ -47,8 +47,42 @@ const struct arm_smmu_impl calxeda_impl = {
 };
 
 
+static int cavium_cfg_probe(struct arm_smmu_device *smmu)
+{
+	static atomic_t context_count = ATOMIC_INIT(0);
+	/*
+	 * Cavium CN88xx erratum #27704.
+	 * Ensure ASID and VMID allocation is unique across all SMMUs in
+	 * the system.
+	 */
+	smmu->cavium_id_base = atomic_fetch_add(smmu->num_context_banks,
+						   &context_count);
+	dev_notice(smmu->dev, "\tenabling workaround for Cavium erratum 27704\n");
+
+	return 0;
+}
+
+const struct arm_smmu_impl cavium_impl = {
+	.cfg_probe = cavium_cfg_probe,
+};
+
+
 struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu)
 {
+	/*
+	 * We will inevitably have to combine model-specific implementation
+	 * quirks with platform-specific integration quirks, but everything
+	 * we currently support happens to work out as straightforward
+	 * mutually-exclusive assignments.
+	 */
+	switch (smmu->model) {
+	case CAVIUM_SMMUV2:
+		smmu->impl = &cavium_impl;
+		break;
+	default:
+		break;
+	}
+
 	if (of_property_read_bool(smmu->dev->of_node,
 				  "calxeda,smmu-secure-config-access"))
 		smmu->impl = &calxeda_impl;
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 432d781f05f3..362b6b5a28ee 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -155,8 +155,6 @@ struct arm_smmu_domain {
 	struct iommu_domain		domain;
 };
 
-static atomic_t cavium_smmu_context_count = ATOMIC_INIT(0);
-
 static bool using_legacy_binding, using_generic_binding;
 
 static inline int arm_smmu_rpm_get(struct arm_smmu_device *smmu)
@@ -1804,18 +1802,6 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
 	}
 	dev_notice(smmu->dev, "\t%u context banks (%u stage-2 only)\n",
 		   smmu->num_context_banks, smmu->num_s2_context_banks);
-	/*
-	 * Cavium CN88xx erratum #27704.
-	 * Ensure ASID and VMID allocation is unique across all SMMUs in
-	 * the system.
-	 */
-	if (smmu->model == CAVIUM_SMMUV2) {
-		smmu->cavium_id_base =
-			atomic_add_return(smmu->num_context_banks,
-					  &cavium_smmu_context_count);
-		smmu->cavium_id_base -= smmu->num_context_banks;
-		dev_notice(smmu->dev, "\tenabling workaround for Cavium erratum 27704\n");
-	}
 	smmu->cbs = devm_kcalloc(smmu->dev, smmu->num_context_banks,
 				 sizeof(*smmu->cbs), GFP_KERNEL);
 	if (!smmu->cbs)
@@ -1884,6 +1870,9 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
 		dev_notice(smmu->dev, "\tStage-2: %lu-bit IPA -> %lu-bit PA\n",
 			   smmu->ipa_size, smmu->pa_size);
 
+	if (smmu->impl && smmu->impl->cfg_probe)
+		return smmu->impl->cfg_probe(smmu);
+
 	return 0;
 }
 
diff --git a/drivers/iommu/arm-smmu.h b/drivers/iommu/arm-smmu.h
index d4fd29d70705..f4e90f33fce2 100644
--- a/drivers/iommu/arm-smmu.h
+++ b/drivers/iommu/arm-smmu.h
@@ -287,6 +287,7 @@ struct arm_smmu_impl {
 	u64 (*read_reg64)(struct arm_smmu_device *smmu, int page, int offset);
 	void (*write_reg64)(struct arm_smmu_device *smmu, int page, int offset,
 			    u64 val);
+	int (*cfg_probe)(struct arm_smmu_device *smmu);
 };
 
 static inline void __iomem *arm_smmu_page(struct arm_smmu_device *smmu, int n)