iommu/arm-smmu: Add context init implementation hook

Allocating and initialising a context for a domain is another point
where certain implementations are known to want special behaviour.
Currently the other half of the Cavium workaround comes into play here,
so let's finish the job to get the whole thing right out of the way.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 38 insertions, 4 deletions

diff --git a/drivers/iommu/arm-smmu-impl.c b/drivers/iommu/arm-smmu-impl.c
index 4dc8b1c4befb..e22e9004f449 100644
--- a/drivers/iommu/arm-smmu-impl.c
+++ b/drivers/iommu/arm-smmu-impl.c
@@ -48,25 +48,60 @@ const struct arm_smmu_impl calxeda_impl = {
 };
 
 
+struct cavium_smmu {
+	struct arm_smmu_device smmu;
+	u32 id_base;
+};
+
 static int cavium_cfg_probe(struct arm_smmu_device *smmu)
 {
 	static atomic_t context_count = ATOMIC_INIT(0);
+	struct cavium_smmu *cs = container_of(smmu, struct cavium_smmu, smmu);
 	/*
 	 * 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);
+	cs->id_base = atomic_fetch_add(smmu->num_context_banks, &context_count);
 	dev_notice(smmu->dev, "\tenabling workaround for Cavium erratum 27704\n");
 
 	return 0;
 }
 
+int cavium_init_context(struct arm_smmu_domain *smmu_domain)
+{
+	struct cavium_smmu *cs = container_of(smmu_domain->smmu,
+					      struct cavium_smmu, smmu);
+
+	if (smmu_domain->stage == ARM_SMMU_DOMAIN_S2)
+		smmu_domain->cfg.vmid += cs->id_base;
+	else
+		smmu_domain->cfg.asid += cs->id_base;
+
+	return 0;
+}
+
 const struct arm_smmu_impl cavium_impl = {
 	.cfg_probe = cavium_cfg_probe,
+	.init_context = cavium_init_context,
 };
 
+struct arm_smmu_device *cavium_smmu_impl_init(struct arm_smmu_device *smmu)
+{
+	struct cavium_smmu *cs;
+
+	cs = devm_kzalloc(smmu->dev, sizeof(*cs), GFP_KERNEL);
+	if (!cs)
+		return ERR_PTR(-ENOMEM);
+
+	cs->smmu = *smmu;
+	cs->smmu.impl = &cavium_impl;
+
+	devm_kfree(smmu->dev, smmu);
+
+	return &cs->smmu;
+}
+
 
 #define ARM_MMU500_ACTLR_CPRE		(1 << 1)
 
@@ -126,8 +161,7 @@ struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu)
 		smmu->impl = &arm_mmu500_impl;
 		break;
 	case CAVIUM_SMMUV2:
-		smmu->impl = &cavium_impl;
-		break;
+		return cavium_smmu_impl_init(smmu);
 	default:
 		break;
 	}