iommu/amd: Add support for using AMD IOMMU v2 page table for DMA-API

Introduce init function for setting up DMA domain for DMA-API with
the IOMMU v2 page table.

Co-developed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20220825063939.8360-9-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd/iommu.c

@@ -1653,6 +1653,10 @@ static void do_attach(struct iommu_dev_data *dev_data,
 	domain->dev_iommu[iommu->index] += 1;
 	domain->dev_cnt                 += 1;
 
+	/* Override supported page sizes */
+	if (domain->flags & PD_GIOV_MASK)
+		domain->domain.pgsize_bitmap = AMD_IOMMU_PGSIZES_V2;
+
 	/* Update device table */
 	set_dte_entry(iommu, dev_data->devid, domain,
 		      ats, dev_data->iommu_v2);
@@ -2032,6 +2036,24 @@ static int protection_domain_init_v1(struct protection_domain *domain, int mode)
 	return 0;
 }
 
+static int protection_domain_init_v2(struct protection_domain *domain)
+{
+	spin_lock_init(&domain->lock);
+	domain->id = domain_id_alloc();
+	if (!domain->id)
+		return -ENOMEM;
+	INIT_LIST_HEAD(&domain->dev_list);
+
+	domain->flags |= PD_GIOV_MASK;
+
+	if (domain_enable_v2(domain, 1)) {
+		domain_id_free(domain->id);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
 static struct protection_domain *protection_domain_alloc(unsigned int type)
 {
 	struct io_pgtable_ops *pgtbl_ops;
@@ -2059,6 +2081,9 @@ static struct protection_domain *protection_domain_alloc(unsigned int type)
 	case AMD_IOMMU_V1:
 		ret = protection_domain_init_v1(domain, mode);
 		break;
+	case AMD_IOMMU_V2:
+		ret = protection_domain_init_v2(domain);
+		break;
 	default:
 		ret = -EINVAL;
 	}