iommu/amd: Implement dm_region call-backs

Add the get_dm_regions and put_dm_regions callbacks to the
iommu_ops of the AMD IOMMU driver.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index e43d489..22d38e3 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3412,6 +3412,47 @@
 	return false;
 }
 
+static void amd_iommu_get_dm_regions(struct device *dev,
+				     struct list_head *head)
+{
+	struct unity_map_entry *entry;
+	u16 devid;
+
+	devid = get_device_id(dev);
+
+	list_for_each_entry(entry, &amd_iommu_unity_map, list) {
+		struct iommu_dm_region *region;
+
+		if (devid < entry->devid_start || devid > entry->devid_end)
+			continue;
+
+		region = kzalloc(sizeof(*region), GFP_KERNEL);
+		if (!region) {
+			pr_err("Out of memory allocating dm-regions for %s\n",
+				dev_name(dev));
+			return;
+		}
+
+		region->start = entry->address_start;
+		region->length = entry->address_end - entry->address_start;
+		if (entry->prot & IOMMU_PROT_IR)
+			region->prot |= IOMMU_READ;
+		if (entry->prot & IOMMU_PROT_IW)
+			region->prot |= IOMMU_WRITE;
+
+		list_add_tail(&region->list, head);
+	}
+}
+
+static void amd_iommu_put_dm_regions(struct device *dev,
+				     struct list_head *head)
+{
+	struct iommu_dm_region *entry, *next;
+
+	list_for_each_entry_safe(entry, next, head, list)
+		kfree(entry);
+}
+
 static const struct iommu_ops amd_iommu_ops = {
 	.capable = amd_iommu_capable,
 	.domain_alloc = amd_iommu_domain_alloc,
@@ -3422,6 +3463,8 @@
 	.unmap = amd_iommu_unmap,
 	.map_sg = default_iommu_map_sg,
 	.iova_to_phys = amd_iommu_iova_to_phys,
+	.get_dm_regions = amd_iommu_get_dm_regions,
+	.put_dm_regions = amd_iommu_put_dm_regions,
 	.pgsize_bitmap	= AMD_IOMMU_PGSIZES,
 };