iommu/amd: Fix hotplug with iommu=pt

commit 2c9195e9 upstream.

This did not work because devices are not put into the
pt_domain. Fix this.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
[bwh: Backported to 3.2: do not use iommu_dev_data::passthrough]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/iommu/amd_iommu.c

@@ -1865,6 +1865,11 @@ static int device_change_notifier(struct notifier_block *nb,
 
 		iommu_init_device(dev);
 
+		if (iommu_pass_through) {
+			attach_device(dev, pt_domain);
+			break;
+		}
+
 		domain = domain_for_device(dev);
 
 		/* allocate a protection domain if a device is added */
@@ -1880,10 +1885,7 @@ static int device_change_notifier(struct notifier_block *nb,
 		list_add_tail(&dma_domain->list, &iommu_pd_list);
 		spin_unlock_irqrestore(&iommu_pd_list_lock, flags);
 
-		if (!iommu_pass_through)
-			dev->archdata.dma_ops = &amd_iommu_dma_ops;
-		else
-			dev->archdata.dma_ops = &nommu_dma_ops;
+		dev->archdata.dma_ops = &amd_iommu_dma_ops;
 
 		break;
 	case BUS_NOTIFY_DEL_DEVICE: