iommu/amd: Initialize dma_ops for hotplug and sriov devices

commit ac1534a5 upstream.

When a device is added to the system at runtime the AMD
IOMMU driver initializes the necessary data structures to
handle translation for it. But it forgets to change the
per-device dma_ops to point to the AMD IOMMU driver. So
mapping actually never happens and all DMA accesses end in
an IO_PAGE_FAULT. Fix this.
Reported-by: Stefan Assmann <sassmann@redhat.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/iommu/amd_iommu.c

@@ -83,6 +83,8 @@ static struct iommu_ops amd_iommu_ops;
 static ATOMIC_NOTIFIER_HEAD(ppr_notifier);
 int amd_iommu_max_glx_val = -1;
 
+static struct dma_map_ops amd_iommu_dma_ops;
+
 /*
  * general struct to manage commands send to an IOMMU
  */
@@ -2267,6 +2269,13 @@ 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);
 
+		dev_data = get_dev_data(dev);
+
+		if (!dev_data->passthrough)
+			dev->archdata.dma_ops = &amd_iommu_dma_ops;
+		else
+			dev->archdata.dma_ops = &nommu_dma_ops;
+
 		break;
 	case BUS_NOTIFY_DEL_DEVICE: