diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c
index 6e54a0fd31a..e7554154a6d 100644
--- a/arch/powerpc/kernel/dma-iommu.c
+++ b/arch/powerpc/kernel/dma-iommu.c
@@ -19,7 +19,7 @@ static void *dma_iommu_alloc_coherent(struct device *dev, size_t size,
 				      dma_addr_t *dma_handle, gfp_t flag)
 {
 	return iommu_alloc_coherent(dev, get_iommu_table_base(dev), size,
-				    dma_handle, device_to_mask(dev), flag,
+				    dma_handle, dev->coherent_dma_mask, flag,
 				    dev_to_node(dev));
 }
 
diff --git a/arch/powerpc/kernel/vio.c b/arch/powerpc/kernel/vio.c
index b2654058f2e..1b695fdc362 100644
--- a/arch/powerpc/kernel/vio.c
+++ b/arch/powerpc/kernel/vio.c
@@ -1257,6 +1257,10 @@ struct vio_dev *vio_register_device_node(struct device_node *of_node)
 	viodev->dev.parent = &vio_bus_device.dev;
 	viodev->dev.bus = &vio_bus_type;
 	viodev->dev.release = vio_dev_release;
+        /* needed to ensure proper operation of coherent allocations
+         * later, in case driver doesn't set it explicitly */
+        dma_set_mask(&viodev->dev, DMA_BIT_MASK(64));
+        dma_set_coherent_mask(&viodev->dev, DMA_BIT_MASK(64));
 
 	/* register with generic device framework */
 	if (device_register(&viodev->dev)) {