[POWERPC] Set archdata.dma_data for direct DMA in cell_dma_dev_setup()

Store the direct_dma_offset in each device's dma_data in the case
where we're using the direct DMA ops.

We need to make sure we setup the ppc_md.pci_dma_dev_setup() callback
if we're using a non-zero offset.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/cell/iommu.c

@@ -496,9 +496,10 @@ static void cell_dma_dev_setup(struct device *dev)
 	struct cbe_iommu *iommu;
 	struct dev_archdata *archdata = &dev->archdata;
 
-	/* If we run without iommu, no need to do anything */
-	if (get_pci_dma_ops() == &dma_direct_ops)
+	if (get_pci_dma_ops() == &dma_direct_ops) {
+		archdata->dma_data = (void *)dma_direct_offset;
 		return;
+	}
 
 	/* Current implementation uses the first window available in that
 	 * node's iommu. We -might- do something smarter later though it may
@@ -690,6 +691,9 @@ static int __init cell_iommu_init_disabled(void)
 
 	dma_direct_offset += base;
 
+	if (dma_direct_offset != 0)
+		ppc_md.pci_dma_dev_setup = cell_pci_dma_dev_setup;
+
 	printk("iommu: disabled, direct DMA offset is 0x%lx\n",
 	       dma_direct_offset);