powerpc/cell: cell_dma_dev_setup_iommu() return the iommu table

Make cell_dma_dev_setup_iommu() return a pointer to the struct iommu_table
(or NULL if no table can be found) rather than putting this pointer into
dev->archdata.dma_data (let the caller do that), and rename this function
to cell_get_iommu_table() to reflect this change.

This will allow us to get the iommu table for a device that doesn't have
the table in the archdata.
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/cell/iommu.c

@@ -540,7 +540,7 @@ static unsigned long cell_dma_direct_offset;
 static unsigned long dma_iommu_fixed_base;
 struct dma_mapping_ops dma_iommu_fixed_ops;
 
-static void cell_dma_dev_setup_iommu(struct device *dev)
+static struct iommu_table *cell_get_iommu_table(struct device *dev)
 {
 	struct iommu_window *window;
 	struct cbe_iommu *iommu;
@@ -555,11 +555,11 @@ static void cell_dma_dev_setup_iommu(struct device *dev)
 		printk(KERN_ERR "iommu: missing iommu for %s (node %d)\n",
 		       archdata->of_node ? archdata->of_node->full_name : "?",
 		       archdata->numa_node);
-		return;
+		return NULL;
 	}
 	window = list_entry(iommu->windows.next, struct iommu_window, list);
 
-	archdata->dma_data = &window->table;
+	return &window->table;
 }
 
 static void cell_dma_dev_setup_fixed(struct device *dev);
@@ -572,7 +572,7 @@ static void cell_dma_dev_setup(struct device *dev)
 	if (get_dma_ops(dev) == &dma_iommu_fixed_ops)
 		cell_dma_dev_setup_fixed(dev);
 	else if (get_pci_dma_ops() == &dma_iommu_ops)
-		cell_dma_dev_setup_iommu(dev);
+		archdata->dma_data = cell_get_iommu_table(dev);
 	else if (get_pci_dma_ops() == &dma_direct_ops)
 		archdata->dma_data = (void *)cell_dma_direct_offset;
 	else