[POWERPC] Move allocation of cell IOMMU pad page

There's no need to allocate the pad page unless we're going to actually
use it - so move the allocation to where we know we're going to use it.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 6 insertions, 6 deletions

diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c
index 555d264ad568..8e57e1af3785 100644
--- a/arch/powerpc/platforms/cell/iommu.c
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -344,12 +344,6 @@ static void cell_iommu_setup_page_tables(struct cbe_iommu *iommu,
         iommu->ptab = page_address(page);
         memset(iommu->ptab, 0, ptab_size);
 
-        /* allocate a bogus page for the end of each mapping */
-        page = alloc_pages_node(iommu->nid, GFP_KERNEL, 0);
-        BUG_ON(!page);
-        iommu->pad_page = page_address(page);
-        clear_page(iommu->pad_page);
-
         /* number of pages needed for a page table */
         n_pte_pages = (pages_per_segment *
                        sizeof(unsigned long)) >> IOMMU_PAGE_SHIFT;
@@ -463,6 +457,7 @@ cell_iommu_setup_window(struct cbe_iommu *iommu, struct device_node *np,
                         unsigned long pte_offset)
 {
         struct iommu_window *window;
+        struct page *page;
         u32 ioid;
 
         ioid = cell_iommu_get_ioid(np);
@@ -501,6 +496,11 @@ cell_iommu_setup_window(struct cbe_iommu *iommu, struct device_node *np,
          * This code also assumes that we have a window that starts at 0,
          * which is the case on all spider based blades.
          */
+        page = alloc_pages_node(iommu->nid, GFP_KERNEL, 0);
+        BUG_ON(!page);
+        iommu->pad_page = page_address(page);
+        clear_page(iommu->pad_page);
+
         __set_bit(0, window->table.it_map);
         tce_build_cell(&window->table, window->table.it_offset, 1,
                        (unsigned long)iommu->pad_page, DMA_TO_DEVICE);