staging: gasket: fix DMA direction for extended page tables

Extended page tables should be mapped as DMA_TO_DEVICE, not
bi-directional.
Signed-off-by: Nick Ewalt <nicholasewalt@google.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/gasket/gasket_page_table.c

@@ -320,7 +320,7 @@ static void gasket_free_extended_subtable(struct gasket_page_table *pg_tbl,
 
 	if (pte->dma_addr)
 		dma_unmap_page(pg_tbl->device, pte->dma_addr, PAGE_SIZE,
-			       DMA_BIDIRECTIONAL);
+			       DMA_TO_DEVICE);
 
 	vfree(pte->sublevel);
 
@@ -894,7 +894,7 @@ static int gasket_alloc_extended_subtable(struct gasket_page_table *pg_tbl,
 
 	/* Map the page into DMA space. */
 	pte->dma_addr = dma_map_page(pg_tbl->device, pte->page, 0, PAGE_SIZE,
-				     DMA_BIDIRECTIONAL);
+				     DMA_TO_DEVICE);
 
 	/* make the addresses available to the device */
 	dma_addr = (pte->dma_addr + pte->offset) | GASKET_VALID_SLOT_FLAG;