[net-next PATCH 1/2] mm: add dma_addr_t to struct page

[Jesper Dangaard Brouer <brouer@redhat.com>]

The page_pool API is using page->private to store DMA addresses.
As pointed out by David Miller we can't use that on 32-bit architectures
with 64-bit DMA

This patch adds a new dma_addr_t struct to allow storing DMA addresses

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---
 include/linux/mm_types.h |    8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 2c471a2c43fa..3060700752cc 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -95,6 +95,14 @@ struct page {
 			 */
 			unsigned long private;
 		};
+		struct {	/* page_pool used by netstack */
+			/**
+			 * @dma_addr: Page_pool need to store DMA-addr, and
+			 * cannot use @private, as DMA-mappings can be 64-bit
+			 * even on 32-bit Architectures.
+			 */
+			dma_addr_t dma_addr; /* Shares area with @lru */
+		};
 		struct {	/* slab, slob and slub */
 			union {
 				struct list_head slab_list;	/* uses lru */