drm/ttm: expose CPU address of DMA-allocated pages

Pages allocated using the DMA API have a coherent memory mapping. Make
this mapping visible to drivers so they can decide to use it instead of
creating their own redundant one.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: David Airlie <airlied@linux.ie>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index 202f0a7171e8..1d9f0f1ff52d 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -133,6 +133,7 @@ struct ttm_tt {
  * struct ttm_dma_tt
  *
  * @ttm: Base ttm_tt struct.
+ * @cpu_address: The CPU address of the pages
  * @dma_address: The DMA (bus) addresses of the pages
  * @pages_list: used by some page allocation backend
  *
@@ -142,6 +143,7 @@ struct ttm_tt {
  */
 struct ttm_dma_tt {
         struct ttm_tt ttm;
+        void **cpu_address;
         dma_addr_t *dma_address;
         struct list_head pages_list;
 };