drm/ttm/radeon: add dma32 support.

This add support for using dma32 memory on gpus that really need it.

Currently IGPs are left without DMA32 but we might need to change
that unless we can fix rs690.

Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index 62ed733..ea83dd2 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -121,6 +121,7 @@
 #define TTM_PAGE_FLAG_SWAPPED         (1 << 4)
 #define TTM_PAGE_FLAG_PERSISTANT_SWAP (1 << 5)
 #define TTM_PAGE_FLAG_ZERO_ALLOC      (1 << 6)
+#define TTM_PAGE_FLAG_DMA32           (1 << 7)
 
 enum ttm_caching_state {
 	tt_uncached,
@@ -429,6 +430,8 @@
 	 */
 
 	struct delayed_work wq;
+
+	bool need_dma32;
 };
 
 /**
@@ -648,7 +651,7 @@
 extern int ttm_bo_device_init(struct ttm_bo_device *bdev,
 			      struct ttm_mem_global *mem_glob,
 			      struct ttm_bo_driver *driver,
-			      uint64_t file_page_offset);
+			      uint64_t file_page_offset, bool need_dma32);
 
 /**
  * ttm_bo_reserve: