[PATCH v8 08/15] drm/ttm: Use drm_memcpy_from_wc for TTM bo moves

[Thomas Hellström]

Use fast wc memcpy for reading out of wc memory for TTM bo moves.

Cc: Dave Airlie <airlied at gmail.com>
Cc: Christian König <christian.koenig at amd.com>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
Reviewed-by: Christian König <christian.koenig at amd.com> #v4
--
v4:
- Clarify when we try drm_memcpy_from_wc_dbm (Reported by Matthew Auld)
- Be paranoid about when drm_memcpy_from_wc_dbm may fail (Reported by
  Matthew Auld)
v5:
- Rebase on change to drm_memcpy_from_wc (Suggested by Daniel Vetter)
---
 drivers/gpu/drm/ttm/ttm_bo_util.c | 19 +++----------------
 1 file changed, 3 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index a800998a12b0..30bafac416a5 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -31,6 +31,7 @@
 
 #include <drm/ttm/ttm_bo_driver.h>
 #include <drm/ttm/ttm_placement.h>
+#include <drm/drm_cache.h>
 #include <drm/drm_vma_manager.h>
 #include <linux/dma-buf-map.h>
 #include <linux/io.h>
@@ -118,22 +119,8 @@ void ttm_move_memcpy(struct ttm_buffer_object *bo,
 		dst_ops->map_local(dst_iter, &dst_map, i);
 		src_ops->map_local(src_iter, &src_map, i);
 
-		if (!src_map.is_iomem && !dst_map.is_iomem) {
-			memcpy(dst_map.vaddr, src_map.vaddr, PAGE_SIZE);
-		} else if (!src_map.is_iomem) {
-			dma_buf_map_memcpy_to(&dst_map, src_map.vaddr,
-					      PAGE_SIZE);
-		} else if (!dst_map.is_iomem) {
-			memcpy_fromio(dst_map.vaddr, src_map.vaddr_iomem,
-				      PAGE_SIZE);
-		} else {
-			int j;
-			u32 __iomem *src = src_map.vaddr_iomem;
-			u32 __iomem *dst = dst_map.vaddr_iomem;
-
-			for (j = 0; j < (PAGE_SIZE / sizeof(u32)); ++j)
-				iowrite32(ioread32(src++), dst++);
-		}
+		drm_memcpy_from_wc(&dst_map, &src_map, PAGE_SIZE);
+
 		if (src_ops->unmap_local)
 			src_ops->unmap_local(src_iter, &src_map);
 		if (dst_ops->unmap_local)
-- 
2.31.1