drm/ttm: Use drm_memcpy_from_wc for TTM bo moves

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

Cc: Dave Airlie <airlied@gmail.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com> #v4
Link: https://lore.kernel.org/r/20210602083818.241793-6-thomas.hellstrom@linux.intel.com
Link: https://patchwork.freedesktop.org/patch/msgid/20210602083818.241793-6-thomas.hellstrom@linux.intel.com

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;
+		drm_memcpy_from_wc(&dst_map, &src_map, PAGE_SIZE);
 
-			for (j = 0; j < (PAGE_SIZE / sizeof(u32)); ++j)
-				iowrite32(ioread32(src++), dst++);
-		}
 		if (src_ops->unmap_local)
 			src_ops->unmap_local(src_iter, &src_map);
 		if (dst_ops->unmap_local)