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 -- 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) --- drivers/gpu/drm/ttm/ttm_bo_util.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c index 6ac7744a1a5c..ebff603a97f4 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_memcpy.h> #include <drm/drm_vma_manager.h> #include <linux/dma-buf-map.h> #include <linux/io.h> @@ -91,6 +92,7 @@ void ttm_move_memcpy(struct ttm_buffer_object *bo, const struct ttm_kmap_iter_ops *src_ops = src_iter->ops; struct ttm_tt *ttm = bo->ttm; struct dma_buf_map src_map, dst_map; + bool wc_memcpy; pgoff_t i;
/* Single TTM move. NOP */ @@ -114,11 +116,21 @@ void ttm_move_memcpy(struct ttm_buffer_object *bo, return; }
+ /* + * Condition this on src being WC if needed. However i915 perf + * selftest indicates that for PAGE_SIZE chunks, wc_memcpy + * outperforms memcpy() on all cases except WB->WB where results + * are similar. + */ + wc_memcpy = drm_has_memcpy_from_wc(); + for (i = 0; i < num_pages; ++i) { 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) { + if (wc_memcpy && drm_memcpy_from_wc_dbm(&dst_map, &src_map, PAGE_SIZE)) { + ; + } else 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,