Use fast wc memcpy for reading out of wc memory for TTM bo moves.
Cc: Dave Airlie <airlied@xxxxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
--
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,
--
2.31.1
