[Intel-gfx] [PATCH v7 08/15] drm/ttm: Use drm_memcpy_from_wc for TTM bo moves

Thomas Hellström
2021-05-31T12:20:23Z

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
--
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 6ac7744a1a5c..a46f705ba78b 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)