On Tue, 2024-03-12 at 11:55 +0100, Christian König wrote:
> The BOs in a bulk move must share all the same reservation object
> to make sure that we lock the whole bulk during eviction.
>
> Actually document and enforce that with a warning.
>
> Signed-off-by: Christian König <christian.koenig@xxxxxxx>
Tested with Xe CI,
Reviewed-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/ttm/ttm_resource.c | 1 +
> include/drm/ttm/ttm_resource.h | 3 +++
> 2 files changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_resource.c
> b/drivers/gpu/drm/ttm/ttm_resource.c
> index 65155f2013ca..be8d286513f9 100644
> --- a/drivers/gpu/drm/ttm/ttm_resource.c
> +++ b/drivers/gpu/drm/ttm/ttm_resource.c
> @@ -105,6 +105,7 @@ static void ttm_lru_bulk_move_add(struct
> ttm_lru_bulk_move *bulk,
> pos->first = res;
> pos->last = res;
> } else {
> + WARN_ON(pos->first->bo->base.resv != res->bo-
> >base.resv);
> ttm_lru_bulk_move_pos_tail(pos, res);
> }
> }
> diff --git a/include/drm/ttm/ttm_resource.h
> b/include/drm/ttm/ttm_resource.h
> index 7561023db43d..69769355139f 100644
> --- a/include/drm/ttm/ttm_resource.h
> +++ b/include/drm/ttm/ttm_resource.h
> @@ -251,6 +251,9 @@ struct ttm_lru_bulk_move_pos {
> *
> * Container for the current bulk move state. Should be used with
> * ttm_lru_bulk_move_init() and ttm_bo_set_bulk_move().
> + * All BOs in a bulk_move structure need to share the same
> reservation object to
> + * ensure that the bulk as a whole is locked for eviction even if
> only one BO of
> + * the bulk is evicted.
> */
> struct ttm_lru_bulk_move {
> struct ttm_lru_bulk_move_pos
> pos[TTM_NUM_MEM_TYPES][TTM_MAX_BO_PRIORITY];
