Re: [PATCH 2/4] drm/ttm: Create pinned list

["Christian König" <christian.koenig@amd.com>]

Am 24.08.21 um 23:01 schrieb Andrey Grodzovsky:
> This list will be used to capture all non VRAM BOs not
> on LRU so when device is hot unplugged we can iterate
> the list and unmap DMA mappings before device is removed.
>
> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
> Suggested-by: Christian König <christian.koenig@amd.com>
> ---
>   drivers/gpu/drm/ttm/ttm_bo.c       | 24 +++++++++++++++++++++---
>   drivers/gpu/drm/ttm/ttm_resource.c |  1 +
>   include/drm/ttm/ttm_resource.h     |  1 +
>   3 files changed, 23 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
> index 1b950b45cf4b..84ba76ace58f 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> @@ -69,16 +69,34 @@ static void ttm_bo_mem_space_debug(struct ttm_buffer_object *bo,
>   	}
>   }
>   
> -static void ttm_bo_del_from_lru(struct ttm_buffer_object *bo)
> +static void ttm_bo_del_from_lru_imp(struct ttm_buffer_object *bo, bool final)

I think we should rather inline the only user where we actually need to 
delete the BO from the LRU and then rename the function here to 
ttm_bo_move_to_pinned().

Apart from that looks good to me.

Regards,
Christian.

>   {
>   	struct ttm_device *bdev = bo->bdev;
> +	struct ttm_resource_manager *man = NULL;
>   
> -	list_del_init(&bo->lru);
> +	if (bo->resource)
> +		man = ttm_manager_type(bdev, bo->resource->mem_type);
> +
> +
> +	if (!final && man && man->use_tt)
> +		list_move_tail(&bo->lru, &man->pinned);
> +	else
> +		list_del_init(&bo->lru);
>   
>   	if (bdev->funcs->del_from_lru_notify)
>   		bdev->funcs->del_from_lru_notify(bo);
>   }
>   
> +static inline void ttm_bo_del_from_lru_final(struct ttm_buffer_object *bo)
> +{
> +	ttm_bo_del_from_lru_imp(bo, true);
> +}
> +
> +static inline void ttm_bo_del_from_lru(struct ttm_buffer_object *bo)
> +{
> +	ttm_bo_del_from_lru_imp(bo, false);
> +}
> +
>   static void ttm_bo_bulk_move_set_pos(struct ttm_lru_bulk_move_pos *pos,
>   				     struct ttm_buffer_object *bo)
>   {
> @@ -453,7 +471,7 @@ static void ttm_bo_release(struct kref *kref)
>   	}
>   
>   	spin_lock(&bo->bdev->lru_lock);
> -	ttm_bo_del_from_lru(bo);
> +	ttm_bo_del_from_lru_final(bo);
>   	list_del(&bo->ddestroy);
>   	spin_unlock(&bo->bdev->lru_lock);
>   
> diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c
> index 2431717376e7..91165f77fe0e 100644
> --- a/drivers/gpu/drm/ttm/ttm_resource.c
> +++ b/drivers/gpu/drm/ttm/ttm_resource.c
> @@ -85,6 +85,7 @@ void ttm_resource_manager_init(struct ttm_resource_manager *man,
>   
>   	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i)
>   		INIT_LIST_HEAD(&man->lru[i]);
> +	INIT_LIST_HEAD(&man->pinned);
>   	man->move = NULL;
>   }
>   EXPORT_SYMBOL(ttm_resource_manager_init);
> diff --git a/include/drm/ttm/ttm_resource.h b/include/drm/ttm/ttm_resource.h
> index 140b6b9a8bbe..1ec0d5ebb59f 100644
> --- a/include/drm/ttm/ttm_resource.h
> +++ b/include/drm/ttm/ttm_resource.h
> @@ -130,6 +130,7 @@ struct ttm_resource_manager {
>   	 */
>   
>   	struct list_head lru[TTM_MAX_BO_PRIORITY];
> +	struct list_head pinned;
>   
>   	/*
>   	 * Protected by @move_lock.