Subject: Re: [PATCH 2/3, net-next] net: page_pool: add helper function for retrieving dma direction

From: Jesper Dangaard Brouer <[email-masked]>
Date: Fri, 28 Jun 2019 15:07:01 +0200

On Fri, 28 Jun 2019 13:39:14 +0300
Ilias Apalodimas <[email-masked]> wrote:

> Since the dma direction is stored in page pool params, offer an API
> helper for driver that choose not to keep track of it locally
> 
> Signed-off-by: Ilias Apalodimas <[email-masked]>
> ---
>  include/net/page_pool.h | 9 +++++++++
>  1 file changed, 9 insertions(+)

Acked-by: Jesper Dangaard Brouer <[email-masked]>

This is simple enough and you also explained the downside.
Thanks for adding a helper for this.

> diff --git a/include/net/page_pool.h b/include/net/page_pool.h
> index f07c518ef8a5..ee9c871d2043 100644
> --- a/include/net/page_pool.h
> +++ b/include/net/page_pool.h
> @@ -112,6 +112,15 @@ static inline struct page *page_pool_dev_alloc_pages(struct page_pool *pool)
>  	return page_pool_alloc_pages(pool, gfp);
>  }
>  
> +/* get the stored dma direction. A driver might decide to treat this locally and
> + * avoid the extra cache line from page_pool to determine the direction
> + */
> +static
> +inline enum dma_data_direction page_pool_get_dma_dir(struct page_pool *pool)
> +{
> +	return pool->p.dma_dir;
> +}
> +
>  struct page_pool *page_pool_create(const struct page_pool_params *params);
>  
>  void __page_pool_free(struct page_pool *pool);

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer