Subject: Re: [net-next PATCH V2 1/3] mm: add dma_addr_t to struct page

From: Florian Fainelli <[email-masked]>
Date: Tue, 12 Feb 2019 10:05:39 -0800

On 2/12/19 6:49 AM, Jesper Dangaard Brouer wrote:
> The page_pool API is using page->private to store DMA addresses.
> As pointed out by David Miller we can't use that on 32-bit architectures
> with 64-bit DMA
> 
> This patch adds a new dma_addr_t struct to allow storing DMA addresses
> 
> Signed-off-by: Jesper Dangaard Brouer <[email-masked]>
> Signed-off-by: Ilias Apalodimas <[email-masked]>
> Acked-by: Andrew Morton <[email-masked]>
> ---
>  include/linux/mm_types.h |    7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
> index 2c471a2c43fa..581737bd0878 100644
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -95,6 +95,13 @@ struct page {
>  			 */
>  			unsigned long private;
>  		};
> +		struct {	/* page_pool used by netstack */
> +			/**
> +			 * @dma_addr: page_pool requires a 64-bit value even on
> +			 * 32-bit architectures.
> +			 */

Nit: might require? dma_addr_t, as you mention in the commit may have a
different size based on CONFIG_ARCH_DMA_ADDR_T_64BIT.
-- 
Florian