Subject: Re: [PATCH V3,net-next, 2/4] net: mana: Refactor RX buffer allocation code to prepare for various MTU

From: Leon Romanovsky <[email-masked]>
Date: Thu, 13 Apr 2023 16:04:28 +0300

On Wed, Apr 12, 2023 at 02:16:01PM -0700, Haiyang Zhang wrote:
> Move out common buffer allocation code from mana_process_rx_cqe() and
> mana_alloc_rx_wqe() to helper functions.
> Refactor related variables so they can be changed in one place, and buffer
> sizes are in sync.
> 
> Signed-off-by: Haiyang Zhang <[email-masked]>
> Reviewed-by: Jesse Brandeburg <[email-masked]>
> ---
> V3:
> Refectored to multiple patches for readability. Suggested by Jacob Keller.
> 
> V2:
> Refectored to multiple patches for readability. Suggested by Yunsheng Lin.
> 
> ---
>  drivers/net/ethernet/microsoft/mana/mana_en.c | 154 ++++++++++--------
>  include/net/mana/mana.h                       |   6 +-
>  2 files changed, 91 insertions(+), 69 deletions(-)

<...>

> +static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev,
> +			     dma_addr_t *da, bool is_napi)
> +{
> +	struct page *page;
> +	void *va;
> +
> +	/* Reuse XDP dropped page if available */
> +	if (rxq->xdp_save_va) {
> +		va = rxq->xdp_save_va;
> +		rxq->xdp_save_va = NULL;
> +	} else {
> +		page = dev_alloc_page();

Documentation/networking/page_pool.rst
   10 Basic use involves replacing alloc_pages() calls with the
   11 page_pool_alloc_pages() call.  Drivers should use page_pool_dev_alloc_pages()
   12 replacing dev_alloc_pages().

General question, is this sentence applicable to all new code or only
for XDP related paths?

Thanks