Re: [RFC PATCH net-next 11/11] net: enetc: add TX support for zero-copy XDP sockets

[Maciej Fijalkowski]

On Mon, Feb 06, 2023 at 12:19:21PM +0200, Vladimir Oltean wrote:
> Yikes, ran git format-patch one patch too soon. There's also a hidden,
> bonus patch "12/11" below. Doesn't affect first 11 patches in any way,
> though. Here it is.
> 
> From f7f10232622309d66a7a1ae1932d0c081936d546 Mon Sep 17 00:00:00 2001
> From: Vladimir Oltean <vladimir.oltean@xxxxxxx>
> Date: Tue, 25 Oct 2022 02:32:24 +0300
> Subject: [RFC PATCH net-next 12/12] net: enetc: add support for XDP_TX
>  with zero-copy XDP sockets
> 
> Add support for the case when the BPF program attached to a ring with an
> XSK pool returns the XDP_TX verdict. The frame needs to go back on the
> interface it came from.
> 
> No dma_map or dma_sync_for_device is necessary, just a small impedance
> matching logic with the XDP_TX procedure we have in place for non-XSK,
> since the data structures are different (xdp_buff vs xdp_frame; cannot
> have multi-buffer with XSK).
> 
> In the TX confirmation routine, just release the RX buffer (as opposed
> to non-XSK XDP_TX). Recycling might be possible, but I haven't
> experimented with it.

ugh premature response on 10/11.

> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
> ---
>  drivers/net/ethernet/freescale/enetc/enetc.c | 35 ++++++++++++++++++--
>  drivers/net/ethernet/freescale/enetc/enetc.h |  1 +
>  2 files changed, 34 insertions(+), 2 deletions(-)