Subject: Re: [PATCH v3 iwl-net 3/3] ice: stop storing XDP verdict within ice_rx_buf

From: Maciej Fijalkowski <[email-masked]>
Date: Wed, 22 Jan 2025 13:50:05 +0100

On Mon, Jan 20, 2025 at 04:37:55PM +0000, Simon Horman wrote:
> On Mon, Jan 20, 2025 at 04:50:16PM +0100, Maciej Fijalkowski wrote:
> > Idea behind having ice_rx_buf::act was to simplify and speed up the Rx
> > data path by walking through buffers that were representing cleaned HW
> > Rx descriptors. Since it caused us a major headache recently and we
> > rolled back to old approach that 'puts' Rx buffers right after running
> > XDP prog/creating skb, this is useless now and should be removed.
> > 
> > Get rid of ice_rx_buf::act and related logic. We still need to take care
> > of a corner case where XDP program releases a particular fragment.
> > 
> > Make ice_run_xdp() to return its result and use it within
> > ice_put_rx_mbuf().
> > 
> > Fixes: 2fba7dc5157b ("ice: Add support for XDP multi-buffer on Rx side")
> > Reviewed-by: Przemek Kitszel <[email-masked]>
> > Signed-off-by: Maciej Fijalkowski <[email-masked]>
> > ---
> >  drivers/net/ethernet/intel/ice/ice_txrx.c     | 60 +++++++++++--------
> >  drivers/net/ethernet/intel/ice/ice_txrx.h     |  1 -
> >  drivers/net/ethernet/intel/ice/ice_txrx_lib.h | 43 -------------
> >  3 files changed, 35 insertions(+), 69 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c
> > index 9aa53ad2d8f2..77d75664c14d 100644
> > --- a/drivers/net/ethernet/intel/ice/ice_txrx.c
> > +++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
> > @@ -532,10 +532,10 @@ int ice_setup_rx_ring(struct ice_rx_ring *rx_ring)
> >   *
> >   * Returns any of ICE_XDP_{PASS, CONSUMED, TX, REDIR}
> >   */
> > -static void
> > +static u32
> >  ice_run_xdp(struct ice_rx_ring *rx_ring, struct xdp_buff *xdp,
> >  	    struct bpf_prog *xdp_prog, struct ice_tx_ring *xdp_ring,
> > -	    struct ice_rx_buf *rx_buf, union ice_32b_rx_flex_desc *eop_desc)
> > +	    union ice_32b_rx_flex_desc *eop_desc)
> >  {
> >  	unsigned int ret = ICE_XDP_PASS;
> >  	u32 act;
> 
> nit: The Kernel doc for ice_run_xdp should also be updated to no
>      longer document the rx_buf parameter.

Heh - but after making it to return the verdict again the return
description is valid:D

I have been missing the kdoc descriptions for introduced functions in this
patchset so let me add them as well.

Thanks for review!

> ...