Re: [PATCH net-next v3 4/7] net: lan966x: Update rxq memory model

Horatiu Vultur
2022-11-22T21:18:56Z

The 11/22/2022 12:38, Alexander Lobakin wrote:
>
> From: Horatiu Vultur <horatiu.vultur@microchip.com>
> Date: Mon, 21 Nov 2022 22:28:47 +0100
>
> > By default the rxq memory model is MEM_TYPE_PAGE_SHARED but to be able
> > to reuse pages on the TX side, when the XDP action XDP_TX it is required
> > to update the memory model to PAGE_POOL.
> >
> > Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
> > ---
> > .../net/ethernet/microchip/lan966x/lan966x_fdma.c | 14 ++++++++++++++
> > 1 file changed, 14 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
> > index 384ed34197d58..483d1470c8362 100644
> > --- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
> > +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
> > @@ -78,8 +78,22 @@ static int lan966x_fdma_rx_alloc_page_pool(struct lan966x_rx *rx)
> > .max_len = rx->max_mtu -
> > SKB_DATA_ALIGN(sizeof(struct skb_shared_info)),
> > };
> > + struct lan966x_port *port;
> > + int i;
> >
> > rx->page_pool = page_pool_create(&pp_params);
> > +
> > + for (i = 0; i < lan966x->num_phys_ports; ++i) {
> > + if (!lan966x->ports[i])
> > + continue;
> > +
> > + port = lan966x->ports[i];
> > +
> > + xdp_rxq_info_unreg_mem_model(&port->xdp_rxq);
>
> xdp_rxq_info_unreg_mem_model() can emit a splat if currently the
> corresponding xdp_rxq_info is not registered[0]. Can't we face it
> here if called from lan966x_fdma_init()?

We will not face that issue here because before lan966x_fdma_init is
called, we call lan966x_xdp_port_init which registers xdp_rxq_info.

>
> > + xdp_rxq_info_reg_mem_model(&port->xdp_rxq, MEM_TYPE_PAGE_POOL,
> > + rx->page_pool);
> > + }
> > +
> > return PTR_ERR_OR_ZERO(rx->page_pool);
> > }
> >
> > --
> > 2.38.0
>
> Thanks,
> Olek

--
/Horatiu