Re: [PATCH v2 net-next 7/7] net: ethernet: ti: cpsw: add XDP support

[Ivan Khoronzhuk]

On Fri, May 31, 2019 at 05:46:43PM +0200, Jesper Dangaard Brouer wrote:

Hi Jesper,

> Hi Ivan,
>
> From below code snippets, it looks like you only allocated 1 page_pool
> and sharing it with several RX-queues, as I don't have the full context
> and don't know this driver, I might be wrong?
>
> To be clear, a page_pool object is needed per RX-queue, as it is
> accessing a small RX page cache (which protected by NAPI/softirq).

There is one RX interrupt and one RX NAPI for all rx channels.

> On Thu, 30 May 2019 21:20:39 +0300
> Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx> wrote:
>
> > @@ -1404,6 +1711,14 @@ static int cpsw_ndo_open(struct net_device *ndev)
> >  			enable_irq(cpsw->irqs_table[0]);
> >  		}
> >
> > +		pool_size = cpdma_get_num_rx_descs(cpsw->dma);
> > +		cpsw->page_pool = cpsw_create_page_pool(cpsw, pool_size);
> > +		if (IS_ERR(cpsw->page_pool)) {
> > +			ret = PTR_ERR(cpsw->page_pool);
> > +			cpsw->page_pool = NULL;
> > +			goto err_cleanup;
> > +		}
>
> On Thu, 30 May 2019 21:20:39 +0300
> Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx> wrote:
>
> > @@ -675,10 +742,33 @@ int cpsw_set_ringparam(struct net_device *ndev,
> >  	if (cpsw->usage_count)
> >  		cpdma_chan_split_pool(cpsw->dma);
> >
> > +	for (i = 0; i < cpsw->data.slaves; i++) {
> > +		struct net_device *ndev = cpsw->slaves[i].ndev;
> > +
> > +		if (!(ndev && netif_running(ndev)))
> > +			continue;
> > +
> > +		cpsw_xdp_unreg_rxqs(netdev_priv(ndev));
> > +	}
> > +
> > +	page_pool_destroy(cpsw->page_pool);
> > +	cpsw->page_pool = pool;
> > +
>
> On Thu, 30 May 2019 21:20:39 +0300
> Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx> wrote:
>
> > +void cpsw_xdp_unreg_rxqs(struct cpsw_priv *priv)
> > +{
> > +	struct cpsw_common *cpsw = priv->cpsw;
> > +	int i;
> > +
> > +	for (i = 0; i < cpsw->rx_ch_num; i++)
> > +		xdp_rxq_info_unreg(&priv->xdp_rxq[i]);
> > +}
>
>
> On Thu, 30 May 2019 21:20:39 +0300
> Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx> wrote:
>
> > +int cpsw_xdp_reg_rxq(struct cpsw_priv *priv, int ch)
> > +{
> > +	struct xdp_rxq_info *xdp_rxq = &priv->xdp_rxq[ch];
> > +	struct cpsw_common *cpsw = priv->cpsw;
> > +	int ret;
> > +
> > +	ret = xdp_rxq_info_reg(xdp_rxq, priv->ndev, ch);
> > +	if (ret)
> > +		goto err_cleanup;
> > +
> > +	ret = xdp_rxq_info_reg_mem_model(xdp_rxq, MEM_TYPE_PAGE_POOL,
> > +					 cpsw->page_pool);
> > +	if (ret)
> > +		goto err_cleanup;
> > +
> > +	return 0;
>
>
>
> --
> Best regards,
>  Jesper Dangaard Brouer
>  MSc.CS, Principal Kernel Engineer at Red Hat
>  LinkedIn: http://www.linkedin.com/in/brouer

--
Regards,
Ivan Khoronzhuk