Re: [net-next,v3,7/8] net: macb: add XDP support for gem

[Paolo Abeni <pabeni@redhat.com>]

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---
net: macb: add XDP support for gem

This commit introduces basic XDP support for the macb/gem driver,
implementing support for XDP_TX, XDP_PASS, XDP_DROP, and XDP_REDIRECT
verdicts.

> diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
> index 1ae80938331b..009a44e94726 100644
> --- a/drivers/net/ethernet/cadence/macb.h
> +++ b/drivers/net/ethernet/cadence/macb.h

[ ... ]

> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index fc6ea1391846..152cbf5eb33a 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c

[ ... ]

> @@ -3216,11 +3450,24 @@ static int macb_close(struct net_device *dev)
>  	return 0;
>  }
>
> +static bool gem_xdp_valid_mtu(struct macb *bp, int mtu)
> +{
> +	return __gem_total_rx_buffer_size(gem_max_rx_data_size(mtu + bp->rx_ip_align),
> +					  XDP_PACKET_HEADROOM) <= PAGE_SIZE;
> +}
> +
>  static int macb_change_mtu(struct net_device *dev, int new_mtu)
>  {
> +	struct macb *bp = netdev_priv(dev);
> +
>  	if (netif_running(dev))
>  		return -EBUSY;
>
> +	if (rcu_access_pointer(bp->prog) && !gem_xdp_valid_mtu(bp, new_mtu)) {
> +		netdev_err(dev, "MTU %d too large for XDP", new_mtu);
                                                               ^
This isn't a bug, but the format string is missing a trailing newline.
Every other netdev_err() call in this file ends with '\n', and without it
this message will be concatenated with the next kernel log line.

> +		return -EINVAL;
> +	}
> +
>  	WRITE_ONCE(dev->mtu, new_mtu);
>
>  	return 0;