Subject: Re: [PATCH v2 net-next 08/26] mvpp2: provide .ndo_get_xdp_stats() callback

From: "Russell King (Oracle)" <[email-masked]>
Date: Wed, 24 Nov 2021 11:36:20 +0000

On Tue, Nov 23, 2021 at 05:39:37PM +0100, Alexander Lobakin wrote:
> Same as mvneta, mvpp2 stores 7 XDP counters in per-cpu containers.
> Expose them via generic XDP stats infra.
> 
> Signed-off-by: Alexander Lobakin <[email-masked]>
> Reviewed-by: Jesse Brandeburg <[email-masked]>
> ---
>  .../net/ethernet/marvell/mvpp2/mvpp2_main.c   | 51 +++++++++++++++++++
>  1 file changed, 51 insertions(+)
> 
> diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> index 97bd2ee8a010..58203cde3b60 100644
> --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> @@ -5131,6 +5131,56 @@ mvpp2_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
>  	stats->tx_dropped	= dev->stats.tx_dropped;
>  }
> 
> +static int mvpp2_get_xdp_stats_ndo(const struct net_device *dev, u32 attr_id,
> +				   void *attr_data)
> +{
> +	const struct mvpp2_port *port = netdev_priv(dev);
> +	struct ifla_xdp_stats *xdp_stats = attr_data;
> +	u32 cpu, start;
> +
> +	switch (attr_id) {
> +	case IFLA_XDP_XSTATS_TYPE_XDP:
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	for_each_possible_cpu(cpu) {
> +		const struct mvpp2_pcpu_stats *ps;
> +		u64 xdp_xmit_err;
> +		u64 xdp_redirect;
> +		u64 xdp_tx_err;
> +		u64 xdp_pass;
> +		u64 xdp_drop;
> +		u64 xdp_xmit;
> +		u64 xdp_tx;
> +
> +		ps = per_cpu_ptr(port->stats, cpu);
> +
> +		do {
> +			start = u64_stats_fetch_begin_irq(&ps->syncp);
> +
> +			xdp_redirect = ps->xdp_redirect;
> +			xdp_pass = ps->xdp_pass;
> +			xdp_drop = ps->xdp_drop;
> +			xdp_xmit = ps->xdp_xmit;
> +			xdp_xmit_err = ps->xdp_xmit_err;
> +			xdp_tx = ps->xdp_tx;
> +			xdp_tx_err = ps->xdp_tx_err;
> +		} while (u64_stats_fetch_retry_irq(&ps->syncp, start));
> +
> +		xdp_stats->redirect += xdp_redirect;
> +		xdp_stats->pass += xdp_pass;
> +		xdp_stats->drop += xdp_drop;
> +		xdp_stats->xmit_packets += xdp_xmit;
> +		xdp_stats->xmit_errors += xdp_xmit_err;
> +		xdp_stats->tx += xdp_tx;
> +		xdp_stats->tx_errors  += xdp_tx_err;
> +	}

Actually, the only concern I have here is the duplication between this
function and mvpp2_get_xdp_stats(). It looks to me like these two
functions could share a lot of their code. Please submit a patch to
make that happen. Thanks.

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