Re: [PATCH v2 net-next 07/26] mvneta: add .ndo_get_xdp_stats() callback

[Russell King (Oracle)]

On Tue, Nov 23, 2021 at 05:39:36PM +0100, Alexander Lobakin wrote:
> +	for_each_possible_cpu(cpu) {
> +		const struct mvneta_pcpu_stats *stats;
> +		const struct mvneta_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;
> +		u32 start;
> +
> +		stats = per_cpu_ptr(pp->stats, cpu);
> +		ps = &stats->es.ps;
> +
> +		do {
> +			start = u64_stats_fetch_begin_irq(&stats->syncp);
> +
> +			xdp_drop = ps->xdp_drop;
> +			xdp_pass = ps->xdp_pass;
> +			xdp_redirect = ps->xdp_redirect;
> +			xdp_tx = ps->xdp_tx;
> +			xdp_tx_err = ps->xdp_tx_err;
> +			xdp_xmit = ps->xdp_xmit;
> +			xdp_xmit_err = ps->xdp_xmit_err;
> +		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
> +
> +		xdp_stats->drop += xdp_drop;
> +		xdp_stats->pass += xdp_pass;
> +		xdp_stats->redirect += xdp_redirect;
> +		xdp_stats->tx += xdp_tx;
> +		xdp_stats->tx_errors += xdp_tx_err;
> +		xdp_stats->xmit_packets += xdp_xmit;
> +		xdp_stats->xmit_errors += xdp_xmit_err;

Same comment as for mvpp2 - this could share a lot of code from
mvneta_ethtool_update_pcpu_stats() (although it means we end up
calculating a little more for the alloc error and refill error
that this API doesn't need) but I think sharing that code would be
a good idea.

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