Date:   Wed, 24 Nov 2021 11:39:05 +0000
From:   "Russell King (Oracle)" <linux@armlinux.org.uk>
To:     Alexander Lobakin <alexandr.lobakin@intel.com>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Jesse Brandeburg <jesse.brandeburg@intel.com>,
        Michal Swiatkowski <michal.swiatkowski@linux.intel.com>,
        Maciej Fijalkowski <maciej.fijalkowski@intel.com>,
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        Noam Dagan <ndagan@amazon.com>,
        Saeed Bishara <saeedb@amazon.com>,
        Ioana Ciornei <ioana.ciornei@nxp.com>,
        Claudiu Manoil <claudiu.manoil@nxp.com>,
        Tony Nguyen <anthony.l.nguyen@intel.com>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
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        Sergey Ryazanov <ryazanov.s.a@gmail.com>,
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        Andrei Vagin <avagin@gmail.com>,
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        linux-rdma@vger.kernel.org, bpf@vger.kernel.org,
        virtualization@lists.linux-foundation.org
Subject: Re: [PATCH v2 net-next 07/26] mvneta: add .ndo_get_xdp_stats()
 callback
Message-ID: <YZ4kWXnqZQhSu+mw@shell.armlinux.org.uk>
References: <20211123163955.154512-1-alexandr.lobakin@intel.com>
 <20211123163955.154512-8-alexandr.lobakin@intel.com>
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Sender: Russell King (Oracle) <linux@armlinux.org.uk>
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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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