linux-kernel - Re: [PATCH net-next v1 1/1] net: dsa: microchip: add stats64 support for ksz8 series of switches

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20221207061409.GB19179@pengutronix.de>
Date:   Wed, 7 Dec 2022 07:14:09 +0100
From:   Oleksij Rempel <o.rempel@...gutronix.de>
To:     Vladimir Oltean <olteanv@...il.com>
Cc:     Woojung Huh <woojung.huh@...rochip.com>,
        Andrew Lunn <andrew@...n.ch>, Arun.Ramadoss@...rochip.com,
        Florian Fainelli <f.fainelli@...il.com>,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        Vivien Didelot <vivien.didelot@...il.com>,
        Eric Dumazet <edumazet@...gle.com>,
        Paolo Abeni <pabeni@...hat.com>, kernel@...gutronix.de,
        Jakub Kicinski <kuba@...nel.org>, UNGLinuxDriver@...rochip.com,
        "David S. Miller" <davem@...emloft.net>
Subject: Re: [PATCH net-next v1 1/1] net: dsa: microchip: add stats64 support
 for ksz8 series of switches

On Tue, Dec 06, 2022 at 07:08:01PM +0200, Vladimir Oltean wrote:
> On Mon, Dec 05, 2022 at 06:29:04AM +0100, Oleksij Rempel wrote:
> > +void ksz88xx_r_mib_stats64(struct ksz_device *dev, int port)
> > +{
> > +	struct ethtool_pause_stats *pstats;
> > +	struct rtnl_link_stats64 *stats;
> > +	struct ksz88xx_stats_raw *raw;
> > +	struct ksz_port_mib *mib;
> > +
> > +	mib = &dev->ports[port].mib;
> > +	stats = &mib->stats64;
> > +	pstats = &mib->pause_stats;
> > +	raw = (struct ksz88xx_stats_raw *)mib->counters;
> > +
> > +	spin_lock(&mib->stats64_lock);
> > +
> > +	stats->rx_packets = raw->rx_bcast + raw->rx_mcast + raw->rx_ucast +
> > +		raw->rx_pause;
> > +	stats->tx_packets = raw->tx_bcast + raw->tx_mcast + raw->tx_ucast +
> > +		raw->tx_pause;
> > +
> > +	/* HW counters are counting bytes + FCS which is not acceptable
> > +	 * for rtnl_link_stats64 interface
> > +	 */
> > +	stats->rx_bytes = raw->rx + raw->rx_hi - stats->rx_packets * ETH_FCS_LEN;
> > +	stats->tx_bytes = raw->tx + raw->tx_hi - stats->tx_packets * ETH_FCS_LEN;
> 
> What are rx_hi, tx_hi compared to rx, tx?

rx, tx are packets with normal priority and rx_hi, tx_hi are packets
with high prio.

> > +
> > +	stats->rx_length_errors = raw->rx_undersize + raw->rx_fragments +
> > +		raw->rx_oversize;
> > +
> > +	stats->rx_crc_errors = raw->rx_crc_err;
> > +	stats->rx_frame_errors = raw->rx_align_err;
> > +	stats->rx_dropped = raw->rx_discards;
> > +	stats->rx_errors = stats->rx_length_errors + stats->rx_crc_errors +
> > +		stats->rx_frame_errors  + stats->rx_dropped;
> > +
> > +	stats->tx_window_errors = raw->tx_late_col;
> > +	stats->tx_fifo_errors = raw->tx_discards;
> > +	stats->tx_aborted_errors = raw->tx_exc_col;
> > +	stats->tx_errors = stats->tx_window_errors + stats->tx_fifo_errors +
> > +		stats->tx_aborted_errors;
> > +
> > +	stats->multicast = raw->rx_mcast;
> > +	stats->collisions = raw->tx_total_col;
> > +
> > +	pstats->tx_pause_frames = raw->tx_pause;
> > +	pstats->rx_pause_frames = raw->rx_pause;
> 
> FWIW, ksz_get_pause_stats() can sleep, just ksz_get_stats64() can't. So
> the pause stats don't need to be periodically read (unless you want to
> do that to prevent 32-bit overflows).

KSZ driver is using worker to read stats periodically. Since all needed
locks are already taken, I copy pause stats as well.

Otherwise it will need some different locking, which will make things
look different but do not reduce CPU load. 

Regards,
Oleksij
-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |