net: mscc: ocelot: report ndo_get_stats64 from the wraparound-resistant ocelot->stats
Rather than reading the stats64 counters directly from the 32-bit hardware, it's better to rely on the output produced by the periodic ocelot_port_update_stats(). It would be even better to call ocelot_port_update_stats() right from ocelot_get_stats64() to make sure we report the current values rather than the ones from 2 seconds ago. But we need to export ocelot_port_update_stats() from the switch lib towards the switchdev driver for that, and future work will largely undo that. There are more ocelot-based drivers waiting to be introduced, an example of which is the SPI-controlled VSC7512. In that driver's case, it will be impossible to call ocelot_port_update_stats() from ndo_get_stats64 context, since the latter is atomic, and reading the stats over SPI is sleepable. So the compromise taken here, which will also hold going forward, is to report 64-bit counters to stats64, which are not 100% up to date. Fixes: a556c76a ("net: mscc: Add initial Ocelot switch support") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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