net: dsa: add optional stats64 support

Allow DSA drivers to export stats64
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/dsa.h

@@ -482,7 +482,7 @@ struct dsa_switch_ops {
 	void	(*phylink_fixed_state)(struct dsa_switch *ds, int port,
 				       struct phylink_link_state *state);
 	/*
-	 * ethtool hardware statistics.
+	 * Port statistics counters.
 	 */
 	void	(*get_strings)(struct dsa_switch *ds, int port,
 			       u32 stringset, uint8_t *data);
@@ -491,6 +491,8 @@ struct dsa_switch_ops {
 	int	(*get_sset_count)(struct dsa_switch *ds, int port, int sset);
 	void	(*get_ethtool_phy_stats)(struct dsa_switch *ds,
 					 int port, uint64_t *data);
+	void	(*get_stats64)(struct dsa_switch *ds, int port,
+				   struct rtnl_link_stats64 *s);
 
 	/*
 	 * ethtool Wake-on-LAN

net/dsa/slave.c

@@ -1569,6 +1569,18 @@ static struct devlink_port *dsa_slave_get_devlink_port(struct net_device *dev)
 	return dp->ds->devlink ? &dp->devlink_port : NULL;
 }
 
+static void dsa_slave_get_stats64(struct net_device *dev,
+				  struct rtnl_link_stats64 *s)
+{
+	struct dsa_port *dp = dsa_slave_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (ds->ops->get_stats64)
+		ds->ops->get_stats64(ds, dp->index, s);
+	else
+		dev_get_tstats64(dev, s);
+}
+
 static const struct net_device_ops dsa_slave_netdev_ops = {
 	.ndo_open	 	= dsa_slave_open,
 	.ndo_stop		= dsa_slave_close,
@@ -1588,7 +1600,7 @@ static const struct net_device_ops dsa_slave_netdev_ops = {
 #endif
 	.ndo_get_phys_port_name	= dsa_slave_get_phys_port_name,
 	.ndo_setup_tc		= dsa_slave_setup_tc,
-	.ndo_get_stats64	= dev_get_tstats64,
+	.ndo_get_stats64	= dsa_slave_get_stats64,
 	.ndo_get_port_parent_id	= dsa_slave_get_port_parent_id,
 	.ndo_vlan_rx_add_vid	= dsa_slave_vlan_rx_add_vid,
 	.ndo_vlan_rx_kill_vid	= dsa_slave_vlan_rx_kill_vid,