net: dsa: use net core stats64 handling

Use netdev->tstats instead of a member of dsa_slave_priv for storing
a pointer to the per-cpu counters. This allows us to use core
functionality for statistics handling.
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/dsa/dsa.c

@@ -201,7 +201,6 @@ static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
 {
 	struct dsa_port *cpu_dp = dev->dsa_ptr;
 	struct sk_buff *nskb = NULL;
-	struct pcpu_sw_netstats *s;
 	struct dsa_slave_priv *p;
 
 	if (unlikely(!cpu_dp)) {
@@ -234,11 +233,7 @@ static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
 		skb = nskb;
 	}
 
-	s = this_cpu_ptr(p->stats64);
-	u64_stats_update_begin(&s->syncp);
-	s->rx_packets++;
-	s->rx_bytes += skb->len;
-	u64_stats_update_end(&s->syncp);
+	dev_sw_netstats_rx_add(skb->dev, skb->len);
 
 	if (dsa_skb_defer_rx_timestamp(p, skb))
 		return 0;

net/dsa/dsa_priv.h

@@ -78,8 +78,6 @@ struct dsa_slave_priv {
 	struct sk_buff *	(*xmit)(struct sk_buff *skb,
 					struct net_device *dev);
 
-	struct pcpu_sw_netstats	__percpu *stats64;
-
 	struct gro_cells	gcells;
 
 	/* DSA port data, such as switch, port index, etc. */

net/dsa/slave.c

@@ -575,14 +575,9 @@ static int dsa_realloc_skb(struct sk_buff *skb, struct net_device *dev)
 static netdev_tx_t dsa_slave_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct dsa_slave_priv *p = netdev_priv(dev);
-	struct pcpu_sw_netstats *s;
 	struct sk_buff *nskb;
 
-	s = this_cpu_ptr(p->stats64);
-	u64_stats_update_begin(&s->syncp);
-	s->tx_packets++;
-	s->tx_bytes += skb->len;
-	u64_stats_update_end(&s->syncp);
+	dev_sw_netstats_tx_add(dev, 1, skb->len);
 
 	DSA_SKB_CB(skb)->clone = NULL;
 
@@ -714,7 +709,6 @@ static void dsa_slave_get_ethtool_stats(struct net_device *dev,
 					uint64_t *data)
 {
 	struct dsa_port *dp = dsa_slave_to_port(dev);
-	struct dsa_slave_priv *p = netdev_priv(dev);
 	struct dsa_switch *ds = dp->ds;
 	struct pcpu_sw_netstats *s;
 	unsigned int start;
@@ -723,7 +717,7 @@ static void dsa_slave_get_ethtool_stats(struct net_device *dev,
 	for_each_possible_cpu(i) {
 		u64 tx_packets, tx_bytes, rx_packets, rx_bytes;
 
-		s = per_cpu_ptr(p->stats64, i);
+		s = per_cpu_ptr(dev->tstats, i);
 		do {
 			start = u64_stats_fetch_begin_irq(&s->syncp);
 			tx_packets = s->tx_packets;
@@ -1252,15 +1246,6 @@ static int dsa_slave_setup_tc(struct net_device *dev, enum tc_setup_type type,
 	return ds->ops->port_setup_tc(ds, dp->index, type, type_data);
 }
 
-static void dsa_slave_get_stats64(struct net_device *dev,
-				  struct rtnl_link_stats64 *stats)
-{
-	struct dsa_slave_priv *p = netdev_priv(dev);
-
-	netdev_stats_to_stats64(stats, &dev->stats);
-	dev_fetch_sw_netstats(stats, p->stats64);
-}
-
 static int dsa_slave_get_rxnfc(struct net_device *dev,
 			       struct ethtool_rxnfc *nfc, u32 *rule_locs)
 {
@@ -1636,7 +1621,7 @@ 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	= dsa_slave_get_stats64,
+	.ndo_get_stats64	= dev_get_tstats64,
 	.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,
@@ -1846,8 +1831,8 @@ int dsa_slave_create(struct dsa_port *port)
 	slave_dev->vlan_features = master->vlan_features;
 
 	p = netdev_priv(slave_dev);
-	p->stats64 = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
-	if (!p->stats64) {
+	slave_dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
+	if (!slave_dev->tstats) {
 		free_netdev(slave_dev);
 		return -ENOMEM;
 	}
@@ -1909,7 +1894,7 @@ int dsa_slave_create(struct dsa_port *port)
 out_gcells:
 	gro_cells_destroy(&p->gcells);
 out_free:
-	free_percpu(p->stats64);
+	free_percpu(slave_dev->tstats);
 	free_netdev(slave_dev);
 	port->slave = NULL;
 	return ret;
@@ -1931,7 +1916,7 @@ void dsa_slave_destroy(struct net_device *slave_dev)
 	dsa_slave_notify(slave_dev, DSA_PORT_UNREGISTER);
 	phylink_destroy(dp->pl);
 	gro_cells_destroy(&p->gcells);
-	free_percpu(p->stats64);
+	free_percpu(slave_dev->tstats);
 	free_netdev(slave_dev);
 }