qmi_wwan: switch to core handling of rx/tx byte/packet counters

Use netdev->tstats instead of a member of qmimux_priv for storing
a pointer to the per-cpu counters. This allows us to use core
functionality for statistics handling.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/usb/qmi_wwan.c

@@ -72,7 +72,6 @@ struct qmimux_hdr {
 struct qmimux_priv {
 	struct net_device *real_dev;
 	u8 mux_id;
-	struct pcpu_sw_netstats __percpu *stats64;
 };
 
 static int qmimux_open(struct net_device *dev)
@@ -108,34 +107,19 @@ static netdev_tx_t qmimux_start_xmit(struct sk_buff *skb, struct net_device *dev
 	skb->dev = priv->real_dev;
 	ret = dev_queue_xmit(skb);
 
-	if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
-		struct pcpu_sw_netstats *stats64 = this_cpu_ptr(priv->stats64);
-
-		u64_stats_update_begin(&stats64->syncp);
-		stats64->tx_packets++;
-		stats64->tx_bytes += len;
-		u64_stats_update_end(&stats64->syncp);
-	} else {
+	if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN))
+		dev_sw_netstats_tx_add(dev, 1, len);
+	else
 		dev->stats.tx_dropped++;
-	}
 
 	return ret;
 }
 
-static void qmimux_get_stats64(struct net_device *net,
-			       struct rtnl_link_stats64 *stats)
-{
-	struct qmimux_priv *priv = netdev_priv(net);
-
-	netdev_stats_to_stats64(stats, &net->stats);
-	dev_fetch_sw_netstats(stats, priv->stats64);
-}
-
 static const struct net_device_ops qmimux_netdev_ops = {
 	.ndo_open        = qmimux_open,
 	.ndo_stop        = qmimux_stop,
 	.ndo_start_xmit  = qmimux_start_xmit,
-	.ndo_get_stats64 = qmimux_get_stats64,
+	.ndo_get_stats64 = dev_get_tstats64,
 };
 
 static void qmimux_setup(struct net_device *dev)
@@ -224,14 +208,7 @@ static int qmimux_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 			net->stats.rx_errors++;
 			return 0;
 		} else {
-			struct pcpu_sw_netstats *stats64;
-			struct qmimux_priv *priv = netdev_priv(net);
-
-			stats64 = this_cpu_ptr(priv->stats64);
-			u64_stats_update_begin(&stats64->syncp);
-			stats64->rx_packets++;
-			stats64->rx_bytes += pkt_len;
-			u64_stats_update_end(&stats64->syncp);
+			dev_sw_netstats_rx_add(net, pkt_len);
 		}
 
 skip:
@@ -256,8 +233,8 @@ static int qmimux_register_device(struct net_device *real_dev, u8 mux_id)
 	priv->mux_id = mux_id;
 	priv->real_dev = real_dev;
 
-	priv->stats64 = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
-	if (!priv->stats64) {
+	new_dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
+	if (!new_dev->tstats) {
 		err = -ENOBUFS;
 		goto out_free_newdev;
 	}
@@ -292,7 +269,7 @@ static void qmimux_unregister_device(struct net_device *dev,
 	struct qmimux_priv *priv = netdev_priv(dev);
 	struct net_device *real_dev = priv->real_dev;
 
-	free_percpu(priv->stats64);
+	free_percpu(dev->tstats);
 	netdev_upper_dev_unlink(real_dev, dev);
 	unregister_netdevice_queue(dev, head);