qmi_wwan: add network device usage statistics for qmimux devices

Add proper network device usage statistics for qmimux devices
instead of reporting all-zero values for them.

Fixes: c6adf77953bc ("net: usb: qmi_wwan: add qmap mux protocol support")
Cc: Daniele Palmas <dnlplm@gmail.com>
Signed-off-by: Reinhard Speyerer <rspmn@arcor.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 71 insertions, 5 deletions

diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index fd3d078a1923..b0a96459621f 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -22,6 +22,7 @@
 #include <linux/usb/cdc.h>
 #include <linux/usb/usbnet.h>
 #include <linux/usb/cdc-wdm.h>
+#include <linux/u64_stats_sync.h>
 
 /* This driver supports wwan (3G/LTE/?) devices using a vendor
  * specific management protocol called Qualcomm MSM Interface (QMI) -
@@ -75,6 +76,7 @@ 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)
@@ -101,19 +103,65 @@ static netdev_tx_t qmimux_start_xmit(struct sk_buff *skb, struct net_device *dev
         struct qmimux_priv *priv = netdev_priv(dev);
         unsigned int len = skb->len;
         struct qmimux_hdr *hdr;
+        netdev_tx_t ret;
 
         hdr = skb_push(skb, sizeof(struct qmimux_hdr));
         hdr->pad = 0;
         hdr->mux_id = priv->mux_id;
         hdr->pkt_len = cpu_to_be16(len);
         skb->dev = priv->real_dev;
-        return dev_queue_xmit(skb);
+        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 {
+                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);
+        unsigned int start;
+        int cpu;
+
+        netdev_stats_to_stats64(stats, &net->stats);
+
+        for_each_possible_cpu(cpu) {
+                struct pcpu_sw_netstats *stats64;
+                u64 rx_packets, rx_bytes;
+                u64 tx_packets, tx_bytes;
+
+                stats64 = per_cpu_ptr(priv->stats64, cpu);
+
+                do {
+                        start = u64_stats_fetch_begin_irq(&stats64->syncp);
+                        rx_packets = stats64->rx_packets;
+                        rx_bytes = stats64->rx_bytes;
+                        tx_packets = stats64->tx_packets;
+                        tx_bytes = stats64->tx_bytes;
+                } while (u64_stats_fetch_retry_irq(&stats64->syncp, start));
+
+                stats->rx_packets += rx_packets;
+                stats->rx_bytes += rx_bytes;
+                stats->tx_packets += tx_packets;
+                stats->tx_bytes += tx_bytes;
+        }
 }
 
 static const struct net_device_ops qmimux_netdev_ops = {
-        .ndo_open       = qmimux_open,
-        .ndo_stop       = qmimux_stop,
-        .ndo_start_xmit = qmimux_start_xmit,
+        .ndo_open        = qmimux_open,
+        .ndo_stop        = qmimux_stop,
+        .ndo_start_xmit  = qmimux_start_xmit,
+        .ndo_get_stats64 = qmimux_get_stats64,
 };
 
 static void qmimux_setup(struct net_device *dev)
@@ -198,8 +246,19 @@ static int qmimux_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
                 }
 
                 skb_put_data(skbn, skb->data + offset + qmimux_hdr_sz, pkt_len);
-                if (netif_rx(skbn) != NET_RX_SUCCESS)
+                if (netif_rx(skbn) != NET_RX_SUCCESS) {
+                        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);
+                }
 
 skip:
                 offset += len + qmimux_hdr_sz;
@@ -223,6 +282,12 @@ 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) {
+                err = -ENOBUFS;
+                goto out_free_newdev;
+        }
+
         err = register_netdevice(new_dev);
         if (err < 0)
                 goto out_free_newdev;
@@ -252,6 +317,7 @@ 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);
         netdev_upper_dev_unlink(real_dev, dev);
         unregister_netdevice(dev);