[PATCH 4.14 33/42] qmi_wwan: add network device usage statistics for qmimux devices

Greg Kroah-Hartman
2021-08-13T15:12:49Z

From: Reinhard Speyerer <rspmn@arcor.de>

commit 44f82312fe9113bab6642f4d0eab6b1b7902b6e1 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/usb/qmi_wwan.c | 76 ++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 71 insertions(+), 5 deletions(-)

--- 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) -
@@ -74,6 +75,7 @@ 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)
@@ -100,19 +102,65 @@ static netdev_tx_t qmimux_start_xmit(str
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)
@@ -197,8 +245,19 @@ static int qmimux_rx_fixup(struct usbnet
}

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;
@@ -222,6 +281,12 @@ static int qmimux_register_device(struct
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(str
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_queue(dev, head);