Commit 44f82312fe91 ("qmi_wwan: add network device usage statistics for qmimux devices") of the "qmi_wwan: fix QMAP handling" series https://lore.kernel.org/netdev/cover.1560287477.git.rspmn@arcor.de was not part of the AUTOSEL 4.19 patches.

This will introduce a regression for users of this longterm kernel when multiplexing gets enabled in the forthcoming ModemManager 1.18: https://lists.freedesktop.org/archives/modemmanager-devel/2021-August/008782...

Avoid this by adding the missing patch from the series.

Signed-off-by: Reinhard Speyerer rspmn@arcor.de --- drivers/net/usb/qmi_wwan.c | 76 +++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 71 insertions(+), 5 deletions(-)

diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c index d08e1de26030..54b37a30df18 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) - @@ -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(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) @@ -197,8 +245,19 @@ 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; @@ -222,6 +281,12 @@ 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_queue(dev, head);