[PATCH net] net: wwan: qcom_bam_dmux: account network packets

[Dmitry Sinyavin <sinyavin@gmail.com>]

The BAM-DMUX data path does not update the network device packet and byte
counters. As a result, userspace sees zero traffic even while packets are
being transferred.

Use the standard per-CPU software statistics helpers. Account transmitted
packets after their DMA completion and received packets after removing the
BAM-DMUX header and padding.

Fixes: 21a0ffd9b38c ("net: wwan: Add Qualcomm BAM-DMUX WWAN network driver")
Signed-off-by: Dmitry Sinyavin <sinyavin@gmail.com>
---
Build-tested for ARM with CONFIG_QCOM_BAM_DMUX=m using Clang and W=1.

 drivers/net/wwan/qcom_bam_dmux.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/net/wwan/qcom_bam_dmux.c b/drivers/net/wwan/qcom_bam_dmux.c
index cc6ace8d6437..40c40bc5645a 100644
--- a/drivers/net/wwan/qcom_bam_dmux.c
+++ b/drivers/net/wwan/qcom_bam_dmux.c
@@ -177,8 +177,15 @@ static void bam_dmux_tx_callback(void *data)
 {
 	struct bam_dmux_skb_dma *skb_dma = data;
 	struct sk_buff *skb = skb_dma->skb;
+	struct net_device *netdev = skb->dev;
+	unsigned int len = 0;
+
+	if (netdev)
+		len = ((struct bam_dmux_hdr *)skb->data)->len;
 
 	bam_dmux_tx_done(skb_dma);
+	if (netdev)
+		dev_sw_netstats_tx_add(netdev, 1, len);
 	dev_consume_skb_any(skb);
 }
 
@@ -402,6 +409,7 @@ static const struct net_device_ops bam_dmux_ops = {
 	.ndo_open	= bam_dmux_netdev_open,
 	.ndo_stop	= bam_dmux_netdev_stop,
 	.ndo_start_xmit	= bam_dmux_netdev_start_xmit,
+	.ndo_get_stats64	= dev_get_tstats64,
 };
 
 static const struct device_type wwan_type = {
@@ -421,6 +429,7 @@ static void bam_dmux_netdev_setup(struct net_device *dev)
 	dev->needed_headroom = sizeof(struct bam_dmux_hdr);
 	dev->needed_tailroom = sizeof(u32); /* word-aligned */
 	dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
+	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
 
 	/* This perm addr will be used as interface identifier by IPv6 */
 	dev->addr_assign_type = NET_ADDR_RANDOM;
@@ -533,6 +542,7 @@ static void bam_dmux_cmd_data(struct bam_dmux_skb_dma *skb_dma)
 		break;
 	}
 
+	dev_sw_netstats_rx_add(netdev, skb->len);
 	netif_receive_skb(skb);
 }
 

base-commit: 2188569e7e1b0bc3f3b557dc97ab7a02befc11c8
-- 
2.53.0