net: cdc_ncm/cdc_mbim: adding NCM protocol statistics

To have an idea of the effects of the protocol coalescing it's useful to have some counters showing the different aspects. Due to the asymmetrical usbnet interface the netdev rx_bytes counter has been counting real received payload, while the tx_bytes counter has included the NCM/MBIM framing overhead. This overhead can be many times the payload because of the aggressive padding strategy of this driver, and will vary a lot depending on device and traffic. With very few exceptions, users are only interested in the payload size. Having an somewhat accurate payload byte counter is particularly important for mobile broadband devices, which many NCM devices and of course all MBIM devices are. Users and userspace applications will use this counter to monitor account quotas. Having protocol specific counters for the overhead, we are now able to correct the tx_bytes netdev counter so that it shows the real payload Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net>

net: cdc_ncm/cdc_mbim: adding NCM protocol statistics
To have an idea of the effects of the protocol coalescing it's useful to have some counters showing the different aspects. Due to the asymmetrical usbnet interface the netdev rx_bytes counter has been counting real received payload, while the tx_bytes counter has included the NCM/MBIM framing overhead. This overhead can be many times the payload because of the aggressive padding strategy of this driver, and will vary a lot depending on device and traffic. With very few exceptions, users are only interested in the payload size. Having an somewhat accurate payload byte counter is particularly important for mobile broadband devices, which many NCM devices and of course all MBIM devices are. Users and userspace applications will use this counter to monitor account quotas. Having protocol specific counters for the overhead, we are now able to correct the tx_bytes netdev counter so that it shows the real payload Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net>
Bjørn Mork · David S. Miller · Eric Lee · Eric Lee · Eric Lee · Eric Lee
1 parent 43e4c6dfc0
Showing 3 changed files with 108 additions and 0 deletions Side-by-side Diff
drivers/net/usb/cdc_mbim.c
drivers/net/usb/cdc_ncm.c
include/linux/usb/cdc_ncm.h
@@ -420,6 +420,7 @@
 	struct usb_cdc_ncm_dpe16 *dpe16;
 	int ndpoffset;
 	int loopcount = 50; /* arbitrary max preventing infinite loop */
+	u32 payload = 0;
 	u8 *c;
 	u16 tci;
  
@@ -482,6 +483,7 @@
 			if (!skb)
 				goto error;
 			usbnet_skb_return(dev, skb);
+			payload += len;	/* count payload bytes in this NTB */
 		}
 	}
 err_ndp:
@@ -489,6 +491,10 @@
 	ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
 	if (ndpoffset && loopcount--)
 		goto next_ndp;
+
+	/* update stats */
+	ctx->rx_overhead += skb_in->len - payload;
+	ctx->rx_ntbs++;
  
 	return 1;
 error:
@@ -65,6 +65,68 @@
 static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *hr_timer);
 static struct usb_driver cdc_ncm_driver;
  
+struct cdc_ncm_stats {
+	char stat_string[ETH_GSTRING_LEN];
+	int sizeof_stat;
+	int stat_offset;
+};
+
+#define CDC_NCM_STAT(str, m) { \
+		.stat_string = str, \
+		.sizeof_stat = sizeof(((struct cdc_ncm_ctx *)0)->m), \
+		.stat_offset = offsetof(struct cdc_ncm_ctx, m) }
+#define CDC_NCM_SIMPLE_STAT(m)	CDC_NCM_STAT(__stringify(m), m)
+
+static const struct cdc_ncm_stats cdc_ncm_gstrings_stats[] = {
+	CDC_NCM_SIMPLE_STAT(tx_reason_ntb_full),
+	CDC_NCM_SIMPLE_STAT(tx_reason_ndp_full),
+	CDC_NCM_SIMPLE_STAT(tx_reason_timeout),
+	CDC_NCM_SIMPLE_STAT(tx_reason_max_datagram),
+	CDC_NCM_SIMPLE_STAT(tx_overhead),
+	CDC_NCM_SIMPLE_STAT(tx_ntbs),
+	CDC_NCM_SIMPLE_STAT(rx_overhead),
+	CDC_NCM_SIMPLE_STAT(rx_ntbs),
+};
+
+static int cdc_ncm_get_sset_count(struct net_device __always_unused *netdev, int sset)
+{
+	switch (sset) {
+	case ETH_SS_STATS:
+		return ARRAY_SIZE(cdc_ncm_gstrings_stats);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static void cdc_ncm_get_ethtool_stats(struct net_device *netdev,
+				    struct ethtool_stats __always_unused *stats,
+				    u64 *data)
+{
+	struct usbnet *dev = netdev_priv(netdev);
+	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	int i;
+	char *p = NULL;
+
+	for (i = 0; i < ARRAY_SIZE(cdc_ncm_gstrings_stats); i++) {
+		p = (char *)ctx + cdc_ncm_gstrings_stats[i].stat_offset;
+		data[i] = (cdc_ncm_gstrings_stats[i].sizeof_stat == sizeof(u64)) ? *(u64 *)p : *(u32 *)p;
+	}
+}
+
+static void cdc_ncm_get_strings(struct net_device __always_unused *netdev, u32 stringset, u8 *data)
+{
+	u8 *p = data;
+	int i;
+
+	switch (stringset) {
+	case ETH_SS_STATS:
+		for (i = 0; i < ARRAY_SIZE(cdc_ncm_gstrings_stats); i++) {
+			memcpy(p, cdc_ncm_gstrings_stats[i].stat_string, ETH_GSTRING_LEN);
+			p += ETH_GSTRING_LEN;
+		}
+	}
+}
+
 static int cdc_ncm_get_coalesce(struct net_device *netdev,
 				struct ethtool_coalesce *ec)
 {
@@ -122,6 +184,9 @@
 	.get_msglevel      = usbnet_get_msglevel,
 	.set_msglevel      = usbnet_set_msglevel,
 	.get_ts_info       = ethtool_op_get_ts_info,
+	.get_sset_count    = cdc_ncm_get_sset_count,
+	.get_strings       = cdc_ncm_get_strings,
+	.get_ethtool_stats = cdc_ncm_get_ethtool_stats,
 	.get_coalesce      = cdc_ncm_get_coalesce,
 	.set_coalesce      = cdc_ncm_set_coalesce,
 };
@@ -862,6 +927,9 @@
  
 		/* count total number of frames in this NTB */
 		ctx->tx_curr_frame_num = 0;
+
+		/* recent payload counter for this skb_out */
+		ctx->tx_curr_frame_payload = 0;
 	}
  
 	for (n = ctx->tx_curr_frame_num; n < ctx->tx_max_datagrams; n++) {
@@ -899,6 +967,7 @@
 				ctx->tx_rem_sign = sign;
 				skb = NULL;
 				ready2send = 1;
+				ctx->tx_reason_ntb_full++;	/* count reason for transmitting */
 			}
 			break;
 		}
  
@@ -912,12 +981,14 @@
 		ndp16->dpe16[index].wDatagramIndex = cpu_to_le16(skb_out->len);
 		ndp16->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe16));
 		memcpy(skb_put(skb_out, skb->len), skb->data, skb->len);
+		ctx->tx_curr_frame_payload += skb->len;	/* count real tx payload data */
 		dev_kfree_skb_any(skb);
 		skb = NULL;
  
 		/* send now if this NDP is full */
 		if (index >= CDC_NCM_DPT_DATAGRAMS_MAX) {
 			ready2send = 1;
+			ctx->tx_reason_ndp_full++;	/* count reason for transmitting */
 			break;
 		}
 	}
@@ -947,6 +1018,8 @@
 		goto exit_no_skb;
  
 	} else {
+		if (n == ctx->tx_max_datagrams)
+			ctx->tx_reason_max_datagram++;	/* count reason for transmitting */
 		/* frame goes out */
 		/* variables will be reset at next call */
 	}
@@ -974,6 +1047,17 @@
 	/* return skb */
 	ctx->tx_curr_skb = NULL;
 	dev->net->stats.tx_packets += ctx->tx_curr_frame_num;
+
+	/* keep private stats: framing overhead and number of NTBs */
+	ctx->tx_overhead += skb_out->len - ctx->tx_curr_frame_payload;
+	ctx->tx_ntbs++;
+
+	/* usbnet has already counted all the framing overhead.
+	 * Adjust the stats so that the tx_bytes counter show real
+	 * payload data instead.
+	 */
+	dev->net->stats.tx_bytes -= skb_out->len - ctx->tx_curr_frame_payload;
+
 	return skb_out;
  
 exit_no_skb:
@@ -1014,6 +1098,7 @@
 		cdc_ncm_tx_timeout_start(ctx);
 		spin_unlock_bh(&ctx->mtx);
 	} else if (dev->net != NULL) {
+		ctx->tx_reason_timeout++;	/* count reason for transmitting */
 		spin_unlock_bh(&ctx->mtx);
 		netif_tx_lock_bh(dev->net);
 		usbnet_start_xmit(NULL, dev->net);
@@ -1149,6 +1234,7 @@
 	struct usb_cdc_ncm_dpe16 *dpe16;
 	int ndpoffset;
 	int loopcount = 50; /* arbitrary max preventing infinite loop */
+	u32 payload = 0;
  
 	ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
 	if (ndpoffset < 0)
@@ -1201,6 +1287,7 @@
 			skb->data = ((u8 *)skb_in->data) + offset;
 			skb_set_tail_pointer(skb, len);
 			usbnet_skb_return(dev, skb);
+			payload += len;	/* count payload bytes in this NTB */
 		}
 	}
 err_ndp:
@@ -1208,6 +1295,10 @@
 	ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
 	if (ndpoffset && loopcount--)
 		goto next_ndp;
+
+	/* update stats */
+	ctx->rx_overhead += skb_in->len - payload;
+	ctx->rx_ntbs++;
  
 	return 1;
 error:
@@ -116,6 +116,17 @@
 	u16 rx_seq;
 	u16 connected;
 	u16 min_tx_pkt;
+
+	/* statistics */
+	u32 tx_curr_frame_payload;
+	u32 tx_reason_ntb_full;
+	u32 tx_reason_ndp_full;
+	u32 tx_reason_timeout;
+	u32 tx_reason_max_datagram;
+	u64 tx_overhead;
+	u64 tx_ntbs;
+	u64 rx_overhead;
+	u64 rx_ntbs;
 };
  
 u8 cdc_ncm_select_altsetting(struct usb_interface *intf);
...	...	@@ -420,6 +420,7 @@
420	420	struct usb_cdc_ncm_dpe16 *dpe16;
421	421	int ndpoffset;
422	422	int loopcount = 50; /* arbitrary max preventing infinite loop */
	423	+ u32 payload = 0;
423	424	u8 *c;
424	425	u16 tci;
425	426
...	...	@@ -482,6 +483,7 @@
482	483	if (!skb)
483	484	goto error;
484	485	usbnet_skb_return(dev, skb);
	486	+ payload += len; /* count payload bytes in this NTB */
485	487	}
486	488	}
487	489	err_ndp:
...	...	@@ -489,6 +491,10 @@
489	491	ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
490	492	if (ndpoffset && loopcount--)
491	493	goto next_ndp;
	494	+
	495	+ /* update stats */
	496	+ ctx->rx_overhead += skb_in->len - payload;
	497	+ ctx->rx_ntbs++;
492	498
493	499	return 1;
494	500	error:
...	...	@@ -65,6 +65,68 @@
65	65	static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *hr_timer);
66	66	static struct usb_driver cdc_ncm_driver;
67	67
	68	+struct cdc_ncm_stats {
	69	+ char stat_string[ETH_GSTRING_LEN];
	70	+ int sizeof_stat;
	71	+ int stat_offset;
	72	+};
	73	+
	74	+#define CDC_NCM_STAT(str, m) { \
	75	+ .stat_string = str, \
	76	+ .sizeof_stat = sizeof(((struct cdc_ncm_ctx *)0)->m), \
	77	+ .stat_offset = offsetof(struct cdc_ncm_ctx, m) }
	78	+#define CDC_NCM_SIMPLE_STAT(m) CDC_NCM_STAT(__stringify(m), m)
	79	+
	80	+static const struct cdc_ncm_stats cdc_ncm_gstrings_stats[] = {
	81	+ CDC_NCM_SIMPLE_STAT(tx_reason_ntb_full),
	82	+ CDC_NCM_SIMPLE_STAT(tx_reason_ndp_full),
	83	+ CDC_NCM_SIMPLE_STAT(tx_reason_timeout),
	84	+ CDC_NCM_SIMPLE_STAT(tx_reason_max_datagram),
	85	+ CDC_NCM_SIMPLE_STAT(tx_overhead),
	86	+ CDC_NCM_SIMPLE_STAT(tx_ntbs),
	87	+ CDC_NCM_SIMPLE_STAT(rx_overhead),
	88	+ CDC_NCM_SIMPLE_STAT(rx_ntbs),
	89	+};
	90	+
	91	+static int cdc_ncm_get_sset_count(struct net_device __always_unused *netdev, int sset)
	92	+{
	93	+ switch (sset) {
	94	+ case ETH_SS_STATS:
	95	+ return ARRAY_SIZE(cdc_ncm_gstrings_stats);
	96	+ default:
	97	+ return -EOPNOTSUPP;
	98	+ }
	99	+}
	100	+
	101	+static void cdc_ncm_get_ethtool_stats(struct net_device *netdev,
	102	+ struct ethtool_stats __always_unused *stats,
	103	+ u64 *data)
	104	+{
	105	+ struct usbnet *dev = netdev_priv(netdev);
	106	+ struct cdc_ncm_ctx ctx = (struct cdc_ncm_ctx )dev->data[0];
	107	+ int i;
	108	+ char *p = NULL;
	109	+
	110	+ for (i = 0; i < ARRAY_SIZE(cdc_ncm_gstrings_stats); i++) {
	111	+ p = (char *)ctx + cdc_ncm_gstrings_stats[i].stat_offset;
	112	+ data[i] = (cdc_ncm_gstrings_stats[i].sizeof_stat == sizeof(u64)) ? (u64 )p : (u32 )p;
	113	+ }
	114	+}
	115	+
	116	+static void cdc_ncm_get_strings(struct net_device __always_unused netdev, u32 stringset, u8 data)
	117	+{
	118	+ u8 *p = data;
	119	+ int i;
	120	+
	121	+ switch (stringset) {
	122	+ case ETH_SS_STATS:
	123	+ for (i = 0; i < ARRAY_SIZE(cdc_ncm_gstrings_stats); i++) {
	124	+ memcpy(p, cdc_ncm_gstrings_stats[i].stat_string, ETH_GSTRING_LEN);
	125	+ p += ETH_GSTRING_LEN;
	126	+ }
	127	+ }
	128	+}
	129	+
68	130	static int cdc_ncm_get_coalesce(struct net_device *netdev,
69	131	struct ethtool_coalesce *ec)
70	132	{
...	...	@@ -122,6 +184,9 @@
122	184	.get_msglevel = usbnet_get_msglevel,
123	185	.set_msglevel = usbnet_set_msglevel,
124	186	.get_ts_info = ethtool_op_get_ts_info,
	187	+ .get_sset_count = cdc_ncm_get_sset_count,
	188	+ .get_strings = cdc_ncm_get_strings,
	189	+ .get_ethtool_stats = cdc_ncm_get_ethtool_stats,
125	190	.get_coalesce = cdc_ncm_get_coalesce,
126	191	.set_coalesce = cdc_ncm_set_coalesce,
127	192	};
...	...	@@ -862,6 +927,9 @@
862	927
863	928	/* count total number of frames in this NTB */
864	929	ctx->tx_curr_frame_num = 0;
	930	+
	931	+ /* recent payload counter for this skb_out */
	932	+ ctx->tx_curr_frame_payload = 0;
865	933	}
866	934
867	935	for (n = ctx->tx_curr_frame_num; n < ctx->tx_max_datagrams; n++) {
...	...	@@ -899,6 +967,7 @@
899	967	ctx->tx_rem_sign = sign;
900	968	skb = NULL;
901	969	ready2send = 1;
	970	+ ctx->tx_reason_ntb_full++; /* count reason for transmitting */
902	971	}
903	972	break;
904	973	}
905	974
...	...	@@ -912,12 +981,14 @@
912	981	ndp16->dpe16[index].wDatagramIndex = cpu_to_le16(skb_out->len);
913	982	ndp16->wLength = cpu_to_le16(ndplen + sizeof(struct usb_cdc_ncm_dpe16));
914	983	memcpy(skb_put(skb_out, skb->len), skb->data, skb->len);
	984	+ ctx->tx_curr_frame_payload += skb->len; /* count real tx payload data */
915	985	dev_kfree_skb_any(skb);
916	986	skb = NULL;
917	987
918	988	/* send now if this NDP is full */
919	989	if (index >= CDC_NCM_DPT_DATAGRAMS_MAX) {
920	990	ready2send = 1;
	991	+ ctx->tx_reason_ndp_full++; /* count reason for transmitting */
921	992	break;
922	993	}
923	994	}
...	...	@@ -947,6 +1018,8 @@
947	1018	goto exit_no_skb;
948	1019
949	1020	} else {
	1021	+ if (n == ctx->tx_max_datagrams)
	1022	+ ctx->tx_reason_max_datagram++; /* count reason for transmitting */
950	1023	/* frame goes out */
951	1024	/* variables will be reset at next call */
952	1025	}
...	...	@@ -974,6 +1047,17 @@
974	1047	/* return skb */
975	1048	ctx->tx_curr_skb = NULL;
976	1049	dev->net->stats.tx_packets += ctx->tx_curr_frame_num;
	1050	+
	1051	+ /* keep private stats: framing overhead and number of NTBs */
	1052	+ ctx->tx_overhead += skb_out->len - ctx->tx_curr_frame_payload;
	1053	+ ctx->tx_ntbs++;
	1054	+
	1055	+ /* usbnet has already counted all the framing overhead.
	1056	+ * Adjust the stats so that the tx_bytes counter show real
	1057	+ * payload data instead.
	1058	+ */
	1059	+ dev->net->stats.tx_bytes -= skb_out->len - ctx->tx_curr_frame_payload;
	1060	+
977	1061	return skb_out;
978	1062
979	1063	exit_no_skb:
...	...	@@ -1014,6 +1098,7 @@
1014	1098	cdc_ncm_tx_timeout_start(ctx);
1015	1099	spin_unlock_bh(&ctx->mtx);
1016	1100	} else if (dev->net != NULL) {
	1101	+ ctx->tx_reason_timeout++; /* count reason for transmitting */
1017	1102	spin_unlock_bh(&ctx->mtx);
1018	1103	netif_tx_lock_bh(dev->net);
1019	1104	usbnet_start_xmit(NULL, dev->net);
...	...	@@ -1149,6 +1234,7 @@
1149	1234	struct usb_cdc_ncm_dpe16 *dpe16;
1150	1235	int ndpoffset;
1151	1236	int loopcount = 50; /* arbitrary max preventing infinite loop */
	1237	+ u32 payload = 0;
1152	1238
1153	1239	ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
1154	1240	if (ndpoffset < 0)
...	...	@@ -1201,6 +1287,7 @@
1201	1287	skb->data = ((u8 *)skb_in->data) + offset;
1202	1288	skb_set_tail_pointer(skb, len);
1203	1289	usbnet_skb_return(dev, skb);
	1290	+ payload += len; /* count payload bytes in this NTB */
1204	1291	}
1205	1292	}
1206	1293	err_ndp:
...	...	@@ -1208,6 +1295,10 @@
1208	1295	ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
1209	1296	if (ndpoffset && loopcount--)
1210	1297	goto next_ndp;
	1298	+
	1299	+ /* update stats */
	1300	+ ctx->rx_overhead += skb_in->len - payload;
	1301	+ ctx->rx_ntbs++;
1211	1302
1212	1303	return 1;
1213	1304	error:
...	...	@@ -116,6 +116,17 @@
116	116	u16 rx_seq;
117	117	u16 connected;
118	118	u16 min_tx_pkt;
	119	+
	120	+ /* statistics */
	121	+ u32 tx_curr_frame_payload;
	122	+ u32 tx_reason_ntb_full;
	123	+ u32 tx_reason_ndp_full;
	124	+ u32 tx_reason_timeout;
	125	+ u32 tx_reason_max_datagram;
	126	+ u64 tx_overhead;
	127	+ u64 tx_ntbs;
	128	+ u64 rx_overhead;
	129	+ u64 rx_ntbs;
119	130	};
120	131
121	132	u8 cdc_ncm_select_altsetting(struct usb_interface *intf);