[PATCH RFC net-next v1 1/6] ethtool: add interface to read Tx hardware timestamping statistics

[Rahul Rameshbabu <rrameshbabu@nvidia.com>]

Multiple network devices that support hardware timestamping appear to have
common behavior with regards to timestamp handling. Implement common Tx
hardware timestamping statistics in a tx_stats struct_group. Common Rx
hardware timestamping statistics can subsequently be implemented in a
rx_stats struct_group for ethtool_ts_stats.

Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
---
 include/linux/ethtool.h              | 28 +++++++++++++++
 include/uapi/linux/ethtool.h         | 20 +++++++++++
 include/uapi/linux/ethtool_netlink.h | 17 +++++++++
 net/ethtool/netlink.h                |  3 +-
 net/ethtool/stats.c                  | 53 +++++++++++++++++++++++++---
 net/ethtool/strset.c                 |  5 +++
 6 files changed, 120 insertions(+), 6 deletions(-)

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index b90c33607594..1cc1010afaca 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -483,6 +483,31 @@ struct ethtool_rmon_stats {
 	);
 };
 
+/**
+ * struct ethtool_ts_stats - HW timestamping statistics
+ * @layer: input field denoting whether stats should be queried from the DMA or
+ *        PHY timestamping layer. Defaults to the active layer for packet
+ *        timestamping.
+ * @tx_stats: struct group for TX HW timestamping
+ *	@pkts: Number of packets successfully timestamped by the queried
+ *	      layer.
+ *	@lost: Number of packet timestamps that failed to get applied on a
+ *	      packet by the queried layer.
+ *	@late: Number of packet timestamps that were delivered by the
+ *	      hardware but were lost due to arriving too late.
+ *	@err: Number of timestamping errors that occurred on the queried
+ *	     layer.
+ */
+struct ethtool_ts_stats {
+	enum ethtool_ts_stats_layer layer;
+	struct_group(tx_stats,
+		u64 pkts;
+		u64 lost;
+		u64 late;
+		u64 err;
+	);
+};
+
 #define ETH_MODULE_EEPROM_PAGE_LEN	128
 #define ETH_MODULE_MAX_I2C_ADDRESS	0x7f
 
@@ -807,6 +832,7 @@ struct ethtool_rxfh_param {
  * @get_eth_ctrl_stats: Query some of the IEEE 802.3 MAC Ctrl statistics.
  * @get_rmon_stats: Query some of the RMON (RFC 2819) statistics.
  *	Set %ranges to a pointer to zero-terminated array of byte ranges.
+ * @get_eth_ts_stats: Query the device hardware timestamping statistics.
  * @get_module_power_mode: Get the power mode policy for the plug-in module
  *	used by the network device and its operational power mode, if
  *	plugged-in.
@@ -943,6 +969,8 @@ struct ethtool_ops {
 	void	(*get_rmon_stats)(struct net_device *dev,
 				  struct ethtool_rmon_stats *rmon_stats,
 				  const struct ethtool_rmon_hist_range **ranges);
+	void	(*get_ts_stats)(struct net_device *dev,
+				    struct ethtool_ts_stats *ts_stats);
 	int	(*get_module_power_mode)(struct net_device *dev,
 					 struct ethtool_module_power_mode_params *params,
 					 struct netlink_ext_ack *extack);
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 06ef6b78b7de..39edae554fc5 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -681,6 +681,7 @@ enum ethtool_link_ext_substate_module {
  * @ETH_SS_STATS_ETH_MAC: names of IEEE 802.3 MAC statistics
  * @ETH_SS_STATS_ETH_CTRL: names of IEEE 802.3 MAC Control statistics
  * @ETH_SS_STATS_RMON: names of RMON statistics
+ * @ETH_SS_STATS_TS: names of hardware timestamping statistics
  *
  * @ETH_SS_COUNT: number of defined string sets
  */
@@ -706,6 +707,7 @@ enum ethtool_stringset {
 	ETH_SS_STATS_ETH_MAC,
 	ETH_SS_STATS_ETH_CTRL,
 	ETH_SS_STATS_RMON,
+	ETH_SS_STATS_TS,
 
 	/* add new constants above here */
 	ETH_SS_COUNT
@@ -1462,6 +1464,24 @@ struct ethtool_ts_info {
 	__u32	rx_reserved[3];
 };
 
+/**
+ * enum ethtool_ts_stats_layer - layer to query hardware timestamping statistics
+ * @ETHTOOL_TS_STATS_LAYER_ACTIVE:
+ *	retrieve the statistics from the layer that is currently feeding
+ *	hardware timestamps for packets.
+ * @ETHTOOL_TS_STATS_LAYER_DMA:
+ *	retrieve the statistics from the DMA hardware timestamping layer of the
+ *	device.
+ * @ETHTOOL_TS_STATS_PHY:
+ *	retrieve the statistics from the PHY hardware timestamping layer of the
+ *	device.
+ */
+enum ethtool_ts_stats_layer {
+	ETHTOOL_TS_STATS_LAYER_ACTIVE,
+	ETHTOOL_TS_STATS_LAYER_DMA,
+	ETHTOOL_TS_STATS_LAYER_PHY,
+};
+
 /*
  * %ETHTOOL_SFEATURES changes features present in features[].valid to the
  * values of corresponding bits in features[].requested. Bits in .requested
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 3f89074aa06c..55f2a3c8caa0 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -749,6 +749,7 @@ enum {
 	ETHTOOL_A_STATS_GRP,			/* nest - _A_STATS_GRP_* */
 
 	ETHTOOL_A_STATS_SRC,			/* u32 */
+	ETHTOOL_A_STATS_LAYER,			/* u32 */
 
 	/* add new constants above here */
 	__ETHTOOL_A_STATS_CNT,
@@ -760,6 +761,7 @@ enum {
 	ETHTOOL_STATS_ETH_MAC,
 	ETHTOOL_STATS_ETH_CTRL,
 	ETHTOOL_STATS_RMON,
+	ETHTOOL_STATS_TS,
 
 	/* add new constants above here */
 	__ETHTOOL_STATS_CNT
@@ -875,6 +877,21 @@ enum {
 	ETHTOOL_A_STATS_RMON_MAX = (__ETHTOOL_A_STATS_RMON_CNT - 1)
 };
 
+enum {
+	/* hwTimestampingTxPkts */
+	ETHTOOL_A_STATS_TS_TX_PKT,
+	/* hwTimestampingTxLost */
+	ETHTOOL_A_STATS_TS_TX_LOST,
+	/* hwTimestampingTxLate */
+	ETHTOOL_A_STATS_TS_TX_LATE,
+	/* hwTimestampingTxErrors */
+	ETHTOOL_A_STATS_TS_TX_ERRORS,
+
+	/* add new constants above here */
+	__ETHTOOL_A_STATS_TS_CNT,
+	ETHTOOL_A_STATS_TS_MAX = (__ETHTOOL_A_STATS_TS_CNT - 1)
+};
+
 /* MODULE */
 
 enum {
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 9a333a8d04c1..962ecd62aeea 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -429,7 +429,7 @@ extern const struct nla_policy ethnl_tunnel_info_get_policy[ETHTOOL_A_TUNNEL_INF
 extern const struct nla_policy ethnl_fec_get_policy[ETHTOOL_A_FEC_HEADER + 1];
 extern const struct nla_policy ethnl_fec_set_policy[ETHTOOL_A_FEC_AUTO + 1];
 extern const struct nla_policy ethnl_module_eeprom_get_policy[ETHTOOL_A_MODULE_EEPROM_I2C_ADDRESS + 1];
-extern const struct nla_policy ethnl_stats_get_policy[ETHTOOL_A_STATS_SRC + 1];
+extern const struct nla_policy ethnl_stats_get_policy[__ETHTOOL_A_STATS_CNT];
 extern const struct nla_policy ethnl_phc_vclocks_get_policy[ETHTOOL_A_PHC_VCLOCKS_HEADER + 1];
 extern const struct nla_policy ethnl_module_get_policy[ETHTOOL_A_MODULE_HEADER + 1];
 extern const struct nla_policy ethnl_module_set_policy[ETHTOOL_A_MODULE_POWER_MODE_POLICY + 1];
@@ -454,5 +454,6 @@ extern const char stats_eth_phy_names[__ETHTOOL_A_STATS_ETH_PHY_CNT][ETH_GSTRING
 extern const char stats_eth_mac_names[__ETHTOOL_A_STATS_ETH_MAC_CNT][ETH_GSTRING_LEN];
 extern const char stats_eth_ctrl_names[__ETHTOOL_A_STATS_ETH_CTRL_CNT][ETH_GSTRING_LEN];
 extern const char stats_rmon_names[__ETHTOOL_A_STATS_RMON_CNT][ETH_GSTRING_LEN];
+extern const char stats_ts_names[__ETHTOOL_A_STATS_TS_CNT][ETH_GSTRING_LEN];
 
 #endif /* _NET_ETHTOOL_NETLINK_H */
diff --git a/net/ethtool/stats.c b/net/ethtool/stats.c
index 912f0c4fff2f..e4333d77fb31 100644
--- a/net/ethtool/stats.c
+++ b/net/ethtool/stats.c
@@ -8,6 +8,7 @@ struct stats_req_info {
 	struct ethnl_req_info		base;
 	DECLARE_BITMAP(stat_mask, __ETHTOOL_STATS_CNT);
 	enum ethtool_mac_stats_src	src;
+	enum ethtool_ts_stats_layer	layer;
 };
 
 #define STATS_REQINFO(__req_base) \
@@ -20,6 +21,7 @@ struct stats_reply_data {
 		struct ethtool_eth_mac_stats	mac_stats;
 		struct ethtool_eth_ctrl_stats	ctrl_stats;
 		struct ethtool_rmon_stats	rmon_stats;
+		struct ethtool_ts_stats		ts_stats;
 	);
 	const struct ethtool_rmon_hist_range	*rmon_ranges;
 };
@@ -32,6 +34,7 @@ const char stats_std_names[__ETHTOOL_STATS_CNT][ETH_GSTRING_LEN] = {
 	[ETHTOOL_STATS_ETH_MAC]			= "eth-mac",
 	[ETHTOOL_STATS_ETH_CTRL]		= "eth-ctrl",
 	[ETHTOOL_STATS_RMON]			= "rmon",
+	[ETHTOOL_STATS_TS]			= "ts",
 };
 
 const char stats_eth_phy_names[__ETHTOOL_A_STATS_ETH_PHY_CNT][ETH_GSTRING_LEN] = {
@@ -76,18 +79,27 @@ const char stats_rmon_names[__ETHTOOL_A_STATS_RMON_CNT][ETH_GSTRING_LEN] = {
 	[ETHTOOL_A_STATS_RMON_JABBER]		= "etherStatsJabbers",
 };
 
-const struct nla_policy ethnl_stats_get_policy[ETHTOOL_A_STATS_SRC + 1] = {
-	[ETHTOOL_A_STATS_HEADER]	=
-		NLA_POLICY_NESTED(ethnl_header_policy),
-	[ETHTOOL_A_STATS_GROUPS]	= { .type = NLA_NESTED },
-	[ETHTOOL_A_STATS_SRC]		=
+const char stats_ts_names[__ETHTOOL_A_STATS_TS_CNT][ETH_GSTRING_LEN] = {
+	[ETHTOOL_A_STATS_TS_TX_PKT]		= "hwTimestampingTxPkts",
+	[ETHTOOL_A_STATS_TS_TX_LOST]		= "hwTimestampingTxLost",
+	[ETHTOOL_A_STATS_TS_TX_LATE]		= "hwTimestampingTxLate",
+	[ETHTOOL_A_STATS_TS_TX_ERRORS]		= "hwTimestampingTxErrors",
+};
+
+const struct nla_policy ethnl_stats_get_policy[__ETHTOOL_A_STATS_CNT] = {
+	[ETHTOOL_A_STATS_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
+	[ETHTOOL_A_STATS_GROUPS] = { .type = NLA_NESTED },
+	[ETHTOOL_A_STATS_SRC] =
 		NLA_POLICY_MAX(NLA_U32, ETHTOOL_MAC_STATS_SRC_PMAC),
+	[ETHTOOL_A_STATS_LAYER] =
+		NLA_POLICY_MAX(NLA_U32, ETHTOOL_TS_STATS_LAYER_PHY),
 };
 
 static int stats_parse_request(struct ethnl_req_info *req_base,
 			       struct nlattr **tb,
 			       struct netlink_ext_ack *extack)
 {
+	enum ethtool_ts_stats_layer layer = ETHTOOL_TS_STATS_LAYER_ACTIVE;
 	enum ethtool_mac_stats_src src = ETHTOOL_MAC_STATS_SRC_AGGREGATE;
 	struct stats_req_info *req_info = STATS_REQINFO(req_base);
 	bool mod = false;
@@ -104,9 +116,12 @@ static int stats_parse_request(struct ethnl_req_info *req_base,
 		return -EINVAL;
 	}
 
+	if (tb[ETHTOOL_A_STATS_LAYER])
+		layer = nla_get_u32(tb[ETHTOOL_A_STATS_LAYER]);
 	if (tb[ETHTOOL_A_STATS_SRC])
 		src = nla_get_u32(tb[ETHTOOL_A_STATS_SRC]);
 
+	req_info->layer = layer;
 	req_info->src = src;
 
 	return 0;
@@ -118,6 +133,7 @@ static int stats_prepare_data(const struct ethnl_req_info *req_base,
 {
 	const struct stats_req_info *req_info = STATS_REQINFO(req_base);
 	struct stats_reply_data *data = STATS_REPDATA(reply_base);
+	enum ethtool_ts_stats_layer layer = req_info->layer;
 	enum ethtool_mac_stats_src src = req_info->src;
 	struct net_device *dev = reply_base->dev;
 	int ret;
@@ -144,6 +160,7 @@ static int stats_prepare_data(const struct ethnl_req_info *req_base,
 	data->mac_stats.src = src;
 	data->ctrl_stats.src = src;
 	data->rmon_stats.src = src;
+	data->ts_stats.layer = layer;
 
 	if (test_bit(ETHTOOL_STATS_ETH_PHY, req_info->stat_mask) &&
 	    dev->ethtool_ops->get_eth_phy_stats)
@@ -158,6 +175,9 @@ static int stats_prepare_data(const struct ethnl_req_info *req_base,
 	    dev->ethtool_ops->get_rmon_stats)
 		dev->ethtool_ops->get_rmon_stats(dev, &data->rmon_stats,
 						 &data->rmon_ranges);
+	if (test_bit(ETHTOOL_STATS_TS, req_info->stat_mask) &&
+	    dev->ethtool_ops->get_ts_stats)
+		dev->ethtool_ops->get_ts_stats(dev, &data->ts_stats);
 
 	ethnl_ops_complete(dev);
 	return 0;
@@ -194,6 +214,10 @@ static int stats_reply_size(const struct ethnl_req_info *req_base,
 			nla_total_size(4)) *	/* _A_STATS_GRP_HIST_BKT_HI */
 			ETHTOOL_RMON_HIST_MAX * 2;
 	}
+	if (test_bit(ETHTOOL_STATS_TS, req_info->stat_mask)) {
+		n_stats += sizeof(struct ethtool_ts_stats) / sizeof(u64);
+		n_grps++;
+	}
 
 	len += n_grps * (nla_total_size(0) + /* _A_STATS_GRP */
 			 nla_total_size(4) + /* _A_STATS_GRP_ID */
@@ -370,6 +394,22 @@ static int stats_put_rmon_stats(struct sk_buff *skb,
 	return 0;
 }
 
+static int stats_put_ts_stats(struct sk_buff *skb,
+			      const struct stats_reply_data *data)
+{
+	if (stat_put(skb, ETHTOOL_A_STATS_TS_TX_PKT,
+		     data->ts_stats.pkts) ||
+	    stat_put(skb, ETHTOOL_A_STATS_TS_TX_LOST,
+		     data->ts_stats.lost) ||
+	    stat_put(skb, ETHTOOL_A_STATS_TS_TX_LATE,
+		     data->ts_stats.late) ||
+	    stat_put(skb, ETHTOOL_A_STATS_TS_TX_ERRORS,
+		     data->ts_stats.err))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
 static int stats_put_stats(struct sk_buff *skb,
 			   const struct stats_reply_data *data,
 			   u32 id, u32 ss_id,
@@ -423,6 +463,9 @@ static int stats_fill_reply(struct sk_buff *skb,
 	if (!ret && test_bit(ETHTOOL_STATS_RMON, req_info->stat_mask))
 		ret = stats_put_stats(skb, data, ETHTOOL_STATS_RMON,
 				      ETH_SS_STATS_RMON, stats_put_rmon_stats);
+	if (!ret && test_bit(ETHTOOL_STATS_TS, req_info->stat_mask))
+		ret = stats_put_stats(skb, data, ETHTOOL_STATS_TS,
+				      ETH_SS_STATS_TS, stats_put_ts_stats);
 
 	return ret;
 }
diff --git a/net/ethtool/strset.c b/net/ethtool/strset.c
index c678b484a079..ce1e193076c3 100644
--- a/net/ethtool/strset.c
+++ b/net/ethtool/strset.c
@@ -105,6 +105,11 @@ static const struct strset_info info_template[] = {
 		.count		= __ETHTOOL_A_STATS_RMON_CNT,
 		.strings	= stats_rmon_names,
 	},
+	[ETH_SS_STATS_TS] = {
+		.per_dev	= false,
+		.count		= __ETHTOOL_A_STATS_TS_CNT,
+		.strings	= stats_ts_names,
+	},
 };
 
 struct strset_req_info {
-- 
2.42.0