net: Add support for providing the PTP hardware source in tsinfo

Multi-PTP source support within a network topology has been merged,
but the hardware timestamp source is not yet exposed to users.
Currently, users only see the PTP index, which does not indicate
whether the timestamp comes from a PHY or a MAC.

Add support for reporting the hwtstamp source using a
hwtstamp-source field, alongside hwtstamp-phyindex, to describe
the origin of the hardware timestamp.

Remove HWTSTAMP_SOURCE_UNSPEC enum value as it is not used at all.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20250519-feature_ptp_source-v4-1-5d10e19a0265@bootlin.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Documentation/netlink/specs/ethtool.yaml

@@ -98,6 +98,24 @@ definitions:
     name: tcp-data-split
     type: enum
     entries: [ unknown, disabled, enabled ]
+  -
+    name: hwtstamp-source
+    doc: Source of the hardware timestamp
+    enum-name: hwtstamp-source
+    name-prefix: hwtstamp-source-
+    type: enum
+    entries:
+      -
+        name: netdev
+        doc: |
+          Hardware timestamp comes from a MAC or a device
+          which has MAC and PHY integrated
+        value: 1
+      -
+        name: phylib
+        doc: |
+          Hardware timestamp comes from one PHY device
+          of the network topology
 
 attribute-sets:
   -
@@ -896,6 +914,13 @@ attribute-sets:
         name: hwtstamp-provider
         type: nest
         nested-attributes: ts-hwtstamp-provider
+      -
+        name: hwtstamp-source
+        type: u32
+        enum: hwtstamp-source
+      -
+        name: hwtstamp-phyindex
+        type: u32
   -
     name: cable-result
     attr-cnt-name: __ethtool-a-cable-result-cnt
@@ -1981,6 +2006,8 @@ operations:
             - phc-index
             - stats
             - hwtstamp-provider
+            - hwtstamp-source
+            - hwtstamp-phyindex
       dump: *tsinfo-get-op
     -
       name: cable-test-act

include/linux/ethtool.h

@@ -19,6 +19,7 @@
 #include <linux/netlink.h>
 #include <linux/timer_types.h>
 #include <uapi/linux/ethtool.h>
+#include <uapi/linux/ethtool_netlink_generated.h>
 #include <uapi/linux/net_tstamp.h>
 
 #define ETHTOOL_MM_MAX_VERIFY_TIME_MS		128
@@ -830,6 +831,8 @@ struct ethtool_rxfh_param {
  * @so_timestamping: bit mask of the sum of the supported SO_TIMESTAMPING flags
  * @phc_index: device index of the associated PHC, or -1 if there is none
  * @phc_qualifier: qualifier of the associated PHC
+ * @phc_source: source device of the associated PHC
+ * @phc_phyindex: index of PHY device source of the associated PHC
  * @tx_types: bit mask of the supported hwtstamp_tx_types enumeration values
  * @rx_filters: bit mask of the supported hwtstamp_rx_filters enumeration values
  */
@@ -838,6 +841,8 @@ struct kernel_ethtool_ts_info {
 	u32 so_timestamping;
 	int phc_index;
 	enum hwtstamp_provider_qualifier phc_qualifier;
+	enum hwtstamp_source phc_source;
+	int phc_phyindex;
 	enum hwtstamp_tx_types tx_types;
 	enum hwtstamp_rx_filters rx_filters;
 };

include/linux/net_tstamp.h

@@ -4,6 +4,7 @@
 #define _LINUX_NET_TIMESTAMPING_H_
 
 #include <uapi/linux/net_tstamp.h>
+#include <uapi/linux/ethtool_netlink_generated.h>
 
 #define SOF_TIMESTAMPING_SOFTWARE_MASK	(SOF_TIMESTAMPING_RX_SOFTWARE | \
 					 SOF_TIMESTAMPING_TX_SOFTWARE | \
@@ -13,12 +14,6 @@
 					 SOF_TIMESTAMPING_TX_HARDWARE | \
 					 SOF_TIMESTAMPING_RAW_HARDWARE)
 
-enum hwtstamp_source {
-	HWTSTAMP_SOURCE_UNSPEC,
-	HWTSTAMP_SOURCE_NETDEV,
-	HWTSTAMP_SOURCE_PHYLIB,
-};
-
 /**
  * struct hwtstamp_provider_desc - hwtstamp provider description
  *

include/uapi/linux/ethtool_netlink_generated.h

@@ -37,6 +37,18 @@ enum ethtool_tcp_data_split {
 	ETHTOOL_TCP_DATA_SPLIT_ENABLED,
 };
 
+/**
+ * enum hwtstamp_source - Source of the hardware timestamp
+ * @HWTSTAMP_SOURCE_NETDEV: Hardware timestamp comes from a MAC or a device
+ *   which has MAC and PHY integrated
+ * @HWTSTAMP_SOURCE_PHYLIB: Hardware timestamp comes from one PHY device of the
+ *   network topology
+ */
+enum hwtstamp_source {
+	HWTSTAMP_SOURCE_NETDEV = 1,
+	HWTSTAMP_SOURCE_PHYLIB,
+};
+
 enum {
 	ETHTOOL_A_HEADER_UNSPEC,
 	ETHTOOL_A_HEADER_DEV_INDEX,
@@ -401,6 +413,8 @@ enum {
 	ETHTOOL_A_TSINFO_PHC_INDEX,
 	ETHTOOL_A_TSINFO_STATS,
 	ETHTOOL_A_TSINFO_HWTSTAMP_PROVIDER,
+	ETHTOOL_A_TSINFO_HWTSTAMP_SOURCE,
+	ETHTOOL_A_TSINFO_HWTSTAMP_PHYINDEX,
 
 	__ETHTOOL_A_TSINFO_CNT,
 	ETHTOOL_A_TSINFO_MAX = (__ETHTOOL_A_TSINFO_CNT - 1)

net/ethtool/common.c

@@ -921,9 +921,18 @@ int ethtool_get_ts_info_by_phc(struct net_device *dev,
 
 		phy = ethtool_phy_get_ts_info_by_phc(dev, info, hwprov_desc);
 		if (IS_ERR(phy))
-			err = PTR_ERR(phy);
-		else
-			err = 0;
+			return PTR_ERR(phy);
+
+		/* Report the phc source only if we have a real
+		 * phc source with an index.
+		 */
+		if (info->phc_index >= 0) {
+			info->phc_source = HWTSTAMP_SOURCE_PHYLIB;
+			info->phc_phyindex = phy->phyindex;
+		}
+		err = 0;
+	} else if (!err && info->phc_index >= 0) {
+		info->phc_source = HWTSTAMP_SOURCE_NETDEV;
 	}
 
 	info->so_timestamping |= SOF_TIMESTAMPING_RX_SOFTWARE |
@@ -947,10 +956,20 @@ int __ethtool_get_ts_info(struct net_device *dev,
 
 		ethtool_init_tsinfo(info);
 		if (phy_is_default_hwtstamp(phydev) &&
-		    phy_has_tsinfo(phydev))
+		    phy_has_tsinfo(phydev)) {
 			err = phy_ts_info(phydev, info);
-		else if (ops->get_ts_info)
+			/* Report the phc source only if we have a real
+			 * phc source with an index.
+			 */
+			if (!err && info->phc_index >= 0) {
+				info->phc_source = HWTSTAMP_SOURCE_PHYLIB;
+				info->phc_phyindex = phydev->phyindex;
+			}
+		} else if (ops->get_ts_info) {
 			err = ops->get_ts_info(dev, info);
+			if (!err && info->phc_index >= 0)
+				info->phc_source = HWTSTAMP_SOURCE_NETDEV;
+		}
 
 		info->so_timestamping |= SOF_TIMESTAMPING_RX_SOFTWARE |
 					 SOF_TIMESTAMPING_SOFTWARE;

net/ethtool/tsinfo.c

@@ -160,6 +160,12 @@ static int tsinfo_reply_size(const struct ethnl_req_info *req_base,
 		/* _TSINFO_HWTSTAMP_PROVIDER */
 		len += nla_total_size(0) + 2 * nla_total_size(sizeof(u32));
 	}
+	if (ts_info->phc_source) {
+		len += nla_total_size(sizeof(u32));	/* _TSINFO_HWTSTAMP_SOURCE */
+		if (ts_info->phc_phyindex)
+			/* _TSINFO_HWTSTAMP_PHYINDEX */
+			len += nla_total_size(sizeof(u32));
+	}
 	if (req_base->flags & ETHTOOL_FLAG_STATS)
 		len += nla_total_size(0) + /* _TSINFO_STATS */
 		       nla_total_size_64bit(sizeof(u64)) * ETHTOOL_TS_STAT_CNT;
@@ -259,6 +265,16 @@ static int tsinfo_fill_reply(struct sk_buff *skb,
 
 		nla_nest_end(skb, nest);
 	}
+	if (ts_info->phc_source) {
+		if (nla_put_u32(skb, ETHTOOL_A_TSINFO_HWTSTAMP_SOURCE,
+				ts_info->phc_source))
+			return -EMSGSIZE;
+
+		if (ts_info->phc_phyindex &&
+		    nla_put_u32(skb, ETHTOOL_A_TSINFO_HWTSTAMP_PHYINDEX,
+				ts_info->phc_phyindex))
+			return -EMSGSIZE;
+	}
 	if (req_base->flags & ETHTOOL_FLAG_STATS &&
 	    tsinfo_put_stats(skb, &data->stats))
 		return -EMSGSIZE;
@@ -346,6 +362,11 @@ static int ethnl_tsinfo_dump_one_phydev(struct sk_buff *skb,
 	if (ret < 0)
 		goto err;
 
+	if (reply_data->ts_info.phc_index >= 0) {
+		reply_data->ts_info.phc_source = HWTSTAMP_SOURCE_PHYLIB;
+		reply_data->ts_info.phc_phyindex = phydev->phyindex;
+	}
+
 	ret = ethnl_tsinfo_end_dump(skb, dev, req_info, reply_data, ehdr);
 	if (ret < 0)
 		goto err;
@@ -389,6 +410,8 @@ static int ethnl_tsinfo_dump_one_netdev(struct sk_buff *skb,
 		if (ret < 0)
 			goto err;
 
+		if (reply_data->ts_info.phc_index >= 0)
+			reply_data->ts_info.phc_source = HWTSTAMP_SOURCE_NETDEV;
 		ret = ethnl_tsinfo_end_dump(skb, dev, req_info, reply_data,
 					    ehdr);
 		if (ret < 0)