ethtool: add interface to read Tx hardware timestamping statistics

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>
Link: https://lore.kernel.org/r/20240403212931.128541-2-rrameshbabu@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index d0e4a47e0f214bf8d47dcacbaa34c4f80ba8877f..b76916394ec93f4265a66b1ebf89671cccb041e7 100644 (file)
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -565,6 +565,18 @@ attribute-sets:
       -
         name: tx-lpi-timer
         type: u32
+  -
+    name: ts-stat
+    attributes:
+      -
+        name: tx-pkts
+        type: uint
+      -
+        name: tx-lost
+        type: uint
+      -
+        name: tx-err
+        type: uint
   -
     name: tsinfo
     attributes:
@@ -587,6 +599,10 @@ attribute-sets:
       -
         name: phc-index
         type: u32
+      -
+        name: stats
+        type: nest
+        nested-attributes: ts-stat
   -
     name: cable-result
     attributes:
@@ -1394,6 +1410,7 @@ operations:
             - tx-types
             - rx-filters
             - phc-index
+            - stats
       dump: *tsinfo-get-op
     -
       name: cable-test-act

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index d583d9abf2f80698a7f4ca3ef47ce676e71767e1..08d330b0f50fd2a103eb0999a2680651d6580ebb 100644 (file)
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -1237,12 +1237,21 @@ Kernel response contents:
   ``ETHTOOL_A_TSINFO_TX_TYPES``          bitset  supported Tx types
   ``ETHTOOL_A_TSINFO_RX_FILTERS``        bitset  supported Rx filters
   ``ETHTOOL_A_TSINFO_PHC_INDEX``         u32     PTP hw clock index
+  ``ETHTOOL_A_TSINFO_STATS``             nested  HW timestamping statistics
   =====================================  ======  ==========================
 
 ``ETHTOOL_A_TSINFO_PHC_INDEX`` is absent if there is no associated PHC (there
 is no special value for this case). The bitset attributes are omitted if they
 would be empty (no bit set).
 
+Additional hardware timestamping statistics response contents:
+
+  =====================================  ======  ===================================
+  ``ETHTOOL_A_TS_STAT_TX_PKTS``          u64     Packets with Tx HW timestamps
+  ``ETHTOOL_A_TS_STAT_TX_LOST``          u64     Tx HW timestamp not arrived count
+  ``ETHTOOL_A_TS_STAT_TX_ERR``           u64     HW error request Tx timestamp count
+  =====================================  ======  ===================================
+
 CABLE_TEST
 ==========
 

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 9901e563f706ee63374c244204e33a589da044eb..6fd9107d3cc010dd2f1ecdb005c412145c461b6c 100644 (file)
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -480,6 +480,26 @@ struct ethtool_rmon_stats {
        );
 };
 
+/**
+ * struct ethtool_ts_stats - HW timestamping statistics
+ * @pkts: Number of packets successfully timestamped by the hardware.
+ * @lost: Number of hardware timestamping requests where the timestamping
+ *     information from the hardware never arrived for submission with
+ *     the skb.
+ * @err: Number of arbitrary timestamp generation error events that the
+ *     hardware encountered, exclusive of @lost statistics. Cases such
+ *     as resource exhaustion, unavailability, firmware errors, and
+ *     detected illogical timestamp values not submitted with the skb
+ *     are inclusive to this counter.
+ */
+struct ethtool_ts_stats {
+       struct_group(tx_stats,
+               u64 pkts;
+               u64 lost;
+               u64 err;
+       );
+};
+
 #define ETH_MODULE_EEPROM_PAGE_LEN     128
 #define ETH_MODULE_MAX_I2C_ADDRESS     0x7f
 
@@ -755,7 +775,10 @@ struct ethtool_rxfh_param {
  * @get_ts_info: Get the time stamping and PTP hardware clock capabilities.
  *     It may be called with RCU, or rtnl or reference on the device.
  *     Drivers supporting transmit time stamps in software should set this to
- *     ethtool_op_get_ts_info().
+ *     ethtool_op_get_ts_info(). Drivers must not zero statistics which they
+ *     don't report. The stats structure is initialized to ETHTOOL_STAT_NOT_SET
+ *     indicating driver does not report statistics.
+ * @get_ts_stats: Query the device hardware timestamping statistics.
  * @get_module_info: Get the size and type of the eeprom contained within
  *     a plug-in module.
  * @get_module_eeprom: Get the eeprom information from the plug-in module
@@ -898,6 +921,8 @@ struct ethtool_ops {
                                 struct ethtool_dump *, void *);
        int     (*set_dump)(struct net_device *, struct ethtool_dump *);
        int     (*get_ts_info)(struct net_device *, struct ethtool_ts_info *);
+       void    (*get_ts_stats)(struct net_device *dev,
+                               struct ethtool_ts_stats *ts_stats);
        int     (*get_module_info)(struct net_device *,
                                   struct ethtool_modinfo *);
        int     (*get_module_eeprom)(struct net_device *,

diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index accbb1a231df5a8b488eddd8572b038dcd332a2b..708272026d803d225167037fc2960a065520fed1 100644 (file)
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -478,12 +478,26 @@ enum {
        ETHTOOL_A_TSINFO_TX_TYPES,                      /* bitset */
        ETHTOOL_A_TSINFO_RX_FILTERS,                    /* bitset */
        ETHTOOL_A_TSINFO_PHC_INDEX,                     /* u32 */
+       ETHTOOL_A_TSINFO_STATS,                         /* nest - _A_TSINFO_STAT */
 
        /* add new constants above here */
        __ETHTOOL_A_TSINFO_CNT,
        ETHTOOL_A_TSINFO_MAX = (__ETHTOOL_A_TSINFO_CNT - 1)
 };
 
+enum {
+       ETHTOOL_A_TS_STAT_UNSPEC,
+
+       ETHTOOL_A_TS_STAT_TX_PKTS,                      /* u64 */
+       ETHTOOL_A_TS_STAT_TX_LOST,                      /* u64 */
+       ETHTOOL_A_TS_STAT_TX_ERR,                       /* u64 */
+
+       /* add new constants above here */
+       __ETHTOOL_A_TS_STAT_CNT,
+       ETHTOOL_A_TS_STAT_MAX = (__ETHTOOL_A_TS_STAT_CNT - 1)
+
+};
+
 /* PHC VCLOCKS */
 
 enum {

diff --git a/net/ethtool/tsinfo.c b/net/ethtool/tsinfo.c
index 9daed0aab162a17cbed9bfb945e4da37585d0d06..be2755c8d8fde7a2e74225aed4a276a39d72d0f1 100644 (file)
--- a/net/ethtool/tsinfo.c
+++ b/net/ethtool/tsinfo.c
@@ -13,14 +13,18 @@ struct tsinfo_req_info {
 struct tsinfo_reply_data {
        struct ethnl_reply_data         base;
        struct ethtool_ts_info          ts_info;
+       struct ethtool_ts_stats         stats;
 };
 
 #define TSINFO_REPDATA(__reply_base) \
        container_of(__reply_base, struct tsinfo_reply_data, base)
 
+#define ETHTOOL_TS_STAT_CNT \
+       (__ETHTOOL_A_TS_STAT_CNT - (ETHTOOL_A_TS_STAT_UNSPEC + 1))
+
 const struct nla_policy ethnl_tsinfo_get_policy[] = {
        [ETHTOOL_A_TSINFO_HEADER]               =
-               NLA_POLICY_NESTED(ethnl_header_policy),
+               NLA_POLICY_NESTED(ethnl_header_policy_stats),
 };
 
 static int tsinfo_prepare_data(const struct ethnl_req_info *req_base,
@@ -34,6 +38,12 @@ static int tsinfo_prepare_data(const struct ethnl_req_info *req_base,
        ret = ethnl_ops_begin(dev);
        if (ret < 0)
                return ret;
+       if (req_base->flags & ETHTOOL_FLAG_STATS &&
+           dev->ethtool_ops->get_ts_stats) {
+               ethtool_stats_init((u64 *)&data->stats,
+                                  sizeof(data->stats) / sizeof(u64));
+               dev->ethtool_ops->get_ts_stats(dev, &data->stats);
+       }
        ret = __ethtool_get_ts_info(dev, &data->ts_info);
        ethnl_ops_complete(dev);
 
@@ -79,10 +89,47 @@ static int tsinfo_reply_size(const struct ethnl_req_info *req_base,
        }
        if (ts_info->phc_index >= 0)
                len += nla_total_size(sizeof(u32));     /* _TSINFO_PHC_INDEX */
+       if (req_base->flags & ETHTOOL_FLAG_STATS)
+               len += nla_total_size(0) + /* _TSINFO_STATS */
+                      nla_total_size_64bit(sizeof(u64)) * ETHTOOL_TS_STAT_CNT;
 
        return len;
 }
 
+static int tsinfo_put_stat(struct sk_buff *skb, u64 val, u16 attrtype)
+{
+       if (val == ETHTOOL_STAT_NOT_SET)
+               return 0;
+       if (nla_put_uint(skb, attrtype, val))
+               return -EMSGSIZE;
+       return 0;
+}
+
+static int tsinfo_put_stats(struct sk_buff *skb,
+                           const struct ethtool_ts_stats *stats)
+{
+       struct nlattr *nest;
+
+       nest = nla_nest_start(skb, ETHTOOL_A_TSINFO_STATS);
+       if (!nest)
+               return -EMSGSIZE;
+
+       if (tsinfo_put_stat(skb, stats->tx_stats.pkts,
+                           ETHTOOL_A_TS_STAT_TX_PKTS) ||
+           tsinfo_put_stat(skb, stats->tx_stats.lost,
+                           ETHTOOL_A_TS_STAT_TX_LOST) ||
+           tsinfo_put_stat(skb, stats->tx_stats.err,
+                           ETHTOOL_A_TS_STAT_TX_ERR))
+               goto err_cancel;
+
+       nla_nest_end(skb, nest);
+       return 0;
+
+err_cancel:
+       nla_nest_cancel(skb, nest);
+       return -EMSGSIZE;
+}
+
 static int tsinfo_fill_reply(struct sk_buff *skb,
                             const struct ethnl_req_info *req_base,
                             const struct ethnl_reply_data *reply_base)
@@ -119,6 +166,9 @@ static int tsinfo_fill_reply(struct sk_buff *skb,
        if (ts_info->phc_index >= 0 &&
            nla_put_u32(skb, ETHTOOL_A_TSINFO_PHC_INDEX, ts_info->phc_index))
                return -EMSGSIZE;
+       if (req_base->flags & ETHTOOL_FLAG_STATS &&
+           tsinfo_put_stats(skb, &data->stats))
+               return -EMSGSIZE;
 
        return 0;
 }