From 9a0f830f80265bd1ef816e1541ac24bee80e9a3c Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 4 Nov 2022 12:01:25 -0700 Subject: ethtool: linkstate: add a statistic for PHY down events The previous attempt to augment carrier_down (see Link) was not met with much enthusiasm so let's do the simple thing of exposing what some devices already maintain. Add a common ethtool statistic for link going down. Currently users have to maintain per-driver mapping to extract the right stat from the vendor-specific ethtool -S stats. carrier_down does not fit the bill because it counts a lot of software related false positives. Add the statistic to the extended link state API to steer vendors towards implementing all of it. Implement for bnxt and all Linux-controlled PHYs. mlx5 and (possibly) enic also have a counter for this but I leave the implementation to their maintainers. Link: https://lore.kernel.org/r/20220520004500.2250674-1-kuba@kernel.org Reviewed-by: Florian Fainelli Reviewed-by: Michael Chan Reviewed-by: Andrew Lunn Signed-off-by: Jakub Kicinski Link: https://lore.kernel.org/r/20221104190125.684910-1-kuba@kernel.org Signed-off-by: Paolo Abeni --- include/linux/ethtool.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'include/linux/ethtool.h') diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h index 99dc7bfbcd3c..5c51c7fda32a 100644 --- a/include/linux/ethtool.h +++ b/include/linux/ethtool.h @@ -125,6 +125,20 @@ struct ethtool_link_ext_state_info { }; }; +struct ethtool_link_ext_stats { + /* Custom Linux statistic for PHY level link down events. + * In a simpler world it should be equal to netdev->carrier_down_count + * unfortunately netdev also counts local reconfigurations which don't + * actually take the physical link down, not to mention NC-SI which, + * if present, keeps the link up regardless of host state. + * This statistic counts when PHY _actually_ went down, or lost link. + * + * Note that we need u64 for ethtool_stats_init() and comparisons + * to ETHTOOL_STAT_NOT_SET, but only u32 is exposed to the user. + */ + u64 link_down_events; +}; + /** * ethtool_rxfh_indir_default - get default value for RX flow hash indirection * @index: Index in RX flow hash indirection table @@ -481,6 +495,7 @@ struct ethtool_module_power_mode_params { * do not attach ext_substate attribute to netlink message). If link_ext_state * and link_ext_substate are unknown, return -ENODATA. If not implemented, * link_ext_state and link_ext_substate will not be sent to userspace. + * @get_link_ext_stats: Read extra link-related counters. * @get_eeprom_len: Read range of EEPROM addresses for validation of * @get_eeprom and @set_eeprom requests. * Returns 0 if device does not support EEPROM access. @@ -652,6 +667,8 @@ struct ethtool_ops { u32 (*get_link)(struct net_device *); int (*get_link_ext_state)(struct net_device *, struct ethtool_link_ext_state_info *); + void (*get_link_ext_stats)(struct net_device *dev, + struct ethtool_link_ext_stats *stats); int (*get_eeprom_len)(struct net_device *); int (*get_eeprom)(struct net_device *, struct ethtool_eeprom *, u8 *); -- cgit v1.2.3 From f20a0a0519f35a3a34236ed2d38b067c5cb22b9f Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Thu, 17 Nov 2022 02:18:28 +0900 Subject: ethtool: doc: clarify what drivers can implement in their get_drvinfo() Many of the drivers which implement ethtool_ops::get_drvinfo() will prints the .driver, .version or .bus_info of struct ethtool_drvinfo. To have a glance of current state, do: $ git grep -W "get_drvinfo(struct" Printing in those three fields is useless because: - since [1], the driver version should be the kernel version (at least for upstream drivers). Arguably, out of tree drivers might still want to set a custom version, but out of tree is not our focus. - since [2], the core is able to provide default values for .driver and .bus_info. In summary, drivers may provide .fw_version and .erom_version, the rest is expected to be done by the core. In struct ethtool_ops doc from linux/ethtool: rephrase field get_drvinfo() doc to discourage developers from implementing this callback. In struct ethtool_drvinfo doc from uapi/linux/ethtool.h: remove the paragraph mentioning what drivers should do. Rationale: no need to repeat what is already written in struct ethtool_ops doc. But add a note that .fw_version and .erom_version are driver defined. Also update the dummy driver and simply remove the callback in order not to confuse the newcomers: most of the drivers will not need this callback function any more. [1] commit 6a7e25c7fb48 ("net/core: Replace driver version to be kernel version") Link: https://git.kernel.org/torvalds/linux/c/6a7e25c7fb48 [2] commit edaf5df22cb8 ("ethtool: ethtool_get_drvinfo: populate drvinfo fields even if callback exits") Link: https://git.kernel.org/netdev/net-next/c/edaf5df22cb8 Reviewed-by: Leon Romanovsky Signed-off-by: Vincent Mailhol Link: https://lore.kernel.org/r/20221116171828.4093-1-mailhol.vincent@wanadoo.fr Signed-off-by: Jakub Kicinski --- include/linux/ethtool.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux/ethtool.h') diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h index 5c51c7fda32a..9e0a76fc7de9 100644 --- a/include/linux/ethtool.h +++ b/include/linux/ethtool.h @@ -473,10 +473,10 @@ struct ethtool_module_power_mode_params { * parameter. * @supported_coalesce_params: supported types of interrupt coalescing. * @supported_ring_params: supported ring params. - * @get_drvinfo: Report driver/device information. Should only set the - * @driver, @version, @fw_version and @bus_info fields. If not - * implemented, the @driver and @bus_info fields will be filled in - * according to the netdev's parent device. + * @get_drvinfo: Report driver/device information. Modern drivers no + * longer have to implement this callback. Most fields are + * correctly filled in by the core using system information, or + * populated using other driver operations. * @get_regs_len: Get buffer length required for @get_regs * @get_regs: Get device registers * @get_wol: Report whether Wake-on-Lan is enabled -- cgit v1.2.3