From ec29bbf8abaca7b295abd4a4204461ca9f82c3f5 Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Thu, 17 May 2018 01:08:39 -0700 Subject: [PATCH] i40e: add function doc headers for ethtool stats functions Add documentation for the i40e_get_stats_count, i40e_get_stat_strings and i40e_get_ethtool_stats explaining that the number and ordering of statistics must remain constant for a given netdevice. Signed-off-by: Jacob Keller Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- .../net/ethernet/intel/i40e/i40e_ethtool.c | 38 +++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c index 44a2803cb1ec..4b5ecba0148c 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c +++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c @@ -1660,6 +1660,20 @@ done: return err; } +/** + * i40e_get_stats_count - return the stats count for a device + * @netdev: the netdev to return the count for + * + * Returns the total number of statistics for this netdev. Note that even + * though this is a function, it is required that the count for a specific + * netdev must never change. Basing the count on static values such as the + * maximum number of queues or the device type is ok. However, the API for + * obtaining stats is *not* safe against changes based on non-static + * values such as the *current* number of queues, or runtime flags. + * + * If a statistic is not always enabled, return it as part of the count + * anyways, always return its string, and report its value as zero. + **/ static int i40e_get_stats_count(struct net_device *netdev) { struct i40e_netdev_priv *np = netdev_priv(netdev); @@ -1691,6 +1705,20 @@ static int i40e_get_sset_count(struct net_device *netdev, int sset) } } +/** + * i40e_get_ethtool_stats - copy stat values into supplied buffer + * @netdev: the netdev to collect stats for + * @stats: ethtool stats command structure + * @data: ethtool supplied buffer + * + * Copy the stats values for this netdev into the buffer. Expects data to be + * pre-allocated to the size returned by i40e_get_stats_count.. Note that all + * statistics must be copied in a static order, and the count must not change + * for a given netdev. See i40e_get_stats_count for more details. + * + * If a statistic is not currently valid (such as a disabled queue), this + * function reports its value as zero. + **/ static void i40e_get_ethtool_stats(struct net_device *netdev, struct ethtool_stats *stats, u64 *data) { @@ -1787,6 +1815,16 @@ static void i40e_get_ethtool_stats(struct net_device *netdev, *(data++) = pf->stats.priority_xon_2_xoff[j]; } +/** + * i40e_get_stat_strings - copy stat strings into supplied buffer + * @netdev: the netdev to collect strings for + * @data: supplied buffer to copy strings into + * + * Copy the strings related to stats for this netdev. Expects data to be + * pre-allocated with the size reported by i40e_get_stats_count. Note that the + * strings must be copied in a static order and the total count must not + * change for a given netdev. See i40e_get_stats_count for more details. + **/ static void i40e_get_stat_strings(struct net_device *netdev, u8 *data) { struct i40e_netdev_priv *np = netdev_priv(netdev);