From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alice Michael Date: Thu, 17 May 2018 01:08:39 -0700 Subject: [Intel-wired-lan] [next PATCH S92 8/9] i40e: add function doc headers for ethtool stats functions In-Reply-To: <20180517080840.30192-1-alice.michael@intel.com> References: <20180517080840.30192-1-alice.michael@intel.com> Message-ID: <20180517080840.30192-8-alice.michael@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: From: Jacob Keller 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 --- drivers/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 94e1995..487a9a4 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c +++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c @@ -1540,6 +1540,20 @@ static int i40e_set_ringparam(struct net_device *netdev, 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); @@ -1571,6 +1585,20 @@ 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) { @@ -1667,6 +1695,16 @@ 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); -- 2.9.5