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 <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
This commit is contained in:
Jacob Keller 2018-05-17 01:08:39 -07:00 committed by Jeff Kirsher
parent e08696dcd9
commit ec29bbf8ab
1 changed files with 38 additions and 0 deletions

View File

@ -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);