Re: [PATCH v2 net-next] ionic: add support for ethtool extended stat link_down_count

[Larysa Zaremba <larysa.zaremba@intel.com>]

On Thu, Jun 08, 2023 at 10:50:16PM -0700, Shannon Nelson wrote:
> From: Nitya Sunkad <nitya.sunkad@amd.com>
> 
> Following the example of 'commit 9a0f830f8026 ("ethtool: linkstate:
> add a statistic for PHY down events")', added support for link down
> events.
> 
> Added callback ionic_get_link_ext_stats to ionic_ethtool.c to support
> link_down_count, a property of netdev that gets reported exclusively
> on physical link down events.

Commit message hasn't changed since v1, despite the comment about usage of 
"added" vs "add".

> 
> Run ethtool -I <devname> to display the device link down count.
> 
> Signed-off-by: Nitya Sunkad <nitya.sunkad@amd.com>
> Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
> ---
> v2: Report link_down_count only on PF, not on VF
> 
>  drivers/net/ethernet/pensando/ionic/ionic_ethtool.c | 10 ++++++++++
>  drivers/net/ethernet/pensando/ionic/ionic_lif.c     |  1 +
>  drivers/net/ethernet/pensando/ionic/ionic_lif.h     |  1 +
>  3 files changed, 12 insertions(+)
> 
> diff --git a/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c b/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c
> index 9b2b96fa36af..3a6b0a9bc241 100644
> --- a/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c
> +++ b/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c
> @@ -104,6 +104,15 @@ static void ionic_get_regs(struct net_device *netdev, struct ethtool_regs *regs,
>  	memcpy_fromio(p + offset, lif->ionic->idev.dev_cmd_regs->words, size);
>  }
>  
> +static void ionic_get_link_ext_stats(struct net_device *netdev,
> +				     struct ethtool_link_ext_stats *stats)
> +{
> +	struct ionic_lif *lif = netdev_priv(netdev);
> +
> +	if (lif->ionic->pdev->is_physfn)

Maybe

ionic->pdev->device == PCI_DEVICE_ID_PENSANDO_IONIC_ETH_PF

from [0] would be a more reliable way to determine, whether we are dealing with 
a PF?

[0] https://lore.kernel.org/netdev/20191212003344.5571-3-snelson@pensando.io/

> +		stats->link_down_events = lif->link_down_count;
> +}
> +
>  static int ionic_get_link_ksettings(struct net_device *netdev,
>  				    struct ethtool_link_ksettings *ks)
>  {
> @@ -1074,6 +1083,7 @@ static const struct ethtool_ops ionic_ethtool_ops = {
>  	.get_regs_len		= ionic_get_regs_len,
>  	.get_regs		= ionic_get_regs,
>  	.get_link		= ethtool_op_get_link,
> +	.get_link_ext_stats	= ionic_get_link_ext_stats,
>  	.get_link_ksettings	= ionic_get_link_ksettings,
>  	.set_link_ksettings	= ionic_set_link_ksettings,
>  	.get_coalesce		= ionic_get_coalesce,
> diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.c b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
> index 957027e546b3..6ccc1ea91992 100644
> --- a/drivers/net/ethernet/pensando/ionic/ionic_lif.c
> +++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
> @@ -168,6 +168,7 @@ static void ionic_link_status_check(struct ionic_lif *lif)
>  		}
>  	} else {
>  		if (netif_carrier_ok(netdev)) {
> +			lif->link_down_count++;
>  			netdev_info(netdev, "Link down\n");
>  			netif_carrier_off(netdev);
>  		}
> diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.h b/drivers/net/ethernet/pensando/ionic/ionic_lif.h
> index c9c4c46d5a16..fd2ea670e7d8 100644
> --- a/drivers/net/ethernet/pensando/ionic/ionic_lif.h
> +++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.h
> @@ -201,6 +201,7 @@ struct ionic_lif {
>  	u64 hw_features;
>  	bool registered;
>  	u16 lif_type;
> +	unsigned int link_down_count;
>  	unsigned int nmcast;
>  	unsigned int nucast;
>  	unsigned int nvlans;
> -- 
> 2.17.1
> 
>