Subject: Re: [PATCH] enic: add ethtool get_channel support

From: Przemek Kitszel <[email-masked]>
Date: Tue, 18 Jun 2024 18:20:38 +0200

On 6/18/24 18:01, Jon Kohler wrote:
> Add .get_channel to enic_ethtool_ops to enable basic ethtool -l
> support to get the current channel configuration.
> 
> Note that the driver does not support dynamically changing queue
> configuration, so .set_channel is intentionally unused. Instead, users
> should use Cisco's hardware management tools (UCSM/IMC) to modify
> virtual interface card configuration out of band.
> 
> Signed-off-by: Jon Kohler <[email-masked]>
> ---
>   drivers/net/ethernet/cisco/enic/enic_ethtool.c | 18 ++++++++++++++++++
>   1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/net/ethernet/cisco/enic/enic_ethtool.c b/drivers/net/ethernet/cisco/enic/enic_ethtool.c
> index 241906697019..efbc0715b10e 100644
> --- a/drivers/net/ethernet/cisco/enic/enic_ethtool.c
> +++ b/drivers/net/ethernet/cisco/enic/enic_ethtool.c
> @@ -608,6 +608,23 @@ static int enic_get_ts_info(struct net_device *netdev,
>   	return 0;
>   }
>   
> +static void enic_get_channels(struct net_device *netdev,
> +			      struct ethtool_channels *channels)
> +{
> +	struct enic *enic = netdev_priv(netdev);
> +
> +	channels->max_rx = ENIC_RQ_MAX;
> +	channels->max_tx = ENIC_WQ_MAX;
> +	channels->rx_count = enic->rq_count;
> +	channels->tx_count = enic->wq_count;
> +
> +	/* enic doesn't use other channels or combined channels */
> +	channels->combined_count = 0;

my understanding is that effective Rx count is combined_count+rx_count,
analogous for Tx

and:
uapi/linux/ethtool.h:547: * @combined_count: Valid values are in the 
range 1 to the max_combined.

> +	channels->max_combined = 0;
> +	channels->max_other = 0;
> +	channels->other_count = 0;
> +}
> +
>   static const struct ethtool_ops enic_ethtool_ops = {
>   	.supported_coalesce_params = ETHTOOL_COALESCE_USECS |
>   				     ETHTOOL_COALESCE_USE_ADAPTIVE_RX |
> @@ -632,6 +649,7 @@ static const struct ethtool_ops enic_ethtool_ops = {
>   	.set_rxfh = enic_set_rxfh,
>   	.get_link_ksettings = enic_get_ksettings,
>   	.get_ts_info = enic_get_ts_info,
> +	.get_channels = enic_get_channels,
>   };
>   
>   void enic_set_ethtool_ops(struct net_device *netdev)