Re: [PATCH net-next 1/6] gve: Add device option for nic clock synchronization

[Joe Damato <jdamato@fastly.com>]

On Fri, Apr 18, 2025 at 10:12:49PM +0000, Harshitha Ramamurthy wrote:
> From: John Fraker <jfraker@google.com>
> 
> This patch adds the device option and negotiation with the device for
> clock synchronization with the nic. This option is necessary before the
> driver will advertise support for hardware timestamping or other related
> features.
> 
> Co-developed-by: Jeff Rogers <jefrogers@google.com>
> Signed-off-by: Jeff Rogers <jefrogers@google.com>
> Co-developed-by: Ziwei Xiao <ziweixiao@google.com>
> Signed-off-by: Ziwei Xiao <ziweixiao@google.com>
> Reviewed-by: Willem de Bruijn <willemb@google.com>
> Signed-off-by: John Fraker <jfraker@google.com>
> Signed-off-by: Harshitha Ramamurthy <hramamurthy@google.com>
> ---

[...]

> diff --git a/drivers/net/ethernet/google/gve/gve_adminq.c b/drivers/net/ethernet/google/gve/gve_adminq.c
> index 3e8fc33cc11f..ae20d2f7e6e1 100644
> --- a/drivers/net/ethernet/google/gve/gve_adminq.c
> +++ b/drivers/net/ethernet/google/gve/gve_adminq.c
> @@ -46,6 +46,7 @@ void gve_parse_device_option(struct gve_priv *priv,
>  			     struct gve_device_option_buffer_sizes **dev_op_buffer_sizes,
>  			     struct gve_device_option_flow_steering **dev_op_flow_steering,
>  			     struct gve_device_option_rss_config **dev_op_rss_config,
> +			     struct gve_device_option_nic_timestamp **dev_op_nic_timestamp,
>  			     struct gve_device_option_modify_ring **dev_op_modify_ring)
>  {
>  	u32 req_feat_mask = be32_to_cpu(option->required_features_mask);
> @@ -225,6 +226,23 @@ void gve_parse_device_option(struct gve_priv *priv,
>  				 "RSS config");
>  		*dev_op_rss_config = (void *)(option + 1);
>  		break;
> +	case GVE_DEV_OPT_ID_NIC_TIMESTAMP:
> +		if (option_length < sizeof(**dev_op_nic_timestamp) ||
> +		    req_feat_mask != GVE_DEV_OPT_REQ_FEAT_MASK_NIC_TIMESTAMP) {
> +			dev_warn(&priv->pdev->dev, GVE_DEVICE_OPTION_ERROR_FMT,
> +				 "Nic Timestamp",
> +				 (int)sizeof(**dev_op_nic_timestamp),
> +				 GVE_DEV_OPT_REQ_FEAT_MASK_NIC_TIMESTAMP,
> +				 option_length, req_feat_mask);
> +			break;
> +		}
> +
> +		if (option_length > sizeof(**dev_op_nic_timestamp))
> +			dev_warn(&priv->pdev->dev,
> +				 GVE_DEVICE_OPTION_TOO_BIG_FMT,
> +				 "Nic Timestamp");
> +		*dev_op_nic_timestamp = (void *)(option + 1);
> +		break;

Overall: The above pattern is repeated quite a bit. Maybe it's time
to refactor gve_parse_device_option to eliminate all the duplicated
logic via some helpers or macros or something?

Notwithstanding the above:

Reviewed-by: Joe Damato <jdamato@fastly.com>