[PATCH net-next v4 5/8] net: ethtool: netlink: Introduce per-phy DUMP helpers

[Kory Maincent]

On Mon, 24 Mar 2025 11:40:07 +0100
Maxime Chevallier <maxime.chevallier at bootlin.com> wrote:

> As there are multiple ethnl commands that report messages based on
> phy_device information, let's introduce a set of ethnl generic dump
> helpers to allow DUMP support for each PHY on a given netdev.
> 
> This logic iterates over the phy_link_topology of each netdev (or a
> single netdev for filtered DUMP), and call ethnl_default_dump_one() with
> the req_info populated with ifindex + phyindex.
> 
> This allows re-using all the existing infra for phy-targetting commands
> that already use ethnl generic helpers.
> 
> Signed-off-by: Maxime Chevallier <maxime.chevallier at bootlin.com>
> ---
> V4 : No changes
> 
>  net/ethtool/netlink.c | 78 +++++++++++++++++++++++++++++++++++++++++++
>  net/ethtool/netlink.h |  6 ++++
>  2 files changed, 84 insertions(+)
> 
> diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
> index 0345bffa0678..171290eaf406 100644
> --- a/net/ethtool/netlink.c
> +++ b/net/ethtool/netlink.c
> @@ -560,6 +560,84 @@ static int ethnl_default_dump_one(struct sk_buff *skb,
>  	return ret;
>  }
>  
> +/* Specific context for phy-targeting command DUMP operatins. We keep in
> context
> + * the latest phy_index we dumped, in case of an interrupted DUMP.
> + */
> +struct ethnl_dump_ctx_perphy {
> +	unsigned long phy_index;
> +};
> +
> +/**
> + * ethnl_dump_start_perphy() - Initialise a dump for PHY cmds
> + * @ctx: Generic ethnl dump context whose cmd_ctx will be initialized
> + *
> + * Initializes a dump context for ethnl commands that may return
> + * one message per PHY on a single netdev.
> + *
> + * Returns: 0 for success, a negative value for errors.

Minimal nitpick. In the kernel doc Return does not take a s.

> +/**
> + * ethnl_dump_one_dev_perphy() - Dump all PHY-related messages for one netdev
> + * @skb: skb containing the DUMP result
> + * @ctx: Dump context. Will be kept across the DUMP operation.
> + * @info: Genl receive info
> + *
> + * Some commands are related to PHY devices attached to netdevs. As there
> may be
> + * multiple PHYs, this DUMP handler will populate the reply with one message
> per
> + * PHY on a single netdev.
> + *
> + * Returns: 0 for success or when nothing to do, a negative value otherwise.

Same.

Reviewed-by: Kory Maincent <kory.maincent at bootlin.com>

Thank you!
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com