[PATCH net-next v4 13/13] Documentation: networking: document phy_link_topology

[Simon Horman]

On Fri, Dec 15, 2023 at 06:12:35PM +0100, Maxime Chevallier wrote:

...

> +UAPI
> +====
> +
> +There exist a set of netlink commands to query the link topology from userspace,
> +see ``Documentation/networking/ethtool-netlink.rst``.
> +
> +The whole point of having a topology representation is to assign the phyindex
> +field in :c:type:`struct phy_device <phy_device>`. This index is reported to
> +userspace using the ``ETHTOOL_MSG_PHY_GET`` ethtnl command. Performing a DUMP operation
> +will result in all PHYs from all net_device being listed. The DUMP command
> +accepts either a ``ETHTOOL_A_HEADER_DEV_INDEX`` or ``ETHTOOL_A_HEADER_DEV_NAME``
> +to be passed in the request to filter the DUMP to a single net_device.
> +
> +The retrieved index can then be passed as a request parameter using the
> +``ETHTOOL_A_HEADER_PHY_INDEX`` field in the following ethnl commands :
> +
> +* ``ETHTOOL_MSG_STRSET_GET`` to get the stats strig set from a given PHY

string

> +* ``ETHTOOL_MSG_CABLE_TEST_ACT`` and ``ETHTOOL_MSG_CABLE_TEST_ACT``, to perform
> +  cable testing on a given PHY on the link (most likely the outermost PHY)
> +* ``ETHTOOL_MSG_PSE_SET`` and ``ETHTOOL_MSG_PSE_GET`` for PHY-controlled PoE and PSE settings
> +* ``ETHTOOL_MSG_PLCA_GET_CFG``, ``ETHTOOL_MSG_PLCA_SET_CFG`` and ``ETHTOOL_MSG_PLCA_GET_STATUS``
> +  to set the PLCA (Physical Layer Collision Avoidance) parameters
> +
> +Note that the PHY index can be passed to other requests, which will silently
> +ignore it if present and irrelevant.
> -- 
> 2.43.0
>