[RFC PATCH net-next 0/2] ethtool: add interface capabilities and PHY test

This series adds two new ethtool netlink commands:

1. intf-caps-get: Discovers the functional block layout of a network
   interface. Each block represents a hardware point (MAC/PHY/MODULE)
   at a specific 802.3 sublayer (RS/PCS/FEC/PMA/PMD) with its
   supported capabilities (loopback, test patterns, BERT, error
   injection).

2. phy-test-get / phy-test-act: Per-block, per-lane PHY testing using
   test patterns, BERT (Bit Error Ratio Test), and error injection.
   The block_id from intf-caps-get identifies which hardware point
   to test.

The block model uses:
  - component: which hardware entity (MAC, PHY, MODULE)
  - sublayer: which 802.3 layer (RS, PCS, FEC, PMA, PMD)
  - instance: identifies multiple instances of the same component
    (e.g., internal vs external PHY)
  - depth: host-side vs line-side within the same sublayer

Prior discussion on this proposal:
Link: https://lore.kernel.org/netdev/SN7PR11MB810923BBDEC398E860099150FF1B2@SN7PR11MB8109.namprd11.prod.outlook.com/ (local)

Shubham Das (2):
  ethtool: add interface capabilities query (intf-caps-get)
  ethtool: add PHY test framework (phy-test-get, phy-test-act)

 Documentation/netlink/specs/ethtool.yaml      | 206 ++++++++++++++++++
 include/linux/ethtool.h                       |  92 ++++++++
 .../uapi/linux/ethtool_netlink_generated.h    | 104 +++++++++
 net/ethtool/Makefile                          |   2 +-
 net/ethtool/intf_caps.c                       | 130 +++++++++++
 net/ethtool/netlink.c                         |  24 ++
 net/ethtool/netlink.h                         |   7 +
 net/ethtool/phytest.c                         | 171 +++++++++++++++
 8 files changed, 735 insertions(+), 1 deletion(-)
 create mode 100644 net/ethtool/intf_caps.c
 create mode 100644 net/ethtool/phytest.c

-- 
2.25.1