[PATCH v2 net-next 03/12] docs: ethtool-netlink: document interface for MAC Merge layer

From: Vladimir Oltean
Date: Wed Jan 11 2023 - 11:18:47 EST

Show details about the structures passed back and forth related to MAC
Merge layer configuration, state and statistics. The rendered htmldocs
will be much more verbose due to the kerneldoc references.

Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
---
v1->v2: patch is new

Documentation/networking/ethtool-netlink.rst | 103 +++++++++++++++++++
Documentation/networking/statistics.rst | 1 +
2 files changed, 104 insertions(+)

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index f10f8eb44255..490c2280ce4f 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -223,6 +223,8 @@ Userspace to kernel:
``ETHTOOL_MSG_PSE_SET`` set PSE parameters
``ETHTOOL_MSG_PSE_GET`` get PSE parameters
``ETHTOOL_MSG_RSS_GET`` get RSS settings
+ ``ETHTOOL_MSG_MM_GET`` get MAC merge layer state
+ ``ETHTOOL_MSG_MM_SET`` set MAC merge layer parameters
===================================== =================================

Kernel to userspace:
@@ -265,6 +267,7 @@ Kernel to userspace:
``ETHTOOL_MSG_MODULE_GET_REPLY`` transceiver module parameters
``ETHTOOL_MSG_PSE_GET_REPLY`` PSE parameters
``ETHTOOL_MSG_RSS_GET_REPLY`` RSS settings
+ ``ETHTOOL_MSG_MM_GET_REPLY`` MAC merge layer status
======================================== =================================

``GET`` requests are sent by userspace applications to retrieve device
@@ -1716,6 +1719,104 @@ being used. Current supported options are toeplitz, xor or crc32.
ETHTOOL_A_RSS_INDIR attribute returns RSS indrection table where each byte
indicates queue number.

+MM_GET
+======
+
+Retrieve 802.3 MAC Merge parameters.
+
+Request contents:
+
+ ==================================== ====== ==========================
+ ``ETHTOOL_A_MM_HEADER`` nested request header
+ ==================================== ====== ==========================
+
+Kernel response contents:
+
+ ================================ ====== ===================================
+ ``ETHTOOL_A_MM_HEADER`` Nested request header
+
+ ``ETHTOOL_A_MM_SUPPORTED`` Bool set if device supports the MM layer
+
+ ``ETHTOOL_A_MM_PMAC_ENABLED`` Bool set if RX of preemptible and SMD-V
+ frames is enabled
+
+ ``ETHTOOL_A_MM_TX_ENABLED`` Bool set if TX of preemptible frames is
+ administratively enabled (might be
+ inactive if verification failed)
+
+ ``ETHTOOL_A_MM_TX_ACTIVE`` Bool set if TX of preemptible frames is
+ operationally enabled
+
+ ``ETHTOOL_A_MM_ADD_FRAG_SIZE`` U32 minimum size of transmitted
+ non-final fragments, in octets
+
+ ``ETHTOOL_A_MM_VERIFY_ENABLED`` Bool set if TX of SMD-V frames is
+ administratively enabled (TX will
+ not take place when port is not up)
+
+ ``ETHTOOL_A_MM_VERIFY_STATUS`` U8 state of the Verify function
+
+ ``ETHTOOL_A_MM_VERIFY_TIME`` U32 delay between verification attempts
+
+ ``ETHTOOL_A_MM_MAX_VERIFY_TIME`` U32 maximum interval supported by
+ device
+
+ ``ETHTOOL_A_MM_STATS`` Nested IEEE 802.3-2018 subclause 30.14.1
+ oMACMergeEntity statistics counters
+
+ ================================ ====== ===================================
+
+If ``ETHTOOL_A_MM_SUPPORTED`` is reported as false, the other netlink
+attributes will be absent.
+
+The attributes are populated by the device driver through the following
+structure:
+
+.. kernel-doc:: include/linux/ethtool.h
+ :identifiers: ethtool_mm_state
+
+The ``ETHTOOL_A_MM_VERIFY_STATUS`` will report one of the values from
+
+.. kernel-doc:: include/uapi/linux/ethtool.h
+ :identifiers: ethtool_mm_verify_status
+
+If ``ETHTOOL_A_MM_VERIFY_ENABLED`` was passed as false in the ``MM_SET``
+command, ``ETHTOOL_A_MM_VERIFY_STATUS`` will report either
+``ETHTOOL_MM_VERIFY_STATUS_INITIAL`` or ``ETHTOOL_MM_VERIFY_STATUS_DISABLED``,
+otherwise it should report one of the other states.
+
+It is recommended that drivers start with the pMAC disabled, and enable it upon
+user space request. It is also recommended that user space does not depend upon
+the default values from ``ETHTOOL_MSG_MM_GET`` requests.
+
+``ETHTOOL_A_MM_STATS`` are reported if ``ETHTOOL_FLAG_STATS`` was set in
+``ETHTOOL_A_HEADER_FLAGS``. The attribute will be empty if driver did not
+report any statistics. Drivers fill in the statistics in the following
+structure:
+
+.. kernel-doc:: include/linux/ethtool.h
+ :identifiers: ethtool_mm_stats
+
+MM_SET
+======
+
+Modifies the configuration of the 802.3 MAC Merge layer.
+
+Request contents:
+
+ ====================================== ====== ==========================
+ ``ETHTOOL_A_MM_VERIFY_TIME`` u32 see MM_GET description
+ ``ETHTOOL_A_MM_VERIFY_ENABLED`` bool see MM_GET description
+ ``ETHTOOL_A_MM_TX_ENABLED`` bool see MM_GET description
+ ``ETHTOOL_A_MM_PMAC_ENABLED`` bool see MM_GET description
+ ``ETHTOOL_A_MM_ADD_FRAG_SIZE`` u32 see MM_GET description
+ ====================================== ====== ==========================
+
+The attributes are propagated to the driver through the following structure:
+
+.. kernel-doc:: include/linux/ethtool.h
+ :identifiers: ethtool_mm_cfg
+
Request translation
===================

@@ -1817,4 +1918,6 @@ are netlink only.
n/a ``ETHTOOL_MSG_PHC_VCLOCKS_GET``
n/a ``ETHTOOL_MSG_MODULE_GET``
n/a ``ETHTOOL_MSG_MODULE_SET``
+ n/a ``ETHTOOL_MSG_MM_GET``
+ n/a ``ETHTOOL_MSG_MM_SET``
=================================== =====================================
diff --git a/Documentation/networking/statistics.rst b/Documentation/networking/statistics.rst
index c9aeb70dafa2..551b3cc29a41 100644
--- a/Documentation/networking/statistics.rst
+++ b/Documentation/networking/statistics.rst
@@ -171,6 +171,7 @@ statistics are supported in the following commands:

- `ETHTOOL_MSG_PAUSE_GET`
- `ETHTOOL_MSG_FEC_GET`
+ - `ETHTOOL_MSG_MM_GET`

debugfs
-------
--
2.34.1