ethtool: Add an interface for flashing transceiver modules' firmware

CMIS compliant modules such as QSFP-DD might be running a firmware that
can be updated in a vendor-neutral way by exchanging messages between
the host and the module as described in section 7.3.1 of revision 5.2 of
the CMIS standard.

Add a pair of new ethtool messages that allow:

* User space to trigger firmware update of transceiver modules

* The kernel to notify user space about the progress of the process

The user interface is designed to be asynchronous in order to avoid
RTNL being held for too long and to allow several modules to be
updated simultaneously. The interface is designed with CMIS compliant
modules in mind, but kept generic enough to accommodate future use
cases, if these arise.

Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 70 insertions, 0 deletions

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 7ec08e903bab..bfe2eda8580d 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -228,6 +228,7 @@ Userspace to kernel:
   ``ETHTOOL_MSG_PLCA_GET_STATUS``       get PLCA RS status
   ``ETHTOOL_MSG_MM_GET``                get MAC merge layer state
   ``ETHTOOL_MSG_MM_SET``                set MAC merge layer parameters
+  ``ETHTOOL_MSG_MODULE_FW_FLASH_ACT``   flash transceiver module firmware
   ===================================== =================================
 
 Kernel to userspace:
@@ -274,6 +275,7 @@ Kernel to userspace:
   ``ETHTOOL_MSG_PLCA_GET_STATUS_REPLY``    PLCA RS status
   ``ETHTOOL_MSG_PLCA_NTF``                 PLCA RS parameters
   ``ETHTOOL_MSG_MM_GET_REPLY``             MAC merge layer status
+  ``ETHTOOL_MSG_MODULE_FW_FLASH_NTF``      transceiver module flash updates
   ======================================== =================================
 
 ``GET`` requests are sent by userspace applications to retrieve device
@@ -2041,6 +2043,73 @@ The attributes are propagated to the driver through the following structure:
 .. kernel-doc:: include/linux/ethtool.h
     :identifiers: ethtool_mm_cfg
 
+MODULE_FW_FLASH_ACT
+===================
+
+Flashes transceiver module firmware.
+
+Request contents:
+
+  =======================================  ======  ===========================
+  ``ETHTOOL_A_MODULE_FW_FLASH_HEADER``     nested  request header
+  ``ETHTOOL_A_MODULE_FW_FLASH_FILE_NAME``  string  firmware image file name
+  ``ETHTOOL_A_MODULE_FW_FLASH_PASSWORD``   u32     transceiver module password
+  =======================================  ======  ===========================
+
+The firmware update process consists of three logical steps:
+
+1. Downloading a firmware image to the transceiver module and validating it.
+2. Running the firmware image.
+3. Committing the firmware image so that it is run upon reset.
+
+When flash command is given, those three steps are taken in that order.
+
+This message merely schedules the update process and returns immediately
+without blocking. The process then runs asynchronously.
+Since it can take several minutes to complete, during the update process
+notifications are emitted from the kernel to user space updating it about
+the status and progress.
+
+The ``ETHTOOL_A_MODULE_FW_FLASH_FILE_NAME`` attribute encodes the firmware
+image file name. The firmware image is downloaded to the transceiver module,
+validated, run and committed.
+
+The optional ``ETHTOOL_A_MODULE_FW_FLASH_PASSWORD`` attribute encodes a password
+that might be required as part of the transceiver module firmware update
+process.
+
+The firmware update process can take several minutes to complete. Therefore,
+during the update process notifications are emitted from the kernel to user
+space updating it about the status and progress.
+
+
+
+Notification contents:
+
+ +---------------------------------------------------+--------+----------------+
+ | ``ETHTOOL_A_MODULE_FW_FLASH_HEADER``              | nested | reply header   |
+ +---------------------------------------------------+--------+----------------+
+ | ``ETHTOOL_A_MODULE_FW_FLASH_STATUS``              | u32    | status         |
+ +---------------------------------------------------+--------+----------------+
+ | ``ETHTOOL_A_MODULE_FW_FLASH_STATUS_MSG``          | string | status message |
+ +---------------------------------------------------+--------+----------------+
+ | ``ETHTOOL_A_MODULE_FW_FLASH_DONE``                | uint   | progress       |
+ +---------------------------------------------------+--------+----------------+
+ | ``ETHTOOL_A_MODULE_FW_FLASH_TOTAL``               | uint   | total          |
+ +---------------------------------------------------+--------+----------------+
+
+The ``ETHTOOL_A_MODULE_FW_FLASH_STATUS`` attribute encodes the current status
+of the firmware update process. Possible values are:
+
+.. kernel-doc:: include/uapi/linux/ethtool.h
+    :identifiers: ethtool_module_fw_flash_status
+
+The ``ETHTOOL_A_MODULE_FW_FLASH_STATUS_MSG`` attribute encodes a status message
+string.
+
+The ``ETHTOOL_A_MODULE_FW_FLASH_DONE`` and ``ETHTOOL_A_MODULE_FW_FLASH_TOTAL``
+attributes encode the completed and total amount of work, respectively.
+
 Request translation
 ===================
 
@@ -2147,4 +2216,5 @@ are netlink only.
   n/a                                 ``ETHTOOL_MSG_PLCA_GET_STATUS``
   n/a                                 ``ETHTOOL_MSG_MM_GET``
   n/a                                 ``ETHTOOL_MSG_MM_SET``
+  n/a                                 ``ETHTOOL_MSG_MODULE_FW_FLASH_ACT``
   =================================== =====================================