[PATCH net-next v2 16/16] devlink: Add Documentation/networking/devlink/devlink-reload.rst

From: Moshe Shemesh
Date: Wed Oct 07 2020 - 02:14:30 EST


Add devlink reload rst documentation file.
Update index file to include it.

Signed-off-by: Moshe Shemesh <moshe@xxxxxxxxxxxx>
---
v1 -> v2:
- Split first paragraph of devlink reload description to 2 sentences
RFCv5 -> v1:
- Rename reload_action_limit_level to reload_limit
RFCv4 -> RFCv5:
- Rephrase namespace change section
- Rephrase note on actions performed
RFCv3 -> RFCv4:
- Remove reload action fw_activate_no_reset
- Add reload actions limit levels and document the no_reset limit level
constraints
RFCv2 -> RFCv3:
- Devlink reload returns the actions done
- Replace fw_live_patch action by fw_activate_no_reset
- Explain fw_activate meaning
RFCv1 -> RFCv2:
- Instead of reload levels driver,fw_reset,fw_live_patch have reload
actions driver_reinit,fw_activate,fw_live_patch
---
.../networking/devlink/devlink-reload.rst | 81 +++++++++++++++++++
Documentation/networking/devlink/index.rst | 1 +
2 files changed, 82 insertions(+)
create mode 100644 Documentation/networking/devlink/devlink-reload.rst

diff --git a/Documentation/networking/devlink/devlink-reload.rst b/Documentation/networking/devlink/devlink-reload.rst
new file mode 100644
index 000000000000..89a1b67e3af1
--- /dev/null
+++ b/Documentation/networking/devlink/devlink-reload.rst
@@ -0,0 +1,81 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==============
+Devlink Reload
+==============
+
+``devlink-reload`` provides mechanism to reinit driver entities, applying
+``devlink-params`` and ``devlink-resources`` new values. It also provides
+mechanism to activate firmware.
+
+Reload Actions
+==============
+
+User may select a reload action.
+By default ``driver_reinit`` action is selected.
+
+.. list-table:: Possible reload actions
+ :widths: 5 90
+
+ * - Name
+ - Description
+ * - ``driver-reinit``
+ - Devlink driver entities re-initialization, including applying
+ new values to devlink entities which are used during driver
+ load such as ``devlink-params`` in configuration mode
+ ``driverinit`` or ``devlink-resources``
+ * - ``fw_activate``
+ - Firmware activate. Activates new firmware if such image is stored and
+ pending activation. If no limitation specified this action may involve
+ firmware reset. If no new image pending this action will reload current
+ firmware image.
+
+Note that even though user asks for a specific action, the driver
+implementation might require to perform another action alongside with
+it. For example, some driver do not support driver reinitialization
+being performed without fw activation. Therefore, the devlink reload
+command returns the list of actions which were actrually performed.
+
+Reload Limits
+=============
+
+By default reload actions are not limited and driver implementation may
+include reset or downtime as needed to perform the actions.
+
+However, some drivers support action limits, which limit the action
+implementation to specific constraints.
+
+.. list-table:: Possible reload limits
+ :widths: 5 90
+
+ * - Name
+ - Description
+ * - ``no_reset``
+ - No reset allowed, no down time allowed, no link flap and no
+ configuration is lost.
+
+Change Namespace
+================
+
+The netns option allows user to be able to move devlink instances into
+namespaces during devlink reload operation.
+By default all devlink instances are created in init_net and stay there.
+
+example usage
+-------------
+
+.. code:: shell
+
+ $ devlink dev reload help
+ $ devlink dev reload DEV [ netns { PID | NAME | ID } ] [ action { driver_reinit | fw_activate } ] [ limit no_reset ]
+
+ # Run reload command for devlink driver entities re-initialization:
+ $ devlink dev reload pci/0000:82:00.0 action driver_reinit
+ reload_actions_performed:
+ driver_reinit
+
+ # Run reload command to activate firmware:
+ # Note that mlx5 driver reloads the driver while activating firmware
+ $ devlink dev reload pci/0000:82:00.0 action fw_activate
+ reload_actions_performed:
+ driver_reinit fw_activate
diff --git a/Documentation/networking/devlink/index.rst b/Documentation/networking/devlink/index.rst
index 7684ae5c4a4a..d82874760ae2 100644
--- a/Documentation/networking/devlink/index.rst
+++ b/Documentation/networking/devlink/index.rst
@@ -20,6 +20,7 @@ general.
devlink-params
devlink-region
devlink-resource
+ devlink-reload
devlink-trap

Driver-specific documentation
--
2.18.2