diff options
Diffstat (limited to 'Documentation/networking/devlink/index.rst')
| -rw-r--r-- | Documentation/networking/devlink/index.rst | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/Documentation/networking/devlink/index.rst b/Documentation/networking/devlink/index.rst index b49749e2b9a6..e14d7a701b72 100644 --- a/Documentation/networking/devlink/index.rst +++ b/Documentation/networking/devlink/index.rst @@ -18,6 +18,34 @@ netlink commands. Drivers are encouraged to use the devlink instance lock for their own needs. +Drivers need to be cautious when taking devlink instance lock and +taking RTNL lock at the same time. Devlink instance lock needs to be taken +first, only after that RTNL lock could be taken. + +Nested instances +---------------- + +Some objects, like linecards or port functions, could have another +devlink instances created underneath. In that case, drivers should make +sure to respect following rules: + + - Lock ordering should be maintained. If driver needs to take instance + lock of both nested and parent instances at the same time, devlink + instance lock of the parent instance should be taken first, only then + instance lock of the nested instance could be taken. + - Driver should use object-specific helpers to setup the + nested relationship: + + - ``devl_nested_devlink_set()`` - called to setup devlink -> nested + devlink relationship (could be user for multiple nested instances. + - ``devl_port_fn_devlink_set()`` - called to setup port function -> + nested devlink relationship. + - ``devlink_linecard_nested_dl_set()`` - called to setup linecard -> + nested devlink relationship. + +The nested devlink info is exposed to the userspace over object-specific +attributes of devlink netlink. + Interface documentation ----------------------- @@ -52,6 +80,7 @@ parameters, info versions, and other features it supports. bnxt etas_es58x hns3 + i40e ionic ice mlx4 |