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Diffstat (limited to 'Documentation/networking/devlink/index.rst')
| -rw-r--r-- | Documentation/networking/devlink/index.rst | 55 |
1 files changed, 54 insertions, 1 deletions
diff --git a/Documentation/networking/devlink/index.rst b/Documentation/networking/devlink/index.rst index 7684ae5c4a4a..e14d7a701b72 100644 --- a/Documentation/networking/devlink/index.rst +++ b/Documentation/networking/devlink/index.rst @@ -4,6 +4,48 @@ Linux Devlink Documentation devlink is an API to expose device information and resources not directly related to any device class, such as chip-wide/switch-ASIC-wide configuration. +Locking +------- + +Driver facing APIs are currently transitioning to allow more explicit +locking. Drivers can use the existing ``devlink_*`` set of APIs, or +new APIs prefixed by ``devl_*``. The older APIs handle all the locking +in devlink core, but don't allow registration of most sub-objects once +the main devlink object is itself registered. The newer ``devl_*`` APIs assume +the devlink instance lock is already held. Drivers can take the instance +lock by calling ``devl_lock()``. It is also held all callbacks of devlink +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 ----------------------- @@ -18,9 +60,13 @@ general. devlink-info devlink-flash devlink-params + devlink-port devlink-region devlink-resource + devlink-reload + devlink-selftests devlink-trap + devlink-linecard Driver-specific documentation ----------------------------- @@ -32,6 +78,9 @@ parameters, info versions, and other features it supports. :maxdepth: 1 bnxt + etas_es58x + hns3 + i40e ionic ice mlx4 @@ -40,6 +89,10 @@ parameters, info versions, and other features it supports. mv88e6xxx netdevsim nfp - sja1105 qed ti-cpsw-switch + am65-nuss-cpsw-switch + prestera + iosm + octeontx2 + sfc |