1Linux Devlink Documentation 2=========================== 3 4devlink is an API to expose device information and resources not directly 5related to any device class, such as chip-wide/switch-ASIC-wide configuration. 6 7Locking 8------- 9 10Driver facing APIs are currently transitioning to allow more explicit 11locking. Drivers can use the existing ``devlink_*`` set of APIs, or 12new APIs prefixed by ``devl_*``. The older APIs handle all the locking 13in devlink core, but don't allow registration of most sub-objects once 14the main devlink object is itself registered. The newer ``devl_*`` APIs assume 15the devlink instance lock is already held. Drivers can take the instance 16lock by calling ``devl_lock()``. It is also held all callbacks of devlink 17netlink commands. 18 19Drivers are encouraged to use the devlink instance lock for their own needs. 20 21Drivers need to be cautious when taking devlink instance lock and 22taking RTNL lock at the same time. Devlink instance lock needs to be taken 23first, only after that RTNL lock could be taken. 24 25Nested instances 26---------------- 27 28Some objects, like linecards or port functions, could have another 29devlink instances created underneath. In that case, drivers should make 30sure to respect following rules: 31 32 - Lock ordering should be maintained. If driver needs to take instance 33 lock of both nested and parent instances at the same time, devlink 34 instance lock of the parent instance should be taken first, only then 35 instance lock of the nested instance could be taken. 36 - Driver should use object-specific helpers to setup the 37 nested relationship: 38 39 - ``devl_nested_devlink_set()`` - called to setup devlink -> nested 40 devlink relationship (could be user for multiple nested instances. 41 - ``devl_port_fn_devlink_set()`` - called to setup port function -> 42 nested devlink relationship. 43 - ``devlink_linecard_nested_dl_set()`` - called to setup linecard -> 44 nested devlink relationship. 45 46The nested devlink info is exposed to the userspace over object-specific 47attributes of devlink netlink. 48 49Interface documentation 50----------------------- 51 52The following pages describe various interfaces available through devlink in 53general. 54 55.. toctree:: 56 :maxdepth: 1 57 58 devlink-dpipe 59 devlink-health 60 devlink-info 61 devlink-flash 62 devlink-params 63 devlink-port 64 devlink-region 65 devlink-resource 66 devlink-reload 67 devlink-selftests 68 devlink-trap 69 devlink-linecard 70 devlink-eswitch-attr 71 72Driver-specific documentation 73----------------------------- 74 75Each driver that implements ``devlink`` is expected to document what 76parameters, info versions, and other features it supports. 77 78.. toctree:: 79 :maxdepth: 1 80 81 bnxt 82 etas_es58x 83 hns3 84 i40e 85 ionic 86 ice 87 mlx4 88 mlx5 89 mlxsw 90 mv88e6xxx 91 netdevsim 92 nfp 93 qed 94 ti-cpsw-switch 95 am65-nuss-cpsw-switch 96 prestera 97 iosm 98 octeontx2 99 sfc 100