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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-eswitch-attr
60 devlink-flash
61 devlink-health
62 devlink-info
63 devlink-linecard
64 devlink-params
65 devlink-port
66 devlink-region
67 devlink-reload
68 devlink-resource
69 devlink-selftests
70 devlink-trap
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 am65-nuss-cpsw-switch
82 bnxt
83 etas_es58x
84 hns3
85 i40e
86 ice
87 ionic
88 iosm
89 ixgbe
90 kvaser_pciefd
91 kvaser_usb
92 mlx4
93 mlx5
94 mlxsw
95 mv88e6xxx
96 netdevsim
97 nfp
98 octeontx2
99 prestera
100 qed
101 sfc
102 stmmac
103 ti-cpsw-switch
104 zl3073x