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