1 .. SPDX-License-Identifier: GPL-2.0
7 ``devlink`` provides the ability for drivers to register resources, which
8 can allow administrators to see the device restrictions for a given
9 resource, as well as how much of the given resource is currently
10 in use. Additionally, these resources can optionally have configurable size.
11 This could enable the administrator to limit the number of resources that
14 For example, the ``netdevsim`` driver enables ``/IPv4/fib`` and
15 ``/IPv4/fib-rules`` as resources to limit the number of IPv4 FIB entries and
16 rules for a given device.
21 Each resource is represented by an id, and contains information about its
22 current size and related sub resources. To access a sub resource, you
23 specify the path of the resource. For example ``/IPv4/fib`` is the id for
24 the ``fib`` sub-resource under the ``IPv4`` resource.
29 Generic resources are used to describe resources that can be shared by multiple
30 device drivers and their description must be added to the following table:
32 .. list-table:: List of Generic Resources
37 * - ``physical_ports``
38 - A limited capacity of physical ports that the switch ASIC can support
43 The resources exposed by the driver can be observed, for example:
47 $devlink resource show pci/0000:03:00.0
49 name kvd size 245760 unit entry
51 name linear size 98304 occ 0 unit entry size_min 0 size_max 147456 size_gran 128
52 name hash_double size 60416 unit entry size_min 32768 size_max 180224 size_gran 128
53 name hash_single size 87040 unit entry size_min 65536 size_max 212992 size_gran 128
55 Some resource's size can be changed. Examples:
59 $devlink resource set pci/0000:03:00.0 path /kvd/hash_single size 73088
60 $devlink resource set pci/0000:03:00.0 path /kvd/hash_double size 74368
62 The changes do not apply immediately, this can be validated by the 'size_new'
63 attribute, which represents the pending change in size. For example:
67 $devlink resource show pci/0000:03:00.0
69 name kvd size 245760 unit entry size_valid false
71 name linear size 98304 size_new 147456 occ 0 unit entry size_min 0 size_max 147456 size_gran 128
72 name hash_double size 60416 unit entry size_min 32768 size_max 180224 size_gran 128
73 name hash_single size 87040 unit entry size_min 65536 size_max 212992 size_gran 128
75 Note that changes in resource size may require a device reload to properly