Documentation/networking/devlink/devlink-params.rst
Source file repositories/reference/linux-study-clean/Documentation/networking/devlink/devlink-params.rst
File Facts
- System
- Linux kernel
- Corpus path
Documentation/networking/devlink/devlink-params.rst- Extension
.rst- Size
- 6426 bytes
- Lines
- 168
- Domain
- Support Tooling And Documentation
- Bucket
- Documentation
- Inferred role
- Support Tooling And Documentation: documentation
- Status
- atlas-only
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Touches IRQ or DMA behavior; this matters for the representative real-device path.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
.. SPDX-License-Identifier: GPL-2.0
==============
Devlink Params
==============
``devlink`` provides capability for a driver to expose device parameters for low
level device functionality. Since devlink can operate at the device-wide
level, it can be used to provide configuration that may affect multiple
ports on a single device.
This document describes a number of generic parameters that are supported
across multiple drivers. Each driver is also free to add their own
parameters. Each driver must document the specific parameters they support,
whether generic or not.
Configuration modes
===================
Parameters may be set in different configuration modes.
.. list-table:: Possible configuration modes
:widths: 5 90
* - Name
- Description
* - ``runtime``
- set while the driver is running, and takes effect immediately. No
reset is required.
* - ``driverinit``
- applied while the driver initializes. Requires the user to restart
the driver using the ``devlink`` reload command.
* - ``permanent``
- written to the device's non-volatile memory. A hard reset is required
for it to take effect.
Reloading
---------
In order for ``driverinit`` parameters to take effect, the driver must
support reloading via the ``devlink-reload`` command. This command will
request a reload of the device driver.
Default parameter values
=========================
Drivers may optionally export default values for parameters of cmode
``runtime`` and ``permanent``. For ``driverinit`` parameters, the last
value set by the driver will be used as the default value. Drivers can
also support resetting params with cmode ``runtime`` and ``permanent``
to their default values. Resetting ``driverinit`` params is supported
by devlink core without additional driver support needed.
.. _devlink_params_generic:
Generic configuration parameters
================================
The following is a list of generic configuration parameters that drivers may
add. Use of generic parameters is preferred over each driver creating their
own name.
.. list-table:: List of generic parameters
:widths: 5 5 90
* - Name
- Type
- Description
* - ``enable_sriov``
- Boolean
- Enable Single Root I/O Virtualization (SRIOV) in the device.
Annotation
- Atlas domain: Support Tooling And Documentation / Documentation.
- Implementation status: atlas-only.
- IRQ or DMA behavior appears here, which is relevant to the selected PCIe/NVMe device path.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.