Documentation/gpu/nova/guidelines.rst
.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
This document describes the general project guidelines that apply to nova-core and nova-drm.
The Nova project uses the Rust programming language. In this context, all rules
of the Rust for Linux project as documented in
:doc:../../rust/general-information apply. Additionally, the following rules
apply.
Unless technically necessary otherwise (e.g. uAPI), any driver code is written in Rust.
Unless technically necessary, unsafe Rust code must be avoided. In case of technical necessity, unsafe code should be isolated in a separate component providing a safe API for other driver code to use.
All rules of the Rust for Linux project as documented in
:doc:../../rust/coding-guidelines apply.
For a submit checklist, please also see the Rust for Linux Submit checklist addendum <https://rust-for-linux.com/contributing#submit-checklist-addendum>_.
The availability of proper documentation is essential in terms of scalability, accessibility for new contributors and maintainability of a project in general, but especially for a driver running as complex hardware as Nova is targeting.
Hence, adding documentation of any kind is very much encouraged by the project.
Besides that, there are some minimum requirements.
Every non-private structure needs at least a brief doc comment explaining the semantical sense of the structure, as well as potential locking and lifetime requirements. It is encouraged to have the same minimum documentation for non-trivial private structures.
uAPIs must be fully documented with kernel-doc comments; additionally, the semantical behavior must be explained including potential special or corner cases.
The APIs connecting the 1st level driver (nova-core) with 2nd level drivers must be fully documented. This includes doc comments, potential locking and lifetime requirements, as well as example code if applicable.
Abbreviations must be explained when introduced; terminology must be uniquely defined.
Register addresses, layouts, shift values and masks must be defined properly; unless obvious, the semantical sense must be documented. This only applies if the author is able to obtain the corresponding information.