Re: [PATCH v6 10/11] gpu: nova-core: Add base files for r570.144 firmware bindings

["Danilo Krummrich" <dakr@kernel.org>]

Two comments on this, just for the record.

On Sat Sep 13, 2025 at 4:12 PM CEST, Alexandre Courbot wrote:
> From: Alistair Popple <apopple@nvidia.com>
>
> Interacting with the GSP currently requires using definitions from C
> header files. Rust definitions for the types needed for Nova core will
> be generated using the Rust bindgen tool. This patch adds the base
> module to allow inclusion of the generated bindings. The generated
> bindings themselves are added by subsequent patches when they are first
> used.

For now this is perfectly fine, but in the long term we should avoid creating
bindings from C headers. Instead, I'd like to see the tooling that generates the
C headers to generate the Rust data structures (in a more Rust idiomatic way)
right away.

> Currently we only intend to support a single firmware version, 570.144,
> with these bindings. Longer term we intend to move to a more stable GSP
> interface that isn't tied to specific firmware versions.

Yet, we have to prepare for proper abstraction of the firmware API:

(1) This is a community project. And as a community project it has to be
    written in a way that is guaranteed to remain maintainable for the
    community in any case.

    This means that the project can not rely on the hardware vendor to provide
    a stable firmware API; rather it has to written in a way that can deal with
    changing conditions.

    In fact, this is one of the issues why we don't see a way forward with
    nouveau, so we can't lock ourselves in here. :)

(2) While I think attempting to be as stable as possible with the firmware API
    is the correct approach, I also think it is better to reserve yourself some
    flexibility on changing it.

    I much rather prefer a firmware API that is evolving when really necessary,
    than squeezing new features into an existing API (e.g. by adding confusing
    extentions) that just isn't a good fit anymore at some point.

> Signed-off-by: Alistair Popple <apopple@nvidia.com>
> Reviewed-by: John Hubbard <jhubbard@nvidia.com>
> [acourbot@nvidia.com: adapt the bindings module comment a bit]
> Acked-by: Danilo Krummrich <dakr@kernel.org>
> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>