Nouveau - Nov 2025 - [PATCH 3/6] gpu: nova-core: Blackwell: basic GPU identification

On 11/18/25 7:15 PM, Dave Airlie wrote:
> On Wed, 19 Nov 2025 at 12:46, Alexandre Courbot <acourbot at
nvidia.com> wrote:
...
>>> Maybe let's just do the long lists of chipsets for now...?
>>
>> Yeah, I've hit this issue as well. The compiler might remove that
>> limitation in the future, or maybe we can craft a `chipset_range!()`
>> macro that hides the messy casting, but this exhaustive listing also
has
>> the benefit of forcing us to consider every critical site whenever we
>> support a new chipset so I'm actually not too bothered by it.
> 
> I wrote some macros in my nova-core-experiments, had
> chipset_before/after/range I think
> 
aha, I was afraid someone was going to say "macros" out loud, at some
point. And now you've gone and done it. :)

Well, I think we probably want:

a) The ability to clearly specify a chipset range, and

b) For extra credit, maybe: also be able to specify entire GPU
architectures, and architecture ranges.

...again, without too much extraneous noise at the call sites: the goal is
to read it easily:

     GA102..=GA104 | Architecture::Blackwell


for example. Macros are going to require that to be less clean, but
let me poke around and see.

thanks,
-- 
John Hubbard

On Wed, 19 Nov 2025 at 17:08, John Hubbard <jhubbard at nvidia.com>
wrote:
>
> On 11/18/25 7:15 PM, Dave Airlie wrote:
> > On Wed, 19 Nov 2025 at 12:46, Alexandre Courbot <acourbot at
nvidia.com> wrote:
> ...
> >>> Maybe let's just do the long lists of chipsets for now...?
> >>
> >> Yeah, I've hit this issue as well. The compiler might remove
that
> >> limitation in the future, or maybe we can craft a
`chipset_range!()`
> >> macro that hides the messy casting, but this exhaustive listing
also has
> >> the benefit of forcing us to consider every critical site whenever
we
> >> support a new chipset so I'm actually not too bothered by it.
> >
> > I wrote some macros in my nova-core-experiments, had
> > chipset_before/after/range I think
> >
>
> aha, I was afraid someone was going to say "macros" out loud, at
some
> point. And now you've gone and done it. :)
>
> Well, I think we probably want:
>
> a) The ability to clearly specify a chipset range, and
>
> b) For extra credit, maybe: also be able to specify entire GPU
> architectures, and architecture ranges.
>
> ...again, without too much extraneous noise at the call sites: the goal is
> to read it easily:
>
>      GA102..=GA104 | Architecture::Blackwell
>
>
> for example. Macros are going to require that to be less clean, but
> let me poke around and see.
https://gitlab.freedesktop.org/nouvelles/kernel/-/blob/nova-core-experiments-fsp-boot/drivers/gpu/nova-core/gpu.rs?ref_type=heads#L96

is what I did, but yeah probably not going to get nice ranges like that.

Dave.