Re: gpu: nova-core: arm32 build errors

[John Hubbard <jhubbard@nvidia.com>]

On 8/28/25 12:31 PM, Miguel Ojeda wrote:
> On Thu, Aug 28, 2025 at 9:24 PM Danilo Krummrich <dakr@kernel.org> wrote:
>>
>> Maybe I spoke too soon, it's actually pretty painful to keep 32-bit
>> compatibility, even though it would be nice for testing purposes.
>>
>> I'll paste the diff to fix it below, I think that makes it obvious why I say
>> that.
>>
>> Instead, we should really just depend on CONFIG_64BIT (which implies
>> ARCH_DMA_ADDR_T_64BIT).

Yes yes yes. :)

> 
> Yeah, it isn't great.
> 
> If it were just that, maybe it it is worth it (and a `DmaAddress`
> newtype, not just a typedef, could perhaps be nice anyway?), but if
> you think it will become increasingly painful later, then it may be

Oh yes, this is just the tip of the iceberg.

> best to focus on what matters.
> 
> It is unlikely there is going to be actual users on a 32-bit platform, right?

Completely not going to happen, actually. The Open RM driver dropped
support for 32-bit platforms in *2018*, and Nova and Open RM have...a
relationship. For example, they use the same identical firmware (GSP etc).
And so it is inconceivable that we would attempt 32-bit support in
Nova.

So Nova should definitely depend upon 64-bit configs.


thanks,
-- 
John Hubbard