Re: [PATCH 5/7] gpu: nova-core: add extra conversion functions and traits

[Danilo Krummrich <dakr@kernel.org>]

On 10/26/25 3:39 PM, Alexandre Courbot wrote:
> +#[cfg(CONFIG_32BIT)]
> +/// Infallibly converts a `usize` to `u32` on 32-bit platforms.
> +///
> +/// This conversion is always lossless on 32-bit platforms, where a `usize` is the same size as a
> +/// `u32`.
> +///
> +/// Prefer this over the `as` keyword to ensure no lossy conversions are performed.
> +///
> +/// This is for use from a `const` context. For non `const` use, prefer the [`FromAs`] and
> +/// [`IntoAs`] traits.
> +pub(crate) const fn usize_as_u32(value: usize) -> u32 {
> +    kernel::static_assert!(size_of::<u32>() >= size_of::<usize>());
> +
> +    value as u32
> +}

Given that nova-core depends on CONFIG_64BIT, I assume you added this predicting
that we'll move this to the kernel crate.

For core code (and maybe other drivers) I think we also want the same thing for
signed types, but I think it's also fine to add them when moving things into the
kernel crate.