Re: [PATCH v6 30/34] gpu: nova-core: Hopper/Blackwell: larger WPR2 (GSP) heap

[Alexandre Courbot]

On Tue Mar 10, 2026 at 11:11 AM JST, John Hubbard wrote:
<snip>
>      /// Returns the amount of memory to reserve for management purposes for a framebuffer of size
>      /// `fb_size`.
> -    fn management_overhead(fb_size: u64) -> u64 {
> +    fn management_overhead(fb_size: u64) -> Result<u64> {
>          let fb_size_gb = fb_size.div_ceil(u64::from_safe_cast(kernel::sizes::SZ_1G));
>  
>          u64::from(bindings::GSP_FW_HEAP_PARAM_SIZE_PER_GB_FB)
>              .saturating_mul(fb_size_gb)
>              .align_up(GSP_HEAP_ALIGNMENT)
> -            .unwrap_or(u64::MAX)
> +            .ok_or(EINVAL)

Since we are turning this into a fallible method (which I agree is the
good move), can we also turn the multiplication into a checked one?

This (alongside making `wpr_heap_size` fallible) should be in a separate
patch, as it is relevant regardless of Blackwell support.