Re: [PATCH v3 4/5] gpu: nova-core: split FbLayout into FSP and non-FSP versions

[Danilo Krummrich]

On Fri Jul 24, 2026 at 8:56 AM CEST, Eliot Courtney wrote:
> `FbLayout` is currently used for both pre and post FSP architectures. It
> contains ranges for each region of framebuffer, but on post FSP
> architectures, only the size is actually used by GSP. The offsets are
> not decided by the driver.

GSP may be a bit fuzzy here, it should be ACR, right?

Also, maybe we should be more explicit and say that with the FSP architecture
ACR defines the location for each region and the driver only has to provide the
corresponding sizes.

> +/// Framebuffer region sizes needed for GSP-FMC boot.

Some of them (e.g. frts_size or pmu_reserved_size) seem to be hardcoded based on
chipid, architecture or FW version; could this eventually be handled by the
firmware as well?

> +#[derive(Debug)]
> +pub(crate) struct FbSizes {
> +    /// FRTS size, in bytes.
> +    pub(crate) frts_size: u64,
> +    /// WPR2 heap size, in bytes.
> +    pub(crate) wpr2_heap_size: u64,
> +    /// Non-WPR heap size, in bytes.
> +    pub(crate) non_wpr_heap_size: u64,
> +    /// PMU reserved memory size, in bytes.
> +    pub(crate) pmu_reserved_size: u32,
> +    /// Number of VF partitions.
> +    pub(crate) vf_partition_count: u8,
> +}

[...]

> +    pub(crate) fn from_sizes<'a>(
> +        gsp_firmware: &'a GspFirmware,
> +        sizes: &'a FbSizes,
> +    ) -> impl Init<Self> + 'a {
> +        /// VGA workspace size to reserve at the end of the framebuffer, in bytes.
> +        const VGA_WORKSPACE_SIZE: u64 = u64::SZ_128K;

I assume this could also be handled by firmware?