Re: [PATCH 1/3] gpu: nova-core: extract radix3 page table into its own module

[Gary Guo]

On Sun Sep 13, 2026 at 8:54 PM BST, John Hubbard wrote:
> In order to boot the GSP, nova-core loads the GSP firmware image into
> system memory, and the GPU copies it into the framebuffer, the GPU's own
> memory. The GPU finds the GSP firmware image's pages via "radix3", a
> three-level page table of 4 KiB pages that the driver builds. Today the
> table exists as fields within the GSP firmware wrapper, which is fine
> because there is only one radix3 consumer.
>
> The upcoming r000 series[1], however, introduces a second radix3 caller:
> the ucodes firmware image. That is because the GSP has been changed, so
> that it automatically fetches the subset of ucodes that it requires,
> thus reducing the size of the GSP image. This is a helpful change for
> the firmware situation overall, but it will require nova-core to load
> and provide ucodes, in much the same way that it was loading and
> providing the GSP firmware image.
>
> Therefore, split out radix3 into its own module.

I find the name itself confusing if I don't read the docs. The radix in "radix3"
is actually 512 (given 4 KiB page and 64-bit entry) and definitely not 3.

Perhaps name this "radixlv3" or something similar instead? Or perhaps call it
GspPageTable?

Best,
Gary

>
> [1] https://lore.kernel.org/all/20260822015448.238214-1-jhubbard@xxxxxxxxxx/
>
> Assisted-by: LLM
> Reviewed-by: Timur Tabi <ttabi@xxxxxxxxxx>
> Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>