Re: [PATCH 1/3] gpu: nova-core: extract radix3 page table into its own module
From: John Hubbard
Date: Sun Sep 13 2026 - 16:57:28 EST
On 9/13/26 1:36 PM, Gary Guo wrote:
On Sun Sep 13, 2026 at 8:54 PM BST, John Hubbard wrote:Right, it's all about the number of levels, not the radix value, that's
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?
true. Open RM loves "radix3" so much that I've become tone-deaf to the
name. :)
three_level_radix works, but is silly long for this.
Do we really care enough to insist on this, though? I'd be inclined
to ask to just leave it alone.
thanks,
--
John Hubbard