[PATCH 7/8] riscv: dts: spacemit: add initial device tree of SpacemiT K3 SoC

[Guodong Xu]

Hi, Conor and Heinrich

On Thu, Dec 18, 2025 at 8:56 AM Conor Dooley <conor at kernel.org> wrote:
>
> On Wed, Dec 17, 2025 at 09:07:14AM +0100, Heinrich Schuchardt wrote:
> > On 12/17/25 08:11, Guodong Xu wrote:
>
> > > Specifically, I must adhere to
> > > Documentation/devicetree/bindings/riscv/extensions.yaml (and cpus.yaml for
> > > properties like 'riscv,sv39' which stands for the extension Sv39). If I
> > > add extension strings that are not yet defined in these schemas, such as
> > > supm, running 'make dtbs_check W=3' fails with: 'supm' is not one of
> > > ['i', 'm', 'a', ...], followed by "Unevaluated properties are not allowed."
> >
> > If Documentation/devicetree/bindings/riscv/extensions.yaml is incomplete
> > with respect to ratified extensions, I guess the right approach is to amend
> > it and not to curtail the CPU description.
>
> Absolutely. If the cpu supports something that is not documented, then
> please document it rather than omit from the devicetree.

Thanks for the review. May I clarify one thing? Both of you mentioned
document them, given the amount of missing extensions, is it acceptable if
I submit a prerequisite patch that only documents these strings in
riscv/extensions.yaml plus the necessary hwprobe export? Leaving the actual
usage of these extensions (named features) to the future patches.

To provide some context on why I ask: I've investigated the commits & lkml
history of RISC-V extensions since v6.5, and I summarized the current status
regarding the RVA23 profile here:
[1] status in v6.18 (inc. v6.19-rc1):
https://docularxu.github.io/rva23/linux-kernel-coverage.html
[2] support evolution since v6.5:
https://docularxu.github.io/rva23/rva23-kernel-support-evolution.html

Strictly describing the SpacemiT X100/K3 (or any core) as RVA23-compliant
requires adding these extensions that are currently missing from
the kernel bindings:
RVA23U64: Ziccif, Ziccamoa, Zicclsm, Za64rs
RVA23S64: Ss1p13, Ssccptr, Sstvecd, Sstvala, Sscounterenw, Ssu64xl,
          Sha, Shcounterenw, Shvstvala, Shtvala, Shvstvecd, Shvsatpa, Shgatpa
Plus 'Supm', 'Zic64b', 'Ssstateen', 'B' where the kernel supports them but
they are not literally documented in yaml.

Is this approach acceptable to you? If so, I will proceed with submitting them.

Thank you very much.

Best regards,
Guodong Xu