[PATCH v2 11/13] dt-bindings: riscv: Add Supm extension description

[Alex Elder]

On 12/22/25 7:04 AM, Guodong Xu wrote:
> Add description for the Supm extension. Supm indicates support for pointer
> masking in user mode. Supm is mandatory for RVA23S64.
> 
> The Supm extension is ratified in commit d70011dde6c2 ("Update to ratified
> state") of riscv-j-extension.
> 
> Supm depends on either Smnpm or Ssnpm, so add a schema check to enforce
> this dependency.

I have the same general question on this, about whether it's really
necessary for the DT binding to enforce these requirements.  The
RISC-V specifications are what truly defines their meaning, so I
don't really see why the DT framework should need to enforce them.
(That said, I'm sure there are other cases where DT enforces things
it shouldn't have to.)


And now, having looked at these added binding definitions (in patches
07 through 11 in this series), I wonder what exactly is required for
them to be accepted.  For the most part these seem to just be defining
how the extensions specified for RISC-V are to be expressed in
DT files.  It seems to be a fairly straightforward copy from the
ratified specification(s) to the YAML format.

Who need to sign off on it?  Conor?  Paul?  DT maintainers?

Thanks.

					-Alex

> Signed-off-by: Guodong Xu <guodong at riscstar.com>
> ---
> v2: New patch.
> ---
>   Documentation/devicetree/bindings/riscv/extensions.yaml | 16 ++++++++++++++++
>   1 file changed, 16 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml
> index 1066b7e65dab89704dbac449db4aa5605c95b9d3..4997f533b2c0defad88fd59413a6885b5b9e109a 100644
> --- a/Documentation/devicetree/bindings/riscv/extensions.yaml
> +++ b/Documentation/devicetree/bindings/riscv/extensions.yaml
> @@ -267,6 +267,12 @@ properties:
>               ratified in RISC-V Profiles Version 1.0, with commit b1d806605f87
>               ("Updated to ratified state.")
>   
> +        - const: supm
> +          description: |
> +            The standard Supm extension for pointer masking support in user
> +            mode as ratified at commit d70011dde6c2 ("Update to ratified state")
> +            of riscv-j-extension.
> +
>           - const: svade
>             description: |
>               The standard Svade supervisor-level extension for SW-managed PTE A/D
> @@ -892,6 +898,16 @@ properties:
>                   const: shvstvecd
>               - contains:
>                   const: ssstateen
> +      # Supm depends on either Smnpm or Ssnpm
> +      - if:
> +          contains:
> +            const: supm
> +        then:
> +          anyOf:
> +            - contains:
> +                const: smnpm
> +            - contains:
> +                const: ssnpm
>         # Zcb depends on Zca
>         - if:
>             contains:
>