2021-04-07 08:22:22

by Heinrich Schuchardt

Subject: [RFC] dt-bindings: riscv: enum for riscv,isa

In Documentation/devicetree/bindings/riscv/cpus.yaml I find for riscv,isa:

enum:
- rv64imac
- rv64imafdc

This implies that 'rv64imafc' or 'rv64imafdqc' would be illegal values
while these combinations of extensions would be compliant with "The
RISC-V Instruction Set Manual".

To me it does not make much sense to try to enumerate all permissible
permutations of RISC-V extensions.

Shouldn't this enum be removed and replaced by examples?

Best regards

Heinrich

2021-04-23 03:34:07

by Palmer Dabbelt

Subject: Re: [RFC] dt-bindings: riscv: enum for riscv,isa

On Tue, 06 Apr 2021 12:05:34 PDT (-0700), [email protected] wrote:
> In Documentation/devicetree/bindings/riscv/cpus.yaml I find for riscv,isa:
>
> enum:
> - rv64imac
> - rv64imafdc
>
> This implies that 'rv64imafc' or 'rv64imafdqc' would be illegal values
> while these combinations of extensions would be compliant with "The
> RISC-V Instruction Set Manual".
>
> To me it does not make much sense to try to enumerate all permissible
> permutations of RISC-V extensions.
>
> Shouldn't this enum be removed and replaced by examples?

I'm generally OK with that, but I'm not sure how to do it: won't we fail
the scheme checks if we don't have something defined for "riscv,isa"?