On Fri, Dec 24, 2021 at 3:25 PM Jessica Clarke <jrtc27@xxxxxxxxxx> wrote: > > On 24 Dec 2021, at 21:16, Atish Patra <atishp@xxxxxxxxxxxxxx> wrote: > > > > RISC-V ISA extensions can be single letter or multi-letter names. > > The single letter extensions are mostly base extensions and encoded in > > "riscv,isa" DT property. However, parsing the multi-letter extensions > > via the isa string is cumbersome and is not scalable. > > > > Add a new DT node for multi-letter extensions. > > > > Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx> > > --- > > Documentation/devicetree/bindings/riscv/cpus.yaml | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/riscv/cpus.yaml b/Documentation/devicetree/bindings/riscv/cpus.yaml > > index aa5fb64d57eb..6c4eecf389a9 100644 > > --- a/Documentation/devicetree/bindings/riscv/cpus.yaml > > +++ b/Documentation/devicetree/bindings/riscv/cpus.yaml > > @@ -78,6 +78,15 @@ properties: > > - rv64imac > > - rv64imafdc > > > > + riscv,isa-ext: > > + description: > > + Identifies the specific RISC-V instruction set architecture extensions > > + supported by one or multiple harts. All the multi-letter extensions > > + should be listed here as a boolean property. This subnode can be under > > + /cpus or under individual cpu node. In case of former, it represent > > + the common ISA extensions for all harts. The name of the boolean property > > + must match the actual ISA extension name in all lowercase format. > > I don’t see why this needs explicitly calling out, that’s true in > general of cpu node properties (3.8p4 of the Devicetree spec v0.4-rc1 / > v0.3-40-g7e1cc17), not that I like it. > Thanks for pointing it out. I did not realize the DT specification already has a paragraph about this. I will update the description in the next version. > Jess > -- Regards, Atish
