On Thu, Aug 18, 2022 at 07:40:14AM +0200, Andrew Jones wrote: > On Wed, Aug 17, 2022 at 09:12:12PM +0100, Conor Dooley wrote: > > From: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> > > > > The QEMU virt and spike machines currently export a riscv,isa string of > > "rv64imafdcsuh", > > > > While the RISC-V foundation has been ratifying a bunch of extenstions > > etc, the kernel has remained relatively static with what hardware is > > supported - but the same is not true of QEMU. Using the virt machine > > and running dt-validate on the dumped dtb fails, partly due to the > > unexpected isa string. > > > > Rather than enumerate the many many possbilities, change the pattern > > to a regex, with the following assumptions: > > - the single letter order is fixed & we don't care about things that > > can't even do "ima" > > - the standard multi letter extensions are all in a "_z<foo>" format > > where the first letter of <foo> is a valid single letter extension > > - _s & _h are used for supervisor and hyper visor extensions. > > - after the first two chars, a standard multi letter extension name > > could be an english word (ifencei anyone?) so it's not worth > > restricting the charset > > - vendor ISA extensions begind with _x and have no charset restrictions > > - we don't care about an e extension from an OS pov > > - that attempting to validate the contents of the multiletter extensions > > with dt-validate beyond the formatting is a futile, massively verbose > > or unwieldy exercise at best. > > - ima are required > > > > The following limitations also apply: > > - multi letter extension ordering is not enforced. dt-schema does not > > appear to allow for named match groups, so the resulting regex would > > be even more of a headache. > > - ditto for the numbered extensions. > > > > Finally, add me as a maintainer of the binding so that when it breaks > > in the future, I can be held responsible! > > > > Reported-by: Rob Herring <robh@xxxxxxxxxx> > > Link: https://lore.kernel.org/linux-riscv/20220803170552.GA2250266-robh@xxxxxxxxxx/ > > Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> > > --- > > Palmer, feel free to drop the maintainer addition. I just mostly want > > to clean up my own mess on this when they decide to ratify more > > extensions & this comes back up again. > > --- > > Documentation/devicetree/bindings/riscv/cpus.yaml | 5 ++--- > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > diff --git a/Documentation/devicetree/bindings/riscv/cpus.yaml b/Documentation/devicetree/bindings/riscv/cpus.yaml > > index 873dd12f6e89..c0e0bc5dce04 100644 > > --- a/Documentation/devicetree/bindings/riscv/cpus.yaml > > +++ b/Documentation/devicetree/bindings/riscv/cpus.yaml > > @@ -9,6 +9,7 @@ title: RISC-V bindings for 'cpus' DT nodes > > maintainers: > > - Paul Walmsley <paul.walmsley@xxxxxxxxxx> > > - Palmer Dabbelt <palmer@xxxxxxxxxx> > > + - Conor Dooley <conor@xxxxxxxxxx> > > > > description: | > > This document uses some terminology common to the RISC-V community > > @@ -79,9 +80,7 @@ properties: > > insensitive, letters in the riscv,isa string must be all > > lowercase to simplify parsing. > > $ref: "/schemas/types.yaml#/definitions/string" > > - enum: > > - - rv64imac > > - - rv64imafdc > > + pattern: ^rv(?:64|32)imaf?d?q?c?b?v?k?h?(?:(?:_[zsh][imafdqcbvksh]|_x)(?:[a-z])+)*$ Actually we don't want S and H extensions to be treated like Z, but rather like X. Only Z extensions have the category character convention. (And I'm still tempted to just drop the enforcement from Z too, since it adds additional maintenance and we've already settled for something less than complete.) Thanks, drew > > > > # RISC-V requires 'timebase-frequency' in /cpus, so disallow it here > > timebase-frequency: false > > -- > > 2.37.1 > > > > Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
