On Tue, 23 Aug 2022 19:33:19 +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: > - ima are required > - 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 > - convention says that 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 > - as the above is just convention, don't apply any charset restrictions > to reduce future churn > - 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 > > 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/ > Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx> > Acked-by: Guo Ren <guoren@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(-) > Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
