On Mon, Nov 28, 2022 at 10:12:17AM -0800, Palmer Dabbelt wrote: > On Mon, 28 Nov 2022 10:08:05 PST (-0800), Conor Dooley wrote: > > On Mon, Nov 28, 2022 at 09:41:03AM -0800, Palmer Dabbelt wrote: > > > On Thu, 24 Nov 2022 05:42:20 PST (-0800), heiko@xxxxxxxxx wrote: > > > > Am Donnerstag, 24. November 2022, 14:04:41 CET schrieb Conor Dooley: > > > > > I used the wikipedia table for ordering extensions when updating the > > > > > pattern here in foo. > > > > > > > > ^ foo? :-) > > > > > > > > > Unfortunately that table did not match canonical order, as defined by > > > > > the RISC-V ISA Manual, which defines extension ordering in (what is > > > > > currently) Table 41, "Standard ISA extension names". Fix things up by > > > > > re-sorting v (vector) and adding p (packed-simd) & j (dynamic > > > > > languages). The e (reduced integer) and g (general) extensions are still > > > > > intentionally left out. > > > > > > > > > > Link: https://github.com/riscv/riscv-isa-manual/releases/tag/riscv-unpriv-pdf-from-asciidoc-15112022 # Chapter 29.5 > > > > > Fixes: 299824e68bd0 ("dt-bindings: riscv: add new riscv,isa strings for emulators") > > > > > Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> > > > > > > > > So I have compared the new pattern to the isa manual, > > > > and it looks like the order checks out, so > > > > > > Which ISA manual? > > > > For me, isa manual is the above github repo. > > Which commit, though? mutt won't let me paste a clown face emoticon. > > > There have been many mutually incompatible ISA string > > > encoding rules, at least one of them was a change to the extension ordering. > > > It's not entirely clear what the right answer is here, as we can't really > > > parse ISA strings without also knowing the version of the ISA manual we're > > > meant to parse them against. Maybe we just accept everything? > > > > I don't think accepting everything is the right thing to do. A minimal > > amount of validation is still needed here, but I think we can deprecate > > the DT property entirely & make it optional if a new-and-improved way of > > encoding the in DT is used. > > Sorry, by "everything" I meant "everything that's even been allowed by the > ISA manual". Just accetping anything would be bad ;) > > > > IMO it's time to just stop using the ISA string. It's not a stable > > > interface, trying to treat it as such just leads to headaches. We should > > > just come up with some DT-specific way of encoding whatever HW features are > > > in question. Sure it'll be a bit of work to write that all down in the DT > > > bindings, but it's going to be way less work than trying to keep around all > > > this ISA string parsing code. > > > > I'm a glutton for punishment, I'll try and come up with some sort of > > other way to encode this information in DT that requires less parsing > > and validation. As I said on IRC, something that more resembles: > > if (of_property_wahtever("riscv,isa-foo")) { do_enable_foo() } > > That seems way simpler to me, thanks! We'll still need to support whatever > was here as a legacy format, but at least we won't need to add a bunch of > new stuff to it -- that's where the parsing starts to get really > complicated. Yah, and "deprecated" in dt-schema doesn't actually do anything at the moment other than let humans know not to use something. Just gonna have to do some sort of "feature-wise AND" between the existing things we parse from the isa string & whatever riscv,isa-foo stuff later on. > FWIW, there's a similar dicussion going on in GCC land right now. > > > > I know I've said the opposite before, but there's just been way too many > > > breakages here to assume they're going to stop. > > > > :upside_down_face: > > > > Either way, I think these two patches are worth taking in the mean time. > > Yep, just as long as it doesn't break any of the strings that were valid > according to previous versions of the ISA manual I'm fine with it. I don't think so. I had been looking around for a supposed order for where to actually put H, which had been dropped - and the only place I recall seeing that was Wikipedia - which now seems like an awful decision since the order there looks kinda off anything I see in dozen or so spec PDFs I have downloaded. But that's where I got the K & V ordering from that I now think is wrong (and doesn't match any PDF I have). The other changes relax rules and add letters so they should be okay too. > > > > Reviewed-by: Heiko Stuebner <heiko@xxxxxxxxx> > > > > > > > > > --- > > > > > Documentation/devicetree/bindings/riscv/cpus.yaml | 2 +- > > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > > > diff --git a/Documentation/devicetree/bindings/riscv/cpus.yaml b/Documentation/devicetree/bindings/riscv/cpus.yaml > > > > > index e80c967a4fa4..b7462ea2dbe4 100644 > > > > > --- a/Documentation/devicetree/bindings/riscv/cpus.yaml > > > > > +++ b/Documentation/devicetree/bindings/riscv/cpus.yaml > > > > > @@ -80,7 +80,7 @@ properties: > > > > > insensitive, letters in the riscv,isa string must be all > > > > > lowercase to simplify parsing. > > > > > $ref: "/schemas/types.yaml#/definitions/string" > > > > > - pattern: ^rv(?:64|32)imaf?d?q?c?b?v?k?h?(?:z(?:[a-z])+)?(?:_[hsxz](?:[a-z])+)*$ > > > > > + pattern: ^rv(?:64|32)imaf?d?q?c?b?k?j?p?v?h?(?:z(?:[a-z])+)?(?:_[hsxz](?:[a-z])+)*$ > > > > > > > > > > # RISC-V requires 'timebase-frequency' in /cpus, so disallow it here > > > > > timebase-frequency: false > > > > >
