On Thu, Dec 01, 2022 at 11:47:04AM +0100, Heiko Stübner wrote: > Am Donnerstag, 1. Dezember 2022, 10:00:41 CET schrieb Andrew Jones: > > On Wed, Nov 30, 2022 at 11:41:25PM +0000, Conor Dooley wrote: > > > From: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> > > > > > > Ordering between each and every list of extensions is wildly > > > inconsistent. Per discussion on the lists pick the following policy: > > > > > > - The array defining order in /proc/cpuinfo follows a narrow > > > interpretation of the ISA specifications, described in a comment > > > immediately presiding it. > > > > > > - All other lists of extensions are sorted alphabetically. > > > > > > This will hopefully allow for easier review & future additions, and > > > reduce conflicts between patchsets as the number of extensions grows. > > > > > > Link: https://lore.kernel.org/all/20221129144742.2935581-2-conor.dooley@xxxxxxxxxxxxx/ > > > Suggested-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx> > > > Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> > > > --- > > > I could not decide between adding an alphabetical comment to each > > > alphabetical site or not. I did it anyway. Scream if you hate it! > > > > > > I also moved a static branch thingy in this version, but that should not > > > matter, right? riightt? > > > > riiighttt. And it goes away with [1] anyway. > > > > [1] https://lore.kernel.org/all/20221006070818.3616-1-jszhang@xxxxxxxxxx/ > > I'm not sure what became of that series since mid october, though noting > that tightly coupling the patching to extensions alone might cause issues [2] > which some of the "features" like fast-unaligned access, that are not directly > bound to a isa-extension but to an implementation detail > > [2] https://lore.kernel.org/all/1991071.yIU609i1g2@phil/ Jisheng said he'd send a refresh soon. Hopefully your comments will be taken into consideration. It seems like we need both the concepts of cpufeatures and extensions. Where many times a cpufeature directly maps to an extension, but not always. Or, we could shoehorn the non-extension cpufeatures into the extension framework by calling them "derived extensions" or something. > > > > > > > --- > > > arch/riscv/include/asm/hwcap.h | 12 +++++++----- > > > arch/riscv/kernel/cpu.c | 4 ++-- > > > arch/riscv/kernel/cpufeature.c | 6 ++++-- > > > 3 files changed, 13 insertions(+), 9 deletions(-) > > > > > > diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h > > > index b22525290073..ce522aad641a 100644 > > > --- a/arch/riscv/include/asm/hwcap.h > > > +++ b/arch/riscv/include/asm/hwcap.h > > > @@ -51,14 +51,15 @@ extern unsigned long elf_hwcap; > > > * RISCV_ISA_EXT_MAX. 0-25 range is reserved for single letter > > > * extensions while all the multi-letter extensions should define the next > > > * available logical extension id. > > > + * Entries are sorted alphabetically. > > > */ > > > enum riscv_isa_ext_id { > > > RISCV_ISA_EXT_SSCOFPMF = RISCV_ISA_EXT_BASE, > > > + RISCV_ISA_EXT_SSTC, > > > + RISCV_ISA_EXT_SVINVAL, > > > RISCV_ISA_EXT_SVPBMT, > > > RISCV_ISA_EXT_ZICBOM, > > > RISCV_ISA_EXT_ZIHINTPAUSE, > > > - RISCV_ISA_EXT_SSTC, > > > - RISCV_ISA_EXT_SVINVAL, > > > RISCV_ISA_EXT_ID_MAX = RISCV_ISA_EXT_MAX, > > > }; > > > > Unrelated to this patch, but every time I look at this enum I want to post > > the diff below, but I haven't bothered, because this enum also goes away > > with [1]. > > > > @@ -59,8 +59,9 @@ enum riscv_isa_ext_id { > > RISCV_ISA_EXT_ZIHINTPAUSE, > > RISCV_ISA_EXT_SSTC, > > RISCV_ISA_EXT_SVINVAL, > > - RISCV_ISA_EXT_ID_MAX = RISCV_ISA_EXT_MAX, > > + RISCV_ISA_EXT_ID_MAX > > }; > > +static_assert(RISCV_ISA_EXT_ID_MAX <= RISCV_ISA_EXT_MAX); > > that sounds like a very reasonable idea ... what's keeping you? :-) Posted :-) Thanks, drew
