Re: [PATCH v4 07/16] riscv: cpufeature: Extract common elements from extension checking

Charlie Jenkins
2024-05-01T19:48:18Z

On Wed, May 01, 2024 at 12:37:14PM +0100, Conor Dooley wrote:
> On Fri, Apr 26, 2024 at 02:29:21PM -0700, Charlie Jenkins wrote:
> > The __riscv_has_extension_likely() and __riscv_has_extension_unlikely()
> > functions from the vendor_extensions.h can be used to simplify the
> > standard extension checking code as well. Migrate those functions to
> > cpufeature.h and reorganize the code in the file to use the functions.
> >
> > Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
> > ---
> > arch/riscv/include/asm/cpufeature.h | 78 +++++++++++++++++-------------
> > arch/riscv/include/asm/vendor_extensions.h | 28 -----------
> > 2 files changed, 44 insertions(+), 62 deletions(-)
> >
> > diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
> > index fedd479ccfd1..17896ec9ec11 100644
> > --- a/arch/riscv/include/asm/cpufeature.h
> > +++ b/arch/riscv/include/asm/cpufeature.h
> > @@ -98,59 +98,66 @@ extern bool riscv_isa_fallback;
> >
> > unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap);
> >
> > +#define EXT_ALL_VENDORS 0
>
> It's not really "all vendors", it's standard. Otherwise, this seems all

This hooks up into the alternatives:

ALTERNATIVE("nop", "j %l[l_yes]", %[vendor], %[ext], 1)

Where the "vendor" argument is supposed to be 0 if the alternative is
applicable to all vendors. Is there a better way to convey this?

- Charlie

> grand to me,
> Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
>
> Cheers,
> Conor.