[PATCH v4 05/16] riscv: Extend cpufeature.c to detect vendor extensions

[Charlie Jenkins]

On Wed, May 01, 2024 at 12:40:38PM +0100, Conor Dooley wrote:
> On Fri, Apr 26, 2024 at 02:29:19PM -0700, Charlie Jenkins wrote:
> > Separate vendor extensions out into one struct per vendor
> > instead of adding vendor extensions onto riscv_isa_ext.
> > 
> > Add a hidden config RISCV_ISA_VENDOR_EXT to conditionally include this
> > code.
> > 
> > The xtheadvector vendor extension is added using these changes.
> > 
> > Signed-off-by: Charlie Jenkins <charlie at rivosinc.com>
> > ---
> >  arch/riscv/Kconfig                               |  2 +
> >  arch/riscv/Kconfig.vendor                        | 19 ++++++
> >  arch/riscv/include/asm/cpufeature.h              | 18 ++++++
> >  arch/riscv/include/asm/vendor_extensions.h       | 26 ++++++++
> >  arch/riscv/include/asm/vendor_extensions/thead.h | 19 ++++++
> >  arch/riscv/kernel/Makefile                       |  2 +
> >  arch/riscv/kernel/cpufeature.c                   | 77 ++++++++++++++++++------
> >  arch/riscv/kernel/vendor_extensions.c            | 18 ++++++
> >  arch/riscv/kernel/vendor_extensions/Makefile     |  3 +
> >  arch/riscv/kernel/vendor_extensions/thead.c      | 36 +++++++++++
> 
> I see no modifications to cpu.c here, is it intentional that vendor
> stuff isn't gonna show up in /proc/cpuinfo?

I wasn't sure if that's something we were wanting to support since
hwprobe is the prefered api, but I can add that if it is desired.

- Charlie