Re: [PATCH RESEND v7 3/6] arm64: Kconfig: add LSUI Kconfig

Will Deacon
2025-09-15T11:32:32Z

On Mon, Sep 15, 2025 at 11:42:12AM +0100, Yeoreum Yun wrote:
> > On Sat, Aug 16, 2025 at 04:19:26PM +0100, Yeoreum Yun wrote:
> > > Since Armv9.6, FEAT_LSUI supplies the load/store instructions for
> > > previleged level to access to access user memory without clearing
> > > PSTATE.PAN bit.
> > > It's enough to add CONFIG_AS_HAS_LSUI only because the code for LSUI uses
> > > individual `.arch_extension` entries.
> >
> > The subject could be improved slightly: Detect toolchain support for
> > LSUI.
> >
> > >
> > > Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
> > > ---
> > > arch/arm64/Kconfig | 5 +++++
> > > 1 file changed, 5 insertions(+)
> > >
> > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> > > index e9bbfacc35a6..c474de3dce02 100644
> > > --- a/arch/arm64/Kconfig
> > > +++ b/arch/arm64/Kconfig
> > > @@ -2239,6 +2239,11 @@ config ARM64_GCS
> > >
> > > endmenu # "v9.4 architectural features"
> > >
> > > +config AS_HAS_LSUI
> > > + def_bool $(as-instr,.arch_extension lsui)
> > > + help
> > > + Supported by LLVM 20 and later, not yet supported by GNU AS.
> >
> > binutils 2.45 added support for LSUI.
> >
> > Nitpick: we tend to add a two-space indentation from "help".
> >
> > Otherwise it looks fine:
> >
> > Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
>
> Thanks! I'll change the Nitpick and send again.

Please don't resend until we've concluded on the CAS discussion.

Will