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

Yeoreum Yun yeoreum.yun at arm.com
Mon Sep 15 03:42:12 PDT 2025


Hi Catalin,

> 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 at 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 at arm.com>

Thanks! I'll change the Nitpick and send again.

--
Sincerely,
Yeoreum Yun



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