Re: [PATCH 2/6] arm64/Kconfig: add LSUI Kconfig

From: Marc Zyngier
Date: Thu Jun 12 2025 - 02:33:57 EST


On Wed, 11 Jun 2025 18:54:50 +0100,
Yeoreum Yun <yeoreum.yun@xxxxxxx> wrote:
>
> Hi Marc,
>
> > On Wed, 11 Jun 2025 11:49:12 +0100,
> > Yeoreum Yun <yeoreum.yun@xxxxxxx> 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 LUSI uses
> > > indiviual `.arch_extension` entries.
> > >
> > > Signed-off-by: Yeoreum Yun <yeoreum.yun@xxxxxxx>
> > > ---
> > > arch/arm64/Kconfig | 8 +++++++-
> > > 1 file changed, 7 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> > > index 55fc331af337..20f360eef2ac 100644
> > > --- a/arch/arm64/Kconfig
> > > +++ b/arch/arm64/Kconfig
> > > @@ -2237,6 +2237,13 @@ config ARM64_GCS
> > >
> > > endmenu # "v9.4 architectural features"
> > >
> > > +menu "v9.6 architectural features"
> > > +
> > > +config AS_HAS_LSUI
> > > + def_bool $(as-instr,.arch_extension lsui)
> > > +
> > > +endmenu # "v9.6 architectural features"
> > > +
> > > config ARM64_SVE
> > > bool "ARM Scalable Vector Extension support"
> > > default y
> > > @@ -2498,4 +2505,3 @@ endmenu # "CPU Power Management"
> > > source "drivers/acpi/Kconfig"
> > >
> > > source "arch/arm64/kvm/Kconfig"
> > > -
> >
> > Can you please document what toolchain versions have support for this?
> >
> > Thanks,
>
> Okay. But here with comment or Is any other suggested place for
> this?

The help section in the Kconfig option you are introducing would be a
good start.

Thanks,

M.

--
Jazz isn't dead. It just smells funny.