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.

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
---
 arch/arm64/Kconfig | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 93173f0a09c7..36e87a1a1b5c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2227,6 +2227,11 @@ config ARM64_GCS

 endmenu # "ARMv9.4 architectural features"

+config AS_HAS_LSUI
+	def_bool $(as-instr,.arch_extension lsui)
+	help
+	  Supported by LLVM 20+ and binutils 2.45+.
+
 config ARM64_SVE
 	bool "ARM Scalable Vector Extension support"
 	default y
--
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

On Sun, Dec 14, 2025 at 11:22:43AM +0000, 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.
> 
> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
> ---
>  arch/arm64/Kconfig | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 93173f0a09c7..36e87a1a1b5c 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -2227,6 +2227,11 @@ config ARM64_GCS
> 
>  endmenu # "ARMv9.4 architectural features"
> 
> +config AS_HAS_LSUI
> +	def_bool $(as-instr,.arch_extension lsui)
> +	help
> +	  Supported by LLVM 20+ and binutils 2.45+.

This is an internal Kconfig variable so please drop the help text.

Will

On Mon, Jan 19, 2026 at 03:50:43PM +0000, Will Deacon wrote:
> On Sun, Dec 14, 2025 at 11:22:43AM +0000, Yeoreum Yun wrote:

> > +config AS_HAS_LSUI
> > +	def_bool $(as-instr,.arch_extension lsui)
> > +	help
> > +	  Supported by LLVM 20+ and binutils 2.45+.

> This is an internal Kconfig variable so please drop the help text.

It would be useful to keep the information about supported compilers as
a comment though (as is done for some of the other toolchain feature
tests).

> On Mon, Jan 19, 2026 at 03:50:43PM +0000, Will Deacon wrote:
> > On Sun, Dec 14, 2025 at 11:22:43AM +0000, Yeoreum Yun wrote:
>
> > > +config AS_HAS_LSUI
> > > +	def_bool $(as-instr,.arch_extension lsui)
> > > +	help
> > > +	  Supported by LLVM 20+ and binutils 2.45+.
>
> > This is an internal Kconfig variable so please drop the help text.
>
> It would be useful to keep the information about supported compilers as
> a comment though (as is done for some of the other toolchain feature
> tests).

With some comments from other thread,
What about this?

+menu "ARMv9.6 architectural features"
+
+config ARM64_LSUI
+       bool "Support Unprivileged Load Store Instructions (LSUI)"
+       default y
+       depends on AS_HAS_LSUI && !CPU_BIG_ENDIAN
+       help
+         The Unprivileged Load Store Instructions (LSUI) provides
+         variants load/store instructions that access user-space memory
+         from the kernel without clearing PSTATE.PAN bit.
+
+         This feature is supported by LLVM 20+ and binutils 2.45+.
+
+endmenu # "ARMv9.6 architectural feature"
+
 config AS_HAS_LSUI
        def_bool $(as-instr,.arch_extension lsui)
-       help
-         Supported by LLVM 20+ and binutils 2.45+.


--
Sincerely,
Yeoreum Yun