[PATCH v5 3/5] arm64: Kconfig: add LSUI Kconfig

[Yeoreum Yun]

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@xxxxxxx>
---
 arch/arm64/Kconfig | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 393d71124f5d..854e099b7646 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2238,6 +2238,11 @@ 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.
+
 config ARM64_SVE
 	bool "ARM Scalable Vector Extension support"
 	default y
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}