[PATCH 3/3] arm64: rust: Disable neon and fp target features.

Jamie Cunliffe
2023-01-25T16:39:24Z

Disable the neon and fp target features to avoid fp & simd
registers. The use of fp-armv8 will cause a warning from rustc about
an unknown feature that is specified. The target feature is still
passed through to LLVM, this behaviour is documented as part of the
warning. This will be fixed in a future version of the rustc
toolchain.

Signed-off-by: Jamie Cunliffe <Jamie.Cunliffe@arm.com>
---
arch/arm64/Makefile | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index b53ab6aa2dfe..33ae20fc3f56 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -41,6 +41,8 @@ KBUILD_CFLAGS += -mgeneral-regs-only \
KBUILD_CFLAGS += $(call cc-disable-warning, psabi)
KBUILD_AFLAGS += $(compat_vdso)

+KBUILD_RUSTFLAGS += -C target-feature="-neon,-fp-armv8"
+
KBUILD_CFLAGS += $(call cc-option,-mabi=lp64)
KBUILD_AFLAGS += $(call cc-option,-mabi=lp64)

--
2.30.2