LoongArch: Use rustc option -Zdirect-access-external-data

-Zdirect-access-external-data is a new Rust compiler option added in
Rust 1.78, which we use to optimize the access of external data in the
Linux kernel's Rust code. This patch modifies the Rust code in vmlinux
to directly access externa data, using PC-REL instead of GOT. However,
Rust code whithin modules is constrained by the PC-REL addressing range
and is explicitly set to use an indirect method.

Acked-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This commit is contained in:
WANG Rui 2024-07-20 22:41:07 +08:00 committed by Huacai Chen
parent e05d4cd9b8
commit 0d3a632202

View File

@ -105,7 +105,8 @@ KBUILD_CFLAGS += -fno-jump-tables
endif
KBUILD_RUSTFLAGS += --target=loongarch64-unknown-none-softfloat
KBUILD_RUSTFLAGS_MODULE += -Crelocation-model=pic
KBUILD_RUSTFLAGS_KERNEL += -Zdirect-access-external-data=yes
KBUILD_RUSTFLAGS_MODULE += -Zdirect-access-external-data=no
ifeq ($(CONFIG_RELOCATABLE),y)
KBUILD_CFLAGS_KERNEL += -fPIE