[PATCH] loongarch: rust: Switch to use built-in rustc target

[PATCH] loongarch: rust: Switch to use built-in rustc target

[WANG Rui]

This commit switches to using the built-in rustc
loongarch64-unknown-none-softfloat target for LoongArch.

The Rust samples have been tested with this commit.

Signed-off-by: WANG Rui <wangrui@loongson.cn>
---
base-commit: ("rust: Refactor the build target to allow the use of builtin targets")
Link: https://lore.kernel.org/r/20231020155056.3495121-2-Jamie.Cunliffe@arm.com
---
 arch/loongarch/Makefile         | 2 +-
 rust/Makefile                   | 2 +-
 scripts/Makefile                | 2 +-
 scripts/generate_rust_target.rs | 7 +------
 4 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/arch/loongarch/Makefile b/arch/loongarch/Makefile
index df6caf79537a..17aabe7b0315 100644
--- a/arch/loongarch/Makefile
+++ b/arch/loongarch/Makefile
@@ -101,7 +101,7 @@ ifdef CONFIG_OBJTOOL
 KBUILD_CFLAGS			+= -fno-jump-tables
 endif
 
-KBUILD_RUSTFLAGS			+= --target=$(objtree)/scripts/target.json
+KBUILD_RUSTFLAGS			+= --target=loongarch64-unknown-none-softfloat
 KBUILD_RUSTFLAGS_MODULE		+= -Crelocation-model=pic
 
 ifeq ($(CONFIG_RELOCATABLE),y)
diff --git a/rust/Makefile b/rust/Makefile
index fe045dbc701e..cb40a1ce1331 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -437,7 +437,7 @@ $(obj)/core.o: private rustc_objcopy = $(foreach sym,$(redirect-intrinsics),--re
 $(obj)/core.o: private rustc_target_flags = $(core-cfgs)
 $(obj)/core.o: $(RUST_LIB_SRC)/core/src/lib.rs FORCE
 	$(call if_changed_dep,rustc_library)
-ifneq ($(or $(CONFIG_X86_64),$(CONFIG_LOONGARCH)),)
+ifdef CONFIG_X86_64
 $(obj)/core.o: scripts/target.json
 endif
 
diff --git a/scripts/Makefile b/scripts/Makefile
index bc90520a5426..fe56eeef09dd 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -12,7 +12,7 @@ hostprogs-always-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE)	+= insert-sys-cert
 hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS)		+= rustdoc_test_builder
 hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS)		+= rustdoc_test_gen
 
-ifneq ($(or $(CONFIG_X86_64),$(CONFIG_LOONGARCH)),)
+ifdef CONFIG_X86_64
 always-$(CONFIG_RUST)					+= target.json
 filechk_rust_target = $< < include/config/auto.conf
 
diff --git a/scripts/generate_rust_target.rs b/scripts/generate_rust_target.rs
index 54919cf48621..acd3b1acef83 100644
--- a/scripts/generate_rust_target.rs
+++ b/scripts/generate_rust_target.rs
@@ -164,12 +164,7 @@ fn main() {
         ts.push("llvm-target", "x86_64-linux-gnu");
         ts.push("target-pointer-width", "64");
     } else if cfg.has("LOONGARCH") {
-        ts.push("arch", "loongarch64");
-        ts.push("data-layout", "e-m:e-p:64:64-i64:64-i128:128-n64-S128");
-        ts.push("features", "-f,-d");
-        ts.push("llvm-target", "loongarch64-linux-gnusf");
-        ts.push("llvm-abiname", "lp64s");
-        ts.push("target-pointer-width", "64");
+        panic!("loongarch uses the builtin rustc loongarch64-unknown-none-softfloat target");
     } else {
         panic!("Unsupported architecture");
     }
-- 
2.44.0

Re: [PATCH] loongarch: rust: Switch to use built-in rustc target

[Miguel Ojeda]

On Mon, Mar 4, 2024 at 3:14 PM WANG Rui <wangrui@loongson.cn> wrote:
>
> This commit switches to using the built-in rustc
> loongarch64-unknown-none-softfloat target for LoongArch.
>
> The Rust samples have been tested with this commit.
>
> Signed-off-by: WANG Rui <wangrui@loongson.cn>
> ---
> base-commit: ("rust: Refactor the build target to allow the use of builtin targets")

I couldn't apply it on top of commit f82811e22b48 in arm64's tree
(which is the base? -- the offset differs significantly in the arch
Makefile), but I nevertheless applied it manually on top of that one,
build-tested it for loongarch64 and boot-tested it for x86_64:

Acked-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>

Thanks!

Cheers,
Miguel

Re: [PATCH] loongarch: rust: Switch to use built-in rustc target

[WANG Rui]

On Tue, Mar 5, 2024 at 12:09 AM Miguel Ojeda
<miguel.ojeda.sandonis@gmail.com> wrote:
>
> On Mon, Mar 4, 2024 at 3:14 PM WANG Rui <wangrui@loongson.cn> wrote:
> >
> > This commit switches to using the built-in rustc
> > loongarch64-unknown-none-softfloat target for LoongArch.
> >
> > The Rust samples have been tested with this commit.
> >
> > Signed-off-by: WANG Rui <wangrui@loongson.cn>
> > ---
> > base-commit: ("rust: Refactor the build target to allow the use of builtin targets")
>
> I couldn't apply it on top of commit f82811e22b48 in arm64's tree
> (which is the base? -- the offset differs significantly in the arch
> Makefile), but I nevertheless applied it manually on top of that one,
> build-tested it for loongarch64 and boot-tested it for x86_64:
>
> Acked-by: Miguel Ojeda <ojeda@kernel.org>
> Tested-by: Miguel Ojeda <ojeda@kernel.org>

Oops. The actual base is tag next-20240228. I just want to make it
clear that this patch needs to be based on ("rust: Refactor the build
target to allow the use of builtin targets").

Thanks!

Regards,
Rui

>
> Thanks!
>
> Cheers,
> Miguel
>

Re: [PATCH] loongarch: rust: Switch to use built-in rustc target

[Huacai Chen]

Hi, Miguel,

On Tue, Mar 5, 2024 at 12:07 AM Miguel Ojeda
<miguel.ojeda.sandonis@gmail.com> wrote:
>
> On Mon, Mar 4, 2024 at 3:14 PM WANG Rui <wangrui@loongson.cn> wrote:
> >
> > This commit switches to using the built-in rustc
> > loongarch64-unknown-none-softfloat target for LoongArch.
> >
> > The Rust samples have been tested with this commit.
> >
> > Signed-off-by: WANG Rui <wangrui@loongson.cn>
> > ---
> > base-commit: ("rust: Refactor the build target to allow the use of builtin targets")
>
> I couldn't apply it on top of commit f82811e22b48 in arm64's tree
> (which is the base? -- the offset differs significantly in the arch
> Makefile), but I nevertheless applied it manually on top of that one,
> build-tested it for loongarch64 and boot-tested it for x86_64:
>
> Acked-by: Miguel Ojeda <ojeda@kernel.org>
> Tested-by: Miguel Ojeda <ojeda@kernel.org>
The base of the loongarch tree doesn't contain the arm64 modifications
now, so this patch is better to be applied on the rust tree with my
Acked-by. But if you have some trouble doing that, I can also manually
merge the arm64 parts to the loongarch tree, and then apply this
patch. Thanks.

Huacai

>
> Thanks!
>
> Cheers,
> Miguel

Re: [PATCH] loongarch: rust: Switch to use built-in rustc target

[Miguel Ojeda]

On Tue, Mar 5, 2024 at 10:58 AM Huacai Chen <chenhuacai@kernel.org> wrote:
>
> The base of the loongarch tree doesn't contain the arm64 modifications
> now, so this patch is better to be applied on the rust tree with my
> Acked-by. But if you have some trouble doing that, I can also manually
> merge the arm64 parts to the loongarch tree, and then apply this
> patch. Thanks.

The rust tree doesn't have the arm64 changes either (i.e. they are in
the arm64 tree), so we would have the same issue.

Since it is quite late and there is no rush for this, I would suggest
applying it after the merge window in loongarch64 and thus avoiding a
merge. But, of course, up to you!

Thanks!

Cheers,
Miguel

Re: [PATCH] loongarch: rust: Switch to use built-in rustc target

[Huacai Chen]

On Tue, Mar 5, 2024 at 6:10 PM Miguel Ojeda
<miguel.ojeda.sandonis@gmail.com> wrote:
>
> On Tue, Mar 5, 2024 at 10:58 AM Huacai Chen <chenhuacai@kernel.org> wrote:
> >
> > The base of the loongarch tree doesn't contain the arm64 modifications
> > now, so this patch is better to be applied on the rust tree with my
> > Acked-by. But if you have some trouble doing that, I can also manually
> > merge the arm64 parts to the loongarch tree, and then apply this
> > patch. Thanks.
>
> The rust tree doesn't have the arm64 changes either (i.e. they are in
> the arm64 tree), so we would have the same issue.
>
> Since it is quite late and there is no rush for this, I would suggest
> applying it after the merge window in loongarch64 and thus avoiding a
> merge. But, of course, up to you!
OK, then you just need to do nothing, I will apply at a suitable time
with your Acked-by.

Huacai

>
> Thanks!
>
> Cheers,
> Miguel
>