Re: [PATCH] rust: Add PowerPC support

Mukesh Kumar Chaurasiya
2026-02-04T19:18:24Z

On Wed, Feb 04, 2026 at 04:05:04AM +0100, Link Mauve wrote:
> For now only Big Endian 32-bit PowerPC is supported, as that is the only
> hardware I have. This has been tested on the Nintendo Wii so far, but I
> plan on also using it on the GameCube, Wii U and Apple G4.
>
> These changes aren’t the only ones required to get the kernel to compile
> and link on PowerPC, libcore will also have to be changed to not use
> integer division to format u64, u128 and core::time::Duration, otherwise
> __udivdi3() and __umoddi3() will have to be added. I have tested this
> change by replacing the three implementations with unimplemented!() and
> it linked just fine.
>
Hey Link,
I sent a patch with ppc64le support.
https://lore.kernel.org/all/20260204042417.83903-1-mkchauras@gmail.com/

Can i take this patch and put ppc64le support over it and send it out?

Regards,
Mukesh
> Signed-off-by: Link Mauve <linkmauve@linkmauve.fr>
> ---
> Documentation/rust/arch-support.rst | 1 +
> arch/powerpc/Kconfig | 1 +
> arch/powerpc/Makefile | 2 ++
> arch/powerpc/include/asm/jump_label.h | 16 ++++++++++------
> rust/Makefile | 4 +++-
> scripts/generate_rust_target.rs | 10 ++++++++++
> 6 files changed, 27 insertions(+), 7 deletions(-)
>
> diff --git a/Documentation/rust/arch-support.rst b/Documentation/rust/arch-support.rst
> index 6e6a515d0899..70b9e192a7a0 100644
> --- a/Documentation/rust/arch-support.rst
> +++ b/Documentation/rust/arch-support.rst
> @@ -18,6 +18,7 @@ Architecture Level of support Constraints
> ``arm`` Maintained ARMv7 Little Endian only.
> ``arm64`` Maintained Little Endian only.
> ``loongarch`` Maintained \-
> +``powerpc`` Maintained 32-bit Big Endian only.
> ``riscv`` Maintained ``riscv64`` and LLVM/Clang only.
> ``um`` Maintained \-
> ``x86`` Maintained ``x86_64`` only.
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 9537a61ebae0..17db23b82e91 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -283,6 +283,7 @@ config PPC
> select HAVE_REGS_AND_STACK_ACCESS_API
> select HAVE_RELIABLE_STACKTRACE
> select HAVE_RSEQ
> + select HAVE_RUST if PPC32
> select HAVE_SAMPLE_FTRACE_DIRECT if HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
> select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
> select HAVE_SETUP_PER_CPU_AREA if PPC64
> diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
> index a58b1029592c..9fd82c75dcbd 100644
> --- a/arch/powerpc/Makefile
> +++ b/arch/powerpc/Makefile
> @@ -61,6 +61,8 @@ else
> KBUILD_LDFLAGS_MODULE += $(objtree)/arch/powerpc/lib/crtsavres.o
> endif
>
> +KBUILD_RUSTFLAGS += --target=powerpc-unknown-linux-gnu
> +
> ifdef CONFIG_CPU_LITTLE_ENDIAN
> KBUILD_CPPFLAGS += -mlittle-endian
> KBUILD_LDFLAGS += -EL
> diff --git a/arch/powerpc/include/asm/jump_label.h b/arch/powerpc/include/asm/jump_label.h
> index d4eaba459a0e..238f0f625a36 100644
> --- a/arch/powerpc/include/asm/jump_label.h
> +++ b/arch/powerpc/include/asm/jump_label.h
> @@ -15,14 +15,18 @@
> #define JUMP_ENTRY_TYPE stringify_in_c(FTR_ENTRY_LONG)
> #define JUMP_LABEL_NOP_SIZE 4
>
> +/* This macro is also expanded on the Rust side. */
> +#define ARCH_STATIC_BRANCH_ASM(key, label) \
> + "1:\n\t" \
> + "nop # arch_static_branch\n\t" \
> + ".pushsection __jump_table, \"aw\"\n\t" \
> + ".long 1b - ., " label " - .\n\t" \
> + JUMP_ENTRY_TYPE key " - .\n\t" \
> + ".popsection \n\t"
> +
> static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
> {
> - asm goto("1:\n\t"
> - "nop # arch_static_branch\n\t"
> - ".pushsection __jump_table, \"aw\"\n\t"
> - ".long 1b - ., %l[l_yes] - .\n\t"
> - JUMP_ENTRY_TYPE "%c0 - .\n\t"
> - ".popsection \n\t"
> + asm goto(ARCH_STATIC_BRANCH_ASM("%c0", "%l[l_yes]")
> : : "i" (&((char *)key)[branch]) : : l_yes);
>
> return false;
> diff --git a/rust/Makefile b/rust/Makefile
> index 5c0155b83454..377e6fd68524 100644
> --- a/rust/Makefile
> +++ b/rust/Makefile
> @@ -400,13 +400,15 @@ bindgen_skip_c_flags := -mno-fp-ret-in-387 -mpreferred-stack-boundary=% \
> -fno-inline-functions-called-once -fsanitize=bounds-strict \
> -fstrict-flex-arrays=% -fmin-function-alignment=% \
> -fzero-init-padding-bits=% -mno-fdpic \
> - --param=% --param asan-% -fno-isolate-erroneous-paths-dereference
> + --param=% --param asan-% -fno-isolate-erroneous-paths-dereference \
> + -ffixed-r2 -mmultiple -mno-readonly-in-sdata
>
> # Derived from `scripts/Makefile.clang`.
> BINDGEN_TARGET_x86 := x86_64-linux-gnu
> BINDGEN_TARGET_arm64 := aarch64-linux-gnu
> BINDGEN_TARGET_arm := arm-linux-gnueabi
> BINDGEN_TARGET_loongarch := loongarch64-linux-gnusf
> +BINDGEN_TARGET_powerpc := powerpc-linux-gnu
> BINDGEN_TARGET_um := $(BINDGEN_TARGET_$(SUBARCH))
> BINDGEN_TARGET := $(BINDGEN_TARGET_$(SRCARCH))
>
> diff --git a/scripts/generate_rust_target.rs b/scripts/generate_rust_target.rs
> index 38b3416bb979..0054880ba0ea 100644
> --- a/scripts/generate_rust_target.rs
> +++ b/scripts/generate_rust_target.rs
> @@ -188,6 +188,16 @@ fn main() {
> panic!("arm uses the builtin rustc target");
> } else if cfg.has("ARM64") {
> panic!("arm64 uses the builtin rustc aarch64-unknown-none target");
> + } else if cfg.has("PPC32") {
> + ts.push("arch", "powerpc");
> + ts.push("data-layout", "E-m:e-p:32:32-Fn32-i64:64-n32");
> + ts.push("features", "+soft-float");
> + ts.push("llvm-target", "powerpc-unknown-eabi");
> + if cfg.rustc_version_atleast(1, 91, 0) {
> + ts.push("target-pointer-width", 32);
> + } else {
> + ts.push("target-pointer-width", "32");
> + }
> } else if cfg.has("RISCV") {
> if cfg.has("64BIT") {
> panic!("64-bit RISC-V uses the builtin rustc riscv64-unknown-none-elf target");
> --
> 2.52.0
>