[PATCH V17 0/7] Rust Support for powerpc

[PATCH V17 0/7] Rust Support for powerpc

[Mukesh Kumar Chaurasiya (IBM)]

Enable experimental rust support for ppc64le and ppc32be. The patch for
ppc32 has been provided by Link Mauve[1] and ppc64le support[2] has been
merged over it. ppc32 needs some toolchain fixes mentioned in the patch
`rust: Add PowerPC support` and the discussion for that is done here[1].

This has been tested on
- powernv9 hardware
- pseries P11 hardware
- pseries(9, 10) qemu
- powernv(9, 10) qemu
- rustdoc on x86 and powerpc64le
- rusttest on x86 and powerpc64le

We are actively working with our LLVM team to get the target for ppc,
ppc64 and ppc64le in the rust compiler.

[1] https://lore.kernel.org/all/20260204030507.8203-1-linkmauve@linkmauve.fr
[2] https://lore.kernel.org/all/20260204042417.83903-1-mkchauras@gmail.com

Changelog:
V16 -> V17:
- Rebased to latest v7.2-rc2 

V15 -> V16:
- Rebased to latest v7.1-rc4
V15: https://lore.kernel.org/all/20260426105932.2270364-1-mkchauras@gmail.com/

V14 -> V15:
- Fix an issue with rustdoc build on ppc64le
V14: https://lore.kernel.org/all/20260426085725.2090827-1-mkchauras@gmail.com/

V13 -> V14:
- 2nd patch is rewritten (Christian)
- Fixed a small typo in rust/Makefile (Sashiko)
- Fixed commit message in Patch 4 (Sashiko)
V13: https://lore.kernel.org/all/20260424054742.45832-1-mkchauras@gmail.com/

V12 -> V13:
- Added a patch for fixing build issue on ppc32 by Link Mauve
- Added another patch to fix a build issue in dma-buf
- Added another patch to enforce minimum `rustc` version for powerpc
V12: https://lore.kernel.org/all/20260421120958.190430-1-mkchauras@gmail.com/

V11 -> V12:
- Rebased to mainline (rust/Makefile conflict resolved)
V11: https://lore.kernel.org/all/20260417152253.2312961-1-mkchauras@gmail.com/

V10 -> V11:
- Updated `rust/Makefile`
- Not all libraries are move to `rust/host` directory now. Only
  proc_macro2, quote and syn are moved
- Special handling for pin init is added. Details in commit
- Removed mkdir for `rust/host`, this is now handled by toolchain.
V10: https://lore.kernel.org/all/20260406200149.3727922-1-mkchauras@gmail.com/

V9 -> V10:
- rust/Makefile updated with review comments from Miguel
- Patch 1/4 updated with commit message and subject
V9: https://lore.kernel.org/all/20260404121610.1956528-1-mkchauras@gmail.com/

V8 -> V9:
- rust/Makefile updated with a directory instead of abspath
V8: https://lore.kernel.org/all/20260403145308.1042622-1-mkchauras@gmail.com/

V7 -> V8:
- rust/Makefile updated to separate host libraries from target
V7: https://lore.kernel.org/all/20260329160254.2592207-1-mkchauras@gmail.com/

Changelog:
V6 -> V7:
- Documentation removed as powerpc is still under development
- Added a fix for race condition in rust/Makefile
V6: https://lore.kernel.org/all/20260210090023.2587534-1-mkchauras@gmail.com

V5 -> V6:
- Added a missing Tested by from Venkat which got missed since V3
- Support is marked as Maintained instead of experimental
V5: https://lore.kernel.org/all/20260210053756.2088302-1-mkchauras@gmail.com

V4 -> V5:
- Removed a nested ifdef from PPC64 for Little endian toolchain
V4: https://lore.kernel.org/all/20260209105456.1551677-1-mkchauras@gmail.com

V3 -> V4:
- Co-developed-by header added in patch 1
V3: https://lore.kernel.org/all/20260205180429.3280657-1-mkchauras@gmail.com

V2 -> V3:
- Splited HAVE_RUST in 2 lines
- BINDGEN_TARGET_powerpc initialized before assigning the same to
  BINDGEN_TARGET
V2: https://lore.kernel.org/all/20260204210125.613350-1-mkchauras@gmail.com

V1 -> V2:
- jump label fix for rust has been moved to a separate patch
- PPC32 support has been taken
- rust support has been marked experimental
- target.json dependency has been removed
- HAVE_RUST now depends on CPU_LITTLE_ENDIAN for PPC64
V1: https://lore.kernel.org/all/20260204042417.83903-1-mkchauras@gmail.com 

Link Mauve (2):
  rust: Make __udivdi3() and __umoddi3() panic
  rust: Add PowerPC support

Mukesh Kumar Chaurasiya (IBM) (5):
  rust: Fix "multiple candidates for rmeta dependency core" error
  dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is
    disabled
  powerpc/jump_label: adjust inline asm to be consistent
  rust/powerpc: Set min rustc version for powerpc
  powerpc: Enable Rust for ppc64le

 arch/powerpc/Kconfig                  |  2 +
 arch/powerpc/Makefile                 |  7 ++++
 arch/powerpc/include/asm/jump_label.h | 23 ++++++-----
 rust/Makefile                         | 56 +++++++++++++++++----------
 rust/compiler_builtins.rs             |  6 +++
 rust/helpers/helpers.c                |  2 +
 scripts/min-tool-version.sh           |  2 +
 7 files changed, 68 insertions(+), 30 deletions(-)

-- 
2.55.0

[PATCH V17 1/7] rust: Fix "multiple candidates for rmeta dependency core" error

[Mukesh Kumar Chaurasiya (IBM)]

When building Rust code for powerpc64le with LLVM=1 and -j1, rustc
encounters an error: "multiple candidates for `rmeta` dependency `core`
found", with two candidates:
1. The host's standard library from the rustup toolchain
2. The kernel's custom libcore.rmeta in the rust/ directory

This occurs because the build system uses `-L$(objtree)/rust` for host
library builds (proc_macro2, quote, syn), which causes rustc to search
the rust/ directory. During this search, rustc finds both the kernel's
custom libcore.rmeta and gains access to the host's standard library,
creating a conflict.

The solution is to separate host libraries into a dedicated rust/host/
subdirectory and use `-L$(objtree)/rust/host` for host builds instead
of `-L$(objtree)/rust`. This ensures that:

1. Host library builds (proc_macro2, quote, syn) only search rust/host/
   and never encounter the kernel's libcore.rmeta
2. Proc macro builds use `-L$(objtree)/rust/host` to find their
   dependencies

Special handling is added for rustdoc-pin_init, which is a host build
(to access the alloc crate) but depends on proc macros from the main
rust/ directory. It uses explicit `--extern` paths to reference the
proc macros without adding `-L$(objtree)/rust`, which would reintroduce
the conflict.

The rust/host/ directory is added to clean-files to ensure it's removed
during `make clean`.

Link: https://github.com/Rust-for-Linux/linux/issues/105
Link: https://github.com/linuxppc/issues/issues/451
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
---
 rust/Makefile | 42 +++++++++++++++++++++++-------------------
 1 file changed, 23 insertions(+), 19 deletions(-)

diff --git a/rust/Makefile b/rust/Makefile
index a870d1616c71..17b2f329c13d 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -3,6 +3,9 @@
 # Where to place rustdoc generated documentation
 rustdoc_output := $(objtree)/Documentation/output/rust/rustdoc
 
+# Clean generated host directory
+clean-files := host/
+
 obj-$(CONFIG_RUST) += core.o compiler_builtins.o ffi.o
 always-$(CONFIG_RUST) += exports_core_generated.h
 
@@ -33,7 +36,7 @@ endif
 
 obj-$(CONFIG_RUST) += exports.o
 
-always-$(CONFIG_RUST) += libproc_macro2.rlib libquote.rlib libsyn.rlib
+always-$(CONFIG_RUST) += host/libproc_macro2.rlib host/libquote.rlib host/libsyn.rlib
 
 always-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated.rs
 always-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated_kunit.c
@@ -163,7 +166,7 @@ quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $<
 	$(rustc_target_envs) \
 	OBJTREE=$(abspath $(objtree)) \
 	$(RUSTDOC) $(filter-out $(skip_flags) --remap-path-scope=%,$(if $(rustdoc_host),$(rust_common_flags),$(rust_flags))) \
-		$(rustc_target_flags) -L$(objtree)/$(obj) \
+		$(rustc_target_flags) -L$(objtree)/$(obj)$(if $(rustdoc_host),/host) \
 		-Zunstable-options --generate-link-to-definition \
 		--output $(rustdoc_output) \
 		--crate-name $(subst rustdoc-,,$@) \
@@ -261,6 +264,7 @@ rustdoc-pin_init_internal: $(src)/pin-init/internal/src/lib.rs \
 
 rustdoc-pin_init: private rustdoc_host = yes
 rustdoc-pin_init: private rustc_target_flags = $(pin_init-flags) \
+    --extern pin_init_internal=$(objtree)/$(obj)/$(libpin_init_internal_name) \
     --extern alloc --cfg feature=\"alloc\"
 rustdoc-pin_init: $(src)/pin-init/src/lib.rs rustdoc-pin_init_internal \
     rustdoc-macros FORCE
@@ -572,23 +576,23 @@ quiet_cmd_rustc_procmacrolibrary = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_Q
 	$(if $(skip_clippy),$(RUSTC),$(RUSTC_OR_CLIPPY)) \
 		$(filter-out $(skip_flags),$(rust_common_flags) $(rustc_target_flags)) \
 		--emit=dep-info=$(depfile) --emit=link=$@ --crate-type rlib -O \
-		--out-dir $(objtree)/$(obj) -L$(objtree)/$(obj) \
+		--out-dir $(objtree)/$(obj)/host -L$(objtree)/$(obj)/host \
 		--crate-name $(patsubst lib%.rlib,%,$(notdir $@)) $<
 
-$(obj)/libproc_macro2.rlib: private skip_clippy = 1
-$(obj)/libproc_macro2.rlib: private rustc_target_flags = $(proc_macro2-flags)
-$(obj)/libproc_macro2.rlib: $(src)/proc-macro2/lib.rs FORCE
+$(obj)/host/libproc_macro2.rlib: private skip_clippy = 1
+$(obj)/host/libproc_macro2.rlib: private rustc_target_flags = $(proc_macro2-flags)
+$(obj)/host/libproc_macro2.rlib: $(src)/proc-macro2/lib.rs FORCE
 	+$(call if_changed_dep,rustc_procmacrolibrary)
 
-$(obj)/libquote.rlib: private skip_clippy = 1
-$(obj)/libquote.rlib: private skip_flags = $(quote-skip_flags)
-$(obj)/libquote.rlib: private rustc_target_flags = $(quote-flags)
-$(obj)/libquote.rlib: $(src)/quote/lib.rs $(obj)/libproc_macro2.rlib FORCE
+$(obj)/host/libquote.rlib: private skip_clippy = 1
+$(obj)/host/libquote.rlib: private skip_flags = $(quote-skip_flags)
+$(obj)/host/libquote.rlib: private rustc_target_flags = $(quote-flags)
+$(obj)/host/libquote.rlib: $(src)/quote/lib.rs $(obj)/host/libproc_macro2.rlib FORCE
 	+$(call if_changed_dep,rustc_procmacrolibrary)
 
-$(obj)/libsyn.rlib: private skip_clippy = 1
-$(obj)/libsyn.rlib: private rustc_target_flags = $(syn-flags)
-$(obj)/libsyn.rlib: $(src)/syn/lib.rs $(obj)/libquote.rlib FORCE
+$(obj)/host/libsyn.rlib: private skip_clippy = 1
+$(obj)/host/libsyn.rlib: private rustc_target_flags = $(syn-flags)
+$(obj)/host/libsyn.rlib: $(src)/syn/lib.rs $(obj)/host/libquote.rlib FORCE
 	+$(call if_changed_dep,rustc_procmacrolibrary)
 
 quiet_cmd_rustc_procmacro = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) P $@
@@ -598,26 +602,26 @@ quiet_cmd_rustc_procmacro = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET))
 		-Clinker-flavor=gcc -Clinker=$(HOSTCC) \
 		-Clink-args='$(call escsq,$(KBUILD_PROCMACROLDFLAGS))' \
 		--emit=dep-info=$(depfile) --emit=link=$@ --extern proc_macro \
-		--crate-type proc-macro -L$(objtree)/$(obj) \
+		--crate-type proc-macro -L$(objtree)/$(obj)/host \
 		--crate-name $(patsubst lib%.$(procmacro-extension),%,$(notdir $@)) \
 		@$(objtree)/include/generated/rustc_cfg $<
 
 # Procedural macros can only be used with the `rustc` that compiled it.
 $(obj)/$(libzerocopy_derive_name): private skip_clippy = 1
 $(obj)/$(libzerocopy_derive_name): private rustc_target_flags = $(zerocopy_derive-flags)
-$(obj)/$(libzerocopy_derive_name): $(src)/zerocopy-derive/lib.rs $(obj)/libproc_macro2.rlib \
-    $(obj)/libquote.rlib $(obj)/libsyn.rlib FORCE
+$(obj)/$(libzerocopy_derive_name): $(src)/zerocopy-derive/lib.rs $(obj)/host/libproc_macro2.rlib \
+    $(obj)/host/libquote.rlib $(obj)/host/libsyn.rlib FORCE
 	+$(call if_changed_dep,rustc_procmacro)
 
 $(obj)/$(libmacros_name): private rustc_target_flags = \
     --extern proc_macro2 --extern quote --extern syn
-$(obj)/$(libmacros_name): $(src)/macros/lib.rs $(obj)/libproc_macro2.rlib \
-    $(obj)/libquote.rlib $(obj)/libsyn.rlib FORCE
+$(obj)/$(libmacros_name): $(src)/macros/lib.rs $(obj)/host/libproc_macro2.rlib \
+    $(obj)/host/libquote.rlib $(obj)/host/libsyn.rlib FORCE
 	+$(call if_changed_dep,rustc_procmacro)
 
 $(obj)/$(libpin_init_internal_name): private rustc_target_flags = $(pin_init_internal-flags)
 $(obj)/$(libpin_init_internal_name): $(src)/pin-init/internal/src/lib.rs \
-    $(obj)/libproc_macro2.rlib $(obj)/libquote.rlib $(obj)/libsyn.rlib FORCE
+    $(obj)/host/libproc_macro2.rlib $(obj)/host/libquote.rlib $(obj)/host/libsyn.rlib FORCE
 	+$(call if_changed_dep,rustc_procmacro)
 
 # `rustc` requires `-Zunstable-options` to use custom target specifications
-- 
2.55.0

[PATCH V17 2/7] dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is disabled

[Mukesh Kumar Chaurasiya (IBM)]

When building with LLVM=1 for architectures like powerpc where
CONFIG_DMA_SHARED_BUFFER is not enabled, the build fails with:

  ld.lld: error: undefined symbol: dma_resv_reset_max_fences
  >>> referenced by helpers.c
  >>>               rust/helpers/helpers.o:(rust_helper_dma_resv_unlock)

The issue occurs because:
1. CONFIG_DEBUG_MUTEXES=y is enabled
2. CONFIG_DMA_SHARED_BUFFER is not enabled
3. dma_resv_reset_max_fences() is declared in the header when
   CONFIG_DEBUG_MUTEXES is set
4. But the function is only compiled in drivers/dma-buf/dma-resv.c,
   which is only built when CONFIG_DMA_SHARED_BUFFER is enabled
5. Rust helpers call dma_resv_unlock() which calls
   dma_resv_reset_max_fences(), causing an undefined symbol

Fix this by compiling `dma-resv.c` file only when CONFIG_DMA_SHARED_BUFFER
is enabled.

Fixes: 9b836641d3bf ("rust: helpers: Add bindings/wrappers for dma_resv_lock")
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
---
 rust/helpers/helpers.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
index 998e31052e66..4b90a1390ad5 100644
--- a/rust/helpers/helpers.c
+++ b/rust/helpers/helpers.c
@@ -58,7 +58,9 @@
 #include "cred.c"
 #include "device.c"
 #include "dma.c"
+#ifdef CONFIG_DMA_SHARED_BUFFER
 #include "dma-resv.c"
+#endif
 #include "drm.c"
 #include "drm_gpuvm.c"
 #include "err.c"
-- 
2.55.0

[PATCH V17 3/7] powerpc/jump_label: adjust inline asm to be consistent

[Mukesh Kumar Chaurasiya (IBM)]

Added support for a new macro ARCH_STATIC_BRANCH_ASM in powerpc
to avoid duplication of inline asm between C and Rust. This is
inline with 'commit aecaf181651c ("jump_label: adjust inline asm to be consistent")'

Co-developed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://github.com/Rust-for-Linux/linux/issues/105
Link: https://github.com/linuxppc/issues/issues/451
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
---
 arch/powerpc/include/asm/jump_label.h | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/include/asm/jump_label.h b/arch/powerpc/include/asm/jump_label.h
index d4eaba459a0e..3016e9c8d6bc 100644
--- a/arch/powerpc/include/asm/jump_label.h
+++ b/arch/powerpc/include/asm/jump_label.h
@@ -15,14 +15,20 @@
 #define JUMP_ENTRY_TYPE		stringify_in_c(FTR_ENTRY_LONG)
 #define JUMP_LABEL_NOP_SIZE	4
 
+#define JUMP_TABLE_ENTRY(key, label)			\
+	".pushsection __jump_table,  \"aw\"	\n\t"	\
+	".long 1b - ., " label " - .		\n\t"	\
+	JUMP_ENTRY_TYPE key " - .		\n\t"	\
+	".popsection 				\n\t"
+
+#define ARCH_STATIC_BRANCH_ASM(key, label)		\
+	"1:	nop				\n\t"	\
+	JUMP_TABLE_ENTRY(key, label)
+
 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;
@@ -34,10 +40,7 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool
 {
 	asm goto("1:\n\t"
 		 "b %l[l_yes] # arch_static_branch_jump\n\t"
-		 ".pushsection __jump_table,  \"aw\"\n\t"
-		 ".long 1b - ., %l[l_yes] - .\n\t"
-		 JUMP_ENTRY_TYPE "%c0 - .\n\t"
-		 ".popsection \n\t"
+		 JUMP_TABLE_ENTRY("%c0", "%l[l_yes]")
 		 : :  "i" (&((char *)key)[branch]) : : l_yes);
 
 	return false;
-- 
2.55.0

[PATCH V17 4/7] rust/powerpc: Set min rustc version for powerpc

[Mukesh Kumar Chaurasiya (IBM)]

Minimum `rustc` version required for powerpc is 1.95 as some critical
features required for compiling rust code for kernel are not there.

For example Stable inline asm support which got merged in 1.95.

Link: https://github.com/rust-lang/rust/pull/147996
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
---
 scripts/min-tool-version.sh | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
index 031f2192b390..99bfdcaa3396 100755
--- a/scripts/min-tool-version.sh
+++ b/scripts/min-tool-version.sh
@@ -33,6 +33,8 @@ llvm)
 rustc)
 	if [ "$SRCARCH" = "s390" ]; then
 		echo 1.96.0
+	elif [ "$ARCH" = powerpc ]; then
+		echo 1.95.0
 	else
 		echo 1.85.0
 	fi
-- 
2.55.0

[PATCH V17 5/7] rust: Make __udivdi3() and __umoddi3() panic

[Mukesh Kumar Chaurasiya (IBM)]

From: Link Mauve <linkmauve@linkmauve.fr>

The core crate currently depends on these two functions for i64/u64/
i128/u128/core::time::Duration formatting, but we shouldn’t use that in
the kernel so let’s panic if they are ever called.

This doesn’t yet fix drm_panic_qr.rs, which also uses __udivdi3 when
CONFIG_CC_OPTIMIZE_FOR_SIZE=y, but at least makes the rest of the kernel
build on PPC32.

Signed-off-by: Link Mauve <linkmauve@linkmauve.fr>
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
---
 rust/Makefile             | 4 ++++
 rust/compiler_builtins.rs | 6 ++++++
 2 files changed, 10 insertions(+)

diff --git a/rust/Makefile b/rust/Makefile
index 17b2f329c13d..7aa8fcad4c43 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -677,6 +677,10 @@ ifneq ($(or $(CONFIG_ARM64),$(and $(CONFIG_RISCV),$(CONFIG_64BIT))),)
 		__ashrti3 \
 		__ashlti3 __lshrti3
 endif
+ifdef CONFIG_PPC32
+	redirect-intrinsics += \
+		__udivdi3 __umoddi3
+endif
 
 ifdef CONFIG_MODVERSIONS
 cmd_gendwarfksyms = $(if $(skip_gendwarfksyms),, \
diff --git a/rust/compiler_builtins.rs b/rust/compiler_builtins.rs
index dd16c1dc899c..fc6b54636dd5 100644
--- a/rust/compiler_builtins.rs
+++ b/rust/compiler_builtins.rs
@@ -97,5 +97,11 @@ pub extern "C" fn $ident() {
     __aeabi_uldivmod,
 });
 
+#[cfg(target_arch = "powerpc")]
+define_panicking_intrinsics!("`u64` division/modulo should not be used", {
+    __udivdi3,
+    __umoddi3,
+});
+
 // NOTE: if you are adding a new intrinsic here, you should also add it to
 // `redirect-intrinsics` in `rust/Makefile`.
-- 
2.55.0

[PATCH V17 6/7] rust: Add PowerPC support

[Mukesh Kumar Chaurasiya (IBM)]

From: Link Mauve <linkmauve@linkmauve.fr>

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.

Signed-off-by: Link Mauve <linkmauve@linkmauve.fr>
Link: https://github.com/Rust-for-Linux/linux/issues/105
Link: https://github.com/linuxppc/issues/issues/451
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://github.com/rust-lang/compiler-team/issues/986
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
---
 arch/powerpc/Kconfig  | 1 +
 arch/powerpc/Makefile | 2 ++
 rust/Makefile         | 4 +++-
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index f7ce5fff81f0..badd7c99b87f 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -285,6 +285,7 @@ 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..589613eaa5dc 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/rust/Makefile b/rust/Makefile
index 7aa8fcad4c43..61e7dc496fe4 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -448,7 +448,8 @@ bindgen_skip_c_flags := -mno-fp-ret-in-387 -mpreferred-stack-boundary=% \
 	-fstrict-flex-arrays=% -fmin-function-alignment=% \
 	-fzero-init-padding-bits=% -mno-fdpic \
 	-fdiagnostics-show-context -fdiagnostics-show-context=% \
-	--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
@@ -458,6 +459,7 @@ BINDGEN_TARGET_loongarch	:= loongarch64-linux-gnusf
 BINDGEN_TARGET_s390	:= s390x-linux-gnu
 # This is only for i386 UM builds, which need the 32-bit target not -m32
 BINDGEN_TARGET_i386	:= i386-linux-gnu
+BINDGEN_TARGET_powerpc	:= powerpc-linux-gnu
 BINDGEN_TARGET_um	:= $(BINDGEN_TARGET_$(SUBARCH))
 BINDGEN_TARGET		:= $(BINDGEN_TARGET_$(SRCARCH))
 
-- 
2.55.0

[PATCH V17 7/7] powerpc: Enable Rust for ppc64le

[Mukesh Kumar Chaurasiya (IBM)]

Enabling rust support for ppc64le.

Tested on pseries Power11:
╰─❯ dmesg | grep rust
[    0.225728] Initialise system trusted keyrings
[    0.270961] rust_minimal: Rust minimal sample (init)
[    0.270968] rust_minimal: Am I built-in? true
[    0.270974] rust_minimal: test_parameter: 1
[    0.270983] rust_misc_device: Initialising Rust Misc Device Sample
[    0.271012] rust_print: Rust printing macros sample (init)
[    0.271019] rust_print: Emergency message (level 0) without args
[    0.271023] rust_print: Alert message (level 1) without args
[    0.271026] rust_print: Critical message (level 2) without args
[    0.271030] rust_print: Error message (level 3) without args
[    0.271033] rust_print: Warning message (level 4) without args
[    0.271037] rust_print: Notice message (level 5) without args
[    0.271040] rust_print: Info message (level 6) without args
[    0.271043] rust_print: A line that is continued without args
[    0.271054] rust_print: Emergency message (level 0) with args
[    0.271064] rust_print: Alert message (level 1) with args
[    0.271072] rust_print: Critical message (level 2) with args
[    0.271077] rust_print: Error message (level 3) with args
[    0.271083] rust_print: Warning message (level 4) with args
[    0.271091] rust_print: Notice message (level 5) with args
[    0.271097] rust_print: Info message (level 6) with args
[    0.271102] rust_print: A line that is continued with args
[    0.271110] rust_print: 1
[    0.271113] rust_print: "hello, world"
[    0.271121] rust_print: [samples/rust/rust_print_main.rs:35:5] c = "hello, world"
[    0.271129] rust_print: Arc<dyn Display> says 42
[    0.271130] rust_print: Arc<dyn Display> says hello, world
[    0.271136] rust_print: "hello, world"
[    0.271198] usbcore: registered new interface driver rust_driver_usb
[    0.271207] rust_faux_driver: Initialising Rust Faux Device Sample
[    0.271227] faux_driver rust-faux-sample-device: Hello from faux device!
[    0.271297] rust_configfs: Rust configfs sample (init)

Reviewed-by: Link Mauve <linkmauve@linkmauve.fr>
Tested-by: Link Mauve <linkmauve@linkmauve.fr>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Link: https://github.com/Rust-for-Linux/linux/issues/105
Link: https://github.com/linuxppc/issues/issues/451
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://github.com/rust-lang/compiler-team/issues/987
Link: https://github.com/rust-lang/compiler-team/issues/988
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
---
 arch/powerpc/Kconfig  | 1 +
 arch/powerpc/Makefile | 7 ++++++-
 rust/Makefile         | 6 ++++++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index badd7c99b87f..650283107b92 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -286,6 +286,7 @@ config PPC
 	select HAVE_RELIABLE_STACKTRACE
 	select HAVE_RSEQ
 	select HAVE_RUST			if PPC32
+	select HAVE_RUST			if PPC64 && CPU_LITTLE_ENDIAN
 	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 589613eaa5dc..9385db478c59 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -61,7 +61,12 @@ else
 KBUILD_LDFLAGS_MODULE += $(objtree)/arch/powerpc/lib/crtsavres.o
 endif
 
-KBUILD_RUSTFLAGS 	+= --target=powerpc-unknown-linux-gnu
+ifdef CONFIG_PPC64
+KBUILD_RUSTFLAGS	+= --target=powerpc64le-unknown-linux-gnu
+KBUILD_RUSTFLAGS	+= -Ctarget-feature=-mma,-vsx,-hard-float,-altivec
+else
+KBUILD_RUSTFLAGS	+= --target=powerpc-unknown-linux-gnu
+endif
 
 ifdef CONFIG_CPU_LITTLE_ENDIAN
 KBUILD_CPPFLAGS	+= -mlittle-endian
diff --git a/rust/Makefile b/rust/Makefile
index 61e7dc496fe4..d2f74998d3c1 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -459,7 +459,13 @@ BINDGEN_TARGET_loongarch	:= loongarch64-linux-gnusf
 BINDGEN_TARGET_s390	:= s390x-linux-gnu
 # This is only for i386 UM builds, which need the 32-bit target not -m32
 BINDGEN_TARGET_i386	:= i386-linux-gnu
+
+ifdef CONFIG_PPC64
+BINDGEN_TARGET_powerpc	:= powerpc64le-linux-gnu
+else
 BINDGEN_TARGET_powerpc	:= powerpc-linux-gnu
+endif
+
 BINDGEN_TARGET_um	:= $(BINDGEN_TARGET_$(SUBARCH))
 BINDGEN_TARGET		:= $(BINDGEN_TARGET_$(SRCARCH))
 
-- 
2.55.0

Re: [PATCH V17 4/7] rust/powerpc: Set min rustc version for powerpc

[Link Mauve]

Hi,

On Wed, Jul 08, 2026 at 01:54:51PM +0530, Mukesh Kumar Chaurasiya (IBM) wrote:
> Minimum `rustc` version required for powerpc is 1.95 as some critical
> features required for compiling rust code for kernel are not there.
> 
> For example Stable inline asm support which got merged in 1.95.

Didn’t we decide on 1.85.0 with the asm_experimental_arch feature
instead?  And possibly on 64-bit 1.87.0 if it isn’t possible to disable
altivec correctly there?

> 
> Link: https://github.com/rust-lang/rust/pull/147996
> Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
> ---
>  scripts/min-tool-version.sh | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
> index 031f2192b390..99bfdcaa3396 100755
> --- a/scripts/min-tool-version.sh
> +++ b/scripts/min-tool-version.sh
> @@ -33,6 +33,8 @@ llvm)
>  rustc)
>  	if [ "$SRCARCH" = "s390" ]; then
>  		echo 1.96.0
> +	elif [ "$ARCH" = powerpc ]; then
> +		echo 1.95.0
>  	else
>  		echo 1.85.0
>  	fi
> -- 
> 2.55.0
> 
> 

-- 
Link Mauve

Re: [PATCH V17 4/7] rust/powerpc: Set min rustc version for powerpc

[Mukesh Kumar Chaurasiya]

On Wed, Jul 08, 2026 at 10:39:30AM +0200, Link Mauve wrote:
> Hi,
> 
> On Wed, Jul 08, 2026 at 01:54:51PM +0530, Mukesh Kumar Chaurasiya (IBM) wrote:
> > Minimum `rustc` version required for powerpc is 1.95 as some critical
> > features required for compiling rust code for kernel are not there.
> > 
> > For example Stable inline asm support which got merged in 1.95.
> 
> Didn’t we decide on 1.85.0 with the asm_experimental_arch feature
> instead?  And possibly on 64-bit 1.87.0 if it isn’t possible to disable
> altivec correctly there?
> 
1.85.0 or 1.85.1 is not feasible for ppc64le.
PPC maintainer is ok with 1.95 for PPC. It's still experimental for PPC.

Regards,
Mukesh

> > 
> > Link: https://github.com/rust-lang/rust/pull/147996
> > Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
> > ---
> >  scripts/min-tool-version.sh | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
> > index 031f2192b390..99bfdcaa3396 100755
> > --- a/scripts/min-tool-version.sh
> > +++ b/scripts/min-tool-version.sh
> > @@ -33,6 +33,8 @@ llvm)
> >  rustc)
> >  	if [ "$SRCARCH" = "s390" ]; then
> >  		echo 1.96.0
> > +	elif [ "$ARCH" = powerpc ]; then
> > +		echo 1.95.0
> >  	else
> >  		echo 1.85.0
> >  	fi
> > -- 
> > 2.55.0
> > 
> > 
> 
> -- 
> Link Mauve

Re: [PATCH V17 2/7] dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is disabled

[Miguel Ojeda]

On Wed, Jul 8, 2026 at 10:25 AM Mukesh Kumar Chaurasiya (IBM)
<mkchauras@gmail.com> wrote:
>
> When building with LLVM=1 for architectures like powerpc where
> CONFIG_DMA_SHARED_BUFFER is not enabled, the build fails with:
>
>   ld.lld: error: undefined symbol: dma_resv_reset_max_fences
>   >>> referenced by helpers.c
>   >>>               rust/helpers/helpers.o:(rust_helper_dma_resv_unlock)
>
> The issue occurs because:
> 1. CONFIG_DEBUG_MUTEXES=y is enabled
> 2. CONFIG_DMA_SHARED_BUFFER is not enabled
> 3. dma_resv_reset_max_fences() is declared in the header when
>    CONFIG_DEBUG_MUTEXES is set
> 4. But the function is only compiled in drivers/dma-buf/dma-resv.c,
>    which is only built when CONFIG_DMA_SHARED_BUFFER is enabled
> 5. Rust helpers call dma_resv_unlock() which calls
>    dma_resv_reset_max_fences(), causing an undefined symbol
>
> Fix this by compiling `dma-resv.c` file only when CONFIG_DMA_SHARED_BUFFER
> is enabled.
>
> Fixes: 9b836641d3bf ("rust: helpers: Add bindings/wrappers for dma_resv_lock")
> Reviewed-by: Christian König <christian.koenig@amd.com>
> Reviewed-by: Gary Guo <gary@garyguo.net>
> Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>

Andreas sent a similar one to:

  https://lore.kernel.org/rust-for-linux/20260708-dma-shared-buffer-config-v1-1-8c1571000855@kernel.org/

This is earlier, but please see his approach & Sashiko's note.

Backlinking here for reference.

Cheers,
Miguel

Re: [PATCH V17 0/7] Rust Support for powerpc

[Madhavan Srinivasan]

On Wed, 08 Jul 2026 13:54:47 +0530, Mukesh Kumar Chaurasiya (IBM) wrote:
> Enable experimental rust support for ppc64le and ppc32be. The patch for
> ppc32 has been provided by Link Mauve[1] and ppc64le support[2] has been
> merged over it. ppc32 needs some toolchain fixes mentioned in the patch
> `rust: Add PowerPC support` and the discussion for that is done here[1].
> 
> This has been tested on
> - powernv9 hardware
> - pseries P11 hardware
> - pseries(9, 10) qemu
> - powernv(9, 10) qemu
> - rustdoc on x86 and powerpc64le
> - rusttest on x86 and powerpc64le
> 
> [...]

Applied to powerpc/next.

[1/7] rust: Fix "multiple candidates for rmeta dependency core" error
      https://git.kernel.org/powerpc/c/00cdfd072c709c608606461d7d44d4613119bfa9
[2/7] dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is disabled
      https://git.kernel.org/powerpc/c/be809b60cbb61aab96179f44ac3670242ae72996
[3/7] powerpc/jump_label: adjust inline asm to be consistent
      https://git.kernel.org/powerpc/c/13244c0a40139fe66c4c5c5655f4d732a6002957
[4/7] rust/powerpc: Set min rustc version for powerpc
      https://git.kernel.org/powerpc/c/e299147cdc8e19c6421a6b7863dc82a35b09d967
[5/7] rust: Make __udivdi3() and __umoddi3() panic
      https://git.kernel.org/powerpc/c/c93c194e4ee71a734986fd99a8b1ec9fbb7a9b8b
[6/7] rust: Add PowerPC support
      https://git.kernel.org/powerpc/c/73b741adb264967093ef4eb59905618a7e0d0de0
[7/7] powerpc: Enable Rust for ppc64le
      https://git.kernel.org/powerpc/c/bc87cbdb952e9223616b839d64bdb4723aa2ed1d

cheers

Re: [PATCH V17 0/7] Rust Support for powerpc

[Link Mauve]

Hi,

On Mon, Aug 03, 2026 at 12:27:13PM +0530, Madhavan Srinivasan wrote:
> On Wed, 08 Jul 2026 13:54:47 +0530, Mukesh Kumar Chaurasiya (IBM) wrote:
> > Enable experimental rust support for ppc64le and ppc32be. The patch for
> > ppc32 has been provided by Link Mauve[1] and ppc64le support[2] has been
> > merged over it. ppc32 needs some toolchain fixes mentioned in the patch
> > `rust: Add PowerPC support` and the discussion for that is done here[1].
> > 
> > This has been tested on
> > - powernv9 hardware
> > - pseries P11 hardware
> > - pseries(9, 10) qemu
> > - powernv(9, 10) qemu
> > - rustdoc on x86 and powerpc64le
> > - rusttest on x86 and powerpc64le
> > 
> > [...]
> 
> Applied to powerpc/next.
> 
> [1/7] rust: Fix "multiple candidates for rmeta dependency core" error
>       https://git.kernel.org/powerpc/c/00cdfd072c709c608606461d7d44d4613119bfa9
> [2/7] dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is disabled
>       https://git.kernel.org/powerpc/c/be809b60cbb61aab96179f44ac3670242ae72996
> [3/7] powerpc/jump_label: adjust inline asm to be consistent
>       https://git.kernel.org/powerpc/c/13244c0a40139fe66c4c5c5655f4d732a6002957
> [4/7] rust/powerpc: Set min rustc version for powerpc
>       https://git.kernel.org/powerpc/c/e299147cdc8e19c6421a6b7863dc82a35b09d967
> [5/7] rust: Make __udivdi3() and __umoddi3() panic
>       https://git.kernel.org/powerpc/c/c93c194e4ee71a734986fd99a8b1ec9fbb7a9b8b
> [6/7] rust: Add PowerPC support
>       https://git.kernel.org/powerpc/c/73b741adb264967093ef4eb59905618a7e0d0de0
> [7/7] powerpc: Enable Rust for ppc64le
>       https://git.kernel.org/powerpc/c/bc87cbdb952e9223616b839d64bdb4723aa2ed1d
> 
> cheers
> 

I just tested those again in linux-next, with the Wii support series on
top, but now the kernel fails to build due to ARCH_WARN_ASM and
ARCH_WARN_REACHABLE not being defined on PowerPC:
```
error: no rules expected `ARCH_WARN_ASM`
   --> /home/linkmauve/dev/linux/wii/rust/kernel/generated_arch_warn_asm.rs:1:28
    |
  1 | ::kernel::concat_literals!(ARCH_WARN_ASM("{file}", "{line}", "{flags}", "{size}"))
    |                            ^^^^^^^^^^^^^ no rules expected this token in macro call
    |
   ::: ../rust/kernel/lib.rs:279:1
    |
279 | macro_rules! concat_literals {
    | ---------------------------- when calling this macro
    |
    = note: while trying to match sequence start

error: no rules expected `ARCH_WARN_REACHABLE`
   --> /home/linkmauve/dev/linux/wii/rust/kernel/generated_arch_reachable_asm.rs:1:28
    |
  1 | ::kernel::concat_literals!(ARCH_WARN_REACHABLE)
    |                            ^^^^^^^^^^^^^^^^^^^ no rules expected this token in macro call
    |
   ::: ../rust/kernel/lib.rs:279:1
    |
279 | macro_rules! concat_literals {
    | ---------------------------- when calling this macro
    |
    = note: while trying to match sequence start

error: aborting due to 2 previous errors
```

This is in addition to the bindings::kvfree_call_rcu() call, but that
one is already being handled in a different thread.

-- 
Link Mauve

Re: [PATCH V17 0/7] Rust Support for powerpc

[FUJITA Tomonori]

On Tue, 4 Aug 2026 12:11:57 +0200
Link Mauve <linkmauve@linkmauve.fr> wrote:

> Hi,
> 
> On Mon, Aug 03, 2026 at 12:27:13PM +0530, Madhavan Srinivasan wrote:
>> On Wed, 08 Jul 2026 13:54:47 +0530, Mukesh Kumar Chaurasiya (IBM) wrote:
>> > Enable experimental rust support for ppc64le and ppc32be. The patch for
>> > ppc32 has been provided by Link Mauve[1] and ppc64le support[2] has been
>> > merged over it. ppc32 needs some toolchain fixes mentioned in the patch
>> > `rust: Add PowerPC support` and the discussion for that is done here[1].
>> > 
>> > This has been tested on
>> > - powernv9 hardware
>> > - pseries P11 hardware
>> > - pseries(9, 10) qemu
>> > - powernv(9, 10) qemu
>> > - rustdoc on x86 and powerpc64le
>> > - rusttest on x86 and powerpc64le
>> > 
>> > [...]
>> 
>> Applied to powerpc/next.
>> 
>> [1/7] rust: Fix "multiple candidates for rmeta dependency core" error
>>       https://git.kernel.org/powerpc/c/00cdfd072c709c608606461d7d44d4613119bfa9
>> [2/7] dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is disabled
>>       https://git.kernel.org/powerpc/c/be809b60cbb61aab96179f44ac3670242ae72996
>> [3/7] powerpc/jump_label: adjust inline asm to be consistent
>>       https://git.kernel.org/powerpc/c/13244c0a40139fe66c4c5c5655f4d732a6002957
>> [4/7] rust/powerpc: Set min rustc version for powerpc
>>       https://git.kernel.org/powerpc/c/e299147cdc8e19c6421a6b7863dc82a35b09d967
>> [5/7] rust: Make __udivdi3() and __umoddi3() panic
>>       https://git.kernel.org/powerpc/c/c93c194e4ee71a734986fd99a8b1ec9fbb7a9b8b
>> [6/7] rust: Add PowerPC support
>>       https://git.kernel.org/powerpc/c/73b741adb264967093ef4eb59905618a7e0d0de0
>> [7/7] powerpc: Enable Rust for ppc64le
>>       https://git.kernel.org/powerpc/c/bc87cbdb952e9223616b839d64bdb4723aa2ed1d
>> 
>> cheers
>> 
> 
> I just tested those again in linux-next, with the Wii support series on
> top, but now the kernel fails to build due to ARCH_WARN_ASM and
> ARCH_WARN_REACHABLE not being defined on PowerPC:
> ```
> error: no rules expected `ARCH_WARN_ASM`
>    --> /home/linkmauve/dev/linux/wii/rust/kernel/generated_arch_warn_asm.rs:1:28
>     |
>   1 | ::kernel::concat_literals!(ARCH_WARN_ASM("{file}", "{line}", "{flags}", "{size}"))
>     |                            ^^^^^^^^^^^^^ no rules expected this token in macro call
>     |
>    ::: ../rust/kernel/lib.rs:279:1
>     |
> 279 | macro_rules! concat_literals {
>     | ---------------------------- when calling this macro
>     |
>     = note: while trying to match sequence start
> 
> error: no rules expected `ARCH_WARN_REACHABLE`
>    --> /home/linkmauve/dev/linux/wii/rust/kernel/generated_arch_reachable_asm.rs:1:28
>     |
>   1 | ::kernel::concat_literals!(ARCH_WARN_REACHABLE)
>     |                            ^^^^^^^^^^^^^^^^^^^ no rules expected this token in macro call
>     |
>    ::: ../rust/kernel/lib.rs:279:1
>     |
> 279 | macro_rules! concat_literals {
>     | ---------------------------- when calling this macro
>     |
>     = note: while trying to match sequence start
> 
> error: aborting due to 2 previous errors
> ```
> 
> This is in addition to the bindings::kvfree_call_rcu() call, but that
> one is already being handled in a different thread.

Looks like powerpc needs something like the followings:

diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h
index 0db48977c70c..8aba39e0cf26 100644
--- a/arch/powerpc/include/asm/bug.h
+++ b/arch/powerpc/include/asm/bug.h
@@ -32,34 +32,38 @@
 #endif /* verbose */
 
 #else /* !__ASSEMBLER__ */
-/* _EMIT_BUG_ENTRY expects args %0,%1,%2,%3 to be FILE, LINE, flags and
-   sizeof(struct bug_entry), respectively */
 #ifdef CONFIG_DEBUG_BUGVERBOSE
-#define _EMIT_BUG_ENTRY				\
+#define _EMIT_BUG_ENTRY(file, line, flags)	\
 	".section __bug_table,\"aw\"\n"		\
 	"2:	.4byte 1b - .\n"		\
-	"	.4byte %0 - .\n"		\
-	"	.short %1, %2\n"		\
-	".org 2b+%3\n"				\
-	".previous\n"
+	"	.4byte " file " - .\n"		\
+	"	.short " line ", " flags "\n"
 #else
-#define _EMIT_BUG_ENTRY				\
+#define _EMIT_BUG_ENTRY(file, line, flags)	\
 	".section __bug_table,\"aw\"\n"		\
 	"2:	.4byte 1b - .\n"		\
-	"	.short %2\n"			\
-	".org 2b+%3\n"				\
-	".previous\n"
+	"	.short " flags "\n"
 #endif
 
 #define BUG_ENTRY(cond_str, insn, flags, ...)		\
 	__asm__ __volatile__(				\
 		"1:	" insn "\n"			\
-		_EMIT_BUG_ENTRY				\
+		_EMIT_BUG_ENTRY("%0", "%1", "%2")	\
+		".org 2b+%3\n"				\
+		".previous\n"				\
 		: : "i" (WARN_CONDITION_STR(cond_str) __FILE__), "i" (__LINE__),	\
 		  "i" (flags),				\
 		  "i" (sizeof(struct bug_entry)),	\
 		  ##__VA_ARGS__)
 
+#define ARCH_WARN_ASM(file, line, flags, size)		\
+		"1:	twi 31, 0, 0\n"			\
+		_EMIT_BUG_ENTRY(file, line, flags)	\
+		".org 2b+" size "\n"			\
+		".previous\n"
+
+#define ARCH_WARN_REACHABLE
+
 /*
  * BUG_ON() and WARN_ON() do their best to cooperate with compile-time
  * optimisations. However depending on the complexity of the condition

Re: [PATCH V17 0/7] Rust Support for powerpc

[Nathan Chancellor]

On Tue, Aug 04, 2026 at 12:11:57PM +0200, Link Mauve wrote:
> Hi,
> 
> On Mon, Aug 03, 2026 at 12:27:13PM +0530, Madhavan Srinivasan wrote:
> > On Wed, 08 Jul 2026 13:54:47 +0530, Mukesh Kumar Chaurasiya (IBM) wrote:
> > > Enable experimental rust support for ppc64le and ppc32be. The patch for
> > > ppc32 has been provided by Link Mauve[1] and ppc64le support[2] has been
> > > merged over it. ppc32 needs some toolchain fixes mentioned in the patch
> > > `rust: Add PowerPC support` and the discussion for that is done here[1].
> > > 
> > > This has been tested on
> > > - powernv9 hardware
> > > - pseries P11 hardware
> > > - pseries(9, 10) qemu
> > > - powernv(9, 10) qemu
> > > - rustdoc on x86 and powerpc64le
> > > - rusttest on x86 and powerpc64le
> > > 
> > > [...]
> > 
> > Applied to powerpc/next.
> > 
> > [1/7] rust: Fix "multiple candidates for rmeta dependency core" error
> >       https://git.kernel.org/powerpc/c/00cdfd072c709c608606461d7d44d4613119bfa9
> > [2/7] dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is disabled
> >       https://git.kernel.org/powerpc/c/be809b60cbb61aab96179f44ac3670242ae72996
> > [3/7] powerpc/jump_label: adjust inline asm to be consistent
> >       https://git.kernel.org/powerpc/c/13244c0a40139fe66c4c5c5655f4d732a6002957
> > [4/7] rust/powerpc: Set min rustc version for powerpc
> >       https://git.kernel.org/powerpc/c/e299147cdc8e19c6421a6b7863dc82a35b09d967
> > [5/7] rust: Make __udivdi3() and __umoddi3() panic
> >       https://git.kernel.org/powerpc/c/c93c194e4ee71a734986fd99a8b1ec9fbb7a9b8b
> > [6/7] rust: Add PowerPC support
> >       https://git.kernel.org/powerpc/c/73b741adb264967093ef4eb59905618a7e0d0de0
> > [7/7] powerpc: Enable Rust for ppc64le
> >       https://git.kernel.org/powerpc/c/bc87cbdb952e9223616b839d64bdb4723aa2ed1d
> > 
> > cheers
> > 
> 
> I just tested those again in linux-next, with the Wii support series on
> top, but now the kernel fails to build due to ARCH_WARN_ASM and
> ARCH_WARN_REACHABLE not being defined on PowerPC:

I also see the following warnings (in addition to that error):

  warning: unknown and unstable feature specified for `-Ctarget-feature`: `mma`
    |
    = note: it is still passed through to the codegen backend, but use of this feature might be unsound and the behavior of this feature can change in the future
    = help: consider filing a feature request

  warning: unstable feature specified for `-Ctarget-feature`: `vsx`
    |
    = note: this feature is not stably supported; its behavior can change in the future

  warning: unknown and unstable feature specified for `-Ctarget-feature`: `hard-float`
    |
    = note: it is still passed through to the codegen backend, but use of this feature might be unsound and the behavior of this feature can change in the future
    = help: consider filing a feature request

  warning: unstable feature specified for `-Ctarget-feature`: `altivec`
    |
    = note: this feature is not stably supported; its behavior can change in the future

  clang diag: arch/powerpc/include/uapi/asm/ioctl.h:5:9: warning: '_IOC_SIZEBITS' macro redefined [-Wmacro-redefined]
  clang diag: arch/powerpc/include/uapi/asm/ioctl.h:6:9: warning: '_IOC_DIRBITS' macro redefined [-Wmacro-redefined]
  clang diag: arch/powerpc/include/uapi/asm/ioctl.h:8:9: warning: '_IOC_NONE' macro redefined [-Wmacro-redefined]
  clang diag: arch/powerpc/include/uapi/asm/ioctl.h:10:9: warning: '_IOC_WRITE' macro redefined [-Wmacro-redefined]
  warning: 4 warnings emitted

when building this series in next-20260804 with rustc 1.97.1. I am not
sure where the clang diagnostic warnings come from. I assume the target
feature warnings are expected but it would be good to get those
addressed sooner rather than later. I see '-hard-float' has an issue
open

  https://github.com/rust-lang/rust/issues/117347

but I don't think I see issues open for the other ones.

-- 
Cheers,
Nathan

Re: [PATCH V17 0/7] Rust Support for powerpc

[Link Mauve]

Hi,

On Tue, Aug 04, 2026 at 01:22:17PM -0700, Nathan Chancellor wrote:
> On Tue, Aug 04, 2026 at 12:11:57PM +0200, Link Mauve wrote:
> > Hi,
> > 
[…]
> > 
> > I just tested those again in linux-next, with the Wii support series on
> > top, but now the kernel fails to build due to ARCH_WARN_ASM and
> > ARCH_WARN_REACHABLE not being defined on PowerPC:
> 
> I also see the following warnings (in addition to that error):
> 
>   warning: unknown and unstable feature specified for `-Ctarget-feature`: `mma`
>     |
>     = note: it is still passed through to the codegen backend, but use of this feature might be unsound and the behavior of this feature can change in the future
>     = help: consider filing a feature request
> 
>   warning: unstable feature specified for `-Ctarget-feature`: `vsx`
>     |
>     = note: this feature is not stably supported; its behavior can change in the future
> 
>   warning: unknown and unstable feature specified for `-Ctarget-feature`: `hard-float`
>     |
>     = note: it is still passed through to the codegen backend, but use of this feature might be unsound and the behavior of this feature can change in the future
>     = help: consider filing a feature request
> 
>   warning: unstable feature specified for `-Ctarget-feature`: `altivec`
>     |
>     = note: this feature is not stably supported; its behavior can change in the future

Those four are explicitly disabled in arch/powerpc/Makefile, but only
for CONFIG_PPC64, not for CONFIG_PPC…  Maybe they should, I’ve only
tested 32-bit on the Wii which has no altivec or vsx, but has hard
floats, and I’m not sure about mma.

Could you test this patch on your platform?  I’ll submit it properly if
it does fix those four warnings:
```
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 9385db478c59..8fba9310acfa 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -63,10 +63,10 @@ endif

 ifdef CONFIG_PPC64
 KBUILD_RUSTFLAGS       += --target=powerpc64le-unknown-linux-gnu
-KBUILD_RUSTFLAGS       += -Ctarget-feature=-mma,-vsx,-hard-float,-altivec
 else
 KBUILD_RUSTFLAGS       += --target=powerpc-unknown-linux-gnu
 endif
+KBUILD_RUSTFLAGS       += -Ctarget-feature=-mma,-vsx,-hard-float,-altivec

 ifdef CONFIG_CPU_LITTLE_ENDIAN
 KBUILD_CPPFLAGS        += -mlittle-endian
```

> 
>   clang diag: arch/powerpc/include/uapi/asm/ioctl.h:5:9: warning: '_IOC_SIZEBITS' macro redefined [-Wmacro-redefined]
>   clang diag: arch/powerpc/include/uapi/asm/ioctl.h:6:9: warning: '_IOC_DIRBITS' macro redefined [-Wmacro-redefined]
>   clang diag: arch/powerpc/include/uapi/asm/ioctl.h:8:9: warning: '_IOC_NONE' macro redefined [-Wmacro-redefined]
>   clang diag: arch/powerpc/include/uapi/asm/ioctl.h:10:9: warning: '_IOC_WRITE' macro redefined [-Wmacro-redefined]
>   warning: 4 warnings emitted

I have no idea about those.

> 
> when building this series in next-20260804 with rustc 1.97.1. I am not
> sure where the clang diagnostic warnings come from. I assume the target
> feature warnings are expected but it would be good to get those
> addressed sooner rather than later. I see '-hard-float' has an issue
> open
> 
>   https://github.com/rust-lang/rust/issues/117347

In the kernel we want to disallow all floats, unless there is a very
specific and cibled usecase.  This issue is about enabling them.

And no, warnings are never expected, you just tested on a platform
neither of us tested until now. :)

> 
> but I don't think I see issues open for the other ones.
> 
> -- 
> Cheers,
> Nathan

-- 
Link Mauve

Re: [PATCH V17 0/7] Rust Support for powerpc

[Mukesh Kumar Chaurasiya]

On Tue, Aug 04, 2026 at 01:22:17PM -0700, Nathan Chancellor wrote:
> On Tue, Aug 04, 2026 at 12:11:57PM +0200, Link Mauve wrote:
> > Hi,
> > 
> > On Mon, Aug 03, 2026 at 12:27:13PM +0530, Madhavan Srinivasan wrote:
> > > On Wed, 08 Jul 2026 13:54:47 +0530, Mukesh Kumar Chaurasiya (IBM) wrote:
> > > > Enable experimental rust support for ppc64le and ppc32be. The patch for
> > > > ppc32 has been provided by Link Mauve[1] and ppc64le support[2] has been
> > > > merged over it. ppc32 needs some toolchain fixes mentioned in the patch
> > > > `rust: Add PowerPC support` and the discussion for that is done here[1].
> > > > 
> > > > This has been tested on
> > > > - powernv9 hardware
> > > > - pseries P11 hardware
> > > > - pseries(9, 10) qemu
> > > > - powernv(9, 10) qemu
> > > > - rustdoc on x86 and powerpc64le
> > > > - rusttest on x86 and powerpc64le
> > > > 
> > > > [...]
> > > 
> > > Applied to powerpc/next.
> > > 
> > > [1/7] rust: Fix "multiple candidates for rmeta dependency core" error
> > >       https://git.kernel.org/powerpc/c/00cdfd072c709c608606461d7d44d4613119bfa9
> > > [2/7] dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is disabled
> > >       https://git.kernel.org/powerpc/c/be809b60cbb61aab96179f44ac3670242ae72996
> > > [3/7] powerpc/jump_label: adjust inline asm to be consistent
> > >       https://git.kernel.org/powerpc/c/13244c0a40139fe66c4c5c5655f4d732a6002957
> > > [4/7] rust/powerpc: Set min rustc version for powerpc
> > >       https://git.kernel.org/powerpc/c/e299147cdc8e19c6421a6b7863dc82a35b09d967
> > > [5/7] rust: Make __udivdi3() and __umoddi3() panic
> > >       https://git.kernel.org/powerpc/c/c93c194e4ee71a734986fd99a8b1ec9fbb7a9b8b
> > > [6/7] rust: Add PowerPC support
> > >       https://git.kernel.org/powerpc/c/73b741adb264967093ef4eb59905618a7e0d0de0
> > > [7/7] powerpc: Enable Rust for ppc64le
> > >       https://git.kernel.org/powerpc/c/bc87cbdb952e9223616b839d64bdb4723aa2ed1d
> > > 
> > > cheers
> > > 
> > 
> > I just tested those again in linux-next, with the Wii support series on
> > top, but now the kernel fails to build due to ARCH_WARN_ASM and
> > ARCH_WARN_REACHABLE not being defined on PowerPC:
> 
> I also see the following warnings (in addition to that error):
> 
>   warning: unknown and unstable feature specified for `-Ctarget-feature`: `mma`
>     |
>     = note: it is still passed through to the codegen backend, but use of this feature might be unsound and the behavior of this feature can change in the future
>     = help: consider filing a feature request
> 
>   warning: unstable feature specified for `-Ctarget-feature`: `vsx`
>     |
>     = note: this feature is not stably supported; its behavior can change in the future
> 
>   warning: unknown and unstable feature specified for `-Ctarget-feature`: `hard-float`
>     |
>     = note: it is still passed through to the codegen backend, but use of this feature might be unsound and the behavior of this feature can change in the future
>     = help: consider filing a feature request
> 
>   warning: unstable feature specified for `-Ctarget-feature`: `altivec`
>     |
>     = note: this feature is not stably supported; its behavior can change in the future
> 
Hey Nathan,

For these i'll raise issues.
>   clang diag: arch/powerpc/include/uapi/asm/ioctl.h:5:9: warning: '_IOC_SIZEBITS' macro redefined [-Wmacro-redefined]
>   clang diag: arch/powerpc/include/uapi/asm/ioctl.h:6:9: warning: '_IOC_DIRBITS' macro redefined [-Wmacro-redefined]
>   clang diag: arch/powerpc/include/uapi/asm/ioctl.h:8:9: warning: '_IOC_NONE' macro redefined [-Wmacro-redefined]
>   clang diag: arch/powerpc/include/uapi/asm/ioctl.h:10:9: warning: '_IOC_WRITE' macro redefined [-Wmacro-redefined]
>   warning: 4 warnings emitted
> 
For these warnings below diff should fix it. I'll send out a patch soon.

diff --git a/rust/uapi/uapi_helper.h b/rust/uapi/uapi_helper.h
index 06d7d1a2e8da..acec2d2fede7 100644
--- a/rust/uapi/uapi_helper.h
+++ b/rust/uapi/uapi_helper.h
@@ -6,7 +6,7 @@
  * Sorted alphabetically.
  */
 
-#include <uapi/asm-generic/ioctl.h>
+#include <uapi/linux/ioctl.h>
 #include <uapi/drm/drm.h>
 #include <uapi/drm/nova_drm.h>
 #include <uapi/drm/panthor_drm.h>

Regards,
Mukesh

> when building this series in next-20260804 with rustc 1.97.1. I am not
> sure where the clang diagnostic warnings come from. I assume the target
> feature warnings are expected but it would be good to get those
> addressed sooner rather than later. I see '-hard-float' has an issue
> open
> 
>   https://github.com/rust-lang/rust/issues/117347
> 
> but I don't think I see issues open for the other ones.
> 
> -- 
> Cheers,
> Nathan

Re: [PATCH V17 0/7] Rust Support for powerpc

[Mukesh Kumar Chaurasiya]

On Wed, Aug 05, 2026 at 05:40:42PM +0530, Mukesh Kumar Chaurasiya wrote:
> On Tue, Aug 04, 2026 at 01:22:17PM -0700, Nathan Chancellor wrote:
> > On Tue, Aug 04, 2026 at 12:11:57PM +0200, Link Mauve wrote:
> > > Hi,
> > > 
> > > On Mon, Aug 03, 2026 at 12:27:13PM +0530, Madhavan Srinivasan wrote:
> > > > On Wed, 08 Jul 2026 13:54:47 +0530, Mukesh Kumar Chaurasiya (IBM) wrote:
> > > > > Enable experimental rust support for ppc64le and ppc32be. The patch for
> > > > > ppc32 has been provided by Link Mauve[1] and ppc64le support[2] has been
> > > > > merged over it. ppc32 needs some toolchain fixes mentioned in the patch
> > > > > `rust: Add PowerPC support` and the discussion for that is done here[1].
> > > > > 
> > > > > This has been tested on
> > > > > - powernv9 hardware
> > > > > - pseries P11 hardware
> > > > > - pseries(9, 10) qemu
> > > > > - powernv(9, 10) qemu
> > > > > - rustdoc on x86 and powerpc64le
> > > > > - rusttest on x86 and powerpc64le
> > > > > 
> > > > > [...]
> > > > 
> > > > Applied to powerpc/next.
> > > > 
> > > > [1/7] rust: Fix "multiple candidates for rmeta dependency core" error
> > > >       https://git.kernel.org/powerpc/c/00cdfd072c709c608606461d7d44d4613119bfa9
> > > > [2/7] dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is disabled
> > > >       https://git.kernel.org/powerpc/c/be809b60cbb61aab96179f44ac3670242ae72996
> > > > [3/7] powerpc/jump_label: adjust inline asm to be consistent
> > > >       https://git.kernel.org/powerpc/c/13244c0a40139fe66c4c5c5655f4d732a6002957
> > > > [4/7] rust/powerpc: Set min rustc version for powerpc
> > > >       https://git.kernel.org/powerpc/c/e299147cdc8e19c6421a6b7863dc82a35b09d967
> > > > [5/7] rust: Make __udivdi3() and __umoddi3() panic
> > > >       https://git.kernel.org/powerpc/c/c93c194e4ee71a734986fd99a8b1ec9fbb7a9b8b
> > > > [6/7] rust: Add PowerPC support
> > > >       https://git.kernel.org/powerpc/c/73b741adb264967093ef4eb59905618a7e0d0de0
> > > > [7/7] powerpc: Enable Rust for ppc64le
> > > >       https://git.kernel.org/powerpc/c/bc87cbdb952e9223616b839d64bdb4723aa2ed1d
> > > > 
> > > > cheers
> > > > 
> > > 
> > > I just tested those again in linux-next, with the Wii support series on
> > > top, but now the kernel fails to build due to ARCH_WARN_ASM and
> > > ARCH_WARN_REACHABLE not being defined on PowerPC:
> > 
> > I also see the following warnings (in addition to that error):
> > 
> >   warning: unknown and unstable feature specified for `-Ctarget-feature`: `mma`
> >     |
> >     = note: it is still passed through to the codegen backend, but use of this feature might be unsound and the behavior of this feature can change in the future
> >     = help: consider filing a feature request
> > 
> >   warning: unstable feature specified for `-Ctarget-feature`: `vsx`
> >     |
> >     = note: this feature is not stably supported; its behavior can change in the future
> > 
> >   warning: unknown and unstable feature specified for `-Ctarget-feature`: `hard-float`
> >     |
> >     = note: it is still passed through to the codegen backend, but use of this feature might be unsound and the behavior of this feature can change in the future
> >     = help: consider filing a feature request
> > 
> >   warning: unstable feature specified for `-Ctarget-feature`: `altivec`
> >     |
> >     = note: this feature is not stably supported; its behavior can change in the future
> > 
> Hey Nathan,
> 
> For these i'll raise issues.
Here's bug on rustc for the same.
https://github.com/rust-lang/rust/issues/160561

Regards,
Mukesh
> >   clang diag: arch/powerpc/include/uapi/asm/ioctl.h:5:9: warning: '_IOC_SIZEBITS' macro redefined [-Wmacro-redefined]
> >   clang diag: arch/powerpc/include/uapi/asm/ioctl.h:6:9: warning: '_IOC_DIRBITS' macro redefined [-Wmacro-redefined]
> >   clang diag: arch/powerpc/include/uapi/asm/ioctl.h:8:9: warning: '_IOC_NONE' macro redefined [-Wmacro-redefined]
> >   clang diag: arch/powerpc/include/uapi/asm/ioctl.h:10:9: warning: '_IOC_WRITE' macro redefined [-Wmacro-redefined]
> >   warning: 4 warnings emitted
> > 
> For these warnings below diff should fix it. I'll send out a patch soon.
> 
> diff --git a/rust/uapi/uapi_helper.h b/rust/uapi/uapi_helper.h
> index 06d7d1a2e8da..acec2d2fede7 100644
> --- a/rust/uapi/uapi_helper.h
> +++ b/rust/uapi/uapi_helper.h
> @@ -6,7 +6,7 @@
>   * Sorted alphabetically.
>   */
>  
> -#include <uapi/asm-generic/ioctl.h>
> +#include <uapi/linux/ioctl.h>
>  #include <uapi/drm/drm.h>
>  #include <uapi/drm/nova_drm.h>
>  #include <uapi/drm/panthor_drm.h>
> 
> Regards,
> Mukesh
> 
> > when building this series in next-20260804 with rustc 1.97.1. I am not
> > sure where the clang diagnostic warnings come from. I assume the target
> > feature warnings are expected but it would be good to get those
> > addressed sooner rather than later. I see '-hard-float' has an issue
> > open
> > 
> >   https://github.com/rust-lang/rust/issues/117347
> > 
> > but I don't think I see issues open for the other ones.
> > 
> > -- 
> > Cheers,
> > Nathan

Re: [PATCH V17 0/7] Rust Support for powerpc

[Link Mauve]

On Wed, Aug 05, 2026 at 05:40:42PM +0530, Mukesh Kumar Chaurasiya wrote:
[…]
> For these warnings below diff should fix it. I'll send out a patch soon.
> 
> diff --git a/rust/uapi/uapi_helper.h b/rust/uapi/uapi_helper.h
> index 06d7d1a2e8da..acec2d2fede7 100644
> --- a/rust/uapi/uapi_helper.h
> +++ b/rust/uapi/uapi_helper.h
> @@ -6,7 +6,7 @@
>   * Sorted alphabetically.
>   */
>  
> -#include <uapi/asm-generic/ioctl.h>
> +#include <uapi/linux/ioctl.h>
>  #include <uapi/drm/drm.h>
>  #include <uapi/drm/nova_drm.h>
>  #include <uapi/drm/panthor_drm.h>

You likely want to keep the alphabetical sort here.

> 
> Regards,
> Mukesh
> 
> > when building this series in next-20260804 with rustc 1.97.1. I am not
> > sure where the clang diagnostic warnings come from. I assume the target
> > feature warnings are expected but it would be good to get those
> > addressed sooner rather than later. I see '-hard-float' has an issue
> > open
> > 
> >   https://github.com/rust-lang/rust/issues/117347
> > 
> > but I don't think I see issues open for the other ones.
> > 
> > -- 
> > Cheers,
> > Nathan

-- 
Link Mauve

Re: [PATCH V17 0/7] Rust Support for powerpc

[Mukesh Kumar Chaurasiya]

On Wed, Aug 05, 2026 at 02:21:59PM +0200, Link Mauve wrote:
> On Wed, Aug 05, 2026 at 05:40:42PM +0530, Mukesh Kumar Chaurasiya wrote:
> […]
> > For these warnings below diff should fix it. I'll send out a patch soon.
> > 
> > diff --git a/rust/uapi/uapi_helper.h b/rust/uapi/uapi_helper.h
> > index 06d7d1a2e8da..acec2d2fede7 100644
> > --- a/rust/uapi/uapi_helper.h
> > +++ b/rust/uapi/uapi_helper.h
> > @@ -6,7 +6,7 @@
> >   * Sorted alphabetically.
> >   */
> >  
> > -#include <uapi/asm-generic/ioctl.h>
> > +#include <uapi/linux/ioctl.h>
> >  #include <uapi/drm/drm.h>
> >  #include <uapi/drm/nova_drm.h>
> >  #include <uapi/drm/panthor_drm.h>
> 
> You likely want to keep the alphabetical sort here.
> 
Yeah, Thanks,

I'll take care of this in the patch.

Regards,
Mukesh

[...]

Re: [PATCH V17 0/7] Rust Support for powerpc

[Mukesh Kumar Chaurasiya]

On Tue, Aug 04, 2026 at 10:40:35PM +0900, FUJITA Tomonori wrote:
> On Tue, 4 Aug 2026 12:11:57 +0200
> Link Mauve <linkmauve@linkmauve.fr> wrote:
> 
> > Hi,
> > 
> > On Mon, Aug 03, 2026 at 12:27:13PM +0530, Madhavan Srinivasan wrote:
> >> On Wed, 08 Jul 2026 13:54:47 +0530, Mukesh Kumar Chaurasiya (IBM) wrote:
> >> > Enable experimental rust support for ppc64le and ppc32be. The patch for
> >> > ppc32 has been provided by Link Mauve[1] and ppc64le support[2] has been
> >> > merged over it. ppc32 needs some toolchain fixes mentioned in the patch
> >> > `rust: Add PowerPC support` and the discussion for that is done here[1].
> >> > 
> >> > This has been tested on
> >> > - powernv9 hardware
> >> > - pseries P11 hardware
> >> > - pseries(9, 10) qemu
> >> > - powernv(9, 10) qemu
> >> > - rustdoc on x86 and powerpc64le
> >> > - rusttest on x86 and powerpc64le
> >> > 
> >> > [...]
> >> 
> >> Applied to powerpc/next.
> >> 
> >> [1/7] rust: Fix "multiple candidates for rmeta dependency core" error
> >>       https://git.kernel.org/powerpc/c/00cdfd072c709c608606461d7d44d4613119bfa9
> >> [2/7] dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is disabled
> >>       https://git.kernel.org/powerpc/c/be809b60cbb61aab96179f44ac3670242ae72996
> >> [3/7] powerpc/jump_label: adjust inline asm to be consistent
> >>       https://git.kernel.org/powerpc/c/13244c0a40139fe66c4c5c5655f4d732a6002957
> >> [4/7] rust/powerpc: Set min rustc version for powerpc
> >>       https://git.kernel.org/powerpc/c/e299147cdc8e19c6421a6b7863dc82a35b09d967
> >> [5/7] rust: Make __udivdi3() and __umoddi3() panic
> >>       https://git.kernel.org/powerpc/c/c93c194e4ee71a734986fd99a8b1ec9fbb7a9b8b
> >> [6/7] rust: Add PowerPC support
> >>       https://git.kernel.org/powerpc/c/73b741adb264967093ef4eb59905618a7e0d0de0
> >> [7/7] powerpc: Enable Rust for ppc64le
> >>       https://git.kernel.org/powerpc/c/bc87cbdb952e9223616b839d64bdb4723aa2ed1d
> >> 
> >> cheers
> >> 
> > 
> > I just tested those again in linux-next, with the Wii support series on
> > top, but now the kernel fails to build due to ARCH_WARN_ASM and
> > ARCH_WARN_REACHABLE not being defined on PowerPC:
> > ```
> > error: no rules expected `ARCH_WARN_ASM`
> >    --> /home/linkmauve/dev/linux/wii/rust/kernel/generated_arch_warn_asm.rs:1:28
> >     |
> >   1 | ::kernel::concat_literals!(ARCH_WARN_ASM("{file}", "{line}", "{flags}", "{size}"))
> >     |                            ^^^^^^^^^^^^^ no rules expected this token in macro call
> >     |
> >    ::: ../rust/kernel/lib.rs:279:1
> >     |
> > 279 | macro_rules! concat_literals {
> >     | ---------------------------- when calling this macro
> >     |
> >     = note: while trying to match sequence start
> > 
> > error: no rules expected `ARCH_WARN_REACHABLE`
> >    --> /home/linkmauve/dev/linux/wii/rust/kernel/generated_arch_reachable_asm.rs:1:28
> >     |
> >   1 | ::kernel::concat_literals!(ARCH_WARN_REACHABLE)
> >     |                            ^^^^^^^^^^^^^^^^^^^ no rules expected this token in macro call
> >     |
> >    ::: ../rust/kernel/lib.rs:279:1
> >     |
> > 279 | macro_rules! concat_literals {
> >     | ---------------------------- when calling this macro
> >     |
> >     = note: while trying to match sequence start
> > 
> > error: aborting due to 2 previous errors
> > ```
> > 
> > This is in addition to the bindings::kvfree_call_rcu() call, but that
> > one is already being handled in a different thread.
> 
> Looks like powerpc needs something like the followings:
> 
> diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h
> index 0db48977c70c..8aba39e0cf26 100644
> --- a/arch/powerpc/include/asm/bug.h
> +++ b/arch/powerpc/include/asm/bug.h
> @@ -32,34 +32,38 @@
>  #endif /* verbose */
>  
>  #else /* !__ASSEMBLER__ */
> -/* _EMIT_BUG_ENTRY expects args %0,%1,%2,%3 to be FILE, LINE, flags and
> -   sizeof(struct bug_entry), respectively */
>  #ifdef CONFIG_DEBUG_BUGVERBOSE
> -#define _EMIT_BUG_ENTRY				\
> +#define _EMIT_BUG_ENTRY(file, line, flags)	\
>  	".section __bug_table,\"aw\"\n"		\
>  	"2:	.4byte 1b - .\n"		\
> -	"	.4byte %0 - .\n"		\
> -	"	.short %1, %2\n"		\
> -	".org 2b+%3\n"				\
> -	".previous\n"
> +	"	.4byte " file " - .\n"		\
> +	"	.short " line ", " flags "\n"
>  #else
> -#define _EMIT_BUG_ENTRY				\
> +#define _EMIT_BUG_ENTRY(file, line, flags)	\
>  	".section __bug_table,\"aw\"\n"		\
>  	"2:	.4byte 1b - .\n"		\
> -	"	.short %2\n"			\
> -	".org 2b+%3\n"				\
> -	".previous\n"
> +	"	.short " flags "\n"
>  #endif
>  
>  #define BUG_ENTRY(cond_str, insn, flags, ...)		\
>  	__asm__ __volatile__(				\
>  		"1:	" insn "\n"			\
> -		_EMIT_BUG_ENTRY				\
> +		_EMIT_BUG_ENTRY("%0", "%1", "%2")	\
> +		".org 2b+%3\n"				\
> +		".previous\n"				\
>  		: : "i" (WARN_CONDITION_STR(cond_str) __FILE__), "i" (__LINE__),	\
>  		  "i" (flags),				\
>  		  "i" (sizeof(struct bug_entry)),	\
>  		  ##__VA_ARGS__)
>  
> +#define ARCH_WARN_ASM(file, line, flags, size)		\
> +		"1:	twi 31, 0, 0\n"			\
> +		_EMIT_BUG_ENTRY(file, line, flags)	\
> +		".org 2b+" size "\n"			\
> +		".previous\n"
> +
> +#define ARCH_WARN_REACHABLE
> +
>  /*
>   * BUG_ON() and WARN_ON() do their best to cooperate with compile-time
>   * optimisations. However depending on the complexity of the condition

Yeah, This makes sense.

I'll work on this and send out a fix soon.

Thanks and Regards,
Mukesh

Re: [PATCH V17 0/7] Rust Support for powerpc

[Christophe Leroy (CS GROUP)]

Le 04/08/2026 à 15:40, FUJITA Tomonori a écrit :
> [Vous ne recevez pas souvent de courriers de tomo@flapping.org. D?couvrez pourquoi ceci est important ? https://aka.ms/LearnAboutSenderIdentification ]
> 
> On Tue, 4 Aug 2026 12:11:57 +0200
> Link Mauve <linkmauve@linkmauve.fr> wrote:
> 
>> Hi,
>>
>> On Mon, Aug 03, 2026 at 12:27:13PM +0530, Madhavan Srinivasan wrote:
>>> On Wed, 08 Jul 2026 13:54:47 +0530, Mukesh Kumar Chaurasiya (IBM) wrote:
>>>> Enable experimental rust support for ppc64le and ppc32be. The patch for
>>>> ppc32 has been provided by Link Mauve[1] and ppc64le support[2] has been
>>>> merged over it. ppc32 needs some toolchain fixes mentioned in the patch
>>>> `rust: Add PowerPC support` and the discussion for that is done here[1].
>>>>
>>>> This has been tested on
>>>> - powernv9 hardware
>>>> - pseries P11 hardware
>>>> - pseries(9, 10) qemu
>>>> - powernv(9, 10) qemu
>>>> - rustdoc on x86 and powerpc64le
>>>> - rusttest on x86 and powerpc64le
>>>>
>>>> [...]
>>>
>>> Applied to powerpc/next.
>>>
>>> [1/7] rust: Fix "multiple candidates for rmeta dependency core" error
>>>        https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2F00cdfd072c709c608606461d7d44d4613119bfa9&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617198585%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=4qQe1qS37TGv6%2Bf9H56kWVqMYSAHsWiDx5oz8WHZ8%2Bg%3D&reserved=0
>>> [2/7] dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is disabled
>>>        https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2Fbe809b60cbb61aab96179f44ac3670242ae72996&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617235654%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=cw2l64D3ah%2FM3pxFmvMpUnNmcqcSvN3RFoDiYAIR76g%3D&reserved=0
>>> [3/7] powerpc/jump_label: adjust inline asm to be consistent
>>>        https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2F13244c0a40139fe66c4c5c5655f4d732a6002957&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617259593%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=xNvcH9k5RA5ktJupn90VdDuwx4YBvezuDcapqKlYfjs%3D&reserved=0
>>> [4/7] rust/powerpc: Set min rustc version for powerpc
>>>        https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2Fe299147cdc8e19c6421a6b7863dc82a35b09d967&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617280683%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=uNZA7AulROQGv%2B2l4M%2FqC5W4ncWktRoSRRp8eaF%2FcCY%3D&reserved=0
>>> [5/7] rust: Make __udivdi3() and __umoddi3() panic
>>>        https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2Fc93c194e4ee71a734986fd99a8b1ec9fbb7a9b8b&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617303292%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=znZPWXM7k5FpRlekIyUN1bHzmMyk1YESR56WsiwBuMA%3D&reserved=0
>>> [6/7] rust: Add PowerPC support
>>>        https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2F73b741adb264967093ef4eb59905618a7e0d0de0&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617326590%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=aFHGhd7RX%2Ft5%2BMjqt6pBmIKPKAKmFEQndKP1F%2F8HSxk%3D&reserved=0
>>> [7/7] powerpc: Enable Rust for ppc64le
>>>        https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2Fbc87cbdb952e9223616b839d64bdb4723aa2ed1d&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617346994%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=ITEFv9C1CSUVLqJNe5Y8sStUE3KoOVYVzSzbP0qis74%3D&reserved=0
>>>
>>> cheers
>>>
>>
>> I just tested those again in linux-next, with the Wii support series on
>> top, but now the kernel fails to build due to ARCH_WARN_ASM and
>> ARCH_WARN_REACHABLE not being defined on PowerPC:
>> ```
>> error: no rules expected `ARCH_WARN_ASM`
>>     --> /home/linkmauve/dev/linux/wii/rust/kernel/generated_arch_warn_asm.rs:1:28
>>      |
>>    1 | ::kernel::concat_literals!(ARCH_WARN_ASM("{file}", "{line}", "{flags}", "{size}"))
>>      |                            ^^^^^^^^^^^^^ no rules expected this token in macro call
>>      |
>>     ::: ../rust/kernel/lib.rs:279:1
>>      |
>> 279 | macro_rules! concat_literals {
>>      | ---------------------------- when calling this macro
>>      |
>>      = note: while trying to match sequence start
>>
>> error: no rules expected `ARCH_WARN_REACHABLE`
>>     --> /home/linkmauve/dev/linux/wii/rust/kernel/generated_arch_reachable_asm.rs:1:28
>>      |
>>    1 | ::kernel::concat_literals!(ARCH_WARN_REACHABLE)
>>      |                            ^^^^^^^^^^^^^^^^^^^ no rules expected this token in macro call
>>      |
>>     ::: ../rust/kernel/lib.rs:279:1
>>      |
>> 279 | macro_rules! concat_literals {
>>      | ---------------------------- when calling this macro
>>      |
>>      = note: while trying to match sequence start
>>
>> error: aborting due to 2 previous errors
>> ```
>>
>> This is in addition to the bindings::kvfree_call_rcu() call, but that
>> one is already being handled in a different thread.
> 
> Looks like powerpc needs something like the followings:
> 
> diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h
> index 0db48977c70c..8aba39e0cf26 100644
> --- a/arch/powerpc/include/asm/bug.h
> +++ b/arch/powerpc/include/asm/bug.h
> @@ -32,34 +32,38 @@
>   #endif /* verbose */
> 
>   #else /* !__ASSEMBLER__ */
> -/* _EMIT_BUG_ENTRY expects args %0,%1,%2,%3 to be FILE, LINE, flags and
> -   sizeof(struct bug_entry), respectively */
>   #ifdef CONFIG_DEBUG_BUGVERBOSE
> -#define _EMIT_BUG_ENTRY                                \
> +#define _EMIT_BUG_ENTRY(file, line, flags)     \
>          ".section __bug_table,\"aw\"\n"         \
>          "2:     .4byte 1b - .\n"                \
> -       "       .4byte %0 - .\n"                \
> -       "       .short %1, %2\n"                \
> -       ".org 2b+%3\n"                          \
> -       ".previous\n"
> +       "       .4byte " file " - .\n"          \
> +       "       .short " line ", " flags "\n"
>   #else
> -#define _EMIT_BUG_ENTRY                                \
> +#define _EMIT_BUG_ENTRY(file, line, flags)     \
>          ".section __bug_table,\"aw\"\n"         \
>          "2:     .4byte 1b - .\n"                \
> -       "       .short %2\n"                    \
> -       ".org 2b+%3\n"                          \
> -       ".previous\n"
> +       "       .short " flags "\n"
>   #endif
> 
>   #define BUG_ENTRY(cond_str, insn, flags, ...)          \
>          __asm__ __volatile__(                           \
>                  "1:     " insn "\n"                     \
> -               _EMIT_BUG_ENTRY                         \
> +               _EMIT_BUG_ENTRY("%0", "%1", "%2")       \
> +               ".org 2b+%3\n"                          \
> +               ".previous\n"                           \
>                  : : "i" (WARN_CONDITION_STR(cond_str) __FILE__), "i" (__LINE__),        \
>                    "i" (flags),                          \
>                    "i" (sizeof(struct bug_entry)),       \
>                    ##__VA_ARGS__)
> 
> +#define ARCH_WARN_ASM(file, line, flags, size)         \
> +               "1:     twi 31, 0, 0\n"                 \
> +               _EMIT_BUG_ENTRY(file, line, flags)      \
> +               ".org 2b+" size "\n"                    \
> +               ".previous\n"

Will this build ? Isn't ARCH_WARN_ASM() for use in ASM .S files ? 
_EMIT_BUG_ENTRY is defined in a !__ASSEMBLER__ ifdef.

powerpc already has EMIT_BUG_ENTRY macro for ASM for that. Why do you 
need to modify _EMIT_BUG_ENTRY and BUG_ENTRY() which are for C only (in 
a #ifdef !__ASSEMBLER__) ?

https://elixir.bootlin.com/linux/v7.2-rc5/source/arch/powerpc/include/asm/bug.h#L10

Christophe

Re: [PATCH V17 0/7] Rust Support for powerpc

[FUJITA Tomonori]

On Wed, 5 Aug 2026 14:56:41 +0200
"Christophe Leroy (CS GROUP)" <chleroy@kernel.org> wrote:

> 
> 
> Le 04/08/2026 à 15:40, FUJITA Tomonori a écrit :
>> [Vous ne recevez pas souvent de courriers de
>> tomo@flapping.org. D?couvrez pourquoi ceci est important ?
>> https://aka.ms/LearnAboutSenderIdentification ]
>> On Tue, 4 Aug 2026 12:11:57 +0200
>> Link Mauve <linkmauve@linkmauve.fr> wrote:
>> 
>>> Hi,
>>>
>>> On Mon, Aug 03, 2026 at 12:27:13PM +0530, Madhavan Srinivasan wrote:
>>>> On Wed, 08 Jul 2026 13:54:47 +0530, Mukesh Kumar Chaurasiya (IBM)
>>>> wrote:
>>>>> Enable experimental rust support for ppc64le and ppc32be. The patch
>>>>> for
>>>>> ppc32 has been provided by Link Mauve[1] and ppc64le support[2] has
>>>>> been
>>>>> merged over it. ppc32 needs some toolchain fixes mentioned in the
>>>>> patch
>>>>> `rust: Add PowerPC support` and the discussion for that is done
>>>>> here[1].
>>>>>
>>>>> This has been tested on
>>>>> - powernv9 hardware
>>>>> - pseries P11 hardware
>>>>> - pseries(9, 10) qemu
>>>>> - powernv(9, 10) qemu
>>>>> - rustdoc on x86 and powerpc64le
>>>>> - rusttest on x86 and powerpc64le
>>>>>
>>>>> [...]
>>>>
>>>> Applied to powerpc/next.
>>>>
>>>> [1/7] rust: Fix "multiple candidates for rmeta dependency core" error
>>>>        https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2F00cdfd072c709c608606461d7d44d4613119bfa9&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617198585%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=4qQe1qS37TGv6%2Bf9H56kWVqMYSAHsWiDx5oz8WHZ8%2Bg%3D&reserved=0
>>>> [2/7] dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is
>>>> disabled
>>>>        https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2Fbe809b60cbb61aab96179f44ac3670242ae72996&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617235654%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=cw2l64D3ah%2FM3pxFmvMpUnNmcqcSvN3RFoDiYAIR76g%3D&reserved=0
>>>> [3/7] powerpc/jump_label: adjust inline asm to be consistent
>>>>        https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2F13244c0a40139fe66c4c5c5655f4d732a6002957&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617259593%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=xNvcH9k5RA5ktJupn90VdDuwx4YBvezuDcapqKlYfjs%3D&reserved=0
>>>> [4/7] rust/powerpc: Set min rustc version for powerpc
>>>>        https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2Fe299147cdc8e19c6421a6b7863dc82a35b09d967&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617280683%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=uNZA7AulROQGv%2B2l4M%2FqC5W4ncWktRoSRRp8eaF%2FcCY%3D&reserved=0
>>>> [5/7] rust: Make __udivdi3() and __umoddi3() panic
>>>>        https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2Fc93c194e4ee71a734986fd99a8b1ec9fbb7a9b8b&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617303292%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=znZPWXM7k5FpRlekIyUN1bHzmMyk1YESR56WsiwBuMA%3D&reserved=0
>>>> [6/7] rust: Add PowerPC support
>>>>        https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2F73b741adb264967093ef4eb59905618a7e0d0de0&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617326590%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=aFHGhd7RX%2Ft5%2BMjqt6pBmIKPKAKmFEQndKP1F%2F8HSxk%3D&reserved=0
>>>> [7/7] powerpc: Enable Rust for ppc64le
>>>>        https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2Fbc87cbdb952e9223616b839d64bdb4723aa2ed1d&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617346994%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=ITEFv9C1CSUVLqJNe5Y8sStUE3KoOVYVzSzbP0qis74%3D&reserved=0
>>>>
>>>> cheers
>>>>
>>>
>>> I just tested those again in linux-next, with the Wii support series
>>> on
>>> top, but now the kernel fails to build due to ARCH_WARN_ASM and
>>> ARCH_WARN_REACHABLE not being defined on PowerPC:
>>> ```
>>> error: no rules expected `ARCH_WARN_ASM`
>>>     --> /home/linkmauve/dev/linux/wii/rust/kernel/generated_arch_warn_asm.rs:1:28
>>>      |
>>>    1 | ::kernel::concat_literals!(ARCH_WARN_ASM("{file}", "{line}",
>>>    "{flags}", "{size}"))
>>>      |                            ^^^^^^^^^^^^^ no rules expected this token in macro call
>>>      |
>>>     ::: ../rust/kernel/lib.rs:279:1
>>>      |
>>> 279 | macro_rules! concat_literals {
>>>      | ---------------------------- when calling this macro
>>>      |
>>>      = note: while trying to match sequence start
>>>
>>> error: no rules expected `ARCH_WARN_REACHABLE`
>>>     --> /home/linkmauve/dev/linux/wii/rust/kernel/generated_arch_reachable_asm.rs:1:28
>>>      |
>>>    1 | ::kernel::concat_literals!(ARCH_WARN_REACHABLE)
>>>      |                            ^^^^^^^^^^^^^^^^^^^ no rules expected this token in macro call
>>>      |
>>>     ::: ../rust/kernel/lib.rs:279:1
>>>      |
>>> 279 | macro_rules! concat_literals {
>>>      | ---------------------------- when calling this macro
>>>      |
>>>      = note: while trying to match sequence start
>>>
>>> error: aborting due to 2 previous errors
>>> ```
>>>
>>> This is in addition to the bindings::kvfree_call_rcu() call, but that
>>> one is already being handled in a different thread.
>> Looks like powerpc needs something like the followings:
>> diff --git a/arch/powerpc/include/asm/bug.h
>> b/arch/powerpc/include/asm/bug.h
>> index 0db48977c70c..8aba39e0cf26 100644
>> --- a/arch/powerpc/include/asm/bug.h
>> +++ b/arch/powerpc/include/asm/bug.h
>> @@ -32,34 +32,38 @@
>>   #endif /* verbose */
>>   #else /* !__ASSEMBLER__ */
>> -/* _EMIT_BUG_ENTRY expects args %0,%1,%2,%3 to be FILE, LINE, flags
>> -and
>> -   sizeof(struct bug_entry), respectively */
>>   #ifdef CONFIG_DEBUG_BUGVERBOSE
>> -#define _EMIT_BUG_ENTRY                                \
>> +#define _EMIT_BUG_ENTRY(file, line, flags)     \
>>          ".section __bug_table,\"aw\"\n"         \
>>          "2:     .4byte 1b - .\n"                \
>> -       "       .4byte %0 - .\n"                \
>> -       "       .short %1, %2\n"                \
>> -       ".org 2b+%3\n"                          \
>> -       ".previous\n"
>> +       "       .4byte " file " - .\n"          \
>> +       "       .short " line ", " flags "\n"
>>   #else
>> -#define _EMIT_BUG_ENTRY                                \
>> +#define _EMIT_BUG_ENTRY(file, line, flags)     \
>>          ".section __bug_table,\"aw\"\n"         \
>>          "2:     .4byte 1b - .\n"                \
>> -       "       .short %2\n"                    \
>> -       ".org 2b+%3\n"                          \
>> -       ".previous\n"
>> +       "       .short " flags "\n"
>>   #endif
>>   #define BUG_ENTRY(cond_str, insn, flags, ...)          \
>>          __asm__ __volatile__(                           \
>>                  "1:     " insn "\n"                     \
>> -               _EMIT_BUG_ENTRY                         \
>> +               _EMIT_BUG_ENTRY("%0", "%1", "%2")       \
>> +               ".org 2b+%3\n"                          \
>> +               ".previous\n"                           \
>>                  : : "i" (WARN_CONDITION_STR(cond_str) __FILE__), "i" (__LINE__), \
>>                    "i" (flags),                          \
>>                    "i" (sizeof(struct bug_entry)),       \
>>                    ##__VA_ARGS__)
>> +#define ARCH_WARN_ASM(file, line, flags, size)         \
>> +               "1:     twi 31, 0, 0\n"                 \
>> +               _EMIT_BUG_ENTRY(file, line, flags)      \
>> +               ".org 2b+" size "\n"                    \
>> +               ".previous\n"
> 
> Will this build ? Isn't ARCH_WARN_ASM() for use in ASM .S files ?

No. It's used by Rust code; the C preprocessor uses ARCH_WARN_ASM() to
generate the code for Rust inline assembly.