[v2] Rust support for powerpc

[PATCH V2 1/3] powerpc/jump_label: adjust inline asm to be consistent

Posted by Mukesh Kumar Chaurasiya (IBM) 3 days, 12 hours ago

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")'

Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
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..a6b211502bfe 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;
-- 
2.52.0

Re: [PATCH V2 1/3] powerpc/jump_label: adjust inline asm to be consistent

Posted by Alice Ryhl 3 days ago

On Thu, Feb 05, 2026 at 02:31:23AM +0530, Mukesh Kumar Chaurasiya (IBM) wrote:
> 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")'
> 
> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
> Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>

Reviewed-by: Alice Ryhl <aliceryhl@google.com>

Re: [PATCH V2 1/3] powerpc/jump_label: adjust inline asm to be consistent

Posted by Christophe Leroy (CS GROUP) 3 days, 1 hour ago


Le 04/02/2026 à 22:01, Mukesh Kumar Chaurasiya (IBM) a écrit :
> [Vous ne recevez pas souvent de courriers de mkchauras@gmail.com. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ]
> 
> 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")'
> 
> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
> Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>

Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>

> ---
>   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..a6b211502bfe 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;
> --
> 2.52.0
>