Messages in this thread Patch in this message | | | From | Masahiro Yamada <> | Subject | [PATCH v3 10/12] linux/linkage: add ASM() macro to reduce duplication between C/ASM code | Date | Tue, 18 Dec 2018 01:03:25 +0900 |
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We often duplicate similar assembly code to use it from .c and .S files. The difference is mostly the presence of double quotes.
So, here is a new macro ASM(). (We have similar approach for __ASM_FORM(), etc.)
The usage is like this:
#define MY_CODE \ ASM( .section ".text" )\ ASM( movl $1, %eax )
In C context, the preprocessor expands it into:
".section \".text\"" "\n\t" "movl $1, %eax" "\n\t"
This is perfect for the use from the inline asm(...) in .c files.
In assembly context, the preprocessor expands it into:
.section ".text" ; movl $1, %eax ;
This is fine for the use in .S files.
I used double-expansion like __stringify() so that we can use macros in ASM(...).
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> ---
include/linux/linkage.h | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/include/linux/linkage.h b/include/linux/linkage.h index 7c47b1a..80faeae 100644 --- a/include/linux/linkage.h +++ b/include/linux/linkage.h @@ -12,6 +12,14 @@ #define ASM_NL ; #endif +#ifdef __ASSEMBLY__ +#define _ASM(x...) x ASM_NL +#else +#define _ASM(x...) #x __stringify(\n\t) +#endif +/* Doing two levels allows macros to be used in ASM(...) */ +#define ASM(x...) _ASM(x) + #ifdef __cplusplus #define CPP_ASMLINKAGE extern "C" #else -- 2.7.4
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