On Tue, Jan 06, 2015 at 09:20:27PM +1100, Anton Blanchard wrote:
> To use jump labels in assembly we need the HAVE_JUMP_LABEL define,
> so we select a fallback version if the toolchain does not support
> them.
>
> Modify linux/jump_label.h so it can be included by assembly files.
> We also need to add -DCC_HAVE_ASM_GOTO to KBUILD_AFLAGS.
>
> Signed-off-by: Anton Blanchard <anton@xxxxxxxxx>
> ---
> Makefile | 1 +
> include/linux/jump_label.h | 21 +++++++++++++++++----
> 2 files changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index ef748e1..7b83c3f 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -774,6 +774,7 @@ KBUILD_ARFLAGS := $(call ar-option,D)
> # check for 'asm goto'
> ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC)), y)
> KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
> + KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
> endif
>
> include $(srctree)/scripts/Makefile.extrawarn
> diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
> index 98f923b6..f4de473 100644
> --- a/include/linux/jump_label.h
> +++ b/include/linux/jump_label.h
> @@ -45,6 +45,12 @@
> * same as using STATIC_KEY_INIT_FALSE.
> */
>
> +#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
> +# define HAVE_JUMP_LABEL
> +#endif
> +
> +#ifndef __ASSEMBLY__
> +
> #include <linux/types.h>
> #include <linux/compiler.h>
> #include <linux/bug.h>
> @@ -55,7 +61,7 @@ extern bool static_key_initialized;
> "%s used before call to jump_label_init", \
> __func__)
>
> -#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
> +#ifdef HAVE_JUMP_LABEL
>
> struct static_key {
> atomic_t enabled;
> @@ -66,13 +72,18 @@ struct static_key {
> #endif
> };
>
> -# include <asm/jump_label.h>
> -# define HAVE_JUMP_LABEL
> #else
> struct static_key {
> atomic_t enabled;
> };
> -#endif /* CC_HAVE_ASM_GOTO && CONFIG_JUMP_LABEL */
> +#endif /* HAVE_JUMP_LABEL */
> +#endif /* __ASSEMBLY__ */
> +
> +#ifdef HAVE_JUMP_LABEL
> +#include <asm/jump_label.h>
> +#endif
Have you tested this on other archs? Because just looking at x86, it doesn't
seem that asm/jump_label.h can handle being called in assembly.
-- Steve
> +
> +#ifndef __ASSEMBLY__
>
> enum jump_label_type {
> JUMP_LABEL_DISABLE = 0,
> @@ -203,3 +214,5 @@ static inline bool static_key_enabled(struct static_key *key)
> }
>
> #endif /* _LINUX_JUMP_LABEL_H */
> +
> +#endif /* __ASSEMBLY__ */
> --
> 2.1.0
>
> --
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