Re: [PATCH v6 7/7] jump_label: use defined macros instead ofhard-coding for better readability

From: Will Deacon
Date: Fri Dec 13 2013 - 11:01:28 EST


On Tue, Dec 10, 2013 at 04:03:53PM +0000, Jiang Liu wrote:
> Use macro JUMP_LABEL_TRUE_BRANCH instead of hard-coding for better
> readability.
>
> Signed-off-by: Jiang Liu <liuj97@xxxxxxxxx>
> ---
> include/linux/jump_label.h | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)

Whilst this looks alright to me, I think we probably need an ack from Steve
in order to take changes to the core code.

Will


> diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
> index 3999977..192ccba 100644
> --- a/include/linux/jump_label.h
> +++ b/include/linux/jump_label.h
> @@ -81,18 +81,21 @@ struct module;
> #include <linux/atomic.h>
> #ifdef HAVE_JUMP_LABEL
>
> -#define JUMP_LABEL_TRUE_BRANCH 1UL
> +#define JUMP_LABEL_TYPE_FALSE_BRANCH 0UL
> +#define JUMP_LABEL_TYPE_TRUE_BRANCH 1UL
> +#define JUMP_LABEL_TYPE_MASK 1UL
>
> static
> inline struct jump_entry *jump_label_get_entries(struct static_key *key)
> {
> return (struct jump_entry *)((unsigned long)key->entries
> - & ~JUMP_LABEL_TRUE_BRANCH);
> + & ~JUMP_LABEL_TYPE_MASK);
> }
>
> static inline bool jump_label_get_branch_default(struct static_key *key)
> {
> - if ((unsigned long)key->entries & JUMP_LABEL_TRUE_BRANCH)
> + if (((unsigned long)key->entries & JUMP_LABEL_TYPE_MASK) ==
> + JUMP_LABEL_TYPE_TRUE_BRANCH)
> return true;
> return false;
> }
> @@ -123,9 +126,11 @@ extern void static_key_slow_dec(struct static_key *key);
> extern void jump_label_apply_nops(struct module *mod);
>
> #define STATIC_KEY_INIT_TRUE ((struct static_key) \
> - { .enabled = ATOMIC_INIT(1), .entries = (void *)1 })
> + { .enabled = ATOMIC_INIT(1), \
> + .entries = (void *)JUMP_LABEL_TYPE_TRUE_BRANCH })
> #define STATIC_KEY_INIT_FALSE ((struct static_key) \
> - { .enabled = ATOMIC_INIT(0), .entries = (void *)0 })
> + { .enabled = ATOMIC_INIT(0), \
> + .entries = (void *)JUMP_LABEL_TYPE_FALSE_BRANCH })
>
> #else /* !HAVE_JUMP_LABEL */
>
> --
> 1.8.1.2
>
>
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