diff options
| author | Tejun Heo <tj@kernel.org> | 2012-08-08 11:10:25 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2012-08-21 16:28:30 +0200 |
| commit | e52b1db37b89b69ceb08b521a808bd2cf4724481 (patch) | |
| tree | 9f37d5060e57f1b2746047c204b1c96725463f39 | |
| parent | eec19d1a0d04c80e66eef634f7b8f460f2ca5643 (diff) | |
timer: Generalize timer->base flags handling
To prepare for addition of another flag, generalize timer->base flags
handling.
* Rename from TBASE_*_FLAG to TIMER_* and make them LU constants.
* Define and use TIMER_FLAG_MASK for flags masking so that multiple
flags can be handled correctly.
* Don't dereference timer->base directly even if
!tbase_get_deferrable(). All two such places are already passed in
@base, so use it instead.
* Make sure tvec_base's alignment is large enough for timer->base
flags using BUILD_BUG_ON().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: torvalds@linux-foundation.org
Cc: peterz@infradead.org
Link: http://lkml.kernel.org/r/1344449428-24962-2-git-send-email-tj@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | include/linux/timer.h | 6 | ||||
| -rw-r--r-- | kernel/timer.c | 21 |
2 files changed, 17 insertions, 10 deletions
diff --git a/include/linux/timer.h b/include/linux/timer.h index 6abd9138bed..cbd32ec4dd1 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -58,7 +58,9 @@ extern struct tvec_base boot_tvec_bases; * the timer will be serviced when the CPU eventually wakes up with a * subsequent non-deferrable timer. */ -#define TBASE_DEFERRABLE_FLAG (0x1) +#define TIMER_DEFERRABLE 0x1LU + +#define TIMER_FLAG_MASK 0x1LU #define TIMER_INITIALIZER(_function, _expires, _data) { \ .entry = { .prev = TIMER_ENTRY_STATIC }, \ @@ -72,7 +74,7 @@ extern struct tvec_base boot_tvec_bases; } #define TBASE_MAKE_DEFERRED(ptr) ((struct tvec_base *) \ - ((unsigned char *)(ptr) + TBASE_DEFERRABLE_FLAG)) + ((unsigned char *)(ptr) + TIMER_DEFERRABLE)) #define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data) {\ .entry = { .prev = TIMER_ENTRY_STATIC }, \ diff --git a/kernel/timer.c b/kernel/timer.c index a61c09374eb..cf7af56940b 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -92,12 +92,12 @@ static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases; /* Functions below help us manage 'deferrable' flag */ static inline unsigned int tbase_get_deferrable(struct tvec_base *base) { - return ((unsigned int)(unsigned long)base & TBASE_DEFERRABLE_FLAG); + return ((unsigned int)(unsigned long)base & TIMER_DEFERRABLE); } static inline struct tvec_base *tbase_get_base(struct tvec_base *base) { - return ((struct tvec_base *)((unsigned long)base & ~TBASE_DEFERRABLE_FLAG)); + return ((struct tvec_base *)((unsigned long)base & ~TIMER_FLAG_MASK)); } static inline void timer_set_deferrable(struct timer_list *timer) @@ -108,8 +108,9 @@ static inline void timer_set_deferrable(struct timer_list *timer) static inline void timer_set_base(struct timer_list *timer, struct tvec_base *new_base) { - timer->base = (struct tvec_base *)((unsigned long)(new_base) | - tbase_get_deferrable(timer->base)); + unsigned long flags = (unsigned long)timer->base & TIMER_FLAG_MASK; + + timer->base = (struct tvec_base *)((unsigned long)(new_base) | flags); } static unsigned long round_jiffies_common(unsigned long j, int cpu, @@ -686,7 +687,7 @@ detach_expired_timer(struct timer_list *timer, struct tvec_base *base) { detach_timer(timer, true); if (!tbase_get_deferrable(timer->base)) - timer->base->active_timers--; + base->active_timers--; } static int detach_if_pending(struct timer_list *timer, struct tvec_base *base, @@ -697,7 +698,7 @@ static int detach_if_pending(struct timer_list *timer, struct tvec_base *base, detach_timer(timer, clear_pending); if (!tbase_get_deferrable(timer->base)) { - timer->base->active_timers--; + base->active_timers--; if (timer->expires == base->next_timer) base->next_timer = base->timer_jiffies; } @@ -1800,9 +1801,13 @@ static struct notifier_block __cpuinitdata timers_nb = { void __init init_timers(void) { - int err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE, - (void *)(long)smp_processor_id()); + int err; + + /* ensure there are enough low bits for flags in timer->base pointer */ + BUILD_BUG_ON(__alignof__(struct tvec_base) & TIMER_FLAG_MASK); + err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE, + (void *)(long)smp_processor_id()); init_timer_stats(); BUG_ON(err != NOTIFY_OK); |