diff options
Diffstat (limited to 'include/linux/hrtimer.h')
| -rw-r--r-- | include/linux/hrtimer.h | 116 |
1 files changed, 110 insertions, 6 deletions
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index e95c96c971c0..4ecd991431b4 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -41,16 +41,35 @@ enum hrtimer_restart { }; /* - * Bit values to track state of the timer + * hrtimer callback modes: + * + * HRTIMER_CB_SOFTIRQ: Callback must run in softirq context + * HRTIMER_CB_IRQSAFE: Callback may run in hardirq context + * HRTIMER_CB_IRQSAFE_NO_RESTART: Callback may run in hardirq context and + * does not restart the timer + * HRTIMER_CB_IRQSAFE_NO_SOFTIRQ: Callback must run in softirq context + * Special mode for tick emultation + */ +enum hrtimer_cb_mode { + HRTIMER_CB_SOFTIRQ, + HRTIMER_CB_IRQSAFE, + HRTIMER_CB_IRQSAFE_NO_RESTART, + HRTIMER_CB_IRQSAFE_NO_SOFTIRQ, +}; + +/* + * Values to track state of the timer * * Possible states: * * 0x00 inactive * 0x01 enqueued into rbtree * 0x02 callback function running + * 0x04 callback pending (high resolution mode) + * + * Special case: * 0x03 callback function running and enqueued * (was requeued on another CPU) - * * The "callback function running and enqueued" status is only possible on * SMP. It happens for example when a posix timer expired and the callback * queued a signal. Between dropping the lock which protects the posix timer @@ -67,6 +86,7 @@ enum hrtimer_restart { #define HRTIMER_STATE_INACTIVE 0x00 #define HRTIMER_STATE_ENQUEUED 0x01 #define HRTIMER_STATE_CALLBACK 0x02 +#define HRTIMER_STATE_PENDING 0x04 /** * struct hrtimer - the basic hrtimer structure @@ -77,8 +97,17 @@ enum hrtimer_restart { * @function: timer expiry callback function * @base: pointer to the timer base (per cpu and per clock) * @state: state information (See bit values above) + * @cb_mode: high resolution timer feature to select the callback execution + * mode + * @cb_entry: list head to enqueue an expired timer into the callback list + * @start_site: timer statistics field to store the site where the timer + * was started + * @start_comm: timer statistics field to store the name of the process which + * started the timer + * @start_pid: timer statistics field to store the pid of the task which + * started the timer * - * The hrtimer structure must be initialized by init_hrtimer_#CLOCKTYPE() + * The hrtimer structure must be initialized by hrtimer_init() */ struct hrtimer { struct rb_node node; @@ -86,6 +115,10 @@ struct hrtimer { enum hrtimer_restart (*function)(struct hrtimer *); struct hrtimer_clock_base *base; unsigned long state; +#ifdef CONFIG_HIGH_RES_TIMERS + enum hrtimer_cb_mode cb_mode; + struct list_head cb_entry; +#endif }; /** @@ -110,6 +143,9 @@ struct hrtimer_sleeper { * @get_time: function to retrieve the current time of the clock * @get_softirq_time: function to retrieve the current time from the softirq * @softirq_time: the time when running the hrtimer queue in the softirq + * @cb_pending: list of timers where the callback is pending + * @offset: offset of this clock to the monotonic base + * @reprogram: function to reprogram the timer event */ struct hrtimer_clock_base { struct hrtimer_cpu_base *cpu_base; @@ -120,6 +156,12 @@ struct hrtimer_clock_base { ktime_t (*get_time)(void); ktime_t (*get_softirq_time)(void); ktime_t softirq_time; +#ifdef CONFIG_HIGH_RES_TIMERS + ktime_t offset; + int (*reprogram)(struct hrtimer *t, + struct hrtimer_clock_base *b, + ktime_t n); +#endif }; #define HRTIMER_MAX_CLOCK_BASES 2 @@ -131,19 +173,74 @@ struct hrtimer_clock_base { * @lock_key: the lock_class_key for use with lockdep * @clock_base: array of clock bases for this cpu * @curr_timer: the timer which is executing a callback right now + * @expires_next: absolute time of the next event which was scheduled + * via clock_set_next_event() + * @hres_active: State of high resolution mode + * @check_clocks: Indictator, when set evaluate time source and clock + * event devices whether high resolution mode can be + * activated. + * @cb_pending: Expired timers are moved from the rbtree to this + * list in the timer interrupt. The list is processed + * in the softirq. + * @nr_events: Total number of timer interrupt events */ struct hrtimer_cpu_base { spinlock_t lock; struct lock_class_key lock_key; struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES]; +#ifdef CONFIG_HIGH_RES_TIMERS + ktime_t expires_next; + int hres_active; + struct list_head cb_pending; + unsigned long nr_events; +#endif }; +#ifdef CONFIG_HIGH_RES_TIMERS +struct clock_event_device; + +extern void clock_was_set(void); +extern void hrtimer_interrupt(struct clock_event_device *dev); + +/* + * In high resolution mode the time reference must be read accurate + */ +static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) +{ + return timer->base->get_time(); +} + +/* + * The resolution of the clocks. The resolution value is returned in + * the clock_getres() system call to give application programmers an + * idea of the (in)accuracy of timers. Timer values are rounded up to + * this resolution values. + */ +# define KTIME_HIGH_RES (ktime_t) { .tv64 = 1 } +# define KTIME_MONOTONIC_RES KTIME_HIGH_RES + +#else + +# define KTIME_MONOTONIC_RES KTIME_LOW_RES + /* * clock_was_set() is a NOP for non- high-resolution systems. The * time-sorted order guarantees that a timer does not expire early and * is expired in the next softirq when the clock was advanced. */ -#define clock_was_set() do { } while (0) +static inline void clock_was_set(void) { } + +/* + * In non high resolution mode the time reference is taken from + * the base softirq time variable. + */ +static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) +{ + return timer->base->softirq_time; +} + +#endif + extern ktime_t ktime_get(void); extern ktime_t ktime_get_real(void); @@ -168,9 +265,7 @@ static inline int hrtimer_restart(struct hrtimer *timer) extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer); extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp); -#ifdef CONFIG_NO_IDLE_HZ extern ktime_t hrtimer_get_next_event(void); -#endif /* * A timer is active, when it is enqueued into the rbtree or the callback @@ -181,6 +276,15 @@ static inline int hrtimer_active(const struct hrtimer *timer) return timer->state != HRTIMER_STATE_INACTIVE; } +/* + * Helper function to check, whether the timer is on one of the queues + */ +static inline int hrtimer_is_queued(struct hrtimer *timer) +{ + return timer->state & + (HRTIMER_STATE_ENQUEUED | HRTIMER_STATE_PENDING); +} + /* Forward a hrtimer so it expires after now: */ extern unsigned long hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval); |