From 180bf812ceaf01eb8ac69b86f3be0bd57f697668 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Thu, 28 Apr 2011 12:58:11 -0700 Subject: timers: Improve alarmtimer comments and minor fixes This patch addresses a number of minor comment improvements and other minor issues from Thomas' review of the alarmtimers code. CC: Thomas Gleixner Signed-off-by: John Stultz --- include/linux/alarmtimer.h | 12 ++++++++- kernel/time/alarmtimer.c | 67 +++++++++++++++++++--------------------------- 2 files changed, 38 insertions(+), 41 deletions(-) diff --git a/include/linux/alarmtimer.h b/include/linux/alarmtimer.h index 6b364b2e2074..c5d6095b46f8 100644 --- a/include/linux/alarmtimer.h +++ b/include/linux/alarmtimer.h @@ -13,12 +13,22 @@ enum alarmtimer_type { ALARM_NUMTYPE, }; +/** + * struct alarm - Alarm timer structure + * @node: timerqueue node for adding to the event list this value + * also includes the expiration time. + * @period: Period for recuring alarms + * @function: Function pointer to be executed when the timer fires. + * @type: Alarm type (BOOTTIME/REALTIME) + * @enabled: Flag that represents if the alarm is set to fire or not + * @data: Internal data value. + */ struct alarm { struct timerqueue_node node; ktime_t period; void (*function)(struct alarm *); enum alarmtimer_type type; - char enabled; + bool enabled; void *data; }; diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 4058ad79d55f..bed98004ae1a 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -26,7 +26,15 @@ #include #include - +/** + * struct alarm_base - Alarm timer bases + * @lock: Lock for syncrhonized access to the base + * @timerqueue: Timerqueue head managing the list of events + * @timer: hrtimer used to schedule events while running + * @gettime: Function to read the time correlating to the base + * @base_clockid: clockid for the base + * @irqwork Delayed work structure for expiring timers + */ static struct alarm_base { spinlock_t lock; struct timerqueue_head timerqueue; @@ -36,18 +44,16 @@ static struct alarm_base { struct work_struct irqwork; } alarm_bases[ALARM_NUMTYPE]; +/* rtc timer and device for setting alarm wakeups at suspend */ static struct rtc_timer rtctimer; static struct rtc_device *rtcdev; +/* freezer delta & lock used to handle clock_nanosleep triggered wakeups */ static ktime_t freezer_delta; static DEFINE_SPINLOCK(freezer_delta_lock); -/************************************************************************** - * alarmtimer management code - */ - -/* +/** * alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue * @base: pointer to the base where the timer is being run * @alarm: pointer to alarm being enqueued. @@ -67,7 +73,7 @@ static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm) } } -/* +/** * alarmtimer_remove - Removes an alarm timer from an alarm_base timerqueue * @base: pointer to the base where the timer is running * @alarm: pointer to alarm being removed @@ -91,16 +97,16 @@ static void alarmtimer_remove(struct alarm_base *base, struct alarm *alarm) } } -/* +/** * alarmtimer_do_work - Handles alarm being fired. * @work: pointer to workqueue being run * - * When a timer fires, this runs through the timerqueue to see - * which alarm timers, and run those that expired. If there are - * more alarm timers queued, we set the hrtimer to fire in the - * future. + * When a alarm timer fires, this runs through the timerqueue to + * see which alarms expired, and runs those. If there are more alarm + * timers queued for the future, we set the hrtimer to fire when + * when the next future alarm timer expires. */ -void alarmtimer_do_work(struct work_struct *work) +static void alarmtimer_do_work(struct work_struct *work) { struct alarm_base *base = container_of(work, struct alarm_base, irqwork); @@ -141,7 +147,7 @@ void alarmtimer_do_work(struct work_struct *work) } -/* +/** * alarmtimer_fired - Handles alarm hrtimer being fired. * @timer: pointer to hrtimer being run * @@ -156,7 +162,7 @@ static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer) } -/* +/** * alarmtimer_suspend - Suspend time callback * @dev: unused * @state: unused @@ -230,17 +236,11 @@ static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type) } -/************************************************************************** - * alarm kernel interface code - */ - -/* +/** * alarm_init - Initialize an alarm structure * @alarm: ptr to alarm to be initialized * @type: the type of the alarm * @function: callback that is run when the alarm fires - * - * In-kernel interface to initializes the alarm structure. */ void alarm_init(struct alarm *alarm, enum alarmtimer_type type, void (*function)(struct alarm *)) @@ -252,13 +252,11 @@ void alarm_init(struct alarm *alarm, enum alarmtimer_type type, alarm->enabled = 0; } -/* +/** * alarm_start - Sets an alarm to fire * @alarm: ptr to alarm to set * @start: time to run the alarm * @period: period at which the alarm will recur - * - * In-kernel interface set an alarm timer. */ void alarm_start(struct alarm *alarm, ktime_t start, ktime_t period) { @@ -275,11 +273,9 @@ void alarm_start(struct alarm *alarm, ktime_t start, ktime_t period) spin_unlock_irqrestore(&base->lock, flags); } -/* +/** * alarm_cancel - Tries to cancel an alarm timer * @alarm: ptr to alarm to be canceled - * - * In-kernel interface to cancel an alarm timer. */ void alarm_cancel(struct alarm *alarm) { @@ -294,15 +290,9 @@ void alarm_cancel(struct alarm *alarm) } -/************************************************************************** - * alarm posix interface code - */ - -/* +/** * clock2alarm - helper that converts from clockid to alarmtypes * @clockid: clockid. - * - * Helper function that converts from clockids to alarmtypes */ static enum alarmtimer_type clock2alarm(clockid_t clockid) { @@ -313,7 +303,7 @@ static enum alarmtimer_type clock2alarm(clockid_t clockid) return -1; } -/* +/** * alarm_handle_timer - Callback for posix timers * @alarm: alarm that fired * @@ -327,7 +317,7 @@ static void alarm_handle_timer(struct alarm *alarm) ptr->it_overrun++; } -/* +/** * alarm_clock_getres - posix getres interface * @which_clock: clockid * @tp: timespec to fill @@ -598,9 +588,6 @@ out: return ret; } -/************************************************************************** - * alarmtimer initialization code - */ /* Suspend hook structures */ static const struct dev_pm_ops alarmtimer_pm_ops = { -- cgit