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939 lines
24 KiB
939 lines
24 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Alarmtimer interface |
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* |
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* This interface provides a timer which is similarto hrtimers, |
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* but triggers a RTC alarm if the box is suspend. |
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* |
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* This interface is influenced by the Android RTC Alarm timer |
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* interface. |
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* |
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* Copyright (C) 2010 IBM Corperation |
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* |
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* Author: John Stultz <[email protected]> |
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*/ |
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#include <linux/time.h> |
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#include <linux/hrtimer.h> |
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#include <linux/timerqueue.h> |
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#include <linux/rtc.h> |
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#include <linux/sched/signal.h> |
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#include <linux/sched/debug.h> |
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#include <linux/alarmtimer.h> |
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#include <linux/mutex.h> |
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#include <linux/platform_device.h> |
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#include <linux/posix-timers.h> |
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#include <linux/workqueue.h> |
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#include <linux/freezer.h> |
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#include <linux/compat.h> |
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#include <linux/module.h> |
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#include <linux/time_namespace.h> |
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|
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#include "posix-timers.h" |
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|
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#define CREATE_TRACE_POINTS |
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#include <trace/events/alarmtimer.h> |
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|
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/** |
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* struct alarm_base - Alarm timer bases |
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* @lock: Lock for syncrhonized access to the base |
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* @timerqueue: Timerqueue head managing the list of events |
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* @get_ktime: Function to read the time correlating to the base |
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* @get_timespec: Function to read the namespace time correlating to the base |
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* @base_clockid: clockid for the base |
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*/ |
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static struct alarm_base { |
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spinlock_t lock; |
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struct timerqueue_head timerqueue; |
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ktime_t (*get_ktime)(void); |
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void (*get_timespec)(struct timespec64 *tp); |
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clockid_t base_clockid; |
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} alarm_bases[ALARM_NUMTYPE]; |
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|
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#if defined(CONFIG_POSIX_TIMERS) || defined(CONFIG_RTC_CLASS) |
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/* freezer information to handle clock_nanosleep triggered wakeups */ |
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static enum alarmtimer_type freezer_alarmtype; |
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static ktime_t freezer_expires; |
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static ktime_t freezer_delta; |
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static DEFINE_SPINLOCK(freezer_delta_lock); |
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#endif |
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|
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#ifdef CONFIG_RTC_CLASS |
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/* rtc timer and device for setting alarm wakeups at suspend */ |
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static struct rtc_timer rtctimer; |
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static struct rtc_device *rtcdev; |
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static DEFINE_SPINLOCK(rtcdev_lock); |
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|
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/** |
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* alarmtimer_get_rtcdev - Return selected rtcdevice |
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* |
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* This function returns the rtc device to use for wakealarms. |
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*/ |
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struct rtc_device *alarmtimer_get_rtcdev(void) |
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{ |
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unsigned long flags; |
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struct rtc_device *ret; |
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|
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spin_lock_irqsave(&rtcdev_lock, flags); |
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ret = rtcdev; |
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spin_unlock_irqrestore(&rtcdev_lock, flags); |
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|
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return ret; |
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} |
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EXPORT_SYMBOL_GPL(alarmtimer_get_rtcdev); |
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|
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static int alarmtimer_rtc_add_device(struct device *dev, |
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struct class_interface *class_intf) |
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{ |
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unsigned long flags; |
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struct rtc_device *rtc = to_rtc_device(dev); |
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struct platform_device *pdev; |
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int ret = 0; |
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|
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if (rtcdev) |
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return -EBUSY; |
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|
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if (!test_bit(RTC_FEATURE_ALARM, rtc->features)) |
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return -1; |
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if (!device_may_wakeup(rtc->dev.parent)) |
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return -1; |
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pdev = platform_device_register_data(dev, "alarmtimer", |
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PLATFORM_DEVID_AUTO, NULL, 0); |
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if (!IS_ERR(pdev)) |
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device_init_wakeup(&pdev->dev, true); |
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|
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spin_lock_irqsave(&rtcdev_lock, flags); |
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if (!IS_ERR(pdev) && !rtcdev) { |
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if (!try_module_get(rtc->owner)) { |
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ret = -1; |
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goto unlock; |
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} |
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|
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rtcdev = rtc; |
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/* hold a reference so it doesn't go away */ |
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get_device(dev); |
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pdev = NULL; |
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} else { |
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ret = -1; |
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} |
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unlock: |
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spin_unlock_irqrestore(&rtcdev_lock, flags); |
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|
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platform_device_unregister(pdev); |
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|
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return ret; |
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} |
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|
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static inline void alarmtimer_rtc_timer_init(void) |
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{ |
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rtc_timer_init(&rtctimer, NULL, NULL); |
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} |
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|
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static struct class_interface alarmtimer_rtc_interface = { |
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.add_dev = &alarmtimer_rtc_add_device, |
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}; |
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|
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static int alarmtimer_rtc_interface_setup(void) |
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{ |
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alarmtimer_rtc_interface.class = rtc_class; |
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return class_interface_register(&alarmtimer_rtc_interface); |
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} |
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static void alarmtimer_rtc_interface_remove(void) |
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{ |
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class_interface_unregister(&alarmtimer_rtc_interface); |
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} |
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#else |
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static inline int alarmtimer_rtc_interface_setup(void) { return 0; } |
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static inline void alarmtimer_rtc_interface_remove(void) { } |
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static inline void alarmtimer_rtc_timer_init(void) { } |
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#endif |
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|
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/** |
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* alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue |
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* @base: pointer to the base where the timer is being run |
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* @alarm: pointer to alarm being enqueued. |
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* |
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* Adds alarm to a alarm_base timerqueue |
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* |
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* Must hold base->lock when calling. |
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*/ |
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static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm) |
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{ |
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if (alarm->state & ALARMTIMER_STATE_ENQUEUED) |
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timerqueue_del(&base->timerqueue, &alarm->node); |
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|
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timerqueue_add(&base->timerqueue, &alarm->node); |
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alarm->state |= ALARMTIMER_STATE_ENQUEUED; |
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} |
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|
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/** |
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* alarmtimer_dequeue - Removes an alarm timer from an alarm_base timerqueue |
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* @base: pointer to the base where the timer is running |
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* @alarm: pointer to alarm being removed |
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* |
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* Removes alarm to a alarm_base timerqueue |
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* |
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* Must hold base->lock when calling. |
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*/ |
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static void alarmtimer_dequeue(struct alarm_base *base, struct alarm *alarm) |
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{ |
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if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED)) |
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return; |
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timerqueue_del(&base->timerqueue, &alarm->node); |
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alarm->state &= ~ALARMTIMER_STATE_ENQUEUED; |
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} |
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/** |
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* alarmtimer_fired - Handles alarm hrtimer being fired. |
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* @timer: pointer to hrtimer being run |
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* |
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* When a alarm timer fires, this runs through the timerqueue to |
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* see which alarms expired, and runs those. If there are more alarm |
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* timers queued for the future, we set the hrtimer to fire when |
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* the next future alarm timer expires. |
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*/ |
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static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer) |
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{ |
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struct alarm *alarm = container_of(timer, struct alarm, timer); |
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struct alarm_base *base = &alarm_bases[alarm->type]; |
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unsigned long flags; |
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int ret = HRTIMER_NORESTART; |
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int restart = ALARMTIMER_NORESTART; |
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|
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spin_lock_irqsave(&base->lock, flags); |
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alarmtimer_dequeue(base, alarm); |
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spin_unlock_irqrestore(&base->lock, flags); |
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|
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if (alarm->function) |
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restart = alarm->function(alarm, base->get_ktime()); |
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|
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spin_lock_irqsave(&base->lock, flags); |
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if (restart != ALARMTIMER_NORESTART) { |
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hrtimer_set_expires(&alarm->timer, alarm->node.expires); |
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alarmtimer_enqueue(base, alarm); |
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ret = HRTIMER_RESTART; |
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} |
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spin_unlock_irqrestore(&base->lock, flags); |
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trace_alarmtimer_fired(alarm, base->get_ktime()); |
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return ret; |
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} |
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ktime_t alarm_expires_remaining(const struct alarm *alarm) |
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{ |
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struct alarm_base *base = &alarm_bases[alarm->type]; |
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return ktime_sub(alarm->node.expires, base->get_ktime()); |
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} |
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EXPORT_SYMBOL_GPL(alarm_expires_remaining); |
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|
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#ifdef CONFIG_RTC_CLASS |
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/** |
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* alarmtimer_suspend - Suspend time callback |
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* @dev: unused |
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* |
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* When we are going into suspend, we look through the bases |
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* to see which is the soonest timer to expire. We then |
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* set an rtc timer to fire that far into the future, which |
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* will wake us from suspend. |
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*/ |
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static int alarmtimer_suspend(struct device *dev) |
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{ |
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ktime_t min, now, expires; |
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int i, ret, type; |
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struct rtc_device *rtc; |
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unsigned long flags; |
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struct rtc_time tm; |
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spin_lock_irqsave(&freezer_delta_lock, flags); |
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min = freezer_delta; |
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expires = freezer_expires; |
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type = freezer_alarmtype; |
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freezer_delta = 0; |
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spin_unlock_irqrestore(&freezer_delta_lock, flags); |
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rtc = alarmtimer_get_rtcdev(); |
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/* If we have no rtcdev, just return */ |
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if (!rtc) |
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return 0; |
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|
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/* Find the soonest timer to expire*/ |
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for (i = 0; i < ALARM_NUMTYPE; i++) { |
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struct alarm_base *base = &alarm_bases[i]; |
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struct timerqueue_node *next; |
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ktime_t delta; |
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spin_lock_irqsave(&base->lock, flags); |
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next = timerqueue_getnext(&base->timerqueue); |
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spin_unlock_irqrestore(&base->lock, flags); |
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if (!next) |
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continue; |
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delta = ktime_sub(next->expires, base->get_ktime()); |
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if (!min || (delta < min)) { |
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expires = next->expires; |
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min = delta; |
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type = i; |
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} |
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} |
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if (min == 0) |
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return 0; |
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if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) { |
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pm_wakeup_event(dev, 2 * MSEC_PER_SEC); |
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return -EBUSY; |
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} |
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trace_alarmtimer_suspend(expires, type); |
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|
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/* Setup an rtc timer to fire that far in the future */ |
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rtc_timer_cancel(rtc, &rtctimer); |
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rtc_read_time(rtc, &tm); |
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now = rtc_tm_to_ktime(tm); |
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now = ktime_add(now, min); |
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|
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/* Set alarm, if in the past reject suspend briefly to handle */ |
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ret = rtc_timer_start(rtc, &rtctimer, now, 0); |
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if (ret < 0) |
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pm_wakeup_event(dev, MSEC_PER_SEC); |
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return ret; |
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} |
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static int alarmtimer_resume(struct device *dev) |
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{ |
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struct rtc_device *rtc; |
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rtc = alarmtimer_get_rtcdev(); |
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if (rtc) |
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rtc_timer_cancel(rtc, &rtctimer); |
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return 0; |
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} |
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#else |
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static int alarmtimer_suspend(struct device *dev) |
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{ |
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return 0; |
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} |
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|
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static int alarmtimer_resume(struct device *dev) |
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{ |
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return 0; |
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} |
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#endif |
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|
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static void |
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__alarm_init(struct alarm *alarm, enum alarmtimer_type type, |
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enum alarmtimer_restart (*function)(struct alarm *, ktime_t)) |
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{ |
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timerqueue_init(&alarm->node); |
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alarm->timer.function = alarmtimer_fired; |
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alarm->function = function; |
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alarm->type = type; |
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alarm->state = ALARMTIMER_STATE_INACTIVE; |
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} |
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/** |
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* alarm_init - Initialize an alarm structure |
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* @alarm: ptr to alarm to be initialized |
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* @type: the type of the alarm |
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* @function: callback that is run when the alarm fires |
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*/ |
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void alarm_init(struct alarm *alarm, enum alarmtimer_type type, |
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enum alarmtimer_restart (*function)(struct alarm *, ktime_t)) |
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{ |
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hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid, |
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HRTIMER_MODE_ABS); |
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__alarm_init(alarm, type, function); |
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} |
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EXPORT_SYMBOL_GPL(alarm_init); |
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|
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/** |
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* alarm_start - Sets an absolute alarm to fire |
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* @alarm: ptr to alarm to set |
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* @start: time to run the alarm |
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*/ |
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void alarm_start(struct alarm *alarm, ktime_t start) |
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{ |
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struct alarm_base *base = &alarm_bases[alarm->type]; |
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unsigned long flags; |
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|
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spin_lock_irqsave(&base->lock, flags); |
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alarm->node.expires = start; |
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alarmtimer_enqueue(base, alarm); |
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hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS); |
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spin_unlock_irqrestore(&base->lock, flags); |
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|
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trace_alarmtimer_start(alarm, base->get_ktime()); |
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} |
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EXPORT_SYMBOL_GPL(alarm_start); |
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|
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/** |
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* alarm_start_relative - Sets a relative alarm to fire |
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* @alarm: ptr to alarm to set |
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* @start: time relative to now to run the alarm |
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*/ |
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void alarm_start_relative(struct alarm *alarm, ktime_t start) |
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{ |
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struct alarm_base *base = &alarm_bases[alarm->type]; |
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|
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start = ktime_add_safe(start, base->get_ktime()); |
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alarm_start(alarm, start); |
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} |
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EXPORT_SYMBOL_GPL(alarm_start_relative); |
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|
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void alarm_restart(struct alarm *alarm) |
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{ |
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struct alarm_base *base = &alarm_bases[alarm->type]; |
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unsigned long flags; |
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|
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spin_lock_irqsave(&base->lock, flags); |
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hrtimer_set_expires(&alarm->timer, alarm->node.expires); |
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hrtimer_restart(&alarm->timer); |
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alarmtimer_enqueue(base, alarm); |
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spin_unlock_irqrestore(&base->lock, flags); |
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} |
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EXPORT_SYMBOL_GPL(alarm_restart); |
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|
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/** |
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* alarm_try_to_cancel - Tries to cancel an alarm timer |
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* @alarm: ptr to alarm to be canceled |
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* |
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* Returns 1 if the timer was canceled, 0 if it was not running, |
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* and -1 if the callback was running |
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*/ |
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int alarm_try_to_cancel(struct alarm *alarm) |
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{ |
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struct alarm_base *base = &alarm_bases[alarm->type]; |
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unsigned long flags; |
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int ret; |
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|
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spin_lock_irqsave(&base->lock, flags); |
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ret = hrtimer_try_to_cancel(&alarm->timer); |
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if (ret >= 0) |
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alarmtimer_dequeue(base, alarm); |
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spin_unlock_irqrestore(&base->lock, flags); |
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|
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trace_alarmtimer_cancel(alarm, base->get_ktime()); |
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return ret; |
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} |
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EXPORT_SYMBOL_GPL(alarm_try_to_cancel); |
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|
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|
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/** |
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* alarm_cancel - Spins trying to cancel an alarm timer until it is done |
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* @alarm: ptr to alarm to be canceled |
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* |
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* Returns 1 if the timer was canceled, 0 if it was not active. |
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*/ |
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int alarm_cancel(struct alarm *alarm) |
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{ |
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for (;;) { |
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int ret = alarm_try_to_cancel(alarm); |
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if (ret >= 0) |
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return ret; |
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hrtimer_cancel_wait_running(&alarm->timer); |
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} |
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} |
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EXPORT_SYMBOL_GPL(alarm_cancel); |
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|
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|
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u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval) |
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{ |
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u64 overrun = 1; |
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ktime_t delta; |
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|
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delta = ktime_sub(now, alarm->node.expires); |
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|
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if (delta < 0) |
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return 0; |
|
|
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if (unlikely(delta >= interval)) { |
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s64 incr = ktime_to_ns(interval); |
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|
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overrun = ktime_divns(delta, incr); |
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|
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alarm->node.expires = ktime_add_ns(alarm->node.expires, |
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incr*overrun); |
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|
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if (alarm->node.expires > now) |
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return overrun; |
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/* |
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* This (and the ktime_add() below) is the |
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* correction for exact: |
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*/ |
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overrun++; |
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} |
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|
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alarm->node.expires = ktime_add_safe(alarm->node.expires, interval); |
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return overrun; |
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} |
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EXPORT_SYMBOL_GPL(alarm_forward); |
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|
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u64 alarm_forward_now(struct alarm *alarm, ktime_t interval) |
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{ |
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struct alarm_base *base = &alarm_bases[alarm->type]; |
|
|
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return alarm_forward(alarm, base->get_ktime(), interval); |
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} |
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EXPORT_SYMBOL_GPL(alarm_forward_now); |
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|
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#ifdef CONFIG_POSIX_TIMERS |
|
|
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static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type) |
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{ |
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struct alarm_base *base; |
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unsigned long flags; |
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ktime_t delta; |
|
|
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switch(type) { |
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case ALARM_REALTIME: |
|
base = &alarm_bases[ALARM_REALTIME]; |
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type = ALARM_REALTIME_FREEZER; |
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break; |
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case ALARM_BOOTTIME: |
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base = &alarm_bases[ALARM_BOOTTIME]; |
|
type = ALARM_BOOTTIME_FREEZER; |
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break; |
|
default: |
|
WARN_ONCE(1, "Invalid alarm type: %d\n", type); |
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return; |
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} |
|
|
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delta = ktime_sub(absexp, base->get_ktime()); |
|
|
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spin_lock_irqsave(&freezer_delta_lock, flags); |
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if (!freezer_delta || (delta < freezer_delta)) { |
|
freezer_delta = delta; |
|
freezer_expires = absexp; |
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freezer_alarmtype = type; |
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} |
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spin_unlock_irqrestore(&freezer_delta_lock, flags); |
|
} |
|
|
|
/** |
|
* clock2alarm - helper that converts from clockid to alarmtypes |
|
* @clockid: clockid. |
|
*/ |
|
static enum alarmtimer_type clock2alarm(clockid_t clockid) |
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{ |
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if (clockid == CLOCK_REALTIME_ALARM) |
|
return ALARM_REALTIME; |
|
if (clockid == CLOCK_BOOTTIME_ALARM) |
|
return ALARM_BOOTTIME; |
|
return -1; |
|
} |
|
|
|
/** |
|
* alarm_handle_timer - Callback for posix timers |
|
* @alarm: alarm that fired |
|
* @now: time at the timer expiration |
|
* |
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* Posix timer callback for expired alarm timers. |
|
* |
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* Return: whether the timer is to be restarted |
|
*/ |
|
static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm, |
|
ktime_t now) |
|
{ |
|
struct k_itimer *ptr = container_of(alarm, struct k_itimer, |
|
it.alarm.alarmtimer); |
|
enum alarmtimer_restart result = ALARMTIMER_NORESTART; |
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unsigned long flags; |
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int si_private = 0; |
|
|
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spin_lock_irqsave(&ptr->it_lock, flags); |
|
|
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ptr->it_active = 0; |
|
if (ptr->it_interval) |
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si_private = ++ptr->it_requeue_pending; |
|
|
|
if (posix_timer_event(ptr, si_private) && ptr->it_interval) { |
|
/* |
|
* Handle ignored signals and rearm the timer. This will go |
|
* away once we handle ignored signals proper. |
|
*/ |
|
ptr->it_overrun += alarm_forward_now(alarm, ptr->it_interval); |
|
++ptr->it_requeue_pending; |
|
ptr->it_active = 1; |
|
result = ALARMTIMER_RESTART; |
|
} |
|
spin_unlock_irqrestore(&ptr->it_lock, flags); |
|
|
|
return result; |
|
} |
|
|
|
/** |
|
* alarm_timer_rearm - Posix timer callback for rearming timer |
|
* @timr: Pointer to the posixtimer data struct |
|
*/ |
|
static void alarm_timer_rearm(struct k_itimer *timr) |
|
{ |
|
struct alarm *alarm = &timr->it.alarm.alarmtimer; |
|
|
|
timr->it_overrun += alarm_forward_now(alarm, timr->it_interval); |
|
alarm_start(alarm, alarm->node.expires); |
|
} |
|
|
|
/** |
|
* alarm_timer_forward - Posix timer callback for forwarding timer |
|
* @timr: Pointer to the posixtimer data struct |
|
* @now: Current time to forward the timer against |
|
*/ |
|
static s64 alarm_timer_forward(struct k_itimer *timr, ktime_t now) |
|
{ |
|
struct alarm *alarm = &timr->it.alarm.alarmtimer; |
|
|
|
return alarm_forward(alarm, timr->it_interval, now); |
|
} |
|
|
|
/** |
|
* alarm_timer_remaining - Posix timer callback to retrieve remaining time |
|
* @timr: Pointer to the posixtimer data struct |
|
* @now: Current time to calculate against |
|
*/ |
|
static ktime_t alarm_timer_remaining(struct k_itimer *timr, ktime_t now) |
|
{ |
|
struct alarm *alarm = &timr->it.alarm.alarmtimer; |
|
|
|
return ktime_sub(alarm->node.expires, now); |
|
} |
|
|
|
/** |
|
* alarm_timer_try_to_cancel - Posix timer callback to cancel a timer |
|
* @timr: Pointer to the posixtimer data struct |
|
*/ |
|
static int alarm_timer_try_to_cancel(struct k_itimer *timr) |
|
{ |
|
return alarm_try_to_cancel(&timr->it.alarm.alarmtimer); |
|
} |
|
|
|
/** |
|
* alarm_timer_wait_running - Posix timer callback to wait for a timer |
|
* @timr: Pointer to the posixtimer data struct |
|
* |
|
* Called from the core code when timer cancel detected that the callback |
|
* is running. @timr is unlocked and rcu read lock is held to prevent it |
|
* from being freed. |
|
*/ |
|
static void alarm_timer_wait_running(struct k_itimer *timr) |
|
{ |
|
hrtimer_cancel_wait_running(&timr->it.alarm.alarmtimer.timer); |
|
} |
|
|
|
/** |
|
* alarm_timer_arm - Posix timer callback to arm a timer |
|
* @timr: Pointer to the posixtimer data struct |
|
* @expires: The new expiry time |
|
* @absolute: Expiry value is absolute time |
|
* @sigev_none: Posix timer does not deliver signals |
|
*/ |
|
static void alarm_timer_arm(struct k_itimer *timr, ktime_t expires, |
|
bool absolute, bool sigev_none) |
|
{ |
|
struct alarm *alarm = &timr->it.alarm.alarmtimer; |
|
struct alarm_base *base = &alarm_bases[alarm->type]; |
|
|
|
if (!absolute) |
|
expires = ktime_add_safe(expires, base->get_ktime()); |
|
if (sigev_none) |
|
alarm->node.expires = expires; |
|
else |
|
alarm_start(&timr->it.alarm.alarmtimer, expires); |
|
} |
|
|
|
/** |
|
* alarm_clock_getres - posix getres interface |
|
* @which_clock: clockid |
|
* @tp: timespec to fill |
|
* |
|
* Returns the granularity of underlying alarm base clock |
|
*/ |
|
static int alarm_clock_getres(const clockid_t which_clock, struct timespec64 *tp) |
|
{ |
|
if (!alarmtimer_get_rtcdev()) |
|
return -EINVAL; |
|
|
|
tp->tv_sec = 0; |
|
tp->tv_nsec = hrtimer_resolution; |
|
return 0; |
|
} |
|
|
|
/** |
|
* alarm_clock_get_timespec - posix clock_get_timespec interface |
|
* @which_clock: clockid |
|
* @tp: timespec to fill. |
|
* |
|
* Provides the underlying alarm base time in a tasks time namespace. |
|
*/ |
|
static int alarm_clock_get_timespec(clockid_t which_clock, struct timespec64 *tp) |
|
{ |
|
struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)]; |
|
|
|
if (!alarmtimer_get_rtcdev()) |
|
return -EINVAL; |
|
|
|
base->get_timespec(tp); |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* alarm_clock_get_ktime - posix clock_get_ktime interface |
|
* @which_clock: clockid |
|
* |
|
* Provides the underlying alarm base time in the root namespace. |
|
*/ |
|
static ktime_t alarm_clock_get_ktime(clockid_t which_clock) |
|
{ |
|
struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)]; |
|
|
|
if (!alarmtimer_get_rtcdev()) |
|
return -EINVAL; |
|
|
|
return base->get_ktime(); |
|
} |
|
|
|
/** |
|
* alarm_timer_create - posix timer_create interface |
|
* @new_timer: k_itimer pointer to manage |
|
* |
|
* Initializes the k_itimer structure. |
|
*/ |
|
static int alarm_timer_create(struct k_itimer *new_timer) |
|
{ |
|
enum alarmtimer_type type; |
|
|
|
if (!alarmtimer_get_rtcdev()) |
|
return -EOPNOTSUPP; |
|
|
|
if (!capable(CAP_WAKE_ALARM)) |
|
return -EPERM; |
|
|
|
type = clock2alarm(new_timer->it_clock); |
|
alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer); |
|
return 0; |
|
} |
|
|
|
/** |
|
* alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep |
|
* @alarm: ptr to alarm that fired |
|
* @now: time at the timer expiration |
|
* |
|
* Wakes up the task that set the alarmtimer |
|
* |
|
* Return: ALARMTIMER_NORESTART |
|
*/ |
|
static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm, |
|
ktime_t now) |
|
{ |
|
struct task_struct *task = (struct task_struct *)alarm->data; |
|
|
|
alarm->data = NULL; |
|
if (task) |
|
wake_up_process(task); |
|
return ALARMTIMER_NORESTART; |
|
} |
|
|
|
/** |
|
* alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation |
|
* @alarm: ptr to alarmtimer |
|
* @absexp: absolute expiration time |
|
* @type: alarm type (BOOTTIME/REALTIME). |
|
* |
|
* Sets the alarm timer and sleeps until it is fired or interrupted. |
|
*/ |
|
static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp, |
|
enum alarmtimer_type type) |
|
{ |
|
struct restart_block *restart; |
|
alarm->data = (void *)current; |
|
do { |
|
set_current_state(TASK_INTERRUPTIBLE); |
|
alarm_start(alarm, absexp); |
|
if (likely(alarm->data)) |
|
schedule(); |
|
|
|
alarm_cancel(alarm); |
|
} while (alarm->data && !signal_pending(current)); |
|
|
|
__set_current_state(TASK_RUNNING); |
|
|
|
destroy_hrtimer_on_stack(&alarm->timer); |
|
|
|
if (!alarm->data) |
|
return 0; |
|
|
|
if (freezing(current)) |
|
alarmtimer_freezerset(absexp, type); |
|
restart = ¤t->restart_block; |
|
if (restart->nanosleep.type != TT_NONE) { |
|
struct timespec64 rmt; |
|
ktime_t rem; |
|
|
|
rem = ktime_sub(absexp, alarm_bases[type].get_ktime()); |
|
|
|
if (rem <= 0) |
|
return 0; |
|
rmt = ktime_to_timespec64(rem); |
|
|
|
return nanosleep_copyout(restart, &rmt); |
|
} |
|
return -ERESTART_RESTARTBLOCK; |
|
} |
|
|
|
static void |
|
alarm_init_on_stack(struct alarm *alarm, enum alarmtimer_type type, |
|
enum alarmtimer_restart (*function)(struct alarm *, ktime_t)) |
|
{ |
|
hrtimer_init_on_stack(&alarm->timer, alarm_bases[type].base_clockid, |
|
HRTIMER_MODE_ABS); |
|
__alarm_init(alarm, type, function); |
|
} |
|
|
|
/** |
|
* alarm_timer_nsleep_restart - restartblock alarmtimer nsleep |
|
* @restart: ptr to restart block |
|
* |
|
* Handles restarted clock_nanosleep calls |
|
*/ |
|
static long __sched alarm_timer_nsleep_restart(struct restart_block *restart) |
|
{ |
|
enum alarmtimer_type type = restart->nanosleep.clockid; |
|
ktime_t exp = restart->nanosleep.expires; |
|
struct alarm alarm; |
|
|
|
alarm_init_on_stack(&alarm, type, alarmtimer_nsleep_wakeup); |
|
|
|
return alarmtimer_do_nsleep(&alarm, exp, type); |
|
} |
|
|
|
/** |
|
* alarm_timer_nsleep - alarmtimer nanosleep |
|
* @which_clock: clockid |
|
* @flags: determins abstime or relative |
|
* @tsreq: requested sleep time (abs or rel) |
|
* |
|
* Handles clock_nanosleep calls against _ALARM clockids |
|
*/ |
|
static int alarm_timer_nsleep(const clockid_t which_clock, int flags, |
|
const struct timespec64 *tsreq) |
|
{ |
|
enum alarmtimer_type type = clock2alarm(which_clock); |
|
struct restart_block *restart = ¤t->restart_block; |
|
struct alarm alarm; |
|
ktime_t exp; |
|
int ret = 0; |
|
|
|
if (!alarmtimer_get_rtcdev()) |
|
return -EOPNOTSUPP; |
|
|
|
if (flags & ~TIMER_ABSTIME) |
|
return -EINVAL; |
|
|
|
if (!capable(CAP_WAKE_ALARM)) |
|
return -EPERM; |
|
|
|
alarm_init_on_stack(&alarm, type, alarmtimer_nsleep_wakeup); |
|
|
|
exp = timespec64_to_ktime(*tsreq); |
|
/* Convert (if necessary) to absolute time */ |
|
if (flags != TIMER_ABSTIME) { |
|
ktime_t now = alarm_bases[type].get_ktime(); |
|
|
|
exp = ktime_add_safe(now, exp); |
|
} else { |
|
exp = timens_ktime_to_host(which_clock, exp); |
|
} |
|
|
|
ret = alarmtimer_do_nsleep(&alarm, exp, type); |
|
if (ret != -ERESTART_RESTARTBLOCK) |
|
return ret; |
|
|
|
/* abs timers don't set remaining time or restart */ |
|
if (flags == TIMER_ABSTIME) |
|
return -ERESTARTNOHAND; |
|
|
|
restart->nanosleep.clockid = type; |
|
restart->nanosleep.expires = exp; |
|
set_restart_fn(restart, alarm_timer_nsleep_restart); |
|
return ret; |
|
} |
|
|
|
const struct k_clock alarm_clock = { |
|
.clock_getres = alarm_clock_getres, |
|
.clock_get_ktime = alarm_clock_get_ktime, |
|
.clock_get_timespec = alarm_clock_get_timespec, |
|
.timer_create = alarm_timer_create, |
|
.timer_set = common_timer_set, |
|
.timer_del = common_timer_del, |
|
.timer_get = common_timer_get, |
|
.timer_arm = alarm_timer_arm, |
|
.timer_rearm = alarm_timer_rearm, |
|
.timer_forward = alarm_timer_forward, |
|
.timer_remaining = alarm_timer_remaining, |
|
.timer_try_to_cancel = alarm_timer_try_to_cancel, |
|
.timer_wait_running = alarm_timer_wait_running, |
|
.nsleep = alarm_timer_nsleep, |
|
}; |
|
#endif /* CONFIG_POSIX_TIMERS */ |
|
|
|
|
|
/* Suspend hook structures */ |
|
static const struct dev_pm_ops alarmtimer_pm_ops = { |
|
.suspend = alarmtimer_suspend, |
|
.resume = alarmtimer_resume, |
|
}; |
|
|
|
static struct platform_driver alarmtimer_driver = { |
|
.driver = { |
|
.name = "alarmtimer", |
|
.pm = &alarmtimer_pm_ops, |
|
} |
|
}; |
|
|
|
static void get_boottime_timespec(struct timespec64 *tp) |
|
{ |
|
ktime_get_boottime_ts64(tp); |
|
timens_add_boottime(tp); |
|
} |
|
|
|
/** |
|
* alarmtimer_init - Initialize alarm timer code |
|
* |
|
* This function initializes the alarm bases and registers |
|
* the posix clock ids. |
|
*/ |
|
static int __init alarmtimer_init(void) |
|
{ |
|
int error; |
|
int i; |
|
|
|
alarmtimer_rtc_timer_init(); |
|
|
|
/* Initialize alarm bases */ |
|
alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME; |
|
alarm_bases[ALARM_REALTIME].get_ktime = &ktime_get_real; |
|
alarm_bases[ALARM_REALTIME].get_timespec = ktime_get_real_ts64; |
|
alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME; |
|
alarm_bases[ALARM_BOOTTIME].get_ktime = &ktime_get_boottime; |
|
alarm_bases[ALARM_BOOTTIME].get_timespec = get_boottime_timespec; |
|
for (i = 0; i < ALARM_NUMTYPE; i++) { |
|
timerqueue_init_head(&alarm_bases[i].timerqueue); |
|
spin_lock_init(&alarm_bases[i].lock); |
|
} |
|
|
|
error = alarmtimer_rtc_interface_setup(); |
|
if (error) |
|
return error; |
|
|
|
error = platform_driver_register(&alarmtimer_driver); |
|
if (error) |
|
goto out_if; |
|
|
|
return 0; |
|
out_if: |
|
alarmtimer_rtc_interface_remove(); |
|
return error; |
|
} |
|
device_initcall(alarmtimer_init);
|
|
|