| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Alarmtimer interface |
| * |
| * This interface provides a timer which is similarto hrtimers, |
| * but triggers a RTC alarm if the box is suspend. |
| * |
| * This interface is influenced by the Android RTC Alarm timer |
| * interface. |
| * |
| * Copyright (C) 2010 IBM Corperation |
| * |
| * Author: John Stultz <john.stultz@linaro.org> |
| */ |
| #include <linux/time.h> |
| #include <linux/hrtimer.h> |
| #include <linux/timerqueue.h> |
| #include <linux/rtc.h> |
| #include <linux/sched/signal.h> |
| #include <linux/sched/debug.h> |
| #include <linux/alarmtimer.h> |
| #include <linux/mutex.h> |
| #include <linux/platform_device.h> |
| #include <linux/posix-timers.h> |
| #include <linux/workqueue.h> |
| #include <linux/freezer.h> |
| #include <linux/compat.h> |
| #include <linux/module.h> |
| |
| #include "posix-timers.h" |
| |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/alarmtimer.h> |
| |
| /** |
| * struct alarm_base - Alarm timer bases |
| * @lock: Lock for syncrhonized access to the base |
| * @timerqueue: Timerqueue head managing the list of events |
| * @gettime: Function to read the time correlating to the base |
| * @base_clockid: clockid for the base |
| */ |
| static struct alarm_base { |
| spinlock_t lock; |
| struct timerqueue_head timerqueue; |
| ktime_t (*gettime)(void); |
| clockid_t base_clockid; |
| } alarm_bases[ALARM_NUMTYPE]; |
| |
| #if defined(CONFIG_POSIX_TIMERS) || defined(CONFIG_RTC_CLASS) |
| /* freezer information to handle clock_nanosleep triggered wakeups */ |
| static enum alarmtimer_type freezer_alarmtype; |
| static ktime_t freezer_expires; |
| static ktime_t freezer_delta; |
| static DEFINE_SPINLOCK(freezer_delta_lock); |
| #endif |
| |
| #ifdef CONFIG_RTC_CLASS |
| static struct wakeup_source *ws; |
| |
| /* rtc timer and device for setting alarm wakeups at suspend */ |
| static struct rtc_timer rtctimer; |
| static struct rtc_device *rtcdev; |
| static DEFINE_SPINLOCK(rtcdev_lock); |
| |
| /** |
| * alarmtimer_get_rtcdev - Return selected rtcdevice |
| * |
| * This function returns the rtc device to use for wakealarms. |
| * If one has not already been chosen, it checks to see if a |
| * functional rtc device is available. |
| */ |
| struct rtc_device *alarmtimer_get_rtcdev(void) |
| { |
| unsigned long flags; |
| struct rtc_device *ret; |
| |
| spin_lock_irqsave(&rtcdev_lock, flags); |
| ret = rtcdev; |
| spin_unlock_irqrestore(&rtcdev_lock, flags); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(alarmtimer_get_rtcdev); |
| |
| static int alarmtimer_rtc_add_device(struct device *dev, |
| struct class_interface *class_intf) |
| { |
| unsigned long flags; |
| struct rtc_device *rtc = to_rtc_device(dev); |
| struct wakeup_source *__ws; |
| |
| if (rtcdev) |
| return -EBUSY; |
| |
| if (!rtc->ops->set_alarm) |
| return -1; |
| if (!device_may_wakeup(rtc->dev.parent)) |
| return -1; |
| |
| __ws = wakeup_source_register("alarmtimer"); |
| |
| spin_lock_irqsave(&rtcdev_lock, flags); |
| if (!rtcdev) { |
| if (!try_module_get(rtc->owner)) { |
| spin_unlock_irqrestore(&rtcdev_lock, flags); |
| return -1; |
| } |
| |
| rtcdev = rtc; |
| /* hold a reference so it doesn't go away */ |
| get_device(dev); |
| ws = __ws; |
| __ws = NULL; |
| } |
| spin_unlock_irqrestore(&rtcdev_lock, flags); |
| |
| wakeup_source_unregister(__ws); |
| |
| return 0; |
| } |
| |
| static inline void alarmtimer_rtc_timer_init(void) |
| { |
| rtc_timer_init(&rtctimer, NULL, NULL); |
| } |
| |
| static struct class_interface alarmtimer_rtc_interface = { |
| .add_dev = &alarmtimer_rtc_add_device, |
| }; |
| |
| static int alarmtimer_rtc_interface_setup(void) |
| { |
| alarmtimer_rtc_interface.class = rtc_class; |
| return class_interface_register(&alarmtimer_rtc_interface); |
| } |
| static void alarmtimer_rtc_interface_remove(void) |
| { |
| class_interface_unregister(&alarmtimer_rtc_interface); |
| } |
| #else |
| struct rtc_device *alarmtimer_get_rtcdev(void) |
| { |
| return NULL; |
| } |
| #define rtcdev (NULL) |
| static inline int alarmtimer_rtc_interface_setup(void) { return 0; } |
| static inline void alarmtimer_rtc_interface_remove(void) { } |
| static inline void alarmtimer_rtc_timer_init(void) { } |
| #endif |
| |
| /** |
| * 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. |
| * |
| * Adds alarm to a alarm_base timerqueue |
| * |
| * Must hold base->lock when calling. |
| */ |
| static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm) |
| { |
| if (alarm->state & ALARMTIMER_STATE_ENQUEUED) |
| timerqueue_del(&base->timerqueue, &alarm->node); |
| |
| timerqueue_add(&base->timerqueue, &alarm->node); |
| alarm->state |= ALARMTIMER_STATE_ENQUEUED; |
| } |
| |
| /** |
| * alarmtimer_dequeue - 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 |
| * |
| * Removes alarm to a alarm_base timerqueue |
| * |
| * Must hold base->lock when calling. |
| */ |
| static void alarmtimer_dequeue(struct alarm_base *base, struct alarm *alarm) |
| { |
| if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED)) |
| return; |
| |
| timerqueue_del(&base->timerqueue, &alarm->node); |
| alarm->state &= ~ALARMTIMER_STATE_ENQUEUED; |
| } |
| |
| |
| /** |
| * alarmtimer_fired - Handles alarm hrtimer being fired. |
| * @timer: pointer to hrtimer being run |
| * |
| * 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. |
| */ |
| static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer) |
| { |
| struct alarm *alarm = container_of(timer, struct alarm, timer); |
| struct alarm_base *base = &alarm_bases[alarm->type]; |
| unsigned long flags; |
| int ret = HRTIMER_NORESTART; |
| int restart = ALARMTIMER_NORESTART; |
| |
| spin_lock_irqsave(&base->lock, flags); |
| alarmtimer_dequeue(base, alarm); |
| spin_unlock_irqrestore(&base->lock, flags); |
| |
| if (alarm->function) |
| restart = alarm->function(alarm, base->gettime()); |
| |
| spin_lock_irqsave(&base->lock, flags); |
| if (restart != ALARMTIMER_NORESTART) { |
| hrtimer_set_expires(&alarm->timer, alarm->node.expires); |
| alarmtimer_enqueue(base, alarm); |
| ret = HRTIMER_RESTART; |
| } |
| spin_unlock_irqrestore(&base->lock, flags); |
| |
| trace_alarmtimer_fired(alarm, base->gettime()); |
| return ret; |
| |
| } |
| |
| ktime_t alarm_expires_remaining(const struct alarm *alarm) |
| { |
| struct alarm_base *base = &alarm_bases[alarm->type]; |
| return ktime_sub(alarm->node.expires, base->gettime()); |
| } |
| EXPORT_SYMBOL_GPL(alarm_expires_remaining); |
| |
| #ifdef CONFIG_RTC_CLASS |
| /** |
| * alarmtimer_suspend - Suspend time callback |
| * @dev: unused |
| * @state: unused |
| * |
| * When we are going into suspend, we look through the bases |
| * to see which is the soonest timer to expire. We then |
| * set an rtc timer to fire that far into the future, which |
| * will wake us from suspend. |
| */ |
| static int alarmtimer_suspend(struct device *dev) |
| { |
| ktime_t min, now, expires; |
| int i, ret, type; |
| struct rtc_device *rtc; |
| unsigned long flags; |
| struct rtc_time tm; |
| |
| spin_lock_irqsave(&freezer_delta_lock, flags); |
| min = freezer_delta; |
| expires = freezer_expires; |
| type = freezer_alarmtype; |
| freezer_delta = 0; |
| spin_unlock_irqrestore(&freezer_delta_lock, flags); |
| |
| rtc = alarmtimer_get_rtcdev(); |
| /* If we have no rtcdev, just return */ |
| if (!rtc) |
| return 0; |
| |
| /* Find the soonest timer to expire*/ |
| for (i = 0; i < ALARM_NUMTYPE; i++) { |
| struct alarm_base *base = &alarm_bases[i]; |
| struct timerqueue_node *next; |
| ktime_t delta; |
| |
| spin_lock_irqsave(&base->lock, flags); |
| next = timerqueue_getnext(&base->timerqueue); |
| spin_unlock_irqrestore(&base->lock, flags); |
| if (!next) |
| continue; |
| delta = ktime_sub(next->expires, base->gettime()); |
| if (!min || (delta < min)) { |
| expires = next->expires; |
| min = delta; |
| type = i; |
| } |
| } |
| if (min == 0) |
| return 0; |
| |
| if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) { |
| __pm_wakeup_event(ws, 2 * MSEC_PER_SEC); |
| return -EBUSY; |
| } |
| |
| trace_alarmtimer_suspend(expires, type); |
| |
| /* Setup an rtc timer to fire that far in the future */ |
| rtc_timer_cancel(rtc, &rtctimer); |
| rtc_read_time(rtc, &tm); |
| now = rtc_tm_to_ktime(tm); |
| now = ktime_add(now, min); |
| |
| /* Set alarm, if in the past reject suspend briefly to handle */ |
| ret = rtc_timer_start(rtc, &rtctimer, now, 0); |
| if (ret < 0) |
| __pm_wakeup_event(ws, MSEC_PER_SEC); |
| return ret; |
| } |
| |
| static int alarmtimer_resume(struct device *dev) |
| { |
| struct rtc_device *rtc; |
| |
| rtc = alarmtimer_get_rtcdev(); |
| if (rtc) |
| rtc_timer_cancel(rtc, &rtctimer); |
| return 0; |
| } |
| |
| #else |
| static int alarmtimer_suspend(struct device *dev) |
| { |
| return 0; |
| } |
| |
| static int alarmtimer_resume(struct device *dev) |
| { |
| return 0; |
| } |
| #endif |
| |
| static void |
| __alarm_init(struct alarm *alarm, enum alarmtimer_type type, |
| enum alarmtimer_restart (*function)(struct alarm *, ktime_t)) |
| { |
| timerqueue_init(&alarm->node); |
| alarm->timer.function = alarmtimer_fired; |
| alarm->function = function; |
| alarm->type = type; |
| alarm->state = ALARMTIMER_STATE_INACTIVE; |
| } |
| |
| /** |
| * 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 |
| */ |
| void alarm_init(struct alarm *alarm, enum alarmtimer_type type, |
| enum alarmtimer_restart (*function)(struct alarm *, ktime_t)) |
| { |
| hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid, |
| HRTIMER_MODE_ABS); |
| __alarm_init(alarm, type, function); |
| } |
| EXPORT_SYMBOL_GPL(alarm_init); |
| |
| /** |
| * alarm_start - Sets an absolute alarm to fire |
| * @alarm: ptr to alarm to set |
| * @start: time to run the alarm |
| */ |
| void alarm_start(struct alarm *alarm, ktime_t start) |
| { |
| struct alarm_base *base = &alarm_bases[alarm->type]; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&base->lock, flags); |
| alarm->node.expires = start; |
| alarmtimer_enqueue(base, alarm); |
| hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS); |
| spin_unlock_irqrestore(&base->lock, flags); |
| |
| trace_alarmtimer_start(alarm, base->gettime()); |
| } |
| EXPORT_SYMBOL_GPL(alarm_start); |
| |
| /** |
| * alarm_start_relative - Sets a relative alarm to fire |
| * @alarm: ptr to alarm to set |
| * @start: time relative to now to run the alarm |
| */ |
| void alarm_start_relative(struct alarm *alarm, ktime_t start) |
| { |
| struct alarm_base *base = &alarm_bases[alarm->type]; |
| |
| start = ktime_add_safe(start, base->gettime()); |
| alarm_start(alarm, start); |
| } |
| EXPORT_SYMBOL_GPL(alarm_start_relative); |
| |
| void alarm_restart(struct alarm *alarm) |
| { |
| struct alarm_base *base = &alarm_bases[alarm->type]; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&base->lock, flags); |
| hrtimer_set_expires(&alarm->timer, alarm->node.expires); |
| hrtimer_restart(&alarm->timer); |
| alarmtimer_enqueue(base, alarm); |
| spin_unlock_irqrestore(&base->lock, flags); |
| } |
| EXPORT_SYMBOL_GPL(alarm_restart); |
| |
| /** |
| * alarm_try_to_cancel - Tries to cancel an alarm timer |
| * @alarm: ptr to alarm to be canceled |
| * |
| * Returns 1 if the timer was canceled, 0 if it was not running, |
| * and -1 if the callback was running |
| */ |
| int alarm_try_to_cancel(struct alarm *alarm) |
| { |
| struct alarm_base *base = &alarm_bases[alarm->type]; |
| unsigned long flags; |
| int ret; |
| |
| spin_lock_irqsave(&base->lock, flags); |
| ret = hrtimer_try_to_cancel(&alarm->timer); |
| if (ret >= 0) |
| alarmtimer_dequeue(base, alarm); |
| spin_unlock_irqrestore(&base->lock, flags); |
| |
| trace_alarmtimer_cancel(alarm, base->gettime()); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(alarm_try_to_cancel); |
| |
| |
| /** |
| * alarm_cancel - Spins trying to cancel an alarm timer until it is done |
| * @alarm: ptr to alarm to be canceled |
| * |
| * Returns 1 if the timer was canceled, 0 if it was not active. |
| */ |
| int alarm_cancel(struct alarm *alarm) |
| { |
| for (;;) { |
| int ret = alarm_try_to_cancel(alarm); |
| if (ret >= 0) |
| return ret; |
| cpu_relax(); |
| } |
| } |
| EXPORT_SYMBOL_GPL(alarm_cancel); |
| |
| |
| u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval) |
| { |
| u64 overrun = 1; |
| ktime_t delta; |
| |
| delta = ktime_sub(now, alarm->node.expires); |
| |
| if (delta < 0) |
| return 0; |
| |
| if (unlikely(delta >= interval)) { |
| s64 incr = ktime_to_ns(interval); |
| |
| overrun = ktime_divns(delta, incr); |
| |
| alarm->node.expires = ktime_add_ns(alarm->node.expires, |
| incr*overrun); |
| |
| if (alarm->node.expires > now) |
| return overrun; |
| /* |
| * This (and the ktime_add() below) is the |
| * correction for exact: |
| */ |
| overrun++; |
| } |
| |
| alarm->node.expires = ktime_add_safe(alarm->node.expires, interval); |
| return overrun; |
| } |
| EXPORT_SYMBOL_GPL(alarm_forward); |
| |
| u64 alarm_forward_now(struct alarm *alarm, ktime_t interval) |
| { |
| struct alarm_base *base = &alarm_bases[alarm->type]; |
| |
| return alarm_forward(alarm, base->gettime(), interval); |
| } |
| EXPORT_SYMBOL_GPL(alarm_forward_now); |
| |
| #ifdef CONFIG_POSIX_TIMERS |
| |
| static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type) |
| { |
| struct alarm_base *base; |
| unsigned long flags; |
| ktime_t delta; |
| |
| switch(type) { |
| case ALARM_REALTIME: |
| base = &alarm_bases[ALARM_REALTIME]; |
| type = ALARM_REALTIME_FREEZER; |
| break; |
| case ALARM_BOOTTIME: |
| base = &alarm_bases[ALARM_BOOTTIME]; |
| type = ALARM_BOOTTIME_FREEZER; |
| break; |
| default: |
| WARN_ONCE(1, "Invalid alarm type: %d\n", type); |
| return; |
| } |
| |
| delta = ktime_sub(absexp, base->gettime()); |
| |
| spin_lock_irqsave(&freezer_delta_lock, flags); |
| if (!freezer_delta || (delta < freezer_delta)) { |
| freezer_delta = delta; |
| freezer_expires = absexp; |
| freezer_alarmtype = type; |
| } |
| 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) |
| { |
| 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 |
| * |
| * Posix timer callback for expired alarm timers. |
| */ |
| 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; |
| unsigned long flags; |
| int si_private = 0; |
| |
| spin_lock_irqsave(&ptr->it_lock, flags); |
| |
| ptr->it_active = 0; |
| if (ptr->it_interval) |
| 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_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->gettime()); |
| 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 - posix clock_get interface |
| * @which_clock: clockid |
| * @tp: timespec to fill. |
| * |
| * Provides the underlying alarm base time. |
| */ |
| static int alarm_clock_get(clockid_t which_clock, struct timespec64 *tp) |
| { |
| struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)]; |
| |
| if (!alarmtimer_get_rtcdev()) |
| return -EINVAL; |
| |
| *tp = ktime_to_timespec64(base->gettime()); |
| return 0; |
| } |
| |
| /** |
| * 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 -ENOTSUPP; |
| |
| 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 |
| * |
| * Wakes up the task that set the alarmtimer |
| */ |
| 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 |
| * |
| * 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].gettime()); |
| |
| 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) |
| * @rmtp: remaining sleep time saved |
| * |
| * 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 -ENOTSUPP; |
| |
| 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].gettime(); |
| |
| exp = ktime_add_safe(now, 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->fn = alarm_timer_nsleep_restart; |
| restart->nanosleep.clockid = type; |
| restart->nanosleep.expires = exp; |
| return ret; |
| } |
| |
| const struct k_clock alarm_clock = { |
| .clock_getres = alarm_clock_getres, |
| .clock_get = alarm_clock_get, |
| .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, |
| .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, |
| } |
| }; |
| |
| /** |
| * alarmtimer_init - Initialize alarm timer code |
| * |
| * This function initializes the alarm bases and registers |
| * the posix clock ids. |
| */ |
| static int __init alarmtimer_init(void) |
| { |
| struct platform_device *pdev; |
| int error = 0; |
| int i; |
| |
| alarmtimer_rtc_timer_init(); |
| |
| /* Initialize alarm bases */ |
| alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME; |
| alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real; |
| alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME; |
| alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime; |
| 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; |
| |
| pdev = platform_device_register_simple("alarmtimer", -1, NULL, 0); |
| if (IS_ERR(pdev)) { |
| error = PTR_ERR(pdev); |
| goto out_drv; |
| } |
| return 0; |
| |
| out_drv: |
| platform_driver_unregister(&alarmtimer_driver); |
| out_if: |
| alarmtimer_rtc_interface_remove(); |
| return error; |
| } |
| device_initcall(alarmtimer_init); |