v4.19.13 snapshot.
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
new file mode 100644
index 0000000..fa5de5e
--- /dev/null
+++ b/kernel/time/alarmtimer.c
@@ -0,0 +1,904 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#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(now, alarm->node.expires);
+}
+
+/**
+ * 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);