// SPDX-License-Identifier: GPL-2.0
/*
* Alarmtimer interface
*
* This interface provides a timer which is similar to 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 Corporation
*
* Author: John Stultz <[email protected]>
*/
#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 <linux/time_namespace.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
* @get_ktime: Function to read the time correlating to the base
* @get_timespec: Function to read the namespace time correlating to the base
* @base_clockid: clockid for the base
*/
static struct alarm_base {
spinlock_t lock;
struct timerqueue_head timerqueue;
ktime_t (*get_ktime)(void);
void (*get_timespec)(struct timespec64 *tp);
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
/* 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.
*/
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)
{
unsigned long flags;
struct rtc_device *rtc = to_rtc_device(dev);
struct platform_device *pdev;
int ret = 0;
if (rtcdev)
return -EBUSY;
if (!test_bit(RTC_FEATURE_ALARM, rtc->features))
return -1;
if (!device_may_wakeup(rtc->dev.parent))
return -1;
pdev = platform_device_register_data(dev, "alarmtimer",
PLATFORM_DEVID_AUTO, NULL, 0);
if (!IS_ERR(pdev))
device_init_wakeup(&pdev->dev, true);
spin_lock_irqsave(&rtcdev_lock, flags);
if (!IS_ERR(pdev) && !rtcdev) {
if (!try_module_get(rtc->owner)) {
ret = -1;
goto unlock;
}
rtcdev = rtc;
/* hold a reference so it doesn't go away */
get_device(dev);
pdev = NULL;
} else {
ret = -1;
}
unlock:
spin_unlock_irqrestore(&rtcdev_lock, flags);
platform_device_unregister(pdev);
return ret;
}
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
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
* 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->get_ktime());
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->get_ktime());
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->get_ktime());
}
EXPORT_SYMBOL_GPL(alarm_expires_remaining);
#ifdef CONFIG_RTC_CLASS
/**
* alarmtimer_suspend - Suspend time callback
* @dev: 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->get_ktime());
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(dev, 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);
/*
* If the RTC alarm timer only supports a limited time offset, set the
* alarm time to the maximum supported value.
* The system may wake up earlier (possibly much earlier) than expected
* when the alarmtimer runs. This is the best the kernel can do if
* the alarmtimer exceeds the time that the rtc device can be programmed
* for.
*/
min = rtc_bound_alarmtime(rtc, min);
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(dev, 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->get_ktime());
}
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->get_ktime());
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->get_ktime());
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;
hrtimer_cancel_wait_running(&alarm->timer);
}
}
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);
static u64 __alarm_forward_now(struct alarm *alarm, ktime_t interval, bool throttle)
{
struct alarm_base *base = &alarm_bases[alarm->type];
ktime_t now = base->get_ktime();
if (IS_ENABLED(CONFIG_HIGH_RES_TIMERS) && throttle) {
/*
* Same issue as with posix_timer_fn(). Timers which are
* periodic but the signal is ignored can starve the system
* with a very small interval. The real fix which was
* promised in the context of posix_timer_fn() never
* materialized, but someone should really work on it.
*
* To prevent DOS fake @now to be 1 jiffy out which keeps
* the overrun accounting correct but creates an
* inconsistency vs. timer_gettime(2).
*/
ktime_t kj = NSEC_PER_SEC / HZ;
if (interval < kj)
now = ktime_add(now, kj);
}
return alarm_forward(alarm, now, interval);
}
u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
{
return __alarm_forward_now(alarm, interval, false);
}
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->get_ktime());
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
* @now: time at the timer expiration
*
* Posix timer callback for expired alarm timers.
*
* 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;
unsigned long flags;
spin_lock_irqsave(&ptr->it_lock, flags);
if (posix_timer_queue_signal(ptr) && ptr->it_interval) {
/*
* Handle ignored signals and rearm the timer. This will go
* away once we handle ignored signals proper. Ensure that
* small intervals cannot starve the system.
*/
ptr->it_overrun += __alarm_forward_now(alarm, ptr->it_interval, true);
++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 = 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: determines 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;
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);
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