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Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

Browse Source 
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  hrtimer: Make lookup table const
  RTC: Disable CONFIG_RTC_CLASS from being built as a module
  timers: Fix alarmtimer build issues when CONFIG_RTC_CLASS=n
  timers: Remove delayed irqwork from alarmtimers implementation
  timers: Improve alarmtimer comments and minor fixes
  timers: Posix interface for alarm-timers
  timers: Introduce in-kernel alarm-timer interface
  timers: Add rb_init_node() to allow for stack allocated rb nodes
  time: Add timekeeping_inject_sleeptime
This commit is contained in:
Linus Torvalds 2011-05-19 17:45:08 -07:00
commit 78c4def67e
12 changed files with 820 additions and 26 deletions
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7
drivers/rtc/Kconfig
View File

@ -3,10 +3,10 @@
#
config RTC_LIB
tristate
bool
menuconfig RTC_CLASS
tristate "Real Time Clock"
bool "Real Time Clock"
default n
depends on !S390
select RTC_LIB
@ -15,9 +15,6 @@ menuconfig RTC_CLASS
be allowed to plug one or more RTCs to your system. You will
probably want to enable one or more of the interfaces below.
This driver can also be built as a module. If so, the module
will be called rtc-core.
if RTC_CLASS
config RTC_HCTOSYS

23
drivers/rtc/class.c
View File

@ -41,26 +41,21 @@ static void rtc_device_release(struct device *dev)
* system's wall clock; restore it on resume().
*/
static struct timespec delta;
static time_t oldtime;
static struct timespec oldts;
static int rtc_suspend(struct device *dev, pm_message_t mesg)
{
struct rtc_device *rtc = to_rtc_device(dev);
struct rtc_time tm;
struct timespec ts = current_kernel_time();
if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
return 0;
rtc_read_time(rtc, &tm);
ktime_get_ts(&oldts);
rtc_tm_to_time(&tm, &oldtime);
/* RTC precision is 1 second; adjust delta for avg 1/2 sec err */
set_normalized_timespec(&delta,
ts.tv_sec - oldtime,
ts.tv_nsec - (NSEC_PER_SEC >> 1));
return 0;
}
@ -70,10 +65,12 @@ static int rtc_resume(struct device *dev)
struct rtc_time tm;
time_t newtime;
struct timespec time;
struct timespec newts;
if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
return 0;
ktime_get_ts(&newts);
rtc_read_time(rtc, &tm);
if (rtc_valid_tm(&tm) != 0) {
pr_debug("%s: bogus resume time\n", dev_name(&rtc->dev));
@ -85,15 +82,13 @@ static int rtc_resume(struct device *dev)
pr_debug("%s: time travel!\n", dev_name(&rtc->dev));
return 0;
}
/* calculate the RTC time delta */
set_normalized_timespec(&time, newtime - oldtime, 0);
/* restore wall clock using delta against this RTC;
* adjust again for avg 1/2 second RTC sampling error
*/
set_normalized_timespec(&time,
newtime + delta.tv_sec,
(NSEC_PER_SEC >> 1) + delta.tv_nsec);
do_settimeofday(&time);
/* subtract kernel time between rtc_suspend to rtc_resume */
time = timespec_sub(time, timespec_sub(newts, oldts));
timekeeping_inject_sleeptime(&time);
return 0;
}

40
include/linux/alarmtimer.h Normal file
View File

@ -0,0 +1,40 @@
#ifndef _LINUX_ALARMTIMER_H
#define _LINUX_ALARMTIMER_H
#include <linux/time.h>
#include <linux/hrtimer.h>
#include <linux/timerqueue.h>
#include <linux/rtc.h>
enum alarmtimer_type {
ALARM_REALTIME,
ALARM_BOOTTIME,
ALARM_NUMTYPE,
};
/**
* struct alarm - Alarm timer structure
* @node: timerqueue node for adding to the event list this value
* also includes the expiration time.
* @period: Period for recuring alarms
* @function: Function pointer to be executed when the timer fires.
* @type: Alarm type (BOOTTIME/REALTIME)
* @enabled: Flag that represents if the alarm is set to fire or not
* @data: Internal data value.
*/
struct alarm {
struct timerqueue_node node;
ktime_t period;
void (*function)(struct alarm *);
enum alarmtimer_type type;
bool enabled;
void *data;
};
void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
void (*function)(struct alarm *));
void alarm_start(struct alarm *alarm, ktime_t start, ktime_t period);
void alarm_cancel(struct alarm *alarm);
#endif

7
include/linux/capability.h
View File

@ -355,7 +355,12 @@ struct cpu_vfs_cap_data {
#define CAP_SYSLOG 34
#define CAP_LAST_CAP CAP_SYSLOG
/* Allow triggering something that will wake the system */
#define CAP_WAKE_ALARM 35
#define CAP_LAST_CAP CAP_WAKE_ALARM
#define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP)

2
include/linux/posix-timers.h
View File

@ -5,6 +5,7 @@
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/timex.h>
#include <linux/alarmtimer.h>
union cpu_time_count {
cputime_t cpu;
@ -80,6 +81,7 @@ struct k_itimer {
unsigned long incr;
unsigned long expires;
} mmtimer;
struct alarm alarmtimer;
} it;
};

8
include/linux/rbtree.h
View File

@ -136,6 +136,14 @@ static inline void rb_set_color(struct rb_node *rb, int color)
#define RB_EMPTY_NODE(node) (rb_parent(node) == node)
#define RB_CLEAR_NODE(node) (rb_set_parent(node, node))
static inline void rb_init_node(struct rb_node *rb)
{
rb->rb_parent_color = 0;
rb->rb_right = NULL;
rb->rb_left = NULL;
RB_CLEAR_NODE(rb);
}
extern void rb_insert_color(struct rb_node *, struct rb_root *);
extern void rb_erase(struct rb_node *, struct rb_root *);

3
include/linux/time.h
View File

@ -126,6 +126,7 @@ struct timespec __current_kernel_time(void); /* does not take xtime_lock */
struct timespec get_monotonic_coarse(void);
void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
struct timespec *wtom, struct timespec *sleep);
void timekeeping_inject_sleeptime(struct timespec *delta);
#define CURRENT_TIME (current_kernel_time())
#define CURRENT_TIME_SEC ((struct timespec) { get_seconds(), 0 })
@ -294,6 +295,8 @@ struct itimerval {
#define CLOCK_REALTIME_COARSE 5
#define CLOCK_MONOTONIC_COARSE 6
#define CLOCK_BOOTTIME 7
#define CLOCK_REALTIME_ALARM 8
#define CLOCK_BOOTTIME_ALARM 9
/*
* The IDs of various hardware clocks:

2
include/linux/timerqueue.h
View File

@ -39,7 +39,7 @@ struct timerqueue_node *timerqueue_getnext(struct timerqueue_head *head)
static inline void timerqueue_init(struct timerqueue_node *node)
{
RB_CLEAR_NODE(&node->node);
rb_init_node(&node->node);
}
static inline void timerqueue_init_head(struct timerqueue_head *head)

2
kernel/hrtimer.c
View File

@ -81,7 +81,7 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
}
};
static int hrtimer_clock_to_base_table[MAX_CLOCKS] = {
static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = {
[CLOCK_REALTIME] = HRTIMER_BASE_REALTIME,
[CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC,
[CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME,

2
kernel/time/Makefile
View File

@ -1,5 +1,5 @@
obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o timecompare.o
obj-y += timeconv.o posix-clock.o
obj-y += timeconv.o posix-clock.o alarmtimer.o
obj-$(CONFIG_GENERIC_CLOCKEVENTS_BUILD) += clockevents.o
obj-$(CONFIG_GENERIC_CLOCKEVENTS) += tick-common.o

694
kernel/time/alarmtimer.c Normal file
View File

@ -0,0 +1,694 @@
/*
* 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/alarmtimer.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/posix-timers.h>
#include <linux/workqueue.h>
#include <linux/freezer.h>
/**
* struct alarm_base - Alarm timer bases
* @lock: Lock for syncrhonized access to the base
* @timerqueue: Timerqueue head managing the list of events
* @timer: hrtimer used to schedule events while running
* @gettime: Function to read the time correlating to the base
* @base_clockid: clockid for the base
*/
static struct alarm_base {
spinlock_t lock;
struct timerqueue_head timerqueue;
struct hrtimer timer;
ktime_t (*gettime)(void);
clockid_t base_clockid;
} alarm_bases[ALARM_NUMTYPE];
#ifdef CONFIG_RTC_CLASS
/* rtc timer and device for setting alarm wakeups at suspend */
static struct rtc_timer rtctimer;
static struct rtc_device *rtcdev;
#endif
/* freezer delta & lock used to handle clock_nanosleep triggered wakeups */
static ktime_t freezer_delta;
static DEFINE_SPINLOCK(freezer_delta_lock);
/**
* 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 and if necessary sets
* an hrtimer to run.
*
* Must hold base->lock when calling.
*/
static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm)
{
timerqueue_add(&base->timerqueue, &alarm->node);
if (&alarm->node == timerqueue_getnext(&base->timerqueue)) {
hrtimer_try_to_cancel(&base->timer);
hrtimer_start(&base->timer, alarm->node.expires,
HRTIMER_MODE_ABS);
}
}
/**
* alarmtimer_remove - Removes an alarm timer from an alarm_base timerqueue
* @base: pointer to the base where the timer is running
* @alarm: pointer to alarm being removed
*
* Removes alarm to a alarm_base timerqueue and if necessary sets
* a new timer to run.
*
* Must hold base->lock when calling.
*/
static void alarmtimer_remove(struct alarm_base *base, struct alarm *alarm)
{
struct timerqueue_node *next = timerqueue_getnext(&base->timerqueue);
timerqueue_del(&base->timerqueue, &alarm->node);
if (next == &alarm->node) {
hrtimer_try_to_cancel(&base->timer);
next = timerqueue_getnext(&base->timerqueue);
if (!next)
return;
hrtimer_start(&base->timer, next->expires, HRTIMER_MODE_ABS);
}
}
/**
* 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_base *base = container_of(timer, struct alarm_base, timer);
struct timerqueue_node *next;
unsigned long flags;
ktime_t now;
int ret = HRTIMER_NORESTART;
spin_lock_irqsave(&base->lock, flags);
now = base->gettime();
while ((next = timerqueue_getnext(&base->timerqueue))) {
struct alarm *alarm;
ktime_t expired = next->expires;
if (expired.tv64 >= now.tv64)
break;
alarm = container_of(next, struct alarm, node);
timerqueue_del(&base->timerqueue, &alarm->node);
alarm->enabled = 0;
/* Re-add periodic timers */
if (alarm->period.tv64) {
alarm->node.expires = ktime_add(expired, alarm->period);
timerqueue_add(&base->timerqueue, &alarm->node);
alarm->enabled = 1;
}
spin_unlock_irqrestore(&base->lock, flags);
if (alarm->function)
alarm->function(alarm);
spin_lock_irqsave(&base->lock, flags);
}
if (next) {
hrtimer_set_expires(&base->timer, next->expires);
ret = HRTIMER_RESTART;
}
spin_unlock_irqrestore(&base->lock, flags);
return ret;
}
#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)
{
struct rtc_time tm;
ktime_t min, now;
unsigned long flags;
int i;
spin_lock_irqsave(&freezer_delta_lock, flags);
min = freezer_delta;
freezer_delta = ktime_set(0, 0);
spin_unlock_irqrestore(&freezer_delta_lock, flags);
/* If we have no rtcdev, just return */
if (!rtcdev)
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.tv64 || (delta.tv64 < min.tv64))
min = delta;
}
if (min.tv64 == 0)
return 0;
/* XXX - Should we enforce a minimum sleep time? */
WARN_ON(min.tv64 < NSEC_PER_SEC);
/* Setup an rtc timer to fire that far in the future */
rtc_timer_cancel(rtcdev, &rtctimer);
rtc_read_time(rtcdev, &tm);
now = rtc_tm_to_ktime(tm);
now = ktime_add(now, min);
rtc_timer_start(rtcdev, &rtctimer, now, ktime_set(0, 0));
return 0;
}
#else
static int alarmtimer_suspend(struct device *dev)
{
return 0;
}
#endif
static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
{
ktime_t delta;
unsigned long flags;
struct alarm_base *base = &alarm_bases[type];
delta = ktime_sub(absexp, base->gettime());
spin_lock_irqsave(&freezer_delta_lock, flags);
if (!freezer_delta.tv64 || (delta.tv64 < freezer_delta.tv64))
freezer_delta = delta;
spin_unlock_irqrestore(&freezer_delta_lock, flags);
}
/**
* 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,
void (*function)(struct alarm *))
{
timerqueue_init(&alarm->node);
alarm->period = ktime_set(0, 0);
alarm->function = function;
alarm->type = type;
alarm->enabled = 0;
}
/**
* alarm_start - Sets an alarm to fire
* @alarm: ptr to alarm to set
* @start: time to run the alarm
* @period: period at which the alarm will recur
*/
void alarm_start(struct alarm *alarm, ktime_t start, ktime_t period)
{
struct alarm_base *base = &alarm_bases[alarm->type];
unsigned long flags;
spin_lock_irqsave(&base->lock, flags);
if (alarm->enabled)
alarmtimer_remove(base, alarm);
alarm->node.expires = start;
alarm->period = period;
alarmtimer_enqueue(base, alarm);
alarm->enabled = 1;
spin_unlock_irqrestore(&base->lock, flags);
}
/**
* alarm_cancel - Tries to cancel an alarm timer
* @alarm: ptr to alarm to be canceled
*/
void alarm_cancel(struct alarm *alarm)
{
struct alarm_base *base = &alarm_bases[alarm->type];
unsigned long flags;
spin_lock_irqsave(&base->lock, flags);
if (alarm->enabled)
alarmtimer_remove(base, alarm);
alarm->enabled = 0;
spin_unlock_irqrestore(&base->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 void alarm_handle_timer(struct alarm *alarm)
{
struct k_itimer *ptr = container_of(alarm, struct k_itimer,
it.alarmtimer);
if (posix_timer_event(ptr, 0) != 0)
ptr->it_overrun++;
}
/**
* 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 timespec *tp)
{
clockid_t baseid = alarm_bases[clock2alarm(which_clock)].base_clockid;
return hrtimer_get_res(baseid, tp);
}
/**
* 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 timespec *tp)
{
struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)];
*tp = ktime_to_timespec(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;
struct alarm_base *base;
if (!capable(CAP_WAKE_ALARM))
return -EPERM;
type = clock2alarm(new_timer->it_clock);
base = &alarm_bases[type];
alarm_init(&new_timer->it.alarmtimer, type, alarm_handle_timer);
return 0;
}
/**
* alarm_timer_get - posix timer_get interface
* @new_timer: k_itimer pointer
* @cur_setting: itimerspec data to fill
*
* Copies the itimerspec data out from the k_itimer
*/
static void alarm_timer_get(struct k_itimer *timr,
struct itimerspec *cur_setting)
{
cur_setting->it_interval =
ktime_to_timespec(timr->it.alarmtimer.period);
cur_setting->it_value =
ktime_to_timespec(timr->it.alarmtimer.node.expires);
return;
}
/**
* alarm_timer_del - posix timer_del interface
* @timr: k_itimer pointer to be deleted
*
* Cancels any programmed alarms for the given timer.
*/
static int alarm_timer_del(struct k_itimer *timr)
{
alarm_cancel(&timr->it.alarmtimer);
return 0;
}
/**
* alarm_timer_set - posix timer_set interface
* @timr: k_itimer pointer to be deleted
* @flags: timer flags
* @new_setting: itimerspec to be used
* @old_setting: itimerspec being replaced
*
* Sets the timer to new_setting, and starts the timer.
*/
static int alarm_timer_set(struct k_itimer *timr, int flags,
struct itimerspec *new_setting,
struct itimerspec *old_setting)
{
/* Save old values */
old_setting->it_interval =
ktime_to_timespec(timr->it.alarmtimer.period);
old_setting->it_value =
ktime_to_timespec(timr->it.alarmtimer.node.expires);
/* If the timer was already set, cancel it */
alarm_cancel(&timr->it.alarmtimer);
/* start the timer */
alarm_start(&timr->it.alarmtimer,
timespec_to_ktime(new_setting->it_value),
timespec_to_ktime(new_setting->it_interval));
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 void alarmtimer_nsleep_wakeup(struct alarm *alarm)
{
struct task_struct *task = (struct task_struct *)alarm->data;
alarm->data = NULL;
if (task)
wake_up_process(task);
}
/**
* 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)
{
alarm->data = (void *)current;
do {
set_current_state(TASK_INTERRUPTIBLE);
alarm_start(alarm, absexp, ktime_set(0, 0));
if (likely(alarm->data))
schedule();
alarm_cancel(alarm);
} while (alarm->data && !signal_pending(current));
__set_current_state(TASK_RUNNING);
return (alarm->data == NULL);
}
/**
* update_rmtp - Update remaining timespec value
* @exp: expiration time
* @type: timer type
* @rmtp: user pointer to remaining timepsec value
*
* Helper function that fills in rmtp value with time between
* now and the exp value
*/
static int update_rmtp(ktime_t exp, enum alarmtimer_type type,
struct timespec __user *rmtp)
{
struct timespec rmt;
ktime_t rem;
rem = ktime_sub(exp, alarm_bases[type].gettime());
if (rem.tv64 <= 0)
return 0;
rmt = ktime_to_timespec(rem);
if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
return -EFAULT;
return 1;
}
/**
* 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.index;
ktime_t exp;
struct timespec __user *rmtp;
struct alarm alarm;
int ret = 0;
exp.tv64 = restart->nanosleep.expires;
alarm_init(&alarm, type, alarmtimer_nsleep_wakeup);
if (alarmtimer_do_nsleep(&alarm, exp))
goto out;
if (freezing(current))
alarmtimer_freezerset(exp, type);
rmtp = restart->nanosleep.rmtp;
if (rmtp) {
ret = update_rmtp(exp, type, rmtp);
if (ret <= 0)
goto out;
}
/* The other values in restart are already filled in */
ret = -ERESTART_RESTARTBLOCK;
out:
return ret;
}
/**
* 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,
struct timespec *tsreq, struct timespec __user *rmtp)
{
enum alarmtimer_type type = clock2alarm(which_clock);
struct alarm alarm;
ktime_t exp;
int ret = 0;
struct restart_block *restart;
if (!capable(CAP_WAKE_ALARM))
return -EPERM;
alarm_init(&alarm, type, alarmtimer_nsleep_wakeup);
exp = timespec_to_ktime(*tsreq);
/* Convert (if necessary) to absolute time */
if (flags != TIMER_ABSTIME) {
ktime_t now = alarm_bases[type].gettime();
exp = ktime_add(now, exp);
}
if (alarmtimer_do_nsleep(&alarm, exp))
goto out;
if (freezing(current))
alarmtimer_freezerset(exp, type);
/* abs timers don't set remaining time or restart */
if (flags == TIMER_ABSTIME) {
ret = -ERESTARTNOHAND;
goto out;
}
if (rmtp) {
ret = update_rmtp(exp, type, rmtp);
if (ret <= 0)
goto out;
}
restart = &current_thread_info()->restart_block;
restart->fn = alarm_timer_nsleep_restart;
restart->nanosleep.index = type;
restart->nanosleep.expires = exp.tv64;
restart->nanosleep.rmtp = rmtp;
ret = -ERESTART_RESTARTBLOCK;
out:
return ret;
}
/* Suspend hook structures */
static const struct dev_pm_ops alarmtimer_pm_ops = {
.suspend = alarmtimer_suspend,
};
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)
{
int error = 0;
int i;
struct k_clock alarm_clock = {
.clock_getres = alarm_clock_getres,
.clock_get = alarm_clock_get,
.timer_create = alarm_timer_create,
.timer_set = alarm_timer_set,
.timer_del = alarm_timer_del,
.timer_get = alarm_timer_get,
.nsleep = alarm_timer_nsleep,
};
posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock);
posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock);
/* 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);
hrtimer_init(&alarm_bases[i].timer,
alarm_bases[i].base_clockid,
HRTIMER_MODE_ABS);
alarm_bases[i].timer.function = alarmtimer_fired;
}
error = platform_driver_register(&alarmtimer_driver);
platform_device_register_simple("alarmtimer", -1, NULL, 0);
return error;
}
device_initcall(alarmtimer_init);
#ifdef CONFIG_RTC_CLASS
/**
* has_wakealarm - check rtc device has wakealarm ability
* @dev: current device
* @name_ptr: name to be returned
*
* This helper function checks to see if the rtc device can wake
* from suspend.
*/
static int __init has_wakealarm(struct device *dev, void *name_ptr)
{
struct rtc_device *candidate = to_rtc_device(dev);
if (!candidate->ops->set_alarm)
return 0;
if (!device_may_wakeup(candidate->dev.parent))
return 0;
*(const char **)name_ptr = dev_name(dev);
return 1;
}
/**
* alarmtimer_init_late - Late initializing of alarmtimer code
*
* This function locates a rtc device to use for wakealarms.
* Run as late_initcall to make sure rtc devices have been
* registered.
*/
static int __init alarmtimer_init_late(void)
{
char *str;
/* Find an rtc device and init the rtc_timer */
class_find_device(rtc_class, NULL, &str, has_wakealarm);
if (str)
rtcdev = rtc_class_open(str);
if (!rtcdev) {
printk(KERN_WARNING "No RTC device found, ALARM timers will"
" not wake from suspend");
}
rtc_timer_init(&rtctimer, NULL, NULL);
return 0;
}
#else
static int __init alarmtimer_init_late(void)
{
printk(KERN_WARNING "Kernel not built with RTC support, ALARM timers"
" will not wake from suspend");
return 0;
}
#endif
late_initcall(alarmtimer_init_late);

56
kernel/time/timekeeping.c
View File

@ -595,6 +595,58 @@ void __init timekeeping_init(void)
/* time in seconds when suspend began */
static struct timespec timekeeping_suspend_time;
/**
* __timekeeping_inject_sleeptime - Internal function to add sleep interval
* @delta: pointer to a timespec delta value
*
* Takes a timespec offset measuring a suspend interval and properly
* adds the sleep offset to the timekeeping variables.
*/
static void __timekeeping_inject_sleeptime(struct timespec *delta)
{
xtime = timespec_add(xtime, *delta);
wall_to_monotonic = timespec_sub(wall_to_monotonic, *delta);
total_sleep_time = timespec_add(total_sleep_time, *delta);
}
/**
* timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
* @delta: pointer to a timespec delta value
*
* This hook is for architectures that cannot support read_persistent_clock
* because their RTC/persistent clock is only accessible when irqs are enabled.
*
* This function should only be called by rtc_resume(), and allows
* a suspend offset to be injected into the timekeeping values.
*/
void timekeeping_inject_sleeptime(struct timespec *delta)
{
unsigned long flags;
struct timespec ts;
/* Make sure we don't set the clock twice */
read_persistent_clock(&ts);
if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
return;
write_seqlock_irqsave(&xtime_lock, flags);
timekeeping_forward_now();
__timekeeping_inject_sleeptime(delta);
timekeeper.ntp_error = 0;
ntp_clear();
update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
timekeeper.mult);
write_sequnlock_irqrestore(&xtime_lock, flags);
/* signal hrtimers about time change */
clock_was_set();
}
/**
* timekeeping_resume - Resumes the generic timekeeping subsystem.
*
@ -615,9 +667,7 @@ static void timekeeping_resume(void)
if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
ts = timespec_sub(ts, timekeeping_suspend_time);
xtime = timespec_add(xtime, ts);
wall_to_monotonic = timespec_sub(wall_to_monotonic, ts);
total_sleep_time = timespec_add(total_sleep_time, ts);
__timekeeping_inject_sleeptime(&ts);
}
/* re-base the last cycle value */
timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);