Commit e2d8ccef authored by John Stultz's avatar John Stultz Committed by Greg Kroah-Hartman

staging: android-alarm: Convert ALARM_ELAPSED_REALTIME to use CLOCK_BOOTTIME

The ALARM_ELAPSED_REALTIME clock domain in Android pointed
to the need for something similar in linux system-wide
(instead of limited to just the alarm interface).

Thus CLOCK_BOOTTIME was introduced into the upstream kernel
in 2.6.39.

This patch attempts to convert the android alarm timer to utilize
the kernel's CLOCK_BOOTTIME clockid for ALARM_ELAPSED_REALTIME,
instead of managing it itself.

CC: Colin Cross <ccross@android.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Android Kernel Team <kernel-team@android.com>
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 8f9064a8
......@@ -179,8 +179,7 @@ static long alarm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
break;
case ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP:
case ANDROID_ALARM_ELAPSED_REALTIME:
tmp_time =
ktime_to_timespec(alarm_get_elapsed_realtime());
get_monotonic_boottime(&tmp_time);
break;
case ANDROID_ALARM_TYPE_COUNT:
case ANDROID_ALARM_SYSTEMTIME:
......
......@@ -65,7 +65,6 @@ struct alarm_queue {
struct rb_root alarms;
struct rb_node *first;
struct hrtimer timer;
ktime_t delta;
bool stopped;
ktime_t stopped_time;
};
......@@ -107,8 +106,8 @@ static void update_timer_locked(struct alarm_queue *base, bool head_removed)
}
hrtimer_try_to_cancel(&base->timer);
base->timer.node.expires = ktime_add(base->delta, alarm->expires);
base->timer._softexpires = ktime_add(base->delta, alarm->softexpires);
base->timer.node.expires = alarm->expires;
base->timer._softexpires = alarm->softexpires;
hrtimer_start_expires(&base->timer, HRTIMER_MODE_ABS);
}
......@@ -279,10 +278,6 @@ int android_alarm_set_rtc(struct timespec new_time)
alarms[i].stopped = true;
alarms[i].stopped_time = timespec_to_ktime(tmp_time);
}
alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].delta =
alarms[ANDROID_ALARM_ELAPSED_REALTIME].delta =
ktime_sub(alarms[ANDROID_ALARM_ELAPSED_REALTIME].delta,
timespec_to_ktime(timespec_sub(tmp_time, new_time)));
spin_unlock_irqrestore(&alarm_slock, flags);
ret = do_settimeofday(&new_time);
spin_lock_irqsave(&alarm_slock, flags);
......@@ -310,24 +305,6 @@ int android_alarm_set_rtc(struct timespec new_time)
return ret;
}
/**
* alarm_get_elapsed_realtime - get the elapsed real time in ktime_t format
*
* returns the time in ktime_t format
*/
ktime_t alarm_get_elapsed_realtime(void)
{
ktime_t now;
unsigned long flags;
struct alarm_queue *base = &alarms[ANDROID_ALARM_ELAPSED_REALTIME];
spin_lock_irqsave(&alarm_slock, flags);
now = base->stopped ? base->stopped_time : ktime_get_real();
now = ktime_sub(now, base->delta);
spin_unlock_irqrestore(&alarm_slock, flags);
return now;
}
static enum hrtimer_restart alarm_timer_triggered(struct hrtimer *timer)
{
struct alarm_queue *base;
......@@ -339,7 +316,6 @@ static enum hrtimer_restart alarm_timer_triggered(struct hrtimer *timer)
base = container_of(timer, struct alarm_queue, timer);
now = base->stopped ? base->stopped_time : hrtimer_cb_get_time(timer);
now = ktime_sub(now, base->delta);
pr_alarm(INT, "alarm_timer_triggered type %td at %lld\n",
base - alarms, ktime_to_ns(now));
......@@ -536,40 +512,25 @@ static struct platform_driver alarm_driver = {
}
};
static int __init alarm_late_init(void)
{
unsigned long flags;
struct timespec tmp_time, system_time;
/* this needs to run after the rtc is read at boot */
spin_lock_irqsave(&alarm_slock, flags);
/* We read the current rtc and system time so we can later calculate
* elasped realtime to be (boot_systemtime + rtc - boot_rtc) ==
* (rtc - (boot_rtc - boot_systemtime))
*/
getnstimeofday(&tmp_time);
ktime_get_ts(&system_time);
alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].delta =
alarms[ANDROID_ALARM_ELAPSED_REALTIME].delta =
timespec_to_ktime(timespec_sub(tmp_time, system_time));
spin_unlock_irqrestore(&alarm_slock, flags);
return 0;
}
static int __init alarm_driver_init(void)
{
int err;
int i;
for (i = 0; i < ANDROID_ALARM_SYSTEMTIME; i++) {
hrtimer_init(&alarms[i].timer,
hrtimer_init(&alarms[ANDROID_ALARM_RTC_WAKEUP].timer,
CLOCK_REALTIME, HRTIMER_MODE_ABS);
alarms[i].timer.function = alarm_timer_triggered;
}
hrtimer_init(&alarms[ANDROID_ALARM_RTC].timer,
CLOCK_REALTIME, HRTIMER_MODE_ABS);
hrtimer_init(&alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].timer,
CLOCK_BOOTTIME, HRTIMER_MODE_ABS);
hrtimer_init(&alarms[ANDROID_ALARM_ELAPSED_REALTIME].timer,
CLOCK_BOOTTIME, HRTIMER_MODE_ABS);
hrtimer_init(&alarms[ANDROID_ALARM_SYSTEMTIME].timer,
CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
alarms[ANDROID_ALARM_SYSTEMTIME].timer.function = alarm_timer_triggered;
for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++)
alarms[i].timer.function = alarm_timer_triggered;
err = platform_driver_register(&alarm_driver);
if (err < 0)
goto err1;
......@@ -595,7 +556,6 @@ static void __exit alarm_exit(void)
platform_driver_unregister(&alarm_driver);
}
late_initcall(alarm_late_init);
module_init(alarm_driver_init);
module_exit(alarm_exit);
......@@ -37,6 +37,7 @@ enum android_alarm_type {
#include <linux/ktime.h>
#include <linux/rbtree.h>
#include <linux/hrtimer.h>
/*
* The alarm interface is similar to the hrtimer interface but adds support
......@@ -71,7 +72,11 @@ void android_alarm_start_range(struct android_alarm *alarm, ktime_t start,
ktime_t end);
int android_alarm_try_to_cancel(struct android_alarm *alarm);
int android_alarm_cancel(struct android_alarm *alarm);
ktime_t alarm_get_elapsed_realtime(void);
static inline ktime_t alarm_get_elapsed_realtime(void)
{
return ktime_get_boottime();
}
/* set rtc while preserving elapsed realtime */
int android_alarm_set_rtc(const struct timespec ts);
......
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