diff options
| -rw-r--r-- | include/linux/time.h | 2 | ||||
| -rw-r--r-- | kernel/time/timekeeping.c | 37 |
2 files changed, 39 insertions, 0 deletions
diff --git a/include/linux/time.h b/include/linux/time.h index dda9be685ab..4bb05a829be 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -116,6 +116,8 @@ extern int do_setitimer(int which, struct itimerval *value, extern unsigned int alarm_setitimer(unsigned int seconds); extern int do_getitimer(int which, struct itimerval *value); extern void getnstimeofday(struct timespec *tv); +extern void getboottime(struct timespec *ts); +extern void monotonic_to_bootbased(struct timespec *ts); extern struct timespec timespec_trunc(struct timespec t, unsigned gran); extern int timekeeping_is_continuous(void); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 3d1042f82a6..728cedfd3cb 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -36,9 +36,17 @@ EXPORT_SYMBOL(xtime_lock); * at zero at system boot time, so wall_to_monotonic will be negative, * however, we will ALWAYS keep the tv_nsec part positive so we can use * the usual normalization. + * + * wall_to_monotonic is moved after resume from suspend for the monotonic + * time not to jump. We need to add total_sleep_time to wall_to_monotonic + * to get the real boot based time offset. + * + * - wall_to_monotonic is no longer the boot time, getboottime must be + * used instead. */ struct timespec xtime __attribute__ ((aligned (16))); struct timespec wall_to_monotonic __attribute__ ((aligned (16))); +static unsigned long total_sleep_time; /* seconds */ EXPORT_SYMBOL(xtime); @@ -251,6 +259,7 @@ void __init timekeeping_init(void) xtime.tv_nsec = 0; set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec); + total_sleep_time = 0; write_sequnlock_irqrestore(&xtime_lock, flags); } @@ -282,6 +291,7 @@ static int timekeeping_resume(struct sys_device *dev) xtime.tv_sec += sleep_length; wall_to_monotonic.tv_sec -= sleep_length; + total_sleep_time += sleep_length; } /* re-base the last cycle value */ clock->cycle_last = clocksource_read(clock); @@ -476,3 +486,30 @@ void update_wall_time(void) change_clocksource(); update_vsyscall(&xtime, clock); } + +/** + * getboottime - Return the real time of system boot. + * @ts: pointer to the timespec to be set + * + * Returns the time of day in a timespec. + * + * This is based on the wall_to_monotonic offset and the total suspend + * time. Calls to settimeofday will affect the value returned (which + * basically means that however wrong your real time clock is at boot time, + * you get the right time here). + */ +void getboottime(struct timespec *ts) +{ + set_normalized_timespec(ts, + - (wall_to_monotonic.tv_sec + total_sleep_time), + - wall_to_monotonic.tv_nsec); +} + +/** + * monotonic_to_bootbased - Convert the monotonic time to boot based. + * @ts: pointer to the timespec to be converted + */ +void monotonic_to_bootbased(struct timespec *ts) +{ + ts->tv_sec += total_sleep_time; +} |