* This read-write spinlock protects us from races in SMP while
* playing with xtime and avenrun.
*/
-__attribute__((weak)) __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
-
-EXPORT_SYMBOL(xtime_lock);
+__cacheline_aligned_in_smp DEFINE_SEQLOCK(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);
-
+static struct timespec xtime_cache __attribute__ ((aligned (16)));
+void update_xtime_cache(u64 nsec)
+{
+ xtime_cache = xtime;
+ timespec_add_ns(&xtime_cache, nsec);
+}
-static struct clocksource *clock; /* pointer to current clocksource */
+struct clocksource *clock;
#ifdef CONFIG_GENERIC_TIME
/**
- * __get_nsec_offset - Returns nanoseconds since last call to periodic_hook
+ * clocksource_forward_now - update clock to the current time
*
- * private function, must hold xtime_lock lock when being
- * called. Returns the number of nanoseconds since the
- * last call to update_wall_time() (adjusted by NTP scaling)
+ * Forward the current clock to update its state since the last call to
+ * update_wall_time(). This is useful before significant clock changes,
+ * as it avoids having to deal with this time offset explicitly.
*/
-static inline s64 __get_nsec_offset(void)
+static void clocksource_forward_now(void)
{
cycle_t cycle_now, cycle_delta;
- s64 ns_offset;
+ s64 nsec;
- /* read clocksource: */
cycle_now = clocksource_read(clock);
-
- /* calculate the delta since the last update_wall_time: */
cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
+ clock->cycle_last = cycle_now;
- /* convert to nanoseconds: */
- ns_offset = cyc2ns(clock, cycle_delta);
+ nsec = cyc2ns(clock, cycle_delta);
+ timespec_add_ns(&xtime, nsec);
- return ns_offset;
+ nsec = ((s64)cycle_delta * clock->mult_orig) >> clock->shift;
+ clock->raw_time.tv_nsec += nsec;
}
/**
- * __get_realtime_clock_ts - Returns the time of day in a timespec
+ * getnstimeofday - Returns the time of day in a timespec
* @ts: pointer to the timespec to be set
*
- * Returns the time of day in a timespec. Used by
- * do_gettimeofday() and get_realtime_clock_ts().
+ * Returns the time of day in a timespec.
*/
-static inline void __get_realtime_clock_ts(struct timespec *ts)
+void getnstimeofday(struct timespec *ts)
{
+ cycle_t cycle_now, cycle_delta;
unsigned long seq;
s64 nsecs;
seq = read_seqbegin(&xtime_lock);
*ts = xtime;
- nsecs = __get_nsec_offset();
+
+ /* read clocksource: */
+ cycle_now = clocksource_read(clock);
+
+ /* calculate the delta since the last update_wall_time: */
+ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
+
+ /* convert to nanoseconds: */
+ nsecs = cyc2ns(clock, cycle_delta);
} while (read_seqretry(&xtime_lock, seq));
timespec_add_ns(ts, nsecs);
}
-/**
- * getnstimeofday - Returns the time of day in a timespec
- * @ts: pointer to the timespec to be set
- *
- * Returns the time of day in a timespec.
- */
-void getnstimeofday(struct timespec *ts)
-{
- __get_realtime_clock_ts(ts);
-}
-
EXPORT_SYMBOL(getnstimeofday);
/**
* do_gettimeofday - Returns the time of day in a timeval
* @tv: pointer to the timeval to be set
*
- * NOTE: Users should be converted to using get_realtime_clock_ts()
+ * NOTE: Users should be converted to using getnstimeofday()
*/
void do_gettimeofday(struct timeval *tv)
{
struct timespec now;
- __get_realtime_clock_ts(&now);
+ getnstimeofday(&now);
tv->tv_sec = now.tv_sec;
tv->tv_usec = now.tv_nsec/1000;
}
*/
int do_settimeofday(struct timespec *tv)
{
+ struct timespec ts_delta;
unsigned long flags;
- time_t wtm_sec, sec = tv->tv_sec;
- long wtm_nsec, nsec = tv->tv_nsec;
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
write_seqlock_irqsave(&xtime_lock, flags);
- nsec -= __get_nsec_offset();
+ clocksource_forward_now();
+
+ ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec;
+ ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec;
+ wall_to_monotonic = timespec_sub(wall_to_monotonic, ts_delta);
- wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
- wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+ xtime = *tv;
- set_normalized_timespec(&xtime, sec, nsec);
- set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
+ update_xtime_cache(0);
clock->error = 0;
ntp_clear();
static void change_clocksource(void)
{
struct clocksource *new;
- cycle_t now;
- u64 nsec;
new = clocksource_get_next();
if (clock == new)
return;
- now = clocksource_read(new);
- nsec = __get_nsec_offset();
- timespec_add_ns(&xtime, nsec);
+ clocksource_forward_now();
- clock = new;
- clock->cycle_last = now;
+ new->raw_time = clock->raw_time;
+ clock = new;
+ clock->cycle_last = 0;
+ clock->cycle_last = clocksource_read(new);
clock->error = 0;
clock->xtime_nsec = 0;
clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
tick_clock_notify();
+ /*
+ * We're holding xtime lock and waking up klogd would deadlock
+ * us on enqueue. So no printing!
printk(KERN_INFO "Time: %s clocksource has been installed.\n",
clock->name);
+ */
}
#else
+static inline void clocksource_forward_now(void) { }
static inline void change_clocksource(void) { }
#endif
/**
- * timekeeping_is_continuous - check to see if timekeeping is free running
+ * getrawmonotonic - Returns the raw monotonic time in a timespec
+ * @ts: pointer to the timespec to be set
+ *
+ * Returns the raw monotonic time (completely un-modified by ntp)
*/
-int timekeeping_is_continuous(void)
+void getrawmonotonic(struct timespec *ts)
+{
+ unsigned long seq;
+ s64 nsecs;
+ cycle_t cycle_now, cycle_delta;
+
+ do {
+ seq = read_seqbegin(&xtime_lock);
+
+ /* read clocksource: */
+ cycle_now = clocksource_read(clock);
+
+ /* calculate the delta since the last update_wall_time: */
+ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
+
+ /* convert to nanoseconds: */
+ nsecs = ((s64)cycle_delta * clock->mult_orig) >> clock->shift;
+
+ *ts = clock->raw_time;
+
+ } while (read_seqretry(&xtime_lock, seq));
+
+ timespec_add_ns(ts, nsecs);
+}
+EXPORT_SYMBOL(getrawmonotonic);
+
+
+/**
+ * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
+ */
+int timekeeping_valid_for_hres(void)
{
unsigned long seq;
int ret;
write_seqlock_irqsave(&xtime_lock, flags);
- ntp_clear();
+ ntp_init();
clock = clocksource_get_next();
clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH);
xtime.tv_nsec = 0;
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
-
+ update_xtime_cache(0);
+ total_sleep_time = 0;
write_sequnlock_irqrestore(&xtime_lock, flags);
}
unsigned long flags;
unsigned long now = read_persistent_clock();
+ clocksource_resume();
+
write_seqlock_irqsave(&xtime_lock, flags);
if (now && (now > timekeeping_suspend_time)) {
xtime.tv_sec += sleep_length;
wall_to_monotonic.tv_sec -= sleep_length;
+ total_sleep_time += sleep_length;
}
+ update_xtime_cache(0);
/* re-base the last cycle value */
+ clock->cycle_last = 0;
clock->cycle_last = clocksource_read(clock);
clock->error = 0;
timekeeping_suspended = 0;
{
unsigned long flags;
+ timekeeping_suspend_time = read_persistent_clock();
+
write_seqlock_irqsave(&xtime_lock, flags);
+ clocksource_forward_now();
timekeeping_suspended = 1;
- timekeeping_suspend_time = read_persistent_clock();
write_sequnlock_irqrestore(&xtime_lock, flags);
clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
/* sysfs resume/suspend bits for timekeeping */
static struct sysdev_class timekeeping_sysclass = {
+ .name = "timekeeping",
.resume = timekeeping_resume,
.suspend = timekeeping_suspend,
- set_kset_name("timekeeping"),
};
static struct sys_device device_timer = {
* with losing too many ticks, otherwise we would overadjust and
* produce an even larger error. The smaller the adjustment the
* faster we try to adjust for it, as lost ticks can do less harm
- * here. This is tuned so that an error of about 1 msec is adusted
+ * here. This is tuned so that an error of about 1 msec is adjusted
* within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks).
*/
- error2 = clock->error >> (TICK_LENGTH_SHIFT + 22 - 2 * SHIFT_HZ);
+ error2 = clock->error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ);
error2 = abs(error2);
for (look_ahead = 0; error2 > 0; look_ahead++)
error2 >>= 2;
* Now calculate the error in (1 << look_ahead) ticks, but first
* remove the single look ahead already included in the error.
*/
- tick_error = current_tick_length() >>
- (TICK_LENGTH_SHIFT - clock->shift + 1);
+ tick_error = tick_length >> (NTP_SCALE_SHIFT - clock->shift + 1);
tick_error -= clock->xtime_interval >> 1;
error = ((error - tick_error) >> look_ahead) + tick_error;
* this is optimized for the most common adjustments of -1,0,1,
* for other values we can do a bit more work.
*/
-static void clocksource_adjust(struct clocksource *clock, s64 offset)
+static void clocksource_adjust(s64 offset)
{
s64 error, interval = clock->cycle_interval;
int adj;
- error = clock->error >> (TICK_LENGTH_SHIFT - clock->shift - 1);
+ error = clock->error >> (NTP_SCALE_SHIFT - clock->shift - 1);
if (error > interval) {
error >>= 2;
if (likely(error <= interval))
clock->xtime_interval += interval;
clock->xtime_nsec -= offset;
clock->error -= (interval - offset) <<
- (TICK_LENGTH_SHIFT - clock->shift);
+ (NTP_SCALE_SHIFT - clock->shift);
}
/**
#else
offset = clock->cycle_interval;
#endif
- clock->xtime_nsec += (s64)xtime.tv_nsec << clock->shift;
+ clock->xtime_nsec = (s64)xtime.tv_nsec << clock->shift;
/* normally this loop will run just once, however in the
* case of lost or late ticks, it will accumulate correctly.
*/
while (offset >= clock->cycle_interval) {
/* accumulate one interval */
- clock->xtime_nsec += clock->xtime_interval;
- clock->cycle_last += clock->cycle_interval;
offset -= clock->cycle_interval;
+ clock->cycle_last += clock->cycle_interval;
+ clock->xtime_nsec += clock->xtime_interval;
if (clock->xtime_nsec >= (u64)NSEC_PER_SEC << clock->shift) {
clock->xtime_nsec -= (u64)NSEC_PER_SEC << clock->shift;
xtime.tv_sec++;
second_overflow();
}
- /* interpolator bits */
- time_interpolator_update(clock->xtime_interval
- >> clock->shift);
+ clock->raw_time.tv_nsec += clock->raw_interval;
+ if (clock->raw_time.tv_nsec >= NSEC_PER_SEC) {
+ clock->raw_time.tv_nsec -= NSEC_PER_SEC;
+ clock->raw_time.tv_sec++;
+ }
/* accumulate error between NTP and clock interval */
- clock->error += current_tick_length();
- clock->error -= clock->xtime_interval << (TICK_LENGTH_SHIFT - clock->shift);
+ clock->error += tick_length;
+ clock->error -= clock->xtime_interval << (NTP_SCALE_SHIFT - clock->shift);
}
/* correct the clock when NTP error is too big */
- clocksource_adjust(clock, offset);
+ clocksource_adjust(offset);
- /* store full nanoseconds into xtime */
- xtime.tv_nsec = (s64)clock->xtime_nsec >> clock->shift;
+ /* store full nanoseconds into xtime after rounding it up and
+ * add the remainder to the error difference.
+ */
+ xtime.tv_nsec = ((s64)clock->xtime_nsec >> clock->shift) + 1;
clock->xtime_nsec -= (s64)xtime.tv_nsec << clock->shift;
+ clock->error += clock->xtime_nsec << (NTP_SCALE_SHIFT - clock->shift);
+
+ update_xtime_cache(cyc2ns(clock, offset));
/* check to see if there is a new clocksource to use */
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;
+}
+
+unsigned long get_seconds(void)
+{
+ return xtime_cache.tv_sec;
+}
+EXPORT_SYMBOL(get_seconds);
+
+
+struct timespec current_kernel_time(void)
+{
+ struct timespec now;
+ unsigned long seq;
+
+ do {
+ seq = read_seqbegin(&xtime_lock);
+
+ now = xtime_cache;
+ } while (read_seqretry(&xtime_lock, seq));
+
+ return now;
+}
+EXPORT_SYMBOL(current_kernel_time);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff