27 	struct clocksource *clock;  member
31 	/* Number of clock cycles in one NTP interval. */
33 	/* Number of clock shifted nano seconds in one NTP interval. */
40 	/* Clock shifted nano seconds remainder not stored in xtime.tv_nsec. */
45 	/* Shift conversion between clock shifted nano seconds and
48 	/* NTP adjusted clock multiplier */
55  * timekeeper_setup_internals - Set up internals to use clocksource clock.
57  * @clock:		Pointer to clocksource.
59  * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
64 static void timekeeper_setup_internals(struct clocksource *clock)  in timekeeper_setup_internals()  argument
69 	timekeeper.clock = clock;  in timekeeper_setup_internals()
70 	clock->cycle_last = clock->read(clock);  in timekeeper_setup_internals()
72 	/* Do the ns -> cycle conversion first, using original mult */  in timekeeper_setup_internals()
74 	tmp <<= clock->shift;  in timekeeper_setup_internals()
76 	tmp += clock->mult/2;  in timekeeper_setup_internals()
77 	do_div(tmp, clock->mult);  in timekeeper_setup_internals()
84 	/* Go back from cycles -> shifted ns */  in timekeeper_setup_internals()
85 	timekeeper.xtime_interval = (u64) interval * clock->mult;  in timekeeper_setup_internals()
86 	timekeeper.xtime_remainder = ntpinterval - timekeeper.xtime_interval;  in timekeeper_setup_internals()
88 		((u64) interval * clock->mult) >> clock->shift;  in timekeeper_setup_internals()
91 	timekeeper.shift = clock->shift;  in timekeeper_setup_internals()
94 	timekeeper.ntp_error_shift = NTP_SCALE_SHIFT - clock->shift;  in timekeeper_setup_internals()
99 	 * to counteract clock drifting.  in timekeeper_setup_internals()
101 	timekeeper.mult = clock->mult;  in timekeeper_setup_internals()
108 	struct clocksource *clock;  in timekeeping_get_ns()  local
111 	clock = timekeeper.clock;  in timekeeping_get_ns()
112 	cycle_now = clock->read(clock);  in timekeeping_get_ns()
115 	cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;  in timekeeping_get_ns()
125 	struct clocksource *clock;  in timekeeping_get_ns_raw()  local
128 	clock = timekeeper.clock;  in timekeeping_get_ns_raw()
129 	cycle_now = clock->read(clock);  in timekeeping_get_ns_raw()
132 	cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;  in timekeeping_get_ns_raw()
135 	return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);  in timekeeping_get_ns_raw()
139  * This read-write spinlock protects us from races in SMP while
157  * - wall_to_monotonic is no longer the boot time, getboottime must be
165  * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock.
176 	wall_to_monotonic.tv_sec -= leapsecond;  in timekeeping_leap_insert()
177 	update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,  in timekeeping_leap_insert()
182  * timekeeping_forward_now - update clock to the current time
184  * Forward the current clock to update its state since the last call to
185  * update_wall_time(). This is useful before significant clock changes,
191 	struct clocksource *clock;  in timekeeping_forward_now()  local
194 	clock = timekeeper.clock;  in timekeeping_forward_now()
195 	cycle_now = clock->read(clock);  in timekeeping_forward_now()
196 	cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;  in timekeeping_forward_now()
197 	clock->cycle_last = cycle_now;  in timekeeping_forward_now()
207 	nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);  in timekeeping_forward_now()
212  * getnstimeofday - Returns the time of day in a timespec
258 	 * 32-bit architectures without CONFIG_KTIME_SCALAR.  in ktime_get()
265  * ktime_get_ts - get the monotonic clock in timespec format
268  * The function calculates the monotonic clock from the realtime
269  * clock and the wall_to_monotonic offset and stores the result
290 	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,  in ktime_get_ts()
291 				ts->tv_nsec + tomono.tv_nsec + nsecs);  in ktime_get_ts()
298  * getnstime_raw_and_real - get day and raw monotonic time in timespec format
339  * do_gettimeofday - Returns the time of day in a timeval
349 	tv->tv_sec = now.tv_sec;  in do_gettimeofday()
350 	tv->tv_usec = now.tv_nsec/1000;  in do_gettimeofday()
355  * do_settimeofday - Sets the time of day
365 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)  in do_settimeofday()
366 		return -EINVAL;  in do_settimeofday()
372 	ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec;  in do_settimeofday()
373 	ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec;  in do_settimeofday()
381 	update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,  in do_settimeofday()
396  * timekeeping_inject_offset - Adds or subtracts from the current time.
405 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)  in timekeeping_inject_offset()
406 		return -EINVAL;  in timekeeping_inject_offset()
418 	update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,  in timekeeping_inject_offset()
431  * change_clocksource - Swaps clocksources if a new one is available
442 	if (!new->enable || new->enable(new) == 0) {  in change_clocksource()
443 		old = timekeeper.clock;  in change_clocksource()
445 		if (old->disable)  in change_clocksource()
446 			old->disable(old);  in change_clocksource()
452  * timekeeping_notify - Install a new clock source
453  * @clock:		pointer to the clock source
455  * This function is called from clocksource.c after a new, better clock
458 void timekeeping_notify(struct clocksource *clock)  in timekeeping_notify()  argument
460 	if (timekeeper.clock == clock)  in timekeeping_notify()
462 	stop_machine(change_clocksource, clock, NULL);  in timekeeping_notify()
467  * ktime_get_real - get the real (wall-) time in ktime_t format
482  * getrawmonotonic - Returns the raw monotonic time in a timespec
485  * Returns the raw monotonic time (completely un-modified by ntp)
505  * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
515 		ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;  in timekeeping_valid_for_hres()
523  * timekeeping_max_deferment - Returns max time the clocksource can be deferred
530 	return timekeeper.clock->max_idle_ns;  in timekeeping_max_deferment()
534  * read_persistent_clock -  Return time from the persistent clock.
537  * Reads the time from the battery backed persistent clock.
540  *  XXX - Do be sure to remove it once all arches implement it.
544 	ts->tv_sec = 0;  in read_persistent_clock()
545 	ts->tv_nsec = 0;  in read_persistent_clock()
549  * read_boot_clock -  Return time of the system start.
555  *  XXX - Do be sure to remove it once all arches implement it.
559 	ts->tv_sec = 0;  in read_boot_clock()
560 	ts->tv_nsec = 0;  in read_boot_clock()
564  * timekeeping_init - Initializes the clocksource and common timekeeping values
568 	struct clocksource *clock;  in timekeeping_init()  local
579 	clock = clocksource_default_clock();  in timekeeping_init()
580 	if (clock->enable)  in timekeeping_init()
581 		clock->enable(clock);  in timekeeping_init()
582 	timekeeper_setup_internals(clock);  in timekeeping_init()
593 				-boot.tv_sec, -boot.tv_nsec);  in timekeeping_init()
603  * __timekeeping_inject_sleeptime - Internal function to add sleep interval
624  * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
628  * because their RTC/persistent clock is only accessible when irqs are enabled.
638 	/* Make sure we don't set the clock twice */  in timekeeping_inject_sleeptime()
650 	update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,  in timekeeping_inject_sleeptime()
661  * timekeeping_resume - Resumes the generic timekeeping subsystem.
682 	/* re-base the last cycle value */  in timekeeping_resume()
683 	timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);  in timekeeping_resume()
769 	error2 = timekeeper.ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ);  in timekeeping_bigadjust()
779 	tick_error -= timekeeper.xtime_interval >> 1;  in timekeeping_bigadjust()
780 	error = ((error - tick_error) >> look_ahead) + tick_error;  in timekeeping_bigadjust()
786 		error = -error;  in timekeeping_bigadjust()
787 		*interval = -*interval;  in timekeeping_bigadjust()
788 		*offset = -*offset;  in timekeeping_bigadjust()
789 		mult = -1;  in timekeeping_bigadjust()
801  * this is optimized for the most common adjustments of -1,0,1,
813 	 * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs.  in timekeeping_adjust()
822 	error = timekeeper.ntp_error >> (timekeeper.ntp_error_shift - 1);  in timekeeping_adjust()
832 		 * XXX - In update_wall_time, we round up to the next  in timekeeping_adjust()
845 	} else if (error < -interval) {  in timekeeping_adjust()
848 		if (likely(error >= -interval)) {  in timekeeping_adjust()
849 			adj = -1;  in timekeeping_adjust()
850 			interval = -interval;  in timekeeping_adjust()
851 			offset = -offset;  in timekeeping_adjust()
857 	WARN_ONCE(timekeeper.clock->maxadj &&  in timekeeping_adjust()
858 			(timekeeper.mult + adj > timekeeper.clock->mult +  in timekeeping_adjust()
859 						timekeeper.clock->maxadj),  in timekeeping_adjust()
861 			timekeeper.clock->name, (long)timekeeper.mult + adj,  in timekeeping_adjust()
862 			(long)timekeeper.clock->mult +  in timekeeping_adjust()
863 				timekeeper.clock->maxadj);  in timekeeping_adjust()
883 	 * So offset stores the non-accumulated cycles. Thus the current  in timekeeping_adjust()
886 	 * Now, even though we're adjusting the clock frequency, we have  in timekeeping_adjust()
907 	 *	xtime_nsec_2 = xtime_nsec_1 - offset  in timekeeping_adjust()
909 	 *	xtime_nsec -= offset  in timekeeping_adjust()
911 	 * XXX - TODO: Doc ntp_error calculation.  in timekeeping_adjust()
915 	timekeeper.xtime_nsec -= offset;  in timekeeping_adjust()
916 	timekeeper.ntp_error -= (interval - offset) <<  in timekeeping_adjust()
922  * logarithmic_accumulation - shifted accumulation of cycles
940 	offset -= timekeeper.cycle_interval << shift;  in logarithmic_accumulation()
941 	timekeeper.clock->cycle_last += timekeeper.cycle_interval << shift;  in logarithmic_accumulation()
945 		timekeeper.xtime_nsec -= nsecps;  in logarithmic_accumulation()
960 	/* Accumulate error between NTP and clock interval */  in logarithmic_accumulation()
962 	timekeeper.ntp_error -=  in logarithmic_accumulation()
971  * update_wall_time - Uses the current clocksource to increment the wall time
977 	struct clocksource *clock;  in update_wall_time()  local
985 	clock = timekeeper.clock;  in update_wall_time()
990 	offset = (clock->read(clock) - clock->cycle_last) & clock->mask;  in update_wall_time()
1002 	shift = ilog2(offset) - ilog2(timekeeper.cycle_interval);  in update_wall_time()
1005 	maxshift = (8*sizeof(tick_length) - (ilog2(tick_length)+1)) - 1;  in update_wall_time()
1010 			shift--;  in update_wall_time()
1013 	/* correct the clock when NTP error is too big */  in update_wall_time()
1021 	 * its possible the required corrective factor to xtime_nsec could  in update_wall_time()
1033 		s64 neg = -(s64)timekeeper.xtime_nsec;  in update_wall_time()
1044 	timekeeper.xtime_nsec -= (s64) xtime.tv_nsec << timekeeper.shift;  in update_wall_time()
1053 		xtime.tv_nsec -= NSEC_PER_SEC;  in update_wall_time()
1059 	update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,  in update_wall_time()
1064  * getboottime - Return the real time of system boot.
1067  * Returns the wall-time of boot in a timespec.
1071  * basically means that however wrong your real time clock is at boot time,
1081 	set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);  in getboottime()
1087  * get_monotonic_boottime - Returns monotonic time since boot
1112 	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec,  in get_monotonic_boottime()
1113 			ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec + nsecs);  in get_monotonic_boottime()
1118  * ktime_get_boottime - Returns monotonic time since boot in a ktime
1135  * monotonic_to_bootbased - Convert the monotonic time to boot based.
1188  * The 64-bit jiffies value is not atomic - you MUST NOT read it
1200  * get_xtime_and_monotonic_and_sleep_offset() - get xtime, wall_to_monotonic,
1220  * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format
1235  * xtime_update() - advances the timekeeping infrastructure