38 	tc->cc = cc;  in timecounter_init()
39 	tc->cycle_last = cc->read(cc);  in timecounter_init()
40 	tc->nsec = start_tstamp;  in timecounter_init()
45  * timecounter_read_delta - get nanoseconds since last call of this function
61 	cycle_now = tc->cc->read(tc->cc);  in timecounter_read_delta()
64 	cycle_delta = (cycle_now - tc->cycle_last) & tc->cc->mask;  in timecounter_read_delta()
67 	ns_offset = cyclecounter_cyc2ns(tc->cc, cycle_delta);  in timecounter_read_delta()
70 	tc->cycle_last = cycle_now;  in timecounter_read_delta()
81 	nsec += tc->nsec;  in timecounter_read()
82 	tc->nsec = nsec;  in timecounter_read()
91 	u64 cycle_delta = (cycle_tstamp - tc->cycle_last) & tc->cc->mask;  in timecounter_cyc2time()
96 	 * than tc->cycle_last, detect when it is too far in the  in timecounter_cyc2time()
99 	if (cycle_delta > tc->cc->mask / 2) {  in timecounter_cyc2time()
100 		cycle_delta = (tc->cycle_last - cycle_tstamp) & tc->cc->mask;  in timecounter_cyc2time()
101 		nsec = tc->nsec - cyclecounter_cyc2ns(tc->cc, cycle_delta);  in timecounter_cyc2time()
103 		nsec = cyclecounter_cyc2ns(tc->cc, cycle_delta) + tc->nsec;  in timecounter_cyc2time()
111  * clocks_calc_mult_shift - calculate mult/shift factors for scaled math of clocks
121  * @to and @from are frequency values in HZ. For clock sources @to is
122  * NSEC_PER_SEC == 1GHz and @from is the counter frequency. For clock
130  * reduce the conversion accuracy by chosing smaller mult and shift
146 		sftacc--;  in clocks_calc_mult_shift()
151 	 * accuracy and fits the maxsec conversion range:  in clocks_calc_mult_shift()
153 	for (sft = 32; sft > 0; sft--) {  in clocks_calc_mult_shift()
164 /*[Clocksource internal variables]---------
172  *	Name of the user-specified clocksource.
204 	 * watchdog_list will find the unstable clock again.  in clocksource_watchdog_work()
211 	cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG);  in __clocksource_unstable()
212 	cs->flags |= CLOCK_SOURCE_UNSTABLE;  in __clocksource_unstable()
220 	       cs->name, delta);  in clocksource_unstable()
225  * clocksource_mark_unstable - mark clocksource unstable via watchdog
238 	if (!(cs->flags & CLOCK_SOURCE_UNSTABLE)) {  in clocksource_mark_unstable()
239 		if (list_empty(&cs->wd_list))  in clocksource_mark_unstable()
240 			list_add(&cs->wd_list, &watchdog_list);  in clocksource_mark_unstable()
262 		if (cs->flags & CLOCK_SOURCE_UNSTABLE) {  in clocksource_watchdog()
269 		csnow = cs->read(cs);  in clocksource_watchdog()
270 		wdnow = watchdog->read(watchdog);  in clocksource_watchdog()
274 		if (!(cs->flags & CLOCK_SOURCE_WATCHDOG) ||  in clocksource_watchdog()
276 			cs->flags |= CLOCK_SOURCE_WATCHDOG;  in clocksource_watchdog()
277 			cs->wd_last = wdnow;  in clocksource_watchdog()
278 			cs->cs_last = csnow;  in clocksource_watchdog()
282 		wd_nsec = clocksource_cyc2ns((wdnow - cs->wd_last) & watchdog->mask,  in clocksource_watchdog()
283 					     watchdog->mult, watchdog->shift);  in clocksource_watchdog()
285 		cs_nsec = clocksource_cyc2ns((csnow - cs->cs_last) &  in clocksource_watchdog()
286 					     cs->mask, cs->mult, cs->shift);  in clocksource_watchdog()
287 		cs->cs_last = csnow;  in clocksource_watchdog()
288 		cs->wd_last = wdnow;  in clocksource_watchdog()
294 		if ((abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD)) {  in clocksource_watchdog()
295 			clocksource_unstable(cs, cs_nsec - wd_nsec);  in clocksource_watchdog()
299 		if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) &&  in clocksource_watchdog()
300 		    (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) &&  in clocksource_watchdog()
301 		    (watchdog->flags & CLOCK_SOURCE_IS_CONTINUOUS)) {  in clocksource_watchdog()
302 			cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;  in clocksource_watchdog()
304 			 * We just marked the clocksource as highres-capable,  in clocksource_watchdog()
306 			 * transition into high-res mode:  in clocksource_watchdog()
356 		cs->flags &= ~CLOCK_SOURCE_WATCHDOG;  in clocksource_reset_watchdog()
369 	if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {  in clocksource_enqueue_watchdog()
371 		list_add(&cs->wd_list, &watchdog_list);  in clocksource_enqueue_watchdog()
372 		cs->flags &= ~CLOCK_SOURCE_WATCHDOG;  in clocksource_enqueue_watchdog()
375 		if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)  in clocksource_enqueue_watchdog()
376 			cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;  in clocksource_enqueue_watchdog()
378 		if (!watchdog || cs->rating > watchdog->rating) {  in clocksource_enqueue_watchdog()
395 	if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {  in clocksource_dequeue_watchdog()
397 		list_del_init(&cs->wd_list);  in clocksource_dequeue_watchdog()
404 			if (tmp == cs || tmp->flags & CLOCK_SOURCE_MUST_VERIFY)  in clocksource_dequeue_watchdog()
406 			if (!watchdog || tmp->rating > watchdog->rating)  in clocksource_dequeue_watchdog()
410 	cs->flags &= ~CLOCK_SOURCE_WATCHDOG;  in clocksource_dequeue_watchdog()
425 		if (cs->flags & CLOCK_SOURCE_UNSTABLE) {  in clocksource_watchdog_kthread()
426 			list_del_init(&cs->wd_list);  in clocksource_watchdog_kthread()
427 			list_add(&cs->wd_list, &unstable);  in clocksource_watchdog_kthread()
435 		list_del_init(&cs->wd_list);  in clocksource_watchdog_kthread()
446 	if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)  in clocksource_enqueue_watchdog()
447 		cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;  in clocksource_enqueue_watchdog()
457  * clocksource_suspend - suspend the clocksource(s)
464 		if (cs->suspend)  in clocksource_suspend()
465 			cs->suspend(cs);  in clocksource_suspend()
469  * clocksource_resume - resume the clocksource(s)
476 		if (cs->resume)  in clocksource_resume()
477 			cs->resume(cs);  in clocksource_resume()
483  * clocksource_touch_watchdog - Update watchdog
495  * clocksource_max_adjustment- Returns max adjustment amount
505 	ret = (u64)cs->mult * 11;  in clocksource_max_adjustment()
511  * clocksource_max_deferment - Returns max time the clocksource can be deferred
521 	 * cyc2ns function without overflowing a 64-bit signed result. The  in clocksource_max_deferment()
522 	 * maximum number of cycles is equal to ULLONG_MAX/(cs->mult+cs->maxadj)  in clocksource_max_deferment()
524 	 * max_cycles < (2^63)/(cs->mult + cs->maxadj)  in clocksource_max_deferment()
525 	 * max_cycles < 2^(log2((2^63)/(cs->mult + cs->maxadj)))  in clocksource_max_deferment()
526 	 * max_cycles < 2^(log2(2^63) - log2(cs->mult + cs->maxadj))  in clocksource_max_deferment()
527 	 * max_cycles < 2^(63 - log2(cs->mult + cs->maxadj))  in clocksource_max_deferment()
528 	 * max_cycles < 1 << (63 - log2(cs->mult + cs->maxadj))  in clocksource_max_deferment()
533 	max_cycles = 1ULL << (63 - (ilog2(cs->mult + cs->maxadj) + 1));  in clocksource_max_deferment()
537 	 * determined by the minimum of max_cycles and cs->mask.  in clocksource_max_deferment()
541 	max_cycles = min_t(u64, max_cycles, (u64) cs->mask);  in clocksource_max_deferment()
542 	max_nsecs = clocksource_cyc2ns(max_cycles, cs->mult - cs->maxadj,  in clocksource_max_deferment()
543 					cs->shift);  in clocksource_max_deferment()
551 	return max_nsecs - (max_nsecs >> 3);  in clocksource_max_deferment()
557  * clocksource_select - Select the best clocksource available
574 		if (strcmp(cs->name, override_name) != 0)  in clocksource_select()
577 		 * Check to make sure we don't switch to a non-highres  in clocksource_select()
581 		if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) &&  in clocksource_select()
586 			       "HRT/NOHZ mode\n", cs->name);  in clocksource_select()
594 		printk(KERN_INFO "Switching to clocksource %s\n", best->name);  in clocksource_select()
607  * clocksource_done_booting - Called near the end of core bootup
622 	 * Run the watchdog first to eliminate unstable clock sources  in clocksource_done_booting()
643 		if (tmp->rating >= cs->rating)  in clocksource_enqueue()
644 			entry = &tmp->list;  in clocksource_enqueue()
645 	list_add(&cs->list, entry);  in clocksource_enqueue()
649  * __clocksource_updatefreq_scale - Used update clocksource with new freq
654  * This should only be called from the clocksource->enable() method.
672 	sec = (cs->mask - (cs->mask >> 3));  in __clocksource_updatefreq_scale()
677 	else if (sec > 600 && cs->mask > UINT_MAX)  in __clocksource_updatefreq_scale()
680 	clocks_calc_mult_shift(&cs->mult, &cs->shift, freq,  in __clocksource_updatefreq_scale()
688 	cs->maxadj = clocksource_max_adjustment(cs);  in __clocksource_updatefreq_scale()
689 	while ((cs->mult + cs->maxadj < cs->mult)  in __clocksource_updatefreq_scale()
690 		|| (cs->mult - cs->maxadj > cs->mult)) {  in __clocksource_updatefreq_scale()
691 		cs->mult >>= 1;  in __clocksource_updatefreq_scale()
692 		cs->shift--;  in __clocksource_updatefreq_scale()
693 		cs->maxadj = clocksource_max_adjustment(cs);  in __clocksource_updatefreq_scale()
696 	cs->max_idle_ns = clocksource_max_deferment(cs);  in __clocksource_updatefreq_scale()
701  * __clocksource_register_scale - Used to install new clocksources
706  * Returns -EBUSY if registration fails, zero otherwise.
729  * clocksource_register - Used to install new clocksources
732  * Returns -EBUSY if registration fails, zero otherwise.
737 	cs->maxadj = clocksource_max_adjustment(cs);  in clocksource_register()
738 	WARN_ONCE(cs->mult + cs->maxadj < cs->mult,  in clocksource_register()
740 		cs->name);  in clocksource_register()
743 	cs->max_idle_ns = clocksource_max_deferment(cs);  in clocksource_register()
756 	list_del(&cs->list);  in __clocksource_change_rating()
757 	cs->rating = rating;  in __clocksource_change_rating()
763  * clocksource_change_rating - Change the rating of a registered clocksource
776  * clocksource_unregister - remove a registered clocksource
783 	list_del(&cs->list);  in clocksource_unregister()
791  * sysfs_show_current_clocksources - sysfs interface for current clocksource
805 	count = snprintf(buf, PAGE_SIZE, "%s\n", curr_clocksource->name);  in sysfs_show_current_clocksources()
812  * sysfs_override_clocksource - interface for manually overriding clocksource
829 		return -EINVAL;  in sysfs_override_clocksource()
832 	if (buf[count-1] == '\n')  in sysfs_override_clocksource()
833 		count--;  in sysfs_override_clocksource()
848  * sysfs_show_available_clocksources - sysfs interface for listing clocksource
866 		 * Don't show non-HRES clocksource if the tick code is  in sysfs_show_available_clocksources()
870 		    (src->flags & CLOCK_SOURCE_VALID_FOR_HRES))  in sysfs_show_available_clocksources()
872 				  max((ssize_t)PAGE_SIZE - count, (ssize_t)0),  in sysfs_show_available_clocksources()
873 				  "%s ", src->name);  in sysfs_show_available_clocksources()
878 			  max((ssize_t)PAGE_SIZE - count, (ssize_t)0), "\n");  in sysfs_show_available_clocksources()
923  * boot_override_clocksource - boot clock override
941  * boot_override_clock - Compatibility layer for deprecated boot option
944  * DEPRECATED! Takes a clock= boot argument and uses it
950 		printk("Warning: clock=pmtmr is deprecated. "  in boot_override_clock()
954 	printk("Warning! clock= boot option is deprecated. "  in boot_override_clock()
959 __setup("clock=", boot_override_clock);