Lines Matching +full:no +full:- +full:tick +full:- +full:in +full:- +full:suspend
1 // SPDX-License-Identifier: GPL-2.0+
15 #include <linux/tick.h>
20 #include "tick-internal.h"
27 u64 delta = clocksource_delta(end, start, cs->mask, cs->max_raw_delta); in cycles_to_nsec_safe()
29 if (likely(delta < cs->max_cycles)) in cycles_to_nsec_safe()
30 return clocksource_cyc2ns(delta, cs->mult, cs->shift); in cycles_to_nsec_safe()
32 return mul_u64_u32_shr(delta, cs->mult, cs->shift); in cycles_to_nsec_safe()
36 * clocks_calc_mult_shift - calculate mult/shift factors for scaled math of clocks
41 * @maxsec: guaranteed runtime conversion range in seconds
46 * @to and @from are frequency values in HZ. For clock sources @to is
50 * The @maxsec conversion range argument controls the time frame in
52 * calculated mult and shift factors. This guarantees that no 64bit
71 sftacc--; in clocks_calc_mult_shift()
78 for (sft = 32; sft > 0; sft--) { in clocks_calc_mult_shift()
90 /*[Clocksource internal variables]---------
94 * used to calculate the suspend time.
100 * Name of the user-specified clocksource.
125 * a lower bound for cs->uncertainty_margin values when registering clocks.
130 * In other words, by default, even if a clocksource is extremely
131 * precise (for example, with a sub-nanosecond period), the maximum
144 * Default for maximum permissible skew when cs->uncertainty_margin is
145 * not specified, and the lower bound even when cs->uncertainty_margin
147 * clocks with unspecifed cs->uncertainty_margin, so this macro is used
148 * even in CONFIG_CLOCKSOURCE_WATCHDOG=n kernels.
186 * of the kernel, so there is no point in creating a more permanent in clocksource_watchdog_work()
197 list_del(&cs->list); in clocksource_change_rating()
198 cs->rating = rating; in clocksource_change_rating()
204 cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG); in __clocksource_unstable()
205 cs->flags |= CLOCK_SOURCE_UNSTABLE; in __clocksource_unstable()
209 * re-rate and re-select. in __clocksource_unstable()
211 if (list_empty(&cs->list)) { in __clocksource_unstable()
212 cs->rating = 0; in __clocksource_unstable()
216 if (cs->mark_unstable) in __clocksource_unstable()
217 cs->mark_unstable(cs); in __clocksource_unstable()
225 * clocksource_mark_unstable - mark clocksource unstable via watchdog
229 * it defers demotion and re-selection to a kthread.
236 if (!(cs->flags & CLOCK_SOURCE_UNSTABLE)) { in clocksource_mark_unstable()
237 if (!list_empty(&cs->list) && list_empty(&cs->wd_list)) in clocksource_mark_unstable()
238 list_add(&cs->wd_list, &watchdog_list); in clocksource_mark_unstable()
255 int64_t md = 2 * watchdog->uncertainty_margin; in cs_watchdog_read()
263 *wdnow = watchdog->read(watchdog); in cs_watchdog_read()
264 *csnow = cs->read(cs); in cs_watchdog_read()
265 wd_end = watchdog->read(watchdog); in cs_watchdog_read()
266 wd_end2 = watchdog->read(watchdog); in cs_watchdog_read()
270 if (wd_delay <= md + cs->uncertainty_margin) { in cs_watchdog_read()
273 smp_processor_id(), watchdog->name, nretries); in cs_watchdog_read()
279 * Now compute delay in consecutive watchdog read to see if in cs_watchdog_read()
281 * significant delay in reading both clocksource and watchdog. in cs_watchdog_read()
283 * If consecutive WD read-back delay > md, report in cs_watchdog_read()
292 …warn("timekeeping watchdog on CPU%d: wd-%s-wd excessive read-back delay of %lldns vs. limit of %ld… in cs_watchdog_read()
293 smp_processor_id(), cs->name, wd_delay, WATCHDOG_MAX_SKEW, wd_seq_delay, nretries, cs->name); in cs_watchdog_read()
297 pr_info("timekeeping watchdog on CPU%d: %s wd-wd read-back delay of %lldns\n", in cs_watchdog_read()
298 smp_processor_id(), watchdog->name, wd_seq_delay); in cs_watchdog_read()
299 pr_info("wd-%s-wd read-back delay of %lldns, clock-skew test skipped!\n", in cs_watchdog_read()
300 cs->name, wd_delay); in cs_watchdog_read()
320 /* If no checking desired, or no other CPU to check, leave. */ in clocksource_verify_choose_cpus()
340 * and no replacement CPU is selected. This gracefully handles in clocksource_verify_choose_cpus()
346 cpu = cpumask_next(cpu - 1, cpu_online_mask); in clocksource_verify_choose_cpus()
361 csnow_mid = cs->read(cs); in clocksource_verify_one_cpu()
381 pr_warn("Not enough CPUs to check clocksource '%s'.\n", cs->name); in clocksource_verify_percpu()
385 …pr_warn("Checking clocksource %s synchronization from CPU %d to CPUs %*pbl.\n", cs->name, testcpu,… in clocksource_verify_percpu()
389 csnow_begin = cs->read(cs); in clocksource_verify_percpu()
391 csnow_end = cs->read(cs); in clocksource_verify_percpu()
392 delta = (s64)((csnow_mid - csnow_begin) & cs->mask); in clocksource_verify_percpu()
395 delta = (csnow_end - csnow_mid) & cs->mask; in clocksource_verify_percpu()
408 cpumask_pr_args(&cpus_ahead), testcpu, cs->name); in clocksource_verify_percpu()
411 cpumask_pr_args(&cpus_behind), testcpu, cs->name); in clocksource_verify_percpu()
413 pr_warn(" CPU %d check durations %lldns - %lldns for clocksource %s.\n", in clocksource_verify_percpu()
414 testcpu, cs_nsec_min, cs_nsec_max, cs->name); in clocksource_verify_percpu()
423 cs->flags &= ~CLOCK_SOURCE_WATCHDOG; in clocksource_reset_watchdog()
446 if (cs->flags & CLOCK_SOURCE_UNSTABLE) { in clocksource_watchdog()
464 * watchdog check. So give system some space and suspend the in clocksource_watchdog()
470 * cs->last could keep unchanged for 5 minutes, reset in clocksource_watchdog()
479 if (!(cs->flags & CLOCK_SOURCE_WATCHDOG) || in clocksource_watchdog()
481 cs->flags |= CLOCK_SOURCE_WATCHDOG; in clocksource_watchdog()
482 cs->wd_last = wdnow; in clocksource_watchdog()
483 cs->cs_last = csnow; in clocksource_watchdog()
487 wd_nsec = cycles_to_nsec_safe(watchdog, cs->wd_last, wdnow); in clocksource_watchdog()
488 cs_nsec = cycles_to_nsec_safe(cs, cs->cs_last, csnow); in clocksource_watchdog()
489 wdlast = cs->wd_last; /* save these in case we print them */ in clocksource_watchdog()
490 cslast = cs->cs_last; in clocksource_watchdog()
491 cs->cs_last = csnow; in clocksource_watchdog()
492 cs->wd_last = wdnow; in clocksource_watchdog()
499 * on account of ksoftirqd not getting to run in a timely in clocksource_watchdog()
519 md = cs->uncertainty_margin + watchdog->uncertainty_margin; in clocksource_watchdog()
520 if (abs(cs_nsec - wd_nsec) > md) { in clocksource_watchdog()
526 smp_processor_id(), cs->name); in clocksource_watchdog()
528 watchdog->name, wd_nsec, wdnow, wdlast, watchdog->mask); in clocksource_watchdog()
530 cs->name, cs_nsec, csnow, cslast, cs->mask); in clocksource_watchdog()
531 cs_wd_msec = div_s64_rem(cs_nsec - wd_nsec, 1000 * 1000, &wd_rem); in clocksource_watchdog()
534 cs->name, cs_nsec - wd_nsec, cs_wd_msec, watchdog->name, wd_nsec, wd_msec); in clocksource_watchdog()
536 pr_warn(" '%s' is current clocksource.\n", cs->name); in clocksource_watchdog()
538 … '%s' (not '%s') is current clocksource.\n", curr_clocksource->name, cs->name); in clocksource_watchdog()
540 pr_warn(" No current clocksource.\n"); in clocksource_watchdog()
545 if (cs == curr_clocksource && cs->tick_stable) in clocksource_watchdog()
546 cs->tick_stable(cs); in clocksource_watchdog()
548 if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) && in clocksource_watchdog()
549 (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) && in clocksource_watchdog()
550 (watchdog->flags & CLOCK_SOURCE_IS_CONTINUOUS)) { in clocksource_watchdog()
551 /* Mark it valid for high-res. */ in clocksource_watchdog()
552 cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES; in clocksource_watchdog()
566 * clocksource let the tick code know about in clocksource_watchdog()
570 cs->flags |= CLOCK_SOURCE_RESELECT; in clocksource_watchdog()
630 INIT_LIST_HEAD(&cs->wd_list); in clocksource_enqueue_watchdog()
632 if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) { in clocksource_enqueue_watchdog()
634 list_add(&cs->wd_list, &watchdog_list); in clocksource_enqueue_watchdog()
635 cs->flags &= ~CLOCK_SOURCE_WATCHDOG; in clocksource_enqueue_watchdog()
638 if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) in clocksource_enqueue_watchdog()
639 cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES; in clocksource_enqueue_watchdog()
656 if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) in clocksource_select_watchdog()
664 if (!watchdog || cs->rating > watchdog->rating) in clocksource_select_watchdog()
683 if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) { in clocksource_dequeue_watchdog()
685 list_del_init(&cs->wd_list); in clocksource_dequeue_watchdog()
698 /* Do any required per-CPU skew verification. */ in __clocksource_watchdog_kthread()
700 curr_clocksource->flags & CLOCK_SOURCE_UNSTABLE && in __clocksource_watchdog_kthread()
701 curr_clocksource->flags & CLOCK_SOURCE_VERIFY_PERCPU) in __clocksource_watchdog_kthread()
706 if (cs->flags & CLOCK_SOURCE_UNSTABLE) { in __clocksource_watchdog_kthread()
707 list_del_init(&cs->wd_list); in __clocksource_watchdog_kthread()
711 if (cs->flags & CLOCK_SOURCE_RESELECT) { in __clocksource_watchdog_kthread()
712 cs->flags &= ~CLOCK_SOURCE_RESELECT; in __clocksource_watchdog_kthread()
741 if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) in clocksource_enqueue_watchdog()
742 cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES; in clocksource_enqueue_watchdog()
765 * Skip the clocksource which will be stopped in suspend state. in __clocksource_suspend_select()
767 if (!(cs->flags & CLOCK_SOURCE_SUSPEND_NONSTOP)) in __clocksource_suspend_select()
771 * The nonstop clocksource can be selected as the suspend clocksource to in __clocksource_suspend_select()
772 * calculate the suspend time, so it should not supply suspend/resume in __clocksource_suspend_select()
773 * interfaces to suspend the nonstop clocksource when system suspends. in __clocksource_suspend_select()
775 if (cs->suspend || cs->resume) { in __clocksource_suspend_select()
776 pr_warn("Nonstop clocksource %s should not supply suspend/resume interfaces\n", in __clocksource_suspend_select()
777 cs->name); in __clocksource_suspend_select()
781 if (!suspend_clocksource || cs->rating > suspend_clocksource->rating) in __clocksource_suspend_select()
786 * clocksource_suspend_select - Select the best clocksource for suspend timing
807 * clocksource_start_suspend_timing - Start measuring the suspend timing
811 * This function will save the start cycle values of suspend timer to calculate
812 * the suspend time when resuming system.
814 * This function is called late in the suspend process from timekeeping_suspend(),
815 * that means processes are frozen, non-boot cpus and interrupts are disabled
816 * now. It is therefore possible to start the suspend timer without taking the
825 * If current clocksource is the suspend timer, we should use the in clocksource_start_suspend_timing()
827 * from suspend timer. in clocksource_start_suspend_timing()
834 if (suspend_clocksource->enable && in clocksource_start_suspend_timing()
835 suspend_clocksource->enable(suspend_clocksource)) { in clocksource_start_suspend_timing()
836 pr_warn_once("Failed to enable the non-suspend-able clocksource.\n"); in clocksource_start_suspend_timing()
840 suspend_start = suspend_clocksource->read(suspend_clocksource); in clocksource_start_suspend_timing()
844 * clocksource_stop_suspend_timing - Stop measuring the suspend timing
848 * This function will calculate the suspend time from suspend timer.
850 * Returns nanoseconds since suspend started, 0 if no usable suspend clocksource.
852 * This function is called early in the resume process from timekeeping_resume(),
853 * that means there is only one cpu, no processes are running and the interrupts
854 * are disabled. It is therefore possible to stop the suspend timer without
865 * If current clocksource is the suspend timer, we should use the in clocksource_stop_suspend_timing()
867 * avoid same reading from suspend timer. in clocksource_stop_suspend_timing()
872 now = suspend_clocksource->read(suspend_clocksource); in clocksource_stop_suspend_timing()
878 * Disable the suspend timer to save power if current clocksource is in clocksource_stop_suspend_timing()
879 * not the suspend timer. in clocksource_stop_suspend_timing()
881 if (!clocksource_is_suspend(cs) && suspend_clocksource->disable) in clocksource_stop_suspend_timing()
882 suspend_clocksource->disable(suspend_clocksource); in clocksource_stop_suspend_timing()
888 * clocksource_suspend - suspend the clocksource(s)
895 if (cs->suspend) in clocksource_suspend()
896 cs->suspend(cs); in clocksource_suspend()
900 * clocksource_resume - resume the clocksource(s)
907 if (cs->resume) in clocksource_resume()
908 cs->resume(cs); in clocksource_resume()
914 * clocksource_touch_watchdog - Update watchdog
918 * was stopped in code which holds watchdog_lock.
926 * clocksource_max_adjustment- Returns max adjustment amount
936 ret = (u64)cs->mult * 11; in clocksource_max_adjustment()
942 * clocks_calc_max_nsecs - Returns maximum nanoseconds that can be converted
950 * NOTE: This function includes a safety margin of 50%, in other words, we
953 * delayed timers or bad hardware, which might result in time intervals that
962 * cyc2ns() function without overflowing a 64-bit result. in clocks_calc_max_nsecs()
974 max_nsecs = clocksource_cyc2ns(max_cycles, mult - maxadj, shift); in clocks_calc_max_nsecs()
987 * clocksource_update_max_deferment - Updates the clocksource max_idle_ns & max_cycles
993 cs->max_idle_ns = clocks_calc_max_nsecs(cs->mult, cs->shift, in clocksource_update_max_deferment()
994 cs->maxadj, cs->mask, in clocksource_update_max_deferment()
995 &cs->max_cycles); in clocksource_update_max_deferment()
998 * Threshold for detecting negative motion in clocksource_delta(). in clocksource_update_max_deferment()
1004 cs->max_raw_delta = (cs->mask >> 1) + (cs->mask >> 2) + (cs->mask >> 3); in clocksource_update_max_deferment()
1022 if (oneshot && !(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES)) in clocksource_find_best()
1046 if (strcmp(cs->name, override_name) != 0) in __clocksource_select()
1049 * Check to make sure we don't switch to a non-highres in __clocksource_select()
1050 * capable clocksource if the tick code is in oneshot in __clocksource_select()
1053 if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) && oneshot) { in __clocksource_select()
1055 if (cs->flags & CLOCK_SOURCE_UNSTABLE) { in __clocksource_select()
1056 …pr_warn("Override clocksource %s is unstable and not HRT compatible - cannot switch while in HRT/N… in __clocksource_select()
1057 cs->name); in __clocksource_select()
1064 pr_info("Override clocksource %s is not currently HRT compatible - deferring\n", in __clocksource_select()
1065 cs->name); in __clocksource_select()
1075 pr_info("Switched to clocksource %s\n", best->name); in __clocksource_select()
1081 * clocksource_select - Select the best clocksource available
1099 * clocksource_done_booting - Called near the end of core bootup
1130 if (tmp->rating < cs->rating) in clocksource_enqueue()
1132 entry = &tmp->list; in clocksource_enqueue()
1134 list_add(&cs->list, entry); in clocksource_enqueue()
1138 * __clocksource_update_freq_scale - Used update clocksource with new freq
1143 * This should only be called from the clocksource->enable() method.
1154 * Default clocksources are *special* and self-define their mult/shift. in __clocksource_update_freq_scale()
1160 * wrapping around. For clocksources which have a mask > 32-bit in __clocksource_update_freq_scale()
1163 * amount. That results in a shift value of 24 for a in __clocksource_update_freq_scale()
1164 * clocksource with mask >= 40-bit and f >= 4GHz. That maps to in __clocksource_update_freq_scale()
1167 sec = cs->mask; in __clocksource_update_freq_scale()
1172 else if (sec > 600 && cs->mask > UINT_MAX) in __clocksource_update_freq_scale()
1175 clocks_calc_mult_shift(&cs->mult, &cs->shift, freq, in __clocksource_update_freq_scale()
1181 * both scale and freq are non-zero, calculate the clock period, but in __clocksource_update_freq_scale()
1184 * and take the tens-of-milliseconds WATCHDOG_THRESHOLD value in __clocksource_update_freq_scale()
1194 if (scale && freq && !cs->uncertainty_margin) { in __clocksource_update_freq_scale()
1195 cs->uncertainty_margin = NSEC_PER_SEC / (scale * freq); in __clocksource_update_freq_scale()
1196 if (cs->uncertainty_margin < 2 * WATCHDOG_MAX_SKEW) in __clocksource_update_freq_scale()
1197 cs->uncertainty_margin = 2 * WATCHDOG_MAX_SKEW; in __clocksource_update_freq_scale()
1198 } else if (!cs->uncertainty_margin) { in __clocksource_update_freq_scale()
1199 cs->uncertainty_margin = WATCHDOG_THRESHOLD; in __clocksource_update_freq_scale()
1201 WARN_ON_ONCE(cs->uncertainty_margin < 2 * WATCHDOG_MAX_SKEW); in __clocksource_update_freq_scale()
1207 cs->maxadj = clocksource_max_adjustment(cs); in __clocksource_update_freq_scale()
1208 while (freq && ((cs->mult + cs->maxadj < cs->mult) in __clocksource_update_freq_scale()
1209 || (cs->mult - cs->maxadj > cs->mult))) { in __clocksource_update_freq_scale()
1210 cs->mult >>= 1; in __clocksource_update_freq_scale()
1211 cs->shift--; in __clocksource_update_freq_scale()
1212 cs->maxadj = clocksource_max_adjustment(cs); in __clocksource_update_freq_scale()
1216 * Only warn for *special* clocksources that self-define in __clocksource_update_freq_scale()
1219 WARN_ONCE(cs->mult + cs->maxadj < cs->mult, in __clocksource_update_freq_scale()
1221 cs->name); in __clocksource_update_freq_scale()
1226 cs->name, cs->mask, cs->max_cycles, cs->max_idle_ns); in __clocksource_update_freq_scale()
1231 * __clocksource_register_scale - Used to install new clocksources
1236 * Returns -EBUSY if registration fails, zero otherwise.
1247 if (WARN_ON_ONCE((unsigned int)cs->id >= CSID_MAX)) in __clocksource_register_scale()
1248 cs->id = CSID_GENERIC; in __clocksource_register_scale()
1249 if (cs->vdso_clock_mode < 0 || in __clocksource_register_scale()
1250 cs->vdso_clock_mode >= VDSO_CLOCKMODE_MAX) { in __clocksource_register_scale()
1252 cs->name, cs->vdso_clock_mode); in __clocksource_register_scale()
1253 cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE; in __clocksource_register_scale()
1286 return -EBUSY; in clocksource_unbind()
1293 return -EBUSY; in clocksource_unbind()
1298 * Select and try to install a replacement suspend clocksource. in clocksource_unbind()
1299 * If no replacement suspend clocksource, we will just let the in clocksource_unbind()
1300 * clocksource go and have no suspend clocksource. in clocksource_unbind()
1307 list_del_init(&cs->list); in clocksource_unbind()
1314 * clocksource_unregister - remove a registered clocksource
1322 if (!list_empty(&cs->list)) in clocksource_unregister()
1331 * current_clocksource_show - sysfs interface for current clocksource
1345 count = sysfs_emit(buf, "%s\n", curr_clocksource->name); in current_clocksource_show()
1357 return -EINVAL; in sysfs_get_uname()
1360 if (buf[cnt-1] == '\n') in sysfs_get_uname()
1361 cnt--; in sysfs_get_uname()
1369 * current_clocksource_store - interface for manually overriding clocksource
1397 * unbind_clocksource_store - interface for manually unbinding clocksource
1417 ret = -ENODEV; in unbind_clocksource_store()
1420 if (strcmp(cs->name, name)) in unbind_clocksource_store()
1432 * available_clocksource_show - sysfs interface for listing clocksource
1449 * Don't show non-HRES clocksource if the tick code is in available_clocksource_show()
1450 * in one shot mode (highres=on or nohz=on) in available_clocksource_show()
1453 (src->flags & CLOCK_SOURCE_VALID_FOR_HRES)) in available_clocksource_show()
1455 max((ssize_t)PAGE_SIZE - count, (ssize_t)0), in available_clocksource_show()
1456 "%s ", src->name); in available_clocksource_show()
1461 max((ssize_t)PAGE_SIZE - count, (ssize_t)0), "\n"); in available_clocksource_show()
1500 * boot_override_clocksource - boot clock override
1518 * boot_override_clock - Compatibility layer for deprecated boot option
1527 pr_warn("clock=pmtmr is deprecated - use clocksource=acpi_pm\n"); in boot_override_clock()
1530 pr_warn("clock= boot option is deprecated - use clocksource=xyz\n"); in boot_override_clock()