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john stultz85240702007-05-08 00:27:59 -07001/*
2 * linux/kernel/time/timekeeping.c
3 *
4 * Kernel timekeeping code and accessor functions
5 *
6 * This code was moved from linux/kernel/timer.c.
7 * Please see that file for copyright and history logs.
8 *
9 */
10
John Stultzd7b42022012-09-04 15:12:07 -040011#include <linux/timekeeper_internal.h>
john stultz85240702007-05-08 00:27:59 -070012#include <linux/module.h>
13#include <linux/interrupt.h>
14#include <linux/percpu.h>
15#include <linux/init.h>
16#include <linux/mm.h>
Alexey Dobriyand43c36d2009-10-07 17:09:06 +040017#include <linux/sched.h>
Rafael J. Wysockie1a85b22011-03-23 22:16:04 +010018#include <linux/syscore_ops.h>
john stultz85240702007-05-08 00:27:59 -070019#include <linux/clocksource.h>
20#include <linux/jiffies.h>
21#include <linux/time.h>
22#include <linux/tick.h>
Martin Schwidefsky75c51582009-08-14 15:47:30 +020023#include <linux/stop_machine.h>
Marcelo Tosattie0b306f2012-11-27 23:28:59 -020024#include <linux/pvclock_gtod.h>
Gideon Israel Dsouza52f5684c2014-04-07 15:39:20 -070025#include <linux/compiler.h>
john stultz85240702007-05-08 00:27:59 -070026
Thomas Gleixnereb93e4d2013-02-21 22:51:36 +000027#include "tick-internal.h"
John Stultzaa6f9c592013-03-22 11:31:29 -070028#include "ntp_internal.h"
Colin Cross5c835452013-05-21 22:32:14 -070029#include "timekeeping_internal.h"
Martin Schwidefsky155ec602009-08-14 15:47:26 +020030
David Vrabel04397fe92013-06-27 11:35:45 +010031#define TK_CLEAR_NTP (1 << 0)
32#define TK_MIRROR (1 << 1)
David Vrabel780427f2013-06-27 11:35:46 +010033#define TK_CLOCK_WAS_SET (1 << 2)
David Vrabel04397fe92013-06-27 11:35:45 +010034
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +000035/*
36 * The most important data for readout fits into a single 64 byte
37 * cache line.
38 */
39static struct {
40 seqcount_t seq;
41 struct timekeeper timekeeper;
42} tk_core ____cacheline_aligned;
43
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +000044static DEFINE_RAW_SPINLOCK(timekeeper_lock);
Thomas Gleixner48cdc132013-02-21 22:51:40 +000045static struct timekeeper shadow_timekeeper;
Martin Schwidefsky155ec602009-08-14 15:47:26 +020046
Thomas Gleixner4396e052014-07-16 21:05:23 +000047/**
48 * struct tk_fast - NMI safe timekeeper
49 * @seq: Sequence counter for protecting updates. The lowest bit
50 * is the index for the tk_read_base array
51 * @base: tk_read_base array. Access is indexed by the lowest bit of
52 * @seq.
53 *
54 * See @update_fast_timekeeper() below.
55 */
56struct tk_fast {
57 seqcount_t seq;
58 struct tk_read_base base[2];
59};
60
61static struct tk_fast tk_fast_mono ____cacheline_aligned;
62
John Stultz8fcce542011-11-14 11:46:39 -080063/* flag for if timekeeping is suspended */
64int __read_mostly timekeeping_suspended;
65
Feng Tang31ade302013-01-16 00:09:47 +080066/* Flag for if there is a persistent clock on this platform */
67bool __read_mostly persistent_clock_exist = false;
68
John Stultz1e75fa82012-07-13 01:21:53 -040069static inline void tk_normalize_xtime(struct timekeeper *tk)
70{
Thomas Gleixnerd28ede82014-07-16 21:05:16 +000071 while (tk->tkr.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr.shift)) {
72 tk->tkr.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr.shift;
John Stultz1e75fa82012-07-13 01:21:53 -040073 tk->xtime_sec++;
74 }
75}
John Stultz8fcce542011-11-14 11:46:39 -080076
Thomas Gleixnerc905fae2014-07-16 21:04:05 +000077static inline struct timespec64 tk_xtime(struct timekeeper *tk)
78{
79 struct timespec64 ts;
80
81 ts.tv_sec = tk->xtime_sec;
Thomas Gleixnerd28ede82014-07-16 21:05:16 +000082 ts.tv_nsec = (long)(tk->tkr.xtime_nsec >> tk->tkr.shift);
Thomas Gleixnerc905fae2014-07-16 21:04:05 +000083 return ts;
84}
85
John Stultz7d489d12014-07-16 21:04:01 +000086static void tk_set_xtime(struct timekeeper *tk, const struct timespec64 *ts)
John Stultz1e75fa82012-07-13 01:21:53 -040087{
88 tk->xtime_sec = ts->tv_sec;
Thomas Gleixnerd28ede82014-07-16 21:05:16 +000089 tk->tkr.xtime_nsec = (u64)ts->tv_nsec << tk->tkr.shift;
John Stultz1e75fa82012-07-13 01:21:53 -040090}
91
John Stultz7d489d12014-07-16 21:04:01 +000092static void tk_xtime_add(struct timekeeper *tk, const struct timespec64 *ts)
John Stultz1e75fa82012-07-13 01:21:53 -040093{
94 tk->xtime_sec += ts->tv_sec;
Thomas Gleixnerd28ede82014-07-16 21:05:16 +000095 tk->tkr.xtime_nsec += (u64)ts->tv_nsec << tk->tkr.shift;
John Stultz784ffcb2012-08-21 20:30:46 -040096 tk_normalize_xtime(tk);
John Stultz1e75fa82012-07-13 01:21:53 -040097}
John Stultz8fcce542011-11-14 11:46:39 -080098
John Stultz7d489d12014-07-16 21:04:01 +000099static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec64 wtm)
John Stultz6d0ef902012-07-27 14:48:12 -0400100{
John Stultz7d489d12014-07-16 21:04:01 +0000101 struct timespec64 tmp;
John Stultz6d0ef902012-07-27 14:48:12 -0400102
103 /*
104 * Verify consistency of: offset_real = -wall_to_monotonic
105 * before modifying anything
106 */
John Stultz7d489d12014-07-16 21:04:01 +0000107 set_normalized_timespec64(&tmp, -tk->wall_to_monotonic.tv_sec,
John Stultz6d0ef902012-07-27 14:48:12 -0400108 -tk->wall_to_monotonic.tv_nsec);
John Stultz7d489d12014-07-16 21:04:01 +0000109 WARN_ON_ONCE(tk->offs_real.tv64 != timespec64_to_ktime(tmp).tv64);
John Stultz6d0ef902012-07-27 14:48:12 -0400110 tk->wall_to_monotonic = wtm;
John Stultz7d489d12014-07-16 21:04:01 +0000111 set_normalized_timespec64(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
112 tk->offs_real = timespec64_to_ktime(tmp);
John Stultz04005f62013-12-10 17:13:35 -0800113 tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tk->tai_offset, 0));
John Stultz6d0ef902012-07-27 14:48:12 -0400114}
115
Thomas Gleixner47da70d2014-07-16 21:05:00 +0000116static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta)
John Stultz6d0ef902012-07-27 14:48:12 -0400117{
Thomas Gleixner47da70d2014-07-16 21:05:00 +0000118 tk->offs_boot = ktime_add(tk->offs_boot, delta);
John Stultz6d0ef902012-07-27 14:48:12 -0400119}
120
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200121/**
Yijing Wangd26e4fe2013-11-28 16:28:55 +0800122 * tk_setup_internals - Set up internals to use clocksource clock.
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200123 *
Yijing Wangd26e4fe2013-11-28 16:28:55 +0800124 * @tk: The target timekeeper to setup.
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200125 * @clock: Pointer to clocksource.
126 *
127 * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
128 * pair and interval request.
129 *
130 * Unless you're the timekeeping code, you should not be using this!
131 */
John Stultzf726a692012-07-13 01:21:57 -0400132static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200133{
134 cycle_t interval;
Kasper Pedersena386b5a2010-10-20 15:55:15 -0700135 u64 tmp, ntpinterval;
John Stultz1e75fa82012-07-13 01:21:53 -0400136 struct clocksource *old_clock;
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200137
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000138 old_clock = tk->tkr.clock;
139 tk->tkr.clock = clock;
140 tk->tkr.read = clock->read;
141 tk->tkr.mask = clock->mask;
142 tk->tkr.cycle_last = tk->tkr.read(clock);
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200143
144 /* Do the ns -> cycle conversion first, using original mult */
145 tmp = NTP_INTERVAL_LENGTH;
146 tmp <<= clock->shift;
Kasper Pedersena386b5a2010-10-20 15:55:15 -0700147 ntpinterval = tmp;
Martin Schwidefsky0a544192009-08-14 15:47:28 +0200148 tmp += clock->mult/2;
149 do_div(tmp, clock->mult);
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200150 if (tmp == 0)
151 tmp = 1;
152
153 interval = (cycle_t) tmp;
John Stultzf726a692012-07-13 01:21:57 -0400154 tk->cycle_interval = interval;
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200155
156 /* Go back from cycles -> shifted ns */
John Stultzf726a692012-07-13 01:21:57 -0400157 tk->xtime_interval = (u64) interval * clock->mult;
158 tk->xtime_remainder = ntpinterval - tk->xtime_interval;
159 tk->raw_interval =
Martin Schwidefsky0a544192009-08-14 15:47:28 +0200160 ((u64) interval * clock->mult) >> clock->shift;
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200161
John Stultz1e75fa82012-07-13 01:21:53 -0400162 /* if changing clocks, convert xtime_nsec shift units */
163 if (old_clock) {
164 int shift_change = clock->shift - old_clock->shift;
165 if (shift_change < 0)
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000166 tk->tkr.xtime_nsec >>= -shift_change;
John Stultz1e75fa82012-07-13 01:21:53 -0400167 else
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000168 tk->tkr.xtime_nsec <<= shift_change;
John Stultz1e75fa82012-07-13 01:21:53 -0400169 }
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000170 tk->tkr.shift = clock->shift;
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200171
John Stultzf726a692012-07-13 01:21:57 -0400172 tk->ntp_error = 0;
173 tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift;
John Stultz375f45b2014-04-23 20:53:29 -0700174 tk->ntp_tick = ntpinterval << tk->ntp_error_shift;
Martin Schwidefsky0a544192009-08-14 15:47:28 +0200175
176 /*
177 * The timekeeper keeps its own mult values for the currently
178 * active clocksource. These value will be adjusted via NTP
179 * to counteract clock drifting.
180 */
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000181 tk->tkr.mult = clock->mult;
John Stultzdc491592013-12-06 17:25:21 -0800182 tk->ntp_err_mult = 0;
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200183}
john stultz85240702007-05-08 00:27:59 -0700184
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200185/* Timekeeper helper functions. */
Stephen Warren7b1f6202012-11-07 17:58:54 -0700186
187#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
Thomas Gleixnere06fde32014-07-16 21:03:50 +0000188static u32 default_arch_gettimeoffset(void) { return 0; }
189u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset;
Stephen Warren7b1f6202012-11-07 17:58:54 -0700190#else
Thomas Gleixnere06fde32014-07-16 21:03:50 +0000191static inline u32 arch_gettimeoffset(void) { return 0; }
Stephen Warren7b1f6202012-11-07 17:58:54 -0700192#endif
193
Thomas Gleixner0e5ac3a2014-07-16 21:05:18 +0000194static inline s64 timekeeping_get_ns(struct tk_read_base *tkr)
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200195{
Thomas Gleixner3a978372014-07-16 21:05:10 +0000196 cycle_t cycle_now, delta;
John Stultz1e75fa82012-07-13 01:21:53 -0400197 s64 nsec;
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200198
199 /* read clocksource: */
Thomas Gleixner0e5ac3a2014-07-16 21:05:18 +0000200 cycle_now = tkr->read(tkr->clock);
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200201
202 /* calculate the delta since the last update_wall_time: */
Thomas Gleixner0e5ac3a2014-07-16 21:05:18 +0000203 delta = clocksource_delta(cycle_now, tkr->cycle_last, tkr->mask);
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200204
Thomas Gleixner0e5ac3a2014-07-16 21:05:18 +0000205 nsec = delta * tkr->mult + tkr->xtime_nsec;
206 nsec >>= tkr->shift;
John Stultzf2a5a082012-07-13 01:21:55 -0400207
Stephen Warren7b1f6202012-11-07 17:58:54 -0700208 /* If arch requires, add in get_arch_timeoffset() */
Thomas Gleixnere06fde32014-07-16 21:03:50 +0000209 return nsec + arch_gettimeoffset();
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200210}
211
John Stultzf726a692012-07-13 01:21:57 -0400212static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200213{
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000214 struct clocksource *clock = tk->tkr.clock;
Thomas Gleixner3a978372014-07-16 21:05:10 +0000215 cycle_t cycle_now, delta;
John Stultzf2a5a082012-07-13 01:21:55 -0400216 s64 nsec;
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200217
218 /* read clocksource: */
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000219 cycle_now = tk->tkr.read(clock);
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200220
221 /* calculate the delta since the last update_wall_time: */
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000222 delta = clocksource_delta(cycle_now, tk->tkr.cycle_last, tk->tkr.mask);
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200223
John Stultzf2a5a082012-07-13 01:21:55 -0400224 /* convert delta to nanoseconds. */
Thomas Gleixner3a978372014-07-16 21:05:10 +0000225 nsec = clocksource_cyc2ns(delta, clock->mult, clock->shift);
John Stultzf2a5a082012-07-13 01:21:55 -0400226
Stephen Warren7b1f6202012-11-07 17:58:54 -0700227 /* If arch requires, add in get_arch_timeoffset() */
Thomas Gleixnere06fde32014-07-16 21:03:50 +0000228 return nsec + arch_gettimeoffset();
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200229}
230
Thomas Gleixner4396e052014-07-16 21:05:23 +0000231/**
232 * update_fast_timekeeper - Update the fast and NMI safe monotonic timekeeper.
233 * @tk: The timekeeper from which we take the update
234 * @tkf: The fast timekeeper to update
235 * @tbase: The time base for the fast timekeeper (mono/raw)
236 *
237 * We want to use this from any context including NMI and tracing /
238 * instrumenting the timekeeping code itself.
239 *
240 * So we handle this differently than the other timekeeping accessor
241 * functions which retry when the sequence count has changed. The
242 * update side does:
243 *
244 * smp_wmb(); <- Ensure that the last base[1] update is visible
245 * tkf->seq++;
246 * smp_wmb(); <- Ensure that the seqcount update is visible
247 * update(tkf->base[0], tk);
248 * smp_wmb(); <- Ensure that the base[0] update is visible
249 * tkf->seq++;
250 * smp_wmb(); <- Ensure that the seqcount update is visible
251 * update(tkf->base[1], tk);
252 *
253 * The reader side does:
254 *
255 * do {
256 * seq = tkf->seq;
257 * smp_rmb();
258 * idx = seq & 0x01;
259 * now = now(tkf->base[idx]);
260 * smp_rmb();
261 * } while (seq != tkf->seq)
262 *
263 * As long as we update base[0] readers are forced off to
264 * base[1]. Once base[0] is updated readers are redirected to base[0]
265 * and the base[1] update takes place.
266 *
267 * So if a NMI hits the update of base[0] then it will use base[1]
268 * which is still consistent. In the worst case this can result is a
269 * slightly wrong timestamp (a few nanoseconds). See
270 * @ktime_get_mono_fast_ns.
271 */
272static void update_fast_timekeeper(struct timekeeper *tk)
273{
274 struct tk_read_base *base = tk_fast_mono.base;
275
276 /* Force readers off to base[1] */
277 raw_write_seqcount_latch(&tk_fast_mono.seq);
278
279 /* Update base[0] */
280 memcpy(base, &tk->tkr, sizeof(*base));
281
282 /* Force readers back to base[0] */
283 raw_write_seqcount_latch(&tk_fast_mono.seq);
284
285 /* Update base[1] */
286 memcpy(base + 1, base, sizeof(*base));
287}
288
289/**
290 * ktime_get_mono_fast_ns - Fast NMI safe access to clock monotonic
291 *
292 * This timestamp is not guaranteed to be monotonic across an update.
293 * The timestamp is calculated by:
294 *
295 * now = base_mono + clock_delta * slope
296 *
297 * So if the update lowers the slope, readers who are forced to the
298 * not yet updated second array are still using the old steeper slope.
299 *
300 * tmono
301 * ^
302 * | o n
303 * | o n
304 * | u
305 * | o
306 * |o
307 * |12345678---> reader order
308 *
309 * o = old slope
310 * u = update
311 * n = new slope
312 *
313 * So reader 6 will observe time going backwards versus reader 5.
314 *
315 * While other CPUs are likely to be able observe that, the only way
316 * for a CPU local observation is when an NMI hits in the middle of
317 * the update. Timestamps taken from that NMI context might be ahead
318 * of the following timestamps. Callers need to be aware of that and
319 * deal with it.
320 */
321u64 notrace ktime_get_mono_fast_ns(void)
322{
323 struct tk_read_base *tkr;
324 unsigned int seq;
325 u64 now;
326
327 do {
328 seq = raw_read_seqcount(&tk_fast_mono.seq);
329 tkr = tk_fast_mono.base + (seq & 0x01);
330 now = ktime_to_ns(tkr->base_mono) + timekeeping_get_ns(tkr);
331
332 } while (read_seqcount_retry(&tk_fast_mono.seq, seq));
333 return now;
334}
335EXPORT_SYMBOL_GPL(ktime_get_mono_fast_ns);
336
Thomas Gleixnerc905fae2014-07-16 21:04:05 +0000337#ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
338
339static inline void update_vsyscall(struct timekeeper *tk)
340{
John Stultz0680eb12014-08-13 12:47:14 -0700341 struct timespec xt, wm;
Thomas Gleixnerc905fae2014-07-16 21:04:05 +0000342
John Stultze2dff1e2014-07-23 14:35:39 -0700343 xt = timespec64_to_timespec(tk_xtime(tk));
John Stultz0680eb12014-08-13 12:47:14 -0700344 wm = timespec64_to_timespec(tk->wall_to_monotonic);
345 update_vsyscall_old(&xt, &wm, tk->tkr.clock, tk->tkr.mult,
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000346 tk->tkr.cycle_last);
Thomas Gleixnerc905fae2014-07-16 21:04:05 +0000347}
348
349static inline void old_vsyscall_fixup(struct timekeeper *tk)
350{
351 s64 remainder;
352
353 /*
354 * Store only full nanoseconds into xtime_nsec after rounding
355 * it up and add the remainder to the error difference.
356 * XXX - This is necessary to avoid small 1ns inconsistnecies caused
357 * by truncating the remainder in vsyscalls. However, it causes
358 * additional work to be done in timekeeping_adjust(). Once
359 * the vsyscall implementations are converted to use xtime_nsec
360 * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD
361 * users are removed, this can be killed.
362 */
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000363 remainder = tk->tkr.xtime_nsec & ((1ULL << tk->tkr.shift) - 1);
364 tk->tkr.xtime_nsec -= remainder;
365 tk->tkr.xtime_nsec += 1ULL << tk->tkr.shift;
Thomas Gleixnerc905fae2014-07-16 21:04:05 +0000366 tk->ntp_error += remainder << tk->ntp_error_shift;
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000367 tk->ntp_error -= (1ULL << tk->tkr.shift) << tk->ntp_error_shift;
Thomas Gleixnerc905fae2014-07-16 21:04:05 +0000368}
369#else
370#define old_vsyscall_fixup(tk)
371#endif
372
Marcelo Tosattie0b306f2012-11-27 23:28:59 -0200373static RAW_NOTIFIER_HEAD(pvclock_gtod_chain);
374
David Vrabel780427f2013-06-27 11:35:46 +0100375static void update_pvclock_gtod(struct timekeeper *tk, bool was_set)
Marcelo Tosattie0b306f2012-11-27 23:28:59 -0200376{
David Vrabel780427f2013-06-27 11:35:46 +0100377 raw_notifier_call_chain(&pvclock_gtod_chain, was_set, tk);
Marcelo Tosattie0b306f2012-11-27 23:28:59 -0200378}
379
380/**
381 * pvclock_gtod_register_notifier - register a pvclock timedata update listener
Marcelo Tosattie0b306f2012-11-27 23:28:59 -0200382 */
383int pvclock_gtod_register_notifier(struct notifier_block *nb)
384{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000385 struct timekeeper *tk = &tk_core.timekeeper;
Marcelo Tosattie0b306f2012-11-27 23:28:59 -0200386 unsigned long flags;
387 int ret;
388
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +0000389 raw_spin_lock_irqsave(&timekeeper_lock, flags);
Marcelo Tosattie0b306f2012-11-27 23:28:59 -0200390 ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb);
David Vrabel780427f2013-06-27 11:35:46 +0100391 update_pvclock_gtod(tk, true);
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +0000392 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
Marcelo Tosattie0b306f2012-11-27 23:28:59 -0200393
394 return ret;
395}
396EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier);
397
398/**
399 * pvclock_gtod_unregister_notifier - unregister a pvclock
400 * timedata update listener
Marcelo Tosattie0b306f2012-11-27 23:28:59 -0200401 */
402int pvclock_gtod_unregister_notifier(struct notifier_block *nb)
403{
Marcelo Tosattie0b306f2012-11-27 23:28:59 -0200404 unsigned long flags;
405 int ret;
406
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +0000407 raw_spin_lock_irqsave(&timekeeper_lock, flags);
Marcelo Tosattie0b306f2012-11-27 23:28:59 -0200408 ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb);
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +0000409 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
Marcelo Tosattie0b306f2012-11-27 23:28:59 -0200410
411 return ret;
412}
413EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier);
414
Thomas Gleixner7c032df2014-07-16 21:04:10 +0000415/*
416 * Update the ktime_t based scalar nsec members of the timekeeper
417 */
418static inline void tk_update_ktime_data(struct timekeeper *tk)
419{
420 s64 nsec;
421
422 /*
423 * The xtime based monotonic readout is:
424 * nsec = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec + now();
425 * The ktime based monotonic readout is:
426 * nsec = base_mono + now();
427 * ==> base_mono = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec
428 */
429 nsec = (s64)(tk->xtime_sec + tk->wall_to_monotonic.tv_sec);
430 nsec *= NSEC_PER_SEC;
431 nsec += tk->wall_to_monotonic.tv_nsec;
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000432 tk->tkr.base_mono = ns_to_ktime(nsec);
Thomas Gleixnerf519b1a2014-07-16 21:05:04 +0000433
434 /* Update the monotonic raw base */
435 tk->base_raw = timespec64_to_ktime(tk->raw_time);
Thomas Gleixner7c032df2014-07-16 21:04:10 +0000436}
437
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +0000438/* must hold timekeeper_lock */
David Vrabel04397fe92013-06-27 11:35:45 +0100439static void timekeeping_update(struct timekeeper *tk, unsigned int action)
Thomas Gleixnercc062682011-11-13 23:19:49 +0000440{
David Vrabel04397fe92013-06-27 11:35:45 +0100441 if (action & TK_CLEAR_NTP) {
John Stultzf726a692012-07-13 01:21:57 -0400442 tk->ntp_error = 0;
Thomas Gleixnercc062682011-11-13 23:19:49 +0000443 ntp_clear();
444 }
Thomas Gleixner48cdc132013-02-21 22:51:40 +0000445
Thomas Gleixner7c032df2014-07-16 21:04:10 +0000446 tk_update_ktime_data(tk);
447
Thomas Gleixner9bf24192014-09-06 12:24:49 +0200448 update_vsyscall(tk);
449 update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET);
450
David Vrabel04397fe92013-06-27 11:35:45 +0100451 if (action & TK_MIRROR)
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000452 memcpy(&shadow_timekeeper, &tk_core.timekeeper,
453 sizeof(tk_core.timekeeper));
Thomas Gleixner4396e052014-07-16 21:05:23 +0000454
455 update_fast_timekeeper(tk);
Thomas Gleixnercc062682011-11-13 23:19:49 +0000456}
457
john stultz85240702007-05-08 00:27:59 -0700458/**
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200459 * timekeeping_forward_now - update clock to the current time
john stultz85240702007-05-08 00:27:59 -0700460 *
Roman Zippel9a055112008-08-20 16:37:28 -0700461 * Forward the current clock to update its state since the last call to
462 * update_wall_time(). This is useful before significant clock changes,
463 * as it avoids having to deal with this time offset explicitly.
john stultz85240702007-05-08 00:27:59 -0700464 */
John Stultzf726a692012-07-13 01:21:57 -0400465static void timekeeping_forward_now(struct timekeeper *tk)
john stultz85240702007-05-08 00:27:59 -0700466{
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000467 struct clocksource *clock = tk->tkr.clock;
Thomas Gleixner3a978372014-07-16 21:05:10 +0000468 cycle_t cycle_now, delta;
Roman Zippel9a055112008-08-20 16:37:28 -0700469 s64 nsec;
john stultz85240702007-05-08 00:27:59 -0700470
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000471 cycle_now = tk->tkr.read(clock);
472 delta = clocksource_delta(cycle_now, tk->tkr.cycle_last, tk->tkr.mask);
473 tk->tkr.cycle_last = cycle_now;
john stultz85240702007-05-08 00:27:59 -0700474
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000475 tk->tkr.xtime_nsec += delta * tk->tkr.mult;
john stultz7d275582009-05-01 13:10:26 -0700476
Stephen Warren7b1f6202012-11-07 17:58:54 -0700477 /* If arch requires, add in get_arch_timeoffset() */
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000478 tk->tkr.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr.shift;
john stultz7d275582009-05-01 13:10:26 -0700479
John Stultzf726a692012-07-13 01:21:57 -0400480 tk_normalize_xtime(tk);
John Stultz2d422442008-08-20 16:37:30 -0700481
Thomas Gleixner3a978372014-07-16 21:05:10 +0000482 nsec = clocksource_cyc2ns(delta, clock->mult, clock->shift);
John Stultz7d489d12014-07-16 21:04:01 +0000483 timespec64_add_ns(&tk->raw_time, nsec);
john stultz85240702007-05-08 00:27:59 -0700484}
485
486/**
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000487 * __getnstimeofday64 - Returns the time of day in a timespec64.
john stultz85240702007-05-08 00:27:59 -0700488 * @ts: pointer to the timespec to be set
489 *
Kees Cook1e817fb2012-11-19 10:26:16 -0800490 * Updates the time of day in the timespec.
491 * Returns 0 on success, or -ve when suspended (timespec will be undefined).
john stultz85240702007-05-08 00:27:59 -0700492 */
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000493int __getnstimeofday64(struct timespec64 *ts)
john stultz85240702007-05-08 00:27:59 -0700494{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000495 struct timekeeper *tk = &tk_core.timekeeper;
john stultz85240702007-05-08 00:27:59 -0700496 unsigned long seq;
John Stultz1e75fa82012-07-13 01:21:53 -0400497 s64 nsecs = 0;
john stultz85240702007-05-08 00:27:59 -0700498
499 do {
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000500 seq = read_seqcount_begin(&tk_core.seq);
john stultz85240702007-05-08 00:27:59 -0700501
John Stultz4e250fd2012-07-27 14:48:13 -0400502 ts->tv_sec = tk->xtime_sec;
Thomas Gleixner0e5ac3a2014-07-16 21:05:18 +0000503 nsecs = timekeeping_get_ns(&tk->tkr);
john stultz85240702007-05-08 00:27:59 -0700504
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000505 } while (read_seqcount_retry(&tk_core.seq, seq));
john stultz85240702007-05-08 00:27:59 -0700506
John Stultzec145ba2012-09-11 19:26:03 -0400507 ts->tv_nsec = 0;
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000508 timespec64_add_ns(ts, nsecs);
Kees Cook1e817fb2012-11-19 10:26:16 -0800509
510 /*
511 * Do not bail out early, in case there were callers still using
512 * the value, even in the face of the WARN_ON.
513 */
514 if (unlikely(timekeeping_suspended))
515 return -EAGAIN;
516 return 0;
517}
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000518EXPORT_SYMBOL(__getnstimeofday64);
Kees Cook1e817fb2012-11-19 10:26:16 -0800519
520/**
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000521 * getnstimeofday64 - Returns the time of day in a timespec64.
Kees Cook1e817fb2012-11-19 10:26:16 -0800522 * @ts: pointer to the timespec to be set
523 *
524 * Returns the time of day in a timespec (WARN if suspended).
525 */
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000526void getnstimeofday64(struct timespec64 *ts)
Kees Cook1e817fb2012-11-19 10:26:16 -0800527{
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000528 WARN_ON(__getnstimeofday64(ts));
john stultz85240702007-05-08 00:27:59 -0700529}
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000530EXPORT_SYMBOL(getnstimeofday64);
john stultz85240702007-05-08 00:27:59 -0700531
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200532ktime_t ktime_get(void)
533{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000534 struct timekeeper *tk = &tk_core.timekeeper;
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200535 unsigned int seq;
Thomas Gleixnera016a5b2014-07-16 21:04:12 +0000536 ktime_t base;
537 s64 nsecs;
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200538
539 WARN_ON(timekeeping_suspended);
540
541 do {
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000542 seq = read_seqcount_begin(&tk_core.seq);
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000543 base = tk->tkr.base_mono;
Thomas Gleixner0e5ac3a2014-07-16 21:05:18 +0000544 nsecs = timekeeping_get_ns(&tk->tkr);
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200545
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000546 } while (read_seqcount_retry(&tk_core.seq, seq));
John Stultz24e4a8c2014-07-16 21:03:53 +0000547
Thomas Gleixnera016a5b2014-07-16 21:04:12 +0000548 return ktime_add_ns(base, nsecs);
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200549}
550EXPORT_SYMBOL_GPL(ktime_get);
551
Thomas Gleixner0077dc62014-07-16 21:04:13 +0000552static ktime_t *offsets[TK_OFFS_MAX] = {
553 [TK_OFFS_REAL] = &tk_core.timekeeper.offs_real,
554 [TK_OFFS_BOOT] = &tk_core.timekeeper.offs_boot,
555 [TK_OFFS_TAI] = &tk_core.timekeeper.offs_tai,
556};
557
558ktime_t ktime_get_with_offset(enum tk_offsets offs)
559{
560 struct timekeeper *tk = &tk_core.timekeeper;
561 unsigned int seq;
562 ktime_t base, *offset = offsets[offs];
563 s64 nsecs;
564
565 WARN_ON(timekeeping_suspended);
566
567 do {
568 seq = read_seqcount_begin(&tk_core.seq);
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000569 base = ktime_add(tk->tkr.base_mono, *offset);
Thomas Gleixner0e5ac3a2014-07-16 21:05:18 +0000570 nsecs = timekeeping_get_ns(&tk->tkr);
Thomas Gleixner0077dc62014-07-16 21:04:13 +0000571
572 } while (read_seqcount_retry(&tk_core.seq, seq));
573
574 return ktime_add_ns(base, nsecs);
575
576}
577EXPORT_SYMBOL_GPL(ktime_get_with_offset);
578
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200579/**
Thomas Gleixner9a6b5192014-07-16 21:04:22 +0000580 * ktime_mono_to_any() - convert mononotic time to any other time
581 * @tmono: time to convert.
582 * @offs: which offset to use
583 */
584ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs)
585{
586 ktime_t *offset = offsets[offs];
587 unsigned long seq;
588 ktime_t tconv;
589
590 do {
591 seq = read_seqcount_begin(&tk_core.seq);
592 tconv = ktime_add(tmono, *offset);
593 } while (read_seqcount_retry(&tk_core.seq, seq));
594
595 return tconv;
596}
597EXPORT_SYMBOL_GPL(ktime_mono_to_any);
598
599/**
Thomas Gleixnerf519b1a2014-07-16 21:05:04 +0000600 * ktime_get_raw - Returns the raw monotonic time in ktime_t format
601 */
602ktime_t ktime_get_raw(void)
603{
604 struct timekeeper *tk = &tk_core.timekeeper;
605 unsigned int seq;
606 ktime_t base;
607 s64 nsecs;
608
609 do {
610 seq = read_seqcount_begin(&tk_core.seq);
611 base = tk->base_raw;
612 nsecs = timekeeping_get_ns_raw(tk);
613
614 } while (read_seqcount_retry(&tk_core.seq, seq));
615
616 return ktime_add_ns(base, nsecs);
617}
618EXPORT_SYMBOL_GPL(ktime_get_raw);
619
620/**
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000621 * ktime_get_ts64 - get the monotonic clock in timespec64 format
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200622 * @ts: pointer to timespec variable
623 *
624 * The function calculates the monotonic clock from the realtime
625 * clock and the wall_to_monotonic offset and stores the result
626 * in normalized timespec format in the variable pointed to by @ts.
627 */
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000628void ktime_get_ts64(struct timespec64 *ts)
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200629{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000630 struct timekeeper *tk = &tk_core.timekeeper;
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000631 struct timespec64 tomono;
John Stultzec145ba2012-09-11 19:26:03 -0400632 s64 nsec;
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200633 unsigned int seq;
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200634
635 WARN_ON(timekeeping_suspended);
636
637 do {
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000638 seq = read_seqcount_begin(&tk_core.seq);
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000639 ts->tv_sec = tk->xtime_sec;
Thomas Gleixner0e5ac3a2014-07-16 21:05:18 +0000640 nsec = timekeeping_get_ns(&tk->tkr);
John Stultz4e250fd2012-07-27 14:48:13 -0400641 tomono = tk->wall_to_monotonic;
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200642
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000643 } while (read_seqcount_retry(&tk_core.seq, seq));
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200644
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000645 ts->tv_sec += tomono.tv_sec;
646 ts->tv_nsec = 0;
647 timespec64_add_ns(ts, nsec + tomono.tv_nsec);
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200648}
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000649EXPORT_SYMBOL_GPL(ktime_get_ts64);
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200650
Alexander Gordeeve2c18e42011-01-12 17:00:57 -0800651#ifdef CONFIG_NTP_PPS
652
653/**
654 * getnstime_raw_and_real - get day and raw monotonic time in timespec format
655 * @ts_raw: pointer to the timespec to be set to raw monotonic time
656 * @ts_real: pointer to the timespec to be set to the time of day
657 *
658 * This function reads both the time of day and raw monotonic time at the
659 * same time atomically and stores the resulting timestamps in timespec
660 * format.
661 */
662void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
663{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000664 struct timekeeper *tk = &tk_core.timekeeper;
Alexander Gordeeve2c18e42011-01-12 17:00:57 -0800665 unsigned long seq;
666 s64 nsecs_raw, nsecs_real;
667
668 WARN_ON_ONCE(timekeeping_suspended);
669
670 do {
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000671 seq = read_seqcount_begin(&tk_core.seq);
Alexander Gordeeve2c18e42011-01-12 17:00:57 -0800672
John Stultz7d489d12014-07-16 21:04:01 +0000673 *ts_raw = timespec64_to_timespec(tk->raw_time);
John Stultz4e250fd2012-07-27 14:48:13 -0400674 ts_real->tv_sec = tk->xtime_sec;
John Stultz1e75fa82012-07-13 01:21:53 -0400675 ts_real->tv_nsec = 0;
Alexander Gordeeve2c18e42011-01-12 17:00:57 -0800676
John Stultz4e250fd2012-07-27 14:48:13 -0400677 nsecs_raw = timekeeping_get_ns_raw(tk);
Thomas Gleixner0e5ac3a2014-07-16 21:05:18 +0000678 nsecs_real = timekeeping_get_ns(&tk->tkr);
Alexander Gordeeve2c18e42011-01-12 17:00:57 -0800679
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000680 } while (read_seqcount_retry(&tk_core.seq, seq));
Alexander Gordeeve2c18e42011-01-12 17:00:57 -0800681
682 timespec_add_ns(ts_raw, nsecs_raw);
683 timespec_add_ns(ts_real, nsecs_real);
684}
685EXPORT_SYMBOL(getnstime_raw_and_real);
686
687#endif /* CONFIG_NTP_PPS */
688
john stultz85240702007-05-08 00:27:59 -0700689/**
690 * do_gettimeofday - Returns the time of day in a timeval
691 * @tv: pointer to the timeval to be set
692 *
Geert Uytterhoevenefd9ac82008-01-30 13:30:01 +0100693 * NOTE: Users should be converted to using getnstimeofday()
john stultz85240702007-05-08 00:27:59 -0700694 */
695void do_gettimeofday(struct timeval *tv)
696{
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000697 struct timespec64 now;
john stultz85240702007-05-08 00:27:59 -0700698
Thomas Gleixnerd6d29892014-07-16 21:04:04 +0000699 getnstimeofday64(&now);
john stultz85240702007-05-08 00:27:59 -0700700 tv->tv_sec = now.tv_sec;
701 tv->tv_usec = now.tv_nsec/1000;
702}
john stultz85240702007-05-08 00:27:59 -0700703EXPORT_SYMBOL(do_gettimeofday);
Richard Cochrand239f492012-04-27 10:12:42 +0200704
john stultz85240702007-05-08 00:27:59 -0700705/**
706 * do_settimeofday - Sets the time of day
707 * @tv: pointer to the timespec variable containing the new time
708 *
709 * Sets the time of day to the new time and update NTP and notify hrtimers
710 */
Richard Cochran1e6d7672011-02-01 13:50:58 +0000711int do_settimeofday(const struct timespec *tv)
john stultz85240702007-05-08 00:27:59 -0700712{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000713 struct timekeeper *tk = &tk_core.timekeeper;
John Stultz7d489d12014-07-16 21:04:01 +0000714 struct timespec64 ts_delta, xt, tmp;
John Stultz92c1d3e2011-11-14 14:05:44 -0800715 unsigned long flags;
john stultz85240702007-05-08 00:27:59 -0700716
John Stultzcee58482012-08-31 13:30:06 -0400717 if (!timespec_valid_strict(tv))
john stultz85240702007-05-08 00:27:59 -0700718 return -EINVAL;
719
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +0000720 raw_spin_lock_irqsave(&timekeeper_lock, flags);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000721 write_seqcount_begin(&tk_core.seq);
john stultz85240702007-05-08 00:27:59 -0700722
John Stultz4e250fd2012-07-27 14:48:13 -0400723 timekeeping_forward_now(tk);
john stultz85240702007-05-08 00:27:59 -0700724
John Stultz4e250fd2012-07-27 14:48:13 -0400725 xt = tk_xtime(tk);
John Stultz1e75fa82012-07-13 01:21:53 -0400726 ts_delta.tv_sec = tv->tv_sec - xt.tv_sec;
727 ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec;
728
John Stultz7d489d12014-07-16 21:04:01 +0000729 tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts_delta));
john stultz85240702007-05-08 00:27:59 -0700730
John Stultz7d489d12014-07-16 21:04:01 +0000731 tmp = timespec_to_timespec64(*tv);
732 tk_set_xtime(tk, &tmp);
John Stultz1e75fa82012-07-13 01:21:53 -0400733
David Vrabel780427f2013-06-27 11:35:46 +0100734 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
john stultz85240702007-05-08 00:27:59 -0700735
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000736 write_seqcount_end(&tk_core.seq);
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +0000737 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
john stultz85240702007-05-08 00:27:59 -0700738
739 /* signal hrtimers about time change */
740 clock_was_set();
741
742 return 0;
743}
john stultz85240702007-05-08 00:27:59 -0700744EXPORT_SYMBOL(do_settimeofday);
745
John Stultzc528f7c2011-02-01 13:52:17 +0000746/**
747 * timekeeping_inject_offset - Adds or subtracts from the current time.
748 * @tv: pointer to the timespec variable containing the offset
749 *
750 * Adds or subtracts an offset value from the current time.
751 */
752int timekeeping_inject_offset(struct timespec *ts)
753{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000754 struct timekeeper *tk = &tk_core.timekeeper;
John Stultz92c1d3e2011-11-14 14:05:44 -0800755 unsigned long flags;
John Stultz7d489d12014-07-16 21:04:01 +0000756 struct timespec64 ts64, tmp;
John Stultz4e8b1452012-08-08 15:36:20 -0400757 int ret = 0;
John Stultzc528f7c2011-02-01 13:52:17 +0000758
759 if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
760 return -EINVAL;
761
John Stultz7d489d12014-07-16 21:04:01 +0000762 ts64 = timespec_to_timespec64(*ts);
763
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +0000764 raw_spin_lock_irqsave(&timekeeper_lock, flags);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000765 write_seqcount_begin(&tk_core.seq);
John Stultzc528f7c2011-02-01 13:52:17 +0000766
John Stultz4e250fd2012-07-27 14:48:13 -0400767 timekeeping_forward_now(tk);
John Stultzc528f7c2011-02-01 13:52:17 +0000768
John Stultz4e8b1452012-08-08 15:36:20 -0400769 /* Make sure the proposed value is valid */
John Stultz7d489d12014-07-16 21:04:01 +0000770 tmp = timespec64_add(tk_xtime(tk), ts64);
771 if (!timespec64_valid_strict(&tmp)) {
John Stultz4e8b1452012-08-08 15:36:20 -0400772 ret = -EINVAL;
773 goto error;
774 }
John Stultz1e75fa82012-07-13 01:21:53 -0400775
John Stultz7d489d12014-07-16 21:04:01 +0000776 tk_xtime_add(tk, &ts64);
777 tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts64));
John Stultzc528f7c2011-02-01 13:52:17 +0000778
John Stultz4e8b1452012-08-08 15:36:20 -0400779error: /* even if we error out, we forwarded the time, so call update */
David Vrabel780427f2013-06-27 11:35:46 +0100780 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
John Stultzc528f7c2011-02-01 13:52:17 +0000781
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000782 write_seqcount_end(&tk_core.seq);
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +0000783 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
John Stultzc528f7c2011-02-01 13:52:17 +0000784
785 /* signal hrtimers about time change */
786 clock_was_set();
787
John Stultz4e8b1452012-08-08 15:36:20 -0400788 return ret;
John Stultzc528f7c2011-02-01 13:52:17 +0000789}
790EXPORT_SYMBOL(timekeeping_inject_offset);
791
John Stultzcc244dd2012-05-03 12:30:07 -0700792
793/**
794 * timekeeping_get_tai_offset - Returns current TAI offset from UTC
795 *
796 */
797s32 timekeeping_get_tai_offset(void)
798{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000799 struct timekeeper *tk = &tk_core.timekeeper;
John Stultzcc244dd2012-05-03 12:30:07 -0700800 unsigned int seq;
801 s32 ret;
802
803 do {
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000804 seq = read_seqcount_begin(&tk_core.seq);
John Stultzcc244dd2012-05-03 12:30:07 -0700805 ret = tk->tai_offset;
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000806 } while (read_seqcount_retry(&tk_core.seq, seq));
John Stultzcc244dd2012-05-03 12:30:07 -0700807
808 return ret;
809}
810
811/**
812 * __timekeeping_set_tai_offset - Lock free worker function
813 *
814 */
Fengguang Wudd5d70e82013-03-25 12:24:24 -0700815static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset)
John Stultzcc244dd2012-05-03 12:30:07 -0700816{
817 tk->tai_offset = tai_offset;
John Stultz04005f62013-12-10 17:13:35 -0800818 tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tai_offset, 0));
John Stultzcc244dd2012-05-03 12:30:07 -0700819}
820
821/**
822 * timekeeping_set_tai_offset - Sets the current TAI offset from UTC
823 *
824 */
825void timekeeping_set_tai_offset(s32 tai_offset)
826{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000827 struct timekeeper *tk = &tk_core.timekeeper;
John Stultzcc244dd2012-05-03 12:30:07 -0700828 unsigned long flags;
829
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +0000830 raw_spin_lock_irqsave(&timekeeper_lock, flags);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000831 write_seqcount_begin(&tk_core.seq);
John Stultzcc244dd2012-05-03 12:30:07 -0700832 __timekeeping_set_tai_offset(tk, tai_offset);
John Stultzf55c0762013-12-11 18:50:25 -0800833 timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000834 write_seqcount_end(&tk_core.seq);
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +0000835 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
John Stultz4e8f8b32013-04-10 12:41:49 -0700836 clock_was_set();
John Stultzcc244dd2012-05-03 12:30:07 -0700837}
838
john stultz85240702007-05-08 00:27:59 -0700839/**
840 * change_clocksource - Swaps clocksources if a new one is available
841 *
842 * Accumulates current time interval and initializes new clocksource
843 */
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200844static int change_clocksource(void *data)
john stultz85240702007-05-08 00:27:59 -0700845{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000846 struct timekeeper *tk = &tk_core.timekeeper;
Magnus Damm4614e6a2009-04-21 12:24:02 -0700847 struct clocksource *new, *old;
John Stultzf695cf92012-03-14 16:38:15 -0700848 unsigned long flags;
john stultz85240702007-05-08 00:27:59 -0700849
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200850 new = (struct clocksource *) data;
john stultz85240702007-05-08 00:27:59 -0700851
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +0000852 raw_spin_lock_irqsave(&timekeeper_lock, flags);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000853 write_seqcount_begin(&tk_core.seq);
John Stultzf695cf92012-03-14 16:38:15 -0700854
John Stultz4e250fd2012-07-27 14:48:13 -0400855 timekeeping_forward_now(tk);
Thomas Gleixner09ac3692013-04-25 20:31:44 +0000856 /*
857 * If the cs is in module, get a module reference. Succeeds
858 * for built-in code (owner == NULL) as well.
859 */
860 if (try_module_get(new->owner)) {
861 if (!new->enable || new->enable(new) == 0) {
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000862 old = tk->tkr.clock;
Thomas Gleixner09ac3692013-04-25 20:31:44 +0000863 tk_setup_internals(tk, new);
864 if (old->disable)
865 old->disable(old);
866 module_put(old->owner);
867 } else {
868 module_put(new->owner);
869 }
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200870 }
David Vrabel780427f2013-06-27 11:35:46 +0100871 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
John Stultzf695cf92012-03-14 16:38:15 -0700872
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000873 write_seqcount_end(&tk_core.seq);
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +0000874 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
John Stultzf695cf92012-03-14 16:38:15 -0700875
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200876 return 0;
877}
john stultz85240702007-05-08 00:27:59 -0700878
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200879/**
880 * timekeeping_notify - Install a new clock source
881 * @clock: pointer to the clock source
882 *
883 * This function is called from clocksource.c after a new, better clock
884 * source has been registered. The caller holds the clocksource_mutex.
885 */
Thomas Gleixnerba919d12013-04-25 20:31:44 +0000886int timekeeping_notify(struct clocksource *clock)
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200887{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000888 struct timekeeper *tk = &tk_core.timekeeper;
John Stultz4e250fd2012-07-27 14:48:13 -0400889
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000890 if (tk->tkr.clock == clock)
Thomas Gleixnerba919d12013-04-25 20:31:44 +0000891 return 0;
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200892 stop_machine(change_clocksource, clock, NULL);
john stultz85240702007-05-08 00:27:59 -0700893 tick_clock_notify();
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000894 return tk->tkr.clock == clock ? 0 : -1;
john stultz85240702007-05-08 00:27:59 -0700895}
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200896
Thomas Gleixnera40f2622009-07-07 13:00:31 +0200897/**
John Stultz2d422442008-08-20 16:37:30 -0700898 * getrawmonotonic - Returns the raw monotonic time in a timespec
899 * @ts: pointer to the timespec to be set
900 *
901 * Returns the raw monotonic time (completely un-modified by ntp)
902 */
903void getrawmonotonic(struct timespec *ts)
904{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000905 struct timekeeper *tk = &tk_core.timekeeper;
John Stultz7d489d12014-07-16 21:04:01 +0000906 struct timespec64 ts64;
John Stultz2d422442008-08-20 16:37:30 -0700907 unsigned long seq;
908 s64 nsecs;
John Stultz2d422442008-08-20 16:37:30 -0700909
910 do {
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000911 seq = read_seqcount_begin(&tk_core.seq);
John Stultz4e250fd2012-07-27 14:48:13 -0400912 nsecs = timekeeping_get_ns_raw(tk);
John Stultz7d489d12014-07-16 21:04:01 +0000913 ts64 = tk->raw_time;
John Stultz2d422442008-08-20 16:37:30 -0700914
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000915 } while (read_seqcount_retry(&tk_core.seq, seq));
John Stultz2d422442008-08-20 16:37:30 -0700916
John Stultz7d489d12014-07-16 21:04:01 +0000917 timespec64_add_ns(&ts64, nsecs);
918 *ts = timespec64_to_timespec(ts64);
John Stultz2d422442008-08-20 16:37:30 -0700919}
920EXPORT_SYMBOL(getrawmonotonic);
921
John Stultz2d422442008-08-20 16:37:30 -0700922/**
Li Zefancf4fc6c2008-02-08 04:19:24 -0800923 * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
john stultz85240702007-05-08 00:27:59 -0700924 */
Li Zefancf4fc6c2008-02-08 04:19:24 -0800925int timekeeping_valid_for_hres(void)
john stultz85240702007-05-08 00:27:59 -0700926{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000927 struct timekeeper *tk = &tk_core.timekeeper;
john stultz85240702007-05-08 00:27:59 -0700928 unsigned long seq;
929 int ret;
930
931 do {
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000932 seq = read_seqcount_begin(&tk_core.seq);
john stultz85240702007-05-08 00:27:59 -0700933
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000934 ret = tk->tkr.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
john stultz85240702007-05-08 00:27:59 -0700935
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000936 } while (read_seqcount_retry(&tk_core.seq, seq));
john stultz85240702007-05-08 00:27:59 -0700937
938 return ret;
939}
940
941/**
Jon Hunter98962462009-08-18 12:45:10 -0500942 * timekeeping_max_deferment - Returns max time the clocksource can be deferred
Jon Hunter98962462009-08-18 12:45:10 -0500943 */
944u64 timekeeping_max_deferment(void)
945{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000946 struct timekeeper *tk = &tk_core.timekeeper;
John Stultz70471f22011-11-14 12:48:10 -0800947 unsigned long seq;
948 u64 ret;
John Stultz42e71e82012-07-13 01:21:51 -0400949
John Stultz70471f22011-11-14 12:48:10 -0800950 do {
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000951 seq = read_seqcount_begin(&tk_core.seq);
John Stultz70471f22011-11-14 12:48:10 -0800952
Thomas Gleixnerd28ede82014-07-16 21:05:16 +0000953 ret = tk->tkr.clock->max_idle_ns;
John Stultz70471f22011-11-14 12:48:10 -0800954
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000955 } while (read_seqcount_retry(&tk_core.seq, seq));
John Stultz70471f22011-11-14 12:48:10 -0800956
957 return ret;
Jon Hunter98962462009-08-18 12:45:10 -0500958}
959
960/**
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +0200961 * read_persistent_clock - Return time from the persistent clock.
john stultz85240702007-05-08 00:27:59 -0700962 *
963 * Weak dummy function for arches that do not yet support it.
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +0200964 * Reads the time from the battery backed persistent clock.
965 * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
john stultz85240702007-05-08 00:27:59 -0700966 *
967 * XXX - Do be sure to remove it once all arches implement it.
968 */
Gideon Israel Dsouza52f5684c2014-04-07 15:39:20 -0700969void __weak read_persistent_clock(struct timespec *ts)
john stultz85240702007-05-08 00:27:59 -0700970{
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +0200971 ts->tv_sec = 0;
972 ts->tv_nsec = 0;
john stultz85240702007-05-08 00:27:59 -0700973}
974
Martin Schwidefsky23970e32009-08-14 15:47:32 +0200975/**
976 * read_boot_clock - Return time of the system start.
977 *
978 * Weak dummy function for arches that do not yet support it.
979 * Function to read the exact time the system has been started.
980 * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
981 *
982 * XXX - Do be sure to remove it once all arches implement it.
983 */
Gideon Israel Dsouza52f5684c2014-04-07 15:39:20 -0700984void __weak read_boot_clock(struct timespec *ts)
Martin Schwidefsky23970e32009-08-14 15:47:32 +0200985{
986 ts->tv_sec = 0;
987 ts->tv_nsec = 0;
988}
989
john stultz85240702007-05-08 00:27:59 -0700990/*
991 * timekeeping_init - Initializes the clocksource and common timekeeping values
992 */
993void __init timekeeping_init(void)
994{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +0000995 struct timekeeper *tk = &tk_core.timekeeper;
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200996 struct clocksource *clock;
john stultz85240702007-05-08 00:27:59 -0700997 unsigned long flags;
John Stultz7d489d12014-07-16 21:04:01 +0000998 struct timespec64 now, boot, tmp;
999 struct timespec ts;
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +02001000
John Stultz7d489d12014-07-16 21:04:01 +00001001 read_persistent_clock(&ts);
1002 now = timespec_to_timespec64(ts);
1003 if (!timespec64_valid_strict(&now)) {
John Stultz4e8b1452012-08-08 15:36:20 -04001004 pr_warn("WARNING: Persistent clock returned invalid value!\n"
1005 " Check your CMOS/BIOS settings.\n");
1006 now.tv_sec = 0;
1007 now.tv_nsec = 0;
Feng Tang31ade302013-01-16 00:09:47 +08001008 } else if (now.tv_sec || now.tv_nsec)
1009 persistent_clock_exist = true;
John Stultz4e8b1452012-08-08 15:36:20 -04001010
John Stultz7d489d12014-07-16 21:04:01 +00001011 read_boot_clock(&ts);
1012 boot = timespec_to_timespec64(ts);
1013 if (!timespec64_valid_strict(&boot)) {
John Stultz4e8b1452012-08-08 15:36:20 -04001014 pr_warn("WARNING: Boot clock returned invalid value!\n"
1015 " Check your CMOS/BIOS settings.\n");
1016 boot.tv_sec = 0;
1017 boot.tv_nsec = 0;
1018 }
john stultz85240702007-05-08 00:27:59 -07001019
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +00001020 raw_spin_lock_irqsave(&timekeeper_lock, flags);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001021 write_seqcount_begin(&tk_core.seq);
John Stultz06c017f2013-03-22 11:37:28 -07001022 ntp_init();
1023
Martin Schwidefskyf1b82742009-08-14 15:47:21 +02001024 clock = clocksource_default_clock();
Martin Schwidefskya0f7d482009-08-14 15:47:19 +02001025 if (clock->enable)
1026 clock->enable(clock);
John Stultz4e250fd2012-07-27 14:48:13 -04001027 tk_setup_internals(tk, clock);
john stultz85240702007-05-08 00:27:59 -07001028
John Stultz4e250fd2012-07-27 14:48:13 -04001029 tk_set_xtime(tk, &now);
1030 tk->raw_time.tv_sec = 0;
1031 tk->raw_time.tv_nsec = 0;
Thomas Gleixnerf519b1a2014-07-16 21:05:04 +00001032 tk->base_raw.tv64 = 0;
John Stultz1e75fa82012-07-13 01:21:53 -04001033 if (boot.tv_sec == 0 && boot.tv_nsec == 0)
John Stultz4e250fd2012-07-27 14:48:13 -04001034 boot = tk_xtime(tk);
John Stultz1e75fa82012-07-13 01:21:53 -04001035
John Stultz7d489d12014-07-16 21:04:01 +00001036 set_normalized_timespec64(&tmp, -boot.tv_sec, -boot.tv_nsec);
John Stultz4e250fd2012-07-27 14:48:13 -04001037 tk_set_wall_to_mono(tk, tmp);
John Stultz6d0ef902012-07-27 14:48:12 -04001038
Thomas Gleixnerf111adf2014-07-16 21:04:09 +00001039 timekeeping_update(tk, TK_MIRROR);
Thomas Gleixner48cdc132013-02-21 22:51:40 +00001040
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001041 write_seqcount_end(&tk_core.seq);
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +00001042 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
john stultz85240702007-05-08 00:27:59 -07001043}
1044
john stultz85240702007-05-08 00:27:59 -07001045/* time in seconds when suspend began */
John Stultz7d489d12014-07-16 21:04:01 +00001046static struct timespec64 timekeeping_suspend_time;
john stultz85240702007-05-08 00:27:59 -07001047
1048/**
John Stultz304529b2011-04-01 14:32:09 -07001049 * __timekeeping_inject_sleeptime - Internal function to add sleep interval
1050 * @delta: pointer to a timespec delta value
1051 *
1052 * Takes a timespec offset measuring a suspend interval and properly
1053 * adds the sleep offset to the timekeeping variables.
1054 */
John Stultzf726a692012-07-13 01:21:57 -04001055static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
John Stultz7d489d12014-07-16 21:04:01 +00001056 struct timespec64 *delta)
John Stultz304529b2011-04-01 14:32:09 -07001057{
John Stultz7d489d12014-07-16 21:04:01 +00001058 if (!timespec64_valid_strict(delta)) {
John Stultz6d9bcb62014-06-04 16:11:43 -07001059 printk_deferred(KERN_WARNING
1060 "__timekeeping_inject_sleeptime: Invalid "
1061 "sleep delta value!\n");
John Stultzcb5de2f8d2011-06-01 18:18:09 -07001062 return;
1063 }
John Stultzf726a692012-07-13 01:21:57 -04001064 tk_xtime_add(tk, delta);
John Stultz7d489d12014-07-16 21:04:01 +00001065 tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *delta));
Thomas Gleixner47da70d2014-07-16 21:05:00 +00001066 tk_update_sleep_time(tk, timespec64_to_ktime(*delta));
Colin Cross5c835452013-05-21 22:32:14 -07001067 tk_debug_account_sleep_time(delta);
John Stultz304529b2011-04-01 14:32:09 -07001068}
1069
John Stultz304529b2011-04-01 14:32:09 -07001070/**
1071 * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
1072 * @delta: pointer to a timespec delta value
1073 *
1074 * This hook is for architectures that cannot support read_persistent_clock
1075 * because their RTC/persistent clock is only accessible when irqs are enabled.
1076 *
1077 * This function should only be called by rtc_resume(), and allows
1078 * a suspend offset to be injected into the timekeeping values.
1079 */
1080void timekeeping_inject_sleeptime(struct timespec *delta)
1081{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001082 struct timekeeper *tk = &tk_core.timekeeper;
John Stultz7d489d12014-07-16 21:04:01 +00001083 struct timespec64 tmp;
John Stultz92c1d3e2011-11-14 14:05:44 -08001084 unsigned long flags;
John Stultz304529b2011-04-01 14:32:09 -07001085
Feng Tang31ade302013-01-16 00:09:47 +08001086 /*
1087 * Make sure we don't set the clock twice, as timekeeping_resume()
1088 * already did it
1089 */
1090 if (has_persistent_clock())
John Stultz304529b2011-04-01 14:32:09 -07001091 return;
1092
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +00001093 raw_spin_lock_irqsave(&timekeeper_lock, flags);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001094 write_seqcount_begin(&tk_core.seq);
John Stultz70471f22011-11-14 12:48:10 -08001095
John Stultz4e250fd2012-07-27 14:48:13 -04001096 timekeeping_forward_now(tk);
John Stultz304529b2011-04-01 14:32:09 -07001097
John Stultz7d489d12014-07-16 21:04:01 +00001098 tmp = timespec_to_timespec64(*delta);
1099 __timekeeping_inject_sleeptime(tk, &tmp);
John Stultz304529b2011-04-01 14:32:09 -07001100
David Vrabel780427f2013-06-27 11:35:46 +01001101 timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
John Stultz304529b2011-04-01 14:32:09 -07001102
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001103 write_seqcount_end(&tk_core.seq);
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +00001104 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
John Stultz304529b2011-04-01 14:32:09 -07001105
1106 /* signal hrtimers about time change */
1107 clock_was_set();
1108}
1109
John Stultz304529b2011-04-01 14:32:09 -07001110/**
john stultz85240702007-05-08 00:27:59 -07001111 * timekeeping_resume - Resumes the generic timekeeping subsystem.
john stultz85240702007-05-08 00:27:59 -07001112 *
1113 * This is for the generic clocksource timekeeping.
1114 * xtime/wall_to_monotonic/jiffies/etc are
1115 * still managed by arch specific suspend/resume code.
1116 */
Rafael J. Wysockie1a85b22011-03-23 22:16:04 +01001117static void timekeeping_resume(void)
john stultz85240702007-05-08 00:27:59 -07001118{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001119 struct timekeeper *tk = &tk_core.timekeeper;
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001120 struct clocksource *clock = tk->tkr.clock;
John Stultz92c1d3e2011-11-14 14:05:44 -08001121 unsigned long flags;
John Stultz7d489d12014-07-16 21:04:01 +00001122 struct timespec64 ts_new, ts_delta;
1123 struct timespec tmp;
Feng Tange445cf12013-03-12 11:56:48 +08001124 cycle_t cycle_now, cycle_delta;
1125 bool suspendtime_found = false;
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +02001126
John Stultz7d489d12014-07-16 21:04:01 +00001127 read_persistent_clock(&tmp);
1128 ts_new = timespec_to_timespec64(tmp);
john stultz85240702007-05-08 00:27:59 -07001129
Rafael J. Wysockiadc78e62012-08-06 01:40:41 +02001130 clockevents_resume();
Thomas Gleixnerd10ff3f2007-05-14 11:10:02 +02001131 clocksource_resume();
1132
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +00001133 raw_spin_lock_irqsave(&timekeeper_lock, flags);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001134 write_seqcount_begin(&tk_core.seq);
john stultz85240702007-05-08 00:27:59 -07001135
Feng Tange445cf12013-03-12 11:56:48 +08001136 /*
1137 * After system resumes, we need to calculate the suspended time and
1138 * compensate it for the OS time. There are 3 sources that could be
1139 * used: Nonstop clocksource during suspend, persistent clock and rtc
1140 * device.
1141 *
1142 * One specific platform may have 1 or 2 or all of them, and the
1143 * preference will be:
1144 * suspend-nonstop clocksource -> persistent clock -> rtc
1145 * The less preferred source will only be tried if there is no better
1146 * usable source. The rtc part is handled separately in rtc core code.
1147 */
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001148 cycle_now = tk->tkr.read(clock);
Feng Tange445cf12013-03-12 11:56:48 +08001149 if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) &&
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001150 cycle_now > tk->tkr.cycle_last) {
Feng Tange445cf12013-03-12 11:56:48 +08001151 u64 num, max = ULLONG_MAX;
1152 u32 mult = clock->mult;
1153 u32 shift = clock->shift;
1154 s64 nsec = 0;
1155
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001156 cycle_delta = clocksource_delta(cycle_now, tk->tkr.cycle_last,
1157 tk->tkr.mask);
Feng Tange445cf12013-03-12 11:56:48 +08001158
1159 /*
1160 * "cycle_delta * mutl" may cause 64 bits overflow, if the
1161 * suspended time is too long. In that case we need do the
1162 * 64 bits math carefully
1163 */
1164 do_div(max, mult);
1165 if (cycle_delta > max) {
1166 num = div64_u64(cycle_delta, max);
1167 nsec = (((u64) max * mult) >> shift) * num;
1168 cycle_delta -= num * max;
1169 }
1170 nsec += ((u64) cycle_delta * mult) >> shift;
1171
John Stultz7d489d12014-07-16 21:04:01 +00001172 ts_delta = ns_to_timespec64(nsec);
Feng Tange445cf12013-03-12 11:56:48 +08001173 suspendtime_found = true;
John Stultz7d489d12014-07-16 21:04:01 +00001174 } else if (timespec64_compare(&ts_new, &timekeeping_suspend_time) > 0) {
1175 ts_delta = timespec64_sub(ts_new, timekeeping_suspend_time);
Feng Tange445cf12013-03-12 11:56:48 +08001176 suspendtime_found = true;
john stultz85240702007-05-08 00:27:59 -07001177 }
Feng Tange445cf12013-03-12 11:56:48 +08001178
1179 if (suspendtime_found)
1180 __timekeeping_inject_sleeptime(tk, &ts_delta);
1181
1182 /* Re-base the last cycle value */
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001183 tk->tkr.cycle_last = cycle_now;
John Stultz4e250fd2012-07-27 14:48:13 -04001184 tk->ntp_error = 0;
john stultz85240702007-05-08 00:27:59 -07001185 timekeeping_suspended = 0;
David Vrabel780427f2013-06-27 11:35:46 +01001186 timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001187 write_seqcount_end(&tk_core.seq);
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +00001188 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
john stultz85240702007-05-08 00:27:59 -07001189
1190 touch_softlockup_watchdog();
1191
1192 clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL);
1193
1194 /* Resume hrtimers */
Thomas Gleixnerb12a03c2011-05-02 16:48:57 +02001195 hrtimers_resume();
john stultz85240702007-05-08 00:27:59 -07001196}
1197
Rafael J. Wysockie1a85b22011-03-23 22:16:04 +01001198static int timekeeping_suspend(void)
john stultz85240702007-05-08 00:27:59 -07001199{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001200 struct timekeeper *tk = &tk_core.timekeeper;
John Stultz92c1d3e2011-11-14 14:05:44 -08001201 unsigned long flags;
John Stultz7d489d12014-07-16 21:04:01 +00001202 struct timespec64 delta, delta_delta;
1203 static struct timespec64 old_delta;
1204 struct timespec tmp;
john stultz85240702007-05-08 00:27:59 -07001205
John Stultz7d489d12014-07-16 21:04:01 +00001206 read_persistent_clock(&tmp);
1207 timekeeping_suspend_time = timespec_to_timespec64(tmp);
Thomas Gleixner3be90952007-09-16 15:36:43 +02001208
Zoran Markovic0d6bd992013-05-17 11:24:05 -07001209 /*
1210 * On some systems the persistent_clock can not be detected at
1211 * timekeeping_init by its return value, so if we see a valid
1212 * value returned, update the persistent_clock_exists flag.
1213 */
1214 if (timekeeping_suspend_time.tv_sec || timekeeping_suspend_time.tv_nsec)
1215 persistent_clock_exist = true;
1216
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +00001217 raw_spin_lock_irqsave(&timekeeper_lock, flags);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001218 write_seqcount_begin(&tk_core.seq);
John Stultz4e250fd2012-07-27 14:48:13 -04001219 timekeeping_forward_now(tk);
john stultz85240702007-05-08 00:27:59 -07001220 timekeeping_suspended = 1;
John Stultzcb332172011-05-31 22:53:23 -07001221
1222 /*
1223 * To avoid drift caused by repeated suspend/resumes,
1224 * which each can add ~1 second drift error,
1225 * try to compensate so the difference in system time
1226 * and persistent_clock time stays close to constant.
1227 */
John Stultz7d489d12014-07-16 21:04:01 +00001228 delta = timespec64_sub(tk_xtime(tk), timekeeping_suspend_time);
1229 delta_delta = timespec64_sub(delta, old_delta);
John Stultzcb332172011-05-31 22:53:23 -07001230 if (abs(delta_delta.tv_sec) >= 2) {
1231 /*
1232 * if delta_delta is too large, assume time correction
1233 * has occured and set old_delta to the current delta.
1234 */
1235 old_delta = delta;
1236 } else {
1237 /* Otherwise try to adjust old_system to compensate */
1238 timekeeping_suspend_time =
John Stultz7d489d12014-07-16 21:04:01 +00001239 timespec64_add(timekeeping_suspend_time, delta_delta);
John Stultzcb332172011-05-31 22:53:23 -07001240 }
John Stultz330a1612013-12-11 19:10:36 -08001241
1242 timekeeping_update(tk, TK_MIRROR);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001243 write_seqcount_end(&tk_core.seq);
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +00001244 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
john stultz85240702007-05-08 00:27:59 -07001245
1246 clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
Magnus Dammc54a42b2010-02-02 14:41:41 -08001247 clocksource_suspend();
Rafael J. Wysockiadc78e62012-08-06 01:40:41 +02001248 clockevents_suspend();
john stultz85240702007-05-08 00:27:59 -07001249
1250 return 0;
1251}
1252
1253/* sysfs resume/suspend bits for timekeeping */
Rafael J. Wysockie1a85b22011-03-23 22:16:04 +01001254static struct syscore_ops timekeeping_syscore_ops = {
john stultz85240702007-05-08 00:27:59 -07001255 .resume = timekeeping_resume,
1256 .suspend = timekeeping_suspend,
john stultz85240702007-05-08 00:27:59 -07001257};
1258
Rafael J. Wysockie1a85b22011-03-23 22:16:04 +01001259static int __init timekeeping_init_ops(void)
john stultz85240702007-05-08 00:27:59 -07001260{
Rafael J. Wysockie1a85b22011-03-23 22:16:04 +01001261 register_syscore_ops(&timekeeping_syscore_ops);
1262 return 0;
john stultz85240702007-05-08 00:27:59 -07001263}
Rafael J. Wysockie1a85b22011-03-23 22:16:04 +01001264device_initcall(timekeeping_init_ops);
john stultz85240702007-05-08 00:27:59 -07001265
1266/*
John Stultzdc491592013-12-06 17:25:21 -08001267 * Apply a multiplier adjustment to the timekeeper
john stultz85240702007-05-08 00:27:59 -07001268 */
John Stultzdc491592013-12-06 17:25:21 -08001269static __always_inline void timekeeping_apply_adjustment(struct timekeeper *tk,
1270 s64 offset,
1271 bool negative,
1272 int adj_scale)
john stultz85240702007-05-08 00:27:59 -07001273{
John Stultzdc491592013-12-06 17:25:21 -08001274 s64 interval = tk->cycle_interval;
1275 s32 mult_adj = 1;
john stultz85240702007-05-08 00:27:59 -07001276
John Stultzdc491592013-12-06 17:25:21 -08001277 if (negative) {
1278 mult_adj = -mult_adj;
1279 interval = -interval;
1280 offset = -offset;
john stultz85240702007-05-08 00:27:59 -07001281 }
John Stultzdc491592013-12-06 17:25:21 -08001282 mult_adj <<= adj_scale;
1283 interval <<= adj_scale;
1284 offset <<= adj_scale;
john stultz85240702007-05-08 00:27:59 -07001285
John Stultzc2bc1112011-10-27 18:12:42 -07001286 /*
1287 * So the following can be confusing.
1288 *
John Stultzdc491592013-12-06 17:25:21 -08001289 * To keep things simple, lets assume mult_adj == 1 for now.
John Stultzc2bc1112011-10-27 18:12:42 -07001290 *
John Stultzdc491592013-12-06 17:25:21 -08001291 * When mult_adj != 1, remember that the interval and offset values
John Stultzc2bc1112011-10-27 18:12:42 -07001292 * have been appropriately scaled so the math is the same.
1293 *
1294 * The basic idea here is that we're increasing the multiplier
1295 * by one, this causes the xtime_interval to be incremented by
1296 * one cycle_interval. This is because:
1297 * xtime_interval = cycle_interval * mult
1298 * So if mult is being incremented by one:
1299 * xtime_interval = cycle_interval * (mult + 1)
1300 * Its the same as:
1301 * xtime_interval = (cycle_interval * mult) + cycle_interval
1302 * Which can be shortened to:
1303 * xtime_interval += cycle_interval
1304 *
1305 * So offset stores the non-accumulated cycles. Thus the current
1306 * time (in shifted nanoseconds) is:
1307 * now = (offset * adj) + xtime_nsec
1308 * Now, even though we're adjusting the clock frequency, we have
1309 * to keep time consistent. In other words, we can't jump back
1310 * in time, and we also want to avoid jumping forward in time.
1311 *
1312 * So given the same offset value, we need the time to be the same
1313 * both before and after the freq adjustment.
1314 * now = (offset * adj_1) + xtime_nsec_1
1315 * now = (offset * adj_2) + xtime_nsec_2
1316 * So:
1317 * (offset * adj_1) + xtime_nsec_1 =
1318 * (offset * adj_2) + xtime_nsec_2
1319 * And we know:
1320 * adj_2 = adj_1 + 1
1321 * So:
1322 * (offset * adj_1) + xtime_nsec_1 =
1323 * (offset * (adj_1+1)) + xtime_nsec_2
1324 * (offset * adj_1) + xtime_nsec_1 =
1325 * (offset * adj_1) + offset + xtime_nsec_2
1326 * Canceling the sides:
1327 * xtime_nsec_1 = offset + xtime_nsec_2
1328 * Which gives us:
1329 * xtime_nsec_2 = xtime_nsec_1 - offset
1330 * Which simplfies to:
1331 * xtime_nsec -= offset
1332 *
1333 * XXX - TODO: Doc ntp_error calculation.
1334 */
John Stultzdc491592013-12-06 17:25:21 -08001335 tk->tkr.mult += mult_adj;
John Stultzf726a692012-07-13 01:21:57 -04001336 tk->xtime_interval += interval;
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001337 tk->tkr.xtime_nsec -= offset;
John Stultzf726a692012-07-13 01:21:57 -04001338 tk->ntp_error -= (interval - offset) << tk->ntp_error_shift;
John Stultzdc491592013-12-06 17:25:21 -08001339}
John Stultz2a8c0882012-07-13 01:21:56 -04001340
John Stultzdc491592013-12-06 17:25:21 -08001341/*
1342 * Calculate the multiplier adjustment needed to match the frequency
1343 * specified by NTP
1344 */
1345static __always_inline void timekeeping_freqadjust(struct timekeeper *tk,
1346 s64 offset)
1347{
1348 s64 interval = tk->cycle_interval;
1349 s64 xinterval = tk->xtime_interval;
1350 s64 tick_error;
1351 bool negative;
1352 u32 adj;
1353
1354 /* Remove any current error adj from freq calculation */
1355 if (tk->ntp_err_mult)
1356 xinterval -= tk->cycle_interval;
1357
John Stultz375f45b2014-04-23 20:53:29 -07001358 tk->ntp_tick = ntp_tick_length();
1359
John Stultzdc491592013-12-06 17:25:21 -08001360 /* Calculate current error per tick */
1361 tick_error = ntp_tick_length() >> tk->ntp_error_shift;
1362 tick_error -= (xinterval + tk->xtime_remainder);
1363
1364 /* Don't worry about correcting it if its small */
1365 if (likely((tick_error >= 0) && (tick_error <= interval)))
1366 return;
1367
1368 /* preserve the direction of correction */
1369 negative = (tick_error < 0);
1370
1371 /* Sort out the magnitude of the correction */
1372 tick_error = abs(tick_error);
1373 for (adj = 0; tick_error > interval; adj++)
1374 tick_error >>= 1;
1375
1376 /* scale the corrections */
1377 timekeeping_apply_adjustment(tk, offset, negative, adj);
1378}
1379
1380/*
1381 * Adjust the timekeeper's multiplier to the correct frequency
1382 * and also to reduce the accumulated error value.
1383 */
1384static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
1385{
1386 /* Correct for the current frequency error */
1387 timekeeping_freqadjust(tk, offset);
1388
1389 /* Next make a small adjustment to fix any cumulative error */
1390 if (!tk->ntp_err_mult && (tk->ntp_error > 0)) {
1391 tk->ntp_err_mult = 1;
1392 timekeeping_apply_adjustment(tk, offset, 0, 0);
1393 } else if (tk->ntp_err_mult && (tk->ntp_error <= 0)) {
1394 /* Undo any existing error adjustment */
1395 timekeeping_apply_adjustment(tk, offset, 1, 0);
1396 tk->ntp_err_mult = 0;
1397 }
1398
1399 if (unlikely(tk->tkr.clock->maxadj &&
1400 (tk->tkr.mult > tk->tkr.clock->mult + tk->tkr.clock->maxadj))) {
1401 printk_once(KERN_WARNING
1402 "Adjusting %s more than 11%% (%ld vs %ld)\n",
1403 tk->tkr.clock->name, (long)tk->tkr.mult,
1404 (long)tk->tkr.clock->mult + tk->tkr.clock->maxadj);
1405 }
1406
John Stultz2a8c0882012-07-13 01:21:56 -04001407 /*
1408 * It may be possible that when we entered this function, xtime_nsec
1409 * was very small. Further, if we're slightly speeding the clocksource
1410 * in the code above, its possible the required corrective factor to
1411 * xtime_nsec could cause it to underflow.
1412 *
1413 * Now, since we already accumulated the second, cannot simply roll
1414 * the accumulated second back, since the NTP subsystem has been
1415 * notified via second_overflow. So instead we push xtime_nsec forward
1416 * by the amount we underflowed, and add that amount into the error.
1417 *
1418 * We'll correct this error next time through this function, when
1419 * xtime_nsec is not as small.
1420 */
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001421 if (unlikely((s64)tk->tkr.xtime_nsec < 0)) {
1422 s64 neg = -(s64)tk->tkr.xtime_nsec;
1423 tk->tkr.xtime_nsec = 0;
John Stultzf726a692012-07-13 01:21:57 -04001424 tk->ntp_error += neg << tk->ntp_error_shift;
John Stultz2a8c0882012-07-13 01:21:56 -04001425 }
john stultz85240702007-05-08 00:27:59 -07001426}
1427
1428/**
John Stultz1f4f9482012-07-13 01:21:54 -04001429 * accumulate_nsecs_to_secs - Accumulates nsecs into secs
1430 *
1431 * Helper function that accumulates a the nsecs greater then a second
1432 * from the xtime_nsec field to the xtime_secs field.
1433 * It also calls into the NTP code to handle leapsecond processing.
1434 *
1435 */
David Vrabel780427f2013-06-27 11:35:46 +01001436static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk)
John Stultz1f4f9482012-07-13 01:21:54 -04001437{
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001438 u64 nsecps = (u64)NSEC_PER_SEC << tk->tkr.shift;
John Stultz5258d3f2013-12-11 20:07:49 -08001439 unsigned int clock_set = 0;
John Stultz1f4f9482012-07-13 01:21:54 -04001440
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001441 while (tk->tkr.xtime_nsec >= nsecps) {
John Stultz1f4f9482012-07-13 01:21:54 -04001442 int leap;
1443
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001444 tk->tkr.xtime_nsec -= nsecps;
John Stultz1f4f9482012-07-13 01:21:54 -04001445 tk->xtime_sec++;
1446
1447 /* Figure out if its a leap sec and apply if needed */
1448 leap = second_overflow(tk->xtime_sec);
John Stultz6d0ef902012-07-27 14:48:12 -04001449 if (unlikely(leap)) {
John Stultz7d489d12014-07-16 21:04:01 +00001450 struct timespec64 ts;
John Stultz1f4f9482012-07-13 01:21:54 -04001451
John Stultz6d0ef902012-07-27 14:48:12 -04001452 tk->xtime_sec += leap;
1453
1454 ts.tv_sec = leap;
1455 ts.tv_nsec = 0;
1456 tk_set_wall_to_mono(tk,
John Stultz7d489d12014-07-16 21:04:01 +00001457 timespec64_sub(tk->wall_to_monotonic, ts));
John Stultz6d0ef902012-07-27 14:48:12 -04001458
John Stultzcc244dd2012-05-03 12:30:07 -07001459 __timekeeping_set_tai_offset(tk, tk->tai_offset - leap);
1460
John Stultz5258d3f2013-12-11 20:07:49 -08001461 clock_set = TK_CLOCK_WAS_SET;
John Stultz6d0ef902012-07-27 14:48:12 -04001462 }
John Stultz1f4f9482012-07-13 01:21:54 -04001463 }
John Stultz5258d3f2013-12-11 20:07:49 -08001464 return clock_set;
John Stultz1f4f9482012-07-13 01:21:54 -04001465}
1466
John Stultz1f4f9482012-07-13 01:21:54 -04001467/**
john stultza092ff02009-10-02 16:17:53 -07001468 * logarithmic_accumulation - shifted accumulation of cycles
1469 *
1470 * This functions accumulates a shifted interval of cycles into
1471 * into a shifted interval nanoseconds. Allows for O(log) accumulation
1472 * loop.
1473 *
1474 * Returns the unconsumed cycles.
1475 */
John Stultzf726a692012-07-13 01:21:57 -04001476static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
John Stultz5258d3f2013-12-11 20:07:49 -08001477 u32 shift,
1478 unsigned int *clock_set)
john stultza092ff02009-10-02 16:17:53 -07001479{
Thomas Gleixner23a95372013-02-21 22:51:36 +00001480 cycle_t interval = tk->cycle_interval << shift;
Jason Wesseldeda2e82010-08-09 14:20:09 -07001481 u64 raw_nsecs;
john stultza092ff02009-10-02 16:17:53 -07001482
John Stultzf726a692012-07-13 01:21:57 -04001483 /* If the offset is smaller then a shifted interval, do nothing */
Thomas Gleixner23a95372013-02-21 22:51:36 +00001484 if (offset < interval)
john stultza092ff02009-10-02 16:17:53 -07001485 return offset;
1486
1487 /* Accumulate one shifted interval */
Thomas Gleixner23a95372013-02-21 22:51:36 +00001488 offset -= interval;
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001489 tk->tkr.cycle_last += interval;
john stultza092ff02009-10-02 16:17:53 -07001490
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001491 tk->tkr.xtime_nsec += tk->xtime_interval << shift;
John Stultz5258d3f2013-12-11 20:07:49 -08001492 *clock_set |= accumulate_nsecs_to_secs(tk);
john stultza092ff02009-10-02 16:17:53 -07001493
Jason Wesseldeda2e82010-08-09 14:20:09 -07001494 /* Accumulate raw time */
Dan Carpenter5b3900c2012-10-09 10:18:23 +03001495 raw_nsecs = (u64)tk->raw_interval << shift;
John Stultzf726a692012-07-13 01:21:57 -04001496 raw_nsecs += tk->raw_time.tv_nsec;
John Stultzc7dcf872010-08-13 11:30:58 -07001497 if (raw_nsecs >= NSEC_PER_SEC) {
1498 u64 raw_secs = raw_nsecs;
1499 raw_nsecs = do_div(raw_secs, NSEC_PER_SEC);
John Stultzf726a692012-07-13 01:21:57 -04001500 tk->raw_time.tv_sec += raw_secs;
john stultza092ff02009-10-02 16:17:53 -07001501 }
John Stultzf726a692012-07-13 01:21:57 -04001502 tk->raw_time.tv_nsec = raw_nsecs;
john stultza092ff02009-10-02 16:17:53 -07001503
1504 /* Accumulate error between NTP and clock interval */
John Stultz375f45b2014-04-23 20:53:29 -07001505 tk->ntp_error += tk->ntp_tick << shift;
John Stultzf726a692012-07-13 01:21:57 -04001506 tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) <<
1507 (tk->ntp_error_shift + shift);
john stultza092ff02009-10-02 16:17:53 -07001508
1509 return offset;
1510}
1511
john stultz85240702007-05-08 00:27:59 -07001512/**
1513 * update_wall_time - Uses the current clocksource to increment the wall time
1514 *
john stultz85240702007-05-08 00:27:59 -07001515 */
John Stultz47a1b7962013-12-12 13:10:55 -08001516void update_wall_time(void)
john stultz85240702007-05-08 00:27:59 -07001517{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001518 struct timekeeper *real_tk = &tk_core.timekeeper;
Thomas Gleixner48cdc132013-02-21 22:51:40 +00001519 struct timekeeper *tk = &shadow_timekeeper;
john stultz85240702007-05-08 00:27:59 -07001520 cycle_t offset;
john stultza092ff02009-10-02 16:17:53 -07001521 int shift = 0, maxshift;
John Stultz5258d3f2013-12-11 20:07:49 -08001522 unsigned int clock_set = 0;
John Stultz70471f22011-11-14 12:48:10 -08001523 unsigned long flags;
1524
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +00001525 raw_spin_lock_irqsave(&timekeeper_lock, flags);
john stultz85240702007-05-08 00:27:59 -07001526
1527 /* Make sure we're fully resumed: */
1528 if (unlikely(timekeeping_suspended))
John Stultz70471f22011-11-14 12:48:10 -08001529 goto out;
john stultz85240702007-05-08 00:27:59 -07001530
John Stultz592913e2010-07-13 17:56:20 -07001531#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
Thomas Gleixner48cdc132013-02-21 22:51:40 +00001532 offset = real_tk->cycle_interval;
John Stultz592913e2010-07-13 17:56:20 -07001533#else
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001534 offset = clocksource_delta(tk->tkr.read(tk->tkr.clock),
1535 tk->tkr.cycle_last, tk->tkr.mask);
john stultz85240702007-05-08 00:27:59 -07001536#endif
john stultz85240702007-05-08 00:27:59 -07001537
John Stultzbf2ac312012-08-21 20:30:49 -04001538 /* Check if there's really nothing to do */
Thomas Gleixner48cdc132013-02-21 22:51:40 +00001539 if (offset < real_tk->cycle_interval)
John Stultzbf2ac312012-08-21 20:30:49 -04001540 goto out;
1541
john stultza092ff02009-10-02 16:17:53 -07001542 /*
1543 * With NO_HZ we may have to accumulate many cycle_intervals
1544 * (think "ticks") worth of time at once. To do this efficiently,
1545 * we calculate the largest doubling multiple of cycle_intervals
Jim Cromie88b28ad2012-03-14 21:28:56 -06001546 * that is smaller than the offset. We then accumulate that
john stultza092ff02009-10-02 16:17:53 -07001547 * chunk in one go, and then try to consume the next smaller
1548 * doubled multiple.
john stultz85240702007-05-08 00:27:59 -07001549 */
John Stultz4e250fd2012-07-27 14:48:13 -04001550 shift = ilog2(offset) - ilog2(tk->cycle_interval);
john stultza092ff02009-10-02 16:17:53 -07001551 shift = max(0, shift);
Jim Cromie88b28ad2012-03-14 21:28:56 -06001552 /* Bound shift to one less than what overflows tick_length */
John Stultzea7cf492011-11-14 13:18:07 -08001553 maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
john stultza092ff02009-10-02 16:17:53 -07001554 shift = min(shift, maxshift);
John Stultz4e250fd2012-07-27 14:48:13 -04001555 while (offset >= tk->cycle_interval) {
John Stultz5258d3f2013-12-11 20:07:49 -08001556 offset = logarithmic_accumulation(tk, offset, shift,
1557 &clock_set);
John Stultz4e250fd2012-07-27 14:48:13 -04001558 if (offset < tk->cycle_interval<<shift)
John Stultz830ec042010-03-18 14:47:30 -07001559 shift--;
john stultz85240702007-05-08 00:27:59 -07001560 }
1561
1562 /* correct the clock when NTP error is too big */
John Stultz4e250fd2012-07-27 14:48:13 -04001563 timekeeping_adjust(tk, offset);
john stultz85240702007-05-08 00:27:59 -07001564
John Stultz6a867a32010-04-06 14:30:51 -07001565 /*
John Stultz92bb1fc2012-09-04 15:38:12 -04001566 * XXX This can be killed once everyone converts
1567 * to the new update_vsyscall.
1568 */
1569 old_vsyscall_fixup(tk);
john stultz85240702007-05-08 00:27:59 -07001570
John Stultz6a867a32010-04-06 14:30:51 -07001571 /*
1572 * Finally, make sure that after the rounding
John Stultz1e75fa82012-07-13 01:21:53 -04001573 * xtime_nsec isn't larger than NSEC_PER_SEC
John Stultz6a867a32010-04-06 14:30:51 -07001574 */
John Stultz5258d3f2013-12-11 20:07:49 -08001575 clock_set |= accumulate_nsecs_to_secs(tk);
Linus Torvalds83f57a12009-12-22 14:10:37 -08001576
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001577 write_seqcount_begin(&tk_core.seq);
Thomas Gleixner48cdc132013-02-21 22:51:40 +00001578 /*
1579 * Update the real timekeeper.
1580 *
1581 * We could avoid this memcpy by switching pointers, but that
1582 * requires changes to all other timekeeper usage sites as
1583 * well, i.e. move the timekeeper pointer getter into the
1584 * spinlocked/seqcount protected sections. And we trade this
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001585 * memcpy under the tk_core.seq against one before we start
Thomas Gleixner48cdc132013-02-21 22:51:40 +00001586 * updating.
1587 */
1588 memcpy(real_tk, tk, sizeof(*tk));
John Stultz5258d3f2013-12-11 20:07:49 -08001589 timekeeping_update(real_tk, clock_set);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001590 write_seqcount_end(&tk_core.seq);
Thomas Gleixnerca4523c2013-02-21 22:51:40 +00001591out:
Thomas Gleixner9a7a71b2013-02-21 22:51:38 +00001592 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
John Stultz47a1b7962013-12-12 13:10:55 -08001593 if (clock_set)
John Stultzcab5e122014-03-27 16:30:49 -07001594 /* Have to call _delayed version, since in irq context*/
1595 clock_was_set_delayed();
john stultz85240702007-05-08 00:27:59 -07001596}
Tomas Janousek7c3f1a52007-07-15 23:39:41 -07001597
1598/**
1599 * getboottime - Return the real time of system boot.
1600 * @ts: pointer to the timespec to be set
1601 *
John Stultzabb3a4e2011-02-14 17:52:09 -08001602 * Returns the wall-time of boot in a timespec.
Tomas Janousek7c3f1a52007-07-15 23:39:41 -07001603 *
1604 * This is based on the wall_to_monotonic offset and the total suspend
1605 * time. Calls to settimeofday will affect the value returned (which
1606 * basically means that however wrong your real time clock is at boot time,
1607 * you get the right time here).
1608 */
1609void getboottime(struct timespec *ts)
1610{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001611 struct timekeeper *tk = &tk_core.timekeeper;
Thomas Gleixner02cba152014-07-16 21:04:58 +00001612 ktime_t t = ktime_sub(tk->offs_real, tk->offs_boot);
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +02001613
Thomas Gleixner02cba152014-07-16 21:04:58 +00001614 *ts = ktime_to_timespec(t);
Tomas Janousek7c3f1a52007-07-15 23:39:41 -07001615}
Jason Wangc93d89f2010-01-27 19:13:40 +08001616EXPORT_SYMBOL_GPL(getboottime);
Tomas Janousek7c3f1a52007-07-15 23:39:41 -07001617
john stultz17c38b72007-07-24 18:38:34 -07001618unsigned long get_seconds(void)
1619{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001620 struct timekeeper *tk = &tk_core.timekeeper;
John Stultz4e250fd2012-07-27 14:48:13 -04001621
1622 return tk->xtime_sec;
john stultz17c38b72007-07-24 18:38:34 -07001623}
1624EXPORT_SYMBOL(get_seconds);
1625
john stultzda15cfd2009-08-19 19:13:34 -07001626struct timespec __current_kernel_time(void)
1627{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001628 struct timekeeper *tk = &tk_core.timekeeper;
John Stultz4e250fd2012-07-27 14:48:13 -04001629
John Stultz7d489d12014-07-16 21:04:01 +00001630 return timespec64_to_timespec(tk_xtime(tk));
john stultzda15cfd2009-08-19 19:13:34 -07001631}
john stultz17c38b72007-07-24 18:38:34 -07001632
john stultz2c6b47d2007-07-24 17:47:43 -07001633struct timespec current_kernel_time(void)
1634{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001635 struct timekeeper *tk = &tk_core.timekeeper;
John Stultz7d489d12014-07-16 21:04:01 +00001636 struct timespec64 now;
john stultz2c6b47d2007-07-24 17:47:43 -07001637 unsigned long seq;
1638
1639 do {
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001640 seq = read_seqcount_begin(&tk_core.seq);
Linus Torvalds83f57a12009-12-22 14:10:37 -08001641
John Stultz4e250fd2012-07-27 14:48:13 -04001642 now = tk_xtime(tk);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001643 } while (read_seqcount_retry(&tk_core.seq, seq));
john stultz2c6b47d2007-07-24 17:47:43 -07001644
John Stultz7d489d12014-07-16 21:04:01 +00001645 return timespec64_to_timespec(now);
john stultz2c6b47d2007-07-24 17:47:43 -07001646}
john stultz2c6b47d2007-07-24 17:47:43 -07001647EXPORT_SYMBOL(current_kernel_time);
john stultzda15cfd2009-08-19 19:13:34 -07001648
1649struct timespec get_monotonic_coarse(void)
1650{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001651 struct timekeeper *tk = &tk_core.timekeeper;
John Stultz7d489d12014-07-16 21:04:01 +00001652 struct timespec64 now, mono;
john stultzda15cfd2009-08-19 19:13:34 -07001653 unsigned long seq;
1654
1655 do {
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001656 seq = read_seqcount_begin(&tk_core.seq);
Linus Torvalds83f57a12009-12-22 14:10:37 -08001657
John Stultz4e250fd2012-07-27 14:48:13 -04001658 now = tk_xtime(tk);
1659 mono = tk->wall_to_monotonic;
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001660 } while (read_seqcount_retry(&tk_core.seq, seq));
john stultzda15cfd2009-08-19 19:13:34 -07001661
John Stultz7d489d12014-07-16 21:04:01 +00001662 set_normalized_timespec64(&now, now.tv_sec + mono.tv_sec,
john stultzda15cfd2009-08-19 19:13:34 -07001663 now.tv_nsec + mono.tv_nsec);
John Stultz7d489d12014-07-16 21:04:01 +00001664
1665 return timespec64_to_timespec(now);
john stultzda15cfd2009-08-19 19:13:34 -07001666}
Torben Hohn871cf1e2011-01-27 15:58:55 +01001667
1668/*
John Stultzd6ad4182012-02-28 16:50:11 -08001669 * Must hold jiffies_lock
Torben Hohn871cf1e2011-01-27 15:58:55 +01001670 */
1671void do_timer(unsigned long ticks)
1672{
1673 jiffies_64 += ticks;
Torben Hohn871cf1e2011-01-27 15:58:55 +01001674 calc_global_load(ticks);
1675}
Torben Hohn48cf76f72011-01-27 15:59:05 +01001676
1677/**
John Stultz76f41082014-07-16 21:03:52 +00001678 * ktime_get_update_offsets_tick - hrtimer helper
1679 * @offs_real: pointer to storage for monotonic -> realtime offset
1680 * @offs_boot: pointer to storage for monotonic -> boottime offset
1681 * @offs_tai: pointer to storage for monotonic -> clock tai offset
1682 *
1683 * Returns monotonic time at last tick and various offsets
Torben Hohn48cf76f72011-01-27 15:59:05 +01001684 */
John Stultz76f41082014-07-16 21:03:52 +00001685ktime_t ktime_get_update_offsets_tick(ktime_t *offs_real, ktime_t *offs_boot,
1686 ktime_t *offs_tai)
Torben Hohn48cf76f72011-01-27 15:59:05 +01001687{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001688 struct timekeeper *tk = &tk_core.timekeeper;
John Stultz76f41082014-07-16 21:03:52 +00001689 unsigned int seq;
Thomas Gleixner48064f52014-07-16 21:04:20 +00001690 ktime_t base;
1691 u64 nsecs;
Torben Hohn48cf76f72011-01-27 15:59:05 +01001692
1693 do {
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001694 seq = read_seqcount_begin(&tk_core.seq);
John Stultz76f41082014-07-16 21:03:52 +00001695
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001696 base = tk->tkr.base_mono;
1697 nsecs = tk->tkr.xtime_nsec >> tk->tkr.shift;
Thomas Gleixner48064f52014-07-16 21:04:20 +00001698
John Stultz76f41082014-07-16 21:03:52 +00001699 *offs_real = tk->offs_real;
1700 *offs_boot = tk->offs_boot;
1701 *offs_tai = tk->offs_tai;
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001702 } while (read_seqcount_retry(&tk_core.seq, seq));
John Stultz76f41082014-07-16 21:03:52 +00001703
Thomas Gleixner48064f52014-07-16 21:04:20 +00001704 return ktime_add_ns(base, nsecs);
Torben Hohn48cf76f72011-01-27 15:59:05 +01001705}
Torben Hohnf0af911a92011-01-27 15:59:10 +01001706
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001707#ifdef CONFIG_HIGH_RES_TIMERS
1708/**
John Stultz76f41082014-07-16 21:03:52 +00001709 * ktime_get_update_offsets_now - hrtimer helper
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001710 * @offs_real: pointer to storage for monotonic -> realtime offset
1711 * @offs_boot: pointer to storage for monotonic -> boottime offset
Xie XiuQib7bc50e2013-10-18 09:13:30 +08001712 * @offs_tai: pointer to storage for monotonic -> clock tai offset
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001713 *
1714 * Returns current monotonic time and updates the offsets
Xie XiuQib7bc50e2013-10-18 09:13:30 +08001715 * Called from hrtimer_interrupt() or retrigger_next_event()
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001716 */
John Stultz76f41082014-07-16 21:03:52 +00001717ktime_t ktime_get_update_offsets_now(ktime_t *offs_real, ktime_t *offs_boot,
John Stultz90adda92013-01-21 17:00:11 -08001718 ktime_t *offs_tai)
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001719{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001720 struct timekeeper *tk = &tk_core.timekeeper;
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001721 unsigned int seq;
Thomas Gleixnera37c0aa2014-07-16 21:04:19 +00001722 ktime_t base;
1723 u64 nsecs;
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001724
1725 do {
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001726 seq = read_seqcount_begin(&tk_core.seq);
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001727
Thomas Gleixnerd28ede82014-07-16 21:05:16 +00001728 base = tk->tkr.base_mono;
Thomas Gleixner0e5ac3a2014-07-16 21:05:18 +00001729 nsecs = timekeeping_get_ns(&tk->tkr);
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001730
John Stultz4e250fd2012-07-27 14:48:13 -04001731 *offs_real = tk->offs_real;
1732 *offs_boot = tk->offs_boot;
John Stultz90adda92013-01-21 17:00:11 -08001733 *offs_tai = tk->offs_tai;
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001734 } while (read_seqcount_retry(&tk_core.seq, seq));
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001735
Thomas Gleixnera37c0aa2014-07-16 21:04:19 +00001736 return ktime_add_ns(base, nsecs);
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001737}
1738#endif
1739
Torben Hohnf0af911a92011-01-27 15:59:10 +01001740/**
John Stultzaa6f9c592013-03-22 11:31:29 -07001741 * do_adjtimex() - Accessor function to NTP __do_adjtimex function
1742 */
1743int do_adjtimex(struct timex *txc)
1744{
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001745 struct timekeeper *tk = &tk_core.timekeeper;
John Stultz06c017f2013-03-22 11:37:28 -07001746 unsigned long flags;
John Stultz7d489d12014-07-16 21:04:01 +00001747 struct timespec64 ts;
John Stultz4e8f8b32013-04-10 12:41:49 -07001748 s32 orig_tai, tai;
John Stultze4085692013-03-22 12:08:52 -07001749 int ret;
1750
1751 /* Validate the data before disabling interrupts */
1752 ret = ntp_validate_timex(txc);
1753 if (ret)
1754 return ret;
1755
John Stultzcef90372013-03-22 15:04:13 -07001756 if (txc->modes & ADJ_SETOFFSET) {
1757 struct timespec delta;
1758 delta.tv_sec = txc->time.tv_sec;
1759 delta.tv_nsec = txc->time.tv_usec;
1760 if (!(txc->modes & ADJ_NANO))
1761 delta.tv_nsec *= 1000;
1762 ret = timekeeping_inject_offset(&delta);
1763 if (ret)
1764 return ret;
1765 }
1766
Thomas Gleixnerd6d29892014-07-16 21:04:04 +00001767 getnstimeofday64(&ts);
John Stultzaa6f9c592013-03-22 11:31:29 -07001768
John Stultz06c017f2013-03-22 11:37:28 -07001769 raw_spin_lock_irqsave(&timekeeper_lock, flags);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001770 write_seqcount_begin(&tk_core.seq);
John Stultz06c017f2013-03-22 11:37:28 -07001771
John Stultz4e8f8b32013-04-10 12:41:49 -07001772 orig_tai = tai = tk->tai_offset;
John Stultz87ace392013-03-22 12:28:15 -07001773 ret = __do_adjtimex(txc, &ts, &tai);
1774
John Stultz4e8f8b32013-04-10 12:41:49 -07001775 if (tai != orig_tai) {
1776 __timekeeping_set_tai_offset(tk, tai);
John Stultzf55c0762013-12-11 18:50:25 -08001777 timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
John Stultz4e8f8b32013-04-10 12:41:49 -07001778 }
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001779 write_seqcount_end(&tk_core.seq);
John Stultz06c017f2013-03-22 11:37:28 -07001780 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
1781
John Stultz6fdda9a2013-12-10 17:18:18 -08001782 if (tai != orig_tai)
1783 clock_was_set();
1784
John Stultz7bd36012013-09-11 16:50:56 -07001785 ntp_notify_cmos_timer();
1786
John Stultz87ace392013-03-22 12:28:15 -07001787 return ret;
1788}
John Stultzaa6f9c592013-03-22 11:31:29 -07001789
1790#ifdef CONFIG_NTP_PPS
1791/**
1792 * hardpps() - Accessor function to NTP __hardpps function
1793 */
1794void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
1795{
John Stultz06c017f2013-03-22 11:37:28 -07001796 unsigned long flags;
1797
1798 raw_spin_lock_irqsave(&timekeeper_lock, flags);
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001799 write_seqcount_begin(&tk_core.seq);
John Stultz06c017f2013-03-22 11:37:28 -07001800
John Stultzaa6f9c592013-03-22 11:31:29 -07001801 __hardpps(phase_ts, raw_ts);
John Stultz06c017f2013-03-22 11:37:28 -07001802
Thomas Gleixner3fdb14f2014-07-16 21:04:07 +00001803 write_seqcount_end(&tk_core.seq);
John Stultz06c017f2013-03-22 11:37:28 -07001804 raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
John Stultzaa6f9c592013-03-22 11:31:29 -07001805}
1806EXPORT_SYMBOL(hardpps);
1807#endif
1808
1809/**
Torben Hohnf0af911a92011-01-27 15:59:10 +01001810 * xtime_update() - advances the timekeeping infrastructure
1811 * @ticks: number of ticks, that have elapsed since the last call.
1812 *
1813 * Must be called with interrupts disabled.
1814 */
1815void xtime_update(unsigned long ticks)
1816{
John Stultzd6ad4182012-02-28 16:50:11 -08001817 write_seqlock(&jiffies_lock);
Torben Hohnf0af911a92011-01-27 15:59:10 +01001818 do_timer(ticks);
John Stultzd6ad4182012-02-28 16:50:11 -08001819 write_sequnlock(&jiffies_lock);
John Stultz47a1b7962013-12-12 13:10:55 -08001820 update_wall_time();
Torben Hohnf0af911a92011-01-27 15:59:10 +01001821}