blob: 34e5eac81424d98738246415a85d1a98a042bef1 [file] [log] [blame]
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
11#include <linux/module.h>
12#include <linux/interrupt.h>
13#include <linux/percpu.h>
14#include <linux/init.h>
15#include <linux/mm.h>
Alexey Dobriyand43c36d2009-10-07 17:09:06 +040016#include <linux/sched.h>
Rafael J. Wysockie1a85b22011-03-23 22:16:04 +010017#include <linux/syscore_ops.h>
john stultz85240702007-05-08 00:27:59 -070018#include <linux/clocksource.h>
19#include <linux/jiffies.h>
20#include <linux/time.h>
21#include <linux/tick.h>
Martin Schwidefsky75c51582009-08-14 15:47:30 +020022#include <linux/stop_machine.h>
john stultz85240702007-05-08 00:27:59 -070023
Martin Schwidefsky155ec602009-08-14 15:47:26 +020024/* Structure holding internal timekeeping values. */
25struct timekeeper {
26 /* Current clocksource used for timekeeping. */
John Stultz42e71e82012-07-13 01:21:51 -040027 struct clocksource *clock;
Thomas Gleixner058892e2011-11-13 23:19:48 +000028 /* NTP adjusted clock multiplier */
John Stultz42e71e82012-07-13 01:21:51 -040029 u32 mult;
Martin Schwidefsky23ce7212009-08-14 15:47:27 +020030 /* The shift value of the current clocksource. */
John Stultzfee84c42012-07-13 01:21:52 -040031 u32 shift;
Martin Schwidefsky155ec602009-08-14 15:47:26 +020032 /* Number of clock cycles in one NTP interval. */
John Stultz42e71e82012-07-13 01:21:51 -040033 cycle_t cycle_interval;
Martin Schwidefsky155ec602009-08-14 15:47:26 +020034 /* Number of clock shifted nano seconds in one NTP interval. */
John Stultz42e71e82012-07-13 01:21:51 -040035 u64 xtime_interval;
Kasper Pedersena386b5a2010-10-20 15:55:15 -070036 /* shifted nano seconds left over when rounding cycle_interval */
John Stultz42e71e82012-07-13 01:21:51 -040037 s64 xtime_remainder;
Martin Schwidefsky155ec602009-08-14 15:47:26 +020038 /* Raw nano seconds accumulated per NTP interval. */
John Stultz42e71e82012-07-13 01:21:51 -040039 u32 raw_interval;
Martin Schwidefsky155ec602009-08-14 15:47:26 +020040
John Stultz1e75fa82012-07-13 01:21:53 -040041 /* Current CLOCK_REALTIME time in seconds */
42 u64 xtime_sec;
43 /* Clock shifted nano seconds */
John Stultz42e71e82012-07-13 01:21:51 -040044 u64 xtime_nsec;
John Stultz1e75fa82012-07-13 01:21:53 -040045
Martin Schwidefsky155ec602009-08-14 15:47:26 +020046 /* Difference between accumulated time and NTP time in ntp
47 * shifted nano seconds. */
John Stultz42e71e82012-07-13 01:21:51 -040048 s64 ntp_error;
Martin Schwidefsky23ce7212009-08-14 15:47:27 +020049 /* Shift conversion between clock shifted nano seconds and
50 * ntp shifted nano seconds. */
John Stultzfee84c42012-07-13 01:21:52 -040051 u32 ntp_error_shift;
John Stultz00c5fb72011-11-14 11:23:15 -080052
John Stultzd9f72172011-11-14 11:29:32 -080053 /*
54 * wall_to_monotonic is what we need to add to xtime (or xtime corrected
55 * for sub jiffie times) to get to monotonic time. Monotonic is pegged
56 * at zero at system boot time, so wall_to_monotonic will be negative,
57 * however, we will ALWAYS keep the tv_nsec part positive so we can use
58 * the usual normalization.
59 *
60 * wall_to_monotonic is moved after resume from suspend for the
61 * monotonic time not to jump. We need to add total_sleep_time to
62 * wall_to_monotonic to get the real boot based time offset.
63 *
64 * - wall_to_monotonic is no longer the boot time, getboottime must be
65 * used instead.
66 */
John Stultz42e71e82012-07-13 01:21:51 -040067 struct timespec wall_to_monotonic;
Thomas Gleixner5b9fe752012-07-10 18:43:21 -040068 /* Offset clock monotonic -> clock realtime */
John Stultz42e71e82012-07-13 01:21:51 -040069 ktime_t offs_real;
John Stultz6d0ef902012-07-27 14:48:12 -040070 /* time spent in suspend */
71 struct timespec total_sleep_time;
Thomas Gleixner5b9fe752012-07-10 18:43:21 -040072 /* Offset clock monotonic -> clock boottime */
John Stultz42e71e82012-07-13 01:21:51 -040073 ktime_t offs_boot;
John Stultz6d0ef902012-07-27 14:48:12 -040074 /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
75 struct timespec raw_time;
John Stultz70471f22011-11-14 12:48:10 -080076 /* Seqlock for all timekeeper values */
John Stultz42e71e82012-07-13 01:21:51 -040077 seqlock_t lock;
Martin Schwidefsky155ec602009-08-14 15:47:26 +020078};
79
H Hartley Sweetenafa14e72011-01-11 17:59:38 -060080static struct timekeeper timekeeper;
Martin Schwidefsky155ec602009-08-14 15:47:26 +020081
John Stultz8fcce542011-11-14 11:46:39 -080082/*
83 * This read-write spinlock protects us from races in SMP while
84 * playing with xtime.
85 */
86__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
87
John Stultz8fcce542011-11-14 11:46:39 -080088/* flag for if timekeeping is suspended */
89int __read_mostly timekeeping_suspended;
90
John Stultz1e75fa82012-07-13 01:21:53 -040091static inline void tk_normalize_xtime(struct timekeeper *tk)
92{
93 while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) {
94 tk->xtime_nsec -= (u64)NSEC_PER_SEC << tk->shift;
95 tk->xtime_sec++;
96 }
97}
John Stultz8fcce542011-11-14 11:46:39 -080098
John Stultz1e75fa82012-07-13 01:21:53 -040099static struct timespec tk_xtime(struct timekeeper *tk)
100{
101 struct timespec ts;
102
103 ts.tv_sec = tk->xtime_sec;
104 ts.tv_nsec = (long)(tk->xtime_nsec >> tk->shift);
105 return ts;
106}
107
108static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts)
109{
110 tk->xtime_sec = ts->tv_sec;
John Stultzb44d50d2012-07-23 16:22:37 -0400111 tk->xtime_nsec = (u64)ts->tv_nsec << tk->shift;
John Stultz1e75fa82012-07-13 01:21:53 -0400112}
113
114static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts)
115{
116 tk->xtime_sec += ts->tv_sec;
John Stultzb44d50d2012-07-23 16:22:37 -0400117 tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift;
John Stultz784ffcb2012-08-21 20:30:46 -0400118 tk_normalize_xtime(tk);
John Stultz1e75fa82012-07-13 01:21:53 -0400119}
John Stultz8fcce542011-11-14 11:46:39 -0800120
John Stultz6d0ef902012-07-27 14:48:12 -0400121static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm)
122{
123 struct timespec tmp;
124
125 /*
126 * Verify consistency of: offset_real = -wall_to_monotonic
127 * before modifying anything
128 */
129 set_normalized_timespec(&tmp, -tk->wall_to_monotonic.tv_sec,
130 -tk->wall_to_monotonic.tv_nsec);
131 WARN_ON_ONCE(tk->offs_real.tv64 != timespec_to_ktime(tmp).tv64);
132 tk->wall_to_monotonic = wtm;
133 set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
134 tk->offs_real = timespec_to_ktime(tmp);
135}
136
137static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t)
138{
139 /* Verify consistency before modifying */
140 WARN_ON_ONCE(tk->offs_boot.tv64 != timespec_to_ktime(tk->total_sleep_time).tv64);
141
142 tk->total_sleep_time = t;
143 tk->offs_boot = timespec_to_ktime(t);
144}
145
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200146/**
147 * timekeeper_setup_internals - Set up internals to use clocksource clock.
148 *
149 * @clock: Pointer to clocksource.
150 *
151 * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
152 * pair and interval request.
153 *
154 * Unless you're the timekeeping code, you should not be using this!
155 */
John Stultzf726a692012-07-13 01:21:57 -0400156static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200157{
158 cycle_t interval;
Kasper Pedersena386b5a2010-10-20 15:55:15 -0700159 u64 tmp, ntpinterval;
John Stultz1e75fa82012-07-13 01:21:53 -0400160 struct clocksource *old_clock;
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200161
John Stultzf726a692012-07-13 01:21:57 -0400162 old_clock = tk->clock;
163 tk->clock = clock;
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200164 clock->cycle_last = clock->read(clock);
165
166 /* Do the ns -> cycle conversion first, using original mult */
167 tmp = NTP_INTERVAL_LENGTH;
168 tmp <<= clock->shift;
Kasper Pedersena386b5a2010-10-20 15:55:15 -0700169 ntpinterval = tmp;
Martin Schwidefsky0a544192009-08-14 15:47:28 +0200170 tmp += clock->mult/2;
171 do_div(tmp, clock->mult);
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200172 if (tmp == 0)
173 tmp = 1;
174
175 interval = (cycle_t) tmp;
John Stultzf726a692012-07-13 01:21:57 -0400176 tk->cycle_interval = interval;
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200177
178 /* Go back from cycles -> shifted ns */
John Stultzf726a692012-07-13 01:21:57 -0400179 tk->xtime_interval = (u64) interval * clock->mult;
180 tk->xtime_remainder = ntpinterval - tk->xtime_interval;
181 tk->raw_interval =
Martin Schwidefsky0a544192009-08-14 15:47:28 +0200182 ((u64) interval * clock->mult) >> clock->shift;
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200183
John Stultz1e75fa82012-07-13 01:21:53 -0400184 /* if changing clocks, convert xtime_nsec shift units */
185 if (old_clock) {
186 int shift_change = clock->shift - old_clock->shift;
187 if (shift_change < 0)
John Stultzf726a692012-07-13 01:21:57 -0400188 tk->xtime_nsec >>= -shift_change;
John Stultz1e75fa82012-07-13 01:21:53 -0400189 else
John Stultzf726a692012-07-13 01:21:57 -0400190 tk->xtime_nsec <<= shift_change;
John Stultz1e75fa82012-07-13 01:21:53 -0400191 }
John Stultzf726a692012-07-13 01:21:57 -0400192 tk->shift = clock->shift;
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200193
John Stultzf726a692012-07-13 01:21:57 -0400194 tk->ntp_error = 0;
195 tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift;
Martin Schwidefsky0a544192009-08-14 15:47:28 +0200196
197 /*
198 * The timekeeper keeps its own mult values for the currently
199 * active clocksource. These value will be adjusted via NTP
200 * to counteract clock drifting.
201 */
John Stultzf726a692012-07-13 01:21:57 -0400202 tk->mult = clock->mult;
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200203}
john stultz85240702007-05-08 00:27:59 -0700204
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200205/* Timekeeper helper functions. */
John Stultzf726a692012-07-13 01:21:57 -0400206static inline s64 timekeeping_get_ns(struct timekeeper *tk)
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200207{
208 cycle_t cycle_now, cycle_delta;
209 struct clocksource *clock;
John Stultz1e75fa82012-07-13 01:21:53 -0400210 s64 nsec;
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200211
212 /* read clocksource: */
John Stultzf726a692012-07-13 01:21:57 -0400213 clock = tk->clock;
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200214 cycle_now = clock->read(clock);
215
216 /* calculate the delta since the last update_wall_time: */
217 cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
218
John Stultzf726a692012-07-13 01:21:57 -0400219 nsec = cycle_delta * tk->mult + tk->xtime_nsec;
220 nsec >>= tk->shift;
John Stultzf2a5a082012-07-13 01:21:55 -0400221
222 /* If arch requires, add in gettimeoffset() */
223 return nsec + arch_gettimeoffset();
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200224}
225
John Stultzf726a692012-07-13 01:21:57 -0400226static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200227{
228 cycle_t cycle_now, cycle_delta;
229 struct clocksource *clock;
John Stultzf2a5a082012-07-13 01:21:55 -0400230 s64 nsec;
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200231
232 /* read clocksource: */
John Stultzf726a692012-07-13 01:21:57 -0400233 clock = tk->clock;
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200234 cycle_now = clock->read(clock);
235
236 /* calculate the delta since the last update_wall_time: */
237 cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
238
John Stultzf2a5a082012-07-13 01:21:55 -0400239 /* convert delta to nanoseconds. */
240 nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
241
242 /* If arch requires, add in gettimeoffset() */
243 return nsec + arch_gettimeoffset();
Martin Schwidefsky2ba2a302009-08-14 15:47:29 +0200244}
245
Thomas Gleixnercc062682011-11-13 23:19:49 +0000246/* must hold write on timekeeper.lock */
John Stultzf726a692012-07-13 01:21:57 -0400247static void timekeeping_update(struct timekeeper *tk, bool clearntp)
Thomas Gleixnercc062682011-11-13 23:19:49 +0000248{
John Stultz1e75fa82012-07-13 01:21:53 -0400249 struct timespec xt;
250
Thomas Gleixnercc062682011-11-13 23:19:49 +0000251 if (clearntp) {
John Stultzf726a692012-07-13 01:21:57 -0400252 tk->ntp_error = 0;
Thomas Gleixnercc062682011-11-13 23:19:49 +0000253 ntp_clear();
254 }
John Stultzf726a692012-07-13 01:21:57 -0400255 xt = tk_xtime(tk);
256 update_vsyscall(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
Thomas Gleixnercc062682011-11-13 23:19:49 +0000257}
258
john stultz85240702007-05-08 00:27:59 -0700259/**
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200260 * timekeeping_forward_now - update clock to the current time
john stultz85240702007-05-08 00:27:59 -0700261 *
Roman Zippel9a055112008-08-20 16:37:28 -0700262 * Forward the current clock to update its state since the last call to
263 * update_wall_time(). This is useful before significant clock changes,
264 * as it avoids having to deal with this time offset explicitly.
john stultz85240702007-05-08 00:27:59 -0700265 */
John Stultzf726a692012-07-13 01:21:57 -0400266static void timekeeping_forward_now(struct timekeeper *tk)
john stultz85240702007-05-08 00:27:59 -0700267{
268 cycle_t cycle_now, cycle_delta;
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200269 struct clocksource *clock;
Roman Zippel9a055112008-08-20 16:37:28 -0700270 s64 nsec;
john stultz85240702007-05-08 00:27:59 -0700271
John Stultzf726a692012-07-13 01:21:57 -0400272 clock = tk->clock;
Martin Schwidefskya0f7d482009-08-14 15:47:19 +0200273 cycle_now = clock->read(clock);
john stultz85240702007-05-08 00:27:59 -0700274 cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
Roman Zippel9a055112008-08-20 16:37:28 -0700275 clock->cycle_last = cycle_now;
john stultz85240702007-05-08 00:27:59 -0700276
John Stultzf726a692012-07-13 01:21:57 -0400277 tk->xtime_nsec += cycle_delta * tk->mult;
john stultz7d275582009-05-01 13:10:26 -0700278
279 /* If arch requires, add in gettimeoffset() */
Andreas Schwab85dc8f02012-08-21 20:30:47 -0400280 tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift;
john stultz7d275582009-05-01 13:10:26 -0700281
John Stultzf726a692012-07-13 01:21:57 -0400282 tk_normalize_xtime(tk);
John Stultz2d422442008-08-20 16:37:30 -0700283
Martin Schwidefsky0a544192009-08-14 15:47:28 +0200284 nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
John Stultzf726a692012-07-13 01:21:57 -0400285 timespec_add_ns(&tk->raw_time, nsec);
john stultz85240702007-05-08 00:27:59 -0700286}
287
288/**
Geert Uytterhoevenefd9ac82008-01-30 13:30:01 +0100289 * getnstimeofday - Returns the time of day in a timespec
john stultz85240702007-05-08 00:27:59 -0700290 * @ts: pointer to the timespec to be set
291 *
Geert Uytterhoevenefd9ac82008-01-30 13:30:01 +0100292 * Returns the time of day in a timespec.
john stultz85240702007-05-08 00:27:59 -0700293 */
Geert Uytterhoevenefd9ac82008-01-30 13:30:01 +0100294void getnstimeofday(struct timespec *ts)
john stultz85240702007-05-08 00:27:59 -0700295{
John Stultz4e250fd2012-07-27 14:48:13 -0400296 struct timekeeper *tk = &timekeeper;
john stultz85240702007-05-08 00:27:59 -0700297 unsigned long seq;
John Stultz1e75fa82012-07-13 01:21:53 -0400298 s64 nsecs = 0;
john stultz85240702007-05-08 00:27:59 -0700299
Thomas Gleixner1c5745a2008-12-22 23:05:28 +0100300 WARN_ON(timekeeping_suspended);
301
john stultz85240702007-05-08 00:27:59 -0700302 do {
John Stultz4e250fd2012-07-27 14:48:13 -0400303 seq = read_seqbegin(&tk->lock);
john stultz85240702007-05-08 00:27:59 -0700304
John Stultz4e250fd2012-07-27 14:48:13 -0400305 ts->tv_sec = tk->xtime_sec;
306 ts->tv_nsec = timekeeping_get_ns(tk);
john stultz85240702007-05-08 00:27:59 -0700307
John Stultz4e250fd2012-07-27 14:48:13 -0400308 } while (read_seqretry(&tk->lock, seq));
john stultz85240702007-05-08 00:27:59 -0700309
310 timespec_add_ns(ts, nsecs);
311}
john stultz85240702007-05-08 00:27:59 -0700312EXPORT_SYMBOL(getnstimeofday);
313
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200314ktime_t ktime_get(void)
315{
John Stultz4e250fd2012-07-27 14:48:13 -0400316 struct timekeeper *tk = &timekeeper;
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200317 unsigned int seq;
318 s64 secs, nsecs;
319
320 WARN_ON(timekeeping_suspended);
321
322 do {
John Stultz4e250fd2012-07-27 14:48:13 -0400323 seq = read_seqbegin(&tk->lock);
324 secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
325 nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec;
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200326
John Stultz4e250fd2012-07-27 14:48:13 -0400327 } while (read_seqretry(&tk->lock, seq));
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200328 /*
329 * Use ktime_set/ktime_add_ns to create a proper ktime on
330 * 32-bit architectures without CONFIG_KTIME_SCALAR.
331 */
332 return ktime_add_ns(ktime_set(secs, 0), nsecs);
333}
334EXPORT_SYMBOL_GPL(ktime_get);
335
336/**
337 * ktime_get_ts - get the monotonic clock in timespec format
338 * @ts: pointer to timespec variable
339 *
340 * The function calculates the monotonic clock from the realtime
341 * clock and the wall_to_monotonic offset and stores the result
342 * in normalized timespec format in the variable pointed to by @ts.
343 */
344void ktime_get_ts(struct timespec *ts)
345{
John Stultz4e250fd2012-07-27 14:48:13 -0400346 struct timekeeper *tk = &timekeeper;
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200347 struct timespec tomono;
348 unsigned int seq;
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200349
350 WARN_ON(timekeeping_suspended);
351
352 do {
John Stultz4e250fd2012-07-27 14:48:13 -0400353 seq = read_seqbegin(&tk->lock);
354 ts->tv_sec = tk->xtime_sec;
355 ts->tv_nsec = timekeeping_get_ns(tk);
356 tomono = tk->wall_to_monotonic;
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200357
John Stultz4e250fd2012-07-27 14:48:13 -0400358 } while (read_seqretry(&tk->lock, seq));
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200359
360 set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
John Stultz1e75fa82012-07-13 01:21:53 -0400361 ts->tv_nsec + tomono.tv_nsec);
Martin Schwidefsky951ed4d2009-07-07 11:27:28 +0200362}
363EXPORT_SYMBOL_GPL(ktime_get_ts);
364
Alexander Gordeeve2c18e42011-01-12 17:00:57 -0800365#ifdef CONFIG_NTP_PPS
366
367/**
368 * getnstime_raw_and_real - get day and raw monotonic time in timespec format
369 * @ts_raw: pointer to the timespec to be set to raw monotonic time
370 * @ts_real: pointer to the timespec to be set to the time of day
371 *
372 * This function reads both the time of day and raw monotonic time at the
373 * same time atomically and stores the resulting timestamps in timespec
374 * format.
375 */
376void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
377{
John Stultz4e250fd2012-07-27 14:48:13 -0400378 struct timekeeper *tk = &timekeeper;
Alexander Gordeeve2c18e42011-01-12 17:00:57 -0800379 unsigned long seq;
380 s64 nsecs_raw, nsecs_real;
381
382 WARN_ON_ONCE(timekeeping_suspended);
383
384 do {
John Stultz4e250fd2012-07-27 14:48:13 -0400385 seq = read_seqbegin(&tk->lock);
Alexander Gordeeve2c18e42011-01-12 17:00:57 -0800386
John Stultz4e250fd2012-07-27 14:48:13 -0400387 *ts_raw = tk->raw_time;
388 ts_real->tv_sec = tk->xtime_sec;
John Stultz1e75fa82012-07-13 01:21:53 -0400389 ts_real->tv_nsec = 0;
Alexander Gordeeve2c18e42011-01-12 17:00:57 -0800390
John Stultz4e250fd2012-07-27 14:48:13 -0400391 nsecs_raw = timekeeping_get_ns_raw(tk);
392 nsecs_real = timekeeping_get_ns(tk);
Alexander Gordeeve2c18e42011-01-12 17:00:57 -0800393
John Stultz4e250fd2012-07-27 14:48:13 -0400394 } while (read_seqretry(&tk->lock, seq));
Alexander Gordeeve2c18e42011-01-12 17:00:57 -0800395
396 timespec_add_ns(ts_raw, nsecs_raw);
397 timespec_add_ns(ts_real, nsecs_real);
398}
399EXPORT_SYMBOL(getnstime_raw_and_real);
400
401#endif /* CONFIG_NTP_PPS */
402
john stultz85240702007-05-08 00:27:59 -0700403/**
404 * do_gettimeofday - Returns the time of day in a timeval
405 * @tv: pointer to the timeval to be set
406 *
Geert Uytterhoevenefd9ac82008-01-30 13:30:01 +0100407 * NOTE: Users should be converted to using getnstimeofday()
john stultz85240702007-05-08 00:27:59 -0700408 */
409void do_gettimeofday(struct timeval *tv)
410{
411 struct timespec now;
412
Geert Uytterhoevenefd9ac82008-01-30 13:30:01 +0100413 getnstimeofday(&now);
john stultz85240702007-05-08 00:27:59 -0700414 tv->tv_sec = now.tv_sec;
415 tv->tv_usec = now.tv_nsec/1000;
416}
john stultz85240702007-05-08 00:27:59 -0700417EXPORT_SYMBOL(do_gettimeofday);
Richard Cochrand239f492012-04-27 10:12:42 +0200418
john stultz85240702007-05-08 00:27:59 -0700419/**
420 * do_settimeofday - Sets the time of day
421 * @tv: pointer to the timespec variable containing the new time
422 *
423 * Sets the time of day to the new time and update NTP and notify hrtimers
424 */
Richard Cochran1e6d7672011-02-01 13:50:58 +0000425int do_settimeofday(const struct timespec *tv)
john stultz85240702007-05-08 00:27:59 -0700426{
John Stultz4e250fd2012-07-27 14:48:13 -0400427 struct timekeeper *tk = &timekeeper;
John Stultz1e75fa82012-07-13 01:21:53 -0400428 struct timespec ts_delta, xt;
John Stultz92c1d3e2011-11-14 14:05:44 -0800429 unsigned long flags;
john stultz85240702007-05-08 00:27:59 -0700430
John Stultzcee58482012-08-31 13:30:06 -0400431 if (!timespec_valid_strict(tv))
john stultz85240702007-05-08 00:27:59 -0700432 return -EINVAL;
433
John Stultz4e250fd2012-07-27 14:48:13 -0400434 write_seqlock_irqsave(&tk->lock, flags);
john stultz85240702007-05-08 00:27:59 -0700435
John Stultz4e250fd2012-07-27 14:48:13 -0400436 timekeeping_forward_now(tk);
john stultz85240702007-05-08 00:27:59 -0700437
John Stultz4e250fd2012-07-27 14:48:13 -0400438 xt = tk_xtime(tk);
John Stultz1e75fa82012-07-13 01:21:53 -0400439 ts_delta.tv_sec = tv->tv_sec - xt.tv_sec;
440 ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec;
441
John Stultz4e250fd2012-07-27 14:48:13 -0400442 tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts_delta));
john stultz85240702007-05-08 00:27:59 -0700443
John Stultz4e250fd2012-07-27 14:48:13 -0400444 tk_set_xtime(tk, tv);
John Stultz1e75fa82012-07-13 01:21:53 -0400445
John Stultz4e250fd2012-07-27 14:48:13 -0400446 timekeeping_update(tk, true);
john stultz85240702007-05-08 00:27:59 -0700447
John Stultz4e250fd2012-07-27 14:48:13 -0400448 write_sequnlock_irqrestore(&tk->lock, flags);
john stultz85240702007-05-08 00:27:59 -0700449
450 /* signal hrtimers about time change */
451 clock_was_set();
452
453 return 0;
454}
john stultz85240702007-05-08 00:27:59 -0700455EXPORT_SYMBOL(do_settimeofday);
456
John Stultzc528f7c2011-02-01 13:52:17 +0000457/**
458 * timekeeping_inject_offset - Adds or subtracts from the current time.
459 * @tv: pointer to the timespec variable containing the offset
460 *
461 * Adds or subtracts an offset value from the current time.
462 */
463int timekeeping_inject_offset(struct timespec *ts)
464{
John Stultz4e250fd2012-07-27 14:48:13 -0400465 struct timekeeper *tk = &timekeeper;
John Stultz92c1d3e2011-11-14 14:05:44 -0800466 unsigned long flags;
John Stultz4e8b1452012-08-08 15:36:20 -0400467 struct timespec tmp;
468 int ret = 0;
John Stultzc528f7c2011-02-01 13:52:17 +0000469
470 if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
471 return -EINVAL;
472
John Stultz4e250fd2012-07-27 14:48:13 -0400473 write_seqlock_irqsave(&tk->lock, flags);
John Stultzc528f7c2011-02-01 13:52:17 +0000474
John Stultz4e250fd2012-07-27 14:48:13 -0400475 timekeeping_forward_now(tk);
John Stultzc528f7c2011-02-01 13:52:17 +0000476
John Stultz4e8b1452012-08-08 15:36:20 -0400477 /* Make sure the proposed value is valid */
478 tmp = timespec_add(tk_xtime(tk), *ts);
John Stultzcee58482012-08-31 13:30:06 -0400479 if (!timespec_valid_strict(&tmp)) {
John Stultz4e8b1452012-08-08 15:36:20 -0400480 ret = -EINVAL;
481 goto error;
482 }
John Stultz1e75fa82012-07-13 01:21:53 -0400483
John Stultz4e250fd2012-07-27 14:48:13 -0400484 tk_xtime_add(tk, ts);
485 tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts));
John Stultzc528f7c2011-02-01 13:52:17 +0000486
John Stultz4e8b1452012-08-08 15:36:20 -0400487error: /* even if we error out, we forwarded the time, so call update */
John Stultz4e250fd2012-07-27 14:48:13 -0400488 timekeeping_update(tk, true);
John Stultzc528f7c2011-02-01 13:52:17 +0000489
John Stultz4e250fd2012-07-27 14:48:13 -0400490 write_sequnlock_irqrestore(&tk->lock, flags);
John Stultzc528f7c2011-02-01 13:52:17 +0000491
492 /* signal hrtimers about time change */
493 clock_was_set();
494
John Stultz4e8b1452012-08-08 15:36:20 -0400495 return ret;
John Stultzc528f7c2011-02-01 13:52:17 +0000496}
497EXPORT_SYMBOL(timekeeping_inject_offset);
498
john stultz85240702007-05-08 00:27:59 -0700499/**
500 * change_clocksource - Swaps clocksources if a new one is available
501 *
502 * Accumulates current time interval and initializes new clocksource
503 */
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200504static int change_clocksource(void *data)
john stultz85240702007-05-08 00:27:59 -0700505{
John Stultz4e250fd2012-07-27 14:48:13 -0400506 struct timekeeper *tk = &timekeeper;
Magnus Damm4614e6a2009-04-21 12:24:02 -0700507 struct clocksource *new, *old;
John Stultzf695cf92012-03-14 16:38:15 -0700508 unsigned long flags;
john stultz85240702007-05-08 00:27:59 -0700509
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200510 new = (struct clocksource *) data;
john stultz85240702007-05-08 00:27:59 -0700511
John Stultz4e250fd2012-07-27 14:48:13 -0400512 write_seqlock_irqsave(&tk->lock, flags);
John Stultzf695cf92012-03-14 16:38:15 -0700513
John Stultz4e250fd2012-07-27 14:48:13 -0400514 timekeeping_forward_now(tk);
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200515 if (!new->enable || new->enable(new) == 0) {
John Stultz4e250fd2012-07-27 14:48:13 -0400516 old = tk->clock;
517 tk_setup_internals(tk, new);
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200518 if (old->disable)
519 old->disable(old);
520 }
John Stultz4e250fd2012-07-27 14:48:13 -0400521 timekeeping_update(tk, true);
John Stultzf695cf92012-03-14 16:38:15 -0700522
John Stultz4e250fd2012-07-27 14:48:13 -0400523 write_sequnlock_irqrestore(&tk->lock, flags);
John Stultzf695cf92012-03-14 16:38:15 -0700524
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200525 return 0;
526}
john stultz85240702007-05-08 00:27:59 -0700527
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200528/**
529 * timekeeping_notify - Install a new clock source
530 * @clock: pointer to the clock source
531 *
532 * This function is called from clocksource.c after a new, better clock
533 * source has been registered. The caller holds the clocksource_mutex.
534 */
535void timekeeping_notify(struct clocksource *clock)
536{
John Stultz4e250fd2012-07-27 14:48:13 -0400537 struct timekeeper *tk = &timekeeper;
538
539 if (tk->clock == clock)
Magnus Damm4614e6a2009-04-21 12:24:02 -0700540 return;
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200541 stop_machine(change_clocksource, clock, NULL);
john stultz85240702007-05-08 00:27:59 -0700542 tick_clock_notify();
john stultz85240702007-05-08 00:27:59 -0700543}
Martin Schwidefsky75c51582009-08-14 15:47:30 +0200544
Thomas Gleixnera40f2622009-07-07 13:00:31 +0200545/**
546 * ktime_get_real - get the real (wall-) time in ktime_t format
547 *
548 * returns the time in ktime_t format
549 */
550ktime_t ktime_get_real(void)
551{
552 struct timespec now;
553
554 getnstimeofday(&now);
555
556 return timespec_to_ktime(now);
557}
558EXPORT_SYMBOL_GPL(ktime_get_real);
john stultz85240702007-05-08 00:27:59 -0700559
560/**
John Stultz2d422442008-08-20 16:37:30 -0700561 * getrawmonotonic - Returns the raw monotonic time in a timespec
562 * @ts: pointer to the timespec to be set
563 *
564 * Returns the raw monotonic time (completely un-modified by ntp)
565 */
566void getrawmonotonic(struct timespec *ts)
567{
John Stultz4e250fd2012-07-27 14:48:13 -0400568 struct timekeeper *tk = &timekeeper;
John Stultz2d422442008-08-20 16:37:30 -0700569 unsigned long seq;
570 s64 nsecs;
John Stultz2d422442008-08-20 16:37:30 -0700571
572 do {
John Stultz4e250fd2012-07-27 14:48:13 -0400573 seq = read_seqbegin(&tk->lock);
574 nsecs = timekeeping_get_ns_raw(tk);
575 *ts = tk->raw_time;
John Stultz2d422442008-08-20 16:37:30 -0700576
John Stultz4e250fd2012-07-27 14:48:13 -0400577 } while (read_seqretry(&tk->lock, seq));
John Stultz2d422442008-08-20 16:37:30 -0700578
579 timespec_add_ns(ts, nsecs);
580}
581EXPORT_SYMBOL(getrawmonotonic);
582
John Stultz2d422442008-08-20 16:37:30 -0700583/**
Li Zefancf4fc6c2008-02-08 04:19:24 -0800584 * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
john stultz85240702007-05-08 00:27:59 -0700585 */
Li Zefancf4fc6c2008-02-08 04:19:24 -0800586int timekeeping_valid_for_hres(void)
john stultz85240702007-05-08 00:27:59 -0700587{
John Stultz4e250fd2012-07-27 14:48:13 -0400588 struct timekeeper *tk = &timekeeper;
john stultz85240702007-05-08 00:27:59 -0700589 unsigned long seq;
590 int ret;
591
592 do {
John Stultz4e250fd2012-07-27 14:48:13 -0400593 seq = read_seqbegin(&tk->lock);
john stultz85240702007-05-08 00:27:59 -0700594
John Stultz4e250fd2012-07-27 14:48:13 -0400595 ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
john stultz85240702007-05-08 00:27:59 -0700596
John Stultz4e250fd2012-07-27 14:48:13 -0400597 } while (read_seqretry(&tk->lock, seq));
john stultz85240702007-05-08 00:27:59 -0700598
599 return ret;
600}
601
602/**
Jon Hunter98962462009-08-18 12:45:10 -0500603 * timekeeping_max_deferment - Returns max time the clocksource can be deferred
Jon Hunter98962462009-08-18 12:45:10 -0500604 */
605u64 timekeeping_max_deferment(void)
606{
John Stultz4e250fd2012-07-27 14:48:13 -0400607 struct timekeeper *tk = &timekeeper;
John Stultz70471f22011-11-14 12:48:10 -0800608 unsigned long seq;
609 u64 ret;
John Stultz42e71e82012-07-13 01:21:51 -0400610
John Stultz70471f22011-11-14 12:48:10 -0800611 do {
John Stultz4e250fd2012-07-27 14:48:13 -0400612 seq = read_seqbegin(&tk->lock);
John Stultz70471f22011-11-14 12:48:10 -0800613
John Stultz4e250fd2012-07-27 14:48:13 -0400614 ret = tk->clock->max_idle_ns;
John Stultz70471f22011-11-14 12:48:10 -0800615
John Stultz4e250fd2012-07-27 14:48:13 -0400616 } while (read_seqretry(&tk->lock, seq));
John Stultz70471f22011-11-14 12:48:10 -0800617
618 return ret;
Jon Hunter98962462009-08-18 12:45:10 -0500619}
620
621/**
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +0200622 * read_persistent_clock - Return time from the persistent clock.
john stultz85240702007-05-08 00:27:59 -0700623 *
624 * Weak dummy function for arches that do not yet support it.
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +0200625 * Reads the time from the battery backed persistent clock.
626 * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
john stultz85240702007-05-08 00:27:59 -0700627 *
628 * XXX - Do be sure to remove it once all arches implement it.
629 */
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +0200630void __attribute__((weak)) read_persistent_clock(struct timespec *ts)
john stultz85240702007-05-08 00:27:59 -0700631{
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +0200632 ts->tv_sec = 0;
633 ts->tv_nsec = 0;
john stultz85240702007-05-08 00:27:59 -0700634}
635
Martin Schwidefsky23970e32009-08-14 15:47:32 +0200636/**
637 * read_boot_clock - Return time of the system start.
638 *
639 * Weak dummy function for arches that do not yet support it.
640 * Function to read the exact time the system has been started.
641 * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
642 *
643 * XXX - Do be sure to remove it once all arches implement it.
644 */
645void __attribute__((weak)) read_boot_clock(struct timespec *ts)
646{
647 ts->tv_sec = 0;
648 ts->tv_nsec = 0;
649}
650
john stultz85240702007-05-08 00:27:59 -0700651/*
652 * timekeeping_init - Initializes the clocksource and common timekeeping values
653 */
654void __init timekeeping_init(void)
655{
John Stultz4e250fd2012-07-27 14:48:13 -0400656 struct timekeeper *tk = &timekeeper;
Martin Schwidefsky155ec602009-08-14 15:47:26 +0200657 struct clocksource *clock;
john stultz85240702007-05-08 00:27:59 -0700658 unsigned long flags;
John Stultz6d0ef902012-07-27 14:48:12 -0400659 struct timespec now, boot, tmp;
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +0200660
661 read_persistent_clock(&now);
John Stultzcee58482012-08-31 13:30:06 -0400662 if (!timespec_valid_strict(&now)) {
John Stultz4e8b1452012-08-08 15:36:20 -0400663 pr_warn("WARNING: Persistent clock returned invalid value!\n"
664 " Check your CMOS/BIOS settings.\n");
665 now.tv_sec = 0;
666 now.tv_nsec = 0;
667 }
668
Martin Schwidefsky23970e32009-08-14 15:47:32 +0200669 read_boot_clock(&boot);
John Stultzcee58482012-08-31 13:30:06 -0400670 if (!timespec_valid_strict(&boot)) {
John Stultz4e8b1452012-08-08 15:36:20 -0400671 pr_warn("WARNING: Boot clock returned invalid value!\n"
672 " Check your CMOS/BIOS settings.\n");
673 boot.tv_sec = 0;
674 boot.tv_nsec = 0;
675 }
john stultz85240702007-05-08 00:27:59 -0700676
John Stultz4e250fd2012-07-27 14:48:13 -0400677 seqlock_init(&tk->lock);
John Stultz70471f22011-11-14 12:48:10 -0800678
Roman Zippel7dffa3c2008-05-01 04:34:41 -0700679 ntp_init();
john stultz85240702007-05-08 00:27:59 -0700680
John Stultz4e250fd2012-07-27 14:48:13 -0400681 write_seqlock_irqsave(&tk->lock, flags);
Martin Schwidefskyf1b82742009-08-14 15:47:21 +0200682 clock = clocksource_default_clock();
Martin Schwidefskya0f7d482009-08-14 15:47:19 +0200683 if (clock->enable)
684 clock->enable(clock);
John Stultz4e250fd2012-07-27 14:48:13 -0400685 tk_setup_internals(tk, clock);
john stultz85240702007-05-08 00:27:59 -0700686
John Stultz4e250fd2012-07-27 14:48:13 -0400687 tk_set_xtime(tk, &now);
688 tk->raw_time.tv_sec = 0;
689 tk->raw_time.tv_nsec = 0;
John Stultz1e75fa82012-07-13 01:21:53 -0400690 if (boot.tv_sec == 0 && boot.tv_nsec == 0)
John Stultz4e250fd2012-07-27 14:48:13 -0400691 boot = tk_xtime(tk);
John Stultz1e75fa82012-07-13 01:21:53 -0400692
John Stultz6d0ef902012-07-27 14:48:12 -0400693 set_normalized_timespec(&tmp, -boot.tv_sec, -boot.tv_nsec);
John Stultz4e250fd2012-07-27 14:48:13 -0400694 tk_set_wall_to_mono(tk, tmp);
John Stultz6d0ef902012-07-27 14:48:12 -0400695
696 tmp.tv_sec = 0;
697 tmp.tv_nsec = 0;
John Stultz4e250fd2012-07-27 14:48:13 -0400698 tk_set_sleep_time(tk, tmp);
John Stultz6d0ef902012-07-27 14:48:12 -0400699
John Stultz4e250fd2012-07-27 14:48:13 -0400700 write_sequnlock_irqrestore(&tk->lock, flags);
john stultz85240702007-05-08 00:27:59 -0700701}
702
john stultz85240702007-05-08 00:27:59 -0700703/* time in seconds when suspend began */
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +0200704static struct timespec timekeeping_suspend_time;
john stultz85240702007-05-08 00:27:59 -0700705
706/**
John Stultz304529b2011-04-01 14:32:09 -0700707 * __timekeeping_inject_sleeptime - Internal function to add sleep interval
708 * @delta: pointer to a timespec delta value
709 *
710 * Takes a timespec offset measuring a suspend interval and properly
711 * adds the sleep offset to the timekeeping variables.
712 */
John Stultzf726a692012-07-13 01:21:57 -0400713static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
714 struct timespec *delta)
John Stultz304529b2011-04-01 14:32:09 -0700715{
John Stultzcee58482012-08-31 13:30:06 -0400716 if (!timespec_valid_strict(delta)) {
John Stultzcbaa5152011-07-20 15:42:55 -0700717 printk(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid "
John Stultzcb5de2f8d2011-06-01 18:18:09 -0700718 "sleep delta value!\n");
719 return;
720 }
John Stultzf726a692012-07-13 01:21:57 -0400721 tk_xtime_add(tk, delta);
John Stultz6d0ef902012-07-27 14:48:12 -0400722 tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *delta));
723 tk_set_sleep_time(tk, timespec_add(tk->total_sleep_time, *delta));
John Stultz304529b2011-04-01 14:32:09 -0700724}
725
John Stultz304529b2011-04-01 14:32:09 -0700726/**
727 * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
728 * @delta: pointer to a timespec delta value
729 *
730 * This hook is for architectures that cannot support read_persistent_clock
731 * because their RTC/persistent clock is only accessible when irqs are enabled.
732 *
733 * This function should only be called by rtc_resume(), and allows
734 * a suspend offset to be injected into the timekeeping values.
735 */
736void timekeeping_inject_sleeptime(struct timespec *delta)
737{
John Stultz4e250fd2012-07-27 14:48:13 -0400738 struct timekeeper *tk = &timekeeper;
John Stultz92c1d3e2011-11-14 14:05:44 -0800739 unsigned long flags;
John Stultz304529b2011-04-01 14:32:09 -0700740 struct timespec ts;
741
742 /* Make sure we don't set the clock twice */
743 read_persistent_clock(&ts);
744 if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
745 return;
746
John Stultz4e250fd2012-07-27 14:48:13 -0400747 write_seqlock_irqsave(&tk->lock, flags);
John Stultz70471f22011-11-14 12:48:10 -0800748
John Stultz4e250fd2012-07-27 14:48:13 -0400749 timekeeping_forward_now(tk);
John Stultz304529b2011-04-01 14:32:09 -0700750
John Stultz4e250fd2012-07-27 14:48:13 -0400751 __timekeeping_inject_sleeptime(tk, delta);
John Stultz304529b2011-04-01 14:32:09 -0700752
John Stultz4e250fd2012-07-27 14:48:13 -0400753 timekeeping_update(tk, true);
John Stultz304529b2011-04-01 14:32:09 -0700754
John Stultz4e250fd2012-07-27 14:48:13 -0400755 write_sequnlock_irqrestore(&tk->lock, flags);
John Stultz304529b2011-04-01 14:32:09 -0700756
757 /* signal hrtimers about time change */
758 clock_was_set();
759}
760
John Stultz304529b2011-04-01 14:32:09 -0700761/**
john stultz85240702007-05-08 00:27:59 -0700762 * timekeeping_resume - Resumes the generic timekeeping subsystem.
john stultz85240702007-05-08 00:27:59 -0700763 *
764 * This is for the generic clocksource timekeeping.
765 * xtime/wall_to_monotonic/jiffies/etc are
766 * still managed by arch specific suspend/resume code.
767 */
Rafael J. Wysockie1a85b22011-03-23 22:16:04 +0100768static void timekeeping_resume(void)
john stultz85240702007-05-08 00:27:59 -0700769{
John Stultz4e250fd2012-07-27 14:48:13 -0400770 struct timekeeper *tk = &timekeeper;
John Stultz92c1d3e2011-11-14 14:05:44 -0800771 unsigned long flags;
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +0200772 struct timespec ts;
773
774 read_persistent_clock(&ts);
john stultz85240702007-05-08 00:27:59 -0700775
Thomas Gleixnerd10ff3f2007-05-14 11:10:02 +0200776 clocksource_resume();
777
John Stultz4e250fd2012-07-27 14:48:13 -0400778 write_seqlock_irqsave(&tk->lock, flags);
john stultz85240702007-05-08 00:27:59 -0700779
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +0200780 if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
781 ts = timespec_sub(ts, timekeeping_suspend_time);
John Stultz4e250fd2012-07-27 14:48:13 -0400782 __timekeeping_inject_sleeptime(tk, &ts);
john stultz85240702007-05-08 00:27:59 -0700783 }
784 /* re-base the last cycle value */
John Stultz4e250fd2012-07-27 14:48:13 -0400785 tk->clock->cycle_last = tk->clock->read(tk->clock);
786 tk->ntp_error = 0;
john stultz85240702007-05-08 00:27:59 -0700787 timekeeping_suspended = 0;
John Stultz4e250fd2012-07-27 14:48:13 -0400788 timekeeping_update(tk, false);
789 write_sequnlock_irqrestore(&tk->lock, flags);
john stultz85240702007-05-08 00:27:59 -0700790
791 touch_softlockup_watchdog();
792
793 clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL);
794
795 /* Resume hrtimers */
Thomas Gleixnerb12a03c2011-05-02 16:48:57 +0200796 hrtimers_resume();
john stultz85240702007-05-08 00:27:59 -0700797}
798
Rafael J. Wysockie1a85b22011-03-23 22:16:04 +0100799static int timekeeping_suspend(void)
john stultz85240702007-05-08 00:27:59 -0700800{
John Stultz4e250fd2012-07-27 14:48:13 -0400801 struct timekeeper *tk = &timekeeper;
John Stultz92c1d3e2011-11-14 14:05:44 -0800802 unsigned long flags;
John Stultzcb332172011-05-31 22:53:23 -0700803 struct timespec delta, delta_delta;
804 static struct timespec old_delta;
john stultz85240702007-05-08 00:27:59 -0700805
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +0200806 read_persistent_clock(&timekeeping_suspend_time);
Thomas Gleixner3be90952007-09-16 15:36:43 +0200807
John Stultz4e250fd2012-07-27 14:48:13 -0400808 write_seqlock_irqsave(&tk->lock, flags);
809 timekeeping_forward_now(tk);
john stultz85240702007-05-08 00:27:59 -0700810 timekeeping_suspended = 1;
John Stultzcb332172011-05-31 22:53:23 -0700811
812 /*
813 * To avoid drift caused by repeated suspend/resumes,
814 * which each can add ~1 second drift error,
815 * try to compensate so the difference in system time
816 * and persistent_clock time stays close to constant.
817 */
John Stultz4e250fd2012-07-27 14:48:13 -0400818 delta = timespec_sub(tk_xtime(tk), timekeeping_suspend_time);
John Stultzcb332172011-05-31 22:53:23 -0700819 delta_delta = timespec_sub(delta, old_delta);
820 if (abs(delta_delta.tv_sec) >= 2) {
821 /*
822 * if delta_delta is too large, assume time correction
823 * has occured and set old_delta to the current delta.
824 */
825 old_delta = delta;
826 } else {
827 /* Otherwise try to adjust old_system to compensate */
828 timekeeping_suspend_time =
829 timespec_add(timekeeping_suspend_time, delta_delta);
830 }
John Stultz4e250fd2012-07-27 14:48:13 -0400831 write_sequnlock_irqrestore(&tk->lock, flags);
john stultz85240702007-05-08 00:27:59 -0700832
833 clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
Magnus Dammc54a42b2010-02-02 14:41:41 -0800834 clocksource_suspend();
john stultz85240702007-05-08 00:27:59 -0700835
836 return 0;
837}
838
839/* sysfs resume/suspend bits for timekeeping */
Rafael J. Wysockie1a85b22011-03-23 22:16:04 +0100840static struct syscore_ops timekeeping_syscore_ops = {
john stultz85240702007-05-08 00:27:59 -0700841 .resume = timekeeping_resume,
842 .suspend = timekeeping_suspend,
john stultz85240702007-05-08 00:27:59 -0700843};
844
Rafael J. Wysockie1a85b22011-03-23 22:16:04 +0100845static int __init timekeeping_init_ops(void)
john stultz85240702007-05-08 00:27:59 -0700846{
Rafael J. Wysockie1a85b22011-03-23 22:16:04 +0100847 register_syscore_ops(&timekeeping_syscore_ops);
848 return 0;
john stultz85240702007-05-08 00:27:59 -0700849}
850
Rafael J. Wysockie1a85b22011-03-23 22:16:04 +0100851device_initcall(timekeeping_init_ops);
john stultz85240702007-05-08 00:27:59 -0700852
853/*
854 * If the error is already larger, we look ahead even further
855 * to compensate for late or lost adjustments.
856 */
John Stultzf726a692012-07-13 01:21:57 -0400857static __always_inline int timekeeping_bigadjust(struct timekeeper *tk,
858 s64 error, s64 *interval,
john stultz85240702007-05-08 00:27:59 -0700859 s64 *offset)
860{
861 s64 tick_error, i;
862 u32 look_ahead, adj;
863 s32 error2, mult;
864
865 /*
866 * Use the current error value to determine how much to look ahead.
867 * The larger the error the slower we adjust for it to avoid problems
868 * with losing too many ticks, otherwise we would overadjust and
869 * produce an even larger error. The smaller the adjustment the
870 * faster we try to adjust for it, as lost ticks can do less harm
Li Zefan3eb05672008-02-08 04:19:25 -0800871 * here. This is tuned so that an error of about 1 msec is adjusted
john stultz85240702007-05-08 00:27:59 -0700872 * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks).
873 */
John Stultzf726a692012-07-13 01:21:57 -0400874 error2 = tk->ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ);
john stultz85240702007-05-08 00:27:59 -0700875 error2 = abs(error2);
876 for (look_ahead = 0; error2 > 0; look_ahead++)
877 error2 >>= 2;
878
879 /*
880 * Now calculate the error in (1 << look_ahead) ticks, but first
881 * remove the single look ahead already included in the error.
882 */
John Stultzf726a692012-07-13 01:21:57 -0400883 tick_error = ntp_tick_length() >> (tk->ntp_error_shift + 1);
884 tick_error -= tk->xtime_interval >> 1;
john stultz85240702007-05-08 00:27:59 -0700885 error = ((error - tick_error) >> look_ahead) + tick_error;
886
887 /* Finally calculate the adjustment shift value. */
888 i = *interval;
889 mult = 1;
890 if (error < 0) {
891 error = -error;
892 *interval = -*interval;
893 *offset = -*offset;
894 mult = -1;
895 }
896 for (adj = 0; error > i; adj++)
897 error >>= 1;
898
899 *interval <<= adj;
900 *offset <<= adj;
901 return mult << adj;
902}
903
904/*
905 * Adjust the multiplier to reduce the error value,
906 * this is optimized for the most common adjustments of -1,0,1,
907 * for other values we can do a bit more work.
908 */
John Stultzf726a692012-07-13 01:21:57 -0400909static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
john stultz85240702007-05-08 00:27:59 -0700910{
John Stultzf726a692012-07-13 01:21:57 -0400911 s64 error, interval = tk->cycle_interval;
john stultz85240702007-05-08 00:27:59 -0700912 int adj;
913
John Stultzc2bc1112011-10-27 18:12:42 -0700914 /*
Jim Cromie88b28ad2012-03-14 21:28:56 -0600915 * The point of this is to check if the error is greater than half
John Stultzc2bc1112011-10-27 18:12:42 -0700916 * an interval.
917 *
918 * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs.
919 *
920 * Note we subtract one in the shift, so that error is really error*2.
John Stultz3f86f282011-10-27 17:41:17 -0700921 * This "saves" dividing(shifting) interval twice, but keeps the
922 * (error > interval) comparison as still measuring if error is
Jim Cromie88b28ad2012-03-14 21:28:56 -0600923 * larger than half an interval.
John Stultzc2bc1112011-10-27 18:12:42 -0700924 *
John Stultz3f86f282011-10-27 17:41:17 -0700925 * Note: It does not "save" on aggravation when reading the code.
John Stultzc2bc1112011-10-27 18:12:42 -0700926 */
John Stultzf726a692012-07-13 01:21:57 -0400927 error = tk->ntp_error >> (tk->ntp_error_shift - 1);
john stultz85240702007-05-08 00:27:59 -0700928 if (error > interval) {
John Stultzc2bc1112011-10-27 18:12:42 -0700929 /*
930 * We now divide error by 4(via shift), which checks if
Jim Cromie88b28ad2012-03-14 21:28:56 -0600931 * the error is greater than twice the interval.
John Stultzc2bc1112011-10-27 18:12:42 -0700932 * If it is greater, we need a bigadjust, if its smaller,
933 * we can adjust by 1.
934 */
john stultz85240702007-05-08 00:27:59 -0700935 error >>= 2;
John Stultzc2bc1112011-10-27 18:12:42 -0700936 /*
937 * XXX - In update_wall_time, we round up to the next
938 * nanosecond, and store the amount rounded up into
939 * the error. This causes the likely below to be unlikely.
940 *
John Stultz3f86f282011-10-27 17:41:17 -0700941 * The proper fix is to avoid rounding up by using
John Stultz4e250fd2012-07-27 14:48:13 -0400942 * the high precision tk->xtime_nsec instead of
John Stultzc2bc1112011-10-27 18:12:42 -0700943 * xtime.tv_nsec everywhere. Fixing this will take some
944 * time.
945 */
john stultz85240702007-05-08 00:27:59 -0700946 if (likely(error <= interval))
947 adj = 1;
948 else
Ingo Molnar1d17d172012-08-04 21:21:14 +0200949 adj = timekeeping_bigadjust(tk, error, &interval, &offset);
950 } else {
951 if (error < -interval) {
952 /* See comment above, this is just switched for the negative */
953 error >>= 2;
954 if (likely(error >= -interval)) {
955 adj = -1;
956 interval = -interval;
957 offset = -offset;
958 } else {
959 adj = timekeeping_bigadjust(tk, error, &interval, &offset);
960 }
961 } else {
962 goto out_adjust;
963 }
964 }
john stultz85240702007-05-08 00:27:59 -0700965
John Stultzf726a692012-07-13 01:21:57 -0400966 if (unlikely(tk->clock->maxadj &&
967 (tk->mult + adj > tk->clock->mult + tk->clock->maxadj))) {
John Stultze919cfd2012-03-22 19:14:46 -0700968 printk_once(KERN_WARNING
969 "Adjusting %s more than 11%% (%ld vs %ld)\n",
John Stultzf726a692012-07-13 01:21:57 -0400970 tk->clock->name, (long)tk->mult + adj,
971 (long)tk->clock->mult + tk->clock->maxadj);
John Stultze919cfd2012-03-22 19:14:46 -0700972 }
John Stultzc2bc1112011-10-27 18:12:42 -0700973 /*
974 * So the following can be confusing.
975 *
976 * To keep things simple, lets assume adj == 1 for now.
977 *
978 * When adj != 1, remember that the interval and offset values
979 * have been appropriately scaled so the math is the same.
980 *
981 * The basic idea here is that we're increasing the multiplier
982 * by one, this causes the xtime_interval to be incremented by
983 * one cycle_interval. This is because:
984 * xtime_interval = cycle_interval * mult
985 * So if mult is being incremented by one:
986 * xtime_interval = cycle_interval * (mult + 1)
987 * Its the same as:
988 * xtime_interval = (cycle_interval * mult) + cycle_interval
989 * Which can be shortened to:
990 * xtime_interval += cycle_interval
991 *
992 * So offset stores the non-accumulated cycles. Thus the current
993 * time (in shifted nanoseconds) is:
994 * now = (offset * adj) + xtime_nsec
995 * Now, even though we're adjusting the clock frequency, we have
996 * to keep time consistent. In other words, we can't jump back
997 * in time, and we also want to avoid jumping forward in time.
998 *
999 * So given the same offset value, we need the time to be the same
1000 * both before and after the freq adjustment.
1001 * now = (offset * adj_1) + xtime_nsec_1
1002 * now = (offset * adj_2) + xtime_nsec_2
1003 * So:
1004 * (offset * adj_1) + xtime_nsec_1 =
1005 * (offset * adj_2) + xtime_nsec_2
1006 * And we know:
1007 * adj_2 = adj_1 + 1
1008 * So:
1009 * (offset * adj_1) + xtime_nsec_1 =
1010 * (offset * (adj_1+1)) + xtime_nsec_2
1011 * (offset * adj_1) + xtime_nsec_1 =
1012 * (offset * adj_1) + offset + xtime_nsec_2
1013 * Canceling the sides:
1014 * xtime_nsec_1 = offset + xtime_nsec_2
1015 * Which gives us:
1016 * xtime_nsec_2 = xtime_nsec_1 - offset
1017 * Which simplfies to:
1018 * xtime_nsec -= offset
1019 *
1020 * XXX - TODO: Doc ntp_error calculation.
1021 */
John Stultzf726a692012-07-13 01:21:57 -04001022 tk->mult += adj;
1023 tk->xtime_interval += interval;
1024 tk->xtime_nsec -= offset;
1025 tk->ntp_error -= (interval - offset) << tk->ntp_error_shift;
John Stultz2a8c0882012-07-13 01:21:56 -04001026
Ingo Molnar1d17d172012-08-04 21:21:14 +02001027out_adjust:
John Stultz2a8c0882012-07-13 01:21:56 -04001028 /*
1029 * It may be possible that when we entered this function, xtime_nsec
1030 * was very small. Further, if we're slightly speeding the clocksource
1031 * in the code above, its possible the required corrective factor to
1032 * xtime_nsec could cause it to underflow.
1033 *
1034 * Now, since we already accumulated the second, cannot simply roll
1035 * the accumulated second back, since the NTP subsystem has been
1036 * notified via second_overflow. So instead we push xtime_nsec forward
1037 * by the amount we underflowed, and add that amount into the error.
1038 *
1039 * We'll correct this error next time through this function, when
1040 * xtime_nsec is not as small.
1041 */
John Stultzf726a692012-07-13 01:21:57 -04001042 if (unlikely((s64)tk->xtime_nsec < 0)) {
1043 s64 neg = -(s64)tk->xtime_nsec;
1044 tk->xtime_nsec = 0;
1045 tk->ntp_error += neg << tk->ntp_error_shift;
John Stultz2a8c0882012-07-13 01:21:56 -04001046 }
1047
john stultz85240702007-05-08 00:27:59 -07001048}
1049
1050/**
John Stultz1f4f9482012-07-13 01:21:54 -04001051 * accumulate_nsecs_to_secs - Accumulates nsecs into secs
1052 *
1053 * Helper function that accumulates a the nsecs greater then a second
1054 * from the xtime_nsec field to the xtime_secs field.
1055 * It also calls into the NTP code to handle leapsecond processing.
1056 *
1057 */
1058static inline void accumulate_nsecs_to_secs(struct timekeeper *tk)
1059{
1060 u64 nsecps = (u64)NSEC_PER_SEC << tk->shift;
1061
1062 while (tk->xtime_nsec >= nsecps) {
1063 int leap;
1064
1065 tk->xtime_nsec -= nsecps;
1066 tk->xtime_sec++;
1067
1068 /* Figure out if its a leap sec and apply if needed */
1069 leap = second_overflow(tk->xtime_sec);
John Stultz6d0ef902012-07-27 14:48:12 -04001070 if (unlikely(leap)) {
1071 struct timespec ts;
John Stultz1f4f9482012-07-13 01:21:54 -04001072
John Stultz6d0ef902012-07-27 14:48:12 -04001073 tk->xtime_sec += leap;
1074
1075 ts.tv_sec = leap;
1076 ts.tv_nsec = 0;
1077 tk_set_wall_to_mono(tk,
1078 timespec_sub(tk->wall_to_monotonic, ts));
1079
1080 clock_was_set_delayed();
1081 }
John Stultz1f4f9482012-07-13 01:21:54 -04001082 }
1083}
1084
John Stultz1f4f9482012-07-13 01:21:54 -04001085/**
john stultza092ff02009-10-02 16:17:53 -07001086 * logarithmic_accumulation - shifted accumulation of cycles
1087 *
1088 * This functions accumulates a shifted interval of cycles into
1089 * into a shifted interval nanoseconds. Allows for O(log) accumulation
1090 * loop.
1091 *
1092 * Returns the unconsumed cycles.
1093 */
John Stultzf726a692012-07-13 01:21:57 -04001094static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
1095 u32 shift)
john stultza092ff02009-10-02 16:17:53 -07001096{
Jason Wesseldeda2e82010-08-09 14:20:09 -07001097 u64 raw_nsecs;
john stultza092ff02009-10-02 16:17:53 -07001098
John Stultzf726a692012-07-13 01:21:57 -04001099 /* If the offset is smaller then a shifted interval, do nothing */
1100 if (offset < tk->cycle_interval<<shift)
john stultza092ff02009-10-02 16:17:53 -07001101 return offset;
1102
1103 /* Accumulate one shifted interval */
John Stultzf726a692012-07-13 01:21:57 -04001104 offset -= tk->cycle_interval << shift;
1105 tk->clock->cycle_last += tk->cycle_interval << shift;
john stultza092ff02009-10-02 16:17:53 -07001106
John Stultzf726a692012-07-13 01:21:57 -04001107 tk->xtime_nsec += tk->xtime_interval << shift;
1108 accumulate_nsecs_to_secs(tk);
john stultza092ff02009-10-02 16:17:53 -07001109
Jason Wesseldeda2e82010-08-09 14:20:09 -07001110 /* Accumulate raw time */
John Stultzf726a692012-07-13 01:21:57 -04001111 raw_nsecs = tk->raw_interval << shift;
1112 raw_nsecs += tk->raw_time.tv_nsec;
John Stultzc7dcf872010-08-13 11:30:58 -07001113 if (raw_nsecs >= NSEC_PER_SEC) {
1114 u64 raw_secs = raw_nsecs;
1115 raw_nsecs = do_div(raw_secs, NSEC_PER_SEC);
John Stultzf726a692012-07-13 01:21:57 -04001116 tk->raw_time.tv_sec += raw_secs;
john stultza092ff02009-10-02 16:17:53 -07001117 }
John Stultzf726a692012-07-13 01:21:57 -04001118 tk->raw_time.tv_nsec = raw_nsecs;
john stultza092ff02009-10-02 16:17:53 -07001119
1120 /* Accumulate error between NTP and clock interval */
John Stultzf726a692012-07-13 01:21:57 -04001121 tk->ntp_error += ntp_tick_length() << shift;
1122 tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) <<
1123 (tk->ntp_error_shift + shift);
john stultza092ff02009-10-02 16:17:53 -07001124
1125 return offset;
1126}
1127
john stultz85240702007-05-08 00:27:59 -07001128/**
1129 * update_wall_time - Uses the current clocksource to increment the wall time
1130 *
john stultz85240702007-05-08 00:27:59 -07001131 */
Torben Hohn871cf1e2011-01-27 15:58:55 +01001132static void update_wall_time(void)
john stultz85240702007-05-08 00:27:59 -07001133{
Martin Schwidefsky155ec602009-08-14 15:47:26 +02001134 struct clocksource *clock;
John Stultz4e250fd2012-07-27 14:48:13 -04001135 struct timekeeper *tk = &timekeeper;
john stultz85240702007-05-08 00:27:59 -07001136 cycle_t offset;
john stultza092ff02009-10-02 16:17:53 -07001137 int shift = 0, maxshift;
John Stultz70471f22011-11-14 12:48:10 -08001138 unsigned long flags;
John Stultz1e75fa82012-07-13 01:21:53 -04001139 s64 remainder;
John Stultz70471f22011-11-14 12:48:10 -08001140
John Stultz4e250fd2012-07-27 14:48:13 -04001141 write_seqlock_irqsave(&tk->lock, flags);
john stultz85240702007-05-08 00:27:59 -07001142
1143 /* Make sure we're fully resumed: */
1144 if (unlikely(timekeeping_suspended))
John Stultz70471f22011-11-14 12:48:10 -08001145 goto out;
john stultz85240702007-05-08 00:27:59 -07001146
John Stultz4e250fd2012-07-27 14:48:13 -04001147 clock = tk->clock;
John Stultz592913e2010-07-13 17:56:20 -07001148
1149#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
John Stultz4e250fd2012-07-27 14:48:13 -04001150 offset = tk->cycle_interval;
John Stultz592913e2010-07-13 17:56:20 -07001151#else
1152 offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
john stultz85240702007-05-08 00:27:59 -07001153#endif
john stultz85240702007-05-08 00:27:59 -07001154
John Stultzbf2ac312012-08-21 20:30:49 -04001155 /* Check if there's really nothing to do */
1156 if (offset < tk->cycle_interval)
1157 goto out;
1158
john stultza092ff02009-10-02 16:17:53 -07001159 /*
1160 * With NO_HZ we may have to accumulate many cycle_intervals
1161 * (think "ticks") worth of time at once. To do this efficiently,
1162 * we calculate the largest doubling multiple of cycle_intervals
Jim Cromie88b28ad2012-03-14 21:28:56 -06001163 * that is smaller than the offset. We then accumulate that
john stultza092ff02009-10-02 16:17:53 -07001164 * chunk in one go, and then try to consume the next smaller
1165 * doubled multiple.
john stultz85240702007-05-08 00:27:59 -07001166 */
John Stultz4e250fd2012-07-27 14:48:13 -04001167 shift = ilog2(offset) - ilog2(tk->cycle_interval);
john stultza092ff02009-10-02 16:17:53 -07001168 shift = max(0, shift);
Jim Cromie88b28ad2012-03-14 21:28:56 -06001169 /* Bound shift to one less than what overflows tick_length */
John Stultzea7cf492011-11-14 13:18:07 -08001170 maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
john stultza092ff02009-10-02 16:17:53 -07001171 shift = min(shift, maxshift);
John Stultz4e250fd2012-07-27 14:48:13 -04001172 while (offset >= tk->cycle_interval) {
1173 offset = logarithmic_accumulation(tk, offset, shift);
1174 if (offset < tk->cycle_interval<<shift)
John Stultz830ec042010-03-18 14:47:30 -07001175 shift--;
john stultz85240702007-05-08 00:27:59 -07001176 }
1177
1178 /* correct the clock when NTP error is too big */
John Stultz4e250fd2012-07-27 14:48:13 -04001179 timekeeping_adjust(tk, offset);
john stultz85240702007-05-08 00:27:59 -07001180
john stultz6c9bacb2008-12-01 18:34:41 -08001181
John Stultz6a867a32010-04-06 14:30:51 -07001182 /*
John Stultz1e75fa82012-07-13 01:21:53 -04001183 * Store only full nanoseconds into xtime_nsec after rounding
1184 * it up and add the remainder to the error difference.
1185 * XXX - This is necessary to avoid small 1ns inconsistnecies caused
1186 * by truncating the remainder in vsyscalls. However, it causes
1187 * additional work to be done in timekeeping_adjust(). Once
1188 * the vsyscall implementations are converted to use xtime_nsec
1189 * (shifted nanoseconds), this can be killed.
1190 */
John Stultz6ea565a2012-08-21 20:30:48 -04001191 remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1);
John Stultz4e250fd2012-07-27 14:48:13 -04001192 tk->xtime_nsec -= remainder;
John Stultz6ea565a2012-08-21 20:30:48 -04001193 tk->xtime_nsec += 1ULL << tk->shift;
John Stultz4e250fd2012-07-27 14:48:13 -04001194 tk->ntp_error += remainder << tk->ntp_error_shift;
john stultz85240702007-05-08 00:27:59 -07001195
John Stultz6a867a32010-04-06 14:30:51 -07001196 /*
1197 * Finally, make sure that after the rounding
John Stultz1e75fa82012-07-13 01:21:53 -04001198 * xtime_nsec isn't larger than NSEC_PER_SEC
John Stultz6a867a32010-04-06 14:30:51 -07001199 */
John Stultz4e250fd2012-07-27 14:48:13 -04001200 accumulate_nsecs_to_secs(tk);
Linus Torvalds83f57a12009-12-22 14:10:37 -08001201
John Stultz4e250fd2012-07-27 14:48:13 -04001202 timekeeping_update(tk, false);
John Stultz70471f22011-11-14 12:48:10 -08001203
1204out:
John Stultz4e250fd2012-07-27 14:48:13 -04001205 write_sequnlock_irqrestore(&tk->lock, flags);
John Stultz70471f22011-11-14 12:48:10 -08001206
john stultz85240702007-05-08 00:27:59 -07001207}
Tomas Janousek7c3f1a52007-07-15 23:39:41 -07001208
1209/**
1210 * getboottime - Return the real time of system boot.
1211 * @ts: pointer to the timespec to be set
1212 *
John Stultzabb3a4e2011-02-14 17:52:09 -08001213 * Returns the wall-time of boot in a timespec.
Tomas Janousek7c3f1a52007-07-15 23:39:41 -07001214 *
1215 * This is based on the wall_to_monotonic offset and the total suspend
1216 * time. Calls to settimeofday will affect the value returned (which
1217 * basically means that however wrong your real time clock is at boot time,
1218 * you get the right time here).
1219 */
1220void getboottime(struct timespec *ts)
1221{
John Stultz4e250fd2012-07-27 14:48:13 -04001222 struct timekeeper *tk = &timekeeper;
Hiroshi Shimamoto36d47482009-08-25 15:08:30 +09001223 struct timespec boottime = {
John Stultz4e250fd2012-07-27 14:48:13 -04001224 .tv_sec = tk->wall_to_monotonic.tv_sec +
1225 tk->total_sleep_time.tv_sec,
1226 .tv_nsec = tk->wall_to_monotonic.tv_nsec +
1227 tk->total_sleep_time.tv_nsec
Hiroshi Shimamoto36d47482009-08-25 15:08:30 +09001228 };
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +02001229
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +02001230 set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
Tomas Janousek7c3f1a52007-07-15 23:39:41 -07001231}
Jason Wangc93d89f2010-01-27 19:13:40 +08001232EXPORT_SYMBOL_GPL(getboottime);
Tomas Janousek7c3f1a52007-07-15 23:39:41 -07001233
John Stultzabb3a4e2011-02-14 17:52:09 -08001234/**
1235 * get_monotonic_boottime - Returns monotonic time since boot
1236 * @ts: pointer to the timespec to be set
1237 *
1238 * Returns the monotonic time since boot in a timespec.
1239 *
1240 * This is similar to CLOCK_MONTONIC/ktime_get_ts, but also
1241 * includes the time spent in suspend.
1242 */
1243void get_monotonic_boottime(struct timespec *ts)
1244{
John Stultz4e250fd2012-07-27 14:48:13 -04001245 struct timekeeper *tk = &timekeeper;
John Stultzabb3a4e2011-02-14 17:52:09 -08001246 struct timespec tomono, sleep;
1247 unsigned int seq;
John Stultzabb3a4e2011-02-14 17:52:09 -08001248
1249 WARN_ON(timekeeping_suspended);
1250
1251 do {
John Stultz4e250fd2012-07-27 14:48:13 -04001252 seq = read_seqbegin(&tk->lock);
1253 ts->tv_sec = tk->xtime_sec;
1254 ts->tv_nsec = timekeeping_get_ns(tk);
1255 tomono = tk->wall_to_monotonic;
1256 sleep = tk->total_sleep_time;
John Stultzabb3a4e2011-02-14 17:52:09 -08001257
John Stultz4e250fd2012-07-27 14:48:13 -04001258 } while (read_seqretry(&tk->lock, seq));
John Stultzabb3a4e2011-02-14 17:52:09 -08001259
1260 set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec,
John Stultz1e75fa82012-07-13 01:21:53 -04001261 ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec);
John Stultzabb3a4e2011-02-14 17:52:09 -08001262}
1263EXPORT_SYMBOL_GPL(get_monotonic_boottime);
1264
1265/**
1266 * ktime_get_boottime - Returns monotonic time since boot in a ktime
1267 *
1268 * Returns the monotonic time since boot in a ktime
1269 *
1270 * This is similar to CLOCK_MONTONIC/ktime_get, but also
1271 * includes the time spent in suspend.
1272 */
1273ktime_t ktime_get_boottime(void)
1274{
1275 struct timespec ts;
1276
1277 get_monotonic_boottime(&ts);
1278 return timespec_to_ktime(ts);
1279}
1280EXPORT_SYMBOL_GPL(ktime_get_boottime);
1281
Tomas Janousek7c3f1a52007-07-15 23:39:41 -07001282/**
1283 * monotonic_to_bootbased - Convert the monotonic time to boot based.
1284 * @ts: pointer to the timespec to be converted
1285 */
1286void monotonic_to_bootbased(struct timespec *ts)
1287{
John Stultz4e250fd2012-07-27 14:48:13 -04001288 struct timekeeper *tk = &timekeeper;
1289
1290 *ts = timespec_add(*ts, tk->total_sleep_time);
Tomas Janousek7c3f1a52007-07-15 23:39:41 -07001291}
Jason Wangc93d89f2010-01-27 19:13:40 +08001292EXPORT_SYMBOL_GPL(monotonic_to_bootbased);
john stultz2c6b47d2007-07-24 17:47:43 -07001293
john stultz17c38b72007-07-24 18:38:34 -07001294unsigned long get_seconds(void)
1295{
John Stultz4e250fd2012-07-27 14:48:13 -04001296 struct timekeeper *tk = &timekeeper;
1297
1298 return tk->xtime_sec;
john stultz17c38b72007-07-24 18:38:34 -07001299}
1300EXPORT_SYMBOL(get_seconds);
1301
john stultzda15cfd2009-08-19 19:13:34 -07001302struct timespec __current_kernel_time(void)
1303{
John Stultz4e250fd2012-07-27 14:48:13 -04001304 struct timekeeper *tk = &timekeeper;
1305
1306 return tk_xtime(tk);
john stultzda15cfd2009-08-19 19:13:34 -07001307}
john stultz17c38b72007-07-24 18:38:34 -07001308
john stultz2c6b47d2007-07-24 17:47:43 -07001309struct timespec current_kernel_time(void)
1310{
John Stultz4e250fd2012-07-27 14:48:13 -04001311 struct timekeeper *tk = &timekeeper;
john stultz2c6b47d2007-07-24 17:47:43 -07001312 struct timespec now;
1313 unsigned long seq;
1314
1315 do {
John Stultz4e250fd2012-07-27 14:48:13 -04001316 seq = read_seqbegin(&tk->lock);
Linus Torvalds83f57a12009-12-22 14:10:37 -08001317
John Stultz4e250fd2012-07-27 14:48:13 -04001318 now = tk_xtime(tk);
1319 } while (read_seqretry(&tk->lock, seq));
john stultz2c6b47d2007-07-24 17:47:43 -07001320
1321 return now;
1322}
john stultz2c6b47d2007-07-24 17:47:43 -07001323EXPORT_SYMBOL(current_kernel_time);
john stultzda15cfd2009-08-19 19:13:34 -07001324
1325struct timespec get_monotonic_coarse(void)
1326{
John Stultz4e250fd2012-07-27 14:48:13 -04001327 struct timekeeper *tk = &timekeeper;
john stultzda15cfd2009-08-19 19:13:34 -07001328 struct timespec now, mono;
1329 unsigned long seq;
1330
1331 do {
John Stultz4e250fd2012-07-27 14:48:13 -04001332 seq = read_seqbegin(&tk->lock);
Linus Torvalds83f57a12009-12-22 14:10:37 -08001333
John Stultz4e250fd2012-07-27 14:48:13 -04001334 now = tk_xtime(tk);
1335 mono = tk->wall_to_monotonic;
1336 } while (read_seqretry(&tk->lock, seq));
john stultzda15cfd2009-08-19 19:13:34 -07001337
1338 set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
1339 now.tv_nsec + mono.tv_nsec);
1340 return now;
1341}
Torben Hohn871cf1e2011-01-27 15:58:55 +01001342
1343/*
1344 * The 64-bit jiffies value is not atomic - you MUST NOT read it
1345 * without sampling the sequence number in xtime_lock.
1346 * jiffies is defined in the linker script...
1347 */
1348void do_timer(unsigned long ticks)
1349{
1350 jiffies_64 += ticks;
1351 update_wall_time();
1352 calc_global_load(ticks);
1353}
Torben Hohn48cf76f72011-01-27 15:59:05 +01001354
1355/**
John Stultz314ac372011-02-14 18:43:08 -08001356 * get_xtime_and_monotonic_and_sleep_offset() - get xtime, wall_to_monotonic,
1357 * and sleep offsets.
Torben Hohn48cf76f72011-01-27 15:59:05 +01001358 * @xtim: pointer to timespec to be set with xtime
1359 * @wtom: pointer to timespec to be set with wall_to_monotonic
John Stultz314ac372011-02-14 18:43:08 -08001360 * @sleep: pointer to timespec to be set with time in suspend
Torben Hohn48cf76f72011-01-27 15:59:05 +01001361 */
John Stultz314ac372011-02-14 18:43:08 -08001362void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
1363 struct timespec *wtom, struct timespec *sleep)
Torben Hohn48cf76f72011-01-27 15:59:05 +01001364{
John Stultz4e250fd2012-07-27 14:48:13 -04001365 struct timekeeper *tk = &timekeeper;
Torben Hohn48cf76f72011-01-27 15:59:05 +01001366 unsigned long seq;
1367
1368 do {
John Stultz4e250fd2012-07-27 14:48:13 -04001369 seq = read_seqbegin(&tk->lock);
1370 *xtim = tk_xtime(tk);
1371 *wtom = tk->wall_to_monotonic;
1372 *sleep = tk->total_sleep_time;
1373 } while (read_seqretry(&tk->lock, seq));
Torben Hohn48cf76f72011-01-27 15:59:05 +01001374}
Torben Hohnf0af911a92011-01-27 15:59:10 +01001375
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001376#ifdef CONFIG_HIGH_RES_TIMERS
1377/**
1378 * ktime_get_update_offsets - hrtimer helper
1379 * @offs_real: pointer to storage for monotonic -> realtime offset
1380 * @offs_boot: pointer to storage for monotonic -> boottime offset
1381 *
1382 * Returns current monotonic time and updates the offsets
1383 * Called from hrtimer_interupt() or retrigger_next_event()
1384 */
1385ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
1386{
John Stultz4e250fd2012-07-27 14:48:13 -04001387 struct timekeeper *tk = &timekeeper;
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001388 ktime_t now;
1389 unsigned int seq;
1390 u64 secs, nsecs;
1391
1392 do {
John Stultz4e250fd2012-07-27 14:48:13 -04001393 seq = read_seqbegin(&tk->lock);
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001394
John Stultz4e250fd2012-07-27 14:48:13 -04001395 secs = tk->xtime_sec;
1396 nsecs = timekeeping_get_ns(tk);
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001397
John Stultz4e250fd2012-07-27 14:48:13 -04001398 *offs_real = tk->offs_real;
1399 *offs_boot = tk->offs_boot;
1400 } while (read_seqretry(&tk->lock, seq));
Thomas Gleixnerf6c06ab2012-07-10 18:43:24 -04001401
1402 now = ktime_add_ns(ktime_set(secs, 0), nsecs);
1403 now = ktime_sub(now, *offs_real);
1404 return now;
1405}
1406#endif
1407
Torben Hohnf0af911a92011-01-27 15:59:10 +01001408/**
Thomas Gleixner99ee5312011-04-27 14:16:42 +02001409 * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format
1410 */
1411ktime_t ktime_get_monotonic_offset(void)
1412{
John Stultz4e250fd2012-07-27 14:48:13 -04001413 struct timekeeper *tk = &timekeeper;
Thomas Gleixner99ee5312011-04-27 14:16:42 +02001414 unsigned long seq;
1415 struct timespec wtom;
1416
1417 do {
John Stultz4e250fd2012-07-27 14:48:13 -04001418 seq = read_seqbegin(&tk->lock);
1419 wtom = tk->wall_to_monotonic;
1420 } while (read_seqretry(&tk->lock, seq));
John Stultz70471f22011-11-14 12:48:10 -08001421
Thomas Gleixner99ee5312011-04-27 14:16:42 +02001422 return timespec_to_ktime(wtom);
1423}
John Stultza80b83b2012-02-03 00:19:07 -08001424EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset);
1425
Thomas Gleixner99ee5312011-04-27 14:16:42 +02001426/**
Torben Hohnf0af911a92011-01-27 15:59:10 +01001427 * xtime_update() - advances the timekeeping infrastructure
1428 * @ticks: number of ticks, that have elapsed since the last call.
1429 *
1430 * Must be called with interrupts disabled.
1431 */
1432void xtime_update(unsigned long ticks)
1433{
1434 write_seqlock(&xtime_lock);
1435 do_timer(ticks);
1436 write_sequnlock(&xtime_lock);
1437}