Commit | Line | Data |
---|---|---|
8524070b | 1 | /* |
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> | |
d43c36dc | 16 | #include <linux/sched.h> |
e1a85b2c | 17 | #include <linux/syscore_ops.h> |
8524070b | 18 | #include <linux/clocksource.h> |
19 | #include <linux/jiffies.h> | |
20 | #include <linux/time.h> | |
21 | #include <linux/tick.h> | |
75c5158f | 22 | #include <linux/stop_machine.h> |
8524070b | 23 | |
155ec602 MS |
24 | /* Structure holding internal timekeeping values. */ |
25 | struct timekeeper { | |
26 | /* Current clocksource used for timekeeping. */ | |
27 | struct clocksource *clock; | |
23ce7211 MS |
28 | /* The shift value of the current clocksource. */ |
29 | int shift; | |
155ec602 MS |
30 | |
31 | /* Number of clock cycles in one NTP interval. */ | |
32 | cycle_t cycle_interval; | |
33 | /* Number of clock shifted nano seconds in one NTP interval. */ | |
34 | u64 xtime_interval; | |
a386b5af KP |
35 | /* shifted nano seconds left over when rounding cycle_interval */ |
36 | s64 xtime_remainder; | |
155ec602 MS |
37 | /* Raw nano seconds accumulated per NTP interval. */ |
38 | u32 raw_interval; | |
39 | ||
40 | /* Clock shifted nano seconds remainder not stored in xtime.tv_nsec. */ | |
41 | u64 xtime_nsec; | |
42 | /* Difference between accumulated time and NTP time in ntp | |
43 | * shifted nano seconds. */ | |
44 | s64 ntp_error; | |
23ce7211 MS |
45 | /* Shift conversion between clock shifted nano seconds and |
46 | * ntp shifted nano seconds. */ | |
47 | int ntp_error_shift; | |
0a544198 MS |
48 | /* NTP adjusted clock multiplier */ |
49 | u32 mult; | |
00c5fb77 JS |
50 | |
51 | /* time spent in suspend */ | |
52 | struct timespec total_sleep_time; | |
53 | ||
155ec602 MS |
54 | }; |
55 | ||
afa14e7c | 56 | static struct timekeeper timekeeper; |
155ec602 MS |
57 | |
58 | /** | |
59 | * timekeeper_setup_internals - Set up internals to use clocksource clock. | |
60 | * | |
61 | * @clock: Pointer to clocksource. | |
62 | * | |
63 | * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment | |
64 | * pair and interval request. | |
65 | * | |
66 | * Unless you're the timekeeping code, you should not be using this! | |
67 | */ | |
68 | static void timekeeper_setup_internals(struct clocksource *clock) | |
69 | { | |
70 | cycle_t interval; | |
a386b5af | 71 | u64 tmp, ntpinterval; |
155ec602 MS |
72 | |
73 | timekeeper.clock = clock; | |
74 | clock->cycle_last = clock->read(clock); | |
75 | ||
76 | /* Do the ns -> cycle conversion first, using original mult */ | |
77 | tmp = NTP_INTERVAL_LENGTH; | |
78 | tmp <<= clock->shift; | |
a386b5af | 79 | ntpinterval = tmp; |
0a544198 MS |
80 | tmp += clock->mult/2; |
81 | do_div(tmp, clock->mult); | |
155ec602 MS |
82 | if (tmp == 0) |
83 | tmp = 1; | |
84 | ||
85 | interval = (cycle_t) tmp; | |
86 | timekeeper.cycle_interval = interval; | |
87 | ||
88 | /* Go back from cycles -> shifted ns */ | |
89 | timekeeper.xtime_interval = (u64) interval * clock->mult; | |
a386b5af | 90 | timekeeper.xtime_remainder = ntpinterval - timekeeper.xtime_interval; |
155ec602 | 91 | timekeeper.raw_interval = |
0a544198 | 92 | ((u64) interval * clock->mult) >> clock->shift; |
155ec602 MS |
93 | |
94 | timekeeper.xtime_nsec = 0; | |
23ce7211 | 95 | timekeeper.shift = clock->shift; |
155ec602 MS |
96 | |
97 | timekeeper.ntp_error = 0; | |
23ce7211 | 98 | timekeeper.ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; |
0a544198 MS |
99 | |
100 | /* | |
101 | * The timekeeper keeps its own mult values for the currently | |
102 | * active clocksource. These value will be adjusted via NTP | |
103 | * to counteract clock drifting. | |
104 | */ | |
105 | timekeeper.mult = clock->mult; | |
155ec602 | 106 | } |
8524070b | 107 | |
2ba2a305 MS |
108 | /* Timekeeper helper functions. */ |
109 | static inline s64 timekeeping_get_ns(void) | |
110 | { | |
111 | cycle_t cycle_now, cycle_delta; | |
112 | struct clocksource *clock; | |
113 | ||
114 | /* read clocksource: */ | |
115 | clock = timekeeper.clock; | |
116 | cycle_now = clock->read(clock); | |
117 | ||
118 | /* calculate the delta since the last update_wall_time: */ | |
119 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; | |
120 | ||
121 | /* return delta convert to nanoseconds using ntp adjusted mult. */ | |
122 | return clocksource_cyc2ns(cycle_delta, timekeeper.mult, | |
123 | timekeeper.shift); | |
124 | } | |
125 | ||
126 | static inline s64 timekeeping_get_ns_raw(void) | |
127 | { | |
128 | cycle_t cycle_now, cycle_delta; | |
129 | struct clocksource *clock; | |
130 | ||
131 | /* read clocksource: */ | |
132 | clock = timekeeper.clock; | |
133 | cycle_now = clock->read(clock); | |
134 | ||
135 | /* calculate the delta since the last update_wall_time: */ | |
136 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; | |
137 | ||
c9fad429 | 138 | /* return delta convert to nanoseconds. */ |
2ba2a305 MS |
139 | return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); |
140 | } | |
141 | ||
8524070b | 142 | /* |
143 | * This read-write spinlock protects us from races in SMP while | |
dce48a84 | 144 | * playing with xtime. |
8524070b | 145 | */ |
ba2a631b | 146 | __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); |
8524070b | 147 | |
148 | ||
149 | /* | |
150 | * The current time | |
151 | * wall_to_monotonic is what we need to add to xtime (or xtime corrected | |
152 | * for sub jiffie times) to get to monotonic time. Monotonic is pegged | |
153 | * at zero at system boot time, so wall_to_monotonic will be negative, | |
154 | * however, we will ALWAYS keep the tv_nsec part positive so we can use | |
155 | * the usual normalization. | |
7c3f1a57 TJ |
156 | * |
157 | * wall_to_monotonic is moved after resume from suspend for the monotonic | |
158 | * time not to jump. We need to add total_sleep_time to wall_to_monotonic | |
159 | * to get the real boot based time offset. | |
160 | * | |
161 | * - wall_to_monotonic is no longer the boot time, getboottime must be | |
162 | * used instead. | |
8524070b | 163 | */ |
0fb86b06 JS |
164 | static struct timespec xtime __attribute__ ((aligned (16))); |
165 | static struct timespec wall_to_monotonic __attribute__ ((aligned (16))); | |
8524070b | 166 | |
155ec602 MS |
167 | /* |
168 | * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. | |
169 | */ | |
afa14e7c | 170 | static struct timespec raw_time; |
155ec602 | 171 | |
1c5745aa TG |
172 | /* flag for if timekeeping is suspended */ |
173 | int __read_mostly timekeeping_suspended; | |
174 | ||
31089c13 JS |
175 | /* must hold xtime_lock */ |
176 | void timekeeping_leap_insert(int leapsecond) | |
177 | { | |
178 | xtime.tv_sec += leapsecond; | |
179 | wall_to_monotonic.tv_sec -= leapsecond; | |
7615856e JS |
180 | update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, |
181 | timekeeper.mult); | |
31089c13 | 182 | } |
8524070b | 183 | |
8524070b | 184 | /** |
155ec602 | 185 | * timekeeping_forward_now - update clock to the current time |
8524070b | 186 | * |
9a055117 RZ |
187 | * Forward the current clock to update its state since the last call to |
188 | * update_wall_time(). This is useful before significant clock changes, | |
189 | * as it avoids having to deal with this time offset explicitly. | |
8524070b | 190 | */ |
155ec602 | 191 | static void timekeeping_forward_now(void) |
8524070b | 192 | { |
193 | cycle_t cycle_now, cycle_delta; | |
155ec602 | 194 | struct clocksource *clock; |
9a055117 | 195 | s64 nsec; |
8524070b | 196 | |
155ec602 | 197 | clock = timekeeper.clock; |
a0f7d48b | 198 | cycle_now = clock->read(clock); |
8524070b | 199 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; |
9a055117 | 200 | clock->cycle_last = cycle_now; |
8524070b | 201 | |
0a544198 MS |
202 | nsec = clocksource_cyc2ns(cycle_delta, timekeeper.mult, |
203 | timekeeper.shift); | |
7d27558c | 204 | |
205 | /* If arch requires, add in gettimeoffset() */ | |
206 | nsec += arch_gettimeoffset(); | |
207 | ||
9a055117 | 208 | timespec_add_ns(&xtime, nsec); |
2d42244a | 209 | |
0a544198 | 210 | nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); |
155ec602 | 211 | timespec_add_ns(&raw_time, nsec); |
8524070b | 212 | } |
213 | ||
214 | /** | |
efd9ac86 | 215 | * getnstimeofday - Returns the time of day in a timespec |
8524070b | 216 | * @ts: pointer to the timespec to be set |
217 | * | |
efd9ac86 | 218 | * Returns the time of day in a timespec. |
8524070b | 219 | */ |
efd9ac86 | 220 | void getnstimeofday(struct timespec *ts) |
8524070b | 221 | { |
222 | unsigned long seq; | |
223 | s64 nsecs; | |
224 | ||
1c5745aa TG |
225 | WARN_ON(timekeeping_suspended); |
226 | ||
8524070b | 227 | do { |
228 | seq = read_seqbegin(&xtime_lock); | |
229 | ||
230 | *ts = xtime; | |
2ba2a305 | 231 | nsecs = timekeeping_get_ns(); |
8524070b | 232 | |
7d27558c | 233 | /* If arch requires, add in gettimeoffset() */ |
234 | nsecs += arch_gettimeoffset(); | |
235 | ||
8524070b | 236 | } while (read_seqretry(&xtime_lock, seq)); |
237 | ||
238 | timespec_add_ns(ts, nsecs); | |
239 | } | |
240 | ||
8524070b | 241 | EXPORT_SYMBOL(getnstimeofday); |
242 | ||
951ed4d3 MS |
243 | ktime_t ktime_get(void) |
244 | { | |
951ed4d3 MS |
245 | unsigned int seq; |
246 | s64 secs, nsecs; | |
247 | ||
248 | WARN_ON(timekeeping_suspended); | |
249 | ||
250 | do { | |
251 | seq = read_seqbegin(&xtime_lock); | |
252 | secs = xtime.tv_sec + wall_to_monotonic.tv_sec; | |
253 | nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec; | |
2ba2a305 | 254 | nsecs += timekeeping_get_ns(); |
d004e024 HP |
255 | /* If arch requires, add in gettimeoffset() */ |
256 | nsecs += arch_gettimeoffset(); | |
951ed4d3 MS |
257 | |
258 | } while (read_seqretry(&xtime_lock, seq)); | |
259 | /* | |
260 | * Use ktime_set/ktime_add_ns to create a proper ktime on | |
261 | * 32-bit architectures without CONFIG_KTIME_SCALAR. | |
262 | */ | |
263 | return ktime_add_ns(ktime_set(secs, 0), nsecs); | |
264 | } | |
265 | EXPORT_SYMBOL_GPL(ktime_get); | |
266 | ||
267 | /** | |
268 | * ktime_get_ts - get the monotonic clock in timespec format | |
269 | * @ts: pointer to timespec variable | |
270 | * | |
271 | * The function calculates the monotonic clock from the realtime | |
272 | * clock and the wall_to_monotonic offset and stores the result | |
273 | * in normalized timespec format in the variable pointed to by @ts. | |
274 | */ | |
275 | void ktime_get_ts(struct timespec *ts) | |
276 | { | |
951ed4d3 MS |
277 | struct timespec tomono; |
278 | unsigned int seq; | |
279 | s64 nsecs; | |
280 | ||
281 | WARN_ON(timekeeping_suspended); | |
282 | ||
283 | do { | |
284 | seq = read_seqbegin(&xtime_lock); | |
285 | *ts = xtime; | |
286 | tomono = wall_to_monotonic; | |
2ba2a305 | 287 | nsecs = timekeeping_get_ns(); |
d004e024 HP |
288 | /* If arch requires, add in gettimeoffset() */ |
289 | nsecs += arch_gettimeoffset(); | |
951ed4d3 MS |
290 | |
291 | } while (read_seqretry(&xtime_lock, seq)); | |
292 | ||
293 | set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, | |
294 | ts->tv_nsec + tomono.tv_nsec + nsecs); | |
295 | } | |
296 | EXPORT_SYMBOL_GPL(ktime_get_ts); | |
297 | ||
e2c18e49 AG |
298 | #ifdef CONFIG_NTP_PPS |
299 | ||
300 | /** | |
301 | * getnstime_raw_and_real - get day and raw monotonic time in timespec format | |
302 | * @ts_raw: pointer to the timespec to be set to raw monotonic time | |
303 | * @ts_real: pointer to the timespec to be set to the time of day | |
304 | * | |
305 | * This function reads both the time of day and raw monotonic time at the | |
306 | * same time atomically and stores the resulting timestamps in timespec | |
307 | * format. | |
308 | */ | |
309 | void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real) | |
310 | { | |
311 | unsigned long seq; | |
312 | s64 nsecs_raw, nsecs_real; | |
313 | ||
314 | WARN_ON_ONCE(timekeeping_suspended); | |
315 | ||
316 | do { | |
317 | u32 arch_offset; | |
318 | ||
319 | seq = read_seqbegin(&xtime_lock); | |
320 | ||
321 | *ts_raw = raw_time; | |
322 | *ts_real = xtime; | |
323 | ||
324 | nsecs_raw = timekeeping_get_ns_raw(); | |
325 | nsecs_real = timekeeping_get_ns(); | |
326 | ||
327 | /* If arch requires, add in gettimeoffset() */ | |
328 | arch_offset = arch_gettimeoffset(); | |
329 | nsecs_raw += arch_offset; | |
330 | nsecs_real += arch_offset; | |
331 | ||
332 | } while (read_seqretry(&xtime_lock, seq)); | |
333 | ||
334 | timespec_add_ns(ts_raw, nsecs_raw); | |
335 | timespec_add_ns(ts_real, nsecs_real); | |
336 | } | |
337 | EXPORT_SYMBOL(getnstime_raw_and_real); | |
338 | ||
339 | #endif /* CONFIG_NTP_PPS */ | |
340 | ||
8524070b | 341 | /** |
342 | * do_gettimeofday - Returns the time of day in a timeval | |
343 | * @tv: pointer to the timeval to be set | |
344 | * | |
efd9ac86 | 345 | * NOTE: Users should be converted to using getnstimeofday() |
8524070b | 346 | */ |
347 | void do_gettimeofday(struct timeval *tv) | |
348 | { | |
349 | struct timespec now; | |
350 | ||
efd9ac86 | 351 | getnstimeofday(&now); |
8524070b | 352 | tv->tv_sec = now.tv_sec; |
353 | tv->tv_usec = now.tv_nsec/1000; | |
354 | } | |
355 | ||
356 | EXPORT_SYMBOL(do_gettimeofday); | |
357 | /** | |
358 | * do_settimeofday - Sets the time of day | |
359 | * @tv: pointer to the timespec variable containing the new time | |
360 | * | |
361 | * Sets the time of day to the new time and update NTP and notify hrtimers | |
362 | */ | |
1e6d7679 | 363 | int do_settimeofday(const struct timespec *tv) |
8524070b | 364 | { |
9a055117 | 365 | struct timespec ts_delta; |
8524070b | 366 | unsigned long flags; |
8524070b | 367 | |
368 | if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) | |
369 | return -EINVAL; | |
370 | ||
371 | write_seqlock_irqsave(&xtime_lock, flags); | |
372 | ||
155ec602 | 373 | timekeeping_forward_now(); |
9a055117 RZ |
374 | |
375 | ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec; | |
376 | ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec; | |
377 | wall_to_monotonic = timespec_sub(wall_to_monotonic, ts_delta); | |
8524070b | 378 | |
9a055117 | 379 | xtime = *tv; |
8524070b | 380 | |
155ec602 | 381 | timekeeper.ntp_error = 0; |
8524070b | 382 | ntp_clear(); |
383 | ||
7615856e JS |
384 | update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, |
385 | timekeeper.mult); | |
8524070b | 386 | |
387 | write_sequnlock_irqrestore(&xtime_lock, flags); | |
388 | ||
389 | /* signal hrtimers about time change */ | |
390 | clock_was_set(); | |
391 | ||
392 | return 0; | |
393 | } | |
394 | ||
395 | EXPORT_SYMBOL(do_settimeofday); | |
396 | ||
c528f7c6 JS |
397 | |
398 | /** | |
399 | * timekeeping_inject_offset - Adds or subtracts from the current time. | |
400 | * @tv: pointer to the timespec variable containing the offset | |
401 | * | |
402 | * Adds or subtracts an offset value from the current time. | |
403 | */ | |
404 | int timekeeping_inject_offset(struct timespec *ts) | |
405 | { | |
406 | unsigned long flags; | |
407 | ||
408 | if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) | |
409 | return -EINVAL; | |
410 | ||
411 | write_seqlock_irqsave(&xtime_lock, flags); | |
412 | ||
413 | timekeeping_forward_now(); | |
414 | ||
415 | xtime = timespec_add(xtime, *ts); | |
416 | wall_to_monotonic = timespec_sub(wall_to_monotonic, *ts); | |
417 | ||
418 | timekeeper.ntp_error = 0; | |
419 | ntp_clear(); | |
420 | ||
421 | update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, | |
422 | timekeeper.mult); | |
423 | ||
424 | write_sequnlock_irqrestore(&xtime_lock, flags); | |
425 | ||
426 | /* signal hrtimers about time change */ | |
427 | clock_was_set(); | |
428 | ||
429 | return 0; | |
430 | } | |
431 | EXPORT_SYMBOL(timekeeping_inject_offset); | |
432 | ||
8524070b | 433 | /** |
434 | * change_clocksource - Swaps clocksources if a new one is available | |
435 | * | |
436 | * Accumulates current time interval and initializes new clocksource | |
437 | */ | |
75c5158f | 438 | static int change_clocksource(void *data) |
8524070b | 439 | { |
4614e6ad | 440 | struct clocksource *new, *old; |
8524070b | 441 | |
75c5158f | 442 | new = (struct clocksource *) data; |
8524070b | 443 | |
155ec602 | 444 | timekeeping_forward_now(); |
75c5158f MS |
445 | if (!new->enable || new->enable(new) == 0) { |
446 | old = timekeeper.clock; | |
447 | timekeeper_setup_internals(new); | |
448 | if (old->disable) | |
449 | old->disable(old); | |
450 | } | |
451 | return 0; | |
452 | } | |
8524070b | 453 | |
75c5158f MS |
454 | /** |
455 | * timekeeping_notify - Install a new clock source | |
456 | * @clock: pointer to the clock source | |
457 | * | |
458 | * This function is called from clocksource.c after a new, better clock | |
459 | * source has been registered. The caller holds the clocksource_mutex. | |
460 | */ | |
461 | void timekeeping_notify(struct clocksource *clock) | |
462 | { | |
463 | if (timekeeper.clock == clock) | |
4614e6ad | 464 | return; |
75c5158f | 465 | stop_machine(change_clocksource, clock, NULL); |
8524070b | 466 | tick_clock_notify(); |
8524070b | 467 | } |
75c5158f | 468 | |
a40f262c TG |
469 | /** |
470 | * ktime_get_real - get the real (wall-) time in ktime_t format | |
471 | * | |
472 | * returns the time in ktime_t format | |
473 | */ | |
474 | ktime_t ktime_get_real(void) | |
475 | { | |
476 | struct timespec now; | |
477 | ||
478 | getnstimeofday(&now); | |
479 | ||
480 | return timespec_to_ktime(now); | |
481 | } | |
482 | EXPORT_SYMBOL_GPL(ktime_get_real); | |
8524070b | 483 | |
2d42244a JS |
484 | /** |
485 | * getrawmonotonic - Returns the raw monotonic time in a timespec | |
486 | * @ts: pointer to the timespec to be set | |
487 | * | |
488 | * Returns the raw monotonic time (completely un-modified by ntp) | |
489 | */ | |
490 | void getrawmonotonic(struct timespec *ts) | |
491 | { | |
492 | unsigned long seq; | |
493 | s64 nsecs; | |
2d42244a JS |
494 | |
495 | do { | |
496 | seq = read_seqbegin(&xtime_lock); | |
2ba2a305 | 497 | nsecs = timekeeping_get_ns_raw(); |
155ec602 | 498 | *ts = raw_time; |
2d42244a JS |
499 | |
500 | } while (read_seqretry(&xtime_lock, seq)); | |
501 | ||
502 | timespec_add_ns(ts, nsecs); | |
503 | } | |
504 | EXPORT_SYMBOL(getrawmonotonic); | |
505 | ||
506 | ||
8524070b | 507 | /** |
cf4fc6cb | 508 | * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres |
8524070b | 509 | */ |
cf4fc6cb | 510 | int timekeeping_valid_for_hres(void) |
8524070b | 511 | { |
512 | unsigned long seq; | |
513 | int ret; | |
514 | ||
515 | do { | |
516 | seq = read_seqbegin(&xtime_lock); | |
517 | ||
155ec602 | 518 | ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; |
8524070b | 519 | |
520 | } while (read_seqretry(&xtime_lock, seq)); | |
521 | ||
522 | return ret; | |
523 | } | |
524 | ||
98962465 JH |
525 | /** |
526 | * timekeeping_max_deferment - Returns max time the clocksource can be deferred | |
527 | * | |
528 | * Caller must observe xtime_lock via read_seqbegin/read_seqretry to | |
529 | * ensure that the clocksource does not change! | |
530 | */ | |
531 | u64 timekeeping_max_deferment(void) | |
532 | { | |
533 | return timekeeper.clock->max_idle_ns; | |
534 | } | |
535 | ||
8524070b | 536 | /** |
d4f587c6 | 537 | * read_persistent_clock - Return time from the persistent clock. |
8524070b | 538 | * |
539 | * Weak dummy function for arches that do not yet support it. | |
d4f587c6 MS |
540 | * Reads the time from the battery backed persistent clock. |
541 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. | |
8524070b | 542 | * |
543 | * XXX - Do be sure to remove it once all arches implement it. | |
544 | */ | |
d4f587c6 | 545 | void __attribute__((weak)) read_persistent_clock(struct timespec *ts) |
8524070b | 546 | { |
d4f587c6 MS |
547 | ts->tv_sec = 0; |
548 | ts->tv_nsec = 0; | |
8524070b | 549 | } |
550 | ||
23970e38 MS |
551 | /** |
552 | * read_boot_clock - Return time of the system start. | |
553 | * | |
554 | * Weak dummy function for arches that do not yet support it. | |
555 | * Function to read the exact time the system has been started. | |
556 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. | |
557 | * | |
558 | * XXX - Do be sure to remove it once all arches implement it. | |
559 | */ | |
560 | void __attribute__((weak)) read_boot_clock(struct timespec *ts) | |
561 | { | |
562 | ts->tv_sec = 0; | |
563 | ts->tv_nsec = 0; | |
564 | } | |
565 | ||
8524070b | 566 | /* |
567 | * timekeeping_init - Initializes the clocksource and common timekeeping values | |
568 | */ | |
569 | void __init timekeeping_init(void) | |
570 | { | |
155ec602 | 571 | struct clocksource *clock; |
8524070b | 572 | unsigned long flags; |
23970e38 | 573 | struct timespec now, boot; |
d4f587c6 MS |
574 | |
575 | read_persistent_clock(&now); | |
23970e38 | 576 | read_boot_clock(&boot); |
8524070b | 577 | |
578 | write_seqlock_irqsave(&xtime_lock, flags); | |
579 | ||
7dffa3c6 | 580 | ntp_init(); |
8524070b | 581 | |
f1b82746 | 582 | clock = clocksource_default_clock(); |
a0f7d48b MS |
583 | if (clock->enable) |
584 | clock->enable(clock); | |
155ec602 | 585 | timekeeper_setup_internals(clock); |
8524070b | 586 | |
d4f587c6 MS |
587 | xtime.tv_sec = now.tv_sec; |
588 | xtime.tv_nsec = now.tv_nsec; | |
155ec602 MS |
589 | raw_time.tv_sec = 0; |
590 | raw_time.tv_nsec = 0; | |
23970e38 MS |
591 | if (boot.tv_sec == 0 && boot.tv_nsec == 0) { |
592 | boot.tv_sec = xtime.tv_sec; | |
593 | boot.tv_nsec = xtime.tv_nsec; | |
594 | } | |
8524070b | 595 | set_normalized_timespec(&wall_to_monotonic, |
23970e38 | 596 | -boot.tv_sec, -boot.tv_nsec); |
00c5fb77 JS |
597 | timekeeper.total_sleep_time.tv_sec = 0; |
598 | timekeeper.total_sleep_time.tv_nsec = 0; | |
8524070b | 599 | write_sequnlock_irqrestore(&xtime_lock, flags); |
600 | } | |
601 | ||
8524070b | 602 | /* time in seconds when suspend began */ |
d4f587c6 | 603 | static struct timespec timekeeping_suspend_time; |
8524070b | 604 | |
304529b1 JS |
605 | /** |
606 | * __timekeeping_inject_sleeptime - Internal function to add sleep interval | |
607 | * @delta: pointer to a timespec delta value | |
608 | * | |
609 | * Takes a timespec offset measuring a suspend interval and properly | |
610 | * adds the sleep offset to the timekeeping variables. | |
611 | */ | |
612 | static void __timekeeping_inject_sleeptime(struct timespec *delta) | |
613 | { | |
cb5de2f8 | 614 | if (!timespec_valid(delta)) { |
cbaa5152 | 615 | printk(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid " |
cb5de2f8 JS |
616 | "sleep delta value!\n"); |
617 | return; | |
618 | } | |
619 | ||
304529b1 JS |
620 | xtime = timespec_add(xtime, *delta); |
621 | wall_to_monotonic = timespec_sub(wall_to_monotonic, *delta); | |
00c5fb77 JS |
622 | timekeeper.total_sleep_time = timespec_add( |
623 | timekeeper.total_sleep_time, *delta); | |
304529b1 JS |
624 | } |
625 | ||
626 | ||
627 | /** | |
628 | * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values | |
629 | * @delta: pointer to a timespec delta value | |
630 | * | |
631 | * This hook is for architectures that cannot support read_persistent_clock | |
632 | * because their RTC/persistent clock is only accessible when irqs are enabled. | |
633 | * | |
634 | * This function should only be called by rtc_resume(), and allows | |
635 | * a suspend offset to be injected into the timekeeping values. | |
636 | */ | |
637 | void timekeeping_inject_sleeptime(struct timespec *delta) | |
638 | { | |
639 | unsigned long flags; | |
640 | struct timespec ts; | |
641 | ||
642 | /* Make sure we don't set the clock twice */ | |
643 | read_persistent_clock(&ts); | |
644 | if (!(ts.tv_sec == 0 && ts.tv_nsec == 0)) | |
645 | return; | |
646 | ||
647 | write_seqlock_irqsave(&xtime_lock, flags); | |
648 | timekeeping_forward_now(); | |
649 | ||
650 | __timekeeping_inject_sleeptime(delta); | |
651 | ||
652 | timekeeper.ntp_error = 0; | |
653 | ntp_clear(); | |
654 | update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, | |
655 | timekeeper.mult); | |
656 | ||
657 | write_sequnlock_irqrestore(&xtime_lock, flags); | |
658 | ||
659 | /* signal hrtimers about time change */ | |
660 | clock_was_set(); | |
661 | } | |
662 | ||
663 | ||
8524070b | 664 | /** |
665 | * timekeeping_resume - Resumes the generic timekeeping subsystem. | |
8524070b | 666 | * |
667 | * This is for the generic clocksource timekeeping. | |
668 | * xtime/wall_to_monotonic/jiffies/etc are | |
669 | * still managed by arch specific suspend/resume code. | |
670 | */ | |
e1a85b2c | 671 | static void timekeeping_resume(void) |
8524070b | 672 | { |
673 | unsigned long flags; | |
d4f587c6 MS |
674 | struct timespec ts; |
675 | ||
676 | read_persistent_clock(&ts); | |
8524070b | 677 | |
d10ff3fb TG |
678 | clocksource_resume(); |
679 | ||
8524070b | 680 | write_seqlock_irqsave(&xtime_lock, flags); |
681 | ||
d4f587c6 MS |
682 | if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) { |
683 | ts = timespec_sub(ts, timekeeping_suspend_time); | |
304529b1 | 684 | __timekeeping_inject_sleeptime(&ts); |
8524070b | 685 | } |
686 | /* re-base the last cycle value */ | |
155ec602 MS |
687 | timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); |
688 | timekeeper.ntp_error = 0; | |
8524070b | 689 | timekeeping_suspended = 0; |
690 | write_sequnlock_irqrestore(&xtime_lock, flags); | |
691 | ||
692 | touch_softlockup_watchdog(); | |
693 | ||
694 | clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL); | |
695 | ||
696 | /* Resume hrtimers */ | |
b12a03ce | 697 | hrtimers_resume(); |
8524070b | 698 | } |
699 | ||
e1a85b2c | 700 | static int timekeeping_suspend(void) |
8524070b | 701 | { |
702 | unsigned long flags; | |
cb33217b JS |
703 | struct timespec delta, delta_delta; |
704 | static struct timespec old_delta; | |
8524070b | 705 | |
d4f587c6 | 706 | read_persistent_clock(&timekeeping_suspend_time); |
3be90950 | 707 | |
8524070b | 708 | write_seqlock_irqsave(&xtime_lock, flags); |
155ec602 | 709 | timekeeping_forward_now(); |
8524070b | 710 | timekeeping_suspended = 1; |
cb33217b JS |
711 | |
712 | /* | |
713 | * To avoid drift caused by repeated suspend/resumes, | |
714 | * which each can add ~1 second drift error, | |
715 | * try to compensate so the difference in system time | |
716 | * and persistent_clock time stays close to constant. | |
717 | */ | |
718 | delta = timespec_sub(xtime, timekeeping_suspend_time); | |
719 | delta_delta = timespec_sub(delta, old_delta); | |
720 | if (abs(delta_delta.tv_sec) >= 2) { | |
721 | /* | |
722 | * if delta_delta is too large, assume time correction | |
723 | * has occured and set old_delta to the current delta. | |
724 | */ | |
725 | old_delta = delta; | |
726 | } else { | |
727 | /* Otherwise try to adjust old_system to compensate */ | |
728 | timekeeping_suspend_time = | |
729 | timespec_add(timekeeping_suspend_time, delta_delta); | |
730 | } | |
8524070b | 731 | write_sequnlock_irqrestore(&xtime_lock, flags); |
732 | ||
733 | clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); | |
c54a42b1 | 734 | clocksource_suspend(); |
8524070b | 735 | |
736 | return 0; | |
737 | } | |
738 | ||
739 | /* sysfs resume/suspend bits for timekeeping */ | |
e1a85b2c | 740 | static struct syscore_ops timekeeping_syscore_ops = { |
8524070b | 741 | .resume = timekeeping_resume, |
742 | .suspend = timekeeping_suspend, | |
8524070b | 743 | }; |
744 | ||
e1a85b2c | 745 | static int __init timekeeping_init_ops(void) |
8524070b | 746 | { |
e1a85b2c RW |
747 | register_syscore_ops(&timekeeping_syscore_ops); |
748 | return 0; | |
8524070b | 749 | } |
750 | ||
e1a85b2c | 751 | device_initcall(timekeeping_init_ops); |
8524070b | 752 | |
753 | /* | |
754 | * If the error is already larger, we look ahead even further | |
755 | * to compensate for late or lost adjustments. | |
756 | */ | |
155ec602 | 757 | static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval, |
8524070b | 758 | s64 *offset) |
759 | { | |
760 | s64 tick_error, i; | |
761 | u32 look_ahead, adj; | |
762 | s32 error2, mult; | |
763 | ||
764 | /* | |
765 | * Use the current error value to determine how much to look ahead. | |
766 | * The larger the error the slower we adjust for it to avoid problems | |
767 | * with losing too many ticks, otherwise we would overadjust and | |
768 | * produce an even larger error. The smaller the adjustment the | |
769 | * faster we try to adjust for it, as lost ticks can do less harm | |
3eb05676 | 770 | * here. This is tuned so that an error of about 1 msec is adjusted |
8524070b | 771 | * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks). |
772 | */ | |
155ec602 | 773 | error2 = timekeeper.ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ); |
8524070b | 774 | error2 = abs(error2); |
775 | for (look_ahead = 0; error2 > 0; look_ahead++) | |
776 | error2 >>= 2; | |
777 | ||
778 | /* | |
779 | * Now calculate the error in (1 << look_ahead) ticks, but first | |
780 | * remove the single look ahead already included in the error. | |
781 | */ | |
23ce7211 | 782 | tick_error = tick_length >> (timekeeper.ntp_error_shift + 1); |
155ec602 | 783 | tick_error -= timekeeper.xtime_interval >> 1; |
8524070b | 784 | error = ((error - tick_error) >> look_ahead) + tick_error; |
785 | ||
786 | /* Finally calculate the adjustment shift value. */ | |
787 | i = *interval; | |
788 | mult = 1; | |
789 | if (error < 0) { | |
790 | error = -error; | |
791 | *interval = -*interval; | |
792 | *offset = -*offset; | |
793 | mult = -1; | |
794 | } | |
795 | for (adj = 0; error > i; adj++) | |
796 | error >>= 1; | |
797 | ||
798 | *interval <<= adj; | |
799 | *offset <<= adj; | |
800 | return mult << adj; | |
801 | } | |
802 | ||
803 | /* | |
804 | * Adjust the multiplier to reduce the error value, | |
805 | * this is optimized for the most common adjustments of -1,0,1, | |
806 | * for other values we can do a bit more work. | |
807 | */ | |
155ec602 | 808 | static void timekeeping_adjust(s64 offset) |
8524070b | 809 | { |
155ec602 | 810 | s64 error, interval = timekeeper.cycle_interval; |
8524070b | 811 | int adj; |
812 | ||
c2bc1111 JS |
813 | /* |
814 | * The point of this is to check if the error is greater then half | |
815 | * an interval. | |
816 | * | |
817 | * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs. | |
818 | * | |
819 | * Note we subtract one in the shift, so that error is really error*2. | |
3f86f28f JS |
820 | * This "saves" dividing(shifting) interval twice, but keeps the |
821 | * (error > interval) comparison as still measuring if error is | |
c2bc1111 JS |
822 | * larger then half an interval. |
823 | * | |
3f86f28f | 824 | * Note: It does not "save" on aggravation when reading the code. |
c2bc1111 | 825 | */ |
23ce7211 | 826 | error = timekeeper.ntp_error >> (timekeeper.ntp_error_shift - 1); |
8524070b | 827 | if (error > interval) { |
c2bc1111 JS |
828 | /* |
829 | * We now divide error by 4(via shift), which checks if | |
830 | * the error is greater then twice the interval. | |
831 | * If it is greater, we need a bigadjust, if its smaller, | |
832 | * we can adjust by 1. | |
833 | */ | |
8524070b | 834 | error >>= 2; |
c2bc1111 JS |
835 | /* |
836 | * XXX - In update_wall_time, we round up to the next | |
837 | * nanosecond, and store the amount rounded up into | |
838 | * the error. This causes the likely below to be unlikely. | |
839 | * | |
3f86f28f | 840 | * The proper fix is to avoid rounding up by using |
c2bc1111 JS |
841 | * the high precision timekeeper.xtime_nsec instead of |
842 | * xtime.tv_nsec everywhere. Fixing this will take some | |
843 | * time. | |
844 | */ | |
8524070b | 845 | if (likely(error <= interval)) |
846 | adj = 1; | |
847 | else | |
155ec602 | 848 | adj = timekeeping_bigadjust(error, &interval, &offset); |
8524070b | 849 | } else if (error < -interval) { |
c2bc1111 | 850 | /* See comment above, this is just switched for the negative */ |
8524070b | 851 | error >>= 2; |
852 | if (likely(error >= -interval)) { | |
853 | adj = -1; | |
854 | interval = -interval; | |
855 | offset = -offset; | |
856 | } else | |
155ec602 | 857 | adj = timekeeping_bigadjust(error, &interval, &offset); |
c2bc1111 | 858 | } else /* No adjustment needed */ |
8524070b | 859 | return; |
860 | ||
d65670a7 JS |
861 | WARN_ONCE(timekeeper.clock->maxadj && |
862 | (timekeeper.mult + adj > timekeeper.clock->mult + | |
863 | timekeeper.clock->maxadj), | |
864 | "Adjusting %s more then 11%% (%ld vs %ld)\n", | |
865 | timekeeper.clock->name, (long)timekeeper.mult + adj, | |
866 | (long)timekeeper.clock->mult + | |
867 | timekeeper.clock->maxadj); | |
c2bc1111 JS |
868 | /* |
869 | * So the following can be confusing. | |
870 | * | |
871 | * To keep things simple, lets assume adj == 1 for now. | |
872 | * | |
873 | * When adj != 1, remember that the interval and offset values | |
874 | * have been appropriately scaled so the math is the same. | |
875 | * | |
876 | * The basic idea here is that we're increasing the multiplier | |
877 | * by one, this causes the xtime_interval to be incremented by | |
878 | * one cycle_interval. This is because: | |
879 | * xtime_interval = cycle_interval * mult | |
880 | * So if mult is being incremented by one: | |
881 | * xtime_interval = cycle_interval * (mult + 1) | |
882 | * Its the same as: | |
883 | * xtime_interval = (cycle_interval * mult) + cycle_interval | |
884 | * Which can be shortened to: | |
885 | * xtime_interval += cycle_interval | |
886 | * | |
887 | * So offset stores the non-accumulated cycles. Thus the current | |
888 | * time (in shifted nanoseconds) is: | |
889 | * now = (offset * adj) + xtime_nsec | |
890 | * Now, even though we're adjusting the clock frequency, we have | |
891 | * to keep time consistent. In other words, we can't jump back | |
892 | * in time, and we also want to avoid jumping forward in time. | |
893 | * | |
894 | * So given the same offset value, we need the time to be the same | |
895 | * both before and after the freq adjustment. | |
896 | * now = (offset * adj_1) + xtime_nsec_1 | |
897 | * now = (offset * adj_2) + xtime_nsec_2 | |
898 | * So: | |
899 | * (offset * adj_1) + xtime_nsec_1 = | |
900 | * (offset * adj_2) + xtime_nsec_2 | |
901 | * And we know: | |
902 | * adj_2 = adj_1 + 1 | |
903 | * So: | |
904 | * (offset * adj_1) + xtime_nsec_1 = | |
905 | * (offset * (adj_1+1)) + xtime_nsec_2 | |
906 | * (offset * adj_1) + xtime_nsec_1 = | |
907 | * (offset * adj_1) + offset + xtime_nsec_2 | |
908 | * Canceling the sides: | |
909 | * xtime_nsec_1 = offset + xtime_nsec_2 | |
910 | * Which gives us: | |
911 | * xtime_nsec_2 = xtime_nsec_1 - offset | |
912 | * Which simplfies to: | |
913 | * xtime_nsec -= offset | |
914 | * | |
915 | * XXX - TODO: Doc ntp_error calculation. | |
916 | */ | |
0a544198 | 917 | timekeeper.mult += adj; |
155ec602 MS |
918 | timekeeper.xtime_interval += interval; |
919 | timekeeper.xtime_nsec -= offset; | |
920 | timekeeper.ntp_error -= (interval - offset) << | |
23ce7211 | 921 | timekeeper.ntp_error_shift; |
8524070b | 922 | } |
923 | ||
83f57a11 | 924 | |
a092ff0f | 925 | /** |
926 | * logarithmic_accumulation - shifted accumulation of cycles | |
927 | * | |
928 | * This functions accumulates a shifted interval of cycles into | |
929 | * into a shifted interval nanoseconds. Allows for O(log) accumulation | |
930 | * loop. | |
931 | * | |
932 | * Returns the unconsumed cycles. | |
933 | */ | |
934 | static cycle_t logarithmic_accumulation(cycle_t offset, int shift) | |
935 | { | |
936 | u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift; | |
deda2e81 | 937 | u64 raw_nsecs; |
a092ff0f | 938 | |
939 | /* If the offset is smaller then a shifted interval, do nothing */ | |
940 | if (offset < timekeeper.cycle_interval<<shift) | |
941 | return offset; | |
942 | ||
943 | /* Accumulate one shifted interval */ | |
944 | offset -= timekeeper.cycle_interval << shift; | |
945 | timekeeper.clock->cycle_last += timekeeper.cycle_interval << shift; | |
946 | ||
947 | timekeeper.xtime_nsec += timekeeper.xtime_interval << shift; | |
948 | while (timekeeper.xtime_nsec >= nsecps) { | |
949 | timekeeper.xtime_nsec -= nsecps; | |
950 | xtime.tv_sec++; | |
951 | second_overflow(); | |
952 | } | |
953 | ||
deda2e81 JW |
954 | /* Accumulate raw time */ |
955 | raw_nsecs = timekeeper.raw_interval << shift; | |
956 | raw_nsecs += raw_time.tv_nsec; | |
c7dcf87a JS |
957 | if (raw_nsecs >= NSEC_PER_SEC) { |
958 | u64 raw_secs = raw_nsecs; | |
959 | raw_nsecs = do_div(raw_secs, NSEC_PER_SEC); | |
960 | raw_time.tv_sec += raw_secs; | |
a092ff0f | 961 | } |
deda2e81 | 962 | raw_time.tv_nsec = raw_nsecs; |
a092ff0f | 963 | |
964 | /* Accumulate error between NTP and clock interval */ | |
965 | timekeeper.ntp_error += tick_length << shift; | |
a386b5af KP |
966 | timekeeper.ntp_error -= |
967 | (timekeeper.xtime_interval + timekeeper.xtime_remainder) << | |
a092ff0f | 968 | (timekeeper.ntp_error_shift + shift); |
969 | ||
970 | return offset; | |
971 | } | |
972 | ||
83f57a11 | 973 | |
8524070b | 974 | /** |
975 | * update_wall_time - Uses the current clocksource to increment the wall time | |
976 | * | |
977 | * Called from the timer interrupt, must hold a write on xtime_lock. | |
978 | */ | |
871cf1e5 | 979 | static void update_wall_time(void) |
8524070b | 980 | { |
155ec602 | 981 | struct clocksource *clock; |
8524070b | 982 | cycle_t offset; |
a092ff0f | 983 | int shift = 0, maxshift; |
8524070b | 984 | |
985 | /* Make sure we're fully resumed: */ | |
986 | if (unlikely(timekeeping_suspended)) | |
987 | return; | |
988 | ||
155ec602 | 989 | clock = timekeeper.clock; |
592913ec JS |
990 | |
991 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET | |
155ec602 | 992 | offset = timekeeper.cycle_interval; |
592913ec JS |
993 | #else |
994 | offset = (clock->read(clock) - clock->cycle_last) & clock->mask; | |
8524070b | 995 | #endif |
23ce7211 | 996 | timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift; |
8524070b | 997 | |
a092ff0f | 998 | /* |
999 | * With NO_HZ we may have to accumulate many cycle_intervals | |
1000 | * (think "ticks") worth of time at once. To do this efficiently, | |
1001 | * we calculate the largest doubling multiple of cycle_intervals | |
1002 | * that is smaller then the offset. We then accumulate that | |
1003 | * chunk in one go, and then try to consume the next smaller | |
1004 | * doubled multiple. | |
8524070b | 1005 | */ |
a092ff0f | 1006 | shift = ilog2(offset) - ilog2(timekeeper.cycle_interval); |
1007 | shift = max(0, shift); | |
1008 | /* Bound shift to one less then what overflows tick_length */ | |
1009 | maxshift = (8*sizeof(tick_length) - (ilog2(tick_length)+1)) - 1; | |
1010 | shift = min(shift, maxshift); | |
155ec602 | 1011 | while (offset >= timekeeper.cycle_interval) { |
a092ff0f | 1012 | offset = logarithmic_accumulation(offset, shift); |
830ec045 JS |
1013 | if(offset < timekeeper.cycle_interval<<shift) |
1014 | shift--; | |
8524070b | 1015 | } |
1016 | ||
1017 | /* correct the clock when NTP error is too big */ | |
155ec602 | 1018 | timekeeping_adjust(offset); |
8524070b | 1019 | |
6c9bacb4 | 1020 | /* |
1021 | * Since in the loop above, we accumulate any amount of time | |
1022 | * in xtime_nsec over a second into xtime.tv_sec, its possible for | |
1023 | * xtime_nsec to be fairly small after the loop. Further, if we're | |
155ec602 | 1024 | * slightly speeding the clocksource up in timekeeping_adjust(), |
6c9bacb4 | 1025 | * its possible the required corrective factor to xtime_nsec could |
1026 | * cause it to underflow. | |
1027 | * | |
1028 | * Now, we cannot simply roll the accumulated second back, since | |
1029 | * the NTP subsystem has been notified via second_overflow. So | |
1030 | * instead we push xtime_nsec forward by the amount we underflowed, | |
1031 | * and add that amount into the error. | |
1032 | * | |
1033 | * We'll correct this error next time through this function, when | |
1034 | * xtime_nsec is not as small. | |
1035 | */ | |
155ec602 MS |
1036 | if (unlikely((s64)timekeeper.xtime_nsec < 0)) { |
1037 | s64 neg = -(s64)timekeeper.xtime_nsec; | |
1038 | timekeeper.xtime_nsec = 0; | |
23ce7211 | 1039 | timekeeper.ntp_error += neg << timekeeper.ntp_error_shift; |
6c9bacb4 | 1040 | } |
1041 | ||
6a867a39 JS |
1042 | |
1043 | /* | |
1044 | * Store full nanoseconds into xtime after rounding it up and | |
5cd1c9c5 RZ |
1045 | * add the remainder to the error difference. |
1046 | */ | |
23ce7211 MS |
1047 | xtime.tv_nsec = ((s64) timekeeper.xtime_nsec >> timekeeper.shift) + 1; |
1048 | timekeeper.xtime_nsec -= (s64) xtime.tv_nsec << timekeeper.shift; | |
1049 | timekeeper.ntp_error += timekeeper.xtime_nsec << | |
1050 | timekeeper.ntp_error_shift; | |
8524070b | 1051 | |
6a867a39 JS |
1052 | /* |
1053 | * Finally, make sure that after the rounding | |
1054 | * xtime.tv_nsec isn't larger then NSEC_PER_SEC | |
1055 | */ | |
1056 | if (unlikely(xtime.tv_nsec >= NSEC_PER_SEC)) { | |
1057 | xtime.tv_nsec -= NSEC_PER_SEC; | |
1058 | xtime.tv_sec++; | |
1059 | second_overflow(); | |
1060 | } | |
83f57a11 | 1061 | |
8524070b | 1062 | /* check to see if there is a new clocksource to use */ |
7615856e JS |
1063 | update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, |
1064 | timekeeper.mult); | |
8524070b | 1065 | } |
7c3f1a57 TJ |
1066 | |
1067 | /** | |
1068 | * getboottime - Return the real time of system boot. | |
1069 | * @ts: pointer to the timespec to be set | |
1070 | * | |
abb3a4ea | 1071 | * Returns the wall-time of boot in a timespec. |
7c3f1a57 TJ |
1072 | * |
1073 | * This is based on the wall_to_monotonic offset and the total suspend | |
1074 | * time. Calls to settimeofday will affect the value returned (which | |
1075 | * basically means that however wrong your real time clock is at boot time, | |
1076 | * you get the right time here). | |
1077 | */ | |
1078 | void getboottime(struct timespec *ts) | |
1079 | { | |
36d47481 | 1080 | struct timespec boottime = { |
00c5fb77 JS |
1081 | .tv_sec = wall_to_monotonic.tv_sec + |
1082 | timekeeper.total_sleep_time.tv_sec, | |
1083 | .tv_nsec = wall_to_monotonic.tv_nsec + | |
1084 | timekeeper.total_sleep_time.tv_nsec | |
36d47481 | 1085 | }; |
d4f587c6 | 1086 | |
d4f587c6 | 1087 | set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec); |
7c3f1a57 | 1088 | } |
c93d89f3 | 1089 | EXPORT_SYMBOL_GPL(getboottime); |
7c3f1a57 | 1090 | |
abb3a4ea JS |
1091 | |
1092 | /** | |
1093 | * get_monotonic_boottime - Returns monotonic time since boot | |
1094 | * @ts: pointer to the timespec to be set | |
1095 | * | |
1096 | * Returns the monotonic time since boot in a timespec. | |
1097 | * | |
1098 | * This is similar to CLOCK_MONTONIC/ktime_get_ts, but also | |
1099 | * includes the time spent in suspend. | |
1100 | */ | |
1101 | void get_monotonic_boottime(struct timespec *ts) | |
1102 | { | |
1103 | struct timespec tomono, sleep; | |
1104 | unsigned int seq; | |
1105 | s64 nsecs; | |
1106 | ||
1107 | WARN_ON(timekeeping_suspended); | |
1108 | ||
1109 | do { | |
1110 | seq = read_seqbegin(&xtime_lock); | |
1111 | *ts = xtime; | |
1112 | tomono = wall_to_monotonic; | |
00c5fb77 | 1113 | sleep = timekeeper.total_sleep_time; |
abb3a4ea JS |
1114 | nsecs = timekeeping_get_ns(); |
1115 | ||
1116 | } while (read_seqretry(&xtime_lock, seq)); | |
1117 | ||
1118 | set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec, | |
1119 | ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec + nsecs); | |
1120 | } | |
1121 | EXPORT_SYMBOL_GPL(get_monotonic_boottime); | |
1122 | ||
1123 | /** | |
1124 | * ktime_get_boottime - Returns monotonic time since boot in a ktime | |
1125 | * | |
1126 | * Returns the monotonic time since boot in a ktime | |
1127 | * | |
1128 | * This is similar to CLOCK_MONTONIC/ktime_get, but also | |
1129 | * includes the time spent in suspend. | |
1130 | */ | |
1131 | ktime_t ktime_get_boottime(void) | |
1132 | { | |
1133 | struct timespec ts; | |
1134 | ||
1135 | get_monotonic_boottime(&ts); | |
1136 | return timespec_to_ktime(ts); | |
1137 | } | |
1138 | EXPORT_SYMBOL_GPL(ktime_get_boottime); | |
1139 | ||
7c3f1a57 TJ |
1140 | /** |
1141 | * monotonic_to_bootbased - Convert the monotonic time to boot based. | |
1142 | * @ts: pointer to the timespec to be converted | |
1143 | */ | |
1144 | void monotonic_to_bootbased(struct timespec *ts) | |
1145 | { | |
00c5fb77 | 1146 | *ts = timespec_add(*ts, timekeeper.total_sleep_time); |
7c3f1a57 | 1147 | } |
c93d89f3 | 1148 | EXPORT_SYMBOL_GPL(monotonic_to_bootbased); |
2c6b47de | 1149 | |
17c38b74 | 1150 | unsigned long get_seconds(void) |
1151 | { | |
6a867a39 | 1152 | return xtime.tv_sec; |
17c38b74 | 1153 | } |
1154 | EXPORT_SYMBOL(get_seconds); | |
1155 | ||
da15cfda | 1156 | struct timespec __current_kernel_time(void) |
1157 | { | |
6a867a39 | 1158 | return xtime; |
da15cfda | 1159 | } |
17c38b74 | 1160 | |
2c6b47de | 1161 | struct timespec current_kernel_time(void) |
1162 | { | |
1163 | struct timespec now; | |
1164 | unsigned long seq; | |
1165 | ||
1166 | do { | |
1167 | seq = read_seqbegin(&xtime_lock); | |
83f57a11 | 1168 | |
6a867a39 | 1169 | now = xtime; |
2c6b47de | 1170 | } while (read_seqretry(&xtime_lock, seq)); |
1171 | ||
1172 | return now; | |
1173 | } | |
2c6b47de | 1174 | EXPORT_SYMBOL(current_kernel_time); |
da15cfda | 1175 | |
1176 | struct timespec get_monotonic_coarse(void) | |
1177 | { | |
1178 | struct timespec now, mono; | |
1179 | unsigned long seq; | |
1180 | ||
1181 | do { | |
1182 | seq = read_seqbegin(&xtime_lock); | |
83f57a11 | 1183 | |
6a867a39 | 1184 | now = xtime; |
da15cfda | 1185 | mono = wall_to_monotonic; |
1186 | } while (read_seqretry(&xtime_lock, seq)); | |
1187 | ||
1188 | set_normalized_timespec(&now, now.tv_sec + mono.tv_sec, | |
1189 | now.tv_nsec + mono.tv_nsec); | |
1190 | return now; | |
1191 | } | |
871cf1e5 TH |
1192 | |
1193 | /* | |
1194 | * The 64-bit jiffies value is not atomic - you MUST NOT read it | |
1195 | * without sampling the sequence number in xtime_lock. | |
1196 | * jiffies is defined in the linker script... | |
1197 | */ | |
1198 | void do_timer(unsigned long ticks) | |
1199 | { | |
1200 | jiffies_64 += ticks; | |
1201 | update_wall_time(); | |
1202 | calc_global_load(ticks); | |
1203 | } | |
48cf76f7 TH |
1204 | |
1205 | /** | |
314ac371 JS |
1206 | * get_xtime_and_monotonic_and_sleep_offset() - get xtime, wall_to_monotonic, |
1207 | * and sleep offsets. | |
48cf76f7 TH |
1208 | * @xtim: pointer to timespec to be set with xtime |
1209 | * @wtom: pointer to timespec to be set with wall_to_monotonic | |
314ac371 | 1210 | * @sleep: pointer to timespec to be set with time in suspend |
48cf76f7 | 1211 | */ |
314ac371 JS |
1212 | void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim, |
1213 | struct timespec *wtom, struct timespec *sleep) | |
48cf76f7 TH |
1214 | { |
1215 | unsigned long seq; | |
1216 | ||
1217 | do { | |
1218 | seq = read_seqbegin(&xtime_lock); | |
1219 | *xtim = xtime; | |
1220 | *wtom = wall_to_monotonic; | |
00c5fb77 | 1221 | *sleep = timekeeper.total_sleep_time; |
48cf76f7 TH |
1222 | } while (read_seqretry(&xtime_lock, seq)); |
1223 | } | |
f0af911a | 1224 | |
99ee5315 TG |
1225 | /** |
1226 | * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format | |
1227 | */ | |
1228 | ktime_t ktime_get_monotonic_offset(void) | |
1229 | { | |
1230 | unsigned long seq; | |
1231 | struct timespec wtom; | |
1232 | ||
1233 | do { | |
1234 | seq = read_seqbegin(&xtime_lock); | |
1235 | wtom = wall_to_monotonic; | |
1236 | } while (read_seqretry(&xtime_lock, seq)); | |
1237 | return timespec_to_ktime(wtom); | |
1238 | } | |
1239 | ||
f0af911a TH |
1240 | /** |
1241 | * xtime_update() - advances the timekeeping infrastructure | |
1242 | * @ticks: number of ticks, that have elapsed since the last call. | |
1243 | * | |
1244 | * Must be called with interrupts disabled. | |
1245 | */ | |
1246 | void xtime_update(unsigned long ticks) | |
1247 | { | |
1248 | write_seqlock(&xtime_lock); | |
1249 | do_timer(ticks); | |
1250 | write_sequnlock(&xtime_lock); | |
1251 | } |