Commit | Line | Data |
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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; | |
155ec602 MS |
50 | }; |
51 | ||
afa14e7c | 52 | static struct timekeeper timekeeper; |
155ec602 MS |
53 | |
54 | /** | |
55 | * timekeeper_setup_internals - Set up internals to use clocksource clock. | |
56 | * | |
57 | * @clock: Pointer to clocksource. | |
58 | * | |
59 | * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment | |
60 | * pair and interval request. | |
61 | * | |
62 | * Unless you're the timekeeping code, you should not be using this! | |
63 | */ | |
64 | static void timekeeper_setup_internals(struct clocksource *clock) | |
65 | { | |
66 | cycle_t interval; | |
a386b5af | 67 | u64 tmp, ntpinterval; |
155ec602 MS |
68 | |
69 | timekeeper.clock = clock; | |
70 | clock->cycle_last = clock->read(clock); | |
71 | ||
72 | /* Do the ns -> cycle conversion first, using original mult */ | |
73 | tmp = NTP_INTERVAL_LENGTH; | |
74 | tmp <<= clock->shift; | |
a386b5af | 75 | ntpinterval = tmp; |
0a544198 MS |
76 | tmp += clock->mult/2; |
77 | do_div(tmp, clock->mult); | |
155ec602 MS |
78 | if (tmp == 0) |
79 | tmp = 1; | |
80 | ||
81 | interval = (cycle_t) tmp; | |
82 | timekeeper.cycle_interval = interval; | |
83 | ||
84 | /* Go back from cycles -> shifted ns */ | |
85 | timekeeper.xtime_interval = (u64) interval * clock->mult; | |
a386b5af | 86 | timekeeper.xtime_remainder = ntpinterval - timekeeper.xtime_interval; |
155ec602 | 87 | timekeeper.raw_interval = |
0a544198 | 88 | ((u64) interval * clock->mult) >> clock->shift; |
155ec602 MS |
89 | |
90 | timekeeper.xtime_nsec = 0; | |
23ce7211 | 91 | timekeeper.shift = clock->shift; |
155ec602 MS |
92 | |
93 | timekeeper.ntp_error = 0; | |
23ce7211 | 94 | timekeeper.ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; |
0a544198 MS |
95 | |
96 | /* | |
97 | * The timekeeper keeps its own mult values for the currently | |
98 | * active clocksource. These value will be adjusted via NTP | |
99 | * to counteract clock drifting. | |
100 | */ | |
101 | timekeeper.mult = clock->mult; | |
155ec602 | 102 | } |
8524070b | 103 | |
2ba2a305 MS |
104 | /* Timekeeper helper functions. */ |
105 | static inline s64 timekeeping_get_ns(void) | |
106 | { | |
107 | cycle_t cycle_now, cycle_delta; | |
108 | struct clocksource *clock; | |
109 | ||
110 | /* read clocksource: */ | |
111 | clock = timekeeper.clock; | |
112 | cycle_now = clock->read(clock); | |
113 | ||
114 | /* calculate the delta since the last update_wall_time: */ | |
115 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; | |
116 | ||
117 | /* return delta convert to nanoseconds using ntp adjusted mult. */ | |
118 | return clocksource_cyc2ns(cycle_delta, timekeeper.mult, | |
119 | timekeeper.shift); | |
120 | } | |
121 | ||
122 | static inline s64 timekeeping_get_ns_raw(void) | |
123 | { | |
124 | cycle_t cycle_now, cycle_delta; | |
125 | struct clocksource *clock; | |
126 | ||
127 | /* read clocksource: */ | |
128 | clock = timekeeper.clock; | |
129 | cycle_now = clock->read(clock); | |
130 | ||
131 | /* calculate the delta since the last update_wall_time: */ | |
132 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; | |
133 | ||
c9fad429 | 134 | /* return delta convert to nanoseconds. */ |
2ba2a305 MS |
135 | return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); |
136 | } | |
137 | ||
8524070b | 138 | /* |
139 | * This read-write spinlock protects us from races in SMP while | |
dce48a84 | 140 | * playing with xtime. |
8524070b | 141 | */ |
ba2a631b | 142 | __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); |
8524070b | 143 | |
144 | ||
145 | /* | |
146 | * The current time | |
147 | * wall_to_monotonic is what we need to add to xtime (or xtime corrected | |
148 | * for sub jiffie times) to get to monotonic time. Monotonic is pegged | |
149 | * at zero at system boot time, so wall_to_monotonic will be negative, | |
150 | * however, we will ALWAYS keep the tv_nsec part positive so we can use | |
151 | * the usual normalization. | |
7c3f1a57 TJ |
152 | * |
153 | * wall_to_monotonic is moved after resume from suspend for the monotonic | |
154 | * time not to jump. We need to add total_sleep_time to wall_to_monotonic | |
155 | * to get the real boot based time offset. | |
156 | * | |
157 | * - wall_to_monotonic is no longer the boot time, getboottime must be | |
158 | * used instead. | |
8524070b | 159 | */ |
0fb86b06 JS |
160 | static struct timespec xtime __attribute__ ((aligned (16))); |
161 | static struct timespec wall_to_monotonic __attribute__ ((aligned (16))); | |
d4f587c6 | 162 | static struct timespec total_sleep_time; |
8524070b | 163 | |
155ec602 MS |
164 | /* |
165 | * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. | |
166 | */ | |
afa14e7c | 167 | static struct timespec raw_time; |
155ec602 | 168 | |
1c5745aa TG |
169 | /* flag for if timekeeping is suspended */ |
170 | int __read_mostly timekeeping_suspended; | |
171 | ||
31089c13 JS |
172 | /* must hold xtime_lock */ |
173 | void timekeeping_leap_insert(int leapsecond) | |
174 | { | |
175 | xtime.tv_sec += leapsecond; | |
176 | wall_to_monotonic.tv_sec -= leapsecond; | |
7615856e JS |
177 | update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, |
178 | timekeeper.mult); | |
31089c13 | 179 | } |
8524070b | 180 | |
8524070b | 181 | /** |
155ec602 | 182 | * timekeeping_forward_now - update clock to the current time |
8524070b | 183 | * |
9a055117 RZ |
184 | * Forward the current clock to update its state since the last call to |
185 | * update_wall_time(). This is useful before significant clock changes, | |
186 | * as it avoids having to deal with this time offset explicitly. | |
8524070b | 187 | */ |
155ec602 | 188 | static void timekeeping_forward_now(void) |
8524070b | 189 | { |
190 | cycle_t cycle_now, cycle_delta; | |
155ec602 | 191 | struct clocksource *clock; |
9a055117 | 192 | s64 nsec; |
8524070b | 193 | |
155ec602 | 194 | clock = timekeeper.clock; |
a0f7d48b | 195 | cycle_now = clock->read(clock); |
8524070b | 196 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; |
9a055117 | 197 | clock->cycle_last = cycle_now; |
8524070b | 198 | |
0a544198 MS |
199 | nsec = clocksource_cyc2ns(cycle_delta, timekeeper.mult, |
200 | timekeeper.shift); | |
7d27558c | 201 | |
202 | /* If arch requires, add in gettimeoffset() */ | |
203 | nsec += arch_gettimeoffset(); | |
204 | ||
9a055117 | 205 | timespec_add_ns(&xtime, nsec); |
2d42244a | 206 | |
0a544198 | 207 | nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); |
155ec602 | 208 | timespec_add_ns(&raw_time, nsec); |
8524070b | 209 | } |
210 | ||
211 | /** | |
efd9ac86 | 212 | * getnstimeofday - Returns the time of day in a timespec |
8524070b | 213 | * @ts: pointer to the timespec to be set |
214 | * | |
efd9ac86 | 215 | * Returns the time of day in a timespec. |
8524070b | 216 | */ |
efd9ac86 | 217 | void getnstimeofday(struct timespec *ts) |
8524070b | 218 | { |
219 | unsigned long seq; | |
220 | s64 nsecs; | |
221 | ||
1c5745aa TG |
222 | WARN_ON(timekeeping_suspended); |
223 | ||
8524070b | 224 | do { |
225 | seq = read_seqbegin(&xtime_lock); | |
226 | ||
227 | *ts = xtime; | |
2ba2a305 | 228 | nsecs = timekeeping_get_ns(); |
8524070b | 229 | |
7d27558c | 230 | /* If arch requires, add in gettimeoffset() */ |
231 | nsecs += arch_gettimeoffset(); | |
232 | ||
8524070b | 233 | } while (read_seqretry(&xtime_lock, seq)); |
234 | ||
235 | timespec_add_ns(ts, nsecs); | |
236 | } | |
237 | ||
8524070b | 238 | EXPORT_SYMBOL(getnstimeofday); |
239 | ||
951ed4d3 MS |
240 | ktime_t ktime_get(void) |
241 | { | |
951ed4d3 MS |
242 | unsigned int seq; |
243 | s64 secs, nsecs; | |
244 | ||
245 | WARN_ON(timekeeping_suspended); | |
246 | ||
247 | do { | |
248 | seq = read_seqbegin(&xtime_lock); | |
249 | secs = xtime.tv_sec + wall_to_monotonic.tv_sec; | |
250 | nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec; | |
2ba2a305 | 251 | nsecs += timekeeping_get_ns(); |
d004e024 HP |
252 | /* If arch requires, add in gettimeoffset() */ |
253 | nsecs += arch_gettimeoffset(); | |
951ed4d3 MS |
254 | |
255 | } while (read_seqretry(&xtime_lock, seq)); | |
256 | /* | |
257 | * Use ktime_set/ktime_add_ns to create a proper ktime on | |
258 | * 32-bit architectures without CONFIG_KTIME_SCALAR. | |
259 | */ | |
260 | return ktime_add_ns(ktime_set(secs, 0), nsecs); | |
261 | } | |
262 | EXPORT_SYMBOL_GPL(ktime_get); | |
263 | ||
264 | /** | |
265 | * ktime_get_ts - get the monotonic clock in timespec format | |
266 | * @ts: pointer to timespec variable | |
267 | * | |
268 | * The function calculates the monotonic clock from the realtime | |
269 | * clock and the wall_to_monotonic offset and stores the result | |
270 | * in normalized timespec format in the variable pointed to by @ts. | |
271 | */ | |
272 | void ktime_get_ts(struct timespec *ts) | |
273 | { | |
951ed4d3 MS |
274 | struct timespec tomono; |
275 | unsigned int seq; | |
276 | s64 nsecs; | |
277 | ||
278 | WARN_ON(timekeeping_suspended); | |
279 | ||
280 | do { | |
281 | seq = read_seqbegin(&xtime_lock); | |
282 | *ts = xtime; | |
283 | tomono = wall_to_monotonic; | |
2ba2a305 | 284 | nsecs = timekeeping_get_ns(); |
d004e024 HP |
285 | /* If arch requires, add in gettimeoffset() */ |
286 | nsecs += arch_gettimeoffset(); | |
951ed4d3 MS |
287 | |
288 | } while (read_seqretry(&xtime_lock, seq)); | |
289 | ||
290 | set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, | |
291 | ts->tv_nsec + tomono.tv_nsec + nsecs); | |
292 | } | |
293 | EXPORT_SYMBOL_GPL(ktime_get_ts); | |
294 | ||
e2c18e49 AG |
295 | #ifdef CONFIG_NTP_PPS |
296 | ||
297 | /** | |
298 | * getnstime_raw_and_real - get day and raw monotonic time in timespec format | |
299 | * @ts_raw: pointer to the timespec to be set to raw monotonic time | |
300 | * @ts_real: pointer to the timespec to be set to the time of day | |
301 | * | |
302 | * This function reads both the time of day and raw monotonic time at the | |
303 | * same time atomically and stores the resulting timestamps in timespec | |
304 | * format. | |
305 | */ | |
306 | void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real) | |
307 | { | |
308 | unsigned long seq; | |
309 | s64 nsecs_raw, nsecs_real; | |
310 | ||
311 | WARN_ON_ONCE(timekeeping_suspended); | |
312 | ||
313 | do { | |
314 | u32 arch_offset; | |
315 | ||
316 | seq = read_seqbegin(&xtime_lock); | |
317 | ||
318 | *ts_raw = raw_time; | |
319 | *ts_real = xtime; | |
320 | ||
321 | nsecs_raw = timekeeping_get_ns_raw(); | |
322 | nsecs_real = timekeeping_get_ns(); | |
323 | ||
324 | /* If arch requires, add in gettimeoffset() */ | |
325 | arch_offset = arch_gettimeoffset(); | |
326 | nsecs_raw += arch_offset; | |
327 | nsecs_real += arch_offset; | |
328 | ||
329 | } while (read_seqretry(&xtime_lock, seq)); | |
330 | ||
331 | timespec_add_ns(ts_raw, nsecs_raw); | |
332 | timespec_add_ns(ts_real, nsecs_real); | |
333 | } | |
334 | EXPORT_SYMBOL(getnstime_raw_and_real); | |
335 | ||
336 | #endif /* CONFIG_NTP_PPS */ | |
337 | ||
8524070b | 338 | /** |
339 | * do_gettimeofday - Returns the time of day in a timeval | |
340 | * @tv: pointer to the timeval to be set | |
341 | * | |
efd9ac86 | 342 | * NOTE: Users should be converted to using getnstimeofday() |
8524070b | 343 | */ |
344 | void do_gettimeofday(struct timeval *tv) | |
345 | { | |
346 | struct timespec now; | |
347 | ||
efd9ac86 | 348 | getnstimeofday(&now); |
8524070b | 349 | tv->tv_sec = now.tv_sec; |
350 | tv->tv_usec = now.tv_nsec/1000; | |
351 | } | |
352 | ||
353 | EXPORT_SYMBOL(do_gettimeofday); | |
354 | /** | |
355 | * do_settimeofday - Sets the time of day | |
356 | * @tv: pointer to the timespec variable containing the new time | |
357 | * | |
358 | * Sets the time of day to the new time and update NTP and notify hrtimers | |
359 | */ | |
1e6d7679 | 360 | int do_settimeofday(const struct timespec *tv) |
8524070b | 361 | { |
9a055117 | 362 | struct timespec ts_delta; |
8524070b | 363 | unsigned long flags; |
8524070b | 364 | |
365 | if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) | |
366 | return -EINVAL; | |
367 | ||
368 | write_seqlock_irqsave(&xtime_lock, flags); | |
369 | ||
155ec602 | 370 | timekeeping_forward_now(); |
9a055117 RZ |
371 | |
372 | ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec; | |
373 | ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec; | |
374 | wall_to_monotonic = timespec_sub(wall_to_monotonic, ts_delta); | |
8524070b | 375 | |
9a055117 | 376 | xtime = *tv; |
8524070b | 377 | |
155ec602 | 378 | timekeeper.ntp_error = 0; |
8524070b | 379 | ntp_clear(); |
380 | ||
7615856e JS |
381 | update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, |
382 | timekeeper.mult); | |
8524070b | 383 | |
384 | write_sequnlock_irqrestore(&xtime_lock, flags); | |
385 | ||
386 | /* signal hrtimers about time change */ | |
387 | clock_was_set(); | |
388 | ||
389 | return 0; | |
390 | } | |
391 | ||
392 | EXPORT_SYMBOL(do_settimeofday); | |
393 | ||
c528f7c6 JS |
394 | |
395 | /** | |
396 | * timekeeping_inject_offset - Adds or subtracts from the current time. | |
397 | * @tv: pointer to the timespec variable containing the offset | |
398 | * | |
399 | * Adds or subtracts an offset value from the current time. | |
400 | */ | |
401 | int timekeeping_inject_offset(struct timespec *ts) | |
402 | { | |
403 | unsigned long flags; | |
404 | ||
405 | if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) | |
406 | return -EINVAL; | |
407 | ||
408 | write_seqlock_irqsave(&xtime_lock, flags); | |
409 | ||
410 | timekeeping_forward_now(); | |
411 | ||
412 | xtime = timespec_add(xtime, *ts); | |
413 | wall_to_monotonic = timespec_sub(wall_to_monotonic, *ts); | |
414 | ||
415 | timekeeper.ntp_error = 0; | |
416 | ntp_clear(); | |
417 | ||
418 | update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, | |
419 | timekeeper.mult); | |
420 | ||
421 | write_sequnlock_irqrestore(&xtime_lock, flags); | |
422 | ||
423 | /* signal hrtimers about time change */ | |
424 | clock_was_set(); | |
425 | ||
426 | return 0; | |
427 | } | |
428 | EXPORT_SYMBOL(timekeeping_inject_offset); | |
429 | ||
8524070b | 430 | /** |
431 | * change_clocksource - Swaps clocksources if a new one is available | |
432 | * | |
433 | * Accumulates current time interval and initializes new clocksource | |
434 | */ | |
75c5158f | 435 | static int change_clocksource(void *data) |
8524070b | 436 | { |
4614e6ad | 437 | struct clocksource *new, *old; |
8524070b | 438 | |
75c5158f | 439 | new = (struct clocksource *) data; |
8524070b | 440 | |
155ec602 | 441 | timekeeping_forward_now(); |
75c5158f MS |
442 | if (!new->enable || new->enable(new) == 0) { |
443 | old = timekeeper.clock; | |
444 | timekeeper_setup_internals(new); | |
445 | if (old->disable) | |
446 | old->disable(old); | |
447 | } | |
448 | return 0; | |
449 | } | |
8524070b | 450 | |
75c5158f MS |
451 | /** |
452 | * timekeeping_notify - Install a new clock source | |
453 | * @clock: pointer to the clock source | |
454 | * | |
455 | * This function is called from clocksource.c after a new, better clock | |
456 | * source has been registered. The caller holds the clocksource_mutex. | |
457 | */ | |
458 | void timekeeping_notify(struct clocksource *clock) | |
459 | { | |
460 | if (timekeeper.clock == clock) | |
4614e6ad | 461 | return; |
75c5158f | 462 | stop_machine(change_clocksource, clock, NULL); |
8524070b | 463 | tick_clock_notify(); |
8524070b | 464 | } |
75c5158f | 465 | |
a40f262c TG |
466 | /** |
467 | * ktime_get_real - get the real (wall-) time in ktime_t format | |
468 | * | |
469 | * returns the time in ktime_t format | |
470 | */ | |
471 | ktime_t ktime_get_real(void) | |
472 | { | |
473 | struct timespec now; | |
474 | ||
475 | getnstimeofday(&now); | |
476 | ||
477 | return timespec_to_ktime(now); | |
478 | } | |
479 | EXPORT_SYMBOL_GPL(ktime_get_real); | |
8524070b | 480 | |
2d42244a JS |
481 | /** |
482 | * getrawmonotonic - Returns the raw monotonic time in a timespec | |
483 | * @ts: pointer to the timespec to be set | |
484 | * | |
485 | * Returns the raw monotonic time (completely un-modified by ntp) | |
486 | */ | |
487 | void getrawmonotonic(struct timespec *ts) | |
488 | { | |
489 | unsigned long seq; | |
490 | s64 nsecs; | |
2d42244a JS |
491 | |
492 | do { | |
493 | seq = read_seqbegin(&xtime_lock); | |
2ba2a305 | 494 | nsecs = timekeeping_get_ns_raw(); |
155ec602 | 495 | *ts = raw_time; |
2d42244a JS |
496 | |
497 | } while (read_seqretry(&xtime_lock, seq)); | |
498 | ||
499 | timespec_add_ns(ts, nsecs); | |
500 | } | |
501 | EXPORT_SYMBOL(getrawmonotonic); | |
502 | ||
503 | ||
8524070b | 504 | /** |
cf4fc6cb | 505 | * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres |
8524070b | 506 | */ |
cf4fc6cb | 507 | int timekeeping_valid_for_hres(void) |
8524070b | 508 | { |
509 | unsigned long seq; | |
510 | int ret; | |
511 | ||
512 | do { | |
513 | seq = read_seqbegin(&xtime_lock); | |
514 | ||
155ec602 | 515 | ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; |
8524070b | 516 | |
517 | } while (read_seqretry(&xtime_lock, seq)); | |
518 | ||
519 | return ret; | |
520 | } | |
521 | ||
98962465 JH |
522 | /** |
523 | * timekeeping_max_deferment - Returns max time the clocksource can be deferred | |
524 | * | |
525 | * Caller must observe xtime_lock via read_seqbegin/read_seqretry to | |
526 | * ensure that the clocksource does not change! | |
527 | */ | |
528 | u64 timekeeping_max_deferment(void) | |
529 | { | |
530 | return timekeeper.clock->max_idle_ns; | |
531 | } | |
532 | ||
8524070b | 533 | /** |
d4f587c6 | 534 | * read_persistent_clock - Return time from the persistent clock. |
8524070b | 535 | * |
536 | * Weak dummy function for arches that do not yet support it. | |
d4f587c6 MS |
537 | * Reads the time from the battery backed persistent clock. |
538 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. | |
8524070b | 539 | * |
540 | * XXX - Do be sure to remove it once all arches implement it. | |
541 | */ | |
d4f587c6 | 542 | void __attribute__((weak)) read_persistent_clock(struct timespec *ts) |
8524070b | 543 | { |
d4f587c6 MS |
544 | ts->tv_sec = 0; |
545 | ts->tv_nsec = 0; | |
8524070b | 546 | } |
547 | ||
23970e38 MS |
548 | /** |
549 | * read_boot_clock - Return time of the system start. | |
550 | * | |
551 | * Weak dummy function for arches that do not yet support it. | |
552 | * Function to read the exact time the system has been started. | |
553 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. | |
554 | * | |
555 | * XXX - Do be sure to remove it once all arches implement it. | |
556 | */ | |
557 | void __attribute__((weak)) read_boot_clock(struct timespec *ts) | |
558 | { | |
559 | ts->tv_sec = 0; | |
560 | ts->tv_nsec = 0; | |
561 | } | |
562 | ||
8524070b | 563 | /* |
564 | * timekeeping_init - Initializes the clocksource and common timekeeping values | |
565 | */ | |
566 | void __init timekeeping_init(void) | |
567 | { | |
155ec602 | 568 | struct clocksource *clock; |
8524070b | 569 | unsigned long flags; |
23970e38 | 570 | struct timespec now, boot; |
d4f587c6 MS |
571 | |
572 | read_persistent_clock(&now); | |
23970e38 | 573 | read_boot_clock(&boot); |
8524070b | 574 | |
575 | write_seqlock_irqsave(&xtime_lock, flags); | |
576 | ||
7dffa3c6 | 577 | ntp_init(); |
8524070b | 578 | |
f1b82746 | 579 | clock = clocksource_default_clock(); |
a0f7d48b MS |
580 | if (clock->enable) |
581 | clock->enable(clock); | |
155ec602 | 582 | timekeeper_setup_internals(clock); |
8524070b | 583 | |
d4f587c6 MS |
584 | xtime.tv_sec = now.tv_sec; |
585 | xtime.tv_nsec = now.tv_nsec; | |
155ec602 MS |
586 | raw_time.tv_sec = 0; |
587 | raw_time.tv_nsec = 0; | |
23970e38 MS |
588 | if (boot.tv_sec == 0 && boot.tv_nsec == 0) { |
589 | boot.tv_sec = xtime.tv_sec; | |
590 | boot.tv_nsec = xtime.tv_nsec; | |
591 | } | |
8524070b | 592 | set_normalized_timespec(&wall_to_monotonic, |
23970e38 | 593 | -boot.tv_sec, -boot.tv_nsec); |
d4f587c6 MS |
594 | total_sleep_time.tv_sec = 0; |
595 | total_sleep_time.tv_nsec = 0; | |
8524070b | 596 | write_sequnlock_irqrestore(&xtime_lock, flags); |
597 | } | |
598 | ||
8524070b | 599 | /* time in seconds when suspend began */ |
d4f587c6 | 600 | static struct timespec timekeeping_suspend_time; |
8524070b | 601 | |
304529b1 JS |
602 | /** |
603 | * __timekeeping_inject_sleeptime - Internal function to add sleep interval | |
604 | * @delta: pointer to a timespec delta value | |
605 | * | |
606 | * Takes a timespec offset measuring a suspend interval and properly | |
607 | * adds the sleep offset to the timekeeping variables. | |
608 | */ | |
609 | static void __timekeeping_inject_sleeptime(struct timespec *delta) | |
610 | { | |
cb5de2f8 | 611 | if (!timespec_valid(delta)) { |
cbaa5152 | 612 | printk(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid " |
cb5de2f8 JS |
613 | "sleep delta value!\n"); |
614 | return; | |
615 | } | |
616 | ||
304529b1 JS |
617 | xtime = timespec_add(xtime, *delta); |
618 | wall_to_monotonic = timespec_sub(wall_to_monotonic, *delta); | |
619 | total_sleep_time = timespec_add(total_sleep_time, *delta); | |
620 | } | |
621 | ||
622 | ||
623 | /** | |
624 | * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values | |
625 | * @delta: pointer to a timespec delta value | |
626 | * | |
627 | * This hook is for architectures that cannot support read_persistent_clock | |
628 | * because their RTC/persistent clock is only accessible when irqs are enabled. | |
629 | * | |
630 | * This function should only be called by rtc_resume(), and allows | |
631 | * a suspend offset to be injected into the timekeeping values. | |
632 | */ | |
633 | void timekeeping_inject_sleeptime(struct timespec *delta) | |
634 | { | |
635 | unsigned long flags; | |
636 | struct timespec ts; | |
637 | ||
638 | /* Make sure we don't set the clock twice */ | |
639 | read_persistent_clock(&ts); | |
640 | if (!(ts.tv_sec == 0 && ts.tv_nsec == 0)) | |
641 | return; | |
642 | ||
643 | write_seqlock_irqsave(&xtime_lock, flags); | |
644 | timekeeping_forward_now(); | |
645 | ||
646 | __timekeeping_inject_sleeptime(delta); | |
647 | ||
648 | timekeeper.ntp_error = 0; | |
649 | ntp_clear(); | |
650 | update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, | |
651 | timekeeper.mult); | |
652 | ||
653 | write_sequnlock_irqrestore(&xtime_lock, flags); | |
654 | ||
655 | /* signal hrtimers about time change */ | |
656 | clock_was_set(); | |
657 | } | |
658 | ||
659 | ||
8524070b | 660 | /** |
661 | * timekeeping_resume - Resumes the generic timekeeping subsystem. | |
8524070b | 662 | * |
663 | * This is for the generic clocksource timekeeping. | |
664 | * xtime/wall_to_monotonic/jiffies/etc are | |
665 | * still managed by arch specific suspend/resume code. | |
666 | */ | |
e1a85b2c | 667 | static void timekeeping_resume(void) |
8524070b | 668 | { |
669 | unsigned long flags; | |
d4f587c6 MS |
670 | struct timespec ts; |
671 | ||
672 | read_persistent_clock(&ts); | |
8524070b | 673 | |
d10ff3fb TG |
674 | clocksource_resume(); |
675 | ||
8524070b | 676 | write_seqlock_irqsave(&xtime_lock, flags); |
677 | ||
d4f587c6 MS |
678 | if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) { |
679 | ts = timespec_sub(ts, timekeeping_suspend_time); | |
304529b1 | 680 | __timekeeping_inject_sleeptime(&ts); |
8524070b | 681 | } |
682 | /* re-base the last cycle value */ | |
155ec602 MS |
683 | timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); |
684 | timekeeper.ntp_error = 0; | |
8524070b | 685 | timekeeping_suspended = 0; |
686 | write_sequnlock_irqrestore(&xtime_lock, flags); | |
687 | ||
688 | touch_softlockup_watchdog(); | |
689 | ||
690 | clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL); | |
691 | ||
692 | /* Resume hrtimers */ | |
b12a03ce | 693 | hrtimers_resume(); |
8524070b | 694 | } |
695 | ||
e1a85b2c | 696 | static int timekeeping_suspend(void) |
8524070b | 697 | { |
698 | unsigned long flags; | |
cb33217b JS |
699 | struct timespec delta, delta_delta; |
700 | static struct timespec old_delta; | |
8524070b | 701 | |
d4f587c6 | 702 | read_persistent_clock(&timekeeping_suspend_time); |
3be90950 | 703 | |
8524070b | 704 | write_seqlock_irqsave(&xtime_lock, flags); |
155ec602 | 705 | timekeeping_forward_now(); |
8524070b | 706 | timekeeping_suspended = 1; |
cb33217b JS |
707 | |
708 | /* | |
709 | * To avoid drift caused by repeated suspend/resumes, | |
710 | * which each can add ~1 second drift error, | |
711 | * try to compensate so the difference in system time | |
712 | * and persistent_clock time stays close to constant. | |
713 | */ | |
714 | delta = timespec_sub(xtime, timekeeping_suspend_time); | |
715 | delta_delta = timespec_sub(delta, old_delta); | |
716 | if (abs(delta_delta.tv_sec) >= 2) { | |
717 | /* | |
718 | * if delta_delta is too large, assume time correction | |
719 | * has occured and set old_delta to the current delta. | |
720 | */ | |
721 | old_delta = delta; | |
722 | } else { | |
723 | /* Otherwise try to adjust old_system to compensate */ | |
724 | timekeeping_suspend_time = | |
725 | timespec_add(timekeeping_suspend_time, delta_delta); | |
726 | } | |
8524070b | 727 | write_sequnlock_irqrestore(&xtime_lock, flags); |
728 | ||
729 | clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); | |
c54a42b1 | 730 | clocksource_suspend(); |
8524070b | 731 | |
732 | return 0; | |
733 | } | |
734 | ||
735 | /* sysfs resume/suspend bits for timekeeping */ | |
e1a85b2c | 736 | static struct syscore_ops timekeeping_syscore_ops = { |
8524070b | 737 | .resume = timekeeping_resume, |
738 | .suspend = timekeeping_suspend, | |
8524070b | 739 | }; |
740 | ||
e1a85b2c | 741 | static int __init timekeeping_init_ops(void) |
8524070b | 742 | { |
e1a85b2c RW |
743 | register_syscore_ops(&timekeeping_syscore_ops); |
744 | return 0; | |
8524070b | 745 | } |
746 | ||
e1a85b2c | 747 | device_initcall(timekeeping_init_ops); |
8524070b | 748 | |
749 | /* | |
750 | * If the error is already larger, we look ahead even further | |
751 | * to compensate for late or lost adjustments. | |
752 | */ | |
155ec602 | 753 | static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval, |
8524070b | 754 | s64 *offset) |
755 | { | |
756 | s64 tick_error, i; | |
757 | u32 look_ahead, adj; | |
758 | s32 error2, mult; | |
759 | ||
760 | /* | |
761 | * Use the current error value to determine how much to look ahead. | |
762 | * The larger the error the slower we adjust for it to avoid problems | |
763 | * with losing too many ticks, otherwise we would overadjust and | |
764 | * produce an even larger error. The smaller the adjustment the | |
765 | * faster we try to adjust for it, as lost ticks can do less harm | |
3eb05676 | 766 | * here. This is tuned so that an error of about 1 msec is adjusted |
8524070b | 767 | * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks). |
768 | */ | |
155ec602 | 769 | error2 = timekeeper.ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ); |
8524070b | 770 | error2 = abs(error2); |
771 | for (look_ahead = 0; error2 > 0; look_ahead++) | |
772 | error2 >>= 2; | |
773 | ||
774 | /* | |
775 | * Now calculate the error in (1 << look_ahead) ticks, but first | |
776 | * remove the single look ahead already included in the error. | |
777 | */ | |
23ce7211 | 778 | tick_error = tick_length >> (timekeeper.ntp_error_shift + 1); |
155ec602 | 779 | tick_error -= timekeeper.xtime_interval >> 1; |
8524070b | 780 | error = ((error - tick_error) >> look_ahead) + tick_error; |
781 | ||
782 | /* Finally calculate the adjustment shift value. */ | |
783 | i = *interval; | |
784 | mult = 1; | |
785 | if (error < 0) { | |
786 | error = -error; | |
787 | *interval = -*interval; | |
788 | *offset = -*offset; | |
789 | mult = -1; | |
790 | } | |
791 | for (adj = 0; error > i; adj++) | |
792 | error >>= 1; | |
793 | ||
794 | *interval <<= adj; | |
795 | *offset <<= adj; | |
796 | return mult << adj; | |
797 | } | |
798 | ||
799 | /* | |
800 | * Adjust the multiplier to reduce the error value, | |
801 | * this is optimized for the most common adjustments of -1,0,1, | |
802 | * for other values we can do a bit more work. | |
803 | */ | |
155ec602 | 804 | static void timekeeping_adjust(s64 offset) |
8524070b | 805 | { |
155ec602 | 806 | s64 error, interval = timekeeper.cycle_interval; |
8524070b | 807 | int adj; |
808 | ||
c2bc1111 JS |
809 | /* |
810 | * The point of this is to check if the error is greater then half | |
811 | * an interval. | |
812 | * | |
813 | * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs. | |
814 | * | |
815 | * Note we subtract one in the shift, so that error is really error*2. | |
3f86f28f JS |
816 | * This "saves" dividing(shifting) interval twice, but keeps the |
817 | * (error > interval) comparison as still measuring if error is | |
c2bc1111 JS |
818 | * larger then half an interval. |
819 | * | |
3f86f28f | 820 | * Note: It does not "save" on aggravation when reading the code. |
c2bc1111 | 821 | */ |
23ce7211 | 822 | error = timekeeper.ntp_error >> (timekeeper.ntp_error_shift - 1); |
8524070b | 823 | if (error > interval) { |
c2bc1111 JS |
824 | /* |
825 | * We now divide error by 4(via shift), which checks if | |
826 | * the error is greater then twice the interval. | |
827 | * If it is greater, we need a bigadjust, if its smaller, | |
828 | * we can adjust by 1. | |
829 | */ | |
8524070b | 830 | error >>= 2; |
c2bc1111 JS |
831 | /* |
832 | * XXX - In update_wall_time, we round up to the next | |
833 | * nanosecond, and store the amount rounded up into | |
834 | * the error. This causes the likely below to be unlikely. | |
835 | * | |
3f86f28f | 836 | * The proper fix is to avoid rounding up by using |
c2bc1111 JS |
837 | * the high precision timekeeper.xtime_nsec instead of |
838 | * xtime.tv_nsec everywhere. Fixing this will take some | |
839 | * time. | |
840 | */ | |
8524070b | 841 | if (likely(error <= interval)) |
842 | adj = 1; | |
843 | else | |
155ec602 | 844 | adj = timekeeping_bigadjust(error, &interval, &offset); |
8524070b | 845 | } else if (error < -interval) { |
c2bc1111 | 846 | /* See comment above, this is just switched for the negative */ |
8524070b | 847 | error >>= 2; |
848 | if (likely(error >= -interval)) { | |
849 | adj = -1; | |
850 | interval = -interval; | |
851 | offset = -offset; | |
852 | } else | |
155ec602 | 853 | adj = timekeeping_bigadjust(error, &interval, &offset); |
c2bc1111 | 854 | } else /* No adjustment needed */ |
8524070b | 855 | return; |
856 | ||
d65670a7 JS |
857 | WARN_ONCE(timekeeper.clock->maxadj && |
858 | (timekeeper.mult + adj > timekeeper.clock->mult + | |
859 | timekeeper.clock->maxadj), | |
860 | "Adjusting %s more then 11%% (%ld vs %ld)\n", | |
861 | timekeeper.clock->name, (long)timekeeper.mult + adj, | |
862 | (long)timekeeper.clock->mult + | |
863 | timekeeper.clock->maxadj); | |
c2bc1111 JS |
864 | /* |
865 | * So the following can be confusing. | |
866 | * | |
867 | * To keep things simple, lets assume adj == 1 for now. | |
868 | * | |
869 | * When adj != 1, remember that the interval and offset values | |
870 | * have been appropriately scaled so the math is the same. | |
871 | * | |
872 | * The basic idea here is that we're increasing the multiplier | |
873 | * by one, this causes the xtime_interval to be incremented by | |
874 | * one cycle_interval. This is because: | |
875 | * xtime_interval = cycle_interval * mult | |
876 | * So if mult is being incremented by one: | |
877 | * xtime_interval = cycle_interval * (mult + 1) | |
878 | * Its the same as: | |
879 | * xtime_interval = (cycle_interval * mult) + cycle_interval | |
880 | * Which can be shortened to: | |
881 | * xtime_interval += cycle_interval | |
882 | * | |
883 | * So offset stores the non-accumulated cycles. Thus the current | |
884 | * time (in shifted nanoseconds) is: | |
885 | * now = (offset * adj) + xtime_nsec | |
886 | * Now, even though we're adjusting the clock frequency, we have | |
887 | * to keep time consistent. In other words, we can't jump back | |
888 | * in time, and we also want to avoid jumping forward in time. | |
889 | * | |
890 | * So given the same offset value, we need the time to be the same | |
891 | * both before and after the freq adjustment. | |
892 | * now = (offset * adj_1) + xtime_nsec_1 | |
893 | * now = (offset * adj_2) + xtime_nsec_2 | |
894 | * So: | |
895 | * (offset * adj_1) + xtime_nsec_1 = | |
896 | * (offset * adj_2) + xtime_nsec_2 | |
897 | * And we know: | |
898 | * adj_2 = adj_1 + 1 | |
899 | * So: | |
900 | * (offset * adj_1) + xtime_nsec_1 = | |
901 | * (offset * (adj_1+1)) + xtime_nsec_2 | |
902 | * (offset * adj_1) + xtime_nsec_1 = | |
903 | * (offset * adj_1) + offset + xtime_nsec_2 | |
904 | * Canceling the sides: | |
905 | * xtime_nsec_1 = offset + xtime_nsec_2 | |
906 | * Which gives us: | |
907 | * xtime_nsec_2 = xtime_nsec_1 - offset | |
908 | * Which simplfies to: | |
909 | * xtime_nsec -= offset | |
910 | * | |
911 | * XXX - TODO: Doc ntp_error calculation. | |
912 | */ | |
0a544198 | 913 | timekeeper.mult += adj; |
155ec602 MS |
914 | timekeeper.xtime_interval += interval; |
915 | timekeeper.xtime_nsec -= offset; | |
916 | timekeeper.ntp_error -= (interval - offset) << | |
23ce7211 | 917 | timekeeper.ntp_error_shift; |
8524070b | 918 | } |
919 | ||
83f57a11 | 920 | |
a092ff0f | 921 | /** |
922 | * logarithmic_accumulation - shifted accumulation of cycles | |
923 | * | |
924 | * This functions accumulates a shifted interval of cycles into | |
925 | * into a shifted interval nanoseconds. Allows for O(log) accumulation | |
926 | * loop. | |
927 | * | |
928 | * Returns the unconsumed cycles. | |
929 | */ | |
930 | static cycle_t logarithmic_accumulation(cycle_t offset, int shift) | |
931 | { | |
932 | u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift; | |
deda2e81 | 933 | u64 raw_nsecs; |
a092ff0f | 934 | |
935 | /* If the offset is smaller then a shifted interval, do nothing */ | |
936 | if (offset < timekeeper.cycle_interval<<shift) | |
937 | return offset; | |
938 | ||
939 | /* Accumulate one shifted interval */ | |
940 | offset -= timekeeper.cycle_interval << shift; | |
941 | timekeeper.clock->cycle_last += timekeeper.cycle_interval << shift; | |
942 | ||
943 | timekeeper.xtime_nsec += timekeeper.xtime_interval << shift; | |
944 | while (timekeeper.xtime_nsec >= nsecps) { | |
945 | timekeeper.xtime_nsec -= nsecps; | |
946 | xtime.tv_sec++; | |
947 | second_overflow(); | |
948 | } | |
949 | ||
deda2e81 JW |
950 | /* Accumulate raw time */ |
951 | raw_nsecs = timekeeper.raw_interval << shift; | |
952 | raw_nsecs += raw_time.tv_nsec; | |
c7dcf87a JS |
953 | if (raw_nsecs >= NSEC_PER_SEC) { |
954 | u64 raw_secs = raw_nsecs; | |
955 | raw_nsecs = do_div(raw_secs, NSEC_PER_SEC); | |
956 | raw_time.tv_sec += raw_secs; | |
a092ff0f | 957 | } |
deda2e81 | 958 | raw_time.tv_nsec = raw_nsecs; |
a092ff0f | 959 | |
960 | /* Accumulate error between NTP and clock interval */ | |
961 | timekeeper.ntp_error += tick_length << shift; | |
a386b5af KP |
962 | timekeeper.ntp_error -= |
963 | (timekeeper.xtime_interval + timekeeper.xtime_remainder) << | |
a092ff0f | 964 | (timekeeper.ntp_error_shift + shift); |
965 | ||
966 | return offset; | |
967 | } | |
968 | ||
83f57a11 | 969 | |
8524070b | 970 | /** |
971 | * update_wall_time - Uses the current clocksource to increment the wall time | |
972 | * | |
973 | * Called from the timer interrupt, must hold a write on xtime_lock. | |
974 | */ | |
871cf1e5 | 975 | static void update_wall_time(void) |
8524070b | 976 | { |
155ec602 | 977 | struct clocksource *clock; |
8524070b | 978 | cycle_t offset; |
a092ff0f | 979 | int shift = 0, maxshift; |
8524070b | 980 | |
981 | /* Make sure we're fully resumed: */ | |
982 | if (unlikely(timekeeping_suspended)) | |
983 | return; | |
984 | ||
155ec602 | 985 | clock = timekeeper.clock; |
592913ec JS |
986 | |
987 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET | |
155ec602 | 988 | offset = timekeeper.cycle_interval; |
592913ec JS |
989 | #else |
990 | offset = (clock->read(clock) - clock->cycle_last) & clock->mask; | |
8524070b | 991 | #endif |
23ce7211 | 992 | timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift; |
8524070b | 993 | |
a092ff0f | 994 | /* |
995 | * With NO_HZ we may have to accumulate many cycle_intervals | |
996 | * (think "ticks") worth of time at once. To do this efficiently, | |
997 | * we calculate the largest doubling multiple of cycle_intervals | |
998 | * that is smaller then the offset. We then accumulate that | |
999 | * chunk in one go, and then try to consume the next smaller | |
1000 | * doubled multiple. | |
8524070b | 1001 | */ |
a092ff0f | 1002 | shift = ilog2(offset) - ilog2(timekeeper.cycle_interval); |
1003 | shift = max(0, shift); | |
1004 | /* Bound shift to one less then what overflows tick_length */ | |
1005 | maxshift = (8*sizeof(tick_length) - (ilog2(tick_length)+1)) - 1; | |
1006 | shift = min(shift, maxshift); | |
155ec602 | 1007 | while (offset >= timekeeper.cycle_interval) { |
a092ff0f | 1008 | offset = logarithmic_accumulation(offset, shift); |
830ec045 JS |
1009 | if(offset < timekeeper.cycle_interval<<shift) |
1010 | shift--; | |
8524070b | 1011 | } |
1012 | ||
1013 | /* correct the clock when NTP error is too big */ | |
155ec602 | 1014 | timekeeping_adjust(offset); |
8524070b | 1015 | |
6c9bacb4 | 1016 | /* |
1017 | * Since in the loop above, we accumulate any amount of time | |
1018 | * in xtime_nsec over a second into xtime.tv_sec, its possible for | |
1019 | * xtime_nsec to be fairly small after the loop. Further, if we're | |
155ec602 | 1020 | * slightly speeding the clocksource up in timekeeping_adjust(), |
6c9bacb4 | 1021 | * its possible the required corrective factor to xtime_nsec could |
1022 | * cause it to underflow. | |
1023 | * | |
1024 | * Now, we cannot simply roll the accumulated second back, since | |
1025 | * the NTP subsystem has been notified via second_overflow. So | |
1026 | * instead we push xtime_nsec forward by the amount we underflowed, | |
1027 | * and add that amount into the error. | |
1028 | * | |
1029 | * We'll correct this error next time through this function, when | |
1030 | * xtime_nsec is not as small. | |
1031 | */ | |
155ec602 MS |
1032 | if (unlikely((s64)timekeeper.xtime_nsec < 0)) { |
1033 | s64 neg = -(s64)timekeeper.xtime_nsec; | |
1034 | timekeeper.xtime_nsec = 0; | |
23ce7211 | 1035 | timekeeper.ntp_error += neg << timekeeper.ntp_error_shift; |
6c9bacb4 | 1036 | } |
1037 | ||
6a867a39 JS |
1038 | |
1039 | /* | |
1040 | * Store full nanoseconds into xtime after rounding it up and | |
5cd1c9c5 RZ |
1041 | * add the remainder to the error difference. |
1042 | */ | |
23ce7211 MS |
1043 | xtime.tv_nsec = ((s64) timekeeper.xtime_nsec >> timekeeper.shift) + 1; |
1044 | timekeeper.xtime_nsec -= (s64) xtime.tv_nsec << timekeeper.shift; | |
1045 | timekeeper.ntp_error += timekeeper.xtime_nsec << | |
1046 | timekeeper.ntp_error_shift; | |
8524070b | 1047 | |
6a867a39 JS |
1048 | /* |
1049 | * Finally, make sure that after the rounding | |
1050 | * xtime.tv_nsec isn't larger then NSEC_PER_SEC | |
1051 | */ | |
1052 | if (unlikely(xtime.tv_nsec >= NSEC_PER_SEC)) { | |
1053 | xtime.tv_nsec -= NSEC_PER_SEC; | |
1054 | xtime.tv_sec++; | |
1055 | second_overflow(); | |
1056 | } | |
83f57a11 | 1057 | |
8524070b | 1058 | /* check to see if there is a new clocksource to use */ |
7615856e JS |
1059 | update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, |
1060 | timekeeper.mult); | |
8524070b | 1061 | } |
7c3f1a57 TJ |
1062 | |
1063 | /** | |
1064 | * getboottime - Return the real time of system boot. | |
1065 | * @ts: pointer to the timespec to be set | |
1066 | * | |
abb3a4ea | 1067 | * Returns the wall-time of boot in a timespec. |
7c3f1a57 TJ |
1068 | * |
1069 | * This is based on the wall_to_monotonic offset and the total suspend | |
1070 | * time. Calls to settimeofday will affect the value returned (which | |
1071 | * basically means that however wrong your real time clock is at boot time, | |
1072 | * you get the right time here). | |
1073 | */ | |
1074 | void getboottime(struct timespec *ts) | |
1075 | { | |
36d47481 HS |
1076 | struct timespec boottime = { |
1077 | .tv_sec = wall_to_monotonic.tv_sec + total_sleep_time.tv_sec, | |
1078 | .tv_nsec = wall_to_monotonic.tv_nsec + total_sleep_time.tv_nsec | |
1079 | }; | |
d4f587c6 | 1080 | |
d4f587c6 | 1081 | set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec); |
7c3f1a57 | 1082 | } |
c93d89f3 | 1083 | EXPORT_SYMBOL_GPL(getboottime); |
7c3f1a57 | 1084 | |
abb3a4ea JS |
1085 | |
1086 | /** | |
1087 | * get_monotonic_boottime - Returns monotonic time since boot | |
1088 | * @ts: pointer to the timespec to be set | |
1089 | * | |
1090 | * Returns the monotonic time since boot in a timespec. | |
1091 | * | |
1092 | * This is similar to CLOCK_MONTONIC/ktime_get_ts, but also | |
1093 | * includes the time spent in suspend. | |
1094 | */ | |
1095 | void get_monotonic_boottime(struct timespec *ts) | |
1096 | { | |
1097 | struct timespec tomono, sleep; | |
1098 | unsigned int seq; | |
1099 | s64 nsecs; | |
1100 | ||
1101 | WARN_ON(timekeeping_suspended); | |
1102 | ||
1103 | do { | |
1104 | seq = read_seqbegin(&xtime_lock); | |
1105 | *ts = xtime; | |
1106 | tomono = wall_to_monotonic; | |
1107 | sleep = total_sleep_time; | |
1108 | nsecs = timekeeping_get_ns(); | |
1109 | ||
1110 | } while (read_seqretry(&xtime_lock, seq)); | |
1111 | ||
1112 | set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec, | |
1113 | ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec + nsecs); | |
1114 | } | |
1115 | EXPORT_SYMBOL_GPL(get_monotonic_boottime); | |
1116 | ||
1117 | /** | |
1118 | * ktime_get_boottime - Returns monotonic time since boot in a ktime | |
1119 | * | |
1120 | * Returns the monotonic time since boot in a ktime | |
1121 | * | |
1122 | * This is similar to CLOCK_MONTONIC/ktime_get, but also | |
1123 | * includes the time spent in suspend. | |
1124 | */ | |
1125 | ktime_t ktime_get_boottime(void) | |
1126 | { | |
1127 | struct timespec ts; | |
1128 | ||
1129 | get_monotonic_boottime(&ts); | |
1130 | return timespec_to_ktime(ts); | |
1131 | } | |
1132 | EXPORT_SYMBOL_GPL(ktime_get_boottime); | |
1133 | ||
7c3f1a57 TJ |
1134 | /** |
1135 | * monotonic_to_bootbased - Convert the monotonic time to boot based. | |
1136 | * @ts: pointer to the timespec to be converted | |
1137 | */ | |
1138 | void monotonic_to_bootbased(struct timespec *ts) | |
1139 | { | |
ce3bf7ab | 1140 | *ts = timespec_add(*ts, total_sleep_time); |
7c3f1a57 | 1141 | } |
c93d89f3 | 1142 | EXPORT_SYMBOL_GPL(monotonic_to_bootbased); |
2c6b47de | 1143 | |
17c38b74 | 1144 | unsigned long get_seconds(void) |
1145 | { | |
6a867a39 | 1146 | return xtime.tv_sec; |
17c38b74 | 1147 | } |
1148 | EXPORT_SYMBOL(get_seconds); | |
1149 | ||
da15cfda | 1150 | struct timespec __current_kernel_time(void) |
1151 | { | |
6a867a39 | 1152 | return xtime; |
da15cfda | 1153 | } |
17c38b74 | 1154 | |
2c6b47de | 1155 | struct timespec current_kernel_time(void) |
1156 | { | |
1157 | struct timespec now; | |
1158 | unsigned long seq; | |
1159 | ||
1160 | do { | |
1161 | seq = read_seqbegin(&xtime_lock); | |
83f57a11 | 1162 | |
6a867a39 | 1163 | now = xtime; |
2c6b47de | 1164 | } while (read_seqretry(&xtime_lock, seq)); |
1165 | ||
1166 | return now; | |
1167 | } | |
2c6b47de | 1168 | EXPORT_SYMBOL(current_kernel_time); |
da15cfda | 1169 | |
1170 | struct timespec get_monotonic_coarse(void) | |
1171 | { | |
1172 | struct timespec now, mono; | |
1173 | unsigned long seq; | |
1174 | ||
1175 | do { | |
1176 | seq = read_seqbegin(&xtime_lock); | |
83f57a11 | 1177 | |
6a867a39 | 1178 | now = xtime; |
da15cfda | 1179 | mono = wall_to_monotonic; |
1180 | } while (read_seqretry(&xtime_lock, seq)); | |
1181 | ||
1182 | set_normalized_timespec(&now, now.tv_sec + mono.tv_sec, | |
1183 | now.tv_nsec + mono.tv_nsec); | |
1184 | return now; | |
1185 | } | |
871cf1e5 TH |
1186 | |
1187 | /* | |
1188 | * The 64-bit jiffies value is not atomic - you MUST NOT read it | |
1189 | * without sampling the sequence number in xtime_lock. | |
1190 | * jiffies is defined in the linker script... | |
1191 | */ | |
1192 | void do_timer(unsigned long ticks) | |
1193 | { | |
1194 | jiffies_64 += ticks; | |
1195 | update_wall_time(); | |
1196 | calc_global_load(ticks); | |
1197 | } | |
48cf76f7 TH |
1198 | |
1199 | /** | |
314ac371 JS |
1200 | * get_xtime_and_monotonic_and_sleep_offset() - get xtime, wall_to_monotonic, |
1201 | * and sleep offsets. | |
48cf76f7 TH |
1202 | * @xtim: pointer to timespec to be set with xtime |
1203 | * @wtom: pointer to timespec to be set with wall_to_monotonic | |
314ac371 | 1204 | * @sleep: pointer to timespec to be set with time in suspend |
48cf76f7 | 1205 | */ |
314ac371 JS |
1206 | void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim, |
1207 | struct timespec *wtom, struct timespec *sleep) | |
48cf76f7 TH |
1208 | { |
1209 | unsigned long seq; | |
1210 | ||
1211 | do { | |
1212 | seq = read_seqbegin(&xtime_lock); | |
1213 | *xtim = xtime; | |
1214 | *wtom = wall_to_monotonic; | |
314ac371 | 1215 | *sleep = total_sleep_time; |
48cf76f7 TH |
1216 | } while (read_seqretry(&xtime_lock, seq)); |
1217 | } | |
f0af911a | 1218 | |
99ee5315 TG |
1219 | /** |
1220 | * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format | |
1221 | */ | |
1222 | ktime_t ktime_get_monotonic_offset(void) | |
1223 | { | |
1224 | unsigned long seq; | |
1225 | struct timespec wtom; | |
1226 | ||
1227 | do { | |
1228 | seq = read_seqbegin(&xtime_lock); | |
1229 | wtom = wall_to_monotonic; | |
1230 | } while (read_seqretry(&xtime_lock, seq)); | |
1231 | return timespec_to_ktime(wtom); | |
1232 | } | |
1233 | ||
f0af911a TH |
1234 | /** |
1235 | * xtime_update() - advances the timekeeping infrastructure | |
1236 | * @ticks: number of ticks, that have elapsed since the last call. | |
1237 | * | |
1238 | * Must be called with interrupts disabled. | |
1239 | */ | |
1240 | void xtime_update(unsigned long ticks) | |
1241 | { | |
1242 | write_seqlock(&xtime_lock); | |
1243 | do_timer(ticks); | |
1244 | write_sequnlock(&xtime_lock); | |
1245 | } |