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; | |
00c5fb77 | 50 | |
d9f7217a JS |
51 | /* |
52 | * wall_to_monotonic is what we need to add to xtime (or xtime corrected | |
53 | * for sub jiffie times) to get to monotonic time. Monotonic is pegged | |
54 | * at zero at system boot time, so wall_to_monotonic will be negative, | |
55 | * however, we will ALWAYS keep the tv_nsec part positive so we can use | |
56 | * the usual normalization. | |
57 | * | |
58 | * wall_to_monotonic is moved after resume from suspend for the | |
59 | * monotonic time not to jump. We need to add total_sleep_time to | |
60 | * wall_to_monotonic to get the real boot based time offset. | |
61 | * | |
62 | * - wall_to_monotonic is no longer the boot time, getboottime must be | |
63 | * used instead. | |
64 | */ | |
65 | struct timespec wall_to_monotonic; | |
00c5fb77 JS |
66 | /* time spent in suspend */ |
67 | struct timespec total_sleep_time; | |
68 | ||
155ec602 MS |
69 | }; |
70 | ||
afa14e7c | 71 | static struct timekeeper timekeeper; |
155ec602 MS |
72 | |
73 | /** | |
74 | * timekeeper_setup_internals - Set up internals to use clocksource clock. | |
75 | * | |
76 | * @clock: Pointer to clocksource. | |
77 | * | |
78 | * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment | |
79 | * pair and interval request. | |
80 | * | |
81 | * Unless you're the timekeeping code, you should not be using this! | |
82 | */ | |
83 | static void timekeeper_setup_internals(struct clocksource *clock) | |
84 | { | |
85 | cycle_t interval; | |
a386b5af | 86 | u64 tmp, ntpinterval; |
155ec602 MS |
87 | |
88 | timekeeper.clock = clock; | |
89 | clock->cycle_last = clock->read(clock); | |
90 | ||
91 | /* Do the ns -> cycle conversion first, using original mult */ | |
92 | tmp = NTP_INTERVAL_LENGTH; | |
93 | tmp <<= clock->shift; | |
a386b5af | 94 | ntpinterval = tmp; |
0a544198 MS |
95 | tmp += clock->mult/2; |
96 | do_div(tmp, clock->mult); | |
155ec602 MS |
97 | if (tmp == 0) |
98 | tmp = 1; | |
99 | ||
100 | interval = (cycle_t) tmp; | |
101 | timekeeper.cycle_interval = interval; | |
102 | ||
103 | /* Go back from cycles -> shifted ns */ | |
104 | timekeeper.xtime_interval = (u64) interval * clock->mult; | |
a386b5af | 105 | timekeeper.xtime_remainder = ntpinterval - timekeeper.xtime_interval; |
155ec602 | 106 | timekeeper.raw_interval = |
0a544198 | 107 | ((u64) interval * clock->mult) >> clock->shift; |
155ec602 MS |
108 | |
109 | timekeeper.xtime_nsec = 0; | |
23ce7211 | 110 | timekeeper.shift = clock->shift; |
155ec602 MS |
111 | |
112 | timekeeper.ntp_error = 0; | |
23ce7211 | 113 | timekeeper.ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; |
0a544198 MS |
114 | |
115 | /* | |
116 | * The timekeeper keeps its own mult values for the currently | |
117 | * active clocksource. These value will be adjusted via NTP | |
118 | * to counteract clock drifting. | |
119 | */ | |
120 | timekeeper.mult = clock->mult; | |
155ec602 | 121 | } |
8524070b | 122 | |
2ba2a305 MS |
123 | /* Timekeeper helper functions. */ |
124 | static inline s64 timekeeping_get_ns(void) | |
125 | { | |
126 | cycle_t cycle_now, cycle_delta; | |
127 | struct clocksource *clock; | |
128 | ||
129 | /* read clocksource: */ | |
130 | clock = timekeeper.clock; | |
131 | cycle_now = clock->read(clock); | |
132 | ||
133 | /* calculate the delta since the last update_wall_time: */ | |
134 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; | |
135 | ||
136 | /* return delta convert to nanoseconds using ntp adjusted mult. */ | |
137 | return clocksource_cyc2ns(cycle_delta, timekeeper.mult, | |
138 | timekeeper.shift); | |
139 | } | |
140 | ||
141 | static inline s64 timekeeping_get_ns_raw(void) | |
142 | { | |
143 | cycle_t cycle_now, cycle_delta; | |
144 | struct clocksource *clock; | |
145 | ||
146 | /* read clocksource: */ | |
147 | clock = timekeeper.clock; | |
148 | cycle_now = clock->read(clock); | |
149 | ||
150 | /* calculate the delta since the last update_wall_time: */ | |
151 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; | |
152 | ||
c9fad429 | 153 | /* return delta convert to nanoseconds. */ |
2ba2a305 MS |
154 | return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); |
155 | } | |
156 | ||
8524070b | 157 | /* |
158 | * This read-write spinlock protects us from races in SMP while | |
dce48a84 | 159 | * playing with xtime. |
8524070b | 160 | */ |
ba2a631b | 161 | __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); |
8524070b | 162 | |
163 | ||
164 | /* | |
165 | * The current time | |
8524070b | 166 | */ |
0fb86b06 | 167 | static struct timespec xtime __attribute__ ((aligned (16))); |
8524070b | 168 | |
155ec602 MS |
169 | /* |
170 | * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. | |
171 | */ | |
afa14e7c | 172 | static struct timespec raw_time; |
155ec602 | 173 | |
1c5745aa TG |
174 | /* flag for if timekeeping is suspended */ |
175 | int __read_mostly timekeeping_suspended; | |
176 | ||
31089c13 JS |
177 | /* must hold xtime_lock */ |
178 | void timekeeping_leap_insert(int leapsecond) | |
179 | { | |
180 | xtime.tv_sec += leapsecond; | |
d9f7217a JS |
181 | timekeeper.wall_to_monotonic.tv_sec -= leapsecond; |
182 | update_vsyscall(&xtime, &timekeeper.wall_to_monotonic, timekeeper.clock, | |
7615856e | 183 | timekeeper.mult); |
31089c13 | 184 | } |
8524070b | 185 | |
8524070b | 186 | /** |
155ec602 | 187 | * timekeeping_forward_now - update clock to the current time |
8524070b | 188 | * |
9a055117 RZ |
189 | * Forward the current clock to update its state since the last call to |
190 | * update_wall_time(). This is useful before significant clock changes, | |
191 | * as it avoids having to deal with this time offset explicitly. | |
8524070b | 192 | */ |
155ec602 | 193 | static void timekeeping_forward_now(void) |
8524070b | 194 | { |
195 | cycle_t cycle_now, cycle_delta; | |
155ec602 | 196 | struct clocksource *clock; |
9a055117 | 197 | s64 nsec; |
8524070b | 198 | |
155ec602 | 199 | clock = timekeeper.clock; |
a0f7d48b | 200 | cycle_now = clock->read(clock); |
8524070b | 201 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; |
9a055117 | 202 | clock->cycle_last = cycle_now; |
8524070b | 203 | |
0a544198 MS |
204 | nsec = clocksource_cyc2ns(cycle_delta, timekeeper.mult, |
205 | timekeeper.shift); | |
7d27558c | 206 | |
207 | /* If arch requires, add in gettimeoffset() */ | |
208 | nsec += arch_gettimeoffset(); | |
209 | ||
9a055117 | 210 | timespec_add_ns(&xtime, nsec); |
2d42244a | 211 | |
0a544198 | 212 | nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); |
155ec602 | 213 | timespec_add_ns(&raw_time, nsec); |
8524070b | 214 | } |
215 | ||
216 | /** | |
efd9ac86 | 217 | * getnstimeofday - Returns the time of day in a timespec |
8524070b | 218 | * @ts: pointer to the timespec to be set |
219 | * | |
efd9ac86 | 220 | * Returns the time of day in a timespec. |
8524070b | 221 | */ |
efd9ac86 | 222 | void getnstimeofday(struct timespec *ts) |
8524070b | 223 | { |
224 | unsigned long seq; | |
225 | s64 nsecs; | |
226 | ||
1c5745aa TG |
227 | WARN_ON(timekeeping_suspended); |
228 | ||
8524070b | 229 | do { |
230 | seq = read_seqbegin(&xtime_lock); | |
231 | ||
232 | *ts = xtime; | |
2ba2a305 | 233 | nsecs = timekeeping_get_ns(); |
8524070b | 234 | |
7d27558c | 235 | /* If arch requires, add in gettimeoffset() */ |
236 | nsecs += arch_gettimeoffset(); | |
237 | ||
8524070b | 238 | } while (read_seqretry(&xtime_lock, seq)); |
239 | ||
240 | timespec_add_ns(ts, nsecs); | |
241 | } | |
242 | ||
8524070b | 243 | EXPORT_SYMBOL(getnstimeofday); |
244 | ||
951ed4d3 MS |
245 | ktime_t ktime_get(void) |
246 | { | |
951ed4d3 MS |
247 | unsigned int seq; |
248 | s64 secs, nsecs; | |
249 | ||
250 | WARN_ON(timekeeping_suspended); | |
251 | ||
252 | do { | |
253 | seq = read_seqbegin(&xtime_lock); | |
d9f7217a JS |
254 | secs = xtime.tv_sec + timekeeper.wall_to_monotonic.tv_sec; |
255 | nsecs = xtime.tv_nsec + timekeeper.wall_to_monotonic.tv_nsec; | |
2ba2a305 | 256 | nsecs += timekeeping_get_ns(); |
d004e024 HP |
257 | /* If arch requires, add in gettimeoffset() */ |
258 | nsecs += arch_gettimeoffset(); | |
951ed4d3 MS |
259 | |
260 | } while (read_seqretry(&xtime_lock, seq)); | |
261 | /* | |
262 | * Use ktime_set/ktime_add_ns to create a proper ktime on | |
263 | * 32-bit architectures without CONFIG_KTIME_SCALAR. | |
264 | */ | |
265 | return ktime_add_ns(ktime_set(secs, 0), nsecs); | |
266 | } | |
267 | EXPORT_SYMBOL_GPL(ktime_get); | |
268 | ||
269 | /** | |
270 | * ktime_get_ts - get the monotonic clock in timespec format | |
271 | * @ts: pointer to timespec variable | |
272 | * | |
273 | * The function calculates the monotonic clock from the realtime | |
274 | * clock and the wall_to_monotonic offset and stores the result | |
275 | * in normalized timespec format in the variable pointed to by @ts. | |
276 | */ | |
277 | void ktime_get_ts(struct timespec *ts) | |
278 | { | |
951ed4d3 MS |
279 | struct timespec tomono; |
280 | unsigned int seq; | |
281 | s64 nsecs; | |
282 | ||
283 | WARN_ON(timekeeping_suspended); | |
284 | ||
285 | do { | |
286 | seq = read_seqbegin(&xtime_lock); | |
287 | *ts = xtime; | |
d9f7217a | 288 | tomono = timekeeper.wall_to_monotonic; |
2ba2a305 | 289 | nsecs = timekeeping_get_ns(); |
d004e024 HP |
290 | /* If arch requires, add in gettimeoffset() */ |
291 | nsecs += arch_gettimeoffset(); | |
951ed4d3 MS |
292 | |
293 | } while (read_seqretry(&xtime_lock, seq)); | |
294 | ||
295 | set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, | |
296 | ts->tv_nsec + tomono.tv_nsec + nsecs); | |
297 | } | |
298 | EXPORT_SYMBOL_GPL(ktime_get_ts); | |
299 | ||
e2c18e49 AG |
300 | #ifdef CONFIG_NTP_PPS |
301 | ||
302 | /** | |
303 | * getnstime_raw_and_real - get day and raw monotonic time in timespec format | |
304 | * @ts_raw: pointer to the timespec to be set to raw monotonic time | |
305 | * @ts_real: pointer to the timespec to be set to the time of day | |
306 | * | |
307 | * This function reads both the time of day and raw monotonic time at the | |
308 | * same time atomically and stores the resulting timestamps in timespec | |
309 | * format. | |
310 | */ | |
311 | void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real) | |
312 | { | |
313 | unsigned long seq; | |
314 | s64 nsecs_raw, nsecs_real; | |
315 | ||
316 | WARN_ON_ONCE(timekeeping_suspended); | |
317 | ||
318 | do { | |
319 | u32 arch_offset; | |
320 | ||
321 | seq = read_seqbegin(&xtime_lock); | |
322 | ||
323 | *ts_raw = raw_time; | |
324 | *ts_real = xtime; | |
325 | ||
326 | nsecs_raw = timekeeping_get_ns_raw(); | |
327 | nsecs_real = timekeeping_get_ns(); | |
328 | ||
329 | /* If arch requires, add in gettimeoffset() */ | |
330 | arch_offset = arch_gettimeoffset(); | |
331 | nsecs_raw += arch_offset; | |
332 | nsecs_real += arch_offset; | |
333 | ||
334 | } while (read_seqretry(&xtime_lock, seq)); | |
335 | ||
336 | timespec_add_ns(ts_raw, nsecs_raw); | |
337 | timespec_add_ns(ts_real, nsecs_real); | |
338 | } | |
339 | EXPORT_SYMBOL(getnstime_raw_and_real); | |
340 | ||
341 | #endif /* CONFIG_NTP_PPS */ | |
342 | ||
8524070b | 343 | /** |
344 | * do_gettimeofday - Returns the time of day in a timeval | |
345 | * @tv: pointer to the timeval to be set | |
346 | * | |
efd9ac86 | 347 | * NOTE: Users should be converted to using getnstimeofday() |
8524070b | 348 | */ |
349 | void do_gettimeofday(struct timeval *tv) | |
350 | { | |
351 | struct timespec now; | |
352 | ||
efd9ac86 | 353 | getnstimeofday(&now); |
8524070b | 354 | tv->tv_sec = now.tv_sec; |
355 | tv->tv_usec = now.tv_nsec/1000; | |
356 | } | |
357 | ||
358 | EXPORT_SYMBOL(do_gettimeofday); | |
359 | /** | |
360 | * do_settimeofday - Sets the time of day | |
361 | * @tv: pointer to the timespec variable containing the new time | |
362 | * | |
363 | * Sets the time of day to the new time and update NTP and notify hrtimers | |
364 | */ | |
1e6d7679 | 365 | int do_settimeofday(const struct timespec *tv) |
8524070b | 366 | { |
9a055117 | 367 | struct timespec ts_delta; |
8524070b | 368 | unsigned long flags; |
8524070b | 369 | |
370 | if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) | |
371 | return -EINVAL; | |
372 | ||
373 | write_seqlock_irqsave(&xtime_lock, flags); | |
374 | ||
155ec602 | 375 | timekeeping_forward_now(); |
9a055117 RZ |
376 | |
377 | ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec; | |
378 | ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec; | |
d9f7217a JS |
379 | timekeeper.wall_to_monotonic = |
380 | timespec_sub(timekeeper.wall_to_monotonic, ts_delta); | |
8524070b | 381 | |
9a055117 | 382 | xtime = *tv; |
8524070b | 383 | |
155ec602 | 384 | timekeeper.ntp_error = 0; |
8524070b | 385 | ntp_clear(); |
386 | ||
d9f7217a | 387 | update_vsyscall(&xtime, &timekeeper.wall_to_monotonic, timekeeper.clock, |
7615856e | 388 | timekeeper.mult); |
8524070b | 389 | |
390 | write_sequnlock_irqrestore(&xtime_lock, flags); | |
391 | ||
392 | /* signal hrtimers about time change */ | |
393 | clock_was_set(); | |
394 | ||
395 | return 0; | |
396 | } | |
397 | ||
398 | EXPORT_SYMBOL(do_settimeofday); | |
399 | ||
c528f7c6 JS |
400 | |
401 | /** | |
402 | * timekeeping_inject_offset - Adds or subtracts from the current time. | |
403 | * @tv: pointer to the timespec variable containing the offset | |
404 | * | |
405 | * Adds or subtracts an offset value from the current time. | |
406 | */ | |
407 | int timekeeping_inject_offset(struct timespec *ts) | |
408 | { | |
409 | unsigned long flags; | |
410 | ||
411 | if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) | |
412 | return -EINVAL; | |
413 | ||
414 | write_seqlock_irqsave(&xtime_lock, flags); | |
415 | ||
416 | timekeeping_forward_now(); | |
417 | ||
418 | xtime = timespec_add(xtime, *ts); | |
d9f7217a JS |
419 | timekeeper.wall_to_monotonic = |
420 | timespec_sub(timekeeper.wall_to_monotonic, *ts); | |
c528f7c6 JS |
421 | |
422 | timekeeper.ntp_error = 0; | |
423 | ntp_clear(); | |
424 | ||
d9f7217a | 425 | update_vsyscall(&xtime, &timekeeper.wall_to_monotonic, timekeeper.clock, |
c528f7c6 JS |
426 | timekeeper.mult); |
427 | ||
428 | write_sequnlock_irqrestore(&xtime_lock, flags); | |
429 | ||
430 | /* signal hrtimers about time change */ | |
431 | clock_was_set(); | |
432 | ||
433 | return 0; | |
434 | } | |
435 | EXPORT_SYMBOL(timekeeping_inject_offset); | |
436 | ||
8524070b | 437 | /** |
438 | * change_clocksource - Swaps clocksources if a new one is available | |
439 | * | |
440 | * Accumulates current time interval and initializes new clocksource | |
441 | */ | |
75c5158f | 442 | static int change_clocksource(void *data) |
8524070b | 443 | { |
4614e6ad | 444 | struct clocksource *new, *old; |
8524070b | 445 | |
75c5158f | 446 | new = (struct clocksource *) data; |
8524070b | 447 | |
155ec602 | 448 | timekeeping_forward_now(); |
75c5158f MS |
449 | if (!new->enable || new->enable(new) == 0) { |
450 | old = timekeeper.clock; | |
451 | timekeeper_setup_internals(new); | |
452 | if (old->disable) | |
453 | old->disable(old); | |
454 | } | |
455 | return 0; | |
456 | } | |
8524070b | 457 | |
75c5158f MS |
458 | /** |
459 | * timekeeping_notify - Install a new clock source | |
460 | * @clock: pointer to the clock source | |
461 | * | |
462 | * This function is called from clocksource.c after a new, better clock | |
463 | * source has been registered. The caller holds the clocksource_mutex. | |
464 | */ | |
465 | void timekeeping_notify(struct clocksource *clock) | |
466 | { | |
467 | if (timekeeper.clock == clock) | |
4614e6ad | 468 | return; |
75c5158f | 469 | stop_machine(change_clocksource, clock, NULL); |
8524070b | 470 | tick_clock_notify(); |
8524070b | 471 | } |
75c5158f | 472 | |
a40f262c TG |
473 | /** |
474 | * ktime_get_real - get the real (wall-) time in ktime_t format | |
475 | * | |
476 | * returns the time in ktime_t format | |
477 | */ | |
478 | ktime_t ktime_get_real(void) | |
479 | { | |
480 | struct timespec now; | |
481 | ||
482 | getnstimeofday(&now); | |
483 | ||
484 | return timespec_to_ktime(now); | |
485 | } | |
486 | EXPORT_SYMBOL_GPL(ktime_get_real); | |
8524070b | 487 | |
2d42244a JS |
488 | /** |
489 | * getrawmonotonic - Returns the raw monotonic time in a timespec | |
490 | * @ts: pointer to the timespec to be set | |
491 | * | |
492 | * Returns the raw monotonic time (completely un-modified by ntp) | |
493 | */ | |
494 | void getrawmonotonic(struct timespec *ts) | |
495 | { | |
496 | unsigned long seq; | |
497 | s64 nsecs; | |
2d42244a JS |
498 | |
499 | do { | |
500 | seq = read_seqbegin(&xtime_lock); | |
2ba2a305 | 501 | nsecs = timekeeping_get_ns_raw(); |
155ec602 | 502 | *ts = raw_time; |
2d42244a JS |
503 | |
504 | } while (read_seqretry(&xtime_lock, seq)); | |
505 | ||
506 | timespec_add_ns(ts, nsecs); | |
507 | } | |
508 | EXPORT_SYMBOL(getrawmonotonic); | |
509 | ||
510 | ||
8524070b | 511 | /** |
cf4fc6cb | 512 | * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres |
8524070b | 513 | */ |
cf4fc6cb | 514 | int timekeeping_valid_for_hres(void) |
8524070b | 515 | { |
516 | unsigned long seq; | |
517 | int ret; | |
518 | ||
519 | do { | |
520 | seq = read_seqbegin(&xtime_lock); | |
521 | ||
155ec602 | 522 | ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; |
8524070b | 523 | |
524 | } while (read_seqretry(&xtime_lock, seq)); | |
525 | ||
526 | return ret; | |
527 | } | |
528 | ||
98962465 JH |
529 | /** |
530 | * timekeeping_max_deferment - Returns max time the clocksource can be deferred | |
531 | * | |
532 | * Caller must observe xtime_lock via read_seqbegin/read_seqretry to | |
533 | * ensure that the clocksource does not change! | |
534 | */ | |
535 | u64 timekeeping_max_deferment(void) | |
536 | { | |
537 | return timekeeper.clock->max_idle_ns; | |
538 | } | |
539 | ||
8524070b | 540 | /** |
d4f587c6 | 541 | * read_persistent_clock - Return time from the persistent clock. |
8524070b | 542 | * |
543 | * Weak dummy function for arches that do not yet support it. | |
d4f587c6 MS |
544 | * Reads the time from the battery backed persistent clock. |
545 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. | |
8524070b | 546 | * |
547 | * XXX - Do be sure to remove it once all arches implement it. | |
548 | */ | |
d4f587c6 | 549 | void __attribute__((weak)) read_persistent_clock(struct timespec *ts) |
8524070b | 550 | { |
d4f587c6 MS |
551 | ts->tv_sec = 0; |
552 | ts->tv_nsec = 0; | |
8524070b | 553 | } |
554 | ||
23970e38 MS |
555 | /** |
556 | * read_boot_clock - Return time of the system start. | |
557 | * | |
558 | * Weak dummy function for arches that do not yet support it. | |
559 | * Function to read the exact time the system has been started. | |
560 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. | |
561 | * | |
562 | * XXX - Do be sure to remove it once all arches implement it. | |
563 | */ | |
564 | void __attribute__((weak)) read_boot_clock(struct timespec *ts) | |
565 | { | |
566 | ts->tv_sec = 0; | |
567 | ts->tv_nsec = 0; | |
568 | } | |
569 | ||
8524070b | 570 | /* |
571 | * timekeeping_init - Initializes the clocksource and common timekeeping values | |
572 | */ | |
573 | void __init timekeeping_init(void) | |
574 | { | |
155ec602 | 575 | struct clocksource *clock; |
8524070b | 576 | unsigned long flags; |
23970e38 | 577 | struct timespec now, boot; |
d4f587c6 MS |
578 | |
579 | read_persistent_clock(&now); | |
23970e38 | 580 | read_boot_clock(&boot); |
8524070b | 581 | |
582 | write_seqlock_irqsave(&xtime_lock, flags); | |
583 | ||
7dffa3c6 | 584 | ntp_init(); |
8524070b | 585 | |
f1b82746 | 586 | clock = clocksource_default_clock(); |
a0f7d48b MS |
587 | if (clock->enable) |
588 | clock->enable(clock); | |
155ec602 | 589 | timekeeper_setup_internals(clock); |
8524070b | 590 | |
d4f587c6 MS |
591 | xtime.tv_sec = now.tv_sec; |
592 | xtime.tv_nsec = now.tv_nsec; | |
155ec602 MS |
593 | raw_time.tv_sec = 0; |
594 | raw_time.tv_nsec = 0; | |
23970e38 MS |
595 | if (boot.tv_sec == 0 && boot.tv_nsec == 0) { |
596 | boot.tv_sec = xtime.tv_sec; | |
597 | boot.tv_nsec = xtime.tv_nsec; | |
598 | } | |
d9f7217a | 599 | set_normalized_timespec(&timekeeper.wall_to_monotonic, |
23970e38 | 600 | -boot.tv_sec, -boot.tv_nsec); |
00c5fb77 JS |
601 | timekeeper.total_sleep_time.tv_sec = 0; |
602 | timekeeper.total_sleep_time.tv_nsec = 0; | |
8524070b | 603 | write_sequnlock_irqrestore(&xtime_lock, flags); |
604 | } | |
605 | ||
8524070b | 606 | /* time in seconds when suspend began */ |
d4f587c6 | 607 | static struct timespec timekeeping_suspend_time; |
8524070b | 608 | |
304529b1 JS |
609 | /** |
610 | * __timekeeping_inject_sleeptime - Internal function to add sleep interval | |
611 | * @delta: pointer to a timespec delta value | |
612 | * | |
613 | * Takes a timespec offset measuring a suspend interval and properly | |
614 | * adds the sleep offset to the timekeeping variables. | |
615 | */ | |
616 | static void __timekeeping_inject_sleeptime(struct timespec *delta) | |
617 | { | |
cb5de2f8 | 618 | if (!timespec_valid(delta)) { |
cbaa5152 | 619 | printk(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid " |
cb5de2f8 JS |
620 | "sleep delta value!\n"); |
621 | return; | |
622 | } | |
623 | ||
304529b1 | 624 | xtime = timespec_add(xtime, *delta); |
d9f7217a JS |
625 | timekeeper.wall_to_monotonic = |
626 | timespec_sub(timekeeper.wall_to_monotonic, *delta); | |
00c5fb77 JS |
627 | timekeeper.total_sleep_time = timespec_add( |
628 | timekeeper.total_sleep_time, *delta); | |
304529b1 JS |
629 | } |
630 | ||
631 | ||
632 | /** | |
633 | * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values | |
634 | * @delta: pointer to a timespec delta value | |
635 | * | |
636 | * This hook is for architectures that cannot support read_persistent_clock | |
637 | * because their RTC/persistent clock is only accessible when irqs are enabled. | |
638 | * | |
639 | * This function should only be called by rtc_resume(), and allows | |
640 | * a suspend offset to be injected into the timekeeping values. | |
641 | */ | |
642 | void timekeeping_inject_sleeptime(struct timespec *delta) | |
643 | { | |
644 | unsigned long flags; | |
645 | struct timespec ts; | |
646 | ||
647 | /* Make sure we don't set the clock twice */ | |
648 | read_persistent_clock(&ts); | |
649 | if (!(ts.tv_sec == 0 && ts.tv_nsec == 0)) | |
650 | return; | |
651 | ||
652 | write_seqlock_irqsave(&xtime_lock, flags); | |
653 | timekeeping_forward_now(); | |
654 | ||
655 | __timekeeping_inject_sleeptime(delta); | |
656 | ||
657 | timekeeper.ntp_error = 0; | |
658 | ntp_clear(); | |
d9f7217a | 659 | update_vsyscall(&xtime, &timekeeper.wall_to_monotonic, timekeeper.clock, |
304529b1 JS |
660 | timekeeper.mult); |
661 | ||
662 | write_sequnlock_irqrestore(&xtime_lock, flags); | |
663 | ||
664 | /* signal hrtimers about time change */ | |
665 | clock_was_set(); | |
666 | } | |
667 | ||
668 | ||
8524070b | 669 | /** |
670 | * timekeeping_resume - Resumes the generic timekeeping subsystem. | |
8524070b | 671 | * |
672 | * This is for the generic clocksource timekeeping. | |
673 | * xtime/wall_to_monotonic/jiffies/etc are | |
674 | * still managed by arch specific suspend/resume code. | |
675 | */ | |
e1a85b2c | 676 | static void timekeeping_resume(void) |
8524070b | 677 | { |
678 | unsigned long flags; | |
d4f587c6 MS |
679 | struct timespec ts; |
680 | ||
681 | read_persistent_clock(&ts); | |
8524070b | 682 | |
d10ff3fb TG |
683 | clocksource_resume(); |
684 | ||
8524070b | 685 | write_seqlock_irqsave(&xtime_lock, flags); |
686 | ||
d4f587c6 MS |
687 | if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) { |
688 | ts = timespec_sub(ts, timekeeping_suspend_time); | |
304529b1 | 689 | __timekeeping_inject_sleeptime(&ts); |
8524070b | 690 | } |
691 | /* re-base the last cycle value */ | |
155ec602 MS |
692 | timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); |
693 | timekeeper.ntp_error = 0; | |
8524070b | 694 | timekeeping_suspended = 0; |
695 | write_sequnlock_irqrestore(&xtime_lock, flags); | |
696 | ||
697 | touch_softlockup_watchdog(); | |
698 | ||
699 | clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL); | |
700 | ||
701 | /* Resume hrtimers */ | |
b12a03ce | 702 | hrtimers_resume(); |
8524070b | 703 | } |
704 | ||
e1a85b2c | 705 | static int timekeeping_suspend(void) |
8524070b | 706 | { |
707 | unsigned long flags; | |
cb33217b JS |
708 | struct timespec delta, delta_delta; |
709 | static struct timespec old_delta; | |
8524070b | 710 | |
d4f587c6 | 711 | read_persistent_clock(&timekeeping_suspend_time); |
3be90950 | 712 | |
8524070b | 713 | write_seqlock_irqsave(&xtime_lock, flags); |
155ec602 | 714 | timekeeping_forward_now(); |
8524070b | 715 | timekeeping_suspended = 1; |
cb33217b JS |
716 | |
717 | /* | |
718 | * To avoid drift caused by repeated suspend/resumes, | |
719 | * which each can add ~1 second drift error, | |
720 | * try to compensate so the difference in system time | |
721 | * and persistent_clock time stays close to constant. | |
722 | */ | |
723 | delta = timespec_sub(xtime, timekeeping_suspend_time); | |
724 | delta_delta = timespec_sub(delta, old_delta); | |
725 | if (abs(delta_delta.tv_sec) >= 2) { | |
726 | /* | |
727 | * if delta_delta is too large, assume time correction | |
728 | * has occured and set old_delta to the current delta. | |
729 | */ | |
730 | old_delta = delta; | |
731 | } else { | |
732 | /* Otherwise try to adjust old_system to compensate */ | |
733 | timekeeping_suspend_time = | |
734 | timespec_add(timekeeping_suspend_time, delta_delta); | |
735 | } | |
8524070b | 736 | write_sequnlock_irqrestore(&xtime_lock, flags); |
737 | ||
738 | clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); | |
c54a42b1 | 739 | clocksource_suspend(); |
8524070b | 740 | |
741 | return 0; | |
742 | } | |
743 | ||
744 | /* sysfs resume/suspend bits for timekeeping */ | |
e1a85b2c | 745 | static struct syscore_ops timekeeping_syscore_ops = { |
8524070b | 746 | .resume = timekeeping_resume, |
747 | .suspend = timekeeping_suspend, | |
8524070b | 748 | }; |
749 | ||
e1a85b2c | 750 | static int __init timekeeping_init_ops(void) |
8524070b | 751 | { |
e1a85b2c RW |
752 | register_syscore_ops(&timekeeping_syscore_ops); |
753 | return 0; | |
8524070b | 754 | } |
755 | ||
e1a85b2c | 756 | device_initcall(timekeeping_init_ops); |
8524070b | 757 | |
758 | /* | |
759 | * If the error is already larger, we look ahead even further | |
760 | * to compensate for late or lost adjustments. | |
761 | */ | |
155ec602 | 762 | static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval, |
8524070b | 763 | s64 *offset) |
764 | { | |
765 | s64 tick_error, i; | |
766 | u32 look_ahead, adj; | |
767 | s32 error2, mult; | |
768 | ||
769 | /* | |
770 | * Use the current error value to determine how much to look ahead. | |
771 | * The larger the error the slower we adjust for it to avoid problems | |
772 | * with losing too many ticks, otherwise we would overadjust and | |
773 | * produce an even larger error. The smaller the adjustment the | |
774 | * faster we try to adjust for it, as lost ticks can do less harm | |
3eb05676 | 775 | * here. This is tuned so that an error of about 1 msec is adjusted |
8524070b | 776 | * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks). |
777 | */ | |
155ec602 | 778 | error2 = timekeeper.ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ); |
8524070b | 779 | error2 = abs(error2); |
780 | for (look_ahead = 0; error2 > 0; look_ahead++) | |
781 | error2 >>= 2; | |
782 | ||
783 | /* | |
784 | * Now calculate the error in (1 << look_ahead) ticks, but first | |
785 | * remove the single look ahead already included in the error. | |
786 | */ | |
23ce7211 | 787 | tick_error = tick_length >> (timekeeper.ntp_error_shift + 1); |
155ec602 | 788 | tick_error -= timekeeper.xtime_interval >> 1; |
8524070b | 789 | error = ((error - tick_error) >> look_ahead) + tick_error; |
790 | ||
791 | /* Finally calculate the adjustment shift value. */ | |
792 | i = *interval; | |
793 | mult = 1; | |
794 | if (error < 0) { | |
795 | error = -error; | |
796 | *interval = -*interval; | |
797 | *offset = -*offset; | |
798 | mult = -1; | |
799 | } | |
800 | for (adj = 0; error > i; adj++) | |
801 | error >>= 1; | |
802 | ||
803 | *interval <<= adj; | |
804 | *offset <<= adj; | |
805 | return mult << adj; | |
806 | } | |
807 | ||
808 | /* | |
809 | * Adjust the multiplier to reduce the error value, | |
810 | * this is optimized for the most common adjustments of -1,0,1, | |
811 | * for other values we can do a bit more work. | |
812 | */ | |
155ec602 | 813 | static void timekeeping_adjust(s64 offset) |
8524070b | 814 | { |
155ec602 | 815 | s64 error, interval = timekeeper.cycle_interval; |
8524070b | 816 | int adj; |
817 | ||
c2bc1111 JS |
818 | /* |
819 | * The point of this is to check if the error is greater then half | |
820 | * an interval. | |
821 | * | |
822 | * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs. | |
823 | * | |
824 | * Note we subtract one in the shift, so that error is really error*2. | |
3f86f28f JS |
825 | * This "saves" dividing(shifting) interval twice, but keeps the |
826 | * (error > interval) comparison as still measuring if error is | |
c2bc1111 JS |
827 | * larger then half an interval. |
828 | * | |
3f86f28f | 829 | * Note: It does not "save" on aggravation when reading the code. |
c2bc1111 | 830 | */ |
23ce7211 | 831 | error = timekeeper.ntp_error >> (timekeeper.ntp_error_shift - 1); |
8524070b | 832 | if (error > interval) { |
c2bc1111 JS |
833 | /* |
834 | * We now divide error by 4(via shift), which checks if | |
835 | * the error is greater then twice the interval. | |
836 | * If it is greater, we need a bigadjust, if its smaller, | |
837 | * we can adjust by 1. | |
838 | */ | |
8524070b | 839 | error >>= 2; |
c2bc1111 JS |
840 | /* |
841 | * XXX - In update_wall_time, we round up to the next | |
842 | * nanosecond, and store the amount rounded up into | |
843 | * the error. This causes the likely below to be unlikely. | |
844 | * | |
3f86f28f | 845 | * The proper fix is to avoid rounding up by using |
c2bc1111 JS |
846 | * the high precision timekeeper.xtime_nsec instead of |
847 | * xtime.tv_nsec everywhere. Fixing this will take some | |
848 | * time. | |
849 | */ | |
8524070b | 850 | if (likely(error <= interval)) |
851 | adj = 1; | |
852 | else | |
155ec602 | 853 | adj = timekeeping_bigadjust(error, &interval, &offset); |
8524070b | 854 | } else if (error < -interval) { |
c2bc1111 | 855 | /* See comment above, this is just switched for the negative */ |
8524070b | 856 | error >>= 2; |
857 | if (likely(error >= -interval)) { | |
858 | adj = -1; | |
859 | interval = -interval; | |
860 | offset = -offset; | |
861 | } else | |
155ec602 | 862 | adj = timekeeping_bigadjust(error, &interval, &offset); |
c2bc1111 | 863 | } else /* No adjustment needed */ |
8524070b | 864 | return; |
865 | ||
d65670a7 JS |
866 | WARN_ONCE(timekeeper.clock->maxadj && |
867 | (timekeeper.mult + adj > timekeeper.clock->mult + | |
868 | timekeeper.clock->maxadj), | |
869 | "Adjusting %s more then 11%% (%ld vs %ld)\n", | |
870 | timekeeper.clock->name, (long)timekeeper.mult + adj, | |
871 | (long)timekeeper.clock->mult + | |
872 | timekeeper.clock->maxadj); | |
c2bc1111 JS |
873 | /* |
874 | * So the following can be confusing. | |
875 | * | |
876 | * To keep things simple, lets assume adj == 1 for now. | |
877 | * | |
878 | * When adj != 1, remember that the interval and offset values | |
879 | * have been appropriately scaled so the math is the same. | |
880 | * | |
881 | * The basic idea here is that we're increasing the multiplier | |
882 | * by one, this causes the xtime_interval to be incremented by | |
883 | * one cycle_interval. This is because: | |
884 | * xtime_interval = cycle_interval * mult | |
885 | * So if mult is being incremented by one: | |
886 | * xtime_interval = cycle_interval * (mult + 1) | |
887 | * Its the same as: | |
888 | * xtime_interval = (cycle_interval * mult) + cycle_interval | |
889 | * Which can be shortened to: | |
890 | * xtime_interval += cycle_interval | |
891 | * | |
892 | * So offset stores the non-accumulated cycles. Thus the current | |
893 | * time (in shifted nanoseconds) is: | |
894 | * now = (offset * adj) + xtime_nsec | |
895 | * Now, even though we're adjusting the clock frequency, we have | |
896 | * to keep time consistent. In other words, we can't jump back | |
897 | * in time, and we also want to avoid jumping forward in time. | |
898 | * | |
899 | * So given the same offset value, we need the time to be the same | |
900 | * both before and after the freq adjustment. | |
901 | * now = (offset * adj_1) + xtime_nsec_1 | |
902 | * now = (offset * adj_2) + xtime_nsec_2 | |
903 | * So: | |
904 | * (offset * adj_1) + xtime_nsec_1 = | |
905 | * (offset * adj_2) + xtime_nsec_2 | |
906 | * And we know: | |
907 | * adj_2 = adj_1 + 1 | |
908 | * So: | |
909 | * (offset * adj_1) + xtime_nsec_1 = | |
910 | * (offset * (adj_1+1)) + xtime_nsec_2 | |
911 | * (offset * adj_1) + xtime_nsec_1 = | |
912 | * (offset * adj_1) + offset + xtime_nsec_2 | |
913 | * Canceling the sides: | |
914 | * xtime_nsec_1 = offset + xtime_nsec_2 | |
915 | * Which gives us: | |
916 | * xtime_nsec_2 = xtime_nsec_1 - offset | |
917 | * Which simplfies to: | |
918 | * xtime_nsec -= offset | |
919 | * | |
920 | * XXX - TODO: Doc ntp_error calculation. | |
921 | */ | |
0a544198 | 922 | timekeeper.mult += adj; |
155ec602 MS |
923 | timekeeper.xtime_interval += interval; |
924 | timekeeper.xtime_nsec -= offset; | |
925 | timekeeper.ntp_error -= (interval - offset) << | |
23ce7211 | 926 | timekeeper.ntp_error_shift; |
8524070b | 927 | } |
928 | ||
83f57a11 | 929 | |
a092ff0f | 930 | /** |
931 | * logarithmic_accumulation - shifted accumulation of cycles | |
932 | * | |
933 | * This functions accumulates a shifted interval of cycles into | |
934 | * into a shifted interval nanoseconds. Allows for O(log) accumulation | |
935 | * loop. | |
936 | * | |
937 | * Returns the unconsumed cycles. | |
938 | */ | |
939 | static cycle_t logarithmic_accumulation(cycle_t offset, int shift) | |
940 | { | |
941 | u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift; | |
deda2e81 | 942 | u64 raw_nsecs; |
a092ff0f | 943 | |
944 | /* If the offset is smaller then a shifted interval, do nothing */ | |
945 | if (offset < timekeeper.cycle_interval<<shift) | |
946 | return offset; | |
947 | ||
948 | /* Accumulate one shifted interval */ | |
949 | offset -= timekeeper.cycle_interval << shift; | |
950 | timekeeper.clock->cycle_last += timekeeper.cycle_interval << shift; | |
951 | ||
952 | timekeeper.xtime_nsec += timekeeper.xtime_interval << shift; | |
953 | while (timekeeper.xtime_nsec >= nsecps) { | |
954 | timekeeper.xtime_nsec -= nsecps; | |
955 | xtime.tv_sec++; | |
956 | second_overflow(); | |
957 | } | |
958 | ||
deda2e81 JW |
959 | /* Accumulate raw time */ |
960 | raw_nsecs = timekeeper.raw_interval << shift; | |
961 | raw_nsecs += raw_time.tv_nsec; | |
c7dcf87a JS |
962 | if (raw_nsecs >= NSEC_PER_SEC) { |
963 | u64 raw_secs = raw_nsecs; | |
964 | raw_nsecs = do_div(raw_secs, NSEC_PER_SEC); | |
965 | raw_time.tv_sec += raw_secs; | |
a092ff0f | 966 | } |
deda2e81 | 967 | raw_time.tv_nsec = raw_nsecs; |
a092ff0f | 968 | |
969 | /* Accumulate error between NTP and clock interval */ | |
970 | timekeeper.ntp_error += tick_length << shift; | |
a386b5af KP |
971 | timekeeper.ntp_error -= |
972 | (timekeeper.xtime_interval + timekeeper.xtime_remainder) << | |
a092ff0f | 973 | (timekeeper.ntp_error_shift + shift); |
974 | ||
975 | return offset; | |
976 | } | |
977 | ||
83f57a11 | 978 | |
8524070b | 979 | /** |
980 | * update_wall_time - Uses the current clocksource to increment the wall time | |
981 | * | |
982 | * Called from the timer interrupt, must hold a write on xtime_lock. | |
983 | */ | |
871cf1e5 | 984 | static void update_wall_time(void) |
8524070b | 985 | { |
155ec602 | 986 | struct clocksource *clock; |
8524070b | 987 | cycle_t offset; |
a092ff0f | 988 | int shift = 0, maxshift; |
8524070b | 989 | |
990 | /* Make sure we're fully resumed: */ | |
991 | if (unlikely(timekeeping_suspended)) | |
992 | return; | |
993 | ||
155ec602 | 994 | clock = timekeeper.clock; |
592913ec JS |
995 | |
996 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET | |
155ec602 | 997 | offset = timekeeper.cycle_interval; |
592913ec JS |
998 | #else |
999 | offset = (clock->read(clock) - clock->cycle_last) & clock->mask; | |
8524070b | 1000 | #endif |
23ce7211 | 1001 | timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift; |
8524070b | 1002 | |
a092ff0f | 1003 | /* |
1004 | * With NO_HZ we may have to accumulate many cycle_intervals | |
1005 | * (think "ticks") worth of time at once. To do this efficiently, | |
1006 | * we calculate the largest doubling multiple of cycle_intervals | |
1007 | * that is smaller then the offset. We then accumulate that | |
1008 | * chunk in one go, and then try to consume the next smaller | |
1009 | * doubled multiple. | |
8524070b | 1010 | */ |
a092ff0f | 1011 | shift = ilog2(offset) - ilog2(timekeeper.cycle_interval); |
1012 | shift = max(0, shift); | |
1013 | /* Bound shift to one less then what overflows tick_length */ | |
1014 | maxshift = (8*sizeof(tick_length) - (ilog2(tick_length)+1)) - 1; | |
1015 | shift = min(shift, maxshift); | |
155ec602 | 1016 | while (offset >= timekeeper.cycle_interval) { |
a092ff0f | 1017 | offset = logarithmic_accumulation(offset, shift); |
830ec045 JS |
1018 | if(offset < timekeeper.cycle_interval<<shift) |
1019 | shift--; | |
8524070b | 1020 | } |
1021 | ||
1022 | /* correct the clock when NTP error is too big */ | |
155ec602 | 1023 | timekeeping_adjust(offset); |
8524070b | 1024 | |
6c9bacb4 | 1025 | /* |
1026 | * Since in the loop above, we accumulate any amount of time | |
1027 | * in xtime_nsec over a second into xtime.tv_sec, its possible for | |
1028 | * xtime_nsec to be fairly small after the loop. Further, if we're | |
155ec602 | 1029 | * slightly speeding the clocksource up in timekeeping_adjust(), |
6c9bacb4 | 1030 | * its possible the required corrective factor to xtime_nsec could |
1031 | * cause it to underflow. | |
1032 | * | |
1033 | * Now, we cannot simply roll the accumulated second back, since | |
1034 | * the NTP subsystem has been notified via second_overflow. So | |
1035 | * instead we push xtime_nsec forward by the amount we underflowed, | |
1036 | * and add that amount into the error. | |
1037 | * | |
1038 | * We'll correct this error next time through this function, when | |
1039 | * xtime_nsec is not as small. | |
1040 | */ | |
155ec602 MS |
1041 | if (unlikely((s64)timekeeper.xtime_nsec < 0)) { |
1042 | s64 neg = -(s64)timekeeper.xtime_nsec; | |
1043 | timekeeper.xtime_nsec = 0; | |
23ce7211 | 1044 | timekeeper.ntp_error += neg << timekeeper.ntp_error_shift; |
6c9bacb4 | 1045 | } |
1046 | ||
6a867a39 JS |
1047 | |
1048 | /* | |
1049 | * Store full nanoseconds into xtime after rounding it up and | |
5cd1c9c5 RZ |
1050 | * add the remainder to the error difference. |
1051 | */ | |
23ce7211 MS |
1052 | xtime.tv_nsec = ((s64) timekeeper.xtime_nsec >> timekeeper.shift) + 1; |
1053 | timekeeper.xtime_nsec -= (s64) xtime.tv_nsec << timekeeper.shift; | |
1054 | timekeeper.ntp_error += timekeeper.xtime_nsec << | |
1055 | timekeeper.ntp_error_shift; | |
8524070b | 1056 | |
6a867a39 JS |
1057 | /* |
1058 | * Finally, make sure that after the rounding | |
1059 | * xtime.tv_nsec isn't larger then NSEC_PER_SEC | |
1060 | */ | |
1061 | if (unlikely(xtime.tv_nsec >= NSEC_PER_SEC)) { | |
1062 | xtime.tv_nsec -= NSEC_PER_SEC; | |
1063 | xtime.tv_sec++; | |
1064 | second_overflow(); | |
1065 | } | |
83f57a11 | 1066 | |
8524070b | 1067 | /* check to see if there is a new clocksource to use */ |
d9f7217a | 1068 | update_vsyscall(&xtime, &timekeeper.wall_to_monotonic, timekeeper.clock, |
7615856e | 1069 | timekeeper.mult); |
8524070b | 1070 | } |
7c3f1a57 TJ |
1071 | |
1072 | /** | |
1073 | * getboottime - Return the real time of system boot. | |
1074 | * @ts: pointer to the timespec to be set | |
1075 | * | |
abb3a4ea | 1076 | * Returns the wall-time of boot in a timespec. |
7c3f1a57 TJ |
1077 | * |
1078 | * This is based on the wall_to_monotonic offset and the total suspend | |
1079 | * time. Calls to settimeofday will affect the value returned (which | |
1080 | * basically means that however wrong your real time clock is at boot time, | |
1081 | * you get the right time here). | |
1082 | */ | |
1083 | void getboottime(struct timespec *ts) | |
1084 | { | |
36d47481 | 1085 | struct timespec boottime = { |
d9f7217a | 1086 | .tv_sec = timekeeper.wall_to_monotonic.tv_sec + |
00c5fb77 | 1087 | timekeeper.total_sleep_time.tv_sec, |
d9f7217a | 1088 | .tv_nsec = timekeeper.wall_to_monotonic.tv_nsec + |
00c5fb77 | 1089 | timekeeper.total_sleep_time.tv_nsec |
36d47481 | 1090 | }; |
d4f587c6 | 1091 | |
d4f587c6 | 1092 | set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec); |
7c3f1a57 | 1093 | } |
c93d89f3 | 1094 | EXPORT_SYMBOL_GPL(getboottime); |
7c3f1a57 | 1095 | |
abb3a4ea JS |
1096 | |
1097 | /** | |
1098 | * get_monotonic_boottime - Returns monotonic time since boot | |
1099 | * @ts: pointer to the timespec to be set | |
1100 | * | |
1101 | * Returns the monotonic time since boot in a timespec. | |
1102 | * | |
1103 | * This is similar to CLOCK_MONTONIC/ktime_get_ts, but also | |
1104 | * includes the time spent in suspend. | |
1105 | */ | |
1106 | void get_monotonic_boottime(struct timespec *ts) | |
1107 | { | |
1108 | struct timespec tomono, sleep; | |
1109 | unsigned int seq; | |
1110 | s64 nsecs; | |
1111 | ||
1112 | WARN_ON(timekeeping_suspended); | |
1113 | ||
1114 | do { | |
1115 | seq = read_seqbegin(&xtime_lock); | |
1116 | *ts = xtime; | |
d9f7217a | 1117 | tomono = timekeeper.wall_to_monotonic; |
00c5fb77 | 1118 | sleep = timekeeper.total_sleep_time; |
abb3a4ea JS |
1119 | nsecs = timekeeping_get_ns(); |
1120 | ||
1121 | } while (read_seqretry(&xtime_lock, seq)); | |
1122 | ||
1123 | set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec, | |
1124 | ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec + nsecs); | |
1125 | } | |
1126 | EXPORT_SYMBOL_GPL(get_monotonic_boottime); | |
1127 | ||
1128 | /** | |
1129 | * ktime_get_boottime - Returns monotonic time since boot in a ktime | |
1130 | * | |
1131 | * Returns the monotonic time since boot in a ktime | |
1132 | * | |
1133 | * This is similar to CLOCK_MONTONIC/ktime_get, but also | |
1134 | * includes the time spent in suspend. | |
1135 | */ | |
1136 | ktime_t ktime_get_boottime(void) | |
1137 | { | |
1138 | struct timespec ts; | |
1139 | ||
1140 | get_monotonic_boottime(&ts); | |
1141 | return timespec_to_ktime(ts); | |
1142 | } | |
1143 | EXPORT_SYMBOL_GPL(ktime_get_boottime); | |
1144 | ||
7c3f1a57 TJ |
1145 | /** |
1146 | * monotonic_to_bootbased - Convert the monotonic time to boot based. | |
1147 | * @ts: pointer to the timespec to be converted | |
1148 | */ | |
1149 | void monotonic_to_bootbased(struct timespec *ts) | |
1150 | { | |
00c5fb77 | 1151 | *ts = timespec_add(*ts, timekeeper.total_sleep_time); |
7c3f1a57 | 1152 | } |
c93d89f3 | 1153 | EXPORT_SYMBOL_GPL(monotonic_to_bootbased); |
2c6b47de | 1154 | |
17c38b74 | 1155 | unsigned long get_seconds(void) |
1156 | { | |
6a867a39 | 1157 | return xtime.tv_sec; |
17c38b74 | 1158 | } |
1159 | EXPORT_SYMBOL(get_seconds); | |
1160 | ||
da15cfda | 1161 | struct timespec __current_kernel_time(void) |
1162 | { | |
6a867a39 | 1163 | return xtime; |
da15cfda | 1164 | } |
17c38b74 | 1165 | |
2c6b47de | 1166 | struct timespec current_kernel_time(void) |
1167 | { | |
1168 | struct timespec now; | |
1169 | unsigned long seq; | |
1170 | ||
1171 | do { | |
1172 | seq = read_seqbegin(&xtime_lock); | |
83f57a11 | 1173 | |
6a867a39 | 1174 | now = xtime; |
2c6b47de | 1175 | } while (read_seqretry(&xtime_lock, seq)); |
1176 | ||
1177 | return now; | |
1178 | } | |
2c6b47de | 1179 | EXPORT_SYMBOL(current_kernel_time); |
da15cfda | 1180 | |
1181 | struct timespec get_monotonic_coarse(void) | |
1182 | { | |
1183 | struct timespec now, mono; | |
1184 | unsigned long seq; | |
1185 | ||
1186 | do { | |
1187 | seq = read_seqbegin(&xtime_lock); | |
83f57a11 | 1188 | |
6a867a39 | 1189 | now = xtime; |
d9f7217a | 1190 | mono = timekeeper.wall_to_monotonic; |
da15cfda | 1191 | } while (read_seqretry(&xtime_lock, seq)); |
1192 | ||
1193 | set_normalized_timespec(&now, now.tv_sec + mono.tv_sec, | |
1194 | now.tv_nsec + mono.tv_nsec); | |
1195 | return now; | |
1196 | } | |
871cf1e5 TH |
1197 | |
1198 | /* | |
1199 | * The 64-bit jiffies value is not atomic - you MUST NOT read it | |
1200 | * without sampling the sequence number in xtime_lock. | |
1201 | * jiffies is defined in the linker script... | |
1202 | */ | |
1203 | void do_timer(unsigned long ticks) | |
1204 | { | |
1205 | jiffies_64 += ticks; | |
1206 | update_wall_time(); | |
1207 | calc_global_load(ticks); | |
1208 | } | |
48cf76f7 TH |
1209 | |
1210 | /** | |
314ac371 JS |
1211 | * get_xtime_and_monotonic_and_sleep_offset() - get xtime, wall_to_monotonic, |
1212 | * and sleep offsets. | |
48cf76f7 TH |
1213 | * @xtim: pointer to timespec to be set with xtime |
1214 | * @wtom: pointer to timespec to be set with wall_to_monotonic | |
314ac371 | 1215 | * @sleep: pointer to timespec to be set with time in suspend |
48cf76f7 | 1216 | */ |
314ac371 JS |
1217 | void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim, |
1218 | struct timespec *wtom, struct timespec *sleep) | |
48cf76f7 TH |
1219 | { |
1220 | unsigned long seq; | |
1221 | ||
1222 | do { | |
1223 | seq = read_seqbegin(&xtime_lock); | |
1224 | *xtim = xtime; | |
d9f7217a | 1225 | *wtom = timekeeper.wall_to_monotonic; |
00c5fb77 | 1226 | *sleep = timekeeper.total_sleep_time; |
48cf76f7 TH |
1227 | } while (read_seqretry(&xtime_lock, seq)); |
1228 | } | |
f0af911a | 1229 | |
99ee5315 TG |
1230 | /** |
1231 | * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format | |
1232 | */ | |
1233 | ktime_t ktime_get_monotonic_offset(void) | |
1234 | { | |
1235 | unsigned long seq; | |
1236 | struct timespec wtom; | |
1237 | ||
1238 | do { | |
1239 | seq = read_seqbegin(&xtime_lock); | |
d9f7217a | 1240 | wtom = timekeeper.wall_to_monotonic; |
99ee5315 TG |
1241 | } while (read_seqretry(&xtime_lock, seq)); |
1242 | return timespec_to_ktime(wtom); | |
1243 | } | |
1244 | ||
f0af911a TH |
1245 | /** |
1246 | * xtime_update() - advances the timekeeping infrastructure | |
1247 | * @ticks: number of ticks, that have elapsed since the last call. | |
1248 | * | |
1249 | * Must be called with interrupts disabled. | |
1250 | */ | |
1251 | void xtime_update(unsigned long ticks) | |
1252 | { | |
1253 | write_seqlock(&xtime_lock); | |
1254 | do_timer(ticks); | |
1255 | write_sequnlock(&xtime_lock); | |
1256 | } |