Commit | Line | Data |
---|---|---|
8524070b | 1 | /* |
2 | * linux/kernel/time/timekeeping.c | |
3 | * | |
4 | * Kernel timekeeping code and accessor functions | |
5 | * | |
6 | * This code was moved from linux/kernel/timer.c. | |
7 | * Please see that file for copyright and history logs. | |
8 | * | |
9 | */ | |
10 | ||
d7b4202e | 11 | #include <linux/timekeeper_internal.h> |
8524070b | 12 | #include <linux/module.h> |
13 | #include <linux/interrupt.h> | |
14 | #include <linux/percpu.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/mm.h> | |
d43c36dc | 17 | #include <linux/sched.h> |
e1a85b2c | 18 | #include <linux/syscore_ops.h> |
8524070b | 19 | #include <linux/clocksource.h> |
20 | #include <linux/jiffies.h> | |
21 | #include <linux/time.h> | |
22 | #include <linux/tick.h> | |
75c5158f | 23 | #include <linux/stop_machine.h> |
e0b306fe | 24 | #include <linux/pvclock_gtod.h> |
8524070b | 25 | |
155ec602 | 26 | |
afa14e7c | 27 | static struct timekeeper timekeeper; |
155ec602 | 28 | |
8fcce546 JS |
29 | /* flag for if timekeeping is suspended */ |
30 | int __read_mostly timekeeping_suspended; | |
31 | ||
31ade306 FT |
32 | /* Flag for if there is a persistent clock on this platform */ |
33 | bool __read_mostly persistent_clock_exist = false; | |
34 | ||
1e75fa8b JS |
35 | static inline void tk_normalize_xtime(struct timekeeper *tk) |
36 | { | |
37 | while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) { | |
38 | tk->xtime_nsec -= (u64)NSEC_PER_SEC << tk->shift; | |
39 | tk->xtime_sec++; | |
40 | } | |
41 | } | |
42 | ||
1e75fa8b JS |
43 | static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts) |
44 | { | |
45 | tk->xtime_sec = ts->tv_sec; | |
b44d50dc | 46 | tk->xtime_nsec = (u64)ts->tv_nsec << tk->shift; |
1e75fa8b JS |
47 | } |
48 | ||
49 | static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts) | |
50 | { | |
51 | tk->xtime_sec += ts->tv_sec; | |
b44d50dc | 52 | tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift; |
784ffcbb | 53 | tk_normalize_xtime(tk); |
1e75fa8b | 54 | } |
8fcce546 | 55 | |
6d0ef903 JS |
56 | static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm) |
57 | { | |
58 | struct timespec tmp; | |
59 | ||
60 | /* | |
61 | * Verify consistency of: offset_real = -wall_to_monotonic | |
62 | * before modifying anything | |
63 | */ | |
64 | set_normalized_timespec(&tmp, -tk->wall_to_monotonic.tv_sec, | |
65 | -tk->wall_to_monotonic.tv_nsec); | |
66 | WARN_ON_ONCE(tk->offs_real.tv64 != timespec_to_ktime(tmp).tv64); | |
67 | tk->wall_to_monotonic = wtm; | |
68 | set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec); | |
69 | tk->offs_real = timespec_to_ktime(tmp); | |
90adda98 | 70 | tk->offs_tai = ktime_sub(tk->offs_real, ktime_set(tk->tai_offset, 0)); |
6d0ef903 JS |
71 | } |
72 | ||
73 | static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t) | |
74 | { | |
75 | /* Verify consistency before modifying */ | |
76 | WARN_ON_ONCE(tk->offs_boot.tv64 != timespec_to_ktime(tk->total_sleep_time).tv64); | |
77 | ||
78 | tk->total_sleep_time = t; | |
79 | tk->offs_boot = timespec_to_ktime(t); | |
80 | } | |
81 | ||
155ec602 MS |
82 | /** |
83 | * timekeeper_setup_internals - Set up internals to use clocksource clock. | |
84 | * | |
85 | * @clock: Pointer to clocksource. | |
86 | * | |
87 | * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment | |
88 | * pair and interval request. | |
89 | * | |
90 | * Unless you're the timekeeping code, you should not be using this! | |
91 | */ | |
f726a697 | 92 | static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock) |
155ec602 MS |
93 | { |
94 | cycle_t interval; | |
a386b5af | 95 | u64 tmp, ntpinterval; |
1e75fa8b | 96 | struct clocksource *old_clock; |
155ec602 | 97 | |
f726a697 JS |
98 | old_clock = tk->clock; |
99 | tk->clock = clock; | |
155ec602 MS |
100 | clock->cycle_last = clock->read(clock); |
101 | ||
102 | /* Do the ns -> cycle conversion first, using original mult */ | |
103 | tmp = NTP_INTERVAL_LENGTH; | |
104 | tmp <<= clock->shift; | |
a386b5af | 105 | ntpinterval = tmp; |
0a544198 MS |
106 | tmp += clock->mult/2; |
107 | do_div(tmp, clock->mult); | |
155ec602 MS |
108 | if (tmp == 0) |
109 | tmp = 1; | |
110 | ||
111 | interval = (cycle_t) tmp; | |
f726a697 | 112 | tk->cycle_interval = interval; |
155ec602 MS |
113 | |
114 | /* Go back from cycles -> shifted ns */ | |
f726a697 JS |
115 | tk->xtime_interval = (u64) interval * clock->mult; |
116 | tk->xtime_remainder = ntpinterval - tk->xtime_interval; | |
117 | tk->raw_interval = | |
0a544198 | 118 | ((u64) interval * clock->mult) >> clock->shift; |
155ec602 | 119 | |
1e75fa8b JS |
120 | /* if changing clocks, convert xtime_nsec shift units */ |
121 | if (old_clock) { | |
122 | int shift_change = clock->shift - old_clock->shift; | |
123 | if (shift_change < 0) | |
f726a697 | 124 | tk->xtime_nsec >>= -shift_change; |
1e75fa8b | 125 | else |
f726a697 | 126 | tk->xtime_nsec <<= shift_change; |
1e75fa8b | 127 | } |
f726a697 | 128 | tk->shift = clock->shift; |
155ec602 | 129 | |
f726a697 JS |
130 | tk->ntp_error = 0; |
131 | tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; | |
0a544198 MS |
132 | |
133 | /* | |
134 | * The timekeeper keeps its own mult values for the currently | |
135 | * active clocksource. These value will be adjusted via NTP | |
136 | * to counteract clock drifting. | |
137 | */ | |
f726a697 | 138 | tk->mult = clock->mult; |
155ec602 | 139 | } |
8524070b | 140 | |
2ba2a305 | 141 | /* Timekeeper helper functions. */ |
7b1f6207 SW |
142 | |
143 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET | |
144 | u32 (*arch_gettimeoffset)(void); | |
145 | ||
146 | u32 get_arch_timeoffset(void) | |
147 | { | |
148 | if (likely(arch_gettimeoffset)) | |
149 | return arch_gettimeoffset(); | |
150 | return 0; | |
151 | } | |
152 | #else | |
153 | static inline u32 get_arch_timeoffset(void) { return 0; } | |
154 | #endif | |
155 | ||
f726a697 | 156 | static inline s64 timekeeping_get_ns(struct timekeeper *tk) |
2ba2a305 MS |
157 | { |
158 | cycle_t cycle_now, cycle_delta; | |
159 | struct clocksource *clock; | |
1e75fa8b | 160 | s64 nsec; |
2ba2a305 MS |
161 | |
162 | /* read clocksource: */ | |
f726a697 | 163 | clock = tk->clock; |
2ba2a305 MS |
164 | cycle_now = clock->read(clock); |
165 | ||
166 | /* calculate the delta since the last update_wall_time: */ | |
167 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; | |
168 | ||
f726a697 JS |
169 | nsec = cycle_delta * tk->mult + tk->xtime_nsec; |
170 | nsec >>= tk->shift; | |
f2a5a085 | 171 | |
7b1f6207 SW |
172 | /* If arch requires, add in get_arch_timeoffset() */ |
173 | return nsec + get_arch_timeoffset(); | |
2ba2a305 MS |
174 | } |
175 | ||
f726a697 | 176 | static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk) |
2ba2a305 MS |
177 | { |
178 | cycle_t cycle_now, cycle_delta; | |
179 | struct clocksource *clock; | |
f2a5a085 | 180 | s64 nsec; |
2ba2a305 MS |
181 | |
182 | /* read clocksource: */ | |
f726a697 | 183 | clock = tk->clock; |
2ba2a305 MS |
184 | cycle_now = clock->read(clock); |
185 | ||
186 | /* calculate the delta since the last update_wall_time: */ | |
187 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; | |
188 | ||
f2a5a085 JS |
189 | /* convert delta to nanoseconds. */ |
190 | nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); | |
191 | ||
7b1f6207 SW |
192 | /* If arch requires, add in get_arch_timeoffset() */ |
193 | return nsec + get_arch_timeoffset(); | |
2ba2a305 MS |
194 | } |
195 | ||
e0b306fe MT |
196 | static RAW_NOTIFIER_HEAD(pvclock_gtod_chain); |
197 | ||
198 | static void update_pvclock_gtod(struct timekeeper *tk) | |
199 | { | |
200 | raw_notifier_call_chain(&pvclock_gtod_chain, 0, tk); | |
201 | } | |
202 | ||
203 | /** | |
204 | * pvclock_gtod_register_notifier - register a pvclock timedata update listener | |
205 | * | |
206 | * Must hold write on timekeeper.lock | |
207 | */ | |
208 | int pvclock_gtod_register_notifier(struct notifier_block *nb) | |
209 | { | |
210 | struct timekeeper *tk = &timekeeper; | |
211 | unsigned long flags; | |
212 | int ret; | |
213 | ||
214 | write_seqlock_irqsave(&tk->lock, flags); | |
215 | ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb); | |
216 | /* update timekeeping data */ | |
217 | update_pvclock_gtod(tk); | |
218 | write_sequnlock_irqrestore(&tk->lock, flags); | |
219 | ||
220 | return ret; | |
221 | } | |
222 | EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier); | |
223 | ||
224 | /** | |
225 | * pvclock_gtod_unregister_notifier - unregister a pvclock | |
226 | * timedata update listener | |
227 | * | |
228 | * Must hold write on timekeeper.lock | |
229 | */ | |
230 | int pvclock_gtod_unregister_notifier(struct notifier_block *nb) | |
231 | { | |
232 | struct timekeeper *tk = &timekeeper; | |
233 | unsigned long flags; | |
234 | int ret; | |
235 | ||
236 | write_seqlock_irqsave(&tk->lock, flags); | |
237 | ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb); | |
238 | write_sequnlock_irqrestore(&tk->lock, flags); | |
239 | ||
240 | return ret; | |
241 | } | |
242 | EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier); | |
243 | ||
cc06268c | 244 | /* must hold write on timekeeper.lock */ |
f726a697 | 245 | static void timekeeping_update(struct timekeeper *tk, bool clearntp) |
cc06268c TG |
246 | { |
247 | if (clearntp) { | |
f726a697 | 248 | tk->ntp_error = 0; |
cc06268c TG |
249 | ntp_clear(); |
250 | } | |
576094b7 | 251 | update_vsyscall(tk); |
e0b306fe | 252 | update_pvclock_gtod(tk); |
cc06268c TG |
253 | } |
254 | ||
8524070b | 255 | /** |
155ec602 | 256 | * timekeeping_forward_now - update clock to the current time |
8524070b | 257 | * |
9a055117 RZ |
258 | * Forward the current clock to update its state since the last call to |
259 | * update_wall_time(). This is useful before significant clock changes, | |
260 | * as it avoids having to deal with this time offset explicitly. | |
8524070b | 261 | */ |
f726a697 | 262 | static void timekeeping_forward_now(struct timekeeper *tk) |
8524070b | 263 | { |
264 | cycle_t cycle_now, cycle_delta; | |
155ec602 | 265 | struct clocksource *clock; |
9a055117 | 266 | s64 nsec; |
8524070b | 267 | |
f726a697 | 268 | clock = tk->clock; |
a0f7d48b | 269 | cycle_now = clock->read(clock); |
8524070b | 270 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; |
9a055117 | 271 | clock->cycle_last = cycle_now; |
8524070b | 272 | |
f726a697 | 273 | tk->xtime_nsec += cycle_delta * tk->mult; |
7d27558c | 274 | |
7b1f6207 SW |
275 | /* If arch requires, add in get_arch_timeoffset() */ |
276 | tk->xtime_nsec += (u64)get_arch_timeoffset() << tk->shift; | |
7d27558c | 277 | |
f726a697 | 278 | tk_normalize_xtime(tk); |
2d42244a | 279 | |
0a544198 | 280 | nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); |
f726a697 | 281 | timespec_add_ns(&tk->raw_time, nsec); |
8524070b | 282 | } |
283 | ||
284 | /** | |
1e817fb6 | 285 | * __getnstimeofday - Returns the time of day in a timespec. |
8524070b | 286 | * @ts: pointer to the timespec to be set |
287 | * | |
1e817fb6 KC |
288 | * Updates the time of day in the timespec. |
289 | * Returns 0 on success, or -ve when suspended (timespec will be undefined). | |
8524070b | 290 | */ |
1e817fb6 | 291 | int __getnstimeofday(struct timespec *ts) |
8524070b | 292 | { |
4e250fdd | 293 | struct timekeeper *tk = &timekeeper; |
8524070b | 294 | unsigned long seq; |
1e75fa8b | 295 | s64 nsecs = 0; |
8524070b | 296 | |
297 | do { | |
4e250fdd | 298 | seq = read_seqbegin(&tk->lock); |
8524070b | 299 | |
4e250fdd | 300 | ts->tv_sec = tk->xtime_sec; |
ec145bab | 301 | nsecs = timekeeping_get_ns(tk); |
8524070b | 302 | |
4e250fdd | 303 | } while (read_seqretry(&tk->lock, seq)); |
8524070b | 304 | |
ec145bab | 305 | ts->tv_nsec = 0; |
8524070b | 306 | timespec_add_ns(ts, nsecs); |
1e817fb6 KC |
307 | |
308 | /* | |
309 | * Do not bail out early, in case there were callers still using | |
310 | * the value, even in the face of the WARN_ON. | |
311 | */ | |
312 | if (unlikely(timekeeping_suspended)) | |
313 | return -EAGAIN; | |
314 | return 0; | |
315 | } | |
316 | EXPORT_SYMBOL(__getnstimeofday); | |
317 | ||
318 | /** | |
319 | * getnstimeofday - Returns the time of day in a timespec. | |
320 | * @ts: pointer to the timespec to be set | |
321 | * | |
322 | * Returns the time of day in a timespec (WARN if suspended). | |
323 | */ | |
324 | void getnstimeofday(struct timespec *ts) | |
325 | { | |
326 | WARN_ON(__getnstimeofday(ts)); | |
8524070b | 327 | } |
8524070b | 328 | EXPORT_SYMBOL(getnstimeofday); |
329 | ||
951ed4d3 MS |
330 | ktime_t ktime_get(void) |
331 | { | |
4e250fdd | 332 | struct timekeeper *tk = &timekeeper; |
951ed4d3 MS |
333 | unsigned int seq; |
334 | s64 secs, nsecs; | |
335 | ||
336 | WARN_ON(timekeeping_suspended); | |
337 | ||
338 | do { | |
4e250fdd JS |
339 | seq = read_seqbegin(&tk->lock); |
340 | secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; | |
341 | nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec; | |
951ed4d3 | 342 | |
4e250fdd | 343 | } while (read_seqretry(&tk->lock, seq)); |
951ed4d3 MS |
344 | /* |
345 | * Use ktime_set/ktime_add_ns to create a proper ktime on | |
346 | * 32-bit architectures without CONFIG_KTIME_SCALAR. | |
347 | */ | |
348 | return ktime_add_ns(ktime_set(secs, 0), nsecs); | |
349 | } | |
350 | EXPORT_SYMBOL_GPL(ktime_get); | |
351 | ||
352 | /** | |
353 | * ktime_get_ts - get the monotonic clock in timespec format | |
354 | * @ts: pointer to timespec variable | |
355 | * | |
356 | * The function calculates the monotonic clock from the realtime | |
357 | * clock and the wall_to_monotonic offset and stores the result | |
358 | * in normalized timespec format in the variable pointed to by @ts. | |
359 | */ | |
360 | void ktime_get_ts(struct timespec *ts) | |
361 | { | |
4e250fdd | 362 | struct timekeeper *tk = &timekeeper; |
951ed4d3 | 363 | struct timespec tomono; |
ec145bab | 364 | s64 nsec; |
951ed4d3 | 365 | unsigned int seq; |
951ed4d3 MS |
366 | |
367 | WARN_ON(timekeeping_suspended); | |
368 | ||
369 | do { | |
4e250fdd JS |
370 | seq = read_seqbegin(&tk->lock); |
371 | ts->tv_sec = tk->xtime_sec; | |
ec145bab | 372 | nsec = timekeeping_get_ns(tk); |
4e250fdd | 373 | tomono = tk->wall_to_monotonic; |
951ed4d3 | 374 | |
4e250fdd | 375 | } while (read_seqretry(&tk->lock, seq)); |
951ed4d3 | 376 | |
ec145bab JS |
377 | ts->tv_sec += tomono.tv_sec; |
378 | ts->tv_nsec = 0; | |
379 | timespec_add_ns(ts, nsec + tomono.tv_nsec); | |
951ed4d3 MS |
380 | } |
381 | EXPORT_SYMBOL_GPL(ktime_get_ts); | |
382 | ||
1ff3c967 JS |
383 | |
384 | /** | |
385 | * timekeeping_clocktai - Returns the TAI time of day in a timespec | |
386 | * @ts: pointer to the timespec to be set | |
387 | * | |
388 | * Returns the time of day in a timespec. | |
389 | */ | |
390 | void timekeeping_clocktai(struct timespec *ts) | |
391 | { | |
392 | struct timekeeper *tk = &timekeeper; | |
393 | unsigned long seq; | |
394 | u64 nsecs; | |
395 | ||
396 | WARN_ON(timekeeping_suspended); | |
397 | ||
398 | do { | |
399 | seq = read_seqbegin(&tk->lock); | |
400 | ||
401 | ts->tv_sec = tk->xtime_sec + tk->tai_offset; | |
402 | nsecs = timekeeping_get_ns(tk); | |
403 | ||
404 | } while (read_seqretry(&tk->lock, seq)); | |
405 | ||
406 | ts->tv_nsec = 0; | |
407 | timespec_add_ns(ts, nsecs); | |
408 | ||
409 | } | |
410 | EXPORT_SYMBOL(timekeeping_clocktai); | |
411 | ||
412 | ||
90adda98 JS |
413 | /** |
414 | * ktime_get_clocktai - Returns the TAI time of day in a ktime | |
415 | * | |
416 | * Returns the time of day in a ktime. | |
417 | */ | |
418 | ktime_t ktime_get_clocktai(void) | |
419 | { | |
420 | struct timespec ts; | |
421 | ||
422 | timekeeping_clocktai(&ts); | |
423 | return timespec_to_ktime(ts); | |
424 | } | |
425 | EXPORT_SYMBOL(ktime_get_clocktai); | |
426 | ||
e2c18e49 AG |
427 | #ifdef CONFIG_NTP_PPS |
428 | ||
429 | /** | |
430 | * getnstime_raw_and_real - get day and raw monotonic time in timespec format | |
431 | * @ts_raw: pointer to the timespec to be set to raw monotonic time | |
432 | * @ts_real: pointer to the timespec to be set to the time of day | |
433 | * | |
434 | * This function reads both the time of day and raw monotonic time at the | |
435 | * same time atomically and stores the resulting timestamps in timespec | |
436 | * format. | |
437 | */ | |
438 | void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real) | |
439 | { | |
4e250fdd | 440 | struct timekeeper *tk = &timekeeper; |
e2c18e49 AG |
441 | unsigned long seq; |
442 | s64 nsecs_raw, nsecs_real; | |
443 | ||
444 | WARN_ON_ONCE(timekeeping_suspended); | |
445 | ||
446 | do { | |
4e250fdd | 447 | seq = read_seqbegin(&tk->lock); |
e2c18e49 | 448 | |
4e250fdd JS |
449 | *ts_raw = tk->raw_time; |
450 | ts_real->tv_sec = tk->xtime_sec; | |
1e75fa8b | 451 | ts_real->tv_nsec = 0; |
e2c18e49 | 452 | |
4e250fdd JS |
453 | nsecs_raw = timekeeping_get_ns_raw(tk); |
454 | nsecs_real = timekeeping_get_ns(tk); | |
e2c18e49 | 455 | |
4e250fdd | 456 | } while (read_seqretry(&tk->lock, seq)); |
e2c18e49 AG |
457 | |
458 | timespec_add_ns(ts_raw, nsecs_raw); | |
459 | timespec_add_ns(ts_real, nsecs_real); | |
460 | } | |
461 | EXPORT_SYMBOL(getnstime_raw_and_real); | |
462 | ||
463 | #endif /* CONFIG_NTP_PPS */ | |
464 | ||
8524070b | 465 | /** |
466 | * do_gettimeofday - Returns the time of day in a timeval | |
467 | * @tv: pointer to the timeval to be set | |
468 | * | |
efd9ac86 | 469 | * NOTE: Users should be converted to using getnstimeofday() |
8524070b | 470 | */ |
471 | void do_gettimeofday(struct timeval *tv) | |
472 | { | |
473 | struct timespec now; | |
474 | ||
efd9ac86 | 475 | getnstimeofday(&now); |
8524070b | 476 | tv->tv_sec = now.tv_sec; |
477 | tv->tv_usec = now.tv_nsec/1000; | |
478 | } | |
8524070b | 479 | EXPORT_SYMBOL(do_gettimeofday); |
d239f49d | 480 | |
8524070b | 481 | /** |
482 | * do_settimeofday - Sets the time of day | |
483 | * @tv: pointer to the timespec variable containing the new time | |
484 | * | |
485 | * Sets the time of day to the new time and update NTP and notify hrtimers | |
486 | */ | |
1e6d7679 | 487 | int do_settimeofday(const struct timespec *tv) |
8524070b | 488 | { |
4e250fdd | 489 | struct timekeeper *tk = &timekeeper; |
1e75fa8b | 490 | struct timespec ts_delta, xt; |
92c1d3ed | 491 | unsigned long flags; |
8524070b | 492 | |
cee58483 | 493 | if (!timespec_valid_strict(tv)) |
8524070b | 494 | return -EINVAL; |
495 | ||
4e250fdd | 496 | write_seqlock_irqsave(&tk->lock, flags); |
8524070b | 497 | |
4e250fdd | 498 | timekeeping_forward_now(tk); |
9a055117 | 499 | |
4e250fdd | 500 | xt = tk_xtime(tk); |
1e75fa8b JS |
501 | ts_delta.tv_sec = tv->tv_sec - xt.tv_sec; |
502 | ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec; | |
503 | ||
4e250fdd | 504 | tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts_delta)); |
8524070b | 505 | |
4e250fdd | 506 | tk_set_xtime(tk, tv); |
1e75fa8b | 507 | |
4e250fdd | 508 | timekeeping_update(tk, true); |
8524070b | 509 | |
4e250fdd | 510 | write_sequnlock_irqrestore(&tk->lock, flags); |
8524070b | 511 | |
512 | /* signal hrtimers about time change */ | |
513 | clock_was_set(); | |
514 | ||
515 | return 0; | |
516 | } | |
8524070b | 517 | EXPORT_SYMBOL(do_settimeofday); |
518 | ||
c528f7c6 JS |
519 | /** |
520 | * timekeeping_inject_offset - Adds or subtracts from the current time. | |
521 | * @tv: pointer to the timespec variable containing the offset | |
522 | * | |
523 | * Adds or subtracts an offset value from the current time. | |
524 | */ | |
525 | int timekeeping_inject_offset(struct timespec *ts) | |
526 | { | |
4e250fdd | 527 | struct timekeeper *tk = &timekeeper; |
92c1d3ed | 528 | unsigned long flags; |
4e8b1452 JS |
529 | struct timespec tmp; |
530 | int ret = 0; | |
c528f7c6 JS |
531 | |
532 | if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) | |
533 | return -EINVAL; | |
534 | ||
4e250fdd | 535 | write_seqlock_irqsave(&tk->lock, flags); |
c528f7c6 | 536 | |
4e250fdd | 537 | timekeeping_forward_now(tk); |
c528f7c6 | 538 | |
4e8b1452 JS |
539 | /* Make sure the proposed value is valid */ |
540 | tmp = timespec_add(tk_xtime(tk), *ts); | |
cee58483 | 541 | if (!timespec_valid_strict(&tmp)) { |
4e8b1452 JS |
542 | ret = -EINVAL; |
543 | goto error; | |
544 | } | |
1e75fa8b | 545 | |
4e250fdd JS |
546 | tk_xtime_add(tk, ts); |
547 | tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts)); | |
c528f7c6 | 548 | |
4e8b1452 | 549 | error: /* even if we error out, we forwarded the time, so call update */ |
4e250fdd | 550 | timekeeping_update(tk, true); |
c528f7c6 | 551 | |
4e250fdd | 552 | write_sequnlock_irqrestore(&tk->lock, flags); |
c528f7c6 JS |
553 | |
554 | /* signal hrtimers about time change */ | |
555 | clock_was_set(); | |
556 | ||
4e8b1452 | 557 | return ret; |
c528f7c6 JS |
558 | } |
559 | EXPORT_SYMBOL(timekeeping_inject_offset); | |
560 | ||
cc244dda JS |
561 | |
562 | /** | |
563 | * timekeeping_get_tai_offset - Returns current TAI offset from UTC | |
564 | * | |
565 | */ | |
566 | s32 timekeeping_get_tai_offset(void) | |
567 | { | |
568 | struct timekeeper *tk = &timekeeper; | |
569 | unsigned int seq; | |
570 | s32 ret; | |
571 | ||
572 | do { | |
573 | seq = read_seqbegin(&tk->lock); | |
574 | ret = tk->tai_offset; | |
575 | } while (read_seqretry(&tk->lock, seq)); | |
576 | ||
577 | return ret; | |
578 | } | |
579 | ||
580 | /** | |
581 | * __timekeeping_set_tai_offset - Lock free worker function | |
582 | * | |
583 | */ | |
584 | void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset) | |
585 | { | |
586 | tk->tai_offset = tai_offset; | |
90adda98 | 587 | tk->offs_tai = ktime_sub(tk->offs_real, ktime_set(tai_offset, 0)); |
cc244dda JS |
588 | } |
589 | ||
590 | /** | |
591 | * timekeeping_set_tai_offset - Sets the current TAI offset from UTC | |
592 | * | |
593 | */ | |
594 | void timekeeping_set_tai_offset(s32 tai_offset) | |
595 | { | |
596 | struct timekeeper *tk = &timekeeper; | |
597 | unsigned long flags; | |
598 | ||
599 | write_seqlock_irqsave(&tk->lock, flags); | |
600 | __timekeeping_set_tai_offset(tk, tai_offset); | |
601 | write_sequnlock_irqrestore(&tk->lock, flags); | |
602 | } | |
603 | ||
8524070b | 604 | /** |
605 | * change_clocksource - Swaps clocksources if a new one is available | |
606 | * | |
607 | * Accumulates current time interval and initializes new clocksource | |
608 | */ | |
75c5158f | 609 | static int change_clocksource(void *data) |
8524070b | 610 | { |
4e250fdd | 611 | struct timekeeper *tk = &timekeeper; |
4614e6ad | 612 | struct clocksource *new, *old; |
f695cf94 | 613 | unsigned long flags; |
8524070b | 614 | |
75c5158f | 615 | new = (struct clocksource *) data; |
8524070b | 616 | |
4e250fdd | 617 | write_seqlock_irqsave(&tk->lock, flags); |
f695cf94 | 618 | |
4e250fdd | 619 | timekeeping_forward_now(tk); |
75c5158f | 620 | if (!new->enable || new->enable(new) == 0) { |
4e250fdd JS |
621 | old = tk->clock; |
622 | tk_setup_internals(tk, new); | |
75c5158f MS |
623 | if (old->disable) |
624 | old->disable(old); | |
625 | } | |
4e250fdd | 626 | timekeeping_update(tk, true); |
f695cf94 | 627 | |
4e250fdd | 628 | write_sequnlock_irqrestore(&tk->lock, flags); |
f695cf94 | 629 | |
75c5158f MS |
630 | return 0; |
631 | } | |
8524070b | 632 | |
75c5158f MS |
633 | /** |
634 | * timekeeping_notify - Install a new clock source | |
635 | * @clock: pointer to the clock source | |
636 | * | |
637 | * This function is called from clocksource.c after a new, better clock | |
638 | * source has been registered. The caller holds the clocksource_mutex. | |
639 | */ | |
640 | void timekeeping_notify(struct clocksource *clock) | |
641 | { | |
4e250fdd JS |
642 | struct timekeeper *tk = &timekeeper; |
643 | ||
644 | if (tk->clock == clock) | |
4614e6ad | 645 | return; |
75c5158f | 646 | stop_machine(change_clocksource, clock, NULL); |
8524070b | 647 | tick_clock_notify(); |
8524070b | 648 | } |
75c5158f | 649 | |
a40f262c TG |
650 | /** |
651 | * ktime_get_real - get the real (wall-) time in ktime_t format | |
652 | * | |
653 | * returns the time in ktime_t format | |
654 | */ | |
655 | ktime_t ktime_get_real(void) | |
656 | { | |
657 | struct timespec now; | |
658 | ||
659 | getnstimeofday(&now); | |
660 | ||
661 | return timespec_to_ktime(now); | |
662 | } | |
663 | EXPORT_SYMBOL_GPL(ktime_get_real); | |
8524070b | 664 | |
2d42244a JS |
665 | /** |
666 | * getrawmonotonic - Returns the raw monotonic time in a timespec | |
667 | * @ts: pointer to the timespec to be set | |
668 | * | |
669 | * Returns the raw monotonic time (completely un-modified by ntp) | |
670 | */ | |
671 | void getrawmonotonic(struct timespec *ts) | |
672 | { | |
4e250fdd | 673 | struct timekeeper *tk = &timekeeper; |
2d42244a JS |
674 | unsigned long seq; |
675 | s64 nsecs; | |
2d42244a JS |
676 | |
677 | do { | |
4e250fdd JS |
678 | seq = read_seqbegin(&tk->lock); |
679 | nsecs = timekeeping_get_ns_raw(tk); | |
680 | *ts = tk->raw_time; | |
2d42244a | 681 | |
4e250fdd | 682 | } while (read_seqretry(&tk->lock, seq)); |
2d42244a JS |
683 | |
684 | timespec_add_ns(ts, nsecs); | |
685 | } | |
686 | EXPORT_SYMBOL(getrawmonotonic); | |
687 | ||
8524070b | 688 | /** |
cf4fc6cb | 689 | * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres |
8524070b | 690 | */ |
cf4fc6cb | 691 | int timekeeping_valid_for_hres(void) |
8524070b | 692 | { |
4e250fdd | 693 | struct timekeeper *tk = &timekeeper; |
8524070b | 694 | unsigned long seq; |
695 | int ret; | |
696 | ||
697 | do { | |
4e250fdd | 698 | seq = read_seqbegin(&tk->lock); |
8524070b | 699 | |
4e250fdd | 700 | ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; |
8524070b | 701 | |
4e250fdd | 702 | } while (read_seqretry(&tk->lock, seq)); |
8524070b | 703 | |
704 | return ret; | |
705 | } | |
706 | ||
98962465 JH |
707 | /** |
708 | * timekeeping_max_deferment - Returns max time the clocksource can be deferred | |
98962465 JH |
709 | */ |
710 | u64 timekeeping_max_deferment(void) | |
711 | { | |
4e250fdd | 712 | struct timekeeper *tk = &timekeeper; |
70471f2f JS |
713 | unsigned long seq; |
714 | u64 ret; | |
42e71e81 | 715 | |
70471f2f | 716 | do { |
4e250fdd | 717 | seq = read_seqbegin(&tk->lock); |
70471f2f | 718 | |
4e250fdd | 719 | ret = tk->clock->max_idle_ns; |
70471f2f | 720 | |
4e250fdd | 721 | } while (read_seqretry(&tk->lock, seq)); |
70471f2f JS |
722 | |
723 | return ret; | |
98962465 JH |
724 | } |
725 | ||
8524070b | 726 | /** |
d4f587c6 | 727 | * read_persistent_clock - Return time from the persistent clock. |
8524070b | 728 | * |
729 | * Weak dummy function for arches that do not yet support it. | |
d4f587c6 MS |
730 | * Reads the time from the battery backed persistent clock. |
731 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. | |
8524070b | 732 | * |
733 | * XXX - Do be sure to remove it once all arches implement it. | |
734 | */ | |
d4f587c6 | 735 | void __attribute__((weak)) read_persistent_clock(struct timespec *ts) |
8524070b | 736 | { |
d4f587c6 MS |
737 | ts->tv_sec = 0; |
738 | ts->tv_nsec = 0; | |
8524070b | 739 | } |
740 | ||
23970e38 MS |
741 | /** |
742 | * read_boot_clock - Return time of the system start. | |
743 | * | |
744 | * Weak dummy function for arches that do not yet support it. | |
745 | * Function to read the exact time the system has been started. | |
746 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. | |
747 | * | |
748 | * XXX - Do be sure to remove it once all arches implement it. | |
749 | */ | |
750 | void __attribute__((weak)) read_boot_clock(struct timespec *ts) | |
751 | { | |
752 | ts->tv_sec = 0; | |
753 | ts->tv_nsec = 0; | |
754 | } | |
755 | ||
8524070b | 756 | /* |
757 | * timekeeping_init - Initializes the clocksource and common timekeeping values | |
758 | */ | |
759 | void __init timekeeping_init(void) | |
760 | { | |
4e250fdd | 761 | struct timekeeper *tk = &timekeeper; |
155ec602 | 762 | struct clocksource *clock; |
8524070b | 763 | unsigned long flags; |
6d0ef903 | 764 | struct timespec now, boot, tmp; |
d4f587c6 MS |
765 | |
766 | read_persistent_clock(&now); | |
31ade306 | 767 | |
cee58483 | 768 | if (!timespec_valid_strict(&now)) { |
4e8b1452 JS |
769 | pr_warn("WARNING: Persistent clock returned invalid value!\n" |
770 | " Check your CMOS/BIOS settings.\n"); | |
771 | now.tv_sec = 0; | |
772 | now.tv_nsec = 0; | |
31ade306 FT |
773 | } else if (now.tv_sec || now.tv_nsec) |
774 | persistent_clock_exist = true; | |
4e8b1452 | 775 | |
23970e38 | 776 | read_boot_clock(&boot); |
cee58483 | 777 | if (!timespec_valid_strict(&boot)) { |
4e8b1452 JS |
778 | pr_warn("WARNING: Boot clock returned invalid value!\n" |
779 | " Check your CMOS/BIOS settings.\n"); | |
780 | boot.tv_sec = 0; | |
781 | boot.tv_nsec = 0; | |
782 | } | |
8524070b | 783 | |
4e250fdd | 784 | seqlock_init(&tk->lock); |
8524070b | 785 | |
7dffa3c6 | 786 | ntp_init(); |
8524070b | 787 | |
4e250fdd | 788 | write_seqlock_irqsave(&tk->lock, flags); |
f1b82746 | 789 | clock = clocksource_default_clock(); |
a0f7d48b MS |
790 | if (clock->enable) |
791 | clock->enable(clock); | |
4e250fdd | 792 | tk_setup_internals(tk, clock); |
8524070b | 793 | |
4e250fdd JS |
794 | tk_set_xtime(tk, &now); |
795 | tk->raw_time.tv_sec = 0; | |
796 | tk->raw_time.tv_nsec = 0; | |
1e75fa8b | 797 | if (boot.tv_sec == 0 && boot.tv_nsec == 0) |
4e250fdd | 798 | boot = tk_xtime(tk); |
1e75fa8b | 799 | |
6d0ef903 | 800 | set_normalized_timespec(&tmp, -boot.tv_sec, -boot.tv_nsec); |
4e250fdd | 801 | tk_set_wall_to_mono(tk, tmp); |
6d0ef903 JS |
802 | |
803 | tmp.tv_sec = 0; | |
804 | tmp.tv_nsec = 0; | |
4e250fdd | 805 | tk_set_sleep_time(tk, tmp); |
6d0ef903 | 806 | |
4e250fdd | 807 | write_sequnlock_irqrestore(&tk->lock, flags); |
8524070b | 808 | } |
809 | ||
8524070b | 810 | /* time in seconds when suspend began */ |
d4f587c6 | 811 | static struct timespec timekeeping_suspend_time; |
8524070b | 812 | |
304529b1 JS |
813 | /** |
814 | * __timekeeping_inject_sleeptime - Internal function to add sleep interval | |
815 | * @delta: pointer to a timespec delta value | |
816 | * | |
817 | * Takes a timespec offset measuring a suspend interval and properly | |
818 | * adds the sleep offset to the timekeeping variables. | |
819 | */ | |
f726a697 JS |
820 | static void __timekeeping_inject_sleeptime(struct timekeeper *tk, |
821 | struct timespec *delta) | |
304529b1 | 822 | { |
cee58483 | 823 | if (!timespec_valid_strict(delta)) { |
cbaa5152 | 824 | printk(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid " |
cb5de2f8 JS |
825 | "sleep delta value!\n"); |
826 | return; | |
827 | } | |
f726a697 | 828 | tk_xtime_add(tk, delta); |
6d0ef903 JS |
829 | tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *delta)); |
830 | tk_set_sleep_time(tk, timespec_add(tk->total_sleep_time, *delta)); | |
304529b1 JS |
831 | } |
832 | ||
304529b1 JS |
833 | /** |
834 | * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values | |
835 | * @delta: pointer to a timespec delta value | |
836 | * | |
837 | * This hook is for architectures that cannot support read_persistent_clock | |
838 | * because their RTC/persistent clock is only accessible when irqs are enabled. | |
839 | * | |
840 | * This function should only be called by rtc_resume(), and allows | |
841 | * a suspend offset to be injected into the timekeeping values. | |
842 | */ | |
843 | void timekeeping_inject_sleeptime(struct timespec *delta) | |
844 | { | |
4e250fdd | 845 | struct timekeeper *tk = &timekeeper; |
92c1d3ed | 846 | unsigned long flags; |
304529b1 | 847 | |
31ade306 FT |
848 | /* |
849 | * Make sure we don't set the clock twice, as timekeeping_resume() | |
850 | * already did it | |
851 | */ | |
852 | if (has_persistent_clock()) | |
304529b1 JS |
853 | return; |
854 | ||
4e250fdd | 855 | write_seqlock_irqsave(&tk->lock, flags); |
70471f2f | 856 | |
4e250fdd | 857 | timekeeping_forward_now(tk); |
304529b1 | 858 | |
4e250fdd | 859 | __timekeeping_inject_sleeptime(tk, delta); |
304529b1 | 860 | |
4e250fdd | 861 | timekeeping_update(tk, true); |
304529b1 | 862 | |
4e250fdd | 863 | write_sequnlock_irqrestore(&tk->lock, flags); |
304529b1 JS |
864 | |
865 | /* signal hrtimers about time change */ | |
866 | clock_was_set(); | |
867 | } | |
868 | ||
8524070b | 869 | /** |
870 | * timekeeping_resume - Resumes the generic timekeeping subsystem. | |
8524070b | 871 | * |
872 | * This is for the generic clocksource timekeeping. | |
873 | * xtime/wall_to_monotonic/jiffies/etc are | |
874 | * still managed by arch specific suspend/resume code. | |
875 | */ | |
e1a85b2c | 876 | static void timekeeping_resume(void) |
8524070b | 877 | { |
4e250fdd | 878 | struct timekeeper *tk = &timekeeper; |
e445cf1c | 879 | struct clocksource *clock = tk->clock; |
92c1d3ed | 880 | unsigned long flags; |
e445cf1c FT |
881 | struct timespec ts_new, ts_delta; |
882 | cycle_t cycle_now, cycle_delta; | |
883 | bool suspendtime_found = false; | |
d4f587c6 | 884 | |
e445cf1c | 885 | read_persistent_clock(&ts_new); |
8524070b | 886 | |
adc78e6b | 887 | clockevents_resume(); |
d10ff3fb TG |
888 | clocksource_resume(); |
889 | ||
4e250fdd | 890 | write_seqlock_irqsave(&tk->lock, flags); |
8524070b | 891 | |
e445cf1c FT |
892 | /* |
893 | * After system resumes, we need to calculate the suspended time and | |
894 | * compensate it for the OS time. There are 3 sources that could be | |
895 | * used: Nonstop clocksource during suspend, persistent clock and rtc | |
896 | * device. | |
897 | * | |
898 | * One specific platform may have 1 or 2 or all of them, and the | |
899 | * preference will be: | |
900 | * suspend-nonstop clocksource -> persistent clock -> rtc | |
901 | * The less preferred source will only be tried if there is no better | |
902 | * usable source. The rtc part is handled separately in rtc core code. | |
903 | */ | |
904 | cycle_now = clock->read(clock); | |
905 | if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) && | |
906 | cycle_now > clock->cycle_last) { | |
907 | u64 num, max = ULLONG_MAX; | |
908 | u32 mult = clock->mult; | |
909 | u32 shift = clock->shift; | |
910 | s64 nsec = 0; | |
911 | ||
912 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; | |
913 | ||
914 | /* | |
915 | * "cycle_delta * mutl" may cause 64 bits overflow, if the | |
916 | * suspended time is too long. In that case we need do the | |
917 | * 64 bits math carefully | |
918 | */ | |
919 | do_div(max, mult); | |
920 | if (cycle_delta > max) { | |
921 | num = div64_u64(cycle_delta, max); | |
922 | nsec = (((u64) max * mult) >> shift) * num; | |
923 | cycle_delta -= num * max; | |
924 | } | |
925 | nsec += ((u64) cycle_delta * mult) >> shift; | |
926 | ||
927 | ts_delta = ns_to_timespec(nsec); | |
928 | suspendtime_found = true; | |
929 | } else if (timespec_compare(&ts_new, &timekeeping_suspend_time) > 0) { | |
930 | ts_delta = timespec_sub(ts_new, timekeeping_suspend_time); | |
931 | suspendtime_found = true; | |
8524070b | 932 | } |
e445cf1c FT |
933 | |
934 | if (suspendtime_found) | |
935 | __timekeeping_inject_sleeptime(tk, &ts_delta); | |
936 | ||
937 | /* Re-base the last cycle value */ | |
938 | clock->cycle_last = cycle_now; | |
4e250fdd | 939 | tk->ntp_error = 0; |
8524070b | 940 | timekeeping_suspended = 0; |
4e250fdd JS |
941 | timekeeping_update(tk, false); |
942 | write_sequnlock_irqrestore(&tk->lock, flags); | |
8524070b | 943 | |
944 | touch_softlockup_watchdog(); | |
945 | ||
946 | clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL); | |
947 | ||
948 | /* Resume hrtimers */ | |
b12a03ce | 949 | hrtimers_resume(); |
8524070b | 950 | } |
951 | ||
e1a85b2c | 952 | static int timekeeping_suspend(void) |
8524070b | 953 | { |
4e250fdd | 954 | struct timekeeper *tk = &timekeeper; |
92c1d3ed | 955 | unsigned long flags; |
cb33217b JS |
956 | struct timespec delta, delta_delta; |
957 | static struct timespec old_delta; | |
8524070b | 958 | |
d4f587c6 | 959 | read_persistent_clock(&timekeeping_suspend_time); |
3be90950 | 960 | |
4e250fdd JS |
961 | write_seqlock_irqsave(&tk->lock, flags); |
962 | timekeeping_forward_now(tk); | |
8524070b | 963 | timekeeping_suspended = 1; |
cb33217b JS |
964 | |
965 | /* | |
966 | * To avoid drift caused by repeated suspend/resumes, | |
967 | * which each can add ~1 second drift error, | |
968 | * try to compensate so the difference in system time | |
969 | * and persistent_clock time stays close to constant. | |
970 | */ | |
4e250fdd | 971 | delta = timespec_sub(tk_xtime(tk), timekeeping_suspend_time); |
cb33217b JS |
972 | delta_delta = timespec_sub(delta, old_delta); |
973 | if (abs(delta_delta.tv_sec) >= 2) { | |
974 | /* | |
975 | * if delta_delta is too large, assume time correction | |
976 | * has occured and set old_delta to the current delta. | |
977 | */ | |
978 | old_delta = delta; | |
979 | } else { | |
980 | /* Otherwise try to adjust old_system to compensate */ | |
981 | timekeeping_suspend_time = | |
982 | timespec_add(timekeeping_suspend_time, delta_delta); | |
983 | } | |
4e250fdd | 984 | write_sequnlock_irqrestore(&tk->lock, flags); |
8524070b | 985 | |
986 | clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); | |
c54a42b1 | 987 | clocksource_suspend(); |
adc78e6b | 988 | clockevents_suspend(); |
8524070b | 989 | |
990 | return 0; | |
991 | } | |
992 | ||
993 | /* sysfs resume/suspend bits for timekeeping */ | |
e1a85b2c | 994 | static struct syscore_ops timekeeping_syscore_ops = { |
8524070b | 995 | .resume = timekeeping_resume, |
996 | .suspend = timekeeping_suspend, | |
8524070b | 997 | }; |
998 | ||
e1a85b2c | 999 | static int __init timekeeping_init_ops(void) |
8524070b | 1000 | { |
e1a85b2c RW |
1001 | register_syscore_ops(&timekeeping_syscore_ops); |
1002 | return 0; | |
8524070b | 1003 | } |
1004 | ||
e1a85b2c | 1005 | device_initcall(timekeeping_init_ops); |
8524070b | 1006 | |
1007 | /* | |
1008 | * If the error is already larger, we look ahead even further | |
1009 | * to compensate for late or lost adjustments. | |
1010 | */ | |
f726a697 JS |
1011 | static __always_inline int timekeeping_bigadjust(struct timekeeper *tk, |
1012 | s64 error, s64 *interval, | |
8524070b | 1013 | s64 *offset) |
1014 | { | |
1015 | s64 tick_error, i; | |
1016 | u32 look_ahead, adj; | |
1017 | s32 error2, mult; | |
1018 | ||
1019 | /* | |
1020 | * Use the current error value to determine how much to look ahead. | |
1021 | * The larger the error the slower we adjust for it to avoid problems | |
1022 | * with losing too many ticks, otherwise we would overadjust and | |
1023 | * produce an even larger error. The smaller the adjustment the | |
1024 | * faster we try to adjust for it, as lost ticks can do less harm | |
3eb05676 | 1025 | * here. This is tuned so that an error of about 1 msec is adjusted |
8524070b | 1026 | * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks). |
1027 | */ | |
f726a697 | 1028 | error2 = tk->ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ); |
8524070b | 1029 | error2 = abs(error2); |
1030 | for (look_ahead = 0; error2 > 0; look_ahead++) | |
1031 | error2 >>= 2; | |
1032 | ||
1033 | /* | |
1034 | * Now calculate the error in (1 << look_ahead) ticks, but first | |
1035 | * remove the single look ahead already included in the error. | |
1036 | */ | |
f726a697 JS |
1037 | tick_error = ntp_tick_length() >> (tk->ntp_error_shift + 1); |
1038 | tick_error -= tk->xtime_interval >> 1; | |
8524070b | 1039 | error = ((error - tick_error) >> look_ahead) + tick_error; |
1040 | ||
1041 | /* Finally calculate the adjustment shift value. */ | |
1042 | i = *interval; | |
1043 | mult = 1; | |
1044 | if (error < 0) { | |
1045 | error = -error; | |
1046 | *interval = -*interval; | |
1047 | *offset = -*offset; | |
1048 | mult = -1; | |
1049 | } | |
1050 | for (adj = 0; error > i; adj++) | |
1051 | error >>= 1; | |
1052 | ||
1053 | *interval <<= adj; | |
1054 | *offset <<= adj; | |
1055 | return mult << adj; | |
1056 | } | |
1057 | ||
1058 | /* | |
1059 | * Adjust the multiplier to reduce the error value, | |
1060 | * this is optimized for the most common adjustments of -1,0,1, | |
1061 | * for other values we can do a bit more work. | |
1062 | */ | |
f726a697 | 1063 | static void timekeeping_adjust(struct timekeeper *tk, s64 offset) |
8524070b | 1064 | { |
f726a697 | 1065 | s64 error, interval = tk->cycle_interval; |
8524070b | 1066 | int adj; |
1067 | ||
c2bc1111 | 1068 | /* |
88b28adf | 1069 | * The point of this is to check if the error is greater than half |
c2bc1111 JS |
1070 | * an interval. |
1071 | * | |
1072 | * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs. | |
1073 | * | |
1074 | * Note we subtract one in the shift, so that error is really error*2. | |
3f86f28f JS |
1075 | * This "saves" dividing(shifting) interval twice, but keeps the |
1076 | * (error > interval) comparison as still measuring if error is | |
88b28adf | 1077 | * larger than half an interval. |
c2bc1111 | 1078 | * |
3f86f28f | 1079 | * Note: It does not "save" on aggravation when reading the code. |
c2bc1111 | 1080 | */ |
f726a697 | 1081 | error = tk->ntp_error >> (tk->ntp_error_shift - 1); |
8524070b | 1082 | if (error > interval) { |
c2bc1111 JS |
1083 | /* |
1084 | * We now divide error by 4(via shift), which checks if | |
88b28adf | 1085 | * the error is greater than twice the interval. |
c2bc1111 JS |
1086 | * If it is greater, we need a bigadjust, if its smaller, |
1087 | * we can adjust by 1. | |
1088 | */ | |
8524070b | 1089 | error >>= 2; |
c2bc1111 JS |
1090 | /* |
1091 | * XXX - In update_wall_time, we round up to the next | |
1092 | * nanosecond, and store the amount rounded up into | |
1093 | * the error. This causes the likely below to be unlikely. | |
1094 | * | |
3f86f28f | 1095 | * The proper fix is to avoid rounding up by using |
4e250fdd | 1096 | * the high precision tk->xtime_nsec instead of |
c2bc1111 JS |
1097 | * xtime.tv_nsec everywhere. Fixing this will take some |
1098 | * time. | |
1099 | */ | |
8524070b | 1100 | if (likely(error <= interval)) |
1101 | adj = 1; | |
1102 | else | |
1d17d174 IM |
1103 | adj = timekeeping_bigadjust(tk, error, &interval, &offset); |
1104 | } else { | |
1105 | if (error < -interval) { | |
1106 | /* See comment above, this is just switched for the negative */ | |
1107 | error >>= 2; | |
1108 | if (likely(error >= -interval)) { | |
1109 | adj = -1; | |
1110 | interval = -interval; | |
1111 | offset = -offset; | |
1112 | } else { | |
1113 | adj = timekeeping_bigadjust(tk, error, &interval, &offset); | |
1114 | } | |
1115 | } else { | |
1116 | goto out_adjust; | |
1117 | } | |
1118 | } | |
8524070b | 1119 | |
f726a697 JS |
1120 | if (unlikely(tk->clock->maxadj && |
1121 | (tk->mult + adj > tk->clock->mult + tk->clock->maxadj))) { | |
e919cfd4 JS |
1122 | printk_once(KERN_WARNING |
1123 | "Adjusting %s more than 11%% (%ld vs %ld)\n", | |
f726a697 JS |
1124 | tk->clock->name, (long)tk->mult + adj, |
1125 | (long)tk->clock->mult + tk->clock->maxadj); | |
e919cfd4 | 1126 | } |
c2bc1111 JS |
1127 | /* |
1128 | * So the following can be confusing. | |
1129 | * | |
1130 | * To keep things simple, lets assume adj == 1 for now. | |
1131 | * | |
1132 | * When adj != 1, remember that the interval and offset values | |
1133 | * have been appropriately scaled so the math is the same. | |
1134 | * | |
1135 | * The basic idea here is that we're increasing the multiplier | |
1136 | * by one, this causes the xtime_interval to be incremented by | |
1137 | * one cycle_interval. This is because: | |
1138 | * xtime_interval = cycle_interval * mult | |
1139 | * So if mult is being incremented by one: | |
1140 | * xtime_interval = cycle_interval * (mult + 1) | |
1141 | * Its the same as: | |
1142 | * xtime_interval = (cycle_interval * mult) + cycle_interval | |
1143 | * Which can be shortened to: | |
1144 | * xtime_interval += cycle_interval | |
1145 | * | |
1146 | * So offset stores the non-accumulated cycles. Thus the current | |
1147 | * time (in shifted nanoseconds) is: | |
1148 | * now = (offset * adj) + xtime_nsec | |
1149 | * Now, even though we're adjusting the clock frequency, we have | |
1150 | * to keep time consistent. In other words, we can't jump back | |
1151 | * in time, and we also want to avoid jumping forward in time. | |
1152 | * | |
1153 | * So given the same offset value, we need the time to be the same | |
1154 | * both before and after the freq adjustment. | |
1155 | * now = (offset * adj_1) + xtime_nsec_1 | |
1156 | * now = (offset * adj_2) + xtime_nsec_2 | |
1157 | * So: | |
1158 | * (offset * adj_1) + xtime_nsec_1 = | |
1159 | * (offset * adj_2) + xtime_nsec_2 | |
1160 | * And we know: | |
1161 | * adj_2 = adj_1 + 1 | |
1162 | * So: | |
1163 | * (offset * adj_1) + xtime_nsec_1 = | |
1164 | * (offset * (adj_1+1)) + xtime_nsec_2 | |
1165 | * (offset * adj_1) + xtime_nsec_1 = | |
1166 | * (offset * adj_1) + offset + xtime_nsec_2 | |
1167 | * Canceling the sides: | |
1168 | * xtime_nsec_1 = offset + xtime_nsec_2 | |
1169 | * Which gives us: | |
1170 | * xtime_nsec_2 = xtime_nsec_1 - offset | |
1171 | * Which simplfies to: | |
1172 | * xtime_nsec -= offset | |
1173 | * | |
1174 | * XXX - TODO: Doc ntp_error calculation. | |
1175 | */ | |
f726a697 JS |
1176 | tk->mult += adj; |
1177 | tk->xtime_interval += interval; | |
1178 | tk->xtime_nsec -= offset; | |
1179 | tk->ntp_error -= (interval - offset) << tk->ntp_error_shift; | |
2a8c0883 | 1180 | |
1d17d174 | 1181 | out_adjust: |
2a8c0883 JS |
1182 | /* |
1183 | * It may be possible that when we entered this function, xtime_nsec | |
1184 | * was very small. Further, if we're slightly speeding the clocksource | |
1185 | * in the code above, its possible the required corrective factor to | |
1186 | * xtime_nsec could cause it to underflow. | |
1187 | * | |
1188 | * Now, since we already accumulated the second, cannot simply roll | |
1189 | * the accumulated second back, since the NTP subsystem has been | |
1190 | * notified via second_overflow. So instead we push xtime_nsec forward | |
1191 | * by the amount we underflowed, and add that amount into the error. | |
1192 | * | |
1193 | * We'll correct this error next time through this function, when | |
1194 | * xtime_nsec is not as small. | |
1195 | */ | |
f726a697 JS |
1196 | if (unlikely((s64)tk->xtime_nsec < 0)) { |
1197 | s64 neg = -(s64)tk->xtime_nsec; | |
1198 | tk->xtime_nsec = 0; | |
1199 | tk->ntp_error += neg << tk->ntp_error_shift; | |
2a8c0883 JS |
1200 | } |
1201 | ||
8524070b | 1202 | } |
1203 | ||
1f4f9487 JS |
1204 | /** |
1205 | * accumulate_nsecs_to_secs - Accumulates nsecs into secs | |
1206 | * | |
1207 | * Helper function that accumulates a the nsecs greater then a second | |
1208 | * from the xtime_nsec field to the xtime_secs field. | |
1209 | * It also calls into the NTP code to handle leapsecond processing. | |
1210 | * | |
1211 | */ | |
1212 | static inline void accumulate_nsecs_to_secs(struct timekeeper *tk) | |
1213 | { | |
1214 | u64 nsecps = (u64)NSEC_PER_SEC << tk->shift; | |
1215 | ||
1216 | while (tk->xtime_nsec >= nsecps) { | |
1217 | int leap; | |
1218 | ||
1219 | tk->xtime_nsec -= nsecps; | |
1220 | tk->xtime_sec++; | |
1221 | ||
1222 | /* Figure out if its a leap sec and apply if needed */ | |
1223 | leap = second_overflow(tk->xtime_sec); | |
6d0ef903 JS |
1224 | if (unlikely(leap)) { |
1225 | struct timespec ts; | |
1226 | ||
1227 | tk->xtime_sec += leap; | |
1f4f9487 | 1228 | |
6d0ef903 JS |
1229 | ts.tv_sec = leap; |
1230 | ts.tv_nsec = 0; | |
1231 | tk_set_wall_to_mono(tk, | |
1232 | timespec_sub(tk->wall_to_monotonic, ts)); | |
1233 | ||
cc244dda JS |
1234 | __timekeeping_set_tai_offset(tk, tk->tai_offset - leap); |
1235 | ||
6d0ef903 JS |
1236 | clock_was_set_delayed(); |
1237 | } | |
1f4f9487 JS |
1238 | } |
1239 | } | |
1240 | ||
a092ff0f | 1241 | /** |
1242 | * logarithmic_accumulation - shifted accumulation of cycles | |
1243 | * | |
1244 | * This functions accumulates a shifted interval of cycles into | |
1245 | * into a shifted interval nanoseconds. Allows for O(log) accumulation | |
1246 | * loop. | |
1247 | * | |
1248 | * Returns the unconsumed cycles. | |
1249 | */ | |
f726a697 JS |
1250 | static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset, |
1251 | u32 shift) | |
a092ff0f | 1252 | { |
deda2e81 | 1253 | u64 raw_nsecs; |
a092ff0f | 1254 | |
f726a697 JS |
1255 | /* If the offset is smaller then a shifted interval, do nothing */ |
1256 | if (offset < tk->cycle_interval<<shift) | |
a092ff0f | 1257 | return offset; |
1258 | ||
1259 | /* Accumulate one shifted interval */ | |
f726a697 JS |
1260 | offset -= tk->cycle_interval << shift; |
1261 | tk->clock->cycle_last += tk->cycle_interval << shift; | |
a092ff0f | 1262 | |
f726a697 JS |
1263 | tk->xtime_nsec += tk->xtime_interval << shift; |
1264 | accumulate_nsecs_to_secs(tk); | |
a092ff0f | 1265 | |
deda2e81 | 1266 | /* Accumulate raw time */ |
5b3900cd | 1267 | raw_nsecs = (u64)tk->raw_interval << shift; |
f726a697 | 1268 | raw_nsecs += tk->raw_time.tv_nsec; |
c7dcf87a JS |
1269 | if (raw_nsecs >= NSEC_PER_SEC) { |
1270 | u64 raw_secs = raw_nsecs; | |
1271 | raw_nsecs = do_div(raw_secs, NSEC_PER_SEC); | |
f726a697 | 1272 | tk->raw_time.tv_sec += raw_secs; |
a092ff0f | 1273 | } |
f726a697 | 1274 | tk->raw_time.tv_nsec = raw_nsecs; |
a092ff0f | 1275 | |
1276 | /* Accumulate error between NTP and clock interval */ | |
f726a697 JS |
1277 | tk->ntp_error += ntp_tick_length() << shift; |
1278 | tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) << | |
1279 | (tk->ntp_error_shift + shift); | |
a092ff0f | 1280 | |
1281 | return offset; | |
1282 | } | |
1283 | ||
92bb1fcf JS |
1284 | #ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD |
1285 | static inline void old_vsyscall_fixup(struct timekeeper *tk) | |
1286 | { | |
1287 | s64 remainder; | |
1288 | ||
1289 | /* | |
1290 | * Store only full nanoseconds into xtime_nsec after rounding | |
1291 | * it up and add the remainder to the error difference. | |
1292 | * XXX - This is necessary to avoid small 1ns inconsistnecies caused | |
1293 | * by truncating the remainder in vsyscalls. However, it causes | |
1294 | * additional work to be done in timekeeping_adjust(). Once | |
1295 | * the vsyscall implementations are converted to use xtime_nsec | |
1296 | * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD | |
1297 | * users are removed, this can be killed. | |
1298 | */ | |
1299 | remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1); | |
1300 | tk->xtime_nsec -= remainder; | |
1301 | tk->xtime_nsec += 1ULL << tk->shift; | |
1302 | tk->ntp_error += remainder << tk->ntp_error_shift; | |
1303 | ||
1304 | } | |
1305 | #else | |
1306 | #define old_vsyscall_fixup(tk) | |
1307 | #endif | |
1308 | ||
1309 | ||
1310 | ||
8524070b | 1311 | /** |
1312 | * update_wall_time - Uses the current clocksource to increment the wall time | |
1313 | * | |
8524070b | 1314 | */ |
871cf1e5 | 1315 | static void update_wall_time(void) |
8524070b | 1316 | { |
155ec602 | 1317 | struct clocksource *clock; |
4e250fdd | 1318 | struct timekeeper *tk = &timekeeper; |
8524070b | 1319 | cycle_t offset; |
a092ff0f | 1320 | int shift = 0, maxshift; |
70471f2f JS |
1321 | unsigned long flags; |
1322 | ||
4e250fdd | 1323 | write_seqlock_irqsave(&tk->lock, flags); |
8524070b | 1324 | |
1325 | /* Make sure we're fully resumed: */ | |
1326 | if (unlikely(timekeeping_suspended)) | |
70471f2f | 1327 | goto out; |
8524070b | 1328 | |
4e250fdd | 1329 | clock = tk->clock; |
592913ec JS |
1330 | |
1331 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET | |
4e250fdd | 1332 | offset = tk->cycle_interval; |
592913ec JS |
1333 | #else |
1334 | offset = (clock->read(clock) - clock->cycle_last) & clock->mask; | |
8524070b | 1335 | #endif |
8524070b | 1336 | |
bf2ac312 JS |
1337 | /* Check if there's really nothing to do */ |
1338 | if (offset < tk->cycle_interval) | |
1339 | goto out; | |
1340 | ||
a092ff0f | 1341 | /* |
1342 | * With NO_HZ we may have to accumulate many cycle_intervals | |
1343 | * (think "ticks") worth of time at once. To do this efficiently, | |
1344 | * we calculate the largest doubling multiple of cycle_intervals | |
88b28adf | 1345 | * that is smaller than the offset. We then accumulate that |
a092ff0f | 1346 | * chunk in one go, and then try to consume the next smaller |
1347 | * doubled multiple. | |
8524070b | 1348 | */ |
4e250fdd | 1349 | shift = ilog2(offset) - ilog2(tk->cycle_interval); |
a092ff0f | 1350 | shift = max(0, shift); |
88b28adf | 1351 | /* Bound shift to one less than what overflows tick_length */ |
ea7cf49a | 1352 | maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1; |
a092ff0f | 1353 | shift = min(shift, maxshift); |
4e250fdd JS |
1354 | while (offset >= tk->cycle_interval) { |
1355 | offset = logarithmic_accumulation(tk, offset, shift); | |
1356 | if (offset < tk->cycle_interval<<shift) | |
830ec045 | 1357 | shift--; |
8524070b | 1358 | } |
1359 | ||
1360 | /* correct the clock when NTP error is too big */ | |
4e250fdd | 1361 | timekeeping_adjust(tk, offset); |
8524070b | 1362 | |
6a867a39 | 1363 | /* |
92bb1fcf JS |
1364 | * XXX This can be killed once everyone converts |
1365 | * to the new update_vsyscall. | |
1366 | */ | |
1367 | old_vsyscall_fixup(tk); | |
8524070b | 1368 | |
6a867a39 JS |
1369 | /* |
1370 | * Finally, make sure that after the rounding | |
1e75fa8b | 1371 | * xtime_nsec isn't larger than NSEC_PER_SEC |
6a867a39 | 1372 | */ |
4e250fdd | 1373 | accumulate_nsecs_to_secs(tk); |
83f57a11 | 1374 | |
4e250fdd | 1375 | timekeeping_update(tk, false); |
70471f2f JS |
1376 | |
1377 | out: | |
4e250fdd | 1378 | write_sequnlock_irqrestore(&tk->lock, flags); |
70471f2f | 1379 | |
8524070b | 1380 | } |
7c3f1a57 TJ |
1381 | |
1382 | /** | |
1383 | * getboottime - Return the real time of system boot. | |
1384 | * @ts: pointer to the timespec to be set | |
1385 | * | |
abb3a4ea | 1386 | * Returns the wall-time of boot in a timespec. |
7c3f1a57 TJ |
1387 | * |
1388 | * This is based on the wall_to_monotonic offset and the total suspend | |
1389 | * time. Calls to settimeofday will affect the value returned (which | |
1390 | * basically means that however wrong your real time clock is at boot time, | |
1391 | * you get the right time here). | |
1392 | */ | |
1393 | void getboottime(struct timespec *ts) | |
1394 | { | |
4e250fdd | 1395 | struct timekeeper *tk = &timekeeper; |
36d47481 | 1396 | struct timespec boottime = { |
4e250fdd JS |
1397 | .tv_sec = tk->wall_to_monotonic.tv_sec + |
1398 | tk->total_sleep_time.tv_sec, | |
1399 | .tv_nsec = tk->wall_to_monotonic.tv_nsec + | |
1400 | tk->total_sleep_time.tv_nsec | |
36d47481 | 1401 | }; |
d4f587c6 | 1402 | |
d4f587c6 | 1403 | set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec); |
7c3f1a57 | 1404 | } |
c93d89f3 | 1405 | EXPORT_SYMBOL_GPL(getboottime); |
7c3f1a57 | 1406 | |
abb3a4ea JS |
1407 | /** |
1408 | * get_monotonic_boottime - Returns monotonic time since boot | |
1409 | * @ts: pointer to the timespec to be set | |
1410 | * | |
1411 | * Returns the monotonic time since boot in a timespec. | |
1412 | * | |
1413 | * This is similar to CLOCK_MONTONIC/ktime_get_ts, but also | |
1414 | * includes the time spent in suspend. | |
1415 | */ | |
1416 | void get_monotonic_boottime(struct timespec *ts) | |
1417 | { | |
4e250fdd | 1418 | struct timekeeper *tk = &timekeeper; |
abb3a4ea | 1419 | struct timespec tomono, sleep; |
ec145bab | 1420 | s64 nsec; |
abb3a4ea | 1421 | unsigned int seq; |
abb3a4ea JS |
1422 | |
1423 | WARN_ON(timekeeping_suspended); | |
1424 | ||
1425 | do { | |
4e250fdd JS |
1426 | seq = read_seqbegin(&tk->lock); |
1427 | ts->tv_sec = tk->xtime_sec; | |
ec145bab | 1428 | nsec = timekeeping_get_ns(tk); |
4e250fdd JS |
1429 | tomono = tk->wall_to_monotonic; |
1430 | sleep = tk->total_sleep_time; | |
abb3a4ea | 1431 | |
4e250fdd | 1432 | } while (read_seqretry(&tk->lock, seq)); |
abb3a4ea | 1433 | |
ec145bab JS |
1434 | ts->tv_sec += tomono.tv_sec + sleep.tv_sec; |
1435 | ts->tv_nsec = 0; | |
1436 | timespec_add_ns(ts, nsec + tomono.tv_nsec + sleep.tv_nsec); | |
abb3a4ea JS |
1437 | } |
1438 | EXPORT_SYMBOL_GPL(get_monotonic_boottime); | |
1439 | ||
1440 | /** | |
1441 | * ktime_get_boottime - Returns monotonic time since boot in a ktime | |
1442 | * | |
1443 | * Returns the monotonic time since boot in a ktime | |
1444 | * | |
1445 | * This is similar to CLOCK_MONTONIC/ktime_get, but also | |
1446 | * includes the time spent in suspend. | |
1447 | */ | |
1448 | ktime_t ktime_get_boottime(void) | |
1449 | { | |
1450 | struct timespec ts; | |
1451 | ||
1452 | get_monotonic_boottime(&ts); | |
1453 | return timespec_to_ktime(ts); | |
1454 | } | |
1455 | EXPORT_SYMBOL_GPL(ktime_get_boottime); | |
1456 | ||
7c3f1a57 TJ |
1457 | /** |
1458 | * monotonic_to_bootbased - Convert the monotonic time to boot based. | |
1459 | * @ts: pointer to the timespec to be converted | |
1460 | */ | |
1461 | void monotonic_to_bootbased(struct timespec *ts) | |
1462 | { | |
4e250fdd JS |
1463 | struct timekeeper *tk = &timekeeper; |
1464 | ||
1465 | *ts = timespec_add(*ts, tk->total_sleep_time); | |
7c3f1a57 | 1466 | } |
c93d89f3 | 1467 | EXPORT_SYMBOL_GPL(monotonic_to_bootbased); |
2c6b47de | 1468 | |
17c38b74 | 1469 | unsigned long get_seconds(void) |
1470 | { | |
4e250fdd JS |
1471 | struct timekeeper *tk = &timekeeper; |
1472 | ||
1473 | return tk->xtime_sec; | |
17c38b74 | 1474 | } |
1475 | EXPORT_SYMBOL(get_seconds); | |
1476 | ||
da15cfda | 1477 | struct timespec __current_kernel_time(void) |
1478 | { | |
4e250fdd JS |
1479 | struct timekeeper *tk = &timekeeper; |
1480 | ||
1481 | return tk_xtime(tk); | |
da15cfda | 1482 | } |
17c38b74 | 1483 | |
2c6b47de | 1484 | struct timespec current_kernel_time(void) |
1485 | { | |
4e250fdd | 1486 | struct timekeeper *tk = &timekeeper; |
2c6b47de | 1487 | struct timespec now; |
1488 | unsigned long seq; | |
1489 | ||
1490 | do { | |
4e250fdd | 1491 | seq = read_seqbegin(&tk->lock); |
83f57a11 | 1492 | |
4e250fdd JS |
1493 | now = tk_xtime(tk); |
1494 | } while (read_seqretry(&tk->lock, seq)); | |
2c6b47de | 1495 | |
1496 | return now; | |
1497 | } | |
2c6b47de | 1498 | EXPORT_SYMBOL(current_kernel_time); |
da15cfda | 1499 | |
1500 | struct timespec get_monotonic_coarse(void) | |
1501 | { | |
4e250fdd | 1502 | struct timekeeper *tk = &timekeeper; |
da15cfda | 1503 | struct timespec now, mono; |
1504 | unsigned long seq; | |
1505 | ||
1506 | do { | |
4e250fdd | 1507 | seq = read_seqbegin(&tk->lock); |
83f57a11 | 1508 | |
4e250fdd JS |
1509 | now = tk_xtime(tk); |
1510 | mono = tk->wall_to_monotonic; | |
1511 | } while (read_seqretry(&tk->lock, seq)); | |
da15cfda | 1512 | |
1513 | set_normalized_timespec(&now, now.tv_sec + mono.tv_sec, | |
1514 | now.tv_nsec + mono.tv_nsec); | |
1515 | return now; | |
1516 | } | |
871cf1e5 TH |
1517 | |
1518 | /* | |
d6ad4187 | 1519 | * Must hold jiffies_lock |
871cf1e5 TH |
1520 | */ |
1521 | void do_timer(unsigned long ticks) | |
1522 | { | |
1523 | jiffies_64 += ticks; | |
1524 | update_wall_time(); | |
1525 | calc_global_load(ticks); | |
1526 | } | |
48cf76f7 TH |
1527 | |
1528 | /** | |
314ac371 JS |
1529 | * get_xtime_and_monotonic_and_sleep_offset() - get xtime, wall_to_monotonic, |
1530 | * and sleep offsets. | |
48cf76f7 TH |
1531 | * @xtim: pointer to timespec to be set with xtime |
1532 | * @wtom: pointer to timespec to be set with wall_to_monotonic | |
314ac371 | 1533 | * @sleep: pointer to timespec to be set with time in suspend |
48cf76f7 | 1534 | */ |
314ac371 JS |
1535 | void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim, |
1536 | struct timespec *wtom, struct timespec *sleep) | |
48cf76f7 | 1537 | { |
4e250fdd | 1538 | struct timekeeper *tk = &timekeeper; |
48cf76f7 TH |
1539 | unsigned long seq; |
1540 | ||
1541 | do { | |
4e250fdd JS |
1542 | seq = read_seqbegin(&tk->lock); |
1543 | *xtim = tk_xtime(tk); | |
1544 | *wtom = tk->wall_to_monotonic; | |
1545 | *sleep = tk->total_sleep_time; | |
1546 | } while (read_seqretry(&tk->lock, seq)); | |
48cf76f7 | 1547 | } |
f0af911a | 1548 | |
f6c06abf TG |
1549 | #ifdef CONFIG_HIGH_RES_TIMERS |
1550 | /** | |
1551 | * ktime_get_update_offsets - hrtimer helper | |
1552 | * @offs_real: pointer to storage for monotonic -> realtime offset | |
1553 | * @offs_boot: pointer to storage for monotonic -> boottime offset | |
1554 | * | |
1555 | * Returns current monotonic time and updates the offsets | |
1556 | * Called from hrtimer_interupt() or retrigger_next_event() | |
1557 | */ | |
90adda98 JS |
1558 | ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot, |
1559 | ktime_t *offs_tai) | |
f6c06abf | 1560 | { |
4e250fdd | 1561 | struct timekeeper *tk = &timekeeper; |
f6c06abf TG |
1562 | ktime_t now; |
1563 | unsigned int seq; | |
1564 | u64 secs, nsecs; | |
1565 | ||
1566 | do { | |
4e250fdd | 1567 | seq = read_seqbegin(&tk->lock); |
f6c06abf | 1568 | |
4e250fdd JS |
1569 | secs = tk->xtime_sec; |
1570 | nsecs = timekeeping_get_ns(tk); | |
f6c06abf | 1571 | |
4e250fdd JS |
1572 | *offs_real = tk->offs_real; |
1573 | *offs_boot = tk->offs_boot; | |
90adda98 | 1574 | *offs_tai = tk->offs_tai; |
4e250fdd | 1575 | } while (read_seqretry(&tk->lock, seq)); |
f6c06abf TG |
1576 | |
1577 | now = ktime_add_ns(ktime_set(secs, 0), nsecs); | |
1578 | now = ktime_sub(now, *offs_real); | |
1579 | return now; | |
1580 | } | |
1581 | #endif | |
1582 | ||
99ee5315 TG |
1583 | /** |
1584 | * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format | |
1585 | */ | |
1586 | ktime_t ktime_get_monotonic_offset(void) | |
1587 | { | |
4e250fdd | 1588 | struct timekeeper *tk = &timekeeper; |
99ee5315 TG |
1589 | unsigned long seq; |
1590 | struct timespec wtom; | |
1591 | ||
1592 | do { | |
4e250fdd JS |
1593 | seq = read_seqbegin(&tk->lock); |
1594 | wtom = tk->wall_to_monotonic; | |
1595 | } while (read_seqretry(&tk->lock, seq)); | |
70471f2f | 1596 | |
99ee5315 TG |
1597 | return timespec_to_ktime(wtom); |
1598 | } | |
a80b83b7 JS |
1599 | EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset); |
1600 | ||
f0af911a TH |
1601 | /** |
1602 | * xtime_update() - advances the timekeeping infrastructure | |
1603 | * @ticks: number of ticks, that have elapsed since the last call. | |
1604 | * | |
1605 | * Must be called with interrupts disabled. | |
1606 | */ | |
1607 | void xtime_update(unsigned long ticks) | |
1608 | { | |
d6ad4187 | 1609 | write_seqlock(&jiffies_lock); |
f0af911a | 1610 | do_timer(ticks); |
d6ad4187 | 1611 | write_sequnlock(&jiffies_lock); |
f0af911a | 1612 | } |