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> |
52f5684c | 25 | #include <linux/compiler.h> |
8524070b | 26 | |
eb93e4d9 | 27 | #include "tick-internal.h" |
aa6f9c59 | 28 | #include "ntp_internal.h" |
5c83545f | 29 | #include "timekeeping_internal.h" |
155ec602 | 30 | |
04397fe9 DV |
31 | #define TK_CLEAR_NTP (1 << 0) |
32 | #define TK_MIRROR (1 << 1) | |
780427f0 | 33 | #define TK_CLOCK_WAS_SET (1 << 2) |
04397fe9 | 34 | |
3fdb14fd TG |
35 | /* |
36 | * The most important data for readout fits into a single 64 byte | |
37 | * cache line. | |
38 | */ | |
39 | static struct { | |
40 | seqcount_t seq; | |
41 | struct timekeeper timekeeper; | |
42 | } tk_core ____cacheline_aligned; | |
43 | ||
9a7a71b1 | 44 | static DEFINE_RAW_SPINLOCK(timekeeper_lock); |
48cdc135 | 45 | static struct timekeeper shadow_timekeeper; |
155ec602 | 46 | |
4396e058 TG |
47 | /** |
48 | * struct tk_fast - NMI safe timekeeper | |
49 | * @seq: Sequence counter for protecting updates. The lowest bit | |
50 | * is the index for the tk_read_base array | |
51 | * @base: tk_read_base array. Access is indexed by the lowest bit of | |
52 | * @seq. | |
53 | * | |
54 | * See @update_fast_timekeeper() below. | |
55 | */ | |
56 | struct tk_fast { | |
57 | seqcount_t seq; | |
58 | struct tk_read_base base[2]; | |
59 | }; | |
60 | ||
61 | static struct tk_fast tk_fast_mono ____cacheline_aligned; | |
f09cb9a1 | 62 | static struct tk_fast tk_fast_raw ____cacheline_aligned; |
4396e058 | 63 | |
8fcce546 JS |
64 | /* flag for if timekeeping is suspended */ |
65 | int __read_mostly timekeeping_suspended; | |
66 | ||
1e75fa8b JS |
67 | static inline void tk_normalize_xtime(struct timekeeper *tk) |
68 | { | |
876e7881 PZ |
69 | while (tk->tkr_mono.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr_mono.shift)) { |
70 | tk->tkr_mono.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_mono.shift; | |
1e75fa8b JS |
71 | tk->xtime_sec++; |
72 | } | |
73 | } | |
74 | ||
c905fae4 TG |
75 | static inline struct timespec64 tk_xtime(struct timekeeper *tk) |
76 | { | |
77 | struct timespec64 ts; | |
78 | ||
79 | ts.tv_sec = tk->xtime_sec; | |
876e7881 | 80 | ts.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); |
c905fae4 TG |
81 | return ts; |
82 | } | |
83 | ||
7d489d15 | 84 | static void tk_set_xtime(struct timekeeper *tk, const struct timespec64 *ts) |
1e75fa8b JS |
85 | { |
86 | tk->xtime_sec = ts->tv_sec; | |
876e7881 | 87 | tk->tkr_mono.xtime_nsec = (u64)ts->tv_nsec << tk->tkr_mono.shift; |
1e75fa8b JS |
88 | } |
89 | ||
7d489d15 | 90 | static void tk_xtime_add(struct timekeeper *tk, const struct timespec64 *ts) |
1e75fa8b JS |
91 | { |
92 | tk->xtime_sec += ts->tv_sec; | |
876e7881 | 93 | tk->tkr_mono.xtime_nsec += (u64)ts->tv_nsec << tk->tkr_mono.shift; |
784ffcbb | 94 | tk_normalize_xtime(tk); |
1e75fa8b | 95 | } |
8fcce546 | 96 | |
7d489d15 | 97 | static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec64 wtm) |
6d0ef903 | 98 | { |
7d489d15 | 99 | struct timespec64 tmp; |
6d0ef903 JS |
100 | |
101 | /* | |
102 | * Verify consistency of: offset_real = -wall_to_monotonic | |
103 | * before modifying anything | |
104 | */ | |
7d489d15 | 105 | set_normalized_timespec64(&tmp, -tk->wall_to_monotonic.tv_sec, |
6d0ef903 | 106 | -tk->wall_to_monotonic.tv_nsec); |
7d489d15 | 107 | WARN_ON_ONCE(tk->offs_real.tv64 != timespec64_to_ktime(tmp).tv64); |
6d0ef903 | 108 | tk->wall_to_monotonic = wtm; |
7d489d15 JS |
109 | set_normalized_timespec64(&tmp, -wtm.tv_sec, -wtm.tv_nsec); |
110 | tk->offs_real = timespec64_to_ktime(tmp); | |
04005f60 | 111 | tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tk->tai_offset, 0)); |
6d0ef903 JS |
112 | } |
113 | ||
47da70d3 | 114 | static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta) |
6d0ef903 | 115 | { |
47da70d3 | 116 | tk->offs_boot = ktime_add(tk->offs_boot, delta); |
6d0ef903 JS |
117 | } |
118 | ||
3c17ad19 | 119 | #ifdef CONFIG_DEBUG_TIMEKEEPING |
4ca22c26 | 120 | #define WARNING_FREQ (HZ*300) /* 5 minute rate-limiting */ |
4ca22c26 | 121 | |
3c17ad19 JS |
122 | static void timekeeping_check_update(struct timekeeper *tk, cycle_t offset) |
123 | { | |
124 | ||
876e7881 PZ |
125 | cycle_t max_cycles = tk->tkr_mono.clock->max_cycles; |
126 | const char *name = tk->tkr_mono.clock->name; | |
3c17ad19 JS |
127 | |
128 | if (offset > max_cycles) { | |
a558cd02 | 129 | printk_deferred("WARNING: timekeeping: Cycle offset (%lld) is larger than allowed by the '%s' clock's max_cycles value (%lld): time overflow danger\n", |
3c17ad19 | 130 | offset, name, max_cycles); |
a558cd02 | 131 | printk_deferred(" timekeeping: Your kernel is sick, but tries to cope by capping time updates\n"); |
3c17ad19 JS |
132 | } else { |
133 | if (offset > (max_cycles >> 1)) { | |
fc4fa6e1 | 134 | printk_deferred("INFO: timekeeping: Cycle offset (%lld) is larger than the '%s' clock's 50%% safety margin (%lld)\n", |
3c17ad19 JS |
135 | offset, name, max_cycles >> 1); |
136 | printk_deferred(" timekeeping: Your kernel is still fine, but is feeling a bit nervous\n"); | |
137 | } | |
138 | } | |
4ca22c26 | 139 | |
57d05a93 JS |
140 | if (tk->underflow_seen) { |
141 | if (jiffies - tk->last_warning > WARNING_FREQ) { | |
4ca22c26 JS |
142 | printk_deferred("WARNING: Underflow in clocksource '%s' observed, time update ignored.\n", name); |
143 | printk_deferred(" Please report this, consider using a different clocksource, if possible.\n"); | |
144 | printk_deferred(" Your kernel is probably still fine.\n"); | |
57d05a93 | 145 | tk->last_warning = jiffies; |
4ca22c26 | 146 | } |
57d05a93 | 147 | tk->underflow_seen = 0; |
4ca22c26 JS |
148 | } |
149 | ||
57d05a93 JS |
150 | if (tk->overflow_seen) { |
151 | if (jiffies - tk->last_warning > WARNING_FREQ) { | |
4ca22c26 JS |
152 | printk_deferred("WARNING: Overflow in clocksource '%s' observed, time update capped.\n", name); |
153 | printk_deferred(" Please report this, consider using a different clocksource, if possible.\n"); | |
154 | printk_deferred(" Your kernel is probably still fine.\n"); | |
57d05a93 | 155 | tk->last_warning = jiffies; |
4ca22c26 | 156 | } |
57d05a93 | 157 | tk->overflow_seen = 0; |
4ca22c26 | 158 | } |
3c17ad19 | 159 | } |
a558cd02 JS |
160 | |
161 | static inline cycle_t timekeeping_get_delta(struct tk_read_base *tkr) | |
162 | { | |
57d05a93 | 163 | struct timekeeper *tk = &tk_core.timekeeper; |
4ca22c26 JS |
164 | cycle_t now, last, mask, max, delta; |
165 | unsigned int seq; | |
a558cd02 | 166 | |
4ca22c26 JS |
167 | /* |
168 | * Since we're called holding a seqlock, the data may shift | |
169 | * under us while we're doing the calculation. This can cause | |
170 | * false positives, since we'd note a problem but throw the | |
171 | * results away. So nest another seqlock here to atomically | |
172 | * grab the points we are checking with. | |
173 | */ | |
174 | do { | |
175 | seq = read_seqcount_begin(&tk_core.seq); | |
176 | now = tkr->read(tkr->clock); | |
177 | last = tkr->cycle_last; | |
178 | mask = tkr->mask; | |
179 | max = tkr->clock->max_cycles; | |
180 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
a558cd02 | 181 | |
4ca22c26 | 182 | delta = clocksource_delta(now, last, mask); |
a558cd02 | 183 | |
057b87e3 JS |
184 | /* |
185 | * Try to catch underflows by checking if we are seeing small | |
186 | * mask-relative negative values. | |
187 | */ | |
4ca22c26 | 188 | if (unlikely((~delta & mask) < (mask >> 3))) { |
57d05a93 | 189 | tk->underflow_seen = 1; |
057b87e3 | 190 | delta = 0; |
4ca22c26 | 191 | } |
057b87e3 | 192 | |
a558cd02 | 193 | /* Cap delta value to the max_cycles values to avoid mult overflows */ |
4ca22c26 | 194 | if (unlikely(delta > max)) { |
57d05a93 | 195 | tk->overflow_seen = 1; |
a558cd02 | 196 | delta = tkr->clock->max_cycles; |
4ca22c26 | 197 | } |
a558cd02 JS |
198 | |
199 | return delta; | |
200 | } | |
3c17ad19 JS |
201 | #else |
202 | static inline void timekeeping_check_update(struct timekeeper *tk, cycle_t offset) | |
203 | { | |
204 | } | |
a558cd02 JS |
205 | static inline cycle_t timekeeping_get_delta(struct tk_read_base *tkr) |
206 | { | |
207 | cycle_t cycle_now, delta; | |
208 | ||
209 | /* read clocksource */ | |
210 | cycle_now = tkr->read(tkr->clock); | |
211 | ||
212 | /* calculate the delta since the last update_wall_time */ | |
213 | delta = clocksource_delta(cycle_now, tkr->cycle_last, tkr->mask); | |
214 | ||
215 | return delta; | |
216 | } | |
3c17ad19 JS |
217 | #endif |
218 | ||
155ec602 | 219 | /** |
d26e4fe0 | 220 | * tk_setup_internals - Set up internals to use clocksource clock. |
155ec602 | 221 | * |
d26e4fe0 | 222 | * @tk: The target timekeeper to setup. |
155ec602 MS |
223 | * @clock: Pointer to clocksource. |
224 | * | |
225 | * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment | |
226 | * pair and interval request. | |
227 | * | |
228 | * Unless you're the timekeeping code, you should not be using this! | |
229 | */ | |
f726a697 | 230 | static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock) |
155ec602 MS |
231 | { |
232 | cycle_t interval; | |
a386b5af | 233 | u64 tmp, ntpinterval; |
1e75fa8b | 234 | struct clocksource *old_clock; |
155ec602 | 235 | |
2c756feb | 236 | ++tk->cs_was_changed_seq; |
876e7881 PZ |
237 | old_clock = tk->tkr_mono.clock; |
238 | tk->tkr_mono.clock = clock; | |
239 | tk->tkr_mono.read = clock->read; | |
240 | tk->tkr_mono.mask = clock->mask; | |
241 | tk->tkr_mono.cycle_last = tk->tkr_mono.read(clock); | |
155ec602 | 242 | |
4a4ad80d PZ |
243 | tk->tkr_raw.clock = clock; |
244 | tk->tkr_raw.read = clock->read; | |
245 | tk->tkr_raw.mask = clock->mask; | |
246 | tk->tkr_raw.cycle_last = tk->tkr_mono.cycle_last; | |
247 | ||
155ec602 MS |
248 | /* Do the ns -> cycle conversion first, using original mult */ |
249 | tmp = NTP_INTERVAL_LENGTH; | |
250 | tmp <<= clock->shift; | |
a386b5af | 251 | ntpinterval = tmp; |
0a544198 MS |
252 | tmp += clock->mult/2; |
253 | do_div(tmp, clock->mult); | |
155ec602 MS |
254 | if (tmp == 0) |
255 | tmp = 1; | |
256 | ||
257 | interval = (cycle_t) tmp; | |
f726a697 | 258 | tk->cycle_interval = interval; |
155ec602 MS |
259 | |
260 | /* Go back from cycles -> shifted ns */ | |
f726a697 JS |
261 | tk->xtime_interval = (u64) interval * clock->mult; |
262 | tk->xtime_remainder = ntpinterval - tk->xtime_interval; | |
263 | tk->raw_interval = | |
0a544198 | 264 | ((u64) interval * clock->mult) >> clock->shift; |
155ec602 | 265 | |
1e75fa8b JS |
266 | /* if changing clocks, convert xtime_nsec shift units */ |
267 | if (old_clock) { | |
268 | int shift_change = clock->shift - old_clock->shift; | |
269 | if (shift_change < 0) | |
876e7881 | 270 | tk->tkr_mono.xtime_nsec >>= -shift_change; |
1e75fa8b | 271 | else |
876e7881 | 272 | tk->tkr_mono.xtime_nsec <<= shift_change; |
1e75fa8b | 273 | } |
4a4ad80d PZ |
274 | tk->tkr_raw.xtime_nsec = 0; |
275 | ||
876e7881 | 276 | tk->tkr_mono.shift = clock->shift; |
4a4ad80d | 277 | tk->tkr_raw.shift = clock->shift; |
155ec602 | 278 | |
f726a697 JS |
279 | tk->ntp_error = 0; |
280 | tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; | |
375f45b5 | 281 | tk->ntp_tick = ntpinterval << tk->ntp_error_shift; |
0a544198 MS |
282 | |
283 | /* | |
284 | * The timekeeper keeps its own mult values for the currently | |
285 | * active clocksource. These value will be adjusted via NTP | |
286 | * to counteract clock drifting. | |
287 | */ | |
876e7881 | 288 | tk->tkr_mono.mult = clock->mult; |
4a4ad80d | 289 | tk->tkr_raw.mult = clock->mult; |
dc491596 | 290 | tk->ntp_err_mult = 0; |
155ec602 | 291 | } |
8524070b | 292 | |
2ba2a305 | 293 | /* Timekeeper helper functions. */ |
7b1f6207 SW |
294 | |
295 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET | |
e06fde37 TG |
296 | static u32 default_arch_gettimeoffset(void) { return 0; } |
297 | u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset; | |
7b1f6207 | 298 | #else |
e06fde37 | 299 | static inline u32 arch_gettimeoffset(void) { return 0; } |
7b1f6207 SW |
300 | #endif |
301 | ||
6bd58f09 CH |
302 | static inline s64 timekeeping_delta_to_ns(struct tk_read_base *tkr, |
303 | cycle_t delta) | |
304 | { | |
305 | s64 nsec; | |
306 | ||
307 | nsec = delta * tkr->mult + tkr->xtime_nsec; | |
308 | nsec >>= tkr->shift; | |
309 | ||
310 | /* If arch requires, add in get_arch_timeoffset() */ | |
311 | return nsec + arch_gettimeoffset(); | |
312 | } | |
313 | ||
0e5ac3a8 | 314 | static inline s64 timekeeping_get_ns(struct tk_read_base *tkr) |
2ba2a305 | 315 | { |
a558cd02 | 316 | cycle_t delta; |
2ba2a305 | 317 | |
a558cd02 | 318 | delta = timekeeping_get_delta(tkr); |
6bd58f09 CH |
319 | return timekeeping_delta_to_ns(tkr, delta); |
320 | } | |
2ba2a305 | 321 | |
6bd58f09 CH |
322 | static inline s64 timekeeping_cycles_to_ns(struct tk_read_base *tkr, |
323 | cycle_t cycles) | |
324 | { | |
325 | cycle_t delta; | |
f2a5a085 | 326 | |
6bd58f09 CH |
327 | /* calculate the delta since the last update_wall_time */ |
328 | delta = clocksource_delta(cycles, tkr->cycle_last, tkr->mask); | |
329 | return timekeeping_delta_to_ns(tkr, delta); | |
2ba2a305 MS |
330 | } |
331 | ||
4396e058 TG |
332 | /** |
333 | * update_fast_timekeeper - Update the fast and NMI safe monotonic timekeeper. | |
affe3e85 | 334 | * @tkr: Timekeeping readout base from which we take the update |
4396e058 TG |
335 | * |
336 | * We want to use this from any context including NMI and tracing / | |
337 | * instrumenting the timekeeping code itself. | |
338 | * | |
6695b92a | 339 | * Employ the latch technique; see @raw_write_seqcount_latch. |
4396e058 TG |
340 | * |
341 | * So if a NMI hits the update of base[0] then it will use base[1] | |
342 | * which is still consistent. In the worst case this can result is a | |
343 | * slightly wrong timestamp (a few nanoseconds). See | |
344 | * @ktime_get_mono_fast_ns. | |
345 | */ | |
4498e746 | 346 | static void update_fast_timekeeper(struct tk_read_base *tkr, struct tk_fast *tkf) |
4396e058 | 347 | { |
4498e746 | 348 | struct tk_read_base *base = tkf->base; |
4396e058 TG |
349 | |
350 | /* Force readers off to base[1] */ | |
4498e746 | 351 | raw_write_seqcount_latch(&tkf->seq); |
4396e058 TG |
352 | |
353 | /* Update base[0] */ | |
affe3e85 | 354 | memcpy(base, tkr, sizeof(*base)); |
4396e058 TG |
355 | |
356 | /* Force readers back to base[0] */ | |
4498e746 | 357 | raw_write_seqcount_latch(&tkf->seq); |
4396e058 TG |
358 | |
359 | /* Update base[1] */ | |
360 | memcpy(base + 1, base, sizeof(*base)); | |
361 | } | |
362 | ||
363 | /** | |
364 | * ktime_get_mono_fast_ns - Fast NMI safe access to clock monotonic | |
365 | * | |
366 | * This timestamp is not guaranteed to be monotonic across an update. | |
367 | * The timestamp is calculated by: | |
368 | * | |
369 | * now = base_mono + clock_delta * slope | |
370 | * | |
371 | * So if the update lowers the slope, readers who are forced to the | |
372 | * not yet updated second array are still using the old steeper slope. | |
373 | * | |
374 | * tmono | |
375 | * ^ | |
376 | * | o n | |
377 | * | o n | |
378 | * | u | |
379 | * | o | |
380 | * |o | |
381 | * |12345678---> reader order | |
382 | * | |
383 | * o = old slope | |
384 | * u = update | |
385 | * n = new slope | |
386 | * | |
387 | * So reader 6 will observe time going backwards versus reader 5. | |
388 | * | |
389 | * While other CPUs are likely to be able observe that, the only way | |
390 | * for a CPU local observation is when an NMI hits in the middle of | |
391 | * the update. Timestamps taken from that NMI context might be ahead | |
392 | * of the following timestamps. Callers need to be aware of that and | |
393 | * deal with it. | |
394 | */ | |
4498e746 | 395 | static __always_inline u64 __ktime_get_fast_ns(struct tk_fast *tkf) |
4396e058 TG |
396 | { |
397 | struct tk_read_base *tkr; | |
398 | unsigned int seq; | |
399 | u64 now; | |
400 | ||
401 | do { | |
7fc26327 | 402 | seq = raw_read_seqcount_latch(&tkf->seq); |
4498e746 | 403 | tkr = tkf->base + (seq & 0x01); |
876e7881 | 404 | now = ktime_to_ns(tkr->base) + timekeeping_get_ns(tkr); |
4498e746 | 405 | } while (read_seqcount_retry(&tkf->seq, seq)); |
4396e058 | 406 | |
4396e058 TG |
407 | return now; |
408 | } | |
4498e746 PZ |
409 | |
410 | u64 ktime_get_mono_fast_ns(void) | |
411 | { | |
412 | return __ktime_get_fast_ns(&tk_fast_mono); | |
413 | } | |
4396e058 TG |
414 | EXPORT_SYMBOL_GPL(ktime_get_mono_fast_ns); |
415 | ||
f09cb9a1 PZ |
416 | u64 ktime_get_raw_fast_ns(void) |
417 | { | |
418 | return __ktime_get_fast_ns(&tk_fast_raw); | |
419 | } | |
420 | EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns); | |
421 | ||
060407ae RW |
422 | /* Suspend-time cycles value for halted fast timekeeper. */ |
423 | static cycle_t cycles_at_suspend; | |
424 | ||
425 | static cycle_t dummy_clock_read(struct clocksource *cs) | |
426 | { | |
427 | return cycles_at_suspend; | |
428 | } | |
429 | ||
430 | /** | |
431 | * halt_fast_timekeeper - Prevent fast timekeeper from accessing clocksource. | |
432 | * @tk: Timekeeper to snapshot. | |
433 | * | |
434 | * It generally is unsafe to access the clocksource after timekeeping has been | |
435 | * suspended, so take a snapshot of the readout base of @tk and use it as the | |
436 | * fast timekeeper's readout base while suspended. It will return the same | |
437 | * number of cycles every time until timekeeping is resumed at which time the | |
438 | * proper readout base for the fast timekeeper will be restored automatically. | |
439 | */ | |
440 | static void halt_fast_timekeeper(struct timekeeper *tk) | |
441 | { | |
442 | static struct tk_read_base tkr_dummy; | |
876e7881 | 443 | struct tk_read_base *tkr = &tk->tkr_mono; |
060407ae RW |
444 | |
445 | memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy)); | |
446 | cycles_at_suspend = tkr->read(tkr->clock); | |
447 | tkr_dummy.read = dummy_clock_read; | |
4498e746 | 448 | update_fast_timekeeper(&tkr_dummy, &tk_fast_mono); |
f09cb9a1 PZ |
449 | |
450 | tkr = &tk->tkr_raw; | |
451 | memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy)); | |
452 | tkr_dummy.read = dummy_clock_read; | |
453 | update_fast_timekeeper(&tkr_dummy, &tk_fast_raw); | |
060407ae RW |
454 | } |
455 | ||
c905fae4 TG |
456 | #ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD |
457 | ||
458 | static inline void update_vsyscall(struct timekeeper *tk) | |
459 | { | |
0680eb1f | 460 | struct timespec xt, wm; |
c905fae4 | 461 | |
e2dff1ec | 462 | xt = timespec64_to_timespec(tk_xtime(tk)); |
0680eb1f | 463 | wm = timespec64_to_timespec(tk->wall_to_monotonic); |
876e7881 PZ |
464 | update_vsyscall_old(&xt, &wm, tk->tkr_mono.clock, tk->tkr_mono.mult, |
465 | tk->tkr_mono.cycle_last); | |
c905fae4 TG |
466 | } |
467 | ||
468 | static inline void old_vsyscall_fixup(struct timekeeper *tk) | |
469 | { | |
470 | s64 remainder; | |
471 | ||
472 | /* | |
473 | * Store only full nanoseconds into xtime_nsec after rounding | |
474 | * it up and add the remainder to the error difference. | |
475 | * XXX - This is necessary to avoid small 1ns inconsistnecies caused | |
476 | * by truncating the remainder in vsyscalls. However, it causes | |
477 | * additional work to be done in timekeeping_adjust(). Once | |
478 | * the vsyscall implementations are converted to use xtime_nsec | |
479 | * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD | |
480 | * users are removed, this can be killed. | |
481 | */ | |
876e7881 PZ |
482 | remainder = tk->tkr_mono.xtime_nsec & ((1ULL << tk->tkr_mono.shift) - 1); |
483 | tk->tkr_mono.xtime_nsec -= remainder; | |
484 | tk->tkr_mono.xtime_nsec += 1ULL << tk->tkr_mono.shift; | |
c905fae4 | 485 | tk->ntp_error += remainder << tk->ntp_error_shift; |
876e7881 | 486 | tk->ntp_error -= (1ULL << tk->tkr_mono.shift) << tk->ntp_error_shift; |
c905fae4 TG |
487 | } |
488 | #else | |
489 | #define old_vsyscall_fixup(tk) | |
490 | #endif | |
491 | ||
e0b306fe MT |
492 | static RAW_NOTIFIER_HEAD(pvclock_gtod_chain); |
493 | ||
780427f0 | 494 | static void update_pvclock_gtod(struct timekeeper *tk, bool was_set) |
e0b306fe | 495 | { |
780427f0 | 496 | raw_notifier_call_chain(&pvclock_gtod_chain, was_set, tk); |
e0b306fe MT |
497 | } |
498 | ||
499 | /** | |
500 | * pvclock_gtod_register_notifier - register a pvclock timedata update listener | |
e0b306fe MT |
501 | */ |
502 | int pvclock_gtod_register_notifier(struct notifier_block *nb) | |
503 | { | |
3fdb14fd | 504 | struct timekeeper *tk = &tk_core.timekeeper; |
e0b306fe MT |
505 | unsigned long flags; |
506 | int ret; | |
507 | ||
9a7a71b1 | 508 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
e0b306fe | 509 | ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb); |
780427f0 | 510 | update_pvclock_gtod(tk, true); |
9a7a71b1 | 511 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
e0b306fe MT |
512 | |
513 | return ret; | |
514 | } | |
515 | EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier); | |
516 | ||
517 | /** | |
518 | * pvclock_gtod_unregister_notifier - unregister a pvclock | |
519 | * timedata update listener | |
e0b306fe MT |
520 | */ |
521 | int pvclock_gtod_unregister_notifier(struct notifier_block *nb) | |
522 | { | |
e0b306fe MT |
523 | unsigned long flags; |
524 | int ret; | |
525 | ||
9a7a71b1 | 526 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
e0b306fe | 527 | ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb); |
9a7a71b1 | 528 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
e0b306fe MT |
529 | |
530 | return ret; | |
531 | } | |
532 | EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier); | |
533 | ||
833f32d7 JS |
534 | /* |
535 | * tk_update_leap_state - helper to update the next_leap_ktime | |
536 | */ | |
537 | static inline void tk_update_leap_state(struct timekeeper *tk) | |
538 | { | |
539 | tk->next_leap_ktime = ntp_get_next_leap(); | |
540 | if (tk->next_leap_ktime.tv64 != KTIME_MAX) | |
541 | /* Convert to monotonic time */ | |
542 | tk->next_leap_ktime = ktime_sub(tk->next_leap_ktime, tk->offs_real); | |
543 | } | |
544 | ||
7c032df5 TG |
545 | /* |
546 | * Update the ktime_t based scalar nsec members of the timekeeper | |
547 | */ | |
548 | static inline void tk_update_ktime_data(struct timekeeper *tk) | |
549 | { | |
9e3680b1 HS |
550 | u64 seconds; |
551 | u32 nsec; | |
7c032df5 TG |
552 | |
553 | /* | |
554 | * The xtime based monotonic readout is: | |
555 | * nsec = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec + now(); | |
556 | * The ktime based monotonic readout is: | |
557 | * nsec = base_mono + now(); | |
558 | * ==> base_mono = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec | |
559 | */ | |
9e3680b1 HS |
560 | seconds = (u64)(tk->xtime_sec + tk->wall_to_monotonic.tv_sec); |
561 | nsec = (u32) tk->wall_to_monotonic.tv_nsec; | |
876e7881 | 562 | tk->tkr_mono.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec); |
f519b1a2 TG |
563 | |
564 | /* Update the monotonic raw base */ | |
4a4ad80d | 565 | tk->tkr_raw.base = timespec64_to_ktime(tk->raw_time); |
9e3680b1 HS |
566 | |
567 | /* | |
568 | * The sum of the nanoseconds portions of xtime and | |
569 | * wall_to_monotonic can be greater/equal one second. Take | |
570 | * this into account before updating tk->ktime_sec. | |
571 | */ | |
876e7881 | 572 | nsec += (u32)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); |
9e3680b1 HS |
573 | if (nsec >= NSEC_PER_SEC) |
574 | seconds++; | |
575 | tk->ktime_sec = seconds; | |
7c032df5 TG |
576 | } |
577 | ||
9a7a71b1 | 578 | /* must hold timekeeper_lock */ |
04397fe9 | 579 | static void timekeeping_update(struct timekeeper *tk, unsigned int action) |
cc06268c | 580 | { |
04397fe9 | 581 | if (action & TK_CLEAR_NTP) { |
f726a697 | 582 | tk->ntp_error = 0; |
cc06268c TG |
583 | ntp_clear(); |
584 | } | |
48cdc135 | 585 | |
833f32d7 | 586 | tk_update_leap_state(tk); |
7c032df5 TG |
587 | tk_update_ktime_data(tk); |
588 | ||
9bf2419f TG |
589 | update_vsyscall(tk); |
590 | update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); | |
591 | ||
4498e746 | 592 | update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono); |
f09cb9a1 | 593 | update_fast_timekeeper(&tk->tkr_raw, &tk_fast_raw); |
868a3e91 TG |
594 | |
595 | if (action & TK_CLOCK_WAS_SET) | |
596 | tk->clock_was_set_seq++; | |
d1518326 JS |
597 | /* |
598 | * The mirroring of the data to the shadow-timekeeper needs | |
599 | * to happen last here to ensure we don't over-write the | |
600 | * timekeeper structure on the next update with stale data | |
601 | */ | |
602 | if (action & TK_MIRROR) | |
603 | memcpy(&shadow_timekeeper, &tk_core.timekeeper, | |
604 | sizeof(tk_core.timekeeper)); | |
cc06268c TG |
605 | } |
606 | ||
8524070b | 607 | /** |
155ec602 | 608 | * timekeeping_forward_now - update clock to the current time |
8524070b | 609 | * |
9a055117 RZ |
610 | * Forward the current clock to update its state since the last call to |
611 | * update_wall_time(). This is useful before significant clock changes, | |
612 | * as it avoids having to deal with this time offset explicitly. | |
8524070b | 613 | */ |
f726a697 | 614 | static void timekeeping_forward_now(struct timekeeper *tk) |
8524070b | 615 | { |
876e7881 | 616 | struct clocksource *clock = tk->tkr_mono.clock; |
3a978377 | 617 | cycle_t cycle_now, delta; |
9a055117 | 618 | s64 nsec; |
8524070b | 619 | |
876e7881 PZ |
620 | cycle_now = tk->tkr_mono.read(clock); |
621 | delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask); | |
622 | tk->tkr_mono.cycle_last = cycle_now; | |
4a4ad80d | 623 | tk->tkr_raw.cycle_last = cycle_now; |
8524070b | 624 | |
876e7881 | 625 | tk->tkr_mono.xtime_nsec += delta * tk->tkr_mono.mult; |
7d27558c | 626 | |
7b1f6207 | 627 | /* If arch requires, add in get_arch_timeoffset() */ |
876e7881 | 628 | tk->tkr_mono.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_mono.shift; |
7d27558c | 629 | |
f726a697 | 630 | tk_normalize_xtime(tk); |
2d42244a | 631 | |
4a4ad80d | 632 | nsec = clocksource_cyc2ns(delta, tk->tkr_raw.mult, tk->tkr_raw.shift); |
7d489d15 | 633 | timespec64_add_ns(&tk->raw_time, nsec); |
8524070b | 634 | } |
635 | ||
636 | /** | |
d6d29896 | 637 | * __getnstimeofday64 - Returns the time of day in a timespec64. |
8524070b | 638 | * @ts: pointer to the timespec to be set |
639 | * | |
1e817fb6 KC |
640 | * Updates the time of day in the timespec. |
641 | * Returns 0 on success, or -ve when suspended (timespec will be undefined). | |
8524070b | 642 | */ |
d6d29896 | 643 | int __getnstimeofday64(struct timespec64 *ts) |
8524070b | 644 | { |
3fdb14fd | 645 | struct timekeeper *tk = &tk_core.timekeeper; |
8524070b | 646 | unsigned long seq; |
1e75fa8b | 647 | s64 nsecs = 0; |
8524070b | 648 | |
649 | do { | |
3fdb14fd | 650 | seq = read_seqcount_begin(&tk_core.seq); |
8524070b | 651 | |
4e250fdd | 652 | ts->tv_sec = tk->xtime_sec; |
876e7881 | 653 | nsecs = timekeeping_get_ns(&tk->tkr_mono); |
8524070b | 654 | |
3fdb14fd | 655 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
8524070b | 656 | |
ec145bab | 657 | ts->tv_nsec = 0; |
d6d29896 | 658 | timespec64_add_ns(ts, nsecs); |
1e817fb6 KC |
659 | |
660 | /* | |
661 | * Do not bail out early, in case there were callers still using | |
662 | * the value, even in the face of the WARN_ON. | |
663 | */ | |
664 | if (unlikely(timekeeping_suspended)) | |
665 | return -EAGAIN; | |
666 | return 0; | |
667 | } | |
d6d29896 | 668 | EXPORT_SYMBOL(__getnstimeofday64); |
1e817fb6 KC |
669 | |
670 | /** | |
d6d29896 | 671 | * getnstimeofday64 - Returns the time of day in a timespec64. |
5322e4c2 | 672 | * @ts: pointer to the timespec64 to be set |
1e817fb6 | 673 | * |
5322e4c2 | 674 | * Returns the time of day in a timespec64 (WARN if suspended). |
1e817fb6 | 675 | */ |
d6d29896 | 676 | void getnstimeofday64(struct timespec64 *ts) |
1e817fb6 | 677 | { |
d6d29896 | 678 | WARN_ON(__getnstimeofday64(ts)); |
8524070b | 679 | } |
d6d29896 | 680 | EXPORT_SYMBOL(getnstimeofday64); |
8524070b | 681 | |
951ed4d3 MS |
682 | ktime_t ktime_get(void) |
683 | { | |
3fdb14fd | 684 | struct timekeeper *tk = &tk_core.timekeeper; |
951ed4d3 | 685 | unsigned int seq; |
a016a5bd TG |
686 | ktime_t base; |
687 | s64 nsecs; | |
951ed4d3 MS |
688 | |
689 | WARN_ON(timekeeping_suspended); | |
690 | ||
691 | do { | |
3fdb14fd | 692 | seq = read_seqcount_begin(&tk_core.seq); |
876e7881 PZ |
693 | base = tk->tkr_mono.base; |
694 | nsecs = timekeeping_get_ns(&tk->tkr_mono); | |
951ed4d3 | 695 | |
3fdb14fd | 696 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
24e4a8c3 | 697 | |
a016a5bd | 698 | return ktime_add_ns(base, nsecs); |
951ed4d3 MS |
699 | } |
700 | EXPORT_SYMBOL_GPL(ktime_get); | |
701 | ||
6374f912 HG |
702 | u32 ktime_get_resolution_ns(void) |
703 | { | |
704 | struct timekeeper *tk = &tk_core.timekeeper; | |
705 | unsigned int seq; | |
706 | u32 nsecs; | |
707 | ||
708 | WARN_ON(timekeeping_suspended); | |
709 | ||
710 | do { | |
711 | seq = read_seqcount_begin(&tk_core.seq); | |
712 | nsecs = tk->tkr_mono.mult >> tk->tkr_mono.shift; | |
713 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
714 | ||
715 | return nsecs; | |
716 | } | |
717 | EXPORT_SYMBOL_GPL(ktime_get_resolution_ns); | |
718 | ||
0077dc60 TG |
719 | static ktime_t *offsets[TK_OFFS_MAX] = { |
720 | [TK_OFFS_REAL] = &tk_core.timekeeper.offs_real, | |
721 | [TK_OFFS_BOOT] = &tk_core.timekeeper.offs_boot, | |
722 | [TK_OFFS_TAI] = &tk_core.timekeeper.offs_tai, | |
723 | }; | |
724 | ||
725 | ktime_t ktime_get_with_offset(enum tk_offsets offs) | |
726 | { | |
727 | struct timekeeper *tk = &tk_core.timekeeper; | |
728 | unsigned int seq; | |
729 | ktime_t base, *offset = offsets[offs]; | |
730 | s64 nsecs; | |
731 | ||
732 | WARN_ON(timekeeping_suspended); | |
733 | ||
734 | do { | |
735 | seq = read_seqcount_begin(&tk_core.seq); | |
876e7881 PZ |
736 | base = ktime_add(tk->tkr_mono.base, *offset); |
737 | nsecs = timekeeping_get_ns(&tk->tkr_mono); | |
0077dc60 TG |
738 | |
739 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
740 | ||
741 | return ktime_add_ns(base, nsecs); | |
742 | ||
743 | } | |
744 | EXPORT_SYMBOL_GPL(ktime_get_with_offset); | |
745 | ||
9a6b5197 TG |
746 | /** |
747 | * ktime_mono_to_any() - convert mononotic time to any other time | |
748 | * @tmono: time to convert. | |
749 | * @offs: which offset to use | |
750 | */ | |
751 | ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs) | |
752 | { | |
753 | ktime_t *offset = offsets[offs]; | |
754 | unsigned long seq; | |
755 | ktime_t tconv; | |
756 | ||
757 | do { | |
758 | seq = read_seqcount_begin(&tk_core.seq); | |
759 | tconv = ktime_add(tmono, *offset); | |
760 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
761 | ||
762 | return tconv; | |
763 | } | |
764 | EXPORT_SYMBOL_GPL(ktime_mono_to_any); | |
765 | ||
f519b1a2 TG |
766 | /** |
767 | * ktime_get_raw - Returns the raw monotonic time in ktime_t format | |
768 | */ | |
769 | ktime_t ktime_get_raw(void) | |
770 | { | |
771 | struct timekeeper *tk = &tk_core.timekeeper; | |
772 | unsigned int seq; | |
773 | ktime_t base; | |
774 | s64 nsecs; | |
775 | ||
776 | do { | |
777 | seq = read_seqcount_begin(&tk_core.seq); | |
4a4ad80d PZ |
778 | base = tk->tkr_raw.base; |
779 | nsecs = timekeeping_get_ns(&tk->tkr_raw); | |
f519b1a2 TG |
780 | |
781 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
782 | ||
783 | return ktime_add_ns(base, nsecs); | |
784 | } | |
785 | EXPORT_SYMBOL_GPL(ktime_get_raw); | |
786 | ||
951ed4d3 | 787 | /** |
d6d29896 | 788 | * ktime_get_ts64 - get the monotonic clock in timespec64 format |
951ed4d3 MS |
789 | * @ts: pointer to timespec variable |
790 | * | |
791 | * The function calculates the monotonic clock from the realtime | |
792 | * clock and the wall_to_monotonic offset and stores the result | |
5322e4c2 | 793 | * in normalized timespec64 format in the variable pointed to by @ts. |
951ed4d3 | 794 | */ |
d6d29896 | 795 | void ktime_get_ts64(struct timespec64 *ts) |
951ed4d3 | 796 | { |
3fdb14fd | 797 | struct timekeeper *tk = &tk_core.timekeeper; |
d6d29896 | 798 | struct timespec64 tomono; |
ec145bab | 799 | s64 nsec; |
951ed4d3 | 800 | unsigned int seq; |
951ed4d3 MS |
801 | |
802 | WARN_ON(timekeeping_suspended); | |
803 | ||
804 | do { | |
3fdb14fd | 805 | seq = read_seqcount_begin(&tk_core.seq); |
d6d29896 | 806 | ts->tv_sec = tk->xtime_sec; |
876e7881 | 807 | nsec = timekeeping_get_ns(&tk->tkr_mono); |
4e250fdd | 808 | tomono = tk->wall_to_monotonic; |
951ed4d3 | 809 | |
3fdb14fd | 810 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
951ed4d3 | 811 | |
d6d29896 TG |
812 | ts->tv_sec += tomono.tv_sec; |
813 | ts->tv_nsec = 0; | |
814 | timespec64_add_ns(ts, nsec + tomono.tv_nsec); | |
951ed4d3 | 815 | } |
d6d29896 | 816 | EXPORT_SYMBOL_GPL(ktime_get_ts64); |
951ed4d3 | 817 | |
9e3680b1 HS |
818 | /** |
819 | * ktime_get_seconds - Get the seconds portion of CLOCK_MONOTONIC | |
820 | * | |
821 | * Returns the seconds portion of CLOCK_MONOTONIC with a single non | |
822 | * serialized read. tk->ktime_sec is of type 'unsigned long' so this | |
823 | * works on both 32 and 64 bit systems. On 32 bit systems the readout | |
824 | * covers ~136 years of uptime which should be enough to prevent | |
825 | * premature wrap arounds. | |
826 | */ | |
827 | time64_t ktime_get_seconds(void) | |
828 | { | |
829 | struct timekeeper *tk = &tk_core.timekeeper; | |
830 | ||
831 | WARN_ON(timekeeping_suspended); | |
832 | return tk->ktime_sec; | |
833 | } | |
834 | EXPORT_SYMBOL_GPL(ktime_get_seconds); | |
835 | ||
dbe7aa62 HS |
836 | /** |
837 | * ktime_get_real_seconds - Get the seconds portion of CLOCK_REALTIME | |
838 | * | |
839 | * Returns the wall clock seconds since 1970. This replaces the | |
840 | * get_seconds() interface which is not y2038 safe on 32bit systems. | |
841 | * | |
842 | * For 64bit systems the fast access to tk->xtime_sec is preserved. On | |
843 | * 32bit systems the access must be protected with the sequence | |
844 | * counter to provide "atomic" access to the 64bit tk->xtime_sec | |
845 | * value. | |
846 | */ | |
847 | time64_t ktime_get_real_seconds(void) | |
848 | { | |
849 | struct timekeeper *tk = &tk_core.timekeeper; | |
850 | time64_t seconds; | |
851 | unsigned int seq; | |
852 | ||
853 | if (IS_ENABLED(CONFIG_64BIT)) | |
854 | return tk->xtime_sec; | |
855 | ||
856 | do { | |
857 | seq = read_seqcount_begin(&tk_core.seq); | |
858 | seconds = tk->xtime_sec; | |
859 | ||
860 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
861 | ||
862 | return seconds; | |
863 | } | |
864 | EXPORT_SYMBOL_GPL(ktime_get_real_seconds); | |
865 | ||
dee36654 D |
866 | /** |
867 | * __ktime_get_real_seconds - The same as ktime_get_real_seconds | |
868 | * but without the sequence counter protect. This internal function | |
869 | * is called just when timekeeping lock is already held. | |
870 | */ | |
871 | time64_t __ktime_get_real_seconds(void) | |
872 | { | |
873 | struct timekeeper *tk = &tk_core.timekeeper; | |
874 | ||
875 | return tk->xtime_sec; | |
876 | } | |
877 | ||
9da0f49c CH |
878 | /** |
879 | * ktime_get_snapshot - snapshots the realtime/monotonic raw clocks with counter | |
880 | * @systime_snapshot: pointer to struct receiving the system time snapshot | |
881 | */ | |
882 | void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot) | |
883 | { | |
884 | struct timekeeper *tk = &tk_core.timekeeper; | |
885 | unsigned long seq; | |
886 | ktime_t base_raw; | |
887 | ktime_t base_real; | |
888 | s64 nsec_raw; | |
889 | s64 nsec_real; | |
890 | cycle_t now; | |
891 | ||
ba26621e CH |
892 | WARN_ON_ONCE(timekeeping_suspended); |
893 | ||
9da0f49c CH |
894 | do { |
895 | seq = read_seqcount_begin(&tk_core.seq); | |
896 | ||
897 | now = tk->tkr_mono.read(tk->tkr_mono.clock); | |
2c756feb CH |
898 | systime_snapshot->cs_was_changed_seq = tk->cs_was_changed_seq; |
899 | systime_snapshot->clock_was_set_seq = tk->clock_was_set_seq; | |
9da0f49c CH |
900 | base_real = ktime_add(tk->tkr_mono.base, |
901 | tk_core.timekeeper.offs_real); | |
902 | base_raw = tk->tkr_raw.base; | |
903 | nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, now); | |
904 | nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, now); | |
905 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
906 | ||
907 | systime_snapshot->cycles = now; | |
908 | systime_snapshot->real = ktime_add_ns(base_real, nsec_real); | |
909 | systime_snapshot->raw = ktime_add_ns(base_raw, nsec_raw); | |
910 | } | |
911 | EXPORT_SYMBOL_GPL(ktime_get_snapshot); | |
dee36654 | 912 | |
2c756feb CH |
913 | /* Scale base by mult/div checking for overflow */ |
914 | static int scale64_check_overflow(u64 mult, u64 div, u64 *base) | |
915 | { | |
916 | u64 tmp, rem; | |
917 | ||
918 | tmp = div64_u64_rem(*base, div, &rem); | |
919 | ||
920 | if (((int)sizeof(u64)*8 - fls64(mult) < fls64(tmp)) || | |
921 | ((int)sizeof(u64)*8 - fls64(mult) < fls64(rem))) | |
922 | return -EOVERFLOW; | |
923 | tmp *= mult; | |
924 | rem *= mult; | |
925 | ||
926 | do_div(rem, div); | |
927 | *base = tmp + rem; | |
928 | return 0; | |
929 | } | |
930 | ||
931 | /** | |
932 | * adjust_historical_crosststamp - adjust crosstimestamp previous to current interval | |
933 | * @history: Snapshot representing start of history | |
934 | * @partial_history_cycles: Cycle offset into history (fractional part) | |
935 | * @total_history_cycles: Total history length in cycles | |
936 | * @discontinuity: True indicates clock was set on history period | |
937 | * @ts: Cross timestamp that should be adjusted using | |
938 | * partial/total ratio | |
939 | * | |
940 | * Helper function used by get_device_system_crosststamp() to correct the | |
941 | * crosstimestamp corresponding to the start of the current interval to the | |
942 | * system counter value (timestamp point) provided by the driver. The | |
943 | * total_history_* quantities are the total history starting at the provided | |
944 | * reference point and ending at the start of the current interval. The cycle | |
945 | * count between the driver timestamp point and the start of the current | |
946 | * interval is partial_history_cycles. | |
947 | */ | |
948 | static int adjust_historical_crosststamp(struct system_time_snapshot *history, | |
949 | cycle_t partial_history_cycles, | |
950 | cycle_t total_history_cycles, | |
951 | bool discontinuity, | |
952 | struct system_device_crosststamp *ts) | |
953 | { | |
954 | struct timekeeper *tk = &tk_core.timekeeper; | |
955 | u64 corr_raw, corr_real; | |
956 | bool interp_forward; | |
957 | int ret; | |
958 | ||
959 | if (total_history_cycles == 0 || partial_history_cycles == 0) | |
960 | return 0; | |
961 | ||
962 | /* Interpolate shortest distance from beginning or end of history */ | |
963 | interp_forward = partial_history_cycles > total_history_cycles/2 ? | |
964 | true : false; | |
965 | partial_history_cycles = interp_forward ? | |
966 | total_history_cycles - partial_history_cycles : | |
967 | partial_history_cycles; | |
968 | ||
969 | /* | |
970 | * Scale the monotonic raw time delta by: | |
971 | * partial_history_cycles / total_history_cycles | |
972 | */ | |
973 | corr_raw = (u64)ktime_to_ns( | |
974 | ktime_sub(ts->sys_monoraw, history->raw)); | |
975 | ret = scale64_check_overflow(partial_history_cycles, | |
976 | total_history_cycles, &corr_raw); | |
977 | if (ret) | |
978 | return ret; | |
979 | ||
980 | /* | |
981 | * If there is a discontinuity in the history, scale monotonic raw | |
982 | * correction by: | |
983 | * mult(real)/mult(raw) yielding the realtime correction | |
984 | * Otherwise, calculate the realtime correction similar to monotonic | |
985 | * raw calculation | |
986 | */ | |
987 | if (discontinuity) { | |
988 | corr_real = mul_u64_u32_div | |
989 | (corr_raw, tk->tkr_mono.mult, tk->tkr_raw.mult); | |
990 | } else { | |
991 | corr_real = (u64)ktime_to_ns( | |
992 | ktime_sub(ts->sys_realtime, history->real)); | |
993 | ret = scale64_check_overflow(partial_history_cycles, | |
994 | total_history_cycles, &corr_real); | |
995 | if (ret) | |
996 | return ret; | |
997 | } | |
998 | ||
999 | /* Fixup monotonic raw and real time time values */ | |
1000 | if (interp_forward) { | |
1001 | ts->sys_monoraw = ktime_add_ns(history->raw, corr_raw); | |
1002 | ts->sys_realtime = ktime_add_ns(history->real, corr_real); | |
1003 | } else { | |
1004 | ts->sys_monoraw = ktime_sub_ns(ts->sys_monoraw, corr_raw); | |
1005 | ts->sys_realtime = ktime_sub_ns(ts->sys_realtime, corr_real); | |
1006 | } | |
1007 | ||
1008 | return 0; | |
1009 | } | |
1010 | ||
1011 | /* | |
1012 | * cycle_between - true if test occurs chronologically between before and after | |
1013 | */ | |
1014 | static bool cycle_between(cycle_t before, cycle_t test, cycle_t after) | |
1015 | { | |
1016 | if (test > before && test < after) | |
1017 | return true; | |
1018 | if (test < before && before > after) | |
1019 | return true; | |
1020 | return false; | |
1021 | } | |
1022 | ||
8006c245 CH |
1023 | /** |
1024 | * get_device_system_crosststamp - Synchronously capture system/device timestamp | |
2c756feb | 1025 | * @get_time_fn: Callback to get simultaneous device time and |
8006c245 | 1026 | * system counter from the device driver |
2c756feb CH |
1027 | * @ctx: Context passed to get_time_fn() |
1028 | * @history_begin: Historical reference point used to interpolate system | |
1029 | * time when counter provided by the driver is before the current interval | |
8006c245 CH |
1030 | * @xtstamp: Receives simultaneously captured system and device time |
1031 | * | |
1032 | * Reads a timestamp from a device and correlates it to system time | |
1033 | */ | |
1034 | int get_device_system_crosststamp(int (*get_time_fn) | |
1035 | (ktime_t *device_time, | |
1036 | struct system_counterval_t *sys_counterval, | |
1037 | void *ctx), | |
1038 | void *ctx, | |
2c756feb | 1039 | struct system_time_snapshot *history_begin, |
8006c245 CH |
1040 | struct system_device_crosststamp *xtstamp) |
1041 | { | |
1042 | struct system_counterval_t system_counterval; | |
1043 | struct timekeeper *tk = &tk_core.timekeeper; | |
2c756feb | 1044 | cycle_t cycles, now, interval_start; |
6436257b | 1045 | unsigned int clock_was_set_seq = 0; |
8006c245 CH |
1046 | ktime_t base_real, base_raw; |
1047 | s64 nsec_real, nsec_raw; | |
2c756feb | 1048 | u8 cs_was_changed_seq; |
8006c245 | 1049 | unsigned long seq; |
2c756feb | 1050 | bool do_interp; |
8006c245 CH |
1051 | int ret; |
1052 | ||
1053 | do { | |
1054 | seq = read_seqcount_begin(&tk_core.seq); | |
1055 | /* | |
1056 | * Try to synchronously capture device time and a system | |
1057 | * counter value calling back into the device driver | |
1058 | */ | |
1059 | ret = get_time_fn(&xtstamp->device, &system_counterval, ctx); | |
1060 | if (ret) | |
1061 | return ret; | |
1062 | ||
1063 | /* | |
1064 | * Verify that the clocksource associated with the captured | |
1065 | * system counter value is the same as the currently installed | |
1066 | * timekeeper clocksource | |
1067 | */ | |
1068 | if (tk->tkr_mono.clock != system_counterval.cs) | |
1069 | return -ENODEV; | |
2c756feb CH |
1070 | cycles = system_counterval.cycles; |
1071 | ||
1072 | /* | |
1073 | * Check whether the system counter value provided by the | |
1074 | * device driver is on the current timekeeping interval. | |
1075 | */ | |
1076 | now = tk->tkr_mono.read(tk->tkr_mono.clock); | |
1077 | interval_start = tk->tkr_mono.cycle_last; | |
1078 | if (!cycle_between(interval_start, cycles, now)) { | |
1079 | clock_was_set_seq = tk->clock_was_set_seq; | |
1080 | cs_was_changed_seq = tk->cs_was_changed_seq; | |
1081 | cycles = interval_start; | |
1082 | do_interp = true; | |
1083 | } else { | |
1084 | do_interp = false; | |
1085 | } | |
8006c245 CH |
1086 | |
1087 | base_real = ktime_add(tk->tkr_mono.base, | |
1088 | tk_core.timekeeper.offs_real); | |
1089 | base_raw = tk->tkr_raw.base; | |
1090 | ||
1091 | nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, | |
1092 | system_counterval.cycles); | |
1093 | nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, | |
1094 | system_counterval.cycles); | |
1095 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
1096 | ||
1097 | xtstamp->sys_realtime = ktime_add_ns(base_real, nsec_real); | |
1098 | xtstamp->sys_monoraw = ktime_add_ns(base_raw, nsec_raw); | |
2c756feb CH |
1099 | |
1100 | /* | |
1101 | * Interpolate if necessary, adjusting back from the start of the | |
1102 | * current interval | |
1103 | */ | |
1104 | if (do_interp) { | |
1105 | cycle_t partial_history_cycles, total_history_cycles; | |
1106 | bool discontinuity; | |
1107 | ||
1108 | /* | |
1109 | * Check that the counter value occurs after the provided | |
1110 | * history reference and that the history doesn't cross a | |
1111 | * clocksource change | |
1112 | */ | |
1113 | if (!history_begin || | |
1114 | !cycle_between(history_begin->cycles, | |
1115 | system_counterval.cycles, cycles) || | |
1116 | history_begin->cs_was_changed_seq != cs_was_changed_seq) | |
1117 | return -EINVAL; | |
1118 | partial_history_cycles = cycles - system_counterval.cycles; | |
1119 | total_history_cycles = cycles - history_begin->cycles; | |
1120 | discontinuity = | |
1121 | history_begin->clock_was_set_seq != clock_was_set_seq; | |
1122 | ||
1123 | ret = adjust_historical_crosststamp(history_begin, | |
1124 | partial_history_cycles, | |
1125 | total_history_cycles, | |
1126 | discontinuity, xtstamp); | |
1127 | if (ret) | |
1128 | return ret; | |
1129 | } | |
1130 | ||
8006c245 CH |
1131 | return 0; |
1132 | } | |
1133 | EXPORT_SYMBOL_GPL(get_device_system_crosststamp); | |
1134 | ||
8524070b | 1135 | /** |
1136 | * do_gettimeofday - Returns the time of day in a timeval | |
1137 | * @tv: pointer to the timeval to be set | |
1138 | * | |
efd9ac86 | 1139 | * NOTE: Users should be converted to using getnstimeofday() |
8524070b | 1140 | */ |
1141 | void do_gettimeofday(struct timeval *tv) | |
1142 | { | |
d6d29896 | 1143 | struct timespec64 now; |
8524070b | 1144 | |
d6d29896 | 1145 | getnstimeofday64(&now); |
8524070b | 1146 | tv->tv_sec = now.tv_sec; |
1147 | tv->tv_usec = now.tv_nsec/1000; | |
1148 | } | |
8524070b | 1149 | EXPORT_SYMBOL(do_gettimeofday); |
d239f49d | 1150 | |
8524070b | 1151 | /** |
21f7eca5 | 1152 | * do_settimeofday64 - Sets the time of day. |
1153 | * @ts: pointer to the timespec64 variable containing the new time | |
8524070b | 1154 | * |
1155 | * Sets the time of day to the new time and update NTP and notify hrtimers | |
1156 | */ | |
21f7eca5 | 1157 | int do_settimeofday64(const struct timespec64 *ts) |
8524070b | 1158 | { |
3fdb14fd | 1159 | struct timekeeper *tk = &tk_core.timekeeper; |
21f7eca5 | 1160 | struct timespec64 ts_delta, xt; |
92c1d3ed | 1161 | unsigned long flags; |
e1d7ba87 | 1162 | int ret = 0; |
8524070b | 1163 | |
21f7eca5 | 1164 | if (!timespec64_valid_strict(ts)) |
8524070b | 1165 | return -EINVAL; |
1166 | ||
9a7a71b1 | 1167 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1168 | write_seqcount_begin(&tk_core.seq); |
8524070b | 1169 | |
4e250fdd | 1170 | timekeeping_forward_now(tk); |
9a055117 | 1171 | |
4e250fdd | 1172 | xt = tk_xtime(tk); |
21f7eca5 | 1173 | ts_delta.tv_sec = ts->tv_sec - xt.tv_sec; |
1174 | ts_delta.tv_nsec = ts->tv_nsec - xt.tv_nsec; | |
1e75fa8b | 1175 | |
e1d7ba87 WY |
1176 | if (timespec64_compare(&tk->wall_to_monotonic, &ts_delta) > 0) { |
1177 | ret = -EINVAL; | |
1178 | goto out; | |
1179 | } | |
1180 | ||
7d489d15 | 1181 | tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts_delta)); |
8524070b | 1182 | |
21f7eca5 | 1183 | tk_set_xtime(tk, ts); |
e1d7ba87 | 1184 | out: |
780427f0 | 1185 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
8524070b | 1186 | |
3fdb14fd | 1187 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1188 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b | 1189 | |
1190 | /* signal hrtimers about time change */ | |
1191 | clock_was_set(); | |
1192 | ||
e1d7ba87 | 1193 | return ret; |
8524070b | 1194 | } |
21f7eca5 | 1195 | EXPORT_SYMBOL(do_settimeofday64); |
8524070b | 1196 | |
c528f7c6 JS |
1197 | /** |
1198 | * timekeeping_inject_offset - Adds or subtracts from the current time. | |
1199 | * @tv: pointer to the timespec variable containing the offset | |
1200 | * | |
1201 | * Adds or subtracts an offset value from the current time. | |
1202 | */ | |
1203 | int timekeeping_inject_offset(struct timespec *ts) | |
1204 | { | |
3fdb14fd | 1205 | struct timekeeper *tk = &tk_core.timekeeper; |
92c1d3ed | 1206 | unsigned long flags; |
7d489d15 | 1207 | struct timespec64 ts64, tmp; |
4e8b1452 | 1208 | int ret = 0; |
c528f7c6 | 1209 | |
37cf4dc3 | 1210 | if (!timespec_inject_offset_valid(ts)) |
c528f7c6 JS |
1211 | return -EINVAL; |
1212 | ||
7d489d15 JS |
1213 | ts64 = timespec_to_timespec64(*ts); |
1214 | ||
9a7a71b1 | 1215 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1216 | write_seqcount_begin(&tk_core.seq); |
c528f7c6 | 1217 | |
4e250fdd | 1218 | timekeeping_forward_now(tk); |
c528f7c6 | 1219 | |
4e8b1452 | 1220 | /* Make sure the proposed value is valid */ |
7d489d15 | 1221 | tmp = timespec64_add(tk_xtime(tk), ts64); |
e1d7ba87 WY |
1222 | if (timespec64_compare(&tk->wall_to_monotonic, &ts64) > 0 || |
1223 | !timespec64_valid_strict(&tmp)) { | |
4e8b1452 JS |
1224 | ret = -EINVAL; |
1225 | goto error; | |
1226 | } | |
1e75fa8b | 1227 | |
7d489d15 JS |
1228 | tk_xtime_add(tk, &ts64); |
1229 | tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts64)); | |
c528f7c6 | 1230 | |
4e8b1452 | 1231 | error: /* even if we error out, we forwarded the time, so call update */ |
780427f0 | 1232 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
c528f7c6 | 1233 | |
3fdb14fd | 1234 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1235 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
c528f7c6 JS |
1236 | |
1237 | /* signal hrtimers about time change */ | |
1238 | clock_was_set(); | |
1239 | ||
4e8b1452 | 1240 | return ret; |
c528f7c6 JS |
1241 | } |
1242 | EXPORT_SYMBOL(timekeeping_inject_offset); | |
1243 | ||
cc244dda JS |
1244 | |
1245 | /** | |
1246 | * timekeeping_get_tai_offset - Returns current TAI offset from UTC | |
1247 | * | |
1248 | */ | |
1249 | s32 timekeeping_get_tai_offset(void) | |
1250 | { | |
3fdb14fd | 1251 | struct timekeeper *tk = &tk_core.timekeeper; |
cc244dda JS |
1252 | unsigned int seq; |
1253 | s32 ret; | |
1254 | ||
1255 | do { | |
3fdb14fd | 1256 | seq = read_seqcount_begin(&tk_core.seq); |
cc244dda | 1257 | ret = tk->tai_offset; |
3fdb14fd | 1258 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
cc244dda JS |
1259 | |
1260 | return ret; | |
1261 | } | |
1262 | ||
1263 | /** | |
1264 | * __timekeeping_set_tai_offset - Lock free worker function | |
1265 | * | |
1266 | */ | |
dd5d70e8 | 1267 | static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset) |
cc244dda JS |
1268 | { |
1269 | tk->tai_offset = tai_offset; | |
04005f60 | 1270 | tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tai_offset, 0)); |
cc244dda JS |
1271 | } |
1272 | ||
1273 | /** | |
1274 | * timekeeping_set_tai_offset - Sets the current TAI offset from UTC | |
1275 | * | |
1276 | */ | |
1277 | void timekeeping_set_tai_offset(s32 tai_offset) | |
1278 | { | |
3fdb14fd | 1279 | struct timekeeper *tk = &tk_core.timekeeper; |
cc244dda JS |
1280 | unsigned long flags; |
1281 | ||
9a7a71b1 | 1282 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1283 | write_seqcount_begin(&tk_core.seq); |
cc244dda | 1284 | __timekeeping_set_tai_offset(tk, tai_offset); |
f55c0760 | 1285 | timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |
3fdb14fd | 1286 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1287 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
4e8f8b34 | 1288 | clock_was_set(); |
cc244dda JS |
1289 | } |
1290 | ||
8524070b | 1291 | /** |
1292 | * change_clocksource - Swaps clocksources if a new one is available | |
1293 | * | |
1294 | * Accumulates current time interval and initializes new clocksource | |
1295 | */ | |
75c5158f | 1296 | static int change_clocksource(void *data) |
8524070b | 1297 | { |
3fdb14fd | 1298 | struct timekeeper *tk = &tk_core.timekeeper; |
4614e6ad | 1299 | struct clocksource *new, *old; |
f695cf94 | 1300 | unsigned long flags; |
8524070b | 1301 | |
75c5158f | 1302 | new = (struct clocksource *) data; |
8524070b | 1303 | |
9a7a71b1 | 1304 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1305 | write_seqcount_begin(&tk_core.seq); |
f695cf94 | 1306 | |
4e250fdd | 1307 | timekeeping_forward_now(tk); |
09ac369c TG |
1308 | /* |
1309 | * If the cs is in module, get a module reference. Succeeds | |
1310 | * for built-in code (owner == NULL) as well. | |
1311 | */ | |
1312 | if (try_module_get(new->owner)) { | |
1313 | if (!new->enable || new->enable(new) == 0) { | |
876e7881 | 1314 | old = tk->tkr_mono.clock; |
09ac369c TG |
1315 | tk_setup_internals(tk, new); |
1316 | if (old->disable) | |
1317 | old->disable(old); | |
1318 | module_put(old->owner); | |
1319 | } else { | |
1320 | module_put(new->owner); | |
1321 | } | |
75c5158f | 1322 | } |
780427f0 | 1323 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
f695cf94 | 1324 | |
3fdb14fd | 1325 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1326 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
f695cf94 | 1327 | |
75c5158f MS |
1328 | return 0; |
1329 | } | |
8524070b | 1330 | |
75c5158f MS |
1331 | /** |
1332 | * timekeeping_notify - Install a new clock source | |
1333 | * @clock: pointer to the clock source | |
1334 | * | |
1335 | * This function is called from clocksource.c after a new, better clock | |
1336 | * source has been registered. The caller holds the clocksource_mutex. | |
1337 | */ | |
ba919d1c | 1338 | int timekeeping_notify(struct clocksource *clock) |
75c5158f | 1339 | { |
3fdb14fd | 1340 | struct timekeeper *tk = &tk_core.timekeeper; |
4e250fdd | 1341 | |
876e7881 | 1342 | if (tk->tkr_mono.clock == clock) |
ba919d1c | 1343 | return 0; |
75c5158f | 1344 | stop_machine(change_clocksource, clock, NULL); |
8524070b | 1345 | tick_clock_notify(); |
876e7881 | 1346 | return tk->tkr_mono.clock == clock ? 0 : -1; |
8524070b | 1347 | } |
75c5158f | 1348 | |
2d42244a | 1349 | /** |
cdba2ec5 JS |
1350 | * getrawmonotonic64 - Returns the raw monotonic time in a timespec |
1351 | * @ts: pointer to the timespec64 to be set | |
2d42244a JS |
1352 | * |
1353 | * Returns the raw monotonic time (completely un-modified by ntp) | |
1354 | */ | |
cdba2ec5 | 1355 | void getrawmonotonic64(struct timespec64 *ts) |
2d42244a | 1356 | { |
3fdb14fd | 1357 | struct timekeeper *tk = &tk_core.timekeeper; |
7d489d15 | 1358 | struct timespec64 ts64; |
2d42244a JS |
1359 | unsigned long seq; |
1360 | s64 nsecs; | |
2d42244a JS |
1361 | |
1362 | do { | |
3fdb14fd | 1363 | seq = read_seqcount_begin(&tk_core.seq); |
4a4ad80d | 1364 | nsecs = timekeeping_get_ns(&tk->tkr_raw); |
7d489d15 | 1365 | ts64 = tk->raw_time; |
2d42244a | 1366 | |
3fdb14fd | 1367 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
2d42244a | 1368 | |
7d489d15 | 1369 | timespec64_add_ns(&ts64, nsecs); |
cdba2ec5 | 1370 | *ts = ts64; |
2d42244a | 1371 | } |
cdba2ec5 JS |
1372 | EXPORT_SYMBOL(getrawmonotonic64); |
1373 | ||
2d42244a | 1374 | |
8524070b | 1375 | /** |
cf4fc6cb | 1376 | * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres |
8524070b | 1377 | */ |
cf4fc6cb | 1378 | int timekeeping_valid_for_hres(void) |
8524070b | 1379 | { |
3fdb14fd | 1380 | struct timekeeper *tk = &tk_core.timekeeper; |
8524070b | 1381 | unsigned long seq; |
1382 | int ret; | |
1383 | ||
1384 | do { | |
3fdb14fd | 1385 | seq = read_seqcount_begin(&tk_core.seq); |
8524070b | 1386 | |
876e7881 | 1387 | ret = tk->tkr_mono.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; |
8524070b | 1388 | |
3fdb14fd | 1389 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
8524070b | 1390 | |
1391 | return ret; | |
1392 | } | |
1393 | ||
98962465 JH |
1394 | /** |
1395 | * timekeeping_max_deferment - Returns max time the clocksource can be deferred | |
98962465 JH |
1396 | */ |
1397 | u64 timekeeping_max_deferment(void) | |
1398 | { | |
3fdb14fd | 1399 | struct timekeeper *tk = &tk_core.timekeeper; |
70471f2f JS |
1400 | unsigned long seq; |
1401 | u64 ret; | |
42e71e81 | 1402 | |
70471f2f | 1403 | do { |
3fdb14fd | 1404 | seq = read_seqcount_begin(&tk_core.seq); |
70471f2f | 1405 | |
876e7881 | 1406 | ret = tk->tkr_mono.clock->max_idle_ns; |
70471f2f | 1407 | |
3fdb14fd | 1408 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
70471f2f JS |
1409 | |
1410 | return ret; | |
98962465 JH |
1411 | } |
1412 | ||
8524070b | 1413 | /** |
d4f587c6 | 1414 | * read_persistent_clock - Return time from the persistent clock. |
8524070b | 1415 | * |
1416 | * Weak dummy function for arches that do not yet support it. | |
d4f587c6 MS |
1417 | * Reads the time from the battery backed persistent clock. |
1418 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. | |
8524070b | 1419 | * |
1420 | * XXX - Do be sure to remove it once all arches implement it. | |
1421 | */ | |
52f5684c | 1422 | void __weak read_persistent_clock(struct timespec *ts) |
8524070b | 1423 | { |
d4f587c6 MS |
1424 | ts->tv_sec = 0; |
1425 | ts->tv_nsec = 0; | |
8524070b | 1426 | } |
1427 | ||
2ee96632 XP |
1428 | void __weak read_persistent_clock64(struct timespec64 *ts64) |
1429 | { | |
1430 | struct timespec ts; | |
1431 | ||
1432 | read_persistent_clock(&ts); | |
1433 | *ts64 = timespec_to_timespec64(ts); | |
1434 | } | |
1435 | ||
23970e38 | 1436 | /** |
e83d0a41 | 1437 | * read_boot_clock64 - Return time of the system start. |
23970e38 MS |
1438 | * |
1439 | * Weak dummy function for arches that do not yet support it. | |
1440 | * Function to read the exact time the system has been started. | |
e83d0a41 | 1441 | * Returns a timespec64 with tv_sec=0 and tv_nsec=0 if unsupported. |
23970e38 MS |
1442 | * |
1443 | * XXX - Do be sure to remove it once all arches implement it. | |
1444 | */ | |
e83d0a41 | 1445 | void __weak read_boot_clock64(struct timespec64 *ts) |
23970e38 MS |
1446 | { |
1447 | ts->tv_sec = 0; | |
1448 | ts->tv_nsec = 0; | |
1449 | } | |
1450 | ||
0fa88cb4 XP |
1451 | /* Flag for if timekeeping_resume() has injected sleeptime */ |
1452 | static bool sleeptime_injected; | |
1453 | ||
1454 | /* Flag for if there is a persistent clock on this platform */ | |
1455 | static bool persistent_clock_exists; | |
1456 | ||
8524070b | 1457 | /* |
1458 | * timekeeping_init - Initializes the clocksource and common timekeeping values | |
1459 | */ | |
1460 | void __init timekeeping_init(void) | |
1461 | { | |
3fdb14fd | 1462 | struct timekeeper *tk = &tk_core.timekeeper; |
155ec602 | 1463 | struct clocksource *clock; |
8524070b | 1464 | unsigned long flags; |
7d489d15 | 1465 | struct timespec64 now, boot, tmp; |
31ade306 | 1466 | |
2ee96632 | 1467 | read_persistent_clock64(&now); |
7d489d15 | 1468 | if (!timespec64_valid_strict(&now)) { |
4e8b1452 JS |
1469 | pr_warn("WARNING: Persistent clock returned invalid value!\n" |
1470 | " Check your CMOS/BIOS settings.\n"); | |
1471 | now.tv_sec = 0; | |
1472 | now.tv_nsec = 0; | |
31ade306 | 1473 | } else if (now.tv_sec || now.tv_nsec) |
0fa88cb4 | 1474 | persistent_clock_exists = true; |
4e8b1452 | 1475 | |
9a806ddb | 1476 | read_boot_clock64(&boot); |
7d489d15 | 1477 | if (!timespec64_valid_strict(&boot)) { |
4e8b1452 JS |
1478 | pr_warn("WARNING: Boot clock returned invalid value!\n" |
1479 | " Check your CMOS/BIOS settings.\n"); | |
1480 | boot.tv_sec = 0; | |
1481 | boot.tv_nsec = 0; | |
1482 | } | |
8524070b | 1483 | |
9a7a71b1 | 1484 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1485 | write_seqcount_begin(&tk_core.seq); |
06c017fd JS |
1486 | ntp_init(); |
1487 | ||
f1b82746 | 1488 | clock = clocksource_default_clock(); |
a0f7d48b MS |
1489 | if (clock->enable) |
1490 | clock->enable(clock); | |
4e250fdd | 1491 | tk_setup_internals(tk, clock); |
8524070b | 1492 | |
4e250fdd JS |
1493 | tk_set_xtime(tk, &now); |
1494 | tk->raw_time.tv_sec = 0; | |
1495 | tk->raw_time.tv_nsec = 0; | |
1e75fa8b | 1496 | if (boot.tv_sec == 0 && boot.tv_nsec == 0) |
4e250fdd | 1497 | boot = tk_xtime(tk); |
1e75fa8b | 1498 | |
7d489d15 | 1499 | set_normalized_timespec64(&tmp, -boot.tv_sec, -boot.tv_nsec); |
4e250fdd | 1500 | tk_set_wall_to_mono(tk, tmp); |
6d0ef903 | 1501 | |
56fd16ca | 1502 | timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |
48cdc135 | 1503 | |
3fdb14fd | 1504 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1505 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b | 1506 | } |
1507 | ||
264bb3f7 | 1508 | /* time in seconds when suspend began for persistent clock */ |
7d489d15 | 1509 | static struct timespec64 timekeeping_suspend_time; |
8524070b | 1510 | |
304529b1 JS |
1511 | /** |
1512 | * __timekeeping_inject_sleeptime - Internal function to add sleep interval | |
1513 | * @delta: pointer to a timespec delta value | |
1514 | * | |
1515 | * Takes a timespec offset measuring a suspend interval and properly | |
1516 | * adds the sleep offset to the timekeeping variables. | |
1517 | */ | |
f726a697 | 1518 | static void __timekeeping_inject_sleeptime(struct timekeeper *tk, |
7d489d15 | 1519 | struct timespec64 *delta) |
304529b1 | 1520 | { |
7d489d15 | 1521 | if (!timespec64_valid_strict(delta)) { |
6d9bcb62 JS |
1522 | printk_deferred(KERN_WARNING |
1523 | "__timekeeping_inject_sleeptime: Invalid " | |
1524 | "sleep delta value!\n"); | |
cb5de2f8 JS |
1525 | return; |
1526 | } | |
f726a697 | 1527 | tk_xtime_add(tk, delta); |
7d489d15 | 1528 | tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *delta)); |
47da70d3 | 1529 | tk_update_sleep_time(tk, timespec64_to_ktime(*delta)); |
5c83545f | 1530 | tk_debug_account_sleep_time(delta); |
304529b1 JS |
1531 | } |
1532 | ||
7f298139 | 1533 | #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_RTC_HCTOSYS_DEVICE) |
0fa88cb4 XP |
1534 | /** |
1535 | * We have three kinds of time sources to use for sleep time | |
1536 | * injection, the preference order is: | |
1537 | * 1) non-stop clocksource | |
1538 | * 2) persistent clock (ie: RTC accessible when irqs are off) | |
1539 | * 3) RTC | |
1540 | * | |
1541 | * 1) and 2) are used by timekeeping, 3) by RTC subsystem. | |
1542 | * If system has neither 1) nor 2), 3) will be used finally. | |
1543 | * | |
1544 | * | |
1545 | * If timekeeping has injected sleeptime via either 1) or 2), | |
1546 | * 3) becomes needless, so in this case we don't need to call | |
1547 | * rtc_resume(), and this is what timekeeping_rtc_skipresume() | |
1548 | * means. | |
1549 | */ | |
1550 | bool timekeeping_rtc_skipresume(void) | |
1551 | { | |
1552 | return sleeptime_injected; | |
1553 | } | |
1554 | ||
1555 | /** | |
1556 | * 1) can be determined whether to use or not only when doing | |
1557 | * timekeeping_resume() which is invoked after rtc_suspend(), | |
1558 | * so we can't skip rtc_suspend() surely if system has 1). | |
1559 | * | |
1560 | * But if system has 2), 2) will definitely be used, so in this | |
1561 | * case we don't need to call rtc_suspend(), and this is what | |
1562 | * timekeeping_rtc_skipsuspend() means. | |
1563 | */ | |
1564 | bool timekeeping_rtc_skipsuspend(void) | |
1565 | { | |
1566 | return persistent_clock_exists; | |
1567 | } | |
1568 | ||
304529b1 | 1569 | /** |
04d90890 | 1570 | * timekeeping_inject_sleeptime64 - Adds suspend interval to timeekeeping values |
1571 | * @delta: pointer to a timespec64 delta value | |
304529b1 | 1572 | * |
2ee96632 | 1573 | * This hook is for architectures that cannot support read_persistent_clock64 |
304529b1 | 1574 | * because their RTC/persistent clock is only accessible when irqs are enabled. |
0fa88cb4 | 1575 | * and also don't have an effective nonstop clocksource. |
304529b1 JS |
1576 | * |
1577 | * This function should only be called by rtc_resume(), and allows | |
1578 | * a suspend offset to be injected into the timekeeping values. | |
1579 | */ | |
04d90890 | 1580 | void timekeeping_inject_sleeptime64(struct timespec64 *delta) |
304529b1 | 1581 | { |
3fdb14fd | 1582 | struct timekeeper *tk = &tk_core.timekeeper; |
92c1d3ed | 1583 | unsigned long flags; |
304529b1 | 1584 | |
9a7a71b1 | 1585 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1586 | write_seqcount_begin(&tk_core.seq); |
70471f2f | 1587 | |
4e250fdd | 1588 | timekeeping_forward_now(tk); |
304529b1 | 1589 | |
04d90890 | 1590 | __timekeeping_inject_sleeptime(tk, delta); |
304529b1 | 1591 | |
780427f0 | 1592 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
304529b1 | 1593 | |
3fdb14fd | 1594 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1595 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
304529b1 JS |
1596 | |
1597 | /* signal hrtimers about time change */ | |
1598 | clock_was_set(); | |
1599 | } | |
7f298139 | 1600 | #endif |
304529b1 | 1601 | |
8524070b | 1602 | /** |
1603 | * timekeeping_resume - Resumes the generic timekeeping subsystem. | |
8524070b | 1604 | */ |
124cf911 | 1605 | void timekeeping_resume(void) |
8524070b | 1606 | { |
3fdb14fd | 1607 | struct timekeeper *tk = &tk_core.timekeeper; |
876e7881 | 1608 | struct clocksource *clock = tk->tkr_mono.clock; |
92c1d3ed | 1609 | unsigned long flags; |
7d489d15 | 1610 | struct timespec64 ts_new, ts_delta; |
e445cf1c | 1611 | cycle_t cycle_now, cycle_delta; |
d4f587c6 | 1612 | |
0fa88cb4 | 1613 | sleeptime_injected = false; |
2ee96632 | 1614 | read_persistent_clock64(&ts_new); |
8524070b | 1615 | |
adc78e6b | 1616 | clockevents_resume(); |
d10ff3fb TG |
1617 | clocksource_resume(); |
1618 | ||
9a7a71b1 | 1619 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1620 | write_seqcount_begin(&tk_core.seq); |
8524070b | 1621 | |
e445cf1c FT |
1622 | /* |
1623 | * After system resumes, we need to calculate the suspended time and | |
1624 | * compensate it for the OS time. There are 3 sources that could be | |
1625 | * used: Nonstop clocksource during suspend, persistent clock and rtc | |
1626 | * device. | |
1627 | * | |
1628 | * One specific platform may have 1 or 2 or all of them, and the | |
1629 | * preference will be: | |
1630 | * suspend-nonstop clocksource -> persistent clock -> rtc | |
1631 | * The less preferred source will only be tried if there is no better | |
1632 | * usable source. The rtc part is handled separately in rtc core code. | |
1633 | */ | |
876e7881 | 1634 | cycle_now = tk->tkr_mono.read(clock); |
e445cf1c | 1635 | if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) && |
876e7881 | 1636 | cycle_now > tk->tkr_mono.cycle_last) { |
e445cf1c FT |
1637 | u64 num, max = ULLONG_MAX; |
1638 | u32 mult = clock->mult; | |
1639 | u32 shift = clock->shift; | |
1640 | s64 nsec = 0; | |
1641 | ||
876e7881 PZ |
1642 | cycle_delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, |
1643 | tk->tkr_mono.mask); | |
e445cf1c FT |
1644 | |
1645 | /* | |
1646 | * "cycle_delta * mutl" may cause 64 bits overflow, if the | |
1647 | * suspended time is too long. In that case we need do the | |
1648 | * 64 bits math carefully | |
1649 | */ | |
1650 | do_div(max, mult); | |
1651 | if (cycle_delta > max) { | |
1652 | num = div64_u64(cycle_delta, max); | |
1653 | nsec = (((u64) max * mult) >> shift) * num; | |
1654 | cycle_delta -= num * max; | |
1655 | } | |
1656 | nsec += ((u64) cycle_delta * mult) >> shift; | |
1657 | ||
7d489d15 | 1658 | ts_delta = ns_to_timespec64(nsec); |
0fa88cb4 | 1659 | sleeptime_injected = true; |
7d489d15 JS |
1660 | } else if (timespec64_compare(&ts_new, &timekeeping_suspend_time) > 0) { |
1661 | ts_delta = timespec64_sub(ts_new, timekeeping_suspend_time); | |
0fa88cb4 | 1662 | sleeptime_injected = true; |
8524070b | 1663 | } |
e445cf1c | 1664 | |
0fa88cb4 | 1665 | if (sleeptime_injected) |
e445cf1c FT |
1666 | __timekeeping_inject_sleeptime(tk, &ts_delta); |
1667 | ||
1668 | /* Re-base the last cycle value */ | |
876e7881 | 1669 | tk->tkr_mono.cycle_last = cycle_now; |
4a4ad80d PZ |
1670 | tk->tkr_raw.cycle_last = cycle_now; |
1671 | ||
4e250fdd | 1672 | tk->ntp_error = 0; |
8524070b | 1673 | timekeeping_suspended = 0; |
780427f0 | 1674 | timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |
3fdb14fd | 1675 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1676 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b | 1677 | |
1678 | touch_softlockup_watchdog(); | |
1679 | ||
4ffee521 | 1680 | tick_resume(); |
b12a03ce | 1681 | hrtimers_resume(); |
8524070b | 1682 | } |
1683 | ||
124cf911 | 1684 | int timekeeping_suspend(void) |
8524070b | 1685 | { |
3fdb14fd | 1686 | struct timekeeper *tk = &tk_core.timekeeper; |
92c1d3ed | 1687 | unsigned long flags; |
7d489d15 JS |
1688 | struct timespec64 delta, delta_delta; |
1689 | static struct timespec64 old_delta; | |
8524070b | 1690 | |
2ee96632 | 1691 | read_persistent_clock64(&timekeeping_suspend_time); |
3be90950 | 1692 | |
0d6bd995 ZM |
1693 | /* |
1694 | * On some systems the persistent_clock can not be detected at | |
1695 | * timekeeping_init by its return value, so if we see a valid | |
1696 | * value returned, update the persistent_clock_exists flag. | |
1697 | */ | |
1698 | if (timekeeping_suspend_time.tv_sec || timekeeping_suspend_time.tv_nsec) | |
0fa88cb4 | 1699 | persistent_clock_exists = true; |
0d6bd995 | 1700 | |
9a7a71b1 | 1701 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1702 | write_seqcount_begin(&tk_core.seq); |
4e250fdd | 1703 | timekeeping_forward_now(tk); |
8524070b | 1704 | timekeeping_suspended = 1; |
cb33217b | 1705 | |
0fa88cb4 | 1706 | if (persistent_clock_exists) { |
cb33217b | 1707 | /* |
264bb3f7 XP |
1708 | * To avoid drift caused by repeated suspend/resumes, |
1709 | * which each can add ~1 second drift error, | |
1710 | * try to compensate so the difference in system time | |
1711 | * and persistent_clock time stays close to constant. | |
cb33217b | 1712 | */ |
264bb3f7 XP |
1713 | delta = timespec64_sub(tk_xtime(tk), timekeeping_suspend_time); |
1714 | delta_delta = timespec64_sub(delta, old_delta); | |
1715 | if (abs(delta_delta.tv_sec) >= 2) { | |
1716 | /* | |
1717 | * if delta_delta is too large, assume time correction | |
1718 | * has occurred and set old_delta to the current delta. | |
1719 | */ | |
1720 | old_delta = delta; | |
1721 | } else { | |
1722 | /* Otherwise try to adjust old_system to compensate */ | |
1723 | timekeeping_suspend_time = | |
1724 | timespec64_add(timekeeping_suspend_time, delta_delta); | |
1725 | } | |
cb33217b | 1726 | } |
330a1617 JS |
1727 | |
1728 | timekeeping_update(tk, TK_MIRROR); | |
060407ae | 1729 | halt_fast_timekeeper(tk); |
3fdb14fd | 1730 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1731 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b | 1732 | |
4ffee521 | 1733 | tick_suspend(); |
c54a42b1 | 1734 | clocksource_suspend(); |
adc78e6b | 1735 | clockevents_suspend(); |
8524070b | 1736 | |
1737 | return 0; | |
1738 | } | |
1739 | ||
1740 | /* sysfs resume/suspend bits for timekeeping */ | |
e1a85b2c | 1741 | static struct syscore_ops timekeeping_syscore_ops = { |
8524070b | 1742 | .resume = timekeeping_resume, |
1743 | .suspend = timekeeping_suspend, | |
8524070b | 1744 | }; |
1745 | ||
e1a85b2c | 1746 | static int __init timekeeping_init_ops(void) |
8524070b | 1747 | { |
e1a85b2c RW |
1748 | register_syscore_ops(&timekeeping_syscore_ops); |
1749 | return 0; | |
8524070b | 1750 | } |
e1a85b2c | 1751 | device_initcall(timekeeping_init_ops); |
8524070b | 1752 | |
1753 | /* | |
dc491596 | 1754 | * Apply a multiplier adjustment to the timekeeper |
8524070b | 1755 | */ |
dc491596 JS |
1756 | static __always_inline void timekeeping_apply_adjustment(struct timekeeper *tk, |
1757 | s64 offset, | |
1758 | bool negative, | |
1759 | int adj_scale) | |
8524070b | 1760 | { |
dc491596 JS |
1761 | s64 interval = tk->cycle_interval; |
1762 | s32 mult_adj = 1; | |
8524070b | 1763 | |
dc491596 JS |
1764 | if (negative) { |
1765 | mult_adj = -mult_adj; | |
1766 | interval = -interval; | |
1767 | offset = -offset; | |
1d17d174 | 1768 | } |
dc491596 JS |
1769 | mult_adj <<= adj_scale; |
1770 | interval <<= adj_scale; | |
1771 | offset <<= adj_scale; | |
8524070b | 1772 | |
c2bc1111 JS |
1773 | /* |
1774 | * So the following can be confusing. | |
1775 | * | |
dc491596 | 1776 | * To keep things simple, lets assume mult_adj == 1 for now. |
c2bc1111 | 1777 | * |
dc491596 | 1778 | * When mult_adj != 1, remember that the interval and offset values |
c2bc1111 JS |
1779 | * have been appropriately scaled so the math is the same. |
1780 | * | |
1781 | * The basic idea here is that we're increasing the multiplier | |
1782 | * by one, this causes the xtime_interval to be incremented by | |
1783 | * one cycle_interval. This is because: | |
1784 | * xtime_interval = cycle_interval * mult | |
1785 | * So if mult is being incremented by one: | |
1786 | * xtime_interval = cycle_interval * (mult + 1) | |
1787 | * Its the same as: | |
1788 | * xtime_interval = (cycle_interval * mult) + cycle_interval | |
1789 | * Which can be shortened to: | |
1790 | * xtime_interval += cycle_interval | |
1791 | * | |
1792 | * So offset stores the non-accumulated cycles. Thus the current | |
1793 | * time (in shifted nanoseconds) is: | |
1794 | * now = (offset * adj) + xtime_nsec | |
1795 | * Now, even though we're adjusting the clock frequency, we have | |
1796 | * to keep time consistent. In other words, we can't jump back | |
1797 | * in time, and we also want to avoid jumping forward in time. | |
1798 | * | |
1799 | * So given the same offset value, we need the time to be the same | |
1800 | * both before and after the freq adjustment. | |
1801 | * now = (offset * adj_1) + xtime_nsec_1 | |
1802 | * now = (offset * adj_2) + xtime_nsec_2 | |
1803 | * So: | |
1804 | * (offset * adj_1) + xtime_nsec_1 = | |
1805 | * (offset * adj_2) + xtime_nsec_2 | |
1806 | * And we know: | |
1807 | * adj_2 = adj_1 + 1 | |
1808 | * So: | |
1809 | * (offset * adj_1) + xtime_nsec_1 = | |
1810 | * (offset * (adj_1+1)) + xtime_nsec_2 | |
1811 | * (offset * adj_1) + xtime_nsec_1 = | |
1812 | * (offset * adj_1) + offset + xtime_nsec_2 | |
1813 | * Canceling the sides: | |
1814 | * xtime_nsec_1 = offset + xtime_nsec_2 | |
1815 | * Which gives us: | |
1816 | * xtime_nsec_2 = xtime_nsec_1 - offset | |
1817 | * Which simplfies to: | |
1818 | * xtime_nsec -= offset | |
1819 | * | |
1820 | * XXX - TODO: Doc ntp_error calculation. | |
1821 | */ | |
876e7881 | 1822 | if ((mult_adj > 0) && (tk->tkr_mono.mult + mult_adj < mult_adj)) { |
6067dc5a | 1823 | /* NTP adjustment caused clocksource mult overflow */ |
1824 | WARN_ON_ONCE(1); | |
1825 | return; | |
1826 | } | |
1827 | ||
876e7881 | 1828 | tk->tkr_mono.mult += mult_adj; |
f726a697 | 1829 | tk->xtime_interval += interval; |
876e7881 | 1830 | tk->tkr_mono.xtime_nsec -= offset; |
f726a697 | 1831 | tk->ntp_error -= (interval - offset) << tk->ntp_error_shift; |
dc491596 JS |
1832 | } |
1833 | ||
1834 | /* | |
1835 | * Calculate the multiplier adjustment needed to match the frequency | |
1836 | * specified by NTP | |
1837 | */ | |
1838 | static __always_inline void timekeeping_freqadjust(struct timekeeper *tk, | |
1839 | s64 offset) | |
1840 | { | |
1841 | s64 interval = tk->cycle_interval; | |
1842 | s64 xinterval = tk->xtime_interval; | |
ec02b076 JS |
1843 | u32 base = tk->tkr_mono.clock->mult; |
1844 | u32 max = tk->tkr_mono.clock->maxadj; | |
1845 | u32 cur_adj = tk->tkr_mono.mult; | |
dc491596 JS |
1846 | s64 tick_error; |
1847 | bool negative; | |
ec02b076 | 1848 | u32 adj_scale; |
dc491596 JS |
1849 | |
1850 | /* Remove any current error adj from freq calculation */ | |
1851 | if (tk->ntp_err_mult) | |
1852 | xinterval -= tk->cycle_interval; | |
1853 | ||
375f45b5 JS |
1854 | tk->ntp_tick = ntp_tick_length(); |
1855 | ||
dc491596 JS |
1856 | /* Calculate current error per tick */ |
1857 | tick_error = ntp_tick_length() >> tk->ntp_error_shift; | |
1858 | tick_error -= (xinterval + tk->xtime_remainder); | |
1859 | ||
1860 | /* Don't worry about correcting it if its small */ | |
1861 | if (likely((tick_error >= 0) && (tick_error <= interval))) | |
1862 | return; | |
1863 | ||
1864 | /* preserve the direction of correction */ | |
1865 | negative = (tick_error < 0); | |
1866 | ||
ec02b076 JS |
1867 | /* If any adjustment would pass the max, just return */ |
1868 | if (negative && (cur_adj - 1) <= (base - max)) | |
1869 | return; | |
1870 | if (!negative && (cur_adj + 1) >= (base + max)) | |
1871 | return; | |
1872 | /* | |
1873 | * Sort out the magnitude of the correction, but | |
1874 | * avoid making so large a correction that we go | |
1875 | * over the max adjustment. | |
1876 | */ | |
1877 | adj_scale = 0; | |
79211c8e | 1878 | tick_error = abs(tick_error); |
ec02b076 JS |
1879 | while (tick_error > interval) { |
1880 | u32 adj = 1 << (adj_scale + 1); | |
1881 | ||
1882 | /* Check if adjustment gets us within 1 unit from the max */ | |
1883 | if (negative && (cur_adj - adj) <= (base - max)) | |
1884 | break; | |
1885 | if (!negative && (cur_adj + adj) >= (base + max)) | |
1886 | break; | |
1887 | ||
1888 | adj_scale++; | |
dc491596 | 1889 | tick_error >>= 1; |
ec02b076 | 1890 | } |
dc491596 JS |
1891 | |
1892 | /* scale the corrections */ | |
ec02b076 | 1893 | timekeeping_apply_adjustment(tk, offset, negative, adj_scale); |
dc491596 JS |
1894 | } |
1895 | ||
1896 | /* | |
1897 | * Adjust the timekeeper's multiplier to the correct frequency | |
1898 | * and also to reduce the accumulated error value. | |
1899 | */ | |
1900 | static void timekeeping_adjust(struct timekeeper *tk, s64 offset) | |
1901 | { | |
1902 | /* Correct for the current frequency error */ | |
1903 | timekeeping_freqadjust(tk, offset); | |
1904 | ||
1905 | /* Next make a small adjustment to fix any cumulative error */ | |
1906 | if (!tk->ntp_err_mult && (tk->ntp_error > 0)) { | |
1907 | tk->ntp_err_mult = 1; | |
1908 | timekeeping_apply_adjustment(tk, offset, 0, 0); | |
1909 | } else if (tk->ntp_err_mult && (tk->ntp_error <= 0)) { | |
1910 | /* Undo any existing error adjustment */ | |
1911 | timekeeping_apply_adjustment(tk, offset, 1, 0); | |
1912 | tk->ntp_err_mult = 0; | |
1913 | } | |
1914 | ||
876e7881 PZ |
1915 | if (unlikely(tk->tkr_mono.clock->maxadj && |
1916 | (abs(tk->tkr_mono.mult - tk->tkr_mono.clock->mult) | |
1917 | > tk->tkr_mono.clock->maxadj))) { | |
dc491596 JS |
1918 | printk_once(KERN_WARNING |
1919 | "Adjusting %s more than 11%% (%ld vs %ld)\n", | |
876e7881 PZ |
1920 | tk->tkr_mono.clock->name, (long)tk->tkr_mono.mult, |
1921 | (long)tk->tkr_mono.clock->mult + tk->tkr_mono.clock->maxadj); | |
dc491596 | 1922 | } |
2a8c0883 JS |
1923 | |
1924 | /* | |
1925 | * It may be possible that when we entered this function, xtime_nsec | |
1926 | * was very small. Further, if we're slightly speeding the clocksource | |
1927 | * in the code above, its possible the required corrective factor to | |
1928 | * xtime_nsec could cause it to underflow. | |
1929 | * | |
1930 | * Now, since we already accumulated the second, cannot simply roll | |
1931 | * the accumulated second back, since the NTP subsystem has been | |
1932 | * notified via second_overflow. So instead we push xtime_nsec forward | |
1933 | * by the amount we underflowed, and add that amount into the error. | |
1934 | * | |
1935 | * We'll correct this error next time through this function, when | |
1936 | * xtime_nsec is not as small. | |
1937 | */ | |
876e7881 PZ |
1938 | if (unlikely((s64)tk->tkr_mono.xtime_nsec < 0)) { |
1939 | s64 neg = -(s64)tk->tkr_mono.xtime_nsec; | |
1940 | tk->tkr_mono.xtime_nsec = 0; | |
f726a697 | 1941 | tk->ntp_error += neg << tk->ntp_error_shift; |
2a8c0883 | 1942 | } |
8524070b | 1943 | } |
1944 | ||
1f4f9487 JS |
1945 | /** |
1946 | * accumulate_nsecs_to_secs - Accumulates nsecs into secs | |
1947 | * | |
571af55a | 1948 | * Helper function that accumulates the nsecs greater than a second |
1f4f9487 JS |
1949 | * from the xtime_nsec field to the xtime_secs field. |
1950 | * It also calls into the NTP code to handle leapsecond processing. | |
1951 | * | |
1952 | */ | |
780427f0 | 1953 | static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk) |
1f4f9487 | 1954 | { |
876e7881 | 1955 | u64 nsecps = (u64)NSEC_PER_SEC << tk->tkr_mono.shift; |
5258d3f2 | 1956 | unsigned int clock_set = 0; |
1f4f9487 | 1957 | |
876e7881 | 1958 | while (tk->tkr_mono.xtime_nsec >= nsecps) { |
1f4f9487 JS |
1959 | int leap; |
1960 | ||
876e7881 | 1961 | tk->tkr_mono.xtime_nsec -= nsecps; |
1f4f9487 JS |
1962 | tk->xtime_sec++; |
1963 | ||
1964 | /* Figure out if its a leap sec and apply if needed */ | |
1965 | leap = second_overflow(tk->xtime_sec); | |
6d0ef903 | 1966 | if (unlikely(leap)) { |
7d489d15 | 1967 | struct timespec64 ts; |
6d0ef903 JS |
1968 | |
1969 | tk->xtime_sec += leap; | |
1f4f9487 | 1970 | |
6d0ef903 JS |
1971 | ts.tv_sec = leap; |
1972 | ts.tv_nsec = 0; | |
1973 | tk_set_wall_to_mono(tk, | |
7d489d15 | 1974 | timespec64_sub(tk->wall_to_monotonic, ts)); |
6d0ef903 | 1975 | |
cc244dda JS |
1976 | __timekeeping_set_tai_offset(tk, tk->tai_offset - leap); |
1977 | ||
5258d3f2 | 1978 | clock_set = TK_CLOCK_WAS_SET; |
6d0ef903 | 1979 | } |
1f4f9487 | 1980 | } |
5258d3f2 | 1981 | return clock_set; |
1f4f9487 JS |
1982 | } |
1983 | ||
a092ff0f | 1984 | /** |
1985 | * logarithmic_accumulation - shifted accumulation of cycles | |
1986 | * | |
1987 | * This functions accumulates a shifted interval of cycles into | |
1988 | * into a shifted interval nanoseconds. Allows for O(log) accumulation | |
1989 | * loop. | |
1990 | * | |
1991 | * Returns the unconsumed cycles. | |
1992 | */ | |
f726a697 | 1993 | static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset, |
5258d3f2 JS |
1994 | u32 shift, |
1995 | unsigned int *clock_set) | |
a092ff0f | 1996 | { |
23a9537a | 1997 | cycle_t interval = tk->cycle_interval << shift; |
deda2e81 | 1998 | u64 raw_nsecs; |
a092ff0f | 1999 | |
571af55a | 2000 | /* If the offset is smaller than a shifted interval, do nothing */ |
23a9537a | 2001 | if (offset < interval) |
a092ff0f | 2002 | return offset; |
2003 | ||
2004 | /* Accumulate one shifted interval */ | |
23a9537a | 2005 | offset -= interval; |
876e7881 | 2006 | tk->tkr_mono.cycle_last += interval; |
4a4ad80d | 2007 | tk->tkr_raw.cycle_last += interval; |
a092ff0f | 2008 | |
876e7881 | 2009 | tk->tkr_mono.xtime_nsec += tk->xtime_interval << shift; |
5258d3f2 | 2010 | *clock_set |= accumulate_nsecs_to_secs(tk); |
a092ff0f | 2011 | |
deda2e81 | 2012 | /* Accumulate raw time */ |
5b3900cd | 2013 | raw_nsecs = (u64)tk->raw_interval << shift; |
f726a697 | 2014 | raw_nsecs += tk->raw_time.tv_nsec; |
c7dcf87a JS |
2015 | if (raw_nsecs >= NSEC_PER_SEC) { |
2016 | u64 raw_secs = raw_nsecs; | |
2017 | raw_nsecs = do_div(raw_secs, NSEC_PER_SEC); | |
f726a697 | 2018 | tk->raw_time.tv_sec += raw_secs; |
a092ff0f | 2019 | } |
f726a697 | 2020 | tk->raw_time.tv_nsec = raw_nsecs; |
a092ff0f | 2021 | |
2022 | /* Accumulate error between NTP and clock interval */ | |
375f45b5 | 2023 | tk->ntp_error += tk->ntp_tick << shift; |
f726a697 JS |
2024 | tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) << |
2025 | (tk->ntp_error_shift + shift); | |
a092ff0f | 2026 | |
2027 | return offset; | |
2028 | } | |
2029 | ||
8524070b | 2030 | /** |
2031 | * update_wall_time - Uses the current clocksource to increment the wall time | |
2032 | * | |
8524070b | 2033 | */ |
47a1b796 | 2034 | void update_wall_time(void) |
8524070b | 2035 | { |
3fdb14fd | 2036 | struct timekeeper *real_tk = &tk_core.timekeeper; |
48cdc135 | 2037 | struct timekeeper *tk = &shadow_timekeeper; |
8524070b | 2038 | cycle_t offset; |
a092ff0f | 2039 | int shift = 0, maxshift; |
5258d3f2 | 2040 | unsigned int clock_set = 0; |
70471f2f JS |
2041 | unsigned long flags; |
2042 | ||
9a7a71b1 | 2043 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
8524070b | 2044 | |
2045 | /* Make sure we're fully resumed: */ | |
2046 | if (unlikely(timekeeping_suspended)) | |
70471f2f | 2047 | goto out; |
8524070b | 2048 | |
592913ec | 2049 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET |
48cdc135 | 2050 | offset = real_tk->cycle_interval; |
592913ec | 2051 | #else |
876e7881 PZ |
2052 | offset = clocksource_delta(tk->tkr_mono.read(tk->tkr_mono.clock), |
2053 | tk->tkr_mono.cycle_last, tk->tkr_mono.mask); | |
8524070b | 2054 | #endif |
8524070b | 2055 | |
bf2ac312 | 2056 | /* Check if there's really nothing to do */ |
48cdc135 | 2057 | if (offset < real_tk->cycle_interval) |
bf2ac312 JS |
2058 | goto out; |
2059 | ||
3c17ad19 JS |
2060 | /* Do some additional sanity checking */ |
2061 | timekeeping_check_update(real_tk, offset); | |
2062 | ||
a092ff0f | 2063 | /* |
2064 | * With NO_HZ we may have to accumulate many cycle_intervals | |
2065 | * (think "ticks") worth of time at once. To do this efficiently, | |
2066 | * we calculate the largest doubling multiple of cycle_intervals | |
88b28adf | 2067 | * that is smaller than the offset. We then accumulate that |
a092ff0f | 2068 | * chunk in one go, and then try to consume the next smaller |
2069 | * doubled multiple. | |
8524070b | 2070 | */ |
4e250fdd | 2071 | shift = ilog2(offset) - ilog2(tk->cycle_interval); |
a092ff0f | 2072 | shift = max(0, shift); |
88b28adf | 2073 | /* Bound shift to one less than what overflows tick_length */ |
ea7cf49a | 2074 | maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1; |
a092ff0f | 2075 | shift = min(shift, maxshift); |
4e250fdd | 2076 | while (offset >= tk->cycle_interval) { |
5258d3f2 JS |
2077 | offset = logarithmic_accumulation(tk, offset, shift, |
2078 | &clock_set); | |
4e250fdd | 2079 | if (offset < tk->cycle_interval<<shift) |
830ec045 | 2080 | shift--; |
8524070b | 2081 | } |
2082 | ||
2083 | /* correct the clock when NTP error is too big */ | |
4e250fdd | 2084 | timekeeping_adjust(tk, offset); |
8524070b | 2085 | |
6a867a39 | 2086 | /* |
92bb1fcf JS |
2087 | * XXX This can be killed once everyone converts |
2088 | * to the new update_vsyscall. | |
2089 | */ | |
2090 | old_vsyscall_fixup(tk); | |
8524070b | 2091 | |
6a867a39 JS |
2092 | /* |
2093 | * Finally, make sure that after the rounding | |
1e75fa8b | 2094 | * xtime_nsec isn't larger than NSEC_PER_SEC |
6a867a39 | 2095 | */ |
5258d3f2 | 2096 | clock_set |= accumulate_nsecs_to_secs(tk); |
83f57a11 | 2097 | |
3fdb14fd | 2098 | write_seqcount_begin(&tk_core.seq); |
48cdc135 TG |
2099 | /* |
2100 | * Update the real timekeeper. | |
2101 | * | |
2102 | * We could avoid this memcpy by switching pointers, but that | |
2103 | * requires changes to all other timekeeper usage sites as | |
2104 | * well, i.e. move the timekeeper pointer getter into the | |
2105 | * spinlocked/seqcount protected sections. And we trade this | |
3fdb14fd | 2106 | * memcpy under the tk_core.seq against one before we start |
48cdc135 TG |
2107 | * updating. |
2108 | */ | |
906c5557 | 2109 | timekeeping_update(tk, clock_set); |
48cdc135 | 2110 | memcpy(real_tk, tk, sizeof(*tk)); |
906c5557 | 2111 | /* The memcpy must come last. Do not put anything here! */ |
3fdb14fd | 2112 | write_seqcount_end(&tk_core.seq); |
ca4523cd | 2113 | out: |
9a7a71b1 | 2114 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
47a1b796 | 2115 | if (clock_set) |
cab5e127 JS |
2116 | /* Have to call _delayed version, since in irq context*/ |
2117 | clock_was_set_delayed(); | |
8524070b | 2118 | } |
7c3f1a57 TJ |
2119 | |
2120 | /** | |
d08c0cdd JS |
2121 | * getboottime64 - Return the real time of system boot. |
2122 | * @ts: pointer to the timespec64 to be set | |
7c3f1a57 | 2123 | * |
d08c0cdd | 2124 | * Returns the wall-time of boot in a timespec64. |
7c3f1a57 TJ |
2125 | * |
2126 | * This is based on the wall_to_monotonic offset and the total suspend | |
2127 | * time. Calls to settimeofday will affect the value returned (which | |
2128 | * basically means that however wrong your real time clock is at boot time, | |
2129 | * you get the right time here). | |
2130 | */ | |
d08c0cdd | 2131 | void getboottime64(struct timespec64 *ts) |
7c3f1a57 | 2132 | { |
3fdb14fd | 2133 | struct timekeeper *tk = &tk_core.timekeeper; |
02cba159 TG |
2134 | ktime_t t = ktime_sub(tk->offs_real, tk->offs_boot); |
2135 | ||
d08c0cdd | 2136 | *ts = ktime_to_timespec64(t); |
7c3f1a57 | 2137 | } |
d08c0cdd | 2138 | EXPORT_SYMBOL_GPL(getboottime64); |
7c3f1a57 | 2139 | |
17c38b74 | 2140 | unsigned long get_seconds(void) |
2141 | { | |
3fdb14fd | 2142 | struct timekeeper *tk = &tk_core.timekeeper; |
4e250fdd JS |
2143 | |
2144 | return tk->xtime_sec; | |
17c38b74 | 2145 | } |
2146 | EXPORT_SYMBOL(get_seconds); | |
2147 | ||
da15cfda | 2148 | struct timespec __current_kernel_time(void) |
2149 | { | |
3fdb14fd | 2150 | struct timekeeper *tk = &tk_core.timekeeper; |
4e250fdd | 2151 | |
7d489d15 | 2152 | return timespec64_to_timespec(tk_xtime(tk)); |
da15cfda | 2153 | } |
17c38b74 | 2154 | |
8758a240 | 2155 | struct timespec64 current_kernel_time64(void) |
2c6b47de | 2156 | { |
3fdb14fd | 2157 | struct timekeeper *tk = &tk_core.timekeeper; |
7d489d15 | 2158 | struct timespec64 now; |
2c6b47de | 2159 | unsigned long seq; |
2160 | ||
2161 | do { | |
3fdb14fd | 2162 | seq = read_seqcount_begin(&tk_core.seq); |
83f57a11 | 2163 | |
4e250fdd | 2164 | now = tk_xtime(tk); |
3fdb14fd | 2165 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
2c6b47de | 2166 | |
8758a240 | 2167 | return now; |
2c6b47de | 2168 | } |
8758a240 | 2169 | EXPORT_SYMBOL(current_kernel_time64); |
da15cfda | 2170 | |
334334b5 | 2171 | struct timespec64 get_monotonic_coarse64(void) |
da15cfda | 2172 | { |
3fdb14fd | 2173 | struct timekeeper *tk = &tk_core.timekeeper; |
7d489d15 | 2174 | struct timespec64 now, mono; |
da15cfda | 2175 | unsigned long seq; |
2176 | ||
2177 | do { | |
3fdb14fd | 2178 | seq = read_seqcount_begin(&tk_core.seq); |
83f57a11 | 2179 | |
4e250fdd JS |
2180 | now = tk_xtime(tk); |
2181 | mono = tk->wall_to_monotonic; | |
3fdb14fd | 2182 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
da15cfda | 2183 | |
7d489d15 | 2184 | set_normalized_timespec64(&now, now.tv_sec + mono.tv_sec, |
da15cfda | 2185 | now.tv_nsec + mono.tv_nsec); |
7d489d15 | 2186 | |
334334b5 | 2187 | return now; |
da15cfda | 2188 | } |
871cf1e5 TH |
2189 | |
2190 | /* | |
d6ad4187 | 2191 | * Must hold jiffies_lock |
871cf1e5 TH |
2192 | */ |
2193 | void do_timer(unsigned long ticks) | |
2194 | { | |
2195 | jiffies_64 += ticks; | |
871cf1e5 TH |
2196 | calc_global_load(ticks); |
2197 | } | |
48cf76f7 | 2198 | |
f6c06abf | 2199 | /** |
76f41088 | 2200 | * ktime_get_update_offsets_now - hrtimer helper |
868a3e91 | 2201 | * @cwsseq: pointer to check and store the clock was set sequence number |
f6c06abf TG |
2202 | * @offs_real: pointer to storage for monotonic -> realtime offset |
2203 | * @offs_boot: pointer to storage for monotonic -> boottime offset | |
b7bc50e4 | 2204 | * @offs_tai: pointer to storage for monotonic -> clock tai offset |
f6c06abf | 2205 | * |
868a3e91 TG |
2206 | * Returns current monotonic time and updates the offsets if the |
2207 | * sequence number in @cwsseq and timekeeper.clock_was_set_seq are | |
2208 | * different. | |
2209 | * | |
b7bc50e4 | 2210 | * Called from hrtimer_interrupt() or retrigger_next_event() |
f6c06abf | 2211 | */ |
868a3e91 TG |
2212 | ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real, |
2213 | ktime_t *offs_boot, ktime_t *offs_tai) | |
f6c06abf | 2214 | { |
3fdb14fd | 2215 | struct timekeeper *tk = &tk_core.timekeeper; |
f6c06abf | 2216 | unsigned int seq; |
a37c0aad TG |
2217 | ktime_t base; |
2218 | u64 nsecs; | |
f6c06abf TG |
2219 | |
2220 | do { | |
3fdb14fd | 2221 | seq = read_seqcount_begin(&tk_core.seq); |
f6c06abf | 2222 | |
876e7881 PZ |
2223 | base = tk->tkr_mono.base; |
2224 | nsecs = timekeeping_get_ns(&tk->tkr_mono); | |
833f32d7 JS |
2225 | base = ktime_add_ns(base, nsecs); |
2226 | ||
868a3e91 TG |
2227 | if (*cwsseq != tk->clock_was_set_seq) { |
2228 | *cwsseq = tk->clock_was_set_seq; | |
2229 | *offs_real = tk->offs_real; | |
2230 | *offs_boot = tk->offs_boot; | |
2231 | *offs_tai = tk->offs_tai; | |
2232 | } | |
833f32d7 JS |
2233 | |
2234 | /* Handle leapsecond insertion adjustments */ | |
2235 | if (unlikely(base.tv64 >= tk->next_leap_ktime.tv64)) | |
2236 | *offs_real = ktime_sub(tk->offs_real, ktime_set(1, 0)); | |
2237 | ||
3fdb14fd | 2238 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
f6c06abf | 2239 | |
833f32d7 | 2240 | return base; |
f6c06abf | 2241 | } |
f6c06abf | 2242 | |
aa6f9c59 JS |
2243 | /** |
2244 | * do_adjtimex() - Accessor function to NTP __do_adjtimex function | |
2245 | */ | |
2246 | int do_adjtimex(struct timex *txc) | |
2247 | { | |
3fdb14fd | 2248 | struct timekeeper *tk = &tk_core.timekeeper; |
06c017fd | 2249 | unsigned long flags; |
7d489d15 | 2250 | struct timespec64 ts; |
4e8f8b34 | 2251 | s32 orig_tai, tai; |
e4085693 JS |
2252 | int ret; |
2253 | ||
2254 | /* Validate the data before disabling interrupts */ | |
2255 | ret = ntp_validate_timex(txc); | |
2256 | if (ret) | |
2257 | return ret; | |
2258 | ||
cef90377 JS |
2259 | if (txc->modes & ADJ_SETOFFSET) { |
2260 | struct timespec delta; | |
2261 | delta.tv_sec = txc->time.tv_sec; | |
2262 | delta.tv_nsec = txc->time.tv_usec; | |
2263 | if (!(txc->modes & ADJ_NANO)) | |
2264 | delta.tv_nsec *= 1000; | |
2265 | ret = timekeeping_inject_offset(&delta); | |
2266 | if (ret) | |
2267 | return ret; | |
2268 | } | |
2269 | ||
d6d29896 | 2270 | getnstimeofday64(&ts); |
87ace39b | 2271 | |
06c017fd | 2272 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 2273 | write_seqcount_begin(&tk_core.seq); |
06c017fd | 2274 | |
4e8f8b34 | 2275 | orig_tai = tai = tk->tai_offset; |
87ace39b | 2276 | ret = __do_adjtimex(txc, &ts, &tai); |
aa6f9c59 | 2277 | |
4e8f8b34 JS |
2278 | if (tai != orig_tai) { |
2279 | __timekeeping_set_tai_offset(tk, tai); | |
f55c0760 | 2280 | timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |
4e8f8b34 | 2281 | } |
833f32d7 JS |
2282 | tk_update_leap_state(tk); |
2283 | ||
3fdb14fd | 2284 | write_seqcount_end(&tk_core.seq); |
06c017fd JS |
2285 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
2286 | ||
6fdda9a9 JS |
2287 | if (tai != orig_tai) |
2288 | clock_was_set(); | |
2289 | ||
7bd36014 JS |
2290 | ntp_notify_cmos_timer(); |
2291 | ||
87ace39b JS |
2292 | return ret; |
2293 | } | |
aa6f9c59 JS |
2294 | |
2295 | #ifdef CONFIG_NTP_PPS | |
2296 | /** | |
2297 | * hardpps() - Accessor function to NTP __hardpps function | |
2298 | */ | |
7ec88e4b | 2299 | void hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts) |
aa6f9c59 | 2300 | { |
06c017fd JS |
2301 | unsigned long flags; |
2302 | ||
2303 | raw_spin_lock_irqsave(&timekeeper_lock, flags); | |
3fdb14fd | 2304 | write_seqcount_begin(&tk_core.seq); |
06c017fd | 2305 | |
aa6f9c59 | 2306 | __hardpps(phase_ts, raw_ts); |
06c017fd | 2307 | |
3fdb14fd | 2308 | write_seqcount_end(&tk_core.seq); |
06c017fd | 2309 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
aa6f9c59 JS |
2310 | } |
2311 | EXPORT_SYMBOL(hardpps); | |
2312 | #endif | |
2313 | ||
f0af911a TH |
2314 | /** |
2315 | * xtime_update() - advances the timekeeping infrastructure | |
2316 | * @ticks: number of ticks, that have elapsed since the last call. | |
2317 | * | |
2318 | * Must be called with interrupts disabled. | |
2319 | */ | |
2320 | void xtime_update(unsigned long ticks) | |
2321 | { | |
d6ad4187 | 2322 | write_seqlock(&jiffies_lock); |
f0af911a | 2323 | do_timer(ticks); |
d6ad4187 | 2324 | write_sequnlock(&jiffies_lock); |
47a1b796 | 2325 | update_wall_time(); |
f0af911a | 2326 | } |