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); |
27727df2 JS |
404 | now = ktime_to_ns(tkr->base); |
405 | ||
406 | now += clocksource_delta(tkr->read(tkr->clock), | |
407 | tkr->cycle_last, tkr->mask); | |
4498e746 | 408 | } while (read_seqcount_retry(&tkf->seq, seq)); |
4396e058 | 409 | |
4396e058 TG |
410 | return now; |
411 | } | |
4498e746 PZ |
412 | |
413 | u64 ktime_get_mono_fast_ns(void) | |
414 | { | |
415 | return __ktime_get_fast_ns(&tk_fast_mono); | |
416 | } | |
4396e058 TG |
417 | EXPORT_SYMBOL_GPL(ktime_get_mono_fast_ns); |
418 | ||
f09cb9a1 PZ |
419 | u64 ktime_get_raw_fast_ns(void) |
420 | { | |
421 | return __ktime_get_fast_ns(&tk_fast_raw); | |
422 | } | |
423 | EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns); | |
424 | ||
060407ae RW |
425 | /* Suspend-time cycles value for halted fast timekeeper. */ |
426 | static cycle_t cycles_at_suspend; | |
427 | ||
428 | static cycle_t dummy_clock_read(struct clocksource *cs) | |
429 | { | |
430 | return cycles_at_suspend; | |
431 | } | |
432 | ||
433 | /** | |
434 | * halt_fast_timekeeper - Prevent fast timekeeper from accessing clocksource. | |
435 | * @tk: Timekeeper to snapshot. | |
436 | * | |
437 | * It generally is unsafe to access the clocksource after timekeeping has been | |
438 | * suspended, so take a snapshot of the readout base of @tk and use it as the | |
439 | * fast timekeeper's readout base while suspended. It will return the same | |
440 | * number of cycles every time until timekeeping is resumed at which time the | |
441 | * proper readout base for the fast timekeeper will be restored automatically. | |
442 | */ | |
443 | static void halt_fast_timekeeper(struct timekeeper *tk) | |
444 | { | |
445 | static struct tk_read_base tkr_dummy; | |
876e7881 | 446 | struct tk_read_base *tkr = &tk->tkr_mono; |
060407ae RW |
447 | |
448 | memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy)); | |
449 | cycles_at_suspend = tkr->read(tkr->clock); | |
450 | tkr_dummy.read = dummy_clock_read; | |
4498e746 | 451 | update_fast_timekeeper(&tkr_dummy, &tk_fast_mono); |
f09cb9a1 PZ |
452 | |
453 | tkr = &tk->tkr_raw; | |
454 | memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy)); | |
455 | tkr_dummy.read = dummy_clock_read; | |
456 | update_fast_timekeeper(&tkr_dummy, &tk_fast_raw); | |
060407ae RW |
457 | } |
458 | ||
c905fae4 TG |
459 | #ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD |
460 | ||
461 | static inline void update_vsyscall(struct timekeeper *tk) | |
462 | { | |
0680eb1f | 463 | struct timespec xt, wm; |
c905fae4 | 464 | |
e2dff1ec | 465 | xt = timespec64_to_timespec(tk_xtime(tk)); |
0680eb1f | 466 | wm = timespec64_to_timespec(tk->wall_to_monotonic); |
876e7881 PZ |
467 | update_vsyscall_old(&xt, &wm, tk->tkr_mono.clock, tk->tkr_mono.mult, |
468 | tk->tkr_mono.cycle_last); | |
c905fae4 TG |
469 | } |
470 | ||
471 | static inline void old_vsyscall_fixup(struct timekeeper *tk) | |
472 | { | |
473 | s64 remainder; | |
474 | ||
475 | /* | |
476 | * Store only full nanoseconds into xtime_nsec after rounding | |
477 | * it up and add the remainder to the error difference. | |
478 | * XXX - This is necessary to avoid small 1ns inconsistnecies caused | |
479 | * by truncating the remainder in vsyscalls. However, it causes | |
480 | * additional work to be done in timekeeping_adjust(). Once | |
481 | * the vsyscall implementations are converted to use xtime_nsec | |
482 | * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD | |
483 | * users are removed, this can be killed. | |
484 | */ | |
876e7881 | 485 | remainder = tk->tkr_mono.xtime_nsec & ((1ULL << tk->tkr_mono.shift) - 1); |
0209b937 TG |
486 | if (remainder != 0) { |
487 | tk->tkr_mono.xtime_nsec -= remainder; | |
488 | tk->tkr_mono.xtime_nsec += 1ULL << tk->tkr_mono.shift; | |
489 | tk->ntp_error += remainder << tk->ntp_error_shift; | |
490 | tk->ntp_error -= (1ULL << tk->tkr_mono.shift) << tk->ntp_error_shift; | |
491 | } | |
c905fae4 TG |
492 | } |
493 | #else | |
494 | #define old_vsyscall_fixup(tk) | |
495 | #endif | |
496 | ||
e0b306fe MT |
497 | static RAW_NOTIFIER_HEAD(pvclock_gtod_chain); |
498 | ||
780427f0 | 499 | static void update_pvclock_gtod(struct timekeeper *tk, bool was_set) |
e0b306fe | 500 | { |
780427f0 | 501 | raw_notifier_call_chain(&pvclock_gtod_chain, was_set, tk); |
e0b306fe MT |
502 | } |
503 | ||
504 | /** | |
505 | * pvclock_gtod_register_notifier - register a pvclock timedata update listener | |
e0b306fe MT |
506 | */ |
507 | int pvclock_gtod_register_notifier(struct notifier_block *nb) | |
508 | { | |
3fdb14fd | 509 | struct timekeeper *tk = &tk_core.timekeeper; |
e0b306fe MT |
510 | unsigned long flags; |
511 | int ret; | |
512 | ||
9a7a71b1 | 513 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
e0b306fe | 514 | ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb); |
780427f0 | 515 | update_pvclock_gtod(tk, true); |
9a7a71b1 | 516 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
e0b306fe MT |
517 | |
518 | return ret; | |
519 | } | |
520 | EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier); | |
521 | ||
522 | /** | |
523 | * pvclock_gtod_unregister_notifier - unregister a pvclock | |
524 | * timedata update listener | |
e0b306fe MT |
525 | */ |
526 | int pvclock_gtod_unregister_notifier(struct notifier_block *nb) | |
527 | { | |
e0b306fe MT |
528 | unsigned long flags; |
529 | int ret; | |
530 | ||
9a7a71b1 | 531 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
e0b306fe | 532 | ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb); |
9a7a71b1 | 533 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
e0b306fe MT |
534 | |
535 | return ret; | |
536 | } | |
537 | EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier); | |
538 | ||
833f32d7 JS |
539 | /* |
540 | * tk_update_leap_state - helper to update the next_leap_ktime | |
541 | */ | |
542 | static inline void tk_update_leap_state(struct timekeeper *tk) | |
543 | { | |
544 | tk->next_leap_ktime = ntp_get_next_leap(); | |
545 | if (tk->next_leap_ktime.tv64 != KTIME_MAX) | |
546 | /* Convert to monotonic time */ | |
547 | tk->next_leap_ktime = ktime_sub(tk->next_leap_ktime, tk->offs_real); | |
548 | } | |
549 | ||
7c032df5 TG |
550 | /* |
551 | * Update the ktime_t based scalar nsec members of the timekeeper | |
552 | */ | |
553 | static inline void tk_update_ktime_data(struct timekeeper *tk) | |
554 | { | |
9e3680b1 HS |
555 | u64 seconds; |
556 | u32 nsec; | |
7c032df5 TG |
557 | |
558 | /* | |
559 | * The xtime based monotonic readout is: | |
560 | * nsec = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec + now(); | |
561 | * The ktime based monotonic readout is: | |
562 | * nsec = base_mono + now(); | |
563 | * ==> base_mono = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec | |
564 | */ | |
9e3680b1 HS |
565 | seconds = (u64)(tk->xtime_sec + tk->wall_to_monotonic.tv_sec); |
566 | nsec = (u32) tk->wall_to_monotonic.tv_nsec; | |
876e7881 | 567 | tk->tkr_mono.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec); |
f519b1a2 TG |
568 | |
569 | /* Update the monotonic raw base */ | |
4a4ad80d | 570 | tk->tkr_raw.base = timespec64_to_ktime(tk->raw_time); |
9e3680b1 HS |
571 | |
572 | /* | |
573 | * The sum of the nanoseconds portions of xtime and | |
574 | * wall_to_monotonic can be greater/equal one second. Take | |
575 | * this into account before updating tk->ktime_sec. | |
576 | */ | |
876e7881 | 577 | nsec += (u32)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); |
9e3680b1 HS |
578 | if (nsec >= NSEC_PER_SEC) |
579 | seconds++; | |
580 | tk->ktime_sec = seconds; | |
7c032df5 TG |
581 | } |
582 | ||
9a7a71b1 | 583 | /* must hold timekeeper_lock */ |
04397fe9 | 584 | static void timekeeping_update(struct timekeeper *tk, unsigned int action) |
cc06268c | 585 | { |
04397fe9 | 586 | if (action & TK_CLEAR_NTP) { |
f726a697 | 587 | tk->ntp_error = 0; |
cc06268c TG |
588 | ntp_clear(); |
589 | } | |
48cdc135 | 590 | |
833f32d7 | 591 | tk_update_leap_state(tk); |
7c032df5 TG |
592 | tk_update_ktime_data(tk); |
593 | ||
9bf2419f TG |
594 | update_vsyscall(tk); |
595 | update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); | |
596 | ||
4498e746 | 597 | update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono); |
f09cb9a1 | 598 | update_fast_timekeeper(&tk->tkr_raw, &tk_fast_raw); |
868a3e91 TG |
599 | |
600 | if (action & TK_CLOCK_WAS_SET) | |
601 | tk->clock_was_set_seq++; | |
d1518326 JS |
602 | /* |
603 | * The mirroring of the data to the shadow-timekeeper needs | |
604 | * to happen last here to ensure we don't over-write the | |
605 | * timekeeper structure on the next update with stale data | |
606 | */ | |
607 | if (action & TK_MIRROR) | |
608 | memcpy(&shadow_timekeeper, &tk_core.timekeeper, | |
609 | sizeof(tk_core.timekeeper)); | |
cc06268c TG |
610 | } |
611 | ||
8524070b | 612 | /** |
155ec602 | 613 | * timekeeping_forward_now - update clock to the current time |
8524070b | 614 | * |
9a055117 RZ |
615 | * Forward the current clock to update its state since the last call to |
616 | * update_wall_time(). This is useful before significant clock changes, | |
617 | * as it avoids having to deal with this time offset explicitly. | |
8524070b | 618 | */ |
f726a697 | 619 | static void timekeeping_forward_now(struct timekeeper *tk) |
8524070b | 620 | { |
876e7881 | 621 | struct clocksource *clock = tk->tkr_mono.clock; |
3a978377 | 622 | cycle_t cycle_now, delta; |
9a055117 | 623 | s64 nsec; |
8524070b | 624 | |
876e7881 PZ |
625 | cycle_now = tk->tkr_mono.read(clock); |
626 | delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask); | |
627 | tk->tkr_mono.cycle_last = cycle_now; | |
4a4ad80d | 628 | tk->tkr_raw.cycle_last = cycle_now; |
8524070b | 629 | |
876e7881 | 630 | tk->tkr_mono.xtime_nsec += delta * tk->tkr_mono.mult; |
7d27558c | 631 | |
7b1f6207 | 632 | /* If arch requires, add in get_arch_timeoffset() */ |
876e7881 | 633 | tk->tkr_mono.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_mono.shift; |
7d27558c | 634 | |
f726a697 | 635 | tk_normalize_xtime(tk); |
2d42244a | 636 | |
4a4ad80d | 637 | nsec = clocksource_cyc2ns(delta, tk->tkr_raw.mult, tk->tkr_raw.shift); |
7d489d15 | 638 | timespec64_add_ns(&tk->raw_time, nsec); |
8524070b | 639 | } |
640 | ||
641 | /** | |
d6d29896 | 642 | * __getnstimeofday64 - Returns the time of day in a timespec64. |
8524070b | 643 | * @ts: pointer to the timespec to be set |
644 | * | |
1e817fb6 KC |
645 | * Updates the time of day in the timespec. |
646 | * Returns 0 on success, or -ve when suspended (timespec will be undefined). | |
8524070b | 647 | */ |
d6d29896 | 648 | int __getnstimeofday64(struct timespec64 *ts) |
8524070b | 649 | { |
3fdb14fd | 650 | struct timekeeper *tk = &tk_core.timekeeper; |
8524070b | 651 | unsigned long seq; |
1e75fa8b | 652 | s64 nsecs = 0; |
8524070b | 653 | |
654 | do { | |
3fdb14fd | 655 | seq = read_seqcount_begin(&tk_core.seq); |
8524070b | 656 | |
4e250fdd | 657 | ts->tv_sec = tk->xtime_sec; |
876e7881 | 658 | nsecs = timekeeping_get_ns(&tk->tkr_mono); |
8524070b | 659 | |
3fdb14fd | 660 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
8524070b | 661 | |
ec145bab | 662 | ts->tv_nsec = 0; |
d6d29896 | 663 | timespec64_add_ns(ts, nsecs); |
1e817fb6 KC |
664 | |
665 | /* | |
666 | * Do not bail out early, in case there were callers still using | |
667 | * the value, even in the face of the WARN_ON. | |
668 | */ | |
669 | if (unlikely(timekeeping_suspended)) | |
670 | return -EAGAIN; | |
671 | return 0; | |
672 | } | |
d6d29896 | 673 | EXPORT_SYMBOL(__getnstimeofday64); |
1e817fb6 KC |
674 | |
675 | /** | |
d6d29896 | 676 | * getnstimeofday64 - Returns the time of day in a timespec64. |
5322e4c2 | 677 | * @ts: pointer to the timespec64 to be set |
1e817fb6 | 678 | * |
5322e4c2 | 679 | * Returns the time of day in a timespec64 (WARN if suspended). |
1e817fb6 | 680 | */ |
d6d29896 | 681 | void getnstimeofday64(struct timespec64 *ts) |
1e817fb6 | 682 | { |
d6d29896 | 683 | WARN_ON(__getnstimeofday64(ts)); |
8524070b | 684 | } |
d6d29896 | 685 | EXPORT_SYMBOL(getnstimeofday64); |
8524070b | 686 | |
951ed4d3 MS |
687 | ktime_t ktime_get(void) |
688 | { | |
3fdb14fd | 689 | struct timekeeper *tk = &tk_core.timekeeper; |
951ed4d3 | 690 | unsigned int seq; |
a016a5bd TG |
691 | ktime_t base; |
692 | s64 nsecs; | |
951ed4d3 MS |
693 | |
694 | WARN_ON(timekeeping_suspended); | |
695 | ||
696 | do { | |
3fdb14fd | 697 | seq = read_seqcount_begin(&tk_core.seq); |
876e7881 PZ |
698 | base = tk->tkr_mono.base; |
699 | nsecs = timekeeping_get_ns(&tk->tkr_mono); | |
951ed4d3 | 700 | |
3fdb14fd | 701 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
24e4a8c3 | 702 | |
a016a5bd | 703 | return ktime_add_ns(base, nsecs); |
951ed4d3 MS |
704 | } |
705 | EXPORT_SYMBOL_GPL(ktime_get); | |
706 | ||
6374f912 HG |
707 | u32 ktime_get_resolution_ns(void) |
708 | { | |
709 | struct timekeeper *tk = &tk_core.timekeeper; | |
710 | unsigned int seq; | |
711 | u32 nsecs; | |
712 | ||
713 | WARN_ON(timekeeping_suspended); | |
714 | ||
715 | do { | |
716 | seq = read_seqcount_begin(&tk_core.seq); | |
717 | nsecs = tk->tkr_mono.mult >> tk->tkr_mono.shift; | |
718 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
719 | ||
720 | return nsecs; | |
721 | } | |
722 | EXPORT_SYMBOL_GPL(ktime_get_resolution_ns); | |
723 | ||
0077dc60 TG |
724 | static ktime_t *offsets[TK_OFFS_MAX] = { |
725 | [TK_OFFS_REAL] = &tk_core.timekeeper.offs_real, | |
726 | [TK_OFFS_BOOT] = &tk_core.timekeeper.offs_boot, | |
727 | [TK_OFFS_TAI] = &tk_core.timekeeper.offs_tai, | |
728 | }; | |
729 | ||
730 | ktime_t ktime_get_with_offset(enum tk_offsets offs) | |
731 | { | |
732 | struct timekeeper *tk = &tk_core.timekeeper; | |
733 | unsigned int seq; | |
734 | ktime_t base, *offset = offsets[offs]; | |
735 | s64 nsecs; | |
736 | ||
737 | WARN_ON(timekeeping_suspended); | |
738 | ||
739 | do { | |
740 | seq = read_seqcount_begin(&tk_core.seq); | |
876e7881 PZ |
741 | base = ktime_add(tk->tkr_mono.base, *offset); |
742 | nsecs = timekeeping_get_ns(&tk->tkr_mono); | |
0077dc60 TG |
743 | |
744 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
745 | ||
746 | return ktime_add_ns(base, nsecs); | |
747 | ||
748 | } | |
749 | EXPORT_SYMBOL_GPL(ktime_get_with_offset); | |
750 | ||
9a6b5197 TG |
751 | /** |
752 | * ktime_mono_to_any() - convert mononotic time to any other time | |
753 | * @tmono: time to convert. | |
754 | * @offs: which offset to use | |
755 | */ | |
756 | ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs) | |
757 | { | |
758 | ktime_t *offset = offsets[offs]; | |
759 | unsigned long seq; | |
760 | ktime_t tconv; | |
761 | ||
762 | do { | |
763 | seq = read_seqcount_begin(&tk_core.seq); | |
764 | tconv = ktime_add(tmono, *offset); | |
765 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
766 | ||
767 | return tconv; | |
768 | } | |
769 | EXPORT_SYMBOL_GPL(ktime_mono_to_any); | |
770 | ||
f519b1a2 TG |
771 | /** |
772 | * ktime_get_raw - Returns the raw monotonic time in ktime_t format | |
773 | */ | |
774 | ktime_t ktime_get_raw(void) | |
775 | { | |
776 | struct timekeeper *tk = &tk_core.timekeeper; | |
777 | unsigned int seq; | |
778 | ktime_t base; | |
779 | s64 nsecs; | |
780 | ||
781 | do { | |
782 | seq = read_seqcount_begin(&tk_core.seq); | |
4a4ad80d PZ |
783 | base = tk->tkr_raw.base; |
784 | nsecs = timekeeping_get_ns(&tk->tkr_raw); | |
f519b1a2 TG |
785 | |
786 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
787 | ||
788 | return ktime_add_ns(base, nsecs); | |
789 | } | |
790 | EXPORT_SYMBOL_GPL(ktime_get_raw); | |
791 | ||
951ed4d3 | 792 | /** |
d6d29896 | 793 | * ktime_get_ts64 - get the monotonic clock in timespec64 format |
951ed4d3 MS |
794 | * @ts: pointer to timespec variable |
795 | * | |
796 | * The function calculates the monotonic clock from the realtime | |
797 | * clock and the wall_to_monotonic offset and stores the result | |
5322e4c2 | 798 | * in normalized timespec64 format in the variable pointed to by @ts. |
951ed4d3 | 799 | */ |
d6d29896 | 800 | void ktime_get_ts64(struct timespec64 *ts) |
951ed4d3 | 801 | { |
3fdb14fd | 802 | struct timekeeper *tk = &tk_core.timekeeper; |
d6d29896 | 803 | struct timespec64 tomono; |
ec145bab | 804 | s64 nsec; |
951ed4d3 | 805 | unsigned int seq; |
951ed4d3 MS |
806 | |
807 | WARN_ON(timekeeping_suspended); | |
808 | ||
809 | do { | |
3fdb14fd | 810 | seq = read_seqcount_begin(&tk_core.seq); |
d6d29896 | 811 | ts->tv_sec = tk->xtime_sec; |
876e7881 | 812 | nsec = timekeeping_get_ns(&tk->tkr_mono); |
4e250fdd | 813 | tomono = tk->wall_to_monotonic; |
951ed4d3 | 814 | |
3fdb14fd | 815 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
951ed4d3 | 816 | |
d6d29896 TG |
817 | ts->tv_sec += tomono.tv_sec; |
818 | ts->tv_nsec = 0; | |
819 | timespec64_add_ns(ts, nsec + tomono.tv_nsec); | |
951ed4d3 | 820 | } |
d6d29896 | 821 | EXPORT_SYMBOL_GPL(ktime_get_ts64); |
951ed4d3 | 822 | |
9e3680b1 HS |
823 | /** |
824 | * ktime_get_seconds - Get the seconds portion of CLOCK_MONOTONIC | |
825 | * | |
826 | * Returns the seconds portion of CLOCK_MONOTONIC with a single non | |
827 | * serialized read. tk->ktime_sec is of type 'unsigned long' so this | |
828 | * works on both 32 and 64 bit systems. On 32 bit systems the readout | |
829 | * covers ~136 years of uptime which should be enough to prevent | |
830 | * premature wrap arounds. | |
831 | */ | |
832 | time64_t ktime_get_seconds(void) | |
833 | { | |
834 | struct timekeeper *tk = &tk_core.timekeeper; | |
835 | ||
836 | WARN_ON(timekeeping_suspended); | |
837 | return tk->ktime_sec; | |
838 | } | |
839 | EXPORT_SYMBOL_GPL(ktime_get_seconds); | |
840 | ||
dbe7aa62 HS |
841 | /** |
842 | * ktime_get_real_seconds - Get the seconds portion of CLOCK_REALTIME | |
843 | * | |
844 | * Returns the wall clock seconds since 1970. This replaces the | |
845 | * get_seconds() interface which is not y2038 safe on 32bit systems. | |
846 | * | |
847 | * For 64bit systems the fast access to tk->xtime_sec is preserved. On | |
848 | * 32bit systems the access must be protected with the sequence | |
849 | * counter to provide "atomic" access to the 64bit tk->xtime_sec | |
850 | * value. | |
851 | */ | |
852 | time64_t ktime_get_real_seconds(void) | |
853 | { | |
854 | struct timekeeper *tk = &tk_core.timekeeper; | |
855 | time64_t seconds; | |
856 | unsigned int seq; | |
857 | ||
858 | if (IS_ENABLED(CONFIG_64BIT)) | |
859 | return tk->xtime_sec; | |
860 | ||
861 | do { | |
862 | seq = read_seqcount_begin(&tk_core.seq); | |
863 | seconds = tk->xtime_sec; | |
864 | ||
865 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
866 | ||
867 | return seconds; | |
868 | } | |
869 | EXPORT_SYMBOL_GPL(ktime_get_real_seconds); | |
870 | ||
dee36654 D |
871 | /** |
872 | * __ktime_get_real_seconds - The same as ktime_get_real_seconds | |
873 | * but without the sequence counter protect. This internal function | |
874 | * is called just when timekeeping lock is already held. | |
875 | */ | |
876 | time64_t __ktime_get_real_seconds(void) | |
877 | { | |
878 | struct timekeeper *tk = &tk_core.timekeeper; | |
879 | ||
880 | return tk->xtime_sec; | |
881 | } | |
882 | ||
9da0f49c CH |
883 | /** |
884 | * ktime_get_snapshot - snapshots the realtime/monotonic raw clocks with counter | |
885 | * @systime_snapshot: pointer to struct receiving the system time snapshot | |
886 | */ | |
887 | void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot) | |
888 | { | |
889 | struct timekeeper *tk = &tk_core.timekeeper; | |
890 | unsigned long seq; | |
891 | ktime_t base_raw; | |
892 | ktime_t base_real; | |
893 | s64 nsec_raw; | |
894 | s64 nsec_real; | |
895 | cycle_t now; | |
896 | ||
ba26621e CH |
897 | WARN_ON_ONCE(timekeeping_suspended); |
898 | ||
9da0f49c CH |
899 | do { |
900 | seq = read_seqcount_begin(&tk_core.seq); | |
901 | ||
902 | now = tk->tkr_mono.read(tk->tkr_mono.clock); | |
2c756feb CH |
903 | systime_snapshot->cs_was_changed_seq = tk->cs_was_changed_seq; |
904 | systime_snapshot->clock_was_set_seq = tk->clock_was_set_seq; | |
9da0f49c CH |
905 | base_real = ktime_add(tk->tkr_mono.base, |
906 | tk_core.timekeeper.offs_real); | |
907 | base_raw = tk->tkr_raw.base; | |
908 | nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, now); | |
909 | nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, now); | |
910 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
911 | ||
912 | systime_snapshot->cycles = now; | |
913 | systime_snapshot->real = ktime_add_ns(base_real, nsec_real); | |
914 | systime_snapshot->raw = ktime_add_ns(base_raw, nsec_raw); | |
915 | } | |
916 | EXPORT_SYMBOL_GPL(ktime_get_snapshot); | |
dee36654 | 917 | |
2c756feb CH |
918 | /* Scale base by mult/div checking for overflow */ |
919 | static int scale64_check_overflow(u64 mult, u64 div, u64 *base) | |
920 | { | |
921 | u64 tmp, rem; | |
922 | ||
923 | tmp = div64_u64_rem(*base, div, &rem); | |
924 | ||
925 | if (((int)sizeof(u64)*8 - fls64(mult) < fls64(tmp)) || | |
926 | ((int)sizeof(u64)*8 - fls64(mult) < fls64(rem))) | |
927 | return -EOVERFLOW; | |
928 | tmp *= mult; | |
929 | rem *= mult; | |
930 | ||
931 | do_div(rem, div); | |
932 | *base = tmp + rem; | |
933 | return 0; | |
934 | } | |
935 | ||
936 | /** | |
937 | * adjust_historical_crosststamp - adjust crosstimestamp previous to current interval | |
938 | * @history: Snapshot representing start of history | |
939 | * @partial_history_cycles: Cycle offset into history (fractional part) | |
940 | * @total_history_cycles: Total history length in cycles | |
941 | * @discontinuity: True indicates clock was set on history period | |
942 | * @ts: Cross timestamp that should be adjusted using | |
943 | * partial/total ratio | |
944 | * | |
945 | * Helper function used by get_device_system_crosststamp() to correct the | |
946 | * crosstimestamp corresponding to the start of the current interval to the | |
947 | * system counter value (timestamp point) provided by the driver. The | |
948 | * total_history_* quantities are the total history starting at the provided | |
949 | * reference point and ending at the start of the current interval. The cycle | |
950 | * count between the driver timestamp point and the start of the current | |
951 | * interval is partial_history_cycles. | |
952 | */ | |
953 | static int adjust_historical_crosststamp(struct system_time_snapshot *history, | |
954 | cycle_t partial_history_cycles, | |
955 | cycle_t total_history_cycles, | |
956 | bool discontinuity, | |
957 | struct system_device_crosststamp *ts) | |
958 | { | |
959 | struct timekeeper *tk = &tk_core.timekeeper; | |
960 | u64 corr_raw, corr_real; | |
961 | bool interp_forward; | |
962 | int ret; | |
963 | ||
964 | if (total_history_cycles == 0 || partial_history_cycles == 0) | |
965 | return 0; | |
966 | ||
967 | /* Interpolate shortest distance from beginning or end of history */ | |
968 | interp_forward = partial_history_cycles > total_history_cycles/2 ? | |
969 | true : false; | |
970 | partial_history_cycles = interp_forward ? | |
971 | total_history_cycles - partial_history_cycles : | |
972 | partial_history_cycles; | |
973 | ||
974 | /* | |
975 | * Scale the monotonic raw time delta by: | |
976 | * partial_history_cycles / total_history_cycles | |
977 | */ | |
978 | corr_raw = (u64)ktime_to_ns( | |
979 | ktime_sub(ts->sys_monoraw, history->raw)); | |
980 | ret = scale64_check_overflow(partial_history_cycles, | |
981 | total_history_cycles, &corr_raw); | |
982 | if (ret) | |
983 | return ret; | |
984 | ||
985 | /* | |
986 | * If there is a discontinuity in the history, scale monotonic raw | |
987 | * correction by: | |
988 | * mult(real)/mult(raw) yielding the realtime correction | |
989 | * Otherwise, calculate the realtime correction similar to monotonic | |
990 | * raw calculation | |
991 | */ | |
992 | if (discontinuity) { | |
993 | corr_real = mul_u64_u32_div | |
994 | (corr_raw, tk->tkr_mono.mult, tk->tkr_raw.mult); | |
995 | } else { | |
996 | corr_real = (u64)ktime_to_ns( | |
997 | ktime_sub(ts->sys_realtime, history->real)); | |
998 | ret = scale64_check_overflow(partial_history_cycles, | |
999 | total_history_cycles, &corr_real); | |
1000 | if (ret) | |
1001 | return ret; | |
1002 | } | |
1003 | ||
1004 | /* Fixup monotonic raw and real time time values */ | |
1005 | if (interp_forward) { | |
1006 | ts->sys_monoraw = ktime_add_ns(history->raw, corr_raw); | |
1007 | ts->sys_realtime = ktime_add_ns(history->real, corr_real); | |
1008 | } else { | |
1009 | ts->sys_monoraw = ktime_sub_ns(ts->sys_monoraw, corr_raw); | |
1010 | ts->sys_realtime = ktime_sub_ns(ts->sys_realtime, corr_real); | |
1011 | } | |
1012 | ||
1013 | return 0; | |
1014 | } | |
1015 | ||
1016 | /* | |
1017 | * cycle_between - true if test occurs chronologically between before and after | |
1018 | */ | |
1019 | static bool cycle_between(cycle_t before, cycle_t test, cycle_t after) | |
1020 | { | |
1021 | if (test > before && test < after) | |
1022 | return true; | |
1023 | if (test < before && before > after) | |
1024 | return true; | |
1025 | return false; | |
1026 | } | |
1027 | ||
8006c245 CH |
1028 | /** |
1029 | * get_device_system_crosststamp - Synchronously capture system/device timestamp | |
2c756feb | 1030 | * @get_time_fn: Callback to get simultaneous device time and |
8006c245 | 1031 | * system counter from the device driver |
2c756feb CH |
1032 | * @ctx: Context passed to get_time_fn() |
1033 | * @history_begin: Historical reference point used to interpolate system | |
1034 | * time when counter provided by the driver is before the current interval | |
8006c245 CH |
1035 | * @xtstamp: Receives simultaneously captured system and device time |
1036 | * | |
1037 | * Reads a timestamp from a device and correlates it to system time | |
1038 | */ | |
1039 | int get_device_system_crosststamp(int (*get_time_fn) | |
1040 | (ktime_t *device_time, | |
1041 | struct system_counterval_t *sys_counterval, | |
1042 | void *ctx), | |
1043 | void *ctx, | |
2c756feb | 1044 | struct system_time_snapshot *history_begin, |
8006c245 CH |
1045 | struct system_device_crosststamp *xtstamp) |
1046 | { | |
1047 | struct system_counterval_t system_counterval; | |
1048 | struct timekeeper *tk = &tk_core.timekeeper; | |
2c756feb | 1049 | cycle_t cycles, now, interval_start; |
6436257b | 1050 | unsigned int clock_was_set_seq = 0; |
8006c245 CH |
1051 | ktime_t base_real, base_raw; |
1052 | s64 nsec_real, nsec_raw; | |
2c756feb | 1053 | u8 cs_was_changed_seq; |
8006c245 | 1054 | unsigned long seq; |
2c756feb | 1055 | bool do_interp; |
8006c245 CH |
1056 | int ret; |
1057 | ||
1058 | do { | |
1059 | seq = read_seqcount_begin(&tk_core.seq); | |
1060 | /* | |
1061 | * Try to synchronously capture device time and a system | |
1062 | * counter value calling back into the device driver | |
1063 | */ | |
1064 | ret = get_time_fn(&xtstamp->device, &system_counterval, ctx); | |
1065 | if (ret) | |
1066 | return ret; | |
1067 | ||
1068 | /* | |
1069 | * Verify that the clocksource associated with the captured | |
1070 | * system counter value is the same as the currently installed | |
1071 | * timekeeper clocksource | |
1072 | */ | |
1073 | if (tk->tkr_mono.clock != system_counterval.cs) | |
1074 | return -ENODEV; | |
2c756feb CH |
1075 | cycles = system_counterval.cycles; |
1076 | ||
1077 | /* | |
1078 | * Check whether the system counter value provided by the | |
1079 | * device driver is on the current timekeeping interval. | |
1080 | */ | |
1081 | now = tk->tkr_mono.read(tk->tkr_mono.clock); | |
1082 | interval_start = tk->tkr_mono.cycle_last; | |
1083 | if (!cycle_between(interval_start, cycles, now)) { | |
1084 | clock_was_set_seq = tk->clock_was_set_seq; | |
1085 | cs_was_changed_seq = tk->cs_was_changed_seq; | |
1086 | cycles = interval_start; | |
1087 | do_interp = true; | |
1088 | } else { | |
1089 | do_interp = false; | |
1090 | } | |
8006c245 CH |
1091 | |
1092 | base_real = ktime_add(tk->tkr_mono.base, | |
1093 | tk_core.timekeeper.offs_real); | |
1094 | base_raw = tk->tkr_raw.base; | |
1095 | ||
1096 | nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, | |
1097 | system_counterval.cycles); | |
1098 | nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, | |
1099 | system_counterval.cycles); | |
1100 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
1101 | ||
1102 | xtstamp->sys_realtime = ktime_add_ns(base_real, nsec_real); | |
1103 | xtstamp->sys_monoraw = ktime_add_ns(base_raw, nsec_raw); | |
2c756feb CH |
1104 | |
1105 | /* | |
1106 | * Interpolate if necessary, adjusting back from the start of the | |
1107 | * current interval | |
1108 | */ | |
1109 | if (do_interp) { | |
1110 | cycle_t partial_history_cycles, total_history_cycles; | |
1111 | bool discontinuity; | |
1112 | ||
1113 | /* | |
1114 | * Check that the counter value occurs after the provided | |
1115 | * history reference and that the history doesn't cross a | |
1116 | * clocksource change | |
1117 | */ | |
1118 | if (!history_begin || | |
1119 | !cycle_between(history_begin->cycles, | |
1120 | system_counterval.cycles, cycles) || | |
1121 | history_begin->cs_was_changed_seq != cs_was_changed_seq) | |
1122 | return -EINVAL; | |
1123 | partial_history_cycles = cycles - system_counterval.cycles; | |
1124 | total_history_cycles = cycles - history_begin->cycles; | |
1125 | discontinuity = | |
1126 | history_begin->clock_was_set_seq != clock_was_set_seq; | |
1127 | ||
1128 | ret = adjust_historical_crosststamp(history_begin, | |
1129 | partial_history_cycles, | |
1130 | total_history_cycles, | |
1131 | discontinuity, xtstamp); | |
1132 | if (ret) | |
1133 | return ret; | |
1134 | } | |
1135 | ||
8006c245 CH |
1136 | return 0; |
1137 | } | |
1138 | EXPORT_SYMBOL_GPL(get_device_system_crosststamp); | |
1139 | ||
8524070b | 1140 | /** |
1141 | * do_gettimeofday - Returns the time of day in a timeval | |
1142 | * @tv: pointer to the timeval to be set | |
1143 | * | |
efd9ac86 | 1144 | * NOTE: Users should be converted to using getnstimeofday() |
8524070b | 1145 | */ |
1146 | void do_gettimeofday(struct timeval *tv) | |
1147 | { | |
d6d29896 | 1148 | struct timespec64 now; |
8524070b | 1149 | |
d6d29896 | 1150 | getnstimeofday64(&now); |
8524070b | 1151 | tv->tv_sec = now.tv_sec; |
1152 | tv->tv_usec = now.tv_nsec/1000; | |
1153 | } | |
8524070b | 1154 | EXPORT_SYMBOL(do_gettimeofday); |
d239f49d | 1155 | |
8524070b | 1156 | /** |
21f7eca5 | 1157 | * do_settimeofday64 - Sets the time of day. |
1158 | * @ts: pointer to the timespec64 variable containing the new time | |
8524070b | 1159 | * |
1160 | * Sets the time of day to the new time and update NTP and notify hrtimers | |
1161 | */ | |
21f7eca5 | 1162 | int do_settimeofday64(const struct timespec64 *ts) |
8524070b | 1163 | { |
3fdb14fd | 1164 | struct timekeeper *tk = &tk_core.timekeeper; |
21f7eca5 | 1165 | struct timespec64 ts_delta, xt; |
92c1d3ed | 1166 | unsigned long flags; |
e1d7ba87 | 1167 | int ret = 0; |
8524070b | 1168 | |
21f7eca5 | 1169 | if (!timespec64_valid_strict(ts)) |
8524070b | 1170 | return -EINVAL; |
1171 | ||
9a7a71b1 | 1172 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1173 | write_seqcount_begin(&tk_core.seq); |
8524070b | 1174 | |
4e250fdd | 1175 | timekeeping_forward_now(tk); |
9a055117 | 1176 | |
4e250fdd | 1177 | xt = tk_xtime(tk); |
21f7eca5 | 1178 | ts_delta.tv_sec = ts->tv_sec - xt.tv_sec; |
1179 | ts_delta.tv_nsec = ts->tv_nsec - xt.tv_nsec; | |
1e75fa8b | 1180 | |
e1d7ba87 WY |
1181 | if (timespec64_compare(&tk->wall_to_monotonic, &ts_delta) > 0) { |
1182 | ret = -EINVAL; | |
1183 | goto out; | |
1184 | } | |
1185 | ||
7d489d15 | 1186 | tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts_delta)); |
8524070b | 1187 | |
21f7eca5 | 1188 | tk_set_xtime(tk, ts); |
e1d7ba87 | 1189 | out: |
780427f0 | 1190 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
8524070b | 1191 | |
3fdb14fd | 1192 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1193 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b | 1194 | |
1195 | /* signal hrtimers about time change */ | |
1196 | clock_was_set(); | |
1197 | ||
e1d7ba87 | 1198 | return ret; |
8524070b | 1199 | } |
21f7eca5 | 1200 | EXPORT_SYMBOL(do_settimeofday64); |
8524070b | 1201 | |
c528f7c6 JS |
1202 | /** |
1203 | * timekeeping_inject_offset - Adds or subtracts from the current time. | |
1204 | * @tv: pointer to the timespec variable containing the offset | |
1205 | * | |
1206 | * Adds or subtracts an offset value from the current time. | |
1207 | */ | |
1208 | int timekeeping_inject_offset(struct timespec *ts) | |
1209 | { | |
3fdb14fd | 1210 | struct timekeeper *tk = &tk_core.timekeeper; |
92c1d3ed | 1211 | unsigned long flags; |
7d489d15 | 1212 | struct timespec64 ts64, tmp; |
4e8b1452 | 1213 | int ret = 0; |
c528f7c6 | 1214 | |
37cf4dc3 | 1215 | if (!timespec_inject_offset_valid(ts)) |
c528f7c6 JS |
1216 | return -EINVAL; |
1217 | ||
7d489d15 JS |
1218 | ts64 = timespec_to_timespec64(*ts); |
1219 | ||
9a7a71b1 | 1220 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1221 | write_seqcount_begin(&tk_core.seq); |
c528f7c6 | 1222 | |
4e250fdd | 1223 | timekeeping_forward_now(tk); |
c528f7c6 | 1224 | |
4e8b1452 | 1225 | /* Make sure the proposed value is valid */ |
7d489d15 | 1226 | tmp = timespec64_add(tk_xtime(tk), ts64); |
e1d7ba87 WY |
1227 | if (timespec64_compare(&tk->wall_to_monotonic, &ts64) > 0 || |
1228 | !timespec64_valid_strict(&tmp)) { | |
4e8b1452 JS |
1229 | ret = -EINVAL; |
1230 | goto error; | |
1231 | } | |
1e75fa8b | 1232 | |
7d489d15 JS |
1233 | tk_xtime_add(tk, &ts64); |
1234 | tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts64)); | |
c528f7c6 | 1235 | |
4e8b1452 | 1236 | error: /* even if we error out, we forwarded the time, so call update */ |
780427f0 | 1237 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
c528f7c6 | 1238 | |
3fdb14fd | 1239 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1240 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
c528f7c6 JS |
1241 | |
1242 | /* signal hrtimers about time change */ | |
1243 | clock_was_set(); | |
1244 | ||
4e8b1452 | 1245 | return ret; |
c528f7c6 JS |
1246 | } |
1247 | EXPORT_SYMBOL(timekeeping_inject_offset); | |
1248 | ||
cc244dda JS |
1249 | |
1250 | /** | |
1251 | * timekeeping_get_tai_offset - Returns current TAI offset from UTC | |
1252 | * | |
1253 | */ | |
1254 | s32 timekeeping_get_tai_offset(void) | |
1255 | { | |
3fdb14fd | 1256 | struct timekeeper *tk = &tk_core.timekeeper; |
cc244dda JS |
1257 | unsigned int seq; |
1258 | s32 ret; | |
1259 | ||
1260 | do { | |
3fdb14fd | 1261 | seq = read_seqcount_begin(&tk_core.seq); |
cc244dda | 1262 | ret = tk->tai_offset; |
3fdb14fd | 1263 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
cc244dda JS |
1264 | |
1265 | return ret; | |
1266 | } | |
1267 | ||
1268 | /** | |
1269 | * __timekeeping_set_tai_offset - Lock free worker function | |
1270 | * | |
1271 | */ | |
dd5d70e8 | 1272 | static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset) |
cc244dda JS |
1273 | { |
1274 | tk->tai_offset = tai_offset; | |
04005f60 | 1275 | tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tai_offset, 0)); |
cc244dda JS |
1276 | } |
1277 | ||
1278 | /** | |
1279 | * timekeeping_set_tai_offset - Sets the current TAI offset from UTC | |
1280 | * | |
1281 | */ | |
1282 | void timekeeping_set_tai_offset(s32 tai_offset) | |
1283 | { | |
3fdb14fd | 1284 | struct timekeeper *tk = &tk_core.timekeeper; |
cc244dda JS |
1285 | unsigned long flags; |
1286 | ||
9a7a71b1 | 1287 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1288 | write_seqcount_begin(&tk_core.seq); |
cc244dda | 1289 | __timekeeping_set_tai_offset(tk, tai_offset); |
f55c0760 | 1290 | timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |
3fdb14fd | 1291 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1292 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
4e8f8b34 | 1293 | clock_was_set(); |
cc244dda JS |
1294 | } |
1295 | ||
8524070b | 1296 | /** |
1297 | * change_clocksource - Swaps clocksources if a new one is available | |
1298 | * | |
1299 | * Accumulates current time interval and initializes new clocksource | |
1300 | */ | |
75c5158f | 1301 | static int change_clocksource(void *data) |
8524070b | 1302 | { |
3fdb14fd | 1303 | struct timekeeper *tk = &tk_core.timekeeper; |
4614e6ad | 1304 | struct clocksource *new, *old; |
f695cf94 | 1305 | unsigned long flags; |
8524070b | 1306 | |
75c5158f | 1307 | new = (struct clocksource *) data; |
8524070b | 1308 | |
9a7a71b1 | 1309 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1310 | write_seqcount_begin(&tk_core.seq); |
f695cf94 | 1311 | |
4e250fdd | 1312 | timekeeping_forward_now(tk); |
09ac369c TG |
1313 | /* |
1314 | * If the cs is in module, get a module reference. Succeeds | |
1315 | * for built-in code (owner == NULL) as well. | |
1316 | */ | |
1317 | if (try_module_get(new->owner)) { | |
1318 | if (!new->enable || new->enable(new) == 0) { | |
876e7881 | 1319 | old = tk->tkr_mono.clock; |
09ac369c TG |
1320 | tk_setup_internals(tk, new); |
1321 | if (old->disable) | |
1322 | old->disable(old); | |
1323 | module_put(old->owner); | |
1324 | } else { | |
1325 | module_put(new->owner); | |
1326 | } | |
75c5158f | 1327 | } |
780427f0 | 1328 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
f695cf94 | 1329 | |
3fdb14fd | 1330 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1331 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
f695cf94 | 1332 | |
75c5158f MS |
1333 | return 0; |
1334 | } | |
8524070b | 1335 | |
75c5158f MS |
1336 | /** |
1337 | * timekeeping_notify - Install a new clock source | |
1338 | * @clock: pointer to the clock source | |
1339 | * | |
1340 | * This function is called from clocksource.c after a new, better clock | |
1341 | * source has been registered. The caller holds the clocksource_mutex. | |
1342 | */ | |
ba919d1c | 1343 | int timekeeping_notify(struct clocksource *clock) |
75c5158f | 1344 | { |
3fdb14fd | 1345 | struct timekeeper *tk = &tk_core.timekeeper; |
4e250fdd | 1346 | |
876e7881 | 1347 | if (tk->tkr_mono.clock == clock) |
ba919d1c | 1348 | return 0; |
75c5158f | 1349 | stop_machine(change_clocksource, clock, NULL); |
8524070b | 1350 | tick_clock_notify(); |
876e7881 | 1351 | return tk->tkr_mono.clock == clock ? 0 : -1; |
8524070b | 1352 | } |
75c5158f | 1353 | |
2d42244a | 1354 | /** |
cdba2ec5 JS |
1355 | * getrawmonotonic64 - Returns the raw monotonic time in a timespec |
1356 | * @ts: pointer to the timespec64 to be set | |
2d42244a JS |
1357 | * |
1358 | * Returns the raw monotonic time (completely un-modified by ntp) | |
1359 | */ | |
cdba2ec5 | 1360 | void getrawmonotonic64(struct timespec64 *ts) |
2d42244a | 1361 | { |
3fdb14fd | 1362 | struct timekeeper *tk = &tk_core.timekeeper; |
7d489d15 | 1363 | struct timespec64 ts64; |
2d42244a JS |
1364 | unsigned long seq; |
1365 | s64 nsecs; | |
2d42244a JS |
1366 | |
1367 | do { | |
3fdb14fd | 1368 | seq = read_seqcount_begin(&tk_core.seq); |
4a4ad80d | 1369 | nsecs = timekeeping_get_ns(&tk->tkr_raw); |
7d489d15 | 1370 | ts64 = tk->raw_time; |
2d42244a | 1371 | |
3fdb14fd | 1372 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
2d42244a | 1373 | |
7d489d15 | 1374 | timespec64_add_ns(&ts64, nsecs); |
cdba2ec5 | 1375 | *ts = ts64; |
2d42244a | 1376 | } |
cdba2ec5 JS |
1377 | EXPORT_SYMBOL(getrawmonotonic64); |
1378 | ||
2d42244a | 1379 | |
8524070b | 1380 | /** |
cf4fc6cb | 1381 | * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres |
8524070b | 1382 | */ |
cf4fc6cb | 1383 | int timekeeping_valid_for_hres(void) |
8524070b | 1384 | { |
3fdb14fd | 1385 | struct timekeeper *tk = &tk_core.timekeeper; |
8524070b | 1386 | unsigned long seq; |
1387 | int ret; | |
1388 | ||
1389 | do { | |
3fdb14fd | 1390 | seq = read_seqcount_begin(&tk_core.seq); |
8524070b | 1391 | |
876e7881 | 1392 | ret = tk->tkr_mono.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; |
8524070b | 1393 | |
3fdb14fd | 1394 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
8524070b | 1395 | |
1396 | return ret; | |
1397 | } | |
1398 | ||
98962465 JH |
1399 | /** |
1400 | * timekeeping_max_deferment - Returns max time the clocksource can be deferred | |
98962465 JH |
1401 | */ |
1402 | u64 timekeeping_max_deferment(void) | |
1403 | { | |
3fdb14fd | 1404 | struct timekeeper *tk = &tk_core.timekeeper; |
70471f2f JS |
1405 | unsigned long seq; |
1406 | u64 ret; | |
42e71e81 | 1407 | |
70471f2f | 1408 | do { |
3fdb14fd | 1409 | seq = read_seqcount_begin(&tk_core.seq); |
70471f2f | 1410 | |
876e7881 | 1411 | ret = tk->tkr_mono.clock->max_idle_ns; |
70471f2f | 1412 | |
3fdb14fd | 1413 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
70471f2f JS |
1414 | |
1415 | return ret; | |
98962465 JH |
1416 | } |
1417 | ||
8524070b | 1418 | /** |
d4f587c6 | 1419 | * read_persistent_clock - Return time from the persistent clock. |
8524070b | 1420 | * |
1421 | * Weak dummy function for arches that do not yet support it. | |
d4f587c6 MS |
1422 | * Reads the time from the battery backed persistent clock. |
1423 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. | |
8524070b | 1424 | * |
1425 | * XXX - Do be sure to remove it once all arches implement it. | |
1426 | */ | |
52f5684c | 1427 | void __weak read_persistent_clock(struct timespec *ts) |
8524070b | 1428 | { |
d4f587c6 MS |
1429 | ts->tv_sec = 0; |
1430 | ts->tv_nsec = 0; | |
8524070b | 1431 | } |
1432 | ||
2ee96632 XP |
1433 | void __weak read_persistent_clock64(struct timespec64 *ts64) |
1434 | { | |
1435 | struct timespec ts; | |
1436 | ||
1437 | read_persistent_clock(&ts); | |
1438 | *ts64 = timespec_to_timespec64(ts); | |
1439 | } | |
1440 | ||
23970e38 | 1441 | /** |
e83d0a41 | 1442 | * read_boot_clock64 - Return time of the system start. |
23970e38 MS |
1443 | * |
1444 | * Weak dummy function for arches that do not yet support it. | |
1445 | * Function to read the exact time the system has been started. | |
e83d0a41 | 1446 | * Returns a timespec64 with tv_sec=0 and tv_nsec=0 if unsupported. |
23970e38 MS |
1447 | * |
1448 | * XXX - Do be sure to remove it once all arches implement it. | |
1449 | */ | |
e83d0a41 | 1450 | void __weak read_boot_clock64(struct timespec64 *ts) |
23970e38 MS |
1451 | { |
1452 | ts->tv_sec = 0; | |
1453 | ts->tv_nsec = 0; | |
1454 | } | |
1455 | ||
0fa88cb4 XP |
1456 | /* Flag for if timekeeping_resume() has injected sleeptime */ |
1457 | static bool sleeptime_injected; | |
1458 | ||
1459 | /* Flag for if there is a persistent clock on this platform */ | |
1460 | static bool persistent_clock_exists; | |
1461 | ||
8524070b | 1462 | /* |
1463 | * timekeeping_init - Initializes the clocksource and common timekeeping values | |
1464 | */ | |
1465 | void __init timekeeping_init(void) | |
1466 | { | |
3fdb14fd | 1467 | struct timekeeper *tk = &tk_core.timekeeper; |
155ec602 | 1468 | struct clocksource *clock; |
8524070b | 1469 | unsigned long flags; |
7d489d15 | 1470 | struct timespec64 now, boot, tmp; |
31ade306 | 1471 | |
2ee96632 | 1472 | read_persistent_clock64(&now); |
7d489d15 | 1473 | if (!timespec64_valid_strict(&now)) { |
4e8b1452 JS |
1474 | pr_warn("WARNING: Persistent clock returned invalid value!\n" |
1475 | " Check your CMOS/BIOS settings.\n"); | |
1476 | now.tv_sec = 0; | |
1477 | now.tv_nsec = 0; | |
31ade306 | 1478 | } else if (now.tv_sec || now.tv_nsec) |
0fa88cb4 | 1479 | persistent_clock_exists = true; |
4e8b1452 | 1480 | |
9a806ddb | 1481 | read_boot_clock64(&boot); |
7d489d15 | 1482 | if (!timespec64_valid_strict(&boot)) { |
4e8b1452 JS |
1483 | pr_warn("WARNING: Boot clock returned invalid value!\n" |
1484 | " Check your CMOS/BIOS settings.\n"); | |
1485 | boot.tv_sec = 0; | |
1486 | boot.tv_nsec = 0; | |
1487 | } | |
8524070b | 1488 | |
9a7a71b1 | 1489 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1490 | write_seqcount_begin(&tk_core.seq); |
06c017fd JS |
1491 | ntp_init(); |
1492 | ||
f1b82746 | 1493 | clock = clocksource_default_clock(); |
a0f7d48b MS |
1494 | if (clock->enable) |
1495 | clock->enable(clock); | |
4e250fdd | 1496 | tk_setup_internals(tk, clock); |
8524070b | 1497 | |
4e250fdd JS |
1498 | tk_set_xtime(tk, &now); |
1499 | tk->raw_time.tv_sec = 0; | |
1500 | tk->raw_time.tv_nsec = 0; | |
1e75fa8b | 1501 | if (boot.tv_sec == 0 && boot.tv_nsec == 0) |
4e250fdd | 1502 | boot = tk_xtime(tk); |
1e75fa8b | 1503 | |
7d489d15 | 1504 | set_normalized_timespec64(&tmp, -boot.tv_sec, -boot.tv_nsec); |
4e250fdd | 1505 | tk_set_wall_to_mono(tk, tmp); |
6d0ef903 | 1506 | |
56fd16ca | 1507 | timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |
48cdc135 | 1508 | |
3fdb14fd | 1509 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1510 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b | 1511 | } |
1512 | ||
264bb3f7 | 1513 | /* time in seconds when suspend began for persistent clock */ |
7d489d15 | 1514 | static struct timespec64 timekeeping_suspend_time; |
8524070b | 1515 | |
304529b1 JS |
1516 | /** |
1517 | * __timekeeping_inject_sleeptime - Internal function to add sleep interval | |
1518 | * @delta: pointer to a timespec delta value | |
1519 | * | |
1520 | * Takes a timespec offset measuring a suspend interval and properly | |
1521 | * adds the sleep offset to the timekeeping variables. | |
1522 | */ | |
f726a697 | 1523 | static void __timekeeping_inject_sleeptime(struct timekeeper *tk, |
7d489d15 | 1524 | struct timespec64 *delta) |
304529b1 | 1525 | { |
7d489d15 | 1526 | if (!timespec64_valid_strict(delta)) { |
6d9bcb62 JS |
1527 | printk_deferred(KERN_WARNING |
1528 | "__timekeeping_inject_sleeptime: Invalid " | |
1529 | "sleep delta value!\n"); | |
cb5de2f8 JS |
1530 | return; |
1531 | } | |
f726a697 | 1532 | tk_xtime_add(tk, delta); |
7d489d15 | 1533 | tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *delta)); |
47da70d3 | 1534 | tk_update_sleep_time(tk, timespec64_to_ktime(*delta)); |
5c83545f | 1535 | tk_debug_account_sleep_time(delta); |
304529b1 JS |
1536 | } |
1537 | ||
7f298139 | 1538 | #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_RTC_HCTOSYS_DEVICE) |
0fa88cb4 XP |
1539 | /** |
1540 | * We have three kinds of time sources to use for sleep time | |
1541 | * injection, the preference order is: | |
1542 | * 1) non-stop clocksource | |
1543 | * 2) persistent clock (ie: RTC accessible when irqs are off) | |
1544 | * 3) RTC | |
1545 | * | |
1546 | * 1) and 2) are used by timekeeping, 3) by RTC subsystem. | |
1547 | * If system has neither 1) nor 2), 3) will be used finally. | |
1548 | * | |
1549 | * | |
1550 | * If timekeeping has injected sleeptime via either 1) or 2), | |
1551 | * 3) becomes needless, so in this case we don't need to call | |
1552 | * rtc_resume(), and this is what timekeeping_rtc_skipresume() | |
1553 | * means. | |
1554 | */ | |
1555 | bool timekeeping_rtc_skipresume(void) | |
1556 | { | |
1557 | return sleeptime_injected; | |
1558 | } | |
1559 | ||
1560 | /** | |
1561 | * 1) can be determined whether to use or not only when doing | |
1562 | * timekeeping_resume() which is invoked after rtc_suspend(), | |
1563 | * so we can't skip rtc_suspend() surely if system has 1). | |
1564 | * | |
1565 | * But if system has 2), 2) will definitely be used, so in this | |
1566 | * case we don't need to call rtc_suspend(), and this is what | |
1567 | * timekeeping_rtc_skipsuspend() means. | |
1568 | */ | |
1569 | bool timekeeping_rtc_skipsuspend(void) | |
1570 | { | |
1571 | return persistent_clock_exists; | |
1572 | } | |
1573 | ||
304529b1 | 1574 | /** |
04d90890 | 1575 | * timekeeping_inject_sleeptime64 - Adds suspend interval to timeekeeping values |
1576 | * @delta: pointer to a timespec64 delta value | |
304529b1 | 1577 | * |
2ee96632 | 1578 | * This hook is for architectures that cannot support read_persistent_clock64 |
304529b1 | 1579 | * because their RTC/persistent clock is only accessible when irqs are enabled. |
0fa88cb4 | 1580 | * and also don't have an effective nonstop clocksource. |
304529b1 JS |
1581 | * |
1582 | * This function should only be called by rtc_resume(), and allows | |
1583 | * a suspend offset to be injected into the timekeeping values. | |
1584 | */ | |
04d90890 | 1585 | void timekeeping_inject_sleeptime64(struct timespec64 *delta) |
304529b1 | 1586 | { |
3fdb14fd | 1587 | struct timekeeper *tk = &tk_core.timekeeper; |
92c1d3ed | 1588 | unsigned long flags; |
304529b1 | 1589 | |
9a7a71b1 | 1590 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1591 | write_seqcount_begin(&tk_core.seq); |
70471f2f | 1592 | |
4e250fdd | 1593 | timekeeping_forward_now(tk); |
304529b1 | 1594 | |
04d90890 | 1595 | __timekeeping_inject_sleeptime(tk, delta); |
304529b1 | 1596 | |
780427f0 | 1597 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
304529b1 | 1598 | |
3fdb14fd | 1599 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1600 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
304529b1 JS |
1601 | |
1602 | /* signal hrtimers about time change */ | |
1603 | clock_was_set(); | |
1604 | } | |
7f298139 | 1605 | #endif |
304529b1 | 1606 | |
8524070b | 1607 | /** |
1608 | * timekeeping_resume - Resumes the generic timekeeping subsystem. | |
8524070b | 1609 | */ |
124cf911 | 1610 | void timekeeping_resume(void) |
8524070b | 1611 | { |
3fdb14fd | 1612 | struct timekeeper *tk = &tk_core.timekeeper; |
876e7881 | 1613 | struct clocksource *clock = tk->tkr_mono.clock; |
92c1d3ed | 1614 | unsigned long flags; |
7d489d15 | 1615 | struct timespec64 ts_new, ts_delta; |
e445cf1c | 1616 | cycle_t cycle_now, cycle_delta; |
d4f587c6 | 1617 | |
0fa88cb4 | 1618 | sleeptime_injected = false; |
2ee96632 | 1619 | read_persistent_clock64(&ts_new); |
8524070b | 1620 | |
adc78e6b | 1621 | clockevents_resume(); |
d10ff3fb TG |
1622 | clocksource_resume(); |
1623 | ||
9a7a71b1 | 1624 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1625 | write_seqcount_begin(&tk_core.seq); |
8524070b | 1626 | |
e445cf1c FT |
1627 | /* |
1628 | * After system resumes, we need to calculate the suspended time and | |
1629 | * compensate it for the OS time. There are 3 sources that could be | |
1630 | * used: Nonstop clocksource during suspend, persistent clock and rtc | |
1631 | * device. | |
1632 | * | |
1633 | * One specific platform may have 1 or 2 or all of them, and the | |
1634 | * preference will be: | |
1635 | * suspend-nonstop clocksource -> persistent clock -> rtc | |
1636 | * The less preferred source will only be tried if there is no better | |
1637 | * usable source. The rtc part is handled separately in rtc core code. | |
1638 | */ | |
876e7881 | 1639 | cycle_now = tk->tkr_mono.read(clock); |
e445cf1c | 1640 | if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) && |
876e7881 | 1641 | cycle_now > tk->tkr_mono.cycle_last) { |
e445cf1c FT |
1642 | u64 num, max = ULLONG_MAX; |
1643 | u32 mult = clock->mult; | |
1644 | u32 shift = clock->shift; | |
1645 | s64 nsec = 0; | |
1646 | ||
876e7881 PZ |
1647 | cycle_delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, |
1648 | tk->tkr_mono.mask); | |
e445cf1c FT |
1649 | |
1650 | /* | |
1651 | * "cycle_delta * mutl" may cause 64 bits overflow, if the | |
1652 | * suspended time is too long. In that case we need do the | |
1653 | * 64 bits math carefully | |
1654 | */ | |
1655 | do_div(max, mult); | |
1656 | if (cycle_delta > max) { | |
1657 | num = div64_u64(cycle_delta, max); | |
1658 | nsec = (((u64) max * mult) >> shift) * num; | |
1659 | cycle_delta -= num * max; | |
1660 | } | |
1661 | nsec += ((u64) cycle_delta * mult) >> shift; | |
1662 | ||
7d489d15 | 1663 | ts_delta = ns_to_timespec64(nsec); |
0fa88cb4 | 1664 | sleeptime_injected = true; |
7d489d15 JS |
1665 | } else if (timespec64_compare(&ts_new, &timekeeping_suspend_time) > 0) { |
1666 | ts_delta = timespec64_sub(ts_new, timekeeping_suspend_time); | |
0fa88cb4 | 1667 | sleeptime_injected = true; |
8524070b | 1668 | } |
e445cf1c | 1669 | |
0fa88cb4 | 1670 | if (sleeptime_injected) |
e445cf1c FT |
1671 | __timekeeping_inject_sleeptime(tk, &ts_delta); |
1672 | ||
1673 | /* Re-base the last cycle value */ | |
876e7881 | 1674 | tk->tkr_mono.cycle_last = cycle_now; |
4a4ad80d PZ |
1675 | tk->tkr_raw.cycle_last = cycle_now; |
1676 | ||
4e250fdd | 1677 | tk->ntp_error = 0; |
8524070b | 1678 | timekeeping_suspended = 0; |
780427f0 | 1679 | timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |
3fdb14fd | 1680 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1681 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b | 1682 | |
1683 | touch_softlockup_watchdog(); | |
1684 | ||
4ffee521 | 1685 | tick_resume(); |
b12a03ce | 1686 | hrtimers_resume(); |
8524070b | 1687 | } |
1688 | ||
124cf911 | 1689 | int timekeeping_suspend(void) |
8524070b | 1690 | { |
3fdb14fd | 1691 | struct timekeeper *tk = &tk_core.timekeeper; |
92c1d3ed | 1692 | unsigned long flags; |
7d489d15 JS |
1693 | struct timespec64 delta, delta_delta; |
1694 | static struct timespec64 old_delta; | |
8524070b | 1695 | |
2ee96632 | 1696 | read_persistent_clock64(&timekeeping_suspend_time); |
3be90950 | 1697 | |
0d6bd995 ZM |
1698 | /* |
1699 | * On some systems the persistent_clock can not be detected at | |
1700 | * timekeeping_init by its return value, so if we see a valid | |
1701 | * value returned, update the persistent_clock_exists flag. | |
1702 | */ | |
1703 | if (timekeeping_suspend_time.tv_sec || timekeeping_suspend_time.tv_nsec) | |
0fa88cb4 | 1704 | persistent_clock_exists = true; |
0d6bd995 | 1705 | |
9a7a71b1 | 1706 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1707 | write_seqcount_begin(&tk_core.seq); |
4e250fdd | 1708 | timekeeping_forward_now(tk); |
8524070b | 1709 | timekeeping_suspended = 1; |
cb33217b | 1710 | |
0fa88cb4 | 1711 | if (persistent_clock_exists) { |
cb33217b | 1712 | /* |
264bb3f7 XP |
1713 | * To avoid drift caused by repeated suspend/resumes, |
1714 | * which each can add ~1 second drift error, | |
1715 | * try to compensate so the difference in system time | |
1716 | * and persistent_clock time stays close to constant. | |
cb33217b | 1717 | */ |
264bb3f7 XP |
1718 | delta = timespec64_sub(tk_xtime(tk), timekeeping_suspend_time); |
1719 | delta_delta = timespec64_sub(delta, old_delta); | |
1720 | if (abs(delta_delta.tv_sec) >= 2) { | |
1721 | /* | |
1722 | * if delta_delta is too large, assume time correction | |
1723 | * has occurred and set old_delta to the current delta. | |
1724 | */ | |
1725 | old_delta = delta; | |
1726 | } else { | |
1727 | /* Otherwise try to adjust old_system to compensate */ | |
1728 | timekeeping_suspend_time = | |
1729 | timespec64_add(timekeeping_suspend_time, delta_delta); | |
1730 | } | |
cb33217b | 1731 | } |
330a1617 JS |
1732 | |
1733 | timekeeping_update(tk, TK_MIRROR); | |
060407ae | 1734 | halt_fast_timekeeper(tk); |
3fdb14fd | 1735 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1736 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b | 1737 | |
4ffee521 | 1738 | tick_suspend(); |
c54a42b1 | 1739 | clocksource_suspend(); |
adc78e6b | 1740 | clockevents_suspend(); |
8524070b | 1741 | |
1742 | return 0; | |
1743 | } | |
1744 | ||
1745 | /* sysfs resume/suspend bits for timekeeping */ | |
e1a85b2c | 1746 | static struct syscore_ops timekeeping_syscore_ops = { |
8524070b | 1747 | .resume = timekeeping_resume, |
1748 | .suspend = timekeeping_suspend, | |
8524070b | 1749 | }; |
1750 | ||
e1a85b2c | 1751 | static int __init timekeeping_init_ops(void) |
8524070b | 1752 | { |
e1a85b2c RW |
1753 | register_syscore_ops(&timekeeping_syscore_ops); |
1754 | return 0; | |
8524070b | 1755 | } |
e1a85b2c | 1756 | device_initcall(timekeeping_init_ops); |
8524070b | 1757 | |
1758 | /* | |
dc491596 | 1759 | * Apply a multiplier adjustment to the timekeeper |
8524070b | 1760 | */ |
dc491596 JS |
1761 | static __always_inline void timekeeping_apply_adjustment(struct timekeeper *tk, |
1762 | s64 offset, | |
1763 | bool negative, | |
1764 | int adj_scale) | |
8524070b | 1765 | { |
dc491596 JS |
1766 | s64 interval = tk->cycle_interval; |
1767 | s32 mult_adj = 1; | |
8524070b | 1768 | |
dc491596 JS |
1769 | if (negative) { |
1770 | mult_adj = -mult_adj; | |
1771 | interval = -interval; | |
1772 | offset = -offset; | |
1d17d174 | 1773 | } |
dc491596 JS |
1774 | mult_adj <<= adj_scale; |
1775 | interval <<= adj_scale; | |
1776 | offset <<= adj_scale; | |
8524070b | 1777 | |
c2bc1111 JS |
1778 | /* |
1779 | * So the following can be confusing. | |
1780 | * | |
dc491596 | 1781 | * To keep things simple, lets assume mult_adj == 1 for now. |
c2bc1111 | 1782 | * |
dc491596 | 1783 | * When mult_adj != 1, remember that the interval and offset values |
c2bc1111 JS |
1784 | * have been appropriately scaled so the math is the same. |
1785 | * | |
1786 | * The basic idea here is that we're increasing the multiplier | |
1787 | * by one, this causes the xtime_interval to be incremented by | |
1788 | * one cycle_interval. This is because: | |
1789 | * xtime_interval = cycle_interval * mult | |
1790 | * So if mult is being incremented by one: | |
1791 | * xtime_interval = cycle_interval * (mult + 1) | |
1792 | * Its the same as: | |
1793 | * xtime_interval = (cycle_interval * mult) + cycle_interval | |
1794 | * Which can be shortened to: | |
1795 | * xtime_interval += cycle_interval | |
1796 | * | |
1797 | * So offset stores the non-accumulated cycles. Thus the current | |
1798 | * time (in shifted nanoseconds) is: | |
1799 | * now = (offset * adj) + xtime_nsec | |
1800 | * Now, even though we're adjusting the clock frequency, we have | |
1801 | * to keep time consistent. In other words, we can't jump back | |
1802 | * in time, and we also want to avoid jumping forward in time. | |
1803 | * | |
1804 | * So given the same offset value, we need the time to be the same | |
1805 | * both before and after the freq adjustment. | |
1806 | * now = (offset * adj_1) + xtime_nsec_1 | |
1807 | * now = (offset * adj_2) + xtime_nsec_2 | |
1808 | * So: | |
1809 | * (offset * adj_1) + xtime_nsec_1 = | |
1810 | * (offset * adj_2) + xtime_nsec_2 | |
1811 | * And we know: | |
1812 | * adj_2 = adj_1 + 1 | |
1813 | * So: | |
1814 | * (offset * adj_1) + xtime_nsec_1 = | |
1815 | * (offset * (adj_1+1)) + xtime_nsec_2 | |
1816 | * (offset * adj_1) + xtime_nsec_1 = | |
1817 | * (offset * adj_1) + offset + xtime_nsec_2 | |
1818 | * Canceling the sides: | |
1819 | * xtime_nsec_1 = offset + xtime_nsec_2 | |
1820 | * Which gives us: | |
1821 | * xtime_nsec_2 = xtime_nsec_1 - offset | |
1822 | * Which simplfies to: | |
1823 | * xtime_nsec -= offset | |
1824 | * | |
1825 | * XXX - TODO: Doc ntp_error calculation. | |
1826 | */ | |
876e7881 | 1827 | if ((mult_adj > 0) && (tk->tkr_mono.mult + mult_adj < mult_adj)) { |
6067dc5a | 1828 | /* NTP adjustment caused clocksource mult overflow */ |
1829 | WARN_ON_ONCE(1); | |
1830 | return; | |
1831 | } | |
1832 | ||
876e7881 | 1833 | tk->tkr_mono.mult += mult_adj; |
f726a697 | 1834 | tk->xtime_interval += interval; |
876e7881 | 1835 | tk->tkr_mono.xtime_nsec -= offset; |
f726a697 | 1836 | tk->ntp_error -= (interval - offset) << tk->ntp_error_shift; |
dc491596 JS |
1837 | } |
1838 | ||
1839 | /* | |
1840 | * Calculate the multiplier adjustment needed to match the frequency | |
1841 | * specified by NTP | |
1842 | */ | |
1843 | static __always_inline void timekeeping_freqadjust(struct timekeeper *tk, | |
1844 | s64 offset) | |
1845 | { | |
1846 | s64 interval = tk->cycle_interval; | |
1847 | s64 xinterval = tk->xtime_interval; | |
ec02b076 JS |
1848 | u32 base = tk->tkr_mono.clock->mult; |
1849 | u32 max = tk->tkr_mono.clock->maxadj; | |
1850 | u32 cur_adj = tk->tkr_mono.mult; | |
dc491596 JS |
1851 | s64 tick_error; |
1852 | bool negative; | |
ec02b076 | 1853 | u32 adj_scale; |
dc491596 JS |
1854 | |
1855 | /* Remove any current error adj from freq calculation */ | |
1856 | if (tk->ntp_err_mult) | |
1857 | xinterval -= tk->cycle_interval; | |
1858 | ||
375f45b5 JS |
1859 | tk->ntp_tick = ntp_tick_length(); |
1860 | ||
dc491596 JS |
1861 | /* Calculate current error per tick */ |
1862 | tick_error = ntp_tick_length() >> tk->ntp_error_shift; | |
1863 | tick_error -= (xinterval + tk->xtime_remainder); | |
1864 | ||
1865 | /* Don't worry about correcting it if its small */ | |
1866 | if (likely((tick_error >= 0) && (tick_error <= interval))) | |
1867 | return; | |
1868 | ||
1869 | /* preserve the direction of correction */ | |
1870 | negative = (tick_error < 0); | |
1871 | ||
ec02b076 JS |
1872 | /* If any adjustment would pass the max, just return */ |
1873 | if (negative && (cur_adj - 1) <= (base - max)) | |
1874 | return; | |
1875 | if (!negative && (cur_adj + 1) >= (base + max)) | |
1876 | return; | |
1877 | /* | |
1878 | * Sort out the magnitude of the correction, but | |
1879 | * avoid making so large a correction that we go | |
1880 | * over the max adjustment. | |
1881 | */ | |
1882 | adj_scale = 0; | |
79211c8e | 1883 | tick_error = abs(tick_error); |
ec02b076 JS |
1884 | while (tick_error > interval) { |
1885 | u32 adj = 1 << (adj_scale + 1); | |
1886 | ||
1887 | /* Check if adjustment gets us within 1 unit from the max */ | |
1888 | if (negative && (cur_adj - adj) <= (base - max)) | |
1889 | break; | |
1890 | if (!negative && (cur_adj + adj) >= (base + max)) | |
1891 | break; | |
1892 | ||
1893 | adj_scale++; | |
dc491596 | 1894 | tick_error >>= 1; |
ec02b076 | 1895 | } |
dc491596 JS |
1896 | |
1897 | /* scale the corrections */ | |
ec02b076 | 1898 | timekeeping_apply_adjustment(tk, offset, negative, adj_scale); |
dc491596 JS |
1899 | } |
1900 | ||
1901 | /* | |
1902 | * Adjust the timekeeper's multiplier to the correct frequency | |
1903 | * and also to reduce the accumulated error value. | |
1904 | */ | |
1905 | static void timekeeping_adjust(struct timekeeper *tk, s64 offset) | |
1906 | { | |
1907 | /* Correct for the current frequency error */ | |
1908 | timekeeping_freqadjust(tk, offset); | |
1909 | ||
1910 | /* Next make a small adjustment to fix any cumulative error */ | |
1911 | if (!tk->ntp_err_mult && (tk->ntp_error > 0)) { | |
1912 | tk->ntp_err_mult = 1; | |
1913 | timekeeping_apply_adjustment(tk, offset, 0, 0); | |
1914 | } else if (tk->ntp_err_mult && (tk->ntp_error <= 0)) { | |
1915 | /* Undo any existing error adjustment */ | |
1916 | timekeeping_apply_adjustment(tk, offset, 1, 0); | |
1917 | tk->ntp_err_mult = 0; | |
1918 | } | |
1919 | ||
876e7881 PZ |
1920 | if (unlikely(tk->tkr_mono.clock->maxadj && |
1921 | (abs(tk->tkr_mono.mult - tk->tkr_mono.clock->mult) | |
1922 | > tk->tkr_mono.clock->maxadj))) { | |
dc491596 JS |
1923 | printk_once(KERN_WARNING |
1924 | "Adjusting %s more than 11%% (%ld vs %ld)\n", | |
876e7881 PZ |
1925 | tk->tkr_mono.clock->name, (long)tk->tkr_mono.mult, |
1926 | (long)tk->tkr_mono.clock->mult + tk->tkr_mono.clock->maxadj); | |
dc491596 | 1927 | } |
2a8c0883 JS |
1928 | |
1929 | /* | |
1930 | * It may be possible that when we entered this function, xtime_nsec | |
1931 | * was very small. Further, if we're slightly speeding the clocksource | |
1932 | * in the code above, its possible the required corrective factor to | |
1933 | * xtime_nsec could cause it to underflow. | |
1934 | * | |
1935 | * Now, since we already accumulated the second, cannot simply roll | |
1936 | * the accumulated second back, since the NTP subsystem has been | |
1937 | * notified via second_overflow. So instead we push xtime_nsec forward | |
1938 | * by the amount we underflowed, and add that amount into the error. | |
1939 | * | |
1940 | * We'll correct this error next time through this function, when | |
1941 | * xtime_nsec is not as small. | |
1942 | */ | |
876e7881 PZ |
1943 | if (unlikely((s64)tk->tkr_mono.xtime_nsec < 0)) { |
1944 | s64 neg = -(s64)tk->tkr_mono.xtime_nsec; | |
1945 | tk->tkr_mono.xtime_nsec = 0; | |
f726a697 | 1946 | tk->ntp_error += neg << tk->ntp_error_shift; |
2a8c0883 | 1947 | } |
8524070b | 1948 | } |
1949 | ||
1f4f9487 JS |
1950 | /** |
1951 | * accumulate_nsecs_to_secs - Accumulates nsecs into secs | |
1952 | * | |
571af55a | 1953 | * Helper function that accumulates the nsecs greater than a second |
1f4f9487 JS |
1954 | * from the xtime_nsec field to the xtime_secs field. |
1955 | * It also calls into the NTP code to handle leapsecond processing. | |
1956 | * | |
1957 | */ | |
780427f0 | 1958 | static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk) |
1f4f9487 | 1959 | { |
876e7881 | 1960 | u64 nsecps = (u64)NSEC_PER_SEC << tk->tkr_mono.shift; |
5258d3f2 | 1961 | unsigned int clock_set = 0; |
1f4f9487 | 1962 | |
876e7881 | 1963 | while (tk->tkr_mono.xtime_nsec >= nsecps) { |
1f4f9487 JS |
1964 | int leap; |
1965 | ||
876e7881 | 1966 | tk->tkr_mono.xtime_nsec -= nsecps; |
1f4f9487 JS |
1967 | tk->xtime_sec++; |
1968 | ||
1969 | /* Figure out if its a leap sec and apply if needed */ | |
1970 | leap = second_overflow(tk->xtime_sec); | |
6d0ef903 | 1971 | if (unlikely(leap)) { |
7d489d15 | 1972 | struct timespec64 ts; |
6d0ef903 JS |
1973 | |
1974 | tk->xtime_sec += leap; | |
1f4f9487 | 1975 | |
6d0ef903 JS |
1976 | ts.tv_sec = leap; |
1977 | ts.tv_nsec = 0; | |
1978 | tk_set_wall_to_mono(tk, | |
7d489d15 | 1979 | timespec64_sub(tk->wall_to_monotonic, ts)); |
6d0ef903 | 1980 | |
cc244dda JS |
1981 | __timekeeping_set_tai_offset(tk, tk->tai_offset - leap); |
1982 | ||
5258d3f2 | 1983 | clock_set = TK_CLOCK_WAS_SET; |
6d0ef903 | 1984 | } |
1f4f9487 | 1985 | } |
5258d3f2 | 1986 | return clock_set; |
1f4f9487 JS |
1987 | } |
1988 | ||
a092ff0f | 1989 | /** |
1990 | * logarithmic_accumulation - shifted accumulation of cycles | |
1991 | * | |
1992 | * This functions accumulates a shifted interval of cycles into | |
1993 | * into a shifted interval nanoseconds. Allows for O(log) accumulation | |
1994 | * loop. | |
1995 | * | |
1996 | * Returns the unconsumed cycles. | |
1997 | */ | |
f726a697 | 1998 | static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset, |
5258d3f2 JS |
1999 | u32 shift, |
2000 | unsigned int *clock_set) | |
a092ff0f | 2001 | { |
23a9537a | 2002 | cycle_t interval = tk->cycle_interval << shift; |
deda2e81 | 2003 | u64 raw_nsecs; |
a092ff0f | 2004 | |
571af55a | 2005 | /* If the offset is smaller than a shifted interval, do nothing */ |
23a9537a | 2006 | if (offset < interval) |
a092ff0f | 2007 | return offset; |
2008 | ||
2009 | /* Accumulate one shifted interval */ | |
23a9537a | 2010 | offset -= interval; |
876e7881 | 2011 | tk->tkr_mono.cycle_last += interval; |
4a4ad80d | 2012 | tk->tkr_raw.cycle_last += interval; |
a092ff0f | 2013 | |
876e7881 | 2014 | tk->tkr_mono.xtime_nsec += tk->xtime_interval << shift; |
5258d3f2 | 2015 | *clock_set |= accumulate_nsecs_to_secs(tk); |
a092ff0f | 2016 | |
deda2e81 | 2017 | /* Accumulate raw time */ |
5b3900cd | 2018 | raw_nsecs = (u64)tk->raw_interval << shift; |
f726a697 | 2019 | raw_nsecs += tk->raw_time.tv_nsec; |
c7dcf87a JS |
2020 | if (raw_nsecs >= NSEC_PER_SEC) { |
2021 | u64 raw_secs = raw_nsecs; | |
2022 | raw_nsecs = do_div(raw_secs, NSEC_PER_SEC); | |
f726a697 | 2023 | tk->raw_time.tv_sec += raw_secs; |
a092ff0f | 2024 | } |
f726a697 | 2025 | tk->raw_time.tv_nsec = raw_nsecs; |
a092ff0f | 2026 | |
2027 | /* Accumulate error between NTP and clock interval */ | |
375f45b5 | 2028 | tk->ntp_error += tk->ntp_tick << shift; |
f726a697 JS |
2029 | tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) << |
2030 | (tk->ntp_error_shift + shift); | |
a092ff0f | 2031 | |
2032 | return offset; | |
2033 | } | |
2034 | ||
8524070b | 2035 | /** |
2036 | * update_wall_time - Uses the current clocksource to increment the wall time | |
2037 | * | |
8524070b | 2038 | */ |
47a1b796 | 2039 | void update_wall_time(void) |
8524070b | 2040 | { |
3fdb14fd | 2041 | struct timekeeper *real_tk = &tk_core.timekeeper; |
48cdc135 | 2042 | struct timekeeper *tk = &shadow_timekeeper; |
8524070b | 2043 | cycle_t offset; |
a092ff0f | 2044 | int shift = 0, maxshift; |
5258d3f2 | 2045 | unsigned int clock_set = 0; |
70471f2f JS |
2046 | unsigned long flags; |
2047 | ||
9a7a71b1 | 2048 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
8524070b | 2049 | |
2050 | /* Make sure we're fully resumed: */ | |
2051 | if (unlikely(timekeeping_suspended)) | |
70471f2f | 2052 | goto out; |
8524070b | 2053 | |
592913ec | 2054 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET |
48cdc135 | 2055 | offset = real_tk->cycle_interval; |
592913ec | 2056 | #else |
876e7881 PZ |
2057 | offset = clocksource_delta(tk->tkr_mono.read(tk->tkr_mono.clock), |
2058 | tk->tkr_mono.cycle_last, tk->tkr_mono.mask); | |
8524070b | 2059 | #endif |
8524070b | 2060 | |
bf2ac312 | 2061 | /* Check if there's really nothing to do */ |
48cdc135 | 2062 | if (offset < real_tk->cycle_interval) |
bf2ac312 JS |
2063 | goto out; |
2064 | ||
3c17ad19 JS |
2065 | /* Do some additional sanity checking */ |
2066 | timekeeping_check_update(real_tk, offset); | |
2067 | ||
a092ff0f | 2068 | /* |
2069 | * With NO_HZ we may have to accumulate many cycle_intervals | |
2070 | * (think "ticks") worth of time at once. To do this efficiently, | |
2071 | * we calculate the largest doubling multiple of cycle_intervals | |
88b28adf | 2072 | * that is smaller than the offset. We then accumulate that |
a092ff0f | 2073 | * chunk in one go, and then try to consume the next smaller |
2074 | * doubled multiple. | |
8524070b | 2075 | */ |
4e250fdd | 2076 | shift = ilog2(offset) - ilog2(tk->cycle_interval); |
a092ff0f | 2077 | shift = max(0, shift); |
88b28adf | 2078 | /* Bound shift to one less than what overflows tick_length */ |
ea7cf49a | 2079 | maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1; |
a092ff0f | 2080 | shift = min(shift, maxshift); |
4e250fdd | 2081 | while (offset >= tk->cycle_interval) { |
5258d3f2 JS |
2082 | offset = logarithmic_accumulation(tk, offset, shift, |
2083 | &clock_set); | |
4e250fdd | 2084 | if (offset < tk->cycle_interval<<shift) |
830ec045 | 2085 | shift--; |
8524070b | 2086 | } |
2087 | ||
2088 | /* correct the clock when NTP error is too big */ | |
4e250fdd | 2089 | timekeeping_adjust(tk, offset); |
8524070b | 2090 | |
6a867a39 | 2091 | /* |
92bb1fcf JS |
2092 | * XXX This can be killed once everyone converts |
2093 | * to the new update_vsyscall. | |
2094 | */ | |
2095 | old_vsyscall_fixup(tk); | |
8524070b | 2096 | |
6a867a39 JS |
2097 | /* |
2098 | * Finally, make sure that after the rounding | |
1e75fa8b | 2099 | * xtime_nsec isn't larger than NSEC_PER_SEC |
6a867a39 | 2100 | */ |
5258d3f2 | 2101 | clock_set |= accumulate_nsecs_to_secs(tk); |
83f57a11 | 2102 | |
3fdb14fd | 2103 | write_seqcount_begin(&tk_core.seq); |
48cdc135 TG |
2104 | /* |
2105 | * Update the real timekeeper. | |
2106 | * | |
2107 | * We could avoid this memcpy by switching pointers, but that | |
2108 | * requires changes to all other timekeeper usage sites as | |
2109 | * well, i.e. move the timekeeper pointer getter into the | |
2110 | * spinlocked/seqcount protected sections. And we trade this | |
3fdb14fd | 2111 | * memcpy under the tk_core.seq against one before we start |
48cdc135 TG |
2112 | * updating. |
2113 | */ | |
906c5557 | 2114 | timekeeping_update(tk, clock_set); |
48cdc135 | 2115 | memcpy(real_tk, tk, sizeof(*tk)); |
906c5557 | 2116 | /* The memcpy must come last. Do not put anything here! */ |
3fdb14fd | 2117 | write_seqcount_end(&tk_core.seq); |
ca4523cd | 2118 | out: |
9a7a71b1 | 2119 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
47a1b796 | 2120 | if (clock_set) |
cab5e127 JS |
2121 | /* Have to call _delayed version, since in irq context*/ |
2122 | clock_was_set_delayed(); | |
8524070b | 2123 | } |
7c3f1a57 TJ |
2124 | |
2125 | /** | |
d08c0cdd JS |
2126 | * getboottime64 - Return the real time of system boot. |
2127 | * @ts: pointer to the timespec64 to be set | |
7c3f1a57 | 2128 | * |
d08c0cdd | 2129 | * Returns the wall-time of boot in a timespec64. |
7c3f1a57 TJ |
2130 | * |
2131 | * This is based on the wall_to_monotonic offset and the total suspend | |
2132 | * time. Calls to settimeofday will affect the value returned (which | |
2133 | * basically means that however wrong your real time clock is at boot time, | |
2134 | * you get the right time here). | |
2135 | */ | |
d08c0cdd | 2136 | void getboottime64(struct timespec64 *ts) |
7c3f1a57 | 2137 | { |
3fdb14fd | 2138 | struct timekeeper *tk = &tk_core.timekeeper; |
02cba159 TG |
2139 | ktime_t t = ktime_sub(tk->offs_real, tk->offs_boot); |
2140 | ||
d08c0cdd | 2141 | *ts = ktime_to_timespec64(t); |
7c3f1a57 | 2142 | } |
d08c0cdd | 2143 | EXPORT_SYMBOL_GPL(getboottime64); |
7c3f1a57 | 2144 | |
17c38b74 | 2145 | unsigned long get_seconds(void) |
2146 | { | |
3fdb14fd | 2147 | struct timekeeper *tk = &tk_core.timekeeper; |
4e250fdd JS |
2148 | |
2149 | return tk->xtime_sec; | |
17c38b74 | 2150 | } |
2151 | EXPORT_SYMBOL(get_seconds); | |
2152 | ||
da15cfda | 2153 | struct timespec __current_kernel_time(void) |
2154 | { | |
3fdb14fd | 2155 | struct timekeeper *tk = &tk_core.timekeeper; |
4e250fdd | 2156 | |
7d489d15 | 2157 | return timespec64_to_timespec(tk_xtime(tk)); |
da15cfda | 2158 | } |
17c38b74 | 2159 | |
8758a240 | 2160 | struct timespec64 current_kernel_time64(void) |
2c6b47de | 2161 | { |
3fdb14fd | 2162 | struct timekeeper *tk = &tk_core.timekeeper; |
7d489d15 | 2163 | struct timespec64 now; |
2c6b47de | 2164 | unsigned long seq; |
2165 | ||
2166 | do { | |
3fdb14fd | 2167 | seq = read_seqcount_begin(&tk_core.seq); |
83f57a11 | 2168 | |
4e250fdd | 2169 | now = tk_xtime(tk); |
3fdb14fd | 2170 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
2c6b47de | 2171 | |
8758a240 | 2172 | return now; |
2c6b47de | 2173 | } |
8758a240 | 2174 | EXPORT_SYMBOL(current_kernel_time64); |
da15cfda | 2175 | |
334334b5 | 2176 | struct timespec64 get_monotonic_coarse64(void) |
da15cfda | 2177 | { |
3fdb14fd | 2178 | struct timekeeper *tk = &tk_core.timekeeper; |
7d489d15 | 2179 | struct timespec64 now, mono; |
da15cfda | 2180 | unsigned long seq; |
2181 | ||
2182 | do { | |
3fdb14fd | 2183 | seq = read_seqcount_begin(&tk_core.seq); |
83f57a11 | 2184 | |
4e250fdd JS |
2185 | now = tk_xtime(tk); |
2186 | mono = tk->wall_to_monotonic; | |
3fdb14fd | 2187 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
da15cfda | 2188 | |
7d489d15 | 2189 | set_normalized_timespec64(&now, now.tv_sec + mono.tv_sec, |
da15cfda | 2190 | now.tv_nsec + mono.tv_nsec); |
7d489d15 | 2191 | |
334334b5 | 2192 | return now; |
da15cfda | 2193 | } |
eaaa7ec7 | 2194 | EXPORT_SYMBOL(get_monotonic_coarse64); |
871cf1e5 TH |
2195 | |
2196 | /* | |
d6ad4187 | 2197 | * Must hold jiffies_lock |
871cf1e5 TH |
2198 | */ |
2199 | void do_timer(unsigned long ticks) | |
2200 | { | |
2201 | jiffies_64 += ticks; | |
871cf1e5 TH |
2202 | calc_global_load(ticks); |
2203 | } | |
48cf76f7 | 2204 | |
f6c06abf | 2205 | /** |
76f41088 | 2206 | * ktime_get_update_offsets_now - hrtimer helper |
868a3e91 | 2207 | * @cwsseq: pointer to check and store the clock was set sequence number |
f6c06abf TG |
2208 | * @offs_real: pointer to storage for monotonic -> realtime offset |
2209 | * @offs_boot: pointer to storage for monotonic -> boottime offset | |
b7bc50e4 | 2210 | * @offs_tai: pointer to storage for monotonic -> clock tai offset |
f6c06abf | 2211 | * |
868a3e91 TG |
2212 | * Returns current monotonic time and updates the offsets if the |
2213 | * sequence number in @cwsseq and timekeeper.clock_was_set_seq are | |
2214 | * different. | |
2215 | * | |
b7bc50e4 | 2216 | * Called from hrtimer_interrupt() or retrigger_next_event() |
f6c06abf | 2217 | */ |
868a3e91 TG |
2218 | ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real, |
2219 | ktime_t *offs_boot, ktime_t *offs_tai) | |
f6c06abf | 2220 | { |
3fdb14fd | 2221 | struct timekeeper *tk = &tk_core.timekeeper; |
f6c06abf | 2222 | unsigned int seq; |
a37c0aad TG |
2223 | ktime_t base; |
2224 | u64 nsecs; | |
f6c06abf TG |
2225 | |
2226 | do { | |
3fdb14fd | 2227 | seq = read_seqcount_begin(&tk_core.seq); |
f6c06abf | 2228 | |
876e7881 PZ |
2229 | base = tk->tkr_mono.base; |
2230 | nsecs = timekeeping_get_ns(&tk->tkr_mono); | |
833f32d7 JS |
2231 | base = ktime_add_ns(base, nsecs); |
2232 | ||
868a3e91 TG |
2233 | if (*cwsseq != tk->clock_was_set_seq) { |
2234 | *cwsseq = tk->clock_was_set_seq; | |
2235 | *offs_real = tk->offs_real; | |
2236 | *offs_boot = tk->offs_boot; | |
2237 | *offs_tai = tk->offs_tai; | |
2238 | } | |
833f32d7 JS |
2239 | |
2240 | /* Handle leapsecond insertion adjustments */ | |
2241 | if (unlikely(base.tv64 >= tk->next_leap_ktime.tv64)) | |
2242 | *offs_real = ktime_sub(tk->offs_real, ktime_set(1, 0)); | |
2243 | ||
3fdb14fd | 2244 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
f6c06abf | 2245 | |
833f32d7 | 2246 | return base; |
f6c06abf | 2247 | } |
f6c06abf | 2248 | |
aa6f9c59 JS |
2249 | /** |
2250 | * do_adjtimex() - Accessor function to NTP __do_adjtimex function | |
2251 | */ | |
2252 | int do_adjtimex(struct timex *txc) | |
2253 | { | |
3fdb14fd | 2254 | struct timekeeper *tk = &tk_core.timekeeper; |
06c017fd | 2255 | unsigned long flags; |
7d489d15 | 2256 | struct timespec64 ts; |
4e8f8b34 | 2257 | s32 orig_tai, tai; |
e4085693 JS |
2258 | int ret; |
2259 | ||
2260 | /* Validate the data before disabling interrupts */ | |
2261 | ret = ntp_validate_timex(txc); | |
2262 | if (ret) | |
2263 | return ret; | |
2264 | ||
cef90377 JS |
2265 | if (txc->modes & ADJ_SETOFFSET) { |
2266 | struct timespec delta; | |
2267 | delta.tv_sec = txc->time.tv_sec; | |
2268 | delta.tv_nsec = txc->time.tv_usec; | |
2269 | if (!(txc->modes & ADJ_NANO)) | |
2270 | delta.tv_nsec *= 1000; | |
2271 | ret = timekeeping_inject_offset(&delta); | |
2272 | if (ret) | |
2273 | return ret; | |
2274 | } | |
2275 | ||
d6d29896 | 2276 | getnstimeofday64(&ts); |
87ace39b | 2277 | |
06c017fd | 2278 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 2279 | write_seqcount_begin(&tk_core.seq); |
06c017fd | 2280 | |
4e8f8b34 | 2281 | orig_tai = tai = tk->tai_offset; |
87ace39b | 2282 | ret = __do_adjtimex(txc, &ts, &tai); |
aa6f9c59 | 2283 | |
4e8f8b34 JS |
2284 | if (tai != orig_tai) { |
2285 | __timekeeping_set_tai_offset(tk, tai); | |
f55c0760 | 2286 | timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |
4e8f8b34 | 2287 | } |
833f32d7 JS |
2288 | tk_update_leap_state(tk); |
2289 | ||
3fdb14fd | 2290 | write_seqcount_end(&tk_core.seq); |
06c017fd JS |
2291 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
2292 | ||
6fdda9a9 JS |
2293 | if (tai != orig_tai) |
2294 | clock_was_set(); | |
2295 | ||
7bd36014 JS |
2296 | ntp_notify_cmos_timer(); |
2297 | ||
87ace39b JS |
2298 | return ret; |
2299 | } | |
aa6f9c59 JS |
2300 | |
2301 | #ifdef CONFIG_NTP_PPS | |
2302 | /** | |
2303 | * hardpps() - Accessor function to NTP __hardpps function | |
2304 | */ | |
7ec88e4b | 2305 | void hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts) |
aa6f9c59 | 2306 | { |
06c017fd JS |
2307 | unsigned long flags; |
2308 | ||
2309 | raw_spin_lock_irqsave(&timekeeper_lock, flags); | |
3fdb14fd | 2310 | write_seqcount_begin(&tk_core.seq); |
06c017fd | 2311 | |
aa6f9c59 | 2312 | __hardpps(phase_ts, raw_ts); |
06c017fd | 2313 | |
3fdb14fd | 2314 | write_seqcount_end(&tk_core.seq); |
06c017fd | 2315 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
aa6f9c59 JS |
2316 | } |
2317 | EXPORT_SYMBOL(hardpps); | |
2318 | #endif | |
2319 | ||
f0af911a TH |
2320 | /** |
2321 | * xtime_update() - advances the timekeeping infrastructure | |
2322 | * @ticks: number of ticks, that have elapsed since the last call. | |
2323 | * | |
2324 | * Must be called with interrupts disabled. | |
2325 | */ | |
2326 | void xtime_update(unsigned long ticks) | |
2327 | { | |
d6ad4187 | 2328 | write_seqlock(&jiffies_lock); |
f0af911a | 2329 | do_timer(ticks); |
d6ad4187 | 2330 | write_sequnlock(&jiffies_lock); |
47a1b796 | 2331 | update_wall_time(); |
f0af911a | 2332 | } |