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Commit | Line | Data |
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8524070b JS |
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 JS |
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> | |
38b8d208 | 17 | #include <linux/nmi.h> |
d43c36dc | 18 | #include <linux/sched.h> |
4f17722c | 19 | #include <linux/sched/loadavg.h> |
e1a85b2c | 20 | #include <linux/syscore_ops.h> |
8524070b JS |
21 | #include <linux/clocksource.h> |
22 | #include <linux/jiffies.h> | |
23 | #include <linux/time.h> | |
24 | #include <linux/tick.h> | |
75c5158f | 25 | #include <linux/stop_machine.h> |
e0b306fe | 26 | #include <linux/pvclock_gtod.h> |
52f5684c | 27 | #include <linux/compiler.h> |
8524070b | 28 | |
eb93e4d9 | 29 | #include "tick-internal.h" |
aa6f9c59 | 30 | #include "ntp_internal.h" |
5c83545f | 31 | #include "timekeeping_internal.h" |
155ec602 | 32 | |
04397fe9 DV |
33 | #define TK_CLEAR_NTP (1 << 0) |
34 | #define TK_MIRROR (1 << 1) | |
780427f0 | 35 | #define TK_CLOCK_WAS_SET (1 << 2) |
04397fe9 | 36 | |
3fdb14fd TG |
37 | /* |
38 | * The most important data for readout fits into a single 64 byte | |
39 | * cache line. | |
40 | */ | |
41 | static struct { | |
42 | seqcount_t seq; | |
43 | struct timekeeper timekeeper; | |
44 | } tk_core ____cacheline_aligned; | |
45 | ||
9a7a71b1 | 46 | static DEFINE_RAW_SPINLOCK(timekeeper_lock); |
48cdc135 | 47 | static struct timekeeper shadow_timekeeper; |
155ec602 | 48 | |
4396e058 TG |
49 | /** |
50 | * struct tk_fast - NMI safe timekeeper | |
51 | * @seq: Sequence counter for protecting updates. The lowest bit | |
52 | * is the index for the tk_read_base array | |
53 | * @base: tk_read_base array. Access is indexed by the lowest bit of | |
54 | * @seq. | |
55 | * | |
56 | * See @update_fast_timekeeper() below. | |
57 | */ | |
58 | struct tk_fast { | |
59 | seqcount_t seq; | |
60 | struct tk_read_base base[2]; | |
61 | }; | |
62 | ||
63 | static struct tk_fast tk_fast_mono ____cacheline_aligned; | |
f09cb9a1 | 64 | static struct tk_fast tk_fast_raw ____cacheline_aligned; |
4396e058 | 65 | |
8fcce546 JS |
66 | /* flag for if timekeeping is suspended */ |
67 | int __read_mostly timekeeping_suspended; | |
68 | ||
1e75fa8b JS |
69 | static inline void tk_normalize_xtime(struct timekeeper *tk) |
70 | { | |
876e7881 PZ |
71 | while (tk->tkr_mono.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr_mono.shift)) { |
72 | tk->tkr_mono.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_mono.shift; | |
1e75fa8b JS |
73 | tk->xtime_sec++; |
74 | } | |
75 | } | |
76 | ||
c905fae4 TG |
77 | static inline struct timespec64 tk_xtime(struct timekeeper *tk) |
78 | { | |
79 | struct timespec64 ts; | |
80 | ||
81 | ts.tv_sec = tk->xtime_sec; | |
876e7881 | 82 | ts.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); |
c905fae4 TG |
83 | return ts; |
84 | } | |
85 | ||
7d489d15 | 86 | static void tk_set_xtime(struct timekeeper *tk, const struct timespec64 *ts) |
1e75fa8b JS |
87 | { |
88 | tk->xtime_sec = ts->tv_sec; | |
876e7881 | 89 | tk->tkr_mono.xtime_nsec = (u64)ts->tv_nsec << tk->tkr_mono.shift; |
1e75fa8b JS |
90 | } |
91 | ||
7d489d15 | 92 | static void tk_xtime_add(struct timekeeper *tk, const struct timespec64 *ts) |
1e75fa8b JS |
93 | { |
94 | tk->xtime_sec += ts->tv_sec; | |
876e7881 | 95 | tk->tkr_mono.xtime_nsec += (u64)ts->tv_nsec << tk->tkr_mono.shift; |
784ffcbb | 96 | tk_normalize_xtime(tk); |
1e75fa8b | 97 | } |
8fcce546 | 98 | |
7d489d15 | 99 | static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec64 wtm) |
6d0ef903 | 100 | { |
7d489d15 | 101 | struct timespec64 tmp; |
6d0ef903 JS |
102 | |
103 | /* | |
104 | * Verify consistency of: offset_real = -wall_to_monotonic | |
105 | * before modifying anything | |
106 | */ | |
7d489d15 | 107 | set_normalized_timespec64(&tmp, -tk->wall_to_monotonic.tv_sec, |
6d0ef903 | 108 | -tk->wall_to_monotonic.tv_nsec); |
2456e855 | 109 | WARN_ON_ONCE(tk->offs_real != timespec64_to_ktime(tmp)); |
6d0ef903 | 110 | tk->wall_to_monotonic = wtm; |
7d489d15 JS |
111 | set_normalized_timespec64(&tmp, -wtm.tv_sec, -wtm.tv_nsec); |
112 | tk->offs_real = timespec64_to_ktime(tmp); | |
04005f60 | 113 | tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tk->tai_offset, 0)); |
6d0ef903 JS |
114 | } |
115 | ||
47da70d3 | 116 | static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta) |
6d0ef903 | 117 | { |
47da70d3 | 118 | tk->offs_boot = ktime_add(tk->offs_boot, delta); |
6d0ef903 JS |
119 | } |
120 | ||
3c17ad19 | 121 | #ifdef CONFIG_DEBUG_TIMEKEEPING |
4ca22c26 | 122 | #define WARNING_FREQ (HZ*300) /* 5 minute rate-limiting */ |
4ca22c26 | 123 | |
a5a1d1c2 | 124 | static void timekeeping_check_update(struct timekeeper *tk, u64 offset) |
3c17ad19 JS |
125 | { |
126 | ||
a5a1d1c2 | 127 | u64 max_cycles = tk->tkr_mono.clock->max_cycles; |
876e7881 | 128 | const char *name = tk->tkr_mono.clock->name; |
3c17ad19 JS |
129 | |
130 | if (offset > max_cycles) { | |
a558cd02 | 131 | 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 | 132 | offset, name, max_cycles); |
a558cd02 | 133 | printk_deferred(" timekeeping: Your kernel is sick, but tries to cope by capping time updates\n"); |
3c17ad19 JS |
134 | } else { |
135 | if (offset > (max_cycles >> 1)) { | |
fc4fa6e1 | 136 | printk_deferred("INFO: timekeeping: Cycle offset (%lld) is larger than the '%s' clock's 50%% safety margin (%lld)\n", |
3c17ad19 JS |
137 | offset, name, max_cycles >> 1); |
138 | printk_deferred(" timekeeping: Your kernel is still fine, but is feeling a bit nervous\n"); | |
139 | } | |
140 | } | |
4ca22c26 | 141 | |
57d05a93 JS |
142 | if (tk->underflow_seen) { |
143 | if (jiffies - tk->last_warning > WARNING_FREQ) { | |
4ca22c26 JS |
144 | printk_deferred("WARNING: Underflow in clocksource '%s' observed, time update ignored.\n", name); |
145 | printk_deferred(" Please report this, consider using a different clocksource, if possible.\n"); | |
146 | printk_deferred(" Your kernel is probably still fine.\n"); | |
57d05a93 | 147 | tk->last_warning = jiffies; |
4ca22c26 | 148 | } |
57d05a93 | 149 | tk->underflow_seen = 0; |
4ca22c26 JS |
150 | } |
151 | ||
57d05a93 JS |
152 | if (tk->overflow_seen) { |
153 | if (jiffies - tk->last_warning > WARNING_FREQ) { | |
4ca22c26 JS |
154 | printk_deferred("WARNING: Overflow in clocksource '%s' observed, time update capped.\n", name); |
155 | printk_deferred(" Please report this, consider using a different clocksource, if possible.\n"); | |
156 | printk_deferred(" Your kernel is probably still fine.\n"); | |
57d05a93 | 157 | tk->last_warning = jiffies; |
4ca22c26 | 158 | } |
57d05a93 | 159 | tk->overflow_seen = 0; |
4ca22c26 | 160 | } |
3c17ad19 | 161 | } |
a558cd02 | 162 | |
a5a1d1c2 | 163 | static inline u64 timekeeping_get_delta(struct tk_read_base *tkr) |
a558cd02 | 164 | { |
57d05a93 | 165 | struct timekeeper *tk = &tk_core.timekeeper; |
a5a1d1c2 | 166 | u64 now, last, mask, max, delta; |
4ca22c26 | 167 | unsigned int seq; |
a558cd02 | 168 | |
4ca22c26 JS |
169 | /* |
170 | * Since we're called holding a seqlock, the data may shift | |
171 | * under us while we're doing the calculation. This can cause | |
172 | * false positives, since we'd note a problem but throw the | |
173 | * results away. So nest another seqlock here to atomically | |
174 | * grab the points we are checking with. | |
175 | */ | |
176 | do { | |
177 | seq = read_seqcount_begin(&tk_core.seq); | |
178 | now = tkr->read(tkr->clock); | |
179 | last = tkr->cycle_last; | |
180 | mask = tkr->mask; | |
181 | max = tkr->clock->max_cycles; | |
182 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
a558cd02 | 183 | |
4ca22c26 | 184 | delta = clocksource_delta(now, last, mask); |
a558cd02 | 185 | |
057b87e3 JS |
186 | /* |
187 | * Try to catch underflows by checking if we are seeing small | |
188 | * mask-relative negative values. | |
189 | */ | |
4ca22c26 | 190 | if (unlikely((~delta & mask) < (mask >> 3))) { |
57d05a93 | 191 | tk->underflow_seen = 1; |
057b87e3 | 192 | delta = 0; |
4ca22c26 | 193 | } |
057b87e3 | 194 | |
a558cd02 | 195 | /* Cap delta value to the max_cycles values to avoid mult overflows */ |
4ca22c26 | 196 | if (unlikely(delta > max)) { |
57d05a93 | 197 | tk->overflow_seen = 1; |
a558cd02 | 198 | delta = tkr->clock->max_cycles; |
4ca22c26 | 199 | } |
a558cd02 JS |
200 | |
201 | return delta; | |
202 | } | |
3c17ad19 | 203 | #else |
a5a1d1c2 | 204 | static inline void timekeeping_check_update(struct timekeeper *tk, u64 offset) |
3c17ad19 JS |
205 | { |
206 | } | |
a5a1d1c2 | 207 | static inline u64 timekeeping_get_delta(struct tk_read_base *tkr) |
a558cd02 | 208 | { |
a5a1d1c2 | 209 | u64 cycle_now, delta; |
a558cd02 JS |
210 | |
211 | /* read clocksource */ | |
212 | cycle_now = tkr->read(tkr->clock); | |
213 | ||
214 | /* calculate the delta since the last update_wall_time */ | |
215 | delta = clocksource_delta(cycle_now, tkr->cycle_last, tkr->mask); | |
216 | ||
217 | return delta; | |
218 | } | |
3c17ad19 JS |
219 | #endif |
220 | ||
155ec602 | 221 | /** |
d26e4fe0 | 222 | * tk_setup_internals - Set up internals to use clocksource clock. |
155ec602 | 223 | * |
d26e4fe0 | 224 | * @tk: The target timekeeper to setup. |
155ec602 MS |
225 | * @clock: Pointer to clocksource. |
226 | * | |
227 | * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment | |
228 | * pair and interval request. | |
229 | * | |
230 | * Unless you're the timekeeping code, you should not be using this! | |
231 | */ | |
f726a697 | 232 | static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock) |
155ec602 | 233 | { |
a5a1d1c2 | 234 | u64 interval; |
a386b5af | 235 | u64 tmp, ntpinterval; |
1e75fa8b | 236 | struct clocksource *old_clock; |
155ec602 | 237 | |
2c756feb | 238 | ++tk->cs_was_changed_seq; |
876e7881 PZ |
239 | old_clock = tk->tkr_mono.clock; |
240 | tk->tkr_mono.clock = clock; | |
241 | tk->tkr_mono.read = clock->read; | |
242 | tk->tkr_mono.mask = clock->mask; | |
243 | tk->tkr_mono.cycle_last = tk->tkr_mono.read(clock); | |
155ec602 | 244 | |
4a4ad80d PZ |
245 | tk->tkr_raw.clock = clock; |
246 | tk->tkr_raw.read = clock->read; | |
247 | tk->tkr_raw.mask = clock->mask; | |
248 | tk->tkr_raw.cycle_last = tk->tkr_mono.cycle_last; | |
249 | ||
155ec602 MS |
250 | /* Do the ns -> cycle conversion first, using original mult */ |
251 | tmp = NTP_INTERVAL_LENGTH; | |
252 | tmp <<= clock->shift; | |
a386b5af | 253 | ntpinterval = tmp; |
0a544198 MS |
254 | tmp += clock->mult/2; |
255 | do_div(tmp, clock->mult); | |
155ec602 MS |
256 | if (tmp == 0) |
257 | tmp = 1; | |
258 | ||
a5a1d1c2 | 259 | interval = (u64) tmp; |
f726a697 | 260 | tk->cycle_interval = interval; |
155ec602 MS |
261 | |
262 | /* Go back from cycles -> shifted ns */ | |
cbd99e3b | 263 | tk->xtime_interval = interval * clock->mult; |
f726a697 | 264 | tk->xtime_remainder = ntpinterval - tk->xtime_interval; |
cbd99e3b | 265 | tk->raw_interval = (interval * clock->mult) >> clock->shift; |
155ec602 | 266 | |
1e75fa8b JS |
267 | /* if changing clocks, convert xtime_nsec shift units */ |
268 | if (old_clock) { | |
269 | int shift_change = clock->shift - old_clock->shift; | |
270 | if (shift_change < 0) | |
876e7881 | 271 | tk->tkr_mono.xtime_nsec >>= -shift_change; |
1e75fa8b | 272 | else |
876e7881 | 273 | tk->tkr_mono.xtime_nsec <<= shift_change; |
1e75fa8b | 274 | } |
4a4ad80d PZ |
275 | tk->tkr_raw.xtime_nsec = 0; |
276 | ||
876e7881 | 277 | tk->tkr_mono.shift = clock->shift; |
4a4ad80d | 278 | tk->tkr_raw.shift = clock->shift; |
155ec602 | 279 | |
f726a697 JS |
280 | tk->ntp_error = 0; |
281 | tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; | |
375f45b5 | 282 | tk->ntp_tick = ntpinterval << tk->ntp_error_shift; |
0a544198 MS |
283 | |
284 | /* | |
285 | * The timekeeper keeps its own mult values for the currently | |
286 | * active clocksource. These value will be adjusted via NTP | |
287 | * to counteract clock drifting. | |
288 | */ | |
876e7881 | 289 | tk->tkr_mono.mult = clock->mult; |
4a4ad80d | 290 | tk->tkr_raw.mult = clock->mult; |
dc491596 | 291 | tk->ntp_err_mult = 0; |
155ec602 | 292 | } |
8524070b | 293 | |
2ba2a305 | 294 | /* Timekeeper helper functions. */ |
7b1f6207 SW |
295 | |
296 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET | |
e06fde37 TG |
297 | static u32 default_arch_gettimeoffset(void) { return 0; } |
298 | u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset; | |
7b1f6207 | 299 | #else |
e06fde37 | 300 | static inline u32 arch_gettimeoffset(void) { return 0; } |
7b1f6207 SW |
301 | #endif |
302 | ||
a5a1d1c2 | 303 | static inline u64 timekeeping_delta_to_ns(struct tk_read_base *tkr, u64 delta) |
6bd58f09 | 304 | { |
9c164572 | 305 | u64 nsec; |
6bd58f09 CH |
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 | ||
acc89612 | 314 | static inline u64 timekeeping_get_ns(struct tk_read_base *tkr) |
2ba2a305 | 315 | { |
a5a1d1c2 | 316 | u64 delta; |
2ba2a305 | 317 | |
a558cd02 | 318 | delta = timekeeping_get_delta(tkr); |
6bd58f09 CH |
319 | return timekeeping_delta_to_ns(tkr, delta); |
320 | } | |
2ba2a305 | 321 | |
a5a1d1c2 | 322 | static inline u64 timekeeping_cycles_to_ns(struct tk_read_base *tkr, u64 cycles) |
6bd58f09 | 323 | { |
a5a1d1c2 | 324 | u64 delta; |
f2a5a085 | 325 | |
6bd58f09 CH |
326 | /* calculate the delta since the last update_wall_time */ |
327 | delta = clocksource_delta(cycles, tkr->cycle_last, tkr->mask); | |
328 | return timekeeping_delta_to_ns(tkr, delta); | |
2ba2a305 MS |
329 | } |
330 | ||
4396e058 TG |
331 | /** |
332 | * update_fast_timekeeper - Update the fast and NMI safe monotonic timekeeper. | |
affe3e85 | 333 | * @tkr: Timekeeping readout base from which we take the update |
4396e058 TG |
334 | * |
335 | * We want to use this from any context including NMI and tracing / | |
336 | * instrumenting the timekeeping code itself. | |
337 | * | |
6695b92a | 338 | * Employ the latch technique; see @raw_write_seqcount_latch. |
4396e058 TG |
339 | * |
340 | * So if a NMI hits the update of base[0] then it will use base[1] | |
341 | * which is still consistent. In the worst case this can result is a | |
342 | * slightly wrong timestamp (a few nanoseconds). See | |
343 | * @ktime_get_mono_fast_ns. | |
344 | */ | |
4498e746 | 345 | static void update_fast_timekeeper(struct tk_read_base *tkr, struct tk_fast *tkf) |
4396e058 | 346 | { |
4498e746 | 347 | struct tk_read_base *base = tkf->base; |
4396e058 TG |
348 | |
349 | /* Force readers off to base[1] */ | |
4498e746 | 350 | raw_write_seqcount_latch(&tkf->seq); |
4396e058 TG |
351 | |
352 | /* Update base[0] */ | |
affe3e85 | 353 | memcpy(base, tkr, sizeof(*base)); |
4396e058 TG |
354 | |
355 | /* Force readers back to base[0] */ | |
4498e746 | 356 | raw_write_seqcount_latch(&tkf->seq); |
4396e058 TG |
357 | |
358 | /* Update base[1] */ | |
359 | memcpy(base + 1, base, sizeof(*base)); | |
360 | } | |
361 | ||
362 | /** | |
363 | * ktime_get_mono_fast_ns - Fast NMI safe access to clock monotonic | |
364 | * | |
365 | * This timestamp is not guaranteed to be monotonic across an update. | |
366 | * The timestamp is calculated by: | |
367 | * | |
368 | * now = base_mono + clock_delta * slope | |
369 | * | |
370 | * So if the update lowers the slope, readers who are forced to the | |
371 | * not yet updated second array are still using the old steeper slope. | |
372 | * | |
373 | * tmono | |
374 | * ^ | |
375 | * | o n | |
376 | * | o n | |
377 | * | u | |
378 | * | o | |
379 | * |o | |
380 | * |12345678---> reader order | |
381 | * | |
382 | * o = old slope | |
383 | * u = update | |
384 | * n = new slope | |
385 | * | |
386 | * So reader 6 will observe time going backwards versus reader 5. | |
387 | * | |
388 | * While other CPUs are likely to be able observe that, the only way | |
389 | * for a CPU local observation is when an NMI hits in the middle of | |
390 | * the update. Timestamps taken from that NMI context might be ahead | |
391 | * of the following timestamps. Callers need to be aware of that and | |
392 | * deal with it. | |
393 | */ | |
4498e746 | 394 | static __always_inline u64 __ktime_get_fast_ns(struct tk_fast *tkf) |
4396e058 TG |
395 | { |
396 | struct tk_read_base *tkr; | |
397 | unsigned int seq; | |
398 | u64 now; | |
399 | ||
400 | do { | |
7fc26327 | 401 | seq = raw_read_seqcount_latch(&tkf->seq); |
4498e746 | 402 | tkr = tkf->base + (seq & 0x01); |
27727df2 JS |
403 | now = ktime_to_ns(tkr->base); |
404 | ||
58bfea95 JS |
405 | now += timekeeping_delta_to_ns(tkr, |
406 | clocksource_delta( | |
407 | tkr->read(tkr->clock), | |
408 | tkr->cycle_last, | |
409 | tkr->mask)); | |
4498e746 | 410 | } while (read_seqcount_retry(&tkf->seq, seq)); |
4396e058 | 411 | |
4396e058 TG |
412 | return now; |
413 | } | |
4498e746 PZ |
414 | |
415 | u64 ktime_get_mono_fast_ns(void) | |
416 | { | |
417 | return __ktime_get_fast_ns(&tk_fast_mono); | |
418 | } | |
4396e058 TG |
419 | EXPORT_SYMBOL_GPL(ktime_get_mono_fast_ns); |
420 | ||
f09cb9a1 PZ |
421 | u64 ktime_get_raw_fast_ns(void) |
422 | { | |
423 | return __ktime_get_fast_ns(&tk_fast_raw); | |
424 | } | |
425 | EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns); | |
426 | ||
948a5312 JF |
427 | /** |
428 | * ktime_get_boot_fast_ns - NMI safe and fast access to boot clock. | |
429 | * | |
430 | * To keep it NMI safe since we're accessing from tracing, we're not using a | |
431 | * separate timekeeper with updates to monotonic clock and boot offset | |
432 | * protected with seqlocks. This has the following minor side effects: | |
433 | * | |
434 | * (1) Its possible that a timestamp be taken after the boot offset is updated | |
435 | * but before the timekeeper is updated. If this happens, the new boot offset | |
436 | * is added to the old timekeeping making the clock appear to update slightly | |
437 | * earlier: | |
438 | * CPU 0 CPU 1 | |
439 | * timekeeping_inject_sleeptime64() | |
440 | * __timekeeping_inject_sleeptime(tk, delta); | |
441 | * timestamp(); | |
442 | * timekeeping_update(tk, TK_CLEAR_NTP...); | |
443 | * | |
444 | * (2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be | |
445 | * partially updated. Since the tk->offs_boot update is a rare event, this | |
446 | * should be a rare occurrence which postprocessing should be able to handle. | |
447 | */ | |
448 | u64 notrace ktime_get_boot_fast_ns(void) | |
449 | { | |
450 | struct timekeeper *tk = &tk_core.timekeeper; | |
451 | ||
452 | return (ktime_get_mono_fast_ns() + ktime_to_ns(tk->offs_boot)); | |
453 | } | |
454 | EXPORT_SYMBOL_GPL(ktime_get_boot_fast_ns); | |
455 | ||
060407ae | 456 | /* Suspend-time cycles value for halted fast timekeeper. */ |
a5a1d1c2 | 457 | static u64 cycles_at_suspend; |
060407ae | 458 | |
a5a1d1c2 | 459 | static u64 dummy_clock_read(struct clocksource *cs) |
060407ae RW |
460 | { |
461 | return cycles_at_suspend; | |
462 | } | |
463 | ||
464 | /** | |
465 | * halt_fast_timekeeper - Prevent fast timekeeper from accessing clocksource. | |
466 | * @tk: Timekeeper to snapshot. | |
467 | * | |
468 | * It generally is unsafe to access the clocksource after timekeeping has been | |
469 | * suspended, so take a snapshot of the readout base of @tk and use it as the | |
470 | * fast timekeeper's readout base while suspended. It will return the same | |
471 | * number of cycles every time until timekeeping is resumed at which time the | |
472 | * proper readout base for the fast timekeeper will be restored automatically. | |
473 | */ | |
474 | static void halt_fast_timekeeper(struct timekeeper *tk) | |
475 | { | |
476 | static struct tk_read_base tkr_dummy; | |
876e7881 | 477 | struct tk_read_base *tkr = &tk->tkr_mono; |
060407ae RW |
478 | |
479 | memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy)); | |
480 | cycles_at_suspend = tkr->read(tkr->clock); | |
481 | tkr_dummy.read = dummy_clock_read; | |
4498e746 | 482 | update_fast_timekeeper(&tkr_dummy, &tk_fast_mono); |
f09cb9a1 PZ |
483 | |
484 | tkr = &tk->tkr_raw; | |
485 | memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy)); | |
486 | tkr_dummy.read = dummy_clock_read; | |
487 | update_fast_timekeeper(&tkr_dummy, &tk_fast_raw); | |
060407ae RW |
488 | } |
489 | ||
c905fae4 TG |
490 | #ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD |
491 | ||
492 | static inline void update_vsyscall(struct timekeeper *tk) | |
493 | { | |
0680eb1f | 494 | struct timespec xt, wm; |
c905fae4 | 495 | |
e2dff1ec | 496 | xt = timespec64_to_timespec(tk_xtime(tk)); |
0680eb1f | 497 | wm = timespec64_to_timespec(tk->wall_to_monotonic); |
876e7881 PZ |
498 | update_vsyscall_old(&xt, &wm, tk->tkr_mono.clock, tk->tkr_mono.mult, |
499 | tk->tkr_mono.cycle_last); | |
c905fae4 TG |
500 | } |
501 | ||
502 | static inline void old_vsyscall_fixup(struct timekeeper *tk) | |
503 | { | |
504 | s64 remainder; | |
505 | ||
506 | /* | |
507 | * Store only full nanoseconds into xtime_nsec after rounding | |
508 | * it up and add the remainder to the error difference. | |
509 | * XXX - This is necessary to avoid small 1ns inconsistnecies caused | |
510 | * by truncating the remainder in vsyscalls. However, it causes | |
511 | * additional work to be done in timekeeping_adjust(). Once | |
512 | * the vsyscall implementations are converted to use xtime_nsec | |
513 | * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD | |
514 | * users are removed, this can be killed. | |
515 | */ | |
876e7881 | 516 | remainder = tk->tkr_mono.xtime_nsec & ((1ULL << tk->tkr_mono.shift) - 1); |
0209b937 TG |
517 | if (remainder != 0) { |
518 | tk->tkr_mono.xtime_nsec -= remainder; | |
519 | tk->tkr_mono.xtime_nsec += 1ULL << tk->tkr_mono.shift; | |
520 | tk->ntp_error += remainder << tk->ntp_error_shift; | |
521 | tk->ntp_error -= (1ULL << tk->tkr_mono.shift) << tk->ntp_error_shift; | |
522 | } | |
c905fae4 TG |
523 | } |
524 | #else | |
525 | #define old_vsyscall_fixup(tk) | |
526 | #endif | |
527 | ||
e0b306fe MT |
528 | static RAW_NOTIFIER_HEAD(pvclock_gtod_chain); |
529 | ||
780427f0 | 530 | static void update_pvclock_gtod(struct timekeeper *tk, bool was_set) |
e0b306fe | 531 | { |
780427f0 | 532 | raw_notifier_call_chain(&pvclock_gtod_chain, was_set, tk); |
e0b306fe MT |
533 | } |
534 | ||
535 | /** | |
536 | * pvclock_gtod_register_notifier - register a pvclock timedata update listener | |
e0b306fe MT |
537 | */ |
538 | int pvclock_gtod_register_notifier(struct notifier_block *nb) | |
539 | { | |
3fdb14fd | 540 | struct timekeeper *tk = &tk_core.timekeeper; |
e0b306fe MT |
541 | unsigned long flags; |
542 | int ret; | |
543 | ||
9a7a71b1 | 544 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
e0b306fe | 545 | ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb); |
780427f0 | 546 | update_pvclock_gtod(tk, true); |
9a7a71b1 | 547 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
e0b306fe MT |
548 | |
549 | return ret; | |
550 | } | |
551 | EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier); | |
552 | ||
553 | /** | |
554 | * pvclock_gtod_unregister_notifier - unregister a pvclock | |
555 | * timedata update listener | |
e0b306fe MT |
556 | */ |
557 | int pvclock_gtod_unregister_notifier(struct notifier_block *nb) | |
558 | { | |
e0b306fe MT |
559 | unsigned long flags; |
560 | int ret; | |
561 | ||
9a7a71b1 | 562 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
e0b306fe | 563 | ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb); |
9a7a71b1 | 564 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
e0b306fe MT |
565 | |
566 | return ret; | |
567 | } | |
568 | EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier); | |
569 | ||
833f32d7 JS |
570 | /* |
571 | * tk_update_leap_state - helper to update the next_leap_ktime | |
572 | */ | |
573 | static inline void tk_update_leap_state(struct timekeeper *tk) | |
574 | { | |
575 | tk->next_leap_ktime = ntp_get_next_leap(); | |
2456e855 | 576 | if (tk->next_leap_ktime != KTIME_MAX) |
833f32d7 JS |
577 | /* Convert to monotonic time */ |
578 | tk->next_leap_ktime = ktime_sub(tk->next_leap_ktime, tk->offs_real); | |
579 | } | |
580 | ||
7c032df5 TG |
581 | /* |
582 | * Update the ktime_t based scalar nsec members of the timekeeper | |
583 | */ | |
584 | static inline void tk_update_ktime_data(struct timekeeper *tk) | |
585 | { | |
9e3680b1 HS |
586 | u64 seconds; |
587 | u32 nsec; | |
7c032df5 TG |
588 | |
589 | /* | |
590 | * The xtime based monotonic readout is: | |
591 | * nsec = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec + now(); | |
592 | * The ktime based monotonic readout is: | |
593 | * nsec = base_mono + now(); | |
594 | * ==> base_mono = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec | |
595 | */ | |
9e3680b1 HS |
596 | seconds = (u64)(tk->xtime_sec + tk->wall_to_monotonic.tv_sec); |
597 | nsec = (u32) tk->wall_to_monotonic.tv_nsec; | |
876e7881 | 598 | tk->tkr_mono.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec); |
f519b1a2 TG |
599 | |
600 | /* Update the monotonic raw base */ | |
4a4ad80d | 601 | tk->tkr_raw.base = timespec64_to_ktime(tk->raw_time); |
9e3680b1 HS |
602 | |
603 | /* | |
604 | * The sum of the nanoseconds portions of xtime and | |
605 | * wall_to_monotonic can be greater/equal one second. Take | |
606 | * this into account before updating tk->ktime_sec. | |
607 | */ | |
876e7881 | 608 | nsec += (u32)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); |
9e3680b1 HS |
609 | if (nsec >= NSEC_PER_SEC) |
610 | seconds++; | |
611 | tk->ktime_sec = seconds; | |
7c032df5 TG |
612 | } |
613 | ||
9a7a71b1 | 614 | /* must hold timekeeper_lock */ |
04397fe9 | 615 | static void timekeeping_update(struct timekeeper *tk, unsigned int action) |
cc06268c | 616 | { |
04397fe9 | 617 | if (action & TK_CLEAR_NTP) { |
f726a697 | 618 | tk->ntp_error = 0; |
cc06268c TG |
619 | ntp_clear(); |
620 | } | |
48cdc135 | 621 | |
833f32d7 | 622 | tk_update_leap_state(tk); |
7c032df5 TG |
623 | tk_update_ktime_data(tk); |
624 | ||
9bf2419f TG |
625 | update_vsyscall(tk); |
626 | update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); | |
627 | ||
4498e746 | 628 | update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono); |
f09cb9a1 | 629 | update_fast_timekeeper(&tk->tkr_raw, &tk_fast_raw); |
868a3e91 TG |
630 | |
631 | if (action & TK_CLOCK_WAS_SET) | |
632 | tk->clock_was_set_seq++; | |
d1518326 JS |
633 | /* |
634 | * The mirroring of the data to the shadow-timekeeper needs | |
635 | * to happen last here to ensure we don't over-write the | |
636 | * timekeeper structure on the next update with stale data | |
637 | */ | |
638 | if (action & TK_MIRROR) | |
639 | memcpy(&shadow_timekeeper, &tk_core.timekeeper, | |
640 | sizeof(tk_core.timekeeper)); | |
cc06268c TG |
641 | } |
642 | ||
8524070b | 643 | /** |
155ec602 | 644 | * timekeeping_forward_now - update clock to the current time |
8524070b | 645 | * |
9a055117 RZ |
646 | * Forward the current clock to update its state since the last call to |
647 | * update_wall_time(). This is useful before significant clock changes, | |
648 | * as it avoids having to deal with this time offset explicitly. | |
8524070b | 649 | */ |
f726a697 | 650 | static void timekeeping_forward_now(struct timekeeper *tk) |
8524070b | 651 | { |
876e7881 | 652 | struct clocksource *clock = tk->tkr_mono.clock; |
a5a1d1c2 | 653 | u64 cycle_now, delta; |
acc89612 | 654 | u64 nsec; |
8524070b | 655 | |
876e7881 PZ |
656 | cycle_now = tk->tkr_mono.read(clock); |
657 | delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask); | |
658 | tk->tkr_mono.cycle_last = cycle_now; | |
4a4ad80d | 659 | tk->tkr_raw.cycle_last = cycle_now; |
8524070b | 660 | |
876e7881 | 661 | tk->tkr_mono.xtime_nsec += delta * tk->tkr_mono.mult; |
7d27558c | 662 | |
7b1f6207 | 663 | /* If arch requires, add in get_arch_timeoffset() */ |
876e7881 | 664 | tk->tkr_mono.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_mono.shift; |
7d27558c | 665 | |
f726a697 | 666 | tk_normalize_xtime(tk); |
2d42244a | 667 | |
4a4ad80d | 668 | nsec = clocksource_cyc2ns(delta, tk->tkr_raw.mult, tk->tkr_raw.shift); |
7d489d15 | 669 | timespec64_add_ns(&tk->raw_time, nsec); |
8524070b JS |
670 | } |
671 | ||
672 | /** | |
d6d29896 | 673 | * __getnstimeofday64 - Returns the time of day in a timespec64. |
8524070b JS |
674 | * @ts: pointer to the timespec to be set |
675 | * | |
1e817fb6 KC |
676 | * Updates the time of day in the timespec. |
677 | * Returns 0 on success, or -ve when suspended (timespec will be undefined). | |
8524070b | 678 | */ |
d6d29896 | 679 | int __getnstimeofday64(struct timespec64 *ts) |
8524070b | 680 | { |
3fdb14fd | 681 | struct timekeeper *tk = &tk_core.timekeeper; |
8524070b | 682 | unsigned long seq; |
acc89612 | 683 | u64 nsecs; |
8524070b JS |
684 | |
685 | do { | |
3fdb14fd | 686 | seq = read_seqcount_begin(&tk_core.seq); |
8524070b | 687 | |
4e250fdd | 688 | ts->tv_sec = tk->xtime_sec; |
876e7881 | 689 | nsecs = timekeeping_get_ns(&tk->tkr_mono); |
8524070b | 690 | |
3fdb14fd | 691 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
8524070b | 692 | |
ec145bab | 693 | ts->tv_nsec = 0; |
d6d29896 | 694 | timespec64_add_ns(ts, nsecs); |
1e817fb6 KC |
695 | |
696 | /* | |
697 | * Do not bail out early, in case there were callers still using | |
698 | * the value, even in the face of the WARN_ON. | |
699 | */ | |
700 | if (unlikely(timekeeping_suspended)) | |
701 | return -EAGAIN; | |
702 | return 0; | |
703 | } | |
d6d29896 | 704 | EXPORT_SYMBOL(__getnstimeofday64); |
1e817fb6 KC |
705 | |
706 | /** | |
d6d29896 | 707 | * getnstimeofday64 - Returns the time of day in a timespec64. |
5322e4c2 | 708 | * @ts: pointer to the timespec64 to be set |
1e817fb6 | 709 | * |
5322e4c2 | 710 | * Returns the time of day in a timespec64 (WARN if suspended). |
1e817fb6 | 711 | */ |
d6d29896 | 712 | void getnstimeofday64(struct timespec64 *ts) |
1e817fb6 | 713 | { |
d6d29896 | 714 | WARN_ON(__getnstimeofday64(ts)); |
8524070b | 715 | } |
d6d29896 | 716 | EXPORT_SYMBOL(getnstimeofday64); |
8524070b | 717 | |
951ed4d3 MS |
718 | ktime_t ktime_get(void) |
719 | { | |
3fdb14fd | 720 | struct timekeeper *tk = &tk_core.timekeeper; |
951ed4d3 | 721 | unsigned int seq; |
a016a5bd | 722 | ktime_t base; |
acc89612 | 723 | u64 nsecs; |
951ed4d3 MS |
724 | |
725 | WARN_ON(timekeeping_suspended); | |
726 | ||
727 | do { | |
3fdb14fd | 728 | seq = read_seqcount_begin(&tk_core.seq); |
876e7881 PZ |
729 | base = tk->tkr_mono.base; |
730 | nsecs = timekeeping_get_ns(&tk->tkr_mono); | |
951ed4d3 | 731 | |
3fdb14fd | 732 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
24e4a8c3 | 733 | |
a016a5bd | 734 | return ktime_add_ns(base, nsecs); |
951ed4d3 MS |
735 | } |
736 | EXPORT_SYMBOL_GPL(ktime_get); | |
737 | ||
6374f912 HG |
738 | u32 ktime_get_resolution_ns(void) |
739 | { | |
740 | struct timekeeper *tk = &tk_core.timekeeper; | |
741 | unsigned int seq; | |
742 | u32 nsecs; | |
743 | ||
744 | WARN_ON(timekeeping_suspended); | |
745 | ||
746 | do { | |
747 | seq = read_seqcount_begin(&tk_core.seq); | |
748 | nsecs = tk->tkr_mono.mult >> tk->tkr_mono.shift; | |
749 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
750 | ||
751 | return nsecs; | |
752 | } | |
753 | EXPORT_SYMBOL_GPL(ktime_get_resolution_ns); | |
754 | ||
0077dc60 TG |
755 | static ktime_t *offsets[TK_OFFS_MAX] = { |
756 | [TK_OFFS_REAL] = &tk_core.timekeeper.offs_real, | |
757 | [TK_OFFS_BOOT] = &tk_core.timekeeper.offs_boot, | |
758 | [TK_OFFS_TAI] = &tk_core.timekeeper.offs_tai, | |
759 | }; | |
760 | ||
761 | ktime_t ktime_get_with_offset(enum tk_offsets offs) | |
762 | { | |
763 | struct timekeeper *tk = &tk_core.timekeeper; | |
764 | unsigned int seq; | |
765 | ktime_t base, *offset = offsets[offs]; | |
acc89612 | 766 | u64 nsecs; |
0077dc60 TG |
767 | |
768 | WARN_ON(timekeeping_suspended); | |
769 | ||
770 | do { | |
771 | seq = read_seqcount_begin(&tk_core.seq); | |
876e7881 PZ |
772 | base = ktime_add(tk->tkr_mono.base, *offset); |
773 | nsecs = timekeeping_get_ns(&tk->tkr_mono); | |
0077dc60 TG |
774 | |
775 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
776 | ||
777 | return ktime_add_ns(base, nsecs); | |
778 | ||
779 | } | |
780 | EXPORT_SYMBOL_GPL(ktime_get_with_offset); | |
781 | ||
9a6b5197 TG |
782 | /** |
783 | * ktime_mono_to_any() - convert mononotic time to any other time | |
784 | * @tmono: time to convert. | |
785 | * @offs: which offset to use | |
786 | */ | |
787 | ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs) | |
788 | { | |
789 | ktime_t *offset = offsets[offs]; | |
790 | unsigned long seq; | |
791 | ktime_t tconv; | |
792 | ||
793 | do { | |
794 | seq = read_seqcount_begin(&tk_core.seq); | |
795 | tconv = ktime_add(tmono, *offset); | |
796 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
797 | ||
798 | return tconv; | |
799 | } | |
800 | EXPORT_SYMBOL_GPL(ktime_mono_to_any); | |
801 | ||
f519b1a2 TG |
802 | /** |
803 | * ktime_get_raw - Returns the raw monotonic time in ktime_t format | |
804 | */ | |
805 | ktime_t ktime_get_raw(void) | |
806 | { | |
807 | struct timekeeper *tk = &tk_core.timekeeper; | |
808 | unsigned int seq; | |
809 | ktime_t base; | |
acc89612 | 810 | u64 nsecs; |
f519b1a2 TG |
811 | |
812 | do { | |
813 | seq = read_seqcount_begin(&tk_core.seq); | |
4a4ad80d PZ |
814 | base = tk->tkr_raw.base; |
815 | nsecs = timekeeping_get_ns(&tk->tkr_raw); | |
f519b1a2 TG |
816 | |
817 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
818 | ||
819 | return ktime_add_ns(base, nsecs); | |
820 | } | |
821 | EXPORT_SYMBOL_GPL(ktime_get_raw); | |
822 | ||
951ed4d3 | 823 | /** |
d6d29896 | 824 | * ktime_get_ts64 - get the monotonic clock in timespec64 format |
951ed4d3 MS |
825 | * @ts: pointer to timespec variable |
826 | * | |
827 | * The function calculates the monotonic clock from the realtime | |
828 | * clock and the wall_to_monotonic offset and stores the result | |
5322e4c2 | 829 | * in normalized timespec64 format in the variable pointed to by @ts. |
951ed4d3 | 830 | */ |
d6d29896 | 831 | void ktime_get_ts64(struct timespec64 *ts) |
951ed4d3 | 832 | { |
3fdb14fd | 833 | struct timekeeper *tk = &tk_core.timekeeper; |
d6d29896 | 834 | struct timespec64 tomono; |
951ed4d3 | 835 | unsigned int seq; |
acc89612 | 836 | u64 nsec; |
951ed4d3 MS |
837 | |
838 | WARN_ON(timekeeping_suspended); | |
839 | ||
840 | do { | |
3fdb14fd | 841 | seq = read_seqcount_begin(&tk_core.seq); |
d6d29896 | 842 | ts->tv_sec = tk->xtime_sec; |
876e7881 | 843 | nsec = timekeeping_get_ns(&tk->tkr_mono); |
4e250fdd | 844 | tomono = tk->wall_to_monotonic; |
951ed4d3 | 845 | |
3fdb14fd | 846 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
951ed4d3 | 847 | |
d6d29896 TG |
848 | ts->tv_sec += tomono.tv_sec; |
849 | ts->tv_nsec = 0; | |
850 | timespec64_add_ns(ts, nsec + tomono.tv_nsec); | |
951ed4d3 | 851 | } |
d6d29896 | 852 | EXPORT_SYMBOL_GPL(ktime_get_ts64); |
951ed4d3 | 853 | |
9e3680b1 HS |
854 | /** |
855 | * ktime_get_seconds - Get the seconds portion of CLOCK_MONOTONIC | |
856 | * | |
857 | * Returns the seconds portion of CLOCK_MONOTONIC with a single non | |
858 | * serialized read. tk->ktime_sec is of type 'unsigned long' so this | |
859 | * works on both 32 and 64 bit systems. On 32 bit systems the readout | |
860 | * covers ~136 years of uptime which should be enough to prevent | |
861 | * premature wrap arounds. | |
862 | */ | |
863 | time64_t ktime_get_seconds(void) | |
864 | { | |
865 | struct timekeeper *tk = &tk_core.timekeeper; | |
866 | ||
867 | WARN_ON(timekeeping_suspended); | |
868 | return tk->ktime_sec; | |
869 | } | |
870 | EXPORT_SYMBOL_GPL(ktime_get_seconds); | |
871 | ||
dbe7aa62 HS |
872 | /** |
873 | * ktime_get_real_seconds - Get the seconds portion of CLOCK_REALTIME | |
874 | * | |
875 | * Returns the wall clock seconds since 1970. This replaces the | |
876 | * get_seconds() interface which is not y2038 safe on 32bit systems. | |
877 | * | |
878 | * For 64bit systems the fast access to tk->xtime_sec is preserved. On | |
879 | * 32bit systems the access must be protected with the sequence | |
880 | * counter to provide "atomic" access to the 64bit tk->xtime_sec | |
881 | * value. | |
882 | */ | |
883 | time64_t ktime_get_real_seconds(void) | |
884 | { | |
885 | struct timekeeper *tk = &tk_core.timekeeper; | |
886 | time64_t seconds; | |
887 | unsigned int seq; | |
888 | ||
889 | if (IS_ENABLED(CONFIG_64BIT)) | |
890 | return tk->xtime_sec; | |
891 | ||
892 | do { | |
893 | seq = read_seqcount_begin(&tk_core.seq); | |
894 | seconds = tk->xtime_sec; | |
895 | ||
896 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
897 | ||
898 | return seconds; | |
899 | } | |
900 | EXPORT_SYMBOL_GPL(ktime_get_real_seconds); | |
901 | ||
dee36654 D |
902 | /** |
903 | * __ktime_get_real_seconds - The same as ktime_get_real_seconds | |
904 | * but without the sequence counter protect. This internal function | |
905 | * is called just when timekeeping lock is already held. | |
906 | */ | |
907 | time64_t __ktime_get_real_seconds(void) | |
908 | { | |
909 | struct timekeeper *tk = &tk_core.timekeeper; | |
910 | ||
911 | return tk->xtime_sec; | |
912 | } | |
913 | ||
9da0f49c CH |
914 | /** |
915 | * ktime_get_snapshot - snapshots the realtime/monotonic raw clocks with counter | |
916 | * @systime_snapshot: pointer to struct receiving the system time snapshot | |
917 | */ | |
918 | void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot) | |
919 | { | |
920 | struct timekeeper *tk = &tk_core.timekeeper; | |
921 | unsigned long seq; | |
922 | ktime_t base_raw; | |
923 | ktime_t base_real; | |
acc89612 TG |
924 | u64 nsec_raw; |
925 | u64 nsec_real; | |
a5a1d1c2 | 926 | u64 now; |
9da0f49c | 927 | |
ba26621e CH |
928 | WARN_ON_ONCE(timekeeping_suspended); |
929 | ||
9da0f49c CH |
930 | do { |
931 | seq = read_seqcount_begin(&tk_core.seq); | |
932 | ||
933 | now = tk->tkr_mono.read(tk->tkr_mono.clock); | |
2c756feb CH |
934 | systime_snapshot->cs_was_changed_seq = tk->cs_was_changed_seq; |
935 | systime_snapshot->clock_was_set_seq = tk->clock_was_set_seq; | |
9da0f49c CH |
936 | base_real = ktime_add(tk->tkr_mono.base, |
937 | tk_core.timekeeper.offs_real); | |
938 | base_raw = tk->tkr_raw.base; | |
939 | nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, now); | |
940 | nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, now); | |
941 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
942 | ||
943 | systime_snapshot->cycles = now; | |
944 | systime_snapshot->real = ktime_add_ns(base_real, nsec_real); | |
945 | systime_snapshot->raw = ktime_add_ns(base_raw, nsec_raw); | |
946 | } | |
947 | EXPORT_SYMBOL_GPL(ktime_get_snapshot); | |
dee36654 | 948 | |
2c756feb CH |
949 | /* Scale base by mult/div checking for overflow */ |
950 | static int scale64_check_overflow(u64 mult, u64 div, u64 *base) | |
951 | { | |
952 | u64 tmp, rem; | |
953 | ||
954 | tmp = div64_u64_rem(*base, div, &rem); | |
955 | ||
956 | if (((int)sizeof(u64)*8 - fls64(mult) < fls64(tmp)) || | |
957 | ((int)sizeof(u64)*8 - fls64(mult) < fls64(rem))) | |
958 | return -EOVERFLOW; | |
959 | tmp *= mult; | |
960 | rem *= mult; | |
961 | ||
962 | do_div(rem, div); | |
963 | *base = tmp + rem; | |
964 | return 0; | |
965 | } | |
966 | ||
967 | /** | |
968 | * adjust_historical_crosststamp - adjust crosstimestamp previous to current interval | |
969 | * @history: Snapshot representing start of history | |
970 | * @partial_history_cycles: Cycle offset into history (fractional part) | |
971 | * @total_history_cycles: Total history length in cycles | |
972 | * @discontinuity: True indicates clock was set on history period | |
973 | * @ts: Cross timestamp that should be adjusted using | |
974 | * partial/total ratio | |
975 | * | |
976 | * Helper function used by get_device_system_crosststamp() to correct the | |
977 | * crosstimestamp corresponding to the start of the current interval to the | |
978 | * system counter value (timestamp point) provided by the driver. The | |
979 | * total_history_* quantities are the total history starting at the provided | |
980 | * reference point and ending at the start of the current interval. The cycle | |
981 | * count between the driver timestamp point and the start of the current | |
982 | * interval is partial_history_cycles. | |
983 | */ | |
984 | static int adjust_historical_crosststamp(struct system_time_snapshot *history, | |
a5a1d1c2 TG |
985 | u64 partial_history_cycles, |
986 | u64 total_history_cycles, | |
2c756feb CH |
987 | bool discontinuity, |
988 | struct system_device_crosststamp *ts) | |
989 | { | |
990 | struct timekeeper *tk = &tk_core.timekeeper; | |
991 | u64 corr_raw, corr_real; | |
992 | bool interp_forward; | |
993 | int ret; | |
994 | ||
995 | if (total_history_cycles == 0 || partial_history_cycles == 0) | |
996 | return 0; | |
997 | ||
998 | /* Interpolate shortest distance from beginning or end of history */ | |
5fc63f95 | 999 | interp_forward = partial_history_cycles > total_history_cycles / 2; |
2c756feb CH |
1000 | partial_history_cycles = interp_forward ? |
1001 | total_history_cycles - partial_history_cycles : | |
1002 | partial_history_cycles; | |
1003 | ||
1004 | /* | |
1005 | * Scale the monotonic raw time delta by: | |
1006 | * partial_history_cycles / total_history_cycles | |
1007 | */ | |
1008 | corr_raw = (u64)ktime_to_ns( | |
1009 | ktime_sub(ts->sys_monoraw, history->raw)); | |
1010 | ret = scale64_check_overflow(partial_history_cycles, | |
1011 | total_history_cycles, &corr_raw); | |
1012 | if (ret) | |
1013 | return ret; | |
1014 | ||
1015 | /* | |
1016 | * If there is a discontinuity in the history, scale monotonic raw | |
1017 | * correction by: | |
1018 | * mult(real)/mult(raw) yielding the realtime correction | |
1019 | * Otherwise, calculate the realtime correction similar to monotonic | |
1020 | * raw calculation | |
1021 | */ | |
1022 | if (discontinuity) { | |
1023 | corr_real = mul_u64_u32_div | |
1024 | (corr_raw, tk->tkr_mono.mult, tk->tkr_raw.mult); | |
1025 | } else { | |
1026 | corr_real = (u64)ktime_to_ns( | |
1027 | ktime_sub(ts->sys_realtime, history->real)); | |
1028 | ret = scale64_check_overflow(partial_history_cycles, | |
1029 | total_history_cycles, &corr_real); | |
1030 | if (ret) | |
1031 | return ret; | |
1032 | } | |
1033 | ||
1034 | /* Fixup monotonic raw and real time time values */ | |
1035 | if (interp_forward) { | |
1036 | ts->sys_monoraw = ktime_add_ns(history->raw, corr_raw); | |
1037 | ts->sys_realtime = ktime_add_ns(history->real, corr_real); | |
1038 | } else { | |
1039 | ts->sys_monoraw = ktime_sub_ns(ts->sys_monoraw, corr_raw); | |
1040 | ts->sys_realtime = ktime_sub_ns(ts->sys_realtime, corr_real); | |
1041 | } | |
1042 | ||
1043 | return 0; | |
1044 | } | |
1045 | ||
1046 | /* | |
1047 | * cycle_between - true if test occurs chronologically between before and after | |
1048 | */ | |
a5a1d1c2 | 1049 | static bool cycle_between(u64 before, u64 test, u64 after) |
2c756feb CH |
1050 | { |
1051 | if (test > before && test < after) | |
1052 | return true; | |
1053 | if (test < before && before > after) | |
1054 | return true; | |
1055 | return false; | |
1056 | } | |
1057 | ||
8006c245 CH |
1058 | /** |
1059 | * get_device_system_crosststamp - Synchronously capture system/device timestamp | |
2c756feb | 1060 | * @get_time_fn: Callback to get simultaneous device time and |
8006c245 | 1061 | * system counter from the device driver |
2c756feb CH |
1062 | * @ctx: Context passed to get_time_fn() |
1063 | * @history_begin: Historical reference point used to interpolate system | |
1064 | * time when counter provided by the driver is before the current interval | |
8006c245 CH |
1065 | * @xtstamp: Receives simultaneously captured system and device time |
1066 | * | |
1067 | * Reads a timestamp from a device and correlates it to system time | |
1068 | */ | |
1069 | int get_device_system_crosststamp(int (*get_time_fn) | |
1070 | (ktime_t *device_time, | |
1071 | struct system_counterval_t *sys_counterval, | |
1072 | void *ctx), | |
1073 | void *ctx, | |
2c756feb | 1074 | struct system_time_snapshot *history_begin, |
8006c245 CH |
1075 | struct system_device_crosststamp *xtstamp) |
1076 | { | |
1077 | struct system_counterval_t system_counterval; | |
1078 | struct timekeeper *tk = &tk_core.timekeeper; | |
a5a1d1c2 | 1079 | u64 cycles, now, interval_start; |
6436257b | 1080 | unsigned int clock_was_set_seq = 0; |
8006c245 | 1081 | ktime_t base_real, base_raw; |
acc89612 | 1082 | u64 nsec_real, nsec_raw; |
2c756feb | 1083 | u8 cs_was_changed_seq; |
8006c245 | 1084 | unsigned long seq; |
2c756feb | 1085 | bool do_interp; |
8006c245 CH |
1086 | int ret; |
1087 | ||
1088 | do { | |
1089 | seq = read_seqcount_begin(&tk_core.seq); | |
1090 | /* | |
1091 | * Try to synchronously capture device time and a system | |
1092 | * counter value calling back into the device driver | |
1093 | */ | |
1094 | ret = get_time_fn(&xtstamp->device, &system_counterval, ctx); | |
1095 | if (ret) | |
1096 | return ret; | |
1097 | ||
1098 | /* | |
1099 | * Verify that the clocksource associated with the captured | |
1100 | * system counter value is the same as the currently installed | |
1101 | * timekeeper clocksource | |
1102 | */ | |
1103 | if (tk->tkr_mono.clock != system_counterval.cs) | |
1104 | return -ENODEV; | |
2c756feb CH |
1105 | cycles = system_counterval.cycles; |
1106 | ||
1107 | /* | |
1108 | * Check whether the system counter value provided by the | |
1109 | * device driver is on the current timekeeping interval. | |
1110 | */ | |
1111 | now = tk->tkr_mono.read(tk->tkr_mono.clock); | |
1112 | interval_start = tk->tkr_mono.cycle_last; | |
1113 | if (!cycle_between(interval_start, cycles, now)) { | |
1114 | clock_was_set_seq = tk->clock_was_set_seq; | |
1115 | cs_was_changed_seq = tk->cs_was_changed_seq; | |
1116 | cycles = interval_start; | |
1117 | do_interp = true; | |
1118 | } else { | |
1119 | do_interp = false; | |
1120 | } | |
8006c245 CH |
1121 | |
1122 | base_real = ktime_add(tk->tkr_mono.base, | |
1123 | tk_core.timekeeper.offs_real); | |
1124 | base_raw = tk->tkr_raw.base; | |
1125 | ||
1126 | nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, | |
1127 | system_counterval.cycles); | |
1128 | nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, | |
1129 | system_counterval.cycles); | |
1130 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
1131 | ||
1132 | xtstamp->sys_realtime = ktime_add_ns(base_real, nsec_real); | |
1133 | xtstamp->sys_monoraw = ktime_add_ns(base_raw, nsec_raw); | |
2c756feb CH |
1134 | |
1135 | /* | |
1136 | * Interpolate if necessary, adjusting back from the start of the | |
1137 | * current interval | |
1138 | */ | |
1139 | if (do_interp) { | |
a5a1d1c2 | 1140 | u64 partial_history_cycles, total_history_cycles; |
2c756feb CH |
1141 | bool discontinuity; |
1142 | ||
1143 | /* | |
1144 | * Check that the counter value occurs after the provided | |
1145 | * history reference and that the history doesn't cross a | |
1146 | * clocksource change | |
1147 | */ | |
1148 | if (!history_begin || | |
1149 | !cycle_between(history_begin->cycles, | |
1150 | system_counterval.cycles, cycles) || | |
1151 | history_begin->cs_was_changed_seq != cs_was_changed_seq) | |
1152 | return -EINVAL; | |
1153 | partial_history_cycles = cycles - system_counterval.cycles; | |
1154 | total_history_cycles = cycles - history_begin->cycles; | |
1155 | discontinuity = | |
1156 | history_begin->clock_was_set_seq != clock_was_set_seq; | |
1157 | ||
1158 | ret = adjust_historical_crosststamp(history_begin, | |
1159 | partial_history_cycles, | |
1160 | total_history_cycles, | |
1161 | discontinuity, xtstamp); | |
1162 | if (ret) | |
1163 | return ret; | |
1164 | } | |
1165 | ||
8006c245 CH |
1166 | return 0; |
1167 | } | |
1168 | EXPORT_SYMBOL_GPL(get_device_system_crosststamp); | |
1169 | ||
8524070b JS |
1170 | /** |
1171 | * do_gettimeofday - Returns the time of day in a timeval | |
1172 | * @tv: pointer to the timeval to be set | |
1173 | * | |
efd9ac86 | 1174 | * NOTE: Users should be converted to using getnstimeofday() |
8524070b JS |
1175 | */ |
1176 | void do_gettimeofday(struct timeval *tv) | |
1177 | { | |
d6d29896 | 1178 | struct timespec64 now; |
8524070b | 1179 | |
d6d29896 | 1180 | getnstimeofday64(&now); |
8524070b JS |
1181 | tv->tv_sec = now.tv_sec; |
1182 | tv->tv_usec = now.tv_nsec/1000; | |
1183 | } | |
8524070b | 1184 | EXPORT_SYMBOL(do_gettimeofday); |
d239f49d | 1185 | |
8524070b | 1186 | /** |
21f7eca5 | 1187 | * do_settimeofday64 - Sets the time of day. |
1188 | * @ts: pointer to the timespec64 variable containing the new time | |
8524070b JS |
1189 | * |
1190 | * Sets the time of day to the new time and update NTP and notify hrtimers | |
1191 | */ | |
21f7eca5 | 1192 | int do_settimeofday64(const struct timespec64 *ts) |
8524070b | 1193 | { |
3fdb14fd | 1194 | struct timekeeper *tk = &tk_core.timekeeper; |
21f7eca5 | 1195 | struct timespec64 ts_delta, xt; |
92c1d3ed | 1196 | unsigned long flags; |
e1d7ba87 | 1197 | int ret = 0; |
8524070b | 1198 | |
21f7eca5 | 1199 | if (!timespec64_valid_strict(ts)) |
8524070b JS |
1200 | return -EINVAL; |
1201 | ||
9a7a71b1 | 1202 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1203 | write_seqcount_begin(&tk_core.seq); |
8524070b | 1204 | |
4e250fdd | 1205 | timekeeping_forward_now(tk); |
9a055117 | 1206 | |
4e250fdd | 1207 | xt = tk_xtime(tk); |
21f7eca5 | 1208 | ts_delta.tv_sec = ts->tv_sec - xt.tv_sec; |
1209 | ts_delta.tv_nsec = ts->tv_nsec - xt.tv_nsec; | |
1e75fa8b | 1210 | |
e1d7ba87 WY |
1211 | if (timespec64_compare(&tk->wall_to_monotonic, &ts_delta) > 0) { |
1212 | ret = -EINVAL; | |
1213 | goto out; | |
1214 | } | |
1215 | ||
7d489d15 | 1216 | tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts_delta)); |
8524070b | 1217 | |
21f7eca5 | 1218 | tk_set_xtime(tk, ts); |
e1d7ba87 | 1219 | out: |
780427f0 | 1220 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
8524070b | 1221 | |
3fdb14fd | 1222 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1223 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b JS |
1224 | |
1225 | /* signal hrtimers about time change */ | |
1226 | clock_was_set(); | |
1227 | ||
e1d7ba87 | 1228 | return ret; |
8524070b | 1229 | } |
21f7eca5 | 1230 | EXPORT_SYMBOL(do_settimeofday64); |
8524070b | 1231 | |
c528f7c6 JS |
1232 | /** |
1233 | * timekeeping_inject_offset - Adds or subtracts from the current time. | |
1234 | * @tv: pointer to the timespec variable containing the offset | |
1235 | * | |
1236 | * Adds or subtracts an offset value from the current time. | |
1237 | */ | |
1238 | int timekeeping_inject_offset(struct timespec *ts) | |
1239 | { | |
3fdb14fd | 1240 | struct timekeeper *tk = &tk_core.timekeeper; |
92c1d3ed | 1241 | unsigned long flags; |
7d489d15 | 1242 | struct timespec64 ts64, tmp; |
4e8b1452 | 1243 | int ret = 0; |
c528f7c6 | 1244 | |
37cf4dc3 | 1245 | if (!timespec_inject_offset_valid(ts)) |
c528f7c6 JS |
1246 | return -EINVAL; |
1247 | ||
7d489d15 JS |
1248 | ts64 = timespec_to_timespec64(*ts); |
1249 | ||
9a7a71b1 | 1250 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1251 | write_seqcount_begin(&tk_core.seq); |
c528f7c6 | 1252 | |
4e250fdd | 1253 | timekeeping_forward_now(tk); |
c528f7c6 | 1254 | |
4e8b1452 | 1255 | /* Make sure the proposed value is valid */ |
7d489d15 | 1256 | tmp = timespec64_add(tk_xtime(tk), ts64); |
e1d7ba87 WY |
1257 | if (timespec64_compare(&tk->wall_to_monotonic, &ts64) > 0 || |
1258 | !timespec64_valid_strict(&tmp)) { | |
4e8b1452 JS |
1259 | ret = -EINVAL; |
1260 | goto error; | |
1261 | } | |
1e75fa8b | 1262 | |
7d489d15 JS |
1263 | tk_xtime_add(tk, &ts64); |
1264 | tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts64)); | |
c528f7c6 | 1265 | |
4e8b1452 | 1266 | error: /* even if we error out, we forwarded the time, so call update */ |
780427f0 | 1267 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
c528f7c6 | 1268 | |
3fdb14fd | 1269 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1270 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
c528f7c6 JS |
1271 | |
1272 | /* signal hrtimers about time change */ | |
1273 | clock_was_set(); | |
1274 | ||
4e8b1452 | 1275 | return ret; |
c528f7c6 JS |
1276 | } |
1277 | EXPORT_SYMBOL(timekeeping_inject_offset); | |
1278 | ||
cc244dda | 1279 | /** |
40d9f827 | 1280 | * __timekeeping_set_tai_offset - Sets the TAI offset from UTC and monotonic |
cc244dda JS |
1281 | * |
1282 | */ | |
dd5d70e8 | 1283 | static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset) |
cc244dda JS |
1284 | { |
1285 | tk->tai_offset = tai_offset; | |
04005f60 | 1286 | tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tai_offset, 0)); |
cc244dda JS |
1287 | } |
1288 | ||
8524070b JS |
1289 | /** |
1290 | * change_clocksource - Swaps clocksources if a new one is available | |
1291 | * | |
1292 | * Accumulates current time interval and initializes new clocksource | |
1293 | */ | |
75c5158f | 1294 | static int change_clocksource(void *data) |
8524070b | 1295 | { |
3fdb14fd | 1296 | struct timekeeper *tk = &tk_core.timekeeper; |
4614e6ad | 1297 | struct clocksource *new, *old; |
f695cf94 | 1298 | unsigned long flags; |
8524070b | 1299 | |
75c5158f | 1300 | new = (struct clocksource *) data; |
8524070b | 1301 | |
9a7a71b1 | 1302 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1303 | write_seqcount_begin(&tk_core.seq); |
f695cf94 | 1304 | |
4e250fdd | 1305 | timekeeping_forward_now(tk); |
09ac369c TG |
1306 | /* |
1307 | * If the cs is in module, get a module reference. Succeeds | |
1308 | * for built-in code (owner == NULL) as well. | |
1309 | */ | |
1310 | if (try_module_get(new->owner)) { | |
1311 | if (!new->enable || new->enable(new) == 0) { | |
876e7881 | 1312 | old = tk->tkr_mono.clock; |
09ac369c TG |
1313 | tk_setup_internals(tk, new); |
1314 | if (old->disable) | |
1315 | old->disable(old); | |
1316 | module_put(old->owner); | |
1317 | } else { | |
1318 | module_put(new->owner); | |
1319 | } | |
75c5158f | 1320 | } |
780427f0 | 1321 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
f695cf94 | 1322 | |
3fdb14fd | 1323 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1324 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
f695cf94 | 1325 | |
75c5158f MS |
1326 | return 0; |
1327 | } | |
8524070b | 1328 | |
75c5158f MS |
1329 | /** |
1330 | * timekeeping_notify - Install a new clock source | |
1331 | * @clock: pointer to the clock source | |
1332 | * | |
1333 | * This function is called from clocksource.c after a new, better clock | |
1334 | * source has been registered. The caller holds the clocksource_mutex. | |
1335 | */ | |
ba919d1c | 1336 | int timekeeping_notify(struct clocksource *clock) |
75c5158f | 1337 | { |
3fdb14fd | 1338 | struct timekeeper *tk = &tk_core.timekeeper; |
4e250fdd | 1339 | |
876e7881 | 1340 | if (tk->tkr_mono.clock == clock) |
ba919d1c | 1341 | return 0; |
75c5158f | 1342 | stop_machine(change_clocksource, clock, NULL); |
8524070b | 1343 | tick_clock_notify(); |
876e7881 | 1344 | return tk->tkr_mono.clock == clock ? 0 : -1; |
8524070b | 1345 | } |
75c5158f | 1346 | |
2d42244a | 1347 | /** |
cdba2ec5 JS |
1348 | * getrawmonotonic64 - Returns the raw monotonic time in a timespec |
1349 | * @ts: pointer to the timespec64 to be set | |
2d42244a JS |
1350 | * |
1351 | * Returns the raw monotonic time (completely un-modified by ntp) | |
1352 | */ | |
cdba2ec5 | 1353 | void getrawmonotonic64(struct timespec64 *ts) |
2d42244a | 1354 | { |
3fdb14fd | 1355 | struct timekeeper *tk = &tk_core.timekeeper; |
7d489d15 | 1356 | struct timespec64 ts64; |
2d42244a | 1357 | unsigned long seq; |
acc89612 | 1358 | u64 nsecs; |
2d42244a JS |
1359 | |
1360 | do { | |
3fdb14fd | 1361 | seq = read_seqcount_begin(&tk_core.seq); |
4a4ad80d | 1362 | nsecs = timekeeping_get_ns(&tk->tkr_raw); |
7d489d15 | 1363 | ts64 = tk->raw_time; |
2d42244a | 1364 | |
3fdb14fd | 1365 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
2d42244a | 1366 | |
7d489d15 | 1367 | timespec64_add_ns(&ts64, nsecs); |
cdba2ec5 | 1368 | *ts = ts64; |
2d42244a | 1369 | } |
cdba2ec5 JS |
1370 | EXPORT_SYMBOL(getrawmonotonic64); |
1371 | ||
2d42244a | 1372 | |
8524070b | 1373 | /** |
cf4fc6cb | 1374 | * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres |
8524070b | 1375 | */ |
cf4fc6cb | 1376 | int timekeeping_valid_for_hres(void) |
8524070b | 1377 | { |
3fdb14fd | 1378 | struct timekeeper *tk = &tk_core.timekeeper; |
8524070b JS |
1379 | unsigned long seq; |
1380 | int ret; | |
1381 | ||
1382 | do { | |
3fdb14fd | 1383 | seq = read_seqcount_begin(&tk_core.seq); |
8524070b | 1384 | |
876e7881 | 1385 | ret = tk->tkr_mono.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; |
8524070b | 1386 | |
3fdb14fd | 1387 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
8524070b JS |
1388 | |
1389 | return ret; | |
1390 | } | |
1391 | ||
98962465 JH |
1392 | /** |
1393 | * timekeeping_max_deferment - Returns max time the clocksource can be deferred | |
98962465 JH |
1394 | */ |
1395 | u64 timekeeping_max_deferment(void) | |
1396 | { | |
3fdb14fd | 1397 | struct timekeeper *tk = &tk_core.timekeeper; |
70471f2f JS |
1398 | unsigned long seq; |
1399 | u64 ret; | |
42e71e81 | 1400 | |
70471f2f | 1401 | do { |
3fdb14fd | 1402 | seq = read_seqcount_begin(&tk_core.seq); |
70471f2f | 1403 | |
876e7881 | 1404 | ret = tk->tkr_mono.clock->max_idle_ns; |
70471f2f | 1405 | |
3fdb14fd | 1406 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
70471f2f JS |
1407 | |
1408 | return ret; | |
98962465 JH |
1409 | } |
1410 | ||
8524070b | 1411 | /** |
d4f587c6 | 1412 | * read_persistent_clock - Return time from the persistent clock. |
8524070b JS |
1413 | * |
1414 | * Weak dummy function for arches that do not yet support it. | |
d4f587c6 MS |
1415 | * Reads the time from the battery backed persistent clock. |
1416 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. | |
8524070b JS |
1417 | * |
1418 | * XXX - Do be sure to remove it once all arches implement it. | |
1419 | */ | |
52f5684c | 1420 | void __weak read_persistent_clock(struct timespec *ts) |
8524070b | 1421 | { |
d4f587c6 MS |
1422 | ts->tv_sec = 0; |
1423 | ts->tv_nsec = 0; | |
8524070b JS |
1424 | } |
1425 | ||
2ee96632 XP |
1426 | void __weak read_persistent_clock64(struct timespec64 *ts64) |
1427 | { | |
1428 | struct timespec ts; | |
1429 | ||
1430 | read_persistent_clock(&ts); | |
1431 | *ts64 = timespec_to_timespec64(ts); | |
1432 | } | |
1433 | ||
23970e38 | 1434 | /** |
e83d0a41 | 1435 | * read_boot_clock64 - Return time of the system start. |
23970e38 MS |
1436 | * |
1437 | * Weak dummy function for arches that do not yet support it. | |
1438 | * Function to read the exact time the system has been started. | |
e83d0a41 | 1439 | * Returns a timespec64 with tv_sec=0 and tv_nsec=0 if unsupported. |
23970e38 MS |
1440 | * |
1441 | * XXX - Do be sure to remove it once all arches implement it. | |
1442 | */ | |
e83d0a41 | 1443 | void __weak read_boot_clock64(struct timespec64 *ts) |
23970e38 MS |
1444 | { |
1445 | ts->tv_sec = 0; | |
1446 | ts->tv_nsec = 0; | |
1447 | } | |
1448 | ||
0fa88cb4 XP |
1449 | /* Flag for if timekeeping_resume() has injected sleeptime */ |
1450 | static bool sleeptime_injected; | |
1451 | ||
1452 | /* Flag for if there is a persistent clock on this platform */ | |
1453 | static bool persistent_clock_exists; | |
1454 | ||
8524070b JS |
1455 | /* |
1456 | * timekeeping_init - Initializes the clocksource and common timekeeping values | |
1457 | */ | |
1458 | void __init timekeeping_init(void) | |
1459 | { | |
3fdb14fd | 1460 | struct timekeeper *tk = &tk_core.timekeeper; |
155ec602 | 1461 | struct clocksource *clock; |
8524070b | 1462 | unsigned long flags; |
7d489d15 | 1463 | struct timespec64 now, boot, tmp; |
31ade306 | 1464 | |
2ee96632 | 1465 | read_persistent_clock64(&now); |
7d489d15 | 1466 | if (!timespec64_valid_strict(&now)) { |
4e8b1452 JS |
1467 | pr_warn("WARNING: Persistent clock returned invalid value!\n" |
1468 | " Check your CMOS/BIOS settings.\n"); | |
1469 | now.tv_sec = 0; | |
1470 | now.tv_nsec = 0; | |
31ade306 | 1471 | } else if (now.tv_sec || now.tv_nsec) |
0fa88cb4 | 1472 | persistent_clock_exists = true; |
4e8b1452 | 1473 | |
9a806ddb | 1474 | read_boot_clock64(&boot); |
7d489d15 | 1475 | if (!timespec64_valid_strict(&boot)) { |
4e8b1452 JS |
1476 | pr_warn("WARNING: Boot clock returned invalid value!\n" |
1477 | " Check your CMOS/BIOS settings.\n"); | |
1478 | boot.tv_sec = 0; | |
1479 | boot.tv_nsec = 0; | |
1480 | } | |
8524070b | 1481 | |
9a7a71b1 | 1482 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1483 | write_seqcount_begin(&tk_core.seq); |
06c017fd JS |
1484 | ntp_init(); |
1485 | ||
f1b82746 | 1486 | clock = clocksource_default_clock(); |
a0f7d48b MS |
1487 | if (clock->enable) |
1488 | clock->enable(clock); | |
4e250fdd | 1489 | tk_setup_internals(tk, clock); |
8524070b | 1490 | |
4e250fdd JS |
1491 | tk_set_xtime(tk, &now); |
1492 | tk->raw_time.tv_sec = 0; | |
1493 | tk->raw_time.tv_nsec = 0; | |
1e75fa8b | 1494 | if (boot.tv_sec == 0 && boot.tv_nsec == 0) |
4e250fdd | 1495 | boot = tk_xtime(tk); |
1e75fa8b | 1496 | |
7d489d15 | 1497 | set_normalized_timespec64(&tmp, -boot.tv_sec, -boot.tv_nsec); |
4e250fdd | 1498 | tk_set_wall_to_mono(tk, tmp); |
6d0ef903 | 1499 | |
56fd16ca | 1500 | timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |
48cdc135 | 1501 | |
3fdb14fd | 1502 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1503 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b JS |
1504 | } |
1505 | ||
264bb3f7 | 1506 | /* time in seconds when suspend began for persistent clock */ |
7d489d15 | 1507 | static struct timespec64 timekeeping_suspend_time; |
8524070b | 1508 | |
304529b1 JS |
1509 | /** |
1510 | * __timekeeping_inject_sleeptime - Internal function to add sleep interval | |
1511 | * @delta: pointer to a timespec delta value | |
1512 | * | |
1513 | * Takes a timespec offset measuring a suspend interval and properly | |
1514 | * adds the sleep offset to the timekeeping variables. | |
1515 | */ | |
f726a697 | 1516 | static void __timekeeping_inject_sleeptime(struct timekeeper *tk, |
7d489d15 | 1517 | struct timespec64 *delta) |
304529b1 | 1518 | { |
7d489d15 | 1519 | if (!timespec64_valid_strict(delta)) { |
6d9bcb62 JS |
1520 | printk_deferred(KERN_WARNING |
1521 | "__timekeeping_inject_sleeptime: Invalid " | |
1522 | "sleep delta value!\n"); | |
cb5de2f8 JS |
1523 | return; |
1524 | } | |
f726a697 | 1525 | tk_xtime_add(tk, delta); |
7d489d15 | 1526 | tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *delta)); |
47da70d3 | 1527 | tk_update_sleep_time(tk, timespec64_to_ktime(*delta)); |
5c83545f | 1528 | tk_debug_account_sleep_time(delta); |
304529b1 JS |
1529 | } |
1530 | ||
7f298139 | 1531 | #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_RTC_HCTOSYS_DEVICE) |
0fa88cb4 XP |
1532 | /** |
1533 | * We have three kinds of time sources to use for sleep time | |
1534 | * injection, the preference order is: | |
1535 | * 1) non-stop clocksource | |
1536 | * 2) persistent clock (ie: RTC accessible when irqs are off) | |
1537 | * 3) RTC | |
1538 | * | |
1539 | * 1) and 2) are used by timekeeping, 3) by RTC subsystem. | |
1540 | * If system has neither 1) nor 2), 3) will be used finally. | |
1541 | * | |
1542 | * | |
1543 | * If timekeeping has injected sleeptime via either 1) or 2), | |
1544 | * 3) becomes needless, so in this case we don't need to call | |
1545 | * rtc_resume(), and this is what timekeeping_rtc_skipresume() | |
1546 | * means. | |
1547 | */ | |
1548 | bool timekeeping_rtc_skipresume(void) | |
1549 | { | |
1550 | return sleeptime_injected; | |
1551 | } | |
1552 | ||
1553 | /** | |
1554 | * 1) can be determined whether to use or not only when doing | |
1555 | * timekeeping_resume() which is invoked after rtc_suspend(), | |
1556 | * so we can't skip rtc_suspend() surely if system has 1). | |
1557 | * | |
1558 | * But if system has 2), 2) will definitely be used, so in this | |
1559 | * case we don't need to call rtc_suspend(), and this is what | |
1560 | * timekeeping_rtc_skipsuspend() means. | |
1561 | */ | |
1562 | bool timekeeping_rtc_skipsuspend(void) | |
1563 | { | |
1564 | return persistent_clock_exists; | |
1565 | } | |
1566 | ||
304529b1 | 1567 | /** |
04d90890 | 1568 | * timekeeping_inject_sleeptime64 - Adds suspend interval to timeekeeping values |
1569 | * @delta: pointer to a timespec64 delta value | |
304529b1 | 1570 | * |
2ee96632 | 1571 | * This hook is for architectures that cannot support read_persistent_clock64 |
304529b1 | 1572 | * because their RTC/persistent clock is only accessible when irqs are enabled. |
0fa88cb4 | 1573 | * and also don't have an effective nonstop clocksource. |
304529b1 JS |
1574 | * |
1575 | * This function should only be called by rtc_resume(), and allows | |
1576 | * a suspend offset to be injected into the timekeeping values. | |
1577 | */ | |
04d90890 | 1578 | void timekeeping_inject_sleeptime64(struct timespec64 *delta) |
304529b1 | 1579 | { |
3fdb14fd | 1580 | struct timekeeper *tk = &tk_core.timekeeper; |
92c1d3ed | 1581 | unsigned long flags; |
304529b1 | 1582 | |
9a7a71b1 | 1583 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1584 | write_seqcount_begin(&tk_core.seq); |
70471f2f | 1585 | |
4e250fdd | 1586 | timekeeping_forward_now(tk); |
304529b1 | 1587 | |
04d90890 | 1588 | __timekeeping_inject_sleeptime(tk, delta); |
304529b1 | 1589 | |
780427f0 | 1590 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
304529b1 | 1591 | |
3fdb14fd | 1592 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1593 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
304529b1 JS |
1594 | |
1595 | /* signal hrtimers about time change */ | |
1596 | clock_was_set(); | |
1597 | } | |
7f298139 | 1598 | #endif |
304529b1 | 1599 | |
8524070b JS |
1600 | /** |
1601 | * timekeeping_resume - Resumes the generic timekeeping subsystem. | |
8524070b | 1602 | */ |
124cf911 | 1603 | void timekeeping_resume(void) |
8524070b | 1604 | { |
3fdb14fd | 1605 | struct timekeeper *tk = &tk_core.timekeeper; |
876e7881 | 1606 | struct clocksource *clock = tk->tkr_mono.clock; |
92c1d3ed | 1607 | unsigned long flags; |
7d489d15 | 1608 | struct timespec64 ts_new, ts_delta; |
a5a1d1c2 | 1609 | u64 cycle_now; |
d4f587c6 | 1610 | |
0fa88cb4 | 1611 | sleeptime_injected = false; |
2ee96632 | 1612 | read_persistent_clock64(&ts_new); |
8524070b | 1613 | |
adc78e6b | 1614 | clockevents_resume(); |
d10ff3fb TG |
1615 | clocksource_resume(); |
1616 | ||
9a7a71b1 | 1617 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1618 | write_seqcount_begin(&tk_core.seq); |
8524070b | 1619 | |
e445cf1c FT |
1620 | /* |
1621 | * After system resumes, we need to calculate the suspended time and | |
1622 | * compensate it for the OS time. There are 3 sources that could be | |
1623 | * used: Nonstop clocksource during suspend, persistent clock and rtc | |
1624 | * device. | |
1625 | * | |
1626 | * One specific platform may have 1 or 2 or all of them, and the | |
1627 | * preference will be: | |
1628 | * suspend-nonstop clocksource -> persistent clock -> rtc | |
1629 | * The less preferred source will only be tried if there is no better | |
1630 | * usable source. The rtc part is handled separately in rtc core code. | |
1631 | */ | |
876e7881 | 1632 | cycle_now = tk->tkr_mono.read(clock); |
e445cf1c | 1633 | if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) && |
876e7881 | 1634 | cycle_now > tk->tkr_mono.cycle_last) { |
c029a2be | 1635 | u64 nsec, cyc_delta; |
e445cf1c | 1636 | |
c029a2be TG |
1637 | cyc_delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, |
1638 | tk->tkr_mono.mask); | |
1639 | nsec = mul_u64_u32_shr(cyc_delta, clock->mult, clock->shift); | |
7d489d15 | 1640 | ts_delta = ns_to_timespec64(nsec); |
0fa88cb4 | 1641 | sleeptime_injected = true; |
7d489d15 JS |
1642 | } else if (timespec64_compare(&ts_new, &timekeeping_suspend_time) > 0) { |
1643 | ts_delta = timespec64_sub(ts_new, timekeeping_suspend_time); | |
0fa88cb4 | 1644 | sleeptime_injected = true; |
8524070b | 1645 | } |
e445cf1c | 1646 | |
0fa88cb4 | 1647 | if (sleeptime_injected) |
e445cf1c FT |
1648 | __timekeeping_inject_sleeptime(tk, &ts_delta); |
1649 | ||
1650 | /* Re-base the last cycle value */ | |
876e7881 | 1651 | tk->tkr_mono.cycle_last = cycle_now; |
4a4ad80d PZ |
1652 | tk->tkr_raw.cycle_last = cycle_now; |
1653 | ||
4e250fdd | 1654 | tk->ntp_error = 0; |
8524070b | 1655 | timekeeping_suspended = 0; |
780427f0 | 1656 | timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |
3fdb14fd | 1657 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1658 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b JS |
1659 | |
1660 | touch_softlockup_watchdog(); | |
1661 | ||
4ffee521 | 1662 | tick_resume(); |
b12a03ce | 1663 | hrtimers_resume(); |
8524070b JS |
1664 | } |
1665 | ||
124cf911 | 1666 | int timekeeping_suspend(void) |
8524070b | 1667 | { |
3fdb14fd | 1668 | struct timekeeper *tk = &tk_core.timekeeper; |
92c1d3ed | 1669 | unsigned long flags; |
7d489d15 JS |
1670 | struct timespec64 delta, delta_delta; |
1671 | static struct timespec64 old_delta; | |
8524070b | 1672 | |
2ee96632 | 1673 | read_persistent_clock64(&timekeeping_suspend_time); |
3be90950 | 1674 | |
0d6bd995 ZM |
1675 | /* |
1676 | * On some systems the persistent_clock can not be detected at | |
1677 | * timekeeping_init by its return value, so if we see a valid | |
1678 | * value returned, update the persistent_clock_exists flag. | |
1679 | */ | |
1680 | if (timekeeping_suspend_time.tv_sec || timekeeping_suspend_time.tv_nsec) | |
0fa88cb4 | 1681 | persistent_clock_exists = true; |
0d6bd995 | 1682 | |
9a7a71b1 | 1683 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1684 | write_seqcount_begin(&tk_core.seq); |
4e250fdd | 1685 | timekeeping_forward_now(tk); |
8524070b | 1686 | timekeeping_suspended = 1; |
cb33217b | 1687 | |
0fa88cb4 | 1688 | if (persistent_clock_exists) { |
cb33217b | 1689 | /* |
264bb3f7 XP |
1690 | * To avoid drift caused by repeated suspend/resumes, |
1691 | * which each can add ~1 second drift error, | |
1692 | * try to compensate so the difference in system time | |
1693 | * and persistent_clock time stays close to constant. | |
cb33217b | 1694 | */ |
264bb3f7 XP |
1695 | delta = timespec64_sub(tk_xtime(tk), timekeeping_suspend_time); |
1696 | delta_delta = timespec64_sub(delta, old_delta); | |
1697 | if (abs(delta_delta.tv_sec) >= 2) { | |
1698 | /* | |
1699 | * if delta_delta is too large, assume time correction | |
1700 | * has occurred and set old_delta to the current delta. | |
1701 | */ | |
1702 | old_delta = delta; | |
1703 | } else { | |
1704 | /* Otherwise try to adjust old_system to compensate */ | |
1705 | timekeeping_suspend_time = | |
1706 | timespec64_add(timekeeping_suspend_time, delta_delta); | |
1707 | } | |
cb33217b | 1708 | } |
330a1617 JS |
1709 | |
1710 | timekeeping_update(tk, TK_MIRROR); | |
060407ae | 1711 | halt_fast_timekeeper(tk); |
3fdb14fd | 1712 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1713 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b | 1714 | |
4ffee521 | 1715 | tick_suspend(); |
c54a42b1 | 1716 | clocksource_suspend(); |
adc78e6b | 1717 | clockevents_suspend(); |
8524070b JS |
1718 | |
1719 | return 0; | |
1720 | } | |
1721 | ||
1722 | /* sysfs resume/suspend bits for timekeeping */ | |
e1a85b2c | 1723 | static struct syscore_ops timekeeping_syscore_ops = { |
8524070b JS |
1724 | .resume = timekeeping_resume, |
1725 | .suspend = timekeeping_suspend, | |
8524070b JS |
1726 | }; |
1727 | ||
e1a85b2c | 1728 | static int __init timekeeping_init_ops(void) |
8524070b | 1729 | { |
e1a85b2c RW |
1730 | register_syscore_ops(&timekeeping_syscore_ops); |
1731 | return 0; | |
8524070b | 1732 | } |
e1a85b2c | 1733 | device_initcall(timekeeping_init_ops); |
8524070b JS |
1734 | |
1735 | /* | |
dc491596 | 1736 | * Apply a multiplier adjustment to the timekeeper |
8524070b | 1737 | */ |
dc491596 JS |
1738 | static __always_inline void timekeeping_apply_adjustment(struct timekeeper *tk, |
1739 | s64 offset, | |
1740 | bool negative, | |
1741 | int adj_scale) | |
8524070b | 1742 | { |
dc491596 JS |
1743 | s64 interval = tk->cycle_interval; |
1744 | s32 mult_adj = 1; | |
8524070b | 1745 | |
dc491596 JS |
1746 | if (negative) { |
1747 | mult_adj = -mult_adj; | |
1748 | interval = -interval; | |
1749 | offset = -offset; | |
1d17d174 | 1750 | } |
dc491596 JS |
1751 | mult_adj <<= adj_scale; |
1752 | interval <<= adj_scale; | |
1753 | offset <<= adj_scale; | |
8524070b | 1754 | |
c2bc1111 JS |
1755 | /* |
1756 | * So the following can be confusing. | |
1757 | * | |
dc491596 | 1758 | * To keep things simple, lets assume mult_adj == 1 for now. |
c2bc1111 | 1759 | * |
dc491596 | 1760 | * When mult_adj != 1, remember that the interval and offset values |
c2bc1111 JS |
1761 | * have been appropriately scaled so the math is the same. |
1762 | * | |
1763 | * The basic idea here is that we're increasing the multiplier | |
1764 | * by one, this causes the xtime_interval to be incremented by | |
1765 | * one cycle_interval. This is because: | |
1766 | * xtime_interval = cycle_interval * mult | |
1767 | * So if mult is being incremented by one: | |
1768 | * xtime_interval = cycle_interval * (mult + 1) | |
1769 | * Its the same as: | |
1770 | * xtime_interval = (cycle_interval * mult) + cycle_interval | |
1771 | * Which can be shortened to: | |
1772 | * xtime_interval += cycle_interval | |
1773 | * | |
1774 | * So offset stores the non-accumulated cycles. Thus the current | |
1775 | * time (in shifted nanoseconds) is: | |
1776 | * now = (offset * adj) + xtime_nsec | |
1777 | * Now, even though we're adjusting the clock frequency, we have | |
1778 | * to keep time consistent. In other words, we can't jump back | |
1779 | * in time, and we also want to avoid jumping forward in time. | |
1780 | * | |
1781 | * So given the same offset value, we need the time to be the same | |
1782 | * both before and after the freq adjustment. | |
1783 | * now = (offset * adj_1) + xtime_nsec_1 | |
1784 | * now = (offset * adj_2) + xtime_nsec_2 | |
1785 | * So: | |
1786 | * (offset * adj_1) + xtime_nsec_1 = | |
1787 | * (offset * adj_2) + xtime_nsec_2 | |
1788 | * And we know: | |
1789 | * adj_2 = adj_1 + 1 | |
1790 | * So: | |
1791 | * (offset * adj_1) + xtime_nsec_1 = | |
1792 | * (offset * (adj_1+1)) + xtime_nsec_2 | |
1793 | * (offset * adj_1) + xtime_nsec_1 = | |
1794 | * (offset * adj_1) + offset + xtime_nsec_2 | |
1795 | * Canceling the sides: | |
1796 | * xtime_nsec_1 = offset + xtime_nsec_2 | |
1797 | * Which gives us: | |
1798 | * xtime_nsec_2 = xtime_nsec_1 - offset | |
1799 | * Which simplfies to: | |
1800 | * xtime_nsec -= offset | |
1801 | * | |
1802 | * XXX - TODO: Doc ntp_error calculation. | |
1803 | */ | |
876e7881 | 1804 | if ((mult_adj > 0) && (tk->tkr_mono.mult + mult_adj < mult_adj)) { |
6067dc5a | 1805 | /* NTP adjustment caused clocksource mult overflow */ |
1806 | WARN_ON_ONCE(1); | |
1807 | return; | |
1808 | } | |
1809 | ||
876e7881 | 1810 | tk->tkr_mono.mult += mult_adj; |
f726a697 | 1811 | tk->xtime_interval += interval; |
876e7881 | 1812 | tk->tkr_mono.xtime_nsec -= offset; |
f726a697 | 1813 | tk->ntp_error -= (interval - offset) << tk->ntp_error_shift; |
dc491596 JS |
1814 | } |
1815 | ||
1816 | /* | |
1817 | * Calculate the multiplier adjustment needed to match the frequency | |
1818 | * specified by NTP | |
1819 | */ | |
1820 | static __always_inline void timekeeping_freqadjust(struct timekeeper *tk, | |
1821 | s64 offset) | |
1822 | { | |
1823 | s64 interval = tk->cycle_interval; | |
1824 | s64 xinterval = tk->xtime_interval; | |
ec02b076 JS |
1825 | u32 base = tk->tkr_mono.clock->mult; |
1826 | u32 max = tk->tkr_mono.clock->maxadj; | |
1827 | u32 cur_adj = tk->tkr_mono.mult; | |
dc491596 JS |
1828 | s64 tick_error; |
1829 | bool negative; | |
ec02b076 | 1830 | u32 adj_scale; |
dc491596 JS |
1831 | |
1832 | /* Remove any current error adj from freq calculation */ | |
1833 | if (tk->ntp_err_mult) | |
1834 | xinterval -= tk->cycle_interval; | |
1835 | ||
375f45b5 JS |
1836 | tk->ntp_tick = ntp_tick_length(); |
1837 | ||
dc491596 JS |
1838 | /* Calculate current error per tick */ |
1839 | tick_error = ntp_tick_length() >> tk->ntp_error_shift; | |
1840 | tick_error -= (xinterval + tk->xtime_remainder); | |
1841 | ||
1842 | /* Don't worry about correcting it if its small */ | |
1843 | if (likely((tick_error >= 0) && (tick_error <= interval))) | |
1844 | return; | |
1845 | ||
1846 | /* preserve the direction of correction */ | |
1847 | negative = (tick_error < 0); | |
1848 | ||
ec02b076 JS |
1849 | /* If any adjustment would pass the max, just return */ |
1850 | if (negative && (cur_adj - 1) <= (base - max)) | |
1851 | return; | |
1852 | if (!negative && (cur_adj + 1) >= (base + max)) | |
1853 | return; | |
1854 | /* | |
1855 | * Sort out the magnitude of the correction, but | |
1856 | * avoid making so large a correction that we go | |
1857 | * over the max adjustment. | |
1858 | */ | |
1859 | adj_scale = 0; | |
79211c8e | 1860 | tick_error = abs(tick_error); |
ec02b076 JS |
1861 | while (tick_error > interval) { |
1862 | u32 adj = 1 << (adj_scale + 1); | |
1863 | ||
1864 | /* Check if adjustment gets us within 1 unit from the max */ | |
1865 | if (negative && (cur_adj - adj) <= (base - max)) | |
1866 | break; | |
1867 | if (!negative && (cur_adj + adj) >= (base + max)) | |
1868 | break; | |
1869 | ||
1870 | adj_scale++; | |
dc491596 | 1871 | tick_error >>= 1; |
ec02b076 | 1872 | } |
dc491596 JS |
1873 | |
1874 | /* scale the corrections */ | |
ec02b076 | 1875 | timekeeping_apply_adjustment(tk, offset, negative, adj_scale); |
dc491596 JS |
1876 | } |
1877 | ||
1878 | /* | |
1879 | * Adjust the timekeeper's multiplier to the correct frequency | |
1880 | * and also to reduce the accumulated error value. | |
1881 | */ | |
1882 | static void timekeeping_adjust(struct timekeeper *tk, s64 offset) | |
1883 | { | |
1884 | /* Correct for the current frequency error */ | |
1885 | timekeeping_freqadjust(tk, offset); | |
1886 | ||
1887 | /* Next make a small adjustment to fix any cumulative error */ | |
1888 | if (!tk->ntp_err_mult && (tk->ntp_error > 0)) { | |
1889 | tk->ntp_err_mult = 1; | |
1890 | timekeeping_apply_adjustment(tk, offset, 0, 0); | |
1891 | } else if (tk->ntp_err_mult && (tk->ntp_error <= 0)) { | |
1892 | /* Undo any existing error adjustment */ | |
1893 | timekeeping_apply_adjustment(tk, offset, 1, 0); | |
1894 | tk->ntp_err_mult = 0; | |
1895 | } | |
1896 | ||
876e7881 PZ |
1897 | if (unlikely(tk->tkr_mono.clock->maxadj && |
1898 | (abs(tk->tkr_mono.mult - tk->tkr_mono.clock->mult) | |
1899 | > tk->tkr_mono.clock->maxadj))) { | |
dc491596 JS |
1900 | printk_once(KERN_WARNING |
1901 | "Adjusting %s more than 11%% (%ld vs %ld)\n", | |
876e7881 PZ |
1902 | tk->tkr_mono.clock->name, (long)tk->tkr_mono.mult, |
1903 | (long)tk->tkr_mono.clock->mult + tk->tkr_mono.clock->maxadj); | |
dc491596 | 1904 | } |
2a8c0883 JS |
1905 | |
1906 | /* | |
1907 | * It may be possible that when we entered this function, xtime_nsec | |
1908 | * was very small. Further, if we're slightly speeding the clocksource | |
1909 | * in the code above, its possible the required corrective factor to | |
1910 | * xtime_nsec could cause it to underflow. | |
1911 | * | |
1912 | * Now, since we already accumulated the second, cannot simply roll | |
1913 | * the accumulated second back, since the NTP subsystem has been | |
1914 | * notified via second_overflow. So instead we push xtime_nsec forward | |
1915 | * by the amount we underflowed, and add that amount into the error. | |
1916 | * | |
1917 | * We'll correct this error next time through this function, when | |
1918 | * xtime_nsec is not as small. | |
1919 | */ | |
876e7881 PZ |
1920 | if (unlikely((s64)tk->tkr_mono.xtime_nsec < 0)) { |
1921 | s64 neg = -(s64)tk->tkr_mono.xtime_nsec; | |
1922 | tk->tkr_mono.xtime_nsec = 0; | |
f726a697 | 1923 | tk->ntp_error += neg << tk->ntp_error_shift; |
2a8c0883 | 1924 | } |
8524070b JS |
1925 | } |
1926 | ||
1f4f9487 JS |
1927 | /** |
1928 | * accumulate_nsecs_to_secs - Accumulates nsecs into secs | |
1929 | * | |
571af55a | 1930 | * Helper function that accumulates the nsecs greater than a second |
1f4f9487 JS |
1931 | * from the xtime_nsec field to the xtime_secs field. |
1932 | * It also calls into the NTP code to handle leapsecond processing. | |
1933 | * | |
1934 | */ | |
780427f0 | 1935 | static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk) |
1f4f9487 | 1936 | { |
876e7881 | 1937 | u64 nsecps = (u64)NSEC_PER_SEC << tk->tkr_mono.shift; |
5258d3f2 | 1938 | unsigned int clock_set = 0; |
1f4f9487 | 1939 | |
876e7881 | 1940 | while (tk->tkr_mono.xtime_nsec >= nsecps) { |
1f4f9487 JS |
1941 | int leap; |
1942 | ||
876e7881 | 1943 | tk->tkr_mono.xtime_nsec -= nsecps; |
1f4f9487 JS |
1944 | tk->xtime_sec++; |
1945 | ||
1946 | /* Figure out if its a leap sec and apply if needed */ | |
1947 | leap = second_overflow(tk->xtime_sec); | |
6d0ef903 | 1948 | if (unlikely(leap)) { |
7d489d15 | 1949 | struct timespec64 ts; |
6d0ef903 JS |
1950 | |
1951 | tk->xtime_sec += leap; | |
1f4f9487 | 1952 | |
6d0ef903 JS |
1953 | ts.tv_sec = leap; |
1954 | ts.tv_nsec = 0; | |
1955 | tk_set_wall_to_mono(tk, | |
7d489d15 | 1956 | timespec64_sub(tk->wall_to_monotonic, ts)); |
6d0ef903 | 1957 | |
cc244dda JS |
1958 | __timekeeping_set_tai_offset(tk, tk->tai_offset - leap); |
1959 | ||
5258d3f2 | 1960 | clock_set = TK_CLOCK_WAS_SET; |
6d0ef903 | 1961 | } |
1f4f9487 | 1962 | } |
5258d3f2 | 1963 | return clock_set; |
1f4f9487 JS |
1964 | } |
1965 | ||
a092ff0f JS |
1966 | /** |
1967 | * logarithmic_accumulation - shifted accumulation of cycles | |
1968 | * | |
1969 | * This functions accumulates a shifted interval of cycles into | |
1970 | * into a shifted interval nanoseconds. Allows for O(log) accumulation | |
1971 | * loop. | |
1972 | * | |
1973 | * Returns the unconsumed cycles. | |
1974 | */ | |
a5a1d1c2 TG |
1975 | static u64 logarithmic_accumulation(struct timekeeper *tk, u64 offset, |
1976 | u32 shift, unsigned int *clock_set) | |
a092ff0f | 1977 | { |
a5a1d1c2 | 1978 | u64 interval = tk->cycle_interval << shift; |
deda2e81 | 1979 | u64 raw_nsecs; |
a092ff0f | 1980 | |
571af55a | 1981 | /* If the offset is smaller than a shifted interval, do nothing */ |
23a9537a | 1982 | if (offset < interval) |
a092ff0f JS |
1983 | return offset; |
1984 | ||
1985 | /* Accumulate one shifted interval */ | |
23a9537a | 1986 | offset -= interval; |
876e7881 | 1987 | tk->tkr_mono.cycle_last += interval; |
4a4ad80d | 1988 | tk->tkr_raw.cycle_last += interval; |
a092ff0f | 1989 | |
876e7881 | 1990 | tk->tkr_mono.xtime_nsec += tk->xtime_interval << shift; |
5258d3f2 | 1991 | *clock_set |= accumulate_nsecs_to_secs(tk); |
a092ff0f | 1992 | |
deda2e81 | 1993 | /* Accumulate raw time */ |
5b3900cd | 1994 | raw_nsecs = (u64)tk->raw_interval << shift; |
f726a697 | 1995 | raw_nsecs += tk->raw_time.tv_nsec; |
c7dcf87a JS |
1996 | if (raw_nsecs >= NSEC_PER_SEC) { |
1997 | u64 raw_secs = raw_nsecs; | |
1998 | raw_nsecs = do_div(raw_secs, NSEC_PER_SEC); | |
f726a697 | 1999 | tk->raw_time.tv_sec += raw_secs; |
a092ff0f | 2000 | } |
f726a697 | 2001 | tk->raw_time.tv_nsec = raw_nsecs; |
a092ff0f JS |
2002 | |
2003 | /* Accumulate error between NTP and clock interval */ | |
375f45b5 | 2004 | tk->ntp_error += tk->ntp_tick << shift; |
f726a697 JS |
2005 | tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) << |
2006 | (tk->ntp_error_shift + shift); | |
a092ff0f JS |
2007 | |
2008 | return offset; | |
2009 | } | |
2010 | ||
8524070b JS |
2011 | /** |
2012 | * update_wall_time - Uses the current clocksource to increment the wall time | |
2013 | * | |
8524070b | 2014 | */ |
47a1b796 | 2015 | void update_wall_time(void) |
8524070b | 2016 | { |
3fdb14fd | 2017 | struct timekeeper *real_tk = &tk_core.timekeeper; |
48cdc135 | 2018 | struct timekeeper *tk = &shadow_timekeeper; |
a5a1d1c2 | 2019 | u64 offset; |
a092ff0f | 2020 | int shift = 0, maxshift; |
5258d3f2 | 2021 | unsigned int clock_set = 0; |
70471f2f JS |
2022 | unsigned long flags; |
2023 | ||
9a7a71b1 | 2024 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
8524070b JS |
2025 | |
2026 | /* Make sure we're fully resumed: */ | |
2027 | if (unlikely(timekeeping_suspended)) | |
70471f2f | 2028 | goto out; |
8524070b | 2029 | |
592913ec | 2030 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET |
48cdc135 | 2031 | offset = real_tk->cycle_interval; |
592913ec | 2032 | #else |
876e7881 PZ |
2033 | offset = clocksource_delta(tk->tkr_mono.read(tk->tkr_mono.clock), |
2034 | tk->tkr_mono.cycle_last, tk->tkr_mono.mask); | |
8524070b | 2035 | #endif |
8524070b | 2036 | |
bf2ac312 | 2037 | /* Check if there's really nothing to do */ |
48cdc135 | 2038 | if (offset < real_tk->cycle_interval) |
bf2ac312 JS |
2039 | goto out; |
2040 | ||
3c17ad19 JS |
2041 | /* Do some additional sanity checking */ |
2042 | timekeeping_check_update(real_tk, offset); | |
2043 | ||
a092ff0f JS |
2044 | /* |
2045 | * With NO_HZ we may have to accumulate many cycle_intervals | |
2046 | * (think "ticks") worth of time at once. To do this efficiently, | |
2047 | * we calculate the largest doubling multiple of cycle_intervals | |
88b28adf | 2048 | * that is smaller than the offset. We then accumulate that |
a092ff0f JS |
2049 | * chunk in one go, and then try to consume the next smaller |
2050 | * doubled multiple. | |
8524070b | 2051 | */ |
4e250fdd | 2052 | shift = ilog2(offset) - ilog2(tk->cycle_interval); |
a092ff0f | 2053 | shift = max(0, shift); |
88b28adf | 2054 | /* Bound shift to one less than what overflows tick_length */ |
ea7cf49a | 2055 | maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1; |
a092ff0f | 2056 | shift = min(shift, maxshift); |
4e250fdd | 2057 | while (offset >= tk->cycle_interval) { |
5258d3f2 JS |
2058 | offset = logarithmic_accumulation(tk, offset, shift, |
2059 | &clock_set); | |
4e250fdd | 2060 | if (offset < tk->cycle_interval<<shift) |
830ec045 | 2061 | shift--; |
8524070b JS |
2062 | } |
2063 | ||
2064 | /* correct the clock when NTP error is too big */ | |
4e250fdd | 2065 | timekeeping_adjust(tk, offset); |
8524070b | 2066 | |
6a867a39 | 2067 | /* |
92bb1fcf JS |
2068 | * XXX This can be killed once everyone converts |
2069 | * to the new update_vsyscall. | |
2070 | */ | |
2071 | old_vsyscall_fixup(tk); | |
8524070b | 2072 | |
6a867a39 JS |
2073 | /* |
2074 | * Finally, make sure that after the rounding | |
1e75fa8b | 2075 | * xtime_nsec isn't larger than NSEC_PER_SEC |
6a867a39 | 2076 | */ |
5258d3f2 | 2077 | clock_set |= accumulate_nsecs_to_secs(tk); |
83f57a11 | 2078 | |
3fdb14fd | 2079 | write_seqcount_begin(&tk_core.seq); |
48cdc135 TG |
2080 | /* |
2081 | * Update the real timekeeper. | |
2082 | * | |
2083 | * We could avoid this memcpy by switching pointers, but that | |
2084 | * requires changes to all other timekeeper usage sites as | |
2085 | * well, i.e. move the timekeeper pointer getter into the | |
2086 | * spinlocked/seqcount protected sections. And we trade this | |
3fdb14fd | 2087 | * memcpy under the tk_core.seq against one before we start |
48cdc135 TG |
2088 | * updating. |
2089 | */ | |
906c5557 | 2090 | timekeeping_update(tk, clock_set); |
48cdc135 | 2091 | memcpy(real_tk, tk, sizeof(*tk)); |
906c5557 | 2092 | /* The memcpy must come last. Do not put anything here! */ |
3fdb14fd | 2093 | write_seqcount_end(&tk_core.seq); |
ca4523cd | 2094 | out: |
9a7a71b1 | 2095 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
47a1b796 | 2096 | if (clock_set) |
cab5e127 JS |
2097 | /* Have to call _delayed version, since in irq context*/ |
2098 | clock_was_set_delayed(); | |
8524070b | 2099 | } |
7c3f1a57 TJ |
2100 | |
2101 | /** | |
d08c0cdd JS |
2102 | * getboottime64 - Return the real time of system boot. |
2103 | * @ts: pointer to the timespec64 to be set | |
7c3f1a57 | 2104 | * |
d08c0cdd | 2105 | * Returns the wall-time of boot in a timespec64. |
7c3f1a57 TJ |
2106 | * |
2107 | * This is based on the wall_to_monotonic offset and the total suspend | |
2108 | * time. Calls to settimeofday will affect the value returned (which | |
2109 | * basically means that however wrong your real time clock is at boot time, | |
2110 | * you get the right time here). | |
2111 | */ | |
d08c0cdd | 2112 | void getboottime64(struct timespec64 *ts) |
7c3f1a57 | 2113 | { |
3fdb14fd | 2114 | struct timekeeper *tk = &tk_core.timekeeper; |
02cba159 TG |
2115 | ktime_t t = ktime_sub(tk->offs_real, tk->offs_boot); |
2116 | ||
d08c0cdd | 2117 | *ts = ktime_to_timespec64(t); |
7c3f1a57 | 2118 | } |
d08c0cdd | 2119 | EXPORT_SYMBOL_GPL(getboottime64); |
7c3f1a57 | 2120 | |
17c38b74 JS |
2121 | unsigned long get_seconds(void) |
2122 | { | |
3fdb14fd | 2123 | struct timekeeper *tk = &tk_core.timekeeper; |
4e250fdd JS |
2124 | |
2125 | return tk->xtime_sec; | |
17c38b74 JS |
2126 | } |
2127 | EXPORT_SYMBOL(get_seconds); | |
2128 | ||
da15cfda JS |
2129 | struct timespec __current_kernel_time(void) |
2130 | { | |
3fdb14fd | 2131 | struct timekeeper *tk = &tk_core.timekeeper; |
4e250fdd | 2132 | |
7d489d15 | 2133 | return timespec64_to_timespec(tk_xtime(tk)); |
da15cfda | 2134 | } |
17c38b74 | 2135 | |
8758a240 | 2136 | struct timespec64 current_kernel_time64(void) |
2c6b47de | 2137 | { |
3fdb14fd | 2138 | struct timekeeper *tk = &tk_core.timekeeper; |
7d489d15 | 2139 | struct timespec64 now; |
2c6b47de JS |
2140 | unsigned long seq; |
2141 | ||
2142 | do { | |
3fdb14fd | 2143 | seq = read_seqcount_begin(&tk_core.seq); |
83f57a11 | 2144 | |
4e250fdd | 2145 | now = tk_xtime(tk); |
3fdb14fd | 2146 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
2c6b47de | 2147 | |
8758a240 | 2148 | return now; |
2c6b47de | 2149 | } |
8758a240 | 2150 | EXPORT_SYMBOL(current_kernel_time64); |
da15cfda | 2151 | |
334334b5 | 2152 | struct timespec64 get_monotonic_coarse64(void) |
da15cfda | 2153 | { |
3fdb14fd | 2154 | struct timekeeper *tk = &tk_core.timekeeper; |
7d489d15 | 2155 | struct timespec64 now, mono; |
da15cfda JS |
2156 | unsigned long seq; |
2157 | ||
2158 | do { | |
3fdb14fd | 2159 | seq = read_seqcount_begin(&tk_core.seq); |
83f57a11 | 2160 | |
4e250fdd JS |
2161 | now = tk_xtime(tk); |
2162 | mono = tk->wall_to_monotonic; | |
3fdb14fd | 2163 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
da15cfda | 2164 | |
7d489d15 | 2165 | set_normalized_timespec64(&now, now.tv_sec + mono.tv_sec, |
da15cfda | 2166 | now.tv_nsec + mono.tv_nsec); |
7d489d15 | 2167 | |
334334b5 | 2168 | return now; |
da15cfda | 2169 | } |
eaaa7ec7 | 2170 | EXPORT_SYMBOL(get_monotonic_coarse64); |
871cf1e5 TH |
2171 | |
2172 | /* | |
d6ad4187 | 2173 | * Must hold jiffies_lock |
871cf1e5 TH |
2174 | */ |
2175 | void do_timer(unsigned long ticks) | |
2176 | { | |
2177 | jiffies_64 += ticks; | |
871cf1e5 TH |
2178 | calc_global_load(ticks); |
2179 | } | |
48cf76f7 | 2180 | |
f6c06abf | 2181 | /** |
76f41088 | 2182 | * ktime_get_update_offsets_now - hrtimer helper |
868a3e91 | 2183 | * @cwsseq: pointer to check and store the clock was set sequence number |
f6c06abf TG |
2184 | * @offs_real: pointer to storage for monotonic -> realtime offset |
2185 | * @offs_boot: pointer to storage for monotonic -> boottime offset | |
b7bc50e4 | 2186 | * @offs_tai: pointer to storage for monotonic -> clock tai offset |
f6c06abf | 2187 | * |
868a3e91 TG |
2188 | * Returns current monotonic time and updates the offsets if the |
2189 | * sequence number in @cwsseq and timekeeper.clock_was_set_seq are | |
2190 | * different. | |
2191 | * | |
b7bc50e4 | 2192 | * Called from hrtimer_interrupt() or retrigger_next_event() |
f6c06abf | 2193 | */ |
868a3e91 TG |
2194 | ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real, |
2195 | ktime_t *offs_boot, ktime_t *offs_tai) | |
f6c06abf | 2196 | { |
3fdb14fd | 2197 | struct timekeeper *tk = &tk_core.timekeeper; |
f6c06abf | 2198 | unsigned int seq; |
a37c0aad TG |
2199 | ktime_t base; |
2200 | u64 nsecs; | |
f6c06abf TG |
2201 | |
2202 | do { | |
3fdb14fd | 2203 | seq = read_seqcount_begin(&tk_core.seq); |
f6c06abf | 2204 | |
876e7881 PZ |
2205 | base = tk->tkr_mono.base; |
2206 | nsecs = timekeeping_get_ns(&tk->tkr_mono); | |
833f32d7 JS |
2207 | base = ktime_add_ns(base, nsecs); |
2208 | ||
868a3e91 TG |
2209 | if (*cwsseq != tk->clock_was_set_seq) { |
2210 | *cwsseq = tk->clock_was_set_seq; | |
2211 | *offs_real = tk->offs_real; | |
2212 | *offs_boot = tk->offs_boot; | |
2213 | *offs_tai = tk->offs_tai; | |
2214 | } | |
833f32d7 JS |
2215 | |
2216 | /* Handle leapsecond insertion adjustments */ | |
2456e855 | 2217 | if (unlikely(base >= tk->next_leap_ktime)) |
833f32d7 JS |
2218 | *offs_real = ktime_sub(tk->offs_real, ktime_set(1, 0)); |
2219 | ||
3fdb14fd | 2220 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
f6c06abf | 2221 | |
833f32d7 | 2222 | return base; |
f6c06abf | 2223 | } |
f6c06abf | 2224 | |
aa6f9c59 JS |
2225 | /** |
2226 | * do_adjtimex() - Accessor function to NTP __do_adjtimex function | |
2227 | */ | |
2228 | int do_adjtimex(struct timex *txc) | |
2229 | { | |
3fdb14fd | 2230 | struct timekeeper *tk = &tk_core.timekeeper; |
06c017fd | 2231 | unsigned long flags; |
7d489d15 | 2232 | struct timespec64 ts; |
4e8f8b34 | 2233 | s32 orig_tai, tai; |
e4085693 JS |
2234 | int ret; |
2235 | ||
2236 | /* Validate the data before disabling interrupts */ | |
2237 | ret = ntp_validate_timex(txc); | |
2238 | if (ret) | |
2239 | return ret; | |
2240 | ||
cef90377 JS |
2241 | if (txc->modes & ADJ_SETOFFSET) { |
2242 | struct timespec delta; | |
2243 | delta.tv_sec = txc->time.tv_sec; | |
2244 | delta.tv_nsec = txc->time.tv_usec; | |
2245 | if (!(txc->modes & ADJ_NANO)) | |
2246 | delta.tv_nsec *= 1000; | |
2247 | ret = timekeeping_inject_offset(&delta); | |
2248 | if (ret) | |
2249 | return ret; | |
2250 | } | |
2251 | ||
d6d29896 | 2252 | getnstimeofday64(&ts); |
87ace39b | 2253 | |
06c017fd | 2254 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 2255 | write_seqcount_begin(&tk_core.seq); |
06c017fd | 2256 | |
4e8f8b34 | 2257 | orig_tai = tai = tk->tai_offset; |
87ace39b | 2258 | ret = __do_adjtimex(txc, &ts, &tai); |
aa6f9c59 | 2259 | |
4e8f8b34 JS |
2260 | if (tai != orig_tai) { |
2261 | __timekeeping_set_tai_offset(tk, tai); | |
f55c0760 | 2262 | timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |
4e8f8b34 | 2263 | } |
833f32d7 JS |
2264 | tk_update_leap_state(tk); |
2265 | ||
3fdb14fd | 2266 | write_seqcount_end(&tk_core.seq); |
06c017fd JS |
2267 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
2268 | ||
6fdda9a9 JS |
2269 | if (tai != orig_tai) |
2270 | clock_was_set(); | |
2271 | ||
7bd36014 JS |
2272 | ntp_notify_cmos_timer(); |
2273 | ||
87ace39b JS |
2274 | return ret; |
2275 | } | |
aa6f9c59 JS |
2276 | |
2277 | #ifdef CONFIG_NTP_PPS | |
2278 | /** | |
2279 | * hardpps() - Accessor function to NTP __hardpps function | |
2280 | */ | |
7ec88e4b | 2281 | void hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts) |
aa6f9c59 | 2282 | { |
06c017fd JS |
2283 | unsigned long flags; |
2284 | ||
2285 | raw_spin_lock_irqsave(&timekeeper_lock, flags); | |
3fdb14fd | 2286 | write_seqcount_begin(&tk_core.seq); |
06c017fd | 2287 | |
aa6f9c59 | 2288 | __hardpps(phase_ts, raw_ts); |
06c017fd | 2289 | |
3fdb14fd | 2290 | write_seqcount_end(&tk_core.seq); |
06c017fd | 2291 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
aa6f9c59 JS |
2292 | } |
2293 | EXPORT_SYMBOL(hardpps); | |
2294 | #endif | |
2295 | ||
f0af911a TH |
2296 | /** |
2297 | * xtime_update() - advances the timekeeping infrastructure | |
2298 | * @ticks: number of ticks, that have elapsed since the last call. | |
2299 | * | |
2300 | * Must be called with interrupts disabled. | |
2301 | */ | |
2302 | void xtime_update(unsigned long ticks) | |
2303 | { | |
d6ad4187 | 2304 | write_seqlock(&jiffies_lock); |
f0af911a | 2305 | do_timer(ticks); |
d6ad4187 | 2306 | write_sequnlock(&jiffies_lock); |
47a1b796 | 2307 | update_wall_time(); |
f0af911a | 2308 | } |