Commit | Line | Data |
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35728b82 | 1 | // SPDX-License-Identifier: GPL-2.0 |
8524070b | 2 | /* |
58c5fc2b TG |
3 | * Kernel timekeeping code and accessor functions. Based on code from |
4 | * timer.c, moved in commit 8524070b7982. | |
8524070b | 5 | */ |
d7b4202e | 6 | #include <linux/timekeeper_internal.h> |
8524070b | 7 | #include <linux/module.h> |
8 | #include <linux/interrupt.h> | |
9 | #include <linux/percpu.h> | |
10 | #include <linux/init.h> | |
11 | #include <linux/mm.h> | |
38b8d208 | 12 | #include <linux/nmi.h> |
d43c36dc | 13 | #include <linux/sched.h> |
4f17722c | 14 | #include <linux/sched/loadavg.h> |
3eca9937 | 15 | #include <linux/sched/clock.h> |
e1a85b2c | 16 | #include <linux/syscore_ops.h> |
8524070b | 17 | #include <linux/clocksource.h> |
18 | #include <linux/jiffies.h> | |
19 | #include <linux/time.h> | |
20 | #include <linux/tick.h> | |
75c5158f | 21 | #include <linux/stop_machine.h> |
e0b306fe | 22 | #include <linux/pvclock_gtod.h> |
52f5684c | 23 | #include <linux/compiler.h> |
2d87a067 | 24 | #include <linux/audit.h> |
8524070b | 25 | |
eb93e4d9 | 26 | #include "tick-internal.h" |
aa6f9c59 | 27 | #include "ntp_internal.h" |
5c83545f | 28 | #include "timekeeping_internal.h" |
155ec602 | 29 | |
04397fe9 DV |
30 | #define TK_CLEAR_NTP (1 << 0) |
31 | #define TK_MIRROR (1 << 1) | |
780427f0 | 32 | #define TK_CLOCK_WAS_SET (1 << 2) |
04397fe9 | 33 | |
b061c7a5 ML |
34 | enum timekeeping_adv_mode { |
35 | /* Update timekeeper when a tick has passed */ | |
36 | TK_ADV_TICK, | |
37 | ||
38 | /* Update timekeeper on a direct frequency change */ | |
39 | TK_ADV_FREQ | |
40 | }; | |
41 | ||
3fdb14fd TG |
42 | /* |
43 | * The most important data for readout fits into a single 64 byte | |
44 | * cache line. | |
45 | */ | |
46 | static struct { | |
47 | seqcount_t seq; | |
48 | struct timekeeper timekeeper; | |
ce10a5b3 BVA |
49 | } tk_core ____cacheline_aligned = { |
50 | .seq = SEQCNT_ZERO(tk_core.seq), | |
51 | }; | |
3fdb14fd | 52 | |
9a7a71b1 | 53 | static DEFINE_RAW_SPINLOCK(timekeeper_lock); |
48cdc135 | 54 | static struct timekeeper shadow_timekeeper; |
155ec602 | 55 | |
4396e058 TG |
56 | /** |
57 | * struct tk_fast - NMI safe timekeeper | |
58 | * @seq: Sequence counter for protecting updates. The lowest bit | |
59 | * is the index for the tk_read_base array | |
60 | * @base: tk_read_base array. Access is indexed by the lowest bit of | |
61 | * @seq. | |
62 | * | |
63 | * See @update_fast_timekeeper() below. | |
64 | */ | |
65 | struct tk_fast { | |
66 | seqcount_t seq; | |
67 | struct tk_read_base base[2]; | |
68 | }; | |
69 | ||
5df32107 PB |
70 | /* Suspend-time cycles value for halted fast timekeeper. */ |
71 | static u64 cycles_at_suspend; | |
72 | ||
73 | static u64 dummy_clock_read(struct clocksource *cs) | |
74 | { | |
75 | return cycles_at_suspend; | |
76 | } | |
77 | ||
78 | static struct clocksource dummy_clock = { | |
79 | .read = dummy_clock_read, | |
80 | }; | |
81 | ||
82 | static struct tk_fast tk_fast_mono ____cacheline_aligned = { | |
83 | .base[0] = { .clock = &dummy_clock, }, | |
84 | .base[1] = { .clock = &dummy_clock, }, | |
85 | }; | |
86 | ||
87 | static struct tk_fast tk_fast_raw ____cacheline_aligned = { | |
88 | .base[0] = { .clock = &dummy_clock, }, | |
89 | .base[1] = { .clock = &dummy_clock, }, | |
90 | }; | |
4396e058 | 91 | |
8fcce546 JS |
92 | /* flag for if timekeeping is suspended */ |
93 | int __read_mostly timekeeping_suspended; | |
94 | ||
1e75fa8b JS |
95 | static inline void tk_normalize_xtime(struct timekeeper *tk) |
96 | { | |
876e7881 PZ |
97 | while (tk->tkr_mono.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr_mono.shift)) { |
98 | tk->tkr_mono.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_mono.shift; | |
1e75fa8b JS |
99 | tk->xtime_sec++; |
100 | } | |
fc6eead7 JS |
101 | while (tk->tkr_raw.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr_raw.shift)) { |
102 | tk->tkr_raw.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_raw.shift; | |
103 | tk->raw_sec++; | |
104 | } | |
1e75fa8b JS |
105 | } |
106 | ||
985e6950 | 107 | static inline struct timespec64 tk_xtime(const struct timekeeper *tk) |
c905fae4 TG |
108 | { |
109 | struct timespec64 ts; | |
110 | ||
111 | ts.tv_sec = tk->xtime_sec; | |
876e7881 | 112 | ts.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); |
c905fae4 TG |
113 | return ts; |
114 | } | |
115 | ||
7d489d15 | 116 | static void tk_set_xtime(struct timekeeper *tk, const struct timespec64 *ts) |
1e75fa8b JS |
117 | { |
118 | tk->xtime_sec = ts->tv_sec; | |
876e7881 | 119 | tk->tkr_mono.xtime_nsec = (u64)ts->tv_nsec << tk->tkr_mono.shift; |
1e75fa8b JS |
120 | } |
121 | ||
7d489d15 | 122 | static void tk_xtime_add(struct timekeeper *tk, const struct timespec64 *ts) |
1e75fa8b JS |
123 | { |
124 | tk->xtime_sec += ts->tv_sec; | |
876e7881 | 125 | tk->tkr_mono.xtime_nsec += (u64)ts->tv_nsec << tk->tkr_mono.shift; |
784ffcbb | 126 | tk_normalize_xtime(tk); |
1e75fa8b | 127 | } |
8fcce546 | 128 | |
7d489d15 | 129 | static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec64 wtm) |
6d0ef903 | 130 | { |
7d489d15 | 131 | struct timespec64 tmp; |
6d0ef903 JS |
132 | |
133 | /* | |
134 | * Verify consistency of: offset_real = -wall_to_monotonic | |
135 | * before modifying anything | |
136 | */ | |
7d489d15 | 137 | set_normalized_timespec64(&tmp, -tk->wall_to_monotonic.tv_sec, |
6d0ef903 | 138 | -tk->wall_to_monotonic.tv_nsec); |
2456e855 | 139 | WARN_ON_ONCE(tk->offs_real != timespec64_to_ktime(tmp)); |
6d0ef903 | 140 | tk->wall_to_monotonic = wtm; |
7d489d15 JS |
141 | set_normalized_timespec64(&tmp, -wtm.tv_sec, -wtm.tv_nsec); |
142 | tk->offs_real = timespec64_to_ktime(tmp); | |
04005f60 | 143 | tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tk->tai_offset, 0)); |
6d0ef903 JS |
144 | } |
145 | ||
47da70d3 | 146 | static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta) |
6d0ef903 | 147 | { |
a3ed0e43 | 148 | tk->offs_boot = ktime_add(tk->offs_boot, delta); |
6d0ef903 JS |
149 | } |
150 | ||
ceea5e37 JS |
151 | /* |
152 | * tk_clock_read - atomic clocksource read() helper | |
153 | * | |
154 | * This helper is necessary to use in the read paths because, while the | |
155 | * seqlock ensures we don't return a bad value while structures are updated, | |
156 | * it doesn't protect from potential crashes. There is the possibility that | |
157 | * the tkr's clocksource may change between the read reference, and the | |
158 | * clock reference passed to the read function. This can cause crashes if | |
159 | * the wrong clocksource is passed to the wrong read function. | |
160 | * This isn't necessary to use when holding the timekeeper_lock or doing | |
161 | * a read of the fast-timekeeper tkrs (which is protected by its own locking | |
162 | * and update logic). | |
163 | */ | |
985e6950 | 164 | static inline u64 tk_clock_read(const struct tk_read_base *tkr) |
ceea5e37 JS |
165 | { |
166 | struct clocksource *clock = READ_ONCE(tkr->clock); | |
167 | ||
168 | return clock->read(clock); | |
169 | } | |
170 | ||
3c17ad19 | 171 | #ifdef CONFIG_DEBUG_TIMEKEEPING |
4ca22c26 | 172 | #define WARNING_FREQ (HZ*300) /* 5 minute rate-limiting */ |
4ca22c26 | 173 | |
a5a1d1c2 | 174 | static void timekeeping_check_update(struct timekeeper *tk, u64 offset) |
3c17ad19 JS |
175 | { |
176 | ||
a5a1d1c2 | 177 | u64 max_cycles = tk->tkr_mono.clock->max_cycles; |
876e7881 | 178 | const char *name = tk->tkr_mono.clock->name; |
3c17ad19 JS |
179 | |
180 | if (offset > max_cycles) { | |
a558cd02 | 181 | 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 | 182 | offset, name, max_cycles); |
a558cd02 | 183 | printk_deferred(" timekeeping: Your kernel is sick, but tries to cope by capping time updates\n"); |
3c17ad19 JS |
184 | } else { |
185 | if (offset > (max_cycles >> 1)) { | |
fc4fa6e1 | 186 | printk_deferred("INFO: timekeeping: Cycle offset (%lld) is larger than the '%s' clock's 50%% safety margin (%lld)\n", |
3c17ad19 JS |
187 | offset, name, max_cycles >> 1); |
188 | printk_deferred(" timekeeping: Your kernel is still fine, but is feeling a bit nervous\n"); | |
189 | } | |
190 | } | |
4ca22c26 | 191 | |
57d05a93 JS |
192 | if (tk->underflow_seen) { |
193 | if (jiffies - tk->last_warning > WARNING_FREQ) { | |
4ca22c26 JS |
194 | printk_deferred("WARNING: Underflow in clocksource '%s' observed, time update ignored.\n", name); |
195 | printk_deferred(" Please report this, consider using a different clocksource, if possible.\n"); | |
196 | printk_deferred(" Your kernel is probably still fine.\n"); | |
57d05a93 | 197 | tk->last_warning = jiffies; |
4ca22c26 | 198 | } |
57d05a93 | 199 | tk->underflow_seen = 0; |
4ca22c26 JS |
200 | } |
201 | ||
57d05a93 JS |
202 | if (tk->overflow_seen) { |
203 | if (jiffies - tk->last_warning > WARNING_FREQ) { | |
4ca22c26 JS |
204 | printk_deferred("WARNING: Overflow in clocksource '%s' observed, time update capped.\n", name); |
205 | printk_deferred(" Please report this, consider using a different clocksource, if possible.\n"); | |
206 | printk_deferred(" Your kernel is probably still fine.\n"); | |
57d05a93 | 207 | tk->last_warning = jiffies; |
4ca22c26 | 208 | } |
57d05a93 | 209 | tk->overflow_seen = 0; |
4ca22c26 | 210 | } |
3c17ad19 | 211 | } |
a558cd02 | 212 | |
985e6950 | 213 | static inline u64 timekeeping_get_delta(const struct tk_read_base *tkr) |
a558cd02 | 214 | { |
57d05a93 | 215 | struct timekeeper *tk = &tk_core.timekeeper; |
a5a1d1c2 | 216 | u64 now, last, mask, max, delta; |
4ca22c26 | 217 | unsigned int seq; |
a558cd02 | 218 | |
4ca22c26 JS |
219 | /* |
220 | * Since we're called holding a seqlock, the data may shift | |
221 | * under us while we're doing the calculation. This can cause | |
222 | * false positives, since we'd note a problem but throw the | |
223 | * results away. So nest another seqlock here to atomically | |
224 | * grab the points we are checking with. | |
225 | */ | |
226 | do { | |
227 | seq = read_seqcount_begin(&tk_core.seq); | |
ceea5e37 | 228 | now = tk_clock_read(tkr); |
4ca22c26 JS |
229 | last = tkr->cycle_last; |
230 | mask = tkr->mask; | |
231 | max = tkr->clock->max_cycles; | |
232 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
a558cd02 | 233 | |
4ca22c26 | 234 | delta = clocksource_delta(now, last, mask); |
a558cd02 | 235 | |
057b87e3 JS |
236 | /* |
237 | * Try to catch underflows by checking if we are seeing small | |
238 | * mask-relative negative values. | |
239 | */ | |
4ca22c26 | 240 | if (unlikely((~delta & mask) < (mask >> 3))) { |
57d05a93 | 241 | tk->underflow_seen = 1; |
057b87e3 | 242 | delta = 0; |
4ca22c26 | 243 | } |
057b87e3 | 244 | |
a558cd02 | 245 | /* Cap delta value to the max_cycles values to avoid mult overflows */ |
4ca22c26 | 246 | if (unlikely(delta > max)) { |
57d05a93 | 247 | tk->overflow_seen = 1; |
a558cd02 | 248 | delta = tkr->clock->max_cycles; |
4ca22c26 | 249 | } |
a558cd02 JS |
250 | |
251 | return delta; | |
252 | } | |
3c17ad19 | 253 | #else |
a5a1d1c2 | 254 | static inline void timekeeping_check_update(struct timekeeper *tk, u64 offset) |
3c17ad19 JS |
255 | { |
256 | } | |
985e6950 | 257 | static inline u64 timekeeping_get_delta(const struct tk_read_base *tkr) |
a558cd02 | 258 | { |
a5a1d1c2 | 259 | u64 cycle_now, delta; |
a558cd02 JS |
260 | |
261 | /* read clocksource */ | |
ceea5e37 | 262 | cycle_now = tk_clock_read(tkr); |
a558cd02 JS |
263 | |
264 | /* calculate the delta since the last update_wall_time */ | |
265 | delta = clocksource_delta(cycle_now, tkr->cycle_last, tkr->mask); | |
266 | ||
267 | return delta; | |
268 | } | |
3c17ad19 JS |
269 | #endif |
270 | ||
155ec602 | 271 | /** |
d26e4fe0 | 272 | * tk_setup_internals - Set up internals to use clocksource clock. |
155ec602 | 273 | * |
d26e4fe0 | 274 | * @tk: The target timekeeper to setup. |
155ec602 MS |
275 | * @clock: Pointer to clocksource. |
276 | * | |
277 | * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment | |
278 | * pair and interval request. | |
279 | * | |
280 | * Unless you're the timekeeping code, you should not be using this! | |
281 | */ | |
f726a697 | 282 | static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock) |
155ec602 | 283 | { |
a5a1d1c2 | 284 | u64 interval; |
a386b5af | 285 | u64 tmp, ntpinterval; |
1e75fa8b | 286 | struct clocksource *old_clock; |
155ec602 | 287 | |
2c756feb | 288 | ++tk->cs_was_changed_seq; |
876e7881 PZ |
289 | old_clock = tk->tkr_mono.clock; |
290 | tk->tkr_mono.clock = clock; | |
876e7881 | 291 | tk->tkr_mono.mask = clock->mask; |
ceea5e37 | 292 | tk->tkr_mono.cycle_last = tk_clock_read(&tk->tkr_mono); |
155ec602 | 293 | |
4a4ad80d | 294 | tk->tkr_raw.clock = clock; |
4a4ad80d PZ |
295 | tk->tkr_raw.mask = clock->mask; |
296 | tk->tkr_raw.cycle_last = tk->tkr_mono.cycle_last; | |
297 | ||
155ec602 MS |
298 | /* Do the ns -> cycle conversion first, using original mult */ |
299 | tmp = NTP_INTERVAL_LENGTH; | |
300 | tmp <<= clock->shift; | |
a386b5af | 301 | ntpinterval = tmp; |
0a544198 MS |
302 | tmp += clock->mult/2; |
303 | do_div(tmp, clock->mult); | |
155ec602 MS |
304 | if (tmp == 0) |
305 | tmp = 1; | |
306 | ||
a5a1d1c2 | 307 | interval = (u64) tmp; |
f726a697 | 308 | tk->cycle_interval = interval; |
155ec602 MS |
309 | |
310 | /* Go back from cycles -> shifted ns */ | |
cbd99e3b | 311 | tk->xtime_interval = interval * clock->mult; |
f726a697 | 312 | tk->xtime_remainder = ntpinterval - tk->xtime_interval; |
3d88d56c | 313 | tk->raw_interval = interval * clock->mult; |
155ec602 | 314 | |
1e75fa8b JS |
315 | /* if changing clocks, convert xtime_nsec shift units */ |
316 | if (old_clock) { | |
317 | int shift_change = clock->shift - old_clock->shift; | |
fc6eead7 | 318 | if (shift_change < 0) { |
876e7881 | 319 | tk->tkr_mono.xtime_nsec >>= -shift_change; |
fc6eead7 JS |
320 | tk->tkr_raw.xtime_nsec >>= -shift_change; |
321 | } else { | |
876e7881 | 322 | tk->tkr_mono.xtime_nsec <<= shift_change; |
fc6eead7 JS |
323 | tk->tkr_raw.xtime_nsec <<= shift_change; |
324 | } | |
1e75fa8b | 325 | } |
4a4ad80d | 326 | |
876e7881 | 327 | tk->tkr_mono.shift = clock->shift; |
4a4ad80d | 328 | tk->tkr_raw.shift = clock->shift; |
155ec602 | 329 | |
f726a697 JS |
330 | tk->ntp_error = 0; |
331 | tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; | |
375f45b5 | 332 | tk->ntp_tick = ntpinterval << tk->ntp_error_shift; |
0a544198 MS |
333 | |
334 | /* | |
335 | * The timekeeper keeps its own mult values for the currently | |
336 | * active clocksource. These value will be adjusted via NTP | |
337 | * to counteract clock drifting. | |
338 | */ | |
876e7881 | 339 | tk->tkr_mono.mult = clock->mult; |
4a4ad80d | 340 | tk->tkr_raw.mult = clock->mult; |
dc491596 | 341 | tk->ntp_err_mult = 0; |
78b98e3c | 342 | tk->skip_second_overflow = 0; |
155ec602 | 343 | } |
8524070b | 344 | |
2ba2a305 | 345 | /* Timekeeper helper functions. */ |
7b1f6207 SW |
346 | |
347 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET | |
e06fde37 TG |
348 | static u32 default_arch_gettimeoffset(void) { return 0; } |
349 | u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset; | |
7b1f6207 | 350 | #else |
e06fde37 | 351 | static inline u32 arch_gettimeoffset(void) { return 0; } |
7b1f6207 SW |
352 | #endif |
353 | ||
985e6950 | 354 | static inline u64 timekeeping_delta_to_ns(const struct tk_read_base *tkr, u64 delta) |
6bd58f09 | 355 | { |
9c164572 | 356 | u64 nsec; |
6bd58f09 CH |
357 | |
358 | nsec = delta * tkr->mult + tkr->xtime_nsec; | |
359 | nsec >>= tkr->shift; | |
360 | ||
361 | /* If arch requires, add in get_arch_timeoffset() */ | |
362 | return nsec + arch_gettimeoffset(); | |
363 | } | |
364 | ||
985e6950 | 365 | static inline u64 timekeeping_get_ns(const struct tk_read_base *tkr) |
2ba2a305 | 366 | { |
a5a1d1c2 | 367 | u64 delta; |
2ba2a305 | 368 | |
a558cd02 | 369 | delta = timekeeping_get_delta(tkr); |
6bd58f09 CH |
370 | return timekeeping_delta_to_ns(tkr, delta); |
371 | } | |
2ba2a305 | 372 | |
985e6950 | 373 | static inline u64 timekeeping_cycles_to_ns(const struct tk_read_base *tkr, u64 cycles) |
6bd58f09 | 374 | { |
a5a1d1c2 | 375 | u64 delta; |
f2a5a085 | 376 | |
6bd58f09 CH |
377 | /* calculate the delta since the last update_wall_time */ |
378 | delta = clocksource_delta(cycles, tkr->cycle_last, tkr->mask); | |
379 | return timekeeping_delta_to_ns(tkr, delta); | |
2ba2a305 MS |
380 | } |
381 | ||
4396e058 TG |
382 | /** |
383 | * update_fast_timekeeper - Update the fast and NMI safe monotonic timekeeper. | |
affe3e85 | 384 | * @tkr: Timekeeping readout base from which we take the update |
4396e058 TG |
385 | * |
386 | * We want to use this from any context including NMI and tracing / | |
387 | * instrumenting the timekeeping code itself. | |
388 | * | |
6695b92a | 389 | * Employ the latch technique; see @raw_write_seqcount_latch. |
4396e058 TG |
390 | * |
391 | * So if a NMI hits the update of base[0] then it will use base[1] | |
392 | * which is still consistent. In the worst case this can result is a | |
393 | * slightly wrong timestamp (a few nanoseconds). See | |
394 | * @ktime_get_mono_fast_ns. | |
395 | */ | |
985e6950 OM |
396 | static void update_fast_timekeeper(const struct tk_read_base *tkr, |
397 | struct tk_fast *tkf) | |
4396e058 | 398 | { |
4498e746 | 399 | struct tk_read_base *base = tkf->base; |
4396e058 TG |
400 | |
401 | /* Force readers off to base[1] */ | |
4498e746 | 402 | raw_write_seqcount_latch(&tkf->seq); |
4396e058 TG |
403 | |
404 | /* Update base[0] */ | |
affe3e85 | 405 | memcpy(base, tkr, sizeof(*base)); |
4396e058 TG |
406 | |
407 | /* Force readers back to base[0] */ | |
4498e746 | 408 | raw_write_seqcount_latch(&tkf->seq); |
4396e058 TG |
409 | |
410 | /* Update base[1] */ | |
411 | memcpy(base + 1, base, sizeof(*base)); | |
412 | } | |
413 | ||
414 | /** | |
415 | * ktime_get_mono_fast_ns - Fast NMI safe access to clock monotonic | |
416 | * | |
417 | * This timestamp is not guaranteed to be monotonic across an update. | |
418 | * The timestamp is calculated by: | |
419 | * | |
420 | * now = base_mono + clock_delta * slope | |
421 | * | |
422 | * So if the update lowers the slope, readers who are forced to the | |
423 | * not yet updated second array are still using the old steeper slope. | |
424 | * | |
425 | * tmono | |
426 | * ^ | |
427 | * | o n | |
428 | * | o n | |
429 | * | u | |
430 | * | o | |
431 | * |o | |
432 | * |12345678---> reader order | |
433 | * | |
434 | * o = old slope | |
435 | * u = update | |
436 | * n = new slope | |
437 | * | |
438 | * So reader 6 will observe time going backwards versus reader 5. | |
439 | * | |
440 | * While other CPUs are likely to be able observe that, the only way | |
441 | * for a CPU local observation is when an NMI hits in the middle of | |
442 | * the update. Timestamps taken from that NMI context might be ahead | |
443 | * of the following timestamps. Callers need to be aware of that and | |
444 | * deal with it. | |
445 | */ | |
4498e746 | 446 | static __always_inline u64 __ktime_get_fast_ns(struct tk_fast *tkf) |
4396e058 TG |
447 | { |
448 | struct tk_read_base *tkr; | |
449 | unsigned int seq; | |
450 | u64 now; | |
451 | ||
452 | do { | |
7fc26327 | 453 | seq = raw_read_seqcount_latch(&tkf->seq); |
4498e746 | 454 | tkr = tkf->base + (seq & 0x01); |
27727df2 JS |
455 | now = ktime_to_ns(tkr->base); |
456 | ||
58bfea95 JS |
457 | now += timekeeping_delta_to_ns(tkr, |
458 | clocksource_delta( | |
ceea5e37 | 459 | tk_clock_read(tkr), |
58bfea95 JS |
460 | tkr->cycle_last, |
461 | tkr->mask)); | |
4498e746 | 462 | } while (read_seqcount_retry(&tkf->seq, seq)); |
4396e058 | 463 | |
4396e058 TG |
464 | return now; |
465 | } | |
4498e746 PZ |
466 | |
467 | u64 ktime_get_mono_fast_ns(void) | |
468 | { | |
469 | return __ktime_get_fast_ns(&tk_fast_mono); | |
470 | } | |
4396e058 TG |
471 | EXPORT_SYMBOL_GPL(ktime_get_mono_fast_ns); |
472 | ||
f09cb9a1 PZ |
473 | u64 ktime_get_raw_fast_ns(void) |
474 | { | |
475 | return __ktime_get_fast_ns(&tk_fast_raw); | |
476 | } | |
477 | EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns); | |
478 | ||
a3ed0e43 TG |
479 | /** |
480 | * ktime_get_boot_fast_ns - NMI safe and fast access to boot clock. | |
481 | * | |
482 | * To keep it NMI safe since we're accessing from tracing, we're not using a | |
483 | * separate timekeeper with updates to monotonic clock and boot offset | |
484 | * protected with seqlocks. This has the following minor side effects: | |
485 | * | |
486 | * (1) Its possible that a timestamp be taken after the boot offset is updated | |
487 | * but before the timekeeper is updated. If this happens, the new boot offset | |
488 | * is added to the old timekeeping making the clock appear to update slightly | |
489 | * earlier: | |
490 | * CPU 0 CPU 1 | |
491 | * timekeeping_inject_sleeptime64() | |
492 | * __timekeeping_inject_sleeptime(tk, delta); | |
493 | * timestamp(); | |
494 | * timekeeping_update(tk, TK_CLEAR_NTP...); | |
495 | * | |
496 | * (2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be | |
497 | * partially updated. Since the tk->offs_boot update is a rare event, this | |
498 | * should be a rare occurrence which postprocessing should be able to handle. | |
499 | */ | |
500 | u64 notrace ktime_get_boot_fast_ns(void) | |
501 | { | |
502 | struct timekeeper *tk = &tk_core.timekeeper; | |
503 | ||
504 | return (ktime_get_mono_fast_ns() + ktime_to_ns(tk->offs_boot)); | |
505 | } | |
506 | EXPORT_SYMBOL_GPL(ktime_get_boot_fast_ns); | |
507 | ||
508 | ||
4c3711d7 TG |
509 | /* |
510 | * See comment for __ktime_get_fast_ns() vs. timestamp ordering | |
511 | */ | |
512 | static __always_inline u64 __ktime_get_real_fast_ns(struct tk_fast *tkf) | |
513 | { | |
514 | struct tk_read_base *tkr; | |
515 | unsigned int seq; | |
516 | u64 now; | |
517 | ||
518 | do { | |
519 | seq = raw_read_seqcount_latch(&tkf->seq); | |
520 | tkr = tkf->base + (seq & 0x01); | |
521 | now = ktime_to_ns(tkr->base_real); | |
522 | ||
523 | now += timekeeping_delta_to_ns(tkr, | |
524 | clocksource_delta( | |
525 | tk_clock_read(tkr), | |
526 | tkr->cycle_last, | |
527 | tkr->mask)); | |
528 | } while (read_seqcount_retry(&tkf->seq, seq)); | |
529 | ||
530 | return now; | |
531 | } | |
532 | ||
533 | /** | |
534 | * ktime_get_real_fast_ns: - NMI safe and fast access to clock realtime. | |
535 | */ | |
536 | u64 ktime_get_real_fast_ns(void) | |
537 | { | |
538 | return __ktime_get_real_fast_ns(&tk_fast_mono); | |
539 | } | |
df27067e | 540 | EXPORT_SYMBOL_GPL(ktime_get_real_fast_ns); |
4c3711d7 | 541 | |
060407ae RW |
542 | /** |
543 | * halt_fast_timekeeper - Prevent fast timekeeper from accessing clocksource. | |
544 | * @tk: Timekeeper to snapshot. | |
545 | * | |
546 | * It generally is unsafe to access the clocksource after timekeeping has been | |
547 | * suspended, so take a snapshot of the readout base of @tk and use it as the | |
548 | * fast timekeeper's readout base while suspended. It will return the same | |
549 | * number of cycles every time until timekeeping is resumed at which time the | |
550 | * proper readout base for the fast timekeeper will be restored automatically. | |
551 | */ | |
985e6950 | 552 | static void halt_fast_timekeeper(const struct timekeeper *tk) |
060407ae RW |
553 | { |
554 | static struct tk_read_base tkr_dummy; | |
985e6950 | 555 | const struct tk_read_base *tkr = &tk->tkr_mono; |
060407ae RW |
556 | |
557 | memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy)); | |
ceea5e37 JS |
558 | cycles_at_suspend = tk_clock_read(tkr); |
559 | tkr_dummy.clock = &dummy_clock; | |
4c3711d7 | 560 | tkr_dummy.base_real = tkr->base + tk->offs_real; |
4498e746 | 561 | update_fast_timekeeper(&tkr_dummy, &tk_fast_mono); |
f09cb9a1 PZ |
562 | |
563 | tkr = &tk->tkr_raw; | |
564 | memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy)); | |
ceea5e37 | 565 | tkr_dummy.clock = &dummy_clock; |
f09cb9a1 | 566 | update_fast_timekeeper(&tkr_dummy, &tk_fast_raw); |
060407ae RW |
567 | } |
568 | ||
e0b306fe MT |
569 | static RAW_NOTIFIER_HEAD(pvclock_gtod_chain); |
570 | ||
780427f0 | 571 | static void update_pvclock_gtod(struct timekeeper *tk, bool was_set) |
e0b306fe | 572 | { |
780427f0 | 573 | raw_notifier_call_chain(&pvclock_gtod_chain, was_set, tk); |
e0b306fe MT |
574 | } |
575 | ||
576 | /** | |
577 | * pvclock_gtod_register_notifier - register a pvclock timedata update listener | |
e0b306fe MT |
578 | */ |
579 | int pvclock_gtod_register_notifier(struct notifier_block *nb) | |
580 | { | |
3fdb14fd | 581 | struct timekeeper *tk = &tk_core.timekeeper; |
e0b306fe MT |
582 | unsigned long flags; |
583 | int ret; | |
584 | ||
9a7a71b1 | 585 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
e0b306fe | 586 | ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb); |
780427f0 | 587 | update_pvclock_gtod(tk, true); |
9a7a71b1 | 588 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
e0b306fe MT |
589 | |
590 | return ret; | |
591 | } | |
592 | EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier); | |
593 | ||
594 | /** | |
595 | * pvclock_gtod_unregister_notifier - unregister a pvclock | |
596 | * timedata update listener | |
e0b306fe MT |
597 | */ |
598 | int pvclock_gtod_unregister_notifier(struct notifier_block *nb) | |
599 | { | |
e0b306fe MT |
600 | unsigned long flags; |
601 | int ret; | |
602 | ||
9a7a71b1 | 603 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
e0b306fe | 604 | ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb); |
9a7a71b1 | 605 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
e0b306fe MT |
606 | |
607 | return ret; | |
608 | } | |
609 | EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier); | |
610 | ||
833f32d7 JS |
611 | /* |
612 | * tk_update_leap_state - helper to update the next_leap_ktime | |
613 | */ | |
614 | static inline void tk_update_leap_state(struct timekeeper *tk) | |
615 | { | |
616 | tk->next_leap_ktime = ntp_get_next_leap(); | |
2456e855 | 617 | if (tk->next_leap_ktime != KTIME_MAX) |
833f32d7 JS |
618 | /* Convert to monotonic time */ |
619 | tk->next_leap_ktime = ktime_sub(tk->next_leap_ktime, tk->offs_real); | |
620 | } | |
621 | ||
7c032df5 TG |
622 | /* |
623 | * Update the ktime_t based scalar nsec members of the timekeeper | |
624 | */ | |
625 | static inline void tk_update_ktime_data(struct timekeeper *tk) | |
626 | { | |
9e3680b1 HS |
627 | u64 seconds; |
628 | u32 nsec; | |
7c032df5 TG |
629 | |
630 | /* | |
631 | * The xtime based monotonic readout is: | |
632 | * nsec = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec + now(); | |
633 | * The ktime based monotonic readout is: | |
634 | * nsec = base_mono + now(); | |
635 | * ==> base_mono = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec | |
636 | */ | |
9e3680b1 HS |
637 | seconds = (u64)(tk->xtime_sec + tk->wall_to_monotonic.tv_sec); |
638 | nsec = (u32) tk->wall_to_monotonic.tv_nsec; | |
876e7881 | 639 | tk->tkr_mono.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec); |
f519b1a2 | 640 | |
9e3680b1 HS |
641 | /* |
642 | * The sum of the nanoseconds portions of xtime and | |
643 | * wall_to_monotonic can be greater/equal one second. Take | |
644 | * this into account before updating tk->ktime_sec. | |
645 | */ | |
876e7881 | 646 | nsec += (u32)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); |
9e3680b1 HS |
647 | if (nsec >= NSEC_PER_SEC) |
648 | seconds++; | |
649 | tk->ktime_sec = seconds; | |
fc6eead7 JS |
650 | |
651 | /* Update the monotonic raw base */ | |
0bcdc098 | 652 | tk->tkr_raw.base = ns_to_ktime(tk->raw_sec * NSEC_PER_SEC); |
7c032df5 TG |
653 | } |
654 | ||
9a7a71b1 | 655 | /* must hold timekeeper_lock */ |
04397fe9 | 656 | static void timekeeping_update(struct timekeeper *tk, unsigned int action) |
cc06268c | 657 | { |
04397fe9 | 658 | if (action & TK_CLEAR_NTP) { |
f726a697 | 659 | tk->ntp_error = 0; |
cc06268c TG |
660 | ntp_clear(); |
661 | } | |
48cdc135 | 662 | |
833f32d7 | 663 | tk_update_leap_state(tk); |
7c032df5 TG |
664 | tk_update_ktime_data(tk); |
665 | ||
9bf2419f TG |
666 | update_vsyscall(tk); |
667 | update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); | |
668 | ||
4c3711d7 | 669 | tk->tkr_mono.base_real = tk->tkr_mono.base + tk->offs_real; |
4498e746 | 670 | update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono); |
f09cb9a1 | 671 | update_fast_timekeeper(&tk->tkr_raw, &tk_fast_raw); |
868a3e91 TG |
672 | |
673 | if (action & TK_CLOCK_WAS_SET) | |
674 | tk->clock_was_set_seq++; | |
d1518326 JS |
675 | /* |
676 | * The mirroring of the data to the shadow-timekeeper needs | |
677 | * to happen last here to ensure we don't over-write the | |
678 | * timekeeper structure on the next update with stale data | |
679 | */ | |
680 | if (action & TK_MIRROR) | |
681 | memcpy(&shadow_timekeeper, &tk_core.timekeeper, | |
682 | sizeof(tk_core.timekeeper)); | |
cc06268c TG |
683 | } |
684 | ||
8524070b | 685 | /** |
155ec602 | 686 | * timekeeping_forward_now - update clock to the current time |
8524070b | 687 | * |
9a055117 RZ |
688 | * Forward the current clock to update its state since the last call to |
689 | * update_wall_time(). This is useful before significant clock changes, | |
690 | * as it avoids having to deal with this time offset explicitly. | |
8524070b | 691 | */ |
f726a697 | 692 | static void timekeeping_forward_now(struct timekeeper *tk) |
8524070b | 693 | { |
a5a1d1c2 | 694 | u64 cycle_now, delta; |
8524070b | 695 | |
ceea5e37 | 696 | cycle_now = tk_clock_read(&tk->tkr_mono); |
876e7881 PZ |
697 | delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask); |
698 | tk->tkr_mono.cycle_last = cycle_now; | |
4a4ad80d | 699 | tk->tkr_raw.cycle_last = cycle_now; |
8524070b | 700 | |
876e7881 | 701 | tk->tkr_mono.xtime_nsec += delta * tk->tkr_mono.mult; |
7d27558c | 702 | |
7b1f6207 | 703 | /* If arch requires, add in get_arch_timeoffset() */ |
876e7881 | 704 | tk->tkr_mono.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_mono.shift; |
7d27558c | 705 | |
2d42244a | 706 | |
fc6eead7 JS |
707 | tk->tkr_raw.xtime_nsec += delta * tk->tkr_raw.mult; |
708 | ||
709 | /* If arch requires, add in get_arch_timeoffset() */ | |
710 | tk->tkr_raw.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_raw.shift; | |
711 | ||
712 | tk_normalize_xtime(tk); | |
8524070b | 713 | } |
714 | ||
715 | /** | |
edca71fe | 716 | * ktime_get_real_ts64 - Returns the time of day in a timespec64. |
8524070b | 717 | * @ts: pointer to the timespec to be set |
718 | * | |
edca71fe | 719 | * Returns the time of day in a timespec64 (WARN if suspended). |
8524070b | 720 | */ |
edca71fe | 721 | void ktime_get_real_ts64(struct timespec64 *ts) |
8524070b | 722 | { |
3fdb14fd | 723 | struct timekeeper *tk = &tk_core.timekeeper; |
e1e41b6c | 724 | unsigned int seq; |
acc89612 | 725 | u64 nsecs; |
8524070b | 726 | |
edca71fe AB |
727 | WARN_ON(timekeeping_suspended); |
728 | ||
8524070b | 729 | do { |
3fdb14fd | 730 | seq = read_seqcount_begin(&tk_core.seq); |
8524070b | 731 | |
4e250fdd | 732 | ts->tv_sec = tk->xtime_sec; |
876e7881 | 733 | nsecs = timekeeping_get_ns(&tk->tkr_mono); |
8524070b | 734 | |
3fdb14fd | 735 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
8524070b | 736 | |
ec145bab | 737 | ts->tv_nsec = 0; |
d6d29896 | 738 | timespec64_add_ns(ts, nsecs); |
8524070b | 739 | } |
edca71fe | 740 | EXPORT_SYMBOL(ktime_get_real_ts64); |
8524070b | 741 | |
951ed4d3 MS |
742 | ktime_t ktime_get(void) |
743 | { | |
3fdb14fd | 744 | struct timekeeper *tk = &tk_core.timekeeper; |
951ed4d3 | 745 | unsigned int seq; |
a016a5bd | 746 | ktime_t base; |
acc89612 | 747 | u64 nsecs; |
951ed4d3 MS |
748 | |
749 | WARN_ON(timekeeping_suspended); | |
750 | ||
751 | do { | |
3fdb14fd | 752 | seq = read_seqcount_begin(&tk_core.seq); |
876e7881 PZ |
753 | base = tk->tkr_mono.base; |
754 | nsecs = timekeeping_get_ns(&tk->tkr_mono); | |
951ed4d3 | 755 | |
3fdb14fd | 756 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
24e4a8c3 | 757 | |
a016a5bd | 758 | return ktime_add_ns(base, nsecs); |
951ed4d3 MS |
759 | } |
760 | EXPORT_SYMBOL_GPL(ktime_get); | |
761 | ||
6374f912 HG |
762 | u32 ktime_get_resolution_ns(void) |
763 | { | |
764 | struct timekeeper *tk = &tk_core.timekeeper; | |
765 | unsigned int seq; | |
766 | u32 nsecs; | |
767 | ||
768 | WARN_ON(timekeeping_suspended); | |
769 | ||
770 | do { | |
771 | seq = read_seqcount_begin(&tk_core.seq); | |
772 | nsecs = tk->tkr_mono.mult >> tk->tkr_mono.shift; | |
773 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
774 | ||
775 | return nsecs; | |
776 | } | |
777 | EXPORT_SYMBOL_GPL(ktime_get_resolution_ns); | |
778 | ||
0077dc60 TG |
779 | static ktime_t *offsets[TK_OFFS_MAX] = { |
780 | [TK_OFFS_REAL] = &tk_core.timekeeper.offs_real, | |
a3ed0e43 | 781 | [TK_OFFS_BOOT] = &tk_core.timekeeper.offs_boot, |
0077dc60 TG |
782 | [TK_OFFS_TAI] = &tk_core.timekeeper.offs_tai, |
783 | }; | |
784 | ||
785 | ktime_t ktime_get_with_offset(enum tk_offsets offs) | |
786 | { | |
787 | struct timekeeper *tk = &tk_core.timekeeper; | |
788 | unsigned int seq; | |
789 | ktime_t base, *offset = offsets[offs]; | |
acc89612 | 790 | u64 nsecs; |
0077dc60 TG |
791 | |
792 | WARN_ON(timekeeping_suspended); | |
793 | ||
794 | do { | |
795 | seq = read_seqcount_begin(&tk_core.seq); | |
876e7881 PZ |
796 | base = ktime_add(tk->tkr_mono.base, *offset); |
797 | nsecs = timekeeping_get_ns(&tk->tkr_mono); | |
0077dc60 TG |
798 | |
799 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
800 | ||
801 | return ktime_add_ns(base, nsecs); | |
802 | ||
803 | } | |
804 | EXPORT_SYMBOL_GPL(ktime_get_with_offset); | |
805 | ||
b9ff604c AB |
806 | ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs) |
807 | { | |
808 | struct timekeeper *tk = &tk_core.timekeeper; | |
809 | unsigned int seq; | |
810 | ktime_t base, *offset = offsets[offs]; | |
e3ff9c36 | 811 | u64 nsecs; |
b9ff604c AB |
812 | |
813 | WARN_ON(timekeeping_suspended); | |
814 | ||
815 | do { | |
816 | seq = read_seqcount_begin(&tk_core.seq); | |
817 | base = ktime_add(tk->tkr_mono.base, *offset); | |
e3ff9c36 | 818 | nsecs = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift; |
b9ff604c AB |
819 | |
820 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
821 | ||
0354c1a3 | 822 | return ktime_add_ns(base, nsecs); |
b9ff604c AB |
823 | } |
824 | EXPORT_SYMBOL_GPL(ktime_get_coarse_with_offset); | |
825 | ||
9a6b5197 TG |
826 | /** |
827 | * ktime_mono_to_any() - convert mononotic time to any other time | |
828 | * @tmono: time to convert. | |
829 | * @offs: which offset to use | |
830 | */ | |
831 | ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs) | |
832 | { | |
833 | ktime_t *offset = offsets[offs]; | |
e1e41b6c | 834 | unsigned int seq; |
9a6b5197 TG |
835 | ktime_t tconv; |
836 | ||
837 | do { | |
838 | seq = read_seqcount_begin(&tk_core.seq); | |
839 | tconv = ktime_add(tmono, *offset); | |
840 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
841 | ||
842 | return tconv; | |
843 | } | |
844 | EXPORT_SYMBOL_GPL(ktime_mono_to_any); | |
845 | ||
f519b1a2 TG |
846 | /** |
847 | * ktime_get_raw - Returns the raw monotonic time in ktime_t format | |
848 | */ | |
849 | ktime_t ktime_get_raw(void) | |
850 | { | |
851 | struct timekeeper *tk = &tk_core.timekeeper; | |
852 | unsigned int seq; | |
853 | ktime_t base; | |
acc89612 | 854 | u64 nsecs; |
f519b1a2 TG |
855 | |
856 | do { | |
857 | seq = read_seqcount_begin(&tk_core.seq); | |
4a4ad80d PZ |
858 | base = tk->tkr_raw.base; |
859 | nsecs = timekeeping_get_ns(&tk->tkr_raw); | |
f519b1a2 TG |
860 | |
861 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
862 | ||
863 | return ktime_add_ns(base, nsecs); | |
864 | } | |
865 | EXPORT_SYMBOL_GPL(ktime_get_raw); | |
866 | ||
951ed4d3 | 867 | /** |
d6d29896 | 868 | * ktime_get_ts64 - get the monotonic clock in timespec64 format |
951ed4d3 MS |
869 | * @ts: pointer to timespec variable |
870 | * | |
871 | * The function calculates the monotonic clock from the realtime | |
872 | * clock and the wall_to_monotonic offset and stores the result | |
5322e4c2 | 873 | * in normalized timespec64 format in the variable pointed to by @ts. |
951ed4d3 | 874 | */ |
d6d29896 | 875 | void ktime_get_ts64(struct timespec64 *ts) |
951ed4d3 | 876 | { |
3fdb14fd | 877 | struct timekeeper *tk = &tk_core.timekeeper; |
d6d29896 | 878 | struct timespec64 tomono; |
951ed4d3 | 879 | unsigned int seq; |
acc89612 | 880 | u64 nsec; |
951ed4d3 MS |
881 | |
882 | WARN_ON(timekeeping_suspended); | |
883 | ||
884 | do { | |
3fdb14fd | 885 | seq = read_seqcount_begin(&tk_core.seq); |
d6d29896 | 886 | ts->tv_sec = tk->xtime_sec; |
876e7881 | 887 | nsec = timekeeping_get_ns(&tk->tkr_mono); |
4e250fdd | 888 | tomono = tk->wall_to_monotonic; |
951ed4d3 | 889 | |
3fdb14fd | 890 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
951ed4d3 | 891 | |
d6d29896 TG |
892 | ts->tv_sec += tomono.tv_sec; |
893 | ts->tv_nsec = 0; | |
894 | timespec64_add_ns(ts, nsec + tomono.tv_nsec); | |
951ed4d3 | 895 | } |
d6d29896 | 896 | EXPORT_SYMBOL_GPL(ktime_get_ts64); |
951ed4d3 | 897 | |
9e3680b1 HS |
898 | /** |
899 | * ktime_get_seconds - Get the seconds portion of CLOCK_MONOTONIC | |
900 | * | |
901 | * Returns the seconds portion of CLOCK_MONOTONIC with a single non | |
902 | * serialized read. tk->ktime_sec is of type 'unsigned long' so this | |
903 | * works on both 32 and 64 bit systems. On 32 bit systems the readout | |
904 | * covers ~136 years of uptime which should be enough to prevent | |
905 | * premature wrap arounds. | |
906 | */ | |
907 | time64_t ktime_get_seconds(void) | |
908 | { | |
909 | struct timekeeper *tk = &tk_core.timekeeper; | |
910 | ||
911 | WARN_ON(timekeeping_suspended); | |
912 | return tk->ktime_sec; | |
913 | } | |
914 | EXPORT_SYMBOL_GPL(ktime_get_seconds); | |
915 | ||
dbe7aa62 HS |
916 | /** |
917 | * ktime_get_real_seconds - Get the seconds portion of CLOCK_REALTIME | |
918 | * | |
919 | * Returns the wall clock seconds since 1970. This replaces the | |
920 | * get_seconds() interface which is not y2038 safe on 32bit systems. | |
921 | * | |
922 | * For 64bit systems the fast access to tk->xtime_sec is preserved. On | |
923 | * 32bit systems the access must be protected with the sequence | |
924 | * counter to provide "atomic" access to the 64bit tk->xtime_sec | |
925 | * value. | |
926 | */ | |
927 | time64_t ktime_get_real_seconds(void) | |
928 | { | |
929 | struct timekeeper *tk = &tk_core.timekeeper; | |
930 | time64_t seconds; | |
931 | unsigned int seq; | |
932 | ||
933 | if (IS_ENABLED(CONFIG_64BIT)) | |
934 | return tk->xtime_sec; | |
935 | ||
936 | do { | |
937 | seq = read_seqcount_begin(&tk_core.seq); | |
938 | seconds = tk->xtime_sec; | |
939 | ||
940 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
941 | ||
942 | return seconds; | |
943 | } | |
944 | EXPORT_SYMBOL_GPL(ktime_get_real_seconds); | |
945 | ||
dee36654 D |
946 | /** |
947 | * __ktime_get_real_seconds - The same as ktime_get_real_seconds | |
948 | * but without the sequence counter protect. This internal function | |
949 | * is called just when timekeeping lock is already held. | |
950 | */ | |
951 | time64_t __ktime_get_real_seconds(void) | |
952 | { | |
953 | struct timekeeper *tk = &tk_core.timekeeper; | |
954 | ||
955 | return tk->xtime_sec; | |
956 | } | |
957 | ||
9da0f49c CH |
958 | /** |
959 | * ktime_get_snapshot - snapshots the realtime/monotonic raw clocks with counter | |
960 | * @systime_snapshot: pointer to struct receiving the system time snapshot | |
961 | */ | |
962 | void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot) | |
963 | { | |
964 | struct timekeeper *tk = &tk_core.timekeeper; | |
e1e41b6c | 965 | unsigned int seq; |
9da0f49c CH |
966 | ktime_t base_raw; |
967 | ktime_t base_real; | |
acc89612 TG |
968 | u64 nsec_raw; |
969 | u64 nsec_real; | |
a5a1d1c2 | 970 | u64 now; |
9da0f49c | 971 | |
ba26621e CH |
972 | WARN_ON_ONCE(timekeeping_suspended); |
973 | ||
9da0f49c CH |
974 | do { |
975 | seq = read_seqcount_begin(&tk_core.seq); | |
ceea5e37 | 976 | now = tk_clock_read(&tk->tkr_mono); |
2c756feb CH |
977 | systime_snapshot->cs_was_changed_seq = tk->cs_was_changed_seq; |
978 | systime_snapshot->clock_was_set_seq = tk->clock_was_set_seq; | |
9da0f49c CH |
979 | base_real = ktime_add(tk->tkr_mono.base, |
980 | tk_core.timekeeper.offs_real); | |
981 | base_raw = tk->tkr_raw.base; | |
982 | nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, now); | |
983 | nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, now); | |
984 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
985 | ||
986 | systime_snapshot->cycles = now; | |
987 | systime_snapshot->real = ktime_add_ns(base_real, nsec_real); | |
988 | systime_snapshot->raw = ktime_add_ns(base_raw, nsec_raw); | |
989 | } | |
990 | EXPORT_SYMBOL_GPL(ktime_get_snapshot); | |
dee36654 | 991 | |
2c756feb CH |
992 | /* Scale base by mult/div checking for overflow */ |
993 | static int scale64_check_overflow(u64 mult, u64 div, u64 *base) | |
994 | { | |
995 | u64 tmp, rem; | |
996 | ||
997 | tmp = div64_u64_rem(*base, div, &rem); | |
998 | ||
999 | if (((int)sizeof(u64)*8 - fls64(mult) < fls64(tmp)) || | |
1000 | ((int)sizeof(u64)*8 - fls64(mult) < fls64(rem))) | |
1001 | return -EOVERFLOW; | |
1002 | tmp *= mult; | |
1003 | rem *= mult; | |
1004 | ||
1005 | do_div(rem, div); | |
1006 | *base = tmp + rem; | |
1007 | return 0; | |
1008 | } | |
1009 | ||
1010 | /** | |
1011 | * adjust_historical_crosststamp - adjust crosstimestamp previous to current interval | |
1012 | * @history: Snapshot representing start of history | |
1013 | * @partial_history_cycles: Cycle offset into history (fractional part) | |
1014 | * @total_history_cycles: Total history length in cycles | |
1015 | * @discontinuity: True indicates clock was set on history period | |
1016 | * @ts: Cross timestamp that should be adjusted using | |
1017 | * partial/total ratio | |
1018 | * | |
1019 | * Helper function used by get_device_system_crosststamp() to correct the | |
1020 | * crosstimestamp corresponding to the start of the current interval to the | |
1021 | * system counter value (timestamp point) provided by the driver. The | |
1022 | * total_history_* quantities are the total history starting at the provided | |
1023 | * reference point and ending at the start of the current interval. The cycle | |
1024 | * count between the driver timestamp point and the start of the current | |
1025 | * interval is partial_history_cycles. | |
1026 | */ | |
1027 | static int adjust_historical_crosststamp(struct system_time_snapshot *history, | |
a5a1d1c2 TG |
1028 | u64 partial_history_cycles, |
1029 | u64 total_history_cycles, | |
2c756feb CH |
1030 | bool discontinuity, |
1031 | struct system_device_crosststamp *ts) | |
1032 | { | |
1033 | struct timekeeper *tk = &tk_core.timekeeper; | |
1034 | u64 corr_raw, corr_real; | |
1035 | bool interp_forward; | |
1036 | int ret; | |
1037 | ||
1038 | if (total_history_cycles == 0 || partial_history_cycles == 0) | |
1039 | return 0; | |
1040 | ||
1041 | /* Interpolate shortest distance from beginning or end of history */ | |
5fc63f95 | 1042 | interp_forward = partial_history_cycles > total_history_cycles / 2; |
2c756feb CH |
1043 | partial_history_cycles = interp_forward ? |
1044 | total_history_cycles - partial_history_cycles : | |
1045 | partial_history_cycles; | |
1046 | ||
1047 | /* | |
1048 | * Scale the monotonic raw time delta by: | |
1049 | * partial_history_cycles / total_history_cycles | |
1050 | */ | |
1051 | corr_raw = (u64)ktime_to_ns( | |
1052 | ktime_sub(ts->sys_monoraw, history->raw)); | |
1053 | ret = scale64_check_overflow(partial_history_cycles, | |
1054 | total_history_cycles, &corr_raw); | |
1055 | if (ret) | |
1056 | return ret; | |
1057 | ||
1058 | /* | |
1059 | * If there is a discontinuity in the history, scale monotonic raw | |
1060 | * correction by: | |
1061 | * mult(real)/mult(raw) yielding the realtime correction | |
1062 | * Otherwise, calculate the realtime correction similar to monotonic | |
1063 | * raw calculation | |
1064 | */ | |
1065 | if (discontinuity) { | |
1066 | corr_real = mul_u64_u32_div | |
1067 | (corr_raw, tk->tkr_mono.mult, tk->tkr_raw.mult); | |
1068 | } else { | |
1069 | corr_real = (u64)ktime_to_ns( | |
1070 | ktime_sub(ts->sys_realtime, history->real)); | |
1071 | ret = scale64_check_overflow(partial_history_cycles, | |
1072 | total_history_cycles, &corr_real); | |
1073 | if (ret) | |
1074 | return ret; | |
1075 | } | |
1076 | ||
1077 | /* Fixup monotonic raw and real time time values */ | |
1078 | if (interp_forward) { | |
1079 | ts->sys_monoraw = ktime_add_ns(history->raw, corr_raw); | |
1080 | ts->sys_realtime = ktime_add_ns(history->real, corr_real); | |
1081 | } else { | |
1082 | ts->sys_monoraw = ktime_sub_ns(ts->sys_monoraw, corr_raw); | |
1083 | ts->sys_realtime = ktime_sub_ns(ts->sys_realtime, corr_real); | |
1084 | } | |
1085 | ||
1086 | return 0; | |
1087 | } | |
1088 | ||
1089 | /* | |
1090 | * cycle_between - true if test occurs chronologically between before and after | |
1091 | */ | |
a5a1d1c2 | 1092 | static bool cycle_between(u64 before, u64 test, u64 after) |
2c756feb CH |
1093 | { |
1094 | if (test > before && test < after) | |
1095 | return true; | |
1096 | if (test < before && before > after) | |
1097 | return true; | |
1098 | return false; | |
1099 | } | |
1100 | ||
8006c245 CH |
1101 | /** |
1102 | * get_device_system_crosststamp - Synchronously capture system/device timestamp | |
2c756feb | 1103 | * @get_time_fn: Callback to get simultaneous device time and |
8006c245 | 1104 | * system counter from the device driver |
2c756feb CH |
1105 | * @ctx: Context passed to get_time_fn() |
1106 | * @history_begin: Historical reference point used to interpolate system | |
1107 | * time when counter provided by the driver is before the current interval | |
8006c245 CH |
1108 | * @xtstamp: Receives simultaneously captured system and device time |
1109 | * | |
1110 | * Reads a timestamp from a device and correlates it to system time | |
1111 | */ | |
1112 | int get_device_system_crosststamp(int (*get_time_fn) | |
1113 | (ktime_t *device_time, | |
1114 | struct system_counterval_t *sys_counterval, | |
1115 | void *ctx), | |
1116 | void *ctx, | |
2c756feb | 1117 | struct system_time_snapshot *history_begin, |
8006c245 CH |
1118 | struct system_device_crosststamp *xtstamp) |
1119 | { | |
1120 | struct system_counterval_t system_counterval; | |
1121 | struct timekeeper *tk = &tk_core.timekeeper; | |
a5a1d1c2 | 1122 | u64 cycles, now, interval_start; |
6436257b | 1123 | unsigned int clock_was_set_seq = 0; |
8006c245 | 1124 | ktime_t base_real, base_raw; |
acc89612 | 1125 | u64 nsec_real, nsec_raw; |
2c756feb | 1126 | u8 cs_was_changed_seq; |
e1e41b6c | 1127 | unsigned int seq; |
2c756feb | 1128 | bool do_interp; |
8006c245 CH |
1129 | int ret; |
1130 | ||
1131 | do { | |
1132 | seq = read_seqcount_begin(&tk_core.seq); | |
1133 | /* | |
1134 | * Try to synchronously capture device time and a system | |
1135 | * counter value calling back into the device driver | |
1136 | */ | |
1137 | ret = get_time_fn(&xtstamp->device, &system_counterval, ctx); | |
1138 | if (ret) | |
1139 | return ret; | |
1140 | ||
1141 | /* | |
1142 | * Verify that the clocksource associated with the captured | |
1143 | * system counter value is the same as the currently installed | |
1144 | * timekeeper clocksource | |
1145 | */ | |
1146 | if (tk->tkr_mono.clock != system_counterval.cs) | |
1147 | return -ENODEV; | |
2c756feb CH |
1148 | cycles = system_counterval.cycles; |
1149 | ||
1150 | /* | |
1151 | * Check whether the system counter value provided by the | |
1152 | * device driver is on the current timekeeping interval. | |
1153 | */ | |
ceea5e37 | 1154 | now = tk_clock_read(&tk->tkr_mono); |
2c756feb CH |
1155 | interval_start = tk->tkr_mono.cycle_last; |
1156 | if (!cycle_between(interval_start, cycles, now)) { | |
1157 | clock_was_set_seq = tk->clock_was_set_seq; | |
1158 | cs_was_changed_seq = tk->cs_was_changed_seq; | |
1159 | cycles = interval_start; | |
1160 | do_interp = true; | |
1161 | } else { | |
1162 | do_interp = false; | |
1163 | } | |
8006c245 CH |
1164 | |
1165 | base_real = ktime_add(tk->tkr_mono.base, | |
1166 | tk_core.timekeeper.offs_real); | |
1167 | base_raw = tk->tkr_raw.base; | |
1168 | ||
1169 | nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, | |
1170 | system_counterval.cycles); | |
1171 | nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, | |
1172 | system_counterval.cycles); | |
1173 | } while (read_seqcount_retry(&tk_core.seq, seq)); | |
1174 | ||
1175 | xtstamp->sys_realtime = ktime_add_ns(base_real, nsec_real); | |
1176 | xtstamp->sys_monoraw = ktime_add_ns(base_raw, nsec_raw); | |
2c756feb CH |
1177 | |
1178 | /* | |
1179 | * Interpolate if necessary, adjusting back from the start of the | |
1180 | * current interval | |
1181 | */ | |
1182 | if (do_interp) { | |
a5a1d1c2 | 1183 | u64 partial_history_cycles, total_history_cycles; |
2c756feb CH |
1184 | bool discontinuity; |
1185 | ||
1186 | /* | |
1187 | * Check that the counter value occurs after the provided | |
1188 | * history reference and that the history doesn't cross a | |
1189 | * clocksource change | |
1190 | */ | |
1191 | if (!history_begin || | |
1192 | !cycle_between(history_begin->cycles, | |
1193 | system_counterval.cycles, cycles) || | |
1194 | history_begin->cs_was_changed_seq != cs_was_changed_seq) | |
1195 | return -EINVAL; | |
1196 | partial_history_cycles = cycles - system_counterval.cycles; | |
1197 | total_history_cycles = cycles - history_begin->cycles; | |
1198 | discontinuity = | |
1199 | history_begin->clock_was_set_seq != clock_was_set_seq; | |
1200 | ||
1201 | ret = adjust_historical_crosststamp(history_begin, | |
1202 | partial_history_cycles, | |
1203 | total_history_cycles, | |
1204 | discontinuity, xtstamp); | |
1205 | if (ret) | |
1206 | return ret; | |
1207 | } | |
1208 | ||
8006c245 CH |
1209 | return 0; |
1210 | } | |
1211 | EXPORT_SYMBOL_GPL(get_device_system_crosststamp); | |
1212 | ||
8524070b | 1213 | /** |
21f7eca5 | 1214 | * do_settimeofday64 - Sets the time of day. |
1215 | * @ts: pointer to the timespec64 variable containing the new time | |
8524070b | 1216 | * |
1217 | * Sets the time of day to the new time and update NTP and notify hrtimers | |
1218 | */ | |
21f7eca5 | 1219 | int do_settimeofday64(const struct timespec64 *ts) |
8524070b | 1220 | { |
3fdb14fd | 1221 | struct timekeeper *tk = &tk_core.timekeeper; |
21f7eca5 | 1222 | struct timespec64 ts_delta, xt; |
92c1d3ed | 1223 | unsigned long flags; |
e1d7ba87 | 1224 | int ret = 0; |
8524070b | 1225 | |
7a8e61f8 | 1226 | if (!timespec64_valid_settod(ts)) |
8524070b | 1227 | return -EINVAL; |
1228 | ||
9a7a71b1 | 1229 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1230 | write_seqcount_begin(&tk_core.seq); |
8524070b | 1231 | |
4e250fdd | 1232 | timekeeping_forward_now(tk); |
9a055117 | 1233 | |
4e250fdd | 1234 | xt = tk_xtime(tk); |
21f7eca5 | 1235 | ts_delta.tv_sec = ts->tv_sec - xt.tv_sec; |
1236 | ts_delta.tv_nsec = ts->tv_nsec - xt.tv_nsec; | |
1e75fa8b | 1237 | |
e1d7ba87 WY |
1238 | if (timespec64_compare(&tk->wall_to_monotonic, &ts_delta) > 0) { |
1239 | ret = -EINVAL; | |
1240 | goto out; | |
1241 | } | |
1242 | ||
7d489d15 | 1243 | tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts_delta)); |
8524070b | 1244 | |
21f7eca5 | 1245 | tk_set_xtime(tk, ts); |
e1d7ba87 | 1246 | out: |
780427f0 | 1247 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
8524070b | 1248 | |
3fdb14fd | 1249 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1250 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b | 1251 | |
1252 | /* signal hrtimers about time change */ | |
1253 | clock_was_set(); | |
1254 | ||
2d87a067 OM |
1255 | if (!ret) |
1256 | audit_tk_injoffset(ts_delta); | |
1257 | ||
e1d7ba87 | 1258 | return ret; |
8524070b | 1259 | } |
21f7eca5 | 1260 | EXPORT_SYMBOL(do_settimeofday64); |
8524070b | 1261 | |
c528f7c6 JS |
1262 | /** |
1263 | * timekeeping_inject_offset - Adds or subtracts from the current time. | |
1264 | * @tv: pointer to the timespec variable containing the offset | |
1265 | * | |
1266 | * Adds or subtracts an offset value from the current time. | |
1267 | */ | |
985e6950 | 1268 | static int timekeeping_inject_offset(const struct timespec64 *ts) |
c528f7c6 | 1269 | { |
3fdb14fd | 1270 | struct timekeeper *tk = &tk_core.timekeeper; |
92c1d3ed | 1271 | unsigned long flags; |
1572fa03 | 1272 | struct timespec64 tmp; |
4e8b1452 | 1273 | int ret = 0; |
c528f7c6 | 1274 | |
1572fa03 | 1275 | if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC) |
c528f7c6 JS |
1276 | return -EINVAL; |
1277 | ||
9a7a71b1 | 1278 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1279 | write_seqcount_begin(&tk_core.seq); |
c528f7c6 | 1280 | |
4e250fdd | 1281 | timekeeping_forward_now(tk); |
c528f7c6 | 1282 | |
4e8b1452 | 1283 | /* Make sure the proposed value is valid */ |
1572fa03 AB |
1284 | tmp = timespec64_add(tk_xtime(tk), *ts); |
1285 | if (timespec64_compare(&tk->wall_to_monotonic, ts) > 0 || | |
7a8e61f8 | 1286 | !timespec64_valid_settod(&tmp)) { |
4e8b1452 JS |
1287 | ret = -EINVAL; |
1288 | goto error; | |
1289 | } | |
1e75fa8b | 1290 | |
1572fa03 AB |
1291 | tk_xtime_add(tk, ts); |
1292 | tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *ts)); | |
c528f7c6 | 1293 | |
4e8b1452 | 1294 | error: /* even if we error out, we forwarded the time, so call update */ |
780427f0 | 1295 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
c528f7c6 | 1296 | |
3fdb14fd | 1297 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1298 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
c528f7c6 JS |
1299 | |
1300 | /* signal hrtimers about time change */ | |
1301 | clock_was_set(); | |
1302 | ||
4e8b1452 | 1303 | return ret; |
c528f7c6 | 1304 | } |
e0956dcc AB |
1305 | |
1306 | /* | |
1307 | * Indicates if there is an offset between the system clock and the hardware | |
1308 | * clock/persistent clock/rtc. | |
1309 | */ | |
1310 | int persistent_clock_is_local; | |
1311 | ||
1312 | /* | |
1313 | * Adjust the time obtained from the CMOS to be UTC time instead of | |
1314 | * local time. | |
1315 | * | |
1316 | * This is ugly, but preferable to the alternatives. Otherwise we | |
1317 | * would either need to write a program to do it in /etc/rc (and risk | |
1318 | * confusion if the program gets run more than once; it would also be | |
1319 | * hard to make the program warp the clock precisely n hours) or | |
1320 | * compile in the timezone information into the kernel. Bad, bad.... | |
1321 | * | |
1322 | * - TYT, 1992-01-01 | |
1323 | * | |
1324 | * The best thing to do is to keep the CMOS clock in universal time (UTC) | |
1325 | * as real UNIX machines always do it. This avoids all headaches about | |
1326 | * daylight saving times and warping kernel clocks. | |
1327 | */ | |
1328 | void timekeeping_warp_clock(void) | |
1329 | { | |
1330 | if (sys_tz.tz_minuteswest != 0) { | |
1572fa03 | 1331 | struct timespec64 adjust; |
e0956dcc AB |
1332 | |
1333 | persistent_clock_is_local = 1; | |
1334 | adjust.tv_sec = sys_tz.tz_minuteswest * 60; | |
1335 | adjust.tv_nsec = 0; | |
1336 | timekeeping_inject_offset(&adjust); | |
1337 | } | |
1338 | } | |
c528f7c6 | 1339 | |
cc244dda | 1340 | /** |
40d9f827 | 1341 | * __timekeeping_set_tai_offset - Sets the TAI offset from UTC and monotonic |
cc244dda JS |
1342 | * |
1343 | */ | |
dd5d70e8 | 1344 | static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset) |
cc244dda JS |
1345 | { |
1346 | tk->tai_offset = tai_offset; | |
04005f60 | 1347 | tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tai_offset, 0)); |
cc244dda JS |
1348 | } |
1349 | ||
8524070b | 1350 | /** |
1351 | * change_clocksource - Swaps clocksources if a new one is available | |
1352 | * | |
1353 | * Accumulates current time interval and initializes new clocksource | |
1354 | */ | |
75c5158f | 1355 | static int change_clocksource(void *data) |
8524070b | 1356 | { |
3fdb14fd | 1357 | struct timekeeper *tk = &tk_core.timekeeper; |
4614e6ad | 1358 | struct clocksource *new, *old; |
f695cf94 | 1359 | unsigned long flags; |
8524070b | 1360 | |
75c5158f | 1361 | new = (struct clocksource *) data; |
8524070b | 1362 | |
9a7a71b1 | 1363 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1364 | write_seqcount_begin(&tk_core.seq); |
f695cf94 | 1365 | |
4e250fdd | 1366 | timekeeping_forward_now(tk); |
09ac369c TG |
1367 | /* |
1368 | * If the cs is in module, get a module reference. Succeeds | |
1369 | * for built-in code (owner == NULL) as well. | |
1370 | */ | |
1371 | if (try_module_get(new->owner)) { | |
1372 | if (!new->enable || new->enable(new) == 0) { | |
876e7881 | 1373 | old = tk->tkr_mono.clock; |
09ac369c TG |
1374 | tk_setup_internals(tk, new); |
1375 | if (old->disable) | |
1376 | old->disable(old); | |
1377 | module_put(old->owner); | |
1378 | } else { | |
1379 | module_put(new->owner); | |
1380 | } | |
75c5158f | 1381 | } |
780427f0 | 1382 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
f695cf94 | 1383 | |
3fdb14fd | 1384 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1385 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
f695cf94 | 1386 | |
75c5158f MS |
1387 | return 0; |
1388 | } | |
8524070b | 1389 | |
75c5158f MS |
1390 | /** |
1391 | * timekeeping_notify - Install a new clock source | |
1392 | * @clock: pointer to the clock source | |
1393 | * | |
1394 | * This function is called from clocksource.c after a new, better clock | |
1395 | * source has been registered. The caller holds the clocksource_mutex. | |
1396 | */ | |
ba919d1c | 1397 | int timekeeping_notify(struct clocksource *clock) |
75c5158f | 1398 | { |
3fdb14fd | 1399 | struct timekeeper *tk = &tk_core.timekeeper; |
4e250fdd | 1400 | |
876e7881 | 1401 | if (tk->tkr_mono.clock == clock) |
ba919d1c | 1402 | return 0; |
75c5158f | 1403 | stop_machine(change_clocksource, clock, NULL); |
8524070b | 1404 | tick_clock_notify(); |
876e7881 | 1405 | return tk->tkr_mono.clock == clock ? 0 : -1; |
8524070b | 1406 | } |
75c5158f | 1407 | |
2d42244a | 1408 | /** |
fb7fcc96 | 1409 | * ktime_get_raw_ts64 - Returns the raw monotonic time in a timespec |
cdba2ec5 | 1410 | * @ts: pointer to the timespec64 to be set |
2d42244a JS |
1411 | * |
1412 | * Returns the raw monotonic time (completely un-modified by ntp) | |
1413 | */ | |
fb7fcc96 | 1414 | void ktime_get_raw_ts64(struct timespec64 *ts) |
2d42244a | 1415 | { |
3fdb14fd | 1416 | struct timekeeper *tk = &tk_core.timekeeper; |
e1e41b6c | 1417 | unsigned int seq; |
acc89612 | 1418 | u64 nsecs; |
2d42244a JS |
1419 | |
1420 | do { | |
3fdb14fd | 1421 | seq = read_seqcount_begin(&tk_core.seq); |
fc6eead7 | 1422 | ts->tv_sec = tk->raw_sec; |
4a4ad80d | 1423 | nsecs = timekeeping_get_ns(&tk->tkr_raw); |
2d42244a | 1424 | |
3fdb14fd | 1425 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
2d42244a | 1426 | |
fc6eead7 JS |
1427 | ts->tv_nsec = 0; |
1428 | timespec64_add_ns(ts, nsecs); | |
2d42244a | 1429 | } |
fb7fcc96 | 1430 | EXPORT_SYMBOL(ktime_get_raw_ts64); |
cdba2ec5 | 1431 | |
2d42244a | 1432 | |
8524070b | 1433 | /** |
cf4fc6cb | 1434 | * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres |
8524070b | 1435 | */ |
cf4fc6cb | 1436 | int timekeeping_valid_for_hres(void) |
8524070b | 1437 | { |
3fdb14fd | 1438 | struct timekeeper *tk = &tk_core.timekeeper; |
e1e41b6c | 1439 | unsigned int seq; |
8524070b | 1440 | int ret; |
1441 | ||
1442 | do { | |
3fdb14fd | 1443 | seq = read_seqcount_begin(&tk_core.seq); |
8524070b | 1444 | |
876e7881 | 1445 | ret = tk->tkr_mono.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; |
8524070b | 1446 | |
3fdb14fd | 1447 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
8524070b | 1448 | |
1449 | return ret; | |
1450 | } | |
1451 | ||
98962465 JH |
1452 | /** |
1453 | * timekeeping_max_deferment - Returns max time the clocksource can be deferred | |
98962465 JH |
1454 | */ |
1455 | u64 timekeeping_max_deferment(void) | |
1456 | { | |
3fdb14fd | 1457 | struct timekeeper *tk = &tk_core.timekeeper; |
e1e41b6c | 1458 | unsigned int seq; |
70471f2f | 1459 | u64 ret; |
42e71e81 | 1460 | |
70471f2f | 1461 | do { |
3fdb14fd | 1462 | seq = read_seqcount_begin(&tk_core.seq); |
70471f2f | 1463 | |
876e7881 | 1464 | ret = tk->tkr_mono.clock->max_idle_ns; |
70471f2f | 1465 | |
3fdb14fd | 1466 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
70471f2f JS |
1467 | |
1468 | return ret; | |
98962465 JH |
1469 | } |
1470 | ||
8524070b | 1471 | /** |
92661788 | 1472 | * read_persistent_clock64 - Return time from the persistent clock. |
8524070b | 1473 | * |
1474 | * Weak dummy function for arches that do not yet support it. | |
d4f587c6 MS |
1475 | * Reads the time from the battery backed persistent clock. |
1476 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. | |
8524070b | 1477 | * |
1478 | * XXX - Do be sure to remove it once all arches implement it. | |
1479 | */ | |
92661788 | 1480 | void __weak read_persistent_clock64(struct timespec64 *ts) |
8524070b | 1481 | { |
d4f587c6 MS |
1482 | ts->tv_sec = 0; |
1483 | ts->tv_nsec = 0; | |
8524070b | 1484 | } |
1485 | ||
23970e38 | 1486 | /** |
3eca9937 PT |
1487 | * read_persistent_wall_and_boot_offset - Read persistent clock, and also offset |
1488 | * from the boot. | |
23970e38 MS |
1489 | * |
1490 | * Weak dummy function for arches that do not yet support it. | |
3eca9937 PT |
1491 | * wall_time - current time as returned by persistent clock |
1492 | * boot_offset - offset that is defined as wall_time - boot_time | |
4b1b7f80 PT |
1493 | * The default function calculates offset based on the current value of |
1494 | * local_clock(). This way architectures that support sched_clock() but don't | |
1495 | * support dedicated boot time clock will provide the best estimate of the | |
1496 | * boot time. | |
23970e38 | 1497 | */ |
3eca9937 PT |
1498 | void __weak __init |
1499 | read_persistent_wall_and_boot_offset(struct timespec64 *wall_time, | |
1500 | struct timespec64 *boot_offset) | |
23970e38 | 1501 | { |
3eca9937 | 1502 | read_persistent_clock64(wall_time); |
4b1b7f80 | 1503 | *boot_offset = ns_to_timespec64(local_clock()); |
23970e38 MS |
1504 | } |
1505 | ||
f473e5f4 MO |
1506 | /* |
1507 | * Flag reflecting whether timekeeping_resume() has injected sleeptime. | |
1508 | * | |
1509 | * The flag starts of false and is only set when a suspend reaches | |
1510 | * timekeeping_suspend(), timekeeping_resume() sets it to false when the | |
1511 | * timekeeper clocksource is not stopping across suspend and has been | |
1512 | * used to update sleep time. If the timekeeper clocksource has stopped | |
1513 | * then the flag stays true and is used by the RTC resume code to decide | |
1514 | * whether sleeptime must be injected and if so the flag gets false then. | |
1515 | * | |
1516 | * If a suspend fails before reaching timekeeping_resume() then the flag | |
1517 | * stays false and prevents erroneous sleeptime injection. | |
1518 | */ | |
1519 | static bool suspend_timing_needed; | |
0fa88cb4 XP |
1520 | |
1521 | /* Flag for if there is a persistent clock on this platform */ | |
1522 | static bool persistent_clock_exists; | |
1523 | ||
8524070b | 1524 | /* |
1525 | * timekeeping_init - Initializes the clocksource and common timekeeping values | |
1526 | */ | |
1527 | void __init timekeeping_init(void) | |
1528 | { | |
3eca9937 | 1529 | struct timespec64 wall_time, boot_offset, wall_to_mono; |
3fdb14fd | 1530 | struct timekeeper *tk = &tk_core.timekeeper; |
155ec602 | 1531 | struct clocksource *clock; |
8524070b | 1532 | unsigned long flags; |
4e8b1452 | 1533 | |
3eca9937 | 1534 | read_persistent_wall_and_boot_offset(&wall_time, &boot_offset); |
7a8e61f8 | 1535 | if (timespec64_valid_settod(&wall_time) && |
3eca9937 PT |
1536 | timespec64_to_ns(&wall_time) > 0) { |
1537 | persistent_clock_exists = true; | |
684ad537 | 1538 | } else if (timespec64_to_ns(&wall_time) != 0) { |
3eca9937 PT |
1539 | pr_warn("Persistent clock returned invalid value"); |
1540 | wall_time = (struct timespec64){0}; | |
4e8b1452 | 1541 | } |
8524070b | 1542 | |
3eca9937 PT |
1543 | if (timespec64_compare(&wall_time, &boot_offset) < 0) |
1544 | boot_offset = (struct timespec64){0}; | |
1545 | ||
1546 | /* | |
1547 | * We want set wall_to_mono, so the following is true: | |
1548 | * wall time + wall_to_mono = boot time | |
1549 | */ | |
1550 | wall_to_mono = timespec64_sub(boot_offset, wall_time); | |
1551 | ||
9a7a71b1 | 1552 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1553 | write_seqcount_begin(&tk_core.seq); |
06c017fd JS |
1554 | ntp_init(); |
1555 | ||
f1b82746 | 1556 | clock = clocksource_default_clock(); |
a0f7d48b MS |
1557 | if (clock->enable) |
1558 | clock->enable(clock); | |
4e250fdd | 1559 | tk_setup_internals(tk, clock); |
8524070b | 1560 | |
3eca9937 | 1561 | tk_set_xtime(tk, &wall_time); |
fc6eead7 | 1562 | tk->raw_sec = 0; |
1e75fa8b | 1563 | |
3eca9937 | 1564 | tk_set_wall_to_mono(tk, wall_to_mono); |
6d0ef903 | 1565 | |
56fd16ca | 1566 | timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |
48cdc135 | 1567 | |
3fdb14fd | 1568 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1569 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b | 1570 | } |
1571 | ||
264bb3f7 | 1572 | /* time in seconds when suspend began for persistent clock */ |
7d489d15 | 1573 | static struct timespec64 timekeeping_suspend_time; |
8524070b | 1574 | |
304529b1 JS |
1575 | /** |
1576 | * __timekeeping_inject_sleeptime - Internal function to add sleep interval | |
1577 | * @delta: pointer to a timespec delta value | |
1578 | * | |
1579 | * Takes a timespec offset measuring a suspend interval and properly | |
1580 | * adds the sleep offset to the timekeeping variables. | |
1581 | */ | |
f726a697 | 1582 | static void __timekeeping_inject_sleeptime(struct timekeeper *tk, |
985e6950 | 1583 | const struct timespec64 *delta) |
304529b1 | 1584 | { |
7d489d15 | 1585 | if (!timespec64_valid_strict(delta)) { |
6d9bcb62 JS |
1586 | printk_deferred(KERN_WARNING |
1587 | "__timekeeping_inject_sleeptime: Invalid " | |
1588 | "sleep delta value!\n"); | |
cb5de2f8 JS |
1589 | return; |
1590 | } | |
f726a697 | 1591 | tk_xtime_add(tk, delta); |
a3ed0e43 | 1592 | tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *delta)); |
47da70d3 | 1593 | tk_update_sleep_time(tk, timespec64_to_ktime(*delta)); |
5c83545f | 1594 | tk_debug_account_sleep_time(delta); |
304529b1 JS |
1595 | } |
1596 | ||
7f298139 | 1597 | #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_RTC_HCTOSYS_DEVICE) |
0fa88cb4 XP |
1598 | /** |
1599 | * We have three kinds of time sources to use for sleep time | |
1600 | * injection, the preference order is: | |
1601 | * 1) non-stop clocksource | |
1602 | * 2) persistent clock (ie: RTC accessible when irqs are off) | |
1603 | * 3) RTC | |
1604 | * | |
1605 | * 1) and 2) are used by timekeeping, 3) by RTC subsystem. | |
1606 | * If system has neither 1) nor 2), 3) will be used finally. | |
1607 | * | |
1608 | * | |
1609 | * If timekeeping has injected sleeptime via either 1) or 2), | |
1610 | * 3) becomes needless, so in this case we don't need to call | |
1611 | * rtc_resume(), and this is what timekeeping_rtc_skipresume() | |
1612 | * means. | |
1613 | */ | |
1614 | bool timekeeping_rtc_skipresume(void) | |
1615 | { | |
f473e5f4 | 1616 | return !suspend_timing_needed; |
0fa88cb4 XP |
1617 | } |
1618 | ||
1619 | /** | |
1620 | * 1) can be determined whether to use or not only when doing | |
1621 | * timekeeping_resume() which is invoked after rtc_suspend(), | |
1622 | * so we can't skip rtc_suspend() surely if system has 1). | |
1623 | * | |
1624 | * But if system has 2), 2) will definitely be used, so in this | |
1625 | * case we don't need to call rtc_suspend(), and this is what | |
1626 | * timekeeping_rtc_skipsuspend() means. | |
1627 | */ | |
1628 | bool timekeeping_rtc_skipsuspend(void) | |
1629 | { | |
1630 | return persistent_clock_exists; | |
1631 | } | |
1632 | ||
304529b1 | 1633 | /** |
04d90890 | 1634 | * timekeeping_inject_sleeptime64 - Adds suspend interval to timeekeeping values |
1635 | * @delta: pointer to a timespec64 delta value | |
304529b1 | 1636 | * |
2ee96632 | 1637 | * This hook is for architectures that cannot support read_persistent_clock64 |
304529b1 | 1638 | * because their RTC/persistent clock is only accessible when irqs are enabled. |
0fa88cb4 | 1639 | * and also don't have an effective nonstop clocksource. |
304529b1 JS |
1640 | * |
1641 | * This function should only be called by rtc_resume(), and allows | |
1642 | * a suspend offset to be injected into the timekeeping values. | |
1643 | */ | |
985e6950 | 1644 | void timekeeping_inject_sleeptime64(const struct timespec64 *delta) |
304529b1 | 1645 | { |
3fdb14fd | 1646 | struct timekeeper *tk = &tk_core.timekeeper; |
92c1d3ed | 1647 | unsigned long flags; |
304529b1 | 1648 | |
9a7a71b1 | 1649 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1650 | write_seqcount_begin(&tk_core.seq); |
70471f2f | 1651 | |
f473e5f4 MO |
1652 | suspend_timing_needed = false; |
1653 | ||
4e250fdd | 1654 | timekeeping_forward_now(tk); |
304529b1 | 1655 | |
04d90890 | 1656 | __timekeeping_inject_sleeptime(tk, delta); |
304529b1 | 1657 | |
780427f0 | 1658 | timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); |
304529b1 | 1659 | |
3fdb14fd | 1660 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1661 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
304529b1 JS |
1662 | |
1663 | /* signal hrtimers about time change */ | |
1664 | clock_was_set(); | |
1665 | } | |
7f298139 | 1666 | #endif |
304529b1 | 1667 | |
8524070b | 1668 | /** |
1669 | * timekeeping_resume - Resumes the generic timekeeping subsystem. | |
8524070b | 1670 | */ |
124cf911 | 1671 | void timekeeping_resume(void) |
8524070b | 1672 | { |
3fdb14fd | 1673 | struct timekeeper *tk = &tk_core.timekeeper; |
876e7881 | 1674 | struct clocksource *clock = tk->tkr_mono.clock; |
92c1d3ed | 1675 | unsigned long flags; |
7d489d15 | 1676 | struct timespec64 ts_new, ts_delta; |
39232ed5 | 1677 | u64 cycle_now, nsec; |
f473e5f4 | 1678 | bool inject_sleeptime = false; |
d4f587c6 | 1679 | |
2ee96632 | 1680 | read_persistent_clock64(&ts_new); |
8524070b | 1681 | |
adc78e6b | 1682 | clockevents_resume(); |
d10ff3fb TG |
1683 | clocksource_resume(); |
1684 | ||
9a7a71b1 | 1685 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1686 | write_seqcount_begin(&tk_core.seq); |
8524070b | 1687 | |
e445cf1c FT |
1688 | /* |
1689 | * After system resumes, we need to calculate the suspended time and | |
1690 | * compensate it for the OS time. There are 3 sources that could be | |
1691 | * used: Nonstop clocksource during suspend, persistent clock and rtc | |
1692 | * device. | |
1693 | * | |
1694 | * One specific platform may have 1 or 2 or all of them, and the | |
1695 | * preference will be: | |
1696 | * suspend-nonstop clocksource -> persistent clock -> rtc | |
1697 | * The less preferred source will only be tried if there is no better | |
1698 | * usable source. The rtc part is handled separately in rtc core code. | |
1699 | */ | |
ceea5e37 | 1700 | cycle_now = tk_clock_read(&tk->tkr_mono); |
39232ed5 BW |
1701 | nsec = clocksource_stop_suspend_timing(clock, cycle_now); |
1702 | if (nsec > 0) { | |
7d489d15 | 1703 | ts_delta = ns_to_timespec64(nsec); |
f473e5f4 | 1704 | inject_sleeptime = true; |
7d489d15 JS |
1705 | } else if (timespec64_compare(&ts_new, &timekeeping_suspend_time) > 0) { |
1706 | ts_delta = timespec64_sub(ts_new, timekeeping_suspend_time); | |
f473e5f4 | 1707 | inject_sleeptime = true; |
8524070b | 1708 | } |
e445cf1c | 1709 | |
f473e5f4 MO |
1710 | if (inject_sleeptime) { |
1711 | suspend_timing_needed = false; | |
e445cf1c | 1712 | __timekeeping_inject_sleeptime(tk, &ts_delta); |
f473e5f4 | 1713 | } |
e445cf1c FT |
1714 | |
1715 | /* Re-base the last cycle value */ | |
876e7881 | 1716 | tk->tkr_mono.cycle_last = cycle_now; |
4a4ad80d PZ |
1717 | tk->tkr_raw.cycle_last = cycle_now; |
1718 | ||
4e250fdd | 1719 | tk->ntp_error = 0; |
8524070b | 1720 | timekeeping_suspended = 0; |
780427f0 | 1721 | timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |
3fdb14fd | 1722 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1723 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b | 1724 | |
1725 | touch_softlockup_watchdog(); | |
1726 | ||
4ffee521 | 1727 | tick_resume(); |
b12a03ce | 1728 | hrtimers_resume(); |
8524070b | 1729 | } |
1730 | ||
124cf911 | 1731 | int timekeeping_suspend(void) |
8524070b | 1732 | { |
3fdb14fd | 1733 | struct timekeeper *tk = &tk_core.timekeeper; |
92c1d3ed | 1734 | unsigned long flags; |
7d489d15 JS |
1735 | struct timespec64 delta, delta_delta; |
1736 | static struct timespec64 old_delta; | |
39232ed5 BW |
1737 | struct clocksource *curr_clock; |
1738 | u64 cycle_now; | |
8524070b | 1739 | |
2ee96632 | 1740 | read_persistent_clock64(&timekeeping_suspend_time); |
3be90950 | 1741 | |
0d6bd995 ZM |
1742 | /* |
1743 | * On some systems the persistent_clock can not be detected at | |
1744 | * timekeeping_init by its return value, so if we see a valid | |
1745 | * value returned, update the persistent_clock_exists flag. | |
1746 | */ | |
1747 | if (timekeeping_suspend_time.tv_sec || timekeeping_suspend_time.tv_nsec) | |
0fa88cb4 | 1748 | persistent_clock_exists = true; |
0d6bd995 | 1749 | |
f473e5f4 MO |
1750 | suspend_timing_needed = true; |
1751 | ||
9a7a71b1 | 1752 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 1753 | write_seqcount_begin(&tk_core.seq); |
4e250fdd | 1754 | timekeeping_forward_now(tk); |
8524070b | 1755 | timekeeping_suspended = 1; |
cb33217b | 1756 | |
39232ed5 BW |
1757 | /* |
1758 | * Since we've called forward_now, cycle_last stores the value | |
1759 | * just read from the current clocksource. Save this to potentially | |
1760 | * use in suspend timing. | |
1761 | */ | |
1762 | curr_clock = tk->tkr_mono.clock; | |
1763 | cycle_now = tk->tkr_mono.cycle_last; | |
1764 | clocksource_start_suspend_timing(curr_clock, cycle_now); | |
1765 | ||
0fa88cb4 | 1766 | if (persistent_clock_exists) { |
cb33217b | 1767 | /* |
264bb3f7 XP |
1768 | * To avoid drift caused by repeated suspend/resumes, |
1769 | * which each can add ~1 second drift error, | |
1770 | * try to compensate so the difference in system time | |
1771 | * and persistent_clock time stays close to constant. | |
cb33217b | 1772 | */ |
264bb3f7 XP |
1773 | delta = timespec64_sub(tk_xtime(tk), timekeeping_suspend_time); |
1774 | delta_delta = timespec64_sub(delta, old_delta); | |
1775 | if (abs(delta_delta.tv_sec) >= 2) { | |
1776 | /* | |
1777 | * if delta_delta is too large, assume time correction | |
1778 | * has occurred and set old_delta to the current delta. | |
1779 | */ | |
1780 | old_delta = delta; | |
1781 | } else { | |
1782 | /* Otherwise try to adjust old_system to compensate */ | |
1783 | timekeeping_suspend_time = | |
1784 | timespec64_add(timekeeping_suspend_time, delta_delta); | |
1785 | } | |
cb33217b | 1786 | } |
330a1617 JS |
1787 | |
1788 | timekeeping_update(tk, TK_MIRROR); | |
060407ae | 1789 | halt_fast_timekeeper(tk); |
3fdb14fd | 1790 | write_seqcount_end(&tk_core.seq); |
9a7a71b1 | 1791 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
8524070b | 1792 | |
4ffee521 | 1793 | tick_suspend(); |
c54a42b1 | 1794 | clocksource_suspend(); |
adc78e6b | 1795 | clockevents_suspend(); |
8524070b | 1796 | |
1797 | return 0; | |
1798 | } | |
1799 | ||
1800 | /* sysfs resume/suspend bits for timekeeping */ | |
e1a85b2c | 1801 | static struct syscore_ops timekeeping_syscore_ops = { |
8524070b | 1802 | .resume = timekeeping_resume, |
1803 | .suspend = timekeeping_suspend, | |
8524070b | 1804 | }; |
1805 | ||
e1a85b2c | 1806 | static int __init timekeeping_init_ops(void) |
8524070b | 1807 | { |
e1a85b2c RW |
1808 | register_syscore_ops(&timekeeping_syscore_ops); |
1809 | return 0; | |
8524070b | 1810 | } |
e1a85b2c | 1811 | device_initcall(timekeeping_init_ops); |
8524070b | 1812 | |
1813 | /* | |
dc491596 | 1814 | * Apply a multiplier adjustment to the timekeeper |
8524070b | 1815 | */ |
dc491596 JS |
1816 | static __always_inline void timekeeping_apply_adjustment(struct timekeeper *tk, |
1817 | s64 offset, | |
78b98e3c | 1818 | s32 mult_adj) |
8524070b | 1819 | { |
dc491596 | 1820 | s64 interval = tk->cycle_interval; |
8524070b | 1821 | |
78b98e3c ML |
1822 | if (mult_adj == 0) { |
1823 | return; | |
1824 | } else if (mult_adj == -1) { | |
dc491596 | 1825 | interval = -interval; |
78b98e3c ML |
1826 | offset = -offset; |
1827 | } else if (mult_adj != 1) { | |
1828 | interval *= mult_adj; | |
1829 | offset *= mult_adj; | |
1d17d174 | 1830 | } |
8524070b | 1831 | |
c2bc1111 JS |
1832 | /* |
1833 | * So the following can be confusing. | |
1834 | * | |
dc491596 | 1835 | * To keep things simple, lets assume mult_adj == 1 for now. |
c2bc1111 | 1836 | * |
dc491596 | 1837 | * When mult_adj != 1, remember that the interval and offset values |
c2bc1111 JS |
1838 | * have been appropriately scaled so the math is the same. |
1839 | * | |
1840 | * The basic idea here is that we're increasing the multiplier | |
1841 | * by one, this causes the xtime_interval to be incremented by | |
1842 | * one cycle_interval. This is because: | |
1843 | * xtime_interval = cycle_interval * mult | |
1844 | * So if mult is being incremented by one: | |
1845 | * xtime_interval = cycle_interval * (mult + 1) | |
1846 | * Its the same as: | |
1847 | * xtime_interval = (cycle_interval * mult) + cycle_interval | |
1848 | * Which can be shortened to: | |
1849 | * xtime_interval += cycle_interval | |
1850 | * | |
1851 | * So offset stores the non-accumulated cycles. Thus the current | |
1852 | * time (in shifted nanoseconds) is: | |
1853 | * now = (offset * adj) + xtime_nsec | |
1854 | * Now, even though we're adjusting the clock frequency, we have | |
1855 | * to keep time consistent. In other words, we can't jump back | |
1856 | * in time, and we also want to avoid jumping forward in time. | |
1857 | * | |
1858 | * So given the same offset value, we need the time to be the same | |
1859 | * both before and after the freq adjustment. | |
1860 | * now = (offset * adj_1) + xtime_nsec_1 | |
1861 | * now = (offset * adj_2) + xtime_nsec_2 | |
1862 | * So: | |
1863 | * (offset * adj_1) + xtime_nsec_1 = | |
1864 | * (offset * adj_2) + xtime_nsec_2 | |
1865 | * And we know: | |
1866 | * adj_2 = adj_1 + 1 | |
1867 | * So: | |
1868 | * (offset * adj_1) + xtime_nsec_1 = | |
1869 | * (offset * (adj_1+1)) + xtime_nsec_2 | |
1870 | * (offset * adj_1) + xtime_nsec_1 = | |
1871 | * (offset * adj_1) + offset + xtime_nsec_2 | |
1872 | * Canceling the sides: | |
1873 | * xtime_nsec_1 = offset + xtime_nsec_2 | |
1874 | * Which gives us: | |
1875 | * xtime_nsec_2 = xtime_nsec_1 - offset | |
1876 | * Which simplfies to: | |
1877 | * xtime_nsec -= offset | |
c2bc1111 | 1878 | */ |
876e7881 | 1879 | if ((mult_adj > 0) && (tk->tkr_mono.mult + mult_adj < mult_adj)) { |
6067dc5a | 1880 | /* NTP adjustment caused clocksource mult overflow */ |
1881 | WARN_ON_ONCE(1); | |
1882 | return; | |
1883 | } | |
1884 | ||
876e7881 | 1885 | tk->tkr_mono.mult += mult_adj; |
f726a697 | 1886 | tk->xtime_interval += interval; |
876e7881 | 1887 | tk->tkr_mono.xtime_nsec -= offset; |
dc491596 JS |
1888 | } |
1889 | ||
1890 | /* | |
78b98e3c ML |
1891 | * Adjust the timekeeper's multiplier to the correct frequency |
1892 | * and also to reduce the accumulated error value. | |
dc491596 | 1893 | */ |
78b98e3c | 1894 | static void timekeeping_adjust(struct timekeeper *tk, s64 offset) |
dc491596 | 1895 | { |
78b98e3c | 1896 | u32 mult; |
dc491596 | 1897 | |
ec02b076 | 1898 | /* |
78b98e3c ML |
1899 | * Determine the multiplier from the current NTP tick length. |
1900 | * Avoid expensive division when the tick length doesn't change. | |
ec02b076 | 1901 | */ |
78b98e3c ML |
1902 | if (likely(tk->ntp_tick == ntp_tick_length())) { |
1903 | mult = tk->tkr_mono.mult - tk->ntp_err_mult; | |
1904 | } else { | |
1905 | tk->ntp_tick = ntp_tick_length(); | |
1906 | mult = div64_u64((tk->ntp_tick >> tk->ntp_error_shift) - | |
1907 | tk->xtime_remainder, tk->cycle_interval); | |
ec02b076 | 1908 | } |
dc491596 | 1909 | |
78b98e3c ML |
1910 | /* |
1911 | * If the clock is behind the NTP time, increase the multiplier by 1 | |
1912 | * to catch up with it. If it's ahead and there was a remainder in the | |
1913 | * tick division, the clock will slow down. Otherwise it will stay | |
1914 | * ahead until the tick length changes to a non-divisible value. | |
1915 | */ | |
1916 | tk->ntp_err_mult = tk->ntp_error > 0 ? 1 : 0; | |
1917 | mult += tk->ntp_err_mult; | |
dc491596 | 1918 | |
78b98e3c | 1919 | timekeeping_apply_adjustment(tk, offset, mult - tk->tkr_mono.mult); |
dc491596 | 1920 | |
876e7881 PZ |
1921 | if (unlikely(tk->tkr_mono.clock->maxadj && |
1922 | (abs(tk->tkr_mono.mult - tk->tkr_mono.clock->mult) | |
1923 | > tk->tkr_mono.clock->maxadj))) { | |
dc491596 JS |
1924 | printk_once(KERN_WARNING |
1925 | "Adjusting %s more than 11%% (%ld vs %ld)\n", | |
876e7881 PZ |
1926 | tk->tkr_mono.clock->name, (long)tk->tkr_mono.mult, |
1927 | (long)tk->tkr_mono.clock->mult + tk->tkr_mono.clock->maxadj); | |
dc491596 | 1928 | } |
2a8c0883 JS |
1929 | |
1930 | /* | |
1931 | * It may be possible that when we entered this function, xtime_nsec | |
1932 | * was very small. Further, if we're slightly speeding the clocksource | |
1933 | * in the code above, its possible the required corrective factor to | |
1934 | * xtime_nsec could cause it to underflow. | |
1935 | * | |
78b98e3c ML |
1936 | * Now, since we have already accumulated the second and the NTP |
1937 | * subsystem has been notified via second_overflow(), we need to skip | |
1938 | * the next update. | |
2a8c0883 | 1939 | */ |
876e7881 | 1940 | if (unlikely((s64)tk->tkr_mono.xtime_nsec < 0)) { |
78b98e3c ML |
1941 | tk->tkr_mono.xtime_nsec += (u64)NSEC_PER_SEC << |
1942 | tk->tkr_mono.shift; | |
1943 | tk->xtime_sec--; | |
1944 | tk->skip_second_overflow = 1; | |
2a8c0883 | 1945 | } |
8524070b | 1946 | } |
1947 | ||
1f4f9487 JS |
1948 | /** |
1949 | * accumulate_nsecs_to_secs - Accumulates nsecs into secs | |
1950 | * | |
571af55a | 1951 | * Helper function that accumulates the nsecs greater than a second |
1f4f9487 JS |
1952 | * from the xtime_nsec field to the xtime_secs field. |
1953 | * It also calls into the NTP code to handle leapsecond processing. | |
1954 | * | |
1955 | */ | |
780427f0 | 1956 | static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk) |
1f4f9487 | 1957 | { |
876e7881 | 1958 | u64 nsecps = (u64)NSEC_PER_SEC << tk->tkr_mono.shift; |
5258d3f2 | 1959 | unsigned int clock_set = 0; |
1f4f9487 | 1960 | |
876e7881 | 1961 | while (tk->tkr_mono.xtime_nsec >= nsecps) { |
1f4f9487 JS |
1962 | int leap; |
1963 | ||
876e7881 | 1964 | tk->tkr_mono.xtime_nsec -= nsecps; |
1f4f9487 JS |
1965 | tk->xtime_sec++; |
1966 | ||
78b98e3c ML |
1967 | /* |
1968 | * Skip NTP update if this second was accumulated before, | |
1969 | * i.e. xtime_nsec underflowed in timekeeping_adjust() | |
1970 | */ | |
1971 | if (unlikely(tk->skip_second_overflow)) { | |
1972 | tk->skip_second_overflow = 0; | |
1973 | continue; | |
1974 | } | |
1975 | ||
1f4f9487 JS |
1976 | /* Figure out if its a leap sec and apply if needed */ |
1977 | leap = second_overflow(tk->xtime_sec); | |
6d0ef903 | 1978 | if (unlikely(leap)) { |
7d489d15 | 1979 | struct timespec64 ts; |
6d0ef903 JS |
1980 | |
1981 | tk->xtime_sec += leap; | |
1f4f9487 | 1982 | |
6d0ef903 JS |
1983 | ts.tv_sec = leap; |
1984 | ts.tv_nsec = 0; | |
1985 | tk_set_wall_to_mono(tk, | |
7d489d15 | 1986 | timespec64_sub(tk->wall_to_monotonic, ts)); |
6d0ef903 | 1987 | |
cc244dda JS |
1988 | __timekeeping_set_tai_offset(tk, tk->tai_offset - leap); |
1989 | ||
5258d3f2 | 1990 | clock_set = TK_CLOCK_WAS_SET; |
6d0ef903 | 1991 | } |
1f4f9487 | 1992 | } |
5258d3f2 | 1993 | return clock_set; |
1f4f9487 JS |
1994 | } |
1995 | ||
a092ff0f | 1996 | /** |
1997 | * logarithmic_accumulation - shifted accumulation of cycles | |
1998 | * | |
1999 | * This functions accumulates a shifted interval of cycles into | |
2000 | * into a shifted interval nanoseconds. Allows for O(log) accumulation | |
2001 | * loop. | |
2002 | * | |
2003 | * Returns the unconsumed cycles. | |
2004 | */ | |
a5a1d1c2 TG |
2005 | static u64 logarithmic_accumulation(struct timekeeper *tk, u64 offset, |
2006 | u32 shift, unsigned int *clock_set) | |
a092ff0f | 2007 | { |
a5a1d1c2 | 2008 | u64 interval = tk->cycle_interval << shift; |
3d88d56c | 2009 | u64 snsec_per_sec; |
a092ff0f | 2010 | |
571af55a | 2011 | /* If the offset is smaller than a shifted interval, do nothing */ |
23a9537a | 2012 | if (offset < interval) |
a092ff0f | 2013 | return offset; |
2014 | ||
2015 | /* Accumulate one shifted interval */ | |
23a9537a | 2016 | offset -= interval; |
876e7881 | 2017 | tk->tkr_mono.cycle_last += interval; |
4a4ad80d | 2018 | tk->tkr_raw.cycle_last += interval; |
a092ff0f | 2019 | |
876e7881 | 2020 | tk->tkr_mono.xtime_nsec += tk->xtime_interval << shift; |
5258d3f2 | 2021 | *clock_set |= accumulate_nsecs_to_secs(tk); |
a092ff0f | 2022 | |
deda2e81 | 2023 | /* Accumulate raw time */ |
3d88d56c JS |
2024 | tk->tkr_raw.xtime_nsec += tk->raw_interval << shift; |
2025 | snsec_per_sec = (u64)NSEC_PER_SEC << tk->tkr_raw.shift; | |
2026 | while (tk->tkr_raw.xtime_nsec >= snsec_per_sec) { | |
2027 | tk->tkr_raw.xtime_nsec -= snsec_per_sec; | |
fc6eead7 | 2028 | tk->raw_sec++; |
a092ff0f | 2029 | } |
2030 | ||
2031 | /* Accumulate error between NTP and clock interval */ | |
375f45b5 | 2032 | tk->ntp_error += tk->ntp_tick << shift; |
f726a697 JS |
2033 | tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) << |
2034 | (tk->ntp_error_shift + shift); | |
a092ff0f | 2035 | |
2036 | return offset; | |
2037 | } | |
2038 | ||
b061c7a5 ML |
2039 | /* |
2040 | * timekeeping_advance - Updates the timekeeper to the current time and | |
2041 | * current NTP tick length | |
8524070b | 2042 | */ |
b061c7a5 | 2043 | static void timekeeping_advance(enum timekeeping_adv_mode mode) |
8524070b | 2044 | { |
3fdb14fd | 2045 | struct timekeeper *real_tk = &tk_core.timekeeper; |
48cdc135 | 2046 | struct timekeeper *tk = &shadow_timekeeper; |
a5a1d1c2 | 2047 | u64 offset; |
a092ff0f | 2048 | int shift = 0, maxshift; |
5258d3f2 | 2049 | unsigned int clock_set = 0; |
70471f2f JS |
2050 | unsigned long flags; |
2051 | ||
9a7a71b1 | 2052 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
8524070b | 2053 | |
2054 | /* Make sure we're fully resumed: */ | |
2055 | if (unlikely(timekeeping_suspended)) | |
70471f2f | 2056 | goto out; |
8524070b | 2057 | |
592913ec | 2058 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET |
48cdc135 | 2059 | offset = real_tk->cycle_interval; |
b061c7a5 ML |
2060 | |
2061 | if (mode != TK_ADV_TICK) | |
2062 | goto out; | |
592913ec | 2063 | #else |
ceea5e37 | 2064 | offset = clocksource_delta(tk_clock_read(&tk->tkr_mono), |
876e7881 | 2065 | tk->tkr_mono.cycle_last, tk->tkr_mono.mask); |
8524070b | 2066 | |
bf2ac312 | 2067 | /* Check if there's really nothing to do */ |
b061c7a5 | 2068 | if (offset < real_tk->cycle_interval && mode == TK_ADV_TICK) |
bf2ac312 | 2069 | goto out; |
b061c7a5 | 2070 | #endif |
bf2ac312 | 2071 | |
3c17ad19 | 2072 | /* Do some additional sanity checking */ |
a529bea8 | 2073 | timekeeping_check_update(tk, offset); |
3c17ad19 | 2074 | |
a092ff0f | 2075 | /* |
2076 | * With NO_HZ we may have to accumulate many cycle_intervals | |
2077 | * (think "ticks") worth of time at once. To do this efficiently, | |
2078 | * we calculate the largest doubling multiple of cycle_intervals | |
88b28adf | 2079 | * that is smaller than the offset. We then accumulate that |
a092ff0f | 2080 | * chunk in one go, and then try to consume the next smaller |
2081 | * doubled multiple. | |
8524070b | 2082 | */ |
4e250fdd | 2083 | shift = ilog2(offset) - ilog2(tk->cycle_interval); |
a092ff0f | 2084 | shift = max(0, shift); |
88b28adf | 2085 | /* Bound shift to one less than what overflows tick_length */ |
ea7cf49a | 2086 | maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1; |
a092ff0f | 2087 | shift = min(shift, maxshift); |
4e250fdd | 2088 | while (offset >= tk->cycle_interval) { |
5258d3f2 JS |
2089 | offset = logarithmic_accumulation(tk, offset, shift, |
2090 | &clock_set); | |
4e250fdd | 2091 | if (offset < tk->cycle_interval<<shift) |
830ec045 | 2092 | shift--; |
8524070b | 2093 | } |
2094 | ||
78b98e3c | 2095 | /* Adjust the multiplier to correct NTP error */ |
4e250fdd | 2096 | timekeeping_adjust(tk, offset); |
8524070b | 2097 | |
6a867a39 JS |
2098 | /* |
2099 | * Finally, make sure that after the rounding | |
1e75fa8b | 2100 | * xtime_nsec isn't larger than NSEC_PER_SEC |
6a867a39 | 2101 | */ |
5258d3f2 | 2102 | clock_set |= accumulate_nsecs_to_secs(tk); |
83f57a11 | 2103 | |
3fdb14fd | 2104 | write_seqcount_begin(&tk_core.seq); |
48cdc135 TG |
2105 | /* |
2106 | * Update the real timekeeper. | |
2107 | * | |
2108 | * We could avoid this memcpy by switching pointers, but that | |
2109 | * requires changes to all other timekeeper usage sites as | |
2110 | * well, i.e. move the timekeeper pointer getter into the | |
2111 | * spinlocked/seqcount protected sections. And we trade this | |
3fdb14fd | 2112 | * memcpy under the tk_core.seq against one before we start |
48cdc135 TG |
2113 | * updating. |
2114 | */ | |
906c5557 | 2115 | timekeeping_update(tk, clock_set); |
48cdc135 | 2116 | memcpy(real_tk, tk, sizeof(*tk)); |
906c5557 | 2117 | /* The memcpy must come last. Do not put anything here! */ |
3fdb14fd | 2118 | write_seqcount_end(&tk_core.seq); |
ca4523cd | 2119 | out: |
9a7a71b1 | 2120 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
47a1b796 | 2121 | if (clock_set) |
cab5e127 JS |
2122 | /* Have to call _delayed version, since in irq context*/ |
2123 | clock_was_set_delayed(); | |
8524070b | 2124 | } |
7c3f1a57 | 2125 | |
b061c7a5 ML |
2126 | /** |
2127 | * update_wall_time - Uses the current clocksource to increment the wall time | |
2128 | * | |
2129 | */ | |
2130 | void update_wall_time(void) | |
2131 | { | |
2132 | timekeeping_advance(TK_ADV_TICK); | |
2133 | } | |
2134 | ||
7c3f1a57 | 2135 | /** |
d08c0cdd JS |
2136 | * getboottime64 - Return the real time of system boot. |
2137 | * @ts: pointer to the timespec64 to be set | |
7c3f1a57 | 2138 | * |
d08c0cdd | 2139 | * Returns the wall-time of boot in a timespec64. |
7c3f1a57 TJ |
2140 | * |
2141 | * This is based on the wall_to_monotonic offset and the total suspend | |
2142 | * time. Calls to settimeofday will affect the value returned (which | |
2143 | * basically means that however wrong your real time clock is at boot time, | |
2144 | * you get the right time here). | |
2145 | */ | |
d08c0cdd | 2146 | void getboottime64(struct timespec64 *ts) |
7c3f1a57 | 2147 | { |
3fdb14fd | 2148 | struct timekeeper *tk = &tk_core.timekeeper; |
a3ed0e43 | 2149 | ktime_t t = ktime_sub(tk->offs_real, tk->offs_boot); |
02cba159 | 2150 | |
d08c0cdd | 2151 | *ts = ktime_to_timespec64(t); |
7c3f1a57 | 2152 | } |
d08c0cdd | 2153 | EXPORT_SYMBOL_GPL(getboottime64); |
7c3f1a57 | 2154 | |
fb7fcc96 | 2155 | void ktime_get_coarse_real_ts64(struct timespec64 *ts) |
2c6b47de | 2156 | { |
3fdb14fd | 2157 | struct timekeeper *tk = &tk_core.timekeeper; |
e1e41b6c | 2158 | unsigned int seq; |
2c6b47de | 2159 | |
2160 | do { | |
3fdb14fd | 2161 | seq = read_seqcount_begin(&tk_core.seq); |
83f57a11 | 2162 | |
fb7fcc96 | 2163 | *ts = tk_xtime(tk); |
3fdb14fd | 2164 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
2c6b47de | 2165 | } |
fb7fcc96 | 2166 | EXPORT_SYMBOL(ktime_get_coarse_real_ts64); |
da15cfda | 2167 | |
fb7fcc96 | 2168 | void ktime_get_coarse_ts64(struct timespec64 *ts) |
da15cfda | 2169 | { |
3fdb14fd | 2170 | struct timekeeper *tk = &tk_core.timekeeper; |
7d489d15 | 2171 | struct timespec64 now, mono; |
e1e41b6c | 2172 | unsigned int seq; |
da15cfda | 2173 | |
2174 | do { | |
3fdb14fd | 2175 | seq = read_seqcount_begin(&tk_core.seq); |
83f57a11 | 2176 | |
4e250fdd JS |
2177 | now = tk_xtime(tk); |
2178 | mono = tk->wall_to_monotonic; | |
3fdb14fd | 2179 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
da15cfda | 2180 | |
fb7fcc96 | 2181 | set_normalized_timespec64(ts, now.tv_sec + mono.tv_sec, |
da15cfda | 2182 | now.tv_nsec + mono.tv_nsec); |
da15cfda | 2183 | } |
fb7fcc96 | 2184 | EXPORT_SYMBOL(ktime_get_coarse_ts64); |
871cf1e5 TH |
2185 | |
2186 | /* | |
d6ad4187 | 2187 | * Must hold jiffies_lock |
871cf1e5 TH |
2188 | */ |
2189 | void do_timer(unsigned long ticks) | |
2190 | { | |
2191 | jiffies_64 += ticks; | |
871cf1e5 TH |
2192 | calc_global_load(ticks); |
2193 | } | |
48cf76f7 | 2194 | |
f6c06abf | 2195 | /** |
76f41088 | 2196 | * ktime_get_update_offsets_now - hrtimer helper |
868a3e91 | 2197 | * @cwsseq: pointer to check and store the clock was set sequence number |
f6c06abf | 2198 | * @offs_real: pointer to storage for monotonic -> realtime offset |
a3ed0e43 | 2199 | * @offs_boot: pointer to storage for monotonic -> boottime offset |
b7bc50e4 | 2200 | * @offs_tai: pointer to storage for monotonic -> clock tai offset |
f6c06abf | 2201 | * |
868a3e91 TG |
2202 | * Returns current monotonic time and updates the offsets if the |
2203 | * sequence number in @cwsseq and timekeeper.clock_was_set_seq are | |
2204 | * different. | |
2205 | * | |
b7bc50e4 | 2206 | * Called from hrtimer_interrupt() or retrigger_next_event() |
f6c06abf | 2207 | */ |
868a3e91 | 2208 | ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real, |
a3ed0e43 | 2209 | ktime_t *offs_boot, ktime_t *offs_tai) |
f6c06abf | 2210 | { |
3fdb14fd | 2211 | struct timekeeper *tk = &tk_core.timekeeper; |
f6c06abf | 2212 | unsigned int seq; |
a37c0aad TG |
2213 | ktime_t base; |
2214 | u64 nsecs; | |
f6c06abf TG |
2215 | |
2216 | do { | |
3fdb14fd | 2217 | seq = read_seqcount_begin(&tk_core.seq); |
f6c06abf | 2218 | |
876e7881 PZ |
2219 | base = tk->tkr_mono.base; |
2220 | nsecs = timekeeping_get_ns(&tk->tkr_mono); | |
833f32d7 JS |
2221 | base = ktime_add_ns(base, nsecs); |
2222 | ||
868a3e91 TG |
2223 | if (*cwsseq != tk->clock_was_set_seq) { |
2224 | *cwsseq = tk->clock_was_set_seq; | |
2225 | *offs_real = tk->offs_real; | |
a3ed0e43 | 2226 | *offs_boot = tk->offs_boot; |
868a3e91 TG |
2227 | *offs_tai = tk->offs_tai; |
2228 | } | |
833f32d7 JS |
2229 | |
2230 | /* Handle leapsecond insertion adjustments */ | |
2456e855 | 2231 | if (unlikely(base >= tk->next_leap_ktime)) |
833f32d7 JS |
2232 | *offs_real = ktime_sub(tk->offs_real, ktime_set(1, 0)); |
2233 | ||
3fdb14fd | 2234 | } while (read_seqcount_retry(&tk_core.seq, seq)); |
f6c06abf | 2235 | |
833f32d7 | 2236 | return base; |
f6c06abf | 2237 | } |
f6c06abf | 2238 | |
e0956dcc | 2239 | /** |
1572fa03 | 2240 | * timekeeping_validate_timex - Ensures the timex is ok for use in do_adjtimex |
e0956dcc | 2241 | */ |
ead25417 | 2242 | static int timekeeping_validate_timex(const struct __kernel_timex *txc) |
e0956dcc AB |
2243 | { |
2244 | if (txc->modes & ADJ_ADJTIME) { | |
2245 | /* singleshot must not be used with any other mode bits */ | |
2246 | if (!(txc->modes & ADJ_OFFSET_SINGLESHOT)) | |
2247 | return -EINVAL; | |
2248 | if (!(txc->modes & ADJ_OFFSET_READONLY) && | |
2249 | !capable(CAP_SYS_TIME)) | |
2250 | return -EPERM; | |
2251 | } else { | |
2252 | /* In order to modify anything, you gotta be super-user! */ | |
2253 | if (txc->modes && !capable(CAP_SYS_TIME)) | |
2254 | return -EPERM; | |
2255 | /* | |
2256 | * if the quartz is off by more than 10% then | |
2257 | * something is VERY wrong! | |
2258 | */ | |
2259 | if (txc->modes & ADJ_TICK && | |
2260 | (txc->tick < 900000/USER_HZ || | |
2261 | txc->tick > 1100000/USER_HZ)) | |
2262 | return -EINVAL; | |
2263 | } | |
2264 | ||
2265 | if (txc->modes & ADJ_SETOFFSET) { | |
2266 | /* In order to inject time, you gotta be super-user! */ | |
2267 | if (!capable(CAP_SYS_TIME)) | |
2268 | return -EPERM; | |
2269 | ||
1572fa03 AB |
2270 | /* |
2271 | * Validate if a timespec/timeval used to inject a time | |
2272 | * offset is valid. Offsets can be postive or negative, so | |
2273 | * we don't check tv_sec. The value of the timeval/timespec | |
2274 | * is the sum of its fields,but *NOTE*: | |
2275 | * The field tv_usec/tv_nsec must always be non-negative and | |
2276 | * we can't have more nanoseconds/microseconds than a second. | |
2277 | */ | |
2278 | if (txc->time.tv_usec < 0) | |
2279 | return -EINVAL; | |
e0956dcc | 2280 | |
1572fa03 AB |
2281 | if (txc->modes & ADJ_NANO) { |
2282 | if (txc->time.tv_usec >= NSEC_PER_SEC) | |
e0956dcc | 2283 | return -EINVAL; |
e0956dcc | 2284 | } else { |
1572fa03 | 2285 | if (txc->time.tv_usec >= USEC_PER_SEC) |
e0956dcc AB |
2286 | return -EINVAL; |
2287 | } | |
2288 | } | |
2289 | ||
2290 | /* | |
2291 | * Check for potential multiplication overflows that can | |
2292 | * only happen on 64-bit systems: | |
2293 | */ | |
2294 | if ((txc->modes & ADJ_FREQUENCY) && (BITS_PER_LONG == 64)) { | |
2295 | if (LLONG_MIN / PPM_SCALE > txc->freq) | |
2296 | return -EINVAL; | |
2297 | if (LLONG_MAX / PPM_SCALE < txc->freq) | |
2298 | return -EINVAL; | |
2299 | } | |
2300 | ||
2301 | return 0; | |
2302 | } | |
2303 | ||
2304 | ||
aa6f9c59 JS |
2305 | /** |
2306 | * do_adjtimex() - Accessor function to NTP __do_adjtimex function | |
2307 | */ | |
ead25417 | 2308 | int do_adjtimex(struct __kernel_timex *txc) |
aa6f9c59 | 2309 | { |
3fdb14fd | 2310 | struct timekeeper *tk = &tk_core.timekeeper; |
7e8eda73 | 2311 | struct audit_ntp_data ad; |
06c017fd | 2312 | unsigned long flags; |
7d489d15 | 2313 | struct timespec64 ts; |
4e8f8b34 | 2314 | s32 orig_tai, tai; |
e4085693 JS |
2315 | int ret; |
2316 | ||
2317 | /* Validate the data before disabling interrupts */ | |
1572fa03 | 2318 | ret = timekeeping_validate_timex(txc); |
e4085693 JS |
2319 | if (ret) |
2320 | return ret; | |
2321 | ||
cef90377 | 2322 | if (txc->modes & ADJ_SETOFFSET) { |
1572fa03 | 2323 | struct timespec64 delta; |
cef90377 JS |
2324 | delta.tv_sec = txc->time.tv_sec; |
2325 | delta.tv_nsec = txc->time.tv_usec; | |
2326 | if (!(txc->modes & ADJ_NANO)) | |
2327 | delta.tv_nsec *= 1000; | |
2328 | ret = timekeeping_inject_offset(&delta); | |
2329 | if (ret) | |
2330 | return ret; | |
2d87a067 OM |
2331 | |
2332 | audit_tk_injoffset(delta); | |
cef90377 JS |
2333 | } |
2334 | ||
7e8eda73 OM |
2335 | audit_ntp_init(&ad); |
2336 | ||
d30faff9 | 2337 | ktime_get_real_ts64(&ts); |
87ace39b | 2338 | |
06c017fd | 2339 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
3fdb14fd | 2340 | write_seqcount_begin(&tk_core.seq); |
06c017fd | 2341 | |
4e8f8b34 | 2342 | orig_tai = tai = tk->tai_offset; |
7e8eda73 | 2343 | ret = __do_adjtimex(txc, &ts, &tai, &ad); |
aa6f9c59 | 2344 | |
4e8f8b34 JS |
2345 | if (tai != orig_tai) { |
2346 | __timekeeping_set_tai_offset(tk, tai); | |
f55c0760 | 2347 | timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); |
4e8f8b34 | 2348 | } |
833f32d7 JS |
2349 | tk_update_leap_state(tk); |
2350 | ||
3fdb14fd | 2351 | write_seqcount_end(&tk_core.seq); |
06c017fd JS |
2352 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
2353 | ||
7e8eda73 OM |
2354 | audit_ntp_log(&ad); |
2355 | ||
b061c7a5 ML |
2356 | /* Update the multiplier immediately if frequency was set directly */ |
2357 | if (txc->modes & (ADJ_FREQUENCY | ADJ_TICK)) | |
2358 | timekeeping_advance(TK_ADV_FREQ); | |
2359 | ||
6fdda9a9 JS |
2360 | if (tai != orig_tai) |
2361 | clock_was_set(); | |
2362 | ||
7bd36014 JS |
2363 | ntp_notify_cmos_timer(); |
2364 | ||
87ace39b JS |
2365 | return ret; |
2366 | } | |
aa6f9c59 JS |
2367 | |
2368 | #ifdef CONFIG_NTP_PPS | |
2369 | /** | |
2370 | * hardpps() - Accessor function to NTP __hardpps function | |
2371 | */ | |
7ec88e4b | 2372 | void hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts) |
aa6f9c59 | 2373 | { |
06c017fd JS |
2374 | unsigned long flags; |
2375 | ||
2376 | raw_spin_lock_irqsave(&timekeeper_lock, flags); | |
3fdb14fd | 2377 | write_seqcount_begin(&tk_core.seq); |
06c017fd | 2378 | |
aa6f9c59 | 2379 | __hardpps(phase_ts, raw_ts); |
06c017fd | 2380 | |
3fdb14fd | 2381 | write_seqcount_end(&tk_core.seq); |
06c017fd | 2382 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
aa6f9c59 JS |
2383 | } |
2384 | EXPORT_SYMBOL(hardpps); | |
a2d81803 | 2385 | #endif /* CONFIG_NTP_PPS */ |
aa6f9c59 | 2386 | |
f0af911a TH |
2387 | /** |
2388 | * xtime_update() - advances the timekeeping infrastructure | |
2389 | * @ticks: number of ticks, that have elapsed since the last call. | |
2390 | * | |
2391 | * Must be called with interrupts disabled. | |
2392 | */ | |
2393 | void xtime_update(unsigned long ticks) | |
2394 | { | |
d6ad4187 | 2395 | write_seqlock(&jiffies_lock); |
f0af911a | 2396 | do_timer(ticks); |
d6ad4187 | 2397 | write_sequnlock(&jiffies_lock); |
47a1b796 | 2398 | update_wall_time(); |
f0af911a | 2399 | } |