| 1 | /* |
| 2 | * linux/kernel/time/timekeeping.c |
| 3 | * |
| 4 | * Kernel timekeeping code and accessor functions |
| 5 | * |
| 6 | * This code was moved from linux/kernel/timer.c. |
| 7 | * Please see that file for copyright and history logs. |
| 8 | * |
| 9 | */ |
| 10 | |
| 11 | #include <linux/timekeeper_internal.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/interrupt.h> |
| 14 | #include <linux/percpu.h> |
| 15 | #include <linux/init.h> |
| 16 | #include <linux/mm.h> |
| 17 | #include <linux/sched.h> |
| 18 | #include <linux/syscore_ops.h> |
| 19 | #include <linux/clocksource.h> |
| 20 | #include <linux/jiffies.h> |
| 21 | #include <linux/time.h> |
| 22 | #include <linux/tick.h> |
| 23 | #include <linux/stop_machine.h> |
| 24 | #include <linux/pvclock_gtod.h> |
| 25 | |
| 26 | #include "tick-internal.h" |
| 27 | #include "ntp_internal.h" |
| 28 | |
| 29 | static struct timekeeper timekeeper; |
| 30 | static DEFINE_RAW_SPINLOCK(timekeeper_lock); |
| 31 | static seqcount_t timekeeper_seq; |
| 32 | |
| 33 | /* flag for if timekeeping is suspended */ |
| 34 | int __read_mostly timekeeping_suspended; |
| 35 | |
| 36 | /* Flag for if there is a persistent clock on this platform */ |
| 37 | bool __read_mostly persistent_clock_exist = false; |
| 38 | |
| 39 | static inline void tk_normalize_xtime(struct timekeeper *tk) |
| 40 | { |
| 41 | while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) { |
| 42 | tk->xtime_nsec -= (u64)NSEC_PER_SEC << tk->shift; |
| 43 | tk->xtime_sec++; |
| 44 | } |
| 45 | } |
| 46 | |
| 47 | static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts) |
| 48 | { |
| 49 | tk->xtime_sec = ts->tv_sec; |
| 50 | tk->xtime_nsec = (u64)ts->tv_nsec << tk->shift; |
| 51 | } |
| 52 | |
| 53 | static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts) |
| 54 | { |
| 55 | tk->xtime_sec += ts->tv_sec; |
| 56 | tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift; |
| 57 | tk_normalize_xtime(tk); |
| 58 | } |
| 59 | |
| 60 | static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm) |
| 61 | { |
| 62 | struct timespec tmp; |
| 63 | |
| 64 | /* |
| 65 | * Verify consistency of: offset_real = -wall_to_monotonic |
| 66 | * before modifying anything |
| 67 | */ |
| 68 | set_normalized_timespec(&tmp, -tk->wall_to_monotonic.tv_sec, |
| 69 | -tk->wall_to_monotonic.tv_nsec); |
| 70 | WARN_ON_ONCE(tk->offs_real.tv64 != timespec_to_ktime(tmp).tv64); |
| 71 | tk->wall_to_monotonic = wtm; |
| 72 | set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec); |
| 73 | tk->offs_real = timespec_to_ktime(tmp); |
| 74 | tk->offs_tai = ktime_sub(tk->offs_real, ktime_set(tk->tai_offset, 0)); |
| 75 | } |
| 76 | |
| 77 | static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t) |
| 78 | { |
| 79 | /* Verify consistency before modifying */ |
| 80 | WARN_ON_ONCE(tk->offs_boot.tv64 != timespec_to_ktime(tk->total_sleep_time).tv64); |
| 81 | |
| 82 | tk->total_sleep_time = t; |
| 83 | tk->offs_boot = timespec_to_ktime(t); |
| 84 | } |
| 85 | |
| 86 | /** |
| 87 | * timekeeper_setup_internals - Set up internals to use clocksource clock. |
| 88 | * |
| 89 | * @clock: Pointer to clocksource. |
| 90 | * |
| 91 | * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment |
| 92 | * pair and interval request. |
| 93 | * |
| 94 | * Unless you're the timekeeping code, you should not be using this! |
| 95 | */ |
| 96 | static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock) |
| 97 | { |
| 98 | cycle_t interval; |
| 99 | u64 tmp, ntpinterval; |
| 100 | struct clocksource *old_clock; |
| 101 | |
| 102 | old_clock = tk->clock; |
| 103 | tk->clock = clock; |
| 104 | clock->cycle_last = clock->read(clock); |
| 105 | |
| 106 | /* Do the ns -> cycle conversion first, using original mult */ |
| 107 | tmp = NTP_INTERVAL_LENGTH; |
| 108 | tmp <<= clock->shift; |
| 109 | ntpinterval = tmp; |
| 110 | tmp += clock->mult/2; |
| 111 | do_div(tmp, clock->mult); |
| 112 | if (tmp == 0) |
| 113 | tmp = 1; |
| 114 | |
| 115 | interval = (cycle_t) tmp; |
| 116 | tk->cycle_interval = interval; |
| 117 | |
| 118 | /* Go back from cycles -> shifted ns */ |
| 119 | tk->xtime_interval = (u64) interval * clock->mult; |
| 120 | tk->xtime_remainder = ntpinterval - tk->xtime_interval; |
| 121 | tk->raw_interval = |
| 122 | ((u64) interval * clock->mult) >> clock->shift; |
| 123 | |
| 124 | /* if changing clocks, convert xtime_nsec shift units */ |
| 125 | if (old_clock) { |
| 126 | int shift_change = clock->shift - old_clock->shift; |
| 127 | if (shift_change < 0) |
| 128 | tk->xtime_nsec >>= -shift_change; |
| 129 | else |
| 130 | tk->xtime_nsec <<= shift_change; |
| 131 | } |
| 132 | tk->shift = clock->shift; |
| 133 | |
| 134 | tk->ntp_error = 0; |
| 135 | tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; |
| 136 | |
| 137 | /* |
| 138 | * The timekeeper keeps its own mult values for the currently |
| 139 | * active clocksource. These value will be adjusted via NTP |
| 140 | * to counteract clock drifting. |
| 141 | */ |
| 142 | tk->mult = clock->mult; |
| 143 | } |
| 144 | |
| 145 | /* Timekeeper helper functions. */ |
| 146 | |
| 147 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET |
| 148 | u32 (*arch_gettimeoffset)(void); |
| 149 | |
| 150 | u32 get_arch_timeoffset(void) |
| 151 | { |
| 152 | if (likely(arch_gettimeoffset)) |
| 153 | return arch_gettimeoffset(); |
| 154 | return 0; |
| 155 | } |
| 156 | #else |
| 157 | static inline u32 get_arch_timeoffset(void) { return 0; } |
| 158 | #endif |
| 159 | |
| 160 | static inline s64 timekeeping_get_ns(struct timekeeper *tk) |
| 161 | { |
| 162 | cycle_t cycle_now, cycle_delta; |
| 163 | struct clocksource *clock; |
| 164 | s64 nsec; |
| 165 | |
| 166 | /* read clocksource: */ |
| 167 | clock = tk->clock; |
| 168 | cycle_now = clock->read(clock); |
| 169 | |
| 170 | /* calculate the delta since the last update_wall_time: */ |
| 171 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; |
| 172 | |
| 173 | nsec = cycle_delta * tk->mult + tk->xtime_nsec; |
| 174 | nsec >>= tk->shift; |
| 175 | |
| 176 | /* If arch requires, add in get_arch_timeoffset() */ |
| 177 | return nsec + get_arch_timeoffset(); |
| 178 | } |
| 179 | |
| 180 | static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk) |
| 181 | { |
| 182 | cycle_t cycle_now, cycle_delta; |
| 183 | struct clocksource *clock; |
| 184 | s64 nsec; |
| 185 | |
| 186 | /* read clocksource: */ |
| 187 | clock = tk->clock; |
| 188 | cycle_now = clock->read(clock); |
| 189 | |
| 190 | /* calculate the delta since the last update_wall_time: */ |
| 191 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; |
| 192 | |
| 193 | /* convert delta to nanoseconds. */ |
| 194 | nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); |
| 195 | |
| 196 | /* If arch requires, add in get_arch_timeoffset() */ |
| 197 | return nsec + get_arch_timeoffset(); |
| 198 | } |
| 199 | |
| 200 | static RAW_NOTIFIER_HEAD(pvclock_gtod_chain); |
| 201 | |
| 202 | static void update_pvclock_gtod(struct timekeeper *tk) |
| 203 | { |
| 204 | raw_notifier_call_chain(&pvclock_gtod_chain, 0, tk); |
| 205 | } |
| 206 | |
| 207 | /** |
| 208 | * pvclock_gtod_register_notifier - register a pvclock timedata update listener |
| 209 | */ |
| 210 | int pvclock_gtod_register_notifier(struct notifier_block *nb) |
| 211 | { |
| 212 | struct timekeeper *tk = &timekeeper; |
| 213 | unsigned long flags; |
| 214 | int ret; |
| 215 | |
| 216 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
| 217 | ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb); |
| 218 | update_pvclock_gtod(tk); |
| 219 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
| 220 | |
| 221 | return ret; |
| 222 | } |
| 223 | EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier); |
| 224 | |
| 225 | /** |
| 226 | * pvclock_gtod_unregister_notifier - unregister a pvclock |
| 227 | * timedata update listener |
| 228 | */ |
| 229 | int pvclock_gtod_unregister_notifier(struct notifier_block *nb) |
| 230 | { |
| 231 | unsigned long flags; |
| 232 | int ret; |
| 233 | |
| 234 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
| 235 | ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb); |
| 236 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
| 237 | |
| 238 | return ret; |
| 239 | } |
| 240 | EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier); |
| 241 | |
| 242 | /* must hold timekeeper_lock */ |
| 243 | static void timekeeping_update(struct timekeeper *tk, bool clearntp) |
| 244 | { |
| 245 | if (clearntp) { |
| 246 | tk->ntp_error = 0; |
| 247 | ntp_clear(); |
| 248 | } |
| 249 | update_vsyscall(tk); |
| 250 | update_pvclock_gtod(tk); |
| 251 | } |
| 252 | |
| 253 | /** |
| 254 | * timekeeping_forward_now - update clock to the current time |
| 255 | * |
| 256 | * Forward the current clock to update its state since the last call to |
| 257 | * update_wall_time(). This is useful before significant clock changes, |
| 258 | * as it avoids having to deal with this time offset explicitly. |
| 259 | */ |
| 260 | static void timekeeping_forward_now(struct timekeeper *tk) |
| 261 | { |
| 262 | cycle_t cycle_now, cycle_delta; |
| 263 | struct clocksource *clock; |
| 264 | s64 nsec; |
| 265 | |
| 266 | clock = tk->clock; |
| 267 | cycle_now = clock->read(clock); |
| 268 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; |
| 269 | clock->cycle_last = cycle_now; |
| 270 | |
| 271 | tk->xtime_nsec += cycle_delta * tk->mult; |
| 272 | |
| 273 | /* If arch requires, add in get_arch_timeoffset() */ |
| 274 | tk->xtime_nsec += (u64)get_arch_timeoffset() << tk->shift; |
| 275 | |
| 276 | tk_normalize_xtime(tk); |
| 277 | |
| 278 | nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); |
| 279 | timespec_add_ns(&tk->raw_time, nsec); |
| 280 | } |
| 281 | |
| 282 | /** |
| 283 | * __getnstimeofday - Returns the time of day in a timespec. |
| 284 | * @ts: pointer to the timespec to be set |
| 285 | * |
| 286 | * Updates the time of day in the timespec. |
| 287 | * Returns 0 on success, or -ve when suspended (timespec will be undefined). |
| 288 | */ |
| 289 | int __getnstimeofday(struct timespec *ts) |
| 290 | { |
| 291 | struct timekeeper *tk = &timekeeper; |
| 292 | unsigned long seq; |
| 293 | s64 nsecs = 0; |
| 294 | |
| 295 | do { |
| 296 | seq = read_seqcount_begin(&timekeeper_seq); |
| 297 | |
| 298 | ts->tv_sec = tk->xtime_sec; |
| 299 | nsecs = timekeeping_get_ns(tk); |
| 300 | |
| 301 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 302 | |
| 303 | ts->tv_nsec = 0; |
| 304 | timespec_add_ns(ts, nsecs); |
| 305 | |
| 306 | /* |
| 307 | * Do not bail out early, in case there were callers still using |
| 308 | * the value, even in the face of the WARN_ON. |
| 309 | */ |
| 310 | if (unlikely(timekeeping_suspended)) |
| 311 | return -EAGAIN; |
| 312 | return 0; |
| 313 | } |
| 314 | EXPORT_SYMBOL(__getnstimeofday); |
| 315 | |
| 316 | /** |
| 317 | * getnstimeofday - Returns the time of day in a timespec. |
| 318 | * @ts: pointer to the timespec to be set |
| 319 | * |
| 320 | * Returns the time of day in a timespec (WARN if suspended). |
| 321 | */ |
| 322 | void getnstimeofday(struct timespec *ts) |
| 323 | { |
| 324 | WARN_ON(__getnstimeofday(ts)); |
| 325 | } |
| 326 | EXPORT_SYMBOL(getnstimeofday); |
| 327 | |
| 328 | ktime_t ktime_get(void) |
| 329 | { |
| 330 | struct timekeeper *tk = &timekeeper; |
| 331 | unsigned int seq; |
| 332 | s64 secs, nsecs; |
| 333 | |
| 334 | WARN_ON(timekeeping_suspended); |
| 335 | |
| 336 | do { |
| 337 | seq = read_seqcount_begin(&timekeeper_seq); |
| 338 | secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; |
| 339 | nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec; |
| 340 | |
| 341 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 342 | /* |
| 343 | * Use ktime_set/ktime_add_ns to create a proper ktime on |
| 344 | * 32-bit architectures without CONFIG_KTIME_SCALAR. |
| 345 | */ |
| 346 | return ktime_add_ns(ktime_set(secs, 0), nsecs); |
| 347 | } |
| 348 | EXPORT_SYMBOL_GPL(ktime_get); |
| 349 | |
| 350 | /** |
| 351 | * ktime_get_ts - get the monotonic clock in timespec format |
| 352 | * @ts: pointer to timespec variable |
| 353 | * |
| 354 | * The function calculates the monotonic clock from the realtime |
| 355 | * clock and the wall_to_monotonic offset and stores the result |
| 356 | * in normalized timespec format in the variable pointed to by @ts. |
| 357 | */ |
| 358 | void ktime_get_ts(struct timespec *ts) |
| 359 | { |
| 360 | struct timekeeper *tk = &timekeeper; |
| 361 | struct timespec tomono; |
| 362 | s64 nsec; |
| 363 | unsigned int seq; |
| 364 | |
| 365 | WARN_ON(timekeeping_suspended); |
| 366 | |
| 367 | do { |
| 368 | seq = read_seqcount_begin(&timekeeper_seq); |
| 369 | ts->tv_sec = tk->xtime_sec; |
| 370 | nsec = timekeeping_get_ns(tk); |
| 371 | tomono = tk->wall_to_monotonic; |
| 372 | |
| 373 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 374 | |
| 375 | ts->tv_sec += tomono.tv_sec; |
| 376 | ts->tv_nsec = 0; |
| 377 | timespec_add_ns(ts, nsec + tomono.tv_nsec); |
| 378 | } |
| 379 | EXPORT_SYMBOL_GPL(ktime_get_ts); |
| 380 | |
| 381 | |
| 382 | /** |
| 383 | * timekeeping_clocktai - Returns the TAI time of day in a timespec |
| 384 | * @ts: pointer to the timespec to be set |
| 385 | * |
| 386 | * Returns the time of day in a timespec. |
| 387 | */ |
| 388 | void timekeeping_clocktai(struct timespec *ts) |
| 389 | { |
| 390 | struct timekeeper *tk = &timekeeper; |
| 391 | unsigned long seq; |
| 392 | u64 nsecs; |
| 393 | |
| 394 | WARN_ON(timekeeping_suspended); |
| 395 | |
| 396 | do { |
| 397 | seq = read_seqcount_begin(&timekeeper_seq); |
| 398 | |
| 399 | ts->tv_sec = tk->xtime_sec + tk->tai_offset; |
| 400 | nsecs = timekeeping_get_ns(tk); |
| 401 | |
| 402 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 403 | |
| 404 | ts->tv_nsec = 0; |
| 405 | timespec_add_ns(ts, nsecs); |
| 406 | |
| 407 | } |
| 408 | EXPORT_SYMBOL(timekeeping_clocktai); |
| 409 | |
| 410 | |
| 411 | /** |
| 412 | * ktime_get_clocktai - Returns the TAI time of day in a ktime |
| 413 | * |
| 414 | * Returns the time of day in a ktime. |
| 415 | */ |
| 416 | ktime_t ktime_get_clocktai(void) |
| 417 | { |
| 418 | struct timespec ts; |
| 419 | |
| 420 | timekeeping_clocktai(&ts); |
| 421 | return timespec_to_ktime(ts); |
| 422 | } |
| 423 | EXPORT_SYMBOL(ktime_get_clocktai); |
| 424 | |
| 425 | #ifdef CONFIG_NTP_PPS |
| 426 | |
| 427 | /** |
| 428 | * getnstime_raw_and_real - get day and raw monotonic time in timespec format |
| 429 | * @ts_raw: pointer to the timespec to be set to raw monotonic time |
| 430 | * @ts_real: pointer to the timespec to be set to the time of day |
| 431 | * |
| 432 | * This function reads both the time of day and raw monotonic time at the |
| 433 | * same time atomically and stores the resulting timestamps in timespec |
| 434 | * format. |
| 435 | */ |
| 436 | void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real) |
| 437 | { |
| 438 | struct timekeeper *tk = &timekeeper; |
| 439 | unsigned long seq; |
| 440 | s64 nsecs_raw, nsecs_real; |
| 441 | |
| 442 | WARN_ON_ONCE(timekeeping_suspended); |
| 443 | |
| 444 | do { |
| 445 | seq = read_seqcount_begin(&timekeeper_seq); |
| 446 | |
| 447 | *ts_raw = tk->raw_time; |
| 448 | ts_real->tv_sec = tk->xtime_sec; |
| 449 | ts_real->tv_nsec = 0; |
| 450 | |
| 451 | nsecs_raw = timekeeping_get_ns_raw(tk); |
| 452 | nsecs_real = timekeeping_get_ns(tk); |
| 453 | |
| 454 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 455 | |
| 456 | timespec_add_ns(ts_raw, nsecs_raw); |
| 457 | timespec_add_ns(ts_real, nsecs_real); |
| 458 | } |
| 459 | EXPORT_SYMBOL(getnstime_raw_and_real); |
| 460 | |
| 461 | #endif /* CONFIG_NTP_PPS */ |
| 462 | |
| 463 | /** |
| 464 | * do_gettimeofday - Returns the time of day in a timeval |
| 465 | * @tv: pointer to the timeval to be set |
| 466 | * |
| 467 | * NOTE: Users should be converted to using getnstimeofday() |
| 468 | */ |
| 469 | void do_gettimeofday(struct timeval *tv) |
| 470 | { |
| 471 | struct timespec now; |
| 472 | |
| 473 | getnstimeofday(&now); |
| 474 | tv->tv_sec = now.tv_sec; |
| 475 | tv->tv_usec = now.tv_nsec/1000; |
| 476 | } |
| 477 | EXPORT_SYMBOL(do_gettimeofday); |
| 478 | |
| 479 | /** |
| 480 | * do_settimeofday - Sets the time of day |
| 481 | * @tv: pointer to the timespec variable containing the new time |
| 482 | * |
| 483 | * Sets the time of day to the new time and update NTP and notify hrtimers |
| 484 | */ |
| 485 | int do_settimeofday(const struct timespec *tv) |
| 486 | { |
| 487 | struct timekeeper *tk = &timekeeper; |
| 488 | struct timespec ts_delta, xt; |
| 489 | unsigned long flags; |
| 490 | |
| 491 | if (!timespec_valid_strict(tv)) |
| 492 | return -EINVAL; |
| 493 | |
| 494 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
| 495 | write_seqcount_begin(&timekeeper_seq); |
| 496 | |
| 497 | timekeeping_forward_now(tk); |
| 498 | |
| 499 | xt = tk_xtime(tk); |
| 500 | ts_delta.tv_sec = tv->tv_sec - xt.tv_sec; |
| 501 | ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec; |
| 502 | |
| 503 | tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts_delta)); |
| 504 | |
| 505 | tk_set_xtime(tk, tv); |
| 506 | |
| 507 | timekeeping_update(tk, true); |
| 508 | |
| 509 | write_seqcount_end(&timekeeper_seq); |
| 510 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
| 511 | |
| 512 | /* signal hrtimers about time change */ |
| 513 | clock_was_set(); |
| 514 | |
| 515 | return 0; |
| 516 | } |
| 517 | EXPORT_SYMBOL(do_settimeofday); |
| 518 | |
| 519 | /** |
| 520 | * timekeeping_inject_offset - Adds or subtracts from the current time. |
| 521 | * @tv: pointer to the timespec variable containing the offset |
| 522 | * |
| 523 | * Adds or subtracts an offset value from the current time. |
| 524 | */ |
| 525 | int timekeeping_inject_offset(struct timespec *ts) |
| 526 | { |
| 527 | struct timekeeper *tk = &timekeeper; |
| 528 | unsigned long flags; |
| 529 | struct timespec tmp; |
| 530 | int ret = 0; |
| 531 | |
| 532 | if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) |
| 533 | return -EINVAL; |
| 534 | |
| 535 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
| 536 | write_seqcount_begin(&timekeeper_seq); |
| 537 | |
| 538 | timekeeping_forward_now(tk); |
| 539 | |
| 540 | /* Make sure the proposed value is valid */ |
| 541 | tmp = timespec_add(tk_xtime(tk), *ts); |
| 542 | if (!timespec_valid_strict(&tmp)) { |
| 543 | ret = -EINVAL; |
| 544 | goto error; |
| 545 | } |
| 546 | |
| 547 | tk_xtime_add(tk, ts); |
| 548 | tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts)); |
| 549 | |
| 550 | error: /* even if we error out, we forwarded the time, so call update */ |
| 551 | timekeeping_update(tk, true); |
| 552 | |
| 553 | write_seqcount_end(&timekeeper_seq); |
| 554 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
| 555 | |
| 556 | /* signal hrtimers about time change */ |
| 557 | clock_was_set(); |
| 558 | |
| 559 | return ret; |
| 560 | } |
| 561 | EXPORT_SYMBOL(timekeeping_inject_offset); |
| 562 | |
| 563 | |
| 564 | /** |
| 565 | * timekeeping_get_tai_offset - Returns current TAI offset from UTC |
| 566 | * |
| 567 | */ |
| 568 | s32 timekeeping_get_tai_offset(void) |
| 569 | { |
| 570 | struct timekeeper *tk = &timekeeper; |
| 571 | unsigned int seq; |
| 572 | s32 ret; |
| 573 | |
| 574 | do { |
| 575 | seq = read_seqcount_begin(&timekeeper_seq); |
| 576 | ret = tk->tai_offset; |
| 577 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 578 | |
| 579 | return ret; |
| 580 | } |
| 581 | |
| 582 | /** |
| 583 | * __timekeeping_set_tai_offset - Lock free worker function |
| 584 | * |
| 585 | */ |
| 586 | static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset) |
| 587 | { |
| 588 | tk->tai_offset = tai_offset; |
| 589 | tk->offs_tai = ktime_sub(tk->offs_real, ktime_set(tai_offset, 0)); |
| 590 | } |
| 591 | |
| 592 | /** |
| 593 | * timekeeping_set_tai_offset - Sets the current TAI offset from UTC |
| 594 | * |
| 595 | */ |
| 596 | void timekeeping_set_tai_offset(s32 tai_offset) |
| 597 | { |
| 598 | struct timekeeper *tk = &timekeeper; |
| 599 | unsigned long flags; |
| 600 | |
| 601 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
| 602 | write_seqcount_begin(&timekeeper_seq); |
| 603 | __timekeeping_set_tai_offset(tk, tai_offset); |
| 604 | write_seqcount_end(&timekeeper_seq); |
| 605 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
| 606 | } |
| 607 | |
| 608 | /** |
| 609 | * change_clocksource - Swaps clocksources if a new one is available |
| 610 | * |
| 611 | * Accumulates current time interval and initializes new clocksource |
| 612 | */ |
| 613 | static int change_clocksource(void *data) |
| 614 | { |
| 615 | struct timekeeper *tk = &timekeeper; |
| 616 | struct clocksource *new, *old; |
| 617 | unsigned long flags; |
| 618 | |
| 619 | new = (struct clocksource *) data; |
| 620 | |
| 621 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
| 622 | write_seqcount_begin(&timekeeper_seq); |
| 623 | |
| 624 | timekeeping_forward_now(tk); |
| 625 | if (!new->enable || new->enable(new) == 0) { |
| 626 | old = tk->clock; |
| 627 | tk_setup_internals(tk, new); |
| 628 | if (old->disable) |
| 629 | old->disable(old); |
| 630 | } |
| 631 | timekeeping_update(tk, true); |
| 632 | |
| 633 | write_seqcount_end(&timekeeper_seq); |
| 634 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
| 635 | |
| 636 | return 0; |
| 637 | } |
| 638 | |
| 639 | /** |
| 640 | * timekeeping_notify - Install a new clock source |
| 641 | * @clock: pointer to the clock source |
| 642 | * |
| 643 | * This function is called from clocksource.c after a new, better clock |
| 644 | * source has been registered. The caller holds the clocksource_mutex. |
| 645 | */ |
| 646 | void timekeeping_notify(struct clocksource *clock) |
| 647 | { |
| 648 | struct timekeeper *tk = &timekeeper; |
| 649 | |
| 650 | if (tk->clock == clock) |
| 651 | return; |
| 652 | stop_machine(change_clocksource, clock, NULL); |
| 653 | tick_clock_notify(); |
| 654 | } |
| 655 | |
| 656 | /** |
| 657 | * ktime_get_real - get the real (wall-) time in ktime_t format |
| 658 | * |
| 659 | * returns the time in ktime_t format |
| 660 | */ |
| 661 | ktime_t ktime_get_real(void) |
| 662 | { |
| 663 | struct timespec now; |
| 664 | |
| 665 | getnstimeofday(&now); |
| 666 | |
| 667 | return timespec_to_ktime(now); |
| 668 | } |
| 669 | EXPORT_SYMBOL_GPL(ktime_get_real); |
| 670 | |
| 671 | /** |
| 672 | * getrawmonotonic - Returns the raw monotonic time in a timespec |
| 673 | * @ts: pointer to the timespec to be set |
| 674 | * |
| 675 | * Returns the raw monotonic time (completely un-modified by ntp) |
| 676 | */ |
| 677 | void getrawmonotonic(struct timespec *ts) |
| 678 | { |
| 679 | struct timekeeper *tk = &timekeeper; |
| 680 | unsigned long seq; |
| 681 | s64 nsecs; |
| 682 | |
| 683 | do { |
| 684 | seq = read_seqcount_begin(&timekeeper_seq); |
| 685 | nsecs = timekeeping_get_ns_raw(tk); |
| 686 | *ts = tk->raw_time; |
| 687 | |
| 688 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 689 | |
| 690 | timespec_add_ns(ts, nsecs); |
| 691 | } |
| 692 | EXPORT_SYMBOL(getrawmonotonic); |
| 693 | |
| 694 | /** |
| 695 | * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres |
| 696 | */ |
| 697 | int timekeeping_valid_for_hres(void) |
| 698 | { |
| 699 | struct timekeeper *tk = &timekeeper; |
| 700 | unsigned long seq; |
| 701 | int ret; |
| 702 | |
| 703 | do { |
| 704 | seq = read_seqcount_begin(&timekeeper_seq); |
| 705 | |
| 706 | ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; |
| 707 | |
| 708 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 709 | |
| 710 | return ret; |
| 711 | } |
| 712 | |
| 713 | /** |
| 714 | * timekeeping_max_deferment - Returns max time the clocksource can be deferred |
| 715 | */ |
| 716 | u64 timekeeping_max_deferment(void) |
| 717 | { |
| 718 | struct timekeeper *tk = &timekeeper; |
| 719 | unsigned long seq; |
| 720 | u64 ret; |
| 721 | |
| 722 | do { |
| 723 | seq = read_seqcount_begin(&timekeeper_seq); |
| 724 | |
| 725 | ret = tk->clock->max_idle_ns; |
| 726 | |
| 727 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 728 | |
| 729 | return ret; |
| 730 | } |
| 731 | |
| 732 | /** |
| 733 | * read_persistent_clock - Return time from the persistent clock. |
| 734 | * |
| 735 | * Weak dummy function for arches that do not yet support it. |
| 736 | * Reads the time from the battery backed persistent clock. |
| 737 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. |
| 738 | * |
| 739 | * XXX - Do be sure to remove it once all arches implement it. |
| 740 | */ |
| 741 | void __attribute__((weak)) read_persistent_clock(struct timespec *ts) |
| 742 | { |
| 743 | ts->tv_sec = 0; |
| 744 | ts->tv_nsec = 0; |
| 745 | } |
| 746 | |
| 747 | /** |
| 748 | * read_boot_clock - Return time of the system start. |
| 749 | * |
| 750 | * Weak dummy function for arches that do not yet support it. |
| 751 | * Function to read the exact time the system has been started. |
| 752 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. |
| 753 | * |
| 754 | * XXX - Do be sure to remove it once all arches implement it. |
| 755 | */ |
| 756 | void __attribute__((weak)) read_boot_clock(struct timespec *ts) |
| 757 | { |
| 758 | ts->tv_sec = 0; |
| 759 | ts->tv_nsec = 0; |
| 760 | } |
| 761 | |
| 762 | /* |
| 763 | * timekeeping_init - Initializes the clocksource and common timekeeping values |
| 764 | */ |
| 765 | void __init timekeeping_init(void) |
| 766 | { |
| 767 | struct timekeeper *tk = &timekeeper; |
| 768 | struct clocksource *clock; |
| 769 | unsigned long flags; |
| 770 | struct timespec now, boot, tmp; |
| 771 | |
| 772 | read_persistent_clock(&now); |
| 773 | |
| 774 | if (!timespec_valid_strict(&now)) { |
| 775 | pr_warn("WARNING: Persistent clock returned invalid value!\n" |
| 776 | " Check your CMOS/BIOS settings.\n"); |
| 777 | now.tv_sec = 0; |
| 778 | now.tv_nsec = 0; |
| 779 | } else if (now.tv_sec || now.tv_nsec) |
| 780 | persistent_clock_exist = true; |
| 781 | |
| 782 | read_boot_clock(&boot); |
| 783 | if (!timespec_valid_strict(&boot)) { |
| 784 | pr_warn("WARNING: Boot clock returned invalid value!\n" |
| 785 | " Check your CMOS/BIOS settings.\n"); |
| 786 | boot.tv_sec = 0; |
| 787 | boot.tv_nsec = 0; |
| 788 | } |
| 789 | |
| 790 | ntp_init(); |
| 791 | |
| 792 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
| 793 | write_seqcount_begin(&timekeeper_seq); |
| 794 | clock = clocksource_default_clock(); |
| 795 | if (clock->enable) |
| 796 | clock->enable(clock); |
| 797 | tk_setup_internals(tk, clock); |
| 798 | |
| 799 | tk_set_xtime(tk, &now); |
| 800 | tk->raw_time.tv_sec = 0; |
| 801 | tk->raw_time.tv_nsec = 0; |
| 802 | if (boot.tv_sec == 0 && boot.tv_nsec == 0) |
| 803 | boot = tk_xtime(tk); |
| 804 | |
| 805 | set_normalized_timespec(&tmp, -boot.tv_sec, -boot.tv_nsec); |
| 806 | tk_set_wall_to_mono(tk, tmp); |
| 807 | |
| 808 | tmp.tv_sec = 0; |
| 809 | tmp.tv_nsec = 0; |
| 810 | tk_set_sleep_time(tk, tmp); |
| 811 | |
| 812 | write_seqcount_end(&timekeeper_seq); |
| 813 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
| 814 | } |
| 815 | |
| 816 | /* time in seconds when suspend began */ |
| 817 | static struct timespec timekeeping_suspend_time; |
| 818 | |
| 819 | /** |
| 820 | * __timekeeping_inject_sleeptime - Internal function to add sleep interval |
| 821 | * @delta: pointer to a timespec delta value |
| 822 | * |
| 823 | * Takes a timespec offset measuring a suspend interval and properly |
| 824 | * adds the sleep offset to the timekeeping variables. |
| 825 | */ |
| 826 | static void __timekeeping_inject_sleeptime(struct timekeeper *tk, |
| 827 | struct timespec *delta) |
| 828 | { |
| 829 | if (!timespec_valid_strict(delta)) { |
| 830 | printk(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid " |
| 831 | "sleep delta value!\n"); |
| 832 | return; |
| 833 | } |
| 834 | tk_xtime_add(tk, delta); |
| 835 | tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *delta)); |
| 836 | tk_set_sleep_time(tk, timespec_add(tk->total_sleep_time, *delta)); |
| 837 | } |
| 838 | |
| 839 | /** |
| 840 | * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values |
| 841 | * @delta: pointer to a timespec delta value |
| 842 | * |
| 843 | * This hook is for architectures that cannot support read_persistent_clock |
| 844 | * because their RTC/persistent clock is only accessible when irqs are enabled. |
| 845 | * |
| 846 | * This function should only be called by rtc_resume(), and allows |
| 847 | * a suspend offset to be injected into the timekeeping values. |
| 848 | */ |
| 849 | void timekeeping_inject_sleeptime(struct timespec *delta) |
| 850 | { |
| 851 | struct timekeeper *tk = &timekeeper; |
| 852 | unsigned long flags; |
| 853 | |
| 854 | /* |
| 855 | * Make sure we don't set the clock twice, as timekeeping_resume() |
| 856 | * already did it |
| 857 | */ |
| 858 | if (has_persistent_clock()) |
| 859 | return; |
| 860 | |
| 861 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
| 862 | write_seqcount_begin(&timekeeper_seq); |
| 863 | |
| 864 | timekeeping_forward_now(tk); |
| 865 | |
| 866 | __timekeeping_inject_sleeptime(tk, delta); |
| 867 | |
| 868 | timekeeping_update(tk, true); |
| 869 | |
| 870 | write_seqcount_end(&timekeeper_seq); |
| 871 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
| 872 | |
| 873 | /* signal hrtimers about time change */ |
| 874 | clock_was_set(); |
| 875 | } |
| 876 | |
| 877 | /** |
| 878 | * timekeeping_resume - Resumes the generic timekeeping subsystem. |
| 879 | * |
| 880 | * This is for the generic clocksource timekeeping. |
| 881 | * xtime/wall_to_monotonic/jiffies/etc are |
| 882 | * still managed by arch specific suspend/resume code. |
| 883 | */ |
| 884 | static void timekeeping_resume(void) |
| 885 | { |
| 886 | struct timekeeper *tk = &timekeeper; |
| 887 | struct clocksource *clock = tk->clock; |
| 888 | unsigned long flags; |
| 889 | struct timespec ts_new, ts_delta; |
| 890 | cycle_t cycle_now, cycle_delta; |
| 891 | bool suspendtime_found = false; |
| 892 | |
| 893 | read_persistent_clock(&ts_new); |
| 894 | |
| 895 | clockevents_resume(); |
| 896 | clocksource_resume(); |
| 897 | |
| 898 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
| 899 | write_seqcount_begin(&timekeeper_seq); |
| 900 | |
| 901 | /* |
| 902 | * After system resumes, we need to calculate the suspended time and |
| 903 | * compensate it for the OS time. There are 3 sources that could be |
| 904 | * used: Nonstop clocksource during suspend, persistent clock and rtc |
| 905 | * device. |
| 906 | * |
| 907 | * One specific platform may have 1 or 2 or all of them, and the |
| 908 | * preference will be: |
| 909 | * suspend-nonstop clocksource -> persistent clock -> rtc |
| 910 | * The less preferred source will only be tried if there is no better |
| 911 | * usable source. The rtc part is handled separately in rtc core code. |
| 912 | */ |
| 913 | cycle_now = clock->read(clock); |
| 914 | if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) && |
| 915 | cycle_now > clock->cycle_last) { |
| 916 | u64 num, max = ULLONG_MAX; |
| 917 | u32 mult = clock->mult; |
| 918 | u32 shift = clock->shift; |
| 919 | s64 nsec = 0; |
| 920 | |
| 921 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; |
| 922 | |
| 923 | /* |
| 924 | * "cycle_delta * mutl" may cause 64 bits overflow, if the |
| 925 | * suspended time is too long. In that case we need do the |
| 926 | * 64 bits math carefully |
| 927 | */ |
| 928 | do_div(max, mult); |
| 929 | if (cycle_delta > max) { |
| 930 | num = div64_u64(cycle_delta, max); |
| 931 | nsec = (((u64) max * mult) >> shift) * num; |
| 932 | cycle_delta -= num * max; |
| 933 | } |
| 934 | nsec += ((u64) cycle_delta * mult) >> shift; |
| 935 | |
| 936 | ts_delta = ns_to_timespec(nsec); |
| 937 | suspendtime_found = true; |
| 938 | } else if (timespec_compare(&ts_new, &timekeeping_suspend_time) > 0) { |
| 939 | ts_delta = timespec_sub(ts_new, timekeeping_suspend_time); |
| 940 | suspendtime_found = true; |
| 941 | } |
| 942 | |
| 943 | if (suspendtime_found) |
| 944 | __timekeeping_inject_sleeptime(tk, &ts_delta); |
| 945 | |
| 946 | /* Re-base the last cycle value */ |
| 947 | clock->cycle_last = cycle_now; |
| 948 | tk->ntp_error = 0; |
| 949 | timekeeping_suspended = 0; |
| 950 | timekeeping_update(tk, false); |
| 951 | write_seqcount_end(&timekeeper_seq); |
| 952 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
| 953 | |
| 954 | touch_softlockup_watchdog(); |
| 955 | |
| 956 | clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL); |
| 957 | |
| 958 | /* Resume hrtimers */ |
| 959 | hrtimers_resume(); |
| 960 | } |
| 961 | |
| 962 | static int timekeeping_suspend(void) |
| 963 | { |
| 964 | struct timekeeper *tk = &timekeeper; |
| 965 | unsigned long flags; |
| 966 | struct timespec delta, delta_delta; |
| 967 | static struct timespec old_delta; |
| 968 | |
| 969 | read_persistent_clock(&timekeeping_suspend_time); |
| 970 | |
| 971 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
| 972 | write_seqcount_begin(&timekeeper_seq); |
| 973 | timekeeping_forward_now(tk); |
| 974 | timekeeping_suspended = 1; |
| 975 | |
| 976 | /* |
| 977 | * To avoid drift caused by repeated suspend/resumes, |
| 978 | * which each can add ~1 second drift error, |
| 979 | * try to compensate so the difference in system time |
| 980 | * and persistent_clock time stays close to constant. |
| 981 | */ |
| 982 | delta = timespec_sub(tk_xtime(tk), timekeeping_suspend_time); |
| 983 | delta_delta = timespec_sub(delta, old_delta); |
| 984 | if (abs(delta_delta.tv_sec) >= 2) { |
| 985 | /* |
| 986 | * if delta_delta is too large, assume time correction |
| 987 | * has occured and set old_delta to the current delta. |
| 988 | */ |
| 989 | old_delta = delta; |
| 990 | } else { |
| 991 | /* Otherwise try to adjust old_system to compensate */ |
| 992 | timekeeping_suspend_time = |
| 993 | timespec_add(timekeeping_suspend_time, delta_delta); |
| 994 | } |
| 995 | write_seqcount_end(&timekeeper_seq); |
| 996 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
| 997 | |
| 998 | clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); |
| 999 | clocksource_suspend(); |
| 1000 | clockevents_suspend(); |
| 1001 | |
| 1002 | return 0; |
| 1003 | } |
| 1004 | |
| 1005 | /* sysfs resume/suspend bits for timekeeping */ |
| 1006 | static struct syscore_ops timekeeping_syscore_ops = { |
| 1007 | .resume = timekeeping_resume, |
| 1008 | .suspend = timekeeping_suspend, |
| 1009 | }; |
| 1010 | |
| 1011 | static int __init timekeeping_init_ops(void) |
| 1012 | { |
| 1013 | register_syscore_ops(&timekeeping_syscore_ops); |
| 1014 | return 0; |
| 1015 | } |
| 1016 | |
| 1017 | device_initcall(timekeeping_init_ops); |
| 1018 | |
| 1019 | /* |
| 1020 | * If the error is already larger, we look ahead even further |
| 1021 | * to compensate for late or lost adjustments. |
| 1022 | */ |
| 1023 | static __always_inline int timekeeping_bigadjust(struct timekeeper *tk, |
| 1024 | s64 error, s64 *interval, |
| 1025 | s64 *offset) |
| 1026 | { |
| 1027 | s64 tick_error, i; |
| 1028 | u32 look_ahead, adj; |
| 1029 | s32 error2, mult; |
| 1030 | |
| 1031 | /* |
| 1032 | * Use the current error value to determine how much to look ahead. |
| 1033 | * The larger the error the slower we adjust for it to avoid problems |
| 1034 | * with losing too many ticks, otherwise we would overadjust and |
| 1035 | * produce an even larger error. The smaller the adjustment the |
| 1036 | * faster we try to adjust for it, as lost ticks can do less harm |
| 1037 | * here. This is tuned so that an error of about 1 msec is adjusted |
| 1038 | * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks). |
| 1039 | */ |
| 1040 | error2 = tk->ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ); |
| 1041 | error2 = abs(error2); |
| 1042 | for (look_ahead = 0; error2 > 0; look_ahead++) |
| 1043 | error2 >>= 2; |
| 1044 | |
| 1045 | /* |
| 1046 | * Now calculate the error in (1 << look_ahead) ticks, but first |
| 1047 | * remove the single look ahead already included in the error. |
| 1048 | */ |
| 1049 | tick_error = ntp_tick_length() >> (tk->ntp_error_shift + 1); |
| 1050 | tick_error -= tk->xtime_interval >> 1; |
| 1051 | error = ((error - tick_error) >> look_ahead) + tick_error; |
| 1052 | |
| 1053 | /* Finally calculate the adjustment shift value. */ |
| 1054 | i = *interval; |
| 1055 | mult = 1; |
| 1056 | if (error < 0) { |
| 1057 | error = -error; |
| 1058 | *interval = -*interval; |
| 1059 | *offset = -*offset; |
| 1060 | mult = -1; |
| 1061 | } |
| 1062 | for (adj = 0; error > i; adj++) |
| 1063 | error >>= 1; |
| 1064 | |
| 1065 | *interval <<= adj; |
| 1066 | *offset <<= adj; |
| 1067 | return mult << adj; |
| 1068 | } |
| 1069 | |
| 1070 | /* |
| 1071 | * Adjust the multiplier to reduce the error value, |
| 1072 | * this is optimized for the most common adjustments of -1,0,1, |
| 1073 | * for other values we can do a bit more work. |
| 1074 | */ |
| 1075 | static void timekeeping_adjust(struct timekeeper *tk, s64 offset) |
| 1076 | { |
| 1077 | s64 error, interval = tk->cycle_interval; |
| 1078 | int adj; |
| 1079 | |
| 1080 | /* |
| 1081 | * The point of this is to check if the error is greater than half |
| 1082 | * an interval. |
| 1083 | * |
| 1084 | * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs. |
| 1085 | * |
| 1086 | * Note we subtract one in the shift, so that error is really error*2. |
| 1087 | * This "saves" dividing(shifting) interval twice, but keeps the |
| 1088 | * (error > interval) comparison as still measuring if error is |
| 1089 | * larger than half an interval. |
| 1090 | * |
| 1091 | * Note: It does not "save" on aggravation when reading the code. |
| 1092 | */ |
| 1093 | error = tk->ntp_error >> (tk->ntp_error_shift - 1); |
| 1094 | if (error > interval) { |
| 1095 | /* |
| 1096 | * We now divide error by 4(via shift), which checks if |
| 1097 | * the error is greater than twice the interval. |
| 1098 | * If it is greater, we need a bigadjust, if its smaller, |
| 1099 | * we can adjust by 1. |
| 1100 | */ |
| 1101 | error >>= 2; |
| 1102 | /* |
| 1103 | * XXX - In update_wall_time, we round up to the next |
| 1104 | * nanosecond, and store the amount rounded up into |
| 1105 | * the error. This causes the likely below to be unlikely. |
| 1106 | * |
| 1107 | * The proper fix is to avoid rounding up by using |
| 1108 | * the high precision tk->xtime_nsec instead of |
| 1109 | * xtime.tv_nsec everywhere. Fixing this will take some |
| 1110 | * time. |
| 1111 | */ |
| 1112 | if (likely(error <= interval)) |
| 1113 | adj = 1; |
| 1114 | else |
| 1115 | adj = timekeeping_bigadjust(tk, error, &interval, &offset); |
| 1116 | } else { |
| 1117 | if (error < -interval) { |
| 1118 | /* See comment above, this is just switched for the negative */ |
| 1119 | error >>= 2; |
| 1120 | if (likely(error >= -interval)) { |
| 1121 | adj = -1; |
| 1122 | interval = -interval; |
| 1123 | offset = -offset; |
| 1124 | } else { |
| 1125 | adj = timekeeping_bigadjust(tk, error, &interval, &offset); |
| 1126 | } |
| 1127 | } else { |
| 1128 | goto out_adjust; |
| 1129 | } |
| 1130 | } |
| 1131 | |
| 1132 | if (unlikely(tk->clock->maxadj && |
| 1133 | (tk->mult + adj > tk->clock->mult + tk->clock->maxadj))) { |
| 1134 | printk_once(KERN_WARNING |
| 1135 | "Adjusting %s more than 11%% (%ld vs %ld)\n", |
| 1136 | tk->clock->name, (long)tk->mult + adj, |
| 1137 | (long)tk->clock->mult + tk->clock->maxadj); |
| 1138 | } |
| 1139 | /* |
| 1140 | * So the following can be confusing. |
| 1141 | * |
| 1142 | * To keep things simple, lets assume adj == 1 for now. |
| 1143 | * |
| 1144 | * When adj != 1, remember that the interval and offset values |
| 1145 | * have been appropriately scaled so the math is the same. |
| 1146 | * |
| 1147 | * The basic idea here is that we're increasing the multiplier |
| 1148 | * by one, this causes the xtime_interval to be incremented by |
| 1149 | * one cycle_interval. This is because: |
| 1150 | * xtime_interval = cycle_interval * mult |
| 1151 | * So if mult is being incremented by one: |
| 1152 | * xtime_interval = cycle_interval * (mult + 1) |
| 1153 | * Its the same as: |
| 1154 | * xtime_interval = (cycle_interval * mult) + cycle_interval |
| 1155 | * Which can be shortened to: |
| 1156 | * xtime_interval += cycle_interval |
| 1157 | * |
| 1158 | * So offset stores the non-accumulated cycles. Thus the current |
| 1159 | * time (in shifted nanoseconds) is: |
| 1160 | * now = (offset * adj) + xtime_nsec |
| 1161 | * Now, even though we're adjusting the clock frequency, we have |
| 1162 | * to keep time consistent. In other words, we can't jump back |
| 1163 | * in time, and we also want to avoid jumping forward in time. |
| 1164 | * |
| 1165 | * So given the same offset value, we need the time to be the same |
| 1166 | * both before and after the freq adjustment. |
| 1167 | * now = (offset * adj_1) + xtime_nsec_1 |
| 1168 | * now = (offset * adj_2) + xtime_nsec_2 |
| 1169 | * So: |
| 1170 | * (offset * adj_1) + xtime_nsec_1 = |
| 1171 | * (offset * adj_2) + xtime_nsec_2 |
| 1172 | * And we know: |
| 1173 | * adj_2 = adj_1 + 1 |
| 1174 | * So: |
| 1175 | * (offset * adj_1) + xtime_nsec_1 = |
| 1176 | * (offset * (adj_1+1)) + xtime_nsec_2 |
| 1177 | * (offset * adj_1) + xtime_nsec_1 = |
| 1178 | * (offset * adj_1) + offset + xtime_nsec_2 |
| 1179 | * Canceling the sides: |
| 1180 | * xtime_nsec_1 = offset + xtime_nsec_2 |
| 1181 | * Which gives us: |
| 1182 | * xtime_nsec_2 = xtime_nsec_1 - offset |
| 1183 | * Which simplfies to: |
| 1184 | * xtime_nsec -= offset |
| 1185 | * |
| 1186 | * XXX - TODO: Doc ntp_error calculation. |
| 1187 | */ |
| 1188 | tk->mult += adj; |
| 1189 | tk->xtime_interval += interval; |
| 1190 | tk->xtime_nsec -= offset; |
| 1191 | tk->ntp_error -= (interval - offset) << tk->ntp_error_shift; |
| 1192 | |
| 1193 | out_adjust: |
| 1194 | /* |
| 1195 | * It may be possible that when we entered this function, xtime_nsec |
| 1196 | * was very small. Further, if we're slightly speeding the clocksource |
| 1197 | * in the code above, its possible the required corrective factor to |
| 1198 | * xtime_nsec could cause it to underflow. |
| 1199 | * |
| 1200 | * Now, since we already accumulated the second, cannot simply roll |
| 1201 | * the accumulated second back, since the NTP subsystem has been |
| 1202 | * notified via second_overflow. So instead we push xtime_nsec forward |
| 1203 | * by the amount we underflowed, and add that amount into the error. |
| 1204 | * |
| 1205 | * We'll correct this error next time through this function, when |
| 1206 | * xtime_nsec is not as small. |
| 1207 | */ |
| 1208 | if (unlikely((s64)tk->xtime_nsec < 0)) { |
| 1209 | s64 neg = -(s64)tk->xtime_nsec; |
| 1210 | tk->xtime_nsec = 0; |
| 1211 | tk->ntp_error += neg << tk->ntp_error_shift; |
| 1212 | } |
| 1213 | |
| 1214 | } |
| 1215 | |
| 1216 | /** |
| 1217 | * accumulate_nsecs_to_secs - Accumulates nsecs into secs |
| 1218 | * |
| 1219 | * Helper function that accumulates a the nsecs greater then a second |
| 1220 | * from the xtime_nsec field to the xtime_secs field. |
| 1221 | * It also calls into the NTP code to handle leapsecond processing. |
| 1222 | * |
| 1223 | */ |
| 1224 | static inline void accumulate_nsecs_to_secs(struct timekeeper *tk) |
| 1225 | { |
| 1226 | u64 nsecps = (u64)NSEC_PER_SEC << tk->shift; |
| 1227 | |
| 1228 | while (tk->xtime_nsec >= nsecps) { |
| 1229 | int leap; |
| 1230 | |
| 1231 | tk->xtime_nsec -= nsecps; |
| 1232 | tk->xtime_sec++; |
| 1233 | |
| 1234 | /* Figure out if its a leap sec and apply if needed */ |
| 1235 | leap = second_overflow(tk->xtime_sec); |
| 1236 | if (unlikely(leap)) { |
| 1237 | struct timespec ts; |
| 1238 | |
| 1239 | tk->xtime_sec += leap; |
| 1240 | |
| 1241 | ts.tv_sec = leap; |
| 1242 | ts.tv_nsec = 0; |
| 1243 | tk_set_wall_to_mono(tk, |
| 1244 | timespec_sub(tk->wall_to_monotonic, ts)); |
| 1245 | |
| 1246 | __timekeeping_set_tai_offset(tk, tk->tai_offset - leap); |
| 1247 | |
| 1248 | clock_was_set_delayed(); |
| 1249 | } |
| 1250 | } |
| 1251 | } |
| 1252 | |
| 1253 | /** |
| 1254 | * logarithmic_accumulation - shifted accumulation of cycles |
| 1255 | * |
| 1256 | * This functions accumulates a shifted interval of cycles into |
| 1257 | * into a shifted interval nanoseconds. Allows for O(log) accumulation |
| 1258 | * loop. |
| 1259 | * |
| 1260 | * Returns the unconsumed cycles. |
| 1261 | */ |
| 1262 | static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset, |
| 1263 | u32 shift) |
| 1264 | { |
| 1265 | cycle_t interval = tk->cycle_interval << shift; |
| 1266 | u64 raw_nsecs; |
| 1267 | |
| 1268 | /* If the offset is smaller then a shifted interval, do nothing */ |
| 1269 | if (offset < interval) |
| 1270 | return offset; |
| 1271 | |
| 1272 | /* Accumulate one shifted interval */ |
| 1273 | offset -= interval; |
| 1274 | tk->clock->cycle_last += interval; |
| 1275 | |
| 1276 | tk->xtime_nsec += tk->xtime_interval << shift; |
| 1277 | accumulate_nsecs_to_secs(tk); |
| 1278 | |
| 1279 | /* Accumulate raw time */ |
| 1280 | raw_nsecs = (u64)tk->raw_interval << shift; |
| 1281 | raw_nsecs += tk->raw_time.tv_nsec; |
| 1282 | if (raw_nsecs >= NSEC_PER_SEC) { |
| 1283 | u64 raw_secs = raw_nsecs; |
| 1284 | raw_nsecs = do_div(raw_secs, NSEC_PER_SEC); |
| 1285 | tk->raw_time.tv_sec += raw_secs; |
| 1286 | } |
| 1287 | tk->raw_time.tv_nsec = raw_nsecs; |
| 1288 | |
| 1289 | /* Accumulate error between NTP and clock interval */ |
| 1290 | tk->ntp_error += ntp_tick_length() << shift; |
| 1291 | tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) << |
| 1292 | (tk->ntp_error_shift + shift); |
| 1293 | |
| 1294 | return offset; |
| 1295 | } |
| 1296 | |
| 1297 | #ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD |
| 1298 | static inline void old_vsyscall_fixup(struct timekeeper *tk) |
| 1299 | { |
| 1300 | s64 remainder; |
| 1301 | |
| 1302 | /* |
| 1303 | * Store only full nanoseconds into xtime_nsec after rounding |
| 1304 | * it up and add the remainder to the error difference. |
| 1305 | * XXX - This is necessary to avoid small 1ns inconsistnecies caused |
| 1306 | * by truncating the remainder in vsyscalls. However, it causes |
| 1307 | * additional work to be done in timekeeping_adjust(). Once |
| 1308 | * the vsyscall implementations are converted to use xtime_nsec |
| 1309 | * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD |
| 1310 | * users are removed, this can be killed. |
| 1311 | */ |
| 1312 | remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1); |
| 1313 | tk->xtime_nsec -= remainder; |
| 1314 | tk->xtime_nsec += 1ULL << tk->shift; |
| 1315 | tk->ntp_error += remainder << tk->ntp_error_shift; |
| 1316 | |
| 1317 | } |
| 1318 | #else |
| 1319 | #define old_vsyscall_fixup(tk) |
| 1320 | #endif |
| 1321 | |
| 1322 | |
| 1323 | |
| 1324 | /** |
| 1325 | * update_wall_time - Uses the current clocksource to increment the wall time |
| 1326 | * |
| 1327 | */ |
| 1328 | static void update_wall_time(void) |
| 1329 | { |
| 1330 | struct clocksource *clock; |
| 1331 | struct timekeeper *tk = &timekeeper; |
| 1332 | cycle_t offset; |
| 1333 | int shift = 0, maxshift; |
| 1334 | unsigned long flags; |
| 1335 | |
| 1336 | raw_spin_lock_irqsave(&timekeeper_lock, flags); |
| 1337 | write_seqcount_begin(&timekeeper_seq); |
| 1338 | |
| 1339 | /* Make sure we're fully resumed: */ |
| 1340 | if (unlikely(timekeeping_suspended)) |
| 1341 | goto out; |
| 1342 | |
| 1343 | clock = tk->clock; |
| 1344 | |
| 1345 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET |
| 1346 | offset = tk->cycle_interval; |
| 1347 | #else |
| 1348 | offset = (clock->read(clock) - clock->cycle_last) & clock->mask; |
| 1349 | #endif |
| 1350 | |
| 1351 | /* Check if there's really nothing to do */ |
| 1352 | if (offset < tk->cycle_interval) |
| 1353 | goto out; |
| 1354 | |
| 1355 | /* |
| 1356 | * With NO_HZ we may have to accumulate many cycle_intervals |
| 1357 | * (think "ticks") worth of time at once. To do this efficiently, |
| 1358 | * we calculate the largest doubling multiple of cycle_intervals |
| 1359 | * that is smaller than the offset. We then accumulate that |
| 1360 | * chunk in one go, and then try to consume the next smaller |
| 1361 | * doubled multiple. |
| 1362 | */ |
| 1363 | shift = ilog2(offset) - ilog2(tk->cycle_interval); |
| 1364 | shift = max(0, shift); |
| 1365 | /* Bound shift to one less than what overflows tick_length */ |
| 1366 | maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1; |
| 1367 | shift = min(shift, maxshift); |
| 1368 | while (offset >= tk->cycle_interval) { |
| 1369 | offset = logarithmic_accumulation(tk, offset, shift); |
| 1370 | if (offset < tk->cycle_interval<<shift) |
| 1371 | shift--; |
| 1372 | } |
| 1373 | |
| 1374 | /* correct the clock when NTP error is too big */ |
| 1375 | timekeeping_adjust(tk, offset); |
| 1376 | |
| 1377 | /* |
| 1378 | * XXX This can be killed once everyone converts |
| 1379 | * to the new update_vsyscall. |
| 1380 | */ |
| 1381 | old_vsyscall_fixup(tk); |
| 1382 | |
| 1383 | /* |
| 1384 | * Finally, make sure that after the rounding |
| 1385 | * xtime_nsec isn't larger than NSEC_PER_SEC |
| 1386 | */ |
| 1387 | accumulate_nsecs_to_secs(tk); |
| 1388 | |
| 1389 | timekeeping_update(tk, false); |
| 1390 | |
| 1391 | out: |
| 1392 | write_seqcount_end(&timekeeper_seq); |
| 1393 | raw_spin_unlock_irqrestore(&timekeeper_lock, flags); |
| 1394 | |
| 1395 | } |
| 1396 | |
| 1397 | /** |
| 1398 | * getboottime - Return the real time of system boot. |
| 1399 | * @ts: pointer to the timespec to be set |
| 1400 | * |
| 1401 | * Returns the wall-time of boot in a timespec. |
| 1402 | * |
| 1403 | * This is based on the wall_to_monotonic offset and the total suspend |
| 1404 | * time. Calls to settimeofday will affect the value returned (which |
| 1405 | * basically means that however wrong your real time clock is at boot time, |
| 1406 | * you get the right time here). |
| 1407 | */ |
| 1408 | void getboottime(struct timespec *ts) |
| 1409 | { |
| 1410 | struct timekeeper *tk = &timekeeper; |
| 1411 | struct timespec boottime = { |
| 1412 | .tv_sec = tk->wall_to_monotonic.tv_sec + |
| 1413 | tk->total_sleep_time.tv_sec, |
| 1414 | .tv_nsec = tk->wall_to_monotonic.tv_nsec + |
| 1415 | tk->total_sleep_time.tv_nsec |
| 1416 | }; |
| 1417 | |
| 1418 | set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec); |
| 1419 | } |
| 1420 | EXPORT_SYMBOL_GPL(getboottime); |
| 1421 | |
| 1422 | /** |
| 1423 | * get_monotonic_boottime - Returns monotonic time since boot |
| 1424 | * @ts: pointer to the timespec to be set |
| 1425 | * |
| 1426 | * Returns the monotonic time since boot in a timespec. |
| 1427 | * |
| 1428 | * This is similar to CLOCK_MONTONIC/ktime_get_ts, but also |
| 1429 | * includes the time spent in suspend. |
| 1430 | */ |
| 1431 | void get_monotonic_boottime(struct timespec *ts) |
| 1432 | { |
| 1433 | struct timekeeper *tk = &timekeeper; |
| 1434 | struct timespec tomono, sleep; |
| 1435 | s64 nsec; |
| 1436 | unsigned int seq; |
| 1437 | |
| 1438 | WARN_ON(timekeeping_suspended); |
| 1439 | |
| 1440 | do { |
| 1441 | seq = read_seqcount_begin(&timekeeper_seq); |
| 1442 | ts->tv_sec = tk->xtime_sec; |
| 1443 | nsec = timekeeping_get_ns(tk); |
| 1444 | tomono = tk->wall_to_monotonic; |
| 1445 | sleep = tk->total_sleep_time; |
| 1446 | |
| 1447 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 1448 | |
| 1449 | ts->tv_sec += tomono.tv_sec + sleep.tv_sec; |
| 1450 | ts->tv_nsec = 0; |
| 1451 | timespec_add_ns(ts, nsec + tomono.tv_nsec + sleep.tv_nsec); |
| 1452 | } |
| 1453 | EXPORT_SYMBOL_GPL(get_monotonic_boottime); |
| 1454 | |
| 1455 | /** |
| 1456 | * ktime_get_boottime - Returns monotonic time since boot in a ktime |
| 1457 | * |
| 1458 | * Returns the monotonic time since boot in a ktime |
| 1459 | * |
| 1460 | * This is similar to CLOCK_MONTONIC/ktime_get, but also |
| 1461 | * includes the time spent in suspend. |
| 1462 | */ |
| 1463 | ktime_t ktime_get_boottime(void) |
| 1464 | { |
| 1465 | struct timespec ts; |
| 1466 | |
| 1467 | get_monotonic_boottime(&ts); |
| 1468 | return timespec_to_ktime(ts); |
| 1469 | } |
| 1470 | EXPORT_SYMBOL_GPL(ktime_get_boottime); |
| 1471 | |
| 1472 | /** |
| 1473 | * monotonic_to_bootbased - Convert the monotonic time to boot based. |
| 1474 | * @ts: pointer to the timespec to be converted |
| 1475 | */ |
| 1476 | void monotonic_to_bootbased(struct timespec *ts) |
| 1477 | { |
| 1478 | struct timekeeper *tk = &timekeeper; |
| 1479 | |
| 1480 | *ts = timespec_add(*ts, tk->total_sleep_time); |
| 1481 | } |
| 1482 | EXPORT_SYMBOL_GPL(monotonic_to_bootbased); |
| 1483 | |
| 1484 | unsigned long get_seconds(void) |
| 1485 | { |
| 1486 | struct timekeeper *tk = &timekeeper; |
| 1487 | |
| 1488 | return tk->xtime_sec; |
| 1489 | } |
| 1490 | EXPORT_SYMBOL(get_seconds); |
| 1491 | |
| 1492 | struct timespec __current_kernel_time(void) |
| 1493 | { |
| 1494 | struct timekeeper *tk = &timekeeper; |
| 1495 | |
| 1496 | return tk_xtime(tk); |
| 1497 | } |
| 1498 | |
| 1499 | struct timespec current_kernel_time(void) |
| 1500 | { |
| 1501 | struct timekeeper *tk = &timekeeper; |
| 1502 | struct timespec now; |
| 1503 | unsigned long seq; |
| 1504 | |
| 1505 | do { |
| 1506 | seq = read_seqcount_begin(&timekeeper_seq); |
| 1507 | |
| 1508 | now = tk_xtime(tk); |
| 1509 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 1510 | |
| 1511 | return now; |
| 1512 | } |
| 1513 | EXPORT_SYMBOL(current_kernel_time); |
| 1514 | |
| 1515 | struct timespec get_monotonic_coarse(void) |
| 1516 | { |
| 1517 | struct timekeeper *tk = &timekeeper; |
| 1518 | struct timespec now, mono; |
| 1519 | unsigned long seq; |
| 1520 | |
| 1521 | do { |
| 1522 | seq = read_seqcount_begin(&timekeeper_seq); |
| 1523 | |
| 1524 | now = tk_xtime(tk); |
| 1525 | mono = tk->wall_to_monotonic; |
| 1526 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 1527 | |
| 1528 | set_normalized_timespec(&now, now.tv_sec + mono.tv_sec, |
| 1529 | now.tv_nsec + mono.tv_nsec); |
| 1530 | return now; |
| 1531 | } |
| 1532 | |
| 1533 | /* |
| 1534 | * Must hold jiffies_lock |
| 1535 | */ |
| 1536 | void do_timer(unsigned long ticks) |
| 1537 | { |
| 1538 | jiffies_64 += ticks; |
| 1539 | update_wall_time(); |
| 1540 | calc_global_load(ticks); |
| 1541 | } |
| 1542 | |
| 1543 | /** |
| 1544 | * get_xtime_and_monotonic_and_sleep_offset() - get xtime, wall_to_monotonic, |
| 1545 | * and sleep offsets. |
| 1546 | * @xtim: pointer to timespec to be set with xtime |
| 1547 | * @wtom: pointer to timespec to be set with wall_to_monotonic |
| 1548 | * @sleep: pointer to timespec to be set with time in suspend |
| 1549 | */ |
| 1550 | void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim, |
| 1551 | struct timespec *wtom, struct timespec *sleep) |
| 1552 | { |
| 1553 | struct timekeeper *tk = &timekeeper; |
| 1554 | unsigned long seq; |
| 1555 | |
| 1556 | do { |
| 1557 | seq = read_seqcount_begin(&timekeeper_seq); |
| 1558 | *xtim = tk_xtime(tk); |
| 1559 | *wtom = tk->wall_to_monotonic; |
| 1560 | *sleep = tk->total_sleep_time; |
| 1561 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 1562 | } |
| 1563 | |
| 1564 | #ifdef CONFIG_HIGH_RES_TIMERS |
| 1565 | /** |
| 1566 | * ktime_get_update_offsets - hrtimer helper |
| 1567 | * @offs_real: pointer to storage for monotonic -> realtime offset |
| 1568 | * @offs_boot: pointer to storage for monotonic -> boottime offset |
| 1569 | * |
| 1570 | * Returns current monotonic time and updates the offsets |
| 1571 | * Called from hrtimer_interupt() or retrigger_next_event() |
| 1572 | */ |
| 1573 | ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot, |
| 1574 | ktime_t *offs_tai) |
| 1575 | { |
| 1576 | struct timekeeper *tk = &timekeeper; |
| 1577 | ktime_t now; |
| 1578 | unsigned int seq; |
| 1579 | u64 secs, nsecs; |
| 1580 | |
| 1581 | do { |
| 1582 | seq = read_seqcount_begin(&timekeeper_seq); |
| 1583 | |
| 1584 | secs = tk->xtime_sec; |
| 1585 | nsecs = timekeeping_get_ns(tk); |
| 1586 | |
| 1587 | *offs_real = tk->offs_real; |
| 1588 | *offs_boot = tk->offs_boot; |
| 1589 | *offs_tai = tk->offs_tai; |
| 1590 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 1591 | |
| 1592 | now = ktime_add_ns(ktime_set(secs, 0), nsecs); |
| 1593 | now = ktime_sub(now, *offs_real); |
| 1594 | return now; |
| 1595 | } |
| 1596 | #endif |
| 1597 | |
| 1598 | /** |
| 1599 | * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format |
| 1600 | */ |
| 1601 | ktime_t ktime_get_monotonic_offset(void) |
| 1602 | { |
| 1603 | struct timekeeper *tk = &timekeeper; |
| 1604 | unsigned long seq; |
| 1605 | struct timespec wtom; |
| 1606 | |
| 1607 | do { |
| 1608 | seq = read_seqcount_begin(&timekeeper_seq); |
| 1609 | wtom = tk->wall_to_monotonic; |
| 1610 | } while (read_seqcount_retry(&timekeeper_seq, seq)); |
| 1611 | |
| 1612 | return timespec_to_ktime(wtom); |
| 1613 | } |
| 1614 | EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset); |
| 1615 | |
| 1616 | /** |
| 1617 | * do_adjtimex() - Accessor function to NTP __do_adjtimex function |
| 1618 | */ |
| 1619 | int do_adjtimex(struct timex *txc) |
| 1620 | { |
| 1621 | return __do_adjtimex(txc); |
| 1622 | } |
| 1623 | |
| 1624 | |
| 1625 | #ifdef CONFIG_NTP_PPS |
| 1626 | /** |
| 1627 | * hardpps() - Accessor function to NTP __hardpps function |
| 1628 | */ |
| 1629 | void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) |
| 1630 | { |
| 1631 | __hardpps(phase_ts, raw_ts); |
| 1632 | } |
| 1633 | EXPORT_SYMBOL(hardpps); |
| 1634 | #endif |
| 1635 | |
| 1636 | /** |
| 1637 | * xtime_update() - advances the timekeeping infrastructure |
| 1638 | * @ticks: number of ticks, that have elapsed since the last call. |
| 1639 | * |
| 1640 | * Must be called with interrupts disabled. |
| 1641 | */ |
| 1642 | void xtime_update(unsigned long ticks) |
| 1643 | { |
| 1644 | write_seqlock(&jiffies_lock); |
| 1645 | do_timer(ticks); |
| 1646 | write_sequnlock(&jiffies_lock); |
| 1647 | } |