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1da177e4 LT |
1 | /* |
2 | * linux/kernel/time.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * | |
6 | * This file contains the interface functions for the various | |
7 | * time related system calls: time, stime, gettimeofday, settimeofday, | |
8 | * adjtime | |
9 | */ | |
10 | /* | |
11 | * Modification history kernel/time.c | |
12 | * | |
13 | * 1993-09-02 Philip Gladstone | |
14 | * Created file with time related functions from sched.c and adjtimex() | |
15 | * 1993-10-08 Torsten Duwe | |
16 | * adjtime interface update and CMOS clock write code | |
17 | * 1995-08-13 Torsten Duwe | |
18 | * kernel PLL updated to 1994-12-13 specs (rfc-1589) | |
19 | * 1999-01-16 Ulrich Windl | |
20 | * Introduced error checking for many cases in adjtimex(). | |
21 | * Updated NTP code according to technical memorandum Jan '96 | |
22 | * "A Kernel Model for Precision Timekeeping" by Dave Mills | |
23 | * Allow time_constant larger than MAXTC(6) for NTP v4 (MAXTC == 10) | |
24 | * (Even though the technical memorandum forbids it) | |
25 | * 2004-07-14 Christoph Lameter | |
26 | * Added getnstimeofday to allow the posix timer functions to return | |
27 | * with nanosecond accuracy | |
28 | */ | |
29 | ||
30 | #include <linux/module.h> | |
31 | #include <linux/timex.h> | |
c59ede7b | 32 | #include <linux/capability.h> |
1da177e4 LT |
33 | #include <linux/errno.h> |
34 | #include <linux/smp_lock.h> | |
35 | #include <linux/syscalls.h> | |
36 | #include <linux/security.h> | |
37 | #include <linux/fs.h> | |
38 | #include <linux/module.h> | |
39 | ||
40 | #include <asm/uaccess.h> | |
41 | #include <asm/unistd.h> | |
42 | ||
43 | /* | |
44 | * The timezone where the local system is located. Used as a default by some | |
45 | * programs who obtain this value by using gettimeofday. | |
46 | */ | |
47 | struct timezone sys_tz; | |
48 | ||
49 | EXPORT_SYMBOL(sys_tz); | |
50 | ||
51 | #ifdef __ARCH_WANT_SYS_TIME | |
52 | ||
53 | /* | |
54 | * sys_time() can be implemented in user-level using | |
55 | * sys_gettimeofday(). Is this for backwards compatibility? If so, | |
56 | * why not move it into the appropriate arch directory (for those | |
57 | * architectures that need it). | |
58 | */ | |
59 | asmlinkage long sys_time(time_t __user * tloc) | |
60 | { | |
61 | time_t i; | |
62 | struct timeval tv; | |
63 | ||
64 | do_gettimeofday(&tv); | |
65 | i = tv.tv_sec; | |
66 | ||
67 | if (tloc) { | |
68 | if (put_user(i,tloc)) | |
69 | i = -EFAULT; | |
70 | } | |
71 | return i; | |
72 | } | |
73 | ||
74 | /* | |
75 | * sys_stime() can be implemented in user-level using | |
76 | * sys_settimeofday(). Is this for backwards compatibility? If so, | |
77 | * why not move it into the appropriate arch directory (for those | |
78 | * architectures that need it). | |
79 | */ | |
80 | ||
81 | asmlinkage long sys_stime(time_t __user *tptr) | |
82 | { | |
83 | struct timespec tv; | |
84 | int err; | |
85 | ||
86 | if (get_user(tv.tv_sec, tptr)) | |
87 | return -EFAULT; | |
88 | ||
89 | tv.tv_nsec = 0; | |
90 | ||
91 | err = security_settime(&tv, NULL); | |
92 | if (err) | |
93 | return err; | |
94 | ||
95 | do_settimeofday(&tv); | |
96 | return 0; | |
97 | } | |
98 | ||
99 | #endif /* __ARCH_WANT_SYS_TIME */ | |
100 | ||
101 | asmlinkage long sys_gettimeofday(struct timeval __user *tv, struct timezone __user *tz) | |
102 | { | |
103 | if (likely(tv != NULL)) { | |
104 | struct timeval ktv; | |
105 | do_gettimeofday(&ktv); | |
106 | if (copy_to_user(tv, &ktv, sizeof(ktv))) | |
107 | return -EFAULT; | |
108 | } | |
109 | if (unlikely(tz != NULL)) { | |
110 | if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) | |
111 | return -EFAULT; | |
112 | } | |
113 | return 0; | |
114 | } | |
115 | ||
116 | /* | |
117 | * Adjust the time obtained from the CMOS to be UTC time instead of | |
118 | * local time. | |
119 | * | |
120 | * This is ugly, but preferable to the alternatives. Otherwise we | |
121 | * would either need to write a program to do it in /etc/rc (and risk | |
122 | * confusion if the program gets run more than once; it would also be | |
123 | * hard to make the program warp the clock precisely n hours) or | |
124 | * compile in the timezone information into the kernel. Bad, bad.... | |
125 | * | |
126 | * - TYT, 1992-01-01 | |
127 | * | |
128 | * The best thing to do is to keep the CMOS clock in universal time (UTC) | |
129 | * as real UNIX machines always do it. This avoids all headaches about | |
130 | * daylight saving times and warping kernel clocks. | |
131 | */ | |
77933d72 | 132 | static inline void warp_clock(void) |
1da177e4 LT |
133 | { |
134 | write_seqlock_irq(&xtime_lock); | |
135 | wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60; | |
136 | xtime.tv_sec += sys_tz.tz_minuteswest * 60; | |
137 | time_interpolator_reset(); | |
138 | write_sequnlock_irq(&xtime_lock); | |
139 | clock_was_set(); | |
140 | } | |
141 | ||
142 | /* | |
143 | * In case for some reason the CMOS clock has not already been running | |
144 | * in UTC, but in some local time: The first time we set the timezone, | |
145 | * we will warp the clock so that it is ticking UTC time instead of | |
146 | * local time. Presumably, if someone is setting the timezone then we | |
147 | * are running in an environment where the programs understand about | |
148 | * timezones. This should be done at boot time in the /etc/rc script, | |
149 | * as soon as possible, so that the clock can be set right. Otherwise, | |
150 | * various programs will get confused when the clock gets warped. | |
151 | */ | |
152 | ||
153 | int do_sys_settimeofday(struct timespec *tv, struct timezone *tz) | |
154 | { | |
155 | static int firsttime = 1; | |
156 | int error = 0; | |
157 | ||
718bcceb TG |
158 | if (!timespec_valid(tv)) |
159 | return -EINVAL; | |
160 | ||
1da177e4 LT |
161 | error = security_settime(tv, tz); |
162 | if (error) | |
163 | return error; | |
164 | ||
165 | if (tz) { | |
166 | /* SMP safe, global irq locking makes it work. */ | |
167 | sys_tz = *tz; | |
168 | if (firsttime) { | |
169 | firsttime = 0; | |
170 | if (!tv) | |
171 | warp_clock(); | |
172 | } | |
173 | } | |
174 | if (tv) | |
175 | { | |
176 | /* SMP safe, again the code in arch/foo/time.c should | |
177 | * globally block out interrupts when it runs. | |
178 | */ | |
179 | return do_settimeofday(tv); | |
180 | } | |
181 | return 0; | |
182 | } | |
183 | ||
184 | asmlinkage long sys_settimeofday(struct timeval __user *tv, | |
185 | struct timezone __user *tz) | |
186 | { | |
187 | struct timeval user_tv; | |
188 | struct timespec new_ts; | |
189 | struct timezone new_tz; | |
190 | ||
191 | if (tv) { | |
192 | if (copy_from_user(&user_tv, tv, sizeof(*tv))) | |
193 | return -EFAULT; | |
194 | new_ts.tv_sec = user_tv.tv_sec; | |
195 | new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; | |
196 | } | |
197 | if (tz) { | |
198 | if (copy_from_user(&new_tz, tz, sizeof(*tz))) | |
199 | return -EFAULT; | |
200 | } | |
201 | ||
202 | return do_sys_settimeofday(tv ? &new_ts : NULL, tz ? &new_tz : NULL); | |
203 | } | |
204 | ||
205 | long pps_offset; /* pps time offset (us) */ | |
206 | long pps_jitter = MAXTIME; /* time dispersion (jitter) (us) */ | |
207 | ||
208 | long pps_freq; /* frequency offset (scaled ppm) */ | |
209 | long pps_stabil = MAXFREQ; /* frequency dispersion (scaled ppm) */ | |
210 | ||
211 | long pps_valid = PPS_VALID; /* pps signal watchdog counter */ | |
212 | ||
213 | int pps_shift = PPS_SHIFT; /* interval duration (s) (shift) */ | |
214 | ||
215 | long pps_jitcnt; /* jitter limit exceeded */ | |
216 | long pps_calcnt; /* calibration intervals */ | |
217 | long pps_errcnt; /* calibration errors */ | |
218 | long pps_stbcnt; /* stability limit exceeded */ | |
219 | ||
220 | /* hook for a loadable hardpps kernel module */ | |
221 | void (*hardpps_ptr)(struct timeval *); | |
222 | ||
223 | /* we call this to notify the arch when the clock is being | |
224 | * controlled. If no such arch routine, do nothing. | |
225 | */ | |
226 | void __attribute__ ((weak)) notify_arch_cmos_timer(void) | |
227 | { | |
228 | return; | |
229 | } | |
230 | ||
231 | /* adjtimex mainly allows reading (and writing, if superuser) of | |
232 | * kernel time-keeping variables. used by xntpd. | |
233 | */ | |
234 | int do_adjtimex(struct timex *txc) | |
235 | { | |
236 | long ltemp, mtemp, save_adjust; | |
237 | int result; | |
238 | ||
239 | /* In order to modify anything, you gotta be super-user! */ | |
240 | if (txc->modes && !capable(CAP_SYS_TIME)) | |
241 | return -EPERM; | |
242 | ||
243 | /* Now we validate the data before disabling interrupts */ | |
244 | ||
245 | if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT) | |
246 | /* singleshot must not be used with any other mode bits */ | |
247 | if (txc->modes != ADJ_OFFSET_SINGLESHOT) | |
248 | return -EINVAL; | |
249 | ||
250 | if (txc->modes != ADJ_OFFSET_SINGLESHOT && (txc->modes & ADJ_OFFSET)) | |
251 | /* adjustment Offset limited to +- .512 seconds */ | |
252 | if (txc->offset <= - MAXPHASE || txc->offset >= MAXPHASE ) | |
253 | return -EINVAL; | |
254 | ||
255 | /* if the quartz is off by more than 10% something is VERY wrong ! */ | |
256 | if (txc->modes & ADJ_TICK) | |
257 | if (txc->tick < 900000/USER_HZ || | |
258 | txc->tick > 1100000/USER_HZ) | |
259 | return -EINVAL; | |
260 | ||
261 | write_seqlock_irq(&xtime_lock); | |
262 | result = time_state; /* mostly `TIME_OK' */ | |
263 | ||
264 | /* Save for later - semantics of adjtime is to return old value */ | |
265 | save_adjust = time_next_adjust ? time_next_adjust : time_adjust; | |
266 | ||
267 | #if 0 /* STA_CLOCKERR is never set yet */ | |
268 | time_status &= ~STA_CLOCKERR; /* reset STA_CLOCKERR */ | |
269 | #endif | |
270 | /* If there are input parameters, then process them */ | |
271 | if (txc->modes) | |
272 | { | |
273 | if (txc->modes & ADJ_STATUS) /* only set allowed bits */ | |
274 | time_status = (txc->status & ~STA_RONLY) | | |
275 | (time_status & STA_RONLY); | |
276 | ||
277 | if (txc->modes & ADJ_FREQUENCY) { /* p. 22 */ | |
278 | if (txc->freq > MAXFREQ || txc->freq < -MAXFREQ) { | |
279 | result = -EINVAL; | |
280 | goto leave; | |
281 | } | |
282 | time_freq = txc->freq - pps_freq; | |
283 | } | |
284 | ||
285 | if (txc->modes & ADJ_MAXERROR) { | |
286 | if (txc->maxerror < 0 || txc->maxerror >= NTP_PHASE_LIMIT) { | |
287 | result = -EINVAL; | |
288 | goto leave; | |
289 | } | |
290 | time_maxerror = txc->maxerror; | |
291 | } | |
292 | ||
293 | if (txc->modes & ADJ_ESTERROR) { | |
294 | if (txc->esterror < 0 || txc->esterror >= NTP_PHASE_LIMIT) { | |
295 | result = -EINVAL; | |
296 | goto leave; | |
297 | } | |
298 | time_esterror = txc->esterror; | |
299 | } | |
300 | ||
301 | if (txc->modes & ADJ_TIMECONST) { /* p. 24 */ | |
302 | if (txc->constant < 0) { /* NTP v4 uses values > 6 */ | |
303 | result = -EINVAL; | |
304 | goto leave; | |
305 | } | |
306 | time_constant = txc->constant; | |
307 | } | |
308 | ||
309 | if (txc->modes & ADJ_OFFSET) { /* values checked earlier */ | |
310 | if (txc->modes == ADJ_OFFSET_SINGLESHOT) { | |
311 | /* adjtime() is independent from ntp_adjtime() */ | |
312 | if ((time_next_adjust = txc->offset) == 0) | |
313 | time_adjust = 0; | |
314 | } | |
315 | else if ( time_status & (STA_PLL | STA_PPSTIME) ) { | |
316 | ltemp = (time_status & (STA_PPSTIME | STA_PPSSIGNAL)) == | |
317 | (STA_PPSTIME | STA_PPSSIGNAL) ? | |
318 | pps_offset : txc->offset; | |
319 | ||
320 | /* | |
321 | * Scale the phase adjustment and | |
322 | * clamp to the operating range. | |
323 | */ | |
324 | if (ltemp > MAXPHASE) | |
325 | time_offset = MAXPHASE << SHIFT_UPDATE; | |
326 | else if (ltemp < -MAXPHASE) | |
327 | time_offset = -(MAXPHASE << SHIFT_UPDATE); | |
328 | else | |
329 | time_offset = ltemp << SHIFT_UPDATE; | |
330 | ||
331 | /* | |
332 | * Select whether the frequency is to be controlled | |
333 | * and in which mode (PLL or FLL). Clamp to the operating | |
334 | * range. Ugly multiply/divide should be replaced someday. | |
335 | */ | |
336 | ||
337 | if (time_status & STA_FREQHOLD || time_reftime == 0) | |
338 | time_reftime = xtime.tv_sec; | |
339 | mtemp = xtime.tv_sec - time_reftime; | |
340 | time_reftime = xtime.tv_sec; | |
341 | if (time_status & STA_FLL) { | |
342 | if (mtemp >= MINSEC) { | |
343 | ltemp = (time_offset / mtemp) << (SHIFT_USEC - | |
344 | SHIFT_UPDATE); | |
1bb34a41 | 345 | time_freq += shift_right(ltemp, SHIFT_KH); |
1da177e4 LT |
346 | } else /* calibration interval too short (p. 12) */ |
347 | result = TIME_ERROR; | |
348 | } else { /* PLL mode */ | |
349 | if (mtemp < MAXSEC) { | |
350 | ltemp *= mtemp; | |
1bb34a41 | 351 | time_freq += shift_right(ltemp,(time_constant + |
1da177e4 | 352 | time_constant + |
1bb34a41 | 353 | SHIFT_KF - SHIFT_USEC)); |
1da177e4 LT |
354 | } else /* calibration interval too long (p. 12) */ |
355 | result = TIME_ERROR; | |
356 | } | |
1bb34a41 | 357 | time_freq = min(time_freq, time_tolerance); |
358 | time_freq = max(time_freq, -time_tolerance); | |
1da177e4 LT |
359 | } /* STA_PLL || STA_PPSTIME */ |
360 | } /* txc->modes & ADJ_OFFSET */ | |
361 | if (txc->modes & ADJ_TICK) { | |
362 | tick_usec = txc->tick; | |
363 | tick_nsec = TICK_USEC_TO_NSEC(tick_usec); | |
364 | } | |
365 | } /* txc->modes */ | |
366 | leave: if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0 | |
367 | || ((time_status & (STA_PPSFREQ|STA_PPSTIME)) != 0 | |
368 | && (time_status & STA_PPSSIGNAL) == 0) | |
369 | /* p. 24, (b) */ | |
370 | || ((time_status & (STA_PPSTIME|STA_PPSJITTER)) | |
371 | == (STA_PPSTIME|STA_PPSJITTER)) | |
372 | /* p. 24, (c) */ | |
373 | || ((time_status & STA_PPSFREQ) != 0 | |
374 | && (time_status & (STA_PPSWANDER|STA_PPSERROR)) != 0)) | |
375 | /* p. 24, (d) */ | |
376 | result = TIME_ERROR; | |
377 | ||
378 | if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT) | |
379 | txc->offset = save_adjust; | |
380 | else { | |
1bb34a41 | 381 | txc->offset = shift_right(time_offset, SHIFT_UPDATE); |
1da177e4 LT |
382 | } |
383 | txc->freq = time_freq + pps_freq; | |
384 | txc->maxerror = time_maxerror; | |
385 | txc->esterror = time_esterror; | |
386 | txc->status = time_status; | |
387 | txc->constant = time_constant; | |
388 | txc->precision = time_precision; | |
389 | txc->tolerance = time_tolerance; | |
390 | txc->tick = tick_usec; | |
391 | txc->ppsfreq = pps_freq; | |
392 | txc->jitter = pps_jitter >> PPS_AVG; | |
393 | txc->shift = pps_shift; | |
394 | txc->stabil = pps_stabil; | |
395 | txc->jitcnt = pps_jitcnt; | |
396 | txc->calcnt = pps_calcnt; | |
397 | txc->errcnt = pps_errcnt; | |
398 | txc->stbcnt = pps_stbcnt; | |
399 | write_sequnlock_irq(&xtime_lock); | |
400 | do_gettimeofday(&txc->time); | |
401 | notify_arch_cmos_timer(); | |
402 | return(result); | |
403 | } | |
404 | ||
405 | asmlinkage long sys_adjtimex(struct timex __user *txc_p) | |
406 | { | |
407 | struct timex txc; /* Local copy of parameter */ | |
408 | int ret; | |
409 | ||
410 | /* Copy the user data space into the kernel copy | |
411 | * structure. But bear in mind that the structures | |
412 | * may change | |
413 | */ | |
414 | if(copy_from_user(&txc, txc_p, sizeof(struct timex))) | |
415 | return -EFAULT; | |
416 | ret = do_adjtimex(&txc); | |
417 | return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret; | |
418 | } | |
419 | ||
420 | inline struct timespec current_kernel_time(void) | |
421 | { | |
422 | struct timespec now; | |
423 | unsigned long seq; | |
424 | ||
425 | do { | |
426 | seq = read_seqbegin(&xtime_lock); | |
427 | ||
428 | now = xtime; | |
429 | } while (read_seqretry(&xtime_lock, seq)); | |
430 | ||
431 | return now; | |
432 | } | |
433 | ||
434 | EXPORT_SYMBOL(current_kernel_time); | |
435 | ||
436 | /** | |
437 | * current_fs_time - Return FS time | |
438 | * @sb: Superblock. | |
439 | * | |
440 | * Return the current time truncated to the time granuality supported by | |
441 | * the fs. | |
442 | */ | |
443 | struct timespec current_fs_time(struct super_block *sb) | |
444 | { | |
445 | struct timespec now = current_kernel_time(); | |
446 | return timespec_trunc(now, sb->s_time_gran); | |
447 | } | |
448 | EXPORT_SYMBOL(current_fs_time); | |
449 | ||
450 | /** | |
451 | * timespec_trunc - Truncate timespec to a granuality | |
452 | * @t: Timespec | |
453 | * @gran: Granuality in ns. | |
454 | * | |
455 | * Truncate a timespec to a granuality. gran must be smaller than a second. | |
456 | * Always rounds down. | |
457 | * | |
458 | * This function should be only used for timestamps returned by | |
459 | * current_kernel_time() or CURRENT_TIME, not with do_gettimeofday() because | |
460 | * it doesn't handle the better resolution of the later. | |
461 | */ | |
462 | struct timespec timespec_trunc(struct timespec t, unsigned gran) | |
463 | { | |
464 | /* | |
465 | * Division is pretty slow so avoid it for common cases. | |
466 | * Currently current_kernel_time() never returns better than | |
467 | * jiffies resolution. Exploit that. | |
468 | */ | |
469 | if (gran <= jiffies_to_usecs(1) * 1000) { | |
470 | /* nothing */ | |
471 | } else if (gran == 1000000000) { | |
472 | t.tv_nsec = 0; | |
473 | } else { | |
474 | t.tv_nsec -= t.tv_nsec % gran; | |
475 | } | |
476 | return t; | |
477 | } | |
478 | EXPORT_SYMBOL(timespec_trunc); | |
479 | ||
480 | #ifdef CONFIG_TIME_INTERPOLATION | |
481 | void getnstimeofday (struct timespec *tv) | |
482 | { | |
483 | unsigned long seq,sec,nsec; | |
484 | ||
485 | do { | |
486 | seq = read_seqbegin(&xtime_lock); | |
487 | sec = xtime.tv_sec; | |
488 | nsec = xtime.tv_nsec+time_interpolator_get_offset(); | |
489 | } while (unlikely(read_seqretry(&xtime_lock, seq))); | |
490 | ||
491 | while (unlikely(nsec >= NSEC_PER_SEC)) { | |
492 | nsec -= NSEC_PER_SEC; | |
493 | ++sec; | |
494 | } | |
495 | tv->tv_sec = sec; | |
496 | tv->tv_nsec = nsec; | |
497 | } | |
498 | EXPORT_SYMBOL_GPL(getnstimeofday); | |
499 | ||
500 | int do_settimeofday (struct timespec *tv) | |
501 | { | |
502 | time_t wtm_sec, sec = tv->tv_sec; | |
503 | long wtm_nsec, nsec = tv->tv_nsec; | |
504 | ||
505 | if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) | |
506 | return -EINVAL; | |
507 | ||
508 | write_seqlock_irq(&xtime_lock); | |
509 | { | |
1da177e4 LT |
510 | wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); |
511 | wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); | |
512 | ||
513 | set_normalized_timespec(&xtime, sec, nsec); | |
514 | set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); | |
515 | ||
516 | time_adjust = 0; /* stop active adjtime() */ | |
517 | time_status |= STA_UNSYNC; | |
518 | time_maxerror = NTP_PHASE_LIMIT; | |
519 | time_esterror = NTP_PHASE_LIMIT; | |
520 | time_interpolator_reset(); | |
521 | } | |
522 | write_sequnlock_irq(&xtime_lock); | |
523 | clock_was_set(); | |
524 | return 0; | |
525 | } | |
943eae03 | 526 | EXPORT_SYMBOL(do_settimeofday); |
1da177e4 LT |
527 | |
528 | void do_gettimeofday (struct timeval *tv) | |
529 | { | |
530 | unsigned long seq, nsec, usec, sec, offset; | |
531 | do { | |
532 | seq = read_seqbegin(&xtime_lock); | |
533 | offset = time_interpolator_get_offset(); | |
534 | sec = xtime.tv_sec; | |
535 | nsec = xtime.tv_nsec; | |
536 | } while (unlikely(read_seqretry(&xtime_lock, seq))); | |
537 | ||
538 | usec = (nsec + offset) / 1000; | |
539 | ||
540 | while (unlikely(usec >= USEC_PER_SEC)) { | |
541 | usec -= USEC_PER_SEC; | |
542 | ++sec; | |
543 | } | |
544 | ||
545 | tv->tv_sec = sec; | |
546 | tv->tv_usec = usec; | |
547 | } | |
548 | ||
549 | EXPORT_SYMBOL(do_gettimeofday); | |
550 | ||
551 | ||
552 | #else | |
553 | /* | |
554 | * Simulate gettimeofday using do_gettimeofday which only allows a timeval | |
555 | * and therefore only yields usec accuracy | |
556 | */ | |
557 | void getnstimeofday(struct timespec *tv) | |
558 | { | |
559 | struct timeval x; | |
560 | ||
561 | do_gettimeofday(&x); | |
562 | tv->tv_sec = x.tv_sec; | |
563 | tv->tv_nsec = x.tv_usec * NSEC_PER_USEC; | |
564 | } | |
c6ecf7ed | 565 | EXPORT_SYMBOL_GPL(getnstimeofday); |
1da177e4 LT |
566 | #endif |
567 | ||
753be622 TG |
568 | /* Converts Gregorian date to seconds since 1970-01-01 00:00:00. |
569 | * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 | |
570 | * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. | |
571 | * | |
572 | * [For the Julian calendar (which was used in Russia before 1917, | |
573 | * Britain & colonies before 1752, anywhere else before 1582, | |
574 | * and is still in use by some communities) leave out the | |
575 | * -year/100+year/400 terms, and add 10.] | |
576 | * | |
577 | * This algorithm was first published by Gauss (I think). | |
578 | * | |
579 | * WARNING: this function will overflow on 2106-02-07 06:28:16 on | |
580 | * machines were long is 32-bit! (However, as time_t is signed, we | |
581 | * will already get problems at other places on 2038-01-19 03:14:08) | |
582 | */ | |
583 | unsigned long | |
f4818900 IM |
584 | mktime(const unsigned int year0, const unsigned int mon0, |
585 | const unsigned int day, const unsigned int hour, | |
586 | const unsigned int min, const unsigned int sec) | |
753be622 | 587 | { |
f4818900 IM |
588 | unsigned int mon = mon0, year = year0; |
589 | ||
590 | /* 1..12 -> 11,12,1..10 */ | |
591 | if (0 >= (int) (mon -= 2)) { | |
592 | mon += 12; /* Puts Feb last since it has leap day */ | |
753be622 TG |
593 | year -= 1; |
594 | } | |
595 | ||
596 | return ((((unsigned long) | |
597 | (year/4 - year/100 + year/400 + 367*mon/12 + day) + | |
598 | year*365 - 719499 | |
599 | )*24 + hour /* now have hours */ | |
600 | )*60 + min /* now have minutes */ | |
601 | )*60 + sec; /* finally seconds */ | |
602 | } | |
603 | ||
199e7056 AM |
604 | EXPORT_SYMBOL(mktime); |
605 | ||
753be622 TG |
606 | /** |
607 | * set_normalized_timespec - set timespec sec and nsec parts and normalize | |
608 | * | |
609 | * @ts: pointer to timespec variable to be set | |
610 | * @sec: seconds to set | |
611 | * @nsec: nanoseconds to set | |
612 | * | |
613 | * Set seconds and nanoseconds field of a timespec variable and | |
614 | * normalize to the timespec storage format | |
615 | * | |
616 | * Note: The tv_nsec part is always in the range of | |
617 | * 0 <= tv_nsec < NSEC_PER_SEC | |
618 | * For negative values only the tv_sec field is negative ! | |
619 | */ | |
f4818900 | 620 | void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec) |
753be622 TG |
621 | { |
622 | while (nsec >= NSEC_PER_SEC) { | |
623 | nsec -= NSEC_PER_SEC; | |
624 | ++sec; | |
625 | } | |
626 | while (nsec < 0) { | |
627 | nsec += NSEC_PER_SEC; | |
628 | --sec; | |
629 | } | |
630 | ts->tv_sec = sec; | |
631 | ts->tv_nsec = nsec; | |
632 | } | |
633 | ||
f8f46da3 TG |
634 | /** |
635 | * ns_to_timespec - Convert nanoseconds to timespec | |
636 | * @nsec: the nanoseconds value to be converted | |
637 | * | |
638 | * Returns the timespec representation of the nsec parameter. | |
639 | */ | |
640 | inline struct timespec ns_to_timespec(const nsec_t nsec) | |
641 | { | |
642 | struct timespec ts; | |
643 | ||
644 | if (nsec) | |
645 | ts.tv_sec = div_long_long_rem_signed(nsec, NSEC_PER_SEC, | |
646 | &ts.tv_nsec); | |
647 | else | |
648 | ts.tv_sec = ts.tv_nsec = 0; | |
649 | ||
650 | return ts; | |
651 | } | |
652 | ||
653 | /** | |
654 | * ns_to_timeval - Convert nanoseconds to timeval | |
655 | * @nsec: the nanoseconds value to be converted | |
656 | * | |
657 | * Returns the timeval representation of the nsec parameter. | |
658 | */ | |
659 | struct timeval ns_to_timeval(const nsec_t nsec) | |
660 | { | |
661 | struct timespec ts = ns_to_timespec(nsec); | |
662 | struct timeval tv; | |
663 | ||
664 | tv.tv_sec = ts.tv_sec; | |
665 | tv.tv_usec = (suseconds_t) ts.tv_nsec / 1000; | |
666 | ||
667 | return tv; | |
668 | } | |
669 | ||
1da177e4 LT |
670 | #if (BITS_PER_LONG < 64) |
671 | u64 get_jiffies_64(void) | |
672 | { | |
673 | unsigned long seq; | |
674 | u64 ret; | |
675 | ||
676 | do { | |
677 | seq = read_seqbegin(&xtime_lock); | |
678 | ret = jiffies_64; | |
679 | } while (read_seqretry(&xtime_lock, seq)); | |
680 | return ret; | |
681 | } | |
682 | ||
683 | EXPORT_SYMBOL(get_jiffies_64); | |
684 | #endif | |
685 | ||
686 | EXPORT_SYMBOL(jiffies); |