Commit | Line | Data |
---|---|---|
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 | |
6fa6c3b1 | 12 | * |
1da177e4 | 13 | * 1993-09-02 Philip Gladstone |
0a0fca9d | 14 | * Created file with time related functions from sched/core.c and adjtimex() |
1da177e4 LT |
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 | ||
9984de1a | 30 | #include <linux/export.h> |
88c4318d | 31 | #include <linux/kernel.h> |
1da177e4 | 32 | #include <linux/timex.h> |
c59ede7b | 33 | #include <linux/capability.h> |
189374ae | 34 | #include <linux/timekeeper_internal.h> |
1da177e4 | 35 | #include <linux/errno.h> |
1da177e4 LT |
36 | #include <linux/syscalls.h> |
37 | #include <linux/security.h> | |
38 | #include <linux/fs.h> | |
71abb3af | 39 | #include <linux/math64.h> |
e3d5a27d | 40 | #include <linux/ptrace.h> |
1da177e4 | 41 | |
7c0f6ba6 | 42 | #include <linux/uaccess.h> |
3a4d44b6 | 43 | #include <linux/compat.h> |
1da177e4 LT |
44 | #include <asm/unistd.h> |
45 | ||
0a227985 | 46 | #include <generated/timeconst.h> |
8b094cd0 | 47 | #include "timekeeping.h" |
bdc80787 | 48 | |
6fa6c3b1 | 49 | /* |
1da177e4 LT |
50 | * The timezone where the local system is located. Used as a default by some |
51 | * programs who obtain this value by using gettimeofday. | |
52 | */ | |
53 | struct timezone sys_tz; | |
54 | ||
55 | EXPORT_SYMBOL(sys_tz); | |
56 | ||
57 | #ifdef __ARCH_WANT_SYS_TIME | |
58 | ||
59 | /* | |
60 | * sys_time() can be implemented in user-level using | |
61 | * sys_gettimeofday(). Is this for backwards compatibility? If so, | |
62 | * why not move it into the appropriate arch directory (for those | |
63 | * architectures that need it). | |
64 | */ | |
58fd3aa2 | 65 | SYSCALL_DEFINE1(time, time_t __user *, tloc) |
1da177e4 | 66 | { |
f20bf612 | 67 | time_t i = get_seconds(); |
1da177e4 LT |
68 | |
69 | if (tloc) { | |
20082208 | 70 | if (put_user(i,tloc)) |
e3d5a27d | 71 | return -EFAULT; |
1da177e4 | 72 | } |
e3d5a27d | 73 | force_successful_syscall_return(); |
1da177e4 LT |
74 | return i; |
75 | } | |
76 | ||
77 | /* | |
78 | * sys_stime() can be implemented in user-level using | |
79 | * sys_settimeofday(). Is this for backwards compatibility? If so, | |
80 | * why not move it into the appropriate arch directory (for those | |
81 | * architectures that need it). | |
82 | */ | |
6fa6c3b1 | 83 | |
58fd3aa2 | 84 | SYSCALL_DEFINE1(stime, time_t __user *, tptr) |
1da177e4 LT |
85 | { |
86 | struct timespec tv; | |
87 | int err; | |
88 | ||
89 | if (get_user(tv.tv_sec, tptr)) | |
90 | return -EFAULT; | |
91 | ||
92 | tv.tv_nsec = 0; | |
93 | ||
94 | err = security_settime(&tv, NULL); | |
95 | if (err) | |
96 | return err; | |
97 | ||
98 | do_settimeofday(&tv); | |
99 | return 0; | |
100 | } | |
101 | ||
102 | #endif /* __ARCH_WANT_SYS_TIME */ | |
103 | ||
b180db2c AV |
104 | #ifdef CONFIG_COMPAT |
105 | #ifdef __ARCH_WANT_COMPAT_SYS_TIME | |
106 | ||
107 | /* compat_time_t is a 32 bit "long" and needs to get converted. */ | |
108 | COMPAT_SYSCALL_DEFINE1(time, compat_time_t __user *, tloc) | |
109 | { | |
110 | struct timeval tv; | |
111 | compat_time_t i; | |
112 | ||
113 | do_gettimeofday(&tv); | |
114 | i = tv.tv_sec; | |
115 | ||
116 | if (tloc) { | |
117 | if (put_user(i,tloc)) | |
118 | return -EFAULT; | |
119 | } | |
120 | force_successful_syscall_return(); | |
121 | return i; | |
122 | } | |
123 | ||
124 | COMPAT_SYSCALL_DEFINE1(stime, compat_time_t __user *, tptr) | |
125 | { | |
126 | struct timespec tv; | |
127 | int err; | |
128 | ||
129 | if (get_user(tv.tv_sec, tptr)) | |
130 | return -EFAULT; | |
131 | ||
132 | tv.tv_nsec = 0; | |
133 | ||
134 | err = security_settime(&tv, NULL); | |
135 | if (err) | |
136 | return err; | |
137 | ||
138 | do_settimeofday(&tv); | |
139 | return 0; | |
140 | } | |
141 | ||
142 | #endif /* __ARCH_WANT_COMPAT_SYS_TIME */ | |
143 | #endif | |
144 | ||
58fd3aa2 HC |
145 | SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv, |
146 | struct timezone __user *, tz) | |
1da177e4 LT |
147 | { |
148 | if (likely(tv != NULL)) { | |
149 | struct timeval ktv; | |
150 | do_gettimeofday(&ktv); | |
151 | if (copy_to_user(tv, &ktv, sizeof(ktv))) | |
152 | return -EFAULT; | |
153 | } | |
154 | if (unlikely(tz != NULL)) { | |
155 | if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) | |
156 | return -EFAULT; | |
157 | } | |
158 | return 0; | |
159 | } | |
160 | ||
84e345e4 PB |
161 | /* |
162 | * Indicates if there is an offset between the system clock and the hardware | |
163 | * clock/persistent clock/rtc. | |
164 | */ | |
165 | int persistent_clock_is_local; | |
166 | ||
1da177e4 LT |
167 | /* |
168 | * Adjust the time obtained from the CMOS to be UTC time instead of | |
169 | * local time. | |
6fa6c3b1 | 170 | * |
1da177e4 LT |
171 | * This is ugly, but preferable to the alternatives. Otherwise we |
172 | * would either need to write a program to do it in /etc/rc (and risk | |
6fa6c3b1 | 173 | * confusion if the program gets run more than once; it would also be |
1da177e4 LT |
174 | * hard to make the program warp the clock precisely n hours) or |
175 | * compile in the timezone information into the kernel. Bad, bad.... | |
176 | * | |
bdc80787 | 177 | * - TYT, 1992-01-01 |
1da177e4 LT |
178 | * |
179 | * The best thing to do is to keep the CMOS clock in universal time (UTC) | |
180 | * as real UNIX machines always do it. This avoids all headaches about | |
181 | * daylight saving times and warping kernel clocks. | |
182 | */ | |
77933d72 | 183 | static inline void warp_clock(void) |
1da177e4 | 184 | { |
c30bd099 DZ |
185 | if (sys_tz.tz_minuteswest != 0) { |
186 | struct timespec adjust; | |
bd45b7a3 | 187 | |
84e345e4 | 188 | persistent_clock_is_local = 1; |
7859e404 JS |
189 | adjust.tv_sec = sys_tz.tz_minuteswest * 60; |
190 | adjust.tv_nsec = 0; | |
191 | timekeeping_inject_offset(&adjust); | |
c30bd099 | 192 | } |
1da177e4 LT |
193 | } |
194 | ||
195 | /* | |
196 | * In case for some reason the CMOS clock has not already been running | |
197 | * in UTC, but in some local time: The first time we set the timezone, | |
198 | * we will warp the clock so that it is ticking UTC time instead of | |
199 | * local time. Presumably, if someone is setting the timezone then we | |
200 | * are running in an environment where the programs understand about | |
201 | * timezones. This should be done at boot time in the /etc/rc script, | |
202 | * as soon as possible, so that the clock can be set right. Otherwise, | |
203 | * various programs will get confused when the clock gets warped. | |
204 | */ | |
205 | ||
86d34732 | 206 | int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz) |
1da177e4 LT |
207 | { |
208 | static int firsttime = 1; | |
209 | int error = 0; | |
210 | ||
86d34732 | 211 | if (tv && !timespec64_valid(tv)) |
718bcceb TG |
212 | return -EINVAL; |
213 | ||
86d34732 | 214 | error = security_settime64(tv, tz); |
1da177e4 LT |
215 | if (error) |
216 | return error; | |
217 | ||
218 | if (tz) { | |
6f7d7984 SL |
219 | /* Verify we're witin the +-15 hrs range */ |
220 | if (tz->tz_minuteswest > 15*60 || tz->tz_minuteswest < -15*60) | |
221 | return -EINVAL; | |
222 | ||
1da177e4 | 223 | sys_tz = *tz; |
2c622148 | 224 | update_vsyscall_tz(); |
1da177e4 LT |
225 | if (firsttime) { |
226 | firsttime = 0; | |
227 | if (!tv) | |
228 | warp_clock(); | |
229 | } | |
230 | } | |
231 | if (tv) | |
86d34732 | 232 | return do_settimeofday64(tv); |
1da177e4 LT |
233 | return 0; |
234 | } | |
235 | ||
58fd3aa2 HC |
236 | SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv, |
237 | struct timezone __user *, tz) | |
1da177e4 | 238 | { |
2ac00f17 | 239 | struct timespec64 new_ts; |
1da177e4 | 240 | struct timeval user_tv; |
1da177e4 LT |
241 | struct timezone new_tz; |
242 | ||
243 | if (tv) { | |
244 | if (copy_from_user(&user_tv, tv, sizeof(*tv))) | |
245 | return -EFAULT; | |
6ada1fc0 SL |
246 | |
247 | if (!timeval_valid(&user_tv)) | |
248 | return -EINVAL; | |
249 | ||
1da177e4 LT |
250 | new_ts.tv_sec = user_tv.tv_sec; |
251 | new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; | |
252 | } | |
253 | if (tz) { | |
254 | if (copy_from_user(&new_tz, tz, sizeof(*tz))) | |
255 | return -EFAULT; | |
256 | } | |
257 | ||
2ac00f17 | 258 | return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL); |
1da177e4 LT |
259 | } |
260 | ||
2b2d0285 AV |
261 | #ifdef CONFIG_COMPAT |
262 | COMPAT_SYSCALL_DEFINE2(gettimeofday, struct compat_timeval __user *, tv, | |
263 | struct timezone __user *, tz) | |
264 | { | |
265 | if (tv) { | |
266 | struct timeval ktv; | |
267 | ||
268 | do_gettimeofday(&ktv); | |
269 | if (compat_put_timeval(&ktv, tv)) | |
270 | return -EFAULT; | |
271 | } | |
272 | if (tz) { | |
273 | if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) | |
274 | return -EFAULT; | |
275 | } | |
276 | ||
277 | return 0; | |
278 | } | |
279 | ||
280 | COMPAT_SYSCALL_DEFINE2(settimeofday, struct compat_timeval __user *, tv, | |
281 | struct timezone __user *, tz) | |
282 | { | |
283 | struct timespec64 new_ts; | |
284 | struct timeval user_tv; | |
285 | struct timezone new_tz; | |
286 | ||
287 | if (tv) { | |
288 | if (compat_get_timeval(&user_tv, tv)) | |
289 | return -EFAULT; | |
290 | new_ts.tv_sec = user_tv.tv_sec; | |
291 | new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; | |
292 | } | |
293 | if (tz) { | |
294 | if (copy_from_user(&new_tz, tz, sizeof(*tz))) | |
295 | return -EFAULT; | |
296 | } | |
297 | ||
298 | return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL); | |
299 | } | |
300 | #endif | |
301 | ||
58fd3aa2 | 302 | SYSCALL_DEFINE1(adjtimex, struct timex __user *, txc_p) |
1da177e4 LT |
303 | { |
304 | struct timex txc; /* Local copy of parameter */ | |
305 | int ret; | |
306 | ||
307 | /* Copy the user data space into the kernel copy | |
308 | * structure. But bear in mind that the structures | |
309 | * may change | |
310 | */ | |
3a4d44b6 | 311 | if (copy_from_user(&txc, txc_p, sizeof(struct timex))) |
1da177e4 LT |
312 | return -EFAULT; |
313 | ret = do_adjtimex(&txc); | |
314 | return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret; | |
315 | } | |
316 | ||
3a4d44b6 AV |
317 | #ifdef CONFIG_COMPAT |
318 | ||
319 | COMPAT_SYSCALL_DEFINE1(adjtimex, struct compat_timex __user *, utp) | |
320 | { | |
321 | struct timex txc; | |
322 | int err, ret; | |
323 | ||
324 | err = compat_get_timex(&txc, utp); | |
325 | if (err) | |
326 | return err; | |
327 | ||
328 | ret = do_adjtimex(&txc); | |
329 | ||
330 | err = compat_put_timex(utp, &txc); | |
331 | if (err) | |
332 | return err; | |
333 | ||
334 | return ret; | |
335 | } | |
336 | #endif | |
337 | ||
753e9c5c ED |
338 | /* |
339 | * Convert jiffies to milliseconds and back. | |
340 | * | |
341 | * Avoid unnecessary multiplications/divisions in the | |
342 | * two most common HZ cases: | |
343 | */ | |
af3b5628 | 344 | unsigned int jiffies_to_msecs(const unsigned long j) |
753e9c5c ED |
345 | { |
346 | #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) | |
347 | return (MSEC_PER_SEC / HZ) * j; | |
348 | #elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) | |
349 | return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC); | |
350 | #else | |
bdc80787 | 351 | # if BITS_PER_LONG == 32 |
88c4318d GU |
352 | return (HZ_TO_MSEC_MUL32 * j + (1ULL << HZ_TO_MSEC_SHR32) - 1) >> |
353 | HZ_TO_MSEC_SHR32; | |
bdc80787 | 354 | # else |
88c4318d | 355 | return DIV_ROUND_UP(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN); |
bdc80787 | 356 | # endif |
753e9c5c ED |
357 | #endif |
358 | } | |
359 | EXPORT_SYMBOL(jiffies_to_msecs); | |
360 | ||
af3b5628 | 361 | unsigned int jiffies_to_usecs(const unsigned long j) |
753e9c5c | 362 | { |
e0758676 FW |
363 | /* |
364 | * Hz usually doesn't go much further MSEC_PER_SEC. | |
365 | * jiffies_to_usecs() and usecs_to_jiffies() depend on that. | |
366 | */ | |
367 | BUILD_BUG_ON(HZ > USEC_PER_SEC); | |
368 | ||
369 | #if !(USEC_PER_SEC % HZ) | |
753e9c5c | 370 | return (USEC_PER_SEC / HZ) * j; |
753e9c5c | 371 | #else |
bdc80787 | 372 | # if BITS_PER_LONG == 32 |
b9095fd8 | 373 | return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32; |
bdc80787 PA |
374 | # else |
375 | return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN; | |
376 | # endif | |
753e9c5c ED |
377 | #endif |
378 | } | |
379 | EXPORT_SYMBOL(jiffies_to_usecs); | |
380 | ||
1da177e4 | 381 | /** |
8ba8e95e | 382 | * timespec_trunc - Truncate timespec to a granularity |
1da177e4 | 383 | * @t: Timespec |
8ba8e95e | 384 | * @gran: Granularity in ns. |
1da177e4 | 385 | * |
de4a95fa KB |
386 | * Truncate a timespec to a granularity. Always rounds down. gran must |
387 | * not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns). | |
1da177e4 LT |
388 | */ |
389 | struct timespec timespec_trunc(struct timespec t, unsigned gran) | |
390 | { | |
de4a95fa KB |
391 | /* Avoid division in the common cases 1 ns and 1 s. */ |
392 | if (gran == 1) { | |
1da177e4 | 393 | /* nothing */ |
de4a95fa | 394 | } else if (gran == NSEC_PER_SEC) { |
1da177e4 | 395 | t.tv_nsec = 0; |
de4a95fa | 396 | } else if (gran > 1 && gran < NSEC_PER_SEC) { |
1da177e4 | 397 | t.tv_nsec -= t.tv_nsec % gran; |
de4a95fa KB |
398 | } else { |
399 | WARN(1, "illegal file time granularity: %u", gran); | |
1da177e4 LT |
400 | } |
401 | return t; | |
402 | } | |
403 | EXPORT_SYMBOL(timespec_trunc); | |
404 | ||
90b6ce9c | 405 | /* |
406 | * mktime64 - Converts date to seconds. | |
407 | * Converts Gregorian date to seconds since 1970-01-01 00:00:00. | |
753be622 TG |
408 | * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 |
409 | * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. | |
410 | * | |
411 | * [For the Julian calendar (which was used in Russia before 1917, | |
412 | * Britain & colonies before 1752, anywhere else before 1582, | |
413 | * and is still in use by some communities) leave out the | |
414 | * -year/100+year/400 terms, and add 10.] | |
415 | * | |
416 | * This algorithm was first published by Gauss (I think). | |
ede5147d DH |
417 | * |
418 | * A leap second can be indicated by calling this function with sec as | |
419 | * 60 (allowable under ISO 8601). The leap second is treated the same | |
420 | * as the following second since they don't exist in UNIX time. | |
421 | * | |
422 | * An encoding of midnight at the end of the day as 24:00:00 - ie. midnight | |
423 | * tomorrow - (allowable under ISO 8601) is supported. | |
753be622 | 424 | */ |
90b6ce9c | 425 | time64_t mktime64(const unsigned int year0, const unsigned int mon0, |
426 | const unsigned int day, const unsigned int hour, | |
427 | const unsigned int min, const unsigned int sec) | |
753be622 | 428 | { |
f4818900 IM |
429 | unsigned int mon = mon0, year = year0; |
430 | ||
431 | /* 1..12 -> 11,12,1..10 */ | |
432 | if (0 >= (int) (mon -= 2)) { | |
433 | mon += 12; /* Puts Feb last since it has leap day */ | |
753be622 TG |
434 | year -= 1; |
435 | } | |
436 | ||
90b6ce9c | 437 | return ((((time64_t) |
753be622 TG |
438 | (year/4 - year/100 + year/400 + 367*mon/12 + day) + |
439 | year*365 - 719499 | |
ede5147d | 440 | )*24 + hour /* now have hours - midnight tomorrow handled here */ |
753be622 TG |
441 | )*60 + min /* now have minutes */ |
442 | )*60 + sec; /* finally seconds */ | |
443 | } | |
90b6ce9c | 444 | EXPORT_SYMBOL(mktime64); |
199e7056 | 445 | |
753be622 TG |
446 | /** |
447 | * set_normalized_timespec - set timespec sec and nsec parts and normalize | |
448 | * | |
449 | * @ts: pointer to timespec variable to be set | |
450 | * @sec: seconds to set | |
451 | * @nsec: nanoseconds to set | |
452 | * | |
453 | * Set seconds and nanoseconds field of a timespec variable and | |
454 | * normalize to the timespec storage format | |
455 | * | |
456 | * Note: The tv_nsec part is always in the range of | |
bdc80787 | 457 | * 0 <= tv_nsec < NSEC_PER_SEC |
753be622 TG |
458 | * For negative values only the tv_sec field is negative ! |
459 | */ | |
12e09337 | 460 | void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec) |
753be622 TG |
461 | { |
462 | while (nsec >= NSEC_PER_SEC) { | |
12e09337 TG |
463 | /* |
464 | * The following asm() prevents the compiler from | |
465 | * optimising this loop into a modulo operation. See | |
466 | * also __iter_div_u64_rem() in include/linux/time.h | |
467 | */ | |
468 | asm("" : "+rm"(nsec)); | |
753be622 TG |
469 | nsec -= NSEC_PER_SEC; |
470 | ++sec; | |
471 | } | |
472 | while (nsec < 0) { | |
12e09337 | 473 | asm("" : "+rm"(nsec)); |
753be622 TG |
474 | nsec += NSEC_PER_SEC; |
475 | --sec; | |
476 | } | |
477 | ts->tv_sec = sec; | |
478 | ts->tv_nsec = nsec; | |
479 | } | |
7c3f944e | 480 | EXPORT_SYMBOL(set_normalized_timespec); |
753be622 | 481 | |
f8f46da3 TG |
482 | /** |
483 | * ns_to_timespec - Convert nanoseconds to timespec | |
484 | * @nsec: the nanoseconds value to be converted | |
485 | * | |
486 | * Returns the timespec representation of the nsec parameter. | |
487 | */ | |
df869b63 | 488 | struct timespec ns_to_timespec(const s64 nsec) |
f8f46da3 TG |
489 | { |
490 | struct timespec ts; | |
f8bd2258 | 491 | s32 rem; |
f8f46da3 | 492 | |
88fc3897 GA |
493 | if (!nsec) |
494 | return (struct timespec) {0, 0}; | |
495 | ||
f8bd2258 RZ |
496 | ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem); |
497 | if (unlikely(rem < 0)) { | |
498 | ts.tv_sec--; | |
499 | rem += NSEC_PER_SEC; | |
500 | } | |
501 | ts.tv_nsec = rem; | |
f8f46da3 TG |
502 | |
503 | return ts; | |
504 | } | |
85795d64 | 505 | EXPORT_SYMBOL(ns_to_timespec); |
f8f46da3 TG |
506 | |
507 | /** | |
508 | * ns_to_timeval - Convert nanoseconds to timeval | |
509 | * @nsec: the nanoseconds value to be converted | |
510 | * | |
511 | * Returns the timeval representation of the nsec parameter. | |
512 | */ | |
df869b63 | 513 | struct timeval ns_to_timeval(const s64 nsec) |
f8f46da3 TG |
514 | { |
515 | struct timespec ts = ns_to_timespec(nsec); | |
516 | struct timeval tv; | |
517 | ||
518 | tv.tv_sec = ts.tv_sec; | |
519 | tv.tv_usec = (suseconds_t) ts.tv_nsec / 1000; | |
520 | ||
521 | return tv; | |
522 | } | |
b7aa0bf7 | 523 | EXPORT_SYMBOL(ns_to_timeval); |
f8f46da3 | 524 | |
49cd6f86 JS |
525 | #if BITS_PER_LONG == 32 |
526 | /** | |
527 | * set_normalized_timespec - set timespec sec and nsec parts and normalize | |
528 | * | |
529 | * @ts: pointer to timespec variable to be set | |
530 | * @sec: seconds to set | |
531 | * @nsec: nanoseconds to set | |
532 | * | |
533 | * Set seconds and nanoseconds field of a timespec variable and | |
534 | * normalize to the timespec storage format | |
535 | * | |
536 | * Note: The tv_nsec part is always in the range of | |
537 | * 0 <= tv_nsec < NSEC_PER_SEC | |
538 | * For negative values only the tv_sec field is negative ! | |
539 | */ | |
540 | void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec) | |
541 | { | |
542 | while (nsec >= NSEC_PER_SEC) { | |
543 | /* | |
544 | * The following asm() prevents the compiler from | |
545 | * optimising this loop into a modulo operation. See | |
546 | * also __iter_div_u64_rem() in include/linux/time.h | |
547 | */ | |
548 | asm("" : "+rm"(nsec)); | |
549 | nsec -= NSEC_PER_SEC; | |
550 | ++sec; | |
551 | } | |
552 | while (nsec < 0) { | |
553 | asm("" : "+rm"(nsec)); | |
554 | nsec += NSEC_PER_SEC; | |
555 | --sec; | |
556 | } | |
557 | ts->tv_sec = sec; | |
558 | ts->tv_nsec = nsec; | |
559 | } | |
560 | EXPORT_SYMBOL(set_normalized_timespec64); | |
561 | ||
562 | /** | |
563 | * ns_to_timespec64 - Convert nanoseconds to timespec64 | |
564 | * @nsec: the nanoseconds value to be converted | |
565 | * | |
566 | * Returns the timespec64 representation of the nsec parameter. | |
567 | */ | |
568 | struct timespec64 ns_to_timespec64(const s64 nsec) | |
569 | { | |
570 | struct timespec64 ts; | |
571 | s32 rem; | |
572 | ||
573 | if (!nsec) | |
574 | return (struct timespec64) {0, 0}; | |
575 | ||
576 | ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem); | |
577 | if (unlikely(rem < 0)) { | |
578 | ts.tv_sec--; | |
579 | rem += NSEC_PER_SEC; | |
580 | } | |
581 | ts.tv_nsec = rem; | |
582 | ||
583 | return ts; | |
584 | } | |
585 | EXPORT_SYMBOL(ns_to_timespec64); | |
586 | #endif | |
ca42aaf0 NMG |
587 | /** |
588 | * msecs_to_jiffies: - convert milliseconds to jiffies | |
589 | * @m: time in milliseconds | |
590 | * | |
591 | * conversion is done as follows: | |
41cf5445 IM |
592 | * |
593 | * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) | |
594 | * | |
595 | * - 'too large' values [that would result in larger than | |
596 | * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. | |
597 | * | |
598 | * - all other values are converted to jiffies by either multiplying | |
ca42aaf0 NMG |
599 | * the input value by a factor or dividing it with a factor and |
600 | * handling any 32-bit overflows. | |
601 | * for the details see __msecs_to_jiffies() | |
41cf5445 | 602 | * |
ca42aaf0 NMG |
603 | * msecs_to_jiffies() checks for the passed in value being a constant |
604 | * via __builtin_constant_p() allowing gcc to eliminate most of the | |
605 | * code, __msecs_to_jiffies() is called if the value passed does not | |
606 | * allow constant folding and the actual conversion must be done at | |
607 | * runtime. | |
608 | * the _msecs_to_jiffies helpers are the HZ dependent conversion | |
609 | * routines found in include/linux/jiffies.h | |
41cf5445 | 610 | */ |
ca42aaf0 | 611 | unsigned long __msecs_to_jiffies(const unsigned int m) |
8b9365d7 | 612 | { |
41cf5445 IM |
613 | /* |
614 | * Negative value, means infinite timeout: | |
615 | */ | |
616 | if ((int)m < 0) | |
8b9365d7 | 617 | return MAX_JIFFY_OFFSET; |
ca42aaf0 | 618 | return _msecs_to_jiffies(m); |
8b9365d7 | 619 | } |
ca42aaf0 | 620 | EXPORT_SYMBOL(__msecs_to_jiffies); |
8b9365d7 | 621 | |
ae60d6a0 | 622 | unsigned long __usecs_to_jiffies(const unsigned int u) |
8b9365d7 IM |
623 | { |
624 | if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) | |
625 | return MAX_JIFFY_OFFSET; | |
ae60d6a0 | 626 | return _usecs_to_jiffies(u); |
8b9365d7 | 627 | } |
ae60d6a0 | 628 | EXPORT_SYMBOL(__usecs_to_jiffies); |
8b9365d7 IM |
629 | |
630 | /* | |
631 | * The TICK_NSEC - 1 rounds up the value to the next resolution. Note | |
632 | * that a remainder subtract here would not do the right thing as the | |
633 | * resolution values don't fall on second boundries. I.e. the line: | |
634 | * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding. | |
d78c9300 AH |
635 | * Note that due to the small error in the multiplier here, this |
636 | * rounding is incorrect for sufficiently large values of tv_nsec, but | |
637 | * well formed timespecs should have tv_nsec < NSEC_PER_SEC, so we're | |
638 | * OK. | |
8b9365d7 IM |
639 | * |
640 | * Rather, we just shift the bits off the right. | |
641 | * | |
642 | * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec | |
643 | * value to a scaled second value. | |
644 | */ | |
d78c9300 | 645 | static unsigned long |
9ca30850 | 646 | __timespec64_to_jiffies(u64 sec, long nsec) |
8b9365d7 | 647 | { |
d78c9300 | 648 | nsec = nsec + TICK_NSEC - 1; |
8b9365d7 IM |
649 | |
650 | if (sec >= MAX_SEC_IN_JIFFIES){ | |
651 | sec = MAX_SEC_IN_JIFFIES; | |
652 | nsec = 0; | |
653 | } | |
9ca30850 | 654 | return ((sec * SEC_CONVERSION) + |
8b9365d7 IM |
655 | (((u64)nsec * NSEC_CONVERSION) >> |
656 | (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC; | |
657 | ||
658 | } | |
d78c9300 | 659 | |
9ca30850 BW |
660 | static unsigned long |
661 | __timespec_to_jiffies(unsigned long sec, long nsec) | |
d78c9300 | 662 | { |
9ca30850 | 663 | return __timespec64_to_jiffies((u64)sec, nsec); |
d78c9300 AH |
664 | } |
665 | ||
9ca30850 BW |
666 | unsigned long |
667 | timespec64_to_jiffies(const struct timespec64 *value) | |
668 | { | |
669 | return __timespec64_to_jiffies(value->tv_sec, value->tv_nsec); | |
670 | } | |
671 | EXPORT_SYMBOL(timespec64_to_jiffies); | |
8b9365d7 IM |
672 | |
673 | void | |
9ca30850 | 674 | jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value) |
8b9365d7 IM |
675 | { |
676 | /* | |
677 | * Convert jiffies to nanoseconds and separate with | |
678 | * one divide. | |
679 | */ | |
f8bd2258 RZ |
680 | u32 rem; |
681 | value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC, | |
682 | NSEC_PER_SEC, &rem); | |
683 | value->tv_nsec = rem; | |
8b9365d7 | 684 | } |
9ca30850 | 685 | EXPORT_SYMBOL(jiffies_to_timespec64); |
8b9365d7 | 686 | |
d78c9300 AH |
687 | /* |
688 | * We could use a similar algorithm to timespec_to_jiffies (with a | |
689 | * different multiplier for usec instead of nsec). But this has a | |
690 | * problem with rounding: we can't exactly add TICK_NSEC - 1 to the | |
691 | * usec value, since it's not necessarily integral. | |
692 | * | |
693 | * We could instead round in the intermediate scaled representation | |
694 | * (i.e. in units of 1/2^(large scale) jiffies) but that's also | |
695 | * perilous: the scaling introduces a small positive error, which | |
696 | * combined with a division-rounding-upward (i.e. adding 2^(scale) - 1 | |
697 | * units to the intermediate before shifting) leads to accidental | |
698 | * overflow and overestimates. | |
8b9365d7 | 699 | * |
d78c9300 AH |
700 | * At the cost of one additional multiplication by a constant, just |
701 | * use the timespec implementation. | |
8b9365d7 IM |
702 | */ |
703 | unsigned long | |
704 | timeval_to_jiffies(const struct timeval *value) | |
705 | { | |
d78c9300 AH |
706 | return __timespec_to_jiffies(value->tv_sec, |
707 | value->tv_usec * NSEC_PER_USEC); | |
8b9365d7 | 708 | } |
456a09dc | 709 | EXPORT_SYMBOL(timeval_to_jiffies); |
8b9365d7 IM |
710 | |
711 | void jiffies_to_timeval(const unsigned long jiffies, struct timeval *value) | |
712 | { | |
713 | /* | |
714 | * Convert jiffies to nanoseconds and separate with | |
715 | * one divide. | |
716 | */ | |
f8bd2258 | 717 | u32 rem; |
8b9365d7 | 718 | |
f8bd2258 RZ |
719 | value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC, |
720 | NSEC_PER_SEC, &rem); | |
721 | value->tv_usec = rem / NSEC_PER_USEC; | |
8b9365d7 | 722 | } |
456a09dc | 723 | EXPORT_SYMBOL(jiffies_to_timeval); |
8b9365d7 IM |
724 | |
725 | /* | |
726 | * Convert jiffies/jiffies_64 to clock_t and back. | |
727 | */ | |
cbbc719f | 728 | clock_t jiffies_to_clock_t(unsigned long x) |
8b9365d7 IM |
729 | { |
730 | #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 | |
6ffc787a DF |
731 | # if HZ < USER_HZ |
732 | return x * (USER_HZ / HZ); | |
733 | # else | |
8b9365d7 | 734 | return x / (HZ / USER_HZ); |
6ffc787a | 735 | # endif |
8b9365d7 | 736 | #else |
71abb3af | 737 | return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ); |
8b9365d7 IM |
738 | #endif |
739 | } | |
740 | EXPORT_SYMBOL(jiffies_to_clock_t); | |
741 | ||
742 | unsigned long clock_t_to_jiffies(unsigned long x) | |
743 | { | |
744 | #if (HZ % USER_HZ)==0 | |
745 | if (x >= ~0UL / (HZ / USER_HZ)) | |
746 | return ~0UL; | |
747 | return x * (HZ / USER_HZ); | |
748 | #else | |
8b9365d7 IM |
749 | /* Don't worry about loss of precision here .. */ |
750 | if (x >= ~0UL / HZ * USER_HZ) | |
751 | return ~0UL; | |
752 | ||
753 | /* .. but do try to contain it here */ | |
71abb3af | 754 | return div_u64((u64)x * HZ, USER_HZ); |
8b9365d7 IM |
755 | #endif |
756 | } | |
757 | EXPORT_SYMBOL(clock_t_to_jiffies); | |
758 | ||
759 | u64 jiffies_64_to_clock_t(u64 x) | |
760 | { | |
761 | #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 | |
6ffc787a | 762 | # if HZ < USER_HZ |
71abb3af | 763 | x = div_u64(x * USER_HZ, HZ); |
ec03d707 | 764 | # elif HZ > USER_HZ |
71abb3af | 765 | x = div_u64(x, HZ / USER_HZ); |
ec03d707 AM |
766 | # else |
767 | /* Nothing to do */ | |
6ffc787a | 768 | # endif |
8b9365d7 IM |
769 | #else |
770 | /* | |
771 | * There are better ways that don't overflow early, | |
772 | * but even this doesn't overflow in hundreds of years | |
773 | * in 64 bits, so.. | |
774 | */ | |
71abb3af | 775 | x = div_u64(x * TICK_NSEC, (NSEC_PER_SEC / USER_HZ)); |
8b9365d7 IM |
776 | #endif |
777 | return x; | |
778 | } | |
8b9365d7 IM |
779 | EXPORT_SYMBOL(jiffies_64_to_clock_t); |
780 | ||
781 | u64 nsec_to_clock_t(u64 x) | |
782 | { | |
783 | #if (NSEC_PER_SEC % USER_HZ) == 0 | |
71abb3af | 784 | return div_u64(x, NSEC_PER_SEC / USER_HZ); |
8b9365d7 | 785 | #elif (USER_HZ % 512) == 0 |
71abb3af | 786 | return div_u64(x * USER_HZ / 512, NSEC_PER_SEC / 512); |
8b9365d7 IM |
787 | #else |
788 | /* | |
789 | * max relative error 5.7e-8 (1.8s per year) for USER_HZ <= 1024, | |
790 | * overflow after 64.99 years. | |
791 | * exact for HZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ... | |
792 | */ | |
71abb3af | 793 | return div_u64(x * 9, (9ull * NSEC_PER_SEC + (USER_HZ / 2)) / USER_HZ); |
8b9365d7 | 794 | #endif |
8b9365d7 IM |
795 | } |
796 | ||
07e5f5e3 FW |
797 | u64 jiffies64_to_nsecs(u64 j) |
798 | { | |
799 | #if !(NSEC_PER_SEC % HZ) | |
800 | return (NSEC_PER_SEC / HZ) * j; | |
801 | # else | |
802 | return div_u64(j * HZ_TO_NSEC_NUM, HZ_TO_NSEC_DEN); | |
803 | #endif | |
804 | } | |
805 | EXPORT_SYMBOL(jiffies64_to_nsecs); | |
806 | ||
b7b20df9 | 807 | /** |
a1dabb6b | 808 | * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64 |
b7b20df9 HS |
809 | * |
810 | * @n: nsecs in u64 | |
811 | * | |
812 | * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. | |
813 | * And this doesn't return MAX_JIFFY_OFFSET since this function is designed | |
814 | * for scheduler, not for use in device drivers to calculate timeout value. | |
815 | * | |
816 | * note: | |
817 | * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) | |
818 | * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years | |
819 | */ | |
a1dabb6b | 820 | u64 nsecs_to_jiffies64(u64 n) |
b7b20df9 HS |
821 | { |
822 | #if (NSEC_PER_SEC % HZ) == 0 | |
823 | /* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */ | |
824 | return div_u64(n, NSEC_PER_SEC / HZ); | |
825 | #elif (HZ % 512) == 0 | |
826 | /* overflow after 292 years if HZ = 1024 */ | |
827 | return div_u64(n * HZ / 512, NSEC_PER_SEC / 512); | |
828 | #else | |
829 | /* | |
830 | * Generic case - optimized for cases where HZ is a multiple of 3. | |
831 | * overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc. | |
832 | */ | |
833 | return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ); | |
834 | #endif | |
835 | } | |
7bd0e226 | 836 | EXPORT_SYMBOL(nsecs_to_jiffies64); |
b7b20df9 | 837 | |
a1dabb6b VP |
838 | /** |
839 | * nsecs_to_jiffies - Convert nsecs in u64 to jiffies | |
840 | * | |
841 | * @n: nsecs in u64 | |
842 | * | |
843 | * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. | |
844 | * And this doesn't return MAX_JIFFY_OFFSET since this function is designed | |
845 | * for scheduler, not for use in device drivers to calculate timeout value. | |
846 | * | |
847 | * note: | |
848 | * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) | |
849 | * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years | |
850 | */ | |
851 | unsigned long nsecs_to_jiffies(u64 n) | |
852 | { | |
853 | return (unsigned long)nsecs_to_jiffies64(n); | |
854 | } | |
d560fed6 | 855 | EXPORT_SYMBOL_GPL(nsecs_to_jiffies); |
a1dabb6b | 856 | |
df0cc053 TG |
857 | /* |
858 | * Add two timespec values and do a safety check for overflow. | |
859 | * It's assumed that both values are valid (>= 0) | |
860 | */ | |
861 | struct timespec timespec_add_safe(const struct timespec lhs, | |
862 | const struct timespec rhs) | |
863 | { | |
864 | struct timespec res; | |
865 | ||
866 | set_normalized_timespec(&res, lhs.tv_sec + rhs.tv_sec, | |
867 | lhs.tv_nsec + rhs.tv_nsec); | |
868 | ||
869 | if (res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec) | |
870 | res.tv_sec = TIME_T_MAX; | |
871 | ||
872 | return res; | |
873 | } | |
bc2c53e5 | 874 | |
bc2c53e5 DD |
875 | /* |
876 | * Add two timespec64 values and do a safety check for overflow. | |
877 | * It's assumed that both values are valid (>= 0). | |
878 | * And, each timespec64 is in normalized form. | |
879 | */ | |
880 | struct timespec64 timespec64_add_safe(const struct timespec64 lhs, | |
881 | const struct timespec64 rhs) | |
882 | { | |
883 | struct timespec64 res; | |
884 | ||
469e857f | 885 | set_normalized_timespec64(&res, (timeu64_t) lhs.tv_sec + rhs.tv_sec, |
bc2c53e5 DD |
886 | lhs.tv_nsec + rhs.tv_nsec); |
887 | ||
888 | if (unlikely(res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)) { | |
889 | res.tv_sec = TIME64_MAX; | |
890 | res.tv_nsec = 0; | |
891 | } | |
892 | ||
893 | return res; | |
894 | } | |
f59dd9c8 DD |
895 | |
896 | int get_timespec64(struct timespec64 *ts, | |
897 | const struct timespec __user *uts) | |
898 | { | |
899 | struct timespec kts; | |
900 | int ret; | |
901 | ||
902 | ret = copy_from_user(&kts, uts, sizeof(kts)); | |
903 | if (ret) | |
904 | return -EFAULT; | |
905 | ||
906 | ts->tv_sec = kts.tv_sec; | |
907 | ts->tv_nsec = kts.tv_nsec; | |
908 | ||
909 | return 0; | |
910 | } | |
911 | EXPORT_SYMBOL_GPL(get_timespec64); | |
912 | ||
913 | int put_timespec64(const struct timespec64 *ts, | |
914 | struct timespec __user *uts) | |
915 | { | |
916 | struct timespec kts = { | |
917 | .tv_sec = ts->tv_sec, | |
918 | .tv_nsec = ts->tv_nsec | |
919 | }; | |
920 | return copy_to_user(uts, &kts, sizeof(kts)) ? -EFAULT : 0; | |
921 | } | |
922 | EXPORT_SYMBOL_GPL(put_timespec64); | |
d5b7ffbf DD |
923 | |
924 | int get_itimerspec64(struct itimerspec64 *it, | |
925 | const struct itimerspec __user *uit) | |
926 | { | |
927 | int ret; | |
928 | ||
929 | ret = get_timespec64(&it->it_interval, &uit->it_interval); | |
930 | if (ret) | |
931 | return ret; | |
932 | ||
933 | ret = get_timespec64(&it->it_value, &uit->it_value); | |
934 | ||
935 | return ret; | |
936 | } | |
937 | EXPORT_SYMBOL_GPL(get_itimerspec64); | |
938 | ||
939 | int put_itimerspec64(const struct itimerspec64 *it, | |
940 | struct itimerspec __user *uit) | |
941 | { | |
942 | int ret; | |
943 | ||
944 | ret = put_timespec64(&it->it_interval, &uit->it_interval); | |
945 | if (ret) | |
946 | return ret; | |
947 | ||
948 | ret = put_timespec64(&it->it_value, &uit->it_value); | |
949 | ||
950 | return ret; | |
951 | } | |
952 | EXPORT_SYMBOL_GPL(put_itimerspec64); |