time.h 8.1 KB

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  1. #ifndef _LINUX_TIME_H
  2. #define _LINUX_TIME_H
  3. # include <linux/cache.h>
  4. # include <linux/seqlock.h>
  5. # include <linux/math64.h>
  6. #include <uapi/linux/time.h>
  7. extern struct timezone sys_tz;
  8. /* Parameters used to convert the timespec values: */
  9. #define MSEC_PER_SEC 1000L
  10. #define USEC_PER_MSEC 1000L
  11. #define NSEC_PER_USEC 1000L
  12. #define NSEC_PER_MSEC 1000000L
  13. #define USEC_PER_SEC 1000000L
  14. #define NSEC_PER_SEC 1000000000L
  15. #define FSEC_PER_SEC 1000000000000000LL
  16. #define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
  17. static inline int timespec_equal(const struct timespec *a,
  18. const struct timespec *b)
  19. {
  20. return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  21. }
  22. /*
  23. * lhs < rhs: return <0
  24. * lhs == rhs: return 0
  25. * lhs > rhs: return >0
  26. */
  27. static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
  28. {
  29. if (lhs->tv_sec < rhs->tv_sec)
  30. return -1;
  31. if (lhs->tv_sec > rhs->tv_sec)
  32. return 1;
  33. return lhs->tv_nsec - rhs->tv_nsec;
  34. }
  35. static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
  36. {
  37. if (lhs->tv_sec < rhs->tv_sec)
  38. return -1;
  39. if (lhs->tv_sec > rhs->tv_sec)
  40. return 1;
  41. return lhs->tv_usec - rhs->tv_usec;
  42. }
  43. extern unsigned long mktime(const unsigned int year, const unsigned int mon,
  44. const unsigned int day, const unsigned int hour,
  45. const unsigned int min, const unsigned int sec);
  46. extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);
  47. /*
  48. * timespec_add_safe assumes both values are positive and checks
  49. * for overflow. It will return TIME_T_MAX if the reutrn would be
  50. * smaller then either of the arguments.
  51. */
  52. extern struct timespec timespec_add_safe(const struct timespec lhs,
  53. const struct timespec rhs);
  54. static inline struct timespec timespec_add(struct timespec lhs,
  55. struct timespec rhs)
  56. {
  57. struct timespec ts_delta;
  58. set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec,
  59. lhs.tv_nsec + rhs.tv_nsec);
  60. return ts_delta;
  61. }
  62. /*
  63. * sub = lhs - rhs, in normalized form
  64. */
  65. static inline struct timespec timespec_sub(struct timespec lhs,
  66. struct timespec rhs)
  67. {
  68. struct timespec ts_delta;
  69. set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
  70. lhs.tv_nsec - rhs.tv_nsec);
  71. return ts_delta;
  72. }
  73. #define KTIME_MAX ((s64)~((u64)1 << 63))
  74. #if (BITS_PER_LONG == 64)
  75. # define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC)
  76. #else
  77. # define KTIME_SEC_MAX LONG_MAX
  78. #endif
  79. /*
  80. * Returns true if the timespec is norm, false if denorm:
  81. */
  82. static inline bool timespec_valid(const struct timespec *ts)
  83. {
  84. /* Dates before 1970 are bogus */
  85. if (ts->tv_sec < 0)
  86. return false;
  87. /* Can't have more nanoseconds then a second */
  88. if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
  89. return false;
  90. return true;
  91. }
  92. static inline bool timespec_valid_strict(const struct timespec *ts)
  93. {
  94. if (!timespec_valid(ts))
  95. return false;
  96. /* Disallow values that could overflow ktime_t */
  97. if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
  98. return false;
  99. return true;
  100. }
  101. extern bool persistent_clock_exist;
  102. #ifdef ALWAYS_USE_PERSISTENT_CLOCK
  103. #define has_persistent_clock() true
  104. #else
  105. static inline bool has_persistent_clock(void)
  106. {
  107. return persistent_clock_exist;
  108. }
  109. #endif
  110. extern void read_persistent_clock(struct timespec *ts);
  111. extern void read_boot_clock(struct timespec *ts);
  112. extern int update_persistent_clock(struct timespec now);
  113. void timekeeping_init(void);
  114. extern int timekeeping_suspended;
  115. unsigned long get_seconds(void);
  116. struct timespec current_kernel_time(void);
  117. struct timespec __current_kernel_time(void); /* does not take xtime_lock */
  118. struct timespec get_monotonic_coarse(void);
  119. void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
  120. struct timespec *wtom, struct timespec *sleep);
  121. void timekeeping_inject_sleeptime(struct timespec *delta);
  122. #define CURRENT_TIME (current_kernel_time())
  123. #define CURRENT_TIME_SEC ((struct timespec) { get_seconds(), 0 })
  124. /* Some architectures do not supply their own clocksource.
  125. * This is mainly the case in architectures that get their
  126. * inter-tick times by reading the counter on their interval
  127. * timer. Since these timers wrap every tick, they're not really
  128. * useful as clocksources. Wrapping them to act like one is possible
  129. * but not very efficient. So we provide a callout these arches
  130. * can implement for use with the jiffies clocksource to provide
  131. * finer then tick granular time.
  132. */
  133. #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
  134. extern u32 arch_gettimeoffset(void);
  135. #else
  136. static inline u32 arch_gettimeoffset(void) { return 0; }
  137. #endif
  138. extern void do_gettimeofday(struct timeval *tv);
  139. extern int do_settimeofday(const struct timespec *tv);
  140. extern int do_sys_settimeofday(const struct timespec *tv,
  141. const struct timezone *tz);
  142. #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
  143. extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);
  144. struct itimerval;
  145. extern int do_setitimer(int which, struct itimerval *value,
  146. struct itimerval *ovalue);
  147. extern unsigned int alarm_setitimer(unsigned int seconds);
  148. extern int do_getitimer(int which, struct itimerval *value);
  149. extern int __getnstimeofday(struct timespec *tv);
  150. extern void getnstimeofday(struct timespec *tv);
  151. extern void getrawmonotonic(struct timespec *ts);
  152. extern void getnstime_raw_and_real(struct timespec *ts_raw,
  153. struct timespec *ts_real);
  154. extern void getboottime(struct timespec *ts);
  155. extern void monotonic_to_bootbased(struct timespec *ts);
  156. extern void get_monotonic_boottime(struct timespec *ts);
  157. extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
  158. extern int timekeeping_valid_for_hres(void);
  159. extern u64 timekeeping_max_deferment(void);
  160. extern int timekeeping_inject_offset(struct timespec *ts);
  161. struct tms;
  162. extern void do_sys_times(struct tms *);
  163. /*
  164. * Similar to the struct tm in userspace <time.h>, but it needs to be here so
  165. * that the kernel source is self contained.
  166. */
  167. struct tm {
  168. /*
  169. * the number of seconds after the minute, normally in the range
  170. * 0 to 59, but can be up to 60 to allow for leap seconds
  171. */
  172. int tm_sec;
  173. /* the number of minutes after the hour, in the range 0 to 59*/
  174. int tm_min;
  175. /* the number of hours past midnight, in the range 0 to 23 */
  176. int tm_hour;
  177. /* the day of the month, in the range 1 to 31 */
  178. int tm_mday;
  179. /* the number of months since January, in the range 0 to 11 */
  180. int tm_mon;
  181. /* the number of years since 1900 */
  182. long tm_year;
  183. /* the number of days since Sunday, in the range 0 to 6 */
  184. int tm_wday;
  185. /* the number of days since January 1, in the range 0 to 365 */
  186. int tm_yday;
  187. };
  188. void time_to_tm(time_t totalsecs, int offset, struct tm *result);
  189. /**
  190. * timespec_to_ns - Convert timespec to nanoseconds
  191. * @ts: pointer to the timespec variable to be converted
  192. *
  193. * Returns the scalar nanosecond representation of the timespec
  194. * parameter.
  195. */
  196. static inline s64 timespec_to_ns(const struct timespec *ts)
  197. {
  198. return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
  199. }
  200. /**
  201. * timeval_to_ns - Convert timeval to nanoseconds
  202. * @ts: pointer to the timeval variable to be converted
  203. *
  204. * Returns the scalar nanosecond representation of the timeval
  205. * parameter.
  206. */
  207. static inline s64 timeval_to_ns(const struct timeval *tv)
  208. {
  209. return ((s64) tv->tv_sec * NSEC_PER_SEC) +
  210. tv->tv_usec * NSEC_PER_USEC;
  211. }
  212. /**
  213. * ns_to_timespec - Convert nanoseconds to timespec
  214. * @nsec: the nanoseconds value to be converted
  215. *
  216. * Returns the timespec representation of the nsec parameter.
  217. */
  218. extern struct timespec ns_to_timespec(const s64 nsec);
  219. /**
  220. * ns_to_timeval - Convert nanoseconds to timeval
  221. * @nsec: the nanoseconds value to be converted
  222. *
  223. * Returns the timeval representation of the nsec parameter.
  224. */
  225. extern struct timeval ns_to_timeval(const s64 nsec);
  226. /**
  227. * timespec_add_ns - Adds nanoseconds to a timespec
  228. * @a: pointer to timespec to be incremented
  229. * @ns: unsigned nanoseconds value to be added
  230. *
  231. * This must always be inlined because its used from the x86-64 vdso,
  232. * which cannot call other kernel functions.
  233. */
  234. static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
  235. {
  236. a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
  237. a->tv_nsec = ns;
  238. }
  239. #endif