include/linux/time.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_TIME_H
   3 #define _LINUX_TIME_H
   4
   5 # include <linux/cache.h>
   6 # include <linux/seqlock.h>
   7 # include <linux/math64.h>
   8 # include <linux/time64.h>
   9
  10 extern struct timezone sys_tz;
  11
  12 int get_timespec64(struct timespec64 *ts,
  13                 const struct timespec __user *uts);
  14 int put_timespec64(const struct timespec64 *ts,
  15                 struct timespec __user *uts);
  16 int get_itimerspec64(struct itimerspec64 *it,
  17                         const struct itimerspec __user *uit);
  18 int put_itimerspec64(const struct itimerspec64 *it,
  19                         struct itimerspec __user *uit);
  20
  21 extern time64_t mktime64(const unsigned int year, const unsigned int mon,
  22                         const unsigned int day, const unsigned int hour,
  23                         const unsigned int min, const unsigned int sec);
  24
  25 /* Some architectures do not supply their own clocksource.
  26  * This is mainly the case in architectures that get their
  27  * inter-tick times by reading the counter on their interval
  28  * timer. Since these timers wrap every tick, they're not really
  29  * useful as clocksources. Wrapping them to act like one is possible
  30  * but not very efficient. So we provide a callout these arches
  31  * can implement for use with the jiffies clocksource to provide
  32  * finer then tick granular time.
  33  */
  34 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
  35 extern u32 (*arch_gettimeoffset)(void);
  36 #endif
  37
  38 struct itimerval;
  39 extern int do_setitimer(int which, struct itimerval *value,
  40                         struct itimerval *ovalue);
  41 extern int do_getitimer(int which, struct itimerval *value);
  42
  43 extern long do_utimes(int dfd, const char __user *filename, struct timespec64 *times, int flags);
  44
  45 /*
  46  * Similar to the struct tm in userspace <time.h>, but it needs to be here so
  47  * that the kernel source is self contained.
  48  */
  49 struct tm {
  50         /*
  51          * the number of seconds after the minute, normally in the range
  52          * 0 to 59, but can be up to 60 to allow for leap seconds
  53          */
  54         int tm_sec;
  55         /* the number of minutes after the hour, in the range 0 to 59*/
  56         int tm_min;
  57         /* the number of hours past midnight, in the range 0 to 23 */
  58         int tm_hour;
  59         /* the day of the month, in the range 1 to 31 */
  60         int tm_mday;
  61         /* the number of months since January, in the range 0 to 11 */
  62         int tm_mon;
  63         /* the number of years since 1900 */
  64         long tm_year;
  65         /* the number of days since Sunday, in the range 0 to 6 */
  66         int tm_wday;
  67         /* the number of days since January 1, in the range 0 to 365 */
  68         int tm_yday;
  69 };
  70
  71 void time64_to_tm(time64_t totalsecs, int offset, struct tm *result);
  72
  73 # include <linux/time32.h>
  74
  75 static inline bool itimerspec64_valid(const struct itimerspec64 *its)
  76 {
  77         if (!timespec64_valid(&(its->it_interval)) ||
  78                 !timespec64_valid(&(its->it_value)))
  79                 return false;
  80
  81         return true;
  82 }
  83
  84 /**
  85  * time_after32 - compare two 32-bit relative times
  86  * @a:  the time which may be after @b
  87  * @b:  the time which may be before @a
  88  *
  89  * time_after32(a, b) returns true if the time @a is after time @b.
  90  * time_before32(b, a) returns true if the time @b is before time @a.
  91  *
  92  * Similar to time_after(), compare two 32-bit timestamps for relative
  93  * times.  This is useful for comparing 32-bit seconds values that can't
  94  * be converted to 64-bit values (e.g. due to disk format or wire protocol
  95  * issues) when it is known that the times are less than 68 years apart.
  96  */
  97 #define time_after32(a, b)      ((s32)((u32)(b) - (u32)(a)) < 0)
  98 #define time_before32(b, a)     time_after32(a, b)
  99 #endif