LXR linux/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
  10extern struct timezone sys_tz;
  11
  12int get_timespec64(struct timespec64 *ts,
  13                const struct __kernel_timespec __user *uts);
  14int put_timespec64(const struct timespec64 *ts,
  15                struct __kernel_timespec __user *uts);
  16int get_itimerspec64(struct itimerspec64 *it,
  17                        const struct __kernel_itimerspec __user *uit);
  18int put_itimerspec64(const struct itimerspec64 *it,
  19                        struct __kernel_itimerspec __user *uit);
  20
  21extern 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
  35extern u32 (*arch_gettimeoffset)(void);
  36#endif
  37
  38#ifdef CONFIG_POSIX_TIMERS
  39extern void clear_itimer(void);
  40#else
  41static inline void clear_itimer(void) {}
  42#endif
  43
  44extern long do_utimes(int dfd, const char __user *filename, struct timespec64 *times, int flags);
  45
  46/*
  47 * Similar to the struct tm in userspace <time.h>, but it needs to be here so
  48 * that the kernel source is self contained.
  49 */
  50struct tm {
  51        /*
  52         * the number of seconds after the minute, normally in the range
  53         * 0 to 59, but can be up to 60 to allow for leap seconds
  54         */
  55        int tm_sec;
  56        /* the number of minutes after the hour, in the range 0 to 59*/
  57        int tm_min;
  58        /* the number of hours past midnight, in the range 0 to 23 */
  59        int tm_hour;
  60        /* the day of the month, in the range 1 to 31 */
  61        int tm_mday;
  62        /* the number of months since January, in the range 0 to 11 */
  63        int tm_mon;
  64        /* the number of years since 1900 */
  65        long tm_year;
  66        /* the number of days since Sunday, in the range 0 to 6 */
  67        int tm_wday;
  68        /* the number of days since January 1, in the range 0 to 365 */
  69        int tm_yday;
  70};
  71
  72void time64_to_tm(time64_t totalsecs, int offset, struct tm *result);
  73
  74# include <linux/time32.h>
  75
  76static inline bool itimerspec64_valid(const struct itimerspec64 *its)
  77{
  78        if (!timespec64_valid(&(its->it_interval)) ||
  79                !timespec64_valid(&(its->it_value)))
  80                return false;
  81
  82        return true;
  83}
  84
  85/**
  86 * time_after32 - compare two 32-bit relative times
  87 * @a:  the time which may be after @b
  88 * @b:  the time which may be before @a
  89 *
  90 * time_after32(a, b) returns true if the time @a is after time @b.
  91 * time_before32(b, a) returns true if the time @b is before time @a.
  92 *
  93 * Similar to time_after(), compare two 32-bit timestamps for relative
  94 * times.  This is useful for comparing 32-bit seconds values that can't
  95 * be converted to 64-bit values (e.g. due to disk format or wire protocol
  96 * issues) when it is known that the times are less than 68 years apart.
  97 */
  98#define time_after32(a, b)      ((s32)((u32)(b) - (u32)(a)) < 0)
  99#define time_before32(b, a)     time_after32(a, b)
 100
 101/**
 102 * time_between32 - check if a 32-bit timestamp is within a given time range
 103 * @t:  the time which may be within [l,h]
 104 * @l:  the lower bound of the range
 105 * @h:  the higher bound of the range
 106 *
 107 * time_before32(t, l, h) returns true if @l <= @t <= @h. All operands are
 108 * treated as 32-bit integers.
 109 *
 110 * Equivalent to !(time_before32(@t, @l) || time_after32(@t, @h)).
 111 */
 112#define time_between32(t, l, h) ((u32)(h) - (u32)(l) >= (u32)(t) - (u32)(l))
 113
 114struct timens_offset {
 115        s64     sec;
 116        u64     nsec;
 117};
 118
 119#endif
 120