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/math64.h>
   7# include <linux/time64.h>
   8
   9extern struct timezone sys_tz;
  10
  11int get_timespec64(struct timespec64 *ts,
  12                const struct __kernel_timespec __user *uts);
  13int put_timespec64(const struct timespec64 *ts,
  14                struct __kernel_timespec __user *uts);
  15int get_itimerspec64(struct itimerspec64 *it,
  16                        const struct __kernel_itimerspec __user *uit);
  17int put_itimerspec64(const struct itimerspec64 *it,
  18                        struct __kernel_itimerspec __user *uit);
  19
  20extern time64_t mktime64(const unsigned int year, const unsigned int mon,
  21                        const unsigned int day, const unsigned int hour,
  22                        const unsigned int min, const unsigned int sec);
  23
  24/* Some architectures do not supply their own clocksource.
  25 * This is mainly the case in architectures that get their
  26 * inter-tick times by reading the counter on their interval
  27 * timer. Since these timers wrap every tick, they're not really
  28 * useful as clocksources. Wrapping them to act like one is possible
  29 * but not very efficient. So we provide a callout these arches
  30 * can implement for use with the jiffies clocksource to provide
  31 * finer then tick granular time.
  32 */
  33#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
  34extern u32 (*arch_gettimeoffset)(void);
  35#endif
  36
  37#ifdef CONFIG_POSIX_TIMERS
  38extern void clear_itimer(void);
  39#else
  40static inline void clear_itimer(void) {}
  41#endif
  42
  43extern 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 */
  49struct 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
  71void time64_to_tm(time64_t totalsecs, int offset, struct tm *result);
  72
  73# include <linux/time32.h>
  74
  75static 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
 100/**
 101 * time_between32 - check if a 32-bit timestamp is within a given time range
 102 * @t:  the time which may be within [l,h]
 103 * @l:  the lower bound of the range
 104 * @h:  the higher bound of the range
 105 *
 106 * time_before32(t, l, h) returns true if @l <= @t <= @h. All operands are
 107 * treated as 32-bit integers.
 108 *
 109 * Equivalent to !(time_before32(@t, @l) || time_after32(@t, @h)).
 110 */
 111#define time_between32(t, l, h) ((u32)(h) - (u32)(l) >= (u32)(t) - (u32)(l))
 112
 113# include <vdso/time.h>
 114
 115#endif
 116