LXR linux/include/linux/time64.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_TIME64_H
   3#define _LINUX_TIME64_H
   4
   5#include <uapi/linux/time.h>
   6#include <linux/math64.h>
   7
   8typedef __s64 time64_t;
   9typedef __u64 timeu64_t;
  10
  11#if __BITS_PER_LONG == 64
  12/* this trick allows us to optimize out timespec64_to_timespec */
  13# define timespec64 timespec
  14#define itimerspec64 itimerspec
  15#else
  16struct timespec64 {
  17        time64_t        tv_sec;                 /* seconds */
  18        long            tv_nsec;                /* nanoseconds */
  19};
  20
  21struct itimerspec64 {
  22        struct timespec64 it_interval;
  23        struct timespec64 it_value;
  24};
  25
  26#endif
  27
  28/* Parameters used to convert the timespec values: */
  29#define MSEC_PER_SEC    1000L
  30#define USEC_PER_MSEC   1000L
  31#define NSEC_PER_USEC   1000L
  32#define NSEC_PER_MSEC   1000000L
  33#define USEC_PER_SEC    1000000L
  34#define NSEC_PER_SEC    1000000000L
  35#define FSEC_PER_SEC    1000000000000000LL
  36
  37/* Located here for timespec[64]_valid_strict */
  38#define TIME64_MAX                      ((s64)~((u64)1 << 63))
  39#define KTIME_MAX                       ((s64)~((u64)1 << 63))
  40#define KTIME_SEC_MAX                   (KTIME_MAX / NSEC_PER_SEC)
  41
  42static inline int timespec64_equal(const struct timespec64 *a,
  43                                   const struct timespec64 *b)
  44{
  45        return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  46}
  47
  48/*
  49 * lhs < rhs:  return <0
  50 * lhs == rhs: return 0
  51 * lhs > rhs:  return >0
  52 */
  53static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
  54{
  55        if (lhs->tv_sec < rhs->tv_sec)
  56                return -1;
  57        if (lhs->tv_sec > rhs->tv_sec)
  58                return 1;
  59        return lhs->tv_nsec - rhs->tv_nsec;
  60}
  61
  62extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
  63
  64static inline struct timespec64 timespec64_add(struct timespec64 lhs,
  65                                                struct timespec64 rhs)
  66{
  67        struct timespec64 ts_delta;
  68        set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
  69                                lhs.tv_nsec + rhs.tv_nsec);
  70        return ts_delta;
  71}
  72
  73/*
  74 * sub = lhs - rhs, in normalized form
  75 */
  76static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
  77                                                struct timespec64 rhs)
  78{
  79        struct timespec64 ts_delta;
  80        set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
  81                                lhs.tv_nsec - rhs.tv_nsec);
  82        return ts_delta;
  83}
  84
  85/*
  86 * Returns true if the timespec64 is norm, false if denorm:
  87 */
  88static inline bool timespec64_valid(const struct timespec64 *ts)
  89{
  90        /* Dates before 1970 are bogus */
  91        if (ts->tv_sec < 0)
  92                return false;
  93        /* Can't have more nanoseconds then a second */
  94        if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
  95                return false;
  96        return true;
  97}
  98
  99static inline bool timespec64_valid_strict(const struct timespec64 *ts)
 100{
 101        if (!timespec64_valid(ts))
 102                return false;
 103        /* Disallow values that could overflow ktime_t */
 104        if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
 105                return false;
 106        return true;
 107}
 108
 109/**
 110 * timespec64_to_ns - Convert timespec64 to nanoseconds
 111 * @ts:         pointer to the timespec64 variable to be converted
 112 *
 113 * Returns the scalar nanosecond representation of the timespec64
 114 * parameter.
 115 */
 116static inline s64 timespec64_to_ns(const struct timespec64 *ts)
 117{
 118        return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 119}
 120
 121/**
 122 * ns_to_timespec64 - Convert nanoseconds to timespec64
 123 * @nsec:       the nanoseconds value to be converted
 124 *
 125 * Returns the timespec64 representation of the nsec parameter.
 126 */
 127extern struct timespec64 ns_to_timespec64(const s64 nsec);
 128
 129/**
 130 * timespec64_add_ns - Adds nanoseconds to a timespec64
 131 * @a:          pointer to timespec64 to be incremented
 132 * @ns:         unsigned nanoseconds value to be added
 133 *
 134 * This must always be inlined because its used from the x86-64 vdso,
 135 * which cannot call other kernel functions.
 136 */
 137static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
 138{
 139        a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 140        a->tv_nsec = ns;
 141}
 142
 143/*
 144 * timespec64_add_safe assumes both values are positive and checks for
 145 * overflow. It will return TIME64_MAX in case of overflow.
 146 */
 147extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
 148                                         const struct timespec64 rhs);
 149
 150#endif /* _LINUX_TIME64_H */
 151