linux/include/linux/time64.h
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   1#ifndef _LINUX_TIME64_H
   2#define _LINUX_TIME64_H
   3
   4#include <uapi/linux/time.h>
   5
   6typedef __s64 time64_t;
   7
   8/*
   9 * This wants to go into uapi/linux/time.h once we agreed about the
  10 * userspace interfaces.
  11 */
  12#if __BITS_PER_LONG == 64
  13# define timespec64 timespec
  14#else
  15struct timespec64 {
  16        time64_t        tv_sec;                 /* seconds */
  17        long            tv_nsec;                /* nanoseconds */
  18};
  19#endif
  20
  21/* Parameters used to convert the timespec values: */
  22#define MSEC_PER_SEC    1000L
  23#define USEC_PER_MSEC   1000L
  24#define NSEC_PER_USEC   1000L
  25#define NSEC_PER_MSEC   1000000L
  26#define USEC_PER_SEC    1000000L
  27#define NSEC_PER_SEC    1000000000L
  28#define FSEC_PER_SEC    1000000000000000LL
  29
  30/* Located here for timespec[64]_valid_strict */
  31#define KTIME_MAX                       ((s64)~((u64)1 << 63))
  32#define KTIME_SEC_MAX                   (KTIME_MAX / NSEC_PER_SEC)
  33
  34#if __BITS_PER_LONG == 64
  35
  36static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
  37{
  38        return ts64;
  39}
  40
  41static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
  42{
  43        return ts;
  44}
  45
  46# define timespec64_equal               timespec_equal
  47# define timespec64_compare             timespec_compare
  48# define set_normalized_timespec64      set_normalized_timespec
  49# define timespec64_add_safe            timespec_add_safe
  50# define timespec64_add                 timespec_add
  51# define timespec64_sub                 timespec_sub
  52# define timespec64_valid               timespec_valid
  53# define timespec64_valid_strict        timespec_valid_strict
  54# define timespec64_to_ns               timespec_to_ns
  55# define ns_to_timespec64               ns_to_timespec
  56# define timespec64_add_ns              timespec_add_ns
  57
  58#else
  59
  60static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
  61{
  62        struct timespec ret;
  63
  64        ret.tv_sec = (time_t)ts64.tv_sec;
  65        ret.tv_nsec = ts64.tv_nsec;
  66        return ret;
  67}
  68
  69static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
  70{
  71        struct timespec64 ret;
  72
  73        ret.tv_sec = ts.tv_sec;
  74        ret.tv_nsec = ts.tv_nsec;
  75        return ret;
  76}
  77
  78static inline int timespec64_equal(const struct timespec64 *a,
  79                                   const struct timespec64 *b)
  80{
  81        return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  82}
  83
  84/*
  85 * lhs < rhs:  return <0
  86 * lhs == rhs: return 0
  87 * lhs > rhs:  return >0
  88 */
  89static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
  90{
  91        if (lhs->tv_sec < rhs->tv_sec)
  92                return -1;
  93        if (lhs->tv_sec > rhs->tv_sec)
  94                return 1;
  95        return lhs->tv_nsec - rhs->tv_nsec;
  96}
  97
  98extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
  99
 100/*
 101 * timespec64_add_safe assumes both values are positive and checks for
 102 * overflow. It will return TIME_T_MAX if the returned value would be
 103 * smaller then either of the arguments.
 104 */
 105extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
 106                                         const struct timespec64 rhs);
 107
 108
 109static inline struct timespec64 timespec64_add(struct timespec64 lhs,
 110                                                struct timespec64 rhs)
 111{
 112        struct timespec64 ts_delta;
 113        set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
 114                                lhs.tv_nsec + rhs.tv_nsec);
 115        return ts_delta;
 116}
 117
 118/*
 119 * sub = lhs - rhs, in normalized form
 120 */
 121static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
 122                                                struct timespec64 rhs)
 123{
 124        struct timespec64 ts_delta;
 125        set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
 126                                lhs.tv_nsec - rhs.tv_nsec);
 127        return ts_delta;
 128}
 129
 130/*
 131 * Returns true if the timespec64 is norm, false if denorm:
 132 */
 133static inline bool timespec64_valid(const struct timespec64 *ts)
 134{
 135        /* Dates before 1970 are bogus */
 136        if (ts->tv_sec < 0)
 137                return false;
 138        /* Can't have more nanoseconds then a second */
 139        if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
 140                return false;
 141        return true;
 142}
 143
 144static inline bool timespec64_valid_strict(const struct timespec64 *ts)
 145{
 146        if (!timespec64_valid(ts))
 147                return false;
 148        /* Disallow values that could overflow ktime_t */
 149        if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
 150                return false;
 151        return true;
 152}
 153
 154/**
 155 * timespec64_to_ns - Convert timespec64 to nanoseconds
 156 * @ts:         pointer to the timespec64 variable to be converted
 157 *
 158 * Returns the scalar nanosecond representation of the timespec64
 159 * parameter.
 160 */
 161static inline s64 timespec64_to_ns(const struct timespec64 *ts)
 162{
 163        return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 164}
 165
 166/**
 167 * ns_to_timespec64 - Convert nanoseconds to timespec64
 168 * @nsec:       the nanoseconds value to be converted
 169 *
 170 * Returns the timespec64 representation of the nsec parameter.
 171 */
 172extern struct timespec64 ns_to_timespec64(const s64 nsec);
 173
 174/**
 175 * timespec64_add_ns - Adds nanoseconds to a timespec64
 176 * @a:          pointer to timespec64 to be incremented
 177 * @ns:         unsigned nanoseconds value to be added
 178 *
 179 * This must always be inlined because its used from the x86-64 vdso,
 180 * which cannot call other kernel functions.
 181 */
 182static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
 183{
 184        a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 185        a->tv_nsec = ns;
 186}
 187
 188#endif
 189
 190#endif /* _LINUX_TIME64_H */
 191