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 <linux/math64.h>
   6
   7typedef __s64 time64_t;
   8typedef __u64 timeu64_t;
   9
  10/* CONFIG_64BIT_TIME enables new 64 bit time_t syscalls in the compat path
  11 * and 32-bit emulation.
  12 */
  13#ifndef CONFIG_64BIT_TIME
  14#define __kernel_timespec timespec
  15#define __kernel_itimerspec itimerspec
  16#endif
  17
  18#include <uapi/linux/time.h>
  19
  20struct timespec64 {
  21        time64_t        tv_sec;                 /* seconds */
  22        long            tv_nsec;                /* nanoseconds */
  23};
  24
  25struct itimerspec64 {
  26        struct timespec64 it_interval;
  27        struct timespec64 it_value;
  28};
  29
  30/* Parameters used to convert the timespec values: */
  31#define MSEC_PER_SEC    1000L
  32#define USEC_PER_MSEC   1000L
  33#define NSEC_PER_USEC   1000L
  34#define NSEC_PER_MSEC   1000000L
  35#define USEC_PER_SEC    1000000L
  36#define NSEC_PER_SEC    1000000000L
  37#define FSEC_PER_SEC    1000000000000000LL
  38
  39/* Located here for timespec[64]_valid_strict */
  40#define TIME64_MAX                      ((s64)~((u64)1 << 63))
  41#define KTIME_MAX                       ((s64)~((u64)1 << 63))
  42#define KTIME_SEC_MAX                   (KTIME_MAX / NSEC_PER_SEC)
  43
  44static inline int timespec64_equal(const struct timespec64 *a,
  45                                   const struct timespec64 *b)
  46{
  47        return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  48}
  49
  50/*
  51 * lhs < rhs:  return <0
  52 * lhs == rhs: return 0
  53 * lhs > rhs:  return >0
  54 */
  55static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
  56{
  57        if (lhs->tv_sec < rhs->tv_sec)
  58                return -1;
  59        if (lhs->tv_sec > rhs->tv_sec)
  60                return 1;
  61        return lhs->tv_nsec - rhs->tv_nsec;
  62}
  63
  64extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
  65
  66static inline struct timespec64 timespec64_add(struct timespec64 lhs,
  67                                                struct timespec64 rhs)
  68{
  69        struct timespec64 ts_delta;
  70        set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
  71                                lhs.tv_nsec + rhs.tv_nsec);
  72        return ts_delta;
  73}
  74
  75/*
  76 * sub = lhs - rhs, in normalized form
  77 */
  78static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
  79                                                struct timespec64 rhs)
  80{
  81        struct timespec64 ts_delta;
  82        set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
  83                                lhs.tv_nsec - rhs.tv_nsec);
  84        return ts_delta;
  85}
  86
  87/*
  88 * Returns true if the timespec64 is norm, false if denorm:
  89 */
  90static inline bool timespec64_valid(const struct timespec64 *ts)
  91{
  92        /* Dates before 1970 are bogus */
  93        if (ts->tv_sec < 0)
  94                return false;
  95        /* Can't have more nanoseconds then a second */
  96        if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
  97                return false;
  98        return true;
  99}
 100
 101static inline bool timespec64_valid_strict(const struct timespec64 *ts)
 102{
 103        if (!timespec64_valid(ts))
 104                return false;
 105        /* Disallow values that could overflow ktime_t */
 106        if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
 107                return false;
 108        return true;
 109}
 110
 111/**
 112 * timespec64_to_ns - Convert timespec64 to nanoseconds
 113 * @ts:         pointer to the timespec64 variable to be converted
 114 *
 115 * Returns the scalar nanosecond representation of the timespec64
 116 * parameter.
 117 */
 118static inline s64 timespec64_to_ns(const struct timespec64 *ts)
 119{
 120        return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 121}
 122
 123/**
 124 * ns_to_timespec64 - Convert nanoseconds to timespec64
 125 * @nsec:       the nanoseconds value to be converted
 126 *
 127 * Returns the timespec64 representation of the nsec parameter.
 128 */
 129extern struct timespec64 ns_to_timespec64(const s64 nsec);
 130
 131/**
 132 * timespec64_add_ns - Adds nanoseconds to a timespec64
 133 * @a:          pointer to timespec64 to be incremented
 134 * @ns:         unsigned nanoseconds value to be added
 135 *
 136 * This must always be inlined because its used from the x86-64 vdso,
 137 * which cannot call other kernel functions.
 138 */
 139static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
 140{
 141        a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 142        a->tv_nsec = ns;
 143}
 144
 145/*
 146 * timespec64_add_safe assumes both values are positive and checks for
 147 * overflow. It will return TIME64_MAX in case of overflow.
 148 */
 149extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
 150                                         const struct timespec64 rhs);
 151
 152#endif /* _LINUX_TIME64_H */
 153