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
   8 typedef __s64 time64_t;
   9 typedef __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
  16 struct timespec64 {
  17         time64_t        tv_sec;                 /* seconds */
  18         long            tv_nsec;                /* nanoseconds */
  19 };
  20
  21 struct 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
  42 static 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  */
  53 static 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
  62 extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
  63
  64 static 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  */
  76 static 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  */
  88 static 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
  99 static 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  */
 116 static 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  */
 127 extern 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  */
 137 static __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  */
 147 extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
 148                                          const struct timespec64 rhs);
 149
 150 #endif /* _LINUX_TIME64_H */