include/linux/time64.h

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