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
   9 /*
  10  * This wants to go into uapi/linux/time.h once we agreed about the
  11  * userspace interfaces.
  12  */
  13 #if __BITS_PER_LONG == 64
  14 # define timespec64 timespec
  15 #else
  16 struct timespec64 {
  17         time64_t        tv_sec;                 /* seconds */
  18         long            tv_nsec;                /* nanoseconds */
  19 };
  20 #endif
  21
  22 /* Parameters used to convert the timespec values: */
  23 #define MSEC_PER_SEC    1000L
  24 #define USEC_PER_MSEC   1000L
  25 #define NSEC_PER_USEC   1000L
  26 #define NSEC_PER_MSEC   1000000L
  27 #define USEC_PER_SEC    1000000L
  28 #define NSEC_PER_SEC    1000000000L
  29 #define FSEC_PER_SEC    1000000000000000LL
  30
  31 /* Located here for timespec[64]_valid_strict */
  32 #define TIME64_MAX                      ((s64)~((u64)1 << 63))
  33 #define KTIME_MAX                       ((s64)~((u64)1 << 63))
  34 #define KTIME_SEC_MAX                   (KTIME_MAX / NSEC_PER_SEC)
  35
  36 #if __BITS_PER_LONG == 64
  37
  38 static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
  39 {
  40         return ts64;
  41 }
  42
  43 static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
  44 {
  45         return ts;
  46 }
  47
  48 # define timespec64_equal               timespec_equal
  49 # define timespec64_compare             timespec_compare
  50 # define set_normalized_timespec64      set_normalized_timespec
  51 # define timespec64_add_safe            timespec_add_safe
  52 # define timespec64_add                 timespec_add
  53 # define timespec64_sub                 timespec_sub
  54 # define timespec64_valid               timespec_valid
  55 # define timespec64_valid_strict        timespec_valid_strict
  56 # define timespec64_to_ns               timespec_to_ns
  57 # define ns_to_timespec64               ns_to_timespec
  58 # define timespec64_add_ns              timespec_add_ns
  59
  60 #else
  61
  62 static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
  63 {
  64         struct timespec ret;
  65
  66         ret.tv_sec = (time_t)ts64.tv_sec;
  67         ret.tv_nsec = ts64.tv_nsec;
  68         return ret;
  69 }
  70
  71 static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
  72 {
  73         struct timespec64 ret;
  74
  75         ret.tv_sec = ts.tv_sec;
  76         ret.tv_nsec = ts.tv_nsec;
  77         return ret;
  78 }
  79
  80 static inline int timespec64_equal(const struct timespec64 *a,
  81                                    const struct timespec64 *b)
  82 {
  83         return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  84 }
  85
  86 /*
  87  * lhs < rhs:  return <0
  88  * lhs == rhs: return 0
  89  * lhs > rhs:  return >0
  90  */
  91 static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
  92 {
  93         if (lhs->tv_sec < rhs->tv_sec)
  94                 return -1;
  95         if (lhs->tv_sec > rhs->tv_sec)
  96                 return 1;
  97         return lhs->tv_nsec - rhs->tv_nsec;
  98 }
  99
 100 extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
 101
 102 /*
 103  * timespec64_add_safe assumes both values are positive and checks for
 104  * overflow. It will return TIME_T_MAX if the returned value would be
 105  * smaller then either of the arguments.
 106  */
 107 extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
 108                                          const struct timespec64 rhs);
 109
 110
 111 static inline struct timespec64 timespec64_add(struct timespec64 lhs,
 112                                                 struct timespec64 rhs)
 113 {
 114         struct timespec64 ts_delta;
 115         set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
 116                                 lhs.tv_nsec + rhs.tv_nsec);
 117         return ts_delta;
 118 }
 119
 120 /*
 121  * sub = lhs - rhs, in normalized form
 122  */
 123 static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
 124                                                 struct timespec64 rhs)
 125 {
 126         struct timespec64 ts_delta;
 127         set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
 128                                 lhs.tv_nsec - rhs.tv_nsec);
 129         return ts_delta;
 130 }
 131
 132 /*
 133  * Returns true if the timespec64 is norm, false if denorm:
 134  */
 135 static inline bool timespec64_valid(const struct timespec64 *ts)
 136 {
 137         /* Dates before 1970 are bogus */
 138         if (ts->tv_sec < 0)
 139                 return false;
 140         /* Can't have more nanoseconds then a second */
 141         if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
 142                 return false;
 143         return true;
 144 }
 145
 146 static inline bool timespec64_valid_strict(const struct timespec64 *ts)
 147 {
 148         if (!timespec64_valid(ts))
 149                 return false;
 150         /* Disallow values that could overflow ktime_t */
 151         if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
 152                 return false;
 153         return true;
 154 }
 155
 156 /**
 157  * timespec64_to_ns - Convert timespec64 to nanoseconds
 158  * @ts:         pointer to the timespec64 variable to be converted
 159  *
 160  * Returns the scalar nanosecond representation of the timespec64
 161  * parameter.
 162  */
 163 static inline s64 timespec64_to_ns(const struct timespec64 *ts)
 164 {
 165         return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 166 }
 167
 168 /**
 169  * ns_to_timespec64 - Convert nanoseconds to timespec64
 170  * @nsec:       the nanoseconds value to be converted
 171  *
 172  * Returns the timespec64 representation of the nsec parameter.
 173  */
 174 extern struct timespec64 ns_to_timespec64(const s64 nsec);
 175
 176 /**
 177  * timespec64_add_ns - Adds nanoseconds to a timespec64
 178  * @a:          pointer to timespec64 to be incremented
 179  * @ns:         unsigned nanoseconds value to be added
 180  *
 181  * This must always be inlined because its used from the x86-64 vdso,
 182  * which cannot call other kernel functions.
 183  */
 184 static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
 185 {
 186         a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 187         a->tv_nsec = ns;
 188 }
 189
 190 #endif
 191
 192 #endif /* _LINUX_TIME64_H */