include/linux/time.h

   1 #ifndef _LINUX_TIME_H
   2 #define _LINUX_TIME_H
   3
   4 # include <linux/cache.h>
   5 # include <linux/seqlock.h>
   6 # include <linux/math64.h>
   7 # include <linux/time64.h>
   8
   9 extern struct timezone sys_tz;
  10
  11 #define TIME_T_MAX      (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
  12
  13 static inline int timespec_equal(const struct timespec *a,
  14                                  const struct timespec *b)
  15 {
  16         return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  17 }
  18
  19 /*
  20  * lhs < rhs:  return <0
  21  * lhs == rhs: return 0
  22  * lhs > rhs:  return >0
  23  */
  24 static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
  25 {
  26         if (lhs->tv_sec < rhs->tv_sec)
  27                 return -1;
  28         if (lhs->tv_sec > rhs->tv_sec)
  29                 return 1;
  30         return lhs->tv_nsec - rhs->tv_nsec;
  31 }
  32
  33 static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
  34 {
  35         if (lhs->tv_sec < rhs->tv_sec)
  36                 return -1;
  37         if (lhs->tv_sec > rhs->tv_sec)
  38                 return 1;
  39         return lhs->tv_usec - rhs->tv_usec;
  40 }
  41
  42 extern time64_t mktime64(const unsigned int year, const unsigned int mon,
  43                         const unsigned int day, const unsigned int hour,
  44                         const unsigned int min, const unsigned int sec);
  45
  46 /**
  47  * Deprecated. Use mktime64().
  48  */
  49 static inline unsigned long mktime(const unsigned int year,
  50                         const unsigned int mon, const unsigned int day,
  51                         const unsigned int hour, const unsigned int min,
  52                         const unsigned int sec)
  53 {
  54         return mktime64(year, mon, day, hour, min, sec);
  55 }
  56
  57 extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);
  58
  59 /*
  60  * timespec_add_safe assumes both values are positive and checks
  61  * for overflow. It will return TIME_T_MAX if the reutrn would be
  62  * smaller then either of the arguments.
  63  */
  64 extern struct timespec timespec_add_safe(const struct timespec lhs,
  65                                          const struct timespec rhs);
  66
  67
  68 static inline struct timespec timespec_add(struct timespec lhs,
  69                                                 struct timespec rhs)
  70 {
  71         struct timespec ts_delta;
  72         set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec,
  73                                 lhs.tv_nsec + rhs.tv_nsec);
  74         return ts_delta;
  75 }
  76
  77 /*
  78  * sub = lhs - rhs, in normalized form
  79  */
  80 static inline struct timespec timespec_sub(struct timespec lhs,
  81                                                 struct timespec rhs)
  82 {
  83         struct timespec ts_delta;
  84         set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
  85                                 lhs.tv_nsec - rhs.tv_nsec);
  86         return ts_delta;
  87 }
  88
  89 /*
  90  * Returns true if the timespec is norm, false if denorm:
  91  */
  92 static inline bool timespec_valid(const struct timespec *ts)
  93 {
  94         /* Dates before 1970 are bogus */
  95         if (ts->tv_sec < 0)
  96                 return false;
  97         /* Can't have more nanoseconds then a second */
  98         if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
  99                 return false;
 100         return true;
 101 }
 102
 103 static inline bool timespec_valid_strict(const struct timespec *ts)
 104 {
 105         if (!timespec_valid(ts))
 106                 return false;
 107         /* Disallow values that could overflow ktime_t */
 108         if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
 109                 return false;
 110         return true;
 111 }
 112
 113 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 114
 115 #define CURRENT_TIME            (current_kernel_time())
 116 #define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 117
 118 /* Some architectures do not supply their own clocksource.
 119  * This is mainly the case in architectures that get their
 120  * inter-tick times by reading the counter on their interval
 121  * timer. Since these timers wrap every tick, they're not really
 122  * useful as clocksources. Wrapping them to act like one is possible
 123  * but not very efficient. So we provide a callout these arches
 124  * can implement for use with the jiffies clocksource to provide
 125  * finer then tick granular time.
 126  */
 127 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 128 extern u32 (*arch_gettimeoffset)(void);
 129 #endif
 130
 131 struct itimerval;
 132 extern int do_setitimer(int which, struct itimerval *value,
 133                         struct itimerval *ovalue);
 134 extern int do_getitimer(int which, struct itimerval *value);
 135
 136 extern unsigned int alarm_setitimer(unsigned int seconds);
 137
 138 extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);
 139
 140 struct tms;
 141 extern void do_sys_times(struct tms *);
 142
 143 /*
 144  * Similar to the struct tm in userspace <time.h>, but it needs to be here so
 145  * that the kernel source is self contained.
 146  */
 147 struct tm {
 148         /*
 149          * the number of seconds after the minute, normally in the range
 150          * 0 to 59, but can be up to 60 to allow for leap seconds
 151          */
 152         int tm_sec;
 153         /* the number of minutes after the hour, in the range 0 to 59*/
 154         int tm_min;
 155         /* the number of hours past midnight, in the range 0 to 23 */
 156         int tm_hour;
 157         /* the day of the month, in the range 1 to 31 */
 158         int tm_mday;
 159         /* the number of months since January, in the range 0 to 11 */
 160         int tm_mon;
 161         /* the number of years since 1900 */
 162         long tm_year;
 163         /* the number of days since Sunday, in the range 0 to 6 */
 164         int tm_wday;
 165         /* the number of days since January 1, in the range 0 to 365 */
 166         int tm_yday;
 167 };
 168
 169 void time_to_tm(time_t totalsecs, int offset, struct tm *result);
 170
 171 /**
 172  * timespec_to_ns - Convert timespec to nanoseconds
 173  * @ts:         pointer to the timespec variable to be converted
 174  *
 175  * Returns the scalar nanosecond representation of the timespec
 176  * parameter.
 177  */
 178 static inline s64 timespec_to_ns(const struct timespec *ts)
 179 {
 180         return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 181 }
 182
 183 /**
 184  * timeval_to_ns - Convert timeval to nanoseconds
 185  * @ts:         pointer to the timeval variable to be converted
 186  *
 187  * Returns the scalar nanosecond representation of the timeval
 188  * parameter.
 189  */
 190 static inline s64 timeval_to_ns(const struct timeval *tv)
 191 {
 192         return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 193                 tv->tv_usec * NSEC_PER_USEC;
 194 }
 195
 196 /**
 197  * ns_to_timespec - Convert nanoseconds to timespec
 198  * @nsec:       the nanoseconds value to be converted
 199  *
 200  * Returns the timespec representation of the nsec parameter.
 201  */
 202 extern struct timespec ns_to_timespec(const s64 nsec);
 203
 204 /**
 205  * ns_to_timeval - Convert nanoseconds to timeval
 206  * @nsec:       the nanoseconds value to be converted
 207  *
 208  * Returns the timeval representation of the nsec parameter.
 209  */
 210 extern struct timeval ns_to_timeval(const s64 nsec);
 211
 212 /**
 213  * timespec_add_ns - Adds nanoseconds to a timespec
 214  * @a:          pointer to timespec to be incremented
 215  * @ns:         unsigned nanoseconds value to be added
 216  *
 217  * This must always be inlined because its used from the x86-64 vdso,
 218  * which cannot call other kernel functions.
 219  */
 220 static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
 221 {
 222         a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 223         a->tv_nsec = ns;
 224 }
 225
 226 #endif