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