include/linux/time.h

   1 #ifndef _LINUX_TIME_H
   2 #define _LINUX_TIME_H
   3
   4 #include <linux/types.h>
   5
   6 #ifdef __KERNEL__
   7 # include <linux/cache.h>
   8 # include <linux/seqlock.h>
   9 # include <linux/math64.h>
  10 #endif
  11
  12 #ifndef _STRUCT_TIMESPEC
  13 #define _STRUCT_TIMESPEC
  14 struct timespec {
  15         time_t  tv_sec;         /* seconds */
  16         long    tv_nsec;        /* nanoseconds */
  17 };
  18 #endif
  19
  20 struct timeval {
  21         time_t          tv_sec;         /* seconds */
  22         suseconds_t     tv_usec;        /* microseconds */
  23 };
  24
  25 struct timezone {
  26         int     tz_minuteswest; /* minutes west of Greenwich */
  27         int     tz_dsttime;     /* type of dst correction */
  28 };
  29
  30 #ifdef __KERNEL__
  31
  32 /* Parameters used to convert the timespec values: */
  33 #define MSEC_PER_SEC    1000L
  34 #define USEC_PER_MSEC   1000L
  35 #define NSEC_PER_USEC   1000L
  36 #define NSEC_PER_MSEC   1000000L
  37 #define USEC_PER_SEC    1000000L
  38 #define NSEC_PER_SEC    1000000000L
  39 #define FSEC_PER_SEC    1000000000000000L
  40
  41 static inline int timespec_equal(const struct timespec *a,
  42                                  const struct timespec *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 timespec_compare(const struct timespec *lhs, const struct timespec *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 static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
  62 {
  63         if (lhs->tv_sec < rhs->tv_sec)
  64                 return -1;
  65         if (lhs->tv_sec > rhs->tv_sec)
  66                 return 1;
  67         return lhs->tv_usec - rhs->tv_usec;
  68 }
  69
  70 extern unsigned long mktime(const unsigned int year, const unsigned int mon,
  71                             const unsigned int day, const unsigned int hour,
  72                             const unsigned int min, const unsigned int sec);
  73
  74 extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
  75
  76 /*
  77  * sub = lhs - rhs, in normalized form
  78  */
  79 static inline struct timespec timespec_sub(struct timespec lhs,
  80                                                 struct timespec rhs)
  81 {
  82         struct timespec ts_delta;
  83         set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
  84                                 lhs.tv_nsec - rhs.tv_nsec);
  85         return ts_delta;
  86 }
  87
  88 /*
  89  * Returns true if the timespec is norm, false if denorm:
  90  */
  91 #define timespec_valid(ts) \
  92         (((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
  93
  94 extern struct timespec xtime;
  95 extern struct timespec wall_to_monotonic;
  96 extern seqlock_t xtime_lock;
  97
  98 extern unsigned long read_persistent_clock(void);
  99 extern int update_persistent_clock(struct timespec now);
 100 extern int no_sync_cmos_clock __read_mostly;
 101 void timekeeping_init(void);
 102
 103 unsigned long get_seconds(void);
 104 struct timespec current_kernel_time(void);
 105
 106 #define CURRENT_TIME            (current_kernel_time())
 107 #define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 108
 109 extern void do_gettimeofday(struct timeval *tv);
 110 extern int do_settimeofday(struct timespec *tv);
 111 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
 112 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 113 extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
 114 struct itimerval;
 115 extern int do_setitimer(int which, struct itimerval *value,
 116                         struct itimerval *ovalue);
 117 extern unsigned int alarm_setitimer(unsigned int seconds);
 118 extern int do_getitimer(int which, struct itimerval *value);
 119 extern void getnstimeofday(struct timespec *tv);
 120 extern void getboottime(struct timespec *ts);
 121 extern void monotonic_to_bootbased(struct timespec *ts);
 122
 123 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 124 extern int timekeeping_valid_for_hres(void);
 125 extern void update_wall_time(void);
 126 extern void update_xtime_cache(u64 nsec);
 127
 128 /**
 129  * timespec_to_ns - Convert timespec to nanoseconds
 130  * @ts:         pointer to the timespec variable to be converted
 131  *
 132  * Returns the scalar nanosecond representation of the timespec
 133  * parameter.
 134  */
 135 static inline s64 timespec_to_ns(const struct timespec *ts)
 136 {
 137         return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 138 }
 139
 140 /**
 141  * timeval_to_ns - Convert timeval to nanoseconds
 142  * @ts:         pointer to the timeval variable to be converted
 143  *
 144  * Returns the scalar nanosecond representation of the timeval
 145  * parameter.
 146  */
 147 static inline s64 timeval_to_ns(const struct timeval *tv)
 148 {
 149         return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 150                 tv->tv_usec * NSEC_PER_USEC;
 151 }
 152
 153 /**
 154  * ns_to_timespec - Convert nanoseconds to timespec
 155  * @nsec:       the nanoseconds value to be converted
 156  *
 157  * Returns the timespec representation of the nsec parameter.
 158  */
 159 extern struct timespec ns_to_timespec(const s64 nsec);
 160
 161 /**
 162  * ns_to_timeval - Convert nanoseconds to timeval
 163  * @nsec:       the nanoseconds value to be converted
 164  *
 165  * Returns the timeval representation of the nsec parameter.
 166  */
 167 extern struct timeval ns_to_timeval(const s64 nsec);
 168
 169 /**
 170  * timespec_add_ns - Adds nanoseconds to a timespec
 171  * @a:          pointer to timespec to be incremented
 172  * @ns:         unsigned nanoseconds value to be added
 173  */
 174 static inline void timespec_add_ns(struct timespec *a, u64 ns)
 175 {
 176         a->tv_sec += iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 177         a->tv_nsec = ns;
 178 }
 179 #endif /* __KERNEL__ */
 180
 181 #define NFDBITS                 __NFDBITS
 182
 183 #define FD_SETSIZE              __FD_SETSIZE
 184 #define FD_SET(fd,fdsetp)       __FD_SET(fd,fdsetp)
 185 #define FD_CLR(fd,fdsetp)       __FD_CLR(fd,fdsetp)
 186 #define FD_ISSET(fd,fdsetp)     __FD_ISSET(fd,fdsetp)
 187 #define FD_ZERO(fdsetp)         __FD_ZERO(fdsetp)
 188
 189 /*
 190  * Names of the interval timers, and structure
 191  * defining a timer setting:
 192  */
 193 #define ITIMER_REAL             0
 194 #define ITIMER_VIRTUAL          1
 195 #define ITIMER_PROF             2
 196
 197 struct itimerspec {
 198         struct timespec it_interval;    /* timer period */
 199         struct timespec it_value;       /* timer expiration */
 200 };
 201
 202 struct itimerval {
 203         struct timeval it_interval;     /* timer interval */
 204         struct timeval it_value;        /* current value */
 205 };
 206
 207 /*
 208  * The IDs of the various system clocks (for POSIX.1b interval timers):
 209  */
 210 #define CLOCK_REALTIME                  0
 211 #define CLOCK_MONOTONIC                 1
 212 #define CLOCK_PROCESS_CPUTIME_ID        2
 213 #define CLOCK_THREAD_CPUTIME_ID         3
 214
 215 /*
 216  * The IDs of various hardware clocks:
 217  */
 218 #define CLOCK_SGI_CYCLE                 10
 219 #define MAX_CLOCKS                      16
 220 #define CLOCKS_MASK                     (CLOCK_REALTIME | CLOCK_MONOTONIC)
 221 #define CLOCKS_MONO                     CLOCK_MONOTONIC
 222
 223 /*
 224  * The various flags for setting POSIX.1b interval timers:
 225  */
 226 #define TIMER_ABSTIME                   0x01
 227
 228 #endif