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/seqlock.h>
   8 #endif
   9
  10 #ifndef _STRUCT_TIMESPEC
  11 #define _STRUCT_TIMESPEC
  12 struct timespec {
  13         time_t  tv_sec;         /* seconds */
  14         long    tv_nsec;        /* nanoseconds */
  15 };
  16 #endif
  17
  18 struct timeval {
  19         time_t          tv_sec;         /* seconds */
  20         suseconds_t     tv_usec;        /* microseconds */
  21 };
  22
  23 struct timezone {
  24         int     tz_minuteswest; /* minutes west of Greenwich */
  25         int     tz_dsttime;     /* type of dst correction */
  26 };
  27
  28 #ifdef __KERNEL__
  29
  30 /* Parameters used to convert the timespec values: */
  31 #define MSEC_PER_SEC    1000L
  32 #define USEC_PER_MSEC   1000L
  33 #define NSEC_PER_USEC   1000L
  34 #define NSEC_PER_MSEC   1000000L
  35 #define USEC_PER_SEC    1000000L
  36 #define NSEC_PER_SEC    1000000000L
  37 #define FSEC_PER_SEC    1000000000000000L
  38
  39 static inline int timespec_equal(struct timespec *a, struct timespec *b)
  40 {
  41         return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  42 }
  43
  44 /*
  45  * lhs < rhs:  return <0
  46  * lhs == rhs: return 0
  47  * lhs > rhs:  return >0
  48  */
  49 static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
  50 {
  51         if (lhs->tv_sec < rhs->tv_sec)
  52                 return -1;
  53         if (lhs->tv_sec > rhs->tv_sec)
  54                 return 1;
  55         return lhs->tv_nsec - rhs->tv_nsec;
  56 }
  57
  58 static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
  59 {
  60         if (lhs->tv_sec < rhs->tv_sec)
  61                 return -1;
  62         if (lhs->tv_sec > rhs->tv_sec)
  63                 return 1;
  64         return lhs->tv_usec - rhs->tv_usec;
  65 }
  66
  67 extern unsigned long mktime(const unsigned int year, const unsigned int mon,
  68                             const unsigned int day, const unsigned int hour,
  69                             const unsigned int min, const unsigned int sec);
  70
  71 extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
  72
  73 /*
  74  * sub = lhs - rhs, in normalized form
  75  */
  76 static inline struct timespec timespec_sub(struct timespec lhs,
  77                                                 struct timespec rhs)
  78 {
  79         struct timespec ts_delta;
  80         set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
  81                                 lhs.tv_nsec - rhs.tv_nsec);
  82         return ts_delta;
  83 }
  84
  85 /*
  86  * Returns true if the timespec is norm, false if denorm:
  87  */
  88 #define timespec_valid(ts) \
  89         (((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
  90
  91 extern struct timespec xtime;
  92 extern struct timespec wall_to_monotonic;
  93 extern seqlock_t xtime_lock __attribute__((weak));
  94
  95 extern unsigned long read_persistent_clock(void);
  96 void timekeeping_init(void);
  97
  98 static inline unsigned long get_seconds(void)
  99 {
 100         return xtime.tv_sec;
 101 }
 102
 103 struct timespec current_kernel_time(void);
 104
 105 #define CURRENT_TIME            (current_kernel_time())
 106 #define CURRENT_TIME_SEC        ((struct timespec) { xtime.tv_sec, 0 })
 107
 108 extern void do_gettimeofday(struct timeval *tv);
 109 extern int do_settimeofday(struct timespec *tv);
 110 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
 111 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 112 extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
 113 struct itimerval;
 114 extern int do_setitimer(int which, struct itimerval *value,
 115                         struct itimerval *ovalue);
 116 extern unsigned int alarm_setitimer(unsigned int seconds);
 117 extern int do_getitimer(int which, struct itimerval *value);
 118 extern void getnstimeofday(struct timespec *tv);
 119
 120 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 121 extern int timekeeping_is_continuous(void);
 122 extern void update_wall_time(void);
 123
 124 /**
 125  * timespec_to_ns - Convert timespec to nanoseconds
 126  * @ts:         pointer to the timespec variable to be converted
 127  *
 128  * Returns the scalar nanosecond representation of the timespec
 129  * parameter.
 130  */
 131 static inline s64 timespec_to_ns(const struct timespec *ts)
 132 {
 133         return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 134 }
 135
 136 /**
 137  * timeval_to_ns - Convert timeval to nanoseconds
 138  * @ts:         pointer to the timeval variable to be converted
 139  *
 140  * Returns the scalar nanosecond representation of the timeval
 141  * parameter.
 142  */
 143 static inline s64 timeval_to_ns(const struct timeval *tv)
 144 {
 145         return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 146                 tv->tv_usec * NSEC_PER_USEC;
 147 }
 148
 149 /**
 150  * ns_to_timespec - Convert nanoseconds to timespec
 151  * @nsec:       the nanoseconds value to be converted
 152  *
 153  * Returns the timespec representation of the nsec parameter.
 154  */
 155 extern struct timespec ns_to_timespec(const s64 nsec);
 156
 157 /**
 158  * ns_to_timeval - Convert nanoseconds to timeval
 159  * @nsec:       the nanoseconds value to be converted
 160  *
 161  * Returns the timeval representation of the nsec parameter.
 162  */
 163 extern struct timeval ns_to_timeval(const s64 nsec);
 164
 165 /**
 166  * timespec_add_ns - Adds nanoseconds to a timespec
 167  * @a:          pointer to timespec to be incremented
 168  * @ns:         unsigned nanoseconds value to be added
 169  */
 170 static inline void timespec_add_ns(struct timespec *a, u64 ns)
 171 {
 172         ns += a->tv_nsec;
 173         while(unlikely(ns >= NSEC_PER_SEC)) {
 174                 ns -= NSEC_PER_SEC;
 175                 a->tv_sec++;
 176         }
 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