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(const struct timespec *a,
  40                                  const struct timespec *b)
  41 {
  42         return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  43 }
  44
  45 /*
  46  * lhs < rhs:  return <0
  47  * lhs == rhs: return 0
  48  * lhs > rhs:  return >0
  49  */
  50 static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
  51 {
  52         if (lhs->tv_sec < rhs->tv_sec)
  53                 return -1;
  54         if (lhs->tv_sec > rhs->tv_sec)
  55                 return 1;
  56         return lhs->tv_nsec - rhs->tv_nsec;
  57 }
  58
  59 static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
  60 {
  61         if (lhs->tv_sec < rhs->tv_sec)
  62                 return -1;
  63         if (lhs->tv_sec > rhs->tv_sec)
  64                 return 1;
  65         return lhs->tv_usec - rhs->tv_usec;
  66 }
  67
  68 extern unsigned long mktime(const unsigned int year, const unsigned int mon,
  69                             const unsigned int day, const unsigned int hour,
  70                             const unsigned int min, const unsigned int sec);
  71
  72 extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
  73
  74 /*
  75  * sub = lhs - rhs, in normalized form
  76  */
  77 static inline struct timespec timespec_sub(struct timespec lhs,
  78                                                 struct timespec rhs)
  79 {
  80         struct timespec ts_delta;
  81         set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
  82                                 lhs.tv_nsec - rhs.tv_nsec);
  83         return ts_delta;
  84 }
  85
  86 /*
  87  * Returns true if the timespec is norm, false if denorm:
  88  */
  89 #define timespec_valid(ts) \
  90         (((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
  91
  92 extern struct timespec xtime;
  93 extern struct timespec wall_to_monotonic;
  94 extern seqlock_t xtime_lock __attribute__((weak));
  95
  96 extern unsigned long read_persistent_clock(void);
  97 void timekeeping_init(void);
  98
  99 static inline unsigned long get_seconds(void)
 100 {
 101         return xtime.tv_sec;
 102 }
 103
 104 struct timespec current_kernel_time(void);
 105
 106 #define CURRENT_TIME            (current_kernel_time())
 107 #define CURRENT_TIME_SEC        ((struct timespec) { xtime.tv_sec, 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_is_continuous(void);
 125 extern void update_wall_time(void);
 126
 127 /**
 128  * timespec_to_ns - Convert timespec to nanoseconds
 129  * @ts:         pointer to the timespec variable to be converted
 130  *
 131  * Returns the scalar nanosecond representation of the timespec
 132  * parameter.
 133  */
 134 static inline s64 timespec_to_ns(const struct timespec *ts)
 135 {
 136         return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 137 }
 138
 139 /**
 140  * timeval_to_ns - Convert timeval to nanoseconds
 141  * @ts:         pointer to the timeval variable to be converted
 142  *
 143  * Returns the scalar nanosecond representation of the timeval
 144  * parameter.
 145  */
 146 static inline s64 timeval_to_ns(const struct timeval *tv)
 147 {
 148         return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 149                 tv->tv_usec * NSEC_PER_USEC;
 150 }
 151
 152 /**
 153  * ns_to_timespec - Convert nanoseconds to timespec
 154  * @nsec:       the nanoseconds value to be converted
 155  *
 156  * Returns the timespec representation of the nsec parameter.
 157  */
 158 extern struct timespec ns_to_timespec(const s64 nsec);
 159
 160 /**
 161  * ns_to_timeval - Convert nanoseconds to timeval
 162  * @nsec:       the nanoseconds value to be converted
 163  *
 164  * Returns the timeval representation of the nsec parameter.
 165  */
 166 extern struct timeval ns_to_timeval(const s64 nsec);
 167
 168 /**
 169  * timespec_add_ns - Adds nanoseconds to a timespec
 170  * @a:          pointer to timespec to be incremented
 171  * @ns:         unsigned nanoseconds value to be added
 172  */
 173 static inline void timespec_add_ns(struct timespec *a, u64 ns)
 174 {
 175         ns += a->tv_nsec;
 176         while(unlikely(ns >= NSEC_PER_SEC)) {
 177                 ns -= NSEC_PER_SEC;
 178                 a->tv_sec++;
 179         }
 180         a->tv_nsec = ns;
 181 }
 182 #endif /* __KERNEL__ */
 183
 184 #define NFDBITS                 __NFDBITS
 185
 186 #define FD_SETSIZE              __FD_SETSIZE
 187 #define FD_SET(fd,fdsetp)       __FD_SET(fd,fdsetp)
 188 #define FD_CLR(fd,fdsetp)       __FD_CLR(fd,fdsetp)
 189 #define FD_ISSET(fd,fdsetp)     __FD_ISSET(fd,fdsetp)
 190 #define FD_ZERO(fdsetp)         __FD_ZERO(fdsetp)
 191
 192 /*
 193  * Names of the interval timers, and structure
 194  * defining a timer setting:
 195  */
 196 #define ITIMER_REAL             0
 197 #define ITIMER_VIRTUAL          1
 198 #define ITIMER_PROF             2
 199
 200 struct itimerspec {
 201         struct timespec it_interval;    /* timer period */
 202         struct timespec it_value;       /* timer expiration */
 203 };
 204
 205 struct itimerval {
 206         struct timeval it_interval;     /* timer interval */
 207         struct timeval it_value;        /* current value */
 208 };
 209
 210 /*
 211  * The IDs of the various system clocks (for POSIX.1b interval timers):
 212  */
 213 #define CLOCK_REALTIME                  0
 214 #define CLOCK_MONOTONIC                 1
 215 #define CLOCK_PROCESS_CPUTIME_ID        2
 216 #define CLOCK_THREAD_CPUTIME_ID         3
 217
 218 /*
 219  * The IDs of various hardware clocks:
 220  */
 221 #define CLOCK_SGI_CYCLE                 10
 222 #define MAX_CLOCKS                      16
 223 #define CLOCKS_MASK                     (CLOCK_REALTIME | CLOCK_MONOTONIC)
 224 #define CLOCKS_MONO                     CLOCK_MONOTONIC
 225
 226 /*
 227  * The various flags for setting POSIX.1b interval timers:
 228  */
 229 #define TIMER_ABSTIME                   0x01
 230
 231 #endif