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 extern void getboottime(struct timespec *ts);
 120 extern void monotonic_to_bootbased(struct timespec *ts);
 121
 122 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 123 extern int timekeeping_is_continuous(void);
 124 extern void update_wall_time(void);
 125
 126 /**
 127  * timespec_to_ns - Convert timespec to nanoseconds
 128  * @ts:         pointer to the timespec variable to be converted
 129  *
 130  * Returns the scalar nanosecond representation of the timespec
 131  * parameter.
 132  */
 133 static inline s64 timespec_to_ns(const struct timespec *ts)
 134 {
 135         return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 136 }
 137
 138 /**
 139  * timeval_to_ns - Convert timeval to nanoseconds
 140  * @ts:         pointer to the timeval variable to be converted
 141  *
 142  * Returns the scalar nanosecond representation of the timeval
 143  * parameter.
 144  */
 145 static inline s64 timeval_to_ns(const struct timeval *tv)
 146 {
 147         return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 148                 tv->tv_usec * NSEC_PER_USEC;
 149 }
 150
 151 /**
 152  * ns_to_timespec - Convert nanoseconds to timespec
 153  * @nsec:       the nanoseconds value to be converted
 154  *
 155  * Returns the timespec representation of the nsec parameter.
 156  */
 157 extern struct timespec ns_to_timespec(const s64 nsec);
 158
 159 /**
 160  * ns_to_timeval - Convert nanoseconds to timeval
 161  * @nsec:       the nanoseconds value to be converted
 162  *
 163  * Returns the timeval representation of the nsec parameter.
 164  */
 165 extern struct timeval ns_to_timeval(const s64 nsec);
 166
 167 /**
 168  * timespec_add_ns - Adds nanoseconds to a timespec
 169  * @a:          pointer to timespec to be incremented
 170  * @ns:         unsigned nanoseconds value to be added
 171  */
 172 static inline void timespec_add_ns(struct timespec *a, u64 ns)
 173 {
 174         ns += a->tv_nsec;
 175         while(unlikely(ns >= NSEC_PER_SEC)) {
 176                 ns -= NSEC_PER_SEC;
 177                 a->tv_sec++;
 178         }
 179         a->tv_nsec = ns;
 180 }
 181 #endif /* __KERNEL__ */
 182
 183 #define NFDBITS                 __NFDBITS
 184
 185 #define FD_SETSIZE              __FD_SETSIZE
 186 #define FD_SET(fd,fdsetp)       __FD_SET(fd,fdsetp)
 187 #define FD_CLR(fd,fdsetp)       __FD_CLR(fd,fdsetp)
 188 #define FD_ISSET(fd,fdsetp)     __FD_ISSET(fd,fdsetp)
 189 #define FD_ZERO(fdsetp)         __FD_ZERO(fdsetp)
 190
 191 /*
 192  * Names of the interval timers, and structure
 193  * defining a timer setting:
 194  */
 195 #define ITIMER_REAL             0
 196 #define ITIMER_VIRTUAL          1
 197 #define ITIMER_PROF             2
 198
 199 struct itimerspec {
 200         struct timespec it_interval;    /* timer period */
 201         struct timespec it_value;       /* timer expiration */
 202 };
 203
 204 struct itimerval {
 205         struct timeval it_interval;     /* timer interval */
 206         struct timeval it_value;        /* current value */
 207 };
 208
 209 /*
 210  * The IDs of the various system clocks (for POSIX.1b interval timers):
 211  */
 212 #define CLOCK_REALTIME                  0
 213 #define CLOCK_MONOTONIC                 1
 214 #define CLOCK_PROCESS_CPUTIME_ID        2
 215 #define CLOCK_THREAD_CPUTIME_ID         3
 216
 217 /*
 218  * The IDs of various hardware clocks:
 219  */
 220 #define CLOCK_SGI_CYCLE                 10
 221 #define MAX_CLOCKS                      16
 222 #define CLOCKS_MASK                     (CLOCK_REALTIME | CLOCK_MONOTONIC)
 223 #define CLOCKS_MONO                     CLOCK_MONOTONIC
 224
 225 /*
 226  * The various flags for setting POSIX.1b interval timers:
 227  */
 228 #define TIMER_ABSTIME                   0x01
 229
 230 #endif