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 extern struct timezone sys_tz;
  33
  34 /* Parameters used to convert the timespec values: */
  35 #define MSEC_PER_SEC    1000L
  36 #define USEC_PER_MSEC   1000L
  37 #define NSEC_PER_USEC   1000L
  38 #define NSEC_PER_MSEC   1000000L
  39 #define USEC_PER_SEC    1000000L
  40 #define NSEC_PER_SEC    1000000000L
  41 #define FSEC_PER_SEC    1000000000000000L
  42
  43 static inline int timespec_equal(const struct timespec *a,
  44                                  const struct timespec *b)
  45 {
  46         return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  47 }
  48
  49 /*
  50  * lhs < rhs:  return <0
  51  * lhs == rhs: return 0
  52  * lhs > rhs:  return >0
  53  */
  54 static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
  55 {
  56         if (lhs->tv_sec < rhs->tv_sec)
  57                 return -1;
  58         if (lhs->tv_sec > rhs->tv_sec)
  59                 return 1;
  60         return lhs->tv_nsec - rhs->tv_nsec;
  61 }
  62
  63 static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
  64 {
  65         if (lhs->tv_sec < rhs->tv_sec)
  66                 return -1;
  67         if (lhs->tv_sec > rhs->tv_sec)
  68                 return 1;
  69         return lhs->tv_usec - rhs->tv_usec;
  70 }
  71
  72 extern unsigned long mktime(const unsigned int year, const unsigned int mon,
  73                             const unsigned int day, const unsigned int hour,
  74                             const unsigned int min, const unsigned int sec);
  75
  76 extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
  77
  78 /*
  79  * sub = lhs - rhs, in normalized form
  80  */
  81 static inline struct timespec timespec_sub(struct timespec lhs,
  82                                                 struct timespec rhs)
  83 {
  84         struct timespec ts_delta;
  85         set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
  86                                 lhs.tv_nsec - rhs.tv_nsec);
  87         return ts_delta;
  88 }
  89
  90 /*
  91  * Returns true if the timespec is norm, false if denorm:
  92  */
  93 #define timespec_valid(ts) \
  94         (((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
  95
  96 extern struct timespec xtime;
  97 extern struct timespec wall_to_monotonic;
  98 extern seqlock_t xtime_lock;
  99
 100 extern unsigned long read_persistent_clock(void);
 101 extern int update_persistent_clock(struct timespec now);
 102 extern int no_sync_cmos_clock __read_mostly;
 103 void timekeeping_init(void);
 104
 105 unsigned long get_seconds(void);
 106 struct timespec current_kernel_time(void);
 107
 108 #define CURRENT_TIME            (current_kernel_time())
 109 #define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 110
 111 extern void do_gettimeofday(struct timeval *tv);
 112 extern int do_settimeofday(struct timespec *tv);
 113 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
 114 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 115 extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
 116 struct itimerval;
 117 extern int do_setitimer(int which, struct itimerval *value,
 118                         struct itimerval *ovalue);
 119 extern unsigned int alarm_setitimer(unsigned int seconds);
 120 extern int do_getitimer(int which, struct itimerval *value);
 121 extern void getnstimeofday(struct timespec *tv);
 122 extern void getboottime(struct timespec *ts);
 123 extern void monotonic_to_bootbased(struct timespec *ts);
 124
 125 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 126 extern int timekeeping_valid_for_hres(void);
 127 extern void update_wall_time(void);
 128 extern void update_xtime_cache(u64 nsec);
 129
 130 /**
 131  * timespec_to_ns - Convert timespec to nanoseconds
 132  * @ts:         pointer to the timespec variable to be converted
 133  *
 134  * Returns the scalar nanosecond representation of the timespec
 135  * parameter.
 136  */
 137 static inline s64 timespec_to_ns(const struct timespec *ts)
 138 {
 139         return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 140 }
 141
 142 /**
 143  * timeval_to_ns - Convert timeval to nanoseconds
 144  * @ts:         pointer to the timeval variable to be converted
 145  *
 146  * Returns the scalar nanosecond representation of the timeval
 147  * parameter.
 148  */
 149 static inline s64 timeval_to_ns(const struct timeval *tv)
 150 {
 151         return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 152                 tv->tv_usec * NSEC_PER_USEC;
 153 }
 154
 155 /**
 156  * ns_to_timespec - Convert nanoseconds to timespec
 157  * @nsec:       the nanoseconds value to be converted
 158  *
 159  * Returns the timespec representation of the nsec parameter.
 160  */
 161 extern struct timespec ns_to_timespec(const s64 nsec);
 162
 163 /**
 164  * ns_to_timeval - Convert nanoseconds to timeval
 165  * @nsec:       the nanoseconds value to be converted
 166  *
 167  * Returns the timeval representation of the nsec parameter.
 168  */
 169 extern struct timeval ns_to_timeval(const s64 nsec);
 170
 171 /**
 172  * timespec_add_ns - Adds nanoseconds to a timespec
 173  * @a:          pointer to timespec to be incremented
 174  * @ns:         unsigned nanoseconds value to be added
 175  *
 176  * This must always be inlined because its used from the x86-64 vdso,
 177  * which cannot call other kernel functions.
 178  */
 179 static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
 180 {
 181         a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 182         a->tv_nsec = ns;
 183 }
 184 #endif /* __KERNEL__ */
 185
 186 #define NFDBITS                 __NFDBITS
 187
 188 #define FD_SETSIZE              __FD_SETSIZE
 189 #define FD_SET(fd,fdsetp)       __FD_SET(fd,fdsetp)
 190 #define FD_CLR(fd,fdsetp)       __FD_CLR(fd,fdsetp)
 191 #define FD_ISSET(fd,fdsetp)     __FD_ISSET(fd,fdsetp)
 192 #define FD_ZERO(fdsetp)         __FD_ZERO(fdsetp)
 193
 194 /*
 195  * Names of the interval timers, and structure
 196  * defining a timer setting:
 197  */
 198 #define ITIMER_REAL             0
 199 #define ITIMER_VIRTUAL          1
 200 #define ITIMER_PROF             2
 201
 202 struct itimerspec {
 203         struct timespec it_interval;    /* timer period */
 204         struct timespec it_value;       /* timer expiration */
 205 };
 206
 207 struct itimerval {
 208         struct timeval it_interval;     /* timer interval */
 209         struct timeval it_value;        /* current value */
 210 };
 211
 212 /*
 213  * The IDs of the various system clocks (for POSIX.1b interval timers):
 214  */
 215 #define CLOCK_REALTIME                  0
 216 #define CLOCK_MONOTONIC                 1
 217 #define CLOCK_PROCESS_CPUTIME_ID        2
 218 #define CLOCK_THREAD_CPUTIME_ID         3
 219
 220 /*
 221  * The IDs of various hardware clocks:
 222  */
 223 #define CLOCK_SGI_CYCLE                 10
 224 #define MAX_CLOCKS                      16
 225 #define CLOCKS_MASK                     (CLOCK_REALTIME | CLOCK_MONOTONIC)
 226 #define CLOCKS_MONO                     CLOCK_MONOTONIC
 227
 228 /*
 229  * The various flags for setting POSIX.1b interval timers:
 230  */
 231 #define TIMER_ABSTIME                   0x01
 232
 233 #endif