LXR linux/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
  12struct timespec {
  13        time_t  tv_sec;         /* seconds */
  14        long    tv_nsec;        /* nanoseconds */
  15};
  16#endif
  17
  18struct timeval {
  19        time_t          tv_sec;         /* seconds */
  20        suseconds_t     tv_usec;        /* microseconds */
  21};
  22
  23struct 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
  39static 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 */
  49static 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
  58static 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
  67extern 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
  71extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
  72
  73/*
  74 * sub = lhs - rhs, in normalized form
  75 */
  76static 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
  91extern struct timespec xtime;
  92extern struct timespec wall_to_monotonic;
  93extern seqlock_t xtime_lock __attribute__((weak));
  94
  95extern unsigned long read_persistent_clock(void);
  96void timekeeping_init(void);
  97
  98static inline unsigned long get_seconds(void)
  99{
 100        return xtime.tv_sec;
 101}
 102
 103struct 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
 108extern void do_gettimeofday(struct timeval *tv);
 109extern int do_settimeofday(struct timespec *tv);
 110extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
 111#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 112extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
 113struct itimerval;
 114extern int do_setitimer(int which, struct itimerval *value,
 115                        struct itimerval *ovalue);
 116extern unsigned int alarm_setitimer(unsigned int seconds);
 117extern int do_getitimer(int which, struct itimerval *value);
 118extern void getnstimeofday(struct timespec *tv);
 119
 120extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 121extern int timekeeping_is_continuous(void);
 122extern 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 */
 131static 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 */
 143static 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 */
 155extern 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 */
 163extern 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 */
 170static 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
 197struct itimerspec {
 198        struct timespec it_interval;    /* timer period */
 199        struct timespec it_value;       /* timer expiration */
 200};
 201
 202struct 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
 229