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/cache.h>
   8# include <linux/seqlock.h>
   9#endif
  10
  11#ifndef _STRUCT_TIMESPEC
  12#define _STRUCT_TIMESPEC
  13struct timespec {
  14        time_t  tv_sec;         /* seconds */
  15        long    tv_nsec;        /* nanoseconds */
  16};
  17#endif
  18
  19struct timeval {
  20        time_t          tv_sec;         /* seconds */
  21        suseconds_t     tv_usec;        /* microseconds */
  22};
  23
  24struct timezone {
  25        int     tz_minuteswest; /* minutes west of Greenwich */
  26        int     tz_dsttime;     /* type of dst correction */
  27};
  28
  29#ifdef __KERNEL__
  30
  31/* Parameters used to convert the timespec values: */
  32#define MSEC_PER_SEC    1000L
  33#define USEC_PER_MSEC   1000L
  34#define NSEC_PER_USEC   1000L
  35#define NSEC_PER_MSEC   1000000L
  36#define USEC_PER_SEC    1000000L
  37#define NSEC_PER_SEC    1000000000L
  38#define FSEC_PER_SEC    1000000000000000L
  39
  40static inline int timespec_equal(const struct timespec *a,
  41                                 const struct timespec *b)
  42{
  43        return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  44}
  45
  46/*
  47 * lhs < rhs:  return <0
  48 * lhs == rhs: return 0
  49 * lhs > rhs:  return >0
  50 */
  51static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
  52{
  53        if (lhs->tv_sec < rhs->tv_sec)
  54                return -1;
  55        if (lhs->tv_sec > rhs->tv_sec)
  56                return 1;
  57        return lhs->tv_nsec - rhs->tv_nsec;
  58}
  59
  60static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
  61{
  62        if (lhs->tv_sec < rhs->tv_sec)
  63                return -1;
  64        if (lhs->tv_sec > rhs->tv_sec)
  65                return 1;
  66        return lhs->tv_usec - rhs->tv_usec;
  67}
  68
  69extern unsigned long mktime(const unsigned int year, const unsigned int mon,
  70                            const unsigned int day, const unsigned int hour,
  71                            const unsigned int min, const unsigned int sec);
  72
  73extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
  74
  75/*
  76 * sub = lhs - rhs, in normalized form
  77 */
  78static inline struct timespec timespec_sub(struct timespec lhs,
  79                                                struct timespec rhs)
  80{
  81        struct timespec ts_delta;
  82        set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
  83                                lhs.tv_nsec - rhs.tv_nsec);
  84        return ts_delta;
  85}
  86
  87/*
  88 * Returns true if the timespec is norm, false if denorm:
  89 */
  90#define timespec_valid(ts) \
  91        (((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
  92
  93extern struct timespec xtime;
  94extern struct timespec wall_to_monotonic;
  95extern seqlock_t xtime_lock;
  96
  97extern unsigned long read_persistent_clock(void);
  98extern int update_persistent_clock(struct timespec now);
  99extern int no_sync_cmos_clock __read_mostly;
 100void timekeeping_init(void);
 101
 102unsigned long get_seconds(void);
 103struct timespec current_kernel_time(void);
 104
 105#define CURRENT_TIME            (current_kernel_time())
 106#define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 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);
 119extern void getboottime(struct timespec *ts);
 120extern void monotonic_to_bootbased(struct timespec *ts);
 121
 122extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 123extern int timekeeping_valid_for_hres(void);
 124extern void update_wall_time(void);
 125extern void update_xtime_cache(u64 nsec);
 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 */
 134static 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 */
 146static 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 */
 158extern 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 */
 166extern 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 */
 173static inline void timespec_add_ns(struct timespec *a, u64 ns)
 174{
 175        ns += a->tv_nsec;
 176        while(unlikely(ns >= NSEC_PER_SEC)) {
 177                /* The following asm() prevents the compiler from
 178                 * optimising this loop into a modulo operation.  */
 179                asm("" : "+r"(ns));
 180
 181                ns -= NSEC_PER_SEC;
 182                a->tv_sec++;
 183        }
 184        a->tv_nsec = ns;
 185}
 186#endif /* __KERNEL__ */
 187
 188#define NFDBITS                 __NFDBITS
 189
 190#define FD_SETSIZE              __FD_SETSIZE
 191#define FD_SET(fd,fdsetp)       __FD_SET(fd,fdsetp)
 192#define FD_CLR(fd,fdsetp)       __FD_CLR(fd,fdsetp)
 193#define FD_ISSET(fd,fdsetp)     __FD_ISSET(fd,fdsetp)
 194#define FD_ZERO(fdsetp)         __FD_ZERO(fdsetp)
 195
 196/*
 197 * Names of the interval timers, and structure
 198 * defining a timer setting:
 199 */
 200#define ITIMER_REAL             0
 201#define ITIMER_VIRTUAL          1
 202#define ITIMER_PROF             2
 203
 204struct itimerspec {
 205        struct timespec it_interval;    /* timer period */
 206        struct timespec it_value;       /* timer expiration */
 207};
 208
 209struct itimerval {
 210        struct timeval it_interval;     /* timer interval */
 211        struct timeval it_value;        /* current value */
 212};
 213
 214/*
 215 * The IDs of the various system clocks (for POSIX.1b interval timers):
 216 */
 217#define CLOCK_REALTIME                  0
 218#define CLOCK_MONOTONIC                 1
 219#define CLOCK_PROCESS_CPUTIME_ID        2
 220#define CLOCK_THREAD_CPUTIME_ID         3
 221
 222/*
 223 * The IDs of various hardware clocks:
 224 */
 225#define CLOCK_SGI_CYCLE                 10
 226#define MAX_CLOCKS                      16
 227#define CLOCKS_MASK                     (CLOCK_REALTIME | CLOCK_MONOTONIC)
 228#define CLOCKS_MONO                     CLOCK_MONOTONIC
 229
 230/*
 231 * The various flags for setting POSIX.1b interval timers:
 232 */
 233#define TIMER_ABSTIME                   0x01
 234
 235#endif
 236