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# include <linux/math64.h>
  10#endif
  11
  12#ifndef _STRUCT_TIMESPEC
  13#define _STRUCT_TIMESPEC
  14struct timespec {
  15        time_t  tv_sec;         /* seconds */
  16        long    tv_nsec;        /* nanoseconds */
  17};
  18#endif
  19
  20struct timeval {
  21        time_t          tv_sec;         /* seconds */
  22        suseconds_t     tv_usec;        /* microseconds */
  23};
  24
  25struct timezone {
  26        int     tz_minuteswest; /* minutes west of Greenwich */
  27        int     tz_dsttime;     /* type of dst correction */
  28};
  29
  30#ifdef __KERNEL__
  31
  32/* Parameters used to convert the timespec values: */
  33#define MSEC_PER_SEC    1000L
  34#define USEC_PER_MSEC   1000L
  35#define NSEC_PER_USEC   1000L
  36#define NSEC_PER_MSEC   1000000L
  37#define USEC_PER_SEC    1000000L
  38#define NSEC_PER_SEC    1000000000L
  39#define FSEC_PER_SEC    1000000000000000L
  40
  41static inline int timespec_equal(const struct timespec *a,
  42                                 const struct timespec *b)
  43{
  44        return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  45}
  46
  47/*
  48 * lhs < rhs:  return <0
  49 * lhs == rhs: return 0
  50 * lhs > rhs:  return >0
  51 */
  52static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
  53{
  54        if (lhs->tv_sec < rhs->tv_sec)
  55                return -1;
  56        if (lhs->tv_sec > rhs->tv_sec)
  57                return 1;
  58        return lhs->tv_nsec - rhs->tv_nsec;
  59}
  60
  61static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
  62{
  63        if (lhs->tv_sec < rhs->tv_sec)
  64                return -1;
  65        if (lhs->tv_sec > rhs->tv_sec)
  66                return 1;
  67        return lhs->tv_usec - rhs->tv_usec;
  68}
  69
  70extern unsigned long mktime(const unsigned int year, const unsigned int mon,
  71                            const unsigned int day, const unsigned int hour,
  72                            const unsigned int min, const unsigned int sec);
  73
  74extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
  75
  76/*
  77 * sub = lhs - rhs, in normalized form
  78 */
  79static inline struct timespec timespec_sub(struct timespec lhs,
  80                                                struct timespec rhs)
  81{
  82        struct timespec ts_delta;
  83        set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
  84                                lhs.tv_nsec - rhs.tv_nsec);
  85        return ts_delta;
  86}
  87
  88/*
  89 * Returns true if the timespec is norm, false if denorm:
  90 */
  91#define timespec_valid(ts) \
  92        (((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
  93
  94extern struct timespec xtime;
  95extern struct timespec wall_to_monotonic;
  96extern seqlock_t xtime_lock;
  97
  98extern unsigned long read_persistent_clock(void);
  99extern int update_persistent_clock(struct timespec now);
 100extern int no_sync_cmos_clock __read_mostly;
 101void timekeeping_init(void);
 102
 103unsigned long get_seconds(void);
 104struct timespec current_kernel_time(void);
 105
 106#define CURRENT_TIME            (current_kernel_time())
 107#define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 108
 109extern void do_gettimeofday(struct timeval *tv);
 110extern int do_settimeofday(struct timespec *tv);
 111extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
 112#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 113extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
 114struct itimerval;
 115extern int do_setitimer(int which, struct itimerval *value,
 116                        struct itimerval *ovalue);
 117extern unsigned int alarm_setitimer(unsigned int seconds);
 118extern int do_getitimer(int which, struct itimerval *value);
 119extern void getnstimeofday(struct timespec *tv);
 120extern void getboottime(struct timespec *ts);
 121extern void monotonic_to_bootbased(struct timespec *ts);
 122
 123extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 124extern int timekeeping_valid_for_hres(void);
 125extern void update_wall_time(void);
 126extern void update_xtime_cache(u64 nsec);
 127
 128/**
 129 * timespec_to_ns - Convert timespec to nanoseconds
 130 * @ts:         pointer to the timespec variable to be converted
 131 *
 132 * Returns the scalar nanosecond representation of the timespec
 133 * parameter.
 134 */
 135static inline s64 timespec_to_ns(const struct timespec *ts)
 136{
 137        return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 138}
 139
 140/**
 141 * timeval_to_ns - Convert timeval to nanoseconds
 142 * @ts:         pointer to the timeval variable to be converted
 143 *
 144 * Returns the scalar nanosecond representation of the timeval
 145 * parameter.
 146 */
 147static inline s64 timeval_to_ns(const struct timeval *tv)
 148{
 149        return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 150                tv->tv_usec * NSEC_PER_USEC;
 151}
 152
 153/**
 154 * ns_to_timespec - Convert nanoseconds to timespec
 155 * @nsec:       the nanoseconds value to be converted
 156 *
 157 * Returns the timespec representation of the nsec parameter.
 158 */
 159extern struct timespec ns_to_timespec(const s64 nsec);
 160
 161/**
 162 * ns_to_timeval - Convert nanoseconds to timeval
 163 * @nsec:       the nanoseconds value to be converted
 164 *
 165 * Returns the timeval representation of the nsec parameter.
 166 */
 167extern struct timeval ns_to_timeval(const s64 nsec);
 168
 169/**
 170 * timespec_add_ns - Adds nanoseconds to a timespec
 171 * @a:          pointer to timespec to be incremented
 172 * @ns:         unsigned nanoseconds value to be added
 173 *
 174 * This must always be inlined because its used from the x86-64 vdso,
 175 * which cannot call other kernel functions.
 176 */
 177static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
 178{
 179        a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 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
 200struct itimerspec {
 201        struct timespec it_interval;    /* timer period */
 202        struct timespec it_value;       /* timer expiration */
 203};
 204
 205struct 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
 232