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        __kernel_time_t tv_sec;                 /* seconds */
  16        long            tv_nsec;                /* nanoseconds */
  17};
  18#endif
  19
  20struct timeval {
  21        __kernel_time_t         tv_sec;         /* seconds */
  22        __kernel_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
  32extern 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#define TIME_T_MAX      (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
  44
  45static inline int timespec_equal(const struct timespec *a,
  46                                 const struct timespec *b)
  47{
  48        return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  49}
  50
  51/*
  52 * lhs < rhs:  return <0
  53 * lhs == rhs: return 0
  54 * lhs > rhs:  return >0
  55 */
  56static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
  57{
  58        if (lhs->tv_sec < rhs->tv_sec)
  59                return -1;
  60        if (lhs->tv_sec > rhs->tv_sec)
  61                return 1;
  62        return lhs->tv_nsec - rhs->tv_nsec;
  63}
  64
  65static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
  66{
  67        if (lhs->tv_sec < rhs->tv_sec)
  68                return -1;
  69        if (lhs->tv_sec > rhs->tv_sec)
  70                return 1;
  71        return lhs->tv_usec - rhs->tv_usec;
  72}
  73
  74extern unsigned long mktime(const unsigned int year, const unsigned int mon,
  75                            const unsigned int day, const unsigned int hour,
  76                            const unsigned int min, const unsigned int sec);
  77
  78extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);
  79extern struct timespec timespec_add_safe(const struct timespec lhs,
  80                                         const struct timespec rhs);
  81
  82/*
  83 * sub = lhs - rhs, in normalized form
  84 */
  85static inline struct timespec timespec_sub(struct timespec lhs,
  86                                                struct timespec rhs)
  87{
  88        struct timespec ts_delta;
  89        set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
  90                                lhs.tv_nsec - rhs.tv_nsec);
  91        return ts_delta;
  92}
  93
  94/*
  95 * Returns true if the timespec is norm, false if denorm:
  96 */
  97#define timespec_valid(ts) \
  98        (((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
  99
 100extern struct timespec xtime;
 101extern struct timespec wall_to_monotonic;
 102extern seqlock_t xtime_lock;
 103
 104extern void read_persistent_clock(struct timespec *ts);
 105extern void read_boot_clock(struct timespec *ts);
 106extern int update_persistent_clock(struct timespec now);
 107extern int no_sync_cmos_clock __read_mostly;
 108void timekeeping_init(void);
 109extern int timekeeping_suspended;
 110
 111unsigned long get_seconds(void);
 112struct timespec current_kernel_time(void);
 113struct timespec __current_kernel_time(void); /* does not hold xtime_lock */
 114struct timespec get_monotonic_coarse(void);
 115
 116#define CURRENT_TIME            (current_kernel_time())
 117#define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 118
 119/* Some architectures do not supply their own clocksource.
 120 * This is mainly the case in architectures that get their
 121 * inter-tick times by reading the counter on their interval
 122 * timer. Since these timers wrap every tick, they're not really
 123 * useful as clocksources. Wrapping them to act like one is possible
 124 * but not very efficient. So we provide a callout these arches
 125 * can implement for use with the jiffies clocksource to provide
 126 * finer then tick granular time.
 127 */
 128#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 129extern u32 arch_gettimeoffset(void);
 130#else
 131static inline u32 arch_gettimeoffset(void) { return 0; }
 132#endif
 133
 134extern void do_gettimeofday(struct timeval *tv);
 135extern int do_settimeofday(struct timespec *tv);
 136extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
 137#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 138extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
 139struct itimerval;
 140extern int do_setitimer(int which, struct itimerval *value,
 141                        struct itimerval *ovalue);
 142extern unsigned int alarm_setitimer(unsigned int seconds);
 143extern int do_getitimer(int which, struct itimerval *value);
 144extern void getnstimeofday(struct timespec *tv);
 145extern void getrawmonotonic(struct timespec *ts);
 146extern void getboottime(struct timespec *ts);
 147extern void monotonic_to_bootbased(struct timespec *ts);
 148
 149extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 150extern int timekeeping_valid_for_hres(void);
 151extern u64 timekeeping_max_deferment(void);
 152extern void update_wall_time(void);
 153extern void update_xtime_cache(u64 nsec);
 154extern void timekeeping_leap_insert(int leapsecond);
 155
 156struct tms;
 157extern void do_sys_times(struct tms *);
 158
 159/*
 160 * Similar to the struct tm in userspace <time.h>, but it needs to be here so
 161 * that the kernel source is self contained.
 162 */
 163struct tm {
 164        /*
 165         * the number of seconds after the minute, normally in the range
 166         * 0 to 59, but can be up to 60 to allow for leap seconds
 167         */
 168        int tm_sec;
 169        /* the number of minutes after the hour, in the range 0 to 59*/
 170        int tm_min;
 171        /* the number of hours past midnight, in the range 0 to 23 */
 172        int tm_hour;
 173        /* the day of the month, in the range 1 to 31 */
 174        int tm_mday;
 175        /* the number of months since January, in the range 0 to 11 */
 176        int tm_mon;
 177        /* the number of years since 1900 */
 178        long tm_year;
 179        /* the number of days since Sunday, in the range 0 to 6 */
 180        int tm_wday;
 181        /* the number of days since January 1, in the range 0 to 365 */
 182        int tm_yday;
 183};
 184
 185void time_to_tm(time_t totalsecs, int offset, struct tm *result);
 186
 187/**
 188 * timespec_to_ns - Convert timespec to nanoseconds
 189 * @ts:         pointer to the timespec variable to be converted
 190 *
 191 * Returns the scalar nanosecond representation of the timespec
 192 * parameter.
 193 */
 194static inline s64 timespec_to_ns(const struct timespec *ts)
 195{
 196        return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 197}
 198
 199/**
 200 * timeval_to_ns - Convert timeval to nanoseconds
 201 * @ts:         pointer to the timeval variable to be converted
 202 *
 203 * Returns the scalar nanosecond representation of the timeval
 204 * parameter.
 205 */
 206static inline s64 timeval_to_ns(const struct timeval *tv)
 207{
 208        return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 209                tv->tv_usec * NSEC_PER_USEC;
 210}
 211
 212/**
 213 * ns_to_timespec - Convert nanoseconds to timespec
 214 * @nsec:       the nanoseconds value to be converted
 215 *
 216 * Returns the timespec representation of the nsec parameter.
 217 */
 218extern struct timespec ns_to_timespec(const s64 nsec);
 219
 220/**
 221 * ns_to_timeval - Convert nanoseconds to timeval
 222 * @nsec:       the nanoseconds value to be converted
 223 *
 224 * Returns the timeval representation of the nsec parameter.
 225 */
 226extern struct timeval ns_to_timeval(const s64 nsec);
 227
 228/**
 229 * timespec_add_ns - Adds nanoseconds to a timespec
 230 * @a:          pointer to timespec to be incremented
 231 * @ns:         unsigned nanoseconds value to be added
 232 *
 233 * This must always be inlined because its used from the x86-64 vdso,
 234 * which cannot call other kernel functions.
 235 */
 236static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
 237{
 238        a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 239        a->tv_nsec = ns;
 240}
 241#endif /* __KERNEL__ */
 242
 243#define NFDBITS                 __NFDBITS
 244
 245#define FD_SETSIZE              __FD_SETSIZE
 246#define FD_SET(fd,fdsetp)       __FD_SET(fd,fdsetp)
 247#define FD_CLR(fd,fdsetp)       __FD_CLR(fd,fdsetp)
 248#define FD_ISSET(fd,fdsetp)     __FD_ISSET(fd,fdsetp)
 249#define FD_ZERO(fdsetp)         __FD_ZERO(fdsetp)
 250
 251/*
 252 * Names of the interval timers, and structure
 253 * defining a timer setting:
 254 */
 255#define ITIMER_REAL             0
 256#define ITIMER_VIRTUAL          1
 257#define ITIMER_PROF             2
 258
 259struct itimerspec {
 260        struct timespec it_interval;    /* timer period */
 261        struct timespec it_value;       /* timer expiration */
 262};
 263
 264struct itimerval {
 265        struct timeval it_interval;     /* timer interval */
 266        struct timeval it_value;        /* current value */
 267};
 268
 269/*
 270 * The IDs of the various system clocks (for POSIX.1b interval timers):
 271 */
 272#define CLOCK_REALTIME                  0
 273#define CLOCK_MONOTONIC                 1
 274#define CLOCK_PROCESS_CPUTIME_ID        2
 275#define CLOCK_THREAD_CPUTIME_ID         3
 276#define CLOCK_MONOTONIC_RAW             4
 277#define CLOCK_REALTIME_COARSE           5
 278#define CLOCK_MONOTONIC_COARSE          6
 279
 280/*
 281 * The IDs of various hardware clocks:
 282 */
 283#define CLOCK_SGI_CYCLE                 10
 284#define MAX_CLOCKS                      16
 285#define CLOCKS_MASK                     (CLOCK_REALTIME | CLOCK_MONOTONIC)
 286#define CLOCKS_MONO                     CLOCK_MONOTONIC
 287
 288/*
 289 * The various flags for setting POSIX.1b interval timers:
 290 */
 291#define TIMER_ABSTIME                   0x01
 292
 293#endif
 294