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, long 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 unsigned long read_persistent_clock(void);
 105extern int update_persistent_clock(struct timespec now);
 106extern int no_sync_cmos_clock __read_mostly;
 107void timekeeping_init(void);
 108extern int timekeeping_suspended;
 109
 110unsigned long get_seconds(void);
 111struct timespec current_kernel_time(void);
 112
 113#define CURRENT_TIME            (current_kernel_time())
 114#define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 115
 116/* Some architectures do not supply their own clocksource.
 117 * This is mainly the case in architectures that get their
 118 * inter-tick times by reading the counter on their interval
 119 * timer. Since these timers wrap every tick, they're not really
 120 * useful as clocksources. Wrapping them to act like one is possible
 121 * but not very efficient. So we provide a callout these arches
 122 * can implement for use with the jiffies clocksource to provide
 123 * finer then tick granular time.
 124 */
 125#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 126extern u32 arch_gettimeoffset(void);
 127#else
 128static inline u32 arch_gettimeoffset(void) { return 0; }
 129#endif
 130
 131extern void do_gettimeofday(struct timeval *tv);
 132extern int do_settimeofday(struct timespec *tv);
 133extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
 134#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 135extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
 136struct itimerval;
 137extern int do_setitimer(int which, struct itimerval *value,
 138                        struct itimerval *ovalue);
 139extern unsigned int alarm_setitimer(unsigned int seconds);
 140extern int do_getitimer(int which, struct itimerval *value);
 141extern void getnstimeofday(struct timespec *tv);
 142extern void getrawmonotonic(struct timespec *ts);
 143extern void getboottime(struct timespec *ts);
 144extern void monotonic_to_bootbased(struct timespec *ts);
 145
 146extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 147extern int timekeeping_valid_for_hres(void);
 148extern void update_wall_time(void);
 149extern void update_xtime_cache(u64 nsec);
 150
 151struct tms;
 152extern void do_sys_times(struct tms *);
 153
 154/**
 155 * timespec_to_ns - Convert timespec to nanoseconds
 156 * @ts:         pointer to the timespec variable to be converted
 157 *
 158 * Returns the scalar nanosecond representation of the timespec
 159 * parameter.
 160 */
 161static inline s64 timespec_to_ns(const struct timespec *ts)
 162{
 163        return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 164}
 165
 166/**
 167 * timeval_to_ns - Convert timeval to nanoseconds
 168 * @ts:         pointer to the timeval variable to be converted
 169 *
 170 * Returns the scalar nanosecond representation of the timeval
 171 * parameter.
 172 */
 173static inline s64 timeval_to_ns(const struct timeval *tv)
 174{
 175        return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 176                tv->tv_usec * NSEC_PER_USEC;
 177}
 178
 179/**
 180 * ns_to_timespec - Convert nanoseconds to timespec
 181 * @nsec:       the nanoseconds value to be converted
 182 *
 183 * Returns the timespec representation of the nsec parameter.
 184 */
 185extern struct timespec ns_to_timespec(const s64 nsec);
 186
 187/**
 188 * ns_to_timeval - Convert nanoseconds to timeval
 189 * @nsec:       the nanoseconds value to be converted
 190 *
 191 * Returns the timeval representation of the nsec parameter.
 192 */
 193extern struct timeval ns_to_timeval(const s64 nsec);
 194
 195/**
 196 * timespec_add_ns - Adds nanoseconds to a timespec
 197 * @a:          pointer to timespec to be incremented
 198 * @ns:         unsigned nanoseconds value to be added
 199 *
 200 * This must always be inlined because its used from the x86-64 vdso,
 201 * which cannot call other kernel functions.
 202 */
 203static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
 204{
 205        a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 206        a->tv_nsec = ns;
 207}
 208#endif /* __KERNEL__ */
 209
 210#define NFDBITS                 __NFDBITS
 211
 212#define FD_SETSIZE              __FD_SETSIZE
 213#define FD_SET(fd,fdsetp)       __FD_SET(fd,fdsetp)
 214#define FD_CLR(fd,fdsetp)       __FD_CLR(fd,fdsetp)
 215#define FD_ISSET(fd,fdsetp)     __FD_ISSET(fd,fdsetp)
 216#define FD_ZERO(fdsetp)         __FD_ZERO(fdsetp)
 217
 218/*
 219 * Names of the interval timers, and structure
 220 * defining a timer setting:
 221 */
 222#define ITIMER_REAL             0
 223#define ITIMER_VIRTUAL          1
 224#define ITIMER_PROF             2
 225
 226struct itimerspec {
 227        struct timespec it_interval;    /* timer period */
 228        struct timespec it_value;       /* timer expiration */
 229};
 230
 231struct itimerval {
 232        struct timeval it_interval;     /* timer interval */
 233        struct timeval it_value;        /* current value */
 234};
 235
 236/*
 237 * The IDs of the various system clocks (for POSIX.1b interval timers):
 238 */
 239#define CLOCK_REALTIME                  0
 240#define CLOCK_MONOTONIC                 1
 241#define CLOCK_PROCESS_CPUTIME_ID        2
 242#define CLOCK_THREAD_CPUTIME_ID         3
 243#define CLOCK_MONOTONIC_RAW             4
 244
 245/*
 246 * The IDs of various hardware clocks:
 247 */
 248#define CLOCK_SGI_CYCLE                 10
 249#define MAX_CLOCKS                      16
 250#define CLOCKS_MASK                     (CLOCK_REALTIME | CLOCK_MONOTONIC)
 251#define CLOCKS_MONO                     CLOCK_MONOTONIC
 252
 253/*
 254 * The various flags for setting POSIX.1b interval timers:
 255 */
 256#define TIMER_ABSTIME                   0x01
 257
 258#endif
 259