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
  14 struct timespec {
  15         __kernel_time_t tv_sec;                 /* seconds */
  16         long            tv_nsec;                /* nanoseconds */
  17 };
  18 #endif
  19
  20 struct timeval {
  21         __kernel_time_t         tv_sec;         /* seconds */
  22         __kernel_suseconds_t    tv_usec;        /* microseconds */
  23 };
  24
  25 struct timezone {
  26         int     tz_minuteswest; /* minutes west of Greenwich */
  27         int     tz_dsttime;     /* type of dst correction */
  28 };
  29
  30 #ifdef __KERNEL__
  31
  32 extern 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
  45 static 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  */
  56 static 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
  65 static 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
  74 extern 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
  78 extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
  79 extern struct timespec timespec_add_safe(const struct timespec lhs,
  80                                          const struct timespec rhs);
  81
  82 /*
  83  * sub = lhs - rhs, in normalized form
  84  */
  85 static 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
 100 extern struct timespec xtime;
 101 extern struct timespec wall_to_monotonic;
 102 extern seqlock_t xtime_lock;
 103
 104 extern unsigned long read_persistent_clock(void);
 105 extern int update_persistent_clock(struct timespec now);
 106 extern int no_sync_cmos_clock __read_mostly;
 107 void timekeeping_init(void);
 108 extern int timekeeping_suspended;
 109
 110 unsigned long get_seconds(void);
 111 struct 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
 126 extern u32 arch_gettimeoffset(void);
 127 #else
 128 static inline u32 arch_gettimeoffset(void) { return 0; }
 129 #endif
 130
 131 extern void do_gettimeofday(struct timeval *tv);
 132 extern int do_settimeofday(struct timespec *tv);
 133 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
 134 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 135 extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
 136 struct itimerval;
 137 extern int do_setitimer(int which, struct itimerval *value,
 138                         struct itimerval *ovalue);
 139 extern unsigned int alarm_setitimer(unsigned int seconds);
 140 extern int do_getitimer(int which, struct itimerval *value);
 141 extern void getnstimeofday(struct timespec *tv);
 142 extern void getrawmonotonic(struct timespec *ts);
 143 extern void getboottime(struct timespec *ts);
 144 extern void monotonic_to_bootbased(struct timespec *ts);
 145
 146 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 147 extern int timekeeping_valid_for_hres(void);
 148 extern void update_wall_time(void);
 149 extern void update_xtime_cache(u64 nsec);
 150
 151 struct tms;
 152 extern 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  */
 161 static 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  */
 173 static 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  */
 185 extern 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  */
 193 extern 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  */
 203 static __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
 226 struct itimerspec {
 227         struct timespec it_interval;    /* timer period */
 228         struct timespec it_value;       /* timer expiration */
 229 };
 230
 231 struct 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