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
  13 struct timespec {
  14         time_t  tv_sec;         /* seconds */
  15         long    tv_nsec;        /* nanoseconds */
  16 };
  17 #endif
  18
  19 struct timeval {
  20         time_t          tv_sec;         /* seconds */
  21         suseconds_t     tv_usec;        /* microseconds */
  22 };
  23
  24 struct 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
  40 static 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  */
  51 static 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
  60 static 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
  69 extern 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
  73 extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
  74
  75 /*
  76  * sub = lhs - rhs, in normalized form
  77  */
  78 static 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
  93 extern struct timespec xtime;
  94 extern struct timespec wall_to_monotonic;
  95 extern seqlock_t xtime_lock;
  96
  97 extern unsigned long read_persistent_clock(void);
  98 extern int update_persistent_clock(struct timespec now);
  99 extern int no_sync_cmos_clock __read_mostly;
 100 void timekeeping_init(void);
 101
 102 unsigned long get_seconds(void);
 103 struct timespec current_kernel_time(void);
 104
 105 #define CURRENT_TIME            (current_kernel_time())
 106 #define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 107
 108 extern void do_gettimeofday(struct timeval *tv);
 109 extern int do_settimeofday(struct timespec *tv);
 110 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
 111 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 112 extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
 113 struct itimerval;
 114 extern int do_setitimer(int which, struct itimerval *value,
 115                         struct itimerval *ovalue);
 116 extern unsigned int alarm_setitimer(unsigned int seconds);
 117 extern int do_getitimer(int which, struct itimerval *value);
 118 extern void getnstimeofday(struct timespec *tv);
 119 extern void getboottime(struct timespec *ts);
 120 extern void monotonic_to_bootbased(struct timespec *ts);
 121
 122 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 123 extern int timekeeping_valid_for_hres(void);
 124 extern void update_wall_time(void);
 125 extern 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  */
 134 static 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  */
 146 static 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  */
 158 extern 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  */
 166 extern 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  */
 173 static 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
 204 struct itimerspec {
 205         struct timespec it_interval;    /* timer period */
 206         struct timespec it_value;       /* timer expiration */
 207 };
 208
 209 struct 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