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    1000000000000000LL
  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, s64 nsec);
  79
  80 /*
  81  * timespec_add_safe assumes both values are positive and checks
  82  * for overflow. It will return TIME_T_MAX if the reutrn would be
  83  * smaller then either of the arguments.
  84  */
  85 extern struct timespec timespec_add_safe(const struct timespec lhs,
  86                                          const struct timespec rhs);
  87
  88
  89 static inline struct timespec timespec_add(struct timespec lhs,
  90                                                 struct timespec rhs)
  91 {
  92         struct timespec ts_delta;
  93         set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec,
  94                                 lhs.tv_nsec + rhs.tv_nsec);
  95         return ts_delta;
  96 }
  97
  98 /*
  99  * sub = lhs - rhs, in normalized form
 100  */
 101 static inline struct timespec timespec_sub(struct timespec lhs,
 102                                                 struct timespec rhs)
 103 {
 104         struct timespec ts_delta;
 105         set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
 106                                 lhs.tv_nsec - rhs.tv_nsec);
 107         return ts_delta;
 108 }
 109
 110 /*
 111  * Returns true if the timespec is norm, false if denorm:
 112  */
 113 #define timespec_valid(ts) \
 114         (((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
 115
 116 extern seqlock_t xtime_lock;
 117
 118 extern void read_persistent_clock(struct timespec *ts);
 119 extern void read_boot_clock(struct timespec *ts);
 120 extern int update_persistent_clock(struct timespec now);
 121 extern int no_sync_cmos_clock __read_mostly;
 122 void timekeeping_init(void);
 123 extern int timekeeping_suspended;
 124
 125 unsigned long get_seconds(void);
 126 struct timespec current_kernel_time(void);
 127 struct timespec __current_kernel_time(void); /* does not take xtime_lock */
 128 struct timespec __get_wall_to_monotonic(void); /* does not take xtime_lock */
 129 struct timespec get_monotonic_coarse(void);
 130
 131 #define CURRENT_TIME            (current_kernel_time())
 132 #define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 133
 134 /* Some architectures do not supply their own clocksource.
 135  * This is mainly the case in architectures that get their
 136  * inter-tick times by reading the counter on their interval
 137  * timer. Since these timers wrap every tick, they're not really
 138  * useful as clocksources. Wrapping them to act like one is possible
 139  * but not very efficient. So we provide a callout these arches
 140  * can implement for use with the jiffies clocksource to provide
 141  * finer then tick granular time.
 142  */
 143 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 144 extern u32 arch_gettimeoffset(void);
 145 #else
 146 static inline u32 arch_gettimeoffset(void) { return 0; }
 147 #endif
 148
 149 extern void do_gettimeofday(struct timeval *tv);
 150 extern int do_settimeofday(struct timespec *tv);
 151 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
 152 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 153 extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);
 154 struct itimerval;
 155 extern int do_setitimer(int which, struct itimerval *value,
 156                         struct itimerval *ovalue);
 157 extern unsigned int alarm_setitimer(unsigned int seconds);
 158 extern int do_getitimer(int which, struct itimerval *value);
 159 extern void getnstimeofday(struct timespec *tv);
 160 extern void getrawmonotonic(struct timespec *ts);
 161 extern void getnstime_raw_and_real(struct timespec *ts_raw,
 162                 struct timespec *ts_real);
 163 extern void getboottime(struct timespec *ts);
 164 extern void monotonic_to_bootbased(struct timespec *ts);
 165
 166 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 167 extern int timekeeping_valid_for_hres(void);
 168 extern u64 timekeeping_max_deferment(void);
 169 extern void update_wall_time(void);
 170 extern void timekeeping_leap_insert(int leapsecond);
 171
 172 struct tms;
 173 extern void do_sys_times(struct tms *);
 174
 175 /*
 176  * Similar to the struct tm in userspace <time.h>, but it needs to be here so
 177  * that the kernel source is self contained.
 178  */
 179 struct tm {
 180         /*
 181          * the number of seconds after the minute, normally in the range
 182          * 0 to 59, but can be up to 60 to allow for leap seconds
 183          */
 184         int tm_sec;
 185         /* the number of minutes after the hour, in the range 0 to 59*/
 186         int tm_min;
 187         /* the number of hours past midnight, in the range 0 to 23 */
 188         int tm_hour;
 189         /* the day of the month, in the range 1 to 31 */
 190         int tm_mday;
 191         /* the number of months since January, in the range 0 to 11 */
 192         int tm_mon;
 193         /* the number of years since 1900 */
 194         long tm_year;
 195         /* the number of days since Sunday, in the range 0 to 6 */
 196         int tm_wday;
 197         /* the number of days since January 1, in the range 0 to 365 */
 198         int tm_yday;
 199 };
 200
 201 void time_to_tm(time_t totalsecs, int offset, struct tm *result);
 202
 203 /**
 204  * timespec_to_ns - Convert timespec to nanoseconds
 205  * @ts:         pointer to the timespec variable to be converted
 206  *
 207  * Returns the scalar nanosecond representation of the timespec
 208  * parameter.
 209  */
 210 static inline s64 timespec_to_ns(const struct timespec *ts)
 211 {
 212         return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 213 }
 214
 215 /**
 216  * timeval_to_ns - Convert timeval to nanoseconds
 217  * @ts:         pointer to the timeval variable to be converted
 218  *
 219  * Returns the scalar nanosecond representation of the timeval
 220  * parameter.
 221  */
 222 static inline s64 timeval_to_ns(const struct timeval *tv)
 223 {
 224         return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 225                 tv->tv_usec * NSEC_PER_USEC;
 226 }
 227
 228 /**
 229  * ns_to_timespec - Convert nanoseconds to timespec
 230  * @nsec:       the nanoseconds value to be converted
 231  *
 232  * Returns the timespec representation of the nsec parameter.
 233  */
 234 extern struct timespec ns_to_timespec(const s64 nsec);
 235
 236 /**
 237  * ns_to_timeval - Convert nanoseconds to timeval
 238  * @nsec:       the nanoseconds value to be converted
 239  *
 240  * Returns the timeval representation of the nsec parameter.
 241  */
 242 extern struct timeval ns_to_timeval(const s64 nsec);
 243
 244 /**
 245  * timespec_add_ns - Adds nanoseconds to a timespec
 246  * @a:          pointer to timespec to be incremented
 247  * @ns:         unsigned nanoseconds value to be added
 248  *
 249  * This must always be inlined because its used from the x86-64 vdso,
 250  * which cannot call other kernel functions.
 251  */
 252 static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
 253 {
 254         a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 255         a->tv_nsec = ns;
 256 }
 257 #endif /* __KERNEL__ */
 258
 259 #define NFDBITS                 __NFDBITS
 260
 261 #define FD_SETSIZE              __FD_SETSIZE
 262 #define FD_SET(fd,fdsetp)       __FD_SET(fd,fdsetp)
 263 #define FD_CLR(fd,fdsetp)       __FD_CLR(fd,fdsetp)
 264 #define FD_ISSET(fd,fdsetp)     __FD_ISSET(fd,fdsetp)
 265 #define FD_ZERO(fdsetp)         __FD_ZERO(fdsetp)
 266
 267 /*
 268  * Names of the interval timers, and structure
 269  * defining a timer setting:
 270  */
 271 #define ITIMER_REAL             0
 272 #define ITIMER_VIRTUAL          1
 273 #define ITIMER_PROF             2
 274
 275 struct itimerspec {
 276         struct timespec it_interval;    /* timer period */
 277         struct timespec it_value;       /* timer expiration */
 278 };
 279
 280 struct itimerval {
 281         struct timeval it_interval;     /* timer interval */
 282         struct timeval it_value;        /* current value */
 283 };
 284
 285 /*
 286  * The IDs of the various system clocks (for POSIX.1b interval timers):
 287  */
 288 #define CLOCK_REALTIME                  0
 289 #define CLOCK_MONOTONIC                 1
 290 #define CLOCK_PROCESS_CPUTIME_ID        2
 291 #define CLOCK_THREAD_CPUTIME_ID         3
 292 #define CLOCK_MONOTONIC_RAW             4
 293 #define CLOCK_REALTIME_COARSE           5
 294 #define CLOCK_MONOTONIC_COARSE          6
 295
 296 /*
 297  * The IDs of various hardware clocks:
 298  */
 299 #define CLOCK_SGI_CYCLE                 10
 300 #define MAX_CLOCKS                      16
 301 #define CLOCKS_MASK                     (CLOCK_REALTIME | CLOCK_MONOTONIC)
 302 #define CLOCKS_MONO                     CLOCK_MONOTONIC
 303
 304 /*
 305  * The various flags for setting POSIX.1b interval timers:
 306  */
 307 #define TIMER_ABSTIME                   0x01
 308
 309 #endif