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, s64 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 #define KTIME_MAX                       ((s64)~((u64)1 << 63))
  95 #if (BITS_PER_LONG == 64)
  96 # define KTIME_SEC_MAX                  (KTIME_MAX / NSEC_PER_SEC)
  97 #else
  98 # define KTIME_SEC_MAX                  LONG_MAX
  99 #endif
 100
 101 /*
 102  * Returns true if the timespec is norm, false if denorm:
 103  */
 104 static inline bool timespec_valid(const struct timespec *ts)
 105 {
 106         /* Dates before 1970 are bogus */
 107         if (ts->tv_sec < 0)
 108                 return false;
 109         /* Can't have more nanoseconds then a second */
 110         if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
 111                 return false;
 112         return true;
 113 }
 114
 115 static inline bool timespec_valid_strict(const struct timespec *ts)
 116 {
 117         if (!timespec_valid(ts))
 118                 return false;
 119         /* Disallow values that could overflow ktime_t */
 120         if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
 121                 return false;
 122         return true;
 123 }
 124
 125 extern struct timespec xtime;
 126 extern struct timespec wall_to_monotonic;
 127 extern seqlock_t xtime_lock;
 128
 129 extern void read_persistent_clock(struct timespec *ts);
 130 extern void read_boot_clock(struct timespec *ts);
 131 extern int update_persistent_clock(struct timespec now);
 132 extern int no_sync_cmos_clock __read_mostly;
 133 void timekeeping_init(void);
 134 extern int timekeeping_suspended;
 135
 136 unsigned long get_seconds(void);
 137 struct timespec current_kernel_time(void);
 138 struct timespec __current_kernel_time(void); /* does not hold xtime_lock */
 139 struct timespec get_monotonic_coarse(void);
 140
 141 #define CURRENT_TIME            (current_kernel_time())
 142 #define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 143
 144 /* Some architectures do not supply their own clocksource.
 145  * This is mainly the case in architectures that get their
 146  * inter-tick times by reading the counter on their interval
 147  * timer. Since these timers wrap every tick, they're not really
 148  * useful as clocksources. Wrapping them to act like one is possible
 149  * but not very efficient. So we provide a callout these arches
 150  * can implement for use with the jiffies clocksource to provide
 151  * finer then tick granular time.
 152  */
 153 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 154 extern u32 arch_gettimeoffset(void);
 155 #else
 156 static inline u32 arch_gettimeoffset(void) { return 0; }
 157 #endif
 158
 159 extern void do_gettimeofday(struct timeval *tv);
 160 extern int do_settimeofday(struct timespec *tv);
 161 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
 162 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 163 extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
 164 struct itimerval;
 165 extern int do_setitimer(int which, struct itimerval *value,
 166                         struct itimerval *ovalue);
 167 extern unsigned int alarm_setitimer(unsigned int seconds);
 168 extern int do_getitimer(int which, struct itimerval *value);
 169 extern void getnstimeofday(struct timespec *tv);
 170 extern void getrawmonotonic(struct timespec *ts);
 171 extern void getboottime(struct timespec *ts);
 172 extern void monotonic_to_bootbased(struct timespec *ts);
 173
 174 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 175 extern int timekeeping_valid_for_hres(void);
 176 extern u64 timekeeping_max_deferment(void);
 177 extern void update_wall_time(void);
 178 extern void update_xtime_cache(u64 nsec);
 179 extern void timekeeping_leap_insert(int leapsecond);
 180
 181 struct tms;
 182 extern void do_sys_times(struct tms *);
 183
 184 /*
 185  * Similar to the struct tm in userspace <time.h>, but it needs to be here so
 186  * that the kernel source is self contained.
 187  */
 188 struct tm {
 189         /*
 190          * the number of seconds after the minute, normally in the range
 191          * 0 to 59, but can be up to 60 to allow for leap seconds
 192          */
 193         int tm_sec;
 194         /* the number of minutes after the hour, in the range 0 to 59*/
 195         int tm_min;
 196         /* the number of hours past midnight, in the range 0 to 23 */
 197         int tm_hour;
 198         /* the day of the month, in the range 1 to 31 */
 199         int tm_mday;
 200         /* the number of months since January, in the range 0 to 11 */
 201         int tm_mon;
 202         /* the number of years since 1900 */
 203         long tm_year;
 204         /* the number of days since Sunday, in the range 0 to 6 */
 205         int tm_wday;
 206         /* the number of days since January 1, in the range 0 to 365 */
 207         int tm_yday;
 208 };
 209
 210 void time_to_tm(time_t totalsecs, int offset, struct tm *result);
 211
 212 /**
 213  * timespec_to_ns - Convert timespec to nanoseconds
 214  * @ts:         pointer to the timespec variable to be converted
 215  *
 216  * Returns the scalar nanosecond representation of the timespec
 217  * parameter.
 218  */
 219 static inline s64 timespec_to_ns(const struct timespec *ts)
 220 {
 221         return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 222 }
 223
 224 /**
 225  * timeval_to_ns - Convert timeval to nanoseconds
 226  * @ts:         pointer to the timeval variable to be converted
 227  *
 228  * Returns the scalar nanosecond representation of the timeval
 229  * parameter.
 230  */
 231 static inline s64 timeval_to_ns(const struct timeval *tv)
 232 {
 233         return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 234                 tv->tv_usec * NSEC_PER_USEC;
 235 }
 236
 237 /**
 238  * ns_to_timespec - Convert nanoseconds to timespec
 239  * @nsec:       the nanoseconds value to be converted
 240  *
 241  * Returns the timespec representation of the nsec parameter.
 242  */
 243 extern struct timespec ns_to_timespec(const s64 nsec);
 244
 245 /**
 246  * ns_to_timeval - Convert nanoseconds to timeval
 247  * @nsec:       the nanoseconds value to be converted
 248  *
 249  * Returns the timeval representation of the nsec parameter.
 250  */
 251 extern struct timeval ns_to_timeval(const s64 nsec);
 252
 253 /**
 254  * timespec_add_ns - Adds nanoseconds to a timespec
 255  * @a:          pointer to timespec to be incremented
 256  * @ns:         unsigned nanoseconds value to be added
 257  *
 258  * This must always be inlined because its used from the x86-64 vdso,
 259  * which cannot call other kernel functions.
 260  */
 261 static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
 262 {
 263         a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 264         a->tv_nsec = ns;
 265 }
 266 #endif /* __KERNEL__ */
 267
 268 #define NFDBITS                 __NFDBITS
 269
 270 #define FD_SETSIZE              __FD_SETSIZE
 271 #define FD_SET(fd,fdsetp)       __FD_SET(fd,fdsetp)
 272 #define FD_CLR(fd,fdsetp)       __FD_CLR(fd,fdsetp)
 273 #define FD_ISSET(fd,fdsetp)     __FD_ISSET(fd,fdsetp)
 274 #define FD_ZERO(fdsetp)         __FD_ZERO(fdsetp)
 275
 276 /*
 277  * Names of the interval timers, and structure
 278  * defining a timer setting:
 279  */
 280 #define ITIMER_REAL             0
 281 #define ITIMER_VIRTUAL          1
 282 #define ITIMER_PROF             2
 283
 284 struct itimerspec {
 285         struct timespec it_interval;    /* timer period */
 286         struct timespec it_value;       /* timer expiration */
 287 };
 288
 289 struct itimerval {
 290         struct timeval it_interval;     /* timer interval */
 291         struct timeval it_value;        /* current value */
 292 };
 293
 294 /*
 295  * The IDs of the various system clocks (for POSIX.1b interval timers):
 296  */
 297 #define CLOCK_REALTIME                  0
 298 #define CLOCK_MONOTONIC                 1
 299 #define CLOCK_PROCESS_CPUTIME_ID        2
 300 #define CLOCK_THREAD_CPUTIME_ID         3
 301 #define CLOCK_MONOTONIC_RAW             4
 302 #define CLOCK_REALTIME_COARSE           5
 303 #define CLOCK_MONOTONIC_COARSE          6
 304
 305 /*
 306  * The IDs of various hardware clocks:
 307  */
 308 #define CLOCK_SGI_CYCLE                 10
 309 #define MAX_CLOCKS                      16
 310 #define CLOCKS_MASK                     (CLOCK_REALTIME | CLOCK_MONOTONIC)
 311 #define CLOCKS_MONO                     CLOCK_MONOTONIC
 312
 313 /*
 314  * The various flags for setting POSIX.1b interval timers:
 315  */
 316 #define TIMER_ABSTIME                   0x01
 317
 318 #endif