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 #define KTIME_MAX                       ((s64)~((u64)1 << 63))
 111 #if (BITS_PER_LONG == 64)
 112 # define KTIME_SEC_MAX                  (KTIME_MAX / NSEC_PER_SEC)
 113 #else
 114 # define KTIME_SEC_MAX                  LONG_MAX
 115 #endif
 116
 117 /*
 118  * Returns true if the timespec is norm, false if denorm:
 119  */
 120 static inline bool timespec_valid(const struct timespec *ts)
 121 {
 122         /* Dates before 1970 are bogus */
 123         if (ts->tv_sec < 0)
 124                 return false;
 125         /* Can't have more nanoseconds then a second */
 126         if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
 127                 return false;
 128         /* Disallow values that could overflow ktime_t */
 129         if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
 130                 return false;
 131         return true;
 132 }
 133
 134 extern void read_persistent_clock(struct timespec *ts);
 135 extern void read_boot_clock(struct timespec *ts);
 136 extern int update_persistent_clock(struct timespec now);
 137 void timekeeping_init(void);
 138 extern int timekeeping_suspended;
 139
 140 unsigned long get_seconds(void);
 141 struct timespec current_kernel_time(void);
 142 struct timespec __current_kernel_time(void); /* does not take xtime_lock */
 143 struct timespec get_monotonic_coarse(void);
 144 void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
 145                                 struct timespec *wtom, struct timespec *sleep);
 146 void timekeeping_inject_sleeptime(struct timespec *delta);
 147
 148 #define CURRENT_TIME            (current_kernel_time())
 149 #define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 150
 151 /* Some architectures do not supply their own clocksource.
 152  * This is mainly the case in architectures that get their
 153  * inter-tick times by reading the counter on their interval
 154  * timer. Since these timers wrap every tick, they're not really
 155  * useful as clocksources. Wrapping them to act like one is possible
 156  * but not very efficient. So we provide a callout these arches
 157  * can implement for use with the jiffies clocksource to provide
 158  * finer then tick granular time.
 159  */
 160 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 161 extern u32 arch_gettimeoffset(void);
 162 #else
 163 static inline u32 arch_gettimeoffset(void) { return 0; }
 164 #endif
 165
 166 extern void do_gettimeofday(struct timeval *tv);
 167 extern int do_settimeofday(const struct timespec *tv);
 168 extern int do_sys_settimeofday(const struct timespec *tv,
 169                                const struct timezone *tz);
 170 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 171 extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);
 172 struct itimerval;
 173 extern int do_setitimer(int which, struct itimerval *value,
 174                         struct itimerval *ovalue);
 175 extern unsigned int alarm_setitimer(unsigned int seconds);
 176 extern int do_getitimer(int which, struct itimerval *value);
 177 extern void getnstimeofday(struct timespec *tv);
 178 extern void getrawmonotonic(struct timespec *ts);
 179 extern void getnstime_raw_and_real(struct timespec *ts_raw,
 180                 struct timespec *ts_real);
 181 extern void getboottime(struct timespec *ts);
 182 extern void monotonic_to_bootbased(struct timespec *ts);
 183 extern void get_monotonic_boottime(struct timespec *ts);
 184
 185 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 186 extern int timekeeping_valid_for_hres(void);
 187 extern u64 timekeeping_max_deferment(void);
 188 extern int timekeeping_inject_offset(struct timespec *ts);
 189
 190 struct tms;
 191 extern void do_sys_times(struct tms *);
 192
 193 /*
 194  * Similar to the struct tm in userspace <time.h>, but it needs to be here so
 195  * that the kernel source is self contained.
 196  */
 197 struct tm {
 198         /*
 199          * the number of seconds after the minute, normally in the range
 200          * 0 to 59, but can be up to 60 to allow for leap seconds
 201          */
 202         int tm_sec;
 203         /* the number of minutes after the hour, in the range 0 to 59*/
 204         int tm_min;
 205         /* the number of hours past midnight, in the range 0 to 23 */
 206         int tm_hour;
 207         /* the day of the month, in the range 1 to 31 */
 208         int tm_mday;
 209         /* the number of months since January, in the range 0 to 11 */
 210         int tm_mon;
 211         /* the number of years since 1900 */
 212         long tm_year;
 213         /* the number of days since Sunday, in the range 0 to 6 */
 214         int tm_wday;
 215         /* the number of days since January 1, in the range 0 to 365 */
 216         int tm_yday;
 217 };
 218
 219 void time_to_tm(time_t totalsecs, int offset, struct tm *result);
 220
 221 /**
 222  * timespec_to_ns - Convert timespec to nanoseconds
 223  * @ts:         pointer to the timespec variable to be converted
 224  *
 225  * Returns the scalar nanosecond representation of the timespec
 226  * parameter.
 227  */
 228 static inline s64 timespec_to_ns(const struct timespec *ts)
 229 {
 230         return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 231 }
 232
 233 /**
 234  * timeval_to_ns - Convert timeval to nanoseconds
 235  * @ts:         pointer to the timeval variable to be converted
 236  *
 237  * Returns the scalar nanosecond representation of the timeval
 238  * parameter.
 239  */
 240 static inline s64 timeval_to_ns(const struct timeval *tv)
 241 {
 242         return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 243                 tv->tv_usec * NSEC_PER_USEC;
 244 }
 245
 246 /**
 247  * ns_to_timespec - Convert nanoseconds to timespec
 248  * @nsec:       the nanoseconds value to be converted
 249  *
 250  * Returns the timespec representation of the nsec parameter.
 251  */
 252 extern struct timespec ns_to_timespec(const s64 nsec);
 253
 254 /**
 255  * ns_to_timeval - Convert nanoseconds to timeval
 256  * @nsec:       the nanoseconds value to be converted
 257  *
 258  * Returns the timeval representation of the nsec parameter.
 259  */
 260 extern struct timeval ns_to_timeval(const s64 nsec);
 261
 262 /**
 263  * timespec_add_ns - Adds nanoseconds to a timespec
 264  * @a:          pointer to timespec to be incremented
 265  * @ns:         unsigned nanoseconds value to be added
 266  *
 267  * This must always be inlined because its used from the x86-64 vdso,
 268  * which cannot call other kernel functions.
 269  */
 270 static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
 271 {
 272         a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 273         a->tv_nsec = ns;
 274 }
 275
 276 #endif /* __KERNEL__ */
 277
 278 /*
 279  * Names of the interval timers, and structure
 280  * defining a timer setting:
 281  */
 282 #define ITIMER_REAL             0
 283 #define ITIMER_VIRTUAL          1
 284 #define ITIMER_PROF             2
 285
 286 struct itimerspec {
 287         struct timespec it_interval;    /* timer period */
 288         struct timespec it_value;       /* timer expiration */
 289 };
 290
 291 struct itimerval {
 292         struct timeval it_interval;     /* timer interval */
 293         struct timeval it_value;        /* current value */
 294 };
 295
 296 /*
 297  * The IDs of the various system clocks (for POSIX.1b interval timers):
 298  */
 299 #define CLOCK_REALTIME                  0
 300 #define CLOCK_MONOTONIC                 1
 301 #define CLOCK_PROCESS_CPUTIME_ID        2
 302 #define CLOCK_THREAD_CPUTIME_ID         3
 303 #define CLOCK_MONOTONIC_RAW             4
 304 #define CLOCK_REALTIME_COARSE           5
 305 #define CLOCK_MONOTONIC_COARSE          6
 306 #define CLOCK_BOOTTIME                  7
 307 #define CLOCK_REALTIME_ALARM            8
 308 #define CLOCK_BOOTTIME_ALARM            9
 309
 310 /*
 311  * The IDs of various hardware clocks:
 312  */
 313 #define CLOCK_SGI_CYCLE                 10
 314 #define MAX_CLOCKS                      16
 315 #define CLOCKS_MASK                     (CLOCK_REALTIME | CLOCK_MONOTONIC)
 316 #define CLOCKS_MONO                     CLOCK_MONOTONIC
 317
 318 /*
 319  * The various flags for setting POSIX.1b interval timers:
 320  */
 321 #define TIMER_ABSTIME                   0x01
 322
 323 #endif