include/linux/time.h

   1 #ifndef _LINUX_TIME_H
   2 #define _LINUX_TIME_H
   3
   4 # include <linux/cache.h>
   5 # include <linux/seqlock.h>
   6 # include <linux/math64.h>
   7 #include <uapi/linux/time.h>
   8
   9 extern struct timezone sys_tz;
  10
  11 /* Parameters used to convert the timespec values: */
  12 #define MSEC_PER_SEC    1000L
  13 #define USEC_PER_MSEC   1000L
  14 #define NSEC_PER_USEC   1000L
  15 #define NSEC_PER_MSEC   1000000L
  16 #define USEC_PER_SEC    1000000L
  17 #define NSEC_PER_SEC    1000000000L
  18 #define FSEC_PER_SEC    1000000000000000LL
  19
  20 #define TIME_T_MAX      (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
  21
  22 static inline int timespec_equal(const struct timespec *a,
  23                                  const struct timespec *b)
  24 {
  25         return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  26 }
  27
  28 /*
  29  * lhs < rhs:  return <0
  30  * lhs == rhs: return 0
  31  * lhs > rhs:  return >0
  32  */
  33 static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
  34 {
  35         if (lhs->tv_sec < rhs->tv_sec)
  36                 return -1;
  37         if (lhs->tv_sec > rhs->tv_sec)
  38                 return 1;
  39         return lhs->tv_nsec - rhs->tv_nsec;
  40 }
  41
  42 static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
  43 {
  44         if (lhs->tv_sec < rhs->tv_sec)
  45                 return -1;
  46         if (lhs->tv_sec > rhs->tv_sec)
  47                 return 1;
  48         return lhs->tv_usec - rhs->tv_usec;
  49 }
  50
  51 extern unsigned long mktime(const unsigned int year, const unsigned int mon,
  52                             const unsigned int day, const unsigned int hour,
  53                             const unsigned int min, const unsigned int sec);
  54
  55 extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);
  56
  57 /*
  58  * timespec_add_safe assumes both values are positive and checks
  59  * for overflow. It will return TIME_T_MAX if the reutrn would be
  60  * smaller then either of the arguments.
  61  */
  62 extern struct timespec timespec_add_safe(const struct timespec lhs,
  63                                          const struct timespec rhs);
  64
  65
  66 static inline struct timespec timespec_add(struct timespec lhs,
  67                                                 struct timespec rhs)
  68 {
  69         struct timespec ts_delta;
  70         set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec,
  71                                 lhs.tv_nsec + rhs.tv_nsec);
  72         return ts_delta;
  73 }
  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 #define KTIME_MAX                       ((s64)~((u64)1 << 63))
  88 #if (BITS_PER_LONG == 64)
  89 # define KTIME_SEC_MAX                  (KTIME_MAX / NSEC_PER_SEC)
  90 #else
  91 # define KTIME_SEC_MAX                  LONG_MAX
  92 #endif
  93
  94 /*
  95  * Returns true if the timespec is norm, false if denorm:
  96  */
  97 static inline bool timespec_valid(const struct timespec *ts)
  98 {
  99         /* Dates before 1970 are bogus */
 100         if (ts->tv_sec < 0)
 101                 return false;
 102         /* Can't have more nanoseconds then a second */
 103         if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
 104                 return false;
 105         return true;
 106 }
 107
 108 static inline bool timespec_valid_strict(const struct timespec *ts)
 109 {
 110         if (!timespec_valid(ts))
 111                 return false;
 112         /* Disallow values that could overflow ktime_t */
 113         if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
 114                 return false;
 115         return true;
 116 }
 117
 118 extern bool persistent_clock_exist;
 119
 120 #ifdef ALWAYS_USE_PERSISTENT_CLOCK
 121 #define has_persistent_clock()  true
 122 #else
 123 static inline bool has_persistent_clock(void)
 124 {
 125         return persistent_clock_exist;
 126 }
 127 #endif
 128
 129 extern void read_persistent_clock(struct timespec *ts);
 130 extern void read_boot_clock(struct timespec *ts);
 131 extern int persistent_clock_is_local;
 132 extern int update_persistent_clock(struct timespec now);
 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 take xtime_lock */
 139 struct timespec get_monotonic_coarse(void);
 140 void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
 141                                 struct timespec *wtom, struct timespec *sleep);
 142 void timekeeping_inject_sleeptime(struct timespec *delta);
 143
 144 #define CURRENT_TIME            (current_kernel_time())
 145 #define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 146
 147 /* Some architectures do not supply their own clocksource.
 148  * This is mainly the case in architectures that get their
 149  * inter-tick times by reading the counter on their interval
 150  * timer. Since these timers wrap every tick, they're not really
 151  * useful as clocksources. Wrapping them to act like one is possible
 152  * but not very efficient. So we provide a callout these arches
 153  * can implement for use with the jiffies clocksource to provide
 154  * finer then tick granular time.
 155  */
 156 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 157 extern u32 (*arch_gettimeoffset)(void);
 158 #endif
 159
 160 extern void do_gettimeofday(struct timeval *tv);
 161 extern int do_settimeofday(const struct timespec *tv);
 162 extern int do_sys_settimeofday(const struct timespec *tv,
 163                                const struct timezone *tz);
 164 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 165 extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);
 166 struct itimerval;
 167 extern int do_setitimer(int which, struct itimerval *value,
 168                         struct itimerval *ovalue);
 169 extern unsigned int alarm_setitimer(unsigned int seconds);
 170 extern int do_getitimer(int which, struct itimerval *value);
 171 extern int __getnstimeofday(struct timespec *tv);
 172 extern void getnstimeofday(struct timespec *tv);
 173 extern void getrawmonotonic(struct timespec *ts);
 174 extern void getnstime_raw_and_real(struct timespec *ts_raw,
 175                 struct timespec *ts_real);
 176 extern void getboottime(struct timespec *ts);
 177 extern void monotonic_to_bootbased(struct timespec *ts);
 178 extern void get_monotonic_boottime(struct timespec *ts);
 179
 180 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 181 extern int timekeeping_valid_for_hres(void);
 182 extern u64 timekeeping_max_deferment(void);
 183 extern int timekeeping_inject_offset(struct timespec *ts);
 184
 185 struct tms;
 186 extern void do_sys_times(struct tms *);
 187
 188 /*
 189  * Similar to the struct tm in userspace <time.h>, but it needs to be here so
 190  * that the kernel source is self contained.
 191  */
 192 struct tm {
 193         /*
 194          * the number of seconds after the minute, normally in the range
 195          * 0 to 59, but can be up to 60 to allow for leap seconds
 196          */
 197         int tm_sec;
 198         /* the number of minutes after the hour, in the range 0 to 59*/
 199         int tm_min;
 200         /* the number of hours past midnight, in the range 0 to 23 */
 201         int tm_hour;
 202         /* the day of the month, in the range 1 to 31 */
 203         int tm_mday;
 204         /* the number of months since January, in the range 0 to 11 */
 205         int tm_mon;
 206         /* the number of years since 1900 */
 207         long tm_year;
 208         /* the number of days since Sunday, in the range 0 to 6 */
 209         int tm_wday;
 210         /* the number of days since January 1, in the range 0 to 365 */
 211         int tm_yday;
 212 };
 213
 214 void time_to_tm(time_t totalsecs, int offset, struct tm *result);
 215
 216 /**
 217  * timespec_to_ns - Convert timespec to nanoseconds
 218  * @ts:         pointer to the timespec variable to be converted
 219  *
 220  * Returns the scalar nanosecond representation of the timespec
 221  * parameter.
 222  */
 223 static inline s64 timespec_to_ns(const struct timespec *ts)
 224 {
 225         return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 226 }
 227
 228 /**
 229  * timeval_to_ns - Convert timeval to nanoseconds
 230  * @ts:         pointer to the timeval variable to be converted
 231  *
 232  * Returns the scalar nanosecond representation of the timeval
 233  * parameter.
 234  */
 235 static inline s64 timeval_to_ns(const struct timeval *tv)
 236 {
 237         return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 238                 tv->tv_usec * NSEC_PER_USEC;
 239 }
 240
 241 /**
 242  * ns_to_timespec - Convert nanoseconds to timespec
 243  * @nsec:       the nanoseconds value to be converted
 244  *
 245  * Returns the timespec representation of the nsec parameter.
 246  */
 247 extern struct timespec ns_to_timespec(const s64 nsec);
 248
 249 /**
 250  * ns_to_timeval - Convert nanoseconds to timeval
 251  * @nsec:       the nanoseconds value to be converted
 252  *
 253  * Returns the timeval representation of the nsec parameter.
 254  */
 255 extern struct timeval ns_to_timeval(const s64 nsec);
 256
 257 /**
 258  * timespec_add_ns - Adds nanoseconds to a timespec
 259  * @a:          pointer to timespec to be incremented
 260  * @ns:         unsigned nanoseconds value to be added
 261  *
 262  * This must always be inlined because its used from the x86-64 vdso,
 263  * which cannot call other kernel functions.
 264  */
 265 static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
 266 {
 267         a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 268         a->tv_nsec = ns;
 269 }
 270
 271 #endif