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 /* Located here for timespec_valid_strict */
  23 #define KTIME_MAX                       ((s64)~((u64)1 << 63))
  24 #define KTIME_SEC_MAX                   (KTIME_MAX / NSEC_PER_SEC)
  25
  26 static inline int timespec_equal(const struct timespec *a,
  27                                  const struct timespec *b)
  28 {
  29         return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
  30 }
  31
  32 /*
  33  * lhs < rhs:  return <0
  34  * lhs == rhs: return 0
  35  * lhs > rhs:  return >0
  36  */
  37 static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
  38 {
  39         if (lhs->tv_sec < rhs->tv_sec)
  40                 return -1;
  41         if (lhs->tv_sec > rhs->tv_sec)
  42                 return 1;
  43         return lhs->tv_nsec - rhs->tv_nsec;
  44 }
  45
  46 static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
  47 {
  48         if (lhs->tv_sec < rhs->tv_sec)
  49                 return -1;
  50         if (lhs->tv_sec > rhs->tv_sec)
  51                 return 1;
  52         return lhs->tv_usec - rhs->tv_usec;
  53 }
  54
  55 extern unsigned long mktime(const unsigned int year, const unsigned int mon,
  56                             const unsigned int day, const unsigned int hour,
  57                             const unsigned int min, const unsigned int sec);
  58
  59 extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);
  60
  61 /*
  62  * timespec_add_safe assumes both values are positive and checks
  63  * for overflow. It will return TIME_T_MAX if the reutrn would be
  64  * smaller then either of the arguments.
  65  */
  66 extern struct timespec timespec_add_safe(const struct timespec lhs,
  67                                          const struct timespec rhs);
  68
  69
  70 static inline struct timespec timespec_add(struct timespec lhs,
  71                                                 struct timespec rhs)
  72 {
  73         struct timespec ts_delta;
  74         set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec,
  75                                 lhs.tv_nsec + rhs.tv_nsec);
  76         return ts_delta;
  77 }
  78
  79 /*
  80  * sub = lhs - rhs, in normalized form
  81  */
  82 static inline struct timespec timespec_sub(struct timespec lhs,
  83                                                 struct timespec rhs)
  84 {
  85         struct timespec ts_delta;
  86         set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
  87                                 lhs.tv_nsec - rhs.tv_nsec);
  88         return ts_delta;
  89 }
  90
  91 /*
  92  * Returns true if the timespec is norm, false if denorm:
  93  */
  94 static inline bool timespec_valid(const struct timespec *ts)
  95 {
  96         /* Dates before 1970 are bogus */
  97         if (ts->tv_sec < 0)
  98                 return false;
  99         /* Can't have more nanoseconds then a second */
 100         if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
 101                 return false;
 102         return true;
 103 }
 104
 105 static inline bool timespec_valid_strict(const struct timespec *ts)
 106 {
 107         if (!timespec_valid(ts))
 108                 return false;
 109         /* Disallow values that could overflow ktime_t */
 110         if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
 111                 return false;
 112         return true;
 113 }
 114
 115 extern bool persistent_clock_exist;
 116
 117 static inline bool has_persistent_clock(void)
 118 {
 119         return persistent_clock_exist;
 120 }
 121
 122 extern void read_persistent_clock(struct timespec *ts);
 123 extern void read_boot_clock(struct timespec *ts);
 124 extern int persistent_clock_is_local;
 125 extern int update_persistent_clock(struct timespec now);
 126 void timekeeping_init(void);
 127 extern int timekeeping_suspended;
 128
 129 unsigned long get_seconds(void);
 130 struct timespec current_kernel_time(void);
 131 struct timespec __current_kernel_time(void); /* does not take xtime_lock */
 132 struct timespec get_monotonic_coarse(void);
 133 void timekeeping_inject_sleeptime(struct timespec *delta);
 134
 135 #define CURRENT_TIME            (current_kernel_time())
 136 #define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 137
 138 /* Some architectures do not supply their own clocksource.
 139  * This is mainly the case in architectures that get their
 140  * inter-tick times by reading the counter on their interval
 141  * timer. Since these timers wrap every tick, they're not really
 142  * useful as clocksources. Wrapping them to act like one is possible
 143  * but not very efficient. So we provide a callout these arches
 144  * can implement for use with the jiffies clocksource to provide
 145  * finer then tick granular time.
 146  */
 147 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 148 extern u32 (*arch_gettimeoffset)(void);
 149 #endif
 150
 151 extern void do_gettimeofday(struct timeval *tv);
 152 extern int do_settimeofday(const struct timespec *tv);
 153 extern int do_sys_settimeofday(const struct timespec *tv,
 154                                const struct timezone *tz);
 155 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 156 extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);
 157 struct itimerval;
 158 extern int do_setitimer(int which, struct itimerval *value,
 159                         struct itimerval *ovalue);
 160 extern unsigned int alarm_setitimer(unsigned int seconds);
 161 extern int do_getitimer(int which, struct itimerval *value);
 162 extern int __getnstimeofday(struct timespec *tv);
 163 extern void getnstimeofday(struct timespec *tv);
 164 extern void getrawmonotonic(struct timespec *ts);
 165 extern void getnstime_raw_and_real(struct timespec *ts_raw,
 166                 struct timespec *ts_real);
 167 extern void getboottime(struct timespec *ts);
 168 extern void monotonic_to_bootbased(struct timespec *ts);
 169 extern void get_monotonic_boottime(struct timespec *ts);
 170
 171 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 172 extern int timekeeping_valid_for_hres(void);
 173 extern u64 timekeeping_max_deferment(void);
 174 extern int timekeeping_inject_offset(struct timespec *ts);
 175 extern s32 timekeeping_get_tai_offset(void);
 176 extern void timekeeping_set_tai_offset(s32 tai_offset);
 177 extern void timekeeping_clocktai(struct timespec *ts);
 178
 179 struct tms;
 180 extern void do_sys_times(struct tms *);
 181
 182 /*
 183  * Similar to the struct tm in userspace <time.h>, but it needs to be here so
 184  * that the kernel source is self contained.
 185  */
 186 struct tm {
 187         /*
 188          * the number of seconds after the minute, normally in the range
 189          * 0 to 59, but can be up to 60 to allow for leap seconds
 190          */
 191         int tm_sec;
 192         /* the number of minutes after the hour, in the range 0 to 59*/
 193         int tm_min;
 194         /* the number of hours past midnight, in the range 0 to 23 */
 195         int tm_hour;
 196         /* the day of the month, in the range 1 to 31 */
 197         int tm_mday;
 198         /* the number of months since January, in the range 0 to 11 */
 199         int tm_mon;
 200         /* the number of years since 1900 */
 201         long tm_year;
 202         /* the number of days since Sunday, in the range 0 to 6 */
 203         int tm_wday;
 204         /* the number of days since January 1, in the range 0 to 365 */
 205         int tm_yday;
 206 };
 207
 208 void time_to_tm(time_t totalsecs, int offset, struct tm *result);
 209
 210 /**
 211  * timespec_to_ns - Convert timespec to nanoseconds
 212  * @ts:         pointer to the timespec variable to be converted
 213  *
 214  * Returns the scalar nanosecond representation of the timespec
 215  * parameter.
 216  */
 217 static inline s64 timespec_to_ns(const struct timespec *ts)
 218 {
 219         return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 220 }
 221
 222 /**
 223  * timeval_to_ns - Convert timeval to nanoseconds
 224  * @ts:         pointer to the timeval variable to be converted
 225  *
 226  * Returns the scalar nanosecond representation of the timeval
 227  * parameter.
 228  */
 229 static inline s64 timeval_to_ns(const struct timeval *tv)
 230 {
 231         return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 232                 tv->tv_usec * NSEC_PER_USEC;
 233 }
 234
 235 /**
 236  * ns_to_timespec - Convert nanoseconds to timespec
 237  * @nsec:       the nanoseconds value to be converted
 238  *
 239  * Returns the timespec representation of the nsec parameter.
 240  */
 241 extern struct timespec ns_to_timespec(const s64 nsec);
 242
 243 /**
 244  * ns_to_timeval - Convert nanoseconds to timeval
 245  * @nsec:       the nanoseconds value to be converted
 246  *
 247  * Returns the timeval representation of the nsec parameter.
 248  */
 249 extern struct timeval ns_to_timeval(const s64 nsec);
 250
 251 /**
 252  * timespec_add_ns - Adds nanoseconds to a timespec
 253  * @a:          pointer to timespec to be incremented
 254  * @ns:         unsigned nanoseconds value to be added
 255  *
 256  * This must always be inlined because its used from the x86-64 vdso,
 257  * which cannot call other kernel functions.
 258  */
 259 static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
 260 {
 261         a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 262         a->tv_nsec = ns;
 263 }
 264
 265 #endif