linux/include/linux/time.h
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   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
  14struct timespec {
  15        __kernel_time_t tv_sec;                 /* seconds */
  16        long            tv_nsec;                /* nanoseconds */
  17};
  18#endif
  19
  20struct timeval {
  21        __kernel_time_t         tv_sec;         /* seconds */
  22        __kernel_suseconds_t    tv_usec;        /* microseconds */
  23};
  24
  25struct timezone {
  26        int     tz_minuteswest; /* minutes west of Greenwich */
  27        int     tz_dsttime;     /* type of dst correction */
  28};
  29
  30#ifdef __KERNEL__
  31
  32extern 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
  45static 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 */
  56static 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
  65static 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
  74extern 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
  78extern 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 */
  85extern struct timespec timespec_add_safe(const struct timespec lhs,
  86                                         const struct timespec rhs);
  87
  88
  89static 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 */
 101static 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 */
 120static 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        return true;
 129}
 130
 131static inline bool timespec_valid_strict(const struct timespec *ts)
 132{
 133        if (!timespec_valid(ts))
 134                return false;
 135        /* Disallow values that could overflow ktime_t */
 136        if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
 137                return false;
 138        return true;
 139}
 140
 141extern void read_persistent_clock(struct timespec *ts);
 142extern void read_boot_clock(struct timespec *ts);
 143extern int update_persistent_clock(struct timespec now);
 144void timekeeping_init(void);
 145extern int timekeeping_suspended;
 146
 147unsigned long get_seconds(void);
 148struct timespec current_kernel_time(void);
 149struct timespec __current_kernel_time(void); /* does not take xtime_lock */
 150struct timespec get_monotonic_coarse(void);
 151void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
 152                                struct timespec *wtom, struct timespec *sleep);
 153void timekeeping_inject_sleeptime(struct timespec *delta);
 154
 155#define CURRENT_TIME            (current_kernel_time())
 156#define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 157
 158/* Some architectures do not supply their own clocksource.
 159 * This is mainly the case in architectures that get their
 160 * inter-tick times by reading the counter on their interval
 161 * timer. Since these timers wrap every tick, they're not really
 162 * useful as clocksources. Wrapping them to act like one is possible
 163 * but not very efficient. So we provide a callout these arches
 164 * can implement for use with the jiffies clocksource to provide
 165 * finer then tick granular time.
 166 */
 167#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 168extern u32 arch_gettimeoffset(void);
 169#else
 170static inline u32 arch_gettimeoffset(void) { return 0; }
 171#endif
 172
 173extern void do_gettimeofday(struct timeval *tv);
 174extern int do_settimeofday(const struct timespec *tv);
 175extern int do_sys_settimeofday(const struct timespec *tv,
 176                               const struct timezone *tz);
 177#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 178extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);
 179struct itimerval;
 180extern int do_setitimer(int which, struct itimerval *value,
 181                        struct itimerval *ovalue);
 182extern unsigned int alarm_setitimer(unsigned int seconds);
 183extern int do_getitimer(int which, struct itimerval *value);
 184extern void getnstimeofday(struct timespec *tv);
 185extern void getrawmonotonic(struct timespec *ts);
 186extern void getnstime_raw_and_real(struct timespec *ts_raw,
 187                struct timespec *ts_real);
 188extern void getboottime(struct timespec *ts);
 189extern void monotonic_to_bootbased(struct timespec *ts);
 190extern void get_monotonic_boottime(struct timespec *ts);
 191
 192extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 193extern int timekeeping_valid_for_hres(void);
 194extern u64 timekeeping_max_deferment(void);
 195extern int timekeeping_inject_offset(struct timespec *ts);
 196
 197struct tms;
 198extern void do_sys_times(struct tms *);
 199
 200/*
 201 * Similar to the struct tm in userspace <time.h>, but it needs to be here so
 202 * that the kernel source is self contained.
 203 */
 204struct tm {
 205        /*
 206         * the number of seconds after the minute, normally in the range
 207         * 0 to 59, but can be up to 60 to allow for leap seconds
 208         */
 209        int tm_sec;
 210        /* the number of minutes after the hour, in the range 0 to 59*/
 211        int tm_min;
 212        /* the number of hours past midnight, in the range 0 to 23 */
 213        int tm_hour;
 214        /* the day of the month, in the range 1 to 31 */
 215        int tm_mday;
 216        /* the number of months since January, in the range 0 to 11 */
 217        int tm_mon;
 218        /* the number of years since 1900 */
 219        long tm_year;
 220        /* the number of days since Sunday, in the range 0 to 6 */
 221        int tm_wday;
 222        /* the number of days since January 1, in the range 0 to 365 */
 223        int tm_yday;
 224};
 225
 226void time_to_tm(time_t totalsecs, int offset, struct tm *result);
 227
 228/**
 229 * timespec_to_ns - Convert timespec to nanoseconds
 230 * @ts:         pointer to the timespec variable to be converted
 231 *
 232 * Returns the scalar nanosecond representation of the timespec
 233 * parameter.
 234 */
 235static inline s64 timespec_to_ns(const struct timespec *ts)
 236{
 237        return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 238}
 239
 240/**
 241 * timeval_to_ns - Convert timeval to nanoseconds
 242 * @ts:         pointer to the timeval variable to be converted
 243 *
 244 * Returns the scalar nanosecond representation of the timeval
 245 * parameter.
 246 */
 247static inline s64 timeval_to_ns(const struct timeval *tv)
 248{
 249        return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 250                tv->tv_usec * NSEC_PER_USEC;
 251}
 252
 253/**
 254 * ns_to_timespec - Convert nanoseconds to timespec
 255 * @nsec:       the nanoseconds value to be converted
 256 *
 257 * Returns the timespec representation of the nsec parameter.
 258 */
 259extern struct timespec ns_to_timespec(const s64 nsec);
 260
 261/**
 262 * ns_to_timeval - Convert nanoseconds to timeval
 263 * @nsec:       the nanoseconds value to be converted
 264 *
 265 * Returns the timeval representation of the nsec parameter.
 266 */
 267extern struct timeval ns_to_timeval(const s64 nsec);
 268
 269/**
 270 * timespec_add_ns - Adds nanoseconds to a timespec
 271 * @a:          pointer to timespec to be incremented
 272 * @ns:         unsigned nanoseconds value to be added
 273 *
 274 * This must always be inlined because its used from the x86-64 vdso,
 275 * which cannot call other kernel functions.
 276 */
 277static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
 278{
 279        a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 280        a->tv_nsec = ns;
 281}
 282
 283#endif /* __KERNEL__ */
 284
 285/*
 286 * Names of the interval timers, and structure
 287 * defining a timer setting:
 288 */
 289#define ITIMER_REAL             0
 290#define ITIMER_VIRTUAL          1
 291#define ITIMER_PROF             2
 292
 293struct itimerspec {
 294        struct timespec it_interval;    /* timer period */
 295        struct timespec it_value;       /* timer expiration */
 296};
 297
 298struct itimerval {
 299        struct timeval it_interval;     /* timer interval */
 300        struct timeval it_value;        /* current value */
 301};
 302
 303/*
 304 * The IDs of the various system clocks (for POSIX.1b interval timers):
 305 */
 306#define CLOCK_REALTIME                  0
 307#define CLOCK_MONOTONIC                 1
 308#define CLOCK_PROCESS_CPUTIME_ID        2
 309#define CLOCK_THREAD_CPUTIME_ID         3
 310#define CLOCK_MONOTONIC_RAW             4
 311#define CLOCK_REALTIME_COARSE           5
 312#define CLOCK_MONOTONIC_COARSE          6
 313#define CLOCK_BOOTTIME                  7
 314#define CLOCK_REALTIME_ALARM            8
 315#define CLOCK_BOOTTIME_ALARM            9
 316
 317/*
 318 * The IDs of various hardware clocks:
 319 */
 320#define CLOCK_SGI_CYCLE                 10
 321#define MAX_CLOCKS                      16
 322#define CLOCKS_MASK                     (CLOCK_REALTIME | CLOCK_MONOTONIC)
 323#define CLOCKS_MONO                     CLOCK_MONOTONIC
 324
 325/*
 326 * The various flags for setting POSIX.1b interval timers:
 327 */
 328#define TIMER_ABSTIME                   0x01
 329
 330#endif
 331
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