linux/include/linux/time.h
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   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
   9extern 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
  22static 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 */
  33static 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
  42static 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
  51extern 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
  55extern 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 */
  62extern struct timespec timespec_add_safe(const struct timespec lhs,
  63                                         const struct timespec rhs);
  64
  65
  66static 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 */
  78static 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 */
  97static 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
 108static 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
 118extern void read_persistent_clock(struct timespec *ts);
 119extern void read_boot_clock(struct timespec *ts);
 120extern int update_persistent_clock(struct timespec now);
 121void timekeeping_init(void);
 122extern int timekeeping_suspended;
 123
 124unsigned long get_seconds(void);
 125struct timespec current_kernel_time(void);
 126struct timespec __current_kernel_time(void); /* does not take xtime_lock */
 127struct timespec get_monotonic_coarse(void);
 128void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
 129                                struct timespec *wtom, struct timespec *sleep);
 130void timekeeping_inject_sleeptime(struct timespec *delta);
 131
 132#define CURRENT_TIME            (current_kernel_time())
 133#define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 134
 135/* Some architectures do not supply their own clocksource.
 136 * This is mainly the case in architectures that get their
 137 * inter-tick times by reading the counter on their interval
 138 * timer. Since these timers wrap every tick, they're not really
 139 * useful as clocksources. Wrapping them to act like one is possible
 140 * but not very efficient. So we provide a callout these arches
 141 * can implement for use with the jiffies clocksource to provide
 142 * finer then tick granular time.
 143 */
 144#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
 145extern u32 arch_gettimeoffset(void);
 146#else
 147static inline u32 arch_gettimeoffset(void) { return 0; }
 148#endif
 149
 150extern void do_gettimeofday(struct timeval *tv);
 151extern int do_settimeofday(const struct timespec *tv);
 152extern int do_sys_settimeofday(const struct timespec *tv,
 153                               const struct timezone *tz);
 154#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 155extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);
 156struct itimerval;
 157extern int do_setitimer(int which, struct itimerval *value,
 158                        struct itimerval *ovalue);
 159extern unsigned int alarm_setitimer(unsigned int seconds);
 160extern int do_getitimer(int which, struct itimerval *value);
 161extern void getnstimeofday(struct timespec *tv);
 162extern void getrawmonotonic(struct timespec *ts);
 163extern void getnstime_raw_and_real(struct timespec *ts_raw,
 164                struct timespec *ts_real);
 165extern void getboottime(struct timespec *ts);
 166extern void monotonic_to_bootbased(struct timespec *ts);
 167extern void get_monotonic_boottime(struct timespec *ts);
 168
 169extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 170extern int timekeeping_valid_for_hres(void);
 171extern u64 timekeeping_max_deferment(void);
 172extern int timekeeping_inject_offset(struct timespec *ts);
 173
 174struct tms;
 175extern void do_sys_times(struct tms *);
 176
 177/*
 178 * Similar to the struct tm in userspace <time.h>, but it needs to be here so
 179 * that the kernel source is self contained.
 180 */
 181struct tm {
 182        /*
 183         * the number of seconds after the minute, normally in the range
 184         * 0 to 59, but can be up to 60 to allow for leap seconds
 185         */
 186        int tm_sec;
 187        /* the number of minutes after the hour, in the range 0 to 59*/
 188        int tm_min;
 189        /* the number of hours past midnight, in the range 0 to 23 */
 190        int tm_hour;
 191        /* the day of the month, in the range 1 to 31 */
 192        int tm_mday;
 193        /* the number of months since January, in the range 0 to 11 */
 194        int tm_mon;
 195        /* the number of years since 1900 */
 196        long tm_year;
 197        /* the number of days since Sunday, in the range 0 to 6 */
 198        int tm_wday;
 199        /* the number of days since January 1, in the range 0 to 365 */
 200        int tm_yday;
 201};
 202
 203void time_to_tm(time_t totalsecs, int offset, struct tm *result);
 204
 205/**
 206 * timespec_to_ns - Convert timespec to nanoseconds
 207 * @ts:         pointer to the timespec variable to be converted
 208 *
 209 * Returns the scalar nanosecond representation of the timespec
 210 * parameter.
 211 */
 212static inline s64 timespec_to_ns(const struct timespec *ts)
 213{
 214        return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
 215}
 216
 217/**
 218 * timeval_to_ns - Convert timeval to nanoseconds
 219 * @ts:         pointer to the timeval variable to be converted
 220 *
 221 * Returns the scalar nanosecond representation of the timeval
 222 * parameter.
 223 */
 224static inline s64 timeval_to_ns(const struct timeval *tv)
 225{
 226        return ((s64) tv->tv_sec * NSEC_PER_SEC) +
 227                tv->tv_usec * NSEC_PER_USEC;
 228}
 229
 230/**
 231 * ns_to_timespec - Convert nanoseconds to timespec
 232 * @nsec:       the nanoseconds value to be converted
 233 *
 234 * Returns the timespec representation of the nsec parameter.
 235 */
 236extern struct timespec ns_to_timespec(const s64 nsec);
 237
 238/**
 239 * ns_to_timeval - Convert nanoseconds to timeval
 240 * @nsec:       the nanoseconds value to be converted
 241 *
 242 * Returns the timeval representation of the nsec parameter.
 243 */
 244extern struct timeval ns_to_timeval(const s64 nsec);
 245
 246/**
 247 * timespec_add_ns - Adds nanoseconds to a timespec
 248 * @a:          pointer to timespec to be incremented
 249 * @ns:         unsigned nanoseconds value to be added
 250 *
 251 * This must always be inlined because its used from the x86-64 vdso,
 252 * which cannot call other kernel functions.
 253 */
 254static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
 255{
 256        a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
 257        a->tv_nsec = ns;
 258}
 259
 260#endif
 261
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