#ifndef _LINUX_TIME_H
#define _LINUX_TIME_H

#include <linux/types.h>

#ifdef __KERNEL__
# include <linux/cache.h>
# include <linux/seqlock.h>
# include <linux/math64.h>
#endif

#ifndef _STRUCT_TIMESPEC
#define _STRUCT_TIMESPEC
struct timespec {
        __kernel_time_t tv_sec;                 /* seconds */
        long            tv_nsec;                /* nanoseconds */
};
#endif

struct timeval {
        __kernel_time_t         tv_sec;         /* seconds */
        __kernel_suseconds_t    tv_usec;        /* microseconds */
};

struct timezone {
        int     tz_minuteswest; /* minutes west of Greenwich */
        int     tz_dsttime;     /* type of dst correction */
};

#ifdef __KERNEL__

extern struct timezone sys_tz;

/* Parameters used to convert the timespec values: */
#define MSEC_PER_SEC    1000L
#define USEC_PER_MSEC   1000L
#define NSEC_PER_USEC   1000L
#define NSEC_PER_MSEC   1000000L
#define USEC_PER_SEC    1000000L
#define NSEC_PER_SEC    1000000000L
#define FSEC_PER_SEC    1000000000000000L

#define TIME_T_MAX      (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)

static inline int timespec_equal(const struct timespec *a,
                                 const struct timespec *b)
{
        return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
}

/*
 * lhs < rhs:  return <0
 * lhs == rhs: return 0
 * lhs > rhs:  return >0
 */
static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
{
        if (lhs->tv_sec < rhs->tv_sec)
                return -1;
        if (lhs->tv_sec > rhs->tv_sec)
                return 1;
        return lhs->tv_nsec - rhs->tv_nsec;
}

static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
{
        if (lhs->tv_sec < rhs->tv_sec)
                return -1;
        if (lhs->tv_sec > rhs->tv_sec)
                return 1;
        return lhs->tv_usec - rhs->tv_usec;
}

extern unsigned long mktime(const unsigned int year, const unsigned int mon,
                            const unsigned int day, const unsigned int hour,
                            const unsigned int min, const unsigned int sec);

extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);
extern struct timespec timespec_add_safe(const struct timespec lhs,
                                         const struct timespec rhs);

/*
 * sub = lhs - rhs, in normalized form
 */
static inline struct timespec timespec_sub(struct timespec lhs,
                                                struct timespec rhs)
{
        struct timespec ts_delta;
        set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
                                lhs.tv_nsec - rhs.tv_nsec);
        return ts_delta;
}

/*
 * Returns true if the timespec is norm, false if denorm:
 */
#define timespec_valid(ts) \
        (((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))

extern struct timespec xtime;
extern struct timespec wall_to_monotonic;
extern seqlock_t xtime_lock;

extern void read_persistent_clock(struct timespec *ts);
extern void read_boot_clock(struct timespec *ts);
extern int update_persistent_clock(struct timespec now);
extern int no_sync_cmos_clock __read_mostly;
void timekeeping_init(void);
extern int timekeeping_suspended;

unsigned long get_seconds(void);
struct timespec current_kernel_time(void);
struct timespec __current_kernel_time(void); /* does not hold xtime_lock */
struct timespec get_monotonic_coarse(void);

#define CURRENT_TIME            (current_kernel_time())
#define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })

/* Some architectures do not supply their own clocksource.
 * This is mainly the case in architectures that get their
 * inter-tick times by reading the counter on their interval
 * timer. Since these timers wrap every tick, they're not really
 * useful as clocksources. Wrapping them to act like one is possible
 * but not very efficient. So we provide a callout these arches
 * can implement for use with the jiffies clocksource to provide
 * finer then tick granular time.
 */
#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
extern u32 arch_gettimeoffset(void);
#else
static inline u32 arch_gettimeoffset(void) { return 0; }
#endif

extern void do_gettimeofday(struct timeval *tv);
extern int do_settimeofday(struct timespec *tv);
extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
struct itimerval;
extern int do_setitimer(int which, struct itimerval *value,
                        struct itimerval *ovalue);
extern unsigned int alarm_setitimer(unsigned int seconds);
extern int do_getitimer(int which, struct itimerval *value);
extern void getnstimeofday(struct timespec *tv);
extern void getrawmonotonic(struct timespec *ts);
extern void getboottime(struct timespec *ts);
extern void monotonic_to_bootbased(struct timespec *ts);

extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
extern int timekeeping_valid_for_hres(void);
extern void update_wall_time(void);
extern void update_xtime_cache(u64 nsec);
extern void timekeeping_leap_insert(int leapsecond);

struct tms;
extern void do_sys_times(struct tms *);

/*
 * Similar to the struct tm in userspace <time.h>, but it needs to be here so
 * that the kernel source is self contained.
 */
struct tm {
        /*
         * the number of seconds after the minute, normally in the range
         * 0 to 59, but can be up to 60 to allow for leap seconds
         */
        int tm_sec;
        /* the number of minutes after the hour, in the range 0 to 59*/
        int tm_min;
        /* the number of hours past midnight, in the range 0 to 23 */
        int tm_hour;
        /* the day of the month, in the range 1 to 31 */
        int tm_mday;
        /* the number of months since January, in the range 0 to 11 */
        int tm_mon;
        /* the number of years since 1900 */
        long tm_year;
        /* the number of days since Sunday, in the range 0 to 6 */
        int tm_wday;
        /* the number of days since January 1, in the range 0 to 365 */
        int tm_yday;
};

void time_to_tm(time_t totalsecs, int offset, struct tm *result);

/**
 * timespec_to_ns - Convert timespec to nanoseconds
 * @ts:         pointer to the timespec variable to be converted
 *
 * Returns the scalar nanosecond representation of the timespec
 * parameter.
 */
static inline s64 timespec_to_ns(const struct timespec *ts)
{
        return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
}

/**
 * timeval_to_ns - Convert timeval to nanoseconds
 * @ts:         pointer to the timeval variable to be converted
 *
 * Returns the scalar nanosecond representation of the timeval
 * parameter.
 */
static inline s64 timeval_to_ns(const struct timeval *tv)
{
        return ((s64) tv->tv_sec * NSEC_PER_SEC) +
                tv->tv_usec * NSEC_PER_USEC;
}

/**
 * ns_to_timespec - Convert nanoseconds to timespec
 * @nsec:       the nanoseconds value to be converted
 *
 * Returns the timespec representation of the nsec parameter.
 */
extern struct timespec ns_to_timespec(const s64 nsec);

/**
 * ns_to_timeval - Convert nanoseconds to timeval
 * @nsec:       the nanoseconds value to be converted
 *
 * Returns the timeval representation of the nsec parameter.
 */
extern struct timeval ns_to_timeval(const s64 nsec);

/**
 * timespec_add_ns - Adds nanoseconds to a timespec
 * @a:          pointer to timespec to be incremented
 * @ns:         unsigned nanoseconds value to be added
 *
 * This must always be inlined because its used from the x86-64 vdso,
 * which cannot call other kernel functions.
 */
static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
{
        a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
        a->tv_nsec = ns;
}
#endif /* __KERNEL__ */

#define NFDBITS                 __NFDBITS

#define FD_SETSIZE              __FD_SETSIZE
#define FD_SET(fd,fdsetp)       __FD_SET(fd,fdsetp)
#define FD_CLR(fd,fdsetp)       __FD_CLR(fd,fdsetp)
#define FD_ISSET(fd,fdsetp)     __FD_ISSET(fd,fdsetp)
#define FD_ZERO(fdsetp)         __FD_ZERO(fdsetp)

/*
 * Names of the interval timers, and structure
 * defining a timer setting:
 */
#define ITIMER_REAL             0
#define ITIMER_VIRTUAL          1
#define ITIMER_PROF             2

struct itimerspec {
        struct timespec it_interval;    /* timer period */
        struct timespec it_value;       /* timer expiration */
};

struct itimerval {
        struct timeval it_interval;     /* timer interval */
        struct timeval it_value;        /* current value */
};

/*
 * The IDs of the various system clocks (for POSIX.1b interval timers):
 */
#define CLOCK_REALTIME                  0
#define CLOCK_MONOTONIC                 1
#define CLOCK_PROCESS_CPUTIME_ID        2
#define CLOCK_THREAD_CPUTIME_ID         3
#define CLOCK_MONOTONIC_RAW             4
#define CLOCK_REALTIME_COARSE           5
#define CLOCK_MONOTONIC_COARSE          6

/*
 * The IDs of various hardware clocks:
 */
#define CLOCK_SGI_CYCLE                 10
#define MAX_CLOCKS                      16
#define CLOCKS_MASK                     (CLOCK_REALTIME | CLOCK_MONOTONIC)
#define CLOCKS_MONO                     CLOCK_MONOTONIC

/*
 * The various flags for setting POSIX.1b interval timers:
 */
#define TIMER_ABSTIME                   0x01

#endif