WebSVN – Kolibri OS – Diff – /drivers/ddk/linux/time.c


/*
 *  linux/kernel/time.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  This file contains the interface functions for the various
 *  time related system calls: time, stime, gettimeofday, settimeofday,
 *			       adjtime
 */
/*
 * Modification history kernel/time.c
 *
 * 1993-09-02    Philip Gladstone
 *      Created file with time related functions from sched/core.c and adjtimex()
 * 1993-10-08    Torsten Duwe
 *      adjtime interface update and CMOS clock write code
 * 1995-08-13    Torsten Duwe
 *      kernel PLL updated to 1994-12-13 specs (rfc-1589)
 * 1999-01-16    Ulrich Windl
 *	Introduced error checking for many cases in adjtimex().
 *	Updated NTP code according to technical memorandum Jan '96
 *	"A Kernel Model for Precision Timekeeping" by Dave Mills
 *	Allow time_constant larger than MAXTC(6) for NTP v4 (MAXTC == 10)
 *	(Even though the technical memorandum forbids it)
 * 2004-07-14	 Christoph Lameter
 *	Added getnstimeofday to allow the posix timer functions to return
 *	with nanosecond accuracy
 */
 
#include 
#include 
#include 
 
 
 
#define HZ_TO_MSEC_MUL32 0xA0000000
#define HZ_TO_MSEC_ADJ32 0x0
#define HZ_TO_MSEC_SHR32 28
#define HZ_TO_MSEC_MUL64 0xA000000000000000
#define HZ_TO_MSEC_ADJ64 0x0
#define HZ_TO_MSEC_SHR64 60
#define MSEC_TO_HZ_MUL32 0xCCCCCCCD
#define MSEC_TO_HZ_ADJ32 0x733333333
#define MSEC_TO_HZ_SHR32 35
#define MSEC_TO_HZ_MUL64 0xCCCCCCCCCCCCCCCD
#define MSEC_TO_HZ_ADJ64 0x73333333333333333
#define MSEC_TO_HZ_SHR64 67
#define HZ_TO_MSEC_NUM 10
#define HZ_TO_MSEC_DEN 1
#define MSEC_TO_HZ_NUM 1
#define MSEC_TO_HZ_DEN 10
 
#define HZ_TO_USEC_MUL32 0x9C400000
#define HZ_TO_USEC_ADJ32 0x0
#define HZ_TO_USEC_SHR32 18
#define HZ_TO_USEC_MUL64 0x9C40000000000000
#define HZ_TO_USEC_ADJ64 0x0
#define HZ_TO_USEC_SHR64 50
#define USEC_TO_HZ_MUL32 0xD1B71759
#define USEC_TO_HZ_ADJ32 0x1FFF2E48E8A7
#define USEC_TO_HZ_SHR32 45
#define USEC_TO_HZ_MUL64 0xD1B71758E219652C
#define USEC_TO_HZ_ADJ64 0x1FFF2E48E8A71DE69AD4
#define USEC_TO_HZ_SHR64 77
#define HZ_TO_USEC_NUM 10000
#define HZ_TO_USEC_DEN 1
#define USEC_TO_HZ_NUM 1
#define USEC_TO_HZ_DEN 10000
 
 
#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    1000000000000000LL
 
# define USER_HZ        100
/*
 * Convert jiffies to milliseconds and back.
 *
 * Avoid unnecessary multiplications/divisions in the
 * two most common HZ cases:
 */
unsigned int jiffies_to_msecs(const unsigned long j)
{
#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
	return (MSEC_PER_SEC / HZ) * j;
#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC)
	return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC);
#else
# if BITS_PER_LONG == 32
	return (HZ_TO_MSEC_MUL32 * j) >> HZ_TO_MSEC_SHR32;
# else
	return (j * HZ_TO_MSEC_NUM) / HZ_TO_MSEC_DEN;
# endif
#endif
}
EXPORT_SYMBOL(jiffies_to_msecs);
 
unsigned int jiffies_to_usecs(const unsigned long j)
{
#if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ)
        return (USEC_PER_SEC / HZ) * j;
#elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC)
        return (j + (HZ / USEC_PER_SEC) - 1)/(HZ / USEC_PER_SEC);
#else
# if BITS_PER_LONG == 32
	return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32;
# else
	return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN;
# endif
#endif
}
EXPORT_SYMBOL(jiffies_to_usecs);
 
/**
 * timespec_trunc - Truncate timespec to a granularity
 * @t: Timespec
 * @gran: Granularity in ns.
 *
 * Truncate a timespec to a granularity. Always rounds down. gran must
 * not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns).
 */
struct timespec timespec_trunc(struct timespec t, unsigned gran)
{
	/* Avoid division in the common cases 1 ns and 1 s. */
	if (gran == 1) {
		/* nothing */
	} else if (gran == NSEC_PER_SEC) {
		t.tv_nsec = 0;
	} else if (gran > 1 && gran < NSEC_PER_SEC) {
		t.tv_nsec -= t.tv_nsec % gran;
	} else {
		WARN(1, "illegal file time granularity: %u", gran);
	}
	return t;
}
EXPORT_SYMBOL(timespec_trunc);
 
/*
 * mktime64 - Converts date to seconds.
 * Converts Gregorian date to seconds since 1970-01-01 00:00:00.
 * Assumes input in normal date format, i.e. 1980-12-31 23:59:59
 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
 *
 * [For the Julian calendar (which was used in Russia before 1917,
 * Britain & colonies before 1752, anywhere else before 1582,
 * and is still in use by some communities) leave out the
 * -year/100+year/400 terms, and add 10.]
 *
 * This algorithm was first published by Gauss (I think).
 */
time64_t mktime64(const unsigned int year0, const unsigned int mon0,
		const unsigned int day, const unsigned int hour,
		const unsigned int min, const unsigned int sec)
{
	unsigned int mon = mon0, year = year0;
 
	/* 1..12 -> 11,12,1..10 */
	if (0 >= (int) (mon -= 2)) {
		mon += 12;	/* Puts Feb last since it has leap day */
		year -= 1;
	}
 
	return ((((time64_t)
		  (year/4 - year/100 + year/400 + 367*mon/12 + day) +
		  year*365 - 719499
	    )*24 + hour /* now have hours */
	  )*60 + min /* now have minutes */
	)*60 + sec; /* finally seconds */
}
EXPORT_SYMBOL(mktime64);
 
/**
 * set_normalized_timespec - set timespec sec and nsec parts and normalize
 *
 * @ts:		pointer to timespec variable to be set
 * @sec:	seconds to set
 * @nsec:	nanoseconds to set
 *
 * Set seconds and nanoseconds field of a timespec variable and
 * normalize to the timespec storage format
 *
 * Note: The tv_nsec part is always in the range of
 *	0 <= tv_nsec < NSEC_PER_SEC
 * For negative values only the tv_sec field is negative !
 */
void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec)
{
	while (nsec >= NSEC_PER_SEC) {
		/*
		 * The following asm() prevents the compiler from
		 * optimising this loop into a modulo operation. See
		 * also __iter_div_u64_rem() in include/linux/time.h
		 */
		asm("" : "+rm"(nsec));
		nsec -= NSEC_PER_SEC;
		++sec;
	}
	while (nsec < 0) {
		asm("" : "+rm"(nsec));
		nsec += NSEC_PER_SEC;
		--sec;
	}
	ts->tv_sec = sec;
	ts->tv_nsec = nsec;
}
EXPORT_SYMBOL(set_normalized_timespec);
 
/**
 * ns_to_timespec - Convert nanoseconds to timespec
 * @nsec:       the nanoseconds value to be converted
 *
 * Returns the timespec representation of the nsec parameter.
 */
struct timespec ns_to_timespec(const s64 nsec)
{
	struct timespec ts;
	s32 rem;
 
	if (!nsec)
		return (struct timespec) {0, 0};
 
	ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem);
	if (unlikely(rem < 0)) {
		ts.tv_sec--;
		rem += NSEC_PER_SEC;
	}
	ts.tv_nsec = rem;
 
	return ts;
}
EXPORT_SYMBOL(ns_to_timespec);
 
/**
 * ns_to_timeval - Convert nanoseconds to timeval
 * @nsec:       the nanoseconds value to be converted
 *
 * Returns the timeval representation of the nsec parameter.
 */
struct timeval ns_to_timeval(const s64 nsec)
{
	struct timespec ts = ns_to_timespec(nsec);
	struct timeval tv;
 
	tv.tv_sec = ts.tv_sec;
	tv.tv_usec = (suseconds_t) ts.tv_nsec / 1000;
 
	return tv;
}
EXPORT_SYMBOL(ns_to_timeval);
 
#if BITS_PER_LONG == 32
/**
 * set_normalized_timespec - set timespec sec and nsec parts and normalize
 *
 * @ts:		pointer to timespec variable to be set
 * @sec:	seconds to set
 * @nsec:	nanoseconds to set
 *
 * Set seconds and nanoseconds field of a timespec variable and
 * normalize to the timespec storage format
 *
 * Note: The tv_nsec part is always in the range of
 *	0 <= tv_nsec < NSEC_PER_SEC
 * For negative values only the tv_sec field is negative !
 */
void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec)
{
	while (nsec >= NSEC_PER_SEC) {
		/*
		 * The following asm() prevents the compiler from
		 * optimising this loop into a modulo operation. See
		 * also __iter_div_u64_rem() in include/linux/time.h
		 */
		asm("" : "+rm"(nsec));
		nsec -= NSEC_PER_SEC;
		++sec;
	}
	while (nsec < 0) {
		asm("" : "+rm"(nsec));
		nsec += NSEC_PER_SEC;
		--sec;
	}
	ts->tv_sec = sec;
	ts->tv_nsec = nsec;
}
EXPORT_SYMBOL(set_normalized_timespec64);
 
/**
 * ns_to_timespec64 - Convert nanoseconds to timespec64
 * @nsec:       the nanoseconds value to be converted
 *
 * Returns the timespec64 representation of the nsec parameter.
 */
struct timespec64 ns_to_timespec64(const s64 nsec)
{
	struct timespec64 ts;
	s32 rem;
 
	if (!nsec)
		return (struct timespec64) {0, 0};
 
	ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem);
	if (unlikely(rem < 0)) {
		ts.tv_sec--;
		rem += NSEC_PER_SEC;
	}
	ts.tv_nsec = rem;
 
	return ts;
}
EXPORT_SYMBOL(ns_to_timespec64);
#endif
/**
 * msecs_to_jiffies: - convert milliseconds to jiffies
 * @m:	time in milliseconds
 *
 * conversion is done as follows:
 *
 * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET)
 *
 * - 'too large' values [that would result in larger than
 *   MAX_JIFFY_OFFSET values] mean 'infinite timeout' too.
 *
 * - all other values are converted to jiffies by either multiplying
 *   the input value by a factor or dividing it with a factor and
 *   handling any 32-bit overflows.
 *   for the details see __msecs_to_jiffies()
 *
 * msecs_to_jiffies() checks for the passed in value being a constant
 * via __builtin_constant_p() allowing gcc to eliminate most of the
 * code, __msecs_to_jiffies() is called if the value passed does not
 * allow constant folding and the actual conversion must be done at
 * runtime.
 * the _msecs_to_jiffies helpers are the HZ dependent conversion
 * routines found in include/linux/jiffies.h
 */
unsigned long __msecs_to_jiffies(const unsigned int m)
{
	/*
	 * Negative value, means infinite timeout:
	 */
	if ((int)m < 0)
		return MAX_JIFFY_OFFSET;
	return _msecs_to_jiffies(m);
}
EXPORT_SYMBOL(__msecs_to_jiffies);
 
unsigned long __usecs_to_jiffies(const unsigned int u)
{
	if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET))
		return MAX_JIFFY_OFFSET;
	return _usecs_to_jiffies(u);
}
EXPORT_SYMBOL(__usecs_to_jiffies);
 
/*
 * The TICK_NSEC - 1 rounds up the value to the next resolution.  Note
 * that a remainder subtract here would not do the right thing as the
 * resolution values don't fall on second boundries.  I.e. the line:
 * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding.
 * Note that due to the small error in the multiplier here, this
 * rounding is incorrect for sufficiently large values of tv_nsec, but
 * well formed timespecs should have tv_nsec < NSEC_PER_SEC, so we're
 * OK.
 *
 * Rather, we just shift the bits off the right.
 *
 * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec
 * value to a scaled second value.
 */
static unsigned long
__timespec64_to_jiffies(u64 sec, long nsec)
{
	nsec = nsec + TICK_NSEC - 1;
 
	if (sec >= MAX_SEC_IN_JIFFIES){
		sec = MAX_SEC_IN_JIFFIES;
		nsec = 0;
	}
	return ((sec * SEC_CONVERSION) +
		(((u64)nsec * NSEC_CONVERSION) >>
		 (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC;
 
}
 
static unsigned long
__timespec_to_jiffies(unsigned long sec, long nsec)
{
	return __timespec64_to_jiffies((u64)sec, nsec);
}
 
unsigned long
timespec64_to_jiffies(const struct timespec64 *value)
{
	return __timespec64_to_jiffies(value->tv_sec, value->tv_nsec);
}
EXPORT_SYMBOL(timespec64_to_jiffies);
 
void
jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value)
{
	/*
	 * Convert jiffies to nanoseconds and separate with
	 * one divide.
	 */
	u32 rem;
	value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC,
				    NSEC_PER_SEC, &rem);
	value->tv_nsec = rem;
}
EXPORT_SYMBOL(jiffies_to_timespec64);
 
/*
 * We could use a similar algorithm to timespec_to_jiffies (with a
 * different multiplier for usec instead of nsec). But this has a
 * problem with rounding: we can't exactly add TICK_NSEC - 1 to the
 * usec value, since it's not necessarily integral.
 *
 * We could instead round in the intermediate scaled representation
 * (i.e. in units of 1/2^(large scale) jiffies) but that's also
 * perilous: the scaling introduces a small positive error, which
 * combined with a division-rounding-upward (i.e. adding 2^(scale) - 1
 * units to the intermediate before shifting) leads to accidental
 * overflow and overestimates.
 *
 * At the cost of one additional multiplication by a constant, just
 * use the timespec implementation.
 */
unsigned long
timeval_to_jiffies(const struct timeval *value)
{
	return __timespec_to_jiffies(value->tv_sec,
				     value->tv_usec * NSEC_PER_USEC);
}
EXPORT_SYMBOL(timeval_to_jiffies);
 
void jiffies_to_timeval(const unsigned long jiffies, struct timeval *value)
{
	/*
	 * Convert jiffies to nanoseconds and separate with
	 * one divide.
	 */
	u32 rem;
 
	value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC,
				    NSEC_PER_SEC, &rem);
	value->tv_usec = rem / NSEC_PER_USEC;
}
EXPORT_SYMBOL(jiffies_to_timeval);
 
/*
 * Convert jiffies/jiffies_64 to clock_t and back.
 */
clock_t jiffies_to_clock_t(unsigned long x)
{
#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
# if HZ < USER_HZ
	return x * (USER_HZ / HZ);
# else
	return x / (HZ / USER_HZ);
# endif
#else
	return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ);
#endif
}
EXPORT_SYMBOL(jiffies_to_clock_t);
 
unsigned long clock_t_to_jiffies(unsigned long x)
{
#if (HZ % USER_HZ)==0
	if (x >= ~0UL / (HZ / USER_HZ))
		return ~0UL;
	return x * (HZ / USER_HZ);
#else
	/* Don't worry about loss of precision here .. */
	if (x >= ~0UL / HZ * USER_HZ)
		return ~0UL;
 
	/* .. but do try to contain it here */
	return div_u64((u64)x * HZ, USER_HZ);
#endif
}
EXPORT_SYMBOL(clock_t_to_jiffies);
 
u64 jiffies_64_to_clock_t(u64 x)
{
#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
# if HZ < USER_HZ
	x = div_u64(x * USER_HZ, HZ);
# elif HZ > USER_HZ
	x = div_u64(x, HZ / USER_HZ);
# else
	/* Nothing to do */
# endif
#else
	/*
	 * There are better ways that don't overflow early,
	 * but even this doesn't overflow in hundreds of years
	 * in 64 bits, so..
	 */
	x = div_u64(x * TICK_NSEC, (NSEC_PER_SEC / USER_HZ));
#endif
	return x;
}
EXPORT_SYMBOL(jiffies_64_to_clock_t);
 
u64 nsec_to_clock_t(u64 x)
{
#if (NSEC_PER_SEC % USER_HZ) == 0
	return div_u64(x, NSEC_PER_SEC / USER_HZ);
#elif (USER_HZ % 512) == 0
	return div_u64(x * USER_HZ / 512, NSEC_PER_SEC / 512);
#else
	/*
         * max relative error 5.7e-8 (1.8s per year) for USER_HZ <= 1024,
         * overflow after 64.99 years.
         * exact for HZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ...
         */
	return div_u64(x * 9, (9ull * NSEC_PER_SEC + (USER_HZ / 2)) / USER_HZ);
#endif
}
 
/**
 * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64
 *
 * @n:	nsecs in u64
 *
 * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64.
 * And this doesn't return MAX_JIFFY_OFFSET since this function is designed
 * for scheduler, not for use in device drivers to calculate timeout value.
 *
 * note:
 *   NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512)
 *   ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years
 */
u64 nsecs_to_jiffies64(u64 n)
{
#if (NSEC_PER_SEC % HZ) == 0
	/* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */
	return div_u64(n, NSEC_PER_SEC / HZ);
#elif (HZ % 512) == 0
	/* overflow after 292 years if HZ = 1024 */
	return div_u64(n * HZ / 512, NSEC_PER_SEC / 512);
#else
	/*
	 * Generic case - optimized for cases where HZ is a multiple of 3.
	 * overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc.
	 */
	return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ);
#endif
}
EXPORT_SYMBOL(nsecs_to_jiffies64);
 
/**
 * nsecs_to_jiffies - Convert nsecs in u64 to jiffies
 *
 * @n:	nsecs in u64
 *
 * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64.
 * And this doesn't return MAX_JIFFY_OFFSET since this function is designed
 * for scheduler, not for use in device drivers to calculate timeout value.
 *
 * note:
 *   NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512)
 *   ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years
 */
unsigned long nsecs_to_jiffies(u64 n)
{
	return (unsigned long)nsecs_to_jiffies64(n);
}
EXPORT_SYMBOL_GPL(nsecs_to_jiffies);
 
/*
 * Add two timespec values and do a safety check for overflow.
 * It's assumed that both values are valid (>= 0)
 */
struct timespec timespec_add_safe(const struct timespec lhs,
				  const struct timespec rhs)
{
	struct timespec res;
 
	set_normalized_timespec(&res, lhs.tv_sec + rhs.tv_sec,
				lhs.tv_nsec + rhs.tv_nsec);
 
	if (res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)
		res.tv_sec = TIME_T_MAX;
 
	return res;
}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Rev 6082	Rev 6934
1	/*	1	/*
2	* linux/kernel/time.c	2	* linux/kernel/time.c
3	*	3	*
4	* Copyright (C) 1991, 1992 Linus Torvalds	4	* Copyright (C) 1991, 1992 Linus Torvalds
5	*	5	*
6	* This file contains the interface functions for the various	6	* This file contains the interface functions for the various
7	* time related system calls: time, stime, gettimeofday, settimeofday,	7	* time related system calls: time, stime, gettimeofday, settimeofday,
8	* adjtime	8	* adjtime
9	*/	9	*/
10	/*	10	/*
11	* Modification history kernel/time.c	11	* Modification history kernel/time.c
12	*	12	*
13	* 1993-09-02 Philip Gladstone	13	* 1993-09-02 Philip Gladstone
14	* Created file with time related functions from sched/core.c and adjtimex()	14	* Created file with time related functions from sched/core.c and adjtimex()
15	* 1993-10-08 Torsten Duwe	15	* 1993-10-08 Torsten Duwe
16	* adjtime interface update and CMOS clock write code	16	* adjtime interface update and CMOS clock write code
17	* 1995-08-13 Torsten Duwe	17	* 1995-08-13 Torsten Duwe
18	* kernel PLL updated to 1994-12-13 specs (rfc-1589)	18	* kernel PLL updated to 1994-12-13 specs (rfc-1589)
19	* 1999-01-16 Ulrich Windl	19	* 1999-01-16 Ulrich Windl
20	* Introduced error checking for many cases in adjtimex().	20	* Introduced error checking for many cases in adjtimex().
21	* Updated NTP code according to technical memorandum Jan '96	21	* Updated NTP code according to technical memorandum Jan '96
22	* "A Kernel Model for Precision Timekeeping" by Dave Mills	22	* "A Kernel Model for Precision Timekeeping" by Dave Mills
23	* Allow time_constant larger than MAXTC(6) for NTP v4 (MAXTC == 10)	23	* Allow time_constant larger than MAXTC(6) for NTP v4 (MAXTC == 10)
24	* (Even though the technical memorandum forbids it)	24	* (Even though the technical memorandum forbids it)
25	* 2004-07-14 Christoph Lameter	25	* 2004-07-14 Christoph Lameter
26	* Added getnstimeofday to allow the posix timer functions to return	26	* Added getnstimeofday to allow the posix timer functions to return
27	* with nanosecond accuracy	27	* with nanosecond accuracy
28	*/	28	*/
29		29
30	#include	30	#include
31	#include	31	#include
32	#include	32	#include
33		33
34		34
35		35
36	#define HZ_TO_MSEC_MUL32 0xA0000000	36	#define HZ_TO_MSEC_MUL32 0xA0000000
37	#define HZ_TO_MSEC_ADJ32 0x0	37	#define HZ_TO_MSEC_ADJ32 0x0
38	#define HZ_TO_MSEC_SHR32 28	38	#define HZ_TO_MSEC_SHR32 28
39	#define HZ_TO_MSEC_MUL64 0xA000000000000000	39	#define HZ_TO_MSEC_MUL64 0xA000000000000000
40	#define HZ_TO_MSEC_ADJ64 0x0	40	#define HZ_TO_MSEC_ADJ64 0x0
41	#define HZ_TO_MSEC_SHR64 60	41	#define HZ_TO_MSEC_SHR64 60
42	#define MSEC_TO_HZ_MUL32 0xCCCCCCCD	42	#define MSEC_TO_HZ_MUL32 0xCCCCCCCD
43	#define MSEC_TO_HZ_ADJ32 0x733333333	43	#define MSEC_TO_HZ_ADJ32 0x733333333
44	#define MSEC_TO_HZ_SHR32 35	44	#define MSEC_TO_HZ_SHR32 35
45	#define MSEC_TO_HZ_MUL64 0xCCCCCCCCCCCCCCCD	45	#define MSEC_TO_HZ_MUL64 0xCCCCCCCCCCCCCCCD
46	#define MSEC_TO_HZ_ADJ64 0x73333333333333333	46	#define MSEC_TO_HZ_ADJ64 0x73333333333333333
47	#define MSEC_TO_HZ_SHR64 67	47	#define MSEC_TO_HZ_SHR64 67
48	#define HZ_TO_MSEC_NUM 10	48	#define HZ_TO_MSEC_NUM 10
49	#define HZ_TO_MSEC_DEN 1	49	#define HZ_TO_MSEC_DEN 1
50	#define MSEC_TO_HZ_NUM 1	50	#define MSEC_TO_HZ_NUM 1
51	#define MSEC_TO_HZ_DEN 10	51	#define MSEC_TO_HZ_DEN 10
52		52
53	#define HZ_TO_USEC_MUL32 0x9C400000	53	#define HZ_TO_USEC_MUL32 0x9C400000
54	#define HZ_TO_USEC_ADJ32 0x0	54	#define HZ_TO_USEC_ADJ32 0x0
55	#define HZ_TO_USEC_SHR32 18	55	#define HZ_TO_USEC_SHR32 18
56	#define HZ_TO_USEC_MUL64 0x9C40000000000000	56	#define HZ_TO_USEC_MUL64 0x9C40000000000000
57	#define HZ_TO_USEC_ADJ64 0x0	57	#define HZ_TO_USEC_ADJ64 0x0
58	#define HZ_TO_USEC_SHR64 50	58	#define HZ_TO_USEC_SHR64 50
59	#define USEC_TO_HZ_MUL32 0xD1B71759	59	#define USEC_TO_HZ_MUL32 0xD1B71759
60	#define USEC_TO_HZ_ADJ32 0x1FFF2E48E8A7	60	#define USEC_TO_HZ_ADJ32 0x1FFF2E48E8A7
61	#define USEC_TO_HZ_SHR32 45	61	#define USEC_TO_HZ_SHR32 45
62	#define USEC_TO_HZ_MUL64 0xD1B71758E219652C	62	#define USEC_TO_HZ_MUL64 0xD1B71758E219652C
63	#define USEC_TO_HZ_ADJ64 0x1FFF2E48E8A71DE69AD4	63	#define USEC_TO_HZ_ADJ64 0x1FFF2E48E8A71DE69AD4
64	#define USEC_TO_HZ_SHR64 77	64	#define USEC_TO_HZ_SHR64 77
65	#define HZ_TO_USEC_NUM 10000	65	#define HZ_TO_USEC_NUM 10000
66	#define HZ_TO_USEC_DEN 1	66	#define HZ_TO_USEC_DEN 1
67	#define USEC_TO_HZ_NUM 1	67	#define USEC_TO_HZ_NUM 1
68	#define USEC_TO_HZ_DEN 10000	68	#define USEC_TO_HZ_DEN 10000
69		69
70		70
71	#define MSEC_PER_SEC 1000L	71	#define MSEC_PER_SEC 1000L
72	#define USEC_PER_MSEC 1000L	72	#define USEC_PER_MSEC 1000L
73	#define NSEC_PER_USEC 1000L	73	#define NSEC_PER_USEC 1000L
74	#define NSEC_PER_MSEC 1000000L	74	#define NSEC_PER_MSEC 1000000L
75	#define USEC_PER_SEC 1000000L	75	#define USEC_PER_SEC 1000000L
76	#define NSEC_PER_SEC 1000000000L	76	#define NSEC_PER_SEC 1000000000L
77	#define FSEC_PER_SEC 1000000000000000LL	77	#define FSEC_PER_SEC 1000000000000000LL
78		78
79	# define USER_HZ 100	79	# define USER_HZ 100
80	/*	80	/*
81	* Convert jiffies to milliseconds and back.	81	* Convert jiffies to milliseconds and back.
82	*	82	*
83	* Avoid unnecessary multiplications/divisions in the	83	* Avoid unnecessary multiplications/divisions in the
84	* two most common HZ cases:	84	* two most common HZ cases:
85	*/	85	*/
86	unsigned int jiffies_to_msecs(const unsigned long j)	86	unsigned int jiffies_to_msecs(const unsigned long j)
87	{	87	{
88	#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)	88	#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
89	return (MSEC_PER_SEC / HZ) * j;	89	return (MSEC_PER_SEC / HZ) * j;
90	#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC)	90	#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC)
91	return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC);	91	return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC);
92	#else	92	#else
93	# if BITS_PER_LONG == 32	93	# if BITS_PER_LONG == 32
94	return (HZ_TO_MSEC_MUL32 * j) >> HZ_TO_MSEC_SHR32;	94	return (HZ_TO_MSEC_MUL32 * j) >> HZ_TO_MSEC_SHR32;
95	# else	95	# else
96	return (j * HZ_TO_MSEC_NUM) / HZ_TO_MSEC_DEN;	96	return (j * HZ_TO_MSEC_NUM) / HZ_TO_MSEC_DEN;
97	# endif	97	# endif
98	#endif	98	#endif
99	}	99	}
100	EXPORT_SYMBOL(jiffies_to_msecs);	100	EXPORT_SYMBOL(jiffies_to_msecs);
101		101
102	unsigned int jiffies_to_usecs(const unsigned long j)	102	unsigned int jiffies_to_usecs(const unsigned long j)
103	{	103	{
104	#if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ)	104	#if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ)
105	return (USEC_PER_SEC / HZ) * j;	105	return (USEC_PER_SEC / HZ) * j;
106	#elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC)	106	#elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC)
107	return (j + (HZ / USEC_PER_SEC) - 1)/(HZ / USEC_PER_SEC);	107	return (j + (HZ / USEC_PER_SEC) - 1)/(HZ / USEC_PER_SEC);
108	#else	108	#else
109	# if BITS_PER_LONG == 32	109	# if BITS_PER_LONG == 32
110	return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32;	110	return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32;
111	# else	111	# else
112	return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN;	112	return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN;
113	# endif	113	# endif
114	#endif	114	#endif
115	}	115	}
116	EXPORT_SYMBOL(jiffies_to_usecs);	116	EXPORT_SYMBOL(jiffies_to_usecs);
117		117
118	/**	118	/**
119	* timespec_trunc - Truncate timespec to a granularity	119	* timespec_trunc - Truncate timespec to a granularity
120	* @t: Timespec	120	* @t: Timespec
121	* @gran: Granularity in ns.	121	* @gran: Granularity in ns.
122	*	122	*
123	* Truncate a timespec to a granularity. Always rounds down. gran must	123	* Truncate a timespec to a granularity. Always rounds down. gran must
124	* not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns).	124	* not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns).
125	*/	125	*/
126	struct timespec timespec_trunc(struct timespec t, unsigned gran)	126	struct timespec timespec_trunc(struct timespec t, unsigned gran)
127	{	127	{
128	/* Avoid division in the common cases 1 ns and 1 s. */	128	/* Avoid division in the common cases 1 ns and 1 s. */
129	if (gran == 1) {	129	if (gran == 1) {
130	/* nothing */	130	/* nothing */
131	} else if (gran == NSEC_PER_SEC) {	131	} else if (gran == NSEC_PER_SEC) {
132	t.tv_nsec = 0;	132	t.tv_nsec = 0;
133	} else if (gran > 1 && gran < NSEC_PER_SEC) {	133	} else if (gran > 1 && gran < NSEC_PER_SEC) {
134	t.tv_nsec -= t.tv_nsec % gran;	134	t.tv_nsec -= t.tv_nsec % gran;
135	} else {	135	} else {
136	WARN(1, "illegal file time granularity: %u", gran);	136	WARN(1, "illegal file time granularity: %u", gran);
137	}	137	}
138	return t;	138	return t;
139	}	139	}
140	EXPORT_SYMBOL(timespec_trunc);	140	EXPORT_SYMBOL(timespec_trunc);
141		141
142	/*	142	/*
143	* mktime64 - Converts date to seconds.	143	* mktime64 - Converts date to seconds.
144	* Converts Gregorian date to seconds since 1970-01-01 00:00:00.	144	* Converts Gregorian date to seconds since 1970-01-01 00:00:00.
145	* Assumes input in normal date format, i.e. 1980-12-31 23:59:59	145	* Assumes input in normal date format, i.e. 1980-12-31 23:59:59
146	* => year=1980, mon=12, day=31, hour=23, min=59, sec=59.	146	* => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
147	*	147	*
148	* [For the Julian calendar (which was used in Russia before 1917,	148	* [For the Julian calendar (which was used in Russia before 1917,
149	* Britain & colonies before 1752, anywhere else before 1582,	149	* Britain & colonies before 1752, anywhere else before 1582,
150	* and is still in use by some communities) leave out the	150	* and is still in use by some communities) leave out the
151	* -year/100+year/400 terms, and add 10.]	151	* -year/100+year/400 terms, and add 10.]
152	*	152	*
153	* This algorithm was first published by Gauss (I think).	153	* This algorithm was first published by Gauss (I think).
154	*/	154	*/
155	time64_t mktime64(const unsigned int year0, const unsigned int mon0,	155	time64_t mktime64(const unsigned int year0, const unsigned int mon0,
156	const unsigned int day, const unsigned int hour,	156	const unsigned int day, const unsigned int hour,
157	const unsigned int min, const unsigned int sec)	157	const unsigned int min, const unsigned int sec)
158	{	158	{
159	unsigned int mon = mon0, year = year0;	159	unsigned int mon = mon0, year = year0;
160		160
161	/* 1..12 -> 11,12,1..10 */	161	/* 1..12 -> 11,12,1..10 */
162	if (0 >= (int) (mon -= 2)) {	162	if (0 >= (int) (mon -= 2)) {
163	mon += 12; /* Puts Feb last since it has leap day */	163	mon += 12; /* Puts Feb last since it has leap day */
164	year -= 1;	164	year -= 1;
165	}	165	}
166		166
167	return ((((time64_t)	167	return ((((time64_t)
168	(year/4 - year/100 + year/400 + 367*mon/12 + day) +	168	(year/4 - year/100 + year/400 + 367*mon/12 + day) +
169	year*365 - 719499	169	year*365 - 719499
170	)24 + hour / now have hours */	170	)24 + hour / now have hours */
171	)60 + min / now have minutes */	171	)60 + min / now have minutes */
172	)60 + sec; / finally seconds */	172	)60 + sec; / finally seconds */
173	}	173	}
174	EXPORT_SYMBOL(mktime64);	174	EXPORT_SYMBOL(mktime64);
175		175
176	/**	176	/**
177	* set_normalized_timespec - set timespec sec and nsec parts and normalize	177	* set_normalized_timespec - set timespec sec and nsec parts and normalize
178	*	178	*
179	* @ts: pointer to timespec variable to be set	179	* @ts: pointer to timespec variable to be set
180	* @sec: seconds to set	180	* @sec: seconds to set
181	* @nsec: nanoseconds to set	181	* @nsec: nanoseconds to set
182	*	182	*
183	* Set seconds and nanoseconds field of a timespec variable and	183	* Set seconds and nanoseconds field of a timespec variable and
184	* normalize to the timespec storage format	184	* normalize to the timespec storage format
185	*	185	*
186	* Note: The tv_nsec part is always in the range of	186	* Note: The tv_nsec part is always in the range of
187	* 0 <= tv_nsec < NSEC_PER_SEC	187	* 0 <= tv_nsec < NSEC_PER_SEC
188	* For negative values only the tv_sec field is negative !	188	* For negative values only the tv_sec field is negative !
189	*/	189	*/
190	void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec)	190	void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec)
191	{	191	{
192	while (nsec >= NSEC_PER_SEC) {	192	while (nsec >= NSEC_PER_SEC) {
193	/*	193	/*
194	* The following asm() prevents the compiler from	194	* The following asm() prevents the compiler from
195	* optimising this loop into a modulo operation. See	195	* optimising this loop into a modulo operation. See
196	* also __iter_div_u64_rem() in include/linux/time.h	196	* also __iter_div_u64_rem() in include/linux/time.h
197	*/	197	*/
198	asm("" : "+rm"(nsec));	198	asm("" : "+rm"(nsec));
199	nsec -= NSEC_PER_SEC;	199	nsec -= NSEC_PER_SEC;
200	++sec;	200	++sec;
201	}	201	}
202	while (nsec < 0) {	202	while (nsec < 0) {
203	asm("" : "+rm"(nsec));	203	asm("" : "+rm"(nsec));
204	nsec += NSEC_PER_SEC;	204	nsec += NSEC_PER_SEC;
205	--sec;	205	--sec;
206	}	206	}
207	ts->tv_sec = sec;	207	ts->tv_sec = sec;
208	ts->tv_nsec = nsec;	208	ts->tv_nsec = nsec;
209	}	209	}
210	EXPORT_SYMBOL(set_normalized_timespec);	210	EXPORT_SYMBOL(set_normalized_timespec);
211		211
212	/**	212	/**
213	* ns_to_timespec - Convert nanoseconds to timespec	213	* ns_to_timespec - Convert nanoseconds to timespec
214	* @nsec: the nanoseconds value to be converted	214	* @nsec: the nanoseconds value to be converted
215	*	215	*
216	* Returns the timespec representation of the nsec parameter.	216	* Returns the timespec representation of the nsec parameter.
217	*/	217	*/
218	struct timespec ns_to_timespec(const s64 nsec)	218	struct timespec ns_to_timespec(const s64 nsec)
219	{	219	{
220	struct timespec ts;	220	struct timespec ts;
221	s32 rem;	221	s32 rem;
222		222
223	if (!nsec)	223	if (!nsec)
224	return (struct timespec) {0, 0};	224	return (struct timespec) {0, 0};
225		225
226	ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem);	226	ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem);
227	if (unlikely(rem < 0)) {	227	if (unlikely(rem < 0)) {
228	ts.tv_sec--;	228	ts.tv_sec--;
229	rem += NSEC_PER_SEC;	229	rem += NSEC_PER_SEC;
230	}	230	}
231	ts.tv_nsec = rem;	231	ts.tv_nsec = rem;
232		232
233	return ts;	233	return ts;
234	}	234	}
235	EXPORT_SYMBOL(ns_to_timespec);	235	EXPORT_SYMBOL(ns_to_timespec);
236		236
237	/**	237	/**
238	* ns_to_timeval - Convert nanoseconds to timeval	238	* ns_to_timeval - Convert nanoseconds to timeval
239	* @nsec: the nanoseconds value to be converted	239	* @nsec: the nanoseconds value to be converted
240	*	240	*
241	* Returns the timeval representation of the nsec parameter.	241	* Returns the timeval representation of the nsec parameter.
242	*/	242	*/
243	struct timeval ns_to_timeval(const s64 nsec)	243	struct timeval ns_to_timeval(const s64 nsec)
244	{	244	{
245	struct timespec ts = ns_to_timespec(nsec);	245	struct timespec ts = ns_to_timespec(nsec);
246	struct timeval tv;	246	struct timeval tv;
247		247
248	tv.tv_sec = ts.tv_sec;	248	tv.tv_sec = ts.tv_sec;
249	tv.tv_usec = (suseconds_t) ts.tv_nsec / 1000;	249	tv.tv_usec = (suseconds_t) ts.tv_nsec / 1000;
250		250
251	return tv;	251	return tv;
252	}	252	}
253	EXPORT_SYMBOL(ns_to_timeval);	253	EXPORT_SYMBOL(ns_to_timeval);
254		254
255	#if BITS_PER_LONG == 32	255	#if BITS_PER_LONG == 32
256	/**	256	/**
257	* set_normalized_timespec - set timespec sec and nsec parts and normalize	257	* set_normalized_timespec - set timespec sec and nsec parts and normalize
258	*	258	*
259	* @ts: pointer to timespec variable to be set	259	* @ts: pointer to timespec variable to be set
260	* @sec: seconds to set	260	* @sec: seconds to set
261	* @nsec: nanoseconds to set	261	* @nsec: nanoseconds to set
262	*	262	*
263	* Set seconds and nanoseconds field of a timespec variable and	263	* Set seconds and nanoseconds field of a timespec variable and
264	* normalize to the timespec storage format	264	* normalize to the timespec storage format
265	*	265	*
266	* Note: The tv_nsec part is always in the range of	266	* Note: The tv_nsec part is always in the range of
267	* 0 <= tv_nsec < NSEC_PER_SEC	267	* 0 <= tv_nsec < NSEC_PER_SEC
268	* For negative values only the tv_sec field is negative !	268	* For negative values only the tv_sec field is negative !
269	*/	269	*/
270	void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec)	270	void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec)
271	{	271	{
272	while (nsec >= NSEC_PER_SEC) {	272	while (nsec >= NSEC_PER_SEC) {
273	/*	273	/*
274	* The following asm() prevents the compiler from	274	* The following asm() prevents the compiler from
275	* optimising this loop into a modulo operation. See	275	* optimising this loop into a modulo operation. See
276	* also __iter_div_u64_rem() in include/linux/time.h	276	* also __iter_div_u64_rem() in include/linux/time.h
277	*/	277	*/
278	asm("" : "+rm"(nsec));	278	asm("" : "+rm"(nsec));
279	nsec -= NSEC_PER_SEC;	279	nsec -= NSEC_PER_SEC;
280	++sec;	280	++sec;
281	}	281	}
282	while (nsec < 0) {	282	while (nsec < 0) {
283	asm("" : "+rm"(nsec));	283	asm("" : "+rm"(nsec));
284	nsec += NSEC_PER_SEC;	284	nsec += NSEC_PER_SEC;
285	--sec;	285	--sec;
286	}	286	}
287	ts->tv_sec = sec;	287	ts->tv_sec = sec;
288	ts->tv_nsec = nsec;	288	ts->tv_nsec = nsec;
289	}	289	}
290	EXPORT_SYMBOL(set_normalized_timespec64);	290	EXPORT_SYMBOL(set_normalized_timespec64);
291		291
292	/**	292	/**
293	* ns_to_timespec64 - Convert nanoseconds to timespec64	293	* ns_to_timespec64 - Convert nanoseconds to timespec64
294	* @nsec: the nanoseconds value to be converted	294	* @nsec: the nanoseconds value to be converted
295	*	295	*
296	* Returns the timespec64 representation of the nsec parameter.	296	* Returns the timespec64 representation of the nsec parameter.
297	*/	297	*/
298	struct timespec64 ns_to_timespec64(const s64 nsec)	298	struct timespec64 ns_to_timespec64(const s64 nsec)
299	{	299	{
300	struct timespec64 ts;	300	struct timespec64 ts;
301	s32 rem;	301	s32 rem;
302		302
303	if (!nsec)	303	if (!nsec)
304	return (struct timespec64) {0, 0};	304	return (struct timespec64) {0, 0};
305		305
306	ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem);	306	ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem);
307	if (unlikely(rem < 0)) {	307	if (unlikely(rem < 0)) {
308	ts.tv_sec--;	308	ts.tv_sec--;
309	rem += NSEC_PER_SEC;	309	rem += NSEC_PER_SEC;
310	}	310	}
311	ts.tv_nsec = rem;	311	ts.tv_nsec = rem;
312		312
313	return ts;	313	return ts;
314	}	314	}
315	EXPORT_SYMBOL(ns_to_timespec64);	315	EXPORT_SYMBOL(ns_to_timespec64);
316	#endif	316	#endif
317	/**	317	/**
318	* msecs_to_jiffies: - convert milliseconds to jiffies	318	* msecs_to_jiffies: - convert milliseconds to jiffies
319	* @m: time in milliseconds	319	* @m: time in milliseconds
320	*	320	*
321	* conversion is done as follows:	321	* conversion is done as follows:
322	*	322	*
323	* - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET)	323	* - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET)
324	*	324	*
325	* - 'too large' values [that would result in larger than	325	* - 'too large' values [that would result in larger than
326	* MAX_JIFFY_OFFSET values] mean 'infinite timeout' too.	326	* MAX_JIFFY_OFFSET values] mean 'infinite timeout' too.
327	*	327	*
328	* - all other values are converted to jiffies by either multiplying	328	* - all other values are converted to jiffies by either multiplying
329	* the input value by a factor or dividing it with a factor and	329	* the input value by a factor or dividing it with a factor and
330	* handling any 32-bit overflows.	330	* handling any 32-bit overflows.
331	* for the details see __msecs_to_jiffies()	331	* for the details see __msecs_to_jiffies()
332	*	332	*
333	* msecs_to_jiffies() checks for the passed in value being a constant	333	* msecs_to_jiffies() checks for the passed in value being a constant
334	* via __builtin_constant_p() allowing gcc to eliminate most of the	334	* via __builtin_constant_p() allowing gcc to eliminate most of the
335	* code, __msecs_to_jiffies() is called if the value passed does not	335	* code, __msecs_to_jiffies() is called if the value passed does not
336	* allow constant folding and the actual conversion must be done at	336	* allow constant folding and the actual conversion must be done at
337	* runtime.	337	* runtime.
338	* the _msecs_to_jiffies helpers are the HZ dependent conversion	338	* the _msecs_to_jiffies helpers are the HZ dependent conversion
339	* routines found in include/linux/jiffies.h	339	* routines found in include/linux/jiffies.h
340	*/	340	*/
341	unsigned long __msecs_to_jiffies(const unsigned int m)	341	unsigned long __msecs_to_jiffies(const unsigned int m)
342	{	342	{
343	/*	343	/*
344	* Negative value, means infinite timeout:	344	* Negative value, means infinite timeout:
345	*/	345	*/
346	if ((int)m < 0)	346	if ((int)m < 0)
347	return MAX_JIFFY_OFFSET;	347	return MAX_JIFFY_OFFSET;
348	return _msecs_to_jiffies(m);	348	return _msecs_to_jiffies(m);
349	}	349	}
350	EXPORT_SYMBOL(__msecs_to_jiffies);	350	EXPORT_SYMBOL(__msecs_to_jiffies);
351		351
352	unsigned long __usecs_to_jiffies(const unsigned int u)	352	unsigned long __usecs_to_jiffies(const unsigned int u)
353	{	353	{
354	if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET))	354	if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET))
355	return MAX_JIFFY_OFFSET;	355	return MAX_JIFFY_OFFSET;
356	return _usecs_to_jiffies(u);	356	return _usecs_to_jiffies(u);
357	}	357	}
358	EXPORT_SYMBOL(__usecs_to_jiffies);	358	EXPORT_SYMBOL(__usecs_to_jiffies);
359		359
360	/*	360	/*
361	* The TICK_NSEC - 1 rounds up the value to the next resolution. Note	361	* The TICK_NSEC - 1 rounds up the value to the next resolution. Note
362	* that a remainder subtract here would not do the right thing as the	362	* that a remainder subtract here would not do the right thing as the
363	* resolution values don't fall on second boundries. I.e. the line:	363	* resolution values don't fall on second boundries. I.e. the line:
364	* nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding.	364	* nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding.
365	* Note that due to the small error in the multiplier here, this	365	* Note that due to the small error in the multiplier here, this
366	* rounding is incorrect for sufficiently large values of tv_nsec, but	366	* rounding is incorrect for sufficiently large values of tv_nsec, but
367	* well formed timespecs should have tv_nsec < NSEC_PER_SEC, so we're	367	* well formed timespecs should have tv_nsec < NSEC_PER_SEC, so we're
368	* OK.	368	* OK.
369	*	369	*
370	* Rather, we just shift the bits off the right.	370	* Rather, we just shift the bits off the right.
371	*	371	*
372	* The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec	372	* The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec
373	* value to a scaled second value.	373	* value to a scaled second value.
374	*/	374	*/
375	static unsigned long	375	static unsigned long
376	__timespec64_to_jiffies(u64 sec, long nsec)	376	__timespec64_to_jiffies(u64 sec, long nsec)
377	{	377	{
378	nsec = nsec + TICK_NSEC - 1;	378	nsec = nsec + TICK_NSEC - 1;
379		379
380	if (sec >= MAX_SEC_IN_JIFFIES){	380	if (sec >= MAX_SEC_IN_JIFFIES){
381	sec = MAX_SEC_IN_JIFFIES;	381	sec = MAX_SEC_IN_JIFFIES;
382	nsec = 0;	382	nsec = 0;
383	}	383	}
384	return ((sec * SEC_CONVERSION) +	384	return ((sec * SEC_CONVERSION) +
385	(((u64)nsec * NSEC_CONVERSION) >>	385	(((u64)nsec * NSEC_CONVERSION) >>
386	(NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC;	386	(NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC;
387		387
388	}	388	}
389		389
390	static unsigned long	390	static unsigned long
391	__timespec_to_jiffies(unsigned long sec, long nsec)	391	__timespec_to_jiffies(unsigned long sec, long nsec)
392	{	392	{
393	return __timespec64_to_jiffies((u64)sec, nsec);	393	return __timespec64_to_jiffies((u64)sec, nsec);
394	}	394	}
395		395
396	unsigned long	396	unsigned long
397	timespec64_to_jiffies(const struct timespec64 *value)	397	timespec64_to_jiffies(const struct timespec64 *value)
398	{	398	{
399	return __timespec64_to_jiffies(value->tv_sec, value->tv_nsec);	399	return __timespec64_to_jiffies(value->tv_sec, value->tv_nsec);
400	}	400	}
401	EXPORT_SYMBOL(timespec64_to_jiffies);	401	EXPORT_SYMBOL(timespec64_to_jiffies);
402		402
403	void	403	void
404	jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value)	404	jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value)
405	{	405	{
406	/*	406	/*
407	* Convert jiffies to nanoseconds and separate with	407	* Convert jiffies to nanoseconds and separate with
408	* one divide.	408	* one divide.
409	*/	409	*/
410	u32 rem;	410	u32 rem;
411	value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC,	411	value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC,
412	NSEC_PER_SEC, &rem);	412	NSEC_PER_SEC, &rem);
413	value->tv_nsec = rem;	413	value->tv_nsec = rem;
414	}	414	}
415	EXPORT_SYMBOL(jiffies_to_timespec64);	415	EXPORT_SYMBOL(jiffies_to_timespec64);
416		416
417	/*	417	/*
418	* We could use a similar algorithm to timespec_to_jiffies (with a	418	* We could use a similar algorithm to timespec_to_jiffies (with a
419	* different multiplier for usec instead of nsec). But this has a	419	* different multiplier for usec instead of nsec). But this has a
420	* problem with rounding: we can't exactly add TICK_NSEC - 1 to the	420	* problem with rounding: we can't exactly add TICK_NSEC - 1 to the
421	* usec value, since it's not necessarily integral.	421	* usec value, since it's not necessarily integral.
422	*	422	*
423	* We could instead round in the intermediate scaled representation	423	* We could instead round in the intermediate scaled representation
424	* (i.e. in units of 1/2^(large scale) jiffies) but that's also	424	* (i.e. in units of 1/2^(large scale) jiffies) but that's also
425	* perilous: the scaling introduces a small positive error, which	425	* perilous: the scaling introduces a small positive error, which
426	* combined with a division-rounding-upward (i.e. adding 2^(scale) - 1	426	* combined with a division-rounding-upward (i.e. adding 2^(scale) - 1
427	* units to the intermediate before shifting) leads to accidental	427	* units to the intermediate before shifting) leads to accidental
428	* overflow and overestimates.	428	* overflow and overestimates.
429	*	429	*
430	* At the cost of one additional multiplication by a constant, just	430	* At the cost of one additional multiplication by a constant, just
431	* use the timespec implementation.	431	* use the timespec implementation.
432	*/	432	*/
433	unsigned long	433	unsigned long
434	timeval_to_jiffies(const struct timeval *value)	434	timeval_to_jiffies(const struct timeval *value)
435	{	435	{
436	return __timespec_to_jiffies(value->tv_sec,	436	return __timespec_to_jiffies(value->tv_sec,
437	value->tv_usec * NSEC_PER_USEC);	437	value->tv_usec * NSEC_PER_USEC);
438	}	438	}
439	EXPORT_SYMBOL(timeval_to_jiffies);	439	EXPORT_SYMBOL(timeval_to_jiffies);
440		440
441	void jiffies_to_timeval(const unsigned long jiffies, struct timeval *value)	441	void jiffies_to_timeval(const unsigned long jiffies, struct timeval *value)
442	{	442	{
443	/*	443	/*
444	* Convert jiffies to nanoseconds and separate with	444	* Convert jiffies to nanoseconds and separate with
445	* one divide.	445	* one divide.
446	*/	446	*/
447	u32 rem;	447	u32 rem;
448		448
449	value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC,	449	value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC,
450	NSEC_PER_SEC, &rem);	450	NSEC_PER_SEC, &rem);
451	value->tv_usec = rem / NSEC_PER_USEC;	451	value->tv_usec = rem / NSEC_PER_USEC;
452	}	452	}
453	EXPORT_SYMBOL(jiffies_to_timeval);	453	EXPORT_SYMBOL(jiffies_to_timeval);
454		454
455	/*	455	/*
456	* Convert jiffies/jiffies_64 to clock_t and back.	456	* Convert jiffies/jiffies_64 to clock_t and back.
457	*/	457	*/
458	clock_t jiffies_to_clock_t(unsigned long x)	458	clock_t jiffies_to_clock_t(unsigned long x)
459	{	459	{
460	#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0	460	#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
461	# if HZ < USER_HZ	461	# if HZ < USER_HZ
462	return x * (USER_HZ / HZ);	462	return x * (USER_HZ / HZ);
463	# else	463	# else
464	return x / (HZ / USER_HZ);	464	return x / (HZ / USER_HZ);
465	# endif	465	# endif
466	#else	466	#else
467	return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ);	467	return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ);
468	#endif	468	#endif
469	}	469	}
470	EXPORT_SYMBOL(jiffies_to_clock_t);	470	EXPORT_SYMBOL(jiffies_to_clock_t);
471		471
472	unsigned long clock_t_to_jiffies(unsigned long x)	472	unsigned long clock_t_to_jiffies(unsigned long x)
473	{	473	{
474	#if (HZ % USER_HZ)==0	474	#if (HZ % USER_HZ)==0
475	if (x >= ~0UL / (HZ / USER_HZ))	475	if (x >= ~0UL / (HZ / USER_HZ))
476	return ~0UL;	476	return ~0UL;
477	return x * (HZ / USER_HZ);	477	return x * (HZ / USER_HZ);
478	#else	478	#else
479	/* Don't worry about loss of precision here .. */	479	/* Don't worry about loss of precision here .. */
480	if (x >= ~0UL / HZ * USER_HZ)	480	if (x >= ~0UL / HZ * USER_HZ)
481	return ~0UL;	481	return ~0UL;
482		482
483	/* .. but do try to contain it here */	483	/* .. but do try to contain it here */
484	return div_u64((u64)x * HZ, USER_HZ);	484	return div_u64((u64)x * HZ, USER_HZ);
485	#endif	485	#endif
486	}	486	}
487	EXPORT_SYMBOL(clock_t_to_jiffies);	487	EXPORT_SYMBOL(clock_t_to_jiffies);
488		488
489	u64 jiffies_64_to_clock_t(u64 x)	489	u64 jiffies_64_to_clock_t(u64 x)
490	{	490	{
491	#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0	491	#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
492	# if HZ < USER_HZ	492	# if HZ < USER_HZ
493	x = div_u64(x * USER_HZ, HZ);	493	x = div_u64(x * USER_HZ, HZ);
494	# elif HZ > USER_HZ	494	# elif HZ > USER_HZ
495	x = div_u64(x, HZ / USER_HZ);	495	x = div_u64(x, HZ / USER_HZ);
496	# else	496	# else
497	/* Nothing to do */	497	/* Nothing to do */
498	# endif	498	# endif
499	#else	499	#else
500	/*	500	/*

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(root)/drivers/ddk/linux/time.c – Rev 6082 → 6934