[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / include / linux / jiffies.h

#ifndef _LINUX_JIFFIES_H
#define _LINUX_JIFFIES_H

#include <linux/math64.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <asm/param.h>			/* for HZ */
#include <generated/timeconst.h>

/*
 * The following defines establish the engineering parameters of the PLL
 * model. The HZ variable establishes the timer interrupt frequency, 100 Hz
 * for the SunOS kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the
 * OSF/1 kernel. The SHIFT_HZ define expresses the same value as the
 * nearest power of two in order to avoid hardware multiply operations.
 */
#if HZ >= 12 && HZ < 24
# define SHIFT_HZ	4
#elif HZ >= 24 && HZ < 48
# define SHIFT_HZ	5
#elif HZ >= 48 && HZ < 96
# define SHIFT_HZ	6
#elif HZ >= 96 && HZ < 192
# define SHIFT_HZ	7
#elif HZ >= 192 && HZ < 384
# define SHIFT_HZ	8
#elif HZ >= 384 && HZ < 768
# define SHIFT_HZ	9
#elif HZ >= 768 && HZ < 1536
# define SHIFT_HZ	10
#elif HZ >= 1536 && HZ < 3072
# define SHIFT_HZ	11
#elif HZ >= 3072 && HZ < 6144
# define SHIFT_HZ	12
#elif HZ >= 6144 && HZ < 12288
# define SHIFT_HZ	13
#else
# error Invalid value of HZ.
#endif

/* Suppose we want to divide two numbers NOM and DEN: NOM/DEN, then we can
 * improve accuracy by shifting LSH bits, hence calculating:
 *     (NOM << LSH) / DEN
 * This however means trouble for large NOM, because (NOM << LSH) may no
 * longer fit in 32 bits. The following way of calculating this gives us
 * some slack, under the following conditions:
 *   - (NOM / DEN) fits in (32 - LSH) bits.
 *   - (NOM % DEN) fits in (32 - LSH) bits.
 */
#define SH_DIV(NOM,DEN,LSH) (   (((NOM) / (DEN)) << (LSH))              \
                             + ((((NOM) % (DEN)) << (LSH)) + (DEN) / 2) / (DEN))

/* LATCH is used in the interval timer and ftape setup. */
#define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ)	/* For divider */

extern int register_refined_jiffies(long clock_tick_rate);

/* TICK_NSEC is the time between ticks in nsec assuming SHIFTED_HZ */
#define TICK_NSEC ((NSEC_PER_SEC+HZ/2)/HZ)

/* TICK_USEC is the time between ticks in usec assuming fake USER_HZ */
#define TICK_USEC ((1000000UL + USER_HZ/2) / USER_HZ)

/* some arch's have a small-data section that can be accessed register-relative
 * but that can only take up to, say, 4-byte variables. jiffies being part of
 * an 8-byte variable may not be correctly accessed unless we force the issue
 */
#define __jiffy_data  __attribute__((section(".data")))

/*
 * The 64-bit value is not atomic - you MUST NOT read it
 * without sampling the sequence number in jiffies_lock.
 * get_jiffies_64() will do this for you as appropriate.
 */
extern u64 __jiffy_data jiffies_64;
extern unsigned long volatile __jiffy_data jiffies;

#if (BITS_PER_LONG < 64)
u64 get_jiffies_64(void);
#else
static inline u64 get_jiffies_64(void)
{
	return (u64)jiffies;
}
#endif

/*
 *	These inlines deal with timer wrapping correctly. You are 
 *	strongly encouraged to use them
 *	1. Because people otherwise forget
 *	2. Because if the timer wrap changes in future you won't have to
 *	   alter your driver code.
 *
 * time_after(a,b) returns true if the time a is after time b.
 *
 * Do this with "<0" and ">=0" to only test the sign of the result. A
 * good compiler would generate better code (and a really good compiler
 * wouldn't care). Gcc is currently neither.
 */
#define time_after(a,b)		\
	(typecheck(unsigned long, a) && \
	 typecheck(unsigned long, b) && \
	 ((long)((b) - (a)) < 0))
#define time_before(a,b)	time_after(b,a)

#define time_after_eq(a,b)	\
	(typecheck(unsigned long, a) && \
	 typecheck(unsigned long, b) && \
	 ((long)((a) - (b)) >= 0))
#define time_before_eq(a,b)	time_after_eq(b,a)

/*
 * Calculate whether a is in the range of [b, c].
 */
#define time_in_range(a,b,c) \
	(time_after_eq(a,b) && \
	 time_before_eq(a,c))

/*
 * Calculate whether a is in the range of [b, c).
 */
#define time_in_range_open(a,b,c) \
	(time_after_eq(a,b) && \
	 time_before(a,c))

/* Same as above, but does so with platform independent 64bit types.
 * These must be used when utilizing jiffies_64 (i.e. return value of
 * get_jiffies_64() */
#define time_after64(a,b)	\
	(typecheck(__u64, a) &&	\
	 typecheck(__u64, b) && \
	 ((__s64)((b) - (a)) < 0))
#define time_before64(a,b)	time_after64(b,a)

#define time_after_eq64(a,b)	\
	(typecheck(__u64, a) && \
	 typecheck(__u64, b) && \
	 ((__s64)((a) - (b)) >= 0))
#define time_before_eq64(a,b)	time_after_eq64(b,a)

#define time_in_range64(a, b, c) \
	(time_after_eq64(a, b) && \
	 time_before_eq64(a, c))

/*
 * These four macros compare jiffies and 'a' for convenience.
 */

/* time_is_before_jiffies(a) return true if a is before jiffies */
#define time_is_before_jiffies(a) time_after(jiffies, a)

/* time_is_after_jiffies(a) return true if a is after jiffies */
#define time_is_after_jiffies(a) time_before(jiffies, a)

/* time_is_before_eq_jiffies(a) return true if a is before or equal to jiffies*/
#define time_is_before_eq_jiffies(a) time_after_eq(jiffies, a)

/* time_is_after_eq_jiffies(a) return true if a is after or equal to jiffies*/
#define time_is_after_eq_jiffies(a) time_before_eq(jiffies, a)

/*
 * Have the 32 bit jiffies value wrap 5 minutes after boot
 * so jiffies wrap bugs show up earlier.
 */
#define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ))

/*
 * Change timeval to jiffies, trying to avoid the
 * most obvious overflows..
 *
 * And some not so obvious.
 *
 * Note that we don't want to return LONG_MAX, because
 * for various timeout reasons we often end up having
 * to wait "jiffies+1" in order to guarantee that we wait
 * at _least_ "jiffies" - so "jiffies+1" had better still
 * be positive.
 */
#define MAX_JIFFY_OFFSET ((LONG_MAX >> 1)-1)

extern unsigned long preset_lpj;

/*
 * We want to do realistic conversions of time so we need to use the same
 * values the update wall clock code uses as the jiffies size.  This value
 * is: TICK_NSEC (which is defined in timex.h).  This
 * is a constant and is in nanoseconds.  We will use scaled math
 * with a set of scales defined here as SEC_JIFFIE_SC,  USEC_JIFFIE_SC and
 * NSEC_JIFFIE_SC.  Note that these defines contain nothing but
 * constants and so are computed at compile time.  SHIFT_HZ (computed in
 * timex.h) adjusts the scaling for different HZ values.

 * Scaled math???  What is that?
 *
 * Scaled math is a way to do integer math on values that would,
 * otherwise, either overflow, underflow, or cause undesired div
 * instructions to appear in the execution path.  In short, we "scale"
 * up the operands so they take more bits (more precision, less
 * underflow), do the desired operation and then "scale" the result back
 * by the same amount.  If we do the scaling by shifting we avoid the
 * costly mpy and the dastardly div instructions.

 * Suppose, for example, we want to convert from seconds to jiffies
 * where jiffies is defined in nanoseconds as NSEC_PER_JIFFIE.  The
 * simple math is: jiff = (sec * NSEC_PER_SEC) / NSEC_PER_JIFFIE; We
 * observe that (NSEC_PER_SEC / NSEC_PER_JIFFIE) is a constant which we
 * might calculate at compile time, however, the result will only have
 * about 3-4 bits of precision (less for smaller values of HZ).
 *
 * So, we scale as follows:
 * jiff = (sec) * (NSEC_PER_SEC / NSEC_PER_JIFFIE);
 * jiff = ((sec) * ((NSEC_PER_SEC * SCALE)/ NSEC_PER_JIFFIE)) / SCALE;
 * Then we make SCALE a power of two so:
 * jiff = ((sec) * ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE)) >> SCALE;
 * Now we define:
 * #define SEC_CONV = ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE))
 * jiff = (sec * SEC_CONV) >> SCALE;
 *
 * Often the math we use will expand beyond 32-bits so we tell C how to
 * do this and pass the 64-bit result of the mpy through the ">> SCALE"
 * which should take the result back to 32-bits.  We want this expansion
 * to capture as much precision as possible.  At the same time we don't
 * want to overflow so we pick the SCALE to avoid this.  In this file,
 * that means using a different scale for each range of HZ values (as
 * defined in timex.h).
 *
 * For those who want to know, gcc will give a 64-bit result from a "*"
 * operator if the result is a long long AND at least one of the
 * operands is cast to long long (usually just prior to the "*" so as
 * not to confuse it into thinking it really has a 64-bit operand,
 * which, buy the way, it can do, but it takes more code and at least 2
 * mpys).

 * We also need to be aware that one second in nanoseconds is only a
 * couple of bits away from overflowing a 32-bit word, so we MUST use
 * 64-bits to get the full range time in nanoseconds.

 */

/*
 * Here are the scales we will use.  One for seconds, nanoseconds and
 * microseconds.
 *
 * Within the limits of cpp we do a rough cut at the SEC_JIFFIE_SC and
 * check if the sign bit is set.  If not, we bump the shift count by 1.
 * (Gets an extra bit of precision where we can use it.)
 * We know it is set for HZ = 1024 and HZ = 100 not for 1000.
 * Haven't tested others.

 * Limits of cpp (for #if expressions) only long (no long long), but
 * then we only need the most signicant bit.
 */

#define SEC_JIFFIE_SC (31 - SHIFT_HZ)
#if !((((NSEC_PER_SEC << 2) / TICK_NSEC) << (SEC_JIFFIE_SC - 2)) & 0x80000000)
#undef SEC_JIFFIE_SC
#define SEC_JIFFIE_SC (32 - SHIFT_HZ)
#endif
#define NSEC_JIFFIE_SC (SEC_JIFFIE_SC + 29)
#define SEC_CONVERSION ((unsigned long)((((u64)NSEC_PER_SEC << SEC_JIFFIE_SC) +\
                                TICK_NSEC -1) / (u64)TICK_NSEC))

#define NSEC_CONVERSION ((unsigned long)((((u64)1 << NSEC_JIFFIE_SC) +\
                                        TICK_NSEC -1) / (u64)TICK_NSEC))
/*
 * The maximum jiffie value is (MAX_INT >> 1).  Here we translate that
 * into seconds.  The 64-bit case will overflow if we are not careful,
 * so use the messy SH_DIV macro to do it.  Still all constants.
 */
#if BITS_PER_LONG < 64
# define MAX_SEC_IN_JIFFIES \
	(long)((u64)((u64)MAX_JIFFY_OFFSET * TICK_NSEC) / NSEC_PER_SEC)
#else	/* take care of overflow on 64 bits machines */
# define MAX_SEC_IN_JIFFIES \
	(SH_DIV((MAX_JIFFY_OFFSET >> SEC_JIFFIE_SC) * TICK_NSEC, NSEC_PER_SEC, 1) - 1)

#endif

/*
 * Convert various time units to each other:
 */
extern unsigned int jiffies_to_msecs(const unsigned long j);
extern unsigned int jiffies_to_usecs(const unsigned long j);

static inline u64 jiffies_to_nsecs(const unsigned long j)
{
	return (u64)jiffies_to_usecs(j) * NSEC_PER_USEC;
}

extern unsigned long __msecs_to_jiffies(const unsigned int m);
#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
/*
 * HZ is equal to or smaller than 1000, and 1000 is a nice round
 * multiple of HZ, divide with the factor between them, but round
 * upwards:
 */
static inline unsigned long _msecs_to_jiffies(const unsigned int m)
{
	return (m + (MSEC_PER_SEC / HZ) - 1) / (MSEC_PER_SEC / HZ);
}
#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC)
/*
 * HZ is larger than 1000, and HZ is a nice round multiple of 1000 -
 * simply multiply with the factor between them.
 *
 * But first make sure the multiplication result cannot overflow:
 */
static inline unsigned long _msecs_to_jiffies(const unsigned int m)
{
	if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET))
		return MAX_JIFFY_OFFSET;
	return m * (HZ / MSEC_PER_SEC);
}
#else
/*
 * Generic case - multiply, round and divide. But first check that if
 * we are doing a net multiplication, that we wouldn't overflow:
 */
static inline unsigned long _msecs_to_jiffies(const unsigned int m)
{
	if (HZ > MSEC_PER_SEC && m > jiffies_to_msecs(MAX_JIFFY_OFFSET))
		return MAX_JIFFY_OFFSET;

	return (MSEC_TO_HZ_MUL32 * m + MSEC_TO_HZ_ADJ32) >> MSEC_TO_HZ_SHR32;
}
#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 HZ range specific helpers _msecs_to_jiffies() are called both
 * directly here and from __msecs_to_jiffies() in the case where
 * constant folding is not possible.
 */
static __always_inline unsigned long msecs_to_jiffies(const unsigned int m)
{
	if (__builtin_constant_p(m)) {
		if ((int)m < 0)
			return MAX_JIFFY_OFFSET;
		return _msecs_to_jiffies(m);
	} else {
		return __msecs_to_jiffies(m);
	}
}

extern unsigned long __usecs_to_jiffies(const unsigned int u);
#if !(USEC_PER_SEC % HZ)
static inline unsigned long _usecs_to_jiffies(const unsigned int u)
{
	return (u + (USEC_PER_SEC / HZ) - 1) / (USEC_PER_SEC / HZ);
}
#else
static inline unsigned long _usecs_to_jiffies(const unsigned int u)
{
	return (USEC_TO_HZ_MUL32 * u + USEC_TO_HZ_ADJ32)
		>> USEC_TO_HZ_SHR32;
}
#endif

/**
 * usecs_to_jiffies: - convert microseconds to jiffies
 * @u:	time in microseconds
 *
 * conversion is done as follows:
 *
 * - '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 as for msecs_to_jiffies.
 *
 * usecs_to_jiffies() checks for the passed in value being a constant
 * via __builtin_constant_p() allowing gcc to eliminate most of the
 * code, __usecs_to_jiffies() is called if the value passed does not
 * allow constant folding and the actual conversion must be done at
 * runtime.
 * the HZ range specific helpers _usecs_to_jiffies() are called both
 * directly here and from __msecs_to_jiffies() in the case where
 * constant folding is not possible.
 */
static __always_inline unsigned long usecs_to_jiffies(const unsigned int u)
{
	if (__builtin_constant_p(u)) {
		if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET))
			return MAX_JIFFY_OFFSET;
		return _usecs_to_jiffies(u);
	} else {
		return __usecs_to_jiffies(u);
	}
}

extern unsigned long timespec64_to_jiffies(const struct timespec64 *value);
extern void jiffies_to_timespec64(const unsigned long jiffies,
				  struct timespec64 *value);
static inline unsigned long timespec_to_jiffies(const struct timespec *value)
{
	struct timespec64 ts = timespec_to_timespec64(*value);

	return timespec64_to_jiffies(&ts);
}

static inline void jiffies_to_timespec(const unsigned long jiffies,
				       struct timespec *value)
{
	struct timespec64 ts;

	jiffies_to_timespec64(jiffies, &ts);
	*value = timespec64_to_timespec(ts);
}

extern unsigned long timeval_to_jiffies(const struct timeval *value);
extern void jiffies_to_timeval(const unsigned long jiffies,
			       struct timeval *value);

extern clock_t jiffies_to_clock_t(unsigned long x);
static inline clock_t jiffies_delta_to_clock_t(long delta)
{
	return jiffies_to_clock_t(max(0L, delta));
}

extern unsigned long clock_t_to_jiffies(unsigned long x);
extern u64 jiffies_64_to_clock_t(u64 x);
extern u64 nsec_to_clock_t(u64 x);
extern u64 nsecs_to_jiffies64(u64 n);
extern unsigned long nsecs_to_jiffies(u64 n);

#define TIMESTAMP_SIZE	30

#endif
Commit	Line	Data
1da177e4 LT	1	#ifndef _LINUX_JIFFIES_H
	2	#define _LINUX_JIFFIES_H
	3
f8bd2258	4	#include <linux/math64.h>
1da177e4 LT	5	#include <linux/kernel.h>
	6	#include <linux/types.h>
	7	#include <linux/time.h>
	8	#include <linux/timex.h>
	9	#include <asm/param.h> /* for HZ */
ca42aaf0	10	#include <generated/timeconst.h>
1da177e4 LT	11
	12	/*
	13	* The following defines establish the engineering parameters of the PLL
	14	* model. The HZ variable establishes the timer interrupt frequency, 100 Hz
	15	* for the SunOS kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the
	16	* OSF/1 kernel. The SHIFT_HZ define expresses the same value as the
	17	* nearest power of two in order to avoid hardware multiply operations.
	18	*/
	19	#if HZ >= 12 && HZ < 24
	20	# define SHIFT_HZ 4
	21	#elif HZ >= 24 && HZ < 48
	22	# define SHIFT_HZ 5
	23	#elif HZ >= 48 && HZ < 96
	24	# define SHIFT_HZ 6
	25	#elif HZ >= 96 && HZ < 192
	26	# define SHIFT_HZ 7
	27	#elif HZ >= 192 && HZ < 384
	28	# define SHIFT_HZ 8
	29	#elif HZ >= 384 && HZ < 768
	30	# define SHIFT_HZ 9
	31	#elif HZ >= 768 && HZ < 1536
	32	# define SHIFT_HZ 10
e118adef PM	33	#elif HZ >= 1536 && HZ < 3072
	34	# define SHIFT_HZ 11
	35	#elif HZ >= 3072 && HZ < 6144
	36	# define SHIFT_HZ 12
	37	#elif HZ >= 6144 && HZ < 12288
	38	# define SHIFT_HZ 13
1da177e4	39	#else
37679011	40	# error Invalid value of HZ.
1da177e4 LT	41	#endif
1da177e4 LT	42
25985edc	43	/* Suppose we want to divide two numbers NOM and DEN: NOM/DEN, then we can
1da177e4 LT	44	* improve accuracy by shifting LSH bits, hence calculating:
	45	* (NOM << LSH) / DEN
	46	* This however means trouble for large NOM, because (NOM << LSH) may no
	47	* longer fit in 32 bits. The following way of calculating this gives us
	48	* some slack, under the following conditions:
	49	* - (NOM / DEN) fits in (32 - LSH) bits.
	50	* - (NOM % DEN) fits in (32 - LSH) bits.
	51	*/
0d94df56 UZ	52	#define SH_DIV(NOM,DEN,LSH) ( (((NOM) / (DEN)) << (LSH)) \
0d94df56 UZ	53	+ ((((NOM) % (DEN)) << (LSH)) + (DEN) / 2) / (DEN))
1da177e4	54
a7ea3bbf	55	/* LATCH is used in the interval timer and ftape setup. */
015a830d	56	#define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */
a7ea3bbf	57
b3c869d3	58	extern int register_refined_jiffies(long clock_tick_rate);
1da177e4	59
02ab20ae	60	/* TICK_NSEC is the time between ticks in nsec assuming SHIFTED_HZ */
b3c869d3	61	#define TICK_NSEC ((NSEC_PER_SEC+HZ/2)/HZ)
1da177e4 LT	62
	63	/* TICK_USEC is the time between ticks in usec assuming fake USER_HZ */
	64	#define TICK_USEC ((1000000UL + USER_HZ/2) / USER_HZ)
	65
1da177e4 LT	66	/* some arch's have a small-data section that can be accessed register-relative
	67	* but that can only take up to, say, 4-byte variables. jiffies being part of
	68	* an 8-byte variable may not be correctly accessed unless we force the issue
	69	*/
	70	#define __jiffy_data __attribute__((section(".data")))
	71
	72	/*
98c4f0c3	73	* The 64-bit value is not atomic - you MUST NOT read it
d6ad4187	74	* without sampling the sequence number in jiffies_lock.
1da177e4 LT	75	* get_jiffies_64() will do this for you as appropriate.
	76	*/
	77	extern u64 __jiffy_data jiffies_64;
	78	extern unsigned long volatile __jiffy_data jiffies;
	79
	80	#if (BITS_PER_LONG < 64)
	81	u64 get_jiffies_64(void);
	82	#else
	83	static inline u64 get_jiffies_64(void)
	84	{
	85	return (u64)jiffies;
	86	}
	87	#endif
	88
	89	/*
	90	* These inlines deal with timer wrapping correctly. You are
	91	* strongly encouraged to use them
	92	* 1. Because people otherwise forget
	93	* 2. Because if the timer wrap changes in future you won't have to
	94	* alter your driver code.
	95	*
	96	* time_after(a,b) returns true if the time a is after time b.
	97	*
	98	* Do this with "<0" and ">=0" to only test the sign of the result. A
	99	* good compiler would generate better code (and a really good compiler
	100	* wouldn't care). Gcc is currently neither.
	101	*/
	102	#define time_after(a,b) \
	103	(typecheck(unsigned long, a) && \
	104	typecheck(unsigned long, b) && \
5a581b36	105	((long)((b) - (a)) < 0))
1da177e4 LT	106	#define time_before(a,b) time_after(b,a)
	107
	108	#define time_after_eq(a,b) \
	109	(typecheck(unsigned long, a) && \
	110	typecheck(unsigned long, b) && \
5a581b36	111	((long)((a) - (b)) >= 0))
1da177e4 LT	112	#define time_before_eq(a,b) time_after_eq(b,a)
1da177e4 LT	113
64672d55 PS	114	/*
	115	* Calculate whether a is in the range of [b, c].
	116	*/
c7e15961 FOL	117	#define time_in_range(a,b,c) \
	118	(time_after_eq(a,b) && \
	119	time_before_eq(a,c))
	120
64672d55 PS	121	/*
	122	* Calculate whether a is in the range of [b, c).
	123	*/
	124	#define time_in_range_open(a,b,c) \
	125	(time_after_eq(a,b) && \
	126	time_before(a,c))
	127
3b171672 DZ	128	/* Same as above, but does so with platform independent 64bit types.
	129	* These must be used when utilizing jiffies_64 (i.e. return value of
	130	* get_jiffies_64() */
	131	#define time_after64(a,b) \
	132	(typecheck(__u64, a) && \
	133	typecheck(__u64, b) && \
5a581b36	134	((__s64)((b) - (a)) < 0))
3b171672 DZ	135	#define time_before64(a,b) time_after64(b,a)
	136
	137	#define time_after_eq64(a,b) \
	138	(typecheck(__u64, a) && \
	139	typecheck(__u64, b) && \
5a581b36	140	((__s64)((a) - (b)) >= 0))
3b171672 DZ	141	#define time_before_eq64(a,b) time_after_eq64(b,a)
3b171672 DZ	142
1bc2774d ET	143	#define time_in_range64(a, b, c) \
	144	(time_after_eq64(a, b) && \
	145	time_before_eq64(a, c))
	146
3f34d024 DY	147	/*
	148	* These four macros compare jiffies and 'a' for convenience.
	149	*/
	150
	151	/* time_is_before_jiffies(a) return true if a is before jiffies */
	152	#define time_is_before_jiffies(a) time_after(jiffies, a)
	153
	154	/* time_is_after_jiffies(a) return true if a is after jiffies */
	155	#define time_is_after_jiffies(a) time_before(jiffies, a)
	156
	157	/* time_is_before_eq_jiffies(a) return true if a is before or equal to jiffies*/
	158	#define time_is_before_eq_jiffies(a) time_after_eq(jiffies, a)
	159
	160	/* time_is_after_eq_jiffies(a) return true if a is after or equal to jiffies*/
	161	#define time_is_after_eq_jiffies(a) time_before_eq(jiffies, a)
	162
1da177e4 LT	163	/*
	164	* Have the 32 bit jiffies value wrap 5 minutes after boot
	165	* so jiffies wrap bugs show up earlier.
	166	*/
	167	#define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ))
	168
	169	/*
	170	* Change timeval to jiffies, trying to avoid the
	171	* most obvious overflows..
	172	*
	173	* And some not so obvious.
	174	*
9f907c01	175	* Note that we don't want to return LONG_MAX, because
1da177e4 LT	176	* for various timeout reasons we often end up having
	177	* to wait "jiffies+1" in order to guarantee that we wait
	178	* at _least_ "jiffies" - so "jiffies+1" had better still
	179	* be positive.
	180	*/
9f907c01	181	#define MAX_JIFFY_OFFSET ((LONG_MAX >> 1)-1)
1da177e4	182
bfe8df3d RD	183	extern unsigned long preset_lpj;
bfe8df3d RD	184
1da177e4 LT	185	/*
	186	* We want to do realistic conversions of time so we need to use the same
	187	* values the update wall clock code uses as the jiffies size. This value
	188	* is: TICK_NSEC (which is defined in timex.h). This
3eb05676	189	* is a constant and is in nanoseconds. We will use scaled math
1da177e4 LT	190	* with a set of scales defined here as SEC_JIFFIE_SC, USEC_JIFFIE_SC and
	191	* NSEC_JIFFIE_SC. Note that these defines contain nothing but
	192	* constants and so are computed at compile time. SHIFT_HZ (computed in
	193	* timex.h) adjusts the scaling for different HZ values.
	194
	195	* Scaled math??? What is that?
	196	*
	197	* Scaled math is a way to do integer math on values that would,
	198	* otherwise, either overflow, underflow, or cause undesired div
	199	* instructions to appear in the execution path. In short, we "scale"
	200	* up the operands so they take more bits (more precision, less
	201	* underflow), do the desired operation and then "scale" the result back
	202	* by the same amount. If we do the scaling by shifting we avoid the
	203	* costly mpy and the dastardly div instructions.
	204
	205	* Suppose, for example, we want to convert from seconds to jiffies
	206	* where jiffies is defined in nanoseconds as NSEC_PER_JIFFIE. The
	207	* simple math is: jiff = (sec * NSEC_PER_SEC) / NSEC_PER_JIFFIE; We
	208	* observe that (NSEC_PER_SEC / NSEC_PER_JIFFIE) is a constant which we
	209	* might calculate at compile time, however, the result will only have
	210	* about 3-4 bits of precision (less for smaller values of HZ).
	211	*
	212	* So, we scale as follows:
	213	* jiff = (sec) * (NSEC_PER_SEC / NSEC_PER_JIFFIE);
	214	* jiff = ((sec) * ((NSEC_PER_SEC * SCALE)/ NSEC_PER_JIFFIE)) / SCALE;
	215	* Then we make SCALE a power of two so:
	216	* jiff = ((sec) * ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE)) >> SCALE;
	217	* Now we define:
	218	* #define SEC_CONV = ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE))
	219	* jiff = (sec * SEC_CONV) >> SCALE;
	220	*
	221	* Often the math we use will expand beyond 32-bits so we tell C how to
	222	* do this and pass the 64-bit result of the mpy through the ">> SCALE"
	223	* which should take the result back to 32-bits. We want this expansion
	224	* to capture as much precision as possible. At the same time we don't
	225	* want to overflow so we pick the SCALE to avoid this. In this file,
	226	* that means using a different scale for each range of HZ values (as
	227	* defined in timex.h).
	228	*
	229	* For those who want to know, gcc will give a 64-bit result from a "*"
	230	* operator if the result is a long long AND at least one of the
	231	* operands is cast to long long (usually just prior to the "*" so as
	232	* not to confuse it into thinking it really has a 64-bit operand,
3eb05676	233	* which, buy the way, it can do, but it takes more code and at least 2
1da177e4 LT	234	* mpys).
	235
	236	* We also need to be aware that one second in nanoseconds is only a
	237	* couple of bits away from overflowing a 32-bit word, so we MUST use
	238	* 64-bits to get the full range time in nanoseconds.
	239
	240	*/
	241
	242	/*
	243	* Here are the scales we will use. One for seconds, nanoseconds and
	244	* microseconds.
	245	*
	246	* Within the limits of cpp we do a rough cut at the SEC_JIFFIE_SC and
	247	* check if the sign bit is set. If not, we bump the shift count by 1.
	248	* (Gets an extra bit of precision where we can use it.)
	249	* We know it is set for HZ = 1024 and HZ = 100 not for 1000.
	250	* Haven't tested others.
	251
	252	* Limits of cpp (for #if expressions) only long (no long long), but
	253	* then we only need the most signicant bit.
	254	*/
	255
	256	#define SEC_JIFFIE_SC (31 - SHIFT_HZ)
	257	#if !((((NSEC_PER_SEC << 2) / TICK_NSEC) << (SEC_JIFFIE_SC - 2)) & 0x80000000)
	258	#undef SEC_JIFFIE_SC
	259	#define SEC_JIFFIE_SC (32 - SHIFT_HZ)
	260	#endif
	261	#define NSEC_JIFFIE_SC (SEC_JIFFIE_SC + 29)
1da177e4 LT	262	#define SEC_CONVERSION ((unsigned long)((((u64)NSEC_PER_SEC << SEC_JIFFIE_SC) +\
	263	TICK_NSEC -1) / (u64)TICK_NSEC))
	264
	265	#define NSEC_CONVERSION ((unsigned long)((((u64)1 << NSEC_JIFFIE_SC) +\
	266	TICK_NSEC -1) / (u64)TICK_NSEC))
1da177e4 LT	267	/*
	268	* The maximum jiffie value is (MAX_INT >> 1). Here we translate that
	269	* into seconds. The 64-bit case will overflow if we are not careful,
	270	* so use the messy SH_DIV macro to do it. Still all constants.
	271	*/
	272	#if BITS_PER_LONG < 64
	273	# define MAX_SEC_IN_JIFFIES \
	274	(long)((u64)((u64)MAX_JIFFY_OFFSET * TICK_NSEC) / NSEC_PER_SEC)
	275	#else /* take care of overflow on 64 bits machines */
	276	# define MAX_SEC_IN_JIFFIES \
	277	(SH_DIV((MAX_JIFFY_OFFSET >> SEC_JIFFIE_SC) * TICK_NSEC, NSEC_PER_SEC, 1) - 1)
	278
	279	#endif
	280
	281	/*
8b9365d7	282	* Convert various time units to each other:
1da177e4	283	*/
8b9365d7 IM	284	extern unsigned int jiffies_to_msecs(const unsigned long j);
8b9365d7 IM	285	extern unsigned int jiffies_to_usecs(const unsigned long j);
8fe8ff09 KH	286
	287	static inline u64 jiffies_to_nsecs(const unsigned long j)
	288	{
	289	return (u64)jiffies_to_usecs(j) * NSEC_PER_USEC;
	290	}
	291
ca42aaf0 NMG	292	extern unsigned long __msecs_to_jiffies(const unsigned int m);
	293	#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
	294	/*
	295	* HZ is equal to or smaller than 1000, and 1000 is a nice round
	296	* multiple of HZ, divide with the factor between them, but round
	297	* upwards:
	298	*/
	299	static inline unsigned long _msecs_to_jiffies(const unsigned int m)
	300	{
4e3d9cb0	301	return (m + (MSEC_PER_SEC / HZ) - 1) / (MSEC_PER_SEC / HZ);
ca42aaf0 NMG	302	}
	303	#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC)
	304	/*
	305	* HZ is larger than 1000, and HZ is a nice round multiple of 1000 -
	306	* simply multiply with the factor between them.
	307	*
	308	* But first make sure the multiplication result cannot overflow:
	309	*/
	310	static inline unsigned long _msecs_to_jiffies(const unsigned int m)
	311	{
4e3d9cb0 TG	312	if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET))
	313	return MAX_JIFFY_OFFSET;
	314	return m * (HZ / MSEC_PER_SEC);
ca42aaf0 NMG	315	}
	316	#else
	317	/*
	318	* Generic case - multiply, round and divide. But first check that if
	319	* we are doing a net multiplication, that we wouldn't overflow:
	320	*/
	321	static inline unsigned long _msecs_to_jiffies(const unsigned int m)
	322	{
4e3d9cb0 TG	323	if (HZ > MSEC_PER_SEC && m > jiffies_to_msecs(MAX_JIFFY_OFFSET))
4e3d9cb0 TG	324	return MAX_JIFFY_OFFSET;
ca42aaf0	325
4e3d9cb0	326	return (MSEC_TO_HZ_MUL32 * m + MSEC_TO_HZ_ADJ32) >> MSEC_TO_HZ_SHR32;
ca42aaf0 NMG	327	}
	328	#endif
	329	/**
	330	* msecs_to_jiffies: - convert milliseconds to jiffies
	331	* @m: time in milliseconds
	332	*
	333	* conversion is done as follows:
	334	*
	335	* - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET)
	336	*
	337	* - 'too large' values [that would result in larger than
	338	* MAX_JIFFY_OFFSET values] mean 'infinite timeout' too.
	339	*
	340	* - all other values are converted to jiffies by either multiplying
	341	* the input value by a factor or dividing it with a factor and
	342	* handling any 32-bit overflows.
	343	* for the details see __msecs_to_jiffies()
	344	*
daa67b4b NMG	345	* msecs_to_jiffies() checks for the passed in value being a constant
	346	* via __builtin_constant_p() allowing gcc to eliminate most of the
	347	* code, __msecs_to_jiffies() is called if the value passed does not
	348	* allow constant folding and the actual conversion must be done at
	349	* runtime.
	350	* the HZ range specific helpers _msecs_to_jiffies() are called both
	351	* directly here and from __msecs_to_jiffies() in the case where
	352	* constant folding is not possible.
ca42aaf0	353	*/
accd0b9e	354	static __always_inline unsigned long msecs_to_jiffies(const unsigned int m)
ca42aaf0	355	{
daa67b4b NMG	356	if (__builtin_constant_p(m)) {
	357	if ((int)m < 0)
	358	return MAX_JIFFY_OFFSET;
	359	return _msecs_to_jiffies(m);
	360	} else {
	361	return __msecs_to_jiffies(m);
	362	}
ca42aaf0 NMG	363	}
ca42aaf0 NMG	364
ae60d6a0	365	extern unsigned long __usecs_to_jiffies(const unsigned int u);
e0758676	366	#if !(USEC_PER_SEC % HZ)
ae60d6a0 NMG	367	static inline unsigned long _usecs_to_jiffies(const unsigned int u)
	368	{
	369	return (u + (USEC_PER_SEC / HZ) - 1) / (USEC_PER_SEC / HZ);
	370	}
ae60d6a0 NMG	371	#else
	372	static inline unsigned long _usecs_to_jiffies(const unsigned int u)
	373	{
	374	return (USEC_TO_HZ_MUL32 * u + USEC_TO_HZ_ADJ32)
	375	>> USEC_TO_HZ_SHR32;
	376	}
	377	#endif
	378
c569a23d NMG	379	/**
	380	* usecs_to_jiffies: - convert microseconds to jiffies
	381	* @u: time in microseconds
	382	*
	383	* conversion is done as follows:
	384	*
	385	* - 'too large' values [that would result in larger than
	386	* MAX_JIFFY_OFFSET values] mean 'infinite timeout' too.
	387	*
	388	* - all other values are converted to jiffies by either multiplying
	389	* the input value by a factor or dividing it with a factor and
	390	* handling any 32-bit overflows as for msecs_to_jiffies.
	391	*
	392	* usecs_to_jiffies() checks for the passed in value being a constant
	393	* via __builtin_constant_p() allowing gcc to eliminate most of the
	394	* code, __usecs_to_jiffies() is called if the value passed does not
	395	* allow constant folding and the actual conversion must be done at
	396	* runtime.
	397	* the HZ range specific helpers _usecs_to_jiffies() are called both
	398	* directly here and from __msecs_to_jiffies() in the case where
	399	* constant folding is not possible.
	400	*/
accd0b9e	401	static __always_inline unsigned long usecs_to_jiffies(const unsigned int u)
ae60d6a0	402	{
c569a23d NMG	403	if (__builtin_constant_p(u)) {
	404	if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET))
	405	return MAX_JIFFY_OFFSET;
	406	return _usecs_to_jiffies(u);
	407	} else {
	408	return __usecs_to_jiffies(u);
	409	}
ae60d6a0 NMG	410	}
ae60d6a0 NMG	411
9ca30850 BW	412	extern unsigned long timespec64_to_jiffies(const struct timespec64 *value);
	413	extern void jiffies_to_timespec64(const unsigned long jiffies,
	414	struct timespec64 *value);
	415	static inline unsigned long timespec_to_jiffies(const struct timespec *value)
	416	{
	417	struct timespec64 ts = timespec_to_timespec64(*value);
	418
	419	return timespec64_to_jiffies(&ts);
	420	}
	421
	422	static inline void jiffies_to_timespec(const unsigned long jiffies,
	423	struct timespec *value)
	424	{
	425	struct timespec64 ts;
	426
	427	jiffies_to_timespec64(jiffies, &ts);
	428	*value = timespec64_to_timespec(ts);
	429	}
	430
8b9365d7 IM	431	extern unsigned long timeval_to_jiffies(const struct timeval *value);
	432	extern void jiffies_to_timeval(const unsigned long jiffies,
	433	struct timeval *value);
a399a805	434
cbbc719f	435	extern clock_t jiffies_to_clock_t(unsigned long x);
a399a805 ED	436	static inline clock_t jiffies_delta_to_clock_t(long delta)
	437	{
	438	return jiffies_to_clock_t(max(0L, delta));
	439	}
	440
8b9365d7 IM	441	extern unsigned long clock_t_to_jiffies(unsigned long x);
	442	extern u64 jiffies_64_to_clock_t(u64 x);
	443	extern u64 nsec_to_clock_t(u64 x);
a1dabb6b	444	extern u64 nsecs_to_jiffies64(u64 n);
b7b20df9	445	extern unsigned long nsecs_to_jiffies(u64 n);
8b9365d7 IM	446
8b9365d7 IM	447	#define TIMESTAMP_SIZE 30
1da177e4 LT	448
1da177e4 LT	449	#endif