[PATCH] hrtimer: introduce ktime_t time format

	bool

	depends on X86_SMP || (X86_VOYAGER && SMP)

	default y

config KTIME_SCALAR

	bool

	default y

/*

 *  include/linux/ktime.h

 *

 *  ktime_t - nanosecond-resolution time format.

 *

 *   Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>

 *   Copyright(C) 2005, Red Hat, Inc., Ingo Molnar

 *

 *  data type definitions, declarations, prototypes and macros.

 *

 *  Started by: Thomas Gleixner and Ingo Molnar

 *

 *  For licencing details see kernel-base/COPYING

 */

#ifndef _LINUX_KTIME_H

#define _LINUX_KTIME_H

#include <linux/time.h>

#include <linux/jiffies.h>

/*

 * ktime_t:

 *

 * On 64-bit CPUs a single 64-bit variable is used to store the hrtimers

 * internal representation of time values in scalar nanoseconds. The

 * design plays out best on 64-bit CPUs, where most conversions are

 * NOPs and most arithmetic ktime_t operations are plain arithmetic

 * operations.

 *

 * On 32-bit CPUs an optimized representation of the timespec structure

 * is used to avoid expensive conversions from and to timespecs. The

 * endian-aware order of the tv struct members is choosen to allow

 * mathematical operations on the tv64 member of the union too, which

 * for certain operations produces better code.

 *

 * For architectures with efficient support for 64/32-bit conversions the

 * plain scalar nanosecond based representation can be selected by the

 * config switch CONFIG_KTIME_SCALAR.

 */

typedef union {

	s64	tv64;

#if BITS_PER_LONG != 64 && !defined(CONFIG_KTIME_SCALAR)

	struct {

# ifdef __BIG_ENDIAN

	s32	sec, nsec;

# else

	s32	nsec, sec;

# endif

	} tv;

#endif

} ktime_t;

#define KTIME_MAX			(~((u64)1 << 63))

/*

 * ktime_t definitions when using the 64-bit scalar representation:

 */

#if (BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR)

/* Define a ktime_t variable and initialize it to zero: */

#define DEFINE_KTIME(kt)		ktime_t kt = { .tv64 = 0 }

/**

 * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value

 *

 * @secs:	seconds to set

 * @nsecs:	nanoseconds to set

 *

 * Return the ktime_t representation of the value

 */

static inline ktime_t ktime_set(const long secs, const unsigned long nsecs)

{

	return (ktime_t) { .tv64 = (s64)secs * NSEC_PER_SEC + (s64)nsecs };

}

/* Subtract two ktime_t variables. rem = lhs -rhs: */

#define ktime_sub(lhs, rhs) \

		({ (ktime_t){ .tv64 = (lhs).tv64 - (rhs).tv64 }; })

/* Add two ktime_t variables. res = lhs + rhs: */

#define ktime_add(lhs, rhs) \

		({ (ktime_t){ .tv64 = (lhs).tv64 + (rhs).tv64 }; })

/*

 * Add a ktime_t variable and a scalar nanosecond value.

 * res = kt + nsval:

 */

#define ktime_add_ns(kt, nsval) \

		({ (ktime_t){ .tv64 = (kt).tv64 + (nsval) }; })

/* convert a timespec to ktime_t format: */

#define timespec_to_ktime(ts)		ktime_set((ts).tv_sec, (ts).tv_nsec)

/* convert a timeval to ktime_t format: */

#define timeval_to_ktime(tv)		ktime_set((tv).tv_sec, (tv).tv_usec * 1000)

/* Map the ktime_t to timespec conversion to ns_to_timespec function */

#define ktime_to_timespec(kt)		ns_to_timespec((kt).tv64)

/* Map the ktime_t to timeval conversion to ns_to_timeval function */

#define ktime_to_timeval(kt)		ns_to_timeval((kt).tv64)

/* Map the ktime_t to clock_t conversion to the inline in jiffies.h: */

#define ktime_to_clock_t(kt)		nsec_to_clock_t((kt).tv64)

/* Convert ktime_t to nanoseconds - NOP in the scalar storage format: */

#define ktime_to_ns(kt)			((kt).tv64)

#else

/*

 * Helper macros/inlines to get the ktime_t math right in the timespec

 * representation. The macros are sometimes ugly - their actual use is

 * pretty okay-ish, given the circumstances. We do all this for

 * performance reasons. The pure scalar nsec_t based code was nice and

 * simple, but created too many 64-bit / 32-bit conversions and divisions.

 *

 * Be especially aware that negative values are represented in a way

 * that the tv.sec field is negative and the tv.nsec field is greater

 * or equal to zero but less than nanoseconds per second. This is the

 * same representation which is used by timespecs.

 *

 *   tv.sec < 0 and 0 >= tv.nsec < NSEC_PER_SEC

 */

/* Define a ktime_t variable and initialize it to zero: */

#define DEFINE_KTIME(kt)		ktime_t kt = { .tv64 = 0 }

/* Set a ktime_t variable to a value in sec/nsec representation: */

static inline ktime_t ktime_set(const long secs, const unsigned long nsecs)

{

	return (ktime_t) { .tv = { .sec = secs, .nsec = nsecs } };

}

/**

 * ktime_sub - subtract two ktime_t variables

 *

 * @lhs:	minuend

 * @rhs:	subtrahend

 *

 * Returns the remainder of the substraction

 */

static inline ktime_t ktime_sub(const ktime_t lhs, const ktime_t rhs)

{

	ktime_t res;

	res.tv64 = lhs.tv64 - rhs.tv64;

	if (res.tv.nsec < 0)

		res.tv.nsec += NSEC_PER_SEC;

	return res;

}

/**

 * ktime_add - add two ktime_t variables

 *

 * @add1:	addend1

 * @add2:	addend2

 *

 * Returns the sum of addend1 and addend2

 */

static inline ktime_t ktime_add(const ktime_t add1, const ktime_t add2)

{

	ktime_t res;

	res.tv64 = add1.tv64 + add2.tv64;

	/*

	 * performance trick: the (u32) -NSEC gives 0x00000000Fxxxxxxx

	 * so we subtract NSEC_PER_SEC and add 1 to the upper 32 bit.

	 *

	 * it's equivalent to:

	 *   tv.nsec -= NSEC_PER_SEC

	 *   tv.sec ++;

	 */

	if (res.tv.nsec >= NSEC_PER_SEC)

		res.tv64 += (u32)-NSEC_PER_SEC;

	return res;

}

/**

 * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable

 *

 * @kt:		addend

 * @nsec:	the scalar nsec value to add

 *

 * Returns the sum of kt and nsec in ktime_t format

 */

extern ktime_t ktime_add_ns(const ktime_t kt, u64 nsec);

/**

 * timespec_to_ktime - convert a timespec to ktime_t format

 *

 * @ts:		the timespec variable to convert

 *

 * Returns a ktime_t variable with the converted timespec value

 */

static inline ktime_t timespec_to_ktime(const struct timespec ts)

{

	return (ktime_t) { .tv = { .sec = (s32)ts.tv_sec,

			   	   .nsec = (s32)ts.tv_nsec } };

}

/**

 * timeval_to_ktime - convert a timeval to ktime_t format

 *

 * @tv:		the timeval variable to convert

 *

 * Returns a ktime_t variable with the converted timeval value

 */

static inline ktime_t timeval_to_ktime(const struct timeval tv)

{

	return (ktime_t) { .tv = { .sec = (s32)tv.tv_sec,

				   .nsec = (s32)tv.tv_usec * 1000 } };

}

/**

 * ktime_to_timespec - convert a ktime_t variable to timespec format

 *

 * @kt:		the ktime_t variable to convert

 *

 * Returns the timespec representation of the ktime value

 */

static inline struct timespec ktime_to_timespec(const ktime_t kt)

{

	return (struct timespec) { .tv_sec = (time_t) kt.tv.sec,

				   .tv_nsec = (long) kt.tv.nsec };

}

/**

 * ktime_to_timeval - convert a ktime_t variable to timeval format

 *

 * @kt:		the ktime_t variable to convert

 *

 * Returns the timeval representation of the ktime value

 */

static inline struct timeval ktime_to_timeval(const ktime_t kt)

{

	return (struct timeval) {

		.tv_sec = (time_t) kt.tv.sec,

		.tv_usec = (suseconds_t) (kt.tv.nsec / NSEC_PER_USEC) };

}

/**

 * ktime_to_clock_t - convert a ktime_t variable to clock_t format

 * @kt:		the ktime_t variable to convert

 *

 * Returns a clock_t variable with the converted value

 */

static inline clock_t ktime_to_clock_t(const ktime_t kt)

{

	return nsec_to_clock_t( (u64) kt.tv.sec * NSEC_PER_SEC + kt.tv.nsec);

}

/**

 * ktime_to_ns - convert a ktime_t variable to scalar nanoseconds

 * @kt:		the ktime_t variable to convert

 *

 * Returns the scalar nanoseconds representation of kt

 */

static inline u64 ktime_to_ns(const ktime_t kt)

{

	return (u64) kt.tv.sec * NSEC_PER_SEC + kt.tv.nsec;

}

#endif

#endif