[linux-2.6-block.git] / include / linux / clocksource.h

/*  linux/include/linux/clocksource.h
 *
 *  This file contains the structure definitions for clocksources.
 *
 *  If you are not a clocksource, or timekeeping code, you should
 *  not be including this file!
 */
#ifndef _LINUX_CLOCKSOURCE_H
#define _LINUX_CLOCKSOURCE_H

#include <linux/types.h>
#include <linux/timex.h>
#include <linux/time.h>
#include <linux/list.h>
#include <linux/cache.h>
#include <linux/timer.h>
#include <linux/init.h>
#include <asm/div64.h>
#include <asm/io.h>

/* clocksource cycle base type */
typedef u64 cycle_t;
struct clocksource;

#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
#include <asm/clocksource.h>
#endif

/**
 * struct cyclecounter - hardware abstraction for a free running counter
 *	Provides completely state-free accessors to the underlying hardware.
 *	Depending on which hardware it reads, the cycle counter may wrap
 *	around quickly. Locking rules (if necessary) have to be defined
 *	by the implementor and user of specific instances of this API.
 *
 * @read:		returns the current cycle value
 * @mask:		bitmask for two's complement
 *			subtraction of non 64 bit counters,
 *			see CLOCKSOURCE_MASK() helper macro
 * @mult:		cycle to nanosecond multiplier
 * @shift:		cycle to nanosecond divisor (power of two)
 */
struct cyclecounter {
	cycle_t (*read)(const struct cyclecounter *cc);
	cycle_t mask;
	u32 mult;
	u32 shift;
};

/**
 * struct timecounter - layer above a %struct cyclecounter which counts nanoseconds
 *	Contains the state needed by timecounter_read() to detect
 *	cycle counter wrap around. Initialize with
 *	timecounter_init(). Also used to convert cycle counts into the
 *	corresponding nanosecond counts with timecounter_cyc2time(). Users
 *	of this code are responsible for initializing the underlying
 *	cycle counter hardware, locking issues and reading the time
 *	more often than the cycle counter wraps around. The nanosecond
 *	counter will only wrap around after ~585 years.
 *
 * @cc:			the cycle counter used by this instance
 * @cycle_last:		most recent cycle counter value seen by
 *			timecounter_read()
 * @nsec:		continuously increasing count
 */
struct timecounter {
	const struct cyclecounter *cc;
	cycle_t cycle_last;
	u64 nsec;
};

/**
 * cyclecounter_cyc2ns - converts cycle counter cycles to nanoseconds
 * @tc:		Pointer to cycle counter.
 * @cycles:	Cycles
 *
 * XXX - This could use some mult_lxl_ll() asm optimization. Same code
 * as in cyc2ns, but with unsigned result.
 */
static inline u64 cyclecounter_cyc2ns(const struct cyclecounter *cc,
				      cycle_t cycles)
{
	u64 ret = (u64)cycles;
	ret = (ret * cc->mult) >> cc->shift;
	return ret;
}

/**
 * timecounter_init - initialize a time counter
 * @tc:			Pointer to time counter which is to be initialized/reset
 * @cc:			A cycle counter, ready to be used.
 * @start_tstamp:	Arbitrary initial time stamp.
 *
 * After this call the current cycle register (roughly) corresponds to
 * the initial time stamp. Every call to timecounter_read() increments
 * the time stamp counter by the number of elapsed nanoseconds.
 */
extern void timecounter_init(struct timecounter *tc,
			     const struct cyclecounter *cc,
			     u64 start_tstamp);

/**
 * timecounter_read - return nanoseconds elapsed since timecounter_init()
 *                    plus the initial time stamp
 * @tc:          Pointer to time counter.
 *
 * In other words, keeps track of time since the same epoch as
 * the function which generated the initial time stamp.
 */
extern u64 timecounter_read(struct timecounter *tc);

/**
 * timecounter_cyc2time - convert a cycle counter to same
 *                        time base as values returned by
 *                        timecounter_read()
 * @tc:		Pointer to time counter.
 * @cycle:	a value returned by tc->cc->read()
 *
 * Cycle counts that are converted correctly as long as they
 * fall into the interval [-1/2 max cycle count, +1/2 max cycle count],
 * with "max cycle count" == cs->mask+1.
 *
 * This allows conversion of cycle counter values which were generated
 * in the past.
 */
extern u64 timecounter_cyc2time(struct timecounter *tc,
				cycle_t cycle_tstamp);

/**
 * struct clocksource - hardware abstraction for a free running counter
 *	Provides mostly state-free accessors to the underlying hardware.
 *	This is the structure used for system time.
 *
 * @name:		ptr to clocksource name
 * @list:		list head for registration
 * @rating:		rating value for selection (higher is better)
 *			To avoid rating inflation the following
 *			list should give you a guide as to how
 *			to assign your clocksource a rating
 *			1-99: Unfit for real use
 *				Only available for bootup and testing purposes.
 *			100-199: Base level usability.
 *				Functional for real use, but not desired.
 *			200-299: Good.
 *				A correct and usable clocksource.
 *			300-399: Desired.
 *				A reasonably fast and accurate clocksource.
 *			400-499: Perfect
 *				The ideal clocksource. A must-use where
 *				available.
 * @read:		returns a cycle value, passes clocksource as argument
 * @enable:		optional function to enable the clocksource
 * @disable:		optional function to disable the clocksource
 * @mask:		bitmask for two's complement
 *			subtraction of non 64 bit counters
 * @mult:		cycle to nanosecond multiplier
 * @shift:		cycle to nanosecond divisor (power of two)
 * @max_idle_ns:	max idle time permitted by the clocksource (nsecs)
 * @flags:		flags describing special properties
 * @archdata:		arch-specific data
 * @suspend:		suspend function for the clocksource, if necessary
 * @resume:		resume function for the clocksource, if necessary
 */
struct clocksource {
	/*
	 * Hotpath data, fits in a single cache line when the
	 * clocksource itself is cacheline aligned.
	 */
	cycle_t (*read)(struct clocksource *cs);
	cycle_t cycle_last;
	cycle_t mask;
	u32 mult;
	u32 shift;
	u64 max_idle_ns;

#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
	struct arch_clocksource_data archdata;
#endif

	const char *name;
	struct list_head list;
	int rating;
	int (*enable)(struct clocksource *cs);
	void (*disable)(struct clocksource *cs);
	unsigned long flags;
	void (*suspend)(struct clocksource *cs);
	void (*resume)(struct clocksource *cs);

#ifdef CONFIG_CLOCKSOURCE_WATCHDOG
	/* Watchdog related data, used by the framework */
	struct list_head wd_list;
	cycle_t cs_last;
	cycle_t wd_last;
#endif
} ____cacheline_aligned;

/*
 * Clock source flags bits::
 */
#define CLOCK_SOURCE_IS_CONTINUOUS		0x01
#define CLOCK_SOURCE_MUST_VERIFY		0x02

#define CLOCK_SOURCE_WATCHDOG			0x10
#define CLOCK_SOURCE_VALID_FOR_HRES		0x20
#define CLOCK_SOURCE_UNSTABLE			0x40

/* simplify initialization of mask field */
#define CLOCKSOURCE_MASK(bits) (cycle_t)((bits) < 64 ? ((1ULL<<(bits))-1) : -1)

/**
 * clocksource_khz2mult - calculates mult from khz and shift
 * @khz:		Clocksource frequency in KHz
 * @shift_constant:	Clocksource shift factor
 *
 * Helper functions that converts a khz counter frequency to a timsource
 * multiplier, given the clocksource shift value
 */
static inline u32 clocksource_khz2mult(u32 khz, u32 shift_constant)
{
	/*  khz = cyc/(Million ns)
	 *  mult/2^shift  = ns/cyc
	 *  mult = ns/cyc * 2^shift
	 *  mult = 1Million/khz * 2^shift
	 *  mult = 1000000 * 2^shift / khz
	 *  mult = (1000000<<shift) / khz
	 */
	u64 tmp = ((u64)1000000) << shift_constant;

	tmp += khz/2; /* round for do_div */
	do_div(tmp, khz);

	return (u32)tmp;
}

/**
 * clocksource_hz2mult - calculates mult from hz and shift
 * @hz:			Clocksource frequency in Hz
 * @shift_constant:	Clocksource shift factor
 *
 * Helper functions that converts a hz counter
 * frequency to a timsource multiplier, given the
 * clocksource shift value
 */
static inline u32 clocksource_hz2mult(u32 hz, u32 shift_constant)
{
	/*  hz = cyc/(Billion ns)
	 *  mult/2^shift  = ns/cyc
	 *  mult = ns/cyc * 2^shift
	 *  mult = 1Billion/hz * 2^shift
	 *  mult = 1000000000 * 2^shift / hz
	 *  mult = (1000000000<<shift) / hz
	 */
	u64 tmp = ((u64)1000000000) << shift_constant;

	tmp += hz/2; /* round for do_div */
	do_div(tmp, hz);

	return (u32)tmp;
}

/**
 * clocksource_cyc2ns - converts clocksource cycles to nanoseconds
 *
 * Converts cycles to nanoseconds, using the given mult and shift.
 *
 * XXX - This could use some mult_lxl_ll() asm optimization
 */
static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift)
{
	return ((u64) cycles * mult) >> shift;
}


extern int clocksource_register(struct clocksource*);
extern void clocksource_unregister(struct clocksource*);
extern void clocksource_touch_watchdog(void);
extern struct clocksource* clocksource_get_next(void);
extern void clocksource_change_rating(struct clocksource *cs, int rating);
extern void clocksource_suspend(void);
extern void clocksource_resume(void);
extern struct clocksource * __init __weak clocksource_default_clock(void);
extern void clocksource_mark_unstable(struct clocksource *cs);

extern void
clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec);

/*
 * Don't call __clocksource_register_scale directly, use
 * clocksource_register_hz/khz
 */
extern int
__clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq);
extern void
__clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq);

static inline int clocksource_register_hz(struct clocksource *cs, u32 hz)
{
	return __clocksource_register_scale(cs, 1, hz);
}

static inline int clocksource_register_khz(struct clocksource *cs, u32 khz)
{
	return __clocksource_register_scale(cs, 1000, khz);
}

static inline void __clocksource_updatefreq_hz(struct clocksource *cs, u32 hz)
{
	__clocksource_updatefreq_scale(cs, 1, hz);
}

static inline void __clocksource_updatefreq_khz(struct clocksource *cs, u32 khz)
{
	__clocksource_updatefreq_scale(cs, 1000, khz);
}

static inline void
clocksource_calc_mult_shift(struct clocksource *cs, u32 freq, u32 minsec)
{
	return clocks_calc_mult_shift(&cs->mult, &cs->shift, freq,
				      NSEC_PER_SEC, minsec);
}

#ifdef CONFIG_GENERIC_TIME_VSYSCALL
extern void
update_vsyscall(struct timespec *ts, struct timespec *wtm,
			struct clocksource *c, u32 mult);
extern void update_vsyscall_tz(void);
#else
static inline void
update_vsyscall(struct timespec *ts, struct timespec *wtm,
			struct clocksource *c, u32 mult)
{
}

static inline void update_vsyscall_tz(void)
{
}
#endif

extern void timekeeping_notify(struct clocksource *clock);

extern cycle_t clocksource_mmio_readl_up(struct clocksource *);
extern cycle_t clocksource_mmio_readl_down(struct clocksource *);
extern cycle_t clocksource_mmio_readw_up(struct clocksource *);
extern cycle_t clocksource_mmio_readw_down(struct clocksource *);

extern int clocksource_mmio_init(void __iomem *, const char *,
	unsigned long, int, unsigned, cycle_t (*)(struct clocksource *));

extern int clocksource_i8253_init(void);

#endif /* _LINUX_CLOCKSOURCE_H */
Commit	Line	Data
734efb46	1	/* linux/include/linux/clocksource.h
	2	*
	3	* This file contains the structure definitions for clocksources.
	4	*
	5	* If you are not a clocksource, or timekeeping code, you should
	6	* not be including this file!
	7	*/
	8	#ifndef _LINUX_CLOCKSOURCE_H
	9	#define _LINUX_CLOCKSOURCE_H
	10
	11	#include <linux/types.h>
	12	#include <linux/timex.h>
	13	#include <linux/time.h>
	14	#include <linux/list.h>
329c8d84	15	#include <linux/cache.h>
5d8b34fd	16	#include <linux/timer.h>
f1b82746	17	#include <linux/init.h>
734efb46	18	#include <asm/div64.h>
	19	#include <asm/io.h>
	20
	21	/* clocksource cycle base type */
	22	typedef u64 cycle_t;
5d8b34fd	23	struct clocksource;
734efb46	24
ae7bd11b	25	#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
433bd805	26	#include <asm/clocksource.h>
ae7bd11b	27	#endif
433bd805	28
a038a353 PO	29	/**
	30	* struct cyclecounter - hardware abstraction for a free running counter
	31	* Provides completely state-free accessors to the underlying hardware.
	32	* Depending on which hardware it reads, the cycle counter may wrap
	33	* around quickly. Locking rules (if necessary) have to be defined
	34	* by the implementor and user of specific instances of this API.
	35	*
	36	* @read: returns the current cycle value
	37	* @mask: bitmask for two's complement
	38	* subtraction of non 64 bit counters,
	39	* see CLOCKSOURCE_MASK() helper macro
	40	* @mult: cycle to nanosecond multiplier
	41	* @shift: cycle to nanosecond divisor (power of two)
	42	*/
	43	struct cyclecounter {
	44	cycle_t (read)(const struct cyclecounter cc);
	45	cycle_t mask;
	46	u32 mult;
	47	u32 shift;
	48	};
	49
	50	/**
	51	* struct timecounter - layer above a %struct cyclecounter which counts nanoseconds
	52	* Contains the state needed by timecounter_read() to detect
	53	* cycle counter wrap around. Initialize with
	54	* timecounter_init(). Also used to convert cycle counts into the
	55	* corresponding nanosecond counts with timecounter_cyc2time(). Users
	56	* of this code are responsible for initializing the underlying
	57	* cycle counter hardware, locking issues and reading the time
	58	* more often than the cycle counter wraps around. The nanosecond
	59	* counter will only wrap around after ~585 years.
	60	*
	61	* @cc: the cycle counter used by this instance
	62	* @cycle_last: most recent cycle counter value seen by
	63	* timecounter_read()
	64	* @nsec: continuously increasing count
	65	*/
	66	struct timecounter {
	67	const struct cyclecounter *cc;
	68	cycle_t cycle_last;
	69	u64 nsec;
	70	};
	71
	72	/**
	73	* cyclecounter_cyc2ns - converts cycle counter cycles to nanoseconds
	74	* @tc: Pointer to cycle counter.
	75	* @cycles: Cycles
	76	*
	77	* XXX - This could use some mult_lxl_ll() asm optimization. Same code
	78	* as in cyc2ns, but with unsigned result.
	79	*/
	80	static inline u64 cyclecounter_cyc2ns(const struct cyclecounter *cc,
	81	cycle_t cycles)
	82	{
	83	u64 ret = (u64)cycles;
	84	ret = (ret * cc->mult) >> cc->shift;
	85	return ret;
	86	}
	87
	88	/**
	89	* timecounter_init - initialize a time counter
	90	* @tc: Pointer to time counter which is to be initialized/reset
	91	* @cc: A cycle counter, ready to be used.
	92	* @start_tstamp: Arbitrary initial time stamp.
93	*
94	* After this call the current cycle register (roughly) corresponds to
95	* the initial time stamp. Every call to timecounter_read() increments
96	* the time stamp counter by the number of elapsed nanoseconds.
97	*/
98	extern void timecounter_init(struct timecounter *tc,
99	const struct cyclecounter *cc,
100	u64 start_tstamp);
101
102	/**
103	* timecounter_read - return nanoseconds elapsed since timecounter_init()
104	* plus the initial time stamp
105	* @tc: Pointer to time counter.
106	*
107	* In other words, keeps track of time since the same epoch as
108	* the function which generated the initial time stamp.
109	*/
110	extern u64 timecounter_read(struct timecounter *tc);
111
112	/**
113	* timecounter_cyc2time - convert a cycle counter to same
114	* time base as values returned by
115	* timecounter_read()
116	* @tc: Pointer to time counter.
117	* @cycle: a value returned by tc->cc->read()
118	*
119	* Cycle counts that are converted correctly as long as they
120	* fall into the interval [-1/2 max cycle count, +1/2 max cycle count],
121	* with "max cycle count" == cs->mask+1.
122	*
123	* This allows conversion of cycle counter values which were generated
124	* in the past.
125	*/
126	extern u64 timecounter_cyc2time(struct timecounter *tc,
127	cycle_t cycle_tstamp);
128
734efb46	129	/**
	130	* struct clocksource - hardware abstraction for a free running counter
	131	* Provides mostly state-free accessors to the underlying hardware.
a038a353	132	* This is the structure used for system time.
734efb46	133	*
	134	* @name: ptr to clocksource name
	135	* @list: list head for registration
	136	* @rating: rating value for selection (higher is better)
	137	* To avoid rating inflation the following
	138	* list should give you a guide as to how
	139	* to assign your clocksource a rating
	140	* 1-99: Unfit for real use
	141	* Only available for bootup and testing purposes.
	142	* 100-199: Base level usability.
	143	* Functional for real use, but not desired.
	144	* 200-299: Good.
	145	* A correct and usable clocksource.
	146	* 300-399: Desired.
	147	* A reasonably fast and accurate clocksource.
	148	* 400-499: Perfect
	149	* The ideal clocksource. A must-use where
	150	* available.
8e19608e	151	* @read: returns a cycle value, passes clocksource as argument
4614e6ad MD	152	* @enable: optional function to enable the clocksource
4614e6ad MD	153	* @disable: optional function to disable the clocksource
734efb46	154	* @mask: bitmask for two's complement
734efb46	155	* subtraction of non 64 bit counters
0a544198	156	* @mult: cycle to nanosecond multiplier
734efb46	157	* @shift: cycle to nanosecond divisor (power of two)
98962465	158	* @max_idle_ns: max idle time permitted by the clocksource (nsecs)
73b08d2a	159	* @flags: flags describing special properties
433bd805	160	* @archdata: arch-specific data
c54a42b1	161	* @suspend: suspend function for the clocksource, if necessary
b52f52a0	162	* @resume: resume function for the clocksource, if necessary
734efb46	163	*/
734efb46	164	struct clocksource {
329c8d84	165	/*
369db4c9 TG	166	* Hotpath data, fits in a single cache line when the
369db4c9 TG	167	* clocksource itself is cacheline aligned.
329c8d84	168	*/
8e19608e	169	cycle_t (read)(struct clocksource cs);
369db4c9	170	cycle_t cycle_last;
734efb46	171	cycle_t mask;
	172	u32 mult;
	173	u32 shift;
98962465	174	u64 max_idle_ns;
369db4c9	175
ae7bd11b	176	#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
433bd805	177	struct arch_clocksource_data archdata;
0aa366f3	178	#endif
433bd805	179
369db4c9 TG	180	const char *name;
	181	struct list_head list;
	182	int rating;
369db4c9 TG	183	int (enable)(struct clocksource cs);
	184	void (disable)(struct clocksource cs);
	185	unsigned long flags;
	186	void (suspend)(struct clocksource cs);
	187	void (resume)(struct clocksource cs);
5d8b34fd TG	188
	189	#ifdef CONFIG_CLOCKSOURCE_WATCHDOG
	190	/* Watchdog related data, used by the framework */
	191	struct list_head wd_list;
b5199515	192	cycle_t cs_last;
5d8b34fd TG	193	cycle_t wd_last;
5d8b34fd TG	194	#endif
369db4c9	195	} ____cacheline_aligned;
734efb46	196
73b08d2a TG	197	/*
	198	* Clock source flags bits::
	199	*/
5d8b34fd TG	200	#define CLOCK_SOURCE_IS_CONTINUOUS 0x01
	201	#define CLOCK_SOURCE_MUST_VERIFY 0x02
	202
	203	#define CLOCK_SOURCE_WATCHDOG 0x10
	204	#define CLOCK_SOURCE_VALID_FOR_HRES 0x20
c55c87c8	205	#define CLOCK_SOURCE_UNSTABLE 0x40
73b08d2a	206
7f9f303a	207	/* simplify initialization of mask field */
1d76c262	208	#define CLOCKSOURCE_MASK(bits) (cycle_t)((bits) < 64 ? ((1ULL<<(bits))-1) : -1)
734efb46	209
	210	/**
	211	* clocksource_khz2mult - calculates mult from khz and shift
	212	* @khz: Clocksource frequency in KHz
	213	* @shift_constant: Clocksource shift factor
	214	*
	215	* Helper functions that converts a khz counter frequency to a timsource
	216	* multiplier, given the clocksource shift value
	217	*/
	218	static inline u32 clocksource_khz2mult(u32 khz, u32 shift_constant)
	219	{
	220	/* khz = cyc/(Million ns)
	221	* mult/2^shift = ns/cyc
	222	* mult = ns/cyc * 2^shift
	223	* mult = 1Million/khz * 2^shift
	224	* mult = 1000000 * 2^shift / khz
	225	* mult = (1000000<<shift) / khz
	226	*/
	227	u64 tmp = ((u64)1000000) << shift_constant;
	228
	229	tmp += khz/2; /* round for do_div */
	230	do_div(tmp, khz);
	231
	232	return (u32)tmp;
	233	}
	234
	235	/**
	236	* clocksource_hz2mult - calculates mult from hz and shift
	237	* @hz: Clocksource frequency in Hz
	238	* @shift_constant: Clocksource shift factor
	239	*
	240	* Helper functions that converts a hz counter
	241	* frequency to a timsource multiplier, given the
	242	* clocksource shift value
	243	*/
	244	static inline u32 clocksource_hz2mult(u32 hz, u32 shift_constant)
	245	{
	246	/* hz = cyc/(Billion ns)
	247	* mult/2^shift = ns/cyc
	248	* mult = ns/cyc * 2^shift
	249	* mult = 1Billion/hz * 2^shift
	250	* mult = 1000000000 * 2^shift / hz
	251	* mult = (1000000000<<shift) / hz
	252	*/
	253	u64 tmp = ((u64)1000000000) << shift_constant;
	254
	255	tmp += hz/2; /* round for do_div */
	256	do_div(tmp, hz);
	257
	258	return (u32)tmp;
	259	}
	260
734efb46	261	/**
155ec602	262	* clocksource_cyc2ns - converts clocksource cycles to nanoseconds
734efb46	263	*
155ec602	264	* Converts cycles to nanoseconds, using the given mult and shift.
734efb46	265	*
	266	* XXX - This could use some mult_lxl_ll() asm optimization
	267	*/
155ec602	268	static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift)
734efb46	269	{
155ec602	270	return ((u64) cycles * mult) >> shift;
5eb6d205	271	}
	272
	273
92c7e002	274	extern int clocksource_register(struct clocksource*);
4713e22c	275	extern void clocksource_unregister(struct clocksource*);
7c3078b6	276	extern void clocksource_touch_watchdog(void);
92c7e002 TG	277	extern struct clocksource* clocksource_get_next(void);
92c7e002 TG	278	extern void clocksource_change_rating(struct clocksource *cs, int rating);
c54a42b1	279	extern void clocksource_suspend(void);
b52f52a0	280	extern void clocksource_resume(void);
f1b82746	281	extern struct clocksource * __init __weak clocksource_default_clock(void);
7285dd7f	282	extern void clocksource_mark_unstable(struct clocksource *cs);
734efb46	283
7d2f944a TG	284	extern void
	285	clocks_calc_mult_shift(u32 mult, u32 shift, u32 from, u32 to, u32 minsec);
	286
d7e81c26 JS	287	/*
	288	* Don't call __clocksource_register_scale directly, use
	289	* clocksource_register_hz/khz
	290	*/
	291	extern int
	292	__clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq);
852db46d JS	293	extern void
852db46d JS	294	__clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq);
d7e81c26 JS	295
	296	static inline int clocksource_register_hz(struct clocksource *cs, u32 hz)
	297	{
	298	return __clocksource_register_scale(cs, 1, hz);
	299	}
	300
	301	static inline int clocksource_register_khz(struct clocksource *cs, u32 khz)
	302	{
	303	return __clocksource_register_scale(cs, 1000, khz);
	304	}
	305
852db46d JS	306	static inline void __clocksource_updatefreq_hz(struct clocksource *cs, u32 hz)
	307	{
	308	__clocksource_updatefreq_scale(cs, 1, hz);
	309	}
	310
	311	static inline void __clocksource_updatefreq_khz(struct clocksource *cs, u32 khz)
	312	{
	313	__clocksource_updatefreq_scale(cs, 1000, khz);
	314	}
d7e81c26	315
7d2f944a TG	316	static inline void
	317	clocksource_calc_mult_shift(struct clocksource *cs, u32 freq, u32 minsec)
	318	{
	319	return clocks_calc_mult_shift(&cs->mult, &cs->shift, freq,
	320	NSEC_PER_SEC, minsec);
	321	}
	322
acc9a9dc	323	#ifdef CONFIG_GENERIC_TIME_VSYSCALL
0696b711	324	extern void
7615856e JS	325	update_vsyscall(struct timespec ts, struct timespec wtm,
7615856e JS	326	struct clocksource *c, u32 mult);
2c622148	327	extern void update_vsyscall_tz(void);
acc9a9dc	328	#else
0696b711	329	static inline void
7615856e JS	330	update_vsyscall(struct timespec ts, struct timespec wtm,
7615856e JS	331	struct clocksource *c, u32 mult)
acc9a9dc	332	{
acc9a9dc	333	}
2c622148 TB	334
	335	static inline void update_vsyscall_tz(void)
	336	{
	337	}
acc9a9dc	338	#endif
acc9a9dc	339
75c5158f MS	340	extern void timekeeping_notify(struct clocksource *clock);
75c5158f MS	341
442c8176 RK	342	extern cycle_t clocksource_mmio_readl_up(struct clocksource *);
	343	extern cycle_t clocksource_mmio_readl_down(struct clocksource *);
	344	extern cycle_t clocksource_mmio_readw_up(struct clocksource *);
	345	extern cycle_t clocksource_mmio_readw_down(struct clocksource *);
	346
	347	extern int clocksource_mmio_init(void __iomem , const char ,
	348	unsigned long, int, unsigned, cycle_t ()(struct clocksource ));
	349
8c414ff3 RK	350	extern int clocksource_i8253_init(void);
8c414ff3 RK	351
734efb46	352	#endif /* _LINUX_CLOCKSOURCE_H */