[mirror_ubuntu-bionic-kernel.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;

#include <asm/clocksource.h>

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