[deliverable/linux.git] / arch / m68k / kernel / time.c

/*
 *  linux/arch/m68k/kernel/time.c
 *
 *  Copyright (C) 1991, 1992, 1995  Linus Torvalds
 *
 * This file contains the m68k-specific time handling details.
 * Most of the stuff is located in the machine specific files.
 *
 * 1997-09-10	Updated NTP code according to technical memorandum Jan '96
 *		"A Kernel Model for Precision Timekeeping" by Dave Mills
 */

#include <linux/config.h> /* CONFIG_HEARTBEAT */
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/rtc.h>

#include <asm/machdep.h>
#include <asm/io.h>

#include <linux/time.h>
#include <linux/timex.h>
#include <linux/profile.h>

static inline int set_rtc_mmss(unsigned long nowtime)
{
  if (mach_set_clock_mmss)
    return mach_set_clock_mmss (nowtime);
  return -1;
}

/*
 * timer_interrupt() needs to keep up the real-time clock,
 * as well as call the "do_timer()" routine every clocktick
 */
static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
{
	do_timer(1);
#ifndef CONFIG_SMP
	update_process_times(user_mode(regs));
#endif
	profile_tick(CPU_PROFILING, regs);

#ifdef CONFIG_HEARTBEAT
	/* use power LED as a heartbeat instead -- much more useful
	   for debugging -- based on the version for PReP by Cort */
	/* acts like an actual heart beat -- ie thump-thump-pause... */
	if (mach_heartbeat) {
	    static unsigned cnt = 0, period = 0, dist = 0;

	    if (cnt == 0 || cnt == dist)
		mach_heartbeat( 1 );
	    else if (cnt == 7 || cnt == dist+7)
		mach_heartbeat( 0 );

	    if (++cnt > period) {
		cnt = 0;
		/* The hyperbolic function below modifies the heartbeat period
		 * length in dependency of the current (5min) load. It goes
		 * through the points f(0)=126, f(1)=86, f(5)=51,
		 * f(inf)->30. */
		period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
		dist = period / 4;
	    }
	}
#endif /* CONFIG_HEARTBEAT */
	return IRQ_HANDLED;
}

void time_init(void)
{
	struct rtc_time time;

	if (mach_hwclk) {
		mach_hwclk(0, &time);

		if ((time.tm_year += 1900) < 1970)
			time.tm_year += 100;
		xtime.tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
				      time.tm_hour, time.tm_min, time.tm_sec);
		xtime.tv_nsec = 0;
	}
	wall_to_monotonic.tv_sec = -xtime.tv_sec;

	mach_sched_init(timer_interrupt);
}

/*
 * This version of gettimeofday has near microsecond resolution.
 */
void do_gettimeofday(struct timeval *tv)
{
	unsigned long flags;
	extern unsigned long wall_jiffies;
	unsigned long seq;
	unsigned long usec, sec, lost;
	unsigned long max_ntp_tick = tick_usec - tickadj;

	do {
		seq = read_seqbegin_irqsave(&xtime_lock, flags);

		usec = mach_gettimeoffset();
		lost = jiffies - wall_jiffies;

		/*
		 * If time_adjust is negative then NTP is slowing the clock
		 * so make sure not to go into next possible interval.
		 * Better to lose some accuracy than have time go backwards..
		 */
		if (unlikely(time_adjust < 0)) {
			usec = min(usec, max_ntp_tick);

			if (lost)
				usec += lost * max_ntp_tick;
		}
		else if (unlikely(lost))
			usec += lost * tick_usec;

		sec = xtime.tv_sec;
		usec += xtime.tv_nsec/1000;
	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));


	while (usec >= 1000000) {
		usec -= 1000000;
		sec++;
	}

	tv->tv_sec = sec;
	tv->tv_usec = usec;
}

EXPORT_SYMBOL(do_gettimeofday);

int do_settimeofday(struct timespec *tv)
{
	time_t wtm_sec, sec = tv->tv_sec;
	long wtm_nsec, nsec = tv->tv_nsec;
	extern unsigned long wall_jiffies;

	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
		return -EINVAL;

	write_seqlock_irq(&xtime_lock);
	/* This is revolting. We need to set the xtime.tv_nsec
	 * correctly. However, the value in this location is
	 * is value at the last tick.
	 * Discover what correction gettimeofday
	 * would have done, and then undo it!
	 */
	nsec -= 1000 * (mach_gettimeoffset() +
			(jiffies - wall_jiffies) * (1000000 / HZ));

	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

	set_normalized_timespec(&xtime, sec, nsec);
	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);

	ntp_clear();
	write_sequnlock_irq(&xtime_lock);
	clock_was_set();
	return 0;
}

EXPORT_SYMBOL(do_settimeofday);

/*
 * Scheduler clock - returns current time in ns units.
 */
unsigned long long sched_clock(void)
{
       return (unsigned long long)jiffies*(1000000000/HZ);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/m68k/kernel/time.c
	3	*
	4	* Copyright (C) 1991, 1992, 1995 Linus Torvalds
	5	*
	6	* This file contains the m68k-specific time handling details.
	7	* Most of the stuff is located in the machine specific files.
	8	*
	9	* 1997-09-10 Updated NTP code according to technical memorandum Jan '96
	10	* "A Kernel Model for Precision Timekeeping" by Dave Mills
	11	*/
	12
	13	#include <linux/config.h> /* CONFIG_HEARTBEAT */
	14	#include <linux/errno.h>
	15	#include <linux/module.h>
	16	#include <linux/sched.h>
	17	#include <linux/kernel.h>
	18	#include <linux/param.h>
	19	#include <linux/string.h>
	20	#include <linux/mm.h>
	21	#include <linux/rtc.h>
	22
	23	#include <asm/machdep.h>
	24	#include <asm/io.h>
	25
	26	#include <linux/time.h>
	27	#include <linux/timex.h>
	28	#include <linux/profile.h>
	29
1da177e4 LT	30	static inline int set_rtc_mmss(unsigned long nowtime)
	31	{
	32	if (mach_set_clock_mmss)
	33	return mach_set_clock_mmss (nowtime);
	34	return -1;
	35	}
	36
	37	/*
	38	* timer_interrupt() needs to keep up the real-time clock,
	39	* as well as call the "do_timer()" routine every clocktick
	40	*/
	41	static irqreturn_t timer_interrupt(int irq, void dummy, struct pt_regs regs)
	42	{
3171a030	43	do_timer(1);
1da177e4 LT	44	#ifndef CONFIG_SMP
	45	update_process_times(user_mode(regs));
	46	#endif
	47	profile_tick(CPU_PROFILING, regs);
	48
	49	#ifdef CONFIG_HEARTBEAT
	50	/* use power LED as a heartbeat instead -- much more useful
	51	for debugging -- based on the version for PReP by Cort */
	52	/* acts like an actual heart beat -- ie thump-thump-pause... */
	53	if (mach_heartbeat) {
	54	static unsigned cnt = 0, period = 0, dist = 0;
	55
	56	if (cnt == 0 \|\| cnt == dist)
	57	mach_heartbeat( 1 );
	58	else if (cnt == 7 \|\| cnt == dist+7)
	59	mach_heartbeat( 0 );
	60
	61	if (++cnt > period) {
	62	cnt = 0;
	63	/* The hyperbolic function below modifies the heartbeat period
	64	* length in dependency of the current (5min) load. It goes
	65	* through the points f(0)=126, f(1)=86, f(5)=51,
	66	* f(inf)->30. */
	67	period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
	68	dist = period / 4;
	69	}
	70	}
	71	#endif /* CONFIG_HEARTBEAT */
	72	return IRQ_HANDLED;
	73	}
	74
	75	void time_init(void)
	76	{
	77	struct rtc_time time;
	78
	79	if (mach_hwclk) {
	80	mach_hwclk(0, &time);
	81
	82	if ((time.tm_year += 1900) < 1970)
	83	time.tm_year += 100;
	84	xtime.tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
	85	time.tm_hour, time.tm_min, time.tm_sec);
	86	xtime.tv_nsec = 0;
	87	}
	88	wall_to_monotonic.tv_sec = -xtime.tv_sec;
	89
	90	mach_sched_init(timer_interrupt);
	91	}
	92
	93	/*
	94	* This version of gettimeofday has near microsecond resolution.
	95	*/
	96	void do_gettimeofday(struct timeval *tv)
	97	{
	98	unsigned long flags;
	99	extern unsigned long wall_jiffies;
	100	unsigned long seq;
	101	unsigned long usec, sec, lost;
	102	unsigned long max_ntp_tick = tick_usec - tickadj;
	103
	104	do {
	105	seq = read_seqbegin_irqsave(&xtime_lock, flags);
	106
	107	usec = mach_gettimeoffset();
108	lost = jiffies - wall_jiffies;
109
110	/*
111	* If time_adjust is negative then NTP is slowing the clock
112	* so make sure not to go into next possible interval.
113	* Better to lose some accuracy than have time go backwards..
114	*/
115	if (unlikely(time_adjust < 0)) {
116	usec = min(usec, max_ntp_tick);
117
118	if (lost)
119	usec += lost * max_ntp_tick;
120	}
121	else if (unlikely(lost))
122	usec += lost * tick_usec;
123
124	sec = xtime.tv_sec;
125	usec += xtime.tv_nsec/1000;
126	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
127
128
129	while (usec >= 1000000) {
130	usec -= 1000000;
131	sec++;
132	}
133
134	tv->tv_sec = sec;
135	tv->tv_usec = usec;
136	}
137
138	EXPORT_SYMBOL(do_gettimeofday);
139
140	int do_settimeofday(struct timespec *tv)
141	{
142	time_t wtm_sec, sec = tv->tv_sec;
143	long wtm_nsec, nsec = tv->tv_nsec;
144	extern unsigned long wall_jiffies;
145
146	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
147	return -EINVAL;
148
149	write_seqlock_irq(&xtime_lock);
150	/* This is revolting. We need to set the xtime.tv_nsec
151	* correctly. However, the value in this location is
152	* is value at the last tick.
153	* Discover what correction gettimeofday
154	* would have done, and then undo it!
155	*/
156	nsec -= 1000 * (mach_gettimeoffset() +
157	(jiffies - wall_jiffies) * (1000000 / HZ));
158
159	wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
160	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
161
162	set_normalized_timespec(&xtime, sec, nsec);
163	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
164
b149ee22	165	ntp_clear();
1da177e4 LT	166	write_sequnlock_irq(&xtime_lock);
	167	clock_was_set();
	168	return 0;
	169	}
	170
	171	EXPORT_SYMBOL(do_settimeofday);
	172
	173	/*
	174	* Scheduler clock - returns current time in ns units.
	175	*/
	176	unsigned long long sched_clock(void)
	177	{
	178	return (unsigned long long)jiffies*(1000000000/HZ);
	179	}
	180