mirror of https://gitee.com/openkylin/linux.git
178 lines
4.5 KiB
C
178 lines
4.5 KiB
C
/*
|
|
* linux/arch/m68knommu/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/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/profile.h>
|
|
#include <linux/time.h>
|
|
#include <linux/timex.h>
|
|
|
|
#include <asm/machdep.h>
|
|
#include <asm/io.h>
|
|
#include <asm/irq_regs.h>
|
|
|
|
#define TICK_SIZE (tick_nsec / 1000)
|
|
|
|
|
|
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)
|
|
{
|
|
/* last time the cmos clock got updated */
|
|
static long last_rtc_update=0;
|
|
|
|
/* may need to kick the hardware timer */
|
|
if (mach_tick)
|
|
mach_tick();
|
|
|
|
write_seqlock(&xtime_lock);
|
|
|
|
do_timer(1);
|
|
#ifndef CONFIG_SMP
|
|
update_process_times(user_mode(get_irq_regs()));
|
|
#endif
|
|
if (current->pid)
|
|
profile_tick(CPU_PROFILING);
|
|
|
|
/*
|
|
* If we have an externally synchronized Linux clock, then update
|
|
* CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
|
|
* called as close as possible to 500 ms before the new second starts.
|
|
*/
|
|
if (ntp_synced() &&
|
|
xtime.tv_sec > last_rtc_update + 660 &&
|
|
(xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
|
|
(xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
|
|
if (set_rtc_mmss(xtime.tv_sec) == 0)
|
|
last_rtc_update = xtime.tv_sec;
|
|
else
|
|
last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
|
|
}
|
|
#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 */
|
|
|
|
write_sequnlock(&xtime_lock);
|
|
return(IRQ_HANDLED);
|
|
}
|
|
|
|
void time_init(void)
|
|
{
|
|
unsigned int year, mon, day, hour, min, sec;
|
|
|
|
extern void arch_gettod(int *year, int *mon, int *day, int *hour,
|
|
int *min, int *sec);
|
|
|
|
arch_gettod(&year, &mon, &day, &hour, &min, &sec);
|
|
|
|
if ((year += 1900) < 1970)
|
|
year += 100;
|
|
xtime.tv_sec = mktime(year, mon, day, hour, min, 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;
|
|
unsigned long seq;
|
|
unsigned long usec, sec;
|
|
|
|
do {
|
|
seq = read_seqbegin_irqsave(&xtime_lock, flags);
|
|
usec = mach_gettimeoffset ? mach_gettimeoffset() : 0;
|
|
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;
|
|
|
|
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_usec
|
|
* 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!
|
|
*/
|
|
if (mach_gettimeoffset)
|
|
nsec -= (mach_gettimeoffset() * 1000);
|
|
|
|
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);
|