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Diffstat (limited to 'arch/m68knommu/kernel/time.c')
| -rw-r--r-- | arch/m68knommu/kernel/time.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/arch/m68knommu/kernel/time.c b/arch/m68knommu/kernel/time.c new file mode 100644 index 00000000000..5c3ca671627 --- /dev/null +++ b/arch/m68knommu/kernel/time.c @@ -0,0 +1,198 @@ +/* + * 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/config.h> +#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> + +#define TICK_SIZE (tick_nsec / 1000) + +u64 jiffies_64 = INITIAL_JIFFIES; + +EXPORT_SYMBOL(jiffies_64); + +extern unsigned long wall_jiffies; + + +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) +{ + /* 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(regs); +#ifndef CONFIG_SMP + update_process_times(user_mode(regs)); +#endif + if (current->pid) + profile_tick(CPU_PROFILING, regs); + + /* + * 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 ((time_status & STA_UNSYNC) == 0 && + 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 lost, seq; + unsigned long usec, sec; + + do { + seq = read_seqbegin_irqsave(&xtime_lock, flags); + usec = mach_gettimeoffset ? mach_gettimeoffset() : 0; + lost = jiffies - wall_jiffies; + if (lost) + usec += lost * (1000000 / HZ); + 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); + + time_adjust = 0; /* stop active adjtime() */ + time_status |= STA_UNSYNC; + time_maxerror = NTP_PHASE_LIMIT; + time_esterror = NTP_PHASE_LIMIT; + write_sequnlock_irq(&xtime_lock); + clock_was_set(); + return 0; +} + +/* + * Scheduler clock - returns current time in nanosec units. + */ +unsigned long long sched_clock(void) +{ + return (unsigned long long)jiffies * (1000000000 / HZ); +} + +EXPORT_SYMBOL(do_settimeofday); |