diff options
Diffstat (limited to 'arch/m68k/kernel/time.c')
| -rw-r--r-- | arch/m68k/kernel/time.c | 51 |
1 files changed, 34 insertions, 17 deletions
diff --git a/arch/m68k/kernel/time.c b/arch/m68k/kernel/time.c index 8f11a00d8..107d0de7f 100644 --- a/arch/m68k/kernel/time.c +++ b/arch/m68k/kernel/time.c @@ -5,6 +5,9 @@ * * 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 */ @@ -65,9 +68,10 @@ static void timer_interrupt(int irq, void *dummy, struct pt_regs * regs) * 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_state != TIME_BAD && xtime.tv_sec > last_rtc_update + 660 && - xtime.tv_usec > 500000 - (tick >> 1) && - xtime.tv_usec < 500000 + (tick >> 1)) { + if ((time_status & STA_UNSYNC) == 0 && + xtime.tv_sec > last_rtc_update + 660 && + xtime.tv_usec >= 500000 - ((unsigned) tick) / 2 && + xtime.tv_usec <= 500000 + ((unsigned) tick) / 2) { if (set_rtc_mmss(xtime.tv_sec) == 0) last_rtc_update = xtime.tv_sec; else @@ -146,27 +150,38 @@ void time_init(void) mach_sched_init(timer_interrupt); } +extern rwlock_t xtime_lock; + /* * This version of gettimeofday has near microsecond resolution. */ void do_gettimeofday(struct timeval *tv) { + extern volatile unsigned long lost_ticks; unsigned long flags; - - save_flags(flags); - cli(); - *tv = xtime; - tv->tv_usec += mach_gettimeoffset(); - if (tv->tv_usec >= 1000000) { - tv->tv_usec -= 1000000; - tv->tv_sec++; + unsigned long usec, sec, lost; + + read_lock_irqsave(&xtime_lock, flags); + usec = mach_gettimeoffset(); + lost = lost_ticks; + if (lost) + usec += lost * (1000000/HZ); + sec = xtime.tv_sec; + usec += xtime.tv_usec; + read_unlock_irqrestore(&xtime_lock, flags); + + while (usec >= 1000000) { + usec -= 1000000; + sec++; } - restore_flags(flags); + + tv->tv_sec = sec; + tv->tv_usec = usec; } void do_settimeofday(struct timeval *tv) { - cli(); + write_lock_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. @@ -175,14 +190,16 @@ void do_settimeofday(struct timeval *tv) */ tv->tv_usec -= mach_gettimeoffset(); - if (tv->tv_usec < 0) { + while (tv->tv_usec < 0) { tv->tv_usec += 1000000; tv->tv_sec--; } xtime = *tv; - time_state = TIME_BAD; - time_maxerror = MAXPHASE; - time_esterror = MAXPHASE; + time_adjust = 0; /* stop active adjtime() */ + time_status |= STA_UNSYNC; + time_state = TIME_ERROR; /* p. 24, (a) */ + time_maxerror = NTP_PHASE_LIMIT; + time_esterror = NTP_PHASE_LIMIT; sti(); } |