diff options
Diffstat (limited to 'kernel/time/ntp.c')
| -rw-r--r-- | kernel/time/ntp.c | 133 |
1 files changed, 90 insertions, 43 deletions
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index df9718bac8d0..5125ddd8196b 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -16,6 +16,7 @@ #include <linux/hrtimer.h> #include <linux/capability.h> #include <linux/math64.h> +#include <linux/clocksource.h> #include <asm/timex.h> /* @@ -26,6 +27,8 @@ unsigned long tick_nsec; /* ACTHZ period (nsec) */ u64 tick_length; static u64 tick_length_base; +static struct hrtimer leap_timer; + #define MAX_TICKADJ 500 /* microsecs */ #define MAX_TICKADJ_SCALED (((u64)(MAX_TICKADJ * NSEC_PER_USEC) << \ NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ) @@ -120,64 +123,70 @@ void ntp_clear(void) } /* - * this routine handles the overflow of the microsecond field - * - * The tricky bits of code to handle the accurate clock support - * were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame. - * They were originally developed for SUN and DEC kernels. - * All the kudos should go to Dave for this stuff. + * Leap second processing. If in leap-insert state at the end of the + * day, the system clock is set back one second; if in leap-delete + * state, the system clock is set ahead one second. */ -void second_overflow(void) +static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer) { - s64 time_adj; + enum hrtimer_restart res = HRTIMER_NORESTART; - /* Bump the maxerror field */ - time_maxerror += MAXFREQ / NSEC_PER_USEC; - if (time_maxerror > NTP_PHASE_LIMIT) { - time_maxerror = NTP_PHASE_LIMIT; - time_status |= STA_UNSYNC; - } + write_seqlock_irq(&xtime_lock); - /* - * Leap second processing. If in leap-insert state at the end of the - * day, the system clock is set back one second; if in leap-delete - * state, the system clock is set ahead one second. The microtime() - * routine or external clock driver will insure that reported time is - * always monotonic. The ugly divides should be replaced. - */ switch (time_state) { case TIME_OK: - if (time_status & STA_INS) - time_state = TIME_INS; - else if (time_status & STA_DEL) - time_state = TIME_DEL; break; case TIME_INS: - if (xtime.tv_sec % 86400 == 0) { - xtime.tv_sec--; - wall_to_monotonic.tv_sec++; - time_state = TIME_OOP; - printk(KERN_NOTICE "Clock: inserting leap second " - "23:59:60 UTC\n"); - } + xtime.tv_sec--; + wall_to_monotonic.tv_sec++; + time_state = TIME_OOP; + printk(KERN_NOTICE "Clock: " + "inserting leap second 23:59:60 UTC\n"); + leap_timer.expires = ktime_add_ns(leap_timer.expires, + NSEC_PER_SEC); + res = HRTIMER_RESTART; break; case TIME_DEL: - if ((xtime.tv_sec + 1) % 86400 == 0) { - xtime.tv_sec++; - time_tai--; - wall_to_monotonic.tv_sec--; - time_state = TIME_WAIT; - printk(KERN_NOTICE "Clock: deleting leap second " - "23:59:59 UTC\n"); - } + xtime.tv_sec++; + time_tai--; + wall_to_monotonic.tv_sec--; + time_state = TIME_WAIT; + printk(KERN_NOTICE "Clock: " + "deleting leap second 23:59:59 UTC\n"); break; case TIME_OOP: time_tai++; time_state = TIME_WAIT; - break; + /* fall through */ case TIME_WAIT: if (!(time_status & (STA_INS | STA_DEL))) time_state = TIME_OK; + break; + } + update_vsyscall(&xtime, clock); + + write_sequnlock_irq(&xtime_lock); + + return res; +} + +/* + * this routine handles the overflow of the microsecond field + * + * The tricky bits of code to handle the accurate clock support + * were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame. + * They were originally developed for SUN and DEC kernels. + * All the kudos should go to Dave for this stuff. + */ +void second_overflow(void) +{ + s64 time_adj; + + /* Bump the maxerror field */ + time_maxerror += MAXFREQ / NSEC_PER_USEC; + if (time_maxerror > NTP_PHASE_LIMIT) { + time_maxerror = NTP_PHASE_LIMIT; + time_status |= STA_UNSYNC; } /* @@ -268,7 +277,7 @@ static inline void notify_cmos_timer(void) { } int do_adjtimex(struct timex *txc) { struct timespec ts; - long save_adjust; + long save_adjust, sec; int result; /* In order to modify anything, you gotta be super-user! */ @@ -289,6 +298,10 @@ int do_adjtimex(struct timex *txc) txc->tick > 1100000/USER_HZ) return -EINVAL; + if (time_state != TIME_OK && txc->modes & ADJ_STATUS) + hrtimer_cancel(&leap_timer); + getnstimeofday(&ts); + write_seqlock_irq(&xtime_lock); /* Save for later - semantics of adjtime is to return old value */ @@ -305,6 +318,34 @@ int do_adjtimex(struct timex *txc) /* only set allowed bits */ time_status &= STA_RONLY; time_status |= txc->status & ~STA_RONLY; + + switch (time_state) { + case TIME_OK: + start_timer: + sec = ts.tv_sec; + if (time_status & STA_INS) { + time_state = TIME_INS; + sec += 86400 - sec % 86400; + hrtimer_start(&leap_timer, ktime_set(sec, 0), HRTIMER_MODE_ABS); + } else if (time_status & STA_DEL) { + time_state = TIME_DEL; + sec += 86400 - (sec + 1) % 86400; + hrtimer_start(&leap_timer, ktime_set(sec, 0), HRTIMER_MODE_ABS); + } + break; + case TIME_INS: + case TIME_DEL: + time_state = TIME_OK; + goto start_timer; + break; + case TIME_WAIT: + if (!(time_status & (STA_INS | STA_DEL))) + time_state = TIME_OK; + break; + case TIME_OOP: + hrtimer_restart(&leap_timer); + break; + } } if (txc->modes & ADJ_NANO) @@ -384,7 +425,6 @@ int do_adjtimex(struct timex *txc) txc->stbcnt = 0; write_sequnlock_irq(&xtime_lock); - getnstimeofday(&ts); txc->time.tv_sec = ts.tv_sec; txc->time.tv_usec = ts.tv_nsec; if (!(time_status & STA_NANO)) @@ -402,3 +442,10 @@ static int __init ntp_tick_adj_setup(char *str) } __setup("ntp_tick_adj=", ntp_tick_adj_setup); + +void __init ntp_init(void) +{ + ntp_clear(); + hrtimer_init(&leap_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS); + leap_timer.function = ntp_leap_second; +} |