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author | Thomas Gleixner <tglx@linutronix.de> | 2007-07-21 04:37:37 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-21 17:49:15 -0700 |
commit | 82644459c592a28a3eab682f9b88d81019ddfe8b (patch) | |
tree | 738e4edaf54658912e78a8bcdadc3e2165ecb77a /kernel/time/ntp.c | |
parent | 99bc2fcb283852931fb6bbef40f3df8316b59000 (diff) | |
download | kernel_samsung_espresso10-82644459c592a28a3eab682f9b88d81019ddfe8b.zip kernel_samsung_espresso10-82644459c592a28a3eab682f9b88d81019ddfe8b.tar.gz kernel_samsung_espresso10-82644459c592a28a3eab682f9b88d81019ddfe8b.tar.bz2 |
NTP: move the cmos update code into ntp.c
i386 and sparc64 have the identical code to update the cmos clock. Move it
into kernel/time/ntp.c as there are other architectures coming along with the
same requirements.
[akpm@linux-foundation.org: build fixes]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: David Miller <davem@davemloft.net>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/time/ntp.c')
-rw-r--r-- | kernel/time/ntp.c | 59 |
1 files changed, 56 insertions, 3 deletions
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index b5e3525..cd91237 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -10,6 +10,7 @@ #include <linux/mm.h> #include <linux/time.h> +#include <linux/timer.h> #include <linux/timex.h> #include <linux/jiffies.h> #include <linux/hrtimer.h> @@ -175,12 +176,64 @@ u64 current_tick_length(void) return tick_length; } +#ifdef CONFIG_GENERIC_CMOS_UPDATE -void __attribute__ ((weak)) notify_arch_cmos_timer(void) +/* Disable the cmos update - used by virtualization and embedded */ +int no_sync_cmos_clock __read_mostly; + +static void sync_cmos_clock(unsigned long dummy); + +static DEFINE_TIMER(sync_cmos_timer, sync_cmos_clock, 0, 0); + +static void sync_cmos_clock(unsigned long dummy) +{ + struct timespec now, next; + int fail = 1; + + /* + * 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. + * This code is run on a timer. If the clock is set, that timer + * may not expire at the correct time. Thus, we adjust... + */ + if (!ntp_synced()) + /* + * Not synced, exit, do not restart a timer (if one is + * running, let it run out). + */ + return; + + getnstimeofday(&now); + if (abs(xtime.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) + fail = update_persistent_clock(now); + + next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec; + if (next.tv_nsec <= 0) + next.tv_nsec += NSEC_PER_SEC; + + if (!fail) + next.tv_sec = 659; + else + next.tv_sec = 0; + + if (next.tv_nsec >= NSEC_PER_SEC) { + next.tv_sec++; + next.tv_nsec -= NSEC_PER_SEC; + } + mod_timer(&sync_cmos_timer, jiffies + timespec_to_jiffies(&next)); +} + +static void notify_cmos_timer(void) { - return; + if (no_sync_cmos_clock) + mod_timer(&sync_cmos_timer, jiffies + 1); } +#else +static inline void notify_cmos_timer(void) { } +#endif + /* adjtimex mainly allows reading (and writing, if superuser) of * kernel time-keeping variables. used by xntpd. */ @@ -345,6 +398,6 @@ leave: if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0) txc->stbcnt = 0; write_sequnlock_irq(&xtime_lock); do_gettimeofday(&txc->time); - notify_arch_cmos_timer(); + notify_cmos_timer(); return(result); } |