X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fi386%2Fkernel%2Ftime.c;h=edd00f6cee377715fdc6e73e411d0e2c8fed2026;hb=16c70f8c1b54b61c3b951b6fb220df250fe09b32;hp=22d38b3a66b6488f7344584598cfa892df77d12b;hpb=6a77f38946aaee1cd85eeec6cf4229b204c15071;p=linux-2.6.git diff --git a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c index 22d38b3a6..edd00f6ce 100644 --- a/arch/i386/kernel/time.c +++ b/arch/i386/kernel/time.c @@ -60,7 +60,6 @@ #include "mach_time.h" #include -#include #include @@ -68,145 +67,75 @@ #include "io_ports.h" -extern spinlock_t i8259A_lock; +#include + int pit_latch_buggy; /* extern */ #include "do_timer.h" -u64 jiffies_64 = INITIAL_JIFFIES; - -EXPORT_SYMBOL(jiffies_64); - -unsigned long cpu_khz; /* Detected as we calibrate the TSC */ +unsigned int cpu_khz; /* Detected as we calibrate the TSC */ +EXPORT_SYMBOL(cpu_khz); extern unsigned long wall_jiffies; DEFINE_SPINLOCK(rtc_lock); - -DEFINE_SPINLOCK(i8253_lock); -EXPORT_SYMBOL(i8253_lock); - -struct timer_opts *cur_timer = &timer_none; +EXPORT_SYMBOL(rtc_lock); /* - * This version of gettimeofday has microsecond resolution - * and better than microsecond precision on fast x86 machines with TSC. + * This is a special lock that is owned by the CPU and holds the index + * register we are working with. It is required for NMI access to the + * CMOS/RTC registers. See include/asm-i386/mc146818rtc.h for details. */ -void do_gettimeofday(struct timeval *tv) -{ - unsigned long seq; - unsigned long usec, sec; - unsigned long max_ntp_tick; - - do { - unsigned long lost; - - seq = read_seqbegin(&xtime_lock); - - usec = cur_timer->get_offset(); - lost = jiffies - wall_jiffies; - - /* - * If time_adjust is negative then NTP is slowing the clock - * so make sure not to go into next possible interval. - * Better to lose some accuracy than have time go backwards.. - */ - if (unlikely(time_adjust < 0)) { - max_ntp_tick = (USEC_PER_SEC / HZ) - tickadj; - usec = min(usec, max_ntp_tick); - - if (lost) - usec += lost * max_ntp_tick; - } - else if (unlikely(lost)) - usec += lost * (USEC_PER_SEC / HZ); - - sec = xtime.tv_sec; - usec += (xtime.tv_nsec / 1000); - } while (read_seqretry(&xtime_lock, seq)); - - while (usec >= 1000000) { - usec -= 1000000; - sec++; - } +volatile unsigned long cmos_lock = 0; +EXPORT_SYMBOL(cmos_lock); - tv->tv_sec = sec; - tv->tv_usec = usec; +/* Routines for accessing the CMOS RAM/RTC. */ +unsigned char rtc_cmos_read(unsigned char addr) +{ + unsigned char val; + lock_cmos_prefix(addr); + outb_p(addr, RTC_PORT(0)); + val = inb_p(RTC_PORT(1)); + lock_cmos_suffix(addr); + return val; } +EXPORT_SYMBOL(rtc_cmos_read); -EXPORT_SYMBOL(do_gettimeofday); - -int do_settimeofday(struct timespec *tv) +void rtc_cmos_write(unsigned char val, unsigned char addr) { - 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 "xtime" correctly. However, the - * value in this location is the value at the most recent update of - * wall time. Discover what correction gettimeofday() would have - * made, and then undo it! - */ - nsec -= cur_timer->get_offset() * NSEC_PER_USEC; - nsec -= (jiffies - wall_jiffies) * TICK_NSEC; - - 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; + lock_cmos_prefix(addr); + outb_p(addr, RTC_PORT(0)); + outb_p(val, RTC_PORT(1)); + lock_cmos_suffix(addr); } - -EXPORT_SYMBOL(do_settimeofday); +EXPORT_SYMBOL(rtc_cmos_write); static int set_rtc_mmss(unsigned long nowtime) { int retval; + unsigned long flags; /* gets recalled with irq locally disabled */ - spin_lock(&rtc_lock); + /* XXX - does irqsave resolve this? -johnstul */ + spin_lock_irqsave(&rtc_lock, flags); if (efi_enabled) retval = efi_set_rtc_mmss(nowtime); else retval = mach_set_rtc_mmss(nowtime); - spin_unlock(&rtc_lock); + spin_unlock_irqrestore(&rtc_lock, flags); return retval; } -/* last time the cmos clock got updated */ -static long last_rtc_update; int timer_ack; -/* monotonic_clock(): returns # of nanoseconds passed since time_init() - * Note: This function is required to return accurate - * time even in the absence of multiple timer ticks. - */ -unsigned long long monotonic_clock(void) -{ - return cur_timer->monotonic_clock(); -} -EXPORT_SYMBOL(monotonic_clock); - #if defined(CONFIG_SMP) && defined(CONFIG_FRAME_POINTER) unsigned long profile_pc(struct pt_regs *regs) { unsigned long pc = instruction_pointer(regs); - if (in_lock_functions(pc)) + if (!user_mode_vm(regs) && in_lock_functions(pc)) return *(unsigned long *)(regs->ebp + 4); return pc; @@ -215,12 +144,21 @@ EXPORT_SYMBOL(profile_pc); #endif /* - * timer_interrupt() needs to keep up the real-time clock, - * as well as call the "do_timer()" routine every clocktick + * This is the same as the above, except we _also_ save the current + * Time Stamp Counter value at the time of the timer interrupt, so that + * we later on can estimate the time of day more exactly. */ -static inline void do_timer_interrupt(int irq, void *dev_id, - struct pt_regs *regs) +irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) { + /* + * Here we are in the timer irq handler. We just have irqs locally + * disabled but we don't know if the timer_bh is running on the other + * CPU. We need to avoid to SMP race with it. NOTE: we don' t need + * the irq version of write_lock because as just said we have irq + * locally disabled. -arca + */ + write_seqlock(&xtime_lock); + #ifdef CONFIG_X86_IO_APIC if (timer_ack) { /* @@ -239,28 +177,6 @@ static inline void do_timer_interrupt(int irq, void *dev_id, do_timer_interrupt_hook(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) - >= USEC_AFTER - ((unsigned) TICK_SIZE) / 2 && - (xtime.tv_nsec / 1000) - <= USEC_BEFORE + ((unsigned) TICK_SIZE) / 2) { - /* horrible...FIXME */ - if (efi_enabled) { - if (efi_set_rtc_mmss(xtime.tv_sec) == 0) - last_rtc_update = xtime.tv_sec; - else - last_rtc_update = xtime.tv_sec - 600; - } else 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 */ - } if (MCA_bus) { /* The PS/2 uses level-triggered interrupts. You can't @@ -275,29 +191,14 @@ static inline void do_timer_interrupt(int irq, void *dev_id, irq = inb_p( 0x61 ); /* read the current state */ outb_p( irq|0x80, 0x61 ); /* reset the IRQ */ } -} -/* - * This is the same as the above, except we _also_ save the current - * Time Stamp Counter value at the time of the timer interrupt, so that - * we later on can estimate the time of day more exactly. - */ -irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) -{ - /* - * Here we are in the timer irq handler. We just have irqs locally - * disabled but we don't know if the timer_bh is running on the other - * CPU. We need to avoid to SMP race with it. NOTE: we don' t need - * the irq version of write_lock because as just said we have irq - * locally disabled. -arca - */ - write_seqlock(&xtime_lock); + write_sequnlock(&xtime_lock); - cur_timer->mark_offset(); - - do_timer_interrupt(irq, NULL, regs); +#ifdef CONFIG_X86_LOCAL_APIC + if (using_apic_timer) + smp_send_timer_broadcast_ipi(regs); +#endif - write_sequnlock(&xtime_lock); return IRQ_HANDLED; } @@ -305,22 +206,73 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) unsigned long get_cmos_time(void) { unsigned long retval; + unsigned long flags; - spin_lock(&rtc_lock); + spin_lock_irqsave(&rtc_lock, flags); if (efi_enabled) retval = efi_get_time(); else retval = mach_get_cmos_time(); - spin_unlock(&rtc_lock); + spin_unlock_irqrestore(&rtc_lock, flags); return retval; } +EXPORT_SYMBOL(get_cmos_time); + +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 timeval 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; + + do_gettimeofday(&now); + if (now.tv_usec >= USEC_AFTER - ((unsigned) TICK_SIZE) / 2 && + now.tv_usec <= USEC_BEFORE + ((unsigned) TICK_SIZE) / 2) + fail = set_rtc_mmss(now.tv_sec); + + next.tv_usec = USEC_AFTER - now.tv_usec; + if (next.tv_usec <= 0) + next.tv_usec += USEC_PER_SEC; + + if (!fail) + next.tv_sec = 659; + else + next.tv_sec = 0; + + if (next.tv_usec >= USEC_PER_SEC) { + next.tv_sec++; + next.tv_usec -= USEC_PER_SEC; + } + mod_timer(&sync_cmos_timer, jiffies + timeval_to_jiffies(&next)); +} + +void notify_arch_cmos_timer(void) +{ + mod_timer(&sync_cmos_timer, jiffies + 1); +} static long clock_cmos_diff, sleep_start; -static int timer_suspend(struct sys_device *dev, u32 state) +static int timer_suspend(struct sys_device *dev, pm_message_t state) { /* * Estimate time zone so that set_time can update the clock @@ -341,14 +293,16 @@ static int timer_resume(struct sys_device *dev) if (is_hpet_enabled()) hpet_reenable(); #endif + setup_pit_timer(); sec = get_cmos_time() + clock_cmos_diff; sleep_length = (get_cmos_time() - sleep_start) * HZ; write_seqlock_irqsave(&xtime_lock, flags); xtime.tv_sec = sec; xtime.tv_nsec = 0; - write_sequnlock_irqrestore(&xtime_lock, flags); - jiffies += sleep_length; + jiffies_64 += sleep_length; wall_jiffies += sleep_length; + write_sequnlock_irqrestore(&xtime_lock, flags); + touch_softlockup_watchdog(); return 0; } @@ -378,20 +332,17 @@ device_initcall(time_init_device); #ifdef CONFIG_HPET_TIMER extern void (*late_time_init)(void); /* Duplicate of time_init() below, with hpet_enable part added */ -void __init hpet_time_init(void) +static void __init hpet_time_init(void) { xtime.tv_sec = get_cmos_time(); xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ); set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec); - if (hpet_enable() >= 0) { + if ((hpet_enable() >= 0) && hpet_use_timer) { printk("Using HPET for base-timer\n"); } - cur_timer = select_timer(); - printk(KERN_INFO "Using %s for high-res timesource\n",cur_timer->name); - time_init_hook(); } #endif @@ -413,8 +364,5 @@ void __init time_init(void) set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec); - cur_timer = select_timer(); - printk(KERN_INFO "Using %s for high-res timesource\n",cur_timer->name); - time_init_hook(); }