[PATCH] time: x86_64: split x86_64/kernel/time.c up
[sfrench/cifs-2.6.git] / arch / x86_64 / kernel / time.c
index 335cc91c49b722c87ba12e8b4040c1f0ee38869b..216fc9d742478902ca0109faa3aaf432a73381a8 100644 (file)
 #include <linux/cpufreq.h>
 #include <linux/hpet.h>
 #include <asm/apic.h>
+#include <asm/hpet.h>
 
 #ifdef CONFIG_CPU_FREQ
-static void cpufreq_delayed_get(void);
+extern void cpufreq_delayed_get(void);
 #endif
 extern void i8254_timer_resume(void);
 extern int using_apic_timer;
@@ -55,21 +56,6 @@ DEFINE_SPINLOCK(rtc_lock);
 EXPORT_SYMBOL(rtc_lock);
 DEFINE_SPINLOCK(i8253_lock);
 
-int nohpet __initdata = 0;
-static int notsc __initdata = 0;
-
-#define USEC_PER_TICK (USEC_PER_SEC / HZ)
-#define NSEC_PER_TICK (NSEC_PER_SEC / HZ)
-#define FSEC_PER_TICK (FSEC_PER_SEC / HZ)
-
-#define NS_SCALE       10 /* 2^10, carefully chosen */
-#define US_SCALE       32 /* 2^32, arbitralrily chosen */
-
-unsigned int cpu_khz;                                  /* TSC clocks / usec, not used here */
-EXPORT_SYMBOL(cpu_khz);
-static unsigned long hpet_period;                      /* fsecs / HPET clock */
-unsigned long hpet_tick;                               /* HPET clocks / interrupt */
-int hpet_use_timer;                            /* Use counter of hpet for time keeping, otherwise PIT */
 unsigned long vxtime_hz = PIT_TICK_RATE;
 int report_lost_ticks;                         /* command line option */
 unsigned long long monotonic_base;
@@ -80,34 +66,6 @@ volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES;
 struct timespec __xtime __section_xtime;
 struct timezone __sys_tz __section_sys_tz;
 
-/*
- * do_gettimeoffset() returns microseconds since last timer interrupt was
- * triggered by hardware. A memory read of HPET is slower than a register read
- * of TSC, but much more reliable. It's also synchronized to the timer
- * interrupt. Note that do_gettimeoffset() may return more than hpet_tick, if a
- * timer interrupt has happened already, but vxtime.trigger wasn't updated yet.
- * This is not a problem, because jiffies hasn't updated either. They are bound
- * together by xtime_lock.
- */
-
-static inline unsigned int do_gettimeoffset_tsc(void)
-{
-       unsigned long t;
-       unsigned long x;
-       t = get_cycles_sync();
-       if (t < vxtime.last_tsc) 
-               t = vxtime.last_tsc; /* hack */
-       x = ((t - vxtime.last_tsc) * vxtime.tsc_quot) >> US_SCALE;
-       return x;
-}
-
-static inline unsigned int do_gettimeoffset_hpet(void)
-{
-       /* cap counter read to one tick to avoid inconsistencies */
-       unsigned long counter = hpet_readl(HPET_COUNTER) - vxtime.last;
-       return (min(counter,hpet_tick) * vxtime.quot) >> US_SCALE;
-}
-
 unsigned int (*do_gettimeoffset)(void) = do_gettimeoffset_tsc;
 
 /*
@@ -271,7 +229,7 @@ static void set_rtc_mmss(unsigned long nowtime)
  *             Note: This function is required to return accurate
  *             time even in the absence of multiple timer ticks.
  */
-static inline unsigned long long cycles_2_ns(unsigned long long cyc);
+extern unsigned long long cycles_2_ns(unsigned long long cyc);
 unsigned long long monotonic_clock(void)
 {
        unsigned long seq;
@@ -316,7 +274,7 @@ static noinline void handle_lost_ticks(int lost)
                       KERN_WARNING "Your time source seems to be instable or "
                                "some driver is hogging interupts\n");
                print_symbol("rip %s\n", get_irq_regs()->rip);
-               if (vxtime.mode == VXTIME_TSC && vxtime.hpet_address) {
+               if (vxtime.mode == VXTIME_TSC && hpet_address) {
                        printk(KERN_WARNING "Falling back to HPET\n");
                        if (hpet_use_timer)
                                vxtime.last = hpet_readl(HPET_T0_CMP) - 
@@ -324,6 +282,7 @@ static noinline void handle_lost_ticks(int lost)
                        else
                                vxtime.last = hpet_readl(HPET_COUNTER);
                        vxtime.mode = VXTIME_HPET;
+                       vxtime.hpet_address = hpet_address;
                        do_gettimeoffset = do_gettimeoffset_hpet;
                }
                /* else should fall back to PIT, but code missing. */
@@ -354,7 +313,7 @@ void main_timer_handler(void)
 
        write_seqlock(&xtime_lock);
 
-       if (vxtime.hpet_address)
+       if (hpet_address)
                offset = hpet_readl(HPET_COUNTER);
 
        if (hpet_use_timer) {
@@ -460,40 +419,6 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id)
        return IRQ_HANDLED;
 }
 
-static unsigned int cyc2ns_scale __read_mostly;
-
-static inline void set_cyc2ns_scale(unsigned long cpu_khz)
-{
-       cyc2ns_scale = (NSEC_PER_MSEC << NS_SCALE) / cpu_khz;
-}
-
-static inline unsigned long long cycles_2_ns(unsigned long long cyc)
-{
-       return (cyc * cyc2ns_scale) >> NS_SCALE;
-}
-
-unsigned long long sched_clock(void)
-{
-       unsigned long a = 0;
-
-#if 0
-       /* Don't do a HPET read here. Using TSC always is much faster
-          and HPET may not be mapped yet when the scheduler first runs.
-           Disadvantage is a small drift between CPUs in some configurations,
-          but that should be tolerable. */
-       if (__vxtime.mode == VXTIME_HPET)
-               return (hpet_readl(HPET_COUNTER) * vxtime.quot) >> US_SCALE;
-#endif
-
-       /* Could do CPU core sync here. Opteron can execute rdtsc speculatively,
-          which means it is not completely exact and may not be monotonous between
-          CPUs. But the errors should be too small to matter for scheduling
-          purposes. */
-
-       rdtscll(a);
-       return cycles_2_ns(a);
-}
-
 static unsigned long get_cmos_time(void)
 {
        unsigned int year, mon, day, hour, min, sec;
@@ -545,159 +470,6 @@ static unsigned long get_cmos_time(void)
        return mktime(year, mon, day, hour, min, sec);
 }
 
-#ifdef CONFIG_CPU_FREQ
-
-/* Frequency scaling support. Adjust the TSC based timer when the cpu frequency
-   changes.
-   
-   RED-PEN: On SMP we assume all CPUs run with the same frequency.  It's
-   not that important because current Opteron setups do not support
-   scaling on SMP anyroads.
-
-   Should fix up last_tsc too. Currently gettimeofday in the
-   first tick after the change will be slightly wrong. */
-
-#include <linux/workqueue.h>
-
-static unsigned int cpufreq_delayed_issched = 0;
-static unsigned int cpufreq_init = 0;
-static struct work_struct cpufreq_delayed_get_work;
-
-static void handle_cpufreq_delayed_get(struct work_struct *v)
-{
-       unsigned int cpu;
-       for_each_online_cpu(cpu) {
-               cpufreq_get(cpu);
-       }
-       cpufreq_delayed_issched = 0;
-}
-
-/* if we notice lost ticks, schedule a call to cpufreq_get() as it tries
- * to verify the CPU frequency the timing core thinks the CPU is running
- * at is still correct.
- */
-static void cpufreq_delayed_get(void)
-{
-       static int warned;
-       if (cpufreq_init && !cpufreq_delayed_issched) {
-               cpufreq_delayed_issched = 1;
-               if (!warned) {
-                       warned = 1;
-                       printk(KERN_DEBUG 
-       "Losing some ticks... checking if CPU frequency changed.\n");
-               }
-               schedule_work(&cpufreq_delayed_get_work);
-       }
-}
-
-static unsigned int  ref_freq = 0;
-static unsigned long loops_per_jiffy_ref = 0;
-
-static unsigned long cpu_khz_ref = 0;
-
-static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
-                                void *data)
-{
-        struct cpufreq_freqs *freq = data;
-       unsigned long *lpj, dummy;
-
-       if (cpu_has(&cpu_data[freq->cpu], X86_FEATURE_CONSTANT_TSC))
-               return 0;
-
-       lpj = &dummy;
-       if (!(freq->flags & CPUFREQ_CONST_LOOPS))
-#ifdef CONFIG_SMP
-               lpj = &cpu_data[freq->cpu].loops_per_jiffy;
-#else
-               lpj = &boot_cpu_data.loops_per_jiffy;
-#endif
-
-       if (!ref_freq) {
-               ref_freq = freq->old;
-               loops_per_jiffy_ref = *lpj;
-               cpu_khz_ref = cpu_khz;
-       }
-        if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
-            (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
-           (val == CPUFREQ_RESUMECHANGE)) {
-                *lpj =
-               cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new);
-
-               cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new);
-               if (!(freq->flags & CPUFREQ_CONST_LOOPS))
-                       vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz;
-       }
-       
-       set_cyc2ns_scale(cpu_khz_ref);
-
-       return 0;
-}
-static struct notifier_block time_cpufreq_notifier_block = {
-         .notifier_call  = time_cpufreq_notifier
-};
-
-static int __init cpufreq_tsc(void)
-{
-       INIT_WORK(&cpufreq_delayed_get_work, handle_cpufreq_delayed_get);
-       if (!cpufreq_register_notifier(&time_cpufreq_notifier_block,
-                                      CPUFREQ_TRANSITION_NOTIFIER))
-               cpufreq_init = 1;
-       return 0;
-}
-
-core_initcall(cpufreq_tsc);
-
-#endif
-
-/*
- * calibrate_tsc() calibrates the processor TSC in a very simple way, comparing
- * it to the HPET timer of known frequency.
- */
-
-#define TICK_COUNT 100000000
-#define TICK_MIN   5000
-
-/*
- * Some platforms take periodic SMI interrupts with 5ms duration. Make sure none
- * occurs between the reads of the hpet & TSC.
- */
-static void __init read_hpet_tsc(int *hpet, int *tsc)
-{
-       int tsc1, tsc2, hpet1;
-
-       do {
-               tsc1 = get_cycles_sync();
-               hpet1 = hpet_readl(HPET_COUNTER);
-               tsc2 = get_cycles_sync();
-       } while (tsc2 - tsc1 > TICK_MIN);
-       *hpet = hpet1;
-       *tsc = tsc2;
-}
-
-
-static unsigned int __init hpet_calibrate_tsc(void)
-{
-       int tsc_start, hpet_start;
-       int tsc_now, hpet_now;
-       unsigned long flags;
-
-       local_irq_save(flags);
-       local_irq_disable();
-
-       read_hpet_tsc(&hpet_start, &tsc_start);
-
-       do {
-               local_irq_disable();
-               read_hpet_tsc(&hpet_now, &tsc_now);
-               local_irq_restore(flags);
-       } while ((tsc_now - tsc_start) < TICK_COUNT &&
-                (hpet_now - hpet_start) < TICK_COUNT);
-
-       return (tsc_now - tsc_start) * 1000000000L
-               / ((hpet_now - hpet_start) * hpet_period / 1000);
-}
-
 
 /*
  * pit_calibrate_tsc() uses the speaker output (channel 2) of
@@ -728,124 +500,6 @@ static unsigned int __init pit_calibrate_tsc(void)
        return (end - start) / 50;
 }
 
-#ifdef CONFIG_HPET
-static __init int late_hpet_init(void)
-{
-       struct hpet_data        hd;
-       unsigned int            ntimer;
-
-       if (!vxtime.hpet_address)
-               return 0;
-
-       memset(&hd, 0, sizeof (hd));
-
-       ntimer = hpet_readl(HPET_ID);
-       ntimer = (ntimer & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT;
-       ntimer++;
-
-       /*
-        * Register with driver.
-        * Timer0 and Timer1 is used by platform.
-        */
-       hd.hd_phys_address = vxtime.hpet_address;
-       hd.hd_address = (void __iomem *)fix_to_virt(FIX_HPET_BASE);
-       hd.hd_nirqs = ntimer;
-       hd.hd_flags = HPET_DATA_PLATFORM;
-       hpet_reserve_timer(&hd, 0);
-#ifdef CONFIG_HPET_EMULATE_RTC
-       hpet_reserve_timer(&hd, 1);
-#endif
-       hd.hd_irq[0] = HPET_LEGACY_8254;
-       hd.hd_irq[1] = HPET_LEGACY_RTC;
-       if (ntimer > 2) {
-               struct hpet             *hpet;
-               struct hpet_timer       *timer;
-               int                     i;
-
-               hpet = (struct hpet *) fix_to_virt(FIX_HPET_BASE);
-               timer = &hpet->hpet_timers[2];
-               for (i = 2; i < ntimer; timer++, i++)
-                       hd.hd_irq[i] = (timer->hpet_config &
-                                       Tn_INT_ROUTE_CNF_MASK) >>
-                               Tn_INT_ROUTE_CNF_SHIFT;
-
-       }
-
-       hpet_alloc(&hd);
-       return 0;
-}
-fs_initcall(late_hpet_init);
-#endif
-
-static int hpet_timer_stop_set_go(unsigned long tick)
-{
-       unsigned int cfg;
-
-/*
- * Stop the timers and reset the main counter.
- */
-
-       cfg = hpet_readl(HPET_CFG);
-       cfg &= ~(HPET_CFG_ENABLE | HPET_CFG_LEGACY);
-       hpet_writel(cfg, HPET_CFG);
-       hpet_writel(0, HPET_COUNTER);
-       hpet_writel(0, HPET_COUNTER + 4);
-
-/*
- * Set up timer 0, as periodic with first interrupt to happen at hpet_tick,
- * and period also hpet_tick.
- */
-       if (hpet_use_timer) {
-               hpet_writel(HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL |
-                   HPET_TN_32BIT, HPET_T0_CFG);
-               hpet_writel(hpet_tick, HPET_T0_CMP); /* next interrupt */
-               hpet_writel(hpet_tick, HPET_T0_CMP); /* period */
-               cfg |= HPET_CFG_LEGACY;
-       }
-/*
- * Go!
- */
-
-       cfg |= HPET_CFG_ENABLE;
-       hpet_writel(cfg, HPET_CFG);
-
-       return 0;
-}
-
-static int hpet_init(void)
-{
-       unsigned int id;
-
-       if (!vxtime.hpet_address)
-               return -1;
-       set_fixmap_nocache(FIX_HPET_BASE, vxtime.hpet_address);
-       __set_fixmap(VSYSCALL_HPET, vxtime.hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE);
-
-/*
- * Read the period, compute tick and quotient.
- */
-
-       id = hpet_readl(HPET_ID);
-
-       if (!(id & HPET_ID_VENDOR) || !(id & HPET_ID_NUMBER))
-               return -1;
-
-       hpet_period = hpet_readl(HPET_PERIOD);
-       if (hpet_period < 100000 || hpet_period > 100000000)
-               return -1;
-
-       hpet_tick = (FSEC_PER_TICK + hpet_period / 2) / hpet_period;
-
-       hpet_use_timer = (id & HPET_ID_LEGSUP);
-
-       return hpet_timer_stop_set_go(hpet_tick);
-}
-
-static int hpet_reenable(void)
-{
-       return hpet_timer_stop_set_go(hpet_tick);
-}
-
 #define PIT_MODE 0x43
 #define PIT_CH0  0x40
 
@@ -873,7 +527,7 @@ void __init pit_stop_interrupt(void)
 void __init stop_timer_interrupt(void)
 {
        char *name;
-       if (vxtime.hpet_address) {
+       if (hpet_address) {
                name = "HPET";
                hpet_timer_stop_set_go(0);
        } else {
@@ -896,18 +550,17 @@ static struct irqaction irq0 = {
 void __init time_init(void)
 {
        if (nohpet)
-               vxtime.hpet_address = 0;
-
+               hpet_address = 0;
        xtime.tv_sec = get_cmos_time();
        xtime.tv_nsec = 0;
 
        set_normalized_timespec(&wall_to_monotonic,
                                -xtime.tv_sec, -xtime.tv_nsec);
 
-       if (!hpet_init())
+       if (!hpet_arch_init())
                 vxtime_hz = (FSEC_PER_SEC + hpet_period / 2) / hpet_period;
        else
-               vxtime.hpet_address = 0;
+               hpet_address = 0;
 
        if (hpet_use_timer) {
                /* set tick_nsec to use the proper rate for HPET */
@@ -915,7 +568,7 @@ void __init time_init(void)
                cpu_khz = hpet_calibrate_tsc();
                timename = "HPET";
 #ifdef CONFIG_X86_PM_TIMER
-       } else if (pmtmr_ioport && !vxtime.hpet_address) {
+       } else if (pmtmr_ioport && !hpet_address) {
                vxtime_hz = PM_TIMER_FREQUENCY;
                timename = "PM";
                pit_init();
@@ -939,31 +592,6 @@ void __init time_init(void)
 #endif
 }
 
-/*
- * Make an educated guess if the TSC is trustworthy and synchronized
- * over all CPUs.
- */
-__cpuinit int unsynchronized_tsc(void)
-{
-#ifdef CONFIG_SMP
-       if (apic_is_clustered_box())
-               return 1;
-#endif
-       /* Most intel systems have synchronized TSCs except for
-          multi node systems */
-       if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) {
-#ifdef CONFIG_ACPI
-               /* But TSC doesn't tick in C3 so don't use it there */
-               if (acpi_gbl_FADT.header.length > 0 && acpi_gbl_FADT.C3latency < 1000)
-                       return 1;
-#endif
-               return 0;
-       }
-
-       /* Assume multi socket systems are not synchronized */
-       return num_present_cpus() > 1;
-}
-
 /*
  * Decide what mode gettimeofday should use.
  */
@@ -974,23 +602,24 @@ void time_init_gtod(void)
        if (unsynchronized_tsc())
                notsc = 1;
 
-       if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
+       if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
                vgetcpu_mode = VGETCPU_RDTSCP;
        else
                vgetcpu_mode = VGETCPU_LSL;
 
-       if (vxtime.hpet_address && notsc) {
+       if (hpet_address && notsc) {
                timetype = hpet_use_timer ? "HPET" : "PIT/HPET";
                if (hpet_use_timer)
                        vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
                else
                        vxtime.last = hpet_readl(HPET_COUNTER);
                vxtime.mode = VXTIME_HPET;
+               vxtime.hpet_address = hpet_address;
                do_gettimeoffset = do_gettimeoffset_hpet;
 #ifdef CONFIG_X86_PM_TIMER
        /* Using PM for gettimeofday is quite slow, but we have no other
           choice because the TSC is too unreliable on some systems. */
-       } else if (pmtmr_ioport && !vxtime.hpet_address && notsc) {
+       } else if (pmtmr_ioport && !hpet_address && notsc) {
                timetype = "PM";
                do_gettimeoffset = do_gettimeoffset_pm;
                vxtime.mode = VXTIME_PMTMR;
@@ -1050,7 +679,7 @@ static int timer_resume(struct sys_device *dev)
                sleep_length = 0;
                ctime = sleep_start;
        }
-       if (vxtime.hpet_address)
+       if (hpet_address)
                hpet_reenable();
        else
                i8254_timer_resume();
@@ -1098,269 +727,3 @@ static int time_init_device(void)
 }
 
 device_initcall(time_init_device);
-
-#ifdef CONFIG_HPET_EMULATE_RTC
-/* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET
- * is enabled, we support RTC interrupt functionality in software.
- * RTC has 3 kinds of interrupts:
- * 1) Update Interrupt - generate an interrupt, every sec, when RTC clock
- *    is updated
- * 2) Alarm Interrupt - generate an interrupt at a specific time of day
- * 3) Periodic Interrupt - generate periodic interrupt, with frequencies
- *    2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2)
- * (1) and (2) above are implemented using polling at a frequency of
- * 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt
- * overhead. (DEFAULT_RTC_INT_FREQ)
- * For (3), we use interrupts at 64Hz or user specified periodic
- * frequency, whichever is higher.
- */
-#include <linux/rtc.h>
-
-#define DEFAULT_RTC_INT_FREQ   64
-#define RTC_NUM_INTS           1
-
-static unsigned long UIE_on;
-static unsigned long prev_update_sec;
-
-static unsigned long AIE_on;
-static struct rtc_time alarm_time;
-
-static unsigned long PIE_on;
-static unsigned long PIE_freq = DEFAULT_RTC_INT_FREQ;
-static unsigned long PIE_count;
-
-static unsigned long hpet_rtc_int_freq; /* RTC interrupt frequency */
-static unsigned int hpet_t1_cmp; /* cached comparator register */
-
-int is_hpet_enabled(void)
-{
-       return vxtime.hpet_address != 0;
-}
-
-/*
- * Timer 1 for RTC, we do not use periodic interrupt feature,
- * even if HPET supports periodic interrupts on Timer 1.
- * The reason being, to set up a periodic interrupt in HPET, we need to
- * stop the main counter. And if we do that everytime someone diables/enables
- * RTC, we will have adverse effect on main kernel timer running on Timer 0.
- * So, for the time being, simulate the periodic interrupt in software.
- *
- * hpet_rtc_timer_init() is called for the first time and during subsequent
- * interuppts reinit happens through hpet_rtc_timer_reinit().
- */
-int hpet_rtc_timer_init(void)
-{
-       unsigned int cfg, cnt;
-       unsigned long flags;
-
-       if (!is_hpet_enabled())
-               return 0;
-       /*
-        * Set the counter 1 and enable the interrupts.
-        */
-       if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ))
-               hpet_rtc_int_freq = PIE_freq;
-       else
-               hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
-
-       local_irq_save(flags);
-
-       cnt = hpet_readl(HPET_COUNTER);
-       cnt += ((hpet_tick*HZ)/hpet_rtc_int_freq);
-       hpet_writel(cnt, HPET_T1_CMP);
-       hpet_t1_cmp = cnt;
-
-       cfg = hpet_readl(HPET_T1_CFG);
-       cfg &= ~HPET_TN_PERIODIC;
-       cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
-       hpet_writel(cfg, HPET_T1_CFG);
-
-       local_irq_restore(flags);
-
-       return 1;
-}
-
-static void hpet_rtc_timer_reinit(void)
-{
-       unsigned int cfg, cnt, ticks_per_int, lost_ints;
-
-       if (unlikely(!(PIE_on | AIE_on | UIE_on))) {
-               cfg = hpet_readl(HPET_T1_CFG);
-               cfg &= ~HPET_TN_ENABLE;
-               hpet_writel(cfg, HPET_T1_CFG);
-               return;
-       }
-
-       if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ))
-               hpet_rtc_int_freq = PIE_freq;
-       else
-               hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
-
-       /* It is more accurate to use the comparator value than current count.*/
-       ticks_per_int = hpet_tick * HZ / hpet_rtc_int_freq;
-       hpet_t1_cmp += ticks_per_int;
-       hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
-
-       /*
-        * If the interrupt handler was delayed too long, the write above tries
-        * to schedule the next interrupt in the past and the hardware would
-        * not interrupt until the counter had wrapped around.
-        * So we have to check that the comparator wasn't set to a past time.
-        */
-       cnt = hpet_readl(HPET_COUNTER);
-       if (unlikely((int)(cnt - hpet_t1_cmp) > 0)) {
-               lost_ints = (cnt - hpet_t1_cmp) / ticks_per_int + 1;
-               /* Make sure that, even with the time needed to execute
-                * this code, the next scheduled interrupt has been moved
-                * back to the future: */
-               lost_ints++;
-
-               hpet_t1_cmp += lost_ints * ticks_per_int;
-               hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
-
-               if (PIE_on)
-                       PIE_count += lost_ints;
-
-               printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n",
-                      hpet_rtc_int_freq);
-       }
-}
-
-/*
- * The functions below are called from rtc driver.
- * Return 0 if HPET is not being used.
- * Otherwise do the necessary changes and return 1.
- */
-int hpet_mask_rtc_irq_bit(unsigned long bit_mask)
-{
-       if (!is_hpet_enabled())
-               return 0;
-
-       if (bit_mask & RTC_UIE)
-               UIE_on = 0;
-       if (bit_mask & RTC_PIE)
-               PIE_on = 0;
-       if (bit_mask & RTC_AIE)
-               AIE_on = 0;
-
-       return 1;
-}
-
-int hpet_set_rtc_irq_bit(unsigned long bit_mask)
-{
-       int timer_init_reqd = 0;
-
-       if (!is_hpet_enabled())
-               return 0;
-
-       if (!(PIE_on | AIE_on | UIE_on))
-               timer_init_reqd = 1;
-
-       if (bit_mask & RTC_UIE) {
-               UIE_on = 1;
-       }
-       if (bit_mask & RTC_PIE) {
-               PIE_on = 1;
-               PIE_count = 0;
-       }
-       if (bit_mask & RTC_AIE) {
-               AIE_on = 1;
-       }
-
-       if (timer_init_reqd)
-               hpet_rtc_timer_init();
-
-       return 1;
-}
-
-int hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec)
-{
-       if (!is_hpet_enabled())
-               return 0;
-
-       alarm_time.tm_hour = hrs;
-       alarm_time.tm_min = min;
-       alarm_time.tm_sec = sec;
-
-       return 1;
-}
-
-int hpet_set_periodic_freq(unsigned long freq)
-{
-       if (!is_hpet_enabled())
-               return 0;
-
-       PIE_freq = freq;
-       PIE_count = 0;
-
-       return 1;
-}
-
-int hpet_rtc_dropped_irq(void)
-{
-       if (!is_hpet_enabled())
-               return 0;
-
-       return 1;
-}
-
-irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
-{
-       struct rtc_time curr_time;
-       unsigned long rtc_int_flag = 0;
-       int call_rtc_interrupt = 0;
-
-       hpet_rtc_timer_reinit();
-
-       if (UIE_on | AIE_on) {
-               rtc_get_rtc_time(&curr_time);
-       }
-       if (UIE_on) {
-               if (curr_time.tm_sec != prev_update_sec) {
-                       /* Set update int info, call real rtc int routine */
-                       call_rtc_interrupt = 1;
-                       rtc_int_flag = RTC_UF;
-                       prev_update_sec = curr_time.tm_sec;
-               }
-       }
-       if (PIE_on) {
-               PIE_count++;
-               if (PIE_count >= hpet_rtc_int_freq/PIE_freq) {
-                       /* Set periodic int info, call real rtc int routine */
-                       call_rtc_interrupt = 1;
-                       rtc_int_flag |= RTC_PF;
-                       PIE_count = 0;
-               }
-       }
-       if (AIE_on) {
-               if ((curr_time.tm_sec == alarm_time.tm_sec) &&
-                   (curr_time.tm_min == alarm_time.tm_min) &&
-                   (curr_time.tm_hour == alarm_time.tm_hour)) {
-                       /* Set alarm int info, call real rtc int routine */
-                       call_rtc_interrupt = 1;
-                       rtc_int_flag |= RTC_AF;
-               }
-       }
-       if (call_rtc_interrupt) {
-               rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
-               rtc_interrupt(rtc_int_flag, dev_id);
-       }
-       return IRQ_HANDLED;
-}
-#endif
-
-static int __init nohpet_setup(char *s) 
-{ 
-       nohpet = 1;
-       return 1;
-} 
-
-__setup("nohpet", nohpet_setup);
-
-int __init notsc_setup(char *s)
-{
-       notsc = 1;
-       return 1;
-}
-
-__setup("notsc", notsc_setup);