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Diffstat (limited to 'arch/x86_64/kernel/time.c')
| -rw-r--r-- | arch/x86_64/kernel/time.c | 1366 |
1 files changed, 0 insertions, 1366 deletions
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c deleted file mode 100644 index 1c255ee76e7..00000000000 --- a/arch/x86_64/kernel/time.c +++ /dev/null @@ -1,1366 +0,0 @@ -/* - * linux/arch/x86-64/kernel/time.c - * - * "High Precision Event Timer" based timekeeping. - * - * Copyright (c) 1991,1992,1995 Linus Torvalds - * Copyright (c) 1994 Alan Modra - * Copyright (c) 1995 Markus Kuhn - * Copyright (c) 1996 Ingo Molnar - * Copyright (c) 1998 Andrea Arcangeli - * Copyright (c) 2002,2006 Vojtech Pavlik - * Copyright (c) 2003 Andi Kleen - * RTC support code taken from arch/i386/kernel/timers/time_hpet.c - */ - -#include <linux/kernel.h> -#include <linux/sched.h> -#include <linux/interrupt.h> -#include <linux/init.h> -#include <linux/mc146818rtc.h> -#include <linux/time.h> -#include <linux/ioport.h> -#include <linux/module.h> -#include <linux/device.h> -#include <linux/sysdev.h> -#include <linux/bcd.h> -#include <linux/notifier.h> -#include <linux/cpu.h> -#include <linux/kallsyms.h> -#include <linux/acpi.h> -#ifdef CONFIG_ACPI -#include <acpi/achware.h> /* for PM timer frequency */ -#include <acpi/acpi_bus.h> -#endif -#include <asm/8253pit.h> -#include <asm/pgtable.h> -#include <asm/vsyscall.h> -#include <asm/timex.h> -#include <asm/proto.h> -#include <asm/hpet.h> -#include <asm/sections.h> -#include <linux/cpufreq.h> -#include <linux/hpet.h> -#include <asm/apic.h> - -#ifdef CONFIG_CPU_FREQ -static void cpufreq_delayed_get(void); -#endif -extern void i8254_timer_resume(void); -extern int using_apic_timer; - -static char *timename = NULL; - -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; - -struct vxtime_data __vxtime __section_vxtime; /* for vsyscalls */ - -volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES; -unsigned long __wall_jiffies __section_wall_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; - -/* - * This version of gettimeofday() has microsecond resolution and better than - * microsecond precision, as we're using at least a 10 MHz (usually 14.31818 - * MHz) HPET timer. - */ - -void do_gettimeofday(struct timeval *tv) -{ - unsigned long seq, t; - unsigned int sec, usec; - - do { - seq = read_seqbegin(&xtime_lock); - - sec = xtime.tv_sec; - usec = xtime.tv_nsec / NSEC_PER_USEC; - - /* i386 does some correction here to keep the clock - monotonous even when ntpd is fixing drift. - But they didn't work for me, there is a non monotonic - clock anyways with ntp. - I dropped all corrections now until a real solution can - be found. Note when you fix it here you need to do the same - in arch/x86_64/kernel/vsyscall.c and export all needed - variables in vmlinux.lds. -AK */ - - t = (jiffies - wall_jiffies) * USEC_PER_TICK + - do_gettimeoffset(); - usec += t; - - } while (read_seqretry(&xtime_lock, seq)); - - tv->tv_sec = sec + usec / USEC_PER_SEC; - tv->tv_usec = usec % USEC_PER_SEC; -} - -EXPORT_SYMBOL(do_gettimeofday); - -/* - * settimeofday() first undoes the correction that gettimeofday would do - * on the time, and then saves it. This is ugly, but has been like this for - * ages already. - */ - -int do_settimeofday(struct timespec *tv) -{ - 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); - - nsec -= do_gettimeoffset() * NSEC_PER_USEC + - (jiffies - wall_jiffies) * NSEC_PER_TICK; - - 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); - - ntp_clear(); - - write_sequnlock_irq(&xtime_lock); - clock_was_set(); - return 0; -} - -EXPORT_SYMBOL(do_settimeofday); - -unsigned long profile_pc(struct pt_regs *regs) -{ - unsigned long pc = instruction_pointer(regs); - - /* Assume the lock function has either no stack frame or a copy - of eflags from PUSHF - Eflags always has bits 22 and up cleared unlike kernel addresses. */ - if (!user_mode(regs) && in_lock_functions(pc)) { - unsigned long *sp = (unsigned long *)regs->rsp; - if (sp[0] >> 22) - return sp[0]; - if (sp[1] >> 22) - return sp[1]; - } - return pc; -} -EXPORT_SYMBOL(profile_pc); - -/* - * In order to set the CMOS clock precisely, set_rtc_mmss has to be called 500 - * ms after the second nowtime has started, because when nowtime is written - * into the registers of the CMOS clock, it will jump to the next second - * precisely 500 ms later. Check the Motorola MC146818A or Dallas DS12887 data - * sheet for details. - */ - -static void set_rtc_mmss(unsigned long nowtime) -{ - int real_seconds, real_minutes, cmos_minutes; - unsigned char control, freq_select; - -/* - * IRQs are disabled when we're called from the timer interrupt, - * no need for spin_lock_irqsave() - */ - - spin_lock(&rtc_lock); - -/* - * Tell the clock it's being set and stop it. - */ - - control = CMOS_READ(RTC_CONTROL); - CMOS_WRITE(control | RTC_SET, RTC_CONTROL); - - freq_select = CMOS_READ(RTC_FREQ_SELECT); - CMOS_WRITE(freq_select | RTC_DIV_RESET2, RTC_FREQ_SELECT); - - cmos_minutes = CMOS_READ(RTC_MINUTES); - BCD_TO_BIN(cmos_minutes); - -/* - * since we're only adjusting minutes and seconds, don't interfere with hour - * overflow. This avoids messing with unknown time zones but requires your RTC - * not to be off by more than 15 minutes. Since we're calling it only when - * our clock is externally synchronized using NTP, this shouldn't be a problem. - */ - - real_seconds = nowtime % 60; - real_minutes = nowtime / 60; - if (((abs(real_minutes - cmos_minutes) + 15) / 30) & 1) - real_minutes += 30; /* correct for half hour time zone */ - real_minutes %= 60; - - if (abs(real_minutes - cmos_minutes) >= 30) { - printk(KERN_WARNING "time.c: can't update CMOS clock " - "from %d to %d\n", cmos_minutes, real_minutes); - } else { - BIN_TO_BCD(real_seconds); - BIN_TO_BCD(real_minutes); - CMOS_WRITE(real_seconds, RTC_SECONDS); - CMOS_WRITE(real_minutes, RTC_MINUTES); - } - -/* - * The following flags have to be released exactly in this order, otherwise the - * DS12887 (popular MC146818A clone with integrated battery and quartz) will - * not reset the oscillator and will not update precisely 500 ms later. You - * won't find this mentioned in the Dallas Semiconductor data sheets, but who - * believes data sheets anyway ... -- Markus Kuhn - */ - - CMOS_WRITE(control, RTC_CONTROL); - CMOS_WRITE(freq_select, RTC_FREQ_SELECT); - - spin_unlock(&rtc_lock); -} - - -/* 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. - */ -static inline unsigned long long cycles_2_ns(unsigned long long cyc); -unsigned long long monotonic_clock(void) -{ - unsigned long seq; - u32 last_offset, this_offset, offset; - unsigned long long base; - - if (vxtime.mode == VXTIME_HPET) { - do { - seq = read_seqbegin(&xtime_lock); - - last_offset = vxtime.last; - base = monotonic_base; - this_offset = hpet_readl(HPET_COUNTER); - } while (read_seqretry(&xtime_lock, seq)); - offset = (this_offset - last_offset); - offset *= NSEC_PER_TICK / hpet_tick; - } else { - do { - seq = read_seqbegin(&xtime_lock); - - last_offset = vxtime.last_tsc; - base = monotonic_base; - } while (read_seqretry(&xtime_lock, seq)); - this_offset = get_cycles_sync(); - offset = cycles_2_ns(this_offset - last_offset); - } - return base + offset; -} -EXPORT_SYMBOL(monotonic_clock); - -static noinline void handle_lost_ticks(int lost, struct pt_regs *regs) -{ - static long lost_count; - static int warned; - if (report_lost_ticks) { - printk(KERN_WARNING "time.c: Lost %d timer tick(s)! ", lost); - print_symbol("rip %s)\n", regs->rip); - } - - if (lost_count == 1000 && !warned) { - printk(KERN_WARNING "warning: many lost ticks.\n" - KERN_WARNING "Your time source seems to be instable or " - "some driver is hogging interupts\n"); - print_symbol("rip %s\n", regs->rip); - if (vxtime.mode == VXTIME_TSC && vxtime.hpet_address) { - printk(KERN_WARNING "Falling back to HPET\n"); - if (hpet_use_timer) - vxtime.last = hpet_readl(HPET_T0_CMP) - - hpet_tick; - else - vxtime.last = hpet_readl(HPET_COUNTER); - vxtime.mode = VXTIME_HPET; - do_gettimeoffset = do_gettimeoffset_hpet; - } - /* else should fall back to PIT, but code missing. */ - warned = 1; - } else - lost_count++; - -#ifdef CONFIG_CPU_FREQ - /* In some cases the CPU can change frequency without us noticing - Give cpufreq a change to catch up. */ - if ((lost_count+1) % 25 == 0) - cpufreq_delayed_get(); -#endif -} - -void main_timer_handler(struct pt_regs *regs) -{ - static unsigned long rtc_update = 0; - unsigned long tsc; - int delay = 0, offset = 0, lost = 0; - -/* - * Here we are in the timer irq handler. We have irqs locally disabled (so we - * don't need spin_lock_irqsave()) but we don't know if the timer_bh is running - * on the other CPU, so we need a lock. We also need to lock the vsyscall - * variables, because both do_timer() and us change them -arca+vojtech - */ - - write_seqlock(&xtime_lock); - - if (vxtime.hpet_address) - offset = hpet_readl(HPET_COUNTER); - - if (hpet_use_timer) { - /* if we're using the hpet timer functionality, - * we can more accurately know the counter value - * when the timer interrupt occured. - */ - offset = hpet_readl(HPET_T0_CMP) - hpet_tick; - delay = hpet_readl(HPET_COUNTER) - offset; - } else if (!pmtmr_ioport) { - spin_lock(&i8253_lock); - outb_p(0x00, 0x43); - delay = inb_p(0x40); - delay |= inb(0x40) << 8; - spin_unlock(&i8253_lock); - delay = LATCH - 1 - delay; - } - - tsc = get_cycles_sync(); - - if (vxtime.mode == VXTIME_HPET) { - if (offset - vxtime.last > hpet_tick) { - lost = (offset - vxtime.last) / hpet_tick - 1; - } - - monotonic_base += - (offset - vxtime.last) * NSEC_PER_TICK / hpet_tick; - - vxtime.last = offset; -#ifdef CONFIG_X86_PM_TIMER - } else if (vxtime.mode == VXTIME_PMTMR) { - lost = pmtimer_mark_offset(); -#endif - } else { - offset = (((tsc - vxtime.last_tsc) * - vxtime.tsc_quot) >> US_SCALE) - USEC_PER_TICK; - - if (offset < 0) - offset = 0; - - if (offset > USEC_PER_TICK) { - lost = offset / USEC_PER_TICK; - offset %= USEC_PER_TICK; - } - - monotonic_base += cycles_2_ns(tsc - vxtime.last_tsc); - - vxtime.last_tsc = tsc - vxtime.quot * delay / vxtime.tsc_quot; - - if ((((tsc - vxtime.last_tsc) * - vxtime.tsc_quot) >> US_SCALE) < offset) - vxtime.last_tsc = tsc - - (((long) offset << US_SCALE) / vxtime.tsc_quot) - 1; - } - - if (lost > 0) { - handle_lost_ticks(lost, regs); - jiffies += lost; - } - -/* - * Do the timer stuff. - */ - - do_timer(regs); -#ifndef CONFIG_SMP - update_process_times(user_mode(regs)); -#endif - -/* - * In the SMP case we use the local APIC timer interrupt to do the profiling, - * except when we simulate SMP mode on a uniprocessor system, in that case we - * have to call the local interrupt handler. - */ - - if (!using_apic_timer) - smp_local_timer_interrupt(regs); - -/* - * If we have an externally synchronized Linux clock, then update CMOS clock - * accordingly every ~11 minutes. set_rtc_mmss() will be called in the jiffy - * closest to exactly 500 ms before the next second. If the update fails, we - * don't care, as it'll be updated on the next turn, and the problem (time way - * off) isn't likely to go away much sooner anyway. - */ - - if (ntp_synced() && xtime.tv_sec > rtc_update && - abs(xtime.tv_nsec - 500000000) <= tick_nsec / 2) { - set_rtc_mmss(xtime.tv_sec); - rtc_update = xtime.tv_sec + 660; - } - - write_sequnlock(&xtime_lock); -} - -static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) -{ - if (apic_runs_main_timer > 1) - return IRQ_HANDLED; - main_timer_handler(regs); - if (using_apic_timer) - smp_send_timer_broadcast_ipi(); - 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; - unsigned long flags; - unsigned extyear = 0; - - spin_lock_irqsave(&rtc_lock, flags); - - do { - sec = CMOS_READ(RTC_SECONDS); - min = CMOS_READ(RTC_MINUTES); - hour = CMOS_READ(RTC_HOURS); - day = CMOS_READ(RTC_DAY_OF_MONTH); - mon = CMOS_READ(RTC_MONTH); - year = CMOS_READ(RTC_YEAR); -#ifdef CONFIG_ACPI - if (acpi_fadt.revision >= FADT2_REVISION_ID && - acpi_fadt.century) - extyear = CMOS_READ(acpi_fadt.century); -#endif - } while (sec != CMOS_READ(RTC_SECONDS)); - - spin_unlock_irqrestore(&rtc_lock, flags); - - /* - * We know that x86-64 always uses BCD format, no need to check the - * config register. - */ - - BCD_TO_BIN(sec); - BCD_TO_BIN(min); - BCD_TO_BIN(hour); - BCD_TO_BIN(day); - BCD_TO_BIN(mon); - BCD_TO_BIN(year); - - if (extyear) { - BCD_TO_BIN(extyear); - year += extyear; - printk(KERN_INFO "Extended CMOS year: %d\n", extyear); - } else { - /* - * x86-64 systems only exists since 2002. - * This will work up to Dec 31, 2100 - */ - year += 2000; - } - - 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(void *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, NULL); - 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 - -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(); - - hpet_start = hpet_readl(HPET_COUNTER); - rdtscl(tsc_start); - - do { - local_irq_disable(); - hpet_now = hpet_readl(HPET_COUNTER); - tsc_now = get_cycles_sync(); - 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 - * the PIT. This is better than using the timer interrupt output, - * because we can read the value of the speaker with just one inb(), - * where we need three i/o operations for the interrupt channel. - * We count how many ticks the TSC does in 50 ms. - */ - -static unsigned int __init pit_calibrate_tsc(void) -{ - unsigned long start, end; - unsigned long flags; - - spin_lock_irqsave(&i8253_lock, flags); - - outb((inb(0x61) & ~0x02) | 0x01, 0x61); - - outb(0xb0, 0x43); - outb((PIT_TICK_RATE / (1000 / 50)) & 0xff, 0x42); - outb((PIT_TICK_RATE / (1000 / 50)) >> 8, 0x42); - start = get_cycles_sync(); - while ((inb(0x61) & 0x20) == 0); - end = get_cycles_sync(); - - spin_unlock_irqrestore(&i8253_lock, flags); - - 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 - -static void __init __pit_init(int val, u8 mode) -{ - unsigned long flags; - - spin_lock_irqsave(&i8253_lock, flags); - outb_p(mode, PIT_MODE); - outb_p(val & 0xff, PIT_CH0); /* LSB */ - outb_p(val >> 8, PIT_CH0); /* MSB */ - spin_unlock_irqrestore(&i8253_lock, flags); -} - -void __init pit_init(void) -{ - __pit_init(LATCH, 0x34); /* binary, mode 2, LSB/MSB, ch 0 */ -} - -void __init pit_stop_interrupt(void) -{ - __pit_init(0, 0x30); /* mode 0 */ -} - -void __init stop_timer_interrupt(void) -{ - char *name; - if (vxtime.hpet_address) { - name = "HPET"; - hpet_timer_stop_set_go(0); - } else { - name = "PIT"; - pit_stop_interrupt(); - } - printk(KERN_INFO "timer: %s interrupt stopped.\n", name); -} - -int __init time_setup(char *str) -{ - report_lost_ticks = 1; - return 1; -} - -static struct irqaction irq0 = { - timer_interrupt, IRQF_DISABLED, CPU_MASK_NONE, "timer", NULL, NULL -}; - -static int __cpuinit -time_cpu_notifier(struct notifier_block *nb, unsigned long action, void *hcpu) -{ - unsigned cpu = (unsigned long) hcpu; - if (action == CPU_ONLINE) - vsyscall_set_cpu(cpu); - return NOTIFY_DONE; -} - -void __init time_init(void) -{ - if (nohpet) - vxtime.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()) - vxtime_hz = (FSEC_PER_SEC + hpet_period / 2) / hpet_period; - else - vxtime.hpet_address = 0; - - if (hpet_use_timer) { - /* set tick_nsec to use the proper rate for HPET */ - tick_nsec = TICK_NSEC_HPET; - cpu_khz = hpet_calibrate_tsc(); - timename = "HPET"; -#ifdef CONFIG_X86_PM_TIMER - } else if (pmtmr_ioport && !vxtime.hpet_address) { - vxtime_hz = PM_TIMER_FREQUENCY; - timename = "PM"; - pit_init(); - cpu_khz = pit_calibrate_tsc(); -#endif - } else { - pit_init(); - cpu_khz = pit_calibrate_tsc(); - timename = "PIT"; - } - - vxtime.mode = VXTIME_TSC; - vxtime.quot = (USEC_PER_SEC << US_SCALE) / vxtime_hz; - vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz; - vxtime.last_tsc = get_cycles_sync(); - set_cyc2ns_scale(cpu_khz); - setup_irq(0, &irq0); - hotcpu_notifier(time_cpu_notifier, 0); - time_cpu_notifier(NULL, CPU_ONLINE, (void *)(long)smp_processor_id()); - -#ifndef CONFIG_SMP - time_init_gtod(); -#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_fadt.length > 0 && acpi_fadt.plvl3_lat < 100) - return 1; -#endif - return 0; - } - - /* Assume multi socket systems are not synchronized */ - return num_present_cpus() > 1; -} - -/* - * Decide what mode gettimeofday should use. - */ -void time_init_gtod(void) -{ - char *timetype; - - if (unsynchronized_tsc()) - notsc = 1; - - if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP)) - vgetcpu_mode = VGETCPU_RDTSCP; - else - vgetcpu_mode = VGETCPU_LSL; - - if (vxtime.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; - 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) { - timetype = "PM"; - do_gettimeoffset = do_gettimeoffset_pm; - vxtime.mode = VXTIME_PMTMR; - sysctl_vsyscall = 0; - printk(KERN_INFO "Disabling vsyscall due to use of PM timer\n"); -#endif - } else { - timetype = hpet_use_timer ? "HPET/TSC" : "PIT/TSC"; - vxtime.mode = VXTIME_TSC; - } - - printk(KERN_INFO "time.c: Using %ld.%06ld MHz WALL %s GTOD %s timer.\n", - vxtime_hz / 1000000, vxtime_hz % 1000000, timename, timetype); - printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n", - cpu_khz / 1000, cpu_khz % 1000); - vxtime.quot = (USEC_PER_SEC << US_SCALE) / vxtime_hz; - vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz; - vxtime.last_tsc = get_cycles_sync(); - - set_cyc2ns_scale(cpu_khz); -} - -__setup("report_lost_ticks", time_setup); - -static long clock_cmos_diff; -static unsigned long sleep_start; - -/* - * sysfs support for the timer. - */ - -static int timer_suspend(struct sys_device *dev, pm_message_t state) -{ - /* - * Estimate time zone so that set_time can update the clock - */ - long cmos_time = get_cmos_time(); - - clock_cmos_diff = -cmos_time; - clock_cmos_diff += get_seconds(); - sleep_start = cmos_time; - return 0; -} - -static int timer_resume(struct sys_device *dev) -{ - unsigned long flags; - unsigned long sec; - unsigned long ctime = get_cmos_time(); - long sleep_length = (ctime - sleep_start) * HZ; - - if (sleep_length < 0) { - printk(KERN_WARNING "Time skew detected in timer resume!\n"); - /* The time after the resume must not be earlier than the time - * before the suspend or some nasty things will happen - */ - sleep_length = 0; - ctime = sleep_start; - } - if (vxtime.hpet_address) - hpet_reenable(); - else - i8254_timer_resume(); - - sec = ctime + clock_cmos_diff; - write_seqlock_irqsave(&xtime_lock,flags); - xtime.tv_sec = sec; - xtime.tv_nsec = 0; - if (vxtime.mode == VXTIME_HPET) { - if (hpet_use_timer) - vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick; - else - vxtime.last = hpet_readl(HPET_COUNTER); -#ifdef CONFIG_X86_PM_TIMER - } else if (vxtime.mode == VXTIME_PMTMR) { - pmtimer_resume(); -#endif - } else - vxtime.last_tsc = get_cycles_sync(); - write_sequnlock_irqrestore(&xtime_lock,flags); - jiffies += sleep_length; - wall_jiffies += sleep_length; - monotonic_base += sleep_length * (NSEC_PER_SEC/HZ); - touch_softlockup_watchdog(); - return 0; -} - -static struct sysdev_class timer_sysclass = { - .resume = timer_resume, - .suspend = timer_suspend, - set_kset_name("timer"), -}; - -/* XXX this driverfs stuff should probably go elsewhere later -john */ -static struct sys_device device_timer = { - .id = 0, - .cls = &timer_sysclass, -}; - -static int time_init_device(void) -{ - int error = sysdev_class_register(&timer_sysclass); - if (!error) - error = sysdev_register(&device_timer); - return error; -} - -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, regs); - } - 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); |