1 files changed, 447 insertions, 0 deletions
diff --git a/arch/x86/kernel/time_64.c b/arch/x86/kernel/time_64.c
new file mode 100644
index 00000000000..6d48a4e826d
--- /dev/null
+++ b/arch/x86/kernel/time_64.c
@@ -0,0 +1,447 @@
+/*
+ *  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/i8253.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/hpet.h>
+#include <asm/apic.h>
+#include <asm/hpet.h>
+#include <asm/mpspec.h>
+#include <asm/nmi.h>
+#include <asm/vgtod.h>
+
+static char *timename = NULL;
+
+DEFINE_SPINLOCK(rtc_lock);
+EXPORT_SYMBOL(rtc_lock);
+DEFINE_SPINLOCK(i8253_lock);
+EXPORT_SYMBOL(i8253_lock);
+
+volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES;
+
+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 int set_rtc_mmss(unsigned long nowtime)
+{
+	int retval = 0;
+	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);
+		retval = -1;
+	} 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);
+
+	return retval;
+}
+
+int update_persistent_clock(struct timespec now)
+{
+	return set_rtc_mmss(now.tv_sec);
+}
+
+void main_timer_handler(void)
+{
+/*
+ * 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);
+
+/*
+ * Do the timer stuff.
+ */
+
+	do_timer(1);
+#ifndef CONFIG_SMP
+	update_process_times(user_mode(get_irq_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();
+
+	write_sequnlock(&xtime_lock);
+}
+
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+	if (apic_runs_main_timer > 1)
+		return IRQ_HANDLED;
+	main_timer_handler();
+	if (using_apic_timer)
+		smp_send_timer_broadcast_ipi();
+	return IRQ_HANDLED;
+}
+
+unsigned long read_persistent_clock(void)
+{
+	unsigned int year, mon, day, hour, min, sec;
+	unsigned long flags;
+	unsigned century = 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_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
+					acpi_gbl_FADT.century)
+			century = CMOS_READ(acpi_gbl_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 (century) {
+		BCD_TO_BIN(century);
+		year += century * 100;
+		printk(KERN_INFO "Extended CMOS year: %d\n", century * 100);
+	} 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);
+}
+
+/* calibrate_cpu is used on systems with fixed rate TSCs to determine
+ * processor frequency */
+#define TICK_COUNT 100000000
+static unsigned int __init tsc_calibrate_cpu_khz(void)
+{
+	int tsc_start, tsc_now;
+	int i, no_ctr_free;
+	unsigned long evntsel3 = 0, pmc3 = 0, pmc_now = 0;
+	unsigned long flags;
+
+	for (i = 0; i < 4; i++)
+		if (avail_to_resrv_perfctr_nmi_bit(i))
+			break;
+	no_ctr_free = (i == 4);
+	if (no_ctr_free) {
+		i = 3;
+		rdmsrl(MSR_K7_EVNTSEL3, evntsel3);
+		wrmsrl(MSR_K7_EVNTSEL3, 0);
+		rdmsrl(MSR_K7_PERFCTR3, pmc3);
+	} else {
+		reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i);
+		reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + i);
+	}
+	local_irq_save(flags);
+	/* start meauring cycles, incrementing from 0 */
+	wrmsrl(MSR_K7_PERFCTR0 + i, 0);
+	wrmsrl(MSR_K7_EVNTSEL0 + i, 1 << 22 | 3 << 16 | 0x76);
+	rdtscl(tsc_start);
+	do {
+		rdmsrl(MSR_K7_PERFCTR0 + i, pmc_now);
+		tsc_now = get_cycles_sync();
+	} while ((tsc_now - tsc_start) < TICK_COUNT);
+
+	local_irq_restore(flags);
+	if (no_ctr_free) {
+		wrmsrl(MSR_K7_EVNTSEL3, 0);
+		wrmsrl(MSR_K7_PERFCTR3, pmc3);
+		wrmsrl(MSR_K7_EVNTSEL3, evntsel3);
+	} else {
+		release_perfctr_nmi(MSR_K7_PERFCTR0 + i);
+		release_evntsel_nmi(MSR_K7_EVNTSEL0 + i);
+	}
+
+	return pmc_now * tsc_khz / (tsc_now - tsc_start);
+}
+
+/*
+ * 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;
+}
+
+#define PIT_MODE 0x43
+#define PIT_CH0  0x40
+
+static void __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 pit_stop_interrupt(void)
+{
+	__pit_init(0, 0x30); /* mode 0 */
+}
+
+void stop_timer_interrupt(void)
+{
+	char *name;
+	if (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);
+}
+
+static struct irqaction irq0 = {
+	.handler	= timer_interrupt,
+	.flags		= IRQF_DISABLED | IRQF_IRQPOLL,
+	.mask		= CPU_MASK_NONE,
+	.name		= "timer"
+};
+
+void __init time_init(void)
+{
+	if (nohpet)
+		hpet_address = 0;
+
+	if (hpet_arch_init())
+		hpet_address = 0;
+
+	if (hpet_use_timer) {
+		/* set tick_nsec to use the proper rate for HPET */
+		tick_nsec = TICK_NSEC_HPET;
+		tsc_khz = hpet_calibrate_tsc();
+		timename = "HPET";
+	} else {
+		pit_init();
+		tsc_khz = pit_calibrate_tsc();
+		timename = "PIT";
+	}
+
+	cpu_khz = tsc_khz;
+	if (cpu_has(&boot_cpu_data, X86_FEATURE_CONSTANT_TSC) &&
+		boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
+		boot_cpu_data.x86 == 16)
+		cpu_khz = tsc_calibrate_cpu_khz();
+
+	if (unsynchronized_tsc())
+		mark_tsc_unstable("TSCs unsynchronized");
+
+	if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
+		vgetcpu_mode = VGETCPU_RDTSCP;
+	else
+		vgetcpu_mode = VGETCPU_LSL;
+
+	set_cyc2ns_scale(tsc_khz);
+	printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n",
+		cpu_khz / 1000, cpu_khz % 1000);
+	init_tsc_clocksource();
+
+	setup_irq(0, &irq0);
+}
+
+/*
+ * sysfs support for the timer.
+ */
+
+static int timer_suspend(struct sys_device *dev, pm_message_t state)
+{
+	return 0;
+}
+
+static int timer_resume(struct sys_device *dev)
+{
+	if (hpet_address)
+		hpet_reenable();
+	else
+		i8254_timer_resume();
+	return 0;
+}
+
+static struct sysdev_class timer_sysclass = {
+	.resume = timer_resume,
+	.suspend = timer_suspend,
+	set_kset_name("timer"),
+};
+
+/* XXX this sysfs 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);