/*
- * linux/arch/x86-64/kernel/time.c
- *
* "High Precision Event Timer" based timekeeping.
*
* Copyright (c) 1991,1992,1995 Linus Torvalds
#include <linux/cpu.h>
#include <linux/kallsyms.h>
#include <linux/acpi.h>
+#include <linux/clockchips.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/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;
int retval = 0;
int real_seconds, real_minutes, cmos_minutes;
unsigned char control, freq_select;
+ unsigned long flags;
/*
- * IRQs are disabled when we're called from the timer interrupt,
- * no need for spin_lock_irqsave()
+ * set_rtc_mmss is called when irqs are enabled, so disable irqs here
*/
-
- spin_lock(&rtc_lock);
-
+ spin_lock_irqsave(&rtc_lock, flags);
/*
* Tell the clock it's being set and stop it.
*/
-
control = CMOS_READ(RTC_CONTROL);
CMOS_WRITE(control | RTC_SET, RTC_CONTROL);
CMOS_WRITE(control, RTC_CONTROL);
CMOS_WRITE(freq_select, RTC_FREQ_SELECT);
- spin_unlock(&rtc_lock);
+ spin_unlock_irqrestore(&rtc_lock, flags);
return retval;
}
return set_rtc_mmss(now.tv_sec);
}
-void main_timer_handler(void)
+static irqreturn_t timer_event_interrupt(int irq, void *dev_id)
{
-/*
- * 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.
- */
+ add_pda(irq0_irqs, 1);
- if (!using_apic_timer)
- smp_local_timer_interrupt();
+ global_clock_event->event_handler(global_clock_event);
- 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 century = 0;
spin_lock_irqsave(&rtc_lock, flags);
+ /*
+ * if UIP is clear, then we have >= 244 microseconds before RTC
+ * registers will be updated. Spec sheet says that this is the
+ * reliable way to read RTC - registers invalid (off bus) during update
+ */
+ while ((CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP))
+ cpu_relax();
- 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);
+
+ /* now read all RTC registers while stable with interrupts disabled */
+ 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);
+ 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);
/*
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,
+ .handler = timer_event_interrupt,
+ .flags = IRQF_DISABLED | IRQF_IRQPOLL | IRQF_NOBALANCING,
.mask = CPU_MASK_NONE,
.name = "timer"
};
void __init time_init(void)
{
- if (nohpet)
- hpet_address = 0;
+ if (!hpet_enable())
+ setup_pit_timer();
- if (hpet_arch_init())
- hpet_address = 0;
+ setup_irq(0, &irq0);
- 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";
- }
+ tsc_calibrate();
cpu_khz = tsc_khz;
if (cpu_has(&boot_cpu_data, X86_FEATURE_CONSTANT_TSC) &&
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);
git.samba.org / sfrench / cifs-2.6.git / blobdiff