2 * Copyright (c) 1991,1992,1995 Linus Torvalds
3 * Copyright (c) 1994 Alan Modra
4 * Copyright (c) 1995 Markus Kuhn
5 * Copyright (c) 1996 Ingo Molnar
6 * Copyright (c) 1998 Andrea Arcangeli
7 * Copyright (c) 2002,2006 Vojtech Pavlik
8 * Copyright (c) 2003 Andi Kleen
12 #include <linux/clockchips.h>
13 #include <linux/interrupt.h>
14 #include <linux/i8253.h>
15 #include <linux/time.h>
16 #include <linux/mca.h>
18 #include <asm/vsyscall.h>
19 #include <asm/x86_init.h>
20 #include <asm/i8259.h>
21 #include <asm/timer.h>
26 DEFINE_VVAR(volatile unsigned long, jiffies) = INITIAL_JIFFIES;
29 unsigned long profile_pc(struct pt_regs *regs)
31 unsigned long pc = instruction_pointer(regs);
33 if (!user_mode_vm(regs) && in_lock_functions(pc)) {
34 #ifdef CONFIG_FRAME_POINTER
35 return *(unsigned long *)(regs->bp + sizeof(long));
38 (unsigned long *)kernel_stack_pointer(regs);
40 * Return address is either directly at stack pointer
41 * or above a saved flags. Eflags has bits 22-31 zero,
42 * kernel addresses don't.
52 EXPORT_SYMBOL(profile_pc);
55 * Default timer interrupt handler for PIT/HPET
57 static irqreturn_t timer_interrupt(int irq, void *dev_id)
59 /* Keep nmi watchdog up to date */
60 inc_irq_stat(irq0_irqs);
62 global_clock_event->event_handler(global_clock_event);
64 /* MCA bus quirk: Acknowledge irq0 by setting bit 7 in port 0x61 */
66 outb_p(inb_p(0x61)| 0x80, 0x61);
71 static struct irqaction irq0 = {
72 .handler = timer_interrupt,
73 .flags = IRQF_DISABLED | IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER,
77 void __init setup_default_timer_irq(void)
82 /* Default timer init function */
83 void __init hpet_time_init(void)
87 setup_default_timer_irq();
90 static __init void x86_late_time_init(void)
92 x86_init.timers.timer_init();
97 * Initialize TSC and delay the periodic timer init to
98 * late x86_late_time_init() so ioremap works.
100 void __init time_init(void)
102 late_time_init = x86_late_time_init;