1/*
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
9 *
10 */
11
12#include <linux/clockchips.h>
13#include <linux/interrupt.h>
14#include <linux/i8253.h>
15#include <linux/time.h>
16#include <linux/export.h>
17
18#include <asm/vsyscall.h>
19#include <asm/x86_init.h>
20#include <asm/i8259.h>
21#include <asm/timer.h>
22#include <asm/hpet.h>
23#include <asm/time.h>
24
25#ifdef CONFIG_X86_64
26__visible volatile unsigned long jiffies __cacheline_aligned = INITIAL_JIFFIES;
27#endif
28
29unsigned long profile_pc(struct pt_regs *regs)
30{
31	unsigned long pc = instruction_pointer(regs);
32
33	if (!user_mode(regs) && in_lock_functions(pc)) {
34#ifdef CONFIG_FRAME_POINTER
35		return *(unsigned long *)(regs->bp + sizeof(long));
36#else
37		unsigned long *sp =
38			(unsigned long *)kernel_stack_pointer(regs);
39		/*
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.
43		 */
44		if (sp[0] >> 22)
45			return sp[0];
46		if (sp[1] >> 22)
47			return sp[1];
48#endif
49	}
50	return pc;
51}
52EXPORT_SYMBOL(profile_pc);
53
54/*
55 * Default timer interrupt handler for PIT/HPET
56 */
57static irqreturn_t timer_interrupt(int irq, void *dev_id)
58{
59	global_clock_event->event_handler(global_clock_event);
60	return IRQ_HANDLED;
61}
62
63static struct irqaction irq0  = {
64	.handler = timer_interrupt,
65	.flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER,
66	.name = "timer"
67};
68
69void __init setup_default_timer_irq(void)
70{
71	if (!nr_legacy_irqs())
72		return;
73	setup_irq(0, &irq0);
74}
75
76/* Default timer init function */
77void __init hpet_time_init(void)
78{
79	if (!hpet_enable())
80		setup_pit_timer();
81	setup_default_timer_irq();
82}
83
84static __init void x86_late_time_init(void)
85{
86	x86_init.timers.timer_init();
87	tsc_init();
88}
89
90/*
91 * Initialize TSC and delay the periodic timer init to
92 * late x86_late_time_init() so ioremap works.
93 */
94void __init time_init(void)
95{
96	late_time_init = x86_late_time_init;
97}
98