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 #include <linux/mca.h>
18
19 #include <asm/vsyscall.h>
20 #include <asm/x86_init.h>
21 #include <asm/i8259.h>
22 #include <asm/timer.h>
23 #include <asm/hpet.h>
24 #include <asm/time.h>
25
26 #ifdef CONFIG_X86_64
27 DEFINE_VVAR(volatile unsigned long, jiffies) = INITIAL_JIFFIES;
28 #endif
29
profile_pc(struct pt_regs * regs)30 unsigned long profile_pc(struct pt_regs *regs)
31 {
32 unsigned long pc = instruction_pointer(regs);
33
34 if (!user_mode_vm(regs) && in_lock_functions(pc)) {
35 #ifdef CONFIG_FRAME_POINTER
36 return *(unsigned long *)(regs->bp + sizeof(long));
37 #else
38 unsigned long *sp =
39 (unsigned long *)kernel_stack_pointer(regs);
40 /*
41 * Return address is either directly at stack pointer
42 * or above a saved flags. Eflags has bits 22-31 zero,
43 * kernel addresses don't.
44 */
45 if (sp[0] >> 22)
46 return sp[0];
47 if (sp[1] >> 22)
48 return sp[1];
49 #endif
50 }
51 return pc;
52 }
53 EXPORT_SYMBOL(profile_pc);
54
55 /*
56 * Default timer interrupt handler for PIT/HPET
57 */
timer_interrupt(int irq,void * dev_id)58 static irqreturn_t timer_interrupt(int irq, void *dev_id)
59 {
60 /* Keep nmi watchdog up to date */
61 inc_irq_stat(irq0_irqs);
62
63 global_clock_event->event_handler(global_clock_event);
64
65 /* MCA bus quirk: Acknowledge irq0 by setting bit 7 in port 0x61 */
66 if (MCA_bus)
67 outb_p(inb_p(0x61)| 0x80, 0x61);
68
69 return IRQ_HANDLED;
70 }
71
72 static struct irqaction irq0 = {
73 .handler = timer_interrupt,
74 .flags = IRQF_DISABLED | IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER,
75 .name = "timer"
76 };
77
setup_default_timer_irq(void)78 void __init setup_default_timer_irq(void)
79 {
80 setup_irq(0, &irq0);
81 }
82
83 /* Default timer init function */
hpet_time_init(void)84 void __init hpet_time_init(void)
85 {
86 if (!hpet_enable())
87 setup_pit_timer();
88 setup_default_timer_irq();
89 }
90
x86_late_time_init(void)91 static __init void x86_late_time_init(void)
92 {
93 x86_init.timers.timer_init();
94 tsc_init();
95 }
96
97 /*
98 * Initialize TSC and delay the periodic timer init to
99 * late x86_late_time_init() so ioremap works.
100 */
time_init(void)101 void __init time_init(void)
102 {
103 late_time_init = x86_late_time_init;
104 }
105