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-rw-r--r--arch/x86/kernel/time.c121
1 files changed, 121 insertions, 0 deletions
diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c
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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/time.h>
15#include <linux/mca.h>
16
17#include <asm/vsyscall.h>
18#include <asm/x86_init.h>
19#include <asm/i8259.h>
20#include <asm/i8253.h>
21#include <asm/timer.h>
22#include <asm/hpet.h>
23#include <asm/time.h>
24
25#if defined(CONFIG_X86_32) && defined(CONFIG_X86_IO_APIC)
26int timer_ack;
27#endif
28
29#ifdef CONFIG_X86_64
30volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES;
31#endif
32
33unsigned long profile_pc(struct pt_regs *regs)
34{
35 unsigned long pc = instruction_pointer(regs);
36
37 if (!user_mode_vm(regs) && in_lock_functions(pc)) {
38#ifdef CONFIG_FRAME_POINTER
39 return *(unsigned long *)(regs->bp + sizeof(long));
40#else
41 unsigned long *sp = (unsigned long *)regs->sp;
42 /*
43 * Return address is either directly at stack pointer
44 * or above a saved flags. Eflags has bits 22-31 zero,
45 * kernel addresses don't.
46 */
47 if (sp[0] >> 22)
48 return sp[0];
49 if (sp[1] >> 22)
50 return sp[1];
51#endif
52 }
53 return pc;
54}
55EXPORT_SYMBOL(profile_pc);
56
57/*
58 * Default timer interrupt handler for PIT/HPET
59 */
60static irqreturn_t timer_interrupt(int irq, void *dev_id)
61{
62 /* Keep nmi watchdog up to date */
63 inc_irq_stat(irq0_irqs);
64
65 /* Optimized out for !IO_APIC and x86_64 */
66 if (timer_ack) {
67 /*
68 * Subtle, when I/O APICs are used we have to ack timer IRQ
69 * manually to deassert NMI lines for the watchdog if run
70 * on an 82489DX-based system.
71 */
72 spin_lock(&i8259A_lock);
73 outb(0x0c, PIC_MASTER_OCW3);
74 /* Ack the IRQ; AEOI will end it automatically. */
75 inb(PIC_MASTER_POLL);
76 spin_unlock(&i8259A_lock);
77 }
78
79 global_clock_event->event_handler(global_clock_event);
80
81 /* MCA bus quirk: Acknowledge irq0 by setting bit 7 in port 0x61 */
82 if (MCA_bus)
83 outb_p(inb_p(0x61)| 0x80, 0x61);
84
85 return IRQ_HANDLED;
86}
87
88static struct irqaction irq0 = {
89 .handler = timer_interrupt,
90 .flags = IRQF_DISABLED | IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER,
91 .name = "timer"
92};
93
94void __init setup_default_timer_irq(void)
95{
96 irq0.mask = cpumask_of_cpu(0);
97 setup_irq(0, &irq0);
98}
99
100/* Default timer init function */
101void __init hpet_time_init(void)
102{
103 if (!hpet_enable())
104 setup_pit_timer();
105 setup_default_timer_irq();
106}
107
108static __init void x86_late_time_init(void)
109{
110 x86_init.timers.timer_init();
111 tsc_init();
112}
113
114/*
115 * Initialize TSC and delay the periodic timer init to
116 * late x86_late_time_init() so ioremap works.
117 */
118void __init time_init(void)
119{
120 late_time_init = x86_late_time_init;
121}