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/export.h>
17 #include <linux/mca.h>
19 #include <asm/vsyscall.h>
20 #include <asm/x86_init.h>
21 #include <asm/i8259.h>
22 #include <asm/timer.h>
27 DEFINE_VVAR(volatile unsigned long, jiffies
) = INITIAL_JIFFIES
;
30 unsigned long profile_pc(struct pt_regs
*regs
)
32 unsigned long pc
= instruction_pointer(regs
);
34 if (!user_mode_vm(regs
) && in_lock_functions(pc
)) {
35 #ifdef CONFIG_FRAME_POINTER
36 return *(unsigned long *)(regs
->bp
+ sizeof(long));
39 (unsigned long *)kernel_stack_pointer(regs
);
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.
53 EXPORT_SYMBOL(profile_pc
);
55 static irqreturn_t
timer_interrupt(int irq
, void *dev_id
);
56 static struct irqaction irq0
= {
57 .handler
= timer_interrupt
,
58 .flags
= IRQF_DISABLED
| IRQF_NOBALANCING
| IRQF_IRQPOLL
| IRQF_TIMER
,
63 * Default timer interrupt handler for PIT/HPET
65 static irqreturn_t
timer_interrupt(int irq
, void *dev_id
)
67 /* Keep nmi watchdog up to date */
68 inc_irq_stat(irq0_irqs
);
70 trace_irq_handler_entry(irq
, &irq0
);
71 global_clock_event
->event_handler(global_clock_event
);
72 trace_irq_handler_exit(irq
, &irq0
, 1);
74 /* MCA bus quirk: Acknowledge irq0 by setting bit 7 in port 0x61 */
76 outb_p(inb_p(0x61)| 0x80, 0x61);
81 void __init
setup_default_timer_irq(void)
86 /* Default timer init function */
87 void __init
hpet_time_init(void)
91 setup_default_timer_irq();
94 static __init
void x86_late_time_init(void)
96 x86_init
.timers
.timer_init();
101 * Initialize TSC and delay the periodic timer init to
102 * late x86_late_time_init() so ioremap works.
104 void __init
time_init(void)
106 late_time_init
= x86_late_time_init
;