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/time.h>
15 #include <linux/mca.h>
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>
25 #if defined(CONFIG_X86_32) && defined(CONFIG_X86_IO_APIC)
30 volatile unsigned long __jiffies __section_jiffies
= INITIAL_JIFFIES
;
33 unsigned long profile_pc(struct pt_regs
*regs
)
35 unsigned long pc
= instruction_pointer(regs
);
37 /* Assume the lock function has either no stack frame or a copy
39 Eflags always has bits 22 and up cleared unlike kernel addresses. */
40 if (!user_mode_vm(regs
) && in_lock_functions(pc
)) {
41 #ifdef CONFIG_FRAME_POINTER
42 return *(unsigned long *)(regs
->bp
+ sizeof(long));
44 unsigned long *sp
= (unsigned long *)regs
->sp
;
53 EXPORT_SYMBOL(profile_pc
);
56 * Default timer interrupt handler for PIT/HPET
58 static irqreturn_t
timer_interrupt(int irq
, void *dev_id
)
60 /* Keep nmi watchdog up to date */
61 inc_irq_stat(irq0_irqs
);
63 /* Optimized out for !IO_APIC and x86_64 */
66 * Subtle, when I/O APICs are used we have to ack timer IRQ
67 * manually to deassert NMI lines for the watchdog if run
68 * on an 82489DX-based system.
70 spin_lock(&i8259A_lock
);
71 outb(0x0c, PIC_MASTER_OCW3
);
72 /* Ack the IRQ; AEOI will end it automatically. */
74 spin_unlock(&i8259A_lock
);
77 global_clock_event
->event_handler(global_clock_event
);
79 /* MCA bus quirk: Acknowledge irq0 by setting bit 7 in port 0x61 */
81 outb_p(inb_p(0x61)| 0x80, 0x61);
86 static struct irqaction irq0
= {
87 .handler
= timer_interrupt
,
88 .flags
= IRQF_DISABLED
| IRQF_NOBALANCING
| IRQF_IRQPOLL
| IRQF_TIMER
,
92 void __init
setup_default_timer_irq(void)
94 irq0
.mask
= cpumask_of_cpu(0);
98 /* Default timer init function */
99 void __init
hpet_time_init(void)
103 setup_default_timer_irq();
106 static void x86_late_time_init(void)
108 x86_init
.timers
.timer_init();
112 * Initialize TSC and delay the periodic timer init to
113 * late x86_late_time_init() so ioremap works.
115 void __init
time_init(void)
118 late_time_init
= x86_late_time_init
;