1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 1991,1992,1995 Linus Torvalds
4 * Copyright (c) 1994 Alan Modra
5 * Copyright (c) 1995 Markus Kuhn
6 * Copyright (c) 1996 Ingo Molnar
7 * Copyright (c) 1998 Andrea Arcangeli
8 * Copyright (c) 2002,2006 Vojtech Pavlik
9 * Copyright (c) 2003 Andi Kleen
13 #include <linux/clocksource.h>
14 #include <linux/clockchips.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/i8253.h>
18 #include <linux/time.h>
19 #include <linux/export.h>
21 #include <asm/vsyscall.h>
22 #include <asm/x86_init.h>
23 #include <asm/i8259.h>
24 #include <asm/timer.h>
28 unsigned long profile_pc(struct pt_regs *regs)
30 unsigned long pc = instruction_pointer(regs);
32 if (!user_mode(regs) && in_lock_functions(pc)) {
33 #ifdef CONFIG_FRAME_POINTER
34 return *(unsigned long *)(regs->bp + sizeof(long));
36 unsigned long *sp = (unsigned long *)regs->sp;
38 * Return address is either directly at stack pointer
39 * or above a saved flags. Eflags has bits 22-31 zero,
40 * kernel addresses don't.
50 EXPORT_SYMBOL(profile_pc);
53 * Default timer interrupt handler for PIT/HPET
55 static irqreturn_t timer_interrupt(int irq, void *dev_id)
57 global_clock_event->event_handler(global_clock_event);
61 static struct irqaction irq0 = {
62 .handler = timer_interrupt,
63 .flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER,
67 static void __init setup_default_timer_irq(void)
70 * Unconditionally register the legacy timer; even without legacy
71 * PIC/PIT we need this for the HPET0 in legacy replacement mode.
73 if (setup_irq(0, &irq0))
74 pr_info("Failed to register legacy timer interrupt\n");
77 /* Default timer init function */
78 void __init hpet_time_init(void)
81 if (!pit_timer_init())
85 setup_default_timer_irq();
88 static __init void x86_late_time_init(void)
91 * Before PIT/HPET init, select the interrupt mode. This is required
92 * to make the decision whether PIT should be initialized correct.
94 x86_init.irqs.intr_mode_select();
96 /* Setup the legacy timers */
97 x86_init.timers.timer_init();
100 * After PIT/HPET timers init, set up the final interrupt mode for
103 x86_init.irqs.intr_mode_init();
108 * Initialize TSC and delay the periodic timer init to
109 * late x86_late_time_init() so ioremap works.
111 void __init time_init(void)
113 late_time_init = x86_late_time_init;
117 * Sanity check the vdso related archdata content.
119 void clocksource_arch_init(struct clocksource *cs)
121 if (cs->archdata.vclock_mode == VCLOCK_NONE)
124 if (cs->archdata.vclock_mode > VCLOCK_MAX) {
125 pr_warn("clocksource %s registered with invalid vclock_mode %d. Disabling vclock.\n",
126 cs->name, cs->archdata.vclock_mode);
127 cs->archdata.vclock_mode = VCLOCK_NONE;
130 if (cs->mask != CLOCKSOURCE_MASK(64)) {
131 pr_warn("clocksource %s registered with invalid mask %016llx. Disabling vclock.\n",
133 cs->archdata.vclock_mode = VCLOCK_NONE;