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>
29 __visible volatile unsigned long jiffies __cacheline_aligned_in_smp = INITIAL_JIFFIES;
32 unsigned long profile_pc(struct pt_regs *regs)
34 unsigned long pc = instruction_pointer(regs);
36 if (!user_mode(regs) && in_lock_functions(pc)) {
37 #ifdef CONFIG_FRAME_POINTER
38 return *(unsigned long *)(regs->bp + sizeof(long));
40 unsigned long *sp = (unsigned long *)regs->sp;
42 * Return address is either directly at stack pointer
43 * or above a saved flags. Eflags has bits 22-31 zero,
44 * kernel addresses don't.
54 EXPORT_SYMBOL(profile_pc);
57 * Default timer interrupt handler for PIT/HPET
59 static irqreturn_t timer_interrupt(int irq, void *dev_id)
61 global_clock_event->event_handler(global_clock_event);
65 static void __init setup_default_timer_irq(void)
67 unsigned long flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER;
70 * Unconditionally register the legacy timer interrupt; even
71 * without legacy PIC/PIT we need this for the HPET0 in legacy
74 if (request_irq(0, timer_interrupt, flags, "timer", NULL))
75 pr_info("Failed to register legacy timer interrupt\n");
78 /* Default timer init function */
79 void __init hpet_time_init(void)
82 if (!pit_timer_init())
86 setup_default_timer_irq();
89 static __init void x86_late_time_init(void)
92 * Before PIT/HPET init, select the interrupt mode. This is required
93 * to make the decision whether PIT should be initialized correct.
95 x86_init.irqs.intr_mode_select();
97 /* Setup the legacy timers */
98 x86_init.timers.timer_init();
101 * After PIT/HPET timers init, set up the final interrupt mode for
104 x86_init.irqs.intr_mode_init();
109 * Initialize TSC and delay the periodic timer init to
110 * late x86_late_time_init() so ioremap works.
112 void __init time_init(void)
114 late_time_init = x86_late_time_init;
118 * Sanity check the vdso related archdata content.
120 void clocksource_arch_init(struct clocksource *cs)
122 if (cs->vdso_clock_mode == VDSO_CLOCKMODE_NONE)
125 if (cs->mask != CLOCKSOURCE_MASK(64)) {
126 pr_warn("clocksource %s registered with invalid mask %016llx for VDSO. Disabling VDSO support.\n",
128 cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;