// SPDX-License-Identifier: GPL-2.0/* *  Copyright (c) 1991,1992,1995  Linus Torvalds *  Copyright (c) 1994  Alan Modra *  Copyright (c) 1995  Markus Kuhn *  Copyright (c) 1996  Ingo Molnar *  Copyright (c) 1998  Andrea Arcangeli *  Copyright (c) 2002,2006  Vojtech Pavlik *  Copyright (c) 2003  Andi Kleen * */ #include <linux/clocksource.h>#include <linux/clockchips.h>#include <linux/interrupt.h>#include <linux/irq.h>#include <linux/i8253.h>#include <linux/time.h>#include <linux/export.h> #include <asm/vsyscall.h>#include <asm/x86_init.h>#include <asm/i8259.h>#include <asm/timer.h>#include <asm/hpet.h>#include <asm/time.h> unsigned long profile_pc(struct pt_regs *regs){	return instruction_pointer(regs);}EXPORT_SYMBOL(profile_pc); /* * Default timer interrupt handler for PIT/HPET */static irqreturn_t timer_interrupt(int irq, void *dev_id){	global_clock_event->event_handler(global_clock_event);	return IRQ_HANDLED;} static void __init setup_default_timer_irq(void){	unsigned long flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER; 	/*	 * Unconditionally register the legacy timer interrupt; even	 * without legacy PIC/PIT we need this for the HPET0 in legacy	 * replacement mode.	 */	if (request_irq(0, timer_interrupt, flags, "timer", NULL))		pr_info("Failed to register legacy timer interrupt\n");} /* Default timer init function */void __init hpet_time_init(void){	if (!hpet_enable()) {		if (!pit_timer_init())			return;	} 	setup_default_timer_irq();} static __init void x86_late_time_init(void){	/*	 * Before PIT/HPET init, select the interrupt mode. This is required	 * to make the decision whether PIT should be initialized correct.	 */	x86_init.irqs.intr_mode_select(); 	/* Setup the legacy timers */	x86_init.timers.timer_init(); 	/*	 * After PIT/HPET timers init, set up the final interrupt mode for	 * delivering IRQs.	 */	x86_init.irqs.intr_mode_init();	tsc_init(); 	if (cpu_feature_enabled(X86_FEATURE_WAITPKG))		use_tpause_delay();} /* * Initialize TSC and delay the periodic timer init to * late x86_late_time_init() so ioremap works. */void __init time_init(void){	late_time_init = x86_late_time_init;} /* * Sanity check the vdso related archdata content. */void clocksource_arch_init(struct clocksource *cs){	if (cs->vdso_clock_mode == VDSO_CLOCKMODE_NONE)		return; 	if (cs->mask != CLOCKSOURCE_MASK(64)) {		pr_warn("clocksource %s registered with invalid mask %016llx for VDSO. Disabling VDSO support.\n",			cs->name, cs->mask);		cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;	}}