// SPDX-License-Identifier: GPL-2.0
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/*
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* i8253.c 8253/PIT functions
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*
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*/
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#include <linux/clockchips.h>
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#include <linux/i8253.h>
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#include <linux/export.h>
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#include <linux/smp.h>
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#include <linux/irq.h>
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#include <asm/time.h>
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static irqreturn_t timer_interrupt(int irq, void *dev_id)
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{
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i8253_clockevent.event_handler(&i8253_clockevent);
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return IRQ_HANDLED;
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}
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void __init setup_pit_timer(void)
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{
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unsigned long flags = IRQF_NOBALANCING | IRQF_TIMER;
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clockevent_i8253_init(true);
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if (request_irq(0, timer_interrupt, flags, "timer", NULL))
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pr_err("Failed to request irq 0 (timer)\n");
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}
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static int __init init_pit_clocksource(void)
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{
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if (num_possible_cpus() > 1 || /* PIT does not scale! */
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!clockevent_state_periodic(&i8253_clockevent))
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return 0;
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return clocksource_i8253_init();
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}
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arch_initcall(init_pit_clocksource);
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