// SPDX-License-Identifier: GPL-2.0/* *	linux/arch/alpha/kernel/irq.c * *	Copyright (C) 1995 Linus Torvalds * * This file contains the code used by various IRQ handling routines: * asking for different IRQ's should be done through these routines * instead of just grabbing them. Thus setups with different IRQ numbers * shouldn't result in any weird surprises, and installing new handlers * should be easier. */ #include <linux/kernel.h>#include <linux/module.h>#include <linux/errno.h>#include <linux/kernel_stat.h>#include <linux/signal.h>#include <linux/sched.h>#include <linux/ptrace.h>#include <linux/interrupt.h>#include <linux/random.h>#include <linux/irq.h>#include <linux/proc_fs.h>#include <linux/seq_file.h>#include <linux/profile.h>#include <linux/bitops.h> #include <asm/io.h>#include <linux/uaccess.h>#include "irq_impl.h" volatile unsigned long irq_err_count;DEFINE_PER_CPU(unsigned long, irq_pmi_count); void ack_bad_irq(unsigned int irq){	irq_err_count++;	printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq);} #ifdef CONFIG_SMP static char irq_user_affinity[NR_IRQS]; int irq_select_affinity(unsigned int irq){	struct irq_data *data = irq_get_irq_data(irq);	struct irq_chip *chip;	static int last_cpu;	int cpu = last_cpu + 1; 	if (!data)		return 1;	chip = irq_data_get_irq_chip(data); 	if (!chip->irq_set_affinity || irq_user_affinity[irq])		return 1; 	while (!cpu_possible(cpu) ||	       !cpumask_test_cpu(cpu, irq_default_affinity))		cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);	last_cpu = cpu; 	irq_data_update_affinity(data, cpumask_of(cpu));	chip->irq_set_affinity(data, cpumask_of(cpu), false);	return 0;}#endif /* CONFIG_SMP */ int arch_show_interrupts(struct seq_file *p, int prec){	int j; #ifdef CONFIG_SMP	seq_puts(p, " IPI: ");	for_each_online_cpu(j)		seq_printf(p, "%10lu ", cpu_data[j].ipi_count);	seq_putc(p, '\n');#endif	seq_puts(p, " PMI: ");	for_each_online_cpu(j)		seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j));	seq_puts(p, " Performance Monitoring\n");	seq_printf(p, " ERR: %10lu\n", irq_err_count);	return 0;} /* * handle_irq handles all normal device IRQ's (the special * SMP cross-CPU interrupts have their own specific * handlers). */ #define MAX_ILLEGAL_IRQS 16 voidhandle_irq(int irq){		/* 	 * We ack quickly, we don't want the irq controller	 * thinking we're snobs just because some other CPU has	 * disabled global interrupts (we have already done the	 * INT_ACK cycles, it's too late to try to pretend to the	 * controller that we aren't taking the interrupt).	 *	 * 0 return value means that this irq is already being	 * handled by some other CPU. (or is disabled)	 */	static unsigned int illegal_count=0;	struct irq_desc *desc = irq_to_desc(irq);		if (!desc || ((unsigned) irq > ACTUAL_NR_IRQS &&	    illegal_count < MAX_ILLEGAL_IRQS)) {		irq_err_count++;		illegal_count++;		printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",		       irq);		return;	} 	irq_enter();	generic_handle_irq_desc(desc);	irq_exit();}