arch/alpha/kernel/irq.c

Source file repositories/reference/linux-study-clean/arch/alpha/kernel/irq.c

File Facts

System
Linux kernel
Corpus path
arch/alpha/kernel/irq.c
Extension
.c
Size
3083 bytes
Lines
125
Domain
Architecture Layer
Bucket
arch/alpha
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// 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

Annotation

Implementation Notes