| // 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> |
| |
| 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; |
| |
| cpumask_copy(irq_data_get_affinity_mask(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 |
| |
| void |
| handle_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(); |
| } |