1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/arch/alpha/kernel/irq.c 4 * 5 * Copyright (C) 1995 Linus Torvalds 6 * 7 * This file contains the code used by various IRQ handling routines: 8 * asking for different IRQ's should be done through these routines 9 * instead of just grabbing them. Thus setups with different IRQ numbers 10 * shouldn't result in any weird surprises, and installing new handlers 11 * should be easier. 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/errno.h> 17 #include <linux/kernel_stat.h> 18 #include <linux/signal.h> 19 #include <linux/sched.h> 20 #include <linux/ptrace.h> 21 #include <linux/interrupt.h> 22 #include <linux/random.h> 23 #include <linux/irq.h> 24 #include <linux/proc_fs.h> 25 #include <linux/seq_file.h> 26 #include <linux/profile.h> 27 #include <linux/bitops.h> 28 29 #include <asm/io.h> 30 #include <linux/uaccess.h> 31 #include "irq_impl.h" 32 33 volatile unsigned long irq_err_count; 34 DEFINE_PER_CPU(unsigned long, irq_pmi_count); 35 36 void ack_bad_irq(unsigned int irq) 37 { 38 irq_err_count++; 39 printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq); 40 } 41 42 #ifdef CONFIG_SMP 43 static char irq_user_affinity[NR_IRQS]; 44 45 int irq_select_affinity(unsigned int irq) 46 { 47 struct irq_data *data = irq_get_irq_data(irq); 48 struct irq_chip *chip; 49 static int last_cpu; 50 int cpu = last_cpu + 1; 51 52 if (!data) 53 return 1; 54 chip = irq_data_get_irq_chip(data); 55 56 if (!chip->irq_set_affinity || irq_user_affinity[irq]) 57 return 1; 58 59 while (!cpu_possible(cpu) || 60 !cpumask_test_cpu(cpu, irq_default_affinity)) 61 cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0); 62 last_cpu = cpu; 63 64 irq_data_update_affinity(data, cpumask_of(cpu)); 65 chip->irq_set_affinity(data, cpumask_of(cpu), false); 66 return 0; 67 } 68 #endif /* CONFIG_SMP */ 69 70 int arch_show_interrupts(struct seq_file *p, int prec) 71 { 72 int j; 73 74 #ifdef CONFIG_SMP 75 seq_puts(p, "IPI: "); 76 for_each_online_cpu(j) 77 seq_printf(p, "%10lu ", cpu_data[j].ipi_count); 78 seq_putc(p, '\n'); 79 #endif 80 seq_puts(p, "PMI: "); 81 for_each_online_cpu(j) 82 seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j)); 83 seq_puts(p, " Performance Monitoring\n"); 84 seq_printf(p, "ERR: %10lu\n", irq_err_count); 85 return 0; 86 } 87 88 /* 89 * handle_irq handles all normal device IRQ's (the special 90 * SMP cross-CPU interrupts have their own specific 91 * handlers). 92 */ 93 94 #define MAX_ILLEGAL_IRQS 16 95 96 void 97 handle_irq(int irq) 98 { 99 /* 100 * We ack quickly, we don't want the irq controller 101 * thinking we're snobs just because some other CPU has 102 * disabled global interrupts (we have already done the 103 * INT_ACK cycles, it's too late to try to pretend to the 104 * controller that we aren't taking the interrupt). 105 * 106 * 0 return value means that this irq is already being 107 * handled by some other CPU. (or is disabled) 108 */ 109 static unsigned int illegal_count=0; 110 struct irq_desc *desc = irq_to_desc(irq); 111 112 if (!desc || ((unsigned) irq > ACTUAL_NR_IRQS && 113 illegal_count < MAX_ILLEGAL_IRQS)) { 114 irq_err_count++; 115 illegal_count++; 116 printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n", 117 irq); 118 return; 119 } 120 121 irq_enter(); 122 generic_handle_irq_desc(desc); 123 irq_exit(); 124 } 125