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 32 volatile unsigned long irq_err_count; 33 DEFINE_PER_CPU(unsigned long, irq_pmi_count); 34 35 void ack_bad_irq(unsigned int irq) 36 { 37 irq_err_count++; 38 printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq); 39 } 40 41 #ifdef CONFIG_SMP 42 static char irq_user_affinity[NR_IRQS]; 43 44 int irq_select_affinity(unsigned int irq) 45 { 46 struct irq_data *data = irq_get_irq_data(irq); 47 struct irq_chip *chip; 48 static int last_cpu; 49 int cpu = last_cpu + 1; 50 51 if (!data) 52 return 1; 53 chip = irq_data_get_irq_chip(data); 54 55 if (!chip->irq_set_affinity || irq_user_affinity[irq]) 56 return 1; 57 58 while (!cpu_possible(cpu) || 59 !cpumask_test_cpu(cpu, irq_default_affinity)) 60 cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0); 61 last_cpu = cpu; 62 63 cpumask_copy(irq_data_get_affinity_mask(data), cpumask_of(cpu)); 64 chip->irq_set_affinity(data, cpumask_of(cpu), false); 65 return 0; 66 } 67 #endif /* CONFIG_SMP */ 68 69 int arch_show_interrupts(struct seq_file *p, int prec) 70 { 71 int j; 72 73 #ifdef CONFIG_SMP 74 seq_puts(p, "IPI: "); 75 for_each_online_cpu(j) 76 seq_printf(p, "%10lu ", cpu_data[j].ipi_count); 77 seq_putc(p, '\n'); 78 #endif 79 seq_puts(p, "PMI: "); 80 for_each_online_cpu(j) 81 seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j)); 82 seq_puts(p, " Performance Monitoring\n"); 83 seq_printf(p, "ERR: %10lu\n", irq_err_count); 84 return 0; 85 } 86 87 /* 88 * handle_irq handles all normal device IRQ's (the special 89 * SMP cross-CPU interrupts have their own specific 90 * handlers). 91 */ 92 93 #define MAX_ILLEGAL_IRQS 16 94 95 void 96 handle_irq(int irq) 97 { 98 /* 99 * We ack quickly, we don't want the irq controller 100 * thinking we're snobs just because some other CPU has 101 * disabled global interrupts (we have already done the 102 * INT_ACK cycles, it's too late to try to pretend to the 103 * controller that we aren't taking the interrupt). 104 * 105 * 0 return value means that this irq is already being 106 * handled by some other CPU. (or is disabled) 107 */ 108 static unsigned int illegal_count=0; 109 struct irq_desc *desc = irq_to_desc(irq); 110 111 if (!desc || ((unsigned) irq > ACTUAL_NR_IRQS && 112 illegal_count < MAX_ILLEGAL_IRQS)) { 113 irq_err_count++; 114 illegal_count++; 115 printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n", 116 irq); 117 return; 118 } 119 120 irq_enter(); 121 generic_handle_irq_desc(desc); 122 irq_exit(); 123 } 124