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