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/init.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/system.h> 30 #include <asm/io.h> 31 #include <asm/uaccess.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 cpumask_copy(data->affinity, cpumask_of(cpu)); 65 chip->irq_set_affinity(data, cpumask_of(cpu), false); 66 return 0; 67 } 68 #endif /* CONFIG_SMP */ 69 70 int 71 show_interrupts(struct seq_file *p, void *v) 72 { 73 int j; 74 int irq = *(loff_t *) v; 75 struct irqaction * action; 76 struct irq_desc *desc; 77 unsigned long flags; 78 79 #ifdef CONFIG_SMP 80 if (irq == 0) { 81 seq_puts(p, " "); 82 for_each_online_cpu(j) 83 seq_printf(p, "CPU%d ", j); 84 seq_putc(p, '\n'); 85 } 86 #endif 87 88 if (irq < ACTUAL_NR_IRQS) { 89 desc = irq_to_desc(irq); 90 91 if (!desc) 92 return 0; 93 94 raw_spin_lock_irqsave(&desc->lock, flags); 95 action = desc->action; 96 if (!action) 97 goto unlock; 98 seq_printf(p, "%3d: ", irq); 99 #ifndef CONFIG_SMP 100 seq_printf(p, "%10u ", kstat_irqs(irq)); 101 #else 102 for_each_online_cpu(j) 103 seq_printf(p, "%10u ", kstat_irqs_cpu(irq, j)); 104 #endif 105 seq_printf(p, " %14s", get_irq_desc_chip(desc)->name); 106 seq_printf(p, " %c%s", 107 (action->flags & IRQF_DISABLED)?'+':' ', 108 action->name); 109 110 for (action=action->next; action; action = action->next) { 111 seq_printf(p, ", %c%s", 112 (action->flags & IRQF_DISABLED)?'+':' ', 113 action->name); 114 } 115 116 seq_putc(p, '\n'); 117 unlock: 118 raw_spin_unlock_irqrestore(&desc->lock, flags); 119 } else if (irq == ACTUAL_NR_IRQS) { 120 #ifdef CONFIG_SMP 121 seq_puts(p, "IPI: "); 122 for_each_online_cpu(j) 123 seq_printf(p, "%10lu ", cpu_data[j].ipi_count); 124 seq_putc(p, '\n'); 125 #endif 126 seq_puts(p, "PMI: "); 127 for_each_online_cpu(j) 128 seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j)); 129 seq_puts(p, " Performance Monitoring\n"); 130 seq_printf(p, "ERR: %10lu\n", irq_err_count); 131 } 132 return 0; 133 } 134 135 /* 136 * handle_irq handles all normal device IRQ's (the special 137 * SMP cross-CPU interrupts have their own specific 138 * handlers). 139 */ 140 141 #define MAX_ILLEGAL_IRQS 16 142 143 void 144 handle_irq(int irq) 145 { 146 /* 147 * We ack quickly, we don't want the irq controller 148 * thinking we're snobs just because some other CPU has 149 * disabled global interrupts (we have already done the 150 * INT_ACK cycles, it's too late to try to pretend to the 151 * controller that we aren't taking the interrupt). 152 * 153 * 0 return value means that this irq is already being 154 * handled by some other CPU. (or is disabled) 155 */ 156 static unsigned int illegal_count=0; 157 struct irq_desc *desc = irq_to_desc(irq); 158 159 if (!desc || ((unsigned) irq > ACTUAL_NR_IRQS && 160 illegal_count < MAX_ILLEGAL_IRQS)) { 161 irq_err_count++; 162 illegal_count++; 163 printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n", 164 irq); 165 return; 166 } 167 168 /* 169 * From here we must proceed with IPL_MAX. Note that we do not 170 * explicitly enable interrupts afterwards - some MILO PALcode 171 * (namely LX164 one) seems to have severe problems with RTI 172 * at IPL 0. 173 */ 174 local_irq_disable(); 175 irq_enter(); 176 generic_handle_irq_desc(irq, desc); 177 irq_exit(); 178 } 179