2 * linux/arch/alpha/kernel/irq.c
4 * Copyright (C) 1995 Linus Torvalds
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
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>
29 #include <asm/system.h>
31 #include <asm/uaccess.h>
33 volatile unsigned long irq_err_count;
34 DEFINE_PER_CPU(unsigned long, irq_pmi_count);
36 void ack_bad_irq(unsigned int irq)
39 printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq);
43 static char irq_user_affinity[NR_IRQS];
45 int irq_select_affinity(unsigned int irq)
47 struct irq_desc *desc = irq_to_desc[irq];
49 int cpu = last_cpu + 1;
51 if (!desc || !get_irq_desc_chip(desc)->set_affinity || irq_user_affinity[irq])
54 while (!cpu_possible(cpu) ||
55 !cpumask_test_cpu(cpu, irq_default_affinity))
56 cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
59 cpumask_copy(desc->affinity, cpumask_of(cpu));
60 get_irq_desc_chip(desc)->set_affinity(irq, cpumask_of(cpu));
63 #endif /* CONFIG_SMP */
66 show_interrupts(struct seq_file *p, void *v)
69 int irq = *(loff_t *) v;
70 struct irqaction * action;
71 struct irq_desc *desc;
77 for_each_online_cpu(j)
78 seq_printf(p, "CPU%d ", j);
83 if (irq < ACTUAL_NR_IRQS) {
84 desc = irq_to_desc(irq);
89 raw_spin_lock_irqsave(&desc->lock, flags);
90 action = desc->action;
93 seq_printf(p, "%3d: ", irq);
95 seq_printf(p, "%10u ", kstat_irqs(irq));
97 for_each_online_cpu(j)
98 seq_printf(p, "%10u ", kstat_irqs_cpu(irq, j));
100 seq_printf(p, " %14s", get_irq_desc_chip(desc)->name);
101 seq_printf(p, " %c%s",
102 (action->flags & IRQF_DISABLED)?'+':' ',
105 for (action=action->next; action; action = action->next) {
106 seq_printf(p, ", %c%s",
107 (action->flags & IRQF_DISABLED)?'+':' ',
113 raw_spin_unlock_irqrestore(&desc->lock, flags);
114 } else if (irq == ACTUAL_NR_IRQS) {
116 seq_puts(p, "IPI: ");
117 for_each_online_cpu(j)
118 seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
121 seq_puts(p, "PMI: ");
122 for_each_online_cpu(j)
123 seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j));
124 seq_puts(p, " Performance Monitoring\n");
125 seq_printf(p, "ERR: %10lu\n", irq_err_count);
131 * handle_irq handles all normal device IRQ's (the special
132 * SMP cross-CPU interrupts have their own specific
136 #define MAX_ILLEGAL_IRQS 16
142 * We ack quickly, we don't want the irq controller
143 * thinking we're snobs just because some other CPU has
144 * disabled global interrupts (we have already done the
145 * INT_ACK cycles, it's too late to try to pretend to the
146 * controller that we aren't taking the interrupt).
148 * 0 return value means that this irq is already being
149 * handled by some other CPU. (or is disabled)
151 static unsigned int illegal_count=0;
152 struct irq_desc *desc = irq_to_desc(irq);
154 if (!desc || ((unsigned) irq > ACTUAL_NR_IRQS &&
155 illegal_count < MAX_ILLEGAL_IRQS)) {
158 printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",
164 * From here we must proceed with IPL_MAX. Note that we do not
165 * explicitly enable interrupts afterwards - some MILO PALcode
166 * (namely LX164 one) seems to have severe problems with RTI
171 generic_handle_irq_desc(irq, desc);