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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#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/slab.h>
22#include <linux/random.h>
23#include <linux/init.h>
24#include <linux/irq.h>
25#include <linux/proc_fs.h>
26#include <linux/seq_file.h>
27#include <linux/profile.h>
28#include <linux/bitops.h>
29
30#include <asm/system.h>
31#include <asm/io.h>
32#include <asm/uaccess.h>
33
Linus Torvalds1da177e2005-04-16 15:20:36 -070034volatile unsigned long irq_err_count;
35
Ivan Kokshaysky0595bf32006-01-06 00:12:22 -080036void ack_bad_irq(unsigned int irq)
Linus Torvalds1da177e2005-04-16 15:20:36 -070037{
38 irq_err_count++;
39 printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq);
40}
41
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -070043static char irq_user_affinity[NR_IRQS];
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
Ivan Kokshaysky0595bf32006-01-06 00:12:22 -080045int
46select_smp_affinity(unsigned int irq)
Linus Torvalds1da177e2005-04-16 15:20:36 -070047{
48 static int last_cpu;
49 int cpu = last_cpu + 1;
50
Ingo Molnard1bef4e2006-06-29 02:24:36 -070051 if (!irq_desc[irq].chip->set_affinity || irq_user_affinity[irq])
Ivan Kokshaysky0595bf32006-01-06 00:12:22 -080052 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54 while (!cpu_possible(cpu))
55 cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
56 last_cpu = cpu;
57
Ingo Molnara53da522006-06-29 02:24:38 -070058 irq_desc[irq].affinity = cpumask_of_cpu(cpu);
Ingo Molnard1bef4e2006-06-29 02:24:36 -070059 irq_desc[irq].chip->set_affinity(irq, cpumask_of_cpu(cpu));
Ivan Kokshaysky0595bf32006-01-06 00:12:22 -080060 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070061}
Linus Torvalds1da177e2005-04-16 15:20:36 -070062#endif /* CONFIG_SMP */
63
Linus Torvalds1da177e2005-04-16 15:20:36 -070064int
65show_interrupts(struct seq_file *p, void *v)
66{
67#ifdef CONFIG_SMP
68 int j;
69#endif
Eric Sesterhennc5e3d982006-02-01 03:06:13 -080070 int irq = *(loff_t *) v;
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 struct irqaction * action;
72 unsigned long flags;
73
74#ifdef CONFIG_SMP
Eric Sesterhennc5e3d982006-02-01 03:06:13 -080075 if (irq == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 seq_puts(p, " ");
Eric Sesterhennc5e3d982006-02-01 03:06:13 -080077 for_each_online_cpu(j)
78 seq_printf(p, "CPU%d ", j);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 seq_putc(p, '\n');
80 }
81#endif
82
Eric Sesterhennc5e3d982006-02-01 03:06:13 -080083 if (irq < ACTUAL_NR_IRQS) {
84 spin_lock_irqsave(&irq_desc[irq].lock, flags);
85 action = irq_desc[irq].action;
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 if (!action)
87 goto unlock;
Eric Sesterhennc5e3d982006-02-01 03:06:13 -080088 seq_printf(p, "%3d: ", irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089#ifndef CONFIG_SMP
Eric Sesterhennc5e3d982006-02-01 03:06:13 -080090 seq_printf(p, "%10u ", kstat_irqs(irq));
Linus Torvalds1da177e2005-04-16 15:20:36 -070091#else
Eric Sesterhennc5e3d982006-02-01 03:06:13 -080092 for_each_online_cpu(j)
93 seq_printf(p, "%10u ", kstat_cpu(j).irqs[irq]);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094#endif
Ingo Molnard1bef4e2006-06-29 02:24:36 -070095 seq_printf(p, " %14s", irq_desc[irq].chip->typename);
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 seq_printf(p, " %c%s",
Thomas Gleixnerd18eced2006-07-01 19:29:11 -070097 (action->flags & IRQF_DISABLED)?'+':' ',
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 action->name);
99
100 for (action=action->next; action; action = action->next) {
101 seq_printf(p, ", %c%s",
Thomas Gleixnerd18eced2006-07-01 19:29:11 -0700102 (action->flags & IRQF_DISABLED)?'+':' ',
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 action->name);
104 }
105
106 seq_putc(p, '\n');
107unlock:
Eric Sesterhennc5e3d982006-02-01 03:06:13 -0800108 spin_unlock_irqrestore(&irq_desc[irq].lock, flags);
109 } else if (irq == ACTUAL_NR_IRQS) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110#ifdef CONFIG_SMP
111 seq_puts(p, "IPI: ");
Eric Sesterhennc5e3d982006-02-01 03:06:13 -0800112 for_each_online_cpu(j)
113 seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 seq_putc(p, '\n');
115#endif
116 seq_printf(p, "ERR: %10lu\n", irq_err_count);
117 }
118 return 0;
119}
120
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121/*
122 * handle_irq handles all normal device IRQ's (the special
123 * SMP cross-CPU interrupts have their own specific
124 * handlers).
125 */
126
127#define MAX_ILLEGAL_IRQS 16
128
129void
Al Viro3dbb8c62006-10-08 14:37:32 +0100130handle_irq(int irq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131{
132 /*
133 * We ack quickly, we don't want the irq controller
134 * thinking we're snobs just because some other CPU has
135 * disabled global interrupts (we have already done the
136 * INT_ACK cycles, it's too late to try to pretend to the
137 * controller that we aren't taking the interrupt).
138 *
139 * 0 return value means that this irq is already being
140 * handled by some other CPU. (or is disabled)
141 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 static unsigned int illegal_count=0;
143
144 if ((unsigned) irq > ACTUAL_NR_IRQS && illegal_count < MAX_ILLEGAL_IRQS ) {
145 irq_err_count++;
146 illegal_count++;
147 printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",
148 irq);
149 return;
150 }
151
152 irq_enter();
Ivan Kokshayskyeff2c2f2006-03-09 17:33:37 -0800153 /*
154 * __do_IRQ() must be called with IPL_MAX. Note that we do not
155 * explicitly enable interrupts afterwards - some MILO PALcode
156 * (namely LX164 one) seems to have severe problems with RTI
157 * at IPL 0.
158 */
Ivan Kokshaysky0595bf32006-01-06 00:12:22 -0800159 local_irq_disable();
Al Viro8774cb82006-10-07 14:17:31 +0100160 __do_IRQ(irq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 irq_exit();
162}