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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/arch/arm/kernel/irq.c
3 *
4 * Copyright (C) 1992 Linus Torvalds
5 * Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
6 *
Russell King8749af62005-06-25 19:39:45 +01007 * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
8 * Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
9 * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
10 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 *
15 * This file contains the code used by various IRQ handling routines:
16 * asking for different IRQ's should be done through these routines
17 * instead of just grabbing them. Thus setups with different IRQ numbers
18 * shouldn't result in any weird surprises, and installing new handlers
19 * should be easier.
20 *
21 * IRQ's are in fact implemented a bit like signal handlers for the kernel.
22 * Naturally it's not a 1:1 relation, but there are similarities.
23 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/kernel_stat.h>
25#include <linux/module.h>
26#include <linux/signal.h>
27#include <linux/ioport.h>
28#include <linux/interrupt.h>
Thomas Gleixner4a2581a2006-07-01 22:30:09 +010029#include <linux/irq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <linux/slab.h>
31#include <linux/random.h>
32#include <linux/smp.h>
33#include <linux/init.h>
34#include <linux/seq_file.h>
35#include <linux/errno.h>
36#include <linux/list.h>
37#include <linux/kallsyms.h>
38#include <linux/proc_fs.h>
39
Linus Torvalds1da177e2005-04-16 15:20:36 -070040#include <asm/system.h>
Russell King8749af62005-06-25 19:39:45 +010041#include <asm/mach/time.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
43/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 * No architecture-specific irq_finish function defined in arm/arch/irqs.h.
45 */
46#ifndef irq_finish
47#define irq_finish(irq) do { } while (0)
48#endif
49
Thomas Gleixner4a2581a2006-07-01 22:30:09 +010050void (*init_arch_irq)(void) __initdata = NULL;
51unsigned long irq_err_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
53int show_interrupts(struct seq_file *p, void *v)
54{
55 int i = *(loff_t *) v, cpu;
56 struct irqaction * action;
57 unsigned long flags;
58
59 if (i == 0) {
60 char cpuname[12];
61
62 seq_printf(p, " ");
63 for_each_present_cpu(cpu) {
64 sprintf(cpuname, "CPU%d", cpu);
65 seq_printf(p, " %10s", cpuname);
66 }
67 seq_putc(p, '\n');
68 }
69
70 if (i < NR_IRQS) {
Thomas Gleixner4a2581a2006-07-01 22:30:09 +010071 spin_lock_irqsave(&irq_desc[i].lock, flags);
72 action = irq_desc[i].action;
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 if (!action)
74 goto unlock;
75
76 seq_printf(p, "%3d: ", i);
77 for_each_present_cpu(cpu)
78 seq_printf(p, "%10u ", kstat_cpu(cpu).irqs[i]);
David Brownell38c677c2006-08-01 22:26:25 +010079 seq_printf(p, " %10s", irq_desc[i].chip->name ? : "-");
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 seq_printf(p, " %s", action->name);
81 for (action = action->next; action; action = action->next)
82 seq_printf(p, ", %s", action->name);
83
84 seq_putc(p, '\n');
85unlock:
Thomas Gleixner4a2581a2006-07-01 22:30:09 +010086 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 } else if (i == NR_IRQS) {
88#ifdef CONFIG_ARCH_ACORN
89 show_fiq_list(p, v);
90#endif
91#ifdef CONFIG_SMP
92 show_ipi_list(p);
Russell King37ee16a2005-11-08 19:08:05 +000093 show_local_irqs(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094#endif
95 seq_printf(p, "Err: %10lu\n", irq_err_count);
96 }
97 return 0;
98}
99
Thomas Gleixner4a2581a2006-07-01 22:30:09 +0100100/* Handle bad interrupts */
101static struct irq_desc bad_irq_desc = {
102 .handle_irq = handle_bad_irq,
103 .lock = SPIN_LOCK_UNLOCKED
104};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105
106/*
107 * do_IRQ handles all hardware IRQ's. Decoded IRQs should not
108 * come via this function. Instead, they should provide their
109 * own 'handler'
110 */
Russell King7ab3f8d2007-03-02 15:01:36 +0000111asmlinkage void __exception asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112{
Linus Torvaldse6300152006-10-06 13:11:15 -0700113 struct pt_regs *old_regs = set_irq_regs(regs);
Russell King10dd5ce2006-11-23 11:41:32 +0000114 struct irq_desc *desc = irq_desc + irq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115
116 /*
117 * Some hardware gives randomly wrong interrupts. Rather
118 * than crashing, do something sensible.
119 */
120 if (irq >= NR_IRQS)
121 desc = &bad_irq_desc;
122
123 irq_enter();
Thomas Gleixner4a2581a2006-07-01 22:30:09 +0100124
Linus Torvalds0cd61b62006-10-06 10:53:39 -0700125 desc_handle_irq(irq, desc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
Thomas Gleixner4a2581a2006-07-01 22:30:09 +0100127 /* AT91 specific workaround */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 irq_finish(irq);
129
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 irq_exit();
Linus Torvaldse6300152006-10-06 13:11:15 -0700131 set_irq_regs(old_regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132}
133
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134void set_irq_flags(unsigned int irq, unsigned int iflags)
135{
Russell King10dd5ce2006-11-23 11:41:32 +0000136 struct irq_desc *desc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 unsigned long flags;
138
139 if (irq >= NR_IRQS) {
140 printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq);
141 return;
142 }
143
144 desc = irq_desc + irq;
Thomas Gleixner4a2581a2006-07-01 22:30:09 +0100145 spin_lock_irqsave(&desc->lock, flags);
146 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
147 if (iflags & IRQF_VALID)
148 desc->status &= ~IRQ_NOREQUEST;
149 if (iflags & IRQF_PROBE)
150 desc->status &= ~IRQ_NOPROBE;
151 if (!(iflags & IRQF_NOAUTOEN))
152 desc->status &= ~IRQ_NOAUTOEN;
153 spin_unlock_irqrestore(&desc->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154}
155
156void __init init_IRQ(void)
157{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 int irq;
159
Thomas Gleixner4a2581a2006-07-01 22:30:09 +0100160 for (irq = 0; irq < NR_IRQS; irq++)
Ingo Molnard7e25f32007-02-16 01:28:24 -0800161 irq_desc[irq].status |= IRQ_NOREQUEST | IRQ_NOPROBE;
Thomas Gleixner4a2581a2006-07-01 22:30:09 +0100162
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163#ifdef CONFIG_SMP
164 bad_irq_desc.affinity = CPU_MASK_ALL;
165 bad_irq_desc.cpu = smp_processor_id();
166#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 init_arch_irq();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168}
169
Russell Kinga054a812005-11-02 22:24:33 +0000170#ifdef CONFIG_HOTPLUG_CPU
Thomas Gleixnerf7ede372006-07-11 22:54:34 +0100171
Russell King10dd5ce2006-11-23 11:41:32 +0000172static void route_irq(struct irq_desc *desc, unsigned int irq, unsigned int cpu)
Thomas Gleixnerf7ede372006-07-11 22:54:34 +0100173{
174 pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", irq, desc->cpu, cpu);
175
176 spin_lock_irq(&desc->lock);
177 desc->chip->set_affinity(irq, cpumask_of_cpu(cpu));
178 spin_unlock_irq(&desc->lock);
179}
180
Russell Kinga054a812005-11-02 22:24:33 +0000181/*
182 * The CPU has been marked offline. Migrate IRQs off this CPU. If
183 * the affinity settings do not allow other CPUs, force them onto any
184 * available CPU.
185 */
186void migrate_irqs(void)
187{
188 unsigned int i, cpu = smp_processor_id();
189
190 for (i = 0; i < NR_IRQS; i++) {
Russell King10dd5ce2006-11-23 11:41:32 +0000191 struct irq_desc *desc = irq_desc + i;
Russell Kinga054a812005-11-02 22:24:33 +0000192
193 if (desc->cpu == cpu) {
194 unsigned int newcpu = any_online_cpu(desc->affinity);
195
196 if (newcpu == NR_CPUS) {
197 if (printk_ratelimit())
198 printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n",
199 i, cpu);
200
201 cpus_setall(desc->affinity);
202 newcpu = any_online_cpu(desc->affinity);
203 }
204
205 route_irq(desc, i, newcpu);
206 }
207 }
208}
209#endif /* CONFIG_HOTPLUG_CPU */