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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/random.h>
31#include <linux/smp.h>
32#include <linux/init.h>
33#include <linux/seq_file.h>
34#include <linux/errno.h>
35#include <linux/list.h>
36#include <linux/kallsyms.h>
37#include <linux/proc_fs.h>
38
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#include <asm/system.h>
Russell King897d8522008-08-03 15:04:04 +010040#include <asm/mach/irq.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
eric miao354e6f72010-06-25 09:46:09 +010050unsigned int arch_nr_irqs;
Thomas Gleixner4a2581a2006-07-01 22:30:09 +010051void (*init_arch_irq)(void) __initdata = NULL;
52unsigned long irq_err_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54int show_interrupts(struct seq_file *p, void *v)
55{
56 int i = *(loff_t *) v, cpu;
eric miao354e6f72010-06-25 09:46:09 +010057 struct irq_desc *desc;
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 struct irqaction * action;
59 unsigned long flags;
Russell Kingf13cd412010-11-15 14:33:51 +000060 int prec, n;
61
62 for (prec = 3, n = 1000; prec < 10 && n <= nr_irqs; prec++)
63 n *= 10;
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
65 if (i == 0) {
66 char cpuname[12];
67
Russell Kingf13cd412010-11-15 14:33:51 +000068 seq_printf(p, "%*s ", prec, "");
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 for_each_present_cpu(cpu) {
70 sprintf(cpuname, "CPU%d", cpu);
71 seq_printf(p, " %10s", cpuname);
72 }
73 seq_putc(p, '\n');
74 }
75
eric miao354e6f72010-06-25 09:46:09 +010076 if (i < nr_irqs) {
77 desc = irq_to_desc(i);
78 raw_spin_lock_irqsave(&desc->lock, flags);
79 action = desc->action;
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 if (!action)
81 goto unlock;
82
Russell Kingf13cd412010-11-15 14:33:51 +000083 seq_printf(p, "%*d: ", prec, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 for_each_present_cpu(cpu)
Yinghai Lu0b0f0b12009-01-11 13:35:56 -080085 seq_printf(p, "%10u ", kstat_irqs_cpu(i, cpu));
eric miao354e6f72010-06-25 09:46:09 +010086 seq_printf(p, " %10s", desc->chip->name ? : "-");
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 seq_printf(p, " %s", action->name);
88 for (action = action->next; action; action = action->next)
89 seq_printf(p, ", %s", action->name);
90
91 seq_putc(p, '\n');
92unlock:
eric miao354e6f72010-06-25 09:46:09 +010093 raw_spin_unlock_irqrestore(&desc->lock, flags);
94 } else if (i == nr_irqs) {
Ben Dooksbaa28e32009-08-03 15:11:29 +010095#ifdef CONFIG_FIQ
Russell Kingf13cd412010-11-15 14:33:51 +000096 show_fiq_list(p, prec);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097#endif
98#ifdef CONFIG_SMP
Russell Kingf13cd412010-11-15 14:33:51 +000099 show_ipi_list(p, prec);
Russell Kingec405ea2010-11-15 13:38:06 +0000100#endif
101#ifdef CONFIG_LOCAL_TIMERS
Russell Kingf13cd412010-11-15 14:33:51 +0000102 show_local_irqs(p, prec);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103#endif
Russell Kingf13cd412010-11-15 14:33:51 +0000104 seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 }
106 return 0;
107}
108
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109/*
110 * do_IRQ handles all hardware IRQ's. Decoded IRQs should not
111 * come via this function. Instead, they should provide their
112 * own 'handler'
113 */
Russell King7ab3f8d2007-03-02 15:01:36 +0000114asmlinkage void __exception asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115{
Linus Torvaldse6300152006-10-06 13:11:15 -0700116 struct pt_regs *old_regs = set_irq_regs(regs);
Dmitry Baryshkovd8aa0252008-10-09 13:36:24 +0100117
118 irq_enter();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
120 /*
121 * Some hardware gives randomly wrong interrupts. Rather
122 * than crashing, do something sensible.
123 */
eric miao354e6f72010-06-25 09:46:09 +0100124 if (unlikely(irq >= nr_irqs)) {
Aaro Koskinen7aa55142009-06-22 09:23:36 +0100125 if (printk_ratelimit())
126 printk(KERN_WARNING "Bad IRQ%u\n", irq);
127 ack_bad_irq(irq);
128 } else {
Dmitry Baryshkovd8aa0252008-10-09 13:36:24 +0100129 generic_handle_irq(irq);
Aaro Koskinen7aa55142009-06-22 09:23:36 +0100130 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
Thomas Gleixner4a2581a2006-07-01 22:30:09 +0100132 /* AT91 specific workaround */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 irq_finish(irq);
134
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 irq_exit();
Linus Torvaldse6300152006-10-06 13:11:15 -0700136 set_irq_regs(old_regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137}
138
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139void set_irq_flags(unsigned int irq, unsigned int iflags)
140{
Russell King10dd5ce2006-11-23 11:41:32 +0000141 struct irq_desc *desc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 unsigned long flags;
143
eric miao354e6f72010-06-25 09:46:09 +0100144 if (irq >= nr_irqs) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq);
146 return;
147 }
148
eric miao354e6f72010-06-25 09:46:09 +0100149 desc = irq_to_desc(irq);
Thomas Gleixner239007b2009-11-17 16:46:45 +0100150 raw_spin_lock_irqsave(&desc->lock, flags);
Thomas Gleixner4a2581a2006-07-01 22:30:09 +0100151 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
152 if (iflags & IRQF_VALID)
153 desc->status &= ~IRQ_NOREQUEST;
154 if (iflags & IRQF_PROBE)
155 desc->status &= ~IRQ_NOPROBE;
156 if (!(iflags & IRQF_NOAUTOEN))
157 desc->status &= ~IRQ_NOAUTOEN;
Thomas Gleixner239007b2009-11-17 16:46:45 +0100158 raw_spin_unlock_irqrestore(&desc->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159}
160
161void __init init_IRQ(void)
162{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 init_arch_irq();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164}
165
eric miao354e6f72010-06-25 09:46:09 +0100166#ifdef CONFIG_SPARSE_IRQ
167int __init arch_probe_nr_irqs(void)
168{
169 nr_irqs = arch_nr_irqs ? arch_nr_irqs : NR_IRQS;
Thomas Gleixnerb683de22010-09-27 20:55:03 +0200170 return nr_irqs;
eric miao354e6f72010-06-25 09:46:09 +0100171}
172#endif
173
Russell Kinga054a812005-11-02 22:24:33 +0000174#ifdef CONFIG_HOTPLUG_CPU
Thomas Gleixnerf7ede372006-07-11 22:54:34 +0100175
Russell King10dd5ce2006-11-23 11:41:32 +0000176static void route_irq(struct irq_desc *desc, unsigned int irq, unsigned int cpu)
Thomas Gleixnerf7ede372006-07-11 22:54:34 +0100177{
Catalin Marinas41184f62009-06-19 11:30:12 +0100178 pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", irq, desc->node, cpu);
Thomas Gleixnerf7ede372006-07-11 22:54:34 +0100179
Thomas Gleixner239007b2009-11-17 16:46:45 +0100180 raw_spin_lock_irq(&desc->lock);
Rusty Russell0de26522008-12-13 21:20:26 +1030181 desc->chip->set_affinity(irq, cpumask_of(cpu));
Thomas Gleixner239007b2009-11-17 16:46:45 +0100182 raw_spin_unlock_irq(&desc->lock);
Thomas Gleixnerf7ede372006-07-11 22:54:34 +0100183}
184
Russell Kinga054a812005-11-02 22:24:33 +0000185/*
186 * The CPU has been marked offline. Migrate IRQs off this CPU. If
187 * the affinity settings do not allow other CPUs, force them onto any
188 * available CPU.
189 */
190void migrate_irqs(void)
191{
192 unsigned int i, cpu = smp_processor_id();
eric miao354e6f72010-06-25 09:46:09 +0100193 struct irq_desc *desc;
Russell Kinga054a812005-11-02 22:24:33 +0000194
eric miao354e6f72010-06-25 09:46:09 +0100195 for_each_irq_desc(i, desc) {
Catalin Marinas41184f62009-06-19 11:30:12 +0100196 if (desc->node == cpu) {
Mike Travise65e49d2009-01-12 15:27:13 -0800197 unsigned int newcpu = cpumask_any_and(desc->affinity,
198 cpu_online_mask);
199 if (newcpu >= nr_cpu_ids) {
Russell Kinga054a812005-11-02 22:24:33 +0000200 if (printk_ratelimit())
201 printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n",
202 i, cpu);
203
Mike Travise65e49d2009-01-12 15:27:13 -0800204 cpumask_setall(desc->affinity);
205 newcpu = cpumask_any_and(desc->affinity,
206 cpu_online_mask);
Russell Kinga054a812005-11-02 22:24:33 +0000207 }
208
209 route_irq(desc, i, newcpu);
210 }
211 }
212}
213#endif /* CONFIG_HOTPLUG_CPU */