aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/kernel/irq.c
blob: c0d5c3b3a760fa79624657ebc495b1d7b81b8c66 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
/*
 *  linux/arch/arm/kernel/irq.c
 *
 *  Copyright (C) 1992 Linus Torvalds
 *  Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
 *
 *  Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
 *  Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
 *  Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *  This file contains the code used by various IRQ handling routines:
 *  asking for different IRQ's should be done through these routines
 *  instead of just grabbing them. Thus setups with different IRQ numbers
 *  shouldn't result in any weird surprises, and installing new handlers
 *  should be easier.
 *
 *  IRQ's are in fact implemented a bit like signal handlers for the kernel.
 *  Naturally it's not a 1:1 relation, but there are similarities.
 */
#include <linux/kernel_stat.h>
#include <linux/module.h>
#include <linux/signal.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/random.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/seq_file.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/kallsyms.h>
#include <linux/proc_fs.h>

#include <asm/system.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>

/*
 * No architecture-specific irq_finish function defined in arm/arch/irqs.h.
 */
#ifndef irq_finish
#define irq_finish(irq) do { } while (0)
#endif

unsigned int arch_nr_irqs;
void (*init_arch_irq)(void) __initdata = NULL;
unsigned long irq_err_count;

int show_interrupts(struct seq_file *p, void *v)
{
	int i = *(loff_t *) v, cpu;
	struct irq_desc *desc;
	struct irqaction * action;
	unsigned long flags;

	if (i == 0) {
		char cpuname[12];

		seq_printf(p, "    ");
		for_each_present_cpu(cpu) {
			sprintf(cpuname, "CPU%d", cpu);
			seq_printf(p, " %10s", cpuname);
		}
		seq_putc(p, '\n');
	}

	if (i < nr_irqs) {
		desc = irq_to_desc(i);
		raw_spin_lock_irqsave(&desc->lock, flags);
		action = desc->action;
		if (!action)
			goto unlock;

		seq_printf(p, "%3d: ", i);
		for_each_present_cpu(cpu)
			seq_printf(p, "%10u ", kstat_irqs_cpu(i, cpu));
		seq_printf(p, " %10s", desc->chip->name ? : "-");
		seq_printf(p, "  %s", action->name);
		for (action = action->next; action; action = action->next)
			seq_printf(p, ", %s", action->name);

		seq_putc(p, '\n');
unlock:
		raw_spin_unlock_irqrestore(&desc->lock, flags);
	} else if (i == nr_irqs) {
#ifdef CONFIG_FIQ
		show_fiq_list(p, v);
#endif
#ifdef CONFIG_SMP
		show_ipi_list(p);
		show_local_irqs(p);
#endif
		seq_printf(p, "Err: %10lu\n", irq_err_count);
	}
	return 0;
}

/*
 * do_IRQ handles all hardware IRQ's.  Decoded IRQs should not
 * come via this function.  Instead, they should provide their
 * own 'handler'
 */
asmlinkage void __exception asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
{
	struct pt_regs *old_regs = set_irq_regs(regs);

	irq_enter();

	/*
	 * Some hardware gives randomly wrong interrupts.  Rather
	 * than crashing, do something sensible.
	 */
	if (unlikely(irq >= nr_irqs)) {
		if (printk_ratelimit())
			printk(KERN_WARNING "Bad IRQ%u\n", irq);
		ack_bad_irq(irq);
	} else {
		generic_handle_irq(irq);
	}

	/* AT91 specific workaround */
	irq_finish(irq);

	irq_exit();
	set_irq_regs(old_regs);
}

void set_irq_flags(unsigned int irq, unsigned int iflags)
{
	struct irq_desc *desc;
	unsigned long flags;

	if (irq >= nr_irqs) {
		printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq);
		return;
	}

	desc = irq_to_desc(irq);
	raw_spin_lock_irqsave(&desc->lock, flags);
	desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
	if (iflags & IRQF_VALID)
		desc->status &= ~IRQ_NOREQUEST;
	if (iflags & IRQF_PROBE)
		desc->status &= ~IRQ_NOPROBE;
	if (!(iflags & IRQF_NOAUTOEN))
		desc->status &= ~IRQ_NOAUTOEN;
	raw_spin_unlock_irqrestore(&desc->lock, flags);
}

void __init init_IRQ(void)
{
	struct irq_desc *desc;
	int irq;

	for (irq = 0; irq < nr_irqs; irq++) {
		desc = irq_to_desc_alloc_node(irq, 0);
		desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
	}

	init_arch_irq();
}

#ifdef CONFIG_SPARSE_IRQ
int __init arch_probe_nr_irqs(void)
{
	nr_irqs = arch_nr_irqs ? arch_nr_irqs : NR_IRQS;
	return 0;
}
#endif

#ifdef CONFIG_HOTPLUG_CPU

static void route_irq(struct irq_desc *desc, unsigned int irq, unsigned int cpu)
{
	pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", irq, desc->node, cpu);

	raw_spin_lock_irq(&desc->lock);
	desc->chip->set_affinity(irq, cpumask_of(cpu));
	raw_spin_unlock_irq(&desc->lock);
}

/*
 * The CPU has been marked offline.  Migrate IRQs off this CPU.  If
 * the affinity settings do not allow other CPUs, force them onto any
 * available CPU.
 */
void migrate_irqs(void)
{
	unsigned int i, cpu = smp_processor_id();
	struct irq_desc *desc;

	for_each_irq_desc(i, desc) {
		if (desc->node == cpu) {
			unsigned int newcpu = cpumask_any_and(desc->affinity,
							      cpu_online_mask);
			if (newcpu >= nr_cpu_ids) {
				if (printk_ratelimit())
					printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n",
					       i, cpu);

				cpumask_setall(desc->affinity);
				newcpu = cpumask_any_and(desc->affinity,
							 cpu_online_mask);
			}

			route_irq(desc, i, newcpu);
		}
	}
}
#endif /* CONFIG_HOTPLUG_CPU */