2 * linux/arch/arm/kernel/irq.c
4 * Copyright (C) 1992 Linus Torvalds
5 * Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
7 * 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>.
11 * 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.
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
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.
24 #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>
29 #include <linux/irq.h>
30 #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 #include <linux/ftrace.h>
40 #include <asm/system.h>
41 #include <asm/mach/arch.h>
42 #include <asm/mach/irq.h>
43 #include <asm/mach/time.h>
46 * No architecture-specific irq_finish function defined in arm/arch/irqs.h.
49 #define irq_finish(irq) do { } while (0)
52 unsigned long irq_err_count
;
54 int show_interrupts(struct seq_file
*p
, void *v
)
56 int i
= *(loff_t
*) v
, cpu
;
57 struct irq_desc
*desc
;
58 struct irqaction
* action
;
62 for (prec
= 3, n
= 1000; prec
< 10 && n
<= nr_irqs
; prec
++)
73 seq_printf(p
, "%*s ", prec
, "");
74 for_each_present_cpu(cpu
) {
75 sprintf(cpuname
, "CPU%d", cpu
);
76 seq_printf(p
, " %10s", cpuname
);
82 desc
= irq_to_desc(i
);
83 raw_spin_lock_irqsave(&desc
->lock
, flags
);
84 action
= desc
->action
;
88 seq_printf(p
, "%*d: ", prec
, i
);
89 for_each_present_cpu(cpu
)
90 seq_printf(p
, "%10u ", kstat_irqs_cpu(i
, cpu
));
91 seq_printf(p
, " %10s", desc
->irq_data
.chip
->name
? : "-");
92 seq_printf(p
, " %s", action
->name
);
93 for (action
= action
->next
; action
; action
= action
->next
)
94 seq_printf(p
, ", %s", action
->name
);
98 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
99 } else if (i
== nr_irqs
) {
101 show_fiq_list(p
, prec
);
104 show_ipi_list(p
, prec
);
106 #ifdef CONFIG_LOCAL_TIMERS
107 show_local_irqs(p
, prec
);
109 seq_printf(p
, "%*s: %10lu\n", prec
, "Err", irq_err_count
);
115 * do_IRQ handles all hardware IRQ's. Decoded IRQs should not
116 * come via this function. Instead, they should provide their
119 asmlinkage
void __exception_irq_entry
120 asm_do_IRQ(unsigned int irq
, struct pt_regs
*regs
)
122 struct pt_regs
*old_regs
= set_irq_regs(regs
);
127 * Some hardware gives randomly wrong interrupts. Rather
128 * than crashing, do something sensible.
130 if (unlikely(irq
>= nr_irqs
)) {
131 if (printk_ratelimit())
132 printk(KERN_WARNING
"Bad IRQ%u\n", irq
);
135 generic_handle_irq(irq
);
138 /* AT91 specific workaround */
142 set_irq_regs(old_regs
);
145 void set_irq_flags(unsigned int irq
, unsigned int iflags
)
147 struct irq_desc
*desc
;
150 if (irq
>= nr_irqs
) {
151 printk(KERN_ERR
"Trying to set irq flags for IRQ%d\n", irq
);
155 desc
= irq_to_desc(irq
);
156 raw_spin_lock_irqsave(&desc
->lock
, flags
);
157 desc
->status
|= IRQ_NOREQUEST
| IRQ_NOPROBE
| IRQ_NOAUTOEN
;
158 if (iflags
& IRQF_VALID
)
159 desc
->status
&= ~IRQ_NOREQUEST
;
160 if (iflags
& IRQF_PROBE
)
161 desc
->status
&= ~IRQ_NOPROBE
;
162 if (!(iflags
& IRQF_NOAUTOEN
))
163 desc
->status
&= ~IRQ_NOAUTOEN
;
164 raw_spin_unlock_irqrestore(&desc
->lock
, flags
);
167 void __init
init_IRQ(void)
169 machine_desc
->init_irq();
172 #ifdef CONFIG_SPARSE_IRQ
173 int __init
arch_probe_nr_irqs(void)
175 nr_irqs
= machine_desc
->nr_irqs
? machine_desc
->nr_irqs
: NR_IRQS
;
180 #ifdef CONFIG_HOTPLUG_CPU
182 static void route_irq(struct irq_desc
*desc
, unsigned int irq
, unsigned int cpu
)
184 pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", irq
, desc
->irq_data
.node
, cpu
);
186 raw_spin_lock_irq(&desc
->lock
);
187 desc
->irq_data
.chip
->irq_set_affinity(&desc
->irq_data
,
188 cpumask_of(cpu
), false);
189 raw_spin_unlock_irq(&desc
->lock
);
193 * The CPU has been marked offline. Migrate IRQs off this CPU. If
194 * the affinity settings do not allow other CPUs, force them onto any
197 void migrate_irqs(void)
199 unsigned int i
, cpu
= smp_processor_id();
200 struct irq_desc
*desc
;
202 for_each_irq_desc(i
, desc
) {
203 struct irq_data
*d
= &desc
->irq_data
;
205 if (d
->node
== cpu
) {
206 unsigned int newcpu
= cpumask_any_and(d
->affinity
,
208 if (newcpu
>= nr_cpu_ids
) {
209 if (printk_ratelimit())
210 printk(KERN_INFO
"IRQ%u no longer affine to CPU%u\n",
213 cpumask_setall(d
->affinity
);
214 newcpu
= cpumask_any_and(d
->affinity
,
218 route_irq(desc
, i
, newcpu
);
222 #endif /* CONFIG_HOTPLUG_CPU */