[deliverable/linux.git] / arch / arm / kernel / irq.c

/*
 *  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/ptrace.h>
#include <linux/slab.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/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

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 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) {
		spin_lock_irqsave(&irq_desc[i].lock, flags);
		action = irq_desc[i].action;
		if (!action)
			goto unlock;

		seq_printf(p, "%3d: ", i);
		for_each_present_cpu(cpu)
			seq_printf(p, "%10u ", kstat_cpu(cpu).irqs[i]);
		seq_printf(p, " %10s", irq_desc[i].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:
		spin_unlock_irqrestore(&irq_desc[i].lock, flags);
	} else if (i == NR_IRQS) {
#ifdef CONFIG_ARCH_ACORN
		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;
}

/* Handle bad interrupts */
static struct irq_desc bad_irq_desc = {
	.handle_irq = handle_bad_irq,
	.lock = SPIN_LOCK_UNLOCKED
};

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

	/*
	 * Some hardware gives randomly wrong interrupts.  Rather
	 * than crashing, do something sensible.
	 */
	if (irq >= NR_IRQS)
		desc = &bad_irq_desc;

	irq_enter();

	desc_handle_irq(irq, desc);

	/* 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_desc + irq;
	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;
	spin_unlock_irqrestore(&desc->lock, flags);
}

void __init init_IRQ(void)
{
	int irq;

	for (irq = 0; irq < NR_IRQS; irq++)
		irq_desc[irq].status |= IRQ_NOREQUEST | IRQ_DELAYED_DISABLE |
			IRQ_NOPROBE;

#ifdef CONFIG_SMP
	bad_irq_desc.affinity = CPU_MASK_ALL;
	bad_irq_desc.cpu = smp_processor_id();
#endif
	init_arch_irq();
}

#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->cpu, cpu);

	spin_lock_irq(&desc->lock);
	desc->chip->set_affinity(irq, cpumask_of_cpu(cpu));
	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();

	for (i = 0; i < NR_IRQS; i++) {
		struct irq_desc *desc = irq_desc + i;

		if (desc->cpu == cpu) {
			unsigned int newcpu = any_online_cpu(desc->affinity);

			if (newcpu == NR_CPUS) {
				if (printk_ratelimit())
					printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n",
					       i, cpu);

				cpus_setall(desc->affinity);
				newcpu = any_online_cpu(desc->affinity);
			}

			route_irq(desc, i, newcpu);
		}
	}
}
#endif /* CONFIG_HOTPLUG_CPU */
Commit	Line	Data
1da177e4 LT	1	/*
	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	*
8749af68 RK	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>.
	10	*
1da177e4 LT	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.
	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	*/
1da177e4 LT	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>
4a2581a0	29	#include <linux/irq.h>
1da177e4 LT	30	#include <linux/ptrace.h>
	31	#include <linux/slab.h>
	32	#include <linux/random.h>
	33	#include <linux/smp.h>
	34	#include <linux/init.h>
	35	#include <linux/seq_file.h>
	36	#include <linux/errno.h>
	37	#include <linux/list.h>
	38	#include <linux/kallsyms.h>
	39	#include <linux/proc_fs.h>
	40
1da177e4	41	#include <asm/system.h>
8749af68	42	#include <asm/mach/time.h>
1da177e4	43
1da177e4 LT	44	/*
	45	* No architecture-specific irq_finish function defined in arm/arch/irqs.h.
	46	*/
	47	#ifndef irq_finish
	48	#define irq_finish(irq) do { } while (0)
	49	#endif
	50
4a2581a0 TG	51	void (*init_arch_irq)(void) __initdata = NULL;
4a2581a0 TG	52	unsigned long irq_err_count;
1da177e4 LT	53
	54	int show_interrupts(struct seq_file p, void v)
	55	{
	56	int i = (loff_t ) v, cpu;
	57	struct irqaction * action;
	58	unsigned long flags;
	59
	60	if (i == 0) {
	61	char cpuname[12];
	62
	63	seq_printf(p, " ");
	64	for_each_present_cpu(cpu) {
	65	sprintf(cpuname, "CPU%d", cpu);
	66	seq_printf(p, " %10s", cpuname);
	67	}
	68	seq_putc(p, '\n');
	69	}
	70
	71	if (i < NR_IRQS) {
4a2581a0 TG	72	spin_lock_irqsave(&irq_desc[i].lock, flags);
4a2581a0 TG	73	action = irq_desc[i].action;
1da177e4 LT	74	if (!action)
	75	goto unlock;
	76
	77	seq_printf(p, "%3d: ", i);
	78	for_each_present_cpu(cpu)
	79	seq_printf(p, "%10u ", kstat_cpu(cpu).irqs[i]);
38c677cb	80	seq_printf(p, " %10s", irq_desc[i].chip->name ? : "-");
1da177e4 LT	81	seq_printf(p, " %s", action->name);
	82	for (action = action->next; action; action = action->next)
	83	seq_printf(p, ", %s", action->name);
	84
	85	seq_putc(p, '\n');
	86	unlock:
4a2581a0	87	spin_unlock_irqrestore(&irq_desc[i].lock, flags);
1da177e4 LT	88	} else if (i == NR_IRQS) {
	89	#ifdef CONFIG_ARCH_ACORN
	90	show_fiq_list(p, v);
	91	#endif
	92	#ifdef CONFIG_SMP
	93	show_ipi_list(p);
37ee16ae	94	show_local_irqs(p);
1da177e4 LT	95	#endif
	96	seq_printf(p, "Err: %10lu\n", irq_err_count);
	97	}
	98	return 0;
	99	}
	100
4a2581a0 TG	101	/* Handle bad interrupts */
	102	static struct irq_desc bad_irq_desc = {
	103	.handle_irq = handle_bad_irq,
	104	.lock = SPIN_LOCK_UNLOCKED
	105	};
1da177e4 LT	106
	107	/*
	108	* do_IRQ handles all hardware IRQ's. Decoded IRQs should not
	109	* come via this function. Instead, they should provide their
	110	* own 'handler'
	111	*/
	112	asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
	113	{
e6300155	114	struct pt_regs *old_regs = set_irq_regs(regs);
10dd5ce2	115	struct irq_desc *desc = irq_desc + irq;
1da177e4 LT	116
	117	/*
	118	* Some hardware gives randomly wrong interrupts. Rather
	119	* than crashing, do something sensible.
	120	*/
	121	if (irq >= NR_IRQS)
	122	desc = &bad_irq_desc;
	123
	124	irq_enter();
1da177e4	125
0cd61b68	126	desc_handle_irq(irq, desc);
1da177e4	127
4a2581a0	128	/* AT91 specific workaround */
1da177e4 LT	129	irq_finish(irq);
1da177e4 LT	130
1da177e4	131	irq_exit();
e6300155	132	set_irq_regs(old_regs);
1da177e4 LT	133	}
1da177e4 LT	134
1da177e4 LT	135	void set_irq_flags(unsigned int irq, unsigned int iflags)
1da177e4 LT	136	{
10dd5ce2	137	struct irq_desc *desc;
1da177e4 LT	138	unsigned long flags;
	139
	140	if (irq >= NR_IRQS) {
	141	printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq);
	142	return;
	143	}
	144
	145	desc = irq_desc + irq;
4a2581a0 TG	146	spin_lock_irqsave(&desc->lock, flags);
	147	desc->status \|= IRQ_NOREQUEST \| IRQ_NOPROBE \| IRQ_NOAUTOEN;
	148	if (iflags & IRQF_VALID)
	149	desc->status &= ~IRQ_NOREQUEST;
	150	if (iflags & IRQF_PROBE)
	151	desc->status &= ~IRQ_NOPROBE;
	152	if (!(iflags & IRQF_NOAUTOEN))
	153	desc->status &= ~IRQ_NOAUTOEN;
	154	spin_unlock_irqrestore(&desc->lock, flags);
1da177e4 LT	155	}
	156
	157	void __init init_IRQ(void)
	158	{
1da177e4 LT	159	int irq;
1da177e4 LT	160
4a2581a0 TG	161	for (irq = 0; irq < NR_IRQS; irq++)
	162	irq_desc[irq].status \|= IRQ_NOREQUEST \| IRQ_DELAYED_DISABLE \|
	163	IRQ_NOPROBE;
	164
1da177e4 LT	165	#ifdef CONFIG_SMP
	166	bad_irq_desc.affinity = CPU_MASK_ALL;
	167	bad_irq_desc.cpu = smp_processor_id();
	168	#endif
1da177e4	169	init_arch_irq();
1da177e4 LT	170	}
1da177e4 LT	171
a054a811	172	#ifdef CONFIG_HOTPLUG_CPU
f7ede370	173
10dd5ce2	174	static void route_irq(struct irq_desc *desc, unsigned int irq, unsigned int cpu)
f7ede370 TG	175	{
	176	pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", irq, desc->cpu, cpu);
	177
	178	spin_lock_irq(&desc->lock);
	179	desc->chip->set_affinity(irq, cpumask_of_cpu(cpu));
	180	spin_unlock_irq(&desc->lock);
	181	}
	182
a054a811 RK	183	/*
	184	* The CPU has been marked offline. Migrate IRQs off this CPU. If
	185	* the affinity settings do not allow other CPUs, force them onto any
	186	* available CPU.
	187	*/
	188	void migrate_irqs(void)
	189	{
	190	unsigned int i, cpu = smp_processor_id();
	191
	192	for (i = 0; i < NR_IRQS; i++) {
10dd5ce2	193	struct irq_desc *desc = irq_desc + i;
a054a811 RK	194
	195	if (desc->cpu == cpu) {
	196	unsigned int newcpu = any_online_cpu(desc->affinity);
	197
	198	if (newcpu == NR_CPUS) {
	199	if (printk_ratelimit())
	200	printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n",
	201	i, cpu);
	202
	203	cpus_setall(desc->affinity);
	204	newcpu = any_online_cpu(desc->affinity);
	205	}
	206
	207	route_irq(desc, i, newcpu);
	208	}
	209	}
	210	}
	211	#endif /* CONFIG_HOTPLUG_CPU */