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/*
* 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/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/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
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_irqs_cpu(i, cpu));
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_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_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_NOPROBE;
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->node, cpu);
spin_lock_irq(&desc->lock);
desc->chip->set_affinity(irq, cpumask_of(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->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 */
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