187 lines
4.4 KiB
C
187 lines
4.4 KiB
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/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 <linux/ftrace.h>
|
|
|
|
#include <asm/system.h>
|
|
#include <asm/mach/arch.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 long irq_err_count;
|
|
|
|
int arch_show_interrupts(struct seq_file *p, int prec)
|
|
{
|
|
#ifdef CONFIG_FIQ
|
|
show_fiq_list(p, prec);
|
|
#endif
|
|
#ifdef CONFIG_SMP
|
|
show_ipi_list(p, prec);
|
|
#endif
|
|
#ifdef CONFIG_LOCAL_TIMERS
|
|
show_local_irqs(p, prec);
|
|
#endif
|
|
seq_printf(p, "%*s: %10lu\n", prec, "Err", 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_irq_entry
|
|
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)
|
|
{
|
|
unsigned long clr = 0, set = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
|
|
|
|
if (irq >= nr_irqs) {
|
|
printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq);
|
|
return;
|
|
}
|
|
|
|
if (iflags & IRQF_VALID)
|
|
clr |= IRQ_NOREQUEST;
|
|
if (iflags & IRQF_PROBE)
|
|
clr |= IRQ_NOPROBE;
|
|
if (!(iflags & IRQF_NOAUTOEN))
|
|
clr |= IRQ_NOAUTOEN;
|
|
/* Order is clear bits in "clr" then set bits in "set" */
|
|
irq_modify_status(irq, clr, set & ~clr);
|
|
}
|
|
|
|
void __init init_IRQ(void)
|
|
{
|
|
machine_desc->init_irq();
|
|
}
|
|
|
|
#ifdef CONFIG_SPARSE_IRQ
|
|
int __init arch_probe_nr_irqs(void)
|
|
{
|
|
nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS;
|
|
return nr_irqs;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
|
|
static bool migrate_one_irq(struct irq_data *d)
|
|
{
|
|
unsigned int cpu = cpumask_any_and(d->affinity, cpu_online_mask);
|
|
bool ret = false;
|
|
|
|
if (cpu >= nr_cpu_ids) {
|
|
cpu = cpumask_any(cpu_online_mask);
|
|
ret = true;
|
|
}
|
|
|
|
pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", d->irq, d->node, cpu);
|
|
|
|
d->chip->irq_set_affinity(d, cpumask_of(cpu), true);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
|
|
for_each_irq_desc(i, desc) {
|
|
struct irq_data *d = &desc->irq_data;
|
|
bool affinity_broken = false;
|
|
|
|
raw_spin_lock(&desc->lock);
|
|
do {
|
|
if (desc->action == NULL)
|
|
break;
|
|
|
|
if (d->node != cpu)
|
|
break;
|
|
|
|
affinity_broken = migrate_one_irq(d);
|
|
} while (0);
|
|
raw_spin_unlock(&desc->lock);
|
|
|
|
if (affinity_broken && printk_ratelimit())
|
|
pr_warning("IRQ%u no longer affine to CPU%u\n", i, cpu);
|
|
}
|
|
|
|
local_irq_restore(flags);
|
|
}
|
|
#endif /* CONFIG_HOTPLUG_CPU */
|