diff options
Diffstat (limited to 'arch/arm/kernel/irq.c')
| -rw-r--r-- | arch/arm/kernel/irq.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c new file mode 100644 index 0000000..2f3eb79 --- /dev/null +++ b/arch/arm/kernel/irq.c @@ -0,0 +1,209 @@ +/* + * 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_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 __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 (irq >= NR_IRQS) + handle_bad_irq(irq, &bad_irq_desc); + 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; + +#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 */ |
