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534 lines
13 KiB
534 lines
13 KiB
/*
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* linux/kernel/irq/chip.c
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*
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* Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
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* Copyright (C) 2005-2006, Thomas Gleixner, Russell King
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*
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* This file contains the core interrupt handling code, for irq-chip
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* based architectures.
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*
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* Detailed information is available in Documentation/DocBook/genericirq
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*/
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#include <linux/irq.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/kernel_stat.h>
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#include "internals.h"
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/**
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* set_irq_chip - set the irq chip for an irq
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* @irq: irq number
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* @chip: pointer to irq chip description structure
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*/
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int set_irq_chip(unsigned int irq, struct irq_chip *chip)
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{
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struct irq_desc *desc;
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unsigned long flags;
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if (irq >= NR_IRQS) {
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printk(KERN_ERR "Trying to install chip for IRQ%d\n", irq);
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WARN_ON(1);
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return -EINVAL;
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}
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if (!chip)
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chip = &no_irq_chip;
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desc = irq_desc + irq;
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spin_lock_irqsave(&desc->lock, flags);
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irq_chip_set_defaults(chip);
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desc->chip = chip;
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/*
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* For compatibility only:
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*/
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desc->chip = chip;
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spin_unlock_irqrestore(&desc->lock, flags);
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return 0;
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}
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EXPORT_SYMBOL(set_irq_chip);
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/**
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* set_irq_type - set the irq type for an irq
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* @irq: irq number
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* @type: interrupt type - see include/linux/interrupt.h
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*/
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int set_irq_type(unsigned int irq, unsigned int type)
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{
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struct irq_desc *desc;
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unsigned long flags;
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int ret = -ENXIO;
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if (irq >= NR_IRQS) {
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printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
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return -ENODEV;
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}
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desc = irq_desc + irq;
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if (desc->chip->set_type) {
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spin_lock_irqsave(&desc->lock, flags);
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ret = desc->chip->set_type(irq, type);
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spin_unlock_irqrestore(&desc->lock, flags);
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}
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return ret;
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}
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EXPORT_SYMBOL(set_irq_type);
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/**
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* set_irq_data - set irq type data for an irq
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* @irq: Interrupt number
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* @data: Pointer to interrupt specific data
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*
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* Set the hardware irq controller data for an irq
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*/
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int set_irq_data(unsigned int irq, void *data)
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{
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struct irq_desc *desc;
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unsigned long flags;
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if (irq >= NR_IRQS) {
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printk(KERN_ERR
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"Trying to install controller data for IRQ%d\n", irq);
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return -EINVAL;
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}
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desc = irq_desc + irq;
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spin_lock_irqsave(&desc->lock, flags);
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desc->handler_data = data;
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spin_unlock_irqrestore(&desc->lock, flags);
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return 0;
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}
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EXPORT_SYMBOL(set_irq_data);
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/**
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* set_irq_chip_data - set irq chip data for an irq
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* @irq: Interrupt number
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* @data: Pointer to chip specific data
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*
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* Set the hardware irq chip data for an irq
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*/
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int set_irq_chip_data(unsigned int irq, void *data)
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{
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struct irq_desc *desc = irq_desc + irq;
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unsigned long flags;
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if (irq >= NR_IRQS || !desc->chip) {
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printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
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return -EINVAL;
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}
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spin_lock_irqsave(&desc->lock, flags);
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desc->chip_data = data;
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spin_unlock_irqrestore(&desc->lock, flags);
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return 0;
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}
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EXPORT_SYMBOL(set_irq_chip_data);
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/*
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* default enable function
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*/
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static void default_enable(unsigned int irq)
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{
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struct irq_desc *desc = irq_desc + irq;
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desc->chip->unmask(irq);
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desc->status &= ~IRQ_MASKED;
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}
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/*
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* default disable function
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*/
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static void default_disable(unsigned int irq)
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{
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struct irq_desc *desc = irq_desc + irq;
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if (!(desc->status & IRQ_DELAYED_DISABLE))
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irq_desc[irq].chip->mask(irq);
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}
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/*
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* default startup function
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*/
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static unsigned int default_startup(unsigned int irq)
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{
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irq_desc[irq].chip->enable(irq);
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return 0;
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}
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/*
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* Fixup enable/disable function pointers
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*/
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void irq_chip_set_defaults(struct irq_chip *chip)
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{
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if (!chip->enable)
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chip->enable = default_enable;
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if (!chip->disable)
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chip->disable = default_disable;
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if (!chip->startup)
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chip->startup = default_startup;
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if (!chip->shutdown)
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chip->shutdown = chip->disable;
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if (!chip->name)
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chip->name = chip->typename;
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}
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static inline void mask_ack_irq(struct irq_desc *desc, int irq)
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{
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if (desc->chip->mask_ack)
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desc->chip->mask_ack(irq);
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else {
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desc->chip->mask(irq);
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desc->chip->ack(irq);
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}
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}
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/**
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* handle_simple_irq - Simple and software-decoded IRQs.
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* @irq: the interrupt number
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* @desc: the interrupt description structure for this irq
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* @regs: pointer to a register structure
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*
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* Simple interrupts are either sent from a demultiplexing interrupt
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* handler or come from hardware, where no interrupt hardware control
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* is necessary.
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*
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* Note: The caller is expected to handle the ack, clear, mask and
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* unmask issues if necessary.
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*/
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void fastcall
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handle_simple_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs)
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{
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struct irqaction *action;
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irqreturn_t action_ret;
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const unsigned int cpu = smp_processor_id();
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spin_lock(&desc->lock);
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if (unlikely(desc->status & IRQ_INPROGRESS))
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goto out_unlock;
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desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
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kstat_cpu(cpu).irqs[irq]++;
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action = desc->action;
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if (unlikely(!action || (desc->status & IRQ_DISABLED)))
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goto out_unlock;
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desc->status |= IRQ_INPROGRESS;
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spin_unlock(&desc->lock);
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action_ret = handle_IRQ_event(irq, regs, action);
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if (!noirqdebug)
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note_interrupt(irq, desc, action_ret, regs);
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spin_lock(&desc->lock);
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desc->status &= ~IRQ_INPROGRESS;
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out_unlock:
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spin_unlock(&desc->lock);
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}
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/**
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* handle_level_irq - Level type irq handler
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* @irq: the interrupt number
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* @desc: the interrupt description structure for this irq
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* @regs: pointer to a register structure
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*
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* Level type interrupts are active as long as the hardware line has
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* the active level. This may require to mask the interrupt and unmask
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* it after the associated handler has acknowledged the device, so the
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* interrupt line is back to inactive.
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*/
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void fastcall
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handle_level_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs)
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{
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unsigned int cpu = smp_processor_id();
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struct irqaction *action;
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irqreturn_t action_ret;
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spin_lock(&desc->lock);
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mask_ack_irq(desc, irq);
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if (unlikely(desc->status & IRQ_INPROGRESS))
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goto out;
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desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
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kstat_cpu(cpu).irqs[irq]++;
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/*
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* If its disabled or no action available
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* keep it masked and get out of here
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*/
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action = desc->action;
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if (unlikely(!action || (desc->status & IRQ_DISABLED)))
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goto out;
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desc->status |= IRQ_INPROGRESS;
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spin_unlock(&desc->lock);
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action_ret = handle_IRQ_event(irq, regs, action);
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if (!noirqdebug)
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note_interrupt(irq, desc, action_ret, regs);
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spin_lock(&desc->lock);
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desc->status &= ~IRQ_INPROGRESS;
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out:
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if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
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desc->chip->unmask(irq);
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spin_unlock(&desc->lock);
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}
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/**
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* handle_fasteoi_irq - irq handler for transparent controllers
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* @irq: the interrupt number
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* @desc: the interrupt description structure for this irq
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* @regs: pointer to a register structure
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*
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* Only a single callback will be issued to the chip: an ->eoi()
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* call when the interrupt has been serviced. This enables support
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* for modern forms of interrupt handlers, which handle the flow
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* details in hardware, transparently.
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*/
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void fastcall
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handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc,
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struct pt_regs *regs)
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{
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unsigned int cpu = smp_processor_id();
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struct irqaction *action;
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irqreturn_t action_ret;
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spin_lock(&desc->lock);
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if (unlikely(desc->status & IRQ_INPROGRESS))
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goto out;
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desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
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kstat_cpu(cpu).irqs[irq]++;
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/*
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* If its disabled or no action available
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* keep it masked and get out of here
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*/
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action = desc->action;
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if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
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desc->status |= IRQ_PENDING;
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goto out;
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}
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desc->status |= IRQ_INPROGRESS;
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desc->status &= ~IRQ_PENDING;
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spin_unlock(&desc->lock);
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action_ret = handle_IRQ_event(irq, regs, action);
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if (!noirqdebug)
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note_interrupt(irq, desc, action_ret, regs);
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spin_lock(&desc->lock);
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desc->status &= ~IRQ_INPROGRESS;
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out:
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desc->chip->eoi(irq);
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spin_unlock(&desc->lock);
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}
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/**
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* handle_edge_irq - edge type IRQ handler
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* @irq: the interrupt number
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* @desc: the interrupt description structure for this irq
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* @regs: pointer to a register structure
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*
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* Interrupt occures on the falling and/or rising edge of a hardware
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* signal. The occurence is latched into the irq controller hardware
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* and must be acked in order to be reenabled. After the ack another
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* interrupt can happen on the same source even before the first one
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* is handled by the assosiacted event handler. If this happens it
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* might be necessary to disable (mask) the interrupt depending on the
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* controller hardware. This requires to reenable the interrupt inside
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* of the loop which handles the interrupts which have arrived while
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* the handler was running. If all pending interrupts are handled, the
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* loop is left.
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*/
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void fastcall
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handle_edge_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs)
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{
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const unsigned int cpu = smp_processor_id();
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spin_lock(&desc->lock);
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desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
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/*
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* If we're currently running this IRQ, or its disabled,
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* we shouldn't process the IRQ. Mark it pending, handle
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* the necessary masking and go out
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*/
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if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
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!desc->action)) {
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desc->status |= (IRQ_PENDING | IRQ_MASKED);
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mask_ack_irq(desc, irq);
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goto out_unlock;
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}
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kstat_cpu(cpu).irqs[irq]++;
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/* Start handling the irq */
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desc->chip->ack(irq);
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/* Mark the IRQ currently in progress.*/
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desc->status |= IRQ_INPROGRESS;
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do {
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struct irqaction *action = desc->action;
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irqreturn_t action_ret;
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if (unlikely(!action)) {
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desc->chip->mask(irq);
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goto out_unlock;
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}
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/*
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* When another irq arrived while we were handling
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* one, we could have masked the irq.
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* Renable it, if it was not disabled in meantime.
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*/
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if (unlikely((desc->status &
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(IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
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(IRQ_PENDING | IRQ_MASKED))) {
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desc->chip->unmask(irq);
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desc->status &= ~IRQ_MASKED;
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}
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desc->status &= ~IRQ_PENDING;
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spin_unlock(&desc->lock);
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action_ret = handle_IRQ_event(irq, regs, action);
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if (!noirqdebug)
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note_interrupt(irq, desc, action_ret, regs);
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spin_lock(&desc->lock);
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} while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
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desc->status &= ~IRQ_INPROGRESS;
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out_unlock:
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spin_unlock(&desc->lock);
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}
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#ifdef CONFIG_SMP
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/**
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* handle_percpu_IRQ - Per CPU local irq handler
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* @irq: the interrupt number
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* @desc: the interrupt description structure for this irq
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* @regs: pointer to a register structure
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*
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* Per CPU interrupts on SMP machines without locking requirements
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*/
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void fastcall
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handle_percpu_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs)
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{
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irqreturn_t action_ret;
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kstat_this_cpu.irqs[irq]++;
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if (desc->chip->ack)
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desc->chip->ack(irq);
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action_ret = handle_IRQ_event(irq, regs, desc->action);
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if (!noirqdebug)
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note_interrupt(irq, desc, action_ret, regs);
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if (desc->chip->eoi)
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desc->chip->eoi(irq);
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}
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#endif /* CONFIG_SMP */
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void
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__set_irq_handler(unsigned int irq,
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void fastcall (*handle)(unsigned int, irq_desc_t *,
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struct pt_regs *),
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int is_chained)
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{
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struct irq_desc *desc;
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unsigned long flags;
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if (irq >= NR_IRQS) {
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printk(KERN_ERR
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"Trying to install type control for IRQ%d\n", irq);
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return;
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}
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desc = irq_desc + irq;
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if (!handle)
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handle = handle_bad_irq;
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if (desc->chip == &no_irq_chip) {
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printk(KERN_WARNING "Trying to install %sinterrupt handler "
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"for IRQ%d\n", is_chained ? "chained " : " ", irq);
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/*
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* Some ARM implementations install a handler for really dumb
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* interrupt hardware without setting an irq_chip. This worked
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* with the ARM no_irq_chip but the check in setup_irq would
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* prevent us to setup the interrupt at all. Switch it to
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* dummy_irq_chip for easy transition.
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*/
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desc->chip = &dummy_irq_chip;
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}
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spin_lock_irqsave(&desc->lock, flags);
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/* Uninstall? */
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if (handle == handle_bad_irq) {
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if (desc->chip != &no_irq_chip) {
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desc->chip->mask(irq);
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desc->chip->ack(irq);
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}
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desc->status |= IRQ_DISABLED;
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desc->depth = 1;
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}
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desc->handle_irq = handle;
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if (handle != handle_bad_irq && is_chained) {
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desc->status &= ~IRQ_DISABLED;
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desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
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desc->depth = 0;
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desc->chip->unmask(irq);
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}
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spin_unlock_irqrestore(&desc->lock, flags);
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}
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void
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set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
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void fastcall (*handle)(unsigned int,
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struct irq_desc *,
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struct pt_regs *))
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{
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set_irq_chip(irq, chip);
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__set_irq_handler(irq, handle, 0);
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}
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/*
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* Get a descriptive string for the highlevel handler, for
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* /proc/interrupts output:
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*/
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const char *
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handle_irq_name(void fastcall (*handle)(unsigned int, struct irq_desc *,
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struct pt_regs *))
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{
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if (handle == handle_level_irq)
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return "level ";
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if (handle == handle_fasteoi_irq)
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return "fasteoi";
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if (handle == handle_edge_irq)
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return "edge ";
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if (handle == handle_simple_irq)
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return "simple ";
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#ifdef CONFIG_SMP
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if (handle == handle_percpu_irq)
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return "percpu ";
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#endif
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if (handle == handle_bad_irq)
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return "bad ";
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return NULL;
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}
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