123 lines
2.8 KiB
C
123 lines
2.8 KiB
C
/*
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* linux/kernel/irq/handle.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.
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*
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* Detailed information is available in Documentation/DocBook/genericirq
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*
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*/
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#include <linux/irq.h>
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#include <linux/random.h>
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#include <linux/sched.h>
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#include <linux/interrupt.h>
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#include <linux/kernel_stat.h>
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#include <trace/events/irq.h>
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#include "internals.h"
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/**
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* handle_bad_irq - handle spurious and unhandled irqs
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* @irq: the interrupt number
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* @desc: description of the interrupt
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*
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* Handles spurious and unhandled IRQ's. It also prints a debugmessage.
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*/
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void handle_bad_irq(unsigned int irq, struct irq_desc *desc)
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{
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print_irq_desc(irq, desc);
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kstat_incr_irqs_this_cpu(irq, desc);
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ack_bad_irq(irq);
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}
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/*
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* Special, empty irq handler:
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*/
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irqreturn_t no_action(int cpl, void *dev_id)
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{
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return IRQ_NONE;
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}
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static void warn_no_thread(unsigned int irq, struct irqaction *action)
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{
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if (test_and_set_bit(IRQTF_WARNED, &action->thread_flags))
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return;
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printk(KERN_WARNING "IRQ %d device %s returned IRQ_WAKE_THREAD "
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"but no thread function available.", irq, action->name);
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}
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/**
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* handle_IRQ_event - irq action chain handler
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* @irq: the interrupt number
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* @action: the interrupt action chain for this irq
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*
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* Handles the action chain of an irq event
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*/
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irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
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{
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irqreturn_t ret, retval = IRQ_NONE;
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unsigned int status = 0;
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do {
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trace_irq_handler_entry(irq, action);
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ret = action->handler(irq, action->dev_id);
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trace_irq_handler_exit(irq, action, ret);
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if (WARN_ON_ONCE(!irqs_disabled()))
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local_irq_disable();
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switch (ret) {
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case IRQ_WAKE_THREAD:
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/*
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* Set result to handled so the spurious check
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* does not trigger.
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*/
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ret = IRQ_HANDLED;
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/*
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* Catch drivers which return WAKE_THREAD but
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* did not set up a thread function
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*/
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if (unlikely(!action->thread_fn)) {
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warn_no_thread(irq, action);
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break;
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}
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/*
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* Wake up the handler thread for this
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* action. In case the thread crashed and was
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* killed we just pretend that we handled the
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* interrupt. The hardirq handler above has
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* disabled the device interrupt, so no irq
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* storm is lurking.
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*/
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if (likely(!test_bit(IRQTF_DIED,
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&action->thread_flags))) {
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set_bit(IRQTF_RUNTHREAD, &action->thread_flags);
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wake_up_process(action->thread);
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}
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/* Fall through to add to randomness */
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case IRQ_HANDLED:
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status |= action->flags;
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break;
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default:
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break;
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}
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retval |= ret;
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action = action->next;
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} while (action);
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if (status & IRQF_SAMPLE_RANDOM)
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add_interrupt_randomness(irq);
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return retval;
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}
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