![Jan Beulich](/assets/img/avatar_default.png)
Correct the return type of handle_IRQ_event() (inconsistency noticed during Xen development), and remove redundant declarations. The return type adjustment required breaking out the definition of irqreturn_t into a separate header, in order to satisfy current include order dependencies. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ian Molton <spyro@f2s.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Hirokazu Takata <takata.hirokazu@renesas.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
196 lines
4.8 KiB
C
196 lines
4.8 KiB
C
/*
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* linux/kernel/irq/handle.c
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*
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* Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
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*
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* This file contains the core interrupt handling code.
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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/random.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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* Linux has a controller-independent interrupt architecture.
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* Every controller has a 'controller-template', that is used
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* by the main code to do the right thing. Each driver-visible
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* interrupt source is transparently wired to the apropriate
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* controller. Thus drivers need not be aware of the
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* interrupt-controller.
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*
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* The code is designed to be easily extended with new/different
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* interrupt controllers, without having to do assembly magic or
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* having to touch the generic code.
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*
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* Controller mappings for all interrupt sources:
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*/
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irq_desc_t irq_desc[NR_IRQS] __cacheline_aligned = {
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[0 ... NR_IRQS-1] = {
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.status = IRQ_DISABLED,
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.handler = &no_irq_type,
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.lock = SPIN_LOCK_UNLOCKED
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}
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};
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/*
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* Generic 'no controller' code
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*/
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static void end_none(unsigned int irq) { }
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static void enable_none(unsigned int irq) { }
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static void disable_none(unsigned int irq) { }
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static void shutdown_none(unsigned int irq) { }
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static unsigned int startup_none(unsigned int irq) { return 0; }
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static void ack_none(unsigned int irq)
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{
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/*
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* 'what should we do if we get a hw irq event on an illegal vector'.
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* each architecture has to answer this themself.
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*/
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ack_bad_irq(irq);
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}
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struct hw_interrupt_type no_irq_type = {
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.typename = "none",
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.startup = startup_none,
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.shutdown = shutdown_none,
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.enable = enable_none,
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.disable = disable_none,
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.ack = ack_none,
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.end = end_none,
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.set_affinity = NULL
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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, struct pt_regs *regs)
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{
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return IRQ_NONE;
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}
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/*
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* Have got an event to handle:
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*/
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fastcall irqreturn_t handle_IRQ_event(unsigned int irq, struct pt_regs *regs,
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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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if (!(action->flags & SA_INTERRUPT))
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local_irq_enable();
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do {
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ret = action->handler(irq, action->dev_id, regs);
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if (ret == IRQ_HANDLED)
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status |= action->flags;
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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 & SA_SAMPLE_RANDOM)
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add_interrupt_randomness(irq);
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local_irq_disable();
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return retval;
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}
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/*
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* do_IRQ handles all normal device IRQ's (the special
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* SMP cross-CPU interrupts have their own specific
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* handlers).
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*/
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fastcall unsigned int __do_IRQ(unsigned int irq, struct pt_regs *regs)
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{
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irq_desc_t *desc = irq_desc + irq;
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struct irqaction * action;
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unsigned int status;
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kstat_this_cpu.irqs[irq]++;
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if (CHECK_IRQ_PER_CPU(desc->status)) {
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irqreturn_t action_ret;
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/*
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* No locking required for CPU-local interrupts:
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*/
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if (desc->handler->ack)
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desc->handler->ack(irq);
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action_ret = handle_IRQ_event(irq, regs, desc->action);
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desc->handler->end(irq);
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return 1;
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}
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spin_lock(&desc->lock);
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if (desc->handler->ack)
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desc->handler->ack(irq);
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/*
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* REPLAY is when Linux resends an IRQ that was dropped earlier
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* WAITING is used by probe to mark irqs that are being tested
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*/
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status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
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status |= IRQ_PENDING; /* we _want_ to handle it */
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/*
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* If the IRQ is disabled for whatever reason, we cannot
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* use the action we have.
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*/
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action = NULL;
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if (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) {
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action = desc->action;
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status &= ~IRQ_PENDING; /* we commit to handling */
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status |= IRQ_INPROGRESS; /* we are handling it */
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}
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desc->status = status;
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/*
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* If there is no IRQ handler or it was disabled, exit early.
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* Since we set PENDING, if another processor is handling
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* a different instance of this same irq, the other processor
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* will take care of it.
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*/
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if (unlikely(!action))
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goto out;
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/*
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* Edge triggered interrupts need to remember
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* pending events.
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* This applies to any hw interrupts that allow a second
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* instance of the same irq to arrive while we are in do_IRQ
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* or in the handler. But the code here only handles the _second_
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* instance of the irq, not the third or fourth. So it is mostly
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* useful for irq hardware that does not mask cleanly in an
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* SMP environment.
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*/
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for (;;) {
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irqreturn_t action_ret;
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spin_unlock(&desc->lock);
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action_ret = handle_IRQ_event(irq, regs, action);
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spin_lock(&desc->lock);
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if (!noirqdebug)
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note_interrupt(irq, desc, action_ret, regs);
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if (likely(!(desc->status & IRQ_PENDING)))
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break;
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desc->status &= ~IRQ_PENDING;
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}
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desc->status &= ~IRQ_INPROGRESS;
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out:
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/*
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* The ->end() handler has to deal with interrupts which got
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* disabled while the handler was running.
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*/
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desc->handler->end(irq);
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spin_unlock(&desc->lock);
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return 1;
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}
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