Creation of Cybook 2416 (actually Gen4) repository

kernel/irq/Makefile

@@ -0,0 +1,5 @@
+
+obj-y := handle.o manage.o spurious.o resend.o chip.o devres.o
+obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o
+obj-$(CONFIG_PROC_FS) += proc.o
+obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o

kernel/irq/autoprobe.c

@@ -0,0 +1,202 @@
+/*
+ * linux/kernel/irq/autoprobe.c
+ *
+ * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
+ *
+ * This file contains the interrupt probing code and driver APIs.
+ */
+
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+
+#include "internals.h"
+
+/*
+ * Autodetection depends on the fact that any interrupt that
+ * comes in on to an unassigned handler will get stuck with
+ * "IRQ_WAITING" cleared and the interrupt disabled.
+ */
+static DEFINE_MUTEX(probing_active);
+
+/**
+ *	probe_irq_on	- begin an interrupt autodetect
+ *
+ *	Commence probing for an interrupt. The interrupts are scanned
+ *	and a mask of potential interrupt lines is returned.
+ *
+ */
+unsigned long probe_irq_on(void)
+{
+	struct irq_desc *desc;
+	unsigned long mask;
+	unsigned int i;
+
+	mutex_lock(&probing_active);
+	/*
+	 * something may have generated an irq long ago and we want to
+	 * flush such a longstanding irq before considering it as spurious.
+	 */
+	for (i = NR_IRQS-1; i > 0; i--) {
+		desc = irq_desc + i;
+
+		spin_lock_irq(&desc->lock);
+		if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
+			/*
+			 * An old-style architecture might still have
+			 * the handle_bad_irq handler there:
+			 */
+			compat_irq_chip_set_default_handler(desc);
+
+			/*
+			 * Some chips need to know about probing in
+			 * progress:
+			 */
+			if (desc->chip->set_type)
+				desc->chip->set_type(i, IRQ_TYPE_PROBE);
+			desc->chip->startup(i);
+		}
+		spin_unlock_irq(&desc->lock);
+	}
+
+	/* Wait for longstanding interrupts to trigger. */
+	msleep(20);
+
+	/*
+	 * enable any unassigned irqs
+	 * (we must startup again here because if a longstanding irq
+	 * happened in the previous stage, it may have masked itself)
+	 */
+	for (i = NR_IRQS-1; i > 0; i--) {
+		desc = irq_desc + i;
+
+		spin_lock_irq(&desc->lock);
+		if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
+			desc->status |= IRQ_AUTODETECT | IRQ_WAITING;
+			if (desc->chip->startup(i))
+				desc->status |= IRQ_PENDING;
+		}
+		spin_unlock_irq(&desc->lock);
+	}
+
+	/*
+	 * Wait for spurious interrupts to trigger
+	 */
+	msleep(100);
+
+	/*
+	 * Now filter out any obviously spurious interrupts
+	 */
+	mask = 0;
+	for (i = 0; i < NR_IRQS; i++) {
+		unsigned int status;
+
+		desc = irq_desc + i;
+		spin_lock_irq(&desc->lock);
+		status = desc->status;
+
+		if (status & IRQ_AUTODETECT) {
+			/* It triggered already - consider it spurious. */
+			if (!(status & IRQ_WAITING)) {
+				desc->status = status & ~IRQ_AUTODETECT;
+				desc->chip->shutdown(i);
+			} else
+				if (i < 32)
+					mask |= 1 << i;
+		}
+		spin_unlock_irq(&desc->lock);
+	}
+
+	return mask;
+}
+EXPORT_SYMBOL(probe_irq_on);
+
+/**
+ *	probe_irq_mask - scan a bitmap of interrupt lines
+ *	@val:	mask of interrupts to consider
+ *
+ *	Scan the interrupt lines and return a bitmap of active
+ *	autodetect interrupts. The interrupt probe logic state
+ *	is then returned to its previous value.
+ *
+ *	Note: we need to scan all the irq's even though we will
+ *	only return autodetect irq numbers - just so that we reset
+ *	them all to a known state.
+ */
+unsigned int probe_irq_mask(unsigned long val)
+{
+	unsigned int mask;
+	int i;
+
+	mask = 0;
+	for (i = 0; i < NR_IRQS; i++) {
+		struct irq_desc *desc = irq_desc + i;
+		unsigned int status;
+
+		spin_lock_irq(&desc->lock);
+		status = desc->status;
+
+		if (status & IRQ_AUTODETECT) {
+			if (i < 16 && !(status & IRQ_WAITING))
+				mask |= 1 << i;
+
+			desc->status = status & ~IRQ_AUTODETECT;
+			desc->chip->shutdown(i);
+		}
+		spin_unlock_irq(&desc->lock);
+	}
+	mutex_unlock(&probing_active);
+
+	return mask & val;
+}
+EXPORT_SYMBOL(probe_irq_mask);
+
+/**
+ *	probe_irq_off	- end an interrupt autodetect
+ *	@val: mask of potential interrupts (unused)
+ *
+ *	Scans the unused interrupt lines and returns the line which
+ *	appears to have triggered the interrupt. If no interrupt was
+ *	found then zero is returned. If more than one interrupt is
+ *	found then minus the first candidate is returned to indicate
+ *	their is doubt.
+ *
+ *	The interrupt probe logic state is returned to its previous
+ *	value.
+ *
+ *	BUGS: When used in a module (which arguably shouldn't happen)
+ *	nothing prevents two IRQ probe callers from overlapping. The
+ *	results of this are non-optimal.
+ */
+int probe_irq_off(unsigned long val)
+{
+	int i, irq_found = 0, nr_irqs = 0;
+
+	for (i = 0; i < NR_IRQS; i++) {
+		struct irq_desc *desc = irq_desc + i;
+		unsigned int status;
+
+		spin_lock_irq(&desc->lock);
+		status = desc->status;
+
+		if (status & IRQ_AUTODETECT) {
+			if (!(status & IRQ_WAITING)) {
+				if (!nr_irqs)
+					irq_found = i;
+				nr_irqs++;
+			}
+			desc->status = status & ~IRQ_AUTODETECT;
+			desc->chip->shutdown(i);
+		}
+		spin_unlock_irq(&desc->lock);
+	}
+	mutex_unlock(&probing_active);
+
+	if (nr_irqs > 1)
+		irq_found = -irq_found;
+
+	return irq_found;
+}
+EXPORT_SYMBOL(probe_irq_off);
+

kernel/irq/chip.c

@@ -0,0 +1,599 @@
+/*
+ * linux/kernel/irq/chip.c
+ *
+ * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
+ * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
+ *
+ * This file contains the core interrupt handling code, for irq-chip
+ * based architectures.
+ *
+ * Detailed information is available in Documentation/DocBook/genericirq
+ */
+
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+
+#include "internals.h"
+
+/**
+ *	dynamic_irq_init - initialize a dynamically allocated irq
+ *	@irq:	irq number to initialize
+ */
+void dynamic_irq_init(unsigned int irq)
+{
+	struct irq_desc *desc;
+	unsigned long flags;
+
+	if (irq >= NR_IRQS) {
+		printk(KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
+		WARN_ON(1);
+		return;
+	}
+
+	/* Ensure we don't have left over values from a previous use of this irq */
+	desc = irq_desc + irq;
+	spin_lock_irqsave(&desc->lock, flags);
+	desc->status = IRQ_DISABLED;
+	desc->chip = &no_irq_chip;
+	desc->handle_irq = handle_bad_irq;
+	desc->depth = 1;
+	desc->msi_desc = NULL;
+	desc->handler_data = NULL;
+	desc->chip_data = NULL;
+	desc->action = NULL;
+	desc->irq_count = 0;
+	desc->irqs_unhandled = 0;
+#ifdef CONFIG_SMP
+	desc->affinity = CPU_MASK_ALL;
+#endif
+	spin_unlock_irqrestore(&desc->lock, flags);
+}
+
+/**
+ *	dynamic_irq_cleanup - cleanup a dynamically allocated irq
+ *	@irq:	irq number to initialize
+ */
+void dynamic_irq_cleanup(unsigned int irq)
+{
+	struct irq_desc *desc;
+	unsigned long flags;
+
+	if (irq >= NR_IRQS) {
+		printk(KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq);
+		WARN_ON(1);
+		return;
+	}
+
+	desc = irq_desc + irq;
+	spin_lock_irqsave(&desc->lock, flags);
+	if (desc->action) {
+		spin_unlock_irqrestore(&desc->lock, flags);
+		printk(KERN_ERR "Destroying IRQ%d without calling free_irq\n",
+			irq);
+		WARN_ON(1);
+		return;
+	}
+	desc->msi_desc = NULL;
+	desc->handler_data = NULL;
+	desc->chip_data = NULL;
+	desc->handle_irq = handle_bad_irq;
+	desc->chip = &no_irq_chip;
+	spin_unlock_irqrestore(&desc->lock, flags);
+}
+
+
+/**
+ *	set_irq_chip - set the irq chip for an irq
+ *	@irq:	irq number
+ *	@chip:	pointer to irq chip description structure
+ */
+int set_irq_chip(unsigned int irq, struct irq_chip *chip)
+{
+	struct irq_desc *desc;
+	unsigned long flags;
+
+	if (irq >= NR_IRQS) {
+		printk(KERN_ERR "Trying to install chip for IRQ%d\n", irq);
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	if (!chip)
+		chip = &no_irq_chip;
+
+	desc = irq_desc + irq;
+	spin_lock_irqsave(&desc->lock, flags);
+	irq_chip_set_defaults(chip);
+	desc->chip = chip;
+	spin_unlock_irqrestore(&desc->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(set_irq_chip);
+
+/**
+ *	set_irq_type - set the irq type for an irq
+ *	@irq:	irq number
+ *	@type:	interrupt type - see include/linux/interrupt.h
+ */
+int set_irq_type(unsigned int irq, unsigned int type)
+{
+	struct irq_desc *desc;
+	unsigned long flags;
+	int ret = -ENXIO;
+
+	if (irq >= NR_IRQS) {
+		printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
+		return -ENODEV;
+	}
+
+	desc = irq_desc + irq;
+	if (desc->chip->set_type) {
+		spin_lock_irqsave(&desc->lock, flags);
+		ret = desc->chip->set_type(irq, type);
+		spin_unlock_irqrestore(&desc->lock, flags);
+	}
+	return ret;
+}
+EXPORT_SYMBOL(set_irq_type);
+
+/**
+ *	set_irq_data - set irq type data for an irq
+ *	@irq:	Interrupt number
+ *	@data:	Pointer to interrupt specific data
+ *
+ *	Set the hardware irq controller data for an irq
+ */
+int set_irq_data(unsigned int irq, void *data)
+{
+	struct irq_desc *desc;
+	unsigned long flags;
+
+	if (irq >= NR_IRQS) {
+		printk(KERN_ERR
+		       "Trying to install controller data for IRQ%d\n", irq);
+		return -EINVAL;
+	}
+
+	desc = irq_desc + irq;
+	spin_lock_irqsave(&desc->lock, flags);
+	desc->handler_data = data;
+	spin_unlock_irqrestore(&desc->lock, flags);
+	return 0;
+}
+EXPORT_SYMBOL(set_irq_data);
+
+/**
+ *	set_irq_data - set irq type data for an irq
+ *	@irq:	Interrupt number
+ *	@entry:	Pointer to MSI descriptor data
+ *
+ *	Set the hardware irq controller data for an irq
+ */
+int set_irq_msi(unsigned int irq, struct msi_desc *entry)
+{
+	struct irq_desc *desc;
+	unsigned long flags;
+
+	if (irq >= NR_IRQS) {
+		printk(KERN_ERR
+		       "Trying to install msi data for IRQ%d\n", irq);
+		return -EINVAL;
+	}
+	desc = irq_desc + irq;
+	spin_lock_irqsave(&desc->lock, flags);
+	desc->msi_desc = entry;
+	spin_unlock_irqrestore(&desc->lock, flags);
+	return 0;
+}
+
+/**
+ *	set_irq_chip_data - set irq chip data for an irq
+ *	@irq:	Interrupt number
+ *	@data:	Pointer to chip specific data
+ *
+ *	Set the hardware irq chip data for an irq
+ */
+int set_irq_chip_data(unsigned int irq, void *data)
+{
+	struct irq_desc *desc = irq_desc + irq;
+	unsigned long flags;
+
+	if (irq >= NR_IRQS || !desc->chip) {
+		printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&desc->lock, flags);
+	desc->chip_data = data;
+	spin_unlock_irqrestore(&desc->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(set_irq_chip_data);
+
+/*
+ * default enable function
+ */
+static void default_enable(unsigned int irq)
+{
+	struct irq_desc *desc = irq_desc + irq;
+
+	desc->chip->unmask(irq);
+	desc->status &= ~IRQ_MASKED;
+}
+
+/*
+ * default disable function
+ */
+static void default_disable(unsigned int irq)
+{
+}
+
+/*
+ * default startup function
+ */
+static unsigned int default_startup(unsigned int irq)
+{
+	irq_desc[irq].chip->enable(irq);
+
+	return 0;
+}
+
+/*
+ * Fixup enable/disable function pointers
+ */
+void irq_chip_set_defaults(struct irq_chip *chip)
+{
+	if (!chip->enable)
+		chip->enable = default_enable;
+	if (!chip->disable)
+		chip->disable = default_disable;
+	if (!chip->startup)
+		chip->startup = default_startup;
+	if (!chip->shutdown)
+		chip->shutdown = chip->disable;
+	if (!chip->name)
+		chip->name = chip->typename;
+	if (!chip->end)
+		chip->end = dummy_irq_chip.end;
+}
+
+static inline void mask_ack_irq(struct irq_desc *desc, int irq)
+{
+	if (desc->chip->mask_ack)
+		desc->chip->mask_ack(irq);
+	else {
+		desc->chip->mask(irq);
+		desc->chip->ack(irq);
+	}
+}
+
+/**
+ *	handle_simple_irq - Simple and software-decoded IRQs.
+ *	@irq:	the interrupt number
+ *	@desc:	the interrupt description structure for this irq
+ *
+ *	Simple interrupts are either sent from a demultiplexing interrupt
+ *	handler or come from hardware, where no interrupt hardware control
+ *	is necessary.
+ *
+ *	Note: The caller is expected to handle the ack, clear, mask and
+ *	unmask issues if necessary.
+ */
+void fastcall
+handle_simple_irq(unsigned int irq, struct irq_desc *desc)
+{
+	struct irqaction *action;
+	irqreturn_t action_ret;
+	const unsigned int cpu = smp_processor_id();
+
+	spin_lock(&desc->lock);
+
+	if (unlikely(desc->status & IRQ_INPROGRESS))
+		goto out_unlock;
+	kstat_cpu(cpu).irqs[irq]++;
+
+	action = desc->action;
+	if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
+		if (desc->chip->mask)
+			desc->chip->mask(irq);
+		desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
+		desc->status |= IRQ_PENDING;
+		goto out_unlock;
+	}
+
+	desc->status &= ~(IRQ_REPLAY | IRQ_WAITING | IRQ_PENDING);
+	desc->status |= IRQ_INPROGRESS;
+	spin_unlock(&desc->lock);
+
+	action_ret = handle_IRQ_event(irq, action);
+	if (!noirqdebug)
+		note_interrupt(irq, desc, action_ret);
+
+	spin_lock(&desc->lock);
+	desc->status &= ~IRQ_INPROGRESS;
+out_unlock:
+	spin_unlock(&desc->lock);
+}
+
+/**
+ *	handle_level_irq - Level type irq handler
+ *	@irq:	the interrupt number
+ *	@desc:	the interrupt description structure for this irq
+ *
+ *	Level type interrupts are active as long as the hardware line has
+ *	the active level. This may require to mask the interrupt and unmask
+ *	it after the associated handler has acknowledged the device, so the
+ *	interrupt line is back to inactive.
+ */
+void fastcall
+handle_level_irq(unsigned int irq, struct irq_desc *desc)
+{
+	unsigned int cpu = smp_processor_id();
+	struct irqaction *action;
+	irqreturn_t action_ret;
+
+	spin_lock(&desc->lock);
+	mask_ack_irq(desc, irq);
+
+	if (unlikely(desc->status & IRQ_INPROGRESS))
+		goto out_unlock;
+	desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
+	kstat_cpu(cpu).irqs[irq]++;
+
+	/*
+	 * If its disabled or no action available
+	 * keep it masked and get out of here
+	 */
+	action = desc->action;
+	if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
+		desc->status |= IRQ_PENDING;
+		goto out_unlock;
+	}
+
+	desc->status |= IRQ_INPROGRESS;
+	desc->status &= ~IRQ_PENDING;
+	spin_unlock(&desc->lock);
+
+	action_ret = handle_IRQ_event(irq, action);
+	if (!noirqdebug)
+		note_interrupt(irq, desc, action_ret);
+
+	spin_lock(&desc->lock);
+	desc->status &= ~IRQ_INPROGRESS;
+	if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
+		desc->chip->unmask(irq);
+out_unlock:
+	spin_unlock(&desc->lock);
+}
+
+/**
+ *	handle_fasteoi_irq - irq handler for transparent controllers
+ *	@irq:	the interrupt number
+ *	@desc:	the interrupt description structure for this irq
+ *
+ *	Only a single callback will be issued to the chip: an ->eoi()
+ *	call when the interrupt has been serviced. This enables support
+ *	for modern forms of interrupt handlers, which handle the flow
+ *	details in hardware, transparently.
+ */
+void fastcall
+handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
+{
+	unsigned int cpu = smp_processor_id();
+	struct irqaction *action;
+	irqreturn_t action_ret;
+
+	spin_lock(&desc->lock);
+
+	if (unlikely(desc->status & IRQ_INPROGRESS))
+		goto out;
+
+	desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
+	kstat_cpu(cpu).irqs[irq]++;
+
+	/*
+	 * If its disabled or no action available
+	 * then mask it and get out of here:
+	 */
+	action = desc->action;
+	if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
+		desc->status |= IRQ_PENDING;
+		if (desc->chip->mask)
+			desc->chip->mask(irq);
+		goto out;
+	}
+
+	desc->status |= IRQ_INPROGRESS;
+	desc->status &= ~IRQ_PENDING;
+	spin_unlock(&desc->lock);
+
+	action_ret = handle_IRQ_event(irq, action);
+	if (!noirqdebug)
+		note_interrupt(irq, desc, action_ret);
+
+	spin_lock(&desc->lock);
+	desc->status &= ~IRQ_INPROGRESS;
+out:
+	desc->chip->eoi(irq);
+
+	spin_unlock(&desc->lock);
+}
+
+/**
+ *	handle_edge_irq - edge type IRQ handler
+ *	@irq:	the interrupt number
+ *	@desc:	the interrupt description structure for this irq
+ *
+ *	Interrupt occures on the falling and/or rising edge of a hardware
+ *	signal. The occurence is latched into the irq controller hardware
+ *	and must be acked in order to be reenabled. After the ack another
+ *	interrupt can happen on the same source even before the first one
+ *	is handled by the assosiacted event handler. If this happens it
+ *	might be necessary to disable (mask) the interrupt depending on the
+ *	controller hardware. This requires to reenable the interrupt inside
+ *	of the loop which handles the interrupts which have arrived while
+ *	the handler was running. If all pending interrupts are handled, the
+ *	loop is left.
+ */
+void fastcall
+handle_edge_irq(unsigned int irq, struct irq_desc *desc)
+{
+	const unsigned int cpu = smp_processor_id();
+
+	spin_lock(&desc->lock);
+
+	desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
+
+	/*
+	 * If we're currently running this IRQ, or its disabled,
+	 * we shouldn't process the IRQ. Mark it pending, handle
+	 * the necessary masking and go out
+	 */
+	if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
+		    !desc->action)) {
+		desc->status |= (IRQ_PENDING | IRQ_MASKED);
+		mask_ack_irq(desc, irq);
+		goto out_unlock;
+	}
+
+	kstat_cpu(cpu).irqs[irq]++;
+
+	/* Start handling the irq */
+	desc->chip->ack(irq);
+
+	/* Mark the IRQ currently in progress.*/
+	desc->status |= IRQ_INPROGRESS;
+
+	do {
+		struct irqaction *action = desc->action;
+		irqreturn_t action_ret;
+
+		if (unlikely(!action)) {
+			desc->chip->mask(irq);
+			goto out_unlock;
+		}
+
+		/*
+		 * When another irq arrived while we were handling
+		 * one, we could have masked the irq.
+		 * Renable it, if it was not disabled in meantime.
+		 */
+		if (unlikely((desc->status &
+			       (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
+			      (IRQ_PENDING | IRQ_MASKED))) {
+			desc->chip->unmask(irq);
+			desc->status &= ~IRQ_MASKED;
+		}
+
+		desc->status &= ~IRQ_PENDING;
+		spin_unlock(&desc->lock);
+		action_ret = handle_IRQ_event(irq, action);
+		if (!noirqdebug)
+			note_interrupt(irq, desc, action_ret);
+		spin_lock(&desc->lock);
+
+	} while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
+
+	desc->status &= ~IRQ_INPROGRESS;
+out_unlock:
+	spin_unlock(&desc->lock);
+}
+
+#ifdef CONFIG_SMP
+/**
+ *	handle_percpu_IRQ - Per CPU local irq handler
+ *	@irq:	the interrupt number
+ *	@desc:	the interrupt description structure for this irq
+ *
+ *	Per CPU interrupts on SMP machines without locking requirements
+ */
+void fastcall
+handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
+{
+	irqreturn_t action_ret;
+
+	kstat_this_cpu.irqs[irq]++;
+
+	if (desc->chip->ack)
+		desc->chip->ack(irq);
+
+	action_ret = handle_IRQ_event(irq, desc->action);
+	if (!noirqdebug)
+		note_interrupt(irq, desc, action_ret);
+
+	if (desc->chip->eoi)
+		desc->chip->eoi(irq);
+}
+
+#endif /* CONFIG_SMP */
+
+void
+__set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
+		  const char *name)
+{
+	struct irq_desc *desc;
+	unsigned long flags;
+
+	if (irq >= NR_IRQS) {
+		printk(KERN_ERR
+		       "Trying to install type control for IRQ%d\n", irq);
+		return;
+	}
+
+	desc = irq_desc + irq;
+
+	if (!handle)
+		handle = handle_bad_irq;
+	else if (desc->chip == &no_irq_chip) {
+		printk(KERN_WARNING "Trying to install %sinterrupt handler "
+		       "for IRQ%d\n", is_chained ? "chained " : "", irq);
+		/*
+		 * Some ARM implementations install a handler for really dumb
+		 * interrupt hardware without setting an irq_chip. This worked
+		 * with the ARM no_irq_chip but the check in setup_irq would
+		 * prevent us to setup the interrupt at all. Switch it to
+		 * dummy_irq_chip for easy transition.
+		 */
+		desc->chip = &dummy_irq_chip;
+	}
+
+	spin_lock_irqsave(&desc->lock, flags);
+
+	/* Uninstall? */
+	if (handle == handle_bad_irq) {
+		if (desc->chip != &no_irq_chip)
+			mask_ack_irq(desc, irq);
+		desc->status |= IRQ_DISABLED;
+		desc->depth = 1;
+	}
+	desc->handle_irq = handle;
+	desc->name = name;
+
+	if (handle != handle_bad_irq && is_chained) {
+		desc->status &= ~IRQ_DISABLED;
+		desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
+		desc->depth = 0;
+		desc->chip->unmask(irq);
+	}
+	spin_unlock_irqrestore(&desc->lock, flags);
+}
+
+void
+set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
+			 irq_flow_handler_t handle)
+{
+	set_irq_chip(irq, chip);
+	__set_irq_handler(irq, handle, 0, NULL);
+}
+
+void
+set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
+			      irq_flow_handler_t handle, const char *name)
+{
+	set_irq_chip(irq, chip);
+	__set_irq_handler(irq, handle, 0, name);
+}

kernel/irq/devres.c

@@ -0,0 +1,88 @@
+#include <linux/module.h>
+#include <linux/interrupt.h>
+
+/*
+ * Device resource management aware IRQ request/free implementation.
+ */
+struct irq_devres {
+	unsigned int irq;
+	void *dev_id;
+};
+
+static void devm_irq_release(struct device *dev, void *res)
+{
+	struct irq_devres *this = res;
+
+	free_irq(this->irq, this->dev_id);
+}
+
+static int devm_irq_match(struct device *dev, void *res, void *data)
+{
+	struct irq_devres *this = res, *match = data;
+
+	return this->irq == match->irq && this->dev_id == match->dev_id;
+}
+
+/**
+ *	devm_request_irq - allocate an interrupt line for a managed device
+ *	@dev: device to request interrupt for
+ *	@irq: Interrupt line to allocate
+ *	@handler: Function to be called when the IRQ occurs
+ *	@irqflags: Interrupt type flags
+ *	@devname: An ascii name for the claiming device
+ *	@dev_id: A cookie passed back to the handler function
+ *
+ *	Except for the extra @dev argument, this function takes the
+ *	same arguments and performs the same function as
+ *	request_irq().  IRQs requested with this function will be
+ *	automatically freed on driver detach.
+ *
+ *	If an IRQ allocated with this function needs to be freed
+ *	separately, dev_free_irq() must be used.
+ */
+int devm_request_irq(struct device *dev, unsigned int irq,
+		     irq_handler_t handler, unsigned long irqflags,
+		     const char *devname, void *dev_id)
+{
+	struct irq_devres *dr;
+	int rc;
+
+	dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
+			  GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	rc = request_irq(irq, handler, irqflags, devname, dev_id);
+	if (rc) {
+		devres_free(dr);
+		return rc;
+	}
+
+	dr->irq = irq;
+	dr->dev_id = dev_id;
+	devres_add(dev, dr);
+
+	return 0;
+}
+EXPORT_SYMBOL(devm_request_irq);
+
+/**
+ *	devm_free_irq - free an interrupt
+ *	@dev: device to free interrupt for
+ *	@irq: Interrupt line to free
+ *	@dev_id: Device identity to free
+ *
+ *	Except for the extra @dev argument, this function takes the
+ *	same arguments and performs the same function as free_irq().
+ *	This function instead of free_irq() should be used to manually
+ *	free IRQs allocated with dev_request_irq().
+ */
+void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id)
+{
+	struct irq_devres match_data = { irq, dev_id };
+
+	free_irq(irq, dev_id);
+	WARN_ON(devres_destroy(dev, devm_irq_release, devm_irq_match,
+			       &match_data));
+}
+EXPORT_SYMBOL(devm_free_irq);

kernel/irq/handle.c

@@ -0,0 +1,271 @@
+/*
+ * linux/kernel/irq/handle.c
+ *
+ * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
+ * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
+ *
+ * This file contains the core interrupt handling code.
+ *
+ * Detailed information is available in Documentation/DocBook/genericirq
+ *
+ */
+
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+
+#include "internals.h"
+
+/**
+ * handle_bad_irq - handle spurious and unhandled irqs
+ * @irq:       the interrupt number
+ * @desc:      description of the interrupt
+ * @regs:      pointer to a register structure
+ *
+ * Handles spurious and unhandled IRQ's. It also prints a debugmessage.
+ */
+void fastcall
+handle_bad_irq(unsigned int irq, struct irq_desc *desc)
+{
+	print_irq_desc(irq, desc);
+	kstat_this_cpu.irqs[irq]++;
+	ack_bad_irq(irq);
+}
+
+/*
+ * Linux has a controller-independent interrupt architecture.
+ * Every controller has a 'controller-template', that is used
+ * by the main code to do the right thing. Each driver-visible
+ * interrupt source is transparently wired to the appropriate
+ * controller. Thus drivers need not be aware of the
+ * interrupt-controller.
+ *
+ * The code is designed to be easily extended with new/different
+ * interrupt controllers, without having to do assembly magic or
+ * having to touch the generic code.
+ *
+ * Controller mappings for all interrupt sources:
+ */
+struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned = {
+	[0 ... NR_IRQS-1] = {
+		.status = IRQ_DISABLED,
+		.chip = &no_irq_chip,
+		.handle_irq = handle_bad_irq,
+		.depth = 1,
+		.lock = __SPIN_LOCK_UNLOCKED(irq_desc->lock),
+#ifdef CONFIG_SMP
+		.affinity = CPU_MASK_ALL
+#endif
+	}
+};
+
+/*
+ * What should we do if we get a hw irq event on an illegal vector?
+ * Each architecture has to answer this themself.
+ */
+static void ack_bad(unsigned int irq)
+{
+	print_irq_desc(irq, irq_desc + irq);
+	ack_bad_irq(irq);
+}
+
+/*
+ * NOP functions
+ */
+static void noop(unsigned int irq)
+{
+}
+
+static unsigned int noop_ret(unsigned int irq)
+{
+	return 0;
+}
+
+/*
+ * Generic no controller implementation
+ */
+struct irq_chip no_irq_chip = {
+	.name		= "none",
+	.startup	= noop_ret,
+	.shutdown	= noop,
+	.enable		= noop,
+	.disable	= noop,
+	.ack		= ack_bad,
+	.end		= noop,
+};
+
+/*
+ * Generic dummy implementation which can be used for
+ * real dumb interrupt sources
+ */
+struct irq_chip dummy_irq_chip = {
+	.name		= "dummy",
+	.startup	= noop_ret,
+	.shutdown	= noop,
+	.enable		= noop,
+	.disable	= noop,
+	.ack		= noop,
+	.mask		= noop,
+	.unmask		= noop,
+	.end		= noop,
+};
+
+/*
+ * Special, empty irq handler:
+ */
+irqreturn_t no_action(int cpl, void *dev_id)
+{
+	return IRQ_NONE;
+}
+
+/**
+ * handle_IRQ_event - irq action chain handler
+ * @irq:	the interrupt number
+ * @action:	the interrupt action chain for this irq
+ *
+ * Handles the action chain of an irq event
+ */
+irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
+{
+	irqreturn_t ret, retval = IRQ_NONE;
+	unsigned int status = 0;
+
+	handle_dynamic_tick(action);
+
+	if (!(action->flags & IRQF_DISABLED))
+		local_irq_enable_in_hardirq();
+
+	do {
+		ret = action->handler(irq, action->dev_id);
+		if (ret == IRQ_HANDLED)
+			status |= action->flags;
+		retval |= ret;
+		action = action->next;
+	} while (action);
+
+	if (status & IRQF_SAMPLE_RANDOM)
+		add_interrupt_randomness(irq);
+	local_irq_disable();
+
+	return retval;
+}
+
+#ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
+/**
+ * __do_IRQ - original all in one highlevel IRQ handler
+ * @irq:	the interrupt number
+ *
+ * __do_IRQ handles all normal device IRQ's (the special
+ * SMP cross-CPU interrupts have their own specific
+ * handlers).
+ *
+ * This is the original x86 implementation which is used for every
+ * interrupt type.
+ */
+fastcall unsigned int __do_IRQ(unsigned int irq)
+{
+	struct irq_desc *desc = irq_desc + irq;
+	struct irqaction *action;
+	unsigned int status;
+
+	kstat_this_cpu.irqs[irq]++;
+	if (CHECK_IRQ_PER_CPU(desc->status)) {
+		irqreturn_t action_ret;
+
+		/*
+		 * No locking required for CPU-local interrupts:
+		 */
+		if (desc->chip->ack)
+			desc->chip->ack(irq);
+		action_ret = handle_IRQ_event(irq, desc->action);
+		desc->chip->end(irq);
+		return 1;
+	}
+
+	spin_lock(&desc->lock);
+	if (desc->chip->ack)
+		desc->chip->ack(irq);
+	/*
+	 * REPLAY is when Linux resends an IRQ that was dropped earlier
+	 * WAITING is used by probe to mark irqs that are being tested
+	 */
+	status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
+	status |= IRQ_PENDING; /* we _want_ to handle it */
+
+	/*
+	 * If the IRQ is disabled for whatever reason, we cannot
+	 * use the action we have.
+	 */
+	action = NULL;
+	if (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) {
+		action = desc->action;
+		status &= ~IRQ_PENDING; /* we commit to handling */
+		status |= IRQ_INPROGRESS; /* we are handling it */
+	}
+	desc->status = status;
+
+	/*
+	 * If there is no IRQ handler or it was disabled, exit early.
+	 * Since we set PENDING, if another processor is handling
+	 * a different instance of this same irq, the other processor
+	 * will take care of it.
+	 */
+	if (unlikely(!action))
+		goto out;
+
+	/*
+	 * Edge triggered interrupts need to remember
+	 * pending events.
+	 * This applies to any hw interrupts that allow a second
+	 * instance of the same irq to arrive while we are in do_IRQ
+	 * or in the handler. But the code here only handles the _second_
+	 * instance of the irq, not the third or fourth. So it is mostly
+	 * useful for irq hardware that does not mask cleanly in an
+	 * SMP environment.
+	 */
+	for (;;) {
+		irqreturn_t action_ret;
+
+		spin_unlock(&desc->lock);
+
+		action_ret = handle_IRQ_event(irq, action);
+		if (!noirqdebug)
+			note_interrupt(irq, desc, action_ret);
+
+		spin_lock(&desc->lock);
+		if (likely(!(desc->status & IRQ_PENDING)))
+			break;
+		desc->status &= ~IRQ_PENDING;
+	}
+	desc->status &= ~IRQ_INPROGRESS;
+
+out:
+	/*
+	 * The ->end() handler has to deal with interrupts which got
+	 * disabled while the handler was running.
+	 */
+	desc->chip->end(irq);
+	spin_unlock(&desc->lock);
+
+	return 1;
+}
+#endif
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+
+/*
+ * lockdep: we want to handle all irq_desc locks as a single lock-class:
+ */
+static struct lock_class_key irq_desc_lock_class;
+
+void early_init_irq_lock_class(void)
+{
+	int i;
+
+	for (i = 0; i < NR_IRQS; i++)
+		lockdep_set_class(&irq_desc[i].lock, &irq_desc_lock_class);
+}
+
+#endif

kernel/irq/internals.h

@@ -0,0 +1,64 @@
+/*
+ * IRQ subsystem internal functions and variables:
+ */
+
+extern int noirqdebug;
+
+/* Set default functions for irq_chip structures: */
+extern void irq_chip_set_defaults(struct irq_chip *chip);
+
+/* Set default handler: */
+extern void compat_irq_chip_set_default_handler(struct irq_desc *desc);
+
+#ifdef CONFIG_PROC_FS
+extern void register_irq_proc(unsigned int irq);
+extern void register_handler_proc(unsigned int irq, struct irqaction *action);
+extern void unregister_handler_proc(unsigned int irq, struct irqaction *action);
+#else
+static inline void register_irq_proc(unsigned int irq) { }
+static inline void register_handler_proc(unsigned int irq,
+					 struct irqaction *action) { }
+static inline void unregister_handler_proc(unsigned int irq,
+					   struct irqaction *action) { }
+#endif
+
+/*
+ * Debugging printout:
+ */
+
+#include <linux/kallsyms.h>
+
+#define P(f) if (desc->status & f) printk("%14s set\n", #f)
+
+static inline void print_irq_desc(unsigned int irq, struct irq_desc *desc)
+{
+	printk("irq %d, desc: %p, depth: %d, count: %d, unhandled: %d\n",
+		irq, desc, desc->depth, desc->irq_count, desc->irqs_unhandled);
+	printk("->handle_irq():  %p, ", desc->handle_irq);
+	print_symbol("%s\n", (unsigned long)desc->handle_irq);
+	printk("->chip(): %p, ", desc->chip);
+	print_symbol("%s\n", (unsigned long)desc->chip);
+	printk("->action(): %p\n", desc->action);
+	if (desc->action) {
+		printk("->action->handler(): %p, ", desc->action->handler);
+		print_symbol("%s\n", (unsigned long)desc->action->handler);
+	}
+
+	P(IRQ_INPROGRESS);
+	P(IRQ_DISABLED);
+	P(IRQ_PENDING);
+	P(IRQ_REPLAY);
+	P(IRQ_AUTODETECT);
+	P(IRQ_WAITING);
+	P(IRQ_LEVEL);
+	P(IRQ_MASKED);
+#ifdef CONFIG_IRQ_PER_CPU
+	P(IRQ_PER_CPU);
+#endif
+	P(IRQ_NOPROBE);
+	P(IRQ_NOREQUEST);
+	P(IRQ_NOAUTOEN);
+}
+
+#undef P
+

kernel/irq/manage.c

@@ -0,0 +1,563 @@
+/*
+ * linux/kernel/irq/manage.c
+ *
+ * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
+ * Copyright (C) 2005-2006 Thomas Gleixner
+ *
+ * This file contains driver APIs to the irq subsystem.
+ */
+
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/interrupt.h>
+
+#include "internals.h"
+
+#ifdef CONFIG_SMP
+
+/**
+ *	synchronize_irq - wait for pending IRQ handlers (on other CPUs)
+ *	@irq: interrupt number to wait for
+ *
+ *	This function waits for any pending IRQ handlers for this interrupt
+ *	to complete before returning. If you use this function while
+ *	holding a resource the IRQ handler may need you will deadlock.
+ *
+ *	This function may be called - with care - from IRQ context.
+ */
+void synchronize_irq(unsigned int irq)
+{
+	struct irq_desc *desc = irq_desc + irq;
+
+	if (irq >= NR_IRQS)
+		return;
+
+	while (desc->status & IRQ_INPROGRESS)
+		cpu_relax();
+}
+EXPORT_SYMBOL(synchronize_irq);
+
+/**
+ *	irq_can_set_affinity - Check if the affinity of a given irq can be set
+ *	@irq:		Interrupt to check
+ *
+ */
+int irq_can_set_affinity(unsigned int irq)
+{
+	struct irq_desc *desc = irq_desc + irq;
+
+	if (CHECK_IRQ_PER_CPU(desc->status) || !desc->chip ||
+	    !desc->chip->set_affinity)
+		return 0;
+
+	return 1;
+}
+
+/**
+ *	irq_set_affinity - Set the irq affinity of a given irq
+ *	@irq:		Interrupt to set affinity
+ *	@cpumask:	cpumask
+ *
+ */
+int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
+{
+	struct irq_desc *desc = irq_desc + irq;
+
+	if (!desc->chip->set_affinity)
+		return -EINVAL;
+
+	set_balance_irq_affinity(irq, cpumask);
+
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+	set_pending_irq(irq, cpumask);
+#else
+	desc->affinity = cpumask;
+	desc->chip->set_affinity(irq, cpumask);
+#endif
+	return 0;
+}
+
+#endif
+
+/**
+ *	disable_irq_nosync - disable an irq without waiting
+ *	@irq: Interrupt to disable
+ *
+ *	Disable the selected interrupt line.  Disables and Enables are
+ *	nested.
+ *	Unlike disable_irq(), this function does not ensure existing
+ *	instances of the IRQ handler have completed before returning.
+ *
+ *	This function may be called from IRQ context.
+ */
+void disable_irq_nosync(unsigned int irq)
+{
+	struct irq_desc *desc = irq_desc + irq;
+	unsigned long flags;
+
+	if (irq >= NR_IRQS)
+		return;
+
+	spin_lock_irqsave(&desc->lock, flags);
+	if (!desc->depth++) {
+		desc->status |= IRQ_DISABLED;
+		desc->chip->disable(irq);
+	}
+	spin_unlock_irqrestore(&desc->lock, flags);
+}
+EXPORT_SYMBOL(disable_irq_nosync);
+
+/**
+ *	disable_irq - disable an irq and wait for completion
+ *	@irq: Interrupt to disable
+ *
+ *	Disable the selected interrupt line.  Enables and Disables are
+ *	nested.
+ *	This function waits for any pending IRQ handlers for this interrupt
+ *	to complete before returning. If you use this function while
+ *	holding a resource the IRQ handler may need you will deadlock.
+ *
+ *	This function may be called - with care - from IRQ context.
+ */
+void disable_irq(unsigned int irq)
+{
+	struct irq_desc *desc = irq_desc + irq;
+
+	if (irq >= NR_IRQS)
+		return;
+
+	disable_irq_nosync(irq);
+	if (desc->action)
+		synchronize_irq(irq);
+}
+EXPORT_SYMBOL(disable_irq);
+
+/**
+ *	enable_irq - enable handling of an irq
+ *	@irq: Interrupt to enable
+ *
+ *	Undoes the effect of one call to disable_irq().  If this
+ *	matches the last disable, processing of interrupts on this
+ *	IRQ line is re-enabled.
+ *
+ *	This function may be called from IRQ context.
+ */
+void enable_irq(unsigned int irq)
+{
+	struct irq_desc *desc = irq_desc + irq;
+	unsigned long flags;
+
+	if (irq >= NR_IRQS)
+		return;
+
+	spin_lock_irqsave(&desc->lock, flags);
+	switch (desc->depth) {
+	case 0:
+		printk(KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
+		WARN_ON(1);
+		break;
+	case 1: {
+		unsigned int status = desc->status & ~IRQ_DISABLED;
+
+		/* Prevent probing on this irq: */
+		desc->status = status | IRQ_NOPROBE;
+		check_irq_resend(desc, irq);
+		/* fall-through */
+	}
+	default:
+		desc->depth--;
+	}
+	spin_unlock_irqrestore(&desc->lock, flags);
+}
+EXPORT_SYMBOL(enable_irq);
+
+/**
+ *	set_irq_wake - control irq power management wakeup
+ *	@irq:	interrupt to control
+ *	@on:	enable/disable power management wakeup
+ *
+ *	Enable/disable power management wakeup mode, which is
+ *	disabled by default.  Enables and disables must match,
+ *	just as they match for non-wakeup mode support.
+ *
+ *	Wakeup mode lets this IRQ wake the system from sleep
+ *	states like "suspend to RAM".
+ */
+int set_irq_wake(unsigned int irq, unsigned int on)
+{
+	struct irq_desc *desc = irq_desc + irq;
+	unsigned long flags;
+	int ret = -ENXIO;
+	int (*set_wake)(unsigned, unsigned) = desc->chip->set_wake;
+
+	/* wakeup-capable irqs can be shared between drivers that
+	 * don't need to have the same sleep mode behaviors.
+	 */
+	spin_lock_irqsave(&desc->lock, flags);
+	if (on) {
+		if (desc->wake_depth++ == 0)
+			desc->status |= IRQ_WAKEUP;
+		else
+			set_wake = NULL;
+	} else {
+		if (desc->wake_depth == 0) {
+			printk(KERN_WARNING "Unbalanced IRQ %d "
+					"wake disable\n", irq);
+			WARN_ON(1);
+		} else if (--desc->wake_depth == 0)
+			desc->status &= ~IRQ_WAKEUP;
+		else
+			set_wake = NULL;
+	}
+	if (set_wake)
+		ret = desc->chip->set_wake(irq, on);
+	spin_unlock_irqrestore(&desc->lock, flags);
+	return ret;
+}
+EXPORT_SYMBOL(set_irq_wake);
+
+/*
+ * Internal function that tells the architecture code whether a
+ * particular irq has been exclusively allocated or is available
+ * for driver use.
+ */
+int can_request_irq(unsigned int irq, unsigned long irqflags)
+{
+	struct irqaction *action;
+
+	if (irq >= NR_IRQS || irq_desc[irq].status & IRQ_NOREQUEST)
+		return 0;
+
+	action = irq_desc[irq].action;
+	if (action)
+		if (irqflags & action->flags & IRQF_SHARED)
+			action = NULL;
+
+	return !action;
+}
+
+void compat_irq_chip_set_default_handler(struct irq_desc *desc)
+{
+	/*
+	 * If the architecture still has not overriden
+	 * the flow handler then zap the default. This
+	 * should catch incorrect flow-type setting.
+	 */
+	if (desc->handle_irq == &handle_bad_irq)
+		desc->handle_irq = NULL;
+}
+
+/*
+ * Internal function to register an irqaction - typically used to
+ * allocate special interrupts that are part of the architecture.
+ */
+int setup_irq(unsigned int irq, struct irqaction *new)
+{
+	struct irq_desc *desc = irq_desc + irq;
+	struct irqaction *old, **p;
+	const char *old_name = NULL;
+	unsigned long flags;
+	int shared = 0;
+
+	if (irq >= NR_IRQS)
+		return -EINVAL;
+
+	if (desc->chip == &no_irq_chip)
+		return -ENOSYS;
+	/*
+	 * Some drivers like serial.c use request_irq() heavily,
+	 * so we have to be careful not to interfere with a
+	 * running system.
+	 */
+	if (new->flags & IRQF_SAMPLE_RANDOM) {
+		/*
+		 * This function might sleep, we want to call it first,
+		 * outside of the atomic block.
+		 * Yes, this might clear the entropy pool if the wrong
+		 * driver is attempted to be loaded, without actually
+		 * installing a new handler, but is this really a problem,
+		 * only the sysadmin is able to do this.
+		 */
+		rand_initialize_irq(irq);
+	}
+
+	/*
+	 * The following block of code has to be executed atomically
+	 */
+	spin_lock_irqsave(&desc->lock, flags);
+	p = &desc->action;
+	old = *p;
+	if (old) {
+		/*
+		 * Can't share interrupts unless both agree to and are
+		 * the same type (level, edge, polarity). So both flag
+		 * fields must have IRQF_SHARED set and the bits which
+		 * set the trigger type must match.
+		 */
+		if (!((old->flags & new->flags) & IRQF_SHARED) ||
+		    ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) {
+			old_name = old->name;
+			goto mismatch;
+		}
+
+#if defined(CONFIG_IRQ_PER_CPU)
+		/* All handlers must agree on per-cpuness */
+		if ((old->flags & IRQF_PERCPU) !=
+		    (new->flags & IRQF_PERCPU))
+			goto mismatch;
+#endif
+
+		/* add new interrupt at end of irq queue */
+		do {
+			p = &old->next;
+			old = *p;
+		} while (old);
+		shared = 1;
+	}
+
+	*p = new;
+#if defined(CONFIG_IRQ_PER_CPU)
+	if (new->flags & IRQF_PERCPU)
+		desc->status |= IRQ_PER_CPU;
+#endif
+	/* Exclude IRQ from balancing */
+	if (new->flags & IRQF_NOBALANCING)
+		desc->status |= IRQ_NO_BALANCING;
+
+	if (!shared) {
+		irq_chip_set_defaults(desc->chip);
+
+		/* Setup the type (level, edge polarity) if configured: */
+		if (new->flags & IRQF_TRIGGER_MASK) {
+			if (desc->chip && desc->chip->set_type)
+				desc->chip->set_type(irq,
+						new->flags & IRQF_TRIGGER_MASK);
+			else
+				/*
+				 * IRQF_TRIGGER_* but the PIC does not support
+				 * multiple flow-types?
+				 */
+				printk(KERN_WARNING "No IRQF_TRIGGER set_type "
+				       "function for IRQ %d (%s)\n", irq,
+				       desc->chip ? desc->chip->name :
+				       "unknown");
+		} else
+			compat_irq_chip_set_default_handler(desc);
+
+		desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING |
+				  IRQ_INPROGRESS);
+
+		if (!(desc->status & IRQ_NOAUTOEN)) {
+			desc->depth = 0;
+			desc->status &= ~IRQ_DISABLED;
+			if (desc->chip->startup)
+				desc->chip->startup(irq);
+			else
+				desc->chip->enable(irq);
+		} else
+			/* Undo nested disables: */
+			desc->depth = 1;
+	}
+	/* Reset broken irq detection when installing new handler */
+	desc->irq_count = 0;
+	desc->irqs_unhandled = 0;
+	spin_unlock_irqrestore(&desc->lock, flags);
+
+	new->irq = irq;
+	register_irq_proc(irq);
+	new->dir = NULL;
+	register_handler_proc(irq, new);
+
+	return 0;
+
+mismatch:
+#ifdef CONFIG_DEBUG_SHIRQ
+	if (!(new->flags & IRQF_PROBE_SHARED)) {
+		printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq);
+		if (old_name)
+			printk(KERN_ERR "current handler: %s\n", old_name);
+		dump_stack();
+	}
+#endif
+	spin_unlock_irqrestore(&desc->lock, flags);
+	return -EBUSY;
+}
+
+/**
+ *	free_irq - free an interrupt
+ *	@irq: Interrupt line to free
+ *	@dev_id: Device identity to free
+ *
+ *	Remove an interrupt handler. The handler is removed and if the
+ *	interrupt line is no longer in use by any driver it is disabled.
+ *	On a shared IRQ the caller must ensure the interrupt is disabled
+ *	on the card it drives before calling this function. The function
+ *	does not return until any executing interrupts for this IRQ
+ *	have completed.
+ *
+ *	This function must not be called from interrupt context.
+ */
+void free_irq(unsigned int irq, void *dev_id)
+{
+	struct irq_desc *desc;
+	struct irqaction **p;
+	unsigned long flags;
+	irqreturn_t (*handler)(int, void *) = NULL;
+
+	WARN_ON(in_interrupt());
+	if (irq >= NR_IRQS)
+		return;
+
+	desc = irq_desc + irq;
+	spin_lock_irqsave(&desc->lock, flags);
+	p = &desc->action;
+	for (;;) {
+		struct irqaction *action = *p;
+
+		if (action) {
+			struct irqaction **pp = p;
+
+			p = &action->next;
+			if (action->dev_id != dev_id)
+				continue;
+
+			/* Found it - now remove it from the list of entries */
+			*pp = action->next;
+
+			/* Currently used only by UML, might disappear one day.*/
+#ifdef CONFIG_IRQ_RELEASE_METHOD
+			if (desc->chip->release)
+				desc->chip->release(irq, dev_id);
+#endif
+
+			if (!desc->action) {
+				desc->status |= IRQ_DISABLED;
+				if (desc->chip->shutdown)
+					desc->chip->shutdown(irq);
+				else
+					desc->chip->disable(irq);
+			}
+			spin_unlock_irqrestore(&desc->lock, flags);
+			unregister_handler_proc(irq, action);
+
+			/* Make sure it's not being used on another CPU */
+			synchronize_irq(irq);
+			if (action->flags & IRQF_SHARED)
+				handler = action->handler;
+			kfree(action);
+			return;
+		}
+		printk(KERN_ERR "Trying to free already-free IRQ %d\n", irq);
+		spin_unlock_irqrestore(&desc->lock, flags);
+		return;
+	}
+#ifdef CONFIG_DEBUG_SHIRQ
+	if (handler) {
+		/*
+		 * It's a shared IRQ -- the driver ought to be prepared for it
+		 * to happen even now it's being freed, so let's make sure....
+		 * We do this after actually deregistering it, to make sure that
+		 * a 'real' IRQ doesn't run in parallel with our fake
+		 */
+		handler(irq, dev_id);
+	}
+#endif
+}
+EXPORT_SYMBOL(free_irq);
+
+/**
+ *	request_irq - allocate an interrupt line
+ *	@irq: Interrupt line to allocate
+ *	@handler: Function to be called when the IRQ occurs
+ *	@irqflags: Interrupt type flags
+ *	@devname: An ascii name for the claiming device
+ *	@dev_id: A cookie passed back to the handler function
+ *
+ *	This call allocates interrupt resources and enables the
+ *	interrupt line and IRQ handling. From the point this
+ *	call is made your handler function may be invoked. Since
+ *	your handler function must clear any interrupt the board
+ *	raises, you must take care both to initialise your hardware
+ *	and to set up the interrupt handler in the right order.
+ *
+ *	Dev_id must be globally unique. Normally the address of the
+ *	device data structure is used as the cookie. Since the handler
+ *	receives this value it makes sense to use it.
+ *
+ *	If your interrupt is shared you must pass a non NULL dev_id
+ *	as this is required when freeing the interrupt.
+ *
+ *	Flags:
+ *
+ *	IRQF_SHARED		Interrupt is shared
+ *	IRQF_DISABLED	Disable local interrupts while processing
+ *	IRQF_SAMPLE_RANDOM	The interrupt can be used for entropy
+ *
+ */
+int request_irq(unsigned int irq, irq_handler_t handler,
+		unsigned long irqflags, const char *devname, void *dev_id)
+{
+	struct irqaction *action;
+	int retval;
+
+#ifdef CONFIG_LOCKDEP
+	/*
+	 * Lockdep wants atomic interrupt handlers:
+	 */
+	irqflags |= IRQF_DISABLED;
+#endif
+	/*
+	 * Sanity-check: shared interrupts must pass in a real dev-ID,
+	 * otherwise we'll have trouble later trying to figure out
+	 * which interrupt is which (messes up the interrupt freeing
+	 * logic etc).
+	 */
+	if ((irqflags & IRQF_SHARED) && !dev_id)
+		return -EINVAL;
+	if (irq >= NR_IRQS)
+		return -EINVAL;
+	if (irq_desc[irq].status & IRQ_NOREQUEST)
+		return -EINVAL;
+	if (!handler)
+		return -EINVAL;
+
+	action = kmalloc(sizeof(struct irqaction), GFP_ATOMIC);
+	if (!action)
+		return -ENOMEM;
+
+	action->handler = handler;
+	action->flags = irqflags;
+	cpus_clear(action->mask);
+	action->name = devname;
+	action->next = NULL;
+	action->dev_id = dev_id;
+
+	select_smp_affinity(irq);
+
+#ifdef CONFIG_DEBUG_SHIRQ
+	if (irqflags & IRQF_SHARED) {
+		/*
+		 * It's a shared IRQ -- the driver ought to be prepared for it
+		 * to happen immediately, so let's make sure....
+		 * We do this before actually registering it, to make sure that
+		 * a 'real' IRQ doesn't run in parallel with our fake
+		 */
+		if (irqflags & IRQF_DISABLED) {
+			unsigned long flags;
+
+			local_irq_save(flags);
+			handler(irq, dev_id);
+			local_irq_restore(flags);
+		} else
+			handler(irq, dev_id);
+	}
+#endif
+
+	retval = setup_irq(irq, action);
+	if (retval)
+		kfree(action);
+
+	return retval;
+}
+EXPORT_SYMBOL(request_irq);

kernel/irq/migration.c

@@ -0,0 +1,75 @@
+
+#include <linux/irq.h>
+
+void set_pending_irq(unsigned int irq, cpumask_t mask)
+{
+	struct irq_desc *desc = irq_desc + irq;
+	unsigned long flags;
+
+	spin_lock_irqsave(&desc->lock, flags);
+	desc->status |= IRQ_MOVE_PENDING;
+	irq_desc[irq].pending_mask = mask;
+	spin_unlock_irqrestore(&desc->lock, flags);
+}
+
+void move_masked_irq(int irq)
+{
+	struct irq_desc *desc = irq_desc + irq;
+	cpumask_t tmp;
+
+	if (likely(!(desc->status & IRQ_MOVE_PENDING)))
+		return;
+
+	/*
+	 * Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
+	 */
+	if (CHECK_IRQ_PER_CPU(desc->status)) {
+		WARN_ON(1);
+		return;
+	}
+
+	desc->status &= ~IRQ_MOVE_PENDING;
+
+	if (unlikely(cpus_empty(irq_desc[irq].pending_mask)))
+		return;
+
+	if (!desc->chip->set_affinity)
+		return;
+
+	assert_spin_locked(&desc->lock);
+
+	cpus_and(tmp, irq_desc[irq].pending_mask, cpu_online_map);
+
+	/*
+	 * If there was a valid mask to work with, please
+	 * do the disable, re-program, enable sequence.
+	 * This is *not* particularly important for level triggered
+	 * but in a edge trigger case, we might be setting rte
+	 * when an active trigger is comming in. This could
+	 * cause some ioapics to mal-function.
+	 * Being paranoid i guess!
+	 *
+	 * For correct operation this depends on the caller
+	 * masking the irqs.
+	 */
+	if (likely(!cpus_empty(tmp))) {
+		desc->chip->set_affinity(irq,tmp);
+	}
+	cpus_clear(irq_desc[irq].pending_mask);
+}
+
+void move_native_irq(int irq)
+{
+	struct irq_desc *desc = irq_desc + irq;
+
+	if (likely(!(desc->status & IRQ_MOVE_PENDING)))
+		return;
+
+	if (unlikely(desc->status & IRQ_DISABLED))
+		return;
+
+	desc->chip->mask(irq);
+	move_masked_irq(irq);
+	desc->chip->unmask(irq);
+}
+

kernel/irq/proc.c

@@ -0,0 +1,150 @@
+/*
+ * linux/kernel/irq/proc.c
+ *
+ * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
+ *
+ * This file contains the /proc/irq/ handling code.
+ */
+
+#include <linux/irq.h>
+#include <linux/proc_fs.h>
+#include <linux/interrupt.h>
+
+#include "internals.h"
+
+static struct proc_dir_entry *root_irq_dir;
+
+#ifdef CONFIG_SMP
+
+static int irq_affinity_read_proc(char *page, char **start, off_t off,
+				  int count, int *eof, void *data)
+{
+	int len = cpumask_scnprintf(page, count, irq_desc[(long)data].affinity);
+
+	if (count - len < 2)
+		return -EINVAL;
+	len += sprintf(page + len, "\n");
+	return len;
+}
+
+int no_irq_affinity;
+static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
+				   unsigned long count, void *data)
+{
+	unsigned int irq = (int)(long)data, full_count = count, err;
+	cpumask_t new_value, tmp;
+
+	if (!irq_desc[irq].chip->set_affinity || no_irq_affinity ||
+	    irq_balancing_disabled(irq))
+		return -EIO;
+
+	err = cpumask_parse_user(buffer, count, new_value);
+	if (err)
+		return err;
+
+	/*
+	 * Do not allow disabling IRQs completely - it's a too easy
+	 * way to make the system unusable accidentally :-) At least
+	 * one online CPU still has to be targeted.
+	 */
+	cpus_and(tmp, new_value, cpu_online_map);
+	if (cpus_empty(tmp))
+		/* Special case for empty set - allow the architecture
+		   code to set default SMP affinity. */
+		return select_smp_affinity(irq) ? -EINVAL : full_count;
+
+	irq_set_affinity(irq, new_value);
+
+	return full_count;
+}
+
+#endif
+
+#define MAX_NAMELEN 128
+
+static int name_unique(unsigned int irq, struct irqaction *new_action)
+{
+	struct irq_desc *desc = irq_desc + irq;
+	struct irqaction *action;
+
+	for (action = desc->action ; action; action = action->next)
+		if ((action != new_action) && action->name &&
+				!strcmp(new_action->name, action->name))
+			return 0;
+	return 1;
+}
+
+void register_handler_proc(unsigned int irq, struct irqaction *action)
+{
+	char name [MAX_NAMELEN];
+
+	if (!irq_desc[irq].dir || action->dir || !action->name ||
+					!name_unique(irq, action))
+		return;
+
+	memset(name, 0, MAX_NAMELEN);
+	snprintf(name, MAX_NAMELEN, "%s", action->name);
+
+	/* create /proc/irq/1234/handler/ */
+	action->dir = proc_mkdir(name, irq_desc[irq].dir);
+}
+
+#undef MAX_NAMELEN
+
+#define MAX_NAMELEN 10
+
+void register_irq_proc(unsigned int irq)
+{
+	char name [MAX_NAMELEN];
+
+	if (!root_irq_dir ||
+		(irq_desc[irq].chip == &no_irq_chip) ||
+			irq_desc[irq].dir)
+		return;
+
+	memset(name, 0, MAX_NAMELEN);
+	sprintf(name, "%d", irq);
+
+	/* create /proc/irq/1234 */
+	irq_desc[irq].dir = proc_mkdir(name, root_irq_dir);
+
+#ifdef CONFIG_SMP
+	{
+		struct proc_dir_entry *entry;
+
+		/* create /proc/irq/<irq>/smp_affinity */
+		entry = create_proc_entry("smp_affinity", 0600, irq_desc[irq].dir);
+
+		if (entry) {
+			entry->data = (void *)(long)irq;
+			entry->read_proc = irq_affinity_read_proc;
+			entry->write_proc = irq_affinity_write_proc;
+		}
+	}
+#endif
+}
+
+#undef MAX_NAMELEN
+
+void unregister_handler_proc(unsigned int irq, struct irqaction *action)
+{
+	if (action->dir)
+		remove_proc_entry(action->dir->name, irq_desc[irq].dir);
+}
+
+void init_irq_proc(void)
+{
+	int i;
+
+	/* create /proc/irq */
+	root_irq_dir = proc_mkdir("irq", NULL);
+	if (!root_irq_dir)
+		return;
+
+	/*
+	 * Create entries for all existing IRQs.
+	 */
+	for (i = 0; i < NR_IRQS; i++)
+		register_irq_proc(i);
+}
+

kernel/irq/resend.c

@@ -0,0 +1,77 @@
+/*
+ * linux/kernel/irq/resend.c
+ *
+ * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
+ * Copyright (C) 2005-2006, Thomas Gleixner
+ *
+ * This file contains the IRQ-resend code
+ *
+ * If the interrupt is waiting to be processed, we try to re-run it.
+ * We can't directly run it from here since the caller might be in an
+ * interrupt-protected region. Not all irq controller chips can
+ * retrigger interrupts at the hardware level, so in those cases
+ * we allow the resending of IRQs via a tasklet.
+ */
+
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/interrupt.h>
+
+#include "internals.h"
+
+#ifdef CONFIG_HARDIRQS_SW_RESEND
+
+/* Bitmap to handle software resend of interrupts: */
+static DECLARE_BITMAP(irqs_resend, NR_IRQS);
+
+/*
+ * Run software resends of IRQ's
+ */
+static void resend_irqs(unsigned long arg)
+{
+	struct irq_desc *desc;
+	int irq;
+
+	while (!bitmap_empty(irqs_resend, NR_IRQS)) {
+		irq = find_first_bit(irqs_resend, NR_IRQS);
+		clear_bit(irq, irqs_resend);
+		desc = irq_desc + irq;
+		local_irq_disable();
+		desc->handle_irq(irq, desc);
+		local_irq_enable();
+	}
+}
+
+/* Tasklet to handle resend: */
+static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);
+
+#endif
+
+/*
+ * IRQ resend
+ *
+ * Is called with interrupts disabled and desc->lock held.
+ */
+void check_irq_resend(struct irq_desc *desc, unsigned int irq)
+{
+	unsigned int status = desc->status;
+
+	/*
+	 * Make sure the interrupt is enabled, before resending it:
+	 */
+	desc->chip->enable(irq);
+
+	if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
+		desc->status = (status & ~IRQ_PENDING) | IRQ_REPLAY;
+
+		if (!desc->chip || !desc->chip->retrigger ||
+					!desc->chip->retrigger(irq)) {
+#ifdef CONFIG_HARDIRQS_SW_RESEND
+			/* Set it pending and activate the softirq: */
+			set_bit(irq, irqs_resend);
+			tasklet_schedule(&resend_tasklet);
+#endif
+		}
+	}
+}

kernel/irq/spurious.c

@@ -0,0 +1,210 @@
+/*
+ * linux/kernel/irq/spurious.c
+ *
+ * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
+ *
+ * This file contains spurious interrupt handling.
+ */
+
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/interrupt.h>
+
+static int irqfixup __read_mostly;
+
+/*
+ * Recovery handler for misrouted interrupts.
+ */
+static int misrouted_irq(int irq)
+{
+	int i;
+	int ok = 0;
+	int work = 0;	/* Did we do work for a real IRQ */
+
+	for (i = 1; i < NR_IRQS; i++) {
+		struct irq_desc *desc = irq_desc + i;
+		struct irqaction *action;
+
+		if (i == irq)	/* Already tried */
+			continue;
+
+		spin_lock(&desc->lock);
+		/* Already running on another processor */
+		if (desc->status & IRQ_INPROGRESS) {
+			/*
+			 * Already running: If it is shared get the other
+			 * CPU to go looking for our mystery interrupt too
+			 */
+			if (desc->action && (desc->action->flags & IRQF_SHARED))
+				desc->status |= IRQ_PENDING;
+			spin_unlock(&desc->lock);
+			continue;
+		}
+		/* Honour the normal IRQ locking */
+		desc->status |= IRQ_INPROGRESS;
+		action = desc->action;
+		spin_unlock(&desc->lock);
+
+		while (action) {
+			/* Only shared IRQ handlers are safe to call */
+			if (action->flags & IRQF_SHARED) {
+				if (action->handler(i, action->dev_id) ==
+						IRQ_HANDLED)
+					ok = 1;
+			}
+			action = action->next;
+		}
+		local_irq_disable();
+		/* Now clean up the flags */
+		spin_lock(&desc->lock);
+		action = desc->action;
+
+		/*
+		 * While we were looking for a fixup someone queued a real
+		 * IRQ clashing with our walk:
+		 */
+		while ((desc->status & IRQ_PENDING) && action) {
+			/*
+			 * Perform real IRQ processing for the IRQ we deferred
+			 */
+			work = 1;
+			spin_unlock(&desc->lock);
+			handle_IRQ_event(i, action);
+			spin_lock(&desc->lock);
+			desc->status &= ~IRQ_PENDING;
+		}
+		desc->status &= ~IRQ_INPROGRESS;
+		/*
+		 * If we did actual work for the real IRQ line we must let the
+		 * IRQ controller clean up too
+		 */
+		if (work && desc->chip && desc->chip->end)
+			desc->chip->end(i);
+		spin_unlock(&desc->lock);
+	}
+	/* So the caller can adjust the irq error counts */
+	return ok;
+}
+
+/*
+ * If 99,900 of the previous 100,000 interrupts have not been handled
+ * then assume that the IRQ is stuck in some manner. Drop a diagnostic
+ * and try to turn the IRQ off.
+ *
+ * (The other 100-of-100,000 interrupts may have been a correctly
+ *  functioning device sharing an IRQ with the failing one)
+ *
+ * Called under desc->lock
+ */
+
+static void
+__report_bad_irq(unsigned int irq, struct irq_desc *desc,
+		 irqreturn_t action_ret)
+{
+	struct irqaction *action;
+
+	if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) {
+		printk(KERN_ERR "irq event %d: bogus return value %x\n",
+				irq, action_ret);
+	} else {
+		printk(KERN_ERR "irq %d: nobody cared (try booting with "
+				"the \"irqpoll\" option)\n", irq);
+	}
+	dump_stack();
+	printk(KERN_ERR "handlers:\n");
+
+	action = desc->action;
+	while (action) {
+		printk(KERN_ERR "[<%p>]", action->handler);
+		print_symbol(" (%s)",
+			(unsigned long)action->handler);
+		printk("\n");
+		action = action->next;
+	}
+}
+
+static void
+report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret)
+{
+	static int count = 100;
+
+	if (count > 0) {
+		count--;
+		__report_bad_irq(irq, desc, action_ret);
+	}
+}
+
+void note_interrupt(unsigned int irq, struct irq_desc *desc,
+		    irqreturn_t action_ret)
+{
+	if (unlikely(action_ret != IRQ_HANDLED)) {
+		desc->irqs_unhandled++;
+		if (unlikely(action_ret != IRQ_NONE))
+			report_bad_irq(irq, desc, action_ret);
+	}
+
+	if (unlikely(irqfixup)) {
+		/* Don't punish working computers */
+		if ((irqfixup == 2 && irq == 0) || action_ret == IRQ_NONE) {
+			int ok = misrouted_irq(irq);
+			if (action_ret == IRQ_NONE)
+				desc->irqs_unhandled -= ok;
+		}
+	}
+
+	desc->irq_count++;
+	if (likely(desc->irq_count < 100000))
+		return;
+
+	desc->irq_count = 0;
+	if (unlikely(desc->irqs_unhandled > 99900)) {
+		/*
+		 * The interrupt is stuck
+		 */
+		__report_bad_irq(irq, desc, action_ret);
+		/*
+		 * Now kill the IRQ
+		 */
+		printk(KERN_EMERG "Disabling IRQ #%d\n", irq);
+		desc->status |= IRQ_DISABLED;
+		desc->depth = 1;
+		desc->chip->disable(irq);
+	}
+	desc->irqs_unhandled = 0;
+}
+
+int noirqdebug __read_mostly;
+
+int noirqdebug_setup(char *str)
+{
+	noirqdebug = 1;
+	printk(KERN_INFO "IRQ lockup detection disabled\n");
+
+	return 1;
+}
+
+__setup("noirqdebug", noirqdebug_setup);
+
+static int __init irqfixup_setup(char *str)
+{
+	irqfixup = 1;
+	printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n");
+	printk(KERN_WARNING "This may impact system performance.\n");
+
+	return 1;
+}
+
+__setup("irqfixup", irqfixup_setup);
+
+static int __init irqpoll_setup(char *str)
+{
+	irqfixup = 2;
+	printk(KERN_WARNING "Misrouted IRQ fixup and polling support "
+				"enabled\n");
+	printk(KERN_WARNING "This may significantly impact system "
+				"performance\n");
+	return 1;
+}
+
+__setup("irqpoll", irqpoll_setup);