/*
* linux/kernel/irq/manage.c
*
- * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
+ * 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/config.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/interrupt.h>
+#include <linux/slab.h>
#include "internals.h"
#ifdef CONFIG_SMP
+cpumask_var_t irq_default_affinity;
+
+static int init_irq_default_affinity(void)
+{
+ alloc_cpumask_var(&irq_default_affinity, GFP_KERNEL);
+ cpumask_setall(irq_default_affinity);
+ return 0;
+}
+core_initcall(init_irq_default_affinity);
/**
* synchronize_irq - wait for pending IRQ handlers (on other CPUs)
*/
void synchronize_irq(unsigned int irq)
{
- struct irq_desc *desc = irq_desc + irq;
+ struct irq_desc *desc = irq_to_desc(irq);
+ unsigned int status;
- if (irq >= NR_IRQS)
+ if (!desc)
return;
- while (desc->status & IRQ_INPROGRESS)
- cpu_relax();
+ do {
+ unsigned long flags;
+
+ /*
+ * Wait until we're out of the critical section. This might
+ * give the wrong answer due to the lack of memory barriers.
+ */
+ while (desc->status & IRQ_INPROGRESS)
+ cpu_relax();
+
+ /* Ok, that indicated we're done: double-check carefully. */
+ spin_lock_irqsave(&desc->lock, flags);
+ status = desc->status;
+ spin_unlock_irqrestore(&desc->lock, flags);
+
+ /* Oops, that failed? */
+ } while (status & IRQ_INPROGRESS);
}
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_to_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, const struct cpumask *cpumask)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ unsigned long flags;
+
+ if (!desc->chip->set_affinity)
+ return -EINVAL;
+
+ spin_lock_irqsave(&desc->lock, flags);
+
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+ if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) {
+ cpumask_copy(&desc->affinity, cpumask);
+ desc->chip->set_affinity(irq, cpumask);
+ } else {
+ desc->status |= IRQ_MOVE_PENDING;
+ cpumask_copy(&desc->pending_mask, cpumask);
+ }
+#else
+ cpumask_copy(&desc->affinity, cpumask);
+ desc->chip->set_affinity(irq, cpumask);
+#endif
+ desc->status |= IRQ_AFFINITY_SET;
+ spin_unlock_irqrestore(&desc->lock, flags);
+ return 0;
+}
+
+#ifndef CONFIG_AUTO_IRQ_AFFINITY
+/*
+ * Generic version of the affinity autoselector.
+ */
+int do_irq_select_affinity(unsigned int irq, struct irq_desc *desc)
+{
+ if (!irq_can_set_affinity(irq))
+ return 0;
+
+ /*
+ * Preserve an userspace affinity setup, but make sure that
+ * one of the targets is online.
+ */
+ if (desc->status & (IRQ_AFFINITY_SET | IRQ_NO_BALANCING)) {
+ if (cpumask_any_and(&desc->affinity, cpu_online_mask)
+ < nr_cpu_ids)
+ goto set_affinity;
+ else
+ desc->status &= ~IRQ_AFFINITY_SET;
+ }
+
+ cpumask_and(&desc->affinity, cpu_online_mask, irq_default_affinity);
+set_affinity:
+ desc->chip->set_affinity(irq, &desc->affinity);
+
+ return 0;
+}
+#else
+static inline int do_irq_select_affinity(unsigned int irq, struct irq_desc *d)
+{
+ return irq_select_affinity(irq);
+}
+#endif
+
+/*
+ * Called when affinity is set via /proc/irq
+ */
+int irq_select_affinity_usr(unsigned int irq)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&desc->lock, flags);
+ ret = do_irq_select_affinity(irq, desc);
+ spin_unlock_irqrestore(&desc->lock, flags);
+
+ return ret;
+}
+
+#else
+static inline int do_irq_select_affinity(int irq, struct irq_desc *desc)
+{
+ return 0;
+}
#endif
/**
*/
void disable_irq_nosync(unsigned int irq)
{
- struct irq_desc *desc = irq_desc + irq;
+ struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
- if (irq >= NR_IRQS)
+ if (!desc)
return;
spin_lock_irqsave(&desc->lock, flags);
*/
void disable_irq(unsigned int irq)
{
- struct irq_desc *desc = irq_desc + irq;
+ struct irq_desc *desc = irq_to_desc(irq);
- if (irq >= NR_IRQS)
+ if (!desc)
return;
disable_irq_nosync(irq);
}
EXPORT_SYMBOL(disable_irq);
+static void __enable_irq(struct irq_desc *desc, unsigned int irq)
+{
+ switch (desc->depth) {
+ case 0:
+ WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
+ 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--;
+ }
+}
+
/**
* enable_irq - enable handling of an irq
* @irq: Interrupt to enable
*/
void enable_irq(unsigned int irq)
{
- struct irq_desc *desc = irq_desc + irq;
+ struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
- if (irq >= NR_IRQS)
+ if (!desc)
return;
spin_lock_irqsave(&desc->lock, flags);
- switch (desc->depth) {
- case 0:
- WARN_ON(1);
- break;
- case 1: {
- unsigned int status = desc->status & ~IRQ_DISABLED;
+ __enable_irq(desc, irq);
+ spin_unlock_irqrestore(&desc->lock, flags);
+}
+EXPORT_SYMBOL(enable_irq);
+
+static int set_irq_wake_real(unsigned int irq, unsigned int on)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ int ret = -ENXIO;
- desc->status = status;
- if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
- desc->status = status | IRQ_REPLAY;
- hw_resend_irq(desc->chip,irq);
+ if (desc->chip->set_wake)
+ ret = desc->chip->set_wake(irq, on);
+
+ return ret;
+}
+
+/**
+ * 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_to_desc(irq);
+ unsigned long flags;
+ int ret = 0;
+
+ /* 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) {
+ ret = set_irq_wake_real(irq, on);
+ if (ret)
+ desc->wake_depth = 0;
+ else
+ desc->status |= IRQ_WAKEUP;
+ }
+ } else {
+ if (desc->wake_depth == 0) {
+ WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
+ } else if (--desc->wake_depth == 0) {
+ ret = set_irq_wake_real(irq, on);
+ if (ret)
+ desc->wake_depth = 1;
+ else
+ desc->status &= ~IRQ_WAKEUP;
}
- desc->chip->enable(irq);
- /* fall-through */
- }
- default:
- desc->depth--;
}
+
spin_unlock_irqrestore(&desc->lock, flags);
+ return ret;
}
-EXPORT_SYMBOL(enable_irq);
+EXPORT_SYMBOL(set_irq_wake);
/*
* Internal function that tells the architecture code whether a
*/
int can_request_irq(unsigned int irq, unsigned long irqflags)
{
+ struct irq_desc *desc = irq_to_desc(irq);
struct irqaction *action;
- if (irq >= NR_IRQS)
+ if (!desc)
return 0;
- action = irq_desc[irq].action;
+ if (desc->status & IRQ_NOREQUEST)
+ return 0;
+
+ action = desc->action;
if (action)
- if (irqflags & action->flags & SA_SHIRQ)
+ 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;
+}
+
+int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
+ unsigned long flags)
+{
+ int ret;
+ struct irq_chip *chip = desc->chip;
+
+ if (!chip || !chip->set_type) {
+ /*
+ * IRQF_TRIGGER_* but the PIC does not support multiple
+ * flow-types?
+ */
+ pr_debug("No set_type function for IRQ %d (%s)\n", irq,
+ chip ? (chip->name ? : "unknown") : "unknown");
+ return 0;
+ }
+
+ /* caller masked out all except trigger mode flags */
+ ret = chip->set_type(irq, flags);
+
+ if (ret)
+ pr_err("setting trigger mode %d for irq %u failed (%pF)\n",
+ (int)flags, irq, chip->set_type);
+ else {
+ if (flags & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
+ flags |= IRQ_LEVEL;
+ /* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */
+ desc->status &= ~(IRQ_LEVEL | IRQ_TYPE_SENSE_MASK);
+ desc->status |= flags;
+ }
+
+ return ret;
+}
+
/*
* 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)
+static int
+__setup_irq(unsigned int irq, struct irq_desc * desc, 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;
+ int ret;
- if (irq >= NR_IRQS)
+ if (!desc)
return -EINVAL;
- if (desc->chip == &no_irq_type)
+ 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 & SA_SAMPLE_RANDOM) {
+ if (new->flags & IRQF_SAMPLE_RANDOM) {
/*
* This function might sleep, we want to call it first,
* outside of the atomic block.
p = &desc->action;
old = *p;
if (old) {
- /* Can't share interrupts unless both agree to */
- if (!(old->flags & new->flags & SA_SHIRQ))
+ /*
+ * 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(ARCH_HAS_IRQ_PER_CPU) && defined(SA_PERCPU_IRQ)
+#if defined(CONFIG_IRQ_PER_CPU)
/* All handlers must agree on per-cpuness */
- if ((old->flags & IRQ_PER_CPU) != (new->flags & IRQ_PER_CPU))
+ if ((old->flags & IRQF_PERCPU) !=
+ (new->flags & IRQF_PERCPU))
goto mismatch;
#endif
shared = 1;
}
- *p = new;
-#if defined(ARCH_HAS_IRQ_PER_CPU) && defined(SA_PERCPU_IRQ)
- if (new->flags & SA_PERCPU_IRQ)
- desc->status |= IRQ_PER_CPU;
-#endif
if (!shared) {
- desc->depth = 0;
- desc->status &= ~(IRQ_DISABLED | IRQ_AUTODETECT |
- IRQ_WAITING | IRQ_INPROGRESS);
- if (desc->chip->startup)
+ irq_chip_set_defaults(desc->chip);
+
+ /* Setup the type (level, edge polarity) if configured: */
+ if (new->flags & IRQF_TRIGGER_MASK) {
+ ret = __irq_set_trigger(desc, irq,
+ new->flags & IRQF_TRIGGER_MASK);
+
+ if (ret) {
+ spin_unlock_irqrestore(&desc->lock, flags);
+ return ret;
+ }
+ } else
+ compat_irq_chip_set_default_handler(desc);
+#if defined(CONFIG_IRQ_PER_CPU)
+ if (new->flags & IRQF_PERCPU)
+ desc->status |= IRQ_PER_CPU;
+#endif
+
+ desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING |
+ IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED);
+
+ if (!(desc->status & IRQ_NOAUTOEN)) {
+ desc->depth = 0;
+ desc->status &= ~IRQ_DISABLED;
desc->chip->startup(irq);
- else
- desc->chip->enable(irq);
+ } else
+ /* Undo nested disables: */
+ desc->depth = 1;
+
+ /* Exclude IRQ from balancing if requested */
+ if (new->flags & IRQF_NOBALANCING)
+ desc->status |= IRQ_NO_BALANCING;
+
+ /* Set default affinity mask once everything is setup */
+ do_irq_select_affinity(irq, desc);
+
+ } else if ((new->flags & IRQF_TRIGGER_MASK)
+ && (new->flags & IRQF_TRIGGER_MASK)
+ != (desc->status & IRQ_TYPE_SENSE_MASK)) {
+ /* hope the handler works with the actual trigger mode... */
+ pr_warning("IRQ %d uses trigger mode %d; requested %d\n",
+ irq, (int)(desc->status & IRQ_TYPE_SENSE_MASK),
+ (int)(new->flags & IRQF_TRIGGER_MASK));
+ }
+
+ *p = new;
+
+ /* Reset broken irq detection when installing new handler */
+ desc->irq_count = 0;
+ desc->irqs_unhandled = 0;
+
+ /*
+ * Check whether we disabled the irq via the spurious handler
+ * before. Reenable it and give it another chance.
+ */
+ if (shared && (desc->status & IRQ_SPURIOUS_DISABLED)) {
+ desc->status &= ~IRQ_SPURIOUS_DISABLED;
+ __enable_irq(desc, irq);
}
+
spin_unlock_irqrestore(&desc->lock, flags);
new->irq = irq;
- register_irq_proc(irq);
+ register_irq_proc(irq, desc);
new->dir = NULL;
register_handler_proc(irq, new);
return 0;
mismatch:
- spin_unlock_irqrestore(&desc->lock, flags);
- if (!(new->flags & SA_PROBEIRQ)) {
- printk(KERN_ERR "%s: irq handler mismatch\n", __FUNCTION__);
+#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;
}
/**
+ * setup_irq - setup an interrupt
+ * @irq: Interrupt line to setup
+ * @act: irqaction for the interrupt
+ *
+ * Used to statically setup interrupts in the early boot process.
+ */
+int setup_irq(unsigned int irq, struct irqaction *act)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+
+ return __setup_irq(irq, desc, act);
+}
+
+/**
* free_irq - free an interrupt
* @irq: Interrupt line to free
* @dev_id: Device identity to free
*/
void free_irq(unsigned int irq, void *dev_id)
{
- struct irq_desc *desc;
+ struct irq_desc *desc = irq_to_desc(irq);
struct irqaction **p;
unsigned long flags;
WARN_ON(in_interrupt());
- if (irq >= NR_IRQS)
+
+ if (!desc)
return;
- desc = irq_desc + irq;
spin_lock_irqsave(&desc->lock, flags);
p = &desc->action;
for (;;) {
/* Make sure it's not being used on another CPU */
synchronize_irq(irq);
+#ifdef CONFIG_DEBUG_SHIRQ
+ /*
+ * 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
+ */
+ if (action->flags & IRQF_SHARED) {
+ local_irq_save(flags);
+ action->handler(irq, dev_id);
+ local_irq_restore(flags);
+ }
+#endif
kfree(action);
return;
}
- printk(KERN_ERR "Trying to free free IRQ%d\n", irq);
+ printk(KERN_ERR "Trying to free already-free IRQ %d\n", irq);
+#ifdef CONFIG_DEBUG_SHIRQ
+ dump_stack();
+#endif
spin_unlock_irqrestore(&desc->lock, flags);
return;
}
*
* Flags:
*
- * SA_SHIRQ Interrupt is shared
- * SA_INTERRUPT Disable local interrupts while processing
- * SA_SAMPLE_RANDOM The interrupt can be used for entropy
+ * IRQF_SHARED Interrupt is shared
+ * IRQF_DISABLED Disable local interrupts while processing
+ * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
+ * IRQF_TRIGGER_* Specify active edge(s) or level
*
*/
-int request_irq(unsigned int irq,
- irqreturn_t (*handler)(int, void *, struct pt_regs *),
+int request_irq(unsigned int irq, irq_handler_t handler,
unsigned long irqflags, const char *devname, void *dev_id)
{
struct irqaction *action;
+ struct irq_desc *desc;
int retval;
/*
+ * handle_IRQ_event() always ignores IRQF_DISABLED except for
+ * the _first_ irqaction (sigh). That can cause oopsing, but
+ * the behavior is classified as "will not fix" so we need to
+ * start nudging drivers away from using that idiom.
+ */
+ if ((irqflags & (IRQF_SHARED|IRQF_DISABLED))
+ == (IRQF_SHARED|IRQF_DISABLED))
+ pr_warning("IRQ %d/%s: IRQF_DISABLED is not "
+ "guaranteed on shared IRQs\n",
+ irq, devname);
+
+#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 & SA_SHIRQ) && !dev_id)
+ if ((irqflags & IRQF_SHARED) && !dev_id)
+ return -EINVAL;
+
+ desc = irq_to_desc(irq);
+ if (!desc)
return -EINVAL;
- if (irq >= NR_IRQS)
+
+ if (desc->status & IRQ_NOREQUEST)
return -EINVAL;
if (!handler)
return -EINVAL;
action->next = NULL;
action->dev_id = dev_id;
- select_smp_affinity(irq);
-
- retval = setup_irq(irq, action);
+ retval = __setup_irq(irq, desc, action);
if (retval)
kfree(action);
+#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 disable the irq to make sure that a 'real' IRQ doesn't
+ * run in parallel with our fake.
+ */
+ unsigned long flags;
+
+ disable_irq(irq);
+ local_irq_save(flags);
+
+ handler(irq, dev_id);
+
+ local_irq_restore(flags);
+ enable_irq(irq);
+ }
+#endif
return retval;
}
EXPORT_SYMBOL(request_irq);
-