*/
#include <linux/irq.h>
+#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
#include "internals.h"
-#ifdef CONFIG_SMP
-
/**
* synchronize_irq - wait for pending IRQ handlers (on other CPUs)
* @irq: interrupt number to wait for
*/
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;
do {
/* Oops, that failed? */
} while (status & IRQ_INPROGRESS);
+
+ /*
+ * We made sure that no hardirq handler is running. Now verify
+ * that no threaded handlers are active.
+ */
+ wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
}
EXPORT_SYMBOL(synchronize_irq);
+#ifdef CONFIG_SMP
+cpumask_var_t irq_default_affinity;
+
/**
* 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;
+ struct irq_desc *desc = irq_to_desc(irq);
if (CHECK_IRQ_PER_CPU(desc->status) || !desc->chip ||
!desc->chip->set_affinity)
}
/**
+ * irq_set_thread_affinity - Notify irq threads to adjust affinity
+ * @desc: irq descriptor which has affitnity changed
+ *
+ * We just set IRQTF_AFFINITY and delegate the affinity setting
+ * to the interrupt thread itself. We can not call
+ * set_cpus_allowed_ptr() here as we hold desc->lock and this
+ * code can be called from hard interrupt context.
+ */
+void irq_set_thread_affinity(struct irq_desc *desc)
+{
+ struct irqaction *action = desc->action;
+
+ while (action) {
+ if (action->thread)
+ set_bit(IRQTF_AFFINITY, &action->thread_flags);
+ action = action->next;
+ }
+}
+
+/**
* 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)
+int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
{
- struct irq_desc *desc = irq_desc + irq;
+ struct irq_desc *desc = irq_to_desc(irq);
+ unsigned long flags;
if (!desc->chip->set_affinity)
return -EINVAL;
- set_balance_irq_affinity(irq, cpumask);
+ spin_lock_irqsave(&desc->lock, flags);
#ifdef CONFIG_GENERIC_PENDING_IRQ
- set_pending_irq(irq, cpumask);
+ if (desc->status & IRQ_MOVE_PCNTXT) {
+ if (!desc->chip->set_affinity(irq, cpumask)) {
+ cpumask_copy(desc->affinity, cpumask);
+ irq_set_thread_affinity(desc);
+ }
+ }
+ else {
+ desc->status |= IRQ_MOVE_PENDING;
+ cpumask_copy(desc->pending_mask, cpumask);
+ }
#else
- desc->affinity = cpumask;
- desc->chip->set_affinity(irq, cpumask);
+ if (!desc->chip->set_affinity(irq, cpumask)) {
+ cpumask_copy(desc->affinity, cpumask);
+ irq_set_thread_affinity(desc);
+ }
#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.
+ */
+static int setup_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 setup_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 = setup_affinity(irq, desc);
+ if (!ret)
+ irq_set_thread_affinity(desc);
+ spin_unlock_irqrestore(&desc->lock, flags);
+
+ return ret;
+}
+
+#else
+static inline int setup_affinity(unsigned int irq, struct irq_desc *desc)
+{
+ return 0;
+}
+#endif
+
+void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
+{
+ if (suspend) {
+ if (!desc->action || (desc->action->flags & IRQF_TIMER))
+ return;
+ desc->status |= IRQ_SUSPENDED;
+ }
+
+ if (!desc->depth++) {
+ desc->status |= IRQ_DISABLED;
+ desc->chip->disable(irq);
+ }
+}
+
/**
* disable_irq_nosync - disable an irq without waiting
* @irq: Interrupt to disable
*/
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;
+ chip_bus_lock(irq, desc);
spin_lock_irqsave(&desc->lock, flags);
- if (!desc->depth++) {
- desc->status |= IRQ_DISABLED;
- desc->chip->disable(irq);
- }
+ __disable_irq(desc, irq, false);
spin_unlock_irqrestore(&desc->lock, flags);
+ chip_bus_sync_unlock(irq, desc);
}
EXPORT_SYMBOL(disable_irq_nosync);
*/
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);
-/**
- * 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)
+void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
{
- struct irq_desc *desc = irq_desc + irq;
- unsigned long flags;
-
- if (irq >= NR_IRQS)
- return;
+ if (resume)
+ desc->status &= ~IRQ_SUSPENDED;
- spin_lock_irqsave(&desc->lock, flags);
switch (desc->depth) {
case 0:
- printk(KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
- WARN_ON(1);
+ err_out:
+ WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
break;
case 1: {
unsigned int status = desc->status & ~IRQ_DISABLED;
+ if (desc->status & IRQ_SUSPENDED)
+ goto err_out;
/* Prevent probing on this irq: */
desc->status = status | IRQ_NOPROBE;
check_irq_resend(desc, irq);
default:
desc->depth--;
}
+}
+
+/**
+ * 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 only when
+ * desc->chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
+ */
+void enable_irq(unsigned int irq)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ unsigned long flags;
+
+ if (!desc)
+ return;
+
+ chip_bus_lock(irq, desc);
+ spin_lock_irqsave(&desc->lock, flags);
+ __enable_irq(desc, irq, false);
spin_unlock_irqrestore(&desc->lock, flags);
+ chip_bus_sync_unlock(irq, desc);
}
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;
+
+ 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
*/
int set_irq_wake(unsigned int irq, unsigned int on)
{
- struct irq_desc *desc = irq_desc + irq;
+ struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
- int ret = -ENXIO;
- int (*set_wake)(unsigned, unsigned) = desc->chip->set_wake;
+ 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)
- desc->status |= IRQ_WAKEUP;
- else
- set_wake = NULL;
+ 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) {
- 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;
+ 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;
+ }
}
- if (set_wake)
- ret = desc->chip->set_wake(irq, on);
+
spin_unlock_irqrestore(&desc->lock, flags);
return ret;
}
*/
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 || irq_desc[irq].status & IRQ_NOREQUEST)
+ if (!desc)
+ return 0;
+
+ if (desc->status & IRQ_NOREQUEST)
return 0;
- action = irq_desc[irq].action;
+ action = desc->action;
if (action)
if (irqflags & action->flags & IRQF_SHARED)
action = NULL;
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;
+}
+
+/*
+ * Default primary interrupt handler for threaded interrupts. Is
+ * assigned as primary handler when request_threaded_irq is called
+ * with handler == NULL. Useful for oneshot interrupts.
+ */
+static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
+{
+ return IRQ_WAKE_THREAD;
+}
+
+/*
+ * Primary handler for nested threaded interrupts. Should never be
+ * called.
+ */
+static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
+{
+ WARN(1, "Primary handler called for nested irq %d\n", irq);
+ return IRQ_NONE;
+}
+
+static int irq_wait_for_interrupt(struct irqaction *action)
+{
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ if (test_and_clear_bit(IRQTF_RUNTHREAD,
+ &action->thread_flags)) {
+ __set_current_state(TASK_RUNNING);
+ return 0;
+ }
+ schedule();
+ }
+ return -1;
+}
+
+/*
+ * Oneshot interrupts keep the irq line masked until the threaded
+ * handler finished. unmask if the interrupt has not been disabled and
+ * is marked MASKED.
+ */
+static void irq_finalize_oneshot(unsigned int irq, struct irq_desc *desc)
+{
+ chip_bus_lock(irq, desc);
+ spin_lock_irq(&desc->lock);
+ if (!(desc->status & IRQ_DISABLED) && (desc->status & IRQ_MASKED)) {
+ desc->status &= ~IRQ_MASKED;
+ desc->chip->unmask(irq);
+ }
+ spin_unlock_irq(&desc->lock);
+ chip_bus_sync_unlock(irq, desc);
+}
+
+#ifdef CONFIG_SMP
+/*
+ * Check whether we need to change the affinity of the interrupt thread.
+ */
+static void
+irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
+{
+ cpumask_var_t mask;
+
+ if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
+ return;
+
+ /*
+ * In case we are out of memory we set IRQTF_AFFINITY again and
+ * try again next time
+ */
+ if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
+ set_bit(IRQTF_AFFINITY, &action->thread_flags);
+ return;
+ }
+
+ spin_lock_irq(&desc->lock);
+ cpumask_copy(mask, desc->affinity);
+ spin_unlock_irq(&desc->lock);
+
+ set_cpus_allowed_ptr(current, mask);
+ free_cpumask_var(mask);
+}
+#else
+static inline void
+irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
+#endif
+
+/*
+ * Interrupt handler thread
+ */
+static int irq_thread(void *data)
+{
+ struct sched_param param = { .sched_priority = MAX_USER_RT_PRIO/2, };
+ struct irqaction *action = data;
+ struct irq_desc *desc = irq_to_desc(action->irq);
+ int wake, oneshot = desc->status & IRQ_ONESHOT;
+
+ sched_setscheduler(current, SCHED_FIFO, ¶m);
+ current->irqaction = action;
+
+ while (!irq_wait_for_interrupt(action)) {
+
+ irq_thread_check_affinity(desc, action);
+
+ atomic_inc(&desc->threads_active);
+
+ spin_lock_irq(&desc->lock);
+ if (unlikely(desc->status & IRQ_DISABLED)) {
+ /*
+ * CHECKME: We might need a dedicated
+ * IRQ_THREAD_PENDING flag here, which
+ * retriggers the thread in check_irq_resend()
+ * but AFAICT IRQ_PENDING should be fine as it
+ * retriggers the interrupt itself --- tglx
+ */
+ desc->status |= IRQ_PENDING;
+ spin_unlock_irq(&desc->lock);
+ } else {
+ spin_unlock_irq(&desc->lock);
+
+ action->thread_fn(action->irq, action->dev_id);
+
+ if (oneshot)
+ irq_finalize_oneshot(action->irq, desc);
+ }
+
+ wake = atomic_dec_and_test(&desc->threads_active);
+
+ if (wake && waitqueue_active(&desc->wait_for_threads))
+ wake_up(&desc->wait_for_threads);
+ }
+
+ /*
+ * Clear irqaction. Otherwise exit_irq_thread() would make
+ * fuzz about an active irq thread going into nirvana.
+ */
+ current->irqaction = NULL;
+ return 0;
+}
+
+/*
+ * Called from do_exit()
+ */
+void exit_irq_thread(void)
+{
+ struct task_struct *tsk = current;
+
+ if (!tsk->irqaction)
+ return;
+
+ printk(KERN_ERR
+ "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
+ tsk->comm ? tsk->comm : "", tsk->pid, tsk->irqaction->irq);
+
+ /*
+ * Set the THREAD DIED flag to prevent further wakeups of the
+ * soon to be gone threaded handler.
+ */
+ set_bit(IRQTF_DIED, &tsk->irqaction->flags);
+}
+
/*
* 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;
+ struct irqaction *old, **old_ptr;
const char *old_name = NULL;
unsigned long flags;
- int shared = 0;
+ int nested, shared = 0;
+ int ret;
- if (irq >= NR_IRQS)
+ if (!desc)
return -EINVAL;
if (desc->chip == &no_irq_chip)
rand_initialize_irq(irq);
}
+ /* Oneshot interrupts are not allowed with shared */
+ if ((new->flags & IRQF_ONESHOT) && (new->flags & IRQF_SHARED))
+ return -EINVAL;
+
+ /*
+ * Check whether the interrupt nests into another interrupt
+ * thread.
+ */
+ nested = desc->status & IRQ_NESTED_THREAD;
+ if (nested) {
+ if (!new->thread_fn)
+ return -EINVAL;
+ /*
+ * Replace the primary handler which was provided from
+ * the driver for non nested interrupt handling by the
+ * dummy function which warns when called.
+ */
+ new->handler = irq_nested_primary_handler;
+ }
+
+ /*
+ * Create a handler thread when a thread function is supplied
+ * and the interrupt does not nest into another interrupt
+ * thread.
+ */
+ if (new->thread_fn && !nested) {
+ struct task_struct *t;
+
+ t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
+ new->name);
+ if (IS_ERR(t))
+ return PTR_ERR(t);
+ /*
+ * We keep the reference to the task struct even if
+ * the thread dies to avoid that the interrupt code
+ * references an already freed task_struct.
+ */
+ get_task_struct(t);
+ new->thread = t;
+ }
+
/*
* The following block of code has to be executed atomically
*/
spin_lock_irqsave(&desc->lock, flags);
- p = &desc->action;
- old = *p;
+ old_ptr = &desc->action;
+ old = *old_ptr;
if (old) {
/*
* Can't share interrupts unless both agree to and are
/* add new interrupt at end of irq queue */
do {
- p = &old->next;
- old = *p;
+ old_ptr = &old->next;
+ old = *old_ptr;
} while (old);
shared = 1;
}
- *p = new;
-
- /* Exclude IRQ from balancing */
- if (new->flags & IRQF_NOBALANCING)
- desc->status |= IRQ_NO_BALANCING;
-
if (!shared) {
irq_chip_set_defaults(desc->chip);
-#if defined(CONFIG_IRQ_PER_CPU)
- if (new->flags & IRQF_PERCPU)
- desc->status |= IRQ_PER_CPU;
-#endif
+ init_waitqueue_head(&desc->wait_for_threads);
/* 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");
+ ret = __irq_set_trigger(desc, irq,
+ new->flags & IRQF_TRIGGER_MASK);
+
+ if (ret)
+ goto out_thread;
} 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);
+ desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | IRQ_ONESHOT |
+ IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED);
+
+ if (new->flags & IRQF_ONESHOT)
+ desc->status |= IRQ_ONESHOT;
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);
+ desc->chip->startup(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 */
+ setup_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));
}
+
+ new->irq = irq;
+ *old_ptr = 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, false);
+ }
+
spin_unlock_irqrestore(&desc->lock, flags);
- new->irq = irq;
- register_irq_proc(irq);
+ /*
+ * Strictly no need to wake it up, but hung_task complains
+ * when no hard interrupt wakes the thread up.
+ */
+ if (new->thread)
+ wake_up_process(new->thread);
+
+ register_irq_proc(irq, desc);
new->dir = NULL;
register_handler_proc(irq, new);
dump_stack();
}
#endif
+ ret = -EBUSY;
+
+out_thread:
spin_unlock_irqrestore(&desc->lock, flags);
- return -EBUSY;
+ if (new->thread) {
+ struct task_struct *t = new->thread;
+
+ new->thread = NULL;
+ if (likely(!test_bit(IRQTF_DIED, &new->thread_flags)))
+ kthread_stop(t);
+ put_task_struct(t);
+ }
+ return ret;
}
/**
- * free_irq - free an interrupt
- * @irq: Interrupt line to free
- * @dev_id: Device identity to free
+ * setup_irq - setup an interrupt
+ * @irq: Interrupt line to setup
+ * @act: irqaction for the interrupt
*
- * 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.
+ * Used to statically setup interrupts in the early boot process.
*/
-void free_irq(unsigned int irq, void *dev_id)
+int setup_irq(unsigned int irq, struct irqaction *act)
{
- struct irq_desc *desc;
- struct irqaction **p;
+ struct irq_desc *desc = irq_to_desc(irq);
+
+ return __setup_irq(irq, desc, act);
+}
+EXPORT_SYMBOL_GPL(setup_irq);
+
+ /*
+ * Internal function to unregister an irqaction - used to free
+ * regular and special interrupts that are part of the architecture.
+ */
+static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ struct irqaction *action, **action_ptr;
unsigned long flags;
- WARN_ON(in_interrupt());
- if (irq >= NR_IRQS)
- return;
+ WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
+
+ if (!desc)
+ return NULL;
- desc = irq_desc + irq;
spin_lock_irqsave(&desc->lock, flags);
- p = &desc->action;
+
+ /*
+ * There can be multiple actions per IRQ descriptor, find the right
+ * one based on the dev_id:
+ */
+ action_ptr = &desc->action;
for (;;) {
- struct irqaction *action = *p;
+ action = *action_ptr;
- if (action) {
- struct irqaction **pp = p;
+ if (!action) {
+ WARN(1, "Trying to free already-free IRQ %d\n", irq);
+ spin_unlock_irqrestore(&desc->lock, flags);
- p = &action->next;
- if (action->dev_id != dev_id)
- continue;
+ return NULL;
+ }
- /* Found it - now remove it from the list of entries */
- *pp = action->next;
+ if (action->dev_id == dev_id)
+ break;
+ action_ptr = &action->next;
+ }
- /* Currently used only by UML, might disappear one day.*/
+ /* Found it - now remove it from the list of entries: */
+ *action_ptr = 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);
+ 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);
+ /* If this was the last handler, shut down the IRQ line: */
+ 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);
- /* 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);
- }
+ /*
+ * It's a shared IRQ -- the driver ought to be prepared for an IRQ
+ * event to happen even now it's being freed, so let's make sure that
+ * is so by doing an extra call to the handler ....
+ *
+ * ( 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 already-free IRQ %d\n", irq);
- spin_unlock_irqrestore(&desc->lock, flags);
- return;
+
+ if (action->thread) {
+ if (!test_bit(IRQTF_DIED, &action->thread_flags))
+ kthread_stop(action->thread);
+ put_task_struct(action->thread);
}
+
+ return action;
+}
+
+/**
+ * remove_irq - free an interrupt
+ * @irq: Interrupt line to free
+ * @act: irqaction for the interrupt
+ *
+ * Used to remove interrupts statically setup by the early boot process.
+ */
+void remove_irq(unsigned int irq, struct irqaction *act)
+{
+ __free_irq(irq, act->dev_id);
+}
+EXPORT_SYMBOL_GPL(remove_irq);
+
+/**
+ * free_irq - free an interrupt allocated with request_irq
+ * @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 = irq_to_desc(irq);
+
+ if (!desc)
+ return;
+
+ chip_bus_lock(irq, desc);
+ kfree(__free_irq(irq, dev_id));
+ chip_bus_sync_unlock(irq, desc);
}
EXPORT_SYMBOL(free_irq);
/**
- * request_irq - allocate an interrupt line
+ * request_threaded_irq - allocate an interrupt line
* @irq: Interrupt line to allocate
- * @handler: Function to be called when the IRQ occurs
+ * @handler: Function to be called when the IRQ occurs.
+ * Primary handler for threaded interrupts
+ * If NULL and thread_fn != NULL the default
+ * primary handler is installed
+ * @thread_fn: Function called from the irq handler thread
+ * If NULL, no irq thread is created
* @irqflags: Interrupt type flags
* @devname: An ascii name for the claiming device
* @dev_id: A cookie passed back to the handler function
* raises, you must take care both to initialise your hardware
* and to set up the interrupt handler in the right order.
*
+ * If you want to set up a threaded irq handler for your device
+ * then you need to supply @handler and @thread_fn. @handler ist
+ * still called in hard interrupt context and has to check
+ * whether the interrupt originates from the device. If yes it
+ * needs to disable the interrupt on the device and return
+ * IRQ_WAKE_THREAD which will wake up the handler thread and run
+ * @thread_fn. This split handler design is necessary to support
+ * shared interrupts.
+ *
* 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.
* 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, irq_handler_t handler,
- unsigned long irqflags, const char *devname, void *dev_id)
+int request_threaded_irq(unsigned int irq, irq_handler_t handler,
+ irq_handler_t thread_fn, 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:
*/
if ((irqflags & IRQF_SHARED) && !dev_id)
return -EINVAL;
- if (irq >= NR_IRQS)
- return -EINVAL;
- if (irq_desc[irq].status & IRQ_NOREQUEST)
+
+ desc = irq_to_desc(irq);
+ if (!desc)
return -EINVAL;
- if (!handler)
+
+ if (desc->status & IRQ_NOREQUEST)
return -EINVAL;
- action = kmalloc(sizeof(struct irqaction), GFP_ATOMIC);
+ if (!handler) {
+ if (!thread_fn)
+ return -EINVAL;
+ handler = irq_default_primary_handler;
+ }
+
+ action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
if (!action)
return -ENOMEM;
action->handler = handler;
+ action->thread_fn = thread_fn;
action->flags = irqflags;
- cpus_clear(action->mask);
action->name = devname;
- action->next = NULL;
action->dev_id = dev_id;
- select_smp_affinity(irq);
+ chip_bus_lock(irq, desc);
+ retval = __setup_irq(irq, desc, action);
+ chip_bus_sync_unlock(irq, desc);
+
+ if (retval)
+ kfree(action);
#ifdef CONFIG_DEBUG_SHIRQ
- if (irqflags & IRQF_SHARED) {
+ if (!retval && (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
+ * 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
-
- retval = setup_irq(irq, action);
- if (retval)
- kfree(action);
-
return retval;
}
-EXPORT_SYMBOL(request_irq);
+EXPORT_SYMBOL(request_threaded_irq);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff