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Diffstat (limited to 'kernel/irq/manage.c')
-rw-r--r--kernel/irq/manage.c192
1 files changed, 109 insertions, 83 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 291f0366455..ea119effe09 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -109,7 +109,7 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
/*
* Generic version of the affinity autoselector.
*/
-int do_irq_select_affinity(unsigned int irq, struct irq_desc *desc)
+static int setup_affinity(unsigned int irq, struct irq_desc *desc)
{
if (!irq_can_set_affinity(irq))
return 0;
@@ -133,7 +133,7 @@ set_affinity:
return 0;
}
#else
-static inline int do_irq_select_affinity(unsigned int irq, struct irq_desc *d)
+static inline int setup_affinity(unsigned int irq, struct irq_desc *d)
{
return irq_select_affinity(irq);
}
@@ -149,14 +149,14 @@ int irq_select_affinity_usr(unsigned int irq)
int ret;
spin_lock_irqsave(&desc->lock, flags);
- ret = do_irq_select_affinity(irq, desc);
+ ret = setup_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)
+static inline int setup_affinity(unsigned int irq, struct irq_desc *desc)
{
return 0;
}
@@ -389,9 +389,9 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
* allocate special interrupts that are part of the architecture.
*/
static int
-__setup_irq(unsigned int irq, struct irq_desc * desc, struct irqaction *new)
+__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
{
- struct irqaction *old, **p;
+ struct irqaction *old, **old_ptr;
const char *old_name = NULL;
unsigned long flags;
int shared = 0;
@@ -423,8 +423,8 @@ __setup_irq(unsigned int irq, struct irq_desc * desc, struct irqaction *new)
* 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
@@ -447,8 +447,8 @@ __setup_irq(unsigned int irq, struct irq_desc * desc, struct irqaction *new)
/* 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;
}
@@ -488,7 +488,7 @@ __setup_irq(unsigned int irq, struct irq_desc * desc, struct irqaction *new)
desc->status |= IRQ_NO_BALANCING;
/* Set default affinity mask once everything is setup */
- do_irq_select_affinity(irq, desc);
+ setup_affinity(irq, desc);
} else if ((new->flags & IRQF_TRIGGER_MASK)
&& (new->flags & IRQF_TRIGGER_MASK)
@@ -499,7 +499,7 @@ __setup_irq(unsigned int irq, struct irq_desc * desc, struct irqaction *new)
(int)(new->flags & IRQF_TRIGGER_MASK));
}
- *p = new;
+ *old_ptr = new;
/* Reset broken irq detection when installing new handler */
desc->irq_count = 0;
@@ -549,90 +549,117 @@ int setup_irq(unsigned int irq, struct irqaction *act)
return __setup_irq(irq, desc, act);
}
+EXPORT_SYMBOL_GPL(setup_irq);
-/**
- * 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.
+ /*
+ * Internal function to unregister an irqaction - used to free
+ * regular and special interrupts that are part of the architecture.
*/
-void free_irq(unsigned int irq, void *dev_id)
+static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
{
struct irq_desc *desc = irq_to_desc(irq);
- struct irqaction **p;
+ struct irqaction *action, **action_ptr;
unsigned long flags;
- WARN_ON(in_interrupt());
+ WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
if (!desc)
- return;
+ return NULL;
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);
- }
-#endif
- kfree(action);
- return;
- }
- 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;
+ /*
+ * 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
+ 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)
+{
+ kfree(__free_irq(irq, dev_id));
}
EXPORT_SYMBOL(free_irq);
@@ -679,11 +706,12 @@ int request_irq(unsigned int irq, irq_handler_t handler,
* 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);
+ 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
/*
@@ -709,15 +737,13 @@ int request_irq(unsigned int irq, irq_handler_t handler,
if (!handler)
return -EINVAL;
- action = kmalloc(sizeof(struct irqaction), GFP_ATOMIC);
+ action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
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;
retval = __setup_irq(irq, desc, action);