Merge branch 'cpus4096' into irq/threaded
[safe/jmp/linux-2.6] / kernel / irq / manage.c
index a3a5dc9..6458e99 100644 (file)
@@ -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);