Merge branch 'topic/oss' into for-linus

[pandora-kernel.git] / kernel / irq / manage.c

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 50da676..0ec9ed8 100644 (file)
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -80,14 +80,22 @@ int irq_can_set_affinity(unsigned int irq)
        return 1;
 }
 
-void
-irq_set_thread_affinity(struct irq_desc *desc, const struct cpumask *cpumask)
+/**
+ *     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_cpus_allowed_ptr(action->thread, cpumask);
+                       set_bit(IRQTF_AFFINITY, &action->thread_flags);
                action = action->next;
        }
 }
@@ -112,7 +120,7 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
        if (desc->status & IRQ_MOVE_PCNTXT) {
                if (!desc->chip->set_affinity(irq, cpumask)) {
                        cpumask_copy(desc->affinity, cpumask);
-                       irq_set_thread_affinity(desc, cpumask);
+                       irq_set_thread_affinity(desc);
                }
        }
        else {
@@ -122,7 +130,7 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
 #else
        if (!desc->chip->set_affinity(irq, cpumask)) {
                cpumask_copy(desc->affinity, cpumask);
-               irq_set_thread_affinity(desc, cpumask);
+               irq_set_thread_affinity(desc);
        }
 #endif
        desc->status |= IRQ_AFFINITY_SET;
@@ -176,7 +184,7 @@ int irq_select_affinity_usr(unsigned int irq)
        spin_lock_irqsave(&desc->lock, flags);
        ret = setup_affinity(irq, desc);
        if (!ret)
-               irq_set_thread_affinity(desc, desc->affinity);
+               irq_set_thread_affinity(desc);
        spin_unlock_irqrestore(&desc->lock, flags);
 
        return ret;
@@ -443,6 +451,39 @@ static int irq_wait_for_interrupt(struct irqaction *action)
        return -1;
 }
 
+#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
  */
@@ -458,6 +499,8 @@ static int irq_thread(void *data)
 
        while (!irq_wait_for_interrupt(action)) {
 
+               irq_thread_check_affinity(desc, action);
+
                atomic_inc(&desc->threads_active);
 
                spin_lock_irq(&desc->lock);
@@ -564,7 +607,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                 */
                get_task_struct(t);
                new->thread = t;
-               wake_up_process(t);
        }
 
        /*
@@ -647,6 +689,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                                (int)(new->flags & IRQF_TRIGGER_MASK));
        }
 
+       new->irq = irq;
        *old_ptr = new;
 
        /* Reset broken irq detection when installing new handler */
@@ -664,7 +707,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 
        spin_unlock_irqrestore(&desc->lock, flags);
 
-       new->irq = 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);
@@ -718,7 +767,6 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
 {
        struct irq_desc *desc = irq_to_desc(irq);
        struct irqaction *action, **action_ptr;
-       struct task_struct *irqthread;
        unsigned long flags;
 
        WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
@@ -766,9 +814,6 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
                        desc->chip->disable(irq);
        }
 
-       irqthread = action->thread;
-       action->thread = NULL;
-
        spin_unlock_irqrestore(&desc->lock, flags);
 
        unregister_handler_proc(irq, action);
@@ -776,12 +821,6 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
        /* Make sure it's not being used on another CPU: */
        synchronize_irq(irq);
 
-       if (irqthread) {
-               if (!test_bit(IRQTF_DIED, &action->thread_flags))
-                       kthread_stop(irqthread);
-               put_task_struct(irqthread);
-       }
-
 #ifdef CONFIG_DEBUG_SHIRQ
        /*
         * It's a shared IRQ -- the driver ought to be prepared for an IRQ
@@ -797,6 +836,13 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
                local_irq_restore(flags);
        }
 #endif
+
+       if (action->thread) {
+               if (!test_bit(IRQTF_DIED, &action->thread_flags))
+                       kthread_stop(action->thread);
+               put_task_struct(action->thread);
+       }
+
        return action;
 }