Merge branch 'irq-threaded-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

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

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index d7f7b5f..bde4c66 100644 (file)
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -230,9 +230,11 @@ void disable_irq_nosync(unsigned int irq)
        if (!desc)
                return;
 
+       chip_bus_lock(irq, desc);
        spin_lock_irqsave(&desc->lock, flags);
        __disable_irq(desc, irq, false);
        spin_unlock_irqrestore(&desc->lock, flags);
+       chip_bus_sync_unlock(irq, desc);
 }
 EXPORT_SYMBOL(disable_irq_nosync);
 
@@ -294,7 +296,8 @@ void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
  *     matches the last disable, processing of interrupts on this
  *     IRQ line is re-enabled.
  *
- *     This function may be called from IRQ context.
+ *     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)
 {
@@ -304,9 +307,11 @@ void enable_irq(unsigned int irq)
        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);
 
@@ -446,6 +451,16 @@ 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()) {
@@ -468,12 +483,14 @@ static int irq_wait_for_interrupt(struct irqaction *action)
  */
 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
@@ -593,7 +610,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
        struct irqaction *old, **old_ptr;
        const char *old_name = NULL;
        unsigned long flags;
-       int shared = 0;
+       int nested, shared = 0;
        int ret;
 
        if (!desc)
@@ -623,9 +640,27 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                return -EINVAL;
 
        /*
-        * Threaded handler ?
+        * 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) {
+       if (new->thread_fn && !nested) {
                struct task_struct *t;
 
                t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
@@ -639,7 +674,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                 */
                get_task_struct(t);
                new->thread = t;
-               wake_up_process(t);
        }
 
        /*
@@ -725,6 +759,7 @@ __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 */
@@ -742,7 +777,13 @@ __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);
@@ -904,7 +945,14 @@ EXPORT_SYMBOL_GPL(remove_irq);
  */
 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);
 
@@ -1011,7 +1059,10 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler,
        action->name = devname;
        action->dev_id = dev_id;
 
+       chip_bus_lock(irq, desc);
        retval = __setup_irq(irq, desc, action);
+       chip_bus_sync_unlock(irq, desc);
+
        if (retval)
                kfree(action);