Merge branch 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[safe/jmp/linux-2.6] / kernel / irq / manage.c
index 0a3fd5b..704e488 100644 (file)
@@ -46,9 +46,9 @@ void synchronize_irq(unsigned int irq)
                        cpu_relax();
 
                /* Ok, that indicated we're done: double-check carefully. */
-               spin_lock_irqsave(&desc->lock, flags);
+               raw_spin_lock_irqsave(&desc->lock, flags);
                status = desc->status;
-               spin_unlock_irqrestore(&desc->lock, flags);
+               raw_spin_unlock_irqrestore(&desc->lock, flags);
 
                /* Oops, that failed? */
        } while (status & IRQ_INPROGRESS);
@@ -114,7 +114,7 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
        if (!desc->chip->set_affinity)
                return -EINVAL;
 
-       spin_lock_irqsave(&desc->lock, flags);
+       raw_spin_lock_irqsave(&desc->lock, flags);
 
 #ifdef CONFIG_GENERIC_PENDING_IRQ
        if (desc->status & IRQ_MOVE_PCNTXT) {
@@ -134,7 +134,7 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
        }
 #endif
        desc->status |= IRQ_AFFINITY_SET;
-       spin_unlock_irqrestore(&desc->lock, flags);
+       raw_spin_unlock_irqrestore(&desc->lock, flags);
        return 0;
 }
 
@@ -181,11 +181,11 @@ int irq_select_affinity_usr(unsigned int irq)
        unsigned long flags;
        int ret;
 
-       spin_lock_irqsave(&desc->lock, flags);
+       raw_spin_lock_irqsave(&desc->lock, flags);
        ret = setup_affinity(irq, desc);
        if (!ret)
                irq_set_thread_affinity(desc);
-       spin_unlock_irqrestore(&desc->lock, flags);
+       raw_spin_unlock_irqrestore(&desc->lock, flags);
 
        return ret;
 }
@@ -231,9 +231,9 @@ void disable_irq_nosync(unsigned int irq)
                return;
 
        chip_bus_lock(irq, desc);
-       spin_lock_irqsave(&desc->lock, flags);
+       raw_spin_lock_irqsave(&desc->lock, flags);
        __disable_irq(desc, irq, false);
-       spin_unlock_irqrestore(&desc->lock, flags);
+       raw_spin_unlock_irqrestore(&desc->lock, flags);
        chip_bus_sync_unlock(irq, desc);
 }
 EXPORT_SYMBOL(disable_irq_nosync);
@@ -308,9 +308,9 @@ void enable_irq(unsigned int irq)
                return;
 
        chip_bus_lock(irq, desc);
-       spin_lock_irqsave(&desc->lock, flags);
+       raw_spin_lock_irqsave(&desc->lock, flags);
        __enable_irq(desc, irq, false);
-       spin_unlock_irqrestore(&desc->lock, flags);
+       raw_spin_unlock_irqrestore(&desc->lock, flags);
        chip_bus_sync_unlock(irq, desc);
 }
 EXPORT_SYMBOL(enable_irq);
@@ -347,7 +347,7 @@ int set_irq_wake(unsigned int irq, unsigned int on)
        /* 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);
+       raw_spin_lock_irqsave(&desc->lock, flags);
        if (on) {
                if (desc->wake_depth++ == 0) {
                        ret = set_irq_wake_real(irq, on);
@@ -368,7 +368,7 @@ int set_irq_wake(unsigned int irq, unsigned int on)
                }
        }
 
-       spin_unlock_irqrestore(&desc->lock, flags);
+       raw_spin_unlock_irqrestore(&desc->lock, flags);
        return ret;
 }
 EXPORT_SYMBOL(set_irq_wake);
@@ -382,6 +382,7 @@ int can_request_irq(unsigned int irq, unsigned long irqflags)
 {
        struct irq_desc *desc = irq_to_desc(irq);
        struct irqaction *action;
+       unsigned long flags;
 
        if (!desc)
                return 0;
@@ -389,11 +390,14 @@ int can_request_irq(unsigned int irq, unsigned long irqflags)
        if (desc->status & IRQ_NOREQUEST)
                return 0;
 
+       raw_spin_lock_irqsave(&desc->lock, flags);
        action = desc->action;
        if (action)
                if (irqflags & action->flags & IRQF_SHARED)
                        action = NULL;
 
+       raw_spin_unlock_irqrestore(&desc->lock, flags);
+
        return !action;
 }
 
@@ -451,6 +455,16 @@ 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()) {
@@ -473,13 +487,31 @@ static int irq_wait_for_interrupt(struct irqaction *action)
  */
 static void irq_finalize_oneshot(unsigned int irq, struct irq_desc *desc)
 {
+again:
        chip_bus_lock(irq, desc);
-       spin_lock_irq(&desc->lock);
+       raw_spin_lock_irq(&desc->lock);
+
+       /*
+        * Implausible though it may be we need to protect us against
+        * the following scenario:
+        *
+        * The thread is faster done than the hard interrupt handler
+        * on the other CPU. If we unmask the irq line then the
+        * interrupt can come in again and masks the line, leaves due
+        * to IRQ_INPROGRESS and the irq line is masked forever.
+        */
+       if (unlikely(desc->status & IRQ_INPROGRESS)) {
+               raw_spin_unlock_irq(&desc->lock);
+               chip_bus_sync_unlock(irq, desc);
+               cpu_relax();
+               goto again;
+       }
+
        if (!(desc->status & IRQ_DISABLED) && (desc->status & IRQ_MASKED)) {
                desc->status &= ~IRQ_MASKED;
                desc->chip->unmask(irq);
        }
-       spin_unlock_irq(&desc->lock);
+       raw_spin_unlock_irq(&desc->lock);
        chip_bus_sync_unlock(irq, desc);
 }
 
@@ -504,9 +536,9 @@ irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
                return;
        }
 
-       spin_lock_irq(&desc->lock);
+       raw_spin_lock_irq(&desc->lock);
        cpumask_copy(mask, desc->affinity);
-       spin_unlock_irq(&desc->lock);
+       raw_spin_unlock_irq(&desc->lock);
 
        set_cpus_allowed_ptr(current, mask);
        free_cpumask_var(mask);
@@ -535,7 +567,7 @@ static int irq_thread(void *data)
 
                atomic_inc(&desc->threads_active);
 
-               spin_lock_irq(&desc->lock);
+               raw_spin_lock_irq(&desc->lock);
                if (unlikely(desc->status & IRQ_DISABLED)) {
                        /*
                         * CHECKME: We might need a dedicated
@@ -545,9 +577,9 @@ static int irq_thread(void *data)
                         * retriggers the interrupt itself --- tglx
                         */
                        desc->status |= IRQ_PENDING;
-                       spin_unlock_irq(&desc->lock);
+                       raw_spin_unlock_irq(&desc->lock);
                } else {
-                       spin_unlock_irq(&desc->lock);
+                       raw_spin_unlock_irq(&desc->lock);
 
                        action->thread_fn(action->irq, action->dev_id);
 
@@ -600,7 +632,7 @@ __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)
@@ -630,9 +662,27 @@ __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,
@@ -646,13 +696,12 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                 */
                get_task_struct(t);
                new->thread = t;
-               wake_up_process(t);
        }
 
        /*
         * The following block of code has to be executed atomically
         */
-       spin_lock_irqsave(&desc->lock, flags);
+       raw_spin_lock_irqsave(&desc->lock, flags);
        old_ptr = &desc->action;
        old = *old_ptr;
        if (old) {
@@ -708,6 +757,16 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                if (new->flags & IRQF_ONESHOT)
                        desc->status |= IRQ_ONESHOT;
 
+               /*
+                * Force MSI interrupts to run with interrupts
+                * disabled. The multi vector cards can cause stack
+                * overflows due to nested interrupts when enough of
+                * them are directed to a core and fire at the same
+                * time.
+                */
+               if (desc->msi_desc)
+                       new->flags |= IRQF_DISABLED;
+
                if (!(desc->status & IRQ_NOAUTOEN)) {
                        desc->depth = 0;
                        desc->status &= ~IRQ_DISABLED;
@@ -732,6 +791,7 @@ __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 */
@@ -747,9 +807,15 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                __enable_irq(desc, irq, false);
        }
 
-       spin_unlock_irqrestore(&desc->lock, flags);
+       raw_spin_unlock_irqrestore(&desc->lock, flags);
+
+       /*
+        * 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);
 
-       new->irq = irq;
        register_irq_proc(irq, desc);
        new->dir = NULL;
        register_handler_proc(irq, new);
@@ -768,7 +834,7 @@ mismatch:
        ret = -EBUSY;
 
 out_thread:
-       spin_unlock_irqrestore(&desc->lock, flags);
+       raw_spin_unlock_irqrestore(&desc->lock, flags);
        if (new->thread) {
                struct task_struct *t = new->thread;
 
@@ -810,7 +876,7 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
        if (!desc)
                return NULL;
 
-       spin_lock_irqsave(&desc->lock, flags);
+       raw_spin_lock_irqsave(&desc->lock, flags);
 
        /*
         * There can be multiple actions per IRQ descriptor, find the right
@@ -822,7 +888,7 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
 
                if (!action) {
                        WARN(1, "Trying to free already-free IRQ %d\n", irq);
-                       spin_unlock_irqrestore(&desc->lock, flags);
+                       raw_spin_unlock_irqrestore(&desc->lock, flags);
 
                        return NULL;
                }
@@ -850,7 +916,7 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
                        desc->chip->disable(irq);
        }
 
-       spin_unlock_irqrestore(&desc->lock, flags);
+       raw_spin_unlock_irqrestore(&desc->lock, flags);
 
        unregister_handler_proc(irq, action);
 
@@ -1033,7 +1099,7 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler,
                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....