X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Firq%2Fmanage.c;h=704e488730a517e12a138bba8286bb856c99f369;hb=752f114fb83c5839de37a250b4f8257ed5438341;hp=0a3fd5b524c9a98e0e30491094f3f53b87ec25c5;hpb=70aedd24d20e75198f5a0b11750faabbb56924e2;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 0a3fd5b..704e488 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -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....