genirq: Add irq disabled flag to irq_data state

Some irq_chip implementation require to know the disabled state of the
interrupt in certain callbacks. Add a state flag and accessor to
irq_data.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 5d876c9..8649b0f 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -174,6 +174,8 @@
  *				  from suspend
  * IRDQ_MOVE_PCNTXT		- Interrupt can be moved in process
  *				  context
+ * IRQD_IRQ_DISABLED		- Some chip function need to know the
+ *				  disabled state.
  */
 enum {
 	IRQD_TRIGGER_MASK		= 0xf,
@@ -184,6 +186,7 @@
 	IRQD_LEVEL			= (1 << 13),
 	IRQD_WAKEUP_STATE		= (1 << 14),
 	IRQD_MOVE_PCNTXT		= (1 << 15),
+	IRQD_IRQ_DISABLED		= (1 << 16),
 };
 
 static inline bool irqd_is_setaffinity_pending(struct irq_data *d)
@@ -235,6 +238,11 @@
 	return d->state_use_accessors & IRQD_MOVE_PCNTXT;
 }
 
+static inline bool irqd_irq_disabled(struct irq_data *d)
+{
+	return d->state_use_accessors & IRQD_IRQ_DISABLED;
+}
+
 /**
  * struct irq_chip - hardware interrupt chip descriptor
  *