genirq: Implement irq_set_handler_locked()/irq_set_chip_handler_name_locked()

The main use case for the exisiting __irq_set_*_locked() inlines is to
replace the handler [,chip and name] of an interrupt from a region
which has the irq descriptor lock held, e.g. from the irq_set_type()
callback. The first argument is the irq number, so the functions need
so perform a pointless lookup of the interrupt descriptor for those
cases which have the irq_data pointer handy.

Provide new functions which take an irq_data pointer instead of the
interrupt number, so the lookup of the interrupt descriptor can be
avoided.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>

Conflicts:
	include/linux/irqdesc.h

include/linux/irqdesc.h

@@ -190,6 +190,47 @@ __irq_set_chip_handler_name_locked(unsigned int irq, struct irq_chip *chip,
 	desc->name = name;
 }
 
+/**
+ * irq_set_handler_locked - Set irq handler from a locked region
+ * @data:	Pointer to the irq_data structure which identifies the irq
+ * @handler:	Flow control handler function for this interrupt
+ *
+ * Sets the handler in the irq descriptor associated to @data.
+ *
+ * Must be called with irq_desc locked and valid parameters. Typical
+ * call site is the irq_set_type() callback.
+ */
+static inline void irq_set_handler_locked(struct irq_data *data,
+					  irq_flow_handler_t handler)
+{
+	struct irq_desc *desc = irq_data_to_desc(data);
+
+	desc->handle_irq = handler;
+}
+
+/**
+ * irq_set_chip_handler_name_locked - Set chip, handler and name from a locked region
+ * @data:	Pointer to the irq_data structure for which the chip is set
+ * @chip:	Pointer to the new irq chip
+ * @handler:	Flow control handler function for this interrupt
+ * @name:	Name of the interrupt
+ *
+ * Replace the irq chip at the proper hierarchy level in @data and
+ * sets the handler and name in the associated irq descriptor.
+ *
+ * Must be called with irq_desc locked and valid parameters.
+ */
+static inline void
+irq_set_chip_handler_name_locked(struct irq_data *data, struct irq_chip *chip,
+				 irq_flow_handler_t handler, const char *name)
+{
+	struct irq_desc *desc = irq_data_to_desc(data);
+
+	desc->handle_irq = handler;
+	desc->name = name;
+	data->chip = chip;
+}
+
 static inline int irq_balancing_disabled(unsigned int irq)
 {
 	struct irq_desc *desc;