irqdomain: Make irq_domain_reset_irq_data() available to non-hierarchical users

irq_domain_reset_irq_data() doesn't modify the parent data, so it can be
made available even if irq domain hierarchy is not being built. We'll
subsequently use it in irq_sim code.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20200514083901.23445-2-brgl@bgdev.pl

include/linux/irqdomain.h

@@ -450,6 +450,7 @@ extern void irq_domain_set_info(struct irq_domain *domain, unsigned int virq,
 				irq_hw_number_t hwirq, struct irq_chip *chip,
 				void *chip_data, irq_flow_handler_t handler,
 				void *handler_data, const char *handler_name);
+extern void irq_domain_reset_irq_data(struct irq_data *irq_data);
 #ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
 extern struct irq_domain *irq_domain_create_hierarchy(struct irq_domain *parent,
 			unsigned int flags, unsigned int size,
@@ -491,7 +492,6 @@ extern int irq_domain_set_hwirq_and_chip(struct irq_domain *domain,
 					 irq_hw_number_t hwirq,
 					 struct irq_chip *chip,
 					 void *chip_data);
-extern void irq_domain_reset_irq_data(struct irq_data *irq_data);
 extern void irq_domain_free_irqs_common(struct irq_domain *domain,
 					unsigned int virq,
 					unsigned int nr_irqs);

kernel/irq/irqdomain.c

@@ -1047,6 +1047,18 @@ int irq_domain_alloc_descs(int virq, unsigned int cnt, irq_hw_number_t hwirq,
 	return virq;
 }
 
+/**
+ * irq_domain_reset_irq_data - Clear hwirq, chip and chip_data in @irq_data
+ * @irq_data:	The pointer to irq_data
+ */
+void irq_domain_reset_irq_data(struct irq_data *irq_data)
+{
+	irq_data->hwirq = 0;
+	irq_data->chip = &no_irq_chip;
+	irq_data->chip_data = NULL;
+}
+EXPORT_SYMBOL_GPL(irq_domain_reset_irq_data);
+
 #ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
 /**
  * irq_domain_create_hierarchy - Add a irqdomain into the hierarchy
@@ -1247,18 +1259,6 @@ void irq_domain_set_info(struct irq_domain *domain, unsigned int virq,
 }
 EXPORT_SYMBOL(irq_domain_set_info);
 
-/**
- * irq_domain_reset_irq_data - Clear hwirq, chip and chip_data in @irq_data
- * @irq_data:	The pointer to irq_data
- */
-void irq_domain_reset_irq_data(struct irq_data *irq_data)
-{
-	irq_data->hwirq = 0;
-	irq_data->chip = &no_irq_chip;
-	irq_data->chip_data = NULL;
-}
-EXPORT_SYMBOL_GPL(irq_domain_reset_irq_data);
-
 /**
  * irq_domain_free_irqs_common - Clear irq_data and free the parent
  * @domain:	Interrupt domain to match