irqchip/gic: Add helper function for chip initialisation

For GICs that require runtime power-management it is necessary to
populate the 'parent_device' member of the irqchip structure. In
preparation for supporting such GICs, move the code that initialises
the irqchip structure for a GIC into its own function called
gic_init_chip() where the parent device pointer is also set.

Instead of calling gic_init_chip() from within gic_init_bases(), move
the calls to outside of this function, so that in the future we can
avoid having to pass additional parameters to gic_init_bases() in order
set the parent device pointer or set the name to a specific string.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

drivers/irqchip/irq-gic.c

@@ -1032,29 +1032,31 @@ static const struct irq_domain_ops gic_irq_domain_ops = {
 	.unmap = gic_irq_domain_unmap,
 };
 
-static int gic_init_bases(struct gic_chip_data *gic, int irq_start,
-			  struct fwnode_handle *handle)
+static void gic_init_chip(struct gic_chip_data *gic, struct device *dev,
+			  const char *name, bool use_eoimode1)
 {
-	irq_hw_number_t hwirq_base;
-	int gic_irqs, irq_base, ret;
-
 	/* Initialize irq_chip */
 	gic->chip = gic_chip;
+	gic->chip.name = name;
+	gic->chip.parent_device = dev;
 
-	if (static_key_true(&supports_deactivate) && gic == &gic_data[0]) {
+	if (use_eoimode1) {
 		gic->chip.irq_mask = gic_eoimode1_mask_irq;
 		gic->chip.irq_eoi = gic_eoimode1_eoi_irq;
 		gic->chip.irq_set_vcpu_affinity = gic_irq_set_vcpu_affinity;
-		gic->chip.name = kasprintf(GFP_KERNEL, "GICv2");
-	} else {
-		gic->chip.name = kasprintf(GFP_KERNEL, "GIC-%d",
-					   (int)(gic - &gic_data[0]));
 	}
 
 #ifdef CONFIG_SMP
 	if (gic == &gic_data[0])
 		gic->chip.irq_set_affinity = gic_set_affinity;
 #endif
+}
+
+static int gic_init_bases(struct gic_chip_data *gic, int irq_start,
+			  struct fwnode_handle *handle)
+{
+	irq_hw_number_t hwirq_base;
+	int gic_irqs, irq_base, ret;
 
 	if (IS_ENABLED(CONFIG_GIC_NON_BANKED) && gic->percpu_offset) {
 		/* Frankein-GIC without banked registers... */
@@ -1152,8 +1154,6 @@ static int gic_init_bases(struct gic_chip_data *gic, int irq_start,
 		free_percpu(gic->cpu_base.percpu_base);
 	}
 
-	kfree(gic->chip.name);
-
 	return ret;
 }
 
@@ -1161,7 +1161,8 @@ static int __init __gic_init_bases(struct gic_chip_data *gic,
 				   int irq_start,
 				   struct fwnode_handle *handle)
 {
-	int i;
+	char *name;
+	int i, ret;
 
 	if (WARN_ON(!gic || gic->domain))
 		return -EINVAL;
@@ -1183,7 +1184,19 @@ static int __init __gic_init_bases(struct gic_chip_data *gic,
 			pr_info("GIC: Using split EOI/Deactivate mode\n");
 	}
 
-	return gic_init_bases(gic, irq_start, handle);
+	if (static_key_true(&supports_deactivate) && gic == &gic_data[0]) {
+		name = kasprintf(GFP_KERNEL, "GICv2");
+		gic_init_chip(gic, NULL, name, true);
+	} else {
+		name = kasprintf(GFP_KERNEL, "GIC-%d", (int)(gic-&gic_data[0]));
+		gic_init_chip(gic, NULL, name, false);
+	}
+
+	ret = gic_init_bases(gic, irq_start, handle);
+	if (ret)
+		kfree(name);
+
+	return ret;
 }
 
 void __init gic_init(unsigned int gic_nr, int irq_start,