irqchip/gic: Refactor SMP configuration

As we are about to change quite a lot of the SMP support code,
let's start by moving it around so that it minimizes the amount
of #ifdefery.
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

drivers/irqchip/irq-gic.c

@@ -325,28 +325,6 @@ static int gic_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu)
 	return 0;
 }
 
-#ifdef CONFIG_SMP
-static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
-			    bool force)
-{
-	void __iomem *reg = gic_dist_base(d) + GIC_DIST_TARGET + gic_irq(d);
-	unsigned int cpu;
-
-	if (!force)
-		cpu = cpumask_any_and(mask_val, cpu_online_mask);
-	else
-		cpu = cpumask_first(mask_val);
-
-	if (cpu >= NR_GIC_CPU_IF || cpu >= nr_cpu_ids)
-		return -EINVAL;
-
-	writeb_relaxed(gic_cpu_map[cpu], reg);
-	irq_data_update_effective_affinity(d, cpumask_of(cpu));
-
-	return IRQ_SET_MASK_OK_DONE;
-}
-#endif
-
 static void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)
 {
 	u32 irqstat, irqnr;
@@ -795,6 +773,26 @@ static int gic_pm_init(struct gic_chip_data *gic)
 #endif
 
 #ifdef CONFIG_SMP
+static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
+			    bool force)
+{
+	void __iomem *reg = gic_dist_base(d) + GIC_DIST_TARGET + gic_irq(d);
+	unsigned int cpu;
+
+	if (!force)
+		cpu = cpumask_any_and(mask_val, cpu_online_mask);
+	else
+		cpu = cpumask_first(mask_val);
+
+	if (cpu >= NR_GIC_CPU_IF || cpu >= nr_cpu_ids)
+		return -EINVAL;
+
+	writeb_relaxed(gic_cpu_map[cpu], reg);
+	irq_data_update_effective_affinity(d, cpumask_of(cpu));
+
+	return IRQ_SET_MASK_OK_DONE;
+}
+
 static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
 {
 	int cpu;
@@ -824,6 +822,23 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
 
 	gic_unlock_irqrestore(flags);
 }
+
+static int gic_starting_cpu(unsigned int cpu)
+{
+	gic_cpu_init(&gic_data[0]);
+	return 0;
+}
+
+static __init void gic_smp_init(void)
+{
+	set_smp_cross_call(gic_raise_softirq);
+	cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_GIC_STARTING,
+				  "irqchip/arm/gic:starting",
+				  gic_starting_cpu, NULL);
+}
+#else
+#define gic_smp_init()		do { } while(0)
+#define gic_set_affinity	NULL
 #endif
 
 #ifdef CONFIG_BL_SWITCHER
@@ -1027,12 +1042,6 @@ static int gic_irq_domain_translate(struct irq_domain *d,
 	return -EINVAL;
 }
 
-static int gic_starting_cpu(unsigned int cpu)
-{
-	gic_cpu_init(&gic_data[0]);
-	return 0;
-}
-
 static int gic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
 				unsigned int nr_irqs, void *arg)
 {
@@ -1079,10 +1088,8 @@ static void gic_init_chip(struct gic_chip_data *gic, struct device *dev,
 		gic->chip.irq_set_vcpu_affinity = gic_irq_set_vcpu_affinity;
 	}
 
-#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,
@@ -1199,12 +1206,7 @@ static int __init __gic_init_bases(struct gic_chip_data *gic,
 		 */
 		for (i = 0; i < NR_GIC_CPU_IF; i++)
 			gic_cpu_map[i] = 0xff;
-#ifdef CONFIG_SMP
-		set_smp_cross_call(gic_raise_softirq);
-#endif
-		cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_GIC_STARTING,
-					  "irqchip/arm/gic:starting",
-					  gic_starting_cpu, NULL);
+
 		set_handle_irq(gic_handle_irq);
 		if (static_branch_likely(&supports_deactivate_key))
 			pr_info("GIC: Using split EOI/Deactivate mode\n");
@@ -1221,6 +1223,8 @@ static int __init __gic_init_bases(struct gic_chip_data *gic,
 	ret = gic_init_bases(gic, handle);
 	if (ret)
 		kfree(name);
+	else if (gic == &gic_data[0])
+		gic_smp_init();
 
 	return ret;
 }