KVM: arm64: timer: Refactor IRQ configuration

As we are about to add some more things to the timer IRQ
configuration, move this code out of the main timer init code
into its own set of functions.

No functional changes.
Signed-off-by: Marc Zyngier <maz@kernel.org>

arch/arm64/kvm/arch_timer.c

@@ -973,6 +973,35 @@ static int kvm_timer_dying_cpu(unsigned int cpu)
 	return 0;
 }
 
+static void kvm_irq_fixup_flags(unsigned int virq, u32 *flags)
+{
+	*flags = irq_get_trigger_type(virq);
+	if (*flags != IRQF_TRIGGER_HIGH && *flags != IRQF_TRIGGER_LOW) {
+		kvm_err("Invalid trigger for timer IRQ%d, assuming level low\n",
+			virq);
+		*flags = IRQF_TRIGGER_LOW;
+	}
+}
+
+static int kvm_irq_init(struct arch_timer_kvm_info *info)
+{
+	if (info->virtual_irq <= 0) {
+		kvm_err("kvm_arch_timer: invalid virtual timer IRQ: %d\n",
+			info->virtual_irq);
+		return -ENODEV;
+	}
+
+	host_vtimer_irq = info->virtual_irq;
+	kvm_irq_fixup_flags(host_vtimer_irq, &host_vtimer_irq_flags);
+
+	if (info->physical_irq > 0) {
+		host_ptimer_irq = info->physical_irq;
+		kvm_irq_fixup_flags(host_ptimer_irq, &host_ptimer_irq_flags);
+	}
+
+	return 0;
+}
+
 int kvm_timer_hyp_init(bool has_gic)
 {
 	struct arch_timer_kvm_info *info;
@@ -986,22 +1015,11 @@ int kvm_timer_hyp_init(bool has_gic)
 		return -ENODEV;
 	}
 
-	/* First, do the virtual EL1 timer irq */
-
-	if (info->virtual_irq <= 0) {
-		kvm_err("kvm_arch_timer: invalid virtual timer IRQ: %d\n",
-			info->virtual_irq);
-		return -ENODEV;
-	}
-	host_vtimer_irq = info->virtual_irq;
+	err = kvm_irq_init(info);
+	if (err)
+		return err;
 
-	host_vtimer_irq_flags = irq_get_trigger_type(host_vtimer_irq);
-	if (host_vtimer_irq_flags != IRQF_TRIGGER_HIGH &&
-	    host_vtimer_irq_flags != IRQF_TRIGGER_LOW) {
-		kvm_err("Invalid trigger for vtimer IRQ%d, assuming level low\n",
-			host_vtimer_irq);
-		host_vtimer_irq_flags = IRQF_TRIGGER_LOW;
-	}
+	/* First, do the virtual EL1 timer irq */
 
 	err = request_percpu_irq(host_vtimer_irq, kvm_arch_timer_handler,
 				 "kvm guest vtimer", kvm_get_running_vcpus());
@@ -1027,15 +1045,6 @@ int kvm_timer_hyp_init(bool has_gic)
 	/* Now let's do the physical EL1 timer irq */
 
 	if (info->physical_irq > 0) {
-		host_ptimer_irq = info->physical_irq;
-		host_ptimer_irq_flags = irq_get_trigger_type(host_ptimer_irq);
-		if (host_ptimer_irq_flags != IRQF_TRIGGER_HIGH &&
-		    host_ptimer_irq_flags != IRQF_TRIGGER_LOW) {
-			kvm_err("Invalid trigger for ptimer IRQ%d, assuming level low\n",
-				host_ptimer_irq);
-			host_ptimer_irq_flags = IRQF_TRIGGER_LOW;
-		}
-
 		err = request_percpu_irq(host_ptimer_irq, kvm_arch_timer_handler,
 					 "kvm guest ptimer", kvm_get_running_vcpus());
 		if (err) {