KVM: arm64: vgic-its: Generalize use of vgic_get_irq_kref

Instead of sprinkling raw kref_get() calls everytime we cannot
do a normal vgic_get_irq(), use the existing vgic_get_irq_kref(),
which does the same thing and is paired with a vgic_put_irq().

vgic_get_irq_kref is moved to vgic.h in order to be easily shared.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

virt/kvm/arm/vgic/vgic-its.c

@@ -80,7 +80,7 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid)
 		 * call vgic_put_irq() on the returned pointer once it's
 		 * finished with the IRQ.
 		 */
-		kref_get(&irq->refcount);
+		vgic_get_irq_kref(irq);
 
 		goto out_unlock;
 	}

virt/kvm/arm/vgic/vgic.c

@@ -71,7 +71,7 @@ static struct vgic_irq *vgic_get_lpi(struct kvm *kvm, u32 intid)
 		 * This increases the refcount, the caller is expected to
 		 * call vgic_put_irq() later once it's finished with the IRQ.
 		 */
-		kref_get(&irq->refcount);
+		vgic_get_irq_kref(irq);
 		goto out_unlock;
 	}
 	irq = NULL;
@@ -106,14 +106,6 @@ struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
 	return NULL;
 }
 
-static void vgic_get_irq_kref(struct vgic_irq *irq)
-{
-	if (irq->intid < VGIC_MIN_LPI)
-		return;
-
-	kref_get(&irq->refcount);
-}
-
 /*
  * We can't do anything in here, because we lack the kvm pointer to
  * lock and remove the item from the lpi_list. So we keep this function

virt/kvm/arm/vgic/vgic.h

@@ -64,6 +64,14 @@ int vgic_v2_map_resources(struct kvm *kvm);
 int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address,
 			     enum vgic_type);
 
+static inline void vgic_get_irq_kref(struct vgic_irq *irq)
+{
+	if (irq->intid < VGIC_MIN_LPI)
+		return;
+
+	kref_get(&irq->refcount);
+}
+
 #ifdef CONFIG_KVM_ARM_VGIC_V3
 void vgic_v3_process_maintenance(struct kvm_vcpu *vcpu);
 void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu);