KVM: ARM: vgic: introduce vgic_ops and LR manipulation primitives

In order to split the various register manipulation from the main vgic
code, introduce a vgic_ops structure, and start by abstracting the
LR manipulation code with a couple of accessors.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index f738e5a..17bbe51 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -68,6 +68,24 @@
 	u32 shared[VGIC_NR_SHARED_IRQS  / 4];
 };
 
+struct kvm_vcpu;
+
+#define LR_STATE_PENDING	(1 << 0)
+#define LR_STATE_ACTIVE		(1 << 1)
+#define LR_STATE_MASK		(3 << 0)
+#define LR_EOI_INT		(1 << 2)
+
+struct vgic_lr {
+	u16	irq;
+	u8	source;
+	u8	state;
+};
+
+struct vgic_ops {
+	struct vgic_lr	(*get_lr)(const struct kvm_vcpu *, int);
+	void	(*set_lr)(struct kvm_vcpu *, int, struct vgic_lr);
+};
+
 struct vgic_dist {
 #ifdef CONFIG_KVM_ARM_VGIC
 	spinlock_t		lock;