KVM: ARM: vgic: abstract access to the ELRSR bitmap

Move the GICH_ELRSR access to its own functions, and add them to
the vgic_ops structure.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

include/kvm/arm_vgic.h

@@ -84,6 +84,8 @@ struct vgic_lr {
 struct vgic_ops {
 	struct vgic_lr	(*get_lr)(const struct kvm_vcpu *, int);
 	void	(*set_lr)(struct kvm_vcpu *, int, struct vgic_lr);
+	void	(*sync_lr_elrsr)(struct kvm_vcpu *, int, struct vgic_lr);
+	u64	(*get_elrsr)(const struct kvm_vcpu *vcpu);
 };
 
 struct vgic_dist {

virt/kvm/arm/vgic.c

@@ -1015,9 +1015,32 @@ static void vgic_v2_set_lr(struct kvm_vcpu *vcpu, int lr,
 	vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr] = lr_val;
 }
 
+static void vgic_v2_sync_lr_elrsr(struct kvm_vcpu *vcpu, int lr,
+				  struct vgic_lr lr_desc)
+{
+	if (!(lr_desc.state & LR_STATE_MASK))
+		set_bit(lr, (unsigned long *)vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr);
+}
+
+static u64 vgic_v2_get_elrsr(const struct kvm_vcpu *vcpu)
+{
+	u64 val;
+
+#if BITS_PER_LONG == 64
+	val  = vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr[1];
+	val <<= 32;
+	val |= vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr[0];
+#else
+	val = *(u64 *)vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr;
+#endif
+	return val;
+}
+
 static const struct vgic_ops vgic_ops = {
 	.get_lr			= vgic_v2_get_lr,
 	.set_lr			= vgic_v2_set_lr,
+	.sync_lr_elrsr		= vgic_v2_sync_lr_elrsr,
+	.get_elrsr		= vgic_v2_get_elrsr,
 };
 
 static struct vgic_lr vgic_get_lr(const struct kvm_vcpu *vcpu, int lr)
@@ -1031,6 +1054,17 @@ static void vgic_set_lr(struct kvm_vcpu *vcpu, int lr,
 	vgic_ops.set_lr(vcpu, lr, vlr);
 }
 
+static void vgic_sync_lr_elrsr(struct kvm_vcpu *vcpu, int lr,
+			       struct vgic_lr vlr)
+{
+	vgic_ops.sync_lr_elrsr(vcpu, lr, vlr);
+}
+
+static inline u64 vgic_get_elrsr(struct kvm_vcpu *vcpu)
+{
+	return vgic_ops.get_elrsr(vcpu);
+}
+
 static void vgic_retire_lr(int lr_nr, int irq, struct kvm_vcpu *vcpu)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
@@ -1260,7 +1294,7 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu)
 			 * Despite being EOIed, the LR may not have
 			 * been marked as empty.
 			 */
-			set_bit(lr, (unsigned long *)vgic_cpu->vgic_v2.vgic_elrsr);
+			vgic_sync_lr_elrsr(vcpu, lr, vlr);
 		}
 	}
 
@@ -1278,14 +1312,17 @@ static void __kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+	u64 elrsr;
+	unsigned long *elrsr_ptr;
 	int lr, pending;
 	bool level_pending;
 
 	level_pending = vgic_process_maintenance(vcpu);
+	elrsr = vgic_get_elrsr(vcpu);
+	elrsr_ptr = (unsigned long *)&elrsr;
 
 	/* Clear mappings for empty LRs */
-	for_each_set_bit(lr, (unsigned long *)vgic_cpu->vgic_v2.vgic_elrsr,
-			 vgic_cpu->nr_lr) {
+	for_each_set_bit(lr, elrsr_ptr, vgic_cpu->nr_lr) {
 		struct vgic_lr vlr;
 
 		if (!test_and_clear_bit(lr, vgic_cpu->lr_used))
@@ -1298,8 +1335,7 @@ static void __kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
 	}
 
 	/* Check if we still have something up our sleeve... */
-	pending = find_first_zero_bit((unsigned long *)vgic_cpu->vgic_v2.vgic_elrsr,
-				      vgic_cpu->nr_lr);
+	pending = find_first_zero_bit(elrsr_ptr, vgic_cpu->nr_lr);
 	if (level_pending || pending < vgic_cpu->nr_lr)
 		set_bit(vcpu->vcpu_id, &dist->irq_pending_on_cpu);
 }