KVM: s390: abstract adapter interruption word generation from ISC

The function isc_to_int_word() allows the generation of interruption
words for adapter interrupts.
Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

arch/s390/kvm/interrupt.c

@@ -198,6 +198,11 @@ static uint64_t isc_to_isc_bits(int isc)
 	return (0x80 >> isc) << 24;
 }
 
+static inline u32 isc_to_int_word(u8 isc)
+{
+	return ((u32)isc << 27) | 0x80000000;
+}
+
 static inline u8 int_word_to_isc(u32 int_word)
 {
 	return (int_word & 0x38000000) >> 27;
@@ -992,7 +997,7 @@ static int __must_check __deliver_io(struct kvm_vcpu *vcpu,
 		 */
 		VCPU_EVENT(vcpu, 4, "%s isc %u", "deliver: I/O (AI/gisa)", isc);
 		memset(&io, 0, sizeof(io));
-		io.io_int_word = (isc << 27) | 0x80000000;
+		io.io_int_word = isc_to_int_word(isc);
 		vcpu->stat.deliver_io_int++;
 		trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id,
 			KVM_S390_INT_IO(1, 0, 0, 0),
@@ -2299,7 +2304,7 @@ static int kvm_s390_inject_airq(struct kvm *kvm,
 	struct kvm_s390_interrupt s390int = {
 		.type = KVM_S390_INT_IO(1, 0, 0, 0),
 		.parm = 0,
-		.parm64 = (adapter->isc << 27) | 0x80000000,
+		.parm64 = isc_to_int_word(adapter->isc),
 	};
 	int ret = 0;