[PATCH v1] KVM: s390: use switch vs jump table in interrupt.c

David Hildenbrand
2018-02-06T14:17:43Z

Just like for the interception handlers, let's also use a switch-case
in our interrupt delivery code.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/kvm/interrupt.c | 84 ++++++++++++++++++++++++++++-------------------
1 file changed, 50 insertions(+), 34 deletions(-)

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index aabf46f5f883..3ea9cfa31b16 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -187,12 +187,6 @@ static int cpu_timer_irq_pending(struct kvm_vcpu *vcpu)
return kvm_s390_get_cpu_timer(vcpu) >> 63;
}

-static inline int is_ioirq(unsigned long irq_type)
-{
- return ((irq_type >= IRQ_PEND_IO_ISC_7) &&
- (irq_type <= IRQ_PEND_IO_ISC_0));
-}
-
static uint64_t isc_to_isc_bits(int isc)
{
return (0x80 >> isc) << 24;
@@ -1011,24 +1005,6 @@ static int __must_check __deliver_io(struct kvm_vcpu *vcpu,
return rc;
}

-typedef int (*deliver_irq_t)(struct kvm_vcpu *vcpu);
-
-static const deliver_irq_t deliver_irq_funcs[] = {
- [IRQ_PEND_MCHK_EX] = __deliver_machine_check,
- [IRQ_PEND_MCHK_REP] = __deliver_machine_check,
- [IRQ_PEND_PROG] = __deliver_prog,
- [IRQ_PEND_EXT_EMERGENCY] = __deliver_emergency_signal,
- [IRQ_PEND_EXT_EXTERNAL] = __deliver_external_call,
- [IRQ_PEND_EXT_CLOCK_COMP] = __deliver_ckc,
- [IRQ_PEND_EXT_CPU_TIMER] = __deliver_cpu_timer,
- [IRQ_PEND_RESTART] = __deliver_restart,
- [IRQ_PEND_SET_PREFIX] = __deliver_set_prefix,
- [IRQ_PEND_PFAULT_INIT] = __deliver_pfault_init,
- [IRQ_PEND_EXT_SERVICE] = __deliver_service,
- [IRQ_PEND_PFAULT_DONE] = __deliver_pfault_done,
- [IRQ_PEND_VIRTIO] = __deliver_virtio,
-};
-
/* Check whether an external call is pending (deliverable or not) */
int kvm_s390_ext_call_pending(struct kvm_vcpu *vcpu)
{
@@ -1192,7 +1168,6 @@ void kvm_s390_clear_local_irqs(struct kvm_vcpu *vcpu)
int __must_check kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu)
{
struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
- deliver_irq_t func;
int rc = 0;
unsigned long irq_type;
unsigned long irqs;
@@ -1212,16 +1187,57 @@ int __must_check kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu)
while ((irqs = deliverable_irqs(vcpu)) && !rc) {
/* bits are in the reverse order of interrupt priority */
irq_type = find_last_bit(&irqs, IRQ_PEND_COUNT);
- if (is_ioirq(irq_type)) {
+ switch (irq_type) {
+ case IRQ_PEND_IO_ISC_0:
+ case IRQ_PEND_IO_ISC_1:
+ case IRQ_PEND_IO_ISC_2:
+ case IRQ_PEND_IO_ISC_3:
+ case IRQ_PEND_IO_ISC_4:
+ case IRQ_PEND_IO_ISC_5:
+ case IRQ_PEND_IO_ISC_6:
+ case IRQ_PEND_IO_ISC_7:
rc = __deliver_io(vcpu, irq_type);
- } else {
- func = deliver_irq_funcs[irq_type];
- if (!func) {
- WARN_ON_ONCE(func == NULL);
- clear_bit(irq_type, &li->pending_irqs);
- continue;
- }
- rc = func(vcpu);
+ break;
+ case IRQ_PEND_MCHK_EX:
+ case IRQ_PEND_MCHK_REP:
+ rc = __deliver_machine_check(vcpu);
+ break;
+ case IRQ_PEND_PROG:
+ rc = __deliver_prog(vcpu);
+ break;
+ case IRQ_PEND_EXT_EMERGENCY:
+ rc = __deliver_emergency_signal(vcpu);
+ break;
+ case IRQ_PEND_EXT_EXTERNAL:
+ rc = __deliver_external_call(vcpu);
+ break;
+ case IRQ_PEND_EXT_CLOCK_COMP:
+ rc = __deliver_ckc(vcpu);
+ break;
+ case IRQ_PEND_EXT_CPU_TIMER:
+ rc = __deliver_cpu_timer(vcpu);
+ break;
+ case IRQ_PEND_RESTART:
+ rc = __deliver_restart(vcpu);
+ break;
+ case IRQ_PEND_SET_PREFIX:
+ rc = __deliver_set_prefix(vcpu);
+ break;
+ case IRQ_PEND_PFAULT_INIT:
+ rc = __deliver_pfault_init(vcpu);
+ break;
+ case IRQ_PEND_EXT_SERVICE:
+ rc = __deliver_service(vcpu);
+ break;
+ case IRQ_PEND_PFAULT_DONE:
+ rc = __deliver_pfault_done(vcpu);
+ break;
+ case IRQ_PEND_VIRTIO:
+ rc = __deliver_virtio(vcpu);
+ break;
+ default:
+ WARN_ONCE(1, "Unknown pending irq type %ld", irq_type);
+ clear_bit(irq_type, &li->pending_irqs);
}
}

--
2.14.3