KVM: i8254: simplify atomics in kvm_pit_ack_irq

We already have a helper that does the same thing.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index ab531872757944c6beb8321b97b88e3c74be9afe..7d694ac7f4a4d193f3e1c0d2825ea4f73b1dd37c 100644 (file)
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -236,19 +236,9 @@ static void kvm_pit_ack_irq(struct kvm_irq_ack_notifier *kian)
 {
        struct kvm_kpit_state *ps = container_of(kian, struct kvm_kpit_state,
                                                 irq_ack_notifier);
-       int value;
 
        spin_lock(&ps->inject_lock);
-       value = atomic_dec_return(&ps->pending);
-       if (value < 0)
-               /* spurious acks can be generated if, for example, the
-                * PIC is being reset.  Handle it gracefully here
-                */
-               atomic_inc(&ps->pending);
-       else if (value > 0 && ps->reinject)
-               /* in this case, we had multiple outstanding pit interrupts
-                * that we needed to inject.  Reinject
-                */
+       if (atomic_dec_if_positive(&ps->pending) > 0 && ps->reinject)
                queue_kthread_work(&ps->pit->worker, &ps->pit->expired);
        ps->irq_ack = 1;
        spin_unlock(&ps->inject_lock);