Commit 58862938 authored Nov 20, 2017 by Michael Mueller Committed by Christian Borntraeger Jan 16, 2018

KVM: s390: drop use of spin lock in __floating_irq_kick



It is not required to take to a lock to protect access to the cpuflags
of the local interrupt structure of a vcpu as the performed operation
is an atomic_or.

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>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

parent 2f8311c9

arch/s390/kvm/interrupt.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -1569,7 +1569,6 @@ static void __floating_irq_kick(struct kvm *kvm, u64 type)

		/* make the VCPU drop out of the SIE, or wake it up if sleeping */
		li = &dst_vcpu->arch.local_int;
		spin_lock(&li->lock);
		switch (type) {
		case KVM_S390_MCHK:
		atomic_or(CPUSTAT_STOP_INT, li->cpuflags);
		@@ -1581,7 +1580,6 @@ static void __floating_irq_kick(struct kvm *kvm, u64 type)
		atomic_or(CPUSTAT_EXT_INT, li->cpuflags);
		break;
		}
		spin_unlock(&li->lock);
		kvm_s390_vcpu_wakeup(dst_vcpu);
		}

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