[PATCH 08/10] KVM: arm64: Use guard(spinlock) in psci.c

[Fuad Tabba]

Migrate manual spin_lock() and spin_unlock() calls managing
the vcpu->arch.mp_state_lock to use the guard(spinlock) macro.

This eliminates manual unlock calls on return paths and simplifies
error handling during PSCI calls by replacing unlock goto labels
with direct returns.

Change-Id: Iaf72da18b18aaec8edff91bc30379bed9dd04b2b
Signed-off-by: Fuad Tabba <tabba@xxxxxxxxxx>
---
 arch/arm64/kvm/psci.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index 3b5dbe9a0a0e..04801f8b596a 100644
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c
@@ -62,7 +62,6 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
 	struct vcpu_reset_state *reset_state;
 	struct kvm *kvm = source_vcpu->kvm;
 	struct kvm_vcpu *vcpu = NULL;
-	int ret = PSCI_RET_SUCCESS;
 	unsigned long cpu_id;
 
 	cpu_id = smccc_get_arg1(source_vcpu);
@@ -78,14 +77,13 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
 	if (!vcpu)
 		return PSCI_RET_INVALID_PARAMS;
 
-	spin_lock(&vcpu->arch.mp_state_lock);
+	guard(spinlock)(&vcpu->arch.mp_state_lock);
+
 	if (!kvm_arm_vcpu_stopped(vcpu)) {
 		if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1)
-			ret = PSCI_RET_ALREADY_ON;
+			return PSCI_RET_ALREADY_ON;
 		else
-			ret = PSCI_RET_INVALID_PARAMS;
-
-		goto out_unlock;
+			return PSCI_RET_INVALID_PARAMS;
 	}
 
 	reset_state = &vcpu->arch.reset_state;
@@ -113,9 +111,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
 	WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_RUNNABLE);
 	kvm_vcpu_wake_up(vcpu);
 
-out_unlock:
-	spin_unlock(&vcpu->arch.mp_state_lock);
-	return ret;
+	return PSCI_RET_SUCCESS;
 }
 
 static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
@@ -176,9 +172,8 @@ static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type, u64 flags)
 	 * re-initialized.
 	 */
 	kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
-		spin_lock(&tmp->arch.mp_state_lock);
-		WRITE_ONCE(tmp->arch.mp_state.mp_state, KVM_MP_STATE_STOPPED);
-		spin_unlock(&tmp->arch.mp_state_lock);
+		scoped_guard(spinlock, &tmp->arch.mp_state_lock)
+			WRITE_ONCE(tmp->arch.mp_state.mp_state, KVM_MP_STATE_STOPPED);
 	}
 	kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP);
 

-- 
2.53.0.851.ga537e3e6e9-goog