KVM: arm64: Use guard() to cleanup usage of arm_pmus_lock

Get rid of some goto label patterns by using guard() to drop the
arm_pmus_lock when returning from a function.

Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250305202641.428114-8-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index 120f48136a0f3091402c8c15c95e0863c9c23a98..fee3d0003d54480ec1c1e83f0dcc5f99caf1510d 100644 (file)
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -790,26 +790,23 @@ void kvm_host_pmu_init(struct arm_pmu *pmu)
        if (!pmuv3_implemented(kvm_arm_pmu_get_pmuver_limit()))
                return;
 
-       mutex_lock(&arm_pmus_lock);
+       guard(mutex)(&arm_pmus_lock);
 
        entry = kmalloc(sizeof(*entry), GFP_KERNEL);
        if (!entry)
-               goto out_unlock;
+               return;
 
        entry->arm_pmu = pmu;
        list_add_tail(&entry->entry, &arm_pmus);
-
-out_unlock:
-       mutex_unlock(&arm_pmus_lock);
 }
 
 static struct arm_pmu *kvm_pmu_probe_armpmu(void)
 {
-       struct arm_pmu *tmp, *pmu = NULL;
        struct arm_pmu_entry *entry;
+       struct arm_pmu *pmu;
        int cpu;
 
-       mutex_lock(&arm_pmus_lock);
+       guard(mutex)(&arm_pmus_lock);
 
        /*
         * It is safe to use a stale cpu to iterate the list of PMUs so long as
@@ -830,17 +827,13 @@ static struct arm_pmu *kvm_pmu_probe_armpmu(void)
         */
        cpu = raw_smp_processor_id();
        list_for_each_entry(entry, &arm_pmus, entry) {
-               tmp = entry->arm_pmu;
+               pmu = entry->arm_pmu;
 
-               if (cpumask_test_cpu(cpu, &tmp->supported_cpus)) {
-                       pmu = tmp;
-                       break;
-               }
+               if (cpumask_test_cpu(cpu, &pmu->supported_cpus))
+                       return pmu;
        }
 
-       mutex_unlock(&arm_pmus_lock);
-
-       return pmu;
+       return NULL;
 }
 
 static u64 __compute_pmceid(struct arm_pmu *pmu, bool pmceid1)