[PATCH 2/2] s390/pai: Move locking to event init and delete

[Thomas Richter <tmricht@linux.ibm.com>]

Move mutex locking from per CPU allocation to event allocation.
No functional change.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
---
 arch/s390/kernel/perf_pai.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/s390/kernel/perf_pai.c b/arch/s390/kernel/perf_pai.c
index 7c13f5586c79..03c5bda53ccc 100644
--- a/arch/s390/kernel/perf_pai.c
+++ b/arch/s390/kernel/perf_pai.c
@@ -145,14 +145,12 @@ static void pai_event_destroy_cpu(int idx, int cpu)
 	struct pai_mapptr *mp = per_cpu_ptr(pai_root[idx].mapptr, cpu);
 	struct pai_map *cpump = mp->mapptr;
 
-	mutex_lock(&pai_reserve_mutex);
 	debug_sprintf_event(paidbg, 5, "%s users %d refcnt %u\n",
 			    __func__, cpump->active_events,
 			    refcount_read(&cpump->refcnt));
 	if (refcount_dec_and_test(&cpump->refcnt))
 		pai_free(mp);
 	pai_root_free(idx);
-	mutex_unlock(&pai_reserve_mutex);
 }
 
 static void pai_event_destroy(struct perf_event *event)
@@ -160,6 +158,7 @@ static void pai_event_destroy(struct perf_event *event)
 	int cpu = 0, idx = PAI_PMU_IDX(event);
 
 	free_page(PAI_SAVE_AREA(event));
+	mutex_lock(&pai_reserve_mutex);
 	if (event->cpu == -1) {
 		struct cpumask *mask = PAI_CPU_MASK(event);
 
@@ -169,6 +168,7 @@ static void pai_event_destroy(struct perf_event *event)
 	} else {
 		pai_event_destroy_cpu(idx, event->cpu);
 	}
+	mutex_unlock(&pai_reserve_mutex);
 }
 
 static void paicrypt_event_destroy(struct perf_event *event)
@@ -246,11 +246,10 @@ static int pai_alloc_cpu(int idx, int cpu)
 	struct pai_mapptr *mp;
 	int rc;
 
-	mutex_lock(&pai_reserve_mutex);
 	/* Allocate root node */
 	rc = pai_root_alloc(idx);
 	if (rc)
-		goto unlock;
+		goto out;
 
 	/* Allocate node for this event */
 	mp = per_cpu_ptr(pai_root[idx].mapptr, cpu);
@@ -308,8 +307,7 @@ static int pai_alloc_cpu(int idx, int cpu)
 		 */
 		pai_root_free(idx);
 	}
-unlock:
-	mutex_unlock(&pai_reserve_mutex);
+out:
 	/* If rc is non-zero, no increment of counter/sampler was done. */
 	return rc;
 }
@@ -390,10 +388,12 @@ static int pai_event_init(struct perf_event *event, int idx)
 		}
 	}
 
+	mutex_lock(&pai_reserve_mutex);
 	if (event->cpu >= 0)
 		rc = pai_alloc_cpu(idx, event->cpu);
 	else
 		rc = pai_alloc(event);
+	mutex_unlock(&pai_reserve_mutex);
 	if (rc) {
 		free_page(PAI_SAVE_AREA(event));
 		goto out;
-- 
2.55.0