diff options
Diffstat (limited to 'arch/s390/kernel/perf_pai_ext.c')
| -rw-r--r-- | arch/s390/kernel/perf_pai_ext.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/arch/s390/kernel/perf_pai_ext.c b/arch/s390/kernel/perf_pai_ext.c index fcea307d7529..c57c1a203256 100644 --- a/arch/s390/kernel/perf_pai_ext.c +++ b/arch/s390/kernel/perf_pai_ext.c @@ -50,7 +50,7 @@ struct paiext_map { struct pai_userdata *save; /* Area to store non-zero counters */ enum paievt_mode mode; /* Type of event */ unsigned int active_events; /* # of PAI Extension users */ - unsigned int refcnt; + refcount_t refcnt; struct perf_event *event; /* Perf event for sampling */ struct paiext_cb *paiext_cb; /* PAI extension control block area */ }; @@ -60,14 +60,14 @@ struct paiext_mapptr { }; static struct paiext_root { /* Anchor to per CPU data */ - int refcnt; /* Overall active events */ + refcount_t refcnt; /* Overall active events */ struct paiext_mapptr __percpu *mapptr; } paiext_root; /* Free per CPU data when the last event is removed. */ static void paiext_root_free(void) { - if (!--paiext_root.refcnt) { + if (refcount_dec_and_test(&paiext_root.refcnt)) { free_percpu(paiext_root.mapptr); paiext_root.mapptr = NULL; } @@ -80,17 +80,18 @@ static void paiext_root_free(void) */ static int paiext_root_alloc(void) { - if (++paiext_root.refcnt == 1) { + if (!refcount_inc_not_zero(&paiext_root.refcnt)) { /* The memory is already zeroed. */ paiext_root.mapptr = alloc_percpu(struct paiext_mapptr); if (!paiext_root.mapptr) { - /* Returing without refcnt adjustment is ok. The + /* Returning without refcnt adjustment is ok. The * error code is handled by paiext_alloc() which * decrements refcnt when an event can not be * created. */ return -ENOMEM; } + refcount_set(&paiext_root.refcnt, 1); } return 0; } @@ -122,7 +123,7 @@ static void paiext_event_destroy(struct perf_event *event) mutex_lock(&paiext_reserve_mutex); cpump->event = NULL; - if (!--cpump->refcnt) /* Last reference gone */ + if (refcount_dec_and_test(&cpump->refcnt)) /* Last reference gone */ paiext_free(mp); paiext_root_free(); mutex_unlock(&paiext_reserve_mutex); @@ -163,7 +164,7 @@ static int paiext_alloc(struct perf_event_attr *a, struct perf_event *event) rc = -ENOMEM; cpump = kzalloc(sizeof(*cpump), GFP_KERNEL); if (!cpump) - goto unlock; + goto undo; /* Allocate memory for counter area and counter extraction. * These are @@ -183,27 +184,28 @@ static int paiext_alloc(struct perf_event_attr *a, struct perf_event *event) GFP_KERNEL); if (!cpump->save || !cpump->area || !cpump->paiext_cb) { paiext_free(mp); - goto unlock; + goto undo; } + refcount_set(&cpump->refcnt, 1); cpump->mode = a->sample_period ? PAI_MODE_SAMPLING : PAI_MODE_COUNTING; } else { - /* Multiple invocation, check whats active. + /* Multiple invocation, check what is active. * Supported are multiple counter events or only one sampling * event concurrently at any one time. */ if (cpump->mode == PAI_MODE_SAMPLING || (cpump->mode == PAI_MODE_COUNTING && a->sample_period)) { rc = -EBUSY; - goto unlock; + goto undo; } + refcount_inc(&cpump->refcnt); } rc = 0; cpump->event = event; - ++cpump->refcnt; -unlock: +undo: if (rc) { /* Error in allocation of event, decrement anchor. Since * the event in not created, its destroy() function is never @@ -211,6 +213,7 @@ unlock: */ paiext_root_free(); } +unlock: mutex_unlock(&paiext_reserve_mutex); /* If rc is non-zero, no increment of counter/sampler was done. */ return rc; |