Commit 1f2597cd authored by Thomas Richter's avatar Thomas Richter Committed by Alexander Gordeev
Browse files

s390/pai_ext: replace atomic_t with refcount_t 



The s390 PMU of PAI extension 1 NNPA counters uses atomic_t for
reference counting. Replace this with the proper data type
refcount_t.

No functional change.

Signed-off-by: default avatarThomas Richter <tmricht@linux.ibm.com>
Acked-by: default avatarSumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
parent ecc758ce

arch/s390/kernel/perf_pai_ext.c

+13 −10
Original line number Diff line number Diff line
@@ -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;

	}
@@ -80,7 +80,7 @@ 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) {
@@ -91,6 +91,7 @@ static int paiext_root_alloc(void) 
			 */

			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
@@ -183,8 +184,9 @@ 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 {
@@ -195,15 +197,15 @@ static int paiext_alloc(struct perf_event_attr *a, struct perf_event *event) 
		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 @@ static int paiext_alloc(struct perf_event_attr *a, struct perf_event *event) 
		 */

		paiext_root_free();

	}

unlock:

	mutex_unlock(&paiext_reserve_mutex);

	/* If rc is non-zero, no increment of counter/sampler was done. */

	return rc;