mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-10-06 00:39:48 +00:00
Code Issues Releases Wiki Activity

s390/pai_ext: replace atomic_t with refcount_t

Browse source 
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: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
This commit is contained in:
Thomas Richter 2023-04-27 10:33:31 +02:00 committed by Alexander Gordeev
parent ecc758cee6
commit 1f2597cd36
1 changed files with 13 additions and 10 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

23
arch/s390/kernel/perf_pai_ext.c
View file

@ -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;