s390/pai_crypto: Consolidate PAI crypto allocation and cleanup paths

Introduce paicrypt_free() to centralize memory release for per-CPU
maps and remove duplicated free logic. Replace paicrypt_busy() with
paicrypt_alloc_cpu() returning int error codes instead of ERR_PTR,
and adjust callers accordingly. System-wide allocation now uses
paicrypt_alloc() with consistent error handling. Memory allocation
and free management is now identical to PMU pai_ext.

Reference counting and root anchor management remain unchanged.
Debug output in the destroy path is dropped.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Tested-by: Jan Polensky <japo@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

diff --git a/arch/s390/kernel/perf_pai_crypto.c b/arch/s390/kernel/perf_pai_crypto.c
index f373a1009c456e80ffefcfc8c10754ac166d826a..45604ff9bc9927aa37adbd35820f2f18866ba50b 100644 (file)
--- a/arch/s390/kernel/perf_pai_crypto.c
+++ b/arch/s390/kernel/perf_pai_crypto.c
@@ -80,6 +80,15 @@ static int paicrypt_root_alloc(void)
 /* Release the PMU if event is the last perf event */
 static DEFINE_MUTEX(pai_reserve_mutex);
 
+/* Free all memory allocated for event counting/sampling setup */
+static void paicrypt_free(struct paicrypt_mapptr *mp)
+{
+       free_page((unsigned long)mp->mapptr->page);
+       kvfree(mp->mapptr->save);
+       kfree(mp->mapptr);
+       mp->mapptr = NULL;
+}
+
 /* Adjust usage counters and remove allocated memory when all users are
  * gone.
  */
@@ -93,15 +102,8 @@ static void paicrypt_event_destroy_cpu(struct perf_event *event, int cpu)
                            "refcnt %u\n", __func__, event->attr.config,
                            event->cpu, cpump->active_events,
                            refcount_read(&cpump->refcnt));
-       if (refcount_dec_and_test(&cpump->refcnt)) {
-               debug_sprintf_event(cfm_dbg, 4, "%s page %#lx save %p\n",
-                                   __func__, (unsigned long)cpump->page,
-                                   cpump->save);
-               free_page((unsigned long)cpump->page);
-               kvfree(cpump->save);
-               kfree(cpump);
-               mp->mapptr = NULL;
-       }
+       if (refcount_dec_and_test(&cpump->refcnt))
+               paicrypt_free(mp);
        paicrypt_root_free();
        mutex_unlock(&pai_reserve_mutex);
 }
@@ -175,14 +177,13 @@ static u64 paicrypt_getall(struct perf_event *event)
  *
  * Allocate the memory for the event.
  */
-static struct paicrypt_map *paicrypt_busy(struct perf_event *event, int cpu)
+static int paicrypt_alloc_cpu(struct perf_event *event, int cpu)
 {
        struct paicrypt_map *cpump = NULL;
        struct paicrypt_mapptr *mp;
        int rc;
 
        mutex_lock(&pai_reserve_mutex);
-
        /* Allocate root node */
        rc = paicrypt_root_alloc();
        if (rc)
@@ -192,58 +193,44 @@ static struct paicrypt_map *paicrypt_busy(struct perf_event *event, int cpu)
        mp = per_cpu_ptr(paicrypt_root.mapptr, cpu);
        cpump = mp->mapptr;
        if (!cpump) {                   /* Paicrypt_map allocated? */
+               rc = -ENOMEM;
                cpump = kzalloc(sizeof(*cpump), GFP_KERNEL);
-               if (!cpump) {
-                       rc = -ENOMEM;
-                       goto free_root;
+               if (!cpump)
+                       goto undo;
+               /* Allocate memory for counter page and counter extraction.
+                * Only the first counting event has to allocate a page.
+                */
+               mp->mapptr = cpump;
+               cpump->page = (unsigned long *)get_zeroed_page(GFP_KERNEL);
+               cpump->save = kvmalloc_array(paicrypt_cnt + 1,
+                                            sizeof(struct pai_userdata),
+                                            GFP_KERNEL);
+               if (!cpump->page || !cpump->save) {
+                       paicrypt_free(mp);
+                       goto undo;
                }
                INIT_LIST_HEAD(&cpump->syswide_list);
-       }
-
-       /* Allocate memory for counter page and counter extraction.
-        * Only the first counting event has to allocate a page.
-        */
-       if (cpump->page) {
+               refcount_set(&cpump->refcnt, 1);
+               rc = 0;
+       } else {
                refcount_inc(&cpump->refcnt);
-               goto unlock;
        }
 
-       rc = -ENOMEM;
-       cpump->page = (unsigned long *)get_zeroed_page(GFP_KERNEL);
-       if (!cpump->page)
-               goto free_paicrypt_map;
-       cpump->save = kvmalloc_array(paicrypt_cnt + 1,
-                                    sizeof(struct pai_userdata), GFP_KERNEL);
-       if (!cpump->save) {
-               free_page((unsigned long)cpump->page);
-               cpump->page = NULL;
-               goto free_paicrypt_map;
+undo:
+       if (rc) {
+               /* Error in allocation of event, decrement anchor. Since
+                * the event in not created, its destroy() function is never
+                * invoked. Adjust the reference counter for the anchor.
+                */
+               paicrypt_root_free();
        }
-
-       /* Set mode and reference count */
-       rc = 0;
-       refcount_set(&cpump->refcnt, 1);
-       mp->mapptr = cpump;
-       debug_sprintf_event(cfm_dbg, 5, "%s users %d refcnt %u page %#lx "
-                           "save %p rc %d\n", __func__, cpump->active_events,
-                           refcount_read(&cpump->refcnt),
-                           (unsigned long)cpump->page, cpump->save, rc);
-       goto unlock;
-
-free_paicrypt_map:
-       /* Undo memory allocation */
-       kfree(cpump);
-       mp->mapptr = NULL;
-free_root:
-       paicrypt_root_free();
 unlock:
        mutex_unlock(&pai_reserve_mutex);
-       return rc ? ERR_PTR(rc) : cpump;
+       return rc;
 }
 
-static int paicrypt_event_init_all(struct perf_event *event)
+static int paicrypt_alloc(struct perf_event *event)
 {
-       struct paicrypt_map *cpump;
        struct cpumask *maskptr;
        int cpu, rc = -ENOMEM;
 
@@ -252,12 +239,11 @@ static int paicrypt_event_init_all(struct perf_event *event)
                goto out;
 
        for_each_online_cpu(cpu) {
-               cpump = paicrypt_busy(event, cpu);
-               if (IS_ERR(cpump)) {
+               rc = paicrypt_alloc_cpu(event, cpu);
+               if (rc) {
                        for_each_cpu(cpu, maskptr)
                                paicrypt_event_destroy_cpu(event, cpu);
                        kfree(maskptr);
-                       rc = PTR_ERR(cpump);
                        goto out;
                }
                cpumask_set_cpu(cpu, maskptr);
@@ -279,7 +265,6 @@ out:
 static int paicrypt_event_init(struct perf_event *event)
 {
        struct perf_event_attr *a = &event->attr;
-       struct paicrypt_map *cpump;
        int rc = 0;
 
        /* PAI crypto PMU registered as PERF_TYPE_RAW, check event type */
@@ -301,13 +286,10 @@ static int paicrypt_event_init(struct perf_event *event)
                }
        }
 
-       if (event->cpu >= 0) {
-               cpump = paicrypt_busy(event, event->cpu);
-               if (IS_ERR(cpump))
-                       rc = PTR_ERR(cpump);
-       } else {
-               rc = paicrypt_event_init_all(event);
-       }
+       if (event->cpu >= 0)
+               rc = paicrypt_alloc_cpu(event, event->cpu);
+       else
+               rc = paicrypt_alloc(event);
        if (rc) {
                free_page(PAI_SAVE_AREA(event));
                goto out;