Merging upstream version 6.9.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 54 insertions, 27 deletions

diff --git a/arch/s390/kernel/perf_pai_crypto.c b/arch/s390/kernel/perf_pai_crypto.c
index 335e3f5d71..4ad472d130 100644
--- a/arch/s390/kernel/perf_pai_crypto.c
+++ b/arch/s390/kernel/perf_pai_crypto.c
@@ -97,6 +97,7 @@ static void paicrypt_event_destroy(struct perf_event *event)
 			    event->attr.config, event->cpu,
 			    cpump->active_events, cpump->mode,
 			    refcount_read(&cpump->refcnt));
+	free_page(PAI_SAVE_AREA(event));
 	if (refcount_dec_and_test(&cpump->refcnt)) {
 		debug_sprintf_event(cfm_dbg, 4, "%s page %#lx save %p\n",
 				    __func__, (unsigned long)cpump->page,
@@ -259,6 +260,7 @@ 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 */
 	if (a->type != PERF_TYPE_RAW && event->pmu->type != a->type)
@@ -273,10 +275,21 @@ static int paicrypt_event_init(struct perf_event *event)
 	/* Allow only CRYPTO_ALL for sampling. */
 	if (a->sample_period && a->config != PAI_CRYPTO_BASE)
 		return -EINVAL;
+	/* Get a page to store last counter values for sampling */
+	if (a->sample_period) {
+		PAI_SAVE_AREA(event) = get_zeroed_page(GFP_KERNEL);
+		if (!PAI_SAVE_AREA(event)) {
+			rc = -ENOMEM;
+			goto out;
+		}
+	}
 
 	cpump = paicrypt_busy(event);
-	if (IS_ERR(cpump))
-		return PTR_ERR(cpump);
+	if (IS_ERR(cpump)) {
+		free_page(PAI_SAVE_AREA(event));
+		rc = PTR_ERR(cpump);
+		goto out;
+	}
 
 	event->destroy = paicrypt_event_destroy;
 
@@ -292,7 +305,8 @@ static int paicrypt_event_init(struct perf_event *event)
 	}
 
 	static_branch_inc(&pai_key);
-	return 0;
+out:
+	return rc;
 }
 
 static void paicrypt_read(struct perf_event *event)
@@ -309,20 +323,15 @@ static void paicrypt_read(struct perf_event *event)
 
 static void paicrypt_start(struct perf_event *event, int flags)
 {
+	struct paicrypt_mapptr *mp = this_cpu_ptr(paicrypt_root.mapptr);
+	struct paicrypt_map *cpump = mp->mapptr;
 	u64 sum;
 
-	/* Event initialization sets last_tag to 0. When later on the events
-	 * are deleted and re-added, do not reset the event count value to zero.
-	 * Events are added, deleted and re-added when 2 or more events
-	 * are active at the same time.
-	 */
 	if (!event->attr.sample_period) {	/* Counting */
-		if (!event->hw.last_tag) {
-			event->hw.last_tag = 1;
-			sum = paicrypt_getall(event);	/* Get current value */
-			local64_set(&event->hw.prev_count, sum);
-		}
+		sum = paicrypt_getall(event);	/* Get current value */
+		local64_set(&event->hw.prev_count, sum);
 	} else {				/* Sampling */
+		cpump->event = event;
 		perf_sched_cb_inc(event->pmu);
 	}
 }
@@ -338,7 +347,6 @@ static int paicrypt_add(struct perf_event *event, int flags)
 		WRITE_ONCE(S390_lowcore.ccd, ccd);
 		local_ctl_set_bit(0, CR0_CRYPTOGRAPHY_COUNTER_BIT);
 	}
-	cpump->event = event;
 	if (flags & PERF_EF_START)
 		paicrypt_start(event, PERF_EF_RELOAD);
 	event->hw.state = 0;
@@ -371,23 +379,34 @@ static void paicrypt_del(struct perf_event *event, int flags)
 	}
 }
 
-/* Create raw data and save it in buffer. Returns number of bytes copied.
- * Saves only positive counter entries of the form
+/* Create raw data and save it in buffer. Calculate the delta for each
+ * counter between this invocation and the last invocation.
+ * Returns number of bytes copied.
+ * Saves only entries with positive counter difference of the form
  * 2 bytes: Number of counter
  * 8 bytes: Value of counter
  */
 static size_t paicrypt_copy(struct pai_userdata *userdata, unsigned long *page,
-			    bool exclude_user, bool exclude_kernel)
+			    unsigned long *page_old, bool exclude_user,
+			    bool exclude_kernel)
 {
 	int i, outidx = 0;
 
 	for (i = 1; i <= paicrypt_cnt; i++) {
-		u64 val = 0;
+		u64 val = 0, val_old = 0;
 
-		if (!exclude_kernel)
+		if (!exclude_kernel) {
 			val += paicrypt_getctr(page, i, true);
-		if (!exclude_user)
+			val_old += paicrypt_getctr(page_old, i, true);
+		}
+		if (!exclude_user) {
 			val += paicrypt_getctr(page, i, false);
+			val_old += paicrypt_getctr(page_old, i, false);
+		}
+		if (val >= val_old)
+			val -= val_old;
+		else
+			val = (~0ULL - val_old) + val + 1;
 		if (val) {
 			userdata[outidx].num = i;
 			userdata[outidx].value = val;
@@ -430,8 +449,8 @@ static int paicrypt_push_sample(size_t rawsize, struct paicrypt_map *cpump,
 
 	overflow = perf_event_overflow(event, &data, &regs);
 	perf_event_update_userpage(event);
-	/* Clear lowcore page after read */
-	memset(cpump->page, 0, PAGE_SIZE);
+	/* Save crypto counter lowcore page after reading event data. */
+	memcpy((void *)PAI_SAVE_AREA(event), cpump->page, PAGE_SIZE);
 	return overflow;
 }
 
@@ -447,6 +466,7 @@ static int paicrypt_have_sample(void)
 	if (!event)		/* No event active */
 		return 0;
 	rawsize = paicrypt_copy(cpump->save, cpump->page,
+				(unsigned long *)PAI_SAVE_AREA(event),
 				cpump->event->attr.exclude_user,
 				cpump->event->attr.exclude_kernel);
 	if (rawsize)			/* No incremented counters */
@@ -698,6 +718,12 @@ static int __init attr_event_init_one(struct attribute **attrs, int num)
 {
 	struct perf_pmu_events_attr *pa;
 
+	/* Index larger than array_size, no counter name available */
+	if (num >= ARRAY_SIZE(paicrypt_ctrnames)) {
+		attrs[num] = NULL;
+		return 0;
+	}
+
 	pa = kzalloc(sizeof(*pa), GFP_KERNEL);
 	if (!pa)
 		return -ENOMEM;
@@ -718,11 +744,10 @@ static int __init attr_event_init(void)
 	struct attribute **attrs;
 	int ret, i;
 
-	attrs = kmalloc_array(ARRAY_SIZE(paicrypt_ctrnames) + 1, sizeof(*attrs),
-			      GFP_KERNEL);
+	attrs = kmalloc_array(paicrypt_cnt + 2, sizeof(*attrs), GFP_KERNEL);
 	if (!attrs)
 		return -ENOMEM;
-	for (i = 0; i < ARRAY_SIZE(paicrypt_ctrnames); i++) {
+	for (i = 0; i <= paicrypt_cnt; i++) {
 		ret = attr_event_init_one(attrs, i);
 		if (ret) {
 			attr_event_free(attrs, i);
@@ -746,8 +771,10 @@ static int __init paicrypt_init(void)
 	paicrypt_cnt = ib.num_cc;
 	if (paicrypt_cnt == 0)
 		return 0;
-	if (paicrypt_cnt >= PAI_CRYPTO_MAXCTR)
-		paicrypt_cnt = PAI_CRYPTO_MAXCTR - 1;
+	if (paicrypt_cnt >= PAI_CRYPTO_MAXCTR) {
+		pr_err("Too many PMU pai_crypto counters %d\n", paicrypt_cnt);
+		return -E2BIG;
+	}
 
 	rc = attr_event_init();		/* Export known PAI crypto events */
 	if (rc) {