s390/cpum_cf: Deny all sampling events by counter PMU

[ Upstream commit ce97123 ]

Deny all sampling event by the CPUMF counter facility device driver
and return -ENOENT. This return value is used to try other PMUs.
Up to now events for type PERF_TYPE_HARDWARE were not tested for
sampling and returned later on -EOPNOTSUPP. This ends the search
for alternative PMUs. Change that behavior and try other PMUs
instead.

Fixes: 613a41b ("s390/cpum_cf: Reject request for sampling in event initialization")
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Thomas Richter

arch/s390/kernel/perf_cpum_cf.c

@@ -757,8 +757,6 @@ static int __hw_perf_event_init(struct perf_event *event, unsigned int type)
 		break;
 
 	case PERF_TYPE_HARDWARE:
-		if (is_sampling_event(event))	/* No sampling support */
-			return -ENOENT;
 		ev = attr->config;
 		if (!attr->exclude_user && attr->exclude_kernel) {
 			/*
@@ -856,6 +854,8 @@ static int cpumf_pmu_event_init(struct perf_event *event)
 	unsigned int type = event->attr.type;
 	int err;
 
+	if (is_sampling_event(event))	/* No sampling support */
+		return err;
 	if (type == PERF_TYPE_HARDWARE || type == PERF_TYPE_RAW)
 		err = __hw_perf_event_init(event, type);
 	else if (event->pmu->type == type)