ARC: perf: ARC 700 PMU doesn't support sampling events

The ARC 700 does not have an interrupt associated with it, and as
such it cannot trigger when a counter overflows. As the counters are
48 bit, it will usually take at least 100 days before a counter
overflows, so for mere counting of events, there is no problem.
Sampling is not supported though.
Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/kernel/perf_event.c

@@ -99,6 +99,10 @@ static int arc_pmu_event_init(struct perf_event *event)
 	struct hw_perf_event *hwc = &event->hw;
 	int ret;
 
+	/* ARC 700 PMU does not support sampling events */
+	if (is_sampling_event(event))
+		return -ENOENT;
+
 	switch (event->attr.type) {
 	case PERF_TYPE_HARDWARE:
 		if (event->attr.config >= PERF_COUNT_HW_MAX)