[PATCH v1 1/2] perf list: Avoid a hardcoded cpu PMU name

[Ian Rogers <irogers@google.com>]

Use the first core PMU instead.

On a Raspberry Pi, before:
```
$ perf list
...
  cpu/t1=v1[,t2=v2,t3 ...]/modifier                  [Raw hardware event descriptor]
       [(see 'man perf-list' on how to encode it)]
...
```
After:
```

$ perf list
...
  armv8_cortex_a72/t1=v1[,t2=v2,t3 ...]/modifier     [Raw hardware event descriptor]
       [(see 'man perf-list' on how to encode it)]
...
```

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/print-events.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/tools/perf/util/print-events.c b/tools/perf/util/print-events.c
index a7566edc86a3..b0fc48be623f 100644
--- a/tools/perf/util/print-events.c
+++ b/tools/perf/util/print-events.c
@@ -395,6 +395,8 @@ void print_symbol_events(const struct print_callbacks *print_cb, void *print_sta
  */
 void print_events(const struct print_callbacks *print_cb, void *print_state)
 {
+	char *tmp;
+
 	print_symbol_events(print_cb, print_state, PERF_TYPE_HARDWARE,
 			event_symbols_hw, PERF_COUNT_HW_MAX);
 	print_symbol_events(print_cb, print_state, PERF_TYPE_SOFTWARE,
@@ -418,17 +420,21 @@ void print_events(const struct print_callbacks *print_cb, void *print_state)
 			/*long_desc=*/NULL,
 			/*encoding_desc=*/NULL);
 
-	print_cb->print_event(print_state,
-			/*topic=*/NULL,
-			/*pmu_name=*/NULL,
-			"cpu/t1=v1[,t2=v2,t3 ...]/modifier",
-			/*event_alias=*/NULL,
-			/*scale_unit=*/NULL,
-			/*deprecated=*/false,
-			event_type_descriptors[PERF_TYPE_RAW],
-			"(see 'man perf-list' on how to encode it)",
-			/*long_desc=*/NULL,
-			/*encoding_desc=*/NULL);
+	if (asprintf(&tmp, "%s/t1=v1[,t2=v2,t3 ...]/modifier",
+		     perf_pmus__scan_core(/*pmu=*/NULL)->name) > 0) {
+		print_cb->print_event(print_state,
+				/*topic=*/NULL,
+				/*pmu_name=*/NULL,
+				tmp,
+				/*event_alias=*/NULL,
+				/*scale_unit=*/NULL,
+				/*deprecated=*/false,
+				event_type_descriptors[PERF_TYPE_RAW],
+				"(see 'man perf-list' on how to encode it)",
+				/*long_desc=*/NULL,
+				/*encoding_desc=*/NULL);
+		free(tmp);
+	}
 
 	print_cb->print_event(print_state,
 			/*topic=*/NULL,
-- 
2.42.0.283.g2d96d420d3-goog