perf jevents: Use name for special find value (PMU_EVENTS__NOT_FOUND)

-1000 was used as a special value added in Commit 3d504549 ("perf
pmu-events: Add pmu_events_table__find_event()") to show that 1 table
lacked a PMU/event but that didn't terminate the search in other
tables.

Add a new constant PMU_EVENTS__NOT_FOUND for this value and use it.
Reviewed-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oliver Sang <oliver.sang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Philip Li <philip.li@intel.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Cc: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240730191744.3097329-2-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/pmu-events/jevents.py

@@ -906,7 +906,7 @@ static int pmu_events_table__find_event_pmu(const struct pmu_events_table *table
   do_call:
                 return fn ? fn(&pe, table, data) : 0;
         }
-        return -1000;
+        return PMU_EVENTS__NOT_FOUND;
 }
 
 int pmu_events_table__for_each_event(const struct pmu_events_table *table,
@@ -944,10 +944,10 @@ int pmu_events_table__find_event(const struct pmu_events_table *table,
                         continue;
 
                 ret = pmu_events_table__find_event_pmu(table, table_pmu, name, fn, data);
-                if (ret != -1000)
+                if (ret != PMU_EVENTS__NOT_FOUND)
                         return ret;
         }
-        return -1000;
+        return PMU_EVENTS__NOT_FOUND;
 }
 
 size_t pmu_events_table__num_events(const struct pmu_events_table *table,

tools/perf/pmu-events/pmu-events.h

@@ -70,6 +70,8 @@ struct pmu_metric {
 struct pmu_events_table;
 struct pmu_metrics_table;
 
+#define PMU_EVENTS__NOT_FOUND -1000
+
 typedef int (*pmu_event_iter_fn)(const struct pmu_event *pe,
 				 const struct pmu_events_table *table,
 				 void *data);
@@ -82,6 +84,13 @@ int pmu_events_table__for_each_event(const struct pmu_events_table *table,
 				    struct perf_pmu *pmu,
 				    pmu_event_iter_fn fn,
 				    void *data);
+/*
+ * Search for table and entry matching with pmu__name_match. Each matching event
+ * has fn called on it. 0 implies to success/continue the search while non-zero
+ * means to terminate. The special value PMU_EVENTS__NOT_FOUND is used to
+ * indicate no event was found in one of the tables which doesn't terminate the
+ * search of all tables.
+ */
 int pmu_events_table__find_event(const struct pmu_events_table *table,
                                  struct perf_pmu *pmu,
                                  const char *name,