perf pmu: Remove a hard coded cpu PMU assumption

The property of "cpu" when it has no cpu map is true on S390 with the
PMU cpum_cf. Rather than maintain a list of such PMUs, reuse the
is_core test result from the caller.

Signed-off-by: Ian Rogers <[e-mail]>
Tested-by: Thomas Richter <[e-mail]>
Cc: Ravi Bangoria <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Arnaldo Carvalho de Melo <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Kan Liang <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Namhyung Kim <[e-mail]>

tools/perf/util/pmu.c

···
  * Uncore PMUs have a "cpumask" file under sysfs. CPU PMUs (e.g. on arm/arm64)
  * may have a "cpus" file.
  */
-static struct perf_cpu_map *pmu_cpumask(int dirfd, const char *name)
+static struct perf_cpu_map *pmu_cpumask(int dirfd, const char *name, bool is_core)
 {
 	struct perf_cpu_map *cpus;
 	const char *templates[] = {
···
 			return cpus;
 	}
 
-	return !strcmp(name, "cpu") ? perf_cpu_map__get(cpu_map__online()) : NULL;
+	/* Nothing found, for core PMUs assume this means all CPUs. */
+	return is_core ? perf_cpu_map__get(cpu_map__online()) : NULL;
 }
 
 static bool pmu_is_uncore(int dirfd, const char *name)
···
 	if (!pmu)
 		return NULL;
 
-	pmu->cpus = pmu_cpumask(dirfd, name);
+	pmu->is_core = is_pmu_core(name);
+	pmu->cpus = pmu_cpumask(dirfd, name, pmu->is_core);
 	pmu->name = strdup(name);
 	if (!pmu->name)
 		goto err;
···
 	}
 
 	pmu->type = type;
-	pmu->is_core = is_pmu_core(name);
 	pmu->is_uncore = pmu_is_uncore(dirfd, name);
 	if (pmu->is_uncore)
 		pmu->id = pmu_id(name);