perf cpu_map: Add cpu_map__new_event function

Introducing the cpu_map__new_event function to create a struct cpu_map
object from a cpu_map event.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Kan Liang <kan.liang@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1445784728-21732-10-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index 10af1e7..a0717b9 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -5,6 +5,7 @@
 #include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <linux/bitmap.h>
 #include "asm/bug.h"
 
 static struct cpu_map *cpu_map__default_new(void)
@@ -179,6 +180,47 @@
 	return cpus;
 }
 
+static struct cpu_map *cpu_map__from_entries(struct cpu_map_entries *cpus)
+{
+	struct cpu_map *map;
+
+	map = cpu_map__empty_new(cpus->nr);
+	if (map) {
+		unsigned i;
+
+		for (i = 0; i < cpus->nr; i++)
+			map->map[i] = (int)cpus->cpu[i];
+	}
+
+	return map;
+}
+
+static struct cpu_map *cpu_map__from_mask(struct cpu_map_mask *mask)
+{
+	struct cpu_map *map;
+	int nr, nbits = mask->nr * mask->long_size * BITS_PER_BYTE;
+
+	nr = bitmap_weight(mask->mask, nbits);
+
+	map = cpu_map__empty_new(nr);
+	if (map) {
+		int cpu, i = 0;
+
+		for_each_set_bit(cpu, mask->mask, nbits)
+			map->map[i++] = cpu;
+	}
+	return map;
+
+}
+
+struct cpu_map *cpu_map__new_data(struct cpu_map_data *data)
+{
+	if (data->type == PERF_CPU_MAP__CPUS)
+		return cpu_map__from_entries((struct cpu_map_entries *)data->data);
+	else
+		return cpu_map__from_mask((struct cpu_map_mask *)data->data);
+}
+
 size_t cpu_map__fprintf(struct cpu_map *map, FILE *fp)
 {
 	int i;