perf tools: Add mem2node object

Adding mem2node object to allow the easy lookup of the node for the
physical address.

It has following interface:

  int  mem2node__init(struct mem2node *map, struct perf_env *env);
  void mem2node__exit(struct mem2node *map);
  int  mem2node__node(struct mem2node *map, u64 addr);

The mem2node__toolsinit initialize object from the perf data file
MEM_TOPOLOGY feature data. Following calls to mem2node__node will return
node number for given physical address. The mem2node__exit function
frees the object.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180309101442.9224-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/mem2node.h b/tools/perf/util/mem2node.h
new file mode 100644
index 0000000..59c4752
--- /dev/null
+++ b/tools/perf/util/mem2node.h
@@ -0,0 +1,19 @@
+#ifndef __MEM2NODE_H
+#define __MEM2NODE_H
+
+#include <linux/rbtree.h>
+#include "env.h"
+
+struct phys_entry;
+
+struct mem2node {
+	struct rb_root		 root;
+	struct phys_entry	*entries;
+	int			 cnt;
+};
+
+int  mem2node__init(struct mem2node *map, struct perf_env *env);
+void mem2node__exit(struct mem2node *map);
+int  mem2node__node(struct mem2node *map, u64 addr);
+
+#endif /* __MEM2NODE_H */