diff --git a/tools/perf/util/xyarray.c b/tools/perf/util/xyarray.c
index 7251fdbabceda5e0bb88e4b9ae83f501ea9ad517..c8f415d9877b08503d12e10e1bb0fe463c81e6f1 100644
--- a/tools/perf/util/xyarray.c
+++ b/tools/perf/util/xyarray.c
@@ -12,6 +12,8 @@ struct xyarray *xyarray__new(int xlen, int ylen, size_t entry_size)
 		xy->entry_size = entry_size;
 		xy->row_size   = row_size;
 		xy->entries    = xlen * ylen;
+		xy->max_x      = xlen;
+		xy->max_y      = ylen;
 	}
 
 	return xy;
diff --git a/tools/perf/util/xyarray.h b/tools/perf/util/xyarray.h
index 7f30af371b7ee692f23b9bf4aeb354584f453722..4ba726c9087072184b445ddc4e788d7000ade01d 100644
--- a/tools/perf/util/xyarray.h
+++ b/tools/perf/util/xyarray.h
@@ -7,6 +7,8 @@ struct xyarray {
 	size_t row_size;
 	size_t entry_size;
 	size_t entries;
+	size_t max_x;
+	size_t max_y;
 	char contents[];
 };
 
@@ -19,4 +21,14 @@ static inline void *xyarray__entry(struct xyarray *xy, int x, int y)
 	return &xy->contents[x * xy->row_size + y * xy->entry_size];
 }
 
+static inline int xyarray__max_y(struct xyarray *xy)
+{
+	return xy->max_x;
+}
+
+static inline int xyarray__max_x(struct xyarray *xy)
+{
+	return xy->max_y;
+}
+
 #endif /* _PERF_XYARRAY_H_ */