1. A computer program product for handling a hierarchical cache structure, the computer program product comprising: a computer readable storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising: initiating requests to one level cache of the hierarchical cache structure by another level cache of the hierarchical cache structure, the one level cache being a higher level cache than the other level cache of the hierarchical cache structure, and the hierarchical cache structure comprising a further level cache, the further level cache being a lower level cache than the one level cache; and receiving requests by an instruction cache of the other level cache from an instruction cache of the further level cache, and receiving requests by an instruction cache and a data cache of the other level cache from a data cache of the further level cache.