1. A method of data processing in a cache coherent data processing system including at least first and second coherency domains, said method comprising: a master in the first coherency domain of the cache coherent data processing system selecting a scope of an initial broadcast of an operation from among a first scope including only the first coherency domain and a second scope including both the first and second coherency domains, wherein said selecting includes selecting the scope based at least in part upon a type of the operation; and the master performing an initial broadcast of the operation within the cache coherent data processing system utilizing the selected scope.