ENHANCEMENTS IN SYSTEM/370 TYPE OF DATA PROCESSING APPARATUS

摘要

An enhancement in a system/370 type of data processor permits one program in one address space to obtain access to data in another address space or to call a program in another address space without invoking a supervisor. Each of a plurality of address spaces assigned an Address Space Number (ASN) has an associated set of address translation tables. A second address space can be designated by a program, and when authorized, can cause transfer of data in main memory from one physical location to another associated with the different address space. A program changeable space selection control bit controls use of two different sets of address translation tables associated with two different address spaces. Without invoking a supervisor, a particular program in an assigned address space can call a program in another address space or obtain addressability to data in another address space having an associated set of address translation tables. Addressability to a second address space may be specified by a program if authorized in accordance with the entry of an authority table associated with the second address space, the entry being designated by an authorization index associated with the program.