Abstract: One program in one address space is permitted 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.

Abstract: Permits one program in one address space to obtain access to data 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. 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.

Abstract: 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, with authorization to use a storage protect key other than that specifically assigned to the program by a supervisor when in a new semi-privileged state. Programs executing in a particular address space have supervisor assigned storage protect key masks permitting the program, when authorized, to utilize a storage protect key other than the one specifically assigned by the supervisor. 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, and two different storage protect keys can be utilized.

Abstract: The embodiments relate to special controls in a processor which eliminate synonym entries in a translation lookaside buffer (DLAT) for a system which has DLAT entries that can concurrently translate virtual addresses in multiple address spaces into real main storage addresses. The controls provide a common space bit in any segment table entry (STE) or alternatively in any page table entry (PTE) in any private address space to indicate whether the segment or page, respectively, contains programs and data private to the address space or shared by all address spaces. Each DLAT entry contains a common/private storage indictor which is set to the state of the common space bit in the STE or PTE used in an address translation loaded into the DLAT entry. When the entry is read, the private/common storage indicator controls whether the DLAT can only be used by the address space identified in the DLAT, or by all address spaces.