摘要:
A system, method and computer program product for providing a shared memory translation facility. The method includes receiving a request for access to a memory address from a requestor at a configuration, the receiving at a shared memory translation mechanism. It is determined if the memory address refers to a shared memory object (SMO), the SMO accessible by a plurality of configurations. In response to determining that the memory address refers to the SMO, it is determined if the configuration has access to the SMO. In response to determining that the configuration has access to the SMO, the requestor is provided a system absolute address for the SMO and access to the SMO. In this manner direct interchange of data between the plurality of configurations is allowed.
摘要:
A system, method and computer program product for providing a shared memory translation facility. The method includes receiving a request for access to a memory address from a requestor at a configuration, the receiving at a shared memory translation mechanism. It is determined if the memory address refers to a shared memory object (SMO), the SMO accessible by a plurality of configurations. In response to determining that the memory address refers to the SMO, it is determined if the configuration has access to the SMO. In response to determining that the configuration has access to the SMO, the requestor is provided a system absolute address for the SMO and access to the SMO. In this manner direct interchange of data between the plurality of configurations is allowed.
摘要:
What is provided is an enhanced dynamic address translation facility. In one embodiment, a virtual address to be translated and an initial origin address of a translation table of the hierarchy of translation tables are obtained. An index portion of the virtual address is used to reference an entry in the translation table. If the format control field is enabled, a frame address of a large block of data in main storage is obtained from the translation table entry. The large block of data is a block of at least 1M byte in size. The frame address is then combined with an offset portion of the virtual address to form the translated address of a desired block of data within the large block of data in main storage. The desired large block of data addressed by the translated address is then accessed.
摘要:
What is provided is an enhanced dynamic address translation facility. In one embodiment, a virtual address to be translated and an initial origin address of a translation table of the hierarchy of translation tables are obtained. An index portion of the virtual address is used to reference an entry in the translation table. If a format control field contained in the translation table entry is enabled, the table entry contains a frame address of a large block of data of at least 1M byte in size. The frame address is then combined with an offset portion of the virtual address to form the translated address of a small 4K byte block of data in main storage or memory.
摘要:
A translation table entry contains a change recording override field for controlling whether a change bit is to be set on a store or not. Each 4K byte block of main storage has an associated storage key comprising a change bit. The change recording override field controls whether the change bit of the storage key associated with the desired 4K byte block of main storage is set to 1 for a store operation.
摘要:
What is provided is an enhanced dynamic address translation facility. In one embodiment, a virtual address to be translated and an initial origin address of a translation table of the hierarchy of translation tables are obtained. An index portion of the virtual address is used to reference an entry in the translation table. If a format control field contained in the translation table entry is enabled, the table entry contains a frame address of a large block of data of at least 1M byte in size. The frame address is then combined with an offset portion of the virtual address to form the translated address of a small 4K byte block of data in main storage or memory.
摘要:
What is provided is an enhanced dynamic address translation facility. In one embodiment, a virtual address to be translated and an initial origin address of any one of a region first table, a region second table, a region third table, or a segment table are obtained. Based on the obtained initial origin address, a segment table entry is obtained which contains a format control and DAT protection fields. If the format control field is enabled, obtaining from the translation table entry a segment-frame absolute address of a large block of data in main storage. The segment-frame absolute address is combined with a page index portion and a byte index portion of the virtual address to form a translated address of the desired block of data. If the DAT protection field is not enabled, fetches and stores are permitted to the desired block of data addressed by the translated virtual address.
摘要:
What is provided is an enhanced dynamic address translation facility. In one embodiment, a virtual address to be translated and an initial origin address of a translation table of the hierarchy of translation tables are obtained. An index portion of the virtual address is used to reference an entry in the translation table. If a format control field contained in the translation table entry is enabled, the table entry contains a frame address of a large block of data of at least 1M byte in size. The frame address is then combined with an offset portion of the virtual address to form the translated address of a small 4K byte block of data in main storage or memory.
摘要:
What is provided is an enhanced dynamic address translation facility. In one embodiment, a virtual address to be translated is first obtained and an initial origin address of a translation table of the hierarchy of translation tables is obtained. Based on the obtained initial origin, a segment table entry is obtained. The segment table entry is configured to contain a format control and access validity fields. If the format control and access validity fields are enabled, the segment table entry further contains an access control field, a fetch protection field, and a segment-frame absolute address. Store operations are permitted only if the access control field matches a program access key provided by any one of a Program Status Word or an operand of a program instruction being executed. Fetch operations are permitted if the program access key associated with the virtual address is equal to the segment access control field.
摘要:
What is provided is an enhanced dynamic address translation facility. In one embodiment, a virtual address to be translated is first obtained and an initial origin address of a translation table of the hierarchy of translation tables is obtained. Based on the obtained initial origin, a segment table entry is obtained. The segment table entry is configured to contain a format control and access validity fields. If the format control and access validity fields are enabled, the segment table entry further contains an access control field, a fetch protection field, and a segment-frame absolute address. Store operations are permitted only if the access control field matches a program access key provided by any one of a Program Status Word or an operand of a program instruction being executed. Fetch operations are permitted if the program access key associated with the virtual address is equal to the segment access control field.