Abstract: A task obtained by a communications processor is decomposed into one or more requests that form a request group. The requests of the request group are sent to main memory and responses to those requests are expected. There may be requests for a plurality of request groups being processed concurrently. However, responses to the request groups are to be returned to the communications processor in the order in which the request groups were sent from the communications processor. To ensure this ordering, dependencies between the request groups are tracked by hardware coupled to the communications processor.

Abstract: An instruction is provided to establish various operational parameters for an adapter. These parameters include adapter interruption parameters, input/output address translation parameters, resetting error indications, setting measurement parameters, and setting an interception control, as examples. The instruction specifies a function information block, which is a program representation of a device table entry used by the adapter, to be used in certain situations in establishing the parameters. A store instruction is also provided that stores the current contents of the function information block.

Abstract: Management of storage used by pageable guests of a computing environment is facilitated. A query instruction is provided that details information regarding the storage location indicated in the query. It specifies whether the storage location, if protected, is protected by host-level protection or guest-level protection.

Abstract: A system and method for specifying an access hint for prefetching limited use data. A processing unit receives a data cache block touch (DCBT) instruction having an access hint indicating to the processing unit that a program executing on the data processing system may soon access a cache block addressed within the DCBT instruction. The access hint is contained in a code point stored in a subfield of the DCBT instruction. In response to detecting that the code point is set to a specific value, the data addressed in the DCBT instruction is prefetched into an entry in the lower level cache. The entry may then be updated as a least recently used entry of a plurality of entries in the lower level cache. In response to a new cache block being fetched to the cache, the prefetched cache block is cast out of the cache.

Abstract: Management of storage used by pageable guests of a computing environment is facilitated. A query instruction is provided that details information regarding the storage location indicated in the query. It specifies whether the storage location, if protected, is protected by host-level protection or guest-level protection.

Abstract: Detection, notification and/or processing of events, such as errors associated with adapters, are facilitated. Hardware detects an event, places one or more adapters in an error state to prevent access to/from the adapters, and notifies the operating system of the event.

Abstract: An instruction is provided to establish various operational parameters for an adapter. These parameters include adapter interruption parameters, input/output address translation parameters, resetting error indications, setting measurement parameters, and setting an interception control, as examples. The instruction specifies a function information block, which is a program representation of a device table entry used by the adapter, to be used in certain situations in establishing the parameters. A store instruction is also provided that stores the current contents of the function information block.

Abstract: A measurement facility is provided for capturing and presenting fine-grained usage information for adapter functions in an input/output subsystem. Adapter specific input/output traffic is tracked on a per function basis and the results are dynamically presented to the user. This information is useful for performance tuning, load balancing and usage based charging, as examples.

Abstract: A method for implementing connected input/output (I/O) hub configuration and management includes configuring a first I/O hub in wrap mode with a second I/O hub. The hubs are communicatively coupled via a wrap cable. The method further includes generating data traffic on a computing subsystem that includes the hubs. Generating traffic includes: converting, via the first hub, a request to implement a transaction into an I/O device-readable request packet and transmitting the request packet over the wrap cable; converting, via the second hub, the I/O device-readable (IODR) request packet into a system readable request and transmitting the request over a system bus; converting, via the second hub, the response to an IODR response packet, and transmitting the response packet over the wrap cable; and converting, via the first hub, the IODR response packet into a system readable response packet, and transmitting the response packet over the system bus.

Abstract: A system and a method for failover control comprising: maintaining a primary device table entry (DTE) in a first table activated for a first adapter in communication with a first processor node having a first root complex via a first switch assembly and maintaining a secondary DTE in standby for a second adapter in communication with a second processor node having a second root complex via a second switch assembly; maintaining a primary DTE in a second table activated for the second adapter and maintaining a secondary DTE in standby for the first adapter; and upon a failover, updating the secondary DTE in the first table as an active entry for the second adapter and forming a path to enable traffic to route from the second adapter through the second switch assembly over to the first switch assembly and up to the first root complex of the first processor node.

Abstract: One or more registers used to form an address usable in accessing storage are examined to determine if a zero address event has occurred in forming the address. In response to an indication that a zero address event has occurred in address formation, an alert is provided to the program using the address to access storage.

Abstract: A system and method for specifying an access hint for prefetching limited use data. A processing unit receives a data cache block touch (DCBT) instruction having an access hint indicating to the processing unit that a program executing on the data processing system may soon access a cache block addressed within the DCBT instruction. The access hint is contained in a code point stored in a subfield of the DCBT instruction. In response to detecting that the code point is set to a specific value, the data addressed in the DCBT instruction is prefetched into an entry in the lower level cache. The entry may then be updated as a least recently used entry of a plurality of entries in the lower level cache. In response to a new cache block being fetched to the cache, the prefetched cache block is cast out of the cache.

Abstract: A task obtained by a communications processor is decomposed into one or more requests that form a request group. The requests of the request group are sent to main memory and responses to those requests are expected. There may be requests for a plurality of request groups being processed concurrently. However, responses to the request groups are to be returned to the communications processor in the order in which the request groups were sent from the communications processor. To ensure this ordering, dependencies between the request groups are tracked by hardware coupled to the communications processor.

Abstract: A task obtained by a communications processor is decomposed into one or more requests that form a request group. The requests of the request group are sent to main memory and responses to those requests are expected. There may be requests for a plurality of request groups being processed concurrently. However, responses to the request groups are to be returned to the communications processor in the order in which the request groups were sent from the communications processor. To ensure this ordering, dependencies between the request groups are tracked by hardware coupled to the communications processor.

Abstract: Management of storage used by pageable guests of a computing environment is facilitated. A query instruction is provided that details information regarding the storage location indicated in the query. It specifies whether the storage location, if protected, is protected by host-level protection or guest-level protection.

Abstract: A task obtained by a communications processor is decomposed into one or more requests that form a request group. The requests of the request group are sent to main memory and responses to those requests are expected. There may be requests for a plurality of request groups being processed concurrently. However, responses to the request groups are to be returned to the communications processor in the order in which the request groups were sent from the communications processor. To ensure this ordering, dependencies between the request groups are tracked by hardware coupled to the communications processor.

Abstract: A task obtained by a communications processor is decomposed into one or more requests that form a request group. The requests of the request group are sent to main memory and responses to those requests are expected. There may be requests for a plurality of request groups being processed concurrently. However, responses to the request groups are to be returned to the communications processor in the order in which the request groups were sent from the communications processor. To ensure this ordering, dependencies between the request groups are tracked by hardware coupled to the communications processor.

Abstract: The utilization of a controlled buffer and tags associated with read requests and the transmission of data in response to these requests, along with the transmitted tag information, is used to avoid a read-modify-write operations occurring in a communications adapters whose function it is to assemble various pluralities of data blocks, each with a varying amount of information, into single data packets for transmission from the adapter's memory. The presence of error correction capabilities associated with the adapter's memory would otherwise require the utilization of the read-modify-write operation which is bandwidth limiting.

Abstract: The utilization of a controlled buffer and tags associated with read requests and the transmission of data in response to these requests, along with the transmitted tag information, is used to avoid a read-modify-write operations occurring in a communications adapters whose function it is to assemble various pluralities of data blocks, each with a varying amount of information, into single data packets for transmission from the adapter's memory. The presence of error correction capabilities associated with the adapter's memory would otherwise require the utilization of the read-modify-write operation which is bandwidth limiting.

Abstract: A parallel multiprocessor data processing system having a plurality of nodes for processing data and a switch connected to each of said nodes for switching messages between the nodes, each node having a node processor for defining messages under program control to be sent to another node. Each of the nodes has an I/O processor for controlling the sending of messages to another node via the switch, and a shared memory which can be accessed by both the node processor and the I/O processor. Instructions for the messages to be sent by the I/O processor are stored in mailboxes in the shared memory by the node processor. A comparing circuit compares addresses on the bus to the contents of a plurality of address registers and sets the corresponding bit in a results register for each match. The adapter processor reads the contents of the results register such that the adapter processor may, with a single bus access, determine all mailboxes that have been accessed by the node processor.