Abstract: An apparatus and method for implementing multicast in system area network channel adapters are provided. With the apparatus and method, a multicast packet is received in a channel adapter of an end node. The channel adapter determines which local queue pairs are party of the multicast group identified by a destination local identifier in the multicast data packet. Based on this determination, the channel adapter replicates the data packet and delivers a copy of the data packet to each local queue pair that is part of the multicast group.

Abstract: A method and system are disclosed for logically partitioning resources of a single channel adapter for use in a system area network. Each resource includes a partition identifier register within which is stored a partition identifier. A first one of the resources is assigned to a first partition by storing a first partition identifier in the partition identifier register within the first one of the resources. A second one of the resources is assigned to a second partition by storing a second partition identifier in the partition identifier register within the second one of the resources. Partitioning of the resources is enforced by permitting access to the first resource by only the first partition and permitting access to the second resource by only the second partition by checking the partition identifiers of each resource.

Abstract: A method, computer program product, and data processing system for providing system-area network (SAN) multicasting functionality in a logically partitioned (LPAR) data processing system in which a channel adapter is shared among a plurality of logical partitions is disclosed. A preferred embodiment of the present invention allows LPAR “hypervisor” firmware to assume the responsibility for multicast protocol handling and distribution of packets among logical partitions.

Abstract: An aliased queue pair is provided within a logically partitioned data processing system for each logical partition for the single general services management queue pair that exists within a physical host channel adapter. Packets intended for the logical ports are received at the physical port. Multiple partitions exist within the data processing system. When one of these partitions needs to use one of the logical ports, a queue pair is selected. The queue pair is then associated with the logical port. The queue pair is configured as an aliased general services management queue pair and is used by the partition as if the aliased queue pair were the single general services management queue pair provided in the channel adapter.

Abstract: A circuit arrangement and method selectively reorder speculatively issued memory read requests being communicated to a lower memory level in a multi-level memory architecture. In particular, a memory read request that has been speculatively issued to a lower memory level prior to completion of a cache lookup operation initiated in a cache memory in a higher memory level may be reordered ahead of at least one previously received and pending request awaiting communication to the lower memory level. By doing so, the latency associated with the memory read request is reduced when the request results in a cache miss in the higher level memory, and as a result, system performance is improved.

Abstract: A method, computer program product, and data processing system for providing system-area network (SAN) multicasting functionality in a logically partitioned (LPAR) data processing system in which a channel adapter is shared among a plurality of logical partitions is disclosed. A preferred embodiment of the present invention allows LPAR “hypervisor” firmware to assume the responsibility for multicast protocol handling and distribution of packets among logical partitions.

Abstract: Disclosed is a method and circuit for a receiver to receive data from an associated data transmitter. The receiver may include a signaling module adapted to transmit a Ready-To-Receive (“RTR”) signal to the associated transmitter when a number of vacant bits in a data buffer exceeds a delay associated value.

Abstract: A method, computer program product, and data processing system for providing system-area network (SAN) multicasting functionality in a logically partitioned (LPAR) data processing system in which a channel adapter is shared among a plurality of logical partitions is disclosed. A preferred embodiment of the present invention allows LPAR “hypervisor” firmware to assume the responsibility for multicast protocol handling and distribution of packets among logical partitions.

Abstract: An apparatus and method to transmit unaligned data over an interface bus while providing the appearance of aligned data transfers to the receiving processor. In a preferred embodiment, an alignment mechanism is provided in the bus interface of the receiving processor to align the data transfers transparent to the receiving processor. The alignment mechanism detects an unaligned transfer in the bus command queue and forms multiple commands of aligned data to send to the processor.

Abstract: An apparatus, system and method for providing multiple logical partitions in a system area network are provided Logical partitioning support is provided for host channel adapters which allows multiple operating systems to share the resources of a single physical host channel adapter (HCA). The apparatus, system and method ensures that each operating system is unaware that the HCA hardware resources are being shared with other operating systems and further guarantees that the individual operating systems are prevented from accessing HCA hardware resources which are associated with other operating systems.

Abstract: A circuit arrangement, node, clustered computer system, and method incorporate a primitive communication mechanism for use in exchanging data between adjacent nodes coupled via a point-to-point network. A plurality of network ports are used to couple a node to other nodes in the clustered computer system over point-to-point network interconnects, and a plurality of communication registers are associated with each of the network ports for the purpose of storing data received through their associated network ports. A node desiring to communicate information to another node receives a port identifier from the other node that identifies the network port on the other node through which the pair of nodes are coupled. The port identifier is then used by the node to communicate data to the other node through the use of one or more write operations directed to the communication register on the other node that is associated with the network port identified by the port identifier.

Abstract: A method, apparatus and computer program product are provided for implementing dynamic Virtual Lane buffer reconfiguration in a channel adapter. A first register is provided for communicating an adapter buffer size and allocation capability for the channel adapter. At least one second register is provided for communicating a current port buffer size and one second register is associated with each physical port of the channel adapter. A plurality of third registers is provided for communicating a current VL buffer size, and one third register is associated with each VL of each physical port of the channel adapter. The second register is used for receiving change requests for adjusting the current port buffer size for an associated physical port. The third register is used for receiving change requests for adjusting the current VL buffer size for an associated VL.

Abstract: A method, system, and product in a data processing system are disclosed for managing data transmitted from a first end node to a second end node included in the data processing system. A logical connection is established between the first end node and the second end node prior to transmitting data between the end nodes. An instance number is associated with this particular logical connection. The instance number is included in each packet transmitted between the end nodes while this logical connection remains established. The instance number remains constant during this logical connection. The instance number is altered, such as by incrementing it, each time a logical connection between these end nodes is reestablished. Thus, each packet is associated with a particular instance of the logical connection. When a packet is received, the instance number included in the packet may be used to determine whether the packet is a stale packet transmitted during a previous logical connection between these end nodes.

Abstract: A method in a node for managing authorized attempts to access the node. A packet is received from a source, wherein the packet includes a first key. A determination is made as to whether the first key matches a second key for the node. The packet is dropped without a response to the source if the first key does not match the second key. Information from the packet is stored in response to this absence of a match. The information is sent to a selected recipient in response to a selected event, which may be, for example, either immediately or in response to polling to see if the information is present.

Abstract: An apparatus, system and method for controlling access to facilities based on usage class of a requestor are provided. With the apparatus, system and method, a two level protection mechanism is provided for protecting host channel adapter (HCA) facilities from unauthorized access. With the present invention, a first level of access is provided through virtual address translation and a mechanism for determining if the requestor of access may access a system memory address space page associated with a real address to which the virtual address maps. A second level of access is provided through the allocation of usage classes and determining a required usage class for accessing an HCA facility.

Abstract: A method and apparatus to perform network fabric management is provided. The method and apparatus provide a mechanism by which modifications to components of the network fabric may be made without tearing down existing connections. The apparatus and method facilitate such fabric management by placing send queues in a send queue drain state and suspending the send queues affected by changes to the network fabric while the modifications are being made. Once the modifications are complete, the send queues are place back into an operational state.

Abstract: A method and apparatus for accessing a memory. Access rights for a memory operation are verified using a first data structure in response to receiving a request to perform the operation, wherein the request includes a virtual address for the operation. Responsive to access rights being verified for the memory operation, the virtual address translated into a real address using a second data structure.

Abstract: Dynamic routing of data to multiple processor complexes. PCI address space is subdivided among a plurality of processor complexes. Translation table entries at each processor complex determine which processor complex is to receive a DMA transfer, thereby enabling routing of DMA data to one I/O hub node while accessing translation table entries at another I/O hub node. Further, interrupt requests may be dynamically routed to multiple processor complexes.

Abstract: An apparatus, system and method for providing multiple logical partitions in a system area network are provided Logical partitioning support is provided for host channel adapters which allows multiple operating systems to share the resources of a single physical host channel adapter (HCA). The apparatus, system and method ensures that each operating system is unaware that the HCA hardware resources are being shared with other operating systems and further guarantees that the individual operating systems are prevented from accessing HCA hardware resources which are associated with other operating systems.

Abstract: An apparatus, system and method for controlling access to facilities based on usage class of a requestor are provided. With the apparatus, system and method, a two level protection mechanism is provided for protecting host channel adapter (HCA) facilities from unauthorized access. With the present invention, a first level of access is provided through virtual address translation and a mechanism for determining if the requestor of access may access a system memory address space page associated with a real address to which the virtual address maps. A second level of access is provided through the allocation of usage classes and determining a required usage class for accessing an HCA facility.