Advanced Micro Devices Corporation

Joseph Winkles

Joseph A Bailey

Norman M Hack

Bahadir Erimli

A channel adapter, configured for sending frame data according to link widths selected based on management frames received from a link partner, includes a multiplexer circuit configured for selectively switching the frame data supplied according a prescribed maximum link width, to one of a plurality of available link widths for a transmit bus, and a bus controller. The bus controller is configured for controlling the multiplexer circuit to switch the frame data to one of the available link widths, including the prescribed link width, based the selected link width. Hence, a channel adapter can be configured for an optimum link width for communication with a corresponding channel adapter on a peer node.

Arrangement in a channel adapter for transmitting data according to link widths selected based on received link management packets

A host channel adapter includes a transport layer module, a link layer module, and buffer memory having memory portions configured for storage of transmit data packets output by the transport layer module for transmission by the link layer module on identified virtual lanes. The transport layer module is configured for identifying a virtual lane for each transmit data packet, and for storing the transmit data packet in the corresponding memory portion assigned to the corresponding identified virtual lane. Hence, the transmit data packets output by the transport layer module are stored in the memory portions based on their respective identified virtual lanes, where each memory portion stores the transmit data packets for the corresponding identified virtual lane. The link layer module retrieves the transmit data packets from a selected memory portion corresponding to a currently-serviced virtual lane based on a prescribed virtual lane arbitration. Hence, the link layer module can retrieve the transmit data packets for the currently-serviced virtual lane with minimal processing, based on accessing the corresponding memory portion.

Arrangement in a channel adapter for segregating transmit packet data in transmit buffers based on respective virtual lanes

An host channel adapter embedded within a processor device includes a transport layer module, a transport layer buffer, a link layer module, and a link layer buffer configured for storing at least two packets to be transmitted by the embedded host channel adapter. The transport layer module is configured for generating, for each packet to be transmitted, a transport layer header, and storing in the transport layer buffer the transport layer header and a corresponding identifier that specifies a stored location of a payload for the transport layer header. The link layer module includes payload fetch logic configured for fetching the payload based on the corresponding identifier, enabling the link layer module to construct one of the two packets to be transmitted concurrently during transmission of the second of the two packets.

Embedded channel adapter having link layer configured for concurrent retrieval of payload data during packet transmission

A channel adapter includes a link receive resource configured for initiating packet validation upon detecting a receive counter reaching a prescribed threshold corresponding to reception of an initial header of a data packet. Upon initiating packet validation, the link receive resource determines whether the initial header includes any errors. Any errors detected in the initial header are stored if the errors are detected prior to reception of an end of the data packet. Additional validation operations can be initiated upon reception of the respective headers. Upon receiving the end of the data packet, the link receive resource selectively reports the errors detected in the initial header based on whether any higher-priority error is detected relative to a prescribed error reporting order.

Arrangement in a channel adapter for validating headers concurrently during reception of a packet for minimal validation latency

A host channel adapter is configured for servicing received work notifications based on identifying the work notifications associated with the virtual lanes (VL) having a prescribed ordering position identified by the link layer operations. The host channel adapter, in response to receiving a work notification for a prescribed service level (SL), determines the virtual lane associated with the specified service level based on a prescribed service level to virtual lane mapping. If necessary (e.g., for an unreliable datagram service type), the work notification supplies the prescribed service level (SL) for the host channel adapter. The host channel adapter also determines an ordering position for the determined virtual lane from the link layer module, and selectively services the work notification based on the corresponding ordering position.

Arrangement in a channel adapter for servicing work notifications based on link layer virtual lane processing

An embedded host channel adapter includes a transport layer module, a transport layer buffer, and a link layer module. The transport layer buffer is configured for storing transmit packet entries for virtual lanes serviced by the embedded host channel adapter. The link layer module is configured for supplying virtual lane priority information and virtual lane flow control information, for each virtual lane, to the transport layer module. The link layer module also configured for constructing transmit packets to be transmitted based on retrieval thereof from the transport layer buffer. The transport layer module is configured for selecting one of the virtual lanes for servicing based on the supplied virtual lane priority information and virtual lane flow control information for each of the virtual lanes, enabling the transport layer module to prioritize received work notifications, for generation of respective transmit packet entries.

Embedded channel adapter having transport layer configured for prioritizing selection of work descriptors based on respective virtual lane priorities

A host channel adapter is configured for servicing a work notification, supplied by a host process to an assigned destination address accessable by the host channel adapter, based on matching the assigned destination address with a stored notification address from one of a plurality of queue pair context entries stored within the host channel adapter. The host channel adapter receives a queue pair context entry including a notification address, based on creation of a corresponding queue pair for a host process. The queue pair enables the host process to post a work descriptor and output a work notification to the host channel adapter by writing the work notification to an assigned destination address. The host channel adapter matches the assigned destination address with a stored notification address, and services the work descriptor based on the corresponding queue pair attributes specified in the identified queue pair context entry.

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Austin, TX, United States of America

Joseph Winkles