Abstract: 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.

Abstract: A consumer resource provider is configured for generating a work request to a prescribed virtual destination address on behalf of a user-mode consumer process requiring a memory access. An operating system resource, configured for establishing communications between the consumer resource provider and a host channel adapter configured for servicing the work notifications, assigns virtual address space for use by the consumer resource provider, and respective unique mapping values specified as user mode access for use by the consumer resource provider in executing the memory accesses on behalf of the respective user-mode consumer processes. An address translator includes a translation map for uniquely mapping the virtual address space used by the consumer resource provider to a prescribed physical address space accessible by the host channel adapter.

Abstract: An operating system resource, configured for establishing communications between consumer processes configured for generating respective work notifications and a host channel adapter configured for servicing the work notifications, assigns virtual address space for use by the consumer processes in executing memory accesses, and respective unique mapping values. An address translator includes a translation map for uniquely mapping the virtual address space used by the consumer processes to a prescribed physical address space accessible by the host channel adapter. The address translator, in response to receiving from an identified consumer process the work notification at a virtual address, maps the work notification to a corresponding prescribed physical address based on the corresponding mapping value assigned to the identified consumer process, enabling the host channel adapter to detect the work notification for the consumer process.

Abstract: A computer system includes a read ahead buffer coupled to a memory controller and an input/output controller coupled to an input/output channel. An I/O device provides an initial read request over the input/output channel which specifies an address in system memory. The memory controller retrieves an amount of data from system memory larger than specified by the read request and provides the requested data to the input/output channel and thus the I/O device. At least a portion of the data retrieved from system memory is stored in the read ahead buffer. The read ahead buffer is marked as valid and identified by at least a portion of the address specified in the read request. When the same I/O device performs a subsequent read access, the I/O request circuit determines whether at least a portion of the address of the subsequent read request matches the portion of the address identifying the read ahead buffer and provides a tag match signal as an indication thereof.

Abstract: A computer system includes a read ahead buffer coupled to a memory controller and an input/output controller coupled to an input/output channel. An I/O device provides an initial read request over the input/output channel which specifies an address in system memory. The memory controller retrieves an amount of data from system memory larger than specified by the read request and provides the requested data to the input/output channel and thus the I/O device. At least a portion of the data retrieved from system memory is stored in the read ahead buffer. The read ahead buffer is marked as valid and identified by at least a portion of the address specified in the read request. When the same I/O device performs a subsequent read access, the I/O request circuit determines whether at least a portion of the address of the subsequent read request matches the portion of the address identifying the read ahead buffer and provides a tag match signal as an indication thereof.