Abstract: A method, system and computer program product are provided for implementing cable failover in multiple cable Peripheral Component Interconnect Express (PCIE) IO interconnections to an external IO enclosure. System firmware is provided for implementing health check functions for the PCIE IO interconnections to identify a faulted low byte cable. A cable failover mechanism recovers a PCI link to the external IO enclosure. A multiplexer logic is provided between the PCIE host bridge (PHB) and the cable connected to the IO enclosure to perform a full lane reversal of the PCIE lanes.

Abstract: A PCI host bridge (PHB) includes a warm reset mode and a full reset mode. When a fatal error occurs, the type of fatal error is determined, a reset mode corresponding to that type of fatal error is determined, and a reset corresponding to the reset mode is performed. A full reset clears the error registers, status registers and configuration registers, which then requires the configuration registers to be reconfigured before the PHB can be reinitialized. A warm reset clears the error registers and status registers, but does not clear the configuration registers. A warm reset thus does not require the time to write to the configuration registers, and the PHB can be reinitialized using the existing configuration data in the configuration registers while link training is done in parallel. When initialization of the PHB after a warm reset is not successful, a full reset is performed.

Abstract: An I/O DMA address may be translated for a flexible number of entries in a translation validation table (TVT) for a partitionable endpoint number, when a particular entry in the TVT is accessed based on the partitionable endpoint number. A presence of an extended mode bit can be detected in a particular TVT entry. Based on the presence of the extended mode bit, an entry in the extended TVT can be accessed and used to translate the I/O DMA address to a physical address.

Abstract: An I/O DMA address may be translated for a flexible number of entries in a translation validation table (TVT) for a partitionable endpoint number, when a particular entry in the TVT is accessed based on the partitionable endpoint number. A presence of an extended mode bit can be detected in a particular TVT entry. Based on the presence of the extended mode bit, an entry in the extended TVT can be accessed and used to translate the I/O DMA address to a physical address.

Abstract: A method, system and computer program product are provided for detecting state and sparing of optical Peripheral Component Interconnect Express (PCI-Express or PCIE) cable channels attached to an IO drawer. System firmware is provided for implementing health check functions and state detection and sparing functions. One or more optical cables are connected between a host bridge and a PCIE enclosure, each optical cable includes one or more spare optical channels. An identified failed optical channel is rerouted to the spare optical channel.

Abstract: A PCI function, such as a device driver, may request that additional MSI resources be allocated to an I/O device coupled to a PCI Host Bridge (PHB). However, there may not be any unallocated MSI resource remaining in the PHB. Instead, a hypervisor may request to borrow MSI resources assigned to other PCI functions in the system. For example, the PCI function requesting the additional MSI resources may ask for a certain number of MSI resources for a certain period of time—e.g., a lease. The hypervisor then determines which of the other PCI functions (referred to as a loaning PCI functions) are willing to lend or loan their MSI resources. Once the MSI resources available for lease are known, the hypervisor informs the requesting PCI function of these resources which, in turn, binds the additional MSI resources to the I/O device.

Abstract: A PCI function, such as a device driver, may request that additional MSI resources be allocated to an I/O device coupled to a PCI Host Bridge (PHB). However, there may not be any unallocated MSI resource remaining in the PHB. Instead, a hypervisor may request to borrow MSI resources assigned to other PCI functions in the system. For example, the PCI function requesting the additional MSI resources may ask for a certain number of MSI resources for a certain period of time—e.g., a lease. The hypervisor then determines which of the other PCI functions (referred to as a loaning PCI functions) are willing to lend or loan their MSI resources. Once the MSI resources available for lease are known, the hypervisor informs the requesting PCI function of these resources which, in turn, binds the additional MSI resources to the I/O device.

Abstract: A method and a system for enabling communications on a signaling link include a first and a second device interconnected by the signaling link. The first device performs the method to acquire information from the second device. Based on the information acquired the first device determines to enable the signaling link for operational communications between the first device and the second device. A computer programming product instructs a computer to perform the method.

Abstract: A method, system and computer program product are provided for implementing coherent accelerator function isolation for virtualization in an input/output (IO) adapter in a computer system. A coherent accelerator provides accelerator function units (AFUs), each AFU is adapted to operate independently of the other AFUs to perform a computing task that can be implemented within application software on a processor. The AFU has access to system memory bound to the application software and is adapted to make copies of that memory within AFU memory-cache in the AFU. As part of this memory coherency domain, each of the AFU memory-cache and processor memory-cache is adapted to be aware of changes to data commonly in either cache as well as data changed in memory of which the respective cache contains a copy.

Abstract: Instead of disabling PCI communication between system resources in a host computing device and I/O devices when a PCI Host Bridge (PHB) is reset, the host computing device may include a PCI communication path for maintaining communication between the system resources and the I/O devices. In one embodiment, the redundant PCI communication path includes a second PHB that is maintained in a standby state. The host may monitor the errors generated by a plurality of master PHBs and select a master PHB that satisfies an error threshold. The second PHB (i.e., a servant PHB) and the selected master PHB are synchronized, and the second PHB is coupled to the PCI communication path between the master PHB and a PCI switch. The master PHB can then be reset while the second PHB maintains PCI communication between the host and the I/O devices.

Abstract: A method, system and computer program product are provided for implementing health check for optical cable attached Peripheral Component Interconnect Express (PCIE) enclosures in a computer system. System firmware is provided for implementing health check functions. One or more optical cables are connected between a host bridge and a PCIE enclosure. A PCIE link to the PCIE enclosure is reset responsive to a predefined event. After a set delay, a PCIE link health check is performed verifying PCIE link width and speed.

Abstract: Instead of disabling PCI communication between system resources in a host computing device and I/O devices when a PCI Host Bridge (PHB) is reset, the host computing device may include a PCI communication path for maintaining communication between the system resources and the I/O devices. In one embodiment, the redundant PCI communication path includes a second PHB that is maintained in a standby state. The host may monitor the errors generated by a plurality of master PHBs and select a master PHB that satisfies an error threshold. The second PHB (i.e., a servant PHB) is assigned to backup the master PHB that satisfies the error threshold. The master PHB can then be reset while the second PHB maintains PCI communication between the host and the I/O devices.

Abstract: A method, system and computer program product are provided for implementing health check for optical cable attached Peripheral Component Interconnect Express (PCIE) enclosures in a computer system. System firmware is provided for implementing health check functions. One or more optical cables are connected between a host bridge and a PCIE enclosure. A PCIE link to the PCIE enclosure is reset responsive to a predefined event. After a set delay, a PCIE link health check is performed verifying PCIE link width and speed.

Abstract: A method, system and computer program product are provided for detecting state and sparing of optical Peripheral Component Interconnect Express (PCI-Express or PCIE) cable channels attached to an IO drawer. System firmware is provided for implementing health check functions and state detection and sparing functions. One or more optical cables are connected between a host bridge and an PCIE enclosure, each optical cable includes one or more spare optical channels. An identified failed optical channel is rerouted to the spare optical channel.

Abstract: A method, system and computer program product are provided for detecting state and sparing of optical Peripheral Component Interconnect Express (PCI-Express or PCIE) cable channels attached to an IO drawer. System firmware is provided for implementing health check functions and state detection and sparing functions. One or more optical cables are connected between a host bridge and a PCIE enclosure, each optical cable includes one or more spare optical channels. An identified failed optical channel is rerouted to the spare optical channel.

Abstract: A method, system and computer program product are provided for detecting and configuring an external input/output (IO) enclosure in a computer system. A PCIE Host Bridge (PHB) in a system unit is connected to a plurality of PCIE add-in card slots. One or more cables are connected between the PHB and the external enclosure. System firmware including detecting and configuring functions uses sideband structure for detecting a PCIE cable card and configuring the external input/output (IO) enclosure.

Abstract: A method, system and computer program product are provided for detecting and configuring an external input/output (IO) enclosure in a computer system. A PCIE Host Bridge (PHB) in a system unit is connected to a plurality of PCIE add-in card slots. One or more cables are connected between the PHB and the external enclosure. System firmware including detecting and configuring functions uses sideband structure for detecting a PCIE cable card and configuring the external input/output (IO) enclosure.

Abstract: DMA translation table entries include a consecutive count (CC) field that indicates how many subsequent translation table entries point to successive real page numbers. A DMA address translation mechanism stores a value in the CC field when a translation table entry is stored, and updates the CC field in other affected translation table entries as well. When a translation table entry is read, and the CC field is non-zero, the DMA controller can use multiple RPNs from the access to the single translation table entry. Thus, if a translation table entry has a value of 2 in the CC field, the DMA address translation mechanism knows it can access the real page number (RPN) corresponding to the translation table entry, and also knows it can access the two subsequent RPNs without the need of reading the next two subsequent translation table entries.

Abstract: Instead of disabling PCI communication between system resources in a host computing device and I/O devices when a PCI Host Bridge (PHB) is reset, the host computing device may include a PCI communication path for maintaining communication between the system resources and the I/O devices. In one embodiment, the redundant PCI communication path includes a second PHB that is maintained in a standby state. The host may monitor the errors generated by a plurality of master PHBs and select a master PHB that satisfies an error threshold. The second PHB (i.e., a servant PHB) and the selected master PHB are synchronized, and the second PHB is coupled to the PCI communication path between the master PHB and a PCI switch. The master PHB can then be reset while the second PHB maintains PCI communication between the host and the I/O devices.

Abstract: DMA translation table entries include a consecutive count (CC) field that indicates how many subsequent translation table entries point to successive real page numbers. A DMA address translation mechanism stores a value in the CC field when a translation table entry is stored, and updates the CC field in other affected translation table entries as well. When a translation table entry is read, and the CC field is non-zero, the DMA controller can use multiple RPNs from the access to the single translation table entry. Thus, if a translation table entry has a value of 2 in the CC field, the DMA address translation mechanism knows it can access the real page number (RPN) corresponding to the translation table entry, and also knows it can access the two subsequent RPNs without the need of reading the next two subsequent translation table entries.