Abstract: A technique for triggering a system bus write command with user code includes identifying a specific store-type instruction in a user instruction sequence. The specific store-type instruction is converted into a specific request-type command, which is configured to include core permission controls (that are stored in core configuration registers of a processor core by a trusted kernel) and user created data (stored in a cache memory). Slave devices are configured through register space (that is only accessible by the trusted kernel) with respective slave permission controls. The specific request-type command is then transmitted from the cache memory, via a system bus. In this case, the slave devices that receive the specific request-type command process the specific request-type command when the core permission controls are the same as the respective slave permission controls. The trusted kernel may be included in a hypervisor or an operating system.

Abstract: A design structure for a processor system may be embodied in a machine readable medium for designing, manufacturing or testing a processor integrated circuit. The design structure may embody a processor integrated circuit including multiple processors with respective processor cache memories. The design structure may specify enhanced cache coherency protocols to achieve cache memory integrity in a multi-processor environment. The design structure may describe a processor bus controller manages cache coherency bus interfaces to master devices and slave devices. The design structure may also describe a master I/O device controller and a slave I/O device controller that couple directly to the processor bus controller while system memory couples to the processor bus controller via a memory controller.

Abstract: The present invention provides for a system comprising a peripheral component interface (PCI) host bridge. The PCI host bridge is configured to be coupled to a PCI bus, and to receive a system reset signal, to generate a PCI bus reset signal based on the received system reset signal, to detect a PCI operational mode of the PCI bus, and to generate a voltage indicator signal based on the detected PCI operational mode. A voltage regulator is coupled to the PCI host bridge and configured to receive the voltage indicator signal and to regulate a signaling voltage for the PCI bus based on the voltage indicator signal.

Abstract: An information handling system includes a processor integrated circuit including multiple processors with respective processor cache memories. Enhanced cache coherency protocols achieve cache memory integrity in a multi-processor environment. A processor bus controller manages cache coherency bus interfaces to master devices and slave devices. In one embodiment, a master I/O device controller and a slave I/O device controller couple directly to the processor bus controller while system memory couples to the processor bus controller via a memory controller. In one embodiment, the processor bus controller blocks partial responses that it receives from all devices except the slave I/O device from being included in a combined response that the processor bus controller sends over the cache coherency buses.

Abstract: The present invention provides for a system comprising a peripheral component interface (PCI) host bridge. The PCI host bridge is configured to be coupled to a PCI bus, and to receive a system reset signal, to generate a PCI bus reset signal based on the received system reset signal, to detect a PCI operational mode of the PCI bus, and to generate a voltage indicator signal based on the detected PCI operational mode. A voltage regulator is coupled to the PCI host bridge and configured to receive the voltage indicator signal and to regulate a signaling voltage for the PCI bus based on the voltage indicator signal.

Abstract: Computer implemented method, system and computer usable program code for processing a data request in a data processing system. A read command requesting data is received from a requesting master device. It is determined whether a cache of a processor can provide the requested data. Responsive to a determination that a cache of a processor can provide the requested data, the requested data is routed to the requesting master device on an intervention data bus of the processor separate from a read data bus and a write data bus of the processor.

Abstract: The present invention provides for a system comprising a peripheral component interface (PCI) host bridge. The PCI host bridge is configured to be coupled to a PCI bus, and to receive a system reset signal, to generate a PCI bus reset signal based on the received system reset signal, to detect a PCI operational mode of the PCI bus, and to generate a voltage indicator signal based on the detected PCI operational mode. A voltage regulator is coupled to the PCI host bridge and configured to receive the voltage indicator signal and to regulate a signaling voltage for the PCI bus based on the voltage indicator signal.

Abstract: The present invention provides for a system comprising a peripheral component interface (PCI) host bridge. The PCI host bridge is configured to be coupled to a PCI bus, and to receive a system reset signal, to generate a PCI bus reset signal based on the received system reset signal, to detect a PCI operational mode of the PCI bus, and to generate a voltage indicator signal based on the detected PCI operational mode. A voltage regulator is coupled to the PCI host bridge and configured to receive the voltage indicator signal and to regulate a signaling voltage for the PCI bus based on the voltage indicator signal.

Abstract: The present invention provides for a system comprising a peripheral component interface (PCI) host bridge. The PCI host bridge is configured to be coupled to a PCI bus, and to receive a system reset signal, to generate a PCI bus reset signal based on the received system reset signal, to detect a PCI operational mode of the PCI bus, and to generate a voltage indicator signal based on the detected PCI operational mode. A voltage regulator is coupled to the PCI host bridge and configured to receive the voltage indicator signal and to regulate a signaling voltage for the PCI bus based on the voltage indicator signal.

Abstract: A control mechanism for data bus communications employs channels to which bus transactions are assigned, each channel having independent flow control. The control mechanism enforces an ordering algorithm among channels, whereby at least some transactions may pass other transactions. Channel attributes are programmable to vary the ordering conditions. Preferably, each channel is allocated its own programmable buffer area. The control mechanism independently determines, for each channel, whether buffer space is available and enforces flow control independently for each channel accordingly. Flow control is preferably credit-based, credits representing buffer space or some other capacity of a receiver to receive data. Preferably, the flow control mechanism comprises a central interconnect module controlling internal communications of an integrated circuit chip.

Abstract: In a method and apparatus associated with a bus controller, a set of mechanisms are selectively added to the bus controller, as well as to slave devices connected to the bus controller. A mechanism is also added to one or more master devices connected to the bus controller, in order to provide the master devices with a transaction ordering capability. The added mechanisms collectively achieve the objective of supporting connection of multiple slave devices to a common controller interface, and at the same time allowing pipelined operation of the slave devices. One embodiment of the invention is directed to a method for use with a bus and an associated bus controller, wherein the bus controller has respective master and slave interfaces for use in selectively interconnecting master devices and slave devices. The method comprises the steps of connecting one or more of the master devices to one of the master interfaces, and connecting each of a plurality of slave devices to the same one of the slave interfaces.

Abstract: A technique for triggering a system bus write command with user code includes identifying a specific store-type instruction in a user instruction sequence. The specific store-type instruction is converted into a specific request-type command, which is configured to include core permission controls (that are stored in core configuration registers of a processor core by a trusted kernel) and user created data (stored in a cache memory). Slave devices are configured through register space (that is only accessible by the trusted kernel) with respective slave permission controls. The specific request-type command is then transmitted from the cache memory, via a system bus. In this case, the slave devices that receive the specific request-type command (via the system bus) process the specific request-type command when the core permission controls are the same as the respective slave permission controls.

Abstract: An apparatus is described for data processing in a computer system. The apparatus comprises a data processing device having a data processing master, a functionally coupled data processor core, and a functionally coupled data processor slave. Both the data processing master and the data processing slave are coupled to a common bus or common crossbar switch. The data processing device processes the data associated with transfers to or from the data processor slave. System masters will direct transactions that require data processing to the data processing slave, which will indirectly interact with the target memory slave. System masters will direct transactions that do not require data processing, directly to the target memory slave.

Abstract: A method for maintaining cache coherency for a multi-node system using a specialized bridge which allows for fewer forward progress dependencies. A local node makes a determination whether a request is a local or system request. If the request is a local request, a look-up of a directory in the local node is performed. If an entry in the directory of the local node indicates that data in the request does not have a remote owner and that the request does not have a remote destination, the coherency of the data is resolved on the local node, and a transfer of the data specified in the request is performed if required and if the request is a local request. If the entry indicates that the data has a remote owner or that the request has a remote destination, the request is forwarded to all remote nodes in the multi-node system.

Abstract: An apparatus is described for data processing in a computer system. The apparatus comprises a data processing device having a data processing master, a functionally coupled data processor core, and a functionally coupled data processor slave. Both the data processing master and the data processing slave are coupled to a common bus or common crossbar switch. The data processing device processes the data associated with transfers to or from the data processor slave. System masters will direct transactions that require data processing to the data processing slave, which will indirectly interact with the target memory slave. System masters will direct transactions that do not require data processing, directly to the target memory slave.

Abstract: A method for maintaining cache coherency for a multi-node system using a specialized bridge which allows for fewer forward progress dependencies. A look-up of a local node directory is performed if a request received at a multi-node bridge of the local node is a system request. If a directory entry indicates that data specified in the request has a local owner or local destination, the request is forwarded to the local node. If the local node determines that the request is a local request, a look-up of the local node directory is performed. If the directory entry indicates that data specified in the request has a local owner and local destination, the coherency of the data on the local node is resolved and a transfer of the request data is performed if required. Otherwise, the request is forwarded to all remote nodes in the multi-node system.

Abstract: A communications bus for a digital device includes a credit-based flow control mechanism, in which a sending component maintains a local record of its credits. Credits are returned to the sender by pulsing a single-bit credit return line. A separate mechanism provides a count of available credits from the receiver, the separate mechanism not necessarily being current. The local record is compared to the count of credits from the separate mechanism over a pre-determined time interval, failure of the two values to agree at any time during the interval indicating a probable credit discrepancy. A credit discrepancy is confirmed, preferably by suspending certain bus activity for a sufficiently long period to account for any delay in propagating credit value changes, and re-comparing the values. Preferably, the bus communicates between internal components of an integrated circuit chip.

Abstract: Computer implemented method, system and computer usable program code for processing a data request in a data processing system. A read command requesting data is received from a requesting master device. It is determined whether a cache of a processor can provide the requested data. Responsive to a determination that a cache of a processor can provide the requested data, the requested data is routed to the requesting master device on an intervention data bus of the processor separate from a read data bus and a write data bus of the processor.

Abstract: A control mechanism for data bus communications employs channels to which bus transactions are assigned, each channel having independent flow control. The control mechanism enforces an ordering algorithm among channels, whereby at least some transactions may pass other transactions. Channel attributes are programmable to vary the ordering conditions. Preferably, each channel is allocated its own programmable buffer area. The control mechanism independently determines, for each channel, whether buffer space is available and enforces flow control independently for each channel accordingly. Flow control is preferably credit-based, credits representing buffer space or some other capacity of a receiver to receive data. Preferably, the flow control mechanism comprises a central interconnect module controlling internal communications of an integrated circuit chip.

Abstract: An apparatus is described for data processing in a computer system. The apparatus comprises a data processing device having a data processing master, a functionally coupled data processor core, and a functionally coupled data processor slave. Both the data processing master and the data processing slave are coupled to a common bus or common crossbar switch. The data processing device processes the data associated with transfers to or from the data processor slave. System masters will direct transactions that require data processing to the data processing slave, which will indirectly interact with the target memory slave. System masters will direct transactions that do not require data processing, directly to the target memory slave.