Abstract: A system for communicating command parameters between a processor and a memory flow controller is provided. The system makes use of a channel interface as the primary mechanism for communicating between the processor and a memory flow controller. The channel interface provides channels for communicating with processor facilities, memory flow control facilities, machine state registers, and external processor interrupt facilities, for example. These channels may be designated as blocking or non-blocking. With blocking channels, when no data is available to be read from the corresponding registers, or there is no space available to write to the corresponding registers, the processor is placed in a low power “stall” state. The processor is automatically awakened, via communication across the blocking channel, when data becomes available or space is freed. Thus, the channels of the present invention permit the processor to stay in a low power state.

Abstract: A method, apparatus, and computer usable program code for logical partitioning and virtualization in heterogeneous computer architecture. In one illustrative embodiment, a portion of a first set of processors of a first type is allocated to a partition in a heterogeneous logically partitioned system and a portion of a second set of processors of a second type is allocated to the partition.

Abstract: Mechanisms for communicating with a processor event facility are provided. The mechanisms make use of a channel interface as the primary mechanism for communicating with the processor event facility. The channel interface provides channels for communicating with processor facilities, memory flow control facilities, machine state registers, and external processor interrupt facilities, for example. These channels may be designated as blocking or non-blocking. With blocking channels, when no data is available to be read from the corresponding registers, or there is no space available to write to the corresponding registers, the processor is placed in a low power “stall” state. The processor is automatically awakened, via communication across the blocking channel, when data becomes available or space is freed. Thus, the channels of the present invention permit the processor to stay in a low power state.

Abstract: A mechanism for communicating instructions and data between a processor and external devices are provided. The mechanism makes use of a channel interface as the primary mechanism for communicating between the processor and a memory flow controller. The channel interface provides channels for communicating with processor facilities, memory flow control facilities, machine state registers, and external processor interrupt facilities, for example. These channels may be designated as blocking or non-blocking. With blocking channels, when no data is available to be read from the corresponding registers, or there is no space available to write to the corresponding registers, the processor is placed in a low power “stall” state. The processor is automatically awakened, via communication across the blocking channel, when data becomes available or space is freed. Thus, the channels of the present invention permit the processor to stay in a low power state.

Abstract: A method for communicating instructions and data between a processor and external devices are provided. The method makes use of a channel interface as the primary mechanism for communicating between the processor and a memory flow controller. The channel interface provides channels for communicating with processor facilities, memory flow control facilities, machine state registers, and external processor interrupt facilities, for example. These channels may be designated as blocking or non-blocking. With blocking channels, when no data is available to be read from the corresponding registers, or there is no space available to write to the corresponding registers, the processor is placed in a low power “stall” state. The processor is automatically awakened, via communication across the blocking channel, when data becomes available or space is freed. Thus, the channels of the present invention permit the processor to stay in a low power state.

Abstract: A system for limiting the size of a local storage of a processor is provided. A facility is provided in association with a processor for setting a local storage size limit. This facility is a privileged facility and can only be accessed by the operating system running on a control processor in the multiprocessor system or the associated processor itself. The operating system sets the value stored in the local storage limit register when the operating system initializes a context switch in the processor. When the processor accesses the local storage using a request address, the local storage address corresponding to the request address is compared against the local storage limit size value in order to determine if the local storage address, or a modulo of the local storage address, is used to access the local storage.

Abstract: A mechanism is provided for efficiently managing the operation of a translation buffer. The mechanism is utilized to pre-load a translation buffer to prevent poor operation as a result of slow warming of a cache. A software pre-load mechanism may be provided for preloading a translation look aside buffer (TLB) via a hardware implemented controller. Following preloading of the TLB, control of accessing the TLB may be handed over to the hardware implemented controller. Upon an application context switch operation, the software preload mechanism may be utilized again to preload the TLB with new translation information for the newly active application instance.

Abstract: A system and method for communicating with a processor event facility are provided. The system and method make use of a channel interface as the primary mechanism for communicating with the processor event facility. The channel interface provides channels for communicating with processor facilities, memory flow control facilities, machine state registers, and external processor interrupt facilities, for example. These channels may be designated as blocking or non-blocking. With blocking channels, when no data is available to be read from the corresponding registers, or there is no space available to write to the corresponding registers, the processor is placed in a low power “stall” state. The processor is automatically awakened, via communication across the blocking channel, when data becomes available or space is freed. Thus, the channels of the present invention permit the processor to stay in a low power state.

Abstract: A system for limiting the size of a local storage of a processor is provided. A facility is provided in association with a processor for setting a local storage size limit. This facility is a privileged facility and can only be accessed by the operating system running on a control processor in the multiprocessor system or the associated processor itself. The operating system sets the value stored in the local storage limit register when the operating system initializes a context switch in the processor. When the processor accesses the local storage using a request address, the local storage address corresponding to the request address is compared against the local storage limit size value in order to determine if the local storage address, or a modulo of the local storage address, is used to access the local storage.

Abstract: A buffer, a method, and a computer program product for DMA transfers are provided that are designed to save memory space within a local memory of a processor. The buffer is a return buffer with a portion reserved for DMA lists. A DMA controller accomplishes DMA transfers by: reading address elements from a DMA list located in the DMA list portion; reading the corresponding data from system memory; and copying the corresponding data to the return buffer portion. This buffer saves space because when the buffer begins to fill up the corresponding return data can overwrite the data in the DMA list. Accordingly, the DMA list overlays on top of the return buffer, such that the return data can destruct the DMA list and the extra storage space for the DMA list is saved.

Abstract: A method for limiting the size of a local storage of a processor is provided. A facility is provided in association with a processor for setting a local storage size limit. This facility is a privileged facility and can only be accessed by the operating system running on a control processor in the multiprocessor system or the associated processor itself The operating system sets the value stored in the local storage limit register when the operating system initializes a context switch in the processor. When the processor accesses the local storage using a request address, the local storage address corresponding to the request address is compared against the 1ocal storage limit size value in order to determine if the local storage address, or a modulo of the local storage address, is used to access the local storage.

Abstract: A method for communicating with a processor event facility is provided. The method makes use of a channel interface as the primary mechanism for communicating with the processor event facility. The channel interface provides channels for communicating with processor facilities, memory flow control facilities, machine state registers, and external processor interrupt facilities, for example. These channels may be designated as blocking or non-blocking. With blocking channels, when no data is available to be read from the corresponding registers, or there is no space available to write to the corresponding registers, the processor is placed in a low power “stall” state. The processor is automatically awakened, via communication across the blocking channel, when data becomes available or space is freed. Thus, the channels of the present invention permit the processor to stay in a low power state.

Abstract: A mechanism for communicating instructions and data between a processor and external devices are provided. The mechanism makes use of a channel interface as the primary mechanism for communicating between the processor and a memory flow controller. The channel interface provides channels for communicating with processor facilities, memory flow control facilities, machine state registers, and external processor interrupt facilities, for example. These channels may be designated as blocking or non-blocking. With blocking channels, when no data is available to be read from the corresponding registers, or there is no space available to write to the corresponding registers, the processor is placed in a low power “stall” state. The processor is automatically awakened, via communication across the blocking channel, when data becomes available or space is freed. Thus, the channels of the present invention permit the processor to stay in a low power state.

Abstract: A system and method for communicating command parameters between a processor and a memory flow controller are provided. The system and method make use of a channel interface as the primary mechanism for communicating between the processor and a memory flow controller. The channel interface provides channels for communicating with processor facilities, memory flow control facilities, machine state registers, and external processor interrupt facilities, for example. These channels may be designated as blocking or non-blocking. With blocking channels, when no data is available to be read from the corresponding registers, or there is no space available to write to the corresponding registers, the processor is placed in a low power “stall” state. The processor is automatically awakened, via communication across the blocking channel, when data becomes available or space is freed. Thus, the channels of the present invention permit the processor to stay in a low power state.

Abstract: Exemplary embodiments include a method for enhancing lock acquisition in a multiprocessor system, the method including: sending a lock-load instruction from a first processor to a cache; setting a reservation flag for the first processor, storing a reservation address, storing a shadow register number, and sending lock data to the first processor in response to the lock-load instruction; placing the lock data in target and shadow registers of the first processor; determining from the lock data whether lock is taken; resending the lock-load instruction from the first processor to the cache upon a determination that the lock is taken; determining whether the reservation flag is still set and its main memory address and shadow register number match with the saved reservation address and shadow register number for the first processor; sending a status-quo signal to the first processor without resending the lock data to the first processor upon a determination that the reservation flag is still set for the first p

Abstract: A system and method for communicating command parameters between a processor and a memory flow controller are provided. The system and method make use of a channel interface as the primary mechanism for communicating between the processor and a memory flow controller. The channel interface provides channels for communicating with processor facilities, memory flow control facilities, machine state registers, and external processor interrupt facilities, for example. These channels may be designated as blocking or non-blocking. With blocking channels, when no data is available to be read from the corresponding registers, or there is no space available to write to the corresponding registers, the processor is placed in a low power “stall” state. The processor is automatically awakened, via communication across the blocking channel, when data becomes available or space is freed. Thus, the channels of the present invention permit the processor to stay in a low power state.

Abstract: A system and method for providing a mediated external exception extension for a microprocessor are provided. With the system and method, in response to an external exception, a hypervisor determines if the associated external interrupt is directed to a logical partition (LPAR) that has external interrupt handling enabled. If so, the hypervisor sets appropriate state restore registers (SRRs) and passes control to an external interrupt handler of the LPAR. If external interrupt handling is not currently enabled by the LPAR, the hypervisor sets a mediated exception request and returns control to the LPAR. Once the operating system of the logical partition re-enables external interrupt handling, a mediated external interrupt occurs, state information for the LPAR is set in the SRRs, and the external interrupt handler of the LPAR is invoked. In this way, external interrupts may be received by the hypervisor even when external interrupt handling is disabled.

Abstract: A method, apparatus, and computer usable program code for logical partitioning and virtualization in heterogeneous computer architecture. In one illustrative embodiment, a portion of a first set of processors of a first type is allocated to a partition in a heterogeneous logically partitioned system and a portion of a second set of processors of a second type is allocated to the partition.

Abstract: A method and apparatus for powering down a computer system while saving the state of the system at power down is disclosed. The system maintains the capability to suspend the execution of an application program operating on the system at any point and resuming execution of the application program at that same point at a later time. The time at which the system may be powered down and then powered back up again is totally arbitrary and depends only upon the user of the system. At the time the system is powered off, the contents of all active registers as well as the states of all I/O devices in the system are stored in a special save area of system memory. This special save area is provided with power during the suspended time in order to retain the state of the system at the time it was powered down. By using this special save suspend area, the main memory area of the system is available to any application programs independently of the system save memory requirements.

Abstract: An apparatus and method are provided for disabling the clocking of a processor in a battery operated computer during non-processing times. The clocking is disabled at the conclusion of a processing operation. The clocking can then be re-enabled using interrupts from any one of a plurality of sources, such as an I/O device or a direct memory access. Application programs and operating system programs running on the system can specify the stopping of the system clock and the central processor until a specified event which had been requested occurs, or until an optional time-out period has expired. In this situation, the event is defined as one that results in either a system interrupt from an I/O device or from a direct memory access operation. The stopping of the system clock is a two part operation wherein in the first part the stopping mechanism is first armed. If an interrupt is received subsequent to arming, then it will be processed and the arming mechanism will be reset.