Freescale Semiconductor,inc.

International Business Machines Corporation

Gary L Whisenhunt

Michael D Snyder

Kumar K Gala

William C Moyer

Bryan D Marietta

David B Kramer

Becky Bruce

Giles R Frazier

Bradly George Frey

James Xenidis

Cathy May

Klas Magnus Bruce

Sergio Schuler

Trinh Huy Nguyen

David C Holloway

Matt B Smittle

Sanjay Raghunath Deshpande

Daniel L Bouvier

Kathryn C Stacer

Mihir A Pandya

David F Greenberg

Syed R Rahman

A method and circuit for a data processing system () provide a processor-based partitioned priority blocking mechanism by storing priority levels and associated partition information in special purpose registers (-) located at the processor core () to enable quick and efficient interrupt priority blocking on a partition basis.

Interrupt priority management using partition-based priority blocking processor registers

A method and circuit for a data processing system () provide a processor-based partitioned priority blocking mechanism by storing interrupt identifiers, partition identifiers, thread identifiers, and priority levels associated with accepted interrupt requests in special purpose registers (-) located at the processor core () to enable quick and efficient interrupt priority blocking on a partition basis.

Processor interrupt interface with interrupt partitioning and virtualization enhancements

For use in a data processing system comprising a processor configured to execute a first set of instructions corresponding to a first thread and a second set of instructions corresponding to a second thread, a method is provided. The method comprises in response to execution of a debug related instruction by the first thread while executing the first set of instructions, generating a debug event for processing by the second thread, wherein processing the debug event comprises causing a halting operation related to the processor.

Debug instruction for execution by a first thread to generate a debug event in a second thread to cause a halting operation

A method and circuit for a data processing system provide virtualized instructions for accessing a partitioned device (e.g.,) by executing a control instruction () to encode and store an access command (CMD) in a data payload with a hardware-inserted partition attribute (LPID) for storage to a command register () at a physical address (PA) retrieved from a special purpose register () so that the partitioned device () can determine if the access command can be performed based on local access control information.

Virtualized instruction extensions for system partitioning

A data processing system having a processor and a target device processes decorated instructions (i.e. an instruction having a decoration value). A device of the data processing system such as the processor sends transactions to the target device over a system interconnect. A decorated storage notify (DSN) transaction includes an indication of an instruction operation, an address associated with the instruction operation, and a decoration value (i.e. a command to the target device to perform a function in addition to a store or a load). The transaction on the system interconnect includes an address phase and no data phase, thereby improving system bandwidth. In one form the target device (e.g. a memory with functionality in addition to storage functionality) performs a read-modify-write operation using information at a storage location of the target device.

Data processor for processing a decorated storage notify

A method and circuit for a data processing system provide a partitioned interrupt controller with an efficient deferral mechanism for processing partitioned interrupt requests by executing a control instruction to encode and store a delay command (e.g., DEFER or SUSPEND) in a data payload with a hardware-inserted partition attribute (LPID) for storage to a command register () at a physical address (PA) retrieved from a special purpose register () so that the partitioned interrupt controller () can determine if the delay command can be performed based on local access control information.

Virtualized interrupt delay mechanism

A technique for indicating a safe shared resource condition with respect to a disabled thread provides a mechanism for providing a fast indication to other hardware threads that a temporarily disabled thread can no longer impact shared resources, such as shared special-purpose registers and translation look-aside buffers within the processor core. Signals from pipelines within the core indicates whether any of the instructions pending in the pipeline impact the shared resources and if not, then the thread disable status is presented to the other threads via a state change in a thread status register. Upon receiving an indication that a particular hardware thread is to be disabled, control logic halts the dispatch of instructions for the particular hardware thread, and then waits until any indication that a shared resource is impacted by an instruction has cleared. Then the control logic updates the thread status to indicate the thread is disabled.

Indicating disabled thread to other threads when contending instructions complete execution to ensure safe shared resource condition

A technique for scheduling execution of threads at a processor is disclosed. The technique includes executing a thread de-emphasis instruction of a thread that de-emphasizes the thread until the number of pending memory transactions, such as cache misses, associated with the thread are at or below a threshold. While the thread is de-emphasized, other threads at the processor that have a higher priority can be executed or assigned system resources. Accordingly, the likelihood of a stall in the processor is reduced.

Thread de-emphasis instruction for multithreaded processor

A data processing system having a processor and a target device processes decorated instructions (i.e. an instruction having a decoration value). A device of the data processing system such as the processor sends transactions to the target device over a system interconnect. The transactions include an indication of an instruction operation, an address associated with the instruction operation, a decoration value (i.e. a command to the target device to perform a function in addition to a primary function of the executed instruction), and access permissions associated with the address. The target device (e.g. a memory with functionality in addition to storage functionality) determines whether a decoration operation specified by the decoration value is permissible based on the received access permissions. The target device performs the decoration operation if appropriate permissions exist.

Permissions checking for data processing instructions

Processor with hardware thread control logic indicating disable status when instructions accessing shared resources are completed for safe shared resource condition

A first thread enters a polling loop to wait for a signal from a second thread before processing instructions dependent on the polling loop. When entering the polling loop, the first thread sets a reservation for a predetermined memory address. The first thread then executes a reservation-based instruction that can change the execution state of the first thread. Reservation circuitry of the processing device that was executing the first thread monitors the reservation. In the event that the reservation cleared, such as by the second thread modifying data at the predetermined memory address, the first thread is reinstated to its prior execution state. By using a hardware reservation mechanism to monitor for clearing of a set reservation, repeated memory accesses to the memory address by the first thread can be minimized or avoided while in the polling loop and other threads can be allowed to execute at the processing device with reduced interference from the waiting thread.

Polling using reservation mechanism

A processor implementation supports selection of an execution mode for debug instruction instances based on respective addresses thereof in addressable memory can provide an attractive mechanism for executing debug instructions in a way that allows some instances of the instructions to operate with debug semantics while suppressing other instances by executing them with no-operation (NOP) semantics. In some embodiments, selection of operative execution semantics may be based on attributes of a memory page in which a particular debug instruction instance resides. In some embodiments, portions of an address space may be delimited (e.g., using values stored in bounding registers and addresses of particular debug instruction instances compared against the delimited portions to select appropriate execution semantics. In some embodiments, both types of evaluations may be used in selecting appropriate execution semantics for a particular debug instruction instance.

Qualification of conditional debug instructions based on address

A processing device includes a storage component configured to store instructions associated with a corresponding thread of a plurality of threads, and an execution unit configured to fetch and execute instructions. The processing device further includes a period timer comprising an output to provide an indicator in response to a count value of the period timer reaching a predetermined value based on a clock signal. The processing device additionally includes a plurality of thread forward-progress counter components, each configured to adjust a corresponding execution counter value based on an occurrence of a forward-progress indicator while instructions of a corresponding thread are being executed. The processing device further includes a thread select module configured to select threads of the plurality of threads for execution by the execution unit based a state of the period timer and a state of each of the plurality of thread forward-progress counter components.

Forward progress mechanism for a multithreaded processor

A data processing system and method of operation has a processor coupled to a cache. Cache control circuitry is coupled to the cache and performs error detection. A user programmable error action control register stores a control value for selecting a type of error action to be taken when a cache error is detected. A first value of the control value permits handling of a cache error that is transparent to the processor, and a second value permits handling of the cache error by taking an exception that is visible to the processor. Various alternate actions to a detected error, including error correction or cache line invalidation, may be taken in response to other values of the control value.

Programmable error actions for a cache in a data processing system

A method includes communicating a first message between processors of a multiprocessor system via a coherency interconnect, whereby the first message includes coherency information. The method further includes communicating a second message between processors of the multiprocessor system via the coherency interconnect, whereby the second message includes interprocessor message information. A system includes a coherency interconnect and a processor. The processor includes an interface configured to receive messages from the coherency interconnect, each message including one of coherency information or interprocessor message information. The processor further includes a coherency management module configured to process coherency information obtained from at least one of the messages and an interrupt controller configured to generate an interrupt based on interprocessor message information obtained from at least one of the messages.

Growing community of inventors

Leander, TX, United States of America

Gary L Whisenhunt