Advanced Micro Devices Corporation

Globalfoundries Inc.

Ati Technologies Ulc

Greggory D Donley

Vydhyanathan Kalyanasundharam

Bryan P Broussard

Benjamin Tsien

William Alexander Hughes

Michael K Fertig

Chen-Ping Yang

Philip Ng

Anthony Asaro

Jimshed B Mirza

Maggie Chan

Vincent Cueva

Yaniv Adiri

Kevin Michael Lepak

Narsing Krishna Vijayrao

Patrick N Conway

Chintan S Patel

Alan Dodson Smith

Mark A Silla

Ashwin Chincholi

Systems, apparatuses, and methods for performing efficient power management for a multi-node computing system are disclosed. A computing system includes multiple nodes. When power down negotiation is distributed, negotiation for system-wide power down occurs within a lower level of a node hierarchy prior to negotiation for power down occurring at a higher level of the node hierarchy. When power down negotiation is centralized, a given node combines a state of its clients with indications received on its downstream link and sends an indication on an upstream link based on the combining. Only a root node sends power down requests.

System-wide low power management

Systems, apparatuses, and methods for performing efficient data transfer in a computing system are disclosed. A computing system includes multiple fabric interfaces in clients and a fabric. A packet transmitter in the fabric interface includes multiple queues, each for storing packets of a respective type, and a corresponding address history cache for each queue. Queue arbiters in the packet transmitter select candidate packets for issue and determine when address history caches on both sides of the link store the upper portion of the address. The packet transmitter sends a source identifier and a pointer for the request in the packet on the link, rather than the entire request address, which reduces the size of the packet. The queue arbiters support out-of-order issue from the queues. The queue arbiters detect conflicts with out-of-order issue and adjust the outbound packets and fields stored in the queue entries to avoid data corruption.

Method for maintaining cache consistency during reordering

Systems, apparatuses, and methods for efficient data transfer in a computing system are disclosed. A source generates packets to send across a communication fabric (or fabric) to a destination. The source generates partition enable signals for the partitions of payload data. The source negates an enable signal for a particular partition when the source determines the packet type indicates the particular partition should have an associated asserted enable signal in the packet, but the source also determines the particular partition includes a particular data pattern. Routing components of the fabric disable clock signals to storage elements assigned to store the particular partition. The destination inserts the particular data pattern for the particular partition in the payload data.

Re-purposing byte enables as clock enables for power savings

A computing system uses a memory for storing data, one or more clients for generating network traffic and a communication fabric with network switches. The network switches include centralized storage structures, rather than separate input and output storage structures. The network switches store particular metadata corresponding to received packets in a single, centralized collapsing queue where the age of the packets corresponds to a queue entry position. The payload data of the packets are stored in a separate memory, so the relatively large amount of data is not shifted during the lifetime of the packet in the network switch. The network switches select sparse queue entries in the collapsible queue, deallocate the selected queue entries, and shift remaining allocated queue entries toward a first end of the queue with a delay proportional to the radix of the network switches.

Bandwidth matched scheduler

Systems, apparatuses, and methods for compression of frequent data values across narrow links are disclosed. In one embodiment, a system includes a processor, a link interface unit, and a communication link. The link interface unit is configured to receive a data stream for transmission over the communication link, wherein the data stream is generated by the processor. The link interface unit determines if blocks of data of a first size from the data stream match one or more first data patterns and the link interface unit determines if blocks of data of a second size from the data stream match one or more second data patterns. The link interface unit sends, over the communication link, only blocks of data which do not match the first or second data patterns.

Compression of frequent data values across narrow links

A system including a gasket communicatively coupled between a unified northbridge (UNB) having a cache coherent interconnect (CCI) interface and a processor having an Advanced eXtensible Interface (AXI) coherency extension (ACE). The gasket is configured to translate requests from the processor that include ACE commands into equivalent CCI commands, wherein each request from the processor maps onto a specific CCI request type. The gasket is further configured to translate ACE tags into CCI tags. The gasket is further configured to translate CCI encoded probes from a system resource interface (SRI) into equivalent ACE snoop transactions. The gasket is further configured to translate the memory map to inter-operate with a UNB/coherent HyperTransport (cHT) environment. The gasket is further configured to receive a barrier transaction that is used to provide ordering for transactions.

Input/output memory map unit and northbridge

A method and apparatus of compressing addresses for transmission includes receiving a transaction at a first device from a source that includes a memory address request for a memory location on a second device. It is determined if a first part of the memory address is stored in a cache located on the first device. If the first part of the memory address is not stored in the cache, the first part of the memory address is stored in the cache and the entire memory address and information relating to the storage of the first part is transmitted to the second device. If the first part of the memory address is stored in the cache, only a second part of the memory address and an identifier that indicates a way in which the first part of the address is stored in the cache is transmitted to the second device.

Method and apparatus for compressing addresses

The present invention provides for page table access and dirty bit management in hardware via a new atomic test[0] and OR and Mask. The present invention also provides for a gasket that enables ACE to CCI translations. This gasket further provides request translation between ACE and CCI, deadlock avoidance for victim and probe collision, ARM barrier handling, and power management interactions. The present invention also provides a solution for ARM victim/probe collision handling which deadlocks the unified northbridge. These solutions includes a dedicated writeback virtual channel, probes for IO requests using 4-hop protocol, and a WrBack Reorder Ability in MCT where victims update older requests with data as they pass the requests.

A method and apparatus for controlling affinity of subcaches is disclosed. When a core compute unit evicts a line of victim data, a prioritized search for space allocation on available subcaches is executed, in order of proximity between the subcache and the compute unit. The victim data may be injected into an adjacent subcache if space is available. Otherwise, a line may be evicted from the adjacent subcache to make room for the victim data or the victim data may be sent to the next closest subcache. To retrieve data, a core compute unit sends a Tag Lookup Request message directly to the nearest subcache as well as to a cache controller, which controls routing of messages to all of the subcaches. A Tag Lookup Response message is sent back to the cache controller to indicate if the requested data is located in the nearest sub-cache.

Subcache affinity

A method and apparatus for selectively bypassing a cache in a processor of a computing device are disclosed. A mechanism to provide visibility to transactions on the core to a cache interface (e.g., an L3 cache interface) in a trace controller buffer (TCB) for debugging purposes, by causing selected transactions, which would otherwise be satisfied by the cache, to bypass the cache and be presented to the memory system where they may be logged in the TCB is described. In an embodiment of the invention, there is provided a method for providing processing core request visibility comprising bypassing a higher level cache in response to a processing core request, capturing the processing core request in a TCB, providing a mask to filter the processing core request, and returning a transaction response to a requesting processing core.

Method and apparatus for selectively bypassing a cache for trace collection in a processor

A method and apparatus for accelerated shared data migration between cores. Using an Always Migrate protocol, when a migratory probe hits a directory entry in either modified or owned state, the entry is transitioned to an owned state, and a source done command is sent without sending cache block ownership or state information to the directory.

Method and apparatus for accelerated shared data migration

A method and apparatus for retrieving a state of a processor at a time at which failure is detected. More specifically, the detection of one or more protocol errors results in the halting of operations of one or more system elements, and the retrieving of the state of the processor at the time of the failure.

Queue freeze on protocol error

A method and apparatus for partitioning a cache includes determining an allocation of a subcache out of a plurality of subcaches within the cache for association with a compute unit out of a plurality of compute units. Data is processed by the compute unit, and the compute unit evicts a line. The evicted line is written to the subcache associated with the compute unit.

Growing community of inventors

San Jose, CA, United States of America

Greggory D Donley