The ability to improve a computing system's data throughput capabilities when processing large volumes of data is an ever present challenge. In many instances, processing large data volumes using software executed by a general-purpose processor will be too slow to meet the needs of users. Therefore, it is desirable to either relocate data processing functionality away from software executed by the general-purpose processor of a computer and into firmware deployed on hardware or to partition data processing functionality between such firmware and software. However, when doing so, hardware devices (such as reconfigurable logic devices) need to be interconnected with external resources such as data storage and the software executed by the computer's general-purpose processor in a manner that does not create a bottleneck as data and commands flow back and forth between the hardware and the software.
As used herein, the term “general-purpose processor” will refer to a hardware device that fetches instructions and executes those instructions (for example, an Intel Xeon processor or an AMD Opteron processor). The term “reconfigurable logic” will refer to any logic technology whose form and function can be significantly altered (i.e., reconfigured) in the field post-manufacture. This is to be contrasted with a general-purpose processor whose function can change post-manufacture, but whose form is fixed at manufacture. The term “software” will refer to data processing functionality that is deployed on a general-purpose processor. The term “firmware” will refer to data processing functionality that is deployed on reconfigurable logic.
In an effort to address the needs in the art, the inventors herein disclose a new design for a firmware socket module that interfaces at least one firmware application module deployed on a reconfigurable logic device with external memory and software. The firmware socket module is also preferably deployed on the reconfigurable logic device. The at least one firmware application module is configured to perform a data processing operation on any target data that it receives, wherein the data processing operation that the at least one firmware application module performs is controlled by a software-based command. Preferably, the at least one firmware application module comprises a plurality of firmware application modules that are arranged in a pipeline. Each firmware application module in the pipeline is preferably individually addressable for command information. Thus, commands can be issued to specific firmware application modules in the pipeline to control the data processing operations of those specific firmware application modules.
The firmware socket module is configured to access external memory and software to receive the commands and target data that are to be processed through the firmware application module pipeline. Preferably, the firmware socket module issues transactions to a system bus to perform direct memory access (DMA) transfers of commands and target data from the computer system's memory to itself. The firmware socket module is configured to in turn provide these commands and target data to the first one of the firmware application modules in the pipeline in a predetermined order that is defined by software.
The firmware socket module and firmware application module pipeline are preferably configured to strictly maintain the predetermined order of inbound commands and target data when propagating commands and target data through the system. When target data reaches a firmware application module in the pipeline, the firmware application module performs its specified data processing operation on the target data and then provides the so-processed target data to the next firmware application module in the pipeline. When command data reaches a firmware application module in the pipeline, the firmware application module will check to see whether the command is directed toward it and, if it is, will interpret that command to re-arrange its data processing operation as appropriate. If the command is to be propagated further down the pipeline, then the firmware application module will pass the command to the next firmware application module in the pipeline.
The flow of commands and target data, either into the firmware socket module or into the entry point of the firmware application module pipeline, can be thought of as a single stream in which both commands and target data are interleaved in accordance with the defined order. When it is said that the commands and data are interleaved, this does not require (although it does not exclude) a stream of command/data/command/data/command/data . . . . Instead, the interleaved stream of commands and data described herein encompasses a stream such as command/command/command/data/data/data/data/data/command . . . wherein the order of commands and data in the stream is defined by software and preserved by the firmware socket module when it propagates the stream to the firmware application module pipeline.
Appropriate commands that control the firmware application module's data processing operation should precede that target data in the stream of commands and target data entering the firmware application pipeline, thereby allowing the data processing operations of the firmware application modules to be appropriately controlled prior to processing target data. To facilitate the ease by which this strict ordering of commands and target data is maintained, the firmware socket module is configured to provide both command and target data to the first firmware application module in the pipeline over the same communication path that links the firmware socket module with the first firmware application module of the pipeline.
The natural synchronization between commands and target data provided by this firmware socket module-to-firmware application module pipeline connection avoids complexity in the system and also enhances data throughput. In prior art socket interfaces known to the inventors herein, commands are communicated to data processing modules via a different communication path than the communication path used to communicate target data to data processing modules. When such data processing modules are pipelined, such dual communication paths create management difficulties when attempting to synchronize commands with data. In such cases, when new commands are issued to a data processing module in the pipeline, the entire pipeline will typically need to be flushed of previous commands and previous data before that command and any further target data can be processed through the pipeline, thereby greatly detracting from the pipeline's throughput capabilities. By way of distinction, however, with the present invention one firmware application module of the pipeline can take action on a command while other firmware application modules in the pipeline are simultaneously processing data in accordance with their defined data processing operations. Thus, commands can be issued to firmware application modules to adjust their data processing operations without requiring the entire pipeline to be flushed out.
High level software that is executed by the computer system's general-purpose processor preferably defines the order of commands and data that are eventually propagated through the firmware socket module and the firmware application module pipeline. Lower level device driver software that is also executed by the computer system's general-purpose processor then preferably preserves this defined order of commands and data and makes such ordered commands and data available to the firmware socket module. The device driver software preferably preserves this order by managing an input descriptor pool buffer in which pointers to commands and target data are stored. The firmware socket module will access the input descriptor pool buffer to learn of the commands and target data that are to be delivered to the firmware application module pipeline.
On the outbound side of the firmware socket module (outbound to software), the device driver software preferably maintains separate buffers for output commands and outbound data to notify the firmware socket module of where commands and data that have been processed by the firmware application module should be stored in memory for subsequent access by computer system software.
Among the advantages that the preferred embodiment of the invention provides are the ability to reliably deliver flow-controlled data from software to a reconfigurable logic device and vice versa, and the ability to develop firmware application modules independent of the computer system in which they are deployed (so long as the firmware application modules conform to the signaling requirements of the firmware socket module). These and other features of the present invention will be in part pointed out and in part apparent to those having ordinary skill in the art upon review of the following description and figures.
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