3d2ead38cb
A DMA friendly Stream API for zephyr. Based on ideas from io_uring and iio, a queue based API for I/O operations. Provides a pair of fixed length ringbuffer backed queues for submitting I/O requests and recieving I/O completions. The requests may be chained together to ensure the next operation does not start until the current one is complete. Requests target an abstract rtio_iodev which is expected to wrap all the hardware particulars of how to perform the operation. For example with a SPI bus device, a description of what a read, and write mean can be decided by the iodev wrapping a particular device hanging off of a SPI controller. The queue pair are submitted to an executor which may be a simple inplace looping executor done in the callers execution context (thread/stack) but other executors are expected. A threadpool executor might for example allow for concurrent request chains to execute in parallel. A DMA executor, in conjunction with DMA aware iodevs would allow for hardware offloading of operations going so far as to schedule with priority using hardware arbitration. Both the iodev and executor are definable by a particular SoC, meaning they can work in conjuction to perform IO operations using a particular DMA controller or methodology if desired. The application decides entirely how large the queues are, where the buffers to read/write come from (some executors may have particular demands!), and which executor to submit requests to. Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
89 KiB
756x446px
89 KiB
756x446px
