Hi,I have a SHA256 implementation in an FPGA that keeps the hash state in internal registers, and uses DMA to read input data and return the hash output.
First of all, the result of the hash is inaccessible by DMA, so I've had to add a separate result queue with an interrupt bottom half handler that copies the result back into the request. Is there a better way to do this, e.g. a flag I can set to get a DMA accessible result buffer?
Second, the import/export APIs seem to be synchronous. I'd like to run these through the normal request/result queues along with other requests, but obviously returning -EINPROGRESS from export is a bad idea.
Can I make my export function synchronous by sleeping until the completion interrupt arrives, or is that a bad idea?
I could possibly implement a synchronous interface by always returning the current hash state in the result queue for each asynchronous operation and updating the request in case an export request comes along, is that really the best option?
Simon
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