12/06/2021 09:01, fengchengwen: > Hi all, > > We prepare support Kunpeng DMA engine under rawdev framework, and observed > that > there are two different implementations of the data plane API: > 1. rte_rawdev_enqueue/dequeue_buffers which was implemented by dpaa2_qdma and > octeontx2_dma driver. > 2. rte_ioat_enqueue_xxx/rte_ioat_completed_ops which was implemented by ioat > driver. > > Due to following consideration (mainly performance), we plan to implement API > like ioat (not the same, have some differences) in data plane: > 1. The rte_rawdev_enqueue_buffers use opaque buffer reference which is > vendor's > specific, so it needs first to translate application parameters to opaque > pointer, and then driver writes the opaque data onto hardware, this may > lead > to performance problem. > 2. rte_rawdev_xxx doesn't provide memory barrier API which may need to extend > by opaque data (e.g. add flag to every request), this may introduce some > complexity. > > Also the example/ioat was used to compare DMA and CPU-memcopy performance, > Could we generalized it so that it supports multiple-vendor ? > > I don't know if the community accepts this kind of implementation, so if you > have any comments, please provide feedback.
I would love having a common generic API. I would prefer having drivers under drivers/dma/ directory, rather than rawdev.
