OK, I will send one, thanks
From:Jerin Jacob <[email protected]> To:Thomas Monjalon <[email protected]> Cc:Fengchengwen <[email protected]>;Ferruh Yigit <[email protected]>;dev <[email protected]>;Nipun Gupta <[email protected]>;Hemant Agrawal <[email protected]>;Richardson, Bruce <[email protected]>;Maxime Coquelin <[email protected]>;Honnappa Nagarahalli <[email protected]>;Jerin Jacob <[email protected]>;David Marchand <[email protected]> Date:2021-06-12 16:41:32 Subject:Re: [dpdk-dev] RFC: Kunpeng DMA driver API design decision On Sat, Jun 12, 2021 at 2:01 PM Thomas Monjalon < [email protected]<mailto:[email protected]>> wrote: > > 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. +1 for rte_dmadev. Now that we have multiple DMA drivers, it better to have a common generic API for API. @fengchengwen If you would like to pursue generic DMA API the please propose an RFC for dmadev PUBLIC API before implementing it, We can help you review the proposal of API. > > >
