From: Thomas Monjalon <thomas@monjalon.net>
To: fengchengwen <fengchengwen@huawei.com>
Cc: Ferruh Yigit <ferruh.yigit@intel.com>,
"dev@dpdk.org" <dev@dpdk.org>,
nipun.gupta@nxp.com, hemant.agrawal@nxp.com, "Richardson,
Bruce" <bruce.richardson@intel.com>,
maxime.coquelin@redhat.com, honnappa.nagarahalli@arm.com,
jerinj@marvell.com, david.marchand@redhat.com
Subject: Re: [dpdk-dev] RFC: Kunpeng DMA driver API design decision
Date: Sat, 12 Jun 2021 10:31:33 +0200 [thread overview]
Message-ID: <7807476.CTUdPGCxKm@thomas> (raw)
In-Reply-To: <27a77ca8-9406-1737-ff84-774b2ca561f7@huawei.com>
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.
next prev parent reply other threads:[~2021-06-12 8:31 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-12 7:01 fengchengwen
2021-06-12 8:31 ` Thomas Monjalon [this message]
2021-06-12 8:41 ` Jerin Jacob
2021-06-12 11:53 ` Fengchengwen
2021-06-14 18:18 ` Bruce Richardson
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