From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id E102DA0C40; Sat, 12 Jun 2021 10:41:28 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 5D9714003F; Sat, 12 Jun 2021 10:41:28 +0200 (CEST) Received: from mail-io1-f52.google.com (mail-io1-f52.google.com [209.85.166.52]) by mails.dpdk.org (Postfix) with ESMTP id 3BC964003F for ; Sat, 12 Jun 2021 10:41:27 +0200 (CEST) Received: by mail-io1-f52.google.com with SMTP id q7so33860248iob.4 for ; Sat, 12 Jun 2021 01:41:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=7Gg6qCP2QSeyjasXebXe1iB3XMjOigA1M/ooRzBio7o=; b=uTvxND12OAIoJMZDGDH3Ee+zjUjgkYW2d6XItFwkSh+B4VrhoZwfym4XnRWUCsCYbe YOBJHCtASIBa253CQyA3MOPHwUlVvlay9iLPn9O1Y6AYThaEl2FQAn9PyKi7Rnws/8HX SYLVswvR0yOsAAMruJfB1hJzQRuM/VhknxWQMw4cjFw3trJq8JioRTtaYdBjthtoWOaw Oxg2To7JCjAbDLOM5pUn6mS0HRJw7+twcYXb465ZwidU5qeDAdFyhtQbCwV5B+NcDs8L s/8sE/qgfNzJ+2yawgMTbeR8iyEhMpIfE/zejGWeCTZZvlrlos1S2E6UnmPW65n5xoov RorA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=7Gg6qCP2QSeyjasXebXe1iB3XMjOigA1M/ooRzBio7o=; b=O7fJw5jtMrez71nFEi9P22PgZnpkHFC+sKG3eLDLjadnhALtAvDNSutHncR1e7JvL/ LAXRthxoG/ZqNWXvu9G5rEFaUxQ5Qb4DKogLvhjvEuqQeiu84wNq6k3V+PmSvO8AEpq8 9RsZptNdVfH+DsL9uAk/cHirHTDQnUQNdoDC6SiBWk6soxqhhF4ET8fRpKsteBECvII+ pVWPfJRkoYHlADHvT2ySAKDFJK1bcMPSj3y1W2HkLmFaAXfgTB0ACPx1Y+BgWRsvjhLY SX6NGtgxNTegX4QVsf8k1JwkU8IpOiVBZCFJDdprhFG4BkIRrujPntGVcMfCCRQz8HWj T6jA== X-Gm-Message-State: AOAM531XbugX2xSCrGbuO/+EgOiOdDdzoX2xwD4GZxRIWyKlILsv9V17 RS6Sw5iWp1Zl3ZwfjDNB2i0WwAhLfuj51FoKcNU= X-Google-Smtp-Source: ABdhPJxsayogf6x9AgAvre2f2knPzzJH7FO0uAeIZkldzTfSvKlzPLq+yhPo4vPZt2dCjjW7ACxGM58W6lNKvSLkCts= X-Received: by 2002:a02:a897:: with SMTP id l23mr7499813jam.112.1623487286493; Sat, 12 Jun 2021 01:41:26 -0700 (PDT) MIME-Version: 1.0 References: <27a77ca8-9406-1737-ff84-774b2ca561f7@huawei.com> <7807476.CTUdPGCxKm@thomas> In-Reply-To: <7807476.CTUdPGCxKm@thomas> From: Jerin Jacob Date: Sat, 12 Jun 2021 14:11:10 +0530 Message-ID: To: Thomas Monjalon Cc: fengchengwen , Ferruh Yigit , "dev@dpdk.org" , Nipun Gupta , Hemant Agrawal , "Richardson, Bruce" , Maxime Coquelin , Honnappa Nagarahalli , Jerin Jacob , David Marchand Content-Type: text/plain; charset="UTF-8" Subject: Re: [dpdk-dev] RFC: Kunpeng DMA driver API design decision X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Sat, Jun 12, 2021 at 2:01 PM Thomas Monjalon 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. > > >