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 57CB4A0C41; Wed, 23 Jun 2021 09:01:15 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id D58134003F; Wed, 23 Jun 2021 09:01:14 +0200 (CEST) Received: from mail-io1-f42.google.com (mail-io1-f42.google.com [209.85.166.42]) by mails.dpdk.org (Postfix) with ESMTP id 1FDCA4003E for ; Wed, 23 Jun 2021 09:01:13 +0200 (CEST) Received: by mail-io1-f42.google.com with SMTP id r12so2070936ioa.7 for ; Wed, 23 Jun 2021 00:01:13 -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=3ttCQoXLIm2FTfhYspggb5nZWd9wm7e54bDk6WzErCk=; b=hw51HMq6FMPm/dj927Pht1E6GJxWsYwyEwm417S/XB6pHiVcLDex1TE3vAbQt6J9w0 Rj9XHr+NCC/i5VhPfMtizLAzU+BR6V9a4pDxG8w8QaZP1WZqMItdlu4C6LCB+M9FV6HX prQRI4luMZp67DiHtqcr7x2SIpeQuIfGeH0TqXO258cmNk7URyssHz3Ve0CJKT1c/Az1 oUOvhVCl40kHVZSH/+wb3SThjjRVCgPCr1fL4qrfPdOVdtbHJsbAIvK2oXS5UdhECQRm VixdRcgmwqvQ94Wu0KRLSIQL8+1bzvW9D53PhOShpGsr8YtKJxwWVdc2DgCSu8Y67joS TYfg== 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=3ttCQoXLIm2FTfhYspggb5nZWd9wm7e54bDk6WzErCk=; b=ILQ+7lik7T1BK63LYh40cr27s5dzpMXHPQf5C0igTKVUjvvB19SxWCYWrKbERFwK2+ vq9TjVgzujhxjpL+Oz4tYp0tc8u4iwSY/Pk/BtodRAT1mh6Es3GxAK2OA7fxPFWp9TbJ exjUNq0KWUGqcsBI2j4d0vF8ce6qmw8VVknyf3KR8uUGbOTVaIL1/EbX3Be4qfsyQa+c 0uAkvzm2wYdJfbvuXYOkmJcohjXOGu8VSnqKChAvMugrgx5obsftY6mJypGfOQym1Ifg YbOMSlYJez1VsqYjgLKTbNtJI0Ab8CkZFY6yABK4BbPTC6ttuDFsXYwdZTmq7HkvnI/W HuXQ== X-Gm-Message-State: AOAM5328IsC0swAle8PxMiGtFWohVdzdtSy9NdPKK1WZuU+BeGJvXLsl WoHTy4knC4tHup2GMbWFRZLCrlCQG57TfhzzRvo= X-Google-Smtp-Source: ABdhPJxRDD5XKh2lywD6EmgB2p+UOS8MvyXIid5WreVWEQw+15oQ2D1LXGmfeT3ZO8zVAEEl4XdID7fa3Ti8jFKMtiU= X-Received: by 2002:a05:6638:d4b:: with SMTP id d11mr7570919jak.112.1624431672396; Wed, 23 Jun 2021 00:01:12 -0700 (PDT) MIME-Version: 1.0 References: <1623763327-30987-1-git-send-email-fengchengwen@huawei.com> <98CBD80474FA8B44BF855DF32C47DC35C61860@smartserver.smartshare.dk> In-Reply-To: From: Jerin Jacob Date: Wed, 23 Jun 2021 12:30:46 +0530 Message-ID: To: Bruce Richardson Cc: fengchengwen , =?UTF-8?Q?Morten_Br=C3=B8rup?= , Thomas Monjalon , Ferruh Yigit , dpdk-dev , Nipun Gupta , Hemant Agrawal , Maxime Coquelin , Honnappa Nagarahalli , Jerin Jacob , David Marchand , Satananda Burla , Prasun Kapoor Content-Type: text/plain; charset="UTF-8" Subject: Re: [dpdk-dev] [RFC PATCH] dmadev: introduce DMA device library 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 Wed, Jun 23, 2021 at 12:47 AM Bruce Richardson wrote: > > On Tue, Jun 22, 2021 at 11:01:47PM +0530, Jerin Jacob wrote: > > On Fri, Jun 18, 2021 at 3:25 PM Bruce Richardson > > wrote: > > > > > > > > > > Taking the case of a simple copy op, the parameters we need are: > > > > > > * src > > > * dst > > > * length > > > > OK. Is it the case where no other attribute that supported in HW or > > you are not planning to > > expose that through DPDK generic DMA API. > > > Only other parameters that might be needed can all be specified as flags, > so all we need for a copy op is a general flags field for future expansion. > > > > > > > Depending on the specific hardware there will also be passed in the > > > descriptor a completion address, but we plan for these cases to always have > > > the completions written back to a set location so that we have essentially > > > ring-writeback, as with the hardware which doesn't explicitly have a > > > separate completion address. Beyond that, I believe the only descriptor > > > fields we will use are just the flags field indicating the op type etc. > > > > OK. In HW, we need to have IOVA for completion address that's only the > > constraint. rest looks good to me. > > > That's like what we have, but I was not planning on exposing the completion > address through the API at all, but have it internal to the driver and let > the "completion" APIs just inform the app what is done or not. If we expose > completion addresses, then that leaves the app open to having to parse > different completion formats, so it needs to be internal IMHO. Ack > > /Bruce