Received: by 2002:a05:6902:102b:0:0:0:0 with SMTP id x11csp1023914ybt; Fri, 19 Jun 2020 22:00:04 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyB823nhoyqM7L1gVJbADfmtKmsm9LWq3cbDN5X8w5fsLg1zmX+frfY63XmYNTO8wo8Q4k5 X-Received: by 2002:a17:906:7c56:: with SMTP id g22mr6202534ejp.507.1592629203960; Fri, 19 Jun 2020 22:00:03 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1592629203; cv=none; d=google.com; s=arc-20160816; b=kaXt0GBwe5+8KDiuIVj3zn9zvAdtwsWKQSXwQtRfsLPNoGEZGEOu1G31qIorVG3NEa NWQXxe8uwt5EIlW4r6p6Wl2KEgM3WLGGveeXFqS9FtI1JQJ1rfqVtryTGtALta++iwrz zD3PjWLOU0GUxQYEflpTPXt0BNEZ92SXGadS5LRaV0R6JwLL+aqp4cNl0aT5tEKLP/02 2QKzsLxuWpIPL187CEw9htpUNYHZAZf7lsW4fdQKUQYYGgsv2/ctYcwm+JdzdB6qpOAg 1OCGbRtO0P2NA96fWLc5jETE2OUs3/xfGzr0jbbLxMKk76pe+MgBwz5L8jCmSFjW8vlF cb5w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:in-reply-to:mime-version:user-agent:date :message-id:from:references:cc:to:subject:ironport-sdr:ironport-sdr; bh=9tDQLvyT0JdBgLrHfRdQ5YEh6dOrQ7K2T9Lgk5Q8+hE=; b=llTl6qgY9dgEwBDq4NKzPQit9Mn4MS25A8Ui60m9H+CmPrpWo4IFU9Ef2zoDB9C4Wb 1onr7DfABE18nU0eApiX+O4OsMfG6ajio23Gcc3xDhR7L7wmVRX5B4KCGA6TxH9vSjlU wDP16euhv5tyLOUqRukrOFY/UavotkeEo3ex3GYLBAW5H0op6XGi9Ij7LSbkppZhy0Af YhtWzB0OgOe/9s4+1PD4kcuxB/XpWQdJZGhVyHYS2KJvOsoevkwGX0Uq3I3GIm6eVRm+ o/nVJmbxOFWzuFNzIdt7Xh3Y0klMKGsq2q0xyeJ74G6WWwXIj9HUV+jP3qGI4lr+rL9u vQiw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id f6si5296102ejf.208.2020.06.19.21.59.42; Fri, 19 Jun 2020 22:00:03 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730486AbgFSXbZ (ORCPT + 99 others); Fri, 19 Jun 2020 19:31:25 -0400 Received: from mga17.intel.com ([192.55.52.151]:58563 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730480AbgFSXbZ (ORCPT ); Fri, 19 Jun 2020 19:31:25 -0400 IronPort-SDR: EqpB4QRoaYRhKAkMy9LBBClhFdW6eTBgE2N2fUaKiOzHzrnZn8wXQRlSDSWnuDTsNX5G3OhR4t bDSgg8YkkNtw== X-IronPort-AV: E=McAfee;i="6000,8403,9657"; a="123403550" X-IronPort-AV: E=Sophos;i="5.75,256,1589266800"; d="scan'208";a="123403550" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jun 2020 16:31:25 -0700 IronPort-SDR: xLtwvaWjtaHWQKnz/TlwPD49xVRdUcU8TFHQz4MXD8QUerzEqPstVlodQfZJfyVCVLjF/X+9LY j9N0UTCz3xxA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,256,1589266800"; d="scan'208";a="477780861" Received: from djiang5-mobl1.amr.corp.intel.com (HELO [10.209.171.94]) ([10.209.171.94]) by fmsmga006.fm.intel.com with ESMTP; 19 Jun 2020 16:31:24 -0700 Subject: Re: DMA Engine: Transfer From Userspace To: Federico Vaga , Vinod Koul , Dan Williams Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org References: <5614531.lOV4Wx5bFT@harkonnen> From: Dave Jiang Message-ID: Date: Fri, 19 Jun 2020 16:31:24 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <5614531.lOV4Wx5bFT@harkonnen> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/19/2020 3:47 PM, Federico Vaga wrote: > Hello, > > is there the possibility of using a DMA engine channel from userspace? > > Something like: > - configure DMA using ioctl() (or whatever configuration mechanism) > - read() or write() to trigger the transfer > I may have supposedly promised Vinod to look into possibly providing something like this in the future. But I have not gotten around to do that yet. Currently, no such support.