From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED3FFC33CAF for ; Fri, 17 Jan 2020 00:09:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BF04020684 for ; Fri, 17 Jan 2020 00:09:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=aj.id.au header.i=@aj.id.au header.b="nuEayf3B"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="K9jFKAkE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728895AbgAQAJ4 (ORCPT ); Thu, 16 Jan 2020 19:09:56 -0500 Received: from out2-smtp.messagingengine.com ([66.111.4.26]:54941 "EHLO out2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726958AbgAQAJ4 (ORCPT ); Thu, 16 Jan 2020 19:09:56 -0500 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id D3381220A9; Thu, 16 Jan 2020 19:09:54 -0500 (EST) Received: from imap2 ([10.202.2.52]) by compute4.internal (MEProxy); Thu, 16 Jan 2020 19:09:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aj.id.au; h= mime-version:message-id:in-reply-to:references:date:from:to:cc :subject:content-type; s=fm1; bh=4y285Mn+nF0hNakty6Ped9kTCwL0aOB qAFumkJVyMi4=; b=nuEayf3B1FaV744Uv9IaAHYAg2yJ2lIc+Zw2glZ04dF89A8 RL6SXwX08LExha9D01aXgbmCVNPJgKH7yl/UWQlo1v4ePBU3jYA/kU0vtS3ONL46 ztID4DuVaOKc+DG0tdNQVWrTrC6+Zi2zQ+NzWxaVp4/jNv5yDUnakMw6l9jmIrro BZb4pXLfzUUMPyfuJKjJOaBnoqUwb4juTiyQJFw5EN1hnE1oTt1RDp0c9k/6kbtJ 6HypW5wwK5Ha/HzfUcozpJeBafV2cO99gnZmVoXsdfkFQPnSVPKl3/RiPSpXtAu7 IFugnJMJIleynsF9OzYOuGklT1xF8iuJu19PnmQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=4y285M n+nF0hNakty6Ped9kTCwL0aOBqAFumkJVyMi4=; b=K9jFKAkEM0xhlNwIb99nsw iJWmDSEEumZc0x27W3teLKnVx2i8dr9eYKXJKoh4UV68IKmHIIEtFJc+YlR4gaNe YFq/8IBLCCqFm/7z23Iae2TUF1tQcU84MWuci2MPt5eXlZilbaZ8ajjpJfiUngPN jPpNmlRr3UxdF8h+dr5CVIK6G0g3DwIKJ73U8DtxGOIGAqHSo6O7ew2FuXUAc3uy SkWHosKkpdYTsyCCjmaECod4T7Efes++9dDopUfqFWDjSnSC701vJadCUB4V1F8Q uxInZRHHEd5obM/cG7lT1idLd5a0Mn4CWgQuRT0zCV++MjwBQ/MI6iSzsDPEjwBg == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedugedrtdeigdduiecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefofgggkfgjfhffhffvufgtsehttdertderredtnecuhfhrohhmpedftehnughr vgifucflvghffhgvrhihfdcuoegrnhgurhgvfiesrghjrdhiugdrrghuqeenucfrrghrrg hmpehmrghilhhfrhhomheprghnughrvgifsegrjhdrihgurdgruhenucevlhhushhtvghr ufhiiigvpedt X-ME-Proxy: Received: by mailuser.nyi.internal (Postfix, from userid 501) id E76C1E00A2; Thu, 16 Jan 2020 19:09:53 -0500 (EST) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.1.7-754-g09d1619-fmstable-20200113v1 Mime-Version: 1.0 Message-Id: <3e28410b-805b-4599-88d1-98aa39c926d5@www.fastmail.com> In-Reply-To: <1579123790-6894-8-git-send-email-eajames@linux.ibm.com> References: <1579123790-6894-1-git-send-email-eajames@linux.ibm.com> <1579123790-6894-8-git-send-email-eajames@linux.ibm.com> Date: Fri, 17 Jan 2020 10:39:33 +1030 From: "Andrew Jeffery" To: "Eddie James" , linux-aspeed@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, mark.rutland@arm.com, "Jason Cooper" , "Marc Zyngier" , "Rob Herring" , tglx@linutronix.de, "Joel Stanley" Subject: Re: [PATCH v6 07/12] soc: aspeed: xdma: Add user interface Content-Type: text/plain Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Thu, 16 Jan 2020, at 07:59, Eddie James wrote: > This commits adds a miscdevice to provide a user interface to the XDMA > engine. The interface provides the write operation to start DMA > operations. The DMA parameters are passed as the data to the write call. > The actual data to transfer is NOT passed through write. Note that both > directions of DMA operation are accomplished through the write command; > BMC to host and host to BMC. > > The XDMA driver reserves an area of physical memory for DMA operations, > as the XDMA engine is restricted to accessing certain physical memory > areas on some platforms. This memory forms a pool from which users can > allocate pages for their usage with calls to mmap. The space allocated > by a client will be the space used in the DMA operation. For an > "upstream" (BMC to host) operation, the data in the client's area will > be transferred to the host. For a "downstream" (host to BMC) operation, > the host data will be placed in the client's memory area. > > Poll is also provided in order to determine when the DMA operation is > complete for non-blocking IO. > > Signed-off-by: Eddie James Reviewed-by: Andrew Jeffery