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=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 7D453C433DF for ; Tue, 9 Jun 2020 17:35:06 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 46E3720774 for ; Tue, 9 Jun 2020 17:35:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="p68pIYP8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 46E3720774 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=CEverbA78NslStQVExgsYZqKvFTdsASNo0kNoLiWIYg=; b=p68pIYP8/H5/Qp 2K5CboZJq6iD9wkVFqRVoejL4LzWozCDIG7kUYIJv1yDFZiFvJWSzBtH2rQIqHjPZ8Pe0QyIvmBzp FO7et2nY3Fae/2yKjnfxu9wpSJhMq1CNZAEUgI/LmhrZOZX9oluMVcYHJgN+q2m9at22w7FondO4h PaE0mYpLi+N6LyxXrd7GctVMTV7hQHlwir3WCF1VbLL2pWGXsr0wGBxldIoJW/OCyngPhj/CMJjjI qDfoSn9f+DJP9XDaL/bzhOvOu7J1CwWrm1BjNa6fF4aTk7nbFpVy//GAl1TICnDHqwSHPUlil2VBx POPTerPU3yIIZT6TLTDA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jii9R-0005Ml-L1; Tue, 09 Jun 2020 17:35:05 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jii9N-0004ds-Nq for linux-arm-kernel@lists.infradead.org; Tue, 09 Jun 2020 17:35:03 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 3460168AFE; Tue, 9 Jun 2020 19:34:56 +0200 (CEST) Date: Tue, 9 Jun 2020 19:34:55 +0200 From: Christoph Hellwig To: Vladimir Murzin Subject: Re: [PATCH 2/2] arm-nommu: Add use_reserved_mem() to check if device support reserved memory Message-ID: <20200609173455.GA25467@lst.de> References: <1591605038-8682-1-git-send-email-dillon.minfei@gmail.com> <1591605038-8682-3-git-send-email-dillon.minfei@gmail.com> <90df5646-e0c4-fcac-d934-4cc922230dd2@arm.com> <20200609153646.GA17969@lst.de> <031034fb-b109-7410-3ff8-e78cd12a5552@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200609_103501_944198_FD95C803 X-CRM114-Status: GOOD ( 10.00 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kate Stewart , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Linux Kernel Mailing List , Alexandre Torgue , info@metux.net, linux@armlinux.org.uk, linux-stm32@st-md-mailman.stormreply.com, Rob Herring , Linux ARM , Maxime Coquelin , tglx@linutronix.de, dillon min , Christoph Hellwig , allison@lohutok.net Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Jun 09, 2020 at 05:25:04PM +0100, Vladimir Murzin wrote: > Even though commit mentions ARM, I do not see how mmap would continue > to work for NOMMU with dma-direct. ARM NOMMU needs it's own DMA operations > only in cases where caches are implemented or active, in other cases it > fully relies on dma-direct. > It looks to me that we either should provide NOMMU variant for mmap in > dma/direct or (carefully) fix dma/mapping. I think dma-direct is the right place, the common helpers in dma/mapping.c are basically the red headed stepchilds for misc IOMMU drivers not covered by dma-iommu only. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel