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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 6D747C432C3 for ; Thu, 21 Nov 2019 15:25:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4548220674 for ; Thu, 21 Nov 2019 15:25:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726634AbfKUPZG (ORCPT ); Thu, 21 Nov 2019 10:25:06 -0500 Received: from verein.lst.de ([213.95.11.211]:46698 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726477AbfKUPZG (ORCPT ); Thu, 21 Nov 2019 10:25:06 -0500 Received: by verein.lst.de (Postfix, from userid 2407) id B377668C4E; Thu, 21 Nov 2019 16:24:57 +0100 (CET) Date: Thu, 21 Nov 2019 16:24:57 +0100 From: Christoph Hellwig To: Nicolas Saenz Julienne Cc: Dave Hansen , Andy Lutomirski , Peter Zijlstra , Bjorn Helgaas , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Jens Axboe , Joerg Roedel , Rob Herring , Frank Rowand , Christoph Hellwig , Marek Szyprowski , Robin Murphy , Ralf Baechle , Paul Burton , James Hogan , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , x86@kernel.org, "Rafael J. Wysocki" , Len Brown , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ide@vger.kernel.org, iommu@lists.linux-foundation.org, devicetree@vger.kernel.org Subject: Re: [PATCH v2] dma-mapping: treat dev->bus_dma_mask as a DMA limit Message-ID: <20191121152457.GA525@lst.de> References: <20191121092646.8449-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191121092646.8449-1-nsaenzjulienne@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Thu, Nov 21, 2019 at 10:26:44AM +0100, Nicolas Saenz Julienne wrote: > Using a mask to represent bus DMA constraints has a set of limitations. > The biggest one being it can only hold a power of two (minus one). The > DMA mapping code is already aware of this and treats dev->bus_dma_mask > as a limit. This quirk is already used by some architectures although > still rare. > > With the introduction of the Raspberry Pi 4 we've found a new contender > for the use of bus DMA limits, as its PCIe bus can only address the > lower 3GB of memory (of a total of 4GB). This is impossible to represent > with a mask. To make things worse the device-tree code rounds non power > of two bus DMA limits to the next power of two, which is unacceptable in > this case. > > In the light of this, rename dev->bus_dma_mask to dev->bus_dma_limit all > over the tree and treat it as such. Note that dev->bus_dma_limit should > contain the higher accesible DMA address. > > Signed-off-by: Nicolas Saenz Julienne I've tentatively added this patch to the dma-mapping tree based on Robins principal approval of the last version. That way tomorrows linux-next run should still pick it up. 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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 35E5FC33C9E for ; Thu, 21 Nov 2019 15:25:11 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 0AA4820674 for ; Thu, 21 Nov 2019 15:25:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0AA4820674 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id D38A18884E; Thu, 21 Nov 2019 15:25:10 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id GZfhCRLD28Ye; Thu, 21 Nov 2019 15:25:10 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id 3F3C7887DE; Thu, 21 Nov 2019 15:25:10 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 23F31C1DD8; Thu, 21 Nov 2019 15:25:10 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 92986C18DA for ; Thu, 21 Nov 2019 15:25:08 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 8D64E87F5A for ; Thu, 21 Nov 2019 15:25:08 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id yUeQ-Kw2ZrDZ for ; Thu, 21 Nov 2019 15:25:06 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by whitealder.osuosl.org (Postfix) with ESMTPS id 522A087F85 for ; Thu, 21 Nov 2019 15:25:06 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id B377668C4E; Thu, 21 Nov 2019 16:24:57 +0100 (CET) Date: Thu, 21 Nov 2019 16:24:57 +0100 From: Christoph Hellwig To: Nicolas Saenz Julienne Subject: Re: [PATCH v2] dma-mapping: treat dev->bus_dma_mask as a DMA limit Message-ID: <20191121152457.GA525@lst.de> References: <20191121092646.8449-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20191121092646.8449-1-nsaenzjulienne@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: Peter Zijlstra , Benjamin Herrenschmidt , Dave Hansen , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, Paul Mackerras , Hanjun Guo , Frank Rowand , Christoph Hellwig , "H. Peter Anvin" , Paul Burton , Michael Ellerman , x86@kernel.org, linux-acpi@vger.kernel.org, Ingo Molnar , James Hogan , Len Brown , devicetree@vger.kernel.org, Rob Herring , Borislav Petkov , Andy Lutomirski , Bjorn Helgaas , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Jens Axboe , linuxppc-dev@lists.ozlabs.org, "Rafael J. Wysocki" , linux-mips@vger.kernel.org, Ralf Baechle , iommu@lists.linux-foundation.org, Sudeep Holla , Robin Murphy X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Thu, Nov 21, 2019 at 10:26:44AM +0100, Nicolas Saenz Julienne wrote: > Using a mask to represent bus DMA constraints has a set of limitations. > The biggest one being it can only hold a power of two (minus one). The > DMA mapping code is already aware of this and treats dev->bus_dma_mask > as a limit. This quirk is already used by some architectures although > still rare. > > With the introduction of the Raspberry Pi 4 we've found a new contender > for the use of bus DMA limits, as its PCIe bus can only address the > lower 3GB of memory (of a total of 4GB). This is impossible to represent > with a mask. To make things worse the device-tree code rounds non power > of two bus DMA limits to the next power of two, which is unacceptable in > this case. > > In the light of this, rename dev->bus_dma_mask to dev->bus_dma_limit all > over the tree and treat it as such. Note that dev->bus_dma_limit should > contain the higher accesible DMA address. > > Signed-off-by: Nicolas Saenz Julienne I've tentatively added this patch to the dma-mapping tree based on Robins principal approval of the last version. That way tomorrows linux-next run should still pick it up. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 80B06C432C0 for ; Thu, 21 Nov 2019 15:27:35 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 AF54A20674 for ; Thu, 21 Nov 2019 15:27:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AF54A20674 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 47Jk2X1pNGzDq5y for ; Fri, 22 Nov 2019 02:27:32 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lst.de (client-ip=213.95.11.211; helo=verein.lst.de; envelope-from=hch@lst.de; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=lst.de Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 47Jjzk30B7zDr5L for ; Fri, 22 Nov 2019 02:25:06 +1100 (AEDT) Received: by verein.lst.de (Postfix, from userid 2407) id B377668C4E; Thu, 21 Nov 2019 16:24:57 +0100 (CET) Date: Thu, 21 Nov 2019 16:24:57 +0100 From: Christoph Hellwig To: Nicolas Saenz Julienne Subject: Re: [PATCH v2] dma-mapping: treat dev->bus_dma_mask as a DMA limit Message-ID: <20191121152457.GA525@lst.de> References: <20191121092646.8449-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191121092646.8449-1-nsaenzjulienne@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Zijlstra , Dave Hansen , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, Paul Mackerras , Hanjun Guo , Frank Rowand , Christoph Hellwig , Marek Szyprowski , Lorenzo Pieralisi , "H. Peter Anvin" , Paul Burton , Joerg Roedel , x86@kernel.org, linux-acpi@vger.kernel.org, Ingo Molnar , James Hogan , Len Brown , devicetree@vger.kernel.org, Rob Herring , Borislav Petkov , Andy Lutomirski , Bjorn Helgaas , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Jens Axboe , linuxppc-dev@lists.ozlabs.org, "Rafael J. Wysocki" , linux-mips@vger.kernel.org, Ralf Baechle , iommu@lists.linux-foundation.org, Sudeep Holla , Robin Murphy Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Thu, Nov 21, 2019 at 10:26:44AM +0100, Nicolas Saenz Julienne wrote: > Using a mask to represent bus DMA constraints has a set of limitations. > The biggest one being it can only hold a power of two (minus one). The > DMA mapping code is already aware of this and treats dev->bus_dma_mask > as a limit. This quirk is already used by some architectures although > still rare. > > With the introduction of the Raspberry Pi 4 we've found a new contender > for the use of bus DMA limits, as its PCIe bus can only address the > lower 3GB of memory (of a total of 4GB). This is impossible to represent > with a mask. To make things worse the device-tree code rounds non power > of two bus DMA limits to the next power of two, which is unacceptable in > this case. > > In the light of this, rename dev->bus_dma_mask to dev->bus_dma_limit all > over the tree and treat it as such. Note that dev->bus_dma_limit should > contain the higher accesible DMA address. > > Signed-off-by: Nicolas Saenz Julienne I've tentatively added this patch to the dma-mapping tree based on Robins principal approval of the last version. That way tomorrows linux-next run should still pick it up. 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=-5.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 C8062C432C0 for ; Thu, 21 Nov 2019 15:25:16 +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 9E49220674 for ; Thu, 21 Nov 2019 15:25:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="lcgnVmcM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9E49220674 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=e34fKbdjyJqE8wZ1dvzqwyTTWS35B0f86Ib/lcIwzaM=; b=lcgnVmcMXpK2iH giLDGnBij7KYB1idkudSdtiXcgEbftIJJ62Tm5qfu8CP2+Ho32R42lPmrRNo7c1RFA40C4Vpv0RRJ 6FVkBv4QaF2J76SPdAPNXTONFNCCxsqx9bH2SE9biVKeEHorT8yqbayxmaZsfxuY/T2A8ndGGmScN rSRDsxAosgupQ5GQdiog58863z7FuJMCjoekmB3VxTUpBqFaZ1HHzCFkMLJOaD4M/waDNGzRnTE/3 zQL/ZKAjZy1lfyxZjP0+8kAm/nQ5sVLOzd/t/AEGXA1m8ybCPx591W8txM90QyAskOyX3nIXo0KCY SXVdw3zO6WQN0s083rMg==; 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 1iXoKW-0005iI-IJ; Thu, 21 Nov 2019 15:25:12 +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 1iXoKS-0004XW-Gg for linux-arm-kernel@lists.infradead.org; Thu, 21 Nov 2019 15:25:10 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id B377668C4E; Thu, 21 Nov 2019 16:24:57 +0100 (CET) Date: Thu, 21 Nov 2019 16:24:57 +0100 From: Christoph Hellwig To: Nicolas Saenz Julienne Subject: Re: [PATCH v2] dma-mapping: treat dev->bus_dma_mask as a DMA limit Message-ID: <20191121152457.GA525@lst.de> References: <20191121092646.8449-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20191121092646.8449-1-nsaenzjulienne@suse.de> 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-20191121_072508_723873_2B872BB5 X-CRM114-Status: GOOD ( 14.35 ) 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: Peter Zijlstra , Benjamin Herrenschmidt , Dave Hansen , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, Paul Mackerras , Hanjun Guo , Frank Rowand , Christoph Hellwig , Marek Szyprowski , Lorenzo Pieralisi , "H. Peter Anvin" , Paul Burton , Michael Ellerman , Joerg Roedel , x86@kernel.org, linux-acpi@vger.kernel.org, Ingo Molnar , James Hogan , Len Brown , devicetree@vger.kernel.org, Rob Herring , Borislav Petkov , Andy Lutomirski , Bjorn Helgaas , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Jens Axboe , linuxppc-dev@lists.ozlabs.org, "Rafael J. Wysocki" , linux-mips@vger.kernel.org, Ralf Baechle , iommu@lists.linux-foundation.org, Sudeep Holla , Robin Murphy 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 Thu, Nov 21, 2019 at 10:26:44AM +0100, Nicolas Saenz Julienne wrote: > Using a mask to represent bus DMA constraints has a set of limitations. > The biggest one being it can only hold a power of two (minus one). The > DMA mapping code is already aware of this and treats dev->bus_dma_mask > as a limit. This quirk is already used by some architectures although > still rare. > > With the introduction of the Raspberry Pi 4 we've found a new contender > for the use of bus DMA limits, as its PCIe bus can only address the > lower 3GB of memory (of a total of 4GB). This is impossible to represent > with a mask. To make things worse the device-tree code rounds non power > of two bus DMA limits to the next power of two, which is unacceptable in > this case. > > In the light of this, rename dev->bus_dma_mask to dev->bus_dma_limit all > over the tree and treat it as such. Note that dev->bus_dma_limit should > contain the higher accesible DMA address. > > Signed-off-by: Nicolas Saenz Julienne I've tentatively added this patch to the dma-mapping tree based on Robins principal approval of the last version. That way tomorrows linux-next run should still pick it up. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel