From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751262AbdHCPpO (ORCPT ); Thu, 3 Aug 2017 11:45:14 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:33486 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751158AbdHCPpM (ORCPT ); Thu, 3 Aug 2017 11:45:12 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 49FE5606DC Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=nwatters@codeaurora.org Subject: Re: [PATCH v3 0/5] ACPI: DMA ranges management To: Lorenzo Pieralisi , linux-acpi@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Will Deacon , Hanjun Guo , Feng Kan , Jon Masters , Robert Moore , Robin Murphy , Zhang Rui , "Rafael J. Wysocki" References: <20170803123239.11359-1-lorenzo.pieralisi@arm.com> From: Nate Watterson Message-ID: <3ccac0b0-dd5a-6a70-f253-99f038f69b8c@codeaurora.org> Date: Thu, 3 Aug 2017 11:45:04 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170803123239.11359-1-lorenzo.pieralisi@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Lorenzo, On 8/3/2017 8:32 AM, Lorenzo Pieralisi wrote: > This patch series is v3 of a previous posting: > > v2->v3: > - Fixed DMA masks computation > - Fixed size computation overflow in acpi_dma_get_range() > > v1->v2: > - Reworked acpi_dma_get_range() flow and logs > - Added IORT named component address limits > - Renamed acpi_dev_get_resources() helper function > - Rebased against v4.13-rc3 > > v2: http://lkml.kernel.org/r/20170731152323.32488-1-lorenzo.pieralisi@arm.com > v1: http://lkml.kernel.org/r/20170720144517.32529-1-lorenzo.pieralisi@arm.com > > -- Original cover letter -- > > As reported in: > > http://lkml.kernel.org/r/CAL85gmA_SSCwM80TKdkZqEe+S1beWzDEvdki1kpkmUTDRmSP7g@mail.gmail.com > > the bus connecting devices to an IOMMU bus can be smaller in size than > the IOMMU input address bits which results in devices DMA HW bugs in > particular related to IOVA allocation (ie chopping of higher address > bits owing to system bus HW capabilities mismatch with the IOMMU). > > Fortunately this problem can be solved through an already present but never > used ACPI 6.2 firmware bindings (ie _DMA object) allowing to define the DMA > window for a specific bus in ACPI and therefore all upstream devices > connected to it. > > This small patch series enables _DMA parsing in ACPI core code and > use it in ACPI IORT code in order to detect DMA ranges for devices and > update their data structures to make them work with their related DMA > addressing restrictions. > > Cc: Will Deacon > Cc: Hanjun Guo > Cc: Feng Kan > Cc: Jon Masters > Cc: Robert Moore > Cc: Robin Murphy > Cc: Zhang Rui > Cc: "Rafael J. Wysocki" > > Lorenzo Pieralisi (5): > ACPICA: resource_mgr: Allow _DMA method in walk resources > ACPI: Make acpi_dev_get_resources() method agnostic > ACPI: Introduce DMA ranges parsing > ACPI: Make acpi_dma_configure() DMA regions aware > ACPI/IORT: Add IORT named component memory address limits > > drivers/acpi/acpica/rsxface.c | 7 ++-- > drivers/acpi/arm64/iort.c | 57 ++++++++++++++++++++++++++- > drivers/acpi/resource.c | 82 +++++++++++++++++++++++++++++--------- > drivers/acpi/scan.c | 91 +++++++++++++++++++++++++++++++++++++++---- > include/acpi/acnames.h | 1 + > include/acpi/acpi_bus.h | 2 + > include/linux/acpi.h | 8 ++++ > include/linux/acpi_iort.h | 5 ++- > 8 files changed, 219 insertions(+), 34 deletions(-) > I tested with named components and with _DMA objects at a variety of sizes and verified the configured masks matched the expected values. Tested-by: Nate Watterson One general question I had while testing the patch is whether it is possible to define a complete 64-bit range using the _DMA method. For instance, to get a 64-bit dma_mask I had to use a non-zero MIN value so that LEN would not overflow. QWORDMemory( ResourceConsumer, PosDecode, // _DEC MinFixed, // _MIF MaxFixed, // _MAF Prefetchable, // _MEM ReadWrite, // _RW 0, // _GRA 0x1000, // _MIN 0xffffffffffffffff, // _MAX 0x0, // _TRA 0xfffffffffffff000, // _LEN , , , ) -Nate -- Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.