From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Nowicki Subject: Re: [PATCH 05/11] x86, pci, acpi: Move arch-agnostic MMCONFIG (aka ECAM) and ACPI code out of arch/x86/ directory Date: Thu, 15 Oct 2015 16:34:45 +0200 Message-ID: <561FB985.8070509@linaro.org> References: <20150604102253.GA31773@red-moon> <5570447D.3020705@linaro.org> <557504A2.3060203@linaro.org> <20150608151443.GA16151@red-moon> <55E4340D.6050004@linaro.org> <55ED6010.3020406@linaro.org> <20150908150727.GF29293@red-moon> <55F0388B.1090607@linaro.org> <20150911112018.GA13033@red-moon> <55F6DFF6.4010807@linaro.org> <20151015132200.GA7621@red-moon> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20151015132200.GA7621@red-moon> Sender: linux-pci-owner@vger.kernel.org To: Lorenzo Pieralisi Cc: Bjorn Helgaas , "Rafael J. Wysocki" , "hanjun.guo@linaro.org" , Liviu Dudau , Yijing Wang , Will Deacon , Arnd Bergmann , Catalin Marinas , Jiang Liu , Thomas Gleixner , "suravee.suthikulpanit@amd.com" , "msalter@redhat.com" , "linux-pci@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-acpi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linaro-acpi@lists.linaro.org" List-Id: linux-acpi@vger.kernel.org On 15.10.2015 15:22, Lorenzo Pieralisi wrote: > On Mon, Sep 14, 2015 at 03:55:50PM +0100, Tomasz Nowicki wrote: > > [...] > >>> Well, I still have not figured out whether on arm64 the raw accessors >>> required by ACPICA make sense. >>> >>> So either arm64 relies on the generic MCFG based raw read and writes >>> or we define the global raw read and writes as empty (ie x86 overrides >>> them anyway). >>> >> >> My concerns/ideas related to raw accessors for ARM64, please correct me >> at any point. >> >> ACPI spec - chapter: 19.5.96 OperationRegion (Declare Operation Region) >> defines PCI_Config as one of region types. Every time ASL opcode >> operates on corresponding PCI config space region, ASL interpreter is >> dispatching address space to our raw accessors, please see >> acpi_ex_pci_config_space_handler, acpi_ev_pci_config_region_setup calls. >> What is more important, such operations may happen after (yes after) bus >> enumeration, but always raw accessors are called at the end with the >> {segment, bus, dev, fn} tuple. >> >> Giving above, here are some ideas: >> 1. We force somehow vendors to avoid operations on PCI config regions in >> ASL code. PCI config region definitions still fall into Hardware Reduced >> profile, so new ACPICA special subset for ARM64 is need. Then raw ACPI >> accessors can be empty (and overridden by x86). > > I am coming back to this, I am not sure that PCI config based OperationRegions > fall into Hardware Reduced profile, I will finally start a thread on ASWG > to check that. > > Other than that, are you posting an updated version of this series soon ? > Let me know if you need help refactoring/testing the patches. > I am planing to send updated version next week, but honestly next version does make sense if we figure out raw accessors issue. So I will clean up all around meanwhile and optionally raw accessor. Of course your help in testing is welcomed. Also please have a look at my GICv3/ITS patches, they are important for ACPI PCI. Regards, Tomasz