From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suravee Suthikulpanit Subject: Re: [PATCH v2 2/5] x86/PCI: Support additional MMIO range capabilities Date: Wed, 30 Apr 2014 02:50:21 -0500 Message-ID: <5360AB3D.3020401@amd.com> References: <20140420075936.GA19672@pd.tnic> <20140426091031.GA10166@pd.tnic> <20140428214036.GA32143@pd.tnic> <20140429073309.GE10997@alberich> <20140429102013.GA4726@pd.tnic> <535FC269.2000808@amd.com> <20140429191454.GB4726@pd.tnic> <20140430070042.GN32718@rric.localhost> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140430070042.GN32718@rric.localhost> Sender: linux-pci-owner@vger.kernel.org To: Robert Richter , Myron Stowe Cc: Borislav Petkov , Borislav Petkov , Andreas Herrmann , Bjorn Helgaas , Myron Stowe , Aravind Gopalakrishnan , linux-pci , kim.naru@amd.com, Daniel J Blueman , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86 , Steffen Persvold , "linux-acpi@vger.kernel.org" , LKML , Jan Beulich , Yinghai Lu List-Id: linux-acpi@vger.kernel.org On 04/30/2014 02:00 AM, Robert Richter wrote: > On 29.04.14 15:40:28, Myron Stowe wrote: >> On Tue, Apr 29, 2014 at 1:14 PM, Borislav Petkov wrote: >>> So sounds to me like we want to get rid of the whole IO ECS deal >>> altogether then. >>> >>> Now, I'm wondering whether we should kill it completely since I don't >>> think anyone cares about numa node info being correct on K8, or? I'm >>> specifically turning to our numascale friends who love to have a lot of >>> nodes. :-) > > Maybe I did get you wrong, but IO ECS was introduced with fam10h and > is not related to k8. > >> I think we need to be careful here as there are two unrelated topics >> being discussed together. What started this whole thread was the need >> for sysfs related numa_node information with respect to PCI devices >> (1). Without patch 1, platforms with newer AMD CPUs end up having >> '-1' numa_node values for all PCI devices. >> >> IO ECS has no bearing on patch 1, it only comes into play with patch 2 >> which is concerned with MMIO resource information when MCFG doesn't >> exist. For the particular issue I'm trying to get resolved, patch 2 >> is not needed. However, since we have expended time and effort on >> this subject, perhaps we should get this cleaned up while it has our >> attention. >> >> I'm all for deleting as much of amd_bus.c as possible due to its >> "perennial maintenance headache". The obvious choices seem to be all, >> or some combination, of: >> o removing IO ECS logic, >> o removing IO/MMIO logic (assuming MCFG issues were long enough ago >> to no longer be a concern), >> o start deprecating amd_bus.c by adding logic to skip if BIOS >= 2015 > > I don't see any reason for big changes actually. Just bind the IO ECS > logic to fam10h (either with fam check or pci device depending on the > implementation, xen's flavor would be pci). This is something stricter > than 'if BIOS >= 2015'. It leaves code as it is which is maintainable. > > You implement the new logic for for newer families. No need for one > implementation that fits all. > > -Robert > Actually, if ECS is needed by IBS, then wouldn't this still be needed for every family since 10h and later (except family11h). Suravee