Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752366AbeAJUhy (ORCPT + 1 other); Wed, 10 Jan 2018 15:37:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:52580 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751486AbeAJUhv (ORCPT ); Wed, 10 Jan 2018 15:37:51 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7962120C51 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=helgaas@kernel.org Date: Wed, 10 Jan 2018 14:37:46 -0600 From: Bjorn Helgaas To: christian.koenig@amd.com Cc: bhelgaas@google.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Linus Torvalds , Aaro Koskinen , Andy Shevchenko , Boris Ostrovsky , Juergen Gross , Alex Deucher , David Airlie Subject: Re: [PATCH 2/2] x86/PCI: limit the size of the 64bit window to 256GB v2 Message-ID: <20180110203746.GA241460@bhelgaas-glaptop.roam.corp.google.com> References: <20180110122551.1637-1-christian.koenig@amd.com> <20180110122551.1637-2-christian.koenig@amd.com> <20180110180230.GA227910@bhelgaas-glaptop.roam.corp.google.com> <2382e9b9-aa03-a845-4d67-c01fe52004bf@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2382e9b9-aa03-a845-4d67-c01fe52004bf@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Wed, Jan 10, 2018 at 07:14:56PM +0100, Christian K?nig wrote: > Am 10.01.2018 um 19:02 schrieb Bjorn Helgaas: > >[+cc linux-pci, previous cc list] > > > >On Wed, Jan 10, 2018 at 01:25:51PM +0100, Christian K?nig wrote: > >>Avoid problems with BIOS implementations which don't report all used > >>resources to the OS by only allocating a 256GB window directly below the > >>hardware limit. > >> > >>v2: cleanup code a bit more, update comment and explain the hw limit > >Fixes a silent reboot loop reported by Aaro Koskinen > > on an AMD-based MSI MS-7699/760GA-P43(FX) > >system. > > > >Link: https://lkml.kernel.org/r/20180105220412.fzpwqe4zljdawr36@darkstar.musicnaut.iki.fi > >Reported-by: Aaro Koskinen > > > >>Signed-off-by: Christian K?nig > >>--- > >> arch/x86/pci/fixup.c | 19 +++++++++---------- > >> 1 file changed, 9 insertions(+), 10 deletions(-) > >> > >>diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c > >>index a91280da2ea1..9c1c98d7e3a7 100644 > >>--- a/arch/x86/pci/fixup.c > >>+++ b/arch/x86/pci/fixup.c > >>@@ -662,10 +662,11 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2033, quirk_no_aersid); > >> */ > >> static void pci_amd_enable_64bit_bar(struct pci_dev *dev) > >> { > >>- unsigned i; > >> u32 base, limit, high; > >>- struct resource *res, *conflict; > >> struct pci_dev *other; > >>+ struct resource *res; > >>+ unsigned i; > >>+ int r; > >> if (!(pci_probe & PCI_BIG_ROOT_WINDOW)) > >> return; > >>@@ -702,19 +703,17 @@ static void pci_amd_enable_64bit_bar(struct pci_dev *dev) > >> if (!res) > >> return; > >>+ /* Allocate a 256GB window directly below the 0xfd00000000 hw limit */ > >Can you include a citation for the hardware limit in the changelog? > >I'll try to dig it up myself if you don't beat me to it. > > Sure, no problem. The first one in the series is ok as it is? Yeah, I think so, although it would be good to add doc as Randy suggests. Can you cc the folks involved (in particular, linux-pci) next time, too? > >> res->name = "PCI Bus 0000:00"; > >> res->flags = IORESOURCE_PREFETCH | IORESOURCE_MEM | > >> IORESOURCE_MEM_64 | IORESOURCE_WINDOW; > >>- res->start = 0x100000000ull; > >>+ res->start = 0xbd00000000ull; > >> res->end = 0xfd00000000ull - 1; > >>- /* Just grab the free area behind system memory for this */ > >>- while ((conflict = request_resource_conflict(&iomem_resource, res))) { > >>- if (conflict->end >= res->end) { > >>- kfree(res); > >>- return; > >>- } > >>- res->start = conflict->end + 1; > >>+ r = request_resource(&iomem_resource, res); > >>+ if (r) { > >>+ kfree(res); > >>+ return; > >> } > >> dev_info(&dev->dev, "adding root bus resource %pR\n", res); > >>-- > >>2.11.0 > >> >