Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752447AbeAJSPB (ORCPT + 1 other); Wed, 10 Jan 2018 13:15:01 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:42595 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751665AbeAJSO7 (ORCPT ); Wed, 10 Jan 2018 13:14:59 -0500 X-Google-Smtp-Source: ACJfBotZbRPfDQODJINbRFLq3lyMpYor1S3UuoLlA8CUNRIE9Yxxih8qiwQ6aYVM7+X4adTmKL2CUQ== Reply-To: christian.koenig@amd.com Subject: Re: [PATCH 2/2] x86/PCI: limit the size of the 64bit window to 256GB v2 To: Bjorn Helgaas 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 References: <20180110122551.1637-1-christian.koenig@amd.com> <20180110122551.1637-2-christian.koenig@amd.com> <20180110180230.GA227910@bhelgaas-glaptop.roam.corp.google.com> From: =?UTF-8?Q?Christian_K=c3=b6nig?= Message-ID: <2382e9b9-aa03-a845-4d67-c01fe52004bf@gmail.com> Date: Wed, 10 Jan 2018 19:14:56 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <20180110180230.GA227910@bhelgaas-glaptop.roam.corp.google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: 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 König 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 König >> --- >> 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? Christian. > >> 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 >>