Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934498AbeAKOvu (ORCPT + 1 other); Thu, 11 Jan 2018 09:51:50 -0500 Received: from mail-wr0-f193.google.com ([209.85.128.193]:33723 "EHLO mail-wr0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933026AbeAKOvs (ORCPT ); Thu, 11 Jan 2018 09:51:48 -0500 X-Google-Smtp-Source: ACJfBosr3i1ckeCLzxSViRkX9ckCKNdl3x6I08NeptnCnkn2sBVk6/1YEHyHB1pgh0YvbgdSXJpxIg== Reply-To: christian.koenig@amd.com Subject: Re: [PATCH 2/2] x86/PCI: limit the size of the 64bit window to 256GB v3 To: Bjorn Helgaas Cc: bhelgaas@google.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, torvalds@linux-foundation.org, aaro.koskinen@iki.fi, andy.shevchenko@gmail.com, boris.ostrovsky@oracle.com, jgross@suse.com, alexander.deucher@amd.com, airlied@linux.ie References: <20180111132330.2682-1-christian.koenig@amd.com> <20180111132330.2682-2-christian.koenig@amd.com> <20180111142141.GA3672@bhelgaas-glaptop.roam.corp.google.com> From: =?UTF-8?Q?Christian_K=c3=b6nig?= Message-ID: <12f934df-3a5b-08fb-d313-9c7b9734c361@gmail.com> Date: Thu, 11 Jan 2018 15:51:45 +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: <20180111142141.GA3672@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 11.01.2018 um 15:21 schrieb Bjorn Helgaas: > On Thu, Jan 11, 2018 at 02:23:30PM +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. >> >> For the full hardware documentation see: >> https://support.amd.com/TechDocs/49125_15h_Models_30h-3Fh_BKDG.pdf > If you can supply a section number, I'll add it here. That spec is 700 > pages, so a hint would be useful. Sorry, had to search for that as well. That is noted in section "2.4.6 System Address Map". Do you want to add that or should I resend the patch? Regards, Christian. > >> Fixes a silent reboot loop reported by Aaro Koskinen on >> an AMD-based MSI MS-7699/760GA-P43(FX) system. >> >> v2: cleanup code a bit more, update comment and explain the hw limit >> v3: improve commit message >> >> 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 */ >> 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 >>