From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161179AbcFIVUt (ORCPT ); Thu, 9 Jun 2016 17:20:49 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:51634 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753610AbcFIVUn (ORCPT ); Thu, 9 Jun 2016 17:20:43 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Prarit Bhargava , Bjorn Helgaas , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andi Kleen , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 195/206] x86/PCI: Mark Broadwell-EP Home Agent 1 as having non-compliant BARs Date: Thu, 9 Jun 2016 14:16:44 -0700 Message-Id: <1465507015-23052-196-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1465507015-23052-1-git-send-email-kamal@canonical.com> References: <1465507015-23052-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.2.8-ckt12 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Prarit Bhargava commit da77b67195de1c65bef4908fa29967c4d0af2da2 upstream. Commit b894157145e4 ("x86/PCI: Mark Broadwell-EP Home Agent & PCU as having non-compliant BARs") marked Home Agent 0 & PCU has having non-compliant BARs. Home Agent 1 also has non-compliant BARs. Mark Home Agent 1 as having non-compliant BARs so the PCI core doesn't touch them. The problem with these devices is documented in the Xeon v4 specification update: BDF2 PCI BARs in the Home Agent Will Return Non-Zero Values During Enumeration Problem: During system initialization the Operating System may access the standard PCI BARs (Base Address Registers). Due to this erratum, accesses to the Home Agent BAR registers (Bus 1; Device 18; Function 0,4; Offsets (0x14-0x24) will return non-zero values. Implication: The operating system may issue a warning. Intel has not observed any functional failures due to this erratum. Link: http://www.intel.com/content/www/us/en/processors/xeon/xeon-e5-v4-spec-update.html Fixes: b894157145e4 ("x86/PCI: Mark Broadwell-EP Home Agent & PCU as having non-compliant BARs") Signed-off-by: Prarit Bhargava Signed-off-by: Bjorn Helgaas CC: Thomas Gleixner CC: Ingo Molnar CC: "H. Peter Anvin" CC: Andi Kleen Signed-off-by: Kamal Mostafa --- arch/x86/pci/fixup.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c index f16af96..156fbb6 100644 --- a/arch/x86/pci/fixup.c +++ b/arch/x86/pci/fixup.c @@ -554,9 +554,16 @@ static void twinhead_reserve_killing_zone(struct pci_dev *dev) } DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x27B9, twinhead_reserve_killing_zone); +/* + * Broadwell EP Home Agent BARs erroneously return non-zero values when read. + * + * See http://www.intel.com/content/www/us/en/processors/xeon/xeon-e5-v4-spec-update.html + * entry BDF2. + */ static void pci_bdwep_bar(struct pci_dev *dev) { dev->non_compliant_bars = 1; } +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6f60, pci_bdwep_bar); DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fa0, pci_bdwep_bar); DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, pci_bdwep_bar); -- 2.7.4