From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932424Ab1HFAR5 (ORCPT ); Fri, 5 Aug 2011 20:17:57 -0400 Received: from cantor2.suse.de ([195.135.220.15]:39622 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932374Ab1HFALn (ORCPT ); Fri, 5 Aug 2011 20:11:43 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Fri Aug 5 17:04:14 2011 Message-Id: <20110806000414.736692274@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Fri, 05 Aug 2011 17:03:49 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Don Dutile , Chris Wright , Jesse Barnes Subject: [31/50] PCI: ARI is a PCIe v2 feature In-Reply-To: <20110806000419.GA28392@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.33-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Chris Wright commit 864d296cf948aef0fa32b81407541572583f7572 upstream. The function pci_enable_ari() may mistakenly set the downstream port of a v1 PCIe switch in ARI Forwarding mode. This is a PCIe v2 feature, and with an SR-IOV device on that switch port believing the switch above is ARI capable it may attempt to use functions 8-255, translating into invalid (non-zero) device numbers for that bus. This has been seen to cause Completion Timeouts and general misbehaviour including hangs and panics. Acked-by: Don Dutile Tested-by: Don Dutile Signed-off-by: Chris Wright Signed-off-by: Jesse Barnes Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pci.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1528,7 +1528,7 @@ void pci_enable_ari(struct pci_dev *dev) { int pos; u32 cap; - u16 ctrl; + u16 flags, ctrl; struct pci_dev *bridge; if (!pci_is_pcie(dev) || dev->devfn) @@ -1546,6 +1546,11 @@ void pci_enable_ari(struct pci_dev *dev) if (!pos) return; + /* ARI is a PCIe v2 feature */ + pci_read_config_word(bridge, pos + PCI_EXP_FLAGS, &flags); + if ((flags & PCI_EXP_FLAGS_VERS) < 2) + return; + pci_read_config_dword(bridge, pos + PCI_EXP_DEVCAP2, &cap); if (!(cap & PCI_EXP_DEVCAP2_ARI)) return;