From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933114AbcHNLAL (ORCPT ); Sun, 14 Aug 2016 07:00:11 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51896 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933064AbcHNLAD (ORCPT ); Sun, 14 Aug 2016 07:00:03 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Guilherme G. Piccoli" , "Gavin Shan" , "Michael Ellerman" Date: Sat, 13 Aug 2016 18:42:51 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 074/305] powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism In-Reply-To: X-SA-Exim-Connect-IP: 92.40.249.202 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.37-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "Guilherme G. Piccoli" commit 8445a87f7092bc8336ea1305be9306f26b846d93 upstream. Commit 39baadbf36ce ("powerpc/eeh: Remove eeh information from pci_dn") changed the pci_dn struct by removing its EEH-related members. As part of this clean-up, DDW mechanism was modified to read the device configuration address from eeh_dev struct. As a consequence, now if we disable EEH mechanism on kernel command-line for example, the DDW mechanism will fail, generating a kernel oops by dereferencing a NULL pointer (which turns to be the eeh_dev pointer). This patch just changes the configuration address calculation on DDW functions to a manual calculation based on pci_dn members instead of using eeh_dev-based address. No functional changes were made. This was tested on pSeries, both in PHyp and qemu guest. Fixes: 39baadbf36ce ("powerpc/eeh: Remove eeh information from pci_dn") Reviewed-by: Gavin Shan Signed-off-by: Guilherme G. Piccoli Signed-off-by: Michael Ellerman Signed-off-by: Ben Hutchings --- arch/powerpc/platforms/pseries/iommu.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -826,7 +826,8 @@ machine_arch_initcall(pseries, find_exis static int query_ddw(struct pci_dev *dev, const u32 *ddw_avail, struct ddw_query_response *query) { - struct eeh_dev *edev; + struct device_node *dn; + struct pci_dn *pdn; u32 cfg_addr; u64 buid; int ret; @@ -837,11 +838,10 @@ static int query_ddw(struct pci_dev *dev * Retrieve them from the pci device, not the node with the * dma-window property */ - edev = pci_dev_to_eeh_dev(dev); - cfg_addr = edev->config_addr; - if (edev->pe_config_addr) - cfg_addr = edev->pe_config_addr; - buid = edev->phb->buid; + dn = pci_device_to_OF_node(dev); + pdn = PCI_DN(dn); + buid = pdn->phb->buid; + cfg_addr = (pdn->busno << 8) | pdn->devfn; ret = rtas_call(ddw_avail[0], 3, 5, (u32 *)query, cfg_addr, BUID_HI(buid), BUID_LO(buid)); @@ -855,7 +855,8 @@ static int create_ddw(struct pci_dev *de struct ddw_create_response *create, int page_shift, int window_shift) { - struct eeh_dev *edev; + struct device_node *dn; + struct pci_dn *pdn; u32 cfg_addr; u64 buid; int ret; @@ -866,11 +867,10 @@ static int create_ddw(struct pci_dev *de * Retrieve them from the pci device, not the node with the * dma-window property */ - edev = pci_dev_to_eeh_dev(dev); - cfg_addr = edev->config_addr; - if (edev->pe_config_addr) - cfg_addr = edev->pe_config_addr; - buid = edev->phb->buid; + dn = pci_device_to_OF_node(dev); + pdn = PCI_DN(dn); + buid = pdn->phb->buid; + cfg_addr = (pdn->busno << 8) | pdn->devfn; do { /* extra outputs are LIOBN and dma-addr (hi, lo) */