From patchwork Wed Oct 15 12:03:41 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Pieralisi X-Patchwork-Id: 5085401 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 7BEE19F349 for ; Wed, 15 Oct 2014 12:03:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9C2AD20120 for ; Wed, 15 Oct 2014 12:03:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4BA7A2013A for ; Wed, 15 Oct 2014 12:03:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751533AbaJOMDO (ORCPT ); Wed, 15 Oct 2014 08:03:14 -0400 Received: from service87.mimecast.com ([91.220.42.44]:55473 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752153AbaJOMDN (ORCPT ); Wed, 15 Oct 2014 08:03:13 -0400 Received: from cam-owa2.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.21]) by service87.mimecast.com; Wed, 15 Oct 2014 13:03:11 +0100 Received: from red-moon.cambridge.arm.com ([10.1.255.212]) by cam-owa2.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.3959); Wed, 15 Oct 2014 13:03:08 +0100 From: Lorenzo Pieralisi To: linux-kernel@vger.kernel.org Cc: Arnd Bergmann , Russell King , LAKML , Linux PCI Subject: [PATCH RFC 2/2] arm: kernel: fix pci_mmap_page_range() offset calculation Date: Wed, 15 Oct 2014 13:03:41 +0100 Message-Id: <1413374624-30066-2-git-send-email-lorenzo.pieralisi@arm.com> X-Mailer: git-send-email 2.1.2 In-Reply-To: <1413374624-30066-1-git-send-email-lorenzo.pieralisi@arm.com> References: <1413374624-30066-1-git-send-email-lorenzo.pieralisi@arm.com> X-OriginalArrivalTime: 15 Oct 2014 12:03:08.0915 (UTC) FILETIME=[FC500430:01CFE86F] X-MC-Unique: 114101513031113701 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, SUSPICIOUS_RECIPS, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The pci_mmap_page_range() API should be written to expect offset values representing PCI memory resource addresses as seen by user space, through the pci_resource_to_user() API. ARM relies on the standard implementation of pci_resource_to_user() which actually is an identity map and exports to user space PCI memory resources as they are stored in PCI devices resources (ie BARs) which represent CPU physical addresses (fixed-up using BUS to CPU address conversions) not PCI bus addresses. On platforms where the mapping between CPU and BUS address is not a 1:1 mapping this is erroneous, in that an additional shift is applied to an already fixed-up offset passed from userspace. Hence, this patch removes the mem_offset from the pgoff calculation since the offset as passed from user space already represents the CPU physical address corresponding to the resource to be mapped, ie no additional offset should be applied. Cc: Arnd Bergmann Cc: Russell King Signed-off-by: Lorenzo Pieralisi --- arch/arm/kernel/bios32.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c index 17a26c1..b56fa2d 100644 --- a/arch/arm/kernel/bios32.c +++ b/arch/arm/kernel/bios32.c @@ -626,21 +626,15 @@ int pcibios_enable_device(struct pci_dev *dev, int mask) int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, enum pci_mmap_state mmap_state, int write_combine) { - struct pci_sys_data *root = dev->sysdata; - unsigned long phys; - - if (mmap_state == pci_mmap_io) { + if (mmap_state == pci_mmap_io) return -EINVAL; - } else { - phys = vma->vm_pgoff + (root->mem_offset >> PAGE_SHIFT); - } /* * Mark this as IO */ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); - if (remap_pfn_range(vma, vma->vm_start, phys, + if (remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, vma->vm_end - vma->vm_start, vma->vm_page_prot)) return -EAGAIN;