Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756846AbaJXQ2d (ORCPT ); Fri, 24 Oct 2014 12:28:33 -0400 Received: from foss-mx-na.foss.arm.com ([217.140.108.86]:48385 "EHLO foss-mx-na.foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752680AbaJXQ2b (ORCPT ); Fri, 24 Oct 2014 12:28:31 -0400 From: Lorenzo Pieralisi To: linux-kernel@vger.kernel.org Cc: Lorenzo Pieralisi , Arnd Bergmann , Russell King , LAKML , Linux PCI Subject: [PATCH RFC v2 2/2] arm: kernel: fix pci_mmap_page_range() offset calculation Date: Fri, 24 Oct 2014 17:28:06 +0100 Message-Id: <1414168089-8130-3-git-send-email-lorenzo.pieralisi@arm.com> X-Mailer: git-send-email 2.1.2 In-Reply-To: <1414168089-8130-1-git-send-email-lorenzo.pieralisi@arm.com> References: <1414168089-8130-1-git-send-email-lorenzo.pieralisi@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 structures, which represent CPU physical addresses (fixed-up using BUS to CPU address conversions) not PCI bus addresses. Therefore, on ARM platforms where the mapping between CPU and BUS address is not a 1:1 the current pci_mmap_page_range() implementation 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; -- 2.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/