From: Lorenzo Pieralisi Date: Tue, 27 Jan 2015 09:43:13 +0000 (+0100) Subject: ARM: 8293/1: kernel: fix pci_mmap_page_range() offset calculation X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=415ae101caf9fbf6746a88126494eda333174e90;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git ARM: 8293/1: kernel: fix pci_mmap_page_range() offset calculation 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 Signed-off-by: Lorenzo Pieralisi Acked-by: Bjorn Helgaas Signed-off-by: Russell King --- diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c index ab19b7c03423..fcbbbb1b9e95 100644 --- a/arch/arm/kernel/bios32.c +++ b/arch/arm/kernel/bios32.c @@ -618,21 +618,15 @@ 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;