If phys_addr is not page aligned, ioremap_page_range() will align down it when get pfn by phys_addr >> PAGE_SHIFT. An example in arm64 system with 64KB page size: phys_addr: 0xefff8000 res->start: 0x0 res->end: 0x0ffff PCI_IOBASE: 0xffff7fdffee00000 This will remap virtual address 0xffff7fdffee00000 to phys_addr 0xefff0000, but what we really want is 0xefff8000, which makes later IO access to a mess. And users may even donot know this until find some odd phenemenon. This patch checks whether phys_addr is PAGE_ALIGNED or not to find the primary scene. Signed-off-by: Zhou Wang <wangzhou1@xxxxxxxxxxxxx> Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx> --- drivers/pci/pci.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index f6a4dd1..deb91f0 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3576,6 +3576,9 @@ int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) if (res->end > IO_SPACE_LIMIT) return -EINVAL; + if (!PAGE_ALIGNED(phys_addr)) + return -EINVAL; + return ioremap_page_range(vaddr, vaddr + resource_size(res), phys_addr, pgprot_device(PAGE_KERNEL)); #else -- 1.7.12.4
