x86: introduce max_low_pfn_mapped for 64-bit

when more than 4g memory is installed, don't map the big hole below 4g.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index 6ccd7a108cd4..5281e343dd9f 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -334,7 +334,9 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
                 flags = new_flags;
         }
 
-        if (vma->vm_pgoff <= max_pfn_mapped &&
+        if (((vma->vm_pgoff <= max_low_pfn_mapped) ||
+             (vma->vm_pgoff >= (1UL<<(32 - PAGE_SHIFT)) &&
+              vma->vm_pgoff <= max_pfn_mapped)) &&
             ioremap_change_attr((unsigned long)__va(addr), len, flags)) {
                 free_memtype(addr, addr + len);
                 return -EINVAL;