x86: EFI_PAGE_SHIFT fix

Make x86 EFI code works when EFI_PAGE_SHIFT != PAGE_SHIFT. The
memrage_efi_to_native() provided in this patch can be used on other
EFI platform such as IA64 too.

This patch has been tested on Intel x86_64 platform with EFI 64/32
firmware.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 6 insertions, 6 deletions

diff --git a/arch/x86/kernel/efi_64.c b/arch/x86/kernel/efi_64.c
index d143a1e76b30..d0060fdcccac 100644
--- a/arch/x86/kernel/efi_64.c
+++ b/arch/x86/kernel/efi_64.c
@@ -105,14 +105,14 @@ void __init efi_reserve_bootmem(void)
 
 void __iomem * __init efi_ioremap(unsigned long phys_addr, unsigned long size)
 {
-        static unsigned pages_mapped;
+        static unsigned pages_mapped __initdata;
         unsigned i, pages;
+        unsigned long offset;
 
-        /* phys_addr and size must be page aligned */
-        if ((phys_addr & ~PAGE_MASK) || (size & ~PAGE_MASK))
-                return NULL;
+        pages = PFN_UP(phys_addr + size) - PFN_DOWN(phys_addr);
+        offset = phys_addr & ~PAGE_MASK;
+        phys_addr &= PAGE_MASK;
 
-        pages = size >> PAGE_SHIFT;
         if (pages_mapped + pages > MAX_EFI_IO_PAGES)
                 return NULL;
 
@@ -124,5 +124,5 @@ void __iomem * __init efi_ioremap(unsigned long phys_addr, unsigned long size)
         }
 
         return (void __iomem *)__fix_to_virt(FIX_EFI_IO_MAP_FIRST_PAGE - \
-                                             (pages_mapped - pages));
+                                             (pages_mapped - pages)) + offset;
 }