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, 7 insertions, 0 deletions

diff --git a/include/linux/efi.h b/include/linux/efi.h
index 14813b595802..a5f359a7ad0e 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -18,6 +18,7 @@
 #include <linux/proc_fs.h>
 #include <linux/rtc.h>
 #include <linux/ioport.h>
+#include <linux/pfn.h>
 
 #include <asm/page.h>
 #include <asm/system.h>
@@ -394,4 +395,10 @@ struct efi_generic_dev_path {
         u16 length;
 } __attribute ((packed));
 
+static inline void memrange_efi_to_native(u64 *addr, u64 *npages)
+{
+        *npages = PFN_UP(*addr + (*npages<<EFI_PAGE_SHIFT)) - PFN_DOWN(*addr);
+        *addr &= PAGE_MASK;
+}
+
 #endif /* _LINUX_EFI_H */