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, 1 insertions, 1 deletions

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index a31a579a47ca..9c981c4a3644 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -130,7 +130,7 @@ char *__init __acpi_map_table(unsigned long phys, unsigned long size)
         if (!phys || !size)
                 return NULL;
 
-        if (phys+size <= (max_pfn_mapped << PAGE_SHIFT))
+        if (phys+size <= (max_low_pfn_mapped << PAGE_SHIFT))
                 return __va(phys);
 
         offset = phys & (PAGE_SIZE - 1);