3 files changed, 9 insertions, 1 deletions

diff --git a/arch/x86_64/boot/compressed/misc.c b/arch/x86_64/boot/compressed/misc.c
index fee54dbf1749..fed1167159c3 100644
--- a/arch/x86_64/boot/compressed/misc.c
+++ b/arch/x86_64/boot/compressed/misc.c
@@ -358,7 +358,7 @@ asmlinkage void decompress_kernel(void *rmode, unsigned long heap,
         insize = input_len;
         inptr  = 0;
 
-        if ((ulg)output & 0x1fffffUL)
+        if ((ulg)output & (__KERNEL_ALIGN - 1))
                 error("Destination address not 2M aligned");
         if ((ulg)output >= 0xffffffffffUL)
                 error("Destination address too large");
diff --git a/arch/x86_64/kernel/head64.c b/arch/x86_64/kernel/head64.c
index 6c34bdd22e26..213d90e04755 100644
--- a/arch/x86_64/kernel/head64.c
+++ b/arch/x86_64/kernel/head64.c
@@ -62,6 +62,13 @@ void __init x86_64_start_kernel(char * real_mode_data)
 {
         int i;
 
+        /*
+         * Make sure kernel is aligned to 2MB address. Catching it at compile
+         * time is better. Change your config file and compile the kernel
+         * for a 2MB aligned address (CONFIG_PHYSICAL_START)
+         */
+        BUILD_BUG_ON(CONFIG_PHYSICAL_START & (__KERNEL_ALIGN - 1));
+
         /* clear bss before set_intr_gate with early_idt_handler */
         clear_bss();
 
diff --git a/include/asm-x86_64/page.h b/include/asm-x86_64/page.h
index 40a24d0df090..b17fc16ec2eb 100644
--- a/include/asm-x86_64/page.h
+++ b/include/asm-x86_64/page.h
@@ -78,6 +78,7 @@ extern unsigned long phys_base;
 #endif /* !__ASSEMBLY__ */
 
 #define __PHYSICAL_START        CONFIG_PHYSICAL_START
+#define __KERNEL_ALIGN          0x200000
 #define __START_KERNEL          (__START_KERNEL_map + __PHYSICAL_START)
 #define __START_KERNEL_map      0xffffffff80000000
 #define __PAGE_OFFSET           0xffff810000000000