7 files changed, 46 insertions, 32 deletions
diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile
index 5b84a2d3088..7c0d7be176a 100644
--- a/arch/x86/realmode/rm/Makefile
+++ b/arch/x86/realmode/rm/Makefile
@@ -22,7 +22,7 @@ wakeup-objs	+= video-bios.o
 realmode-y			+= header.o
 realmode-y			+= trampoline_$(BITS).o
 realmode-y			+= stack.o
-realmode-$(CONFIG_X86_32)	+= reboot_32.o
+realmode-y			+= reboot.o
 realmode-$(CONFIG_ACPI_SLEEP)	+= $(wakeup-objs)
 
 targets	+= $(realmode-y)
@@ -52,8 +52,9 @@ $(obj)/realmode.elf: $(obj)/realmode.lds $(REALMODE_OBJS) FORCE
 OBJCOPYFLAGS_realmode.bin := -O binary
 
 targets += realmode.bin
-$(obj)/realmode.bin: $(obj)/realmode.elf $(obj)/realmode.relocs
+$(obj)/realmode.bin: $(obj)/realmode.elf $(obj)/realmode.relocs FORCE
 	$(call if_changed,objcopy)
+	@:
 
 quiet_cmd_relocs = RELOCS  $@
       cmd_relocs = arch/x86/tools/relocs --realmode $< > $@
@@ -64,19 +65,7 @@ $(obj)/realmode.relocs: $(obj)/realmode.elf FORCE
 
 # ---------------------------------------------------------------------------
 
-# How to compile the 16-bit code.  Note we always compile for -march=i386,
-# that way we can complain to the user if the CPU is insufficient.
-KBUILD_CFLAGS	:= $(LINUXINCLUDE) -m32 -g -Os -D_SETUP -D__KERNEL__ -D_WAKEUP \
-		   -I$(srctree)/arch/x86/boot \
-		   -DDISABLE_BRANCH_PROFILING \
-		   -Wall -Wstrict-prototypes \
-		   -march=i386 -mregparm=3 \
-		   -include $(srctree)/$(src)/../../boot/code16gcc.h \
-		   -fno-strict-aliasing -fomit-frame-pointer \
-		   $(call cc-option, -ffreestanding) \
-		   $(call cc-option, -fno-toplevel-reorder,\
-			$(call cc-option, -fno-unit-at-a-time)) \
-		   $(call cc-option, -fno-stack-protector) \
-		   $(call cc-option, -mpreferred-stack-boundary=2)
+KBUILD_CFLAGS	:= $(LINUXINCLUDE) $(REALMODE_CFLAGS) -D_SETUP -D_WAKEUP \
+		   -I$(srctree)/arch/x86/boot
 KBUILD_AFLAGS	:= $(KBUILD_CFLAGS) -D__ASSEMBLY__
 GCOV_PROFILE := n
diff --git a/arch/x86/realmode/rm/header.S b/arch/x86/realmode/rm/header.S
index fadf48378ad..a28221d94e6 100644
--- a/arch/x86/realmode/rm/header.S
+++ b/arch/x86/realmode/rm/header.S
@@ -6,6 +6,7 @@
 
 #include <linux/linkage.h>
 #include <asm/page_types.h>
+#include <asm/segment.h>
 
 #include "realmode.h"
 	
@@ -28,8 +29,9 @@ GLOBAL(real_mode_header)
 	.long	pa_wakeup_header
 #endif
 	/* APM/BIOS reboot */
-#ifdef CONFIG_X86_32
 	.long	pa_machine_real_restart_asm
+#ifdef CONFIG_X86_64
+	.long	__KERNEL32_CS
 #endif
 END(real_mode_header)
 
diff --git a/arch/x86/realmode/rm/reboot_32.S b/arch/x86/realmode/rm/reboot.S
index 114044876b3..d66c607bdc5 100644
--- a/arch/x86/realmode/rm/reboot_32.S
+++ b/arch/x86/realmode/rm/reboot.S
@@ -1,7 +1,8 @@
 #include <linux/linkage.h>
-#include <linux/init.h>
 #include <asm/segment.h>
 #include <asm/page_types.h>
+#include <asm/processor-flags.h>
+#include <asm/msr-index.h>
 #include "realmode.h"
 
 /*
@@ -12,13 +13,35 @@
  * doesn't work with at least one type of 486 motherboard.  It is easy
  * to stop this code working; hence the copious comments.
  *
- * This code is called with the restart type (0 = BIOS, 1 = APM) in %eax.
+ * This code is called with the restart type (0 = BIOS, 1 = APM) in
+ * the primary argument register (%eax for 32 bit, %edi for 64 bit).
  */
 	.section ".text32", "ax"
 	.code32
-
-	.balign	16
 ENTRY(machine_real_restart_asm)
+
+#ifdef CONFIG_X86_64
+	/* Switch to trampoline GDT as it is guaranteed < 4 GiB */
+	movl	$__KERNEL_DS, %eax
+	movl	%eax, %ds
+	lgdtl	pa_tr_gdt
+
+	/* Disable paging to drop us out of long mode */
+	movl	%cr0, %eax
+	andl	$~X86_CR0_PG, %eax
+	movl	%eax, %cr0
+	ljmpl	$__KERNEL32_CS, $pa_machine_real_restart_paging_off
+
+GLOBAL(machine_real_restart_paging_off)
+	xorl	%eax, %eax
+	xorl	%edx, %edx
+	movl	$MSR_EFER, %ecx
+	wrmsr
+
+	movl	%edi, %eax
+	
+#endif /* CONFIG_X86_64 */
+	
 	/* Set up the IDT for real mode. */
 	lidtl	pa_machine_real_restart_idt
 
diff --git a/arch/x86/realmode/rm/trampoline_32.S b/arch/x86/realmode/rm/trampoline_32.S
index c1b2791183e..48ddd76bc4c 100644
--- a/arch/x86/realmode/rm/trampoline_32.S
+++ b/arch/x86/realmode/rm/trampoline_32.S
@@ -20,7 +20,6 @@
  */
 
 #include <linux/linkage.h>
-#include <linux/init.h>
 #include <asm/segment.h>
 #include <asm/page_types.h>
 #include "realmode.h"
diff --git a/arch/x86/realmode/rm/trampoline_64.S b/arch/x86/realmode/rm/trampoline_64.S
index bb360dc39d2..dac7b20d2f9 100644
--- a/arch/x86/realmode/rm/trampoline_64.S
+++ b/arch/x86/realmode/rm/trampoline_64.S
@@ -25,7 +25,6 @@
  */
 
 #include <linux/linkage.h>
-#include <linux/init.h>
 #include <asm/pgtable_types.h>
 #include <asm/page_types.h>
 #include <asm/msr.h>
diff --git a/arch/x86/realmode/rm/wakeup.h b/arch/x86/realmode/rm/wakeup.h
index 9317e0042f2..7dd86a419f5 100644
--- a/arch/x86/realmode/rm/wakeup.h
+++ b/arch/x86/realmode/rm/wakeup.h
@@ -36,5 +36,7 @@ extern struct wakeup_header wakeup_header;
 
 /* Wakeup behavior bits */
 #define WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE     0
+#define WAKEUP_BEHAVIOR_RESTORE_CR4		1
+#define WAKEUP_BEHAVIOR_RESTORE_EFER		2
 
 #endif /* ARCH_X86_KERNEL_ACPI_RM_WAKEUP_H */
diff --git a/arch/x86/realmode/rm/wakeup_asm.S b/arch/x86/realmode/rm/wakeup_asm.S
index 8905166b0bb..9e7e14797a7 100644
--- a/arch/x86/realmode/rm/wakeup_asm.S
+++ b/arch/x86/realmode/rm/wakeup_asm.S
@@ -75,7 +75,7 @@ ENTRY(wakeup_start)
 	lidtl	wakeup_idt
 
 	/* Clear the EFLAGS */
-	pushl	$0
+	pushl $0
 	popfl
 
 	/* Check header signature... */
@@ -93,8 +93,8 @@ ENTRY(wakeup_start)
 
 	/* Restore MISC_ENABLE before entering protected mode, in case
 	   BIOS decided to clear XD_DISABLE during S3. */
-	movl	pmode_behavior, %eax
-	btl	$WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE, %eax
+	movl	pmode_behavior, %edi
+	btl	$WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE, %edi
 	jnc	1f
 
 	movl	pmode_misc_en, %eax
@@ -110,15 +110,15 @@ ENTRY(wakeup_start)
 	movl	pmode_cr3, %eax
 	movl	%eax, %cr3
 
-	movl	pmode_cr4, %ecx
-	jecxz	1f
-	movl	%ecx, %cr4
+	btl	$WAKEUP_BEHAVIOR_RESTORE_CR4, %edi
+	jnc	1f
+	movl	pmode_cr4, %eax
+	movl	%eax, %cr4
 1:
+	btl	$WAKEUP_BEHAVIOR_RESTORE_EFER, %edi
+	jnc	1f
 	movl	pmode_efer, %eax
 	movl	pmode_efer + 4, %edx
-	movl	%eax, %ecx
-	orl	%edx, %ecx
-	jz	1f
 	movl	$MSR_EFER, %ecx
 	wrmsr
 1: