Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix compile error with CONFIG_AS_CFI=n
  Documentation: document debugpat commandline option
  x86: sanitize Kconfig
  x86, suspend, acpi: correct and add comments about Big Real Mode
  x86, suspend, acpi: enter Big Real Mode

Fixed trivial conflict in include/asm-x86/dwarf2.h due to just using
different names for "cfi_ignore" (vs "__cfi_ignore") macro.

1 files changed, 24 insertions, 6 deletions

diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index e6a4b564ccaa..793ad2045f58 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -23,6 +23,15 @@ static unsigned long acpi_realmode;
 static char temp_stack[10240];
 #endif
 
+/* XXX: this macro should move to asm-x86/segment.h and be shared with the
+   boot code... */
+#define GDT_ENTRY(flags, base, limit)		\
+	(((u64)(base & 0xff000000) << 32) |	\
+	 ((u64)flags << 40) |			\
+	 ((u64)(limit & 0x00ff0000) << 32) |	\
+	 ((u64)(base & 0x00ffffff) << 16) |	\
+	 ((u64)(limit & 0x0000ffff)))
+
 /**
  * acpi_save_state_mem - save kernel state
  *
@@ -51,18 +60,27 @@ int acpi_save_state_mem(void)
 	header->video_mode = saved_video_mode;
 
 	header->wakeup_jmp_seg = acpi_wakeup_address >> 4;
+
+	/*
+	 * Set up the wakeup GDT.  We set these up as Big Real Mode,
+	 * that is, with limits set to 4 GB.  At least the Lenovo
+	 * Thinkpad X61 is known to need this for the video BIOS
+	 * initialization quirk to work; this is likely to also
+	 * be the case for other laptops or integrated video devices.
+	 */
+
 	/* GDT[0]: GDT self-pointer */
 	header->wakeup_gdt[0] =
 		(u64)(sizeof(header->wakeup_gdt) - 1) +
 		((u64)(acpi_wakeup_address +
 			((char *)&header->wakeup_gdt - (char *)acpi_realmode))
 				<< 16);
-	/* GDT[1]: real-mode-like code segment */
-	header->wakeup_gdt[1] = (0x009bULL << 40) +
-		((u64)acpi_wakeup_address << 16) + 0xffff;
-	/* GDT[2]: real-mode-like data segment */
-	header->wakeup_gdt[2] = (0x0093ULL << 40) +
-		((u64)acpi_wakeup_address << 16) + 0xffff;
+	/* GDT[1]: big real mode-like code segment */
+	header->wakeup_gdt[1] =
+		GDT_ENTRY(0x809b, acpi_wakeup_address, 0xfffff);
+	/* GDT[2]: big real mode-like data segment */
+	header->wakeup_gdt[2] =
+		GDT_ENTRY(0x8093, acpi_wakeup_address, 0xfffff);
 
 #ifndef CONFIG_64BIT
 	store_gdt((struct desc_ptr *)&header->pmode_gdt);