x86: use the same pgd_list for PAE and 64-bit

Use a standard list threaded through page->lru for maintaining the pgd
list on PAE.  This is the same as 64-bit, and seems saner than using a
non-standard list via page->index.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h
index 269e7e2..cd2524f 100644
--- a/include/asm-x86/pgtable.h
+++ b/include/asm-x86/pgtable.h
@@ -131,6 +131,8 @@
 extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
 
+extern spinlock_t pgd_lock;
+extern struct list_head pgd_list;
 
 /*
  * The following only work if pte_present() is true.