1 files changed, 28 insertions, 0 deletions

diff --git a/include/asm-x86_64/pgalloc.h b/include/asm-x86_64/pgalloc.h
index 08cad2482bcb..43d4c333a8b1 100644
--- a/include/asm-x86_64/pgalloc.h
+++ b/include/asm-x86_64/pgalloc.h
@@ -45,12 +45,39 @@ static inline void pud_free (pud_t *pud)
         free_page((unsigned long)pud);
 }
 
+static inline void pgd_list_add(pgd_t *pgd)
+{
+        struct page *page = virt_to_page(pgd);
+
+        spin_lock(&pgd_lock);
+        page->index = (pgoff_t)pgd_list;
+        if (pgd_list)
+                pgd_list->private = (unsigned long)&page->index;
+        pgd_list = page;
+        page->private = (unsigned long)&pgd_list;
+        spin_unlock(&pgd_lock);
+}
+
+static inline void pgd_list_del(pgd_t *pgd)
+{
+        struct page *next, **pprev, *page = virt_to_page(pgd);
+
+        spin_lock(&pgd_lock);
+        next = (struct page *)page->index;
+        pprev = (struct page **)page->private;
+        *pprev = next;
+        if (next)
+                next->private = (unsigned long)pprev;
+        spin_unlock(&pgd_lock);
+}
+
 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 {
         unsigned boundary;
         pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
         if (!pgd)
                 return NULL;
+        pgd_list_add(pgd);
         /*
          * Copy kernel pointers in from init.
          * Could keep a freelist or slab cache of those because the kernel
@@ -67,6 +94,7 @@ static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 static inline void pgd_free(pgd_t *pgd)
 {
         BUG_ON((unsigned long)pgd & (PAGE_SIZE-1));
+        pgd_list_del(pgd);
         free_page((unsigned long)pgd);
 }