diff --git a/arch/powerpc/mm/subpage-prot.c b/arch/powerpc/mm/subpage-prot.c
index 4cafc0c..a040b81 100644
--- a/arch/powerpc/mm/subpage-prot.c
+++ b/arch/powerpc/mm/subpage-prot.c
@@ -24,9 +24,9 @@
  * Also makes sure that the subpage_prot_table structure is
  * reinitialized for the next user.
  */
-void subpage_prot_free(pgd_t *pgd)
+void subpage_prot_free(struct mm_struct *mm)
 {
-	struct subpage_prot_table *spt = pgd_subpage_prot(pgd);
+	struct subpage_prot_table *spt = &mm->context.spt;
 	unsigned long i, j, addr;
 	u32 **p;
 
@@ -51,6 +51,13 @@
 	spt->maxaddr = 0;
 }
 
+void subpage_prot_init_new_context(struct mm_struct *mm)
+{
+	struct subpage_prot_table *spt = &mm->context.spt;
+
+	memset(spt, 0, sizeof(*spt));
+}
+
 static void hpte_flush_range(struct mm_struct *mm, unsigned long addr,
 			     int npages)
 {
@@ -87,7 +94,7 @@
 static void subpage_prot_clear(unsigned long addr, unsigned long len)
 {
 	struct mm_struct *mm = current->mm;
-	struct subpage_prot_table *spt = pgd_subpage_prot(mm->pgd);
+	struct subpage_prot_table *spt = &mm->context.spt;
 	u32 **spm, *spp;
 	int i, nw;
 	unsigned long next, limit;
@@ -136,7 +143,7 @@
 long sys_subpage_prot(unsigned long addr, unsigned long len, u32 __user *map)
 {
 	struct mm_struct *mm = current->mm;
-	struct subpage_prot_table *spt = pgd_subpage_prot(mm->pgd);
+	struct subpage_prot_table *spt = &mm->context.spt;
 	u32 **spm, *spp;
 	int i, nw;
 	unsigned long next, limit;