1 files changed, 14 insertions, 1 deletions

diff --git a/include/asm-ppc64/mmu_context.h b/include/asm-ppc64/mmu_context.h
index 820dd729b895..4f512e9fa6b8 100644
--- a/include/asm-ppc64/mmu_context.h
+++ b/include/asm-ppc64/mmu_context.h
@@ -16,8 +16,16 @@
  * 2 of the License, or (at your option) any later version.
  */
 
-static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
+/*
+ * Getting into a kernel thread, there is no valid user segment, mark
+ * paca->pgdir NULL so that SLB miss on user addresses will fault
+ */
+static inline void enter_lazy_tlb(struct mm_struct *mm,
+                                  struct task_struct *tsk)
 {
+#ifdef CONFIG_PPC_64K_PAGES
+        get_paca()->pgdir = NULL;
+#endif /* CONFIG_PPC_64K_PAGES */
 }
 
 #define NO_CONTEXT      0
@@ -40,8 +48,13 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
                 cpu_set(smp_processor_id(), next->cpu_vm_mask);
 
         /* No need to flush userspace segments if the mm doesnt change */
+#ifdef CONFIG_PPC_64K_PAGES
+        if (prev == next && get_paca()->pgdir == next->pgd)
+                return;
+#else
         if (prev == next)
                 return;
+#endif /* CONFIG_PPC_64K_PAGES */
 
 #ifdef CONFIG_ALTIVEC
         if (cpu_has_feature(CPU_FTR_ALTIVEC))