Re: [PATCH 02/10] powerpc/mm/slice: Simplify and optimise slice context initialisation

diff --git a/arch/powerpc/mm/mmu_context_book3s64.c b/arch/powerpc/mm/mmu_context_book3s64.c
index 929d9ef7083f..80acad52b006 100644
--- a/arch/powerpc/mm/mmu_context_book3s64.c
+++ b/arch/powerpc/mm/mmu_context_book3s64.c

@@ -93,13 +93,6 @@ static int hash__init_new_context(struct mm_struct *mm)
 	if (index < 0)
 		return index;
 
-	/*
-	 * In the case of exec, use the default limit,
-	 * otherwise inherit it from the mm we are duplicating.
-	 */
-	if (!mm->context.slb_addr_limit)
-		mm->context.slb_addr_limit = DEFAULT_MAP_WINDOW_USER64;

diff --git a/arch/powerpc/mm/mmu_context_nohash.c b/arch/powerpc/mm/mmu_context_nohash.c
index d98f7e5c141b..be8f5c9d4d08 100644
--- a/arch/powerpc/mm/mmu_context_nohash.c
+++ b/arch/powerpc/mm/mmu_context_nohash.c

@@ -332,9 +332,6 @@ int init_new_context(struct task_struct *t, struct mm_struct *mm)
 	pr_hard("initing context for mm @%p\n", mm);
 
 #ifdef	CONFIG_PPC_MM_SLICES
-	if (!mm->context.slb_addr_limit)
-		mm->context.slb_addr_limit = DEFAULT_MAP_WINDOW;
-

diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
index 5e9e1e57d580..af4351b15d01 100644
--- a/arch/powerpc/mm/slice.c
+++ b/arch/powerpc/mm/slice.c

@@ -671,70 +671,29 @@ unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr)
 }
 EXPORT_SYMBOL_GPL(get_slice_psize);
 
-/*
- * This is called by hash_page when it needs to do a lazy conversion of
- * an address space from real 64K pages to combo 4K pages (typically
- * when hitting a non cacheable mapping on a processor or hypervisor
- * that won't allow them for 64K pages).
- *
- * This is also called in init_new_context() to change back the user
- * psize from whatever the parent context had it set to
- * N.B. This may be called before mm->context.id has been set.
- *
- * This function will only change the content of the {low,high)_slice_psize
- * masks, it will not flush SLBs as this shall be handled lazily by the
- * caller.
- */
-void slice_set_user_psize(struct mm_struct *mm, unsigned int psize)
+void slice_init_new_context_exec(struct mm_struct *mm)
 {
-	int index, mask_index;
 	unsigned char *hpsizes, *lpsizes;
-	unsigned long flags;
-	unsigned int old_psize;
-	int i;
-
-	slice_dbg("slice_set_user_psize(mm=%p, psize=%d)\n", mm, psize);
-
-	VM_BUG_ON(radix_enabled());
-	spin_lock_irqsave(&slice_convert_lock, flags);
+	unsigned int psize = mmu_virtual_psize;
 
-	old_psize = mm->context.user_psize;
-	slice_dbg(" old_psize=%d\n", old_psize);
-	if (old_psize == psize)
-		goto bail;
+	slice_dbg("slice_init_new_context_exec(mm=%p)\n", mm);
 
+	/*
+	 * In the case of exec, use the default limit. In the
+	 * case of fork it is just inherited from the mm being
+	 * duplicated.
+	 */
+	mm->context.slb_addr_limit = DEFAULT_MAP_WINDOW_USER64;