powerpc/64s/hash: Provide arch_setup_exec() hooks for hash slice setup

This will be used by the SLB code in the next patch, but for now this
sets the slb_addr_limit to the correct size for 32-bit tasks.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/book3s/64/mmu-hash.h

@@ -487,6 +487,8 @@ int htab_remove_mapping(unsigned long vstart, unsigned long vend,
 extern void pseries_add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages);
 extern void demote_segment_4k(struct mm_struct *mm, unsigned long addr);
 
+extern void hash__setup_new_exec(void);
+
 #ifdef CONFIG_PPC_PSERIES
 void hpte_init_pseries(void);
 #else

arch/powerpc/include/asm/slice.h

@@ -32,6 +32,7 @@ void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
 			   unsigned long len, unsigned int psize);
 
 void slice_init_new_context_exec(struct mm_struct *mm);
+void slice_setup_new_exec(void);
 
 #endif /* __ASSEMBLY__ */
 

arch/powerpc/include/asm/thread_info.h

@@ -72,6 +72,12 @@ static inline struct thread_info *current_thread_info(void)
 }
 
 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
+
+#ifdef CONFIG_PPC_BOOK3S_64
+void arch_setup_new_exec(void);
+#define arch_setup_new_exec arch_setup_new_exec
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 /*

arch/powerpc/kernel/process.c

@@ -1490,6 +1490,15 @@ void flush_thread(void)
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 }
 
+#ifdef CONFIG_PPC_BOOK3S_64
+void arch_setup_new_exec(void)
+{
+	if (radix_enabled())
+		return;
+	hash__setup_new_exec();
+}
+#endif
+
 int set_thread_uses_vas(void)
 {
 #ifdef CONFIG_PPC_BOOK3S_64

arch/powerpc/mm/mmu_context_book3s64.c

@@ -84,6 +84,11 @@ static int hash__init_new_context(struct mm_struct *mm)
 	return index;
 }
 
+void hash__setup_new_exec(void)
+{
+	slice_setup_new_exec();
+}
+
 static int radix__init_new_context(struct mm_struct *mm)
 {
 	unsigned long rts_field;

arch/powerpc/mm/slice.c

@@ -757,6 +757,20 @@ void slice_init_new_context_exec(struct mm_struct *mm)
 		bitmap_fill(mask->high_slices, SLICE_NUM_HIGH);
 }
 
+#ifdef CONFIG_PPC_BOOK3S_64
+void slice_setup_new_exec(void)
+{
+	struct mm_struct *mm = current->mm;
+
+	slice_dbg("slice_setup_new_exec(mm=%p)\n", mm);
+
+	if (!is_32bit_task())
+		return;
+
+	mm->context.slb_addr_limit = DEFAULT_MAP_WINDOW;
+}
+#endif
+
 void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
 			   unsigned long len, unsigned int psize)
 {