powerpc/mm: define subarch SLB_ADDR_LIMIT_DEFAULT

This patch defines a subarch specific SLB_ADDR_LIMIT_DEFAULT
to remove the #ifdefs around the setup of mm->context.slb_addr_limit

It also generalises the use of mm_ctx_set_slb_addr_limit() helper.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/book3s/64/slice.h

@@ -11,4 +11,6 @@
 #define SLICE_NUM_HIGH		(H_PGTABLE_RANGE >> SLICE_HIGH_SHIFT)
 #define GET_HIGH_SLICE_INDEX(addr)	((addr) >> SLICE_HIGH_SHIFT)
 
+#define SLB_ADDR_LIMIT_DEFAULT	DEFAULT_MAP_WINDOW_USER64
+
 #endif /* _ASM_POWERPC_BOOK3S_64_SLICE_H */

arch/powerpc/include/asm/nohash/32/slice.h

@@ -13,6 +13,8 @@
 #define SLICE_NUM_HIGH		0ul
 #define GET_HIGH_SLICE_INDEX(addr)	(addr & 0)
 
+#define SLB_ADDR_LIMIT_DEFAULT	DEFAULT_MAP_WINDOW
+
 #endif /* CONFIG_PPC_MM_SLICES */
 
 #endif /* _ASM_POWERPC_NOHASH_32_SLICE_H */

arch/powerpc/mm/book3s64/hash_utils.c

@@ -1058,7 +1058,7 @@ void __init hash__early_init_mmu(void)
 	htab_initialize();
 
 	init_mm.context.hash_context = &init_hash_mm_context;
-	init_mm.context.hash_context->slb_addr_limit = DEFAULT_MAP_WINDOW_USER64;
+	mm_ctx_set_slb_addr_limit(&init_mm.context, SLB_ADDR_LIMIT_DEFAULT);
 
 	pr_info("Initializing hash mmu with SLB\n");
 	/* Initialize SLB management */

arch/powerpc/mm/nohash/tlb.c

@@ -802,9 +802,7 @@ void __init early_init_mmu(void)
 #endif
 
 #ifdef CONFIG_PPC_MM_SLICES
-#if defined(CONFIG_PPC_8xx)
-	init_mm.context.slb_addr_limit = DEFAULT_MAP_WINDOW;
-#endif
+	mm_ctx_set_slb_addr_limit(&init_mm.context, SLB_ADDR_LIMIT_DEFAULT);
 #endif
 }
 #endif /* CONFIG_PPC64 */

arch/powerpc/mm/slice.c

@@ -704,11 +704,7 @@ void slice_init_new_context_exec(struct mm_struct *mm)
 	 * case of fork it is just inherited from the mm being
 	 * duplicated.
 	 */
-#ifdef CONFIG_PPC64
-	mm_ctx_set_slb_addr_limit(&mm->context, DEFAULT_MAP_WINDOW_USER64);
-#else
-	mm->context.slb_addr_limit = DEFAULT_MAP_WINDOW;
-#endif
+	mm_ctx_set_slb_addr_limit(&mm->context, SLB_ADDR_LIMIT_DEFAULT);
 	mm_ctx_set_user_psize(&mm->context, psize);
 
 	/*