arm64/ipipe: mm tracking data is builtin

arch/arm64/Kconfig

@@ -86,11 +86,6 @@ config ARM64
 	help
 	  ARM 64-bit (AArch64) Linux support.
 
-if IPIPE
-config IPIPE_WANT_ACTIVE_MM
-       def_bool y
-endif
-
 config 64BIT
 	def_bool y
 

arch/arm64/kernel/ipipe.c

@@ -464,10 +464,8 @@ static void __ipipe_do_IRQ(unsigned irq, void *cookie)
 void __switch_mm_inner(struct mm_struct *prev, struct mm_struct *next,
 		       struct task_struct *tsk)
 {
-#ifdef CONFIG_IPIPE_WANT_ACTIVE_MM
 	struct mm_struct ** const active_mm =
 		raw_cpu_ptr(&ipipe_percpu.active_mm);
-#endif /* CONFIG_IPIPE_WANT_ACTIVE_MM */
 #ifdef CONFIG_IPIPE_WANT_PREEMPTIBLE_SWITCH
 	struct thread_info *const tip = current_thread_info();
 	prev = *active_mm;
@@ -476,23 +474,17 @@ void __switch_mm_inner(struct mm_struct *prev, struct mm_struct *next,
 	*active_mm = NULL;
 	barrier();
 	for (;;) {
-		unsigned long flags;
-#endif /* CONFIG_IPIPE_WANT_PREEMPTIBLE_SWITCH */
-
+#endif
 		int rc __maybe_unused = __do_switch_mm(prev, next, tsk, true);
-
 #ifdef CONFIG_IPIPE_WANT_PREEMPTIBLE_SWITCH
+		unsigned long flags;
 		/*
 		 * Reading thread_info flags and setting active_mm
 		 * must be done atomically.
 		 */
 		flags = hard_local_irq_save();
 		if (__test_and_clear_bit(TIF_MMSWITCH_INT, &tip->flags) == 0) {
-			if (rc < 0)
-				*active_mm = prev;
-			else {
-				*active_mm = next;
-			}
+			*active_mm = rc < 0 ? prev : next;
 			hard_local_irq_restore(flags);
 			return;
 		}
@@ -509,23 +501,17 @@ void __switch_mm_inner(struct mm_struct *prev, struct mm_struct *next,
 
 		prev = NULL;
 	}
-#elif defined(CONFIG_IPIPE_WANT_ACTIVE_MM)
-	if (rc < 0)
-		*active_mm = prev;
-	else {
-		*active_mm = next;
-	}
-#endif /* IPIPE_WANT_ACTIVE_MM */
+#else
+	*active_mm = rc < 0 ? prev : next;
+#endif
 }
 
 #ifdef finish_arch_post_lock_switch
 void deferred_switch_mm(struct mm_struct *next)
 {
-#ifdef CONFIG_IPIPE_WANT_ACTIVE_MM
 	struct mm_struct ** const active_mm =
 		raw_cpu_ptr(&ipipe_percpu.active_mm);
 	struct mm_struct *prev = *active_mm;
-#endif /* CONFIG_IPIPE_WANT_ACTIVE_MM */
 #ifdef CONFIG_IPIPE_WANT_PREEMPTIBLE_SWITCH
 	struct thread_info *const tip = current_thread_info();
 	clear_bit(TIF_MMSWITCH_INT, &tip->flags);
@@ -533,9 +519,8 @@ void deferred_switch_mm(struct mm_struct *next)
 	*active_mm = NULL;
 	barrier();
 	for (;;) {
-		unsigned long flags;
-#endif /* CONFIG_IPIPE_WANT_PREEMPTIBLE_SWITCH */
-
+		unsigned long __maybe_unused flags;
+#endif
 		__do_switch_mm(prev, next, NULL, false);
 
 #ifdef CONFIG_IPIPE_WANT_PREEMPTIBLE_SWITCH
@@ -552,9 +537,9 @@ void deferred_switch_mm(struct mm_struct *next)
 		hard_local_irq_restore(flags);
 		prev = NULL;
 	}
-#elif defined(CONFIG_IPIPE_WANT_ACTIVE_MM)
+#else
 	*active_mm = next;
-#endif /* CONFIG_IPIPE_WANT_ACTIVE_MM */
+#endif
 }
 #endif
 #endif /* CONFIG_MMU */