diff --git a/mm/hmm.c b/mm/hmm.c
index bdb49b8..a88a847 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -35,15 +35,16 @@
 
 #define PA_SECTION_SIZE (1UL << PA_SECTION_SHIFT)
 
-
+#if defined(CONFIG_DEVICE_PRIVATE) || defined(CONFIG_DEVICE_PUBLIC)
 /*
  * Device private memory see HMM (Documentation/vm/hmm.txt) or hmm.h
  */
 DEFINE_STATIC_KEY_FALSE(device_private_key);
 EXPORT_SYMBOL(device_private_key);
+#endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */
 
 
-#ifdef CONFIG_HMM
+#if IS_ENABLED(CONFIG_HMM_MIRROR)
 static const struct mmu_notifier_ops hmm_mmu_notifier_ops;
 
 /*
@@ -128,9 +129,7 @@ void hmm_mm_destroy(struct mm_struct *mm)
 {
 	kfree(mm->hmm);
 }
-#endif /* CONFIG_HMM */
 
-#if IS_ENABLED(CONFIG_HMM_MIRROR)
 static void hmm_invalidate_range(struct hmm *hmm,
 				 enum hmm_update_type action,
 				 unsigned long start,