[PATCH] mm/hmm: struct hmm is only use by HMM mirror functionality

[jglisse]

From: JÃrÃme Glisse <jglisse@xxxxxxxxxx>

The struct hmm is only use if the HMM mirror functionality is enabled
move associated code behind CONFIG_HMM_MIRROR to avoid build error if
one enable some of the HMM memory configuration without the mirror
feature.

Signed-off-by: JÃrÃme Glisse <jglisse@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>,
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>,
Cc: Subhash Gutti <sgutti@xxxxxxxxxx>,
Cc: Evgeny Baskakov <ebaskakov@xxxxxxxxxx>
---
 include/linux/hmm.h | 7 +++----
 mm/hmm.c            | 4 +---
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/include/linux/hmm.h b/include/linux/hmm.h
index 5866f31..b4355d7 100644
--- a/include/linux/hmm.h
+++ b/include/linux/hmm.h
@@ -499,7 +499,7 @@ struct hmm_device *hmm_device_new(void *drvdata);
 void hmm_device_put(struct hmm_device *hmm_device);
 #endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */
 
-
+#if IS_ENABLED(CONFIG_HMM_MIRROR)
 /* Below are for HMM internal use only! Not to be used by device driver! */
 void hmm_mm_destroy(struct mm_struct *mm);
 
@@ -507,12 +507,11 @@ static inline void hmm_mm_init(struct mm_struct *mm)
 {
 	mm->hmm = NULL;
 }
-
-#else /* IS_ENABLED(CONFIG_HMM) */
-
+#else /* IS_ENABLED(CONFIG_HMM_MIRROR) */
 /* Below are for HMM internal use only! Not to be used by device driver! */
 static inline void hmm_mm_destroy(struct mm_struct *mm) {}
 static inline void hmm_mm_init(struct mm_struct *mm) {}
+#endif /* IS_ENABLED(CONFIG_HMM_MIRROR) */
 
 #endif /* IS_ENABLED(CONFIG_HMM) */
 #endif /* LINUX_HMM_H */
diff --git a/mm/hmm.c b/mm/hmm.c
index 3faa4d4..7e4f42b 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -43,7 +43,7 @@ DEFINE_STATIC_KEY_FALSE(device_private_key);
 EXPORT_SYMBOL(device_private_key);
 
 
-#ifdef CONFIG_HMM
+#if IS_ENABLED(CONFIG_HMM_MIRROR)
 static const struct mmu_notifier_ops hmm_mmu_notifier_ops;
 
 /*
@@ -128,9 +128,7 @@ 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,
-- 
2.7.5