Revert "mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks"

Revert 5ff7091f5a2ca ("mm, mmu_notifier: annotate mmu notifiers with
blockable invalidate callbacks").

MMU_INVALIDATE_DOES_NOT_BLOCK flags was the only one used and it is no
longer needed since 93065ac753e4 ("mm, oom: distinguish blockable mode for
mmu notifiers").  We now have a full support for per range !blocking
behavior so we can drop the stop gap workaround which the per notifier
flag was used for.

Link: http://lkml.kernel.org/r/20180827112623.8992-4-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 23 deletions

diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 698e371aafe3..9893a6432adf 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -2,7 +2,6 @@
 #ifndef _LINUX_MMU_NOTIFIER_H
 #define _LINUX_MMU_NOTIFIER_H
 
-#include <linux/types.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/mm_types.h>
@@ -11,9 +10,6 @@
 struct mmu_notifier;
 struct mmu_notifier_ops;
 
-/* mmu_notifier_ops flags */
-#define MMU_INVALIDATE_DOES_NOT_BLOCK	(0x01)
-
 #ifdef CONFIG_MMU_NOTIFIER
 
 /*
@@ -31,15 +27,6 @@ struct mmu_notifier_mm {
 
 struct mmu_notifier_ops {
 	/*
-	 * Flags to specify behavior of callbacks for this MMU notifier.
-	 * Used to determine which context an operation may be called.
-	 *
-	 * MMU_INVALIDATE_DOES_NOT_BLOCK: invalidate_range_* callbacks do not
-	 *	block
-	 */
-	int flags;
-
-	/*
 	 * Called either by mmu_notifier_unregister or when the mm is
 	 * being destroyed by exit_mmap, always before all pages are
 	 * freed. This can run concurrently with other mmu notifier
@@ -183,10 +170,6 @@ struct mmu_notifier_ops {
 	 * Note that this function might be called with just a sub-range
 	 * of what was passed to invalidate_range_start()/end(), if
 	 * called between those functions.
-	 *
-	 * If this callback cannot block, and invalidate_range_{start,end}
-	 * cannot block, mmu_notifier_ops.flags should have
-	 * MMU_INVALIDATE_DOES_NOT_BLOCK set.
 	 */
 	void (*invalidate_range)(struct mmu_notifier *mn, struct mm_struct *mm,
 				 unsigned long start, unsigned long end);
@@ -241,7 +224,6 @@ extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
 				  bool only_end);
 extern void __mmu_notifier_invalidate_range(struct mm_struct *mm,
 				  unsigned long start, unsigned long end);
-extern bool mm_has_blockable_invalidate_notifiers(struct mm_struct *mm);
 
 static inline void mmu_notifier_release(struct mm_struct *mm)
 {
@@ -495,11 +477,6 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
 {
 }
 
-static inline bool mm_has_blockable_invalidate_notifiers(struct mm_struct *mm)
-{
-	return false;
-}
-
 static inline void mmu_notifier_mm_init(struct mm_struct *mm)
 {
 }