Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

Pull mmu_notifier updates from Jason Gunthorpe:
 "This small series revises the names in mmu_notifier to make the code
  clearer and more readable"

* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  mm/mmu_notifiers: Use 'interval_sub' as the variable for mmu_interval_notifier
  mm/mmu_notifiers: Use 'subscription' as the variable name for mmu_notifier
  mm/mmu_notifier: Rename struct mmu_notifier_mm to mmu_notifier_subscriptions

6 files changed, 375 insertions, 326 deletions

diff --git a/Documentation/vm/hmm.rst b/Documentation/vm/hmm.rst
index 893a8ba0e9fe..95fec5968362 100644
--- a/Documentation/vm/hmm.rst
+++ b/Documentation/vm/hmm.rst
@@ -149,14 +149,14 @@ CPU page table into a device page table; HMM helps keep both synchronized. A
 device driver that wants to mirror a process address space must start with the
 registration of a mmu_interval_notifier::
 
- mni->ops = &driver_ops;
- int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni,
-			          unsigned long start, unsigned long length,
-			          struct mm_struct *mm);
+ int mmu_interval_notifier_insert(struct mmu_interval_notifier *interval_sub,
+				  struct mm_struct *mm, unsigned long start,
+				  unsigned long length,
+				  const struct mmu_interval_notifier_ops *ops);
 
-During the driver_ops->invalidate() callback the device driver must perform
-the update action to the range (mark range read only, or fully unmap,
-etc.). The device must complete the update before the driver callback returns.
+During the ops->invalidate() callback the device driver must perform the
+update action to the range (mark range read only, or fully unmap, etc.). The
+device must complete the update before the driver callback returns.
 
 When the device driver wants to populate a range of virtual addresses, it can
 use::
@@ -183,7 +183,7 @@ The usage pattern is::
       struct hmm_range range;
       ...
 
-      range.notifier = &mni;
+      range.notifier = &interval_sub;
       range.start = ...;
       range.end = ...;
       range.pfns = ...;
@@ -191,11 +191,11 @@ The usage pattern is::
       range.values = ...;
       range.pfn_shift = ...;
 
-      if (!mmget_not_zero(mni->notifier.mm))
+      if (!mmget_not_zero(interval_sub->notifier.mm))
           return -EFAULT;
 
  again:
-      range.notifier_seq = mmu_interval_read_begin(&mni);
+      range.notifier_seq = mmu_interval_read_begin(&interval_sub);
       down_read(&mm->mmap_sem);
       ret = hmm_range_fault(&range, HMM_RANGE_SNAPSHOT);
       if (ret) {
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 270aa8fd2800..e87bb864bdb2 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -490,7 +490,7 @@ struct mm_struct {
 		/* store ref to file /proc/<pid>/exe symlink points to */
 		struct file __rcu *exe_file;
 #ifdef CONFIG_MMU_NOTIFIER
-		struct mmu_notifier_mm *mmu_notifier_mm;
+		struct mmu_notifier_subscriptions *notifier_subscriptions;
 #endif
 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
 		pgtable_t pmd_huge_pte; /* protected by page_table_lock */
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 9e6caa8ecd19..736f6918335e 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -8,7 +8,7 @@
 #include <linux/srcu.h>
 #include <linux/interval_tree.h>
 
-struct mmu_notifier_mm;
+struct mmu_notifier_subscriptions;
 struct mmu_notifier;
 struct mmu_notifier_range;
 struct mmu_interval_notifier;
@@ -73,7 +73,7 @@ struct mmu_notifier_ops {
 	 * through the gart alias address, so leading to memory
 	 * corruption.
 	 */
-	void (*release)(struct mmu_notifier *mn,
+	void (*release)(struct mmu_notifier *subscription,
 			struct mm_struct *mm);
 
 	/*
@@ -85,7 +85,7 @@ struct mmu_notifier_ops {
 	 * Start-end is necessary in case the secondary MMU is mapping the page
 	 * at a smaller granularity than the primary MMU.
 	 */
-	int (*clear_flush_young)(struct mmu_notifier *mn,
+	int (*clear_flush_young)(struct mmu_notifier *subscription,
 				 struct mm_struct *mm,
 				 unsigned long start,
 				 unsigned long end);
@@ -95,7 +95,7 @@ struct mmu_notifier_ops {
 	 * latter, it is supposed to test-and-clear the young/accessed bitflag
 	 * in the secondary pte, but it may omit flushing the secondary tlb.
 	 */
-	int (*clear_young)(struct mmu_notifier *mn,
+	int (*clear_young)(struct mmu_notifier *subscription,
 			   struct mm_struct *mm,
 			   unsigned long start,
 			   unsigned long end);
@@ -106,7 +106,7 @@ struct mmu_notifier_ops {
 	 * frequently used without actually clearing the flag or tearing
 	 * down the secondary mapping on the page.
 	 */
-	int (*test_young)(struct mmu_notifier *mn,
+	int (*test_young)(struct mmu_notifier *subscription,
 			  struct mm_struct *mm,
 			  unsigned long address);
 
@@ -114,7 +114,7 @@ struct mmu_notifier_ops {
 	 * change_pte is called in cases that pte mapping to page is changed:
 	 * for example, when ksm remaps pte to point to a new shared page.
 	 */
-	void (*change_pte)(struct mmu_notifier *mn,
+	void (*change_pte)(struct mmu_notifier *subscription,
 			   struct mm_struct *mm,
 			   unsigned long address,
 			   pte_t pte);
@@ -169,9 +169,9 @@ struct mmu_notifier_ops {
 	 * invalidate_range_end.
 	 *
 	 */
-	int (*invalidate_range_start)(struct mmu_notifier *mn,
+	int (*invalidate_range_start)(struct mmu_notifier *subscription,
 				      const struct mmu_notifier_range *range);
-	void (*invalidate_range_end)(struct mmu_notifier *mn,
+	void (*invalidate_range_end)(struct mmu_notifier *subscription,
 				     const struct mmu_notifier_range *range);
 
 	/*
@@ -192,8 +192,10 @@ struct mmu_notifier_ops {
 	 * of what was passed to invalidate_range_start()/end(), if
 	 * called between those functions.
 	 */
-	void (*invalidate_range)(struct mmu_notifier *mn, struct mm_struct *mm,
-				 unsigned long start, unsigned long end);
+	void (*invalidate_range)(struct mmu_notifier *subscription,
+				 struct mm_struct *mm,
+				 unsigned long start,
+				 unsigned long end);
 
 	/*
 	 * These callbacks are used with the get/put interface to manage the
@@ -206,7 +208,7 @@ struct mmu_notifier_ops {
 	 * and cannot sleep.
 	 */
 	struct mmu_notifier *(*alloc_notifier)(struct mm_struct *mm);
-	void (*free_notifier)(struct mmu_notifier *mn);
+	void (*free_notifier)(struct mmu_notifier *subscription);
 };
 
 /*
@@ -235,7 +237,7 @@ struct mmu_notifier {
  *              was required but mmu_notifier_range_blockable(range) is false.
  */
 struct mmu_interval_notifier_ops {
-	bool (*invalidate)(struct mmu_interval_notifier *mni,
+	bool (*invalidate)(struct mmu_interval_notifier *interval_sub,
 			   const struct mmu_notifier_range *range,
 			   unsigned long cur_seq);
 };
@@ -265,7 +267,7 @@ struct mmu_notifier_range {
 
 static inline int mm_has_notifiers(struct mm_struct *mm)
 {
-	return unlikely(mm->mmu_notifier_mm);
+	return unlikely(mm->notifier_subscriptions);
 }
 
 struct mmu_notifier *mmu_notifier_get_locked(const struct mmu_notifier_ops *ops,
@@ -280,30 +282,31 @@ mmu_notifier_get(const struct mmu_notifier_ops *ops, struct mm_struct *mm)
 	up_write(&mm->mmap_sem);
 	return ret;
 }
-void mmu_notifier_put(struct mmu_notifier *mn);
+void mmu_notifier_put(struct mmu_notifier *subscription);
 void mmu_notifier_synchronize(void);
 
-extern int mmu_notifier_register(struct mmu_notifier *mn,
+extern int mmu_notifier_register(struct mmu_notifier *subscription,
 				 struct mm_struct *mm);
-extern int __mmu_notifier_register(struct mmu_notifier *mn,
+extern int __mmu_notifier_register(struct mmu_notifier *subscription,
 				   struct mm_struct *mm);
-extern void mmu_notifier_unregister(struct mmu_notifier *mn,
+extern void mmu_notifier_unregister(struct mmu_notifier *subscription,
 				    struct mm_struct *mm);
 
-unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni);
-int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni,
+unsigned long
+mmu_interval_read_begin(struct mmu_interval_notifier *interval_sub);
+int mmu_interval_notifier_insert(struct mmu_interval_notifier *interval_sub,
 				 struct mm_struct *mm, unsigned long start,
 				 unsigned long length,
 				 const struct mmu_interval_notifier_ops *ops);
 int mmu_interval_notifier_insert_locked(
-	struct mmu_interval_notifier *mni, struct mm_struct *mm,
+	struct mmu_interval_notifier *interval_sub, struct mm_struct *mm,
 	unsigned long start, unsigned long length,
 	const struct mmu_interval_notifier_ops *ops);
-void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni);
+void mmu_interval_notifier_remove(struct mmu_interval_notifier *interval_sub);
 
 /**
  * mmu_interval_set_seq - Save the invalidation sequence
- * @mni - The mni passed to invalidate
+ * @interval_sub - The subscription passed to invalidate
  * @cur_seq - The cur_seq passed to the invalidate() callback
  *
  * This must be called unconditionally from the invalidate callback of a
@@ -314,15 +317,16 @@ void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni);
  * If the caller does not call mmu_interval_read_begin() or
  * mmu_interval_read_retry() then this call is not required.
  */
-static inline void mmu_interval_set_seq(struct mmu_interval_notifier *mni,
-					unsigned long cur_seq)
+static inline void
+mmu_interval_set_seq(struct mmu_interval_notifier *interval_sub,
+		     unsigned long cur_seq)
 {
-	WRITE_ONCE(mni->invalidate_seq, cur_seq);
+	WRITE_ONCE(interval_sub->invalidate_seq, cur_seq);
 }
 
 /**
  * mmu_interval_read_retry - End a read side critical section against a VA range
- * mni: The range
+ * interval_sub: The subscription
  * seq: The return of the paired mmu_interval_read_begin()
  *
  * This MUST be called under a user provided lock that is also held
@@ -334,15 +338,16 @@ static inline void mmu_interval_set_seq(struct mmu_interval_notifier *mni,
  * Returns true if an invalidation collided with this critical section, and
  * the caller should retry.
  */
-static inline bool mmu_interval_read_retry(struct mmu_interval_notifier *mni,
-					   unsigned long seq)
+static inline bool
+mmu_interval_read_retry(struct mmu_interval_notifier *interval_sub,
+			unsigned long seq)
 {
-	return mni->invalidate_seq != seq;
+	return interval_sub->invalidate_seq != seq;
 }
 
 /**
  * mmu_interval_check_retry - Test if a collision has occurred
- * mni: The range
+ * interval_sub: The subscription
  * seq: The return of the matching mmu_interval_read_begin()
  *
  * This can be used in the critical section between mmu_interval_read_begin()
@@ -357,14 +362,15 @@ static inline bool mmu_interval_read_retry(struct mmu_interval_notifier *mni,
  * This call can be used as part of loops and other expensive operations to
  * expedite a retry.
  */
-static inline bool mmu_interval_check_retry(struct mmu_interval_notifier *mni,
-					    unsigned long seq)
+static inline bool
+mmu_interval_check_retry(struct mmu_interval_notifier *interval_sub,
+			 unsigned long seq)
 {
 	/* Pairs with the WRITE_ONCE in mmu_interval_set_seq() */
-	return READ_ONCE(mni->invalidate_seq) != seq;
+	return READ_ONCE(interval_sub->invalidate_seq) != seq;
 }
 
-extern void __mmu_notifier_mm_destroy(struct mm_struct *mm);
+extern void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm);
 extern void __mmu_notifier_release(struct mm_struct *mm);
 extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
 					  unsigned long start,
@@ -480,15 +486,15 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
 		__mmu_notifier_invalidate_range(mm, start, end);
 }
 
-static inline void mmu_notifier_mm_init(struct mm_struct *mm)
+static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
 {
-	mm->mmu_notifier_mm = NULL;
+	mm->notifier_subscriptions = NULL;
 }
 
-static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
+static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
 {
 	if (mm_has_notifiers(mm))
-		__mmu_notifier_mm_destroy(mm);
+		__mmu_notifier_subscriptions_destroy(mm);
 }
 
 
@@ -692,11 +698,11 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm,
 {
 }
 
-static inline void mmu_notifier_mm_init(struct mm_struct *mm)
+static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm)
 {
 }
 
-static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
+static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm)
 {
 }
 
diff --git a/kernel/fork.c b/kernel/fork.c
index ef82feb4bddc..60a1295f4384 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -692,7 +692,7 @@ void __mmdrop(struct mm_struct *mm)
 	WARN_ON_ONCE(mm == current->active_mm);
 	mm_free_pgd(mm);
 	destroy_context(mm);
-	mmu_notifier_mm_destroy(mm);
+	mmu_notifier_subscriptions_destroy(mm);
 	check_mm(mm);
 	put_user_ns(mm->user_ns);
 	free_mm(mm);
@@ -1025,7 +1025,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
 	mm_init_aio(mm);
 	mm_init_owner(mm, p);
 	RCU_INIT_POINTER(mm->exe_file, NULL);
-	mmu_notifier_mm_init(mm);
+	mmu_notifier_subscriptions_init(mm);
 	init_tlb_flush_pending(mm);
 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
 	mm->pmd_huge_pte = NULL;
diff --git a/mm/debug.c b/mm/debug.c
index 0461df1207cb..74ee73cf7079 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -153,7 +153,7 @@ void dump_mm(const struct mm_struct *mm)
 #endif
 		"exe_file %px\n"
 #ifdef CONFIG_MMU_NOTIFIER
-		"mmu_notifier_mm %px\n"
+		"notifier_subscriptions %px\n"
 #endif
 #ifdef CONFIG_NUMA_BALANCING
 		"numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n"
@@ -185,7 +185,7 @@ void dump_mm(const struct mm_struct *mm)
 #endif
 		mm->exe_file,
 #ifdef CONFIG_MMU_NOTIFIER
-		mm->mmu_notifier_mm,
+		mm->notifier_subscriptions,
 #endif
 #ifdef CONFIG_NUMA_BALANCING
 		mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq,
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index f76ea05b1cb0..ef3973a5d34a 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -29,12 +29,12 @@ struct lockdep_map __mmu_notifier_invalidate_range_start_map = {
 #endif
 
 /*
- * The mmu notifier_mm structure is allocated and installed in
- * mm->mmu_notifier_mm inside the mm_take_all_locks() protected
+ * The mmu_notifier_subscriptions structure is allocated and installed in
+ * mm->notifier_subscriptions inside the mm_take_all_locks() protected
  * critical section and it's released only when mm_count reaches zero
  * in mmdrop().
  */
-struct mmu_notifier_mm {
+struct mmu_notifier_subscriptions {
 	/* all mmu notifiers registered in this mm are queued in this list */
 	struct hlist_head list;
 	bool has_itree;
@@ -65,80 +65,81 @@ struct mmu_notifier_mm {
  *
  * The write side has two states, fully excluded:
  *  - mm->active_invalidate_ranges != 0
- *  - mnn->invalidate_seq & 1 == True (odd)
+ *  - subscriptions->invalidate_seq & 1 == True (odd)
  *  - some range on the mm_struct is being invalidated
  *  - the itree is not allowed to change
  *
  * And partially excluded:
  *  - mm->active_invalidate_ranges != 0
- *  - mnn->invalidate_seq & 1 == False (even)
+ *  - subscriptions->invalidate_seq & 1 == False (even)
  *  - some range on the mm_struct is being invalidated
  *  - the itree is allowed to change
  *
- * Operations on mmu_notifier_mm->invalidate_seq (under spinlock):
+ * Operations on notifier_subscriptions->invalidate_seq (under spinlock):
  *    seq |= 1  # Begin writing
  *    seq++     # Release the writing state
  *    seq & 1   # True if a writer exists
  *
  * The later state avoids some expensive work on inv_end in the common case of
- * no mni monitoring the VA.
+ * no mmu_interval_notifier monitoring the VA.
  */
-static bool mn_itree_is_invalidating(struct mmu_notifier_mm *mmn_mm)
+static bool
+mn_itree_is_invalidating(struct mmu_notifier_subscriptions *subscriptions)
 {
-	lockdep_assert_held(&mmn_mm->lock);
-	return mmn_mm->invalidate_seq & 1;
+	lockdep_assert_held(&subscriptions->lock);
+	return subscriptions->invalidate_seq & 1;
 }
 
 static struct mmu_interval_notifier *
-mn_itree_inv_start_range(struct mmu_notifier_mm *mmn_mm,
+mn_itree_inv_start_range(struct mmu_notifier_subscriptions *subscriptions,
 			 const struct mmu_notifier_range *range,
 			 unsigned long *seq)
 {
 	struct interval_tree_node *node;
 	struct mmu_interval_notifier *res = NULL;
 
-	spin_lock(&mmn_mm->lock);
-	mmn_mm->active_invalidate_ranges++;
-	node = interval_tree_iter_first(&mmn_mm->itree, range->start,
+	spin_lock(&subscriptions->lock);
+	subscriptions->active_invalidate_ranges++;
+	node = interval_tree_iter_first(&subscriptions->itree, range->start,
 					range->end - 1);
 	if (node) {
-		mmn_mm->invalidate_seq |= 1;
+		subscriptions->invalidate_seq |= 1;
 		res = container_of(node, struct mmu_interval_notifier,
 				   interval_tree);
 	}
 
-	*seq = mmn_mm->invalidate_seq;
-	spin_unlock(&mmn_mm->lock);
+	*seq = subscriptions->invalidate_seq;
+	spin_unlock(&subscriptions->lock);
 	return res;
 }
 
 static struct mmu_interval_notifier *
-mn_itree_inv_next(struct mmu_interval_notifier *mni,
+mn_itree_inv_next(struct mmu_interval_notifier *interval_sub,
 		  const struct mmu_notifier_range *range)
 {
 	struct interval_tree_node *node;
 
-	node = interval_tree_iter_next(&mni->interval_tree, range->start,
-				       range->end - 1);
+	node = interval_tree_iter_next(&interval_sub->interval_tree,
+				       range->start, range->end - 1);
 	if (!node)
 		return NULL;
 	return container_of(node, struct mmu_interval_notifier, interval_tree);
 }
 
-static void mn_itree_inv_end(struct mmu_notifier_mm *mmn_mm)
+static void mn_itree_inv_end(struct mmu_notifier_subscriptions *subscriptions)
 {
-	struct mmu_interval_notifier *mni;
+	struct mmu_interval_notifier *interval_sub;
 	struct hlist_node *next;
 
-	spin_lock(&mmn_mm->lock);
-	if (--mmn_mm->active_invalidate_ranges ||
-	    !mn_itree_is_invalidating(mmn_mm)) {
-		spin_unlock(&mmn_mm->lock);
+	spin_lock(&subscriptions->lock);
+	if (--subscriptions->active_invalidate_ranges ||
+	    !mn_itree_is_invalidating(subscriptions)) {
+		spin_unlock(&subscriptions->lock);
 		return;
 	}
 
 	/* Make invalidate_seq even */
-	mmn_mm->invalidate_seq++;
+	subscriptions->invalidate_seq++;
 
 	/*
 	 * The inv_end incorporates a deferred mechanism like rtnl_unlock().
@@ -146,30 +147,31 @@ static void mn_itree_inv_end(struct mmu_notifier_mm *mmn_mm)
 	 * they are progressed. This arrangement for tree updates is used to
 	 * avoid using a blocking lock during invalidate_range_start.
 	 */
-	hlist_for_each_entry_safe(mni, next, &mmn_mm->deferred_list,
+	hlist_for_each_entry_safe(interval_sub, next,
+				  &subscriptions->deferred_list,
 				  deferred_item) {
-		if (RB_EMPTY_NODE(&mni->interval_tree.rb))
-			interval_tree_insert(&mni->interval_tree,
-					     &mmn_mm->itree);
+		if (RB_EMPTY_NODE(&interval_sub->interval_tree.rb))
+			interval_tree_insert(&interval_sub->interval_tree,
+					     &subscriptions->itree);
 		else
-			interval_tree_remove(&mni->interval_tree,
-					     &mmn_mm->itree);
-		hlist_del(&mni->deferred_item);
+			interval_tree_remove(&interval_sub->interval_tree,
+					     &subscriptions->itree);
+		hlist_del(&interval_sub->deferred_item);
 	}
-	spin_unlock(&mmn_mm->lock);
+	spin_unlock(&subscriptions->lock);
 
-	wake_up_all(&mmn_mm->wq);
+	wake_up_all(&subscriptions->wq);
 }
 
 /**
  * mmu_interval_read_begin - Begin a read side critical section against a VA
  *                           range
- * mni: The range to use
+ * interval_sub: The interval subscription
  *
  * mmu_iterval_read_begin()/mmu_iterval_read_retry() implement a
- * collision-retry scheme similar to seqcount for the VA range under mni. If
- * the mm invokes invalidation during the critical section then
- * mmu_interval_read_retry() will return true.
+ * collision-retry scheme similar to seqcount for the VA range under
+ * subscription. If the mm invokes invalidation during the critical section
+ * then mmu_interval_read_retry() will return true.
  *
  * This is useful to obtain shadow PTEs where teardown or setup of the SPTEs
  * require a blocking context.  The critical region formed by this can sleep,
@@ -180,68 +182,71 @@ static void mn_itree_inv_end(struct mmu_notifier_mm *mmn_mm)
  *
  * The return value should be passed to mmu_interval_read_retry().
  */
-unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
+unsigned long
+mmu_interval_read_begin(struct mmu_interval_notifier *interval_sub)
 {
-	struct mmu_notifier_mm *mmn_mm = mni->mm->mmu_notifier_mm;
+	struct mmu_notifier_subscriptions *subscriptions =
+		interval_sub->mm->notifier_subscriptions;
 	unsigned long seq;
 	bool is_invalidating;
 
 	/*
-	 * If the mni has a different seq value under the user_lock than we
-	 * started with then it has collided.
+	 * If the subscription has a different seq value under the user_lock
+	 * than we started with then it has collided.
 	 *
-	 * If the mni currently has the same seq value as the mmn_mm seq, then
-	 * it is currently between invalidate_start/end and is colliding.
+	 * If the subscription currently has the same seq value as the
+	 * subscriptions seq, then it is currently between
+	 * invalidate_start/end and is colliding.
 	 *
 	 * The locking looks broadly like this:
 	 *   mn_tree_invalidate_start():          mmu_interval_read_begin():
 	 *                                         spin_lock
-	 *                                          seq = READ_ONCE(mni->invalidate_seq);
-	 *                                          seq == mmn_mm->invalidate_seq
+	 *                                          seq = READ_ONCE(interval_sub->invalidate_seq);
+	 *                                          seq == subs->invalidate_seq
 	 *                                         spin_unlock
 	 *    spin_lock
-	 *     seq = ++mmn_mm->invalidate_seq
+	 *     seq = ++subscriptions->invalidate_seq
 	 *    spin_unlock
 	 *     op->invalidate_range():
 	 *       user_lock
 	 *        mmu_interval_set_seq()
-	 *         mni->invalidate_seq = seq
+	 *         interval_sub->invalidate_seq = seq
 	 *       user_unlock
 	 *
 	 *                          [Required: mmu_interval_read_retry() == true]
 	 *
 	 *   mn_itree_inv_end():
 	 *    spin_lock
-	 *     seq = ++mmn_mm->invalidate_seq
+	 *     seq = ++subscriptions->invalidate_seq
 	 *    spin_unlock
 	 *
 	 *                                        user_lock
 	 *                                         mmu_interval_read_retry():
-	 *                                          mni->invalidate_seq != seq
+	 *                                          interval_sub->invalidate_seq != seq
 	 *                                        user_unlock
 	 *
 	 * Barriers are not needed here as any races here are closed by an
 	 * eventual mmu_interval_read_retry(), which provides a barrier via the
 	 * user_lock.
 	 */
-	spin_lock(&mmn_mm->lock);
+	spin_lock(&subscriptions->lock);
 	/* Pairs with the WRITE_ONCE in mmu_interval_set_seq() */
-	seq = READ_ONCE(mni->invalidate_seq);
-	is_invalidating = seq == mmn_mm->invalidate_seq;
-	spin_unlock(&mmn_mm->lock);
+	seq = READ_ONCE(interval_sub->invalidate_seq);
+	is_invalidating = seq == subscriptions->invalidate_seq;
+	spin_unlock(&subscriptions->lock);
 
 	/*
-	 * mni->invalidate_seq must always be set to an odd value via
+	 * interval_sub->invalidate_seq must always be set to an odd value via
 	 * mmu_interval_set_seq() using the provided cur_seq from
 	 * mn_itree_inv_start_range(). This ensures that if seq does wrap we
 	 * will always clear the below sleep in some reasonable time as
-	 * mmn_mm->invalidate_seq is even in the idle state.
+	 * subscriptions->invalidate_seq is even in the idle state.
 	 */
 	lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
 	lock_map_release(&__mmu_notifier_invalidate_range_start_map);
 	if (is_invalidating)
-		wait_event(mmn_mm->wq,
-			   READ_ONCE(mmn_mm->invalidate_seq) != seq);
+		wait_event(subscriptions->wq,
+			   READ_ONCE(subscriptions->invalidate_seq) != seq);
 
 	/*
 	 * Notice that mmu_interval_read_retry() can already be true at this
@@ -253,7 +258,7 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
 }
 EXPORT_SYMBOL_GPL(mmu_interval_read_begin);
 
-static void mn_itree_release(struct mmu_notifier_mm *mmn_mm,
+static void mn_itree_release(struct mmu_notifier_subscriptions *subscriptions,
 			     struct mm_struct *mm)
 {
 	struct mmu_notifier_range range = {
@@ -263,17 +268,20 @@ static void mn_itree_release(struct mmu_notifier_mm *mmn_mm,
 		.start = 0,
 		.end = ULONG_MAX,
 	};
-	struct mmu_interval_notifier *mni;
+	struct mmu_interval_notifier *interval_sub;
 	unsigned long cur_seq;
 	bool ret;
 
-	for (mni = mn_itree_inv_start_range(mmn_mm, &range, &cur_seq); mni;
-	     mni = mn_itree_inv_next(mni, &range)) {
-		ret = mni->ops->invalidate(mni, &range, cur_seq);
+	for (interval_sub =
+		     mn_itree_inv_start_range(subscriptions, &range, &cur_seq);
+	     interval_sub;
+	     interval_sub = mn_itree_inv_next(interval_sub, &range)) {
+		ret = interval_sub->ops->invalidate(interval_sub, &range,
+						    cur_seq);
 		WARN_ON(!ret);
 	}
 
-	mn_itree_inv_end(mmn_mm);
+	mn_itree_inv_end(subscriptions);
 }
 
 /*
@@ -283,15 +291,15 @@ static void mn_itree_release(struct mmu_notifier_mm *mmn_mm,
  * in parallel despite there being no task using this mm any more,
  * through the vmas outside of the exit_mmap context, such as with
  * vmtruncate. This serializes against mmu_notifier_unregister with
- * the mmu_notifier_mm->lock in addition to SRCU and it serializes
- * against the other mmu notifiers with SRCU. struct mmu_notifier_mm
+ * the notifier_subscriptions->lock in addition to SRCU and it serializes
+ * against the other mmu notifiers with SRCU. struct mmu_notifier_subscriptions
  * can't go away from under us as exit_mmap holds an mm_count pin
  * itself.
  */
-static void mn_hlist_release(struct mmu_notifier_mm *mmn_mm,
+static void mn_hlist_release(struct mmu_notifier_subscriptions *subscriptions,
 			     struct mm_struct *mm)
 {
-	struct mmu_notifier *mn;
+	struct mmu_notifier *subscription;
 	int id;
 
 	/*
@@ -299,29 +307,29 @@ static void mn_hlist_release(struct mmu_notifier_mm *mmn_mm,
 	 * ->release returns.
 	 */
 	id = srcu_read_lock(&srcu);
-	hlist_for_each_entry_rcu(mn, &mmn_mm->list, hlist)
+	hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist)
 		/*
 		 * If ->release runs before mmu_notifier_unregister it must be
 		 * handled, as it's the only way for the driver to flush all
 		 * existing sptes and stop the driver from establishing any more
 		 * sptes before all the pages in the mm are freed.
 		 */
-		if (mn->ops->release)
-			mn->ops->release(mn, mm);
+		if (subscription->ops->release)
+			subscription->ops->release(subscription, mm);
 
-	spin_lock(&mmn_mm->lock);
-	while (unlikely(!hlist_empty(&mmn_mm->list))) {
-		mn = hlist_entry(mmn_mm->list.first, struct mmu_notifier,
-				 hlist);
+	spin_lock(&subscriptions->lock);
+	while (unlikely(!hlist_empty(&subscriptions->list))) {
+		subscription = hlist_entry(subscriptions->list.first,
+					   struct mmu_notifier, hlist);
 		/*
 		 * We arrived before mmu_notifier_unregister so
 		 * mmu_notifier_unregister will do nothing other than to wait
 		 * for ->release to finish and for mmu_notifier_unregister to
 		 * return.
 		 */
-		hlist_del_init_rcu(&mn->hlist);
+		hlist_del_init_rcu(&subscription->hlist);
 	}
-	spin_unlock(&mmn_mm->lock);
+	spin_unlock(&subscriptions->lock);
 	srcu_read_unlock(&srcu, id);
 
 	/*
@@ -330,21 +338,22 @@ static void mn_hlist_release(struct mmu_notifier_mm *mmn_mm,
 	 * until the ->release method returns, if it was invoked by
 	 * mmu_notifier_unregister.
 	 *
-	 * The mmu_notifier_mm can't go away from under us because one mm_count
-	 * is held by exit_mmap.
+	 * The notifier_subscriptions can't go away from under us because
+	 * one mm_count is held by exit_mmap.
 	 */
 	synchronize_srcu(&srcu);
 }
 
 void __mmu_notifier_release(struct mm_struct *mm)
 {
-	struct mmu_notifier_mm *mmn_mm = mm->mmu_notifier_mm;
+	struct mmu_notifier_subscriptions *subscriptions =
+		mm->notifier_subscriptions;
 
-	if (mmn_mm->has_itree)
-		mn_itree_release(mmn_mm, mm);
+	if (subscriptions->has_itree)
+		mn_itree_release(subscriptions, mm);
 
-	if (!hlist_empty(&mmn_mm->list))
-		mn_hlist_release(mmn_mm, mm);
+	if (!hlist_empty(&subscriptions->list))
+		mn_hlist_release(subscriptions, mm);
 }
 
 /*
@@ -356,13 +365,15 @@ int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
 					unsigned long start,
 					unsigned long end)
 {
-	struct mmu_notifier *mn;
+	struct mmu_notifier *subscription;
 	int young = 0, id;
 
 	id = srcu_read_lock(&srcu);
-	hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
-		if (mn->ops->clear_flush_young)
-			young |= mn->ops->clear_flush_young(mn, mm, start, end);
+	hlist_for_each_entry_rcu(subscription,
+				 &mm->notifier_subscriptions->list, hlist) {
+		if (subscription->ops->clear_flush_young)
+			young |= subscription->ops->clear_flush_young(
+				subscription, mm, start, end);
 	}
 	srcu_read_unlock(&srcu, id);
 
@@ -373,13 +384,15 @@ int __mmu_notifier_clear_young(struct mm_struct *mm,
 			       unsigned long start,
 			       unsigned long end)
 {
-	struct mmu_notifier *mn;
+	struct mmu_notifier *subscription;
 	int young = 0, id;
 
 	id = srcu_read_lock(&srcu);
-	hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
-		if (mn->ops->clear_young)
-			young |= mn->ops->clear_young(mn, mm, start, end);
+	hlist_for_each_entry_rcu(subscription,
+				 &mm->notifier_subscriptions->list, hlist) {
+		if (subscription->ops->clear_young)
+			young |= subscription->ops->clear_young(subscription,
+								mm, start, end);
 	}
 	srcu_read_unlock(&srcu, id);
 
@@ -389,13 +402,15 @@ int __mmu_notifier_clear_young(struct mm_struct *mm,
 int __mmu_notifier_test_young(struct mm_struct *mm,
 			      unsigned long address)
 {
-	struct mmu_notifier *mn;
+	struct mmu_notifier *subscription;
 	int young = 0, id;
 
 	id = srcu_read_lock(&srcu);
-	hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
-		if (mn->ops->test_young) {
-			young = mn->ops->test_young(mn, mm, address);
+	hlist_for_each_entry_rcu(subscription,
+				 &mm->notifier_subscriptions->list, hlist) {
+		if (subscription->ops->test_young) {
+			young = subscription->ops->test_young(subscription, mm,
+							      address);
 			if (young)
 				break;
 		}
@@ -408,28 +423,33 @@ int __mmu_notifier_test_young(struct mm_struct *mm,
 void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
 			       pte_t pte)
 {
-	struct mmu_notifier *mn;
+	struct mmu_notifier *subscription;
 	int id;
 
 	id = srcu_read_lock(&srcu);
-	hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
-		if (mn->ops->change_pte)
-			mn->ops->change_pte(mn, mm, address, pte);
+	hlist_for_each_entry_rcu(subscription,
+				 &mm->notifier_subscriptions->list, hlist) {
+		if (subscription->ops->change_pte)
+			subscription->ops->change_pte(subscription, mm, address,
+						      pte);
 	}
 	srcu_read_unlock(&srcu, id);
 }
 
-static int mn_itree_invalidate(struct mmu_notifier_mm *mmn_mm,
+static int mn_itree_invalidate(struct mmu_notifier_subscriptions *subscriptions,
 			       const struct mmu_notifier_range *range)
 {
-	struct mmu_interval_notifier *mni;
+	struct mmu_interval_notifier *interval_sub;
 	unsigned long cur_seq;
 
-	for (mni = mn_itree_inv_start_range(mmn_mm, range, &cur_seq); mni;
-	     mni = mn_itree_inv_next(mni, range)) {
+	for (interval_sub =
+		     mn_itree_inv_start_range(subscriptions, range, &cur_seq);
+	     interval_sub;
+	     interval_sub = mn_itree_inv_next(interval_sub, range)) {
 		bool ret;
 
-		ret = mni->ops->invalidate(mni, range, cur_seq);
+		ret = interval_sub->ops->invalidate(interval_sub, range,
+						    cur_seq);
 		if (!ret) {
 			if (WARN_ON(mmu_notifier_range_blockable(range)))
 				continue;
@@ -443,31 +463,36 @@ out_would_block:
 	 * On -EAGAIN the non-blocking caller is not allowed to call
 	 * invalidate_range_end()
 	 */
-	mn_itree_inv_end(mmn_mm);
+	mn_itree_inv_end(subscriptions);
 	return -EAGAIN;
 }
 
-static int mn_hlist_invalidate_range_start(struct mmu_notifier_mm *mmn_mm,
-					   struct mmu_notifier_range *range)
+static int mn_hlist_invalidate_range_start(
+	struct mmu_notifier_subscriptions *subscriptions,
+	struct mmu_notifier_range *range)
 {
-	struct mmu_notifier *mn;
+	struct mmu_notifier *subscription;
 	int ret = 0;
 	int id;
 
 	id = srcu_read_lock(&srcu);
-	hlist_for_each_entry_rcu(mn, &mmn_mm->list, hlist) {
-		if (mn->ops->invalidate_range_start) {
+	hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist) {
+		const struct mmu_notifier_ops *ops = subscription->ops;
+
+		if (ops->invalidate_range_start) {
 			int _ret;
 
 			if (!mmu_notifier_range_blockable(range))
 				non_block_start();
-			_ret = mn->ops->invalidate_range_start(mn, range);
+			_ret = ops->invalidate_range_start(subscription, range);
 			if (!mmu_notifier_range_blockable(range))
 				non_block_end();
 			if (_ret) {
 				pr_info("%pS callback failed with %d in %sblockable context.\n",
-					mn->ops->invalidate_range_start, _ret,
-					!mmu_notifier_range_blockable(range) ? "non-" : "");
+					ops->invalidate_range_start, _ret,
+					!mmu_notifier_range_blockable(range) ?
+						"non-" :
+						"");
 				WARN_ON(mmu_notifier_range_blockable(range) ||
 					_ret != -EAGAIN);
 				ret = _ret;
@@ -481,28 +506,29 @@ static int mn_hlist_invalidate_range_start(struct mmu_notifier_mm *mmn_mm,
 
 int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
 {
-	struct mmu_notifier_mm *mmn_mm = range->mm->mmu_notifier_mm;
+	struct mmu_notifier_subscriptions *subscriptions =
+		range->mm->notifier_subscriptions;
 	int ret;
 
-	if (mmn_mm->has_itree) {
-		ret = mn_itree_invalidate(mmn_mm, range);
+	if (subscriptions->has_itree) {
+		ret = mn_itree_invalidate(subscriptions, range);
 		if (ret)
 			return ret;
 	}
-	if (!hlist_empty(&mmn_mm->list))
-		return mn_hlist_invalidate_range_start(mmn_mm, range);
+	if (!hlist_empty(&subscriptions->list))
+		return mn_hlist_invalidate_range_start(subscriptions, range);
 	return 0;
 }
 
-static void mn_hlist_invalidate_end(struct mmu_notifier_mm *mmn_mm,
-				    struct mmu_notifier_range *range,
-				    bool only_end)
+static void
+mn_hlist_invalidate_end(struct mmu_notifier_subscriptions *subscriptions,
+			struct mmu_notifier_range *range, bool only_end)
 {
-	struct mmu_notifier *mn;
+	struct mmu_notifier *subscription;
 	int id;
 
 	id = srcu_read_lock(&srcu);
-	hlist_for_each_entry_rcu(mn, &mmn_mm->list, hlist) {
+	hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist) {
 		/*
 		 * Call invalidate_range here too to avoid the need for the
 		 * subsystem of having to register an invalidate_range_end
@@ -516,14 +542,16 @@ static void mn_hlist_invalidate_end(struct mmu_notifier_mm *mm