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authorJason Gunthorpe <jgg@mellanox.com>2020-01-14 11:29:52 -0400
committerJason Gunthorpe <jgg@mellanox.com>2020-01-14 11:54:47 -0400
commit5292e24a6acf5694e0a32c31e3321964176bc17e (patch)
tree0b4a46ba0e4b85edcafc5c8339283c2793c6e3dd /mm/mmu_notifier.c
parent1991722a70ffb1f0199a5690a31a5c7822007b1f (diff)
mm/mmu_notifiers: Use 'interval_sub' as the variable for mmu_interval_notifier
The 'interval_sub' is placed on the 'notifier_subscriptions' interval tree. This eliminates the poor name 'mni' for this variable. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'mm/mmu_notifier.c')
-rw-r--r--mm/mmu_notifier.c136
1 files changed, 73 insertions, 63 deletions
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index 12b35d8b444a..ef3973a5d34a 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -81,7 +81,7 @@ struct mmu_notifier_subscriptions {
* 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_subscriptions *subscriptions)
@@ -114,13 +114,13 @@ mn_itree_inv_start_range(struct mmu_notifier_subscriptions *subscriptions,
}
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);
@@ -128,7 +128,7 @@ mn_itree_inv_next(struct mmu_interval_notifier *mni,
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(&subscriptions->lock);
@@ -147,15 +147,16 @@ static void mn_itree_inv_end(struct mmu_notifier_subscriptions *subscriptions)
* 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, &subscriptions->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,
+ 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,
+ interval_tree_remove(&interval_sub->interval_tree,
&subscriptions->itree);
- hlist_del(&mni->deferred_item);
+ hlist_del(&interval_sub->deferred_item);
}
spin_unlock(&subscriptions->lock);
@@ -165,12 +166,12 @@ static void mn_itree_inv_end(struct mmu_notifier_subscriptions *subscriptions)
/**
* 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,
@@ -181,25 +182,26 @@ static void mn_itree_inv_end(struct mmu_notifier_subscriptions *subscriptions)
*
* 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_subscriptions *subscriptions =
- mni->mm->notifier_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 subscriptions
- * 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 = READ_ONCE(interval_sub->invalidate_seq);
* seq == subs->invalidate_seq
* spin_unlock
* spin_lock
@@ -208,7 +210,7 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
* 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]
@@ -220,7 +222,7 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
*
* 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
@@ -229,12 +231,12 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni)
*/
spin_lock(&subscriptions->lock);
/* Pairs with the WRITE_ONCE in mmu_interval_set_seq() */
- seq = READ_ONCE(mni->invalidate_seq);
+ 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
@@ -266,13 +268,16 @@ static void mn_itree_release(struct mmu_notifier_subscriptions *subscriptions,
.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(subscriptions, &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);
}
@@ -434,14 +439,17 @@ void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
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(subscriptions, 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;
@@ -878,20 +886,21 @@ out_unlock:
EXPORT_SYMBOL_GPL(mmu_notifier_put);
static int __mmu_interval_notifier_insert(
- struct mmu_interval_notifier *mni, struct mm_struct *mm,
+ struct mmu_interval_notifier *interval_sub, struct mm_struct *mm,
struct mmu_notifier_subscriptions *subscriptions, unsigned long start,
unsigned long length, const struct mmu_interval_notifier_ops *ops)
{
- mni->mm = mm;
- mni->ops = ops;
- RB_CLEAR_NODE(&mni->interval_tree.rb);
- mni->interval_tree.start = start;
+ interval_sub->mm = mm;
+ interval_sub->ops = ops;
+ RB_CLEAR_NODE(&interval_sub->interval_tree.rb);
+ interval_sub->interval_tree.start = start;
/*
* Note that the representation of the intervals in the interval tree
* considers the ending point as contained in the interval.
*/
if (length == 0 ||
- check_add_overflow(start, length - 1, &mni->interval_tree.last))
+ check_add_overflow(start, length - 1,
+ &interval_sub->interval_tree.last))
return -EOVERFLOW;
/* Must call with a mmget() held */
@@ -911,30 +920,31 @@ static int __mmu_interval_notifier_insert(
* possibility for live lock, instead defer the add to
* mn_itree_inv_end() so this algorithm is deterministic.
*
- * In all cases the value for the mni->invalidate_seq should be
+ * In all cases the value for the interval_sub->invalidate_seq should be
* odd, see mmu_interval_read_begin()
*/
spin_lock(&subscriptions->lock);
if (subscriptions->active_invalidate_ranges) {
if (mn_itree_is_invalidating(subscriptions))
- hlist_add_head(&mni->deferred_item,
+ hlist_add_head(&interval_sub->deferred_item,
&subscriptions->deferred_list);
else {
subscriptions->invalidate_seq |= 1;
- interval_tree_insert(&mni->interval_tree,
+ interval_tree_insert(&interval_sub->interval_tree,
&subscriptions->itree);
}
- mni->invalidate_seq = subscriptions->invalidate_seq;
+ interval_sub->invalidate_seq = subscriptions->invalidate_seq;
} else {
WARN_ON(mn_itree_is_invalidating(subscriptions));
/*
- * The starting seq for a mni not under invalidation should be
- * odd, not equal to the current invalidate_seq and
+ * The starting seq for a subscription not under invalidation
+ * should be odd, not equal to the current invalidate_seq and
* invalidate_seq should not 'wrap' to the new seq any time
* soon.
*/
- mni->invalidate_seq = subscriptions->invalidate_seq - 1;
- interval_tree_insert(&mni->interval_tree,
+ interval_sub->invalidate_seq =
+ subscriptions->invalidate_seq - 1;
+ interval_tree_insert(&interval_sub->interval_tree,
&subscriptions->itree);
}
spin_unlock(&subscriptions->lock);
@@ -943,7 +953,7 @@ static int __mmu_interval_notifier_insert(
/**
* mmu_interval_notifier_insert - Insert an interval notifier
- * @mni: Interval notifier to register
+ * @interval_sub: Interval subscription to register
* @start: Starting virtual address to monitor
* @length: Length of the range to monitor
* @mm : mm_struct to attach to
@@ -956,7 +966,7 @@ static int __mmu_interval_notifier_insert(
* The caller must use the normal interval notifier read flow via
* mmu_interval_read_begin() to establish SPTEs for this range.
*/
-int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni,
+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)
@@ -973,13 +983,13 @@ int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni,
return ret;
subscriptions = mm->notifier_subscriptions;
}
- return __mmu_interval_notifier_insert(mni, mm, subscriptions, start,
- length, ops);
+ return __mmu_interval_notifier_insert(interval_sub, mm, subscriptions,
+ start, length, ops);
}
EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert);
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)
{
@@ -995,14 +1005,14 @@ int mmu_interval_notifier_insert_locked(
return ret;
subscriptions = mm->notifier_subscriptions;
}
- return __mmu_interval_notifier_insert(mni, mm, subscriptions, start,
- length, ops);
+ return __mmu_interval_notifier_insert(interval_sub, mm, subscriptions,
+ start, length, ops);
}
EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert_locked);
/**
* mmu_interval_notifier_remove - Remove a interval notifier
- * @mni: Interval notifier to unregister
+ * @interval_sub: Interval subscription to unregister
*
* This function must be paired with mmu_interval_notifier_insert(). It cannot
* be called from any ops callback.
@@ -1010,9 +1020,9 @@ EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert_locked);
* Once this returns ops callbacks are no longer running on other CPUs and
* will not be called in future.
*/
-void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni)
+void mmu_interval_notifier_remove(struct mmu_interval_notifier *interval_sub)
{
- struct mm_struct *mm = mni->mm;
+ struct mm_struct *mm = interval_sub->mm;
struct mmu_notifier_subscriptions *subscriptions =
mm->notifier_subscriptions;
unsigned long seq = 0;
@@ -1025,16 +1035,16 @@ void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni)
* remove is being called after insert put this on the
* deferred list, but before the deferred list was processed.
*/
- if (RB_EMPTY_NODE(&mni->interval_tree.rb)) {
- hlist_del(&mni->deferred_item);
+ if (RB_EMPTY_NODE(&interval_sub->interval_tree.rb)) {
+ hlist_del(&interval_sub->deferred_item);
} else {
- hlist_add_head(&mni->deferred_item,
+ hlist_add_head(&interval_sub->deferred_item,
&subscriptions->deferred_list);
seq = subscriptions->invalidate_seq;
}
} else {
- WARN_ON(RB_EMPTY_NODE(&mni->interval_tree.rb));
- interval_tree_remove(&mni->interval_tree,
+ WARN_ON(RB_EMPTY_NODE(&interval_sub->interval_tree.rb));
+ interval_tree_remove(&interval_sub->interval_tree,
&subscriptions->itree);
}
spin_unlock(&subscriptions->lock);