Merge branch 'next' into for-linus

Prepare second round of input updates for 5.3 merge window.

1 files changed, 37 insertions, 27 deletions

diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index bad96b476eb6..0bfa10f4410c 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * jump label support
  *
@@ -202,11 +203,13 @@ void static_key_disable(struct static_key *key)
 }
 EXPORT_SYMBOL_GPL(static_key_disable);
 
-static void __static_key_slow_dec_cpuslocked(struct static_key *key,
-					   unsigned long rate_limit,
-					   struct delayed_work *work)
+static bool static_key_slow_try_dec(struct static_key *key)
 {
-	lockdep_assert_cpus_held();
+	int val;
+
+	val = atomic_fetch_add_unless(&key->enabled, -1, 1);
+	if (val == 1)
+		return false;
 
 	/*
 	 * The negative count check is valid even when a negative
@@ -215,63 +218,70 @@ static void __static_key_slow_dec_cpuslocked(struct static_key *key,
 	 * returns is unbalanced, because all other static_key_slow_inc()
 	 * instances block while the update is in progress.
 	 */
-	if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex)) {
-		WARN(atomic_read(&key->enabled) < 0,
-		     "jump label: negative count!\n");
+	WARN(val < 0, "jump label: negative count!\n");
+	return true;
+}
+
+static void __static_key_slow_dec_cpuslocked(struct static_key *key)
+{
+	lockdep_assert_cpus_held();
+
+	if (static_key_slow_try_dec(key))
 		return;
-	}
 
-	if (rate_limit) {
-		atomic_inc(&key->enabled);
-		schedule_delayed_work(work, rate_limit);
-	} else {
+	jump_label_lock();
+	if (atomic_dec_and_test(&key->enabled))
 		jump_label_update(key);
-	}
 	jump_label_unlock();
 }
 
-static void __static_key_slow_dec(struct static_key *key,
-				  unsigned long rate_limit,
-				  struct delayed_work *work)
+static void __static_key_slow_dec(struct static_key *key)
 {
 	cpus_read_lock();
-	__static_key_slow_dec_cpuslocked(key, rate_limit, work);
+	__static_key_slow_dec_cpuslocked(key);
 	cpus_read_unlock();
 }
 
-static void jump_label_update_timeout(struct work_struct *work)
+void jump_label_update_timeout(struct work_struct *work)
 {
 	struct static_key_deferred *key =
 		container_of(work, struct static_key_deferred, work.work);
-	__static_key_slow_dec(&key->key, 0, NULL);
+	__static_key_slow_dec(&key->key);
 }
+EXPORT_SYMBOL_GPL(jump_label_update_timeout);
 
 void static_key_slow_dec(struct static_key *key)
 {
 	STATIC_KEY_CHECK_USE(key);
-	__static_key_slow_dec(key, 0, NULL);
+	__static_key_slow_dec(key);
 }
 EXPORT_SYMBOL_GPL(static_key_slow_dec);
 
 void static_key_slow_dec_cpuslocked(struct static_key *key)
 {
 	STATIC_KEY_CHECK_USE(key);
-	__static_key_slow_dec_cpuslocked(key, 0, NULL);
+	__static_key_slow_dec_cpuslocked(key);
 }
 
-void static_key_slow_dec_deferred(struct static_key_deferred *key)
+void __static_key_slow_dec_deferred(struct static_key *key,
+				    struct delayed_work *work,
+				    unsigned long timeout)
 {
 	STATIC_KEY_CHECK_USE(key);
-	__static_key_slow_dec(&key->key, key->timeout, &key->work);
+
+	if (static_key_slow_try_dec(key))
+		return;
+
+	schedule_delayed_work(work, timeout);
 }
-EXPORT_SYMBOL_GPL(static_key_slow_dec_deferred);
+EXPORT_SYMBOL_GPL(__static_key_slow_dec_deferred);
 
-void static_key_deferred_flush(struct static_key_deferred *key)
+void __static_key_deferred_flush(void *key, struct delayed_work *work)
 {
 	STATIC_KEY_CHECK_USE(key);
-	flush_delayed_work(&key->work);
+	flush_delayed_work(work);
 }
-EXPORT_SYMBOL_GPL(static_key_deferred_flush);
+EXPORT_SYMBOL_GPL(__static_key_deferred_flush);
 
 void jump_label_rate_limit(struct static_key_deferred *key,
 		unsigned long rl)