1 files changed, 7 insertions, 61 deletions

diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index fbbd2eda867e..45fe1b5293d6 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -25,6 +25,7 @@
 #include <linux/spinlock.h>
 #include <linux/interrupt.h>
 #include <linux/debug_locks.h>
+#include <linux/mcs_spinlock.h>
 
 /*
  * In the DEBUG case we are using the "NULL fastpath" for mutexes,
@@ -52,7 +53,7 @@ __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key)
 	INIT_LIST_HEAD(&lock->wait_list);
 	mutex_clear_owner(lock);
 #ifdef CONFIG_MUTEX_SPIN_ON_OWNER
-	lock->spin_mlock = NULL;
+	lock->mcs_lock = NULL;
 #endif
 
 	debug_mutex_init(lock, name, key);
@@ -111,62 +112,7 @@ EXPORT_SYMBOL(mutex_lock);
  * more or less simultaneously, the spinners need to acquire a MCS lock
  * first before spinning on the owner field.
  *
- * We don't inline mspin_lock() so that perf can correctly account for the
- * time spent in this lock function.
  */
-struct mspin_node {
-	struct mspin_node *next ;
-	int		  locked;	/* 1 if lock acquired */
-};
-#define	MLOCK(mutex)	((struct mspin_node **)&((mutex)->spin_mlock))
-
-static noinline
-void mspin_lock(struct mspin_node **lock, struct mspin_node *node)
-{
-	struct mspin_node *prev;
-
-	/* Init node */
-	node->locked = 0;
-	node->next   = NULL;
-
-	prev = xchg(lock, node);
-	if (likely(prev == NULL)) {
-		/* Lock acquired */
-		node->locked = 1;
-		return;
-	}
-	ACCESS_ONCE(prev->next) = node;
-	/*
-	 * Wait until the lock holder passes the lock down.
-	 * Using smp_load_acquire() provides a memory barrier that
-	 * ensures subsequent operations happen after the lock is acquired.
-	 */
-	while (!(smp_load_acquire(&node->locked)))
-		arch_mutex_cpu_relax();
-}
-
-static void mspin_unlock(struct mspin_node **lock, struct mspin_node *node)
-{
-	struct mspin_node *next = ACCESS_ONCE(node->next);
-
-	if (likely(!next)) {
-		/*
-		 * Release the lock by setting it to NULL
-		 */
-		if (cmpxchg(lock, node, NULL) == node)
-			return;
-		/* Wait until the next pointer is set */
-		while (!(next = ACCESS_ONCE(node->next)))
-			arch_mutex_cpu_relax();
-	}
-	/*
-	 * Pass lock to next waiter.
-	 * smp_store_release() provides a memory barrier to ensure
-	 * all operations in the critical section has been completed
-	 * before unlocking.
-	 */
-	smp_store_release(&next->locked, 1);
-}
 
 /*
  * Mutex spinning code migrated from kernel/sched/core.c
@@ -456,7 +402,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 
 	for (;;) {
 		struct task_struct *owner;
-		struct mspin_node  node;
+		struct mcs_spinlock  node;
 
 		if (use_ww_ctx && ww_ctx->acquired > 0) {
 			struct ww_mutex *ww;
@@ -478,10 +424,10 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 		 * If there's an owner, wait for it to either
 		 * release the lock or go to sleep.
 		 */
-		mspin_lock(MLOCK(lock), &node);
+		mcs_spin_lock(&lock->mcs_lock, &node);
 		owner = ACCESS_ONCE(lock->owner);
 		if (owner && !mutex_spin_on_owner(lock, owner)) {
-			mspin_unlock(MLOCK(lock), &node);
+			mcs_spin_unlock(&lock->mcs_lock, &node);
 			goto slowpath;
 		}
 
@@ -496,11 +442,11 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 			}
 
 			mutex_set_owner(lock);
-			mspin_unlock(MLOCK(lock), &node);
+			mcs_spin_unlock(&lock->mcs_lock, &node);
 			preempt_enable();
 			return 0;
 		}
-		mspin_unlock(MLOCK(lock), &node);
+		mcs_spin_unlock(&lock->mcs_lock, &node);
 
 		/*
 		 * When there's no owner, we might have preempted between the