5 files changed, 381 insertions, 359 deletions

diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index 3793ed7feeeb..ccd4260834c5 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -78,40 +78,6 @@ struct mutex_waiter {
 #endif
 };
 
-struct ww_class {
-        atomic_long_t stamp;
-        struct lock_class_key acquire_key;
-        struct lock_class_key mutex_key;
-        const char *acquire_name;
-        const char *mutex_name;
-};
-
-struct ww_acquire_ctx {
-        struct task_struct *task;
-        unsigned long stamp;
-        unsigned acquired;
-#ifdef CONFIG_DEBUG_MUTEXES
-        unsigned done_acquire;
-        struct ww_class *ww_class;
-        struct ww_mutex *contending_lock;
-#endif
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-        struct lockdep_map dep_map;
-#endif
-#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH
-        unsigned deadlock_inject_interval;
-        unsigned deadlock_inject_countdown;
-#endif
-};
-
-struct ww_mutex {
-        struct mutex base;
-        struct ww_acquire_ctx *ctx;
-#ifdef CONFIG_DEBUG_MUTEXES
-        struct ww_class *ww_class;
-#endif
-};
-
 #ifdef CONFIG_DEBUG_MUTEXES
 # include <linux/mutex-debug.h>
 #else
@@ -136,11 +102,8 @@ static inline void mutex_destroy(struct mutex *lock) {}
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 # define __DEP_MAP_MUTEX_INITIALIZER(lockname) \
                 , .dep_map = { .name = #lockname }
-# define __WW_CLASS_MUTEX_INITIALIZER(lockname, ww_class) \
-                , .ww_class = &ww_class
 #else
 # define __DEP_MAP_MUTEX_INITIALIZER(lockname)
-# define __WW_CLASS_MUTEX_INITIALIZER(lockname, ww_class)
 #endif
 
 #define __MUTEX_INITIALIZER(lockname) \
@@ -150,49 +113,13 @@ static inline void mutex_destroy(struct mutex *lock) {}
                 __DEBUG_MUTEX_INITIALIZER(lockname) \
                 __DEP_MAP_MUTEX_INITIALIZER(lockname) }
 
-#define __WW_CLASS_INITIALIZER(ww_class) \
-                { .stamp = ATOMIC_LONG_INIT(0) \
-                , .acquire_name = #ww_class "_acquire" \
-                , .mutex_name = #ww_class "_mutex" }
-
-#define __WW_MUTEX_INITIALIZER(lockname, class) \
-                { .base = { \__MUTEX_INITIALIZER(lockname) } \
-                __WW_CLASS_MUTEX_INITIALIZER(lockname, class) }
-
 #define DEFINE_MUTEX(mutexname) \
         struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
 
-#define DEFINE_WW_CLASS(classname) \
-        struct ww_class classname = __WW_CLASS_INITIALIZER(classname)
-
-#define DEFINE_WW_MUTEX(mutexname, ww_class) \
-        struct ww_mutex mutexname = __WW_MUTEX_INITIALIZER(mutexname, ww_class)
-
-
 extern void __mutex_init(struct mutex *lock, const char *name,
                          struct lock_class_key *key);
 
 /**
- * ww_mutex_init - initialize the w/w mutex
- * @lock: the mutex to be initialized
- * @ww_class: the w/w class the mutex should belong to
- *
- * Initialize the w/w mutex to unlocked state and associate it with the given
- * class.
- *
- * It is not allowed to initialize an already locked mutex.
- */
-static inline void ww_mutex_init(struct ww_mutex *lock,
-                                 struct ww_class *ww_class)
-{
-        __mutex_init(&lock->base, ww_class->mutex_name, &ww_class->mutex_key);
-        lock->ctx = NULL;
-#ifdef CONFIG_DEBUG_MUTEXES
-        lock->ww_class = ww_class;
-#endif
-}
-
-/**
  * mutex_is_locked - is the mutex locked
  * @lock: the mutex to be queried
  *
@@ -246,291 +173,6 @@ extern int __must_check mutex_lock_killable(struct mutex *lock);
 extern int mutex_trylock(struct mutex *lock);
 extern void mutex_unlock(struct mutex *lock);
 
-/**
- * ww_acquire_init - initialize a w/w acquire context
- * @ctx: w/w acquire context to initialize
- * @ww_class: w/w class of the context
- *
- * Initializes an context to acquire multiple mutexes of the given w/w class.
- *
- * Context-based w/w mutex acquiring can be done in any order whatsoever within
- * a given lock class. Deadlocks will be detected and handled with the
- * wait/wound logic.
- *
- * Mixing of context-based w/w mutex acquiring and single w/w mutex locking can
- * result in undetected deadlocks and is so forbidden. Mixing different contexts
- * for the same w/w class when acquiring mutexes can also result in undetected
- * deadlocks, and is hence also forbidden. Both types of abuse will be caught by
- * enabling CONFIG_PROVE_LOCKING.
- *
- * Nesting of acquire contexts for _different_ w/w classes is possible, subject
- * to the usual locking rules between different lock classes.
- *
- * An acquire context must be released with ww_acquire_fini by the same task
- * before the memory is freed. It is recommended to allocate the context itself
- * on the stack.
- */
-static inline void ww_acquire_init(struct ww_acquire_ctx *ctx,
-                                   struct ww_class *ww_class)
-{
-        ctx->task = current;
-        ctx->stamp = atomic_long_inc_return(&ww_class->stamp);
-        ctx->acquired = 0;
-#ifdef CONFIG_DEBUG_MUTEXES
-        ctx->ww_class = ww_class;
-        ctx->done_acquire = 0;
-        ctx->contending_lock = NULL;
-#endif
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-        debug_check_no_locks_freed((void *)ctx, sizeof(*ctx));
-        lockdep_init_map(&ctx->dep_map, ww_class->acquire_name,
-                         &ww_class->acquire_key, 0);
-        mutex_acquire(&ctx->dep_map, 0, 0, _RET_IP_);
-#endif
-#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH
-        ctx->deadlock_inject_interval = 1;
-        ctx->deadlock_inject_countdown = ctx->stamp & 0xf;
-#endif
-}
-
-/**
- * ww_acquire_done - marks the end of the acquire phase
- * @ctx: the acquire context
- *
- * Marks the end of the acquire phase, any further w/w mutex lock calls using
- * this context are forbidden.
- *
- * Calling this function is optional, it is just useful to document w/w mutex
- * code and clearly designated the acquire phase from actually using the locked
- * data structures.
- */
-static inline void ww_acquire_done(struct ww_acquire_ctx *ctx)
-{
-#ifdef CONFIG_DEBUG_MUTEXES
-        lockdep_assert_held(ctx);
-
-        DEBUG_LOCKS_WARN_ON(ctx->done_acquire);
-        ctx->done_acquire = 1;
-#endif
-}
-
-/**
- * ww_acquire_fini - releases a w/w acquire context
- * @ctx: the acquire context to free
- *
- * Releases a w/w acquire context. This must be called _after_ all acquired w/w
- * mutexes have been released with ww_mutex_unlock.
- */
-static inline void ww_acquire_fini(struct ww_acquire_ctx *ctx)
-{
-#ifdef CONFIG_DEBUG_MUTEXES
-        mutex_release(&ctx->dep_map, 0, _THIS_IP_);
-