From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 270CFC07E96 for ; Tue, 13 Jul 2021 16:14:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0CC1E61178 for ; Tue, 13 Jul 2021 16:14:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234110AbhGMQRf (ORCPT ); Tue, 13 Jul 2021 12:17:35 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:54590 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232562AbhGMQQq (ORCPT ); Tue, 13 Jul 2021 12:16:46 -0400 Message-Id: <20210713160749.741589043@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1626192836; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=uOrndOHPQPC+6FBoafYd9HtmTvm+zCxBeOUpXJ5u35M=; b=vDiHtXdCbCaI8MBDEQwMBw06RaGL2meJNhVQ+UnqGUuCDjczO9Fp4IKFeyaDZukznd1pWQ nuyzuikY72bW2KYAkXVv4yvwvVDgd+EFHfYiFNEl5iYTGScxLpwpjqFFReMWXHpCEuEhM6 oFK2vf+4Pdy3IPIZPvHJATCz1tBFWI6+orvQaNv0FynQi9nu9g4hfhSjtKyngIqRV5YWYW 1mTp4VHjTYJYJ8h7zxy29drofThOTZAO2OLomzKdnrS/2rzGcKkmyQNjwHr/WtMrbKbUuC N0ZnxmL4zEQqVPTgG8n/C/aChUsil6q1IT5AGuDZIBpA7Z/emZh6yUsGt4ev9A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1626192836; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=uOrndOHPQPC+6FBoafYd9HtmTvm+zCxBeOUpXJ5u35M=; b=z3GU32xBjJKKmH91jmzxYmIarZwMCyBDoT8alc+sn1U7c/bjahBUWAJuXyguYcoJnwUpL+ 3Cq532S25aYBqcBQ== Date: Tue, 13 Jul 2021 17:11:33 +0200 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Ingo Molnar , Juri Lelli , Steven Rostedt , Daniel Bristot de Oliveira , Will Deacon , Waiman Long , Boqun Feng , Sebastian Andrzej Siewior , Davidlohr Bueso Subject: [patch 39/50] locking/rtmutex: Add mutex variant for RT References: <20210713151054.700719949@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-transfer-encoding: 8-bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Gleixner Add the necessary defines, helpers and API functions for replacing mutex on a PREEMPT_RT enabled kernel with a rtmutex based variant. If PREEMPT_RT is enabled then the regular 'struct mutex' is renamed to 'struct __mutex', which is still typedef'ed as '_mutex_t' to allow the standalone compilation and utilization of ww_mutex. No functional change when CONFIG_PREEMPT_RT=n Signed-off-by: Thomas Gleixner --- include/linux/mutex.h | 53 ++++++++++++++++++- kernel/locking/rtmutex_api.c | 122 +++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 173 insertions(+), 2 deletions(-) --- diff --git a/include/linux/mutex.h b/include/linux/mutex.h index 827c32bb44bc..2cfc234a786d 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -64,7 +64,12 @@ * built on the regular mutex code in RT kernels while mutex itself is * substituted by a rt_mutex. */ -typedef struct mutex { +#ifndef CONFIG_PREEMPT_RT +typedef struct mutex +#else +typedef struct __mutex +#endif +{ atomic_long_t owner; raw_spinlock_t wait_lock; #ifdef CONFIG_MUTEX_SPIN_ON_OWNER @@ -94,6 +99,7 @@ extern void _mutex_t_destroy(_mutex_t *lock); static inline void _mutex_t_destroy(_mutex_t *lock) {} #endif +#ifndef CONFIG_PREEMPT_RT /** * mutex_init - initialize the mutex * @mutex: the mutex to be initialized @@ -159,6 +165,51 @@ static __always_inline int mutex_trylock(struct mutex *lock) return _mutex_t_trylock(lock); } +#else /* !CONFIG_PREEMPT_RT */ +/* + * Preempt-RT variant based on rtmutexes. + */ +#include + +struct mutex { + struct rt_mutex rtmutex; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +}; + +#define __MUTEX_INITIALIZER(mutexname) \ + { \ + .rtmutex = __RT_MUTEX_INITIALIZER(mutexname.rtmutex) \ + __DEP_MAP_MUTEX_INITIALIZER(mutexname) \ + } + +#define DEFINE_MUTEX(mutexname) \ + struct mutex mutexname = __MUTEX_INITIALIZER(mutexname) + +extern void __mutex_rt_init(struct mutex *lock, const char *name, + struct lock_class_key *key); +extern int mutex_trylock(struct mutex *lock); + +static inline void mutex_destroy(struct mutex *lock) { } + +#define mutex_is_locked(l) rt_mutex_is_locked(&(l)->rtmutex) + +#define mutex_init(mutex) \ +do { \ + static struct lock_class_key __key; \ + \ + rt_mutex_init(&(mutex)->rtmutex); \ + __mutex_rt_init((mutex), #mutex, &__key); \ +} while (0) + +#define __mutex_init(mutex, name, key) \ +do { \ + rt_mutex_init(&(mutex)->rtmutex); \ + __mutex_rt_init((mutex), name, key); \ +} while (0) +#endif /* CONFIG_PREEMPT_RT */ + /* * See kernel/locking/mutex.c for detailed documentation of these APIs. * Also see Documentation/locking/mutex-design.rst. diff --git a/kernel/locking/rtmutex_api.c b/kernel/locking/rtmutex_api.c index d9a2ec9c1ad4..1091a53eb99f 100644 --- a/kernel/locking/rtmutex_api.c +++ b/kernel/locking/rtmutex_api.c @@ -512,4 +512,124 @@ void rwsem_rt_mutex_unlock(struct rt_mutex *lock) rt_mutex_slowunlock(lock); } -#endif + +/* Mutexes */ +void __mutex_rt_init(struct mutex *mutex, const char *name, + struct lock_class_key *key) +{ + debug_check_no_locks_freed((void *)mutex, sizeof(*mutex)); + lockdep_init_map(&mutex->dep_map, name, key, 0); +} +EXPORT_SYMBOL(__mutex_rt_init); + +static __always_inline int __mutex_lock_common(struct mutex *lock, + unsigned int state, + unsigned int subclass, + struct lockdep_map *nest_lock, + unsigned long ip) +{ + int ret; + + might_sleep(); + mutex_acquire_nest(&lock->dep_map, subclass, 0, nest_lock, ip); + ret = __rt_mutex_lock(&lock->rtmutex, state); + if (ret) + mutex_release(&lock->dep_map, ip); + else + lock_acquired(&lock->dep_map, ip); + return ret; +} + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void __sched mutex_lock_nested(struct mutex *lock, unsigned int subclass) +{ + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass, NULL, _RET_IP_); +} +EXPORT_SYMBOL_GPL(mutex_lock_nested); + +void __sched _mutex_lock_nest_lock(struct mutex *lock, + struct lockdep_map *nest_lock) +{ + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, nest_lock, _RET_IP_); +} +EXPORT_SYMBOL_GPL(_mutex_lock_nest_lock); + +int __sched mutex_lock_interruptible_nested(struct mutex *lock, + unsigned int subclass) +{ + return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, subclass, NULL, _RET_IP_); +} +EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested); + +int __sched mutex_lock_killable_nested(struct mutex *lock, + unsigned int subclass) +{ + return __mutex_lock_common(lock, TASK_KILLABLE, subclass, NULL, _RET_IP_); +} +EXPORT_SYMBOL_GPL(mutex_lock_killable_nested); + +void __sched mutex_lock_io_nested(struct mutex *lock, unsigned int subclass) +{ + int token; + + might_sleep(); + + token = io_schedule_prepare(); + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass, NULL, _RET_IP_); + io_schedule_finish(token); +} +EXPORT_SYMBOL_GPL(mutex_lock_io_nested); + +#else /* CONFIG_DEBUG_LOCK_ALLOC */ + +void __sched mutex_lock(struct mutex *lock) +{ + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, NULL, _RET_IP_); +} +EXPORT_SYMBOL(mutex_lock); + +int __sched mutex_lock_interruptible(struct mutex *lock) +{ + return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0, NULL, _RET_IP_); +} +EXPORT_SYMBOL(mutex_lock_interruptible); + +int __sched mutex_lock_killable(struct mutex *lock) +{ + return __mutex_lock_common(lock, TASK_KILLABLE, 0, NULL, _RET_IP_); +} +EXPORT_SYMBOL(mutex_lock_killable); + +void __sched mutex_lock_io(struct mutex *lock) +{ + int token = io_schedule_prepare(); + + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, NULL, _RET_IP_); + io_schedule_finish(token); +} +EXPORT_SYMBOL(mutex_lock_io); +#endif /* !CONFIG_DEBUG_LOCK_ALLOC */ + +int __sched mutex_trylock(struct mutex *lock) +{ + int ret; + + if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES) && WARN_ON_ONCE(!in_task())) + return 0; + + ret = __rt_mutex_trylock(&lock->rtmutex); + if (ret) + mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_); + + return ret; +} +EXPORT_SYMBOL(mutex_trylock); + +void __sched mutex_unlock(struct mutex *lock) +{ + mutex_release(&lock->dep_map, _RET_IP_); + __rt_mutex_unlock(&lock->rtmutex); +} +EXPORT_SYMBOL(mutex_unlock); + +#endif /* CONFIG_PREEMPT_RT */