2021-08-16 05:27:57 +08:00
|
|
|
// SPDX-License-Identifier: GPL-2.0-only
|
|
|
|
/*
|
|
|
|
* rtmutex API
|
|
|
|
*/
|
|
|
|
#include <linux/spinlock.h>
|
|
|
|
#include <linux/export.h>
|
|
|
|
|
2021-08-16 05:28:12 +08:00
|
|
|
#define RT_MUTEX_BUILD_MUTEX
|
2021-08-16 05:27:57 +08:00
|
|
|
#include "rtmutex.c"
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Max number of times we'll walk the boosting chain:
|
|
|
|
*/
|
|
|
|
int max_lock_depth = 1024;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Debug aware fast / slowpath lock,trylock,unlock
|
|
|
|
*
|
|
|
|
* The atomic acquire/release ops are compiled away, when either the
|
|
|
|
* architecture does not support cmpxchg or when debugging is enabled.
|
|
|
|
*/
|
|
|
|
static __always_inline int __rt_mutex_lock_common(struct rt_mutex *lock,
|
|
|
|
unsigned int state,
|
|
|
|
unsigned int subclass)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
might_sleep();
|
|
|
|
mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
|
2021-08-16 05:27:58 +08:00
|
|
|
ret = __rt_mutex_lock(&lock->rtmutex, state);
|
2021-08-16 05:27:57 +08:00
|
|
|
if (ret)
|
|
|
|
mutex_release(&lock->dep_map, _RET_IP_);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2021-08-16 05:27:58 +08:00
|
|
|
void rt_mutex_base_init(struct rt_mutex_base *rtb)
|
|
|
|
{
|
|
|
|
__rt_mutex_base_init(rtb);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(rt_mutex_base_init);
|
|
|
|
|
2021-08-16 05:27:57 +08:00
|
|
|
#ifdef CONFIG_DEBUG_LOCK_ALLOC
|
|
|
|
/**
|
|
|
|
* rt_mutex_lock_nested - lock a rt_mutex
|
|
|
|
*
|
|
|
|
* @lock: the rt_mutex to be locked
|
|
|
|
* @subclass: the lockdep subclass
|
|
|
|
*/
|
|
|
|
void __sched rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass)
|
|
|
|
{
|
|
|
|
__rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(rt_mutex_lock_nested);
|
|
|
|
|
|
|
|
#else /* !CONFIG_DEBUG_LOCK_ALLOC */
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rt_mutex_lock - lock a rt_mutex
|
|
|
|
*
|
|
|
|
* @lock: the rt_mutex to be locked
|
|
|
|
*/
|
|
|
|
void __sched rt_mutex_lock(struct rt_mutex *lock)
|
|
|
|
{
|
|
|
|
__rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(rt_mutex_lock);
|
|
|
|
#endif
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rt_mutex_lock_interruptible - lock a rt_mutex interruptible
|
|
|
|
*
|
|
|
|
* @lock: the rt_mutex to be locked
|
|
|
|
*
|
|
|
|
* Returns:
|
|
|
|
* 0 on success
|
|
|
|
* -EINTR when interrupted by a signal
|
|
|
|
*/
|
|
|
|
int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock)
|
|
|
|
{
|
|
|
|
return __rt_mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rt_mutex_trylock - try to lock a rt_mutex
|
|
|
|
*
|
|
|
|
* @lock: the rt_mutex to be locked
|
|
|
|
*
|
|
|
|
* This function can only be called in thread context. It's safe to call it
|
|
|
|
* from atomic regions, but not from hard or soft interrupt context.
|
|
|
|
*
|
|
|
|
* Returns:
|
|
|
|
* 1 on success
|
|
|
|
* 0 on contention
|
|
|
|
*/
|
|
|
|
int __sched rt_mutex_trylock(struct rt_mutex *lock)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES) && WARN_ON_ONCE(!in_task()))
|
|
|
|
return 0;
|
|
|
|
|
2021-08-16 05:27:58 +08:00
|
|
|
ret = __rt_mutex_trylock(&lock->rtmutex);
|
2021-08-16 05:27:57 +08:00
|
|
|
if (ret)
|
|
|
|
mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(rt_mutex_trylock);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rt_mutex_unlock - unlock a rt_mutex
|
|
|
|
*
|
|
|
|
* @lock: the rt_mutex to be unlocked
|
|
|
|
*/
|
|
|
|
void __sched rt_mutex_unlock(struct rt_mutex *lock)
|
|
|
|
{
|
|
|
|
mutex_release(&lock->dep_map, _RET_IP_);
|
2021-08-16 05:27:58 +08:00
|
|
|
__rt_mutex_unlock(&lock->rtmutex);
|
2021-08-16 05:27:57 +08:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(rt_mutex_unlock);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Futex variants, must not use fastpath.
|
|
|
|
*/
|
2021-08-16 05:27:58 +08:00
|
|
|
int __sched rt_mutex_futex_trylock(struct rt_mutex_base *lock)
|
2021-08-16 05:27:57 +08:00
|
|
|
{
|
|
|
|
return rt_mutex_slowtrylock(lock);
|
|
|
|
}
|
|
|
|
|
2021-08-16 05:27:58 +08:00
|
|
|
int __sched __rt_mutex_futex_trylock(struct rt_mutex_base *lock)
|
2021-08-16 05:27:57 +08:00
|
|
|
{
|
|
|
|
return __rt_mutex_slowtrylock(lock);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* __rt_mutex_futex_unlock - Futex variant, that since futex variants
|
|
|
|
* do not use the fast-path, can be simple and will not need to retry.
|
|
|
|
*
|
|
|
|
* @lock: The rt_mutex to be unlocked
|
2021-08-16 05:28:09 +08:00
|
|
|
* @wqh: The wake queue head from which to get the next lock waiter
|
2021-08-16 05:27:57 +08:00
|
|
|
*/
|
2021-08-16 05:27:58 +08:00
|
|
|
bool __sched __rt_mutex_futex_unlock(struct rt_mutex_base *lock,
|
2021-08-16 05:28:09 +08:00
|
|
|
struct rt_wake_q_head *wqh)
|
2021-08-16 05:27:57 +08:00
|
|
|
{
|
|
|
|
lockdep_assert_held(&lock->wait_lock);
|
|
|
|
|
|
|
|
debug_rt_mutex_unlock(lock);
|
|
|
|
|
|
|
|
if (!rt_mutex_has_waiters(lock)) {
|
|
|
|
lock->owner = NULL;
|
|
|
|
return false; /* done */
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* We've already deboosted, mark_wakeup_next_waiter() will
|
|
|
|
* retain preempt_disabled when we drop the wait_lock, to
|
|
|
|
* avoid inversion prior to the wakeup. preempt_disable()
|
|
|
|
* therein pairs with rt_mutex_postunlock().
|
|
|
|
*/
|
2021-08-16 05:28:09 +08:00
|
|
|
mark_wakeup_next_waiter(wqh, lock);
|
2021-08-16 05:27:57 +08:00
|
|
|
|
|
|
|
return true; /* call postunlock() */
|
|
|
|
}
|
|
|
|
|
2021-08-16 05:27:58 +08:00
|
|
|
void __sched rt_mutex_futex_unlock(struct rt_mutex_base *lock)
|
2021-08-16 05:27:57 +08:00
|
|
|
{
|
2021-08-16 05:28:09 +08:00
|
|
|
DEFINE_RT_WAKE_Q(wqh);
|
2021-08-16 05:27:57 +08:00
|
|
|
unsigned long flags;
|
|
|
|
bool postunlock;
|
|
|
|
|
|
|
|
raw_spin_lock_irqsave(&lock->wait_lock, flags);
|
2021-08-16 05:28:09 +08:00
|
|
|
postunlock = __rt_mutex_futex_unlock(lock, &wqh);
|
2021-08-16 05:27:57 +08:00
|
|
|
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
|
|
|
|
|
|
|
|
if (postunlock)
|
2021-08-16 05:28:09 +08:00
|
|
|
rt_mutex_postunlock(&wqh);
|
2021-08-16 05:27:57 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* __rt_mutex_init - initialize the rt_mutex
|
|
|
|
*
|
|
|
|
* @lock: The rt_mutex to be initialized
|
|
|
|
* @name: The lock name used for debugging
|
|
|
|
* @key: The lock class key used for debugging
|
|
|
|
*
|
|
|
|
* Initialize the rt_mutex to unlocked state.
|
|
|
|
*
|
|
|
|
* Initializing of a locked rt_mutex is not allowed
|
|
|
|
*/
|
|
|
|
void __sched __rt_mutex_init(struct rt_mutex *lock, const char *name,
|
2021-08-16 05:27:58 +08:00
|
|
|
struct lock_class_key *key)
|
2021-08-16 05:27:57 +08:00
|
|
|
{
|
|
|
|
debug_check_no_locks_freed((void *)lock, sizeof(*lock));
|
2021-08-16 05:27:58 +08:00
|
|
|
__rt_mutex_base_init(&lock->rtmutex);
|
2021-08-16 05:27:57 +08:00
|
|
|
lockdep_init_map_wait(&lock->dep_map, name, key, 0, LD_WAIT_SLEEP);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(__rt_mutex_init);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a
|
|
|
|
* proxy owner
|
|
|
|
*
|
|
|
|
* @lock: the rt_mutex to be locked
|
|
|
|
* @proxy_owner:the task to set as owner
|
|
|
|
*
|
|
|
|
* No locking. Caller has to do serializing itself
|
|
|
|
*
|
|
|
|
* Special API call for PI-futex support. This initializes the rtmutex and
|
|
|
|
* assigns it to @proxy_owner. Concurrent operations on the rtmutex are not
|
|
|
|
* possible at this point because the pi_state which contains the rtmutex
|
|
|
|
* is not yet visible to other tasks.
|
|
|
|
*/
|
2021-08-16 05:27:58 +08:00
|
|
|
void __sched rt_mutex_init_proxy_locked(struct rt_mutex_base *lock,
|
2021-08-16 05:27:57 +08:00
|
|
|
struct task_struct *proxy_owner)
|
|
|
|
{
|
2021-08-16 05:29:20 +08:00
|
|
|
static struct lock_class_key pi_futex_key;
|
|
|
|
|
2021-08-16 05:27:58 +08:00
|
|
|
__rt_mutex_base_init(lock);
|
2021-08-16 05:29:20 +08:00
|
|
|
/*
|
|
|
|
* On PREEMPT_RT the futex hashbucket spinlock becomes 'sleeping'
|
|
|
|
* and rtmutex based. That causes a lockdep false positive, because
|
|
|
|
* some of the futex functions invoke spin_unlock(&hb->lock) with
|
|
|
|
* the wait_lock of the rtmutex associated to the pi_futex held.
|
|
|
|
* spin_unlock() in turn takes wait_lock of the rtmutex on which
|
|
|
|
* the spinlock is based, which makes lockdep notice a lock
|
|
|
|
* recursion. Give the futex/rtmutex wait_lock a separate key.
|
|
|
|
*/
|
|
|
|
lockdep_set_class(&lock->wait_lock, &pi_futex_key);
|
2021-08-16 05:27:57 +08:00
|
|
|
rt_mutex_set_owner(lock, proxy_owner);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rt_mutex_proxy_unlock - release a lock on behalf of owner
|
|
|
|
*
|
|
|
|
* @lock: the rt_mutex to be locked
|
|
|
|
*
|
|
|
|
* No locking. Caller has to do serializing itself
|
|
|
|
*
|
|
|
|
* Special API call for PI-futex support. This just cleans up the rtmutex
|
|
|
|
* (debugging) state. Concurrent operations on this rt_mutex are not
|
|
|
|
* possible because it belongs to the pi_state which is about to be freed
|
|
|
|
* and it is not longer visible to other tasks.
|
|
|
|
*/
|
2021-08-16 05:27:58 +08:00
|
|
|
void __sched rt_mutex_proxy_unlock(struct rt_mutex_base *lock)
|
2021-08-16 05:27:57 +08:00
|
|
|
{
|
|
|
|
debug_rt_mutex_proxy_unlock(lock);
|
|
|
|
rt_mutex_set_owner(lock, NULL);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* __rt_mutex_start_proxy_lock() - Start lock acquisition for another task
|
|
|
|
* @lock: the rt_mutex to take
|
|
|
|
* @waiter: the pre-initialized rt_mutex_waiter
|
|
|
|
* @task: the task to prepare
|
|
|
|
*
|
|
|
|
* Starts the rt_mutex acquire; it enqueues the @waiter and does deadlock
|
|
|
|
* detection. It does not wait, see rt_mutex_wait_proxy_lock() for that.
|
|
|
|
*
|
|
|
|
* NOTE: does _NOT_ remove the @waiter on failure; must either call
|
|
|
|
* rt_mutex_wait_proxy_lock() or rt_mutex_cleanup_proxy_lock() after this.
|
|
|
|
*
|
|
|
|
* Returns:
|
|
|
|
* 0 - task blocked on lock
|
|
|
|
* 1 - acquired the lock for task, caller should wake it up
|
|
|
|
* <0 - error
|
|
|
|
*
|
|
|
|
* Special API call for PI-futex support.
|
|
|
|
*/
|
2021-08-16 05:27:58 +08:00
|
|
|
int __sched __rt_mutex_start_proxy_lock(struct rt_mutex_base *lock,
|
2021-08-16 05:27:57 +08:00
|
|
|
struct rt_mutex_waiter *waiter,
|
|
|
|
struct task_struct *task)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
lockdep_assert_held(&lock->wait_lock);
|
|
|
|
|
|
|
|
if (try_to_take_rt_mutex(lock, task, NULL))
|
|
|
|
return 1;
|
|
|
|
|
|
|
|
/* We enforce deadlock detection for futexes */
|
2021-08-16 05:28:58 +08:00
|
|
|
ret = task_blocks_on_rt_mutex(lock, waiter, task, NULL,
|
2021-08-16 05:27:57 +08:00
|
|
|
RT_MUTEX_FULL_CHAINWALK);
|
|
|
|
|
|
|
|
if (ret && !rt_mutex_owner(lock)) {
|
|
|
|
/*
|
|
|
|
* Reset the return value. We might have
|
|
|
|
* returned with -EDEADLK and the owner
|
|
|
|
* released the lock while we were walking the
|
|
|
|
* pi chain. Let the waiter sort it out.
|
|
|
|
*/
|
|
|
|
ret = 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rt_mutex_start_proxy_lock() - Start lock acquisition for another task
|
|
|
|
* @lock: the rt_mutex to take
|
|
|
|
* @waiter: the pre-initialized rt_mutex_waiter
|
|
|
|
* @task: the task to prepare
|
|
|
|
*
|
|
|
|
* Starts the rt_mutex acquire; it enqueues the @waiter and does deadlock
|
|
|
|
* detection. It does not wait, see rt_mutex_wait_proxy_lock() for that.
|
|
|
|
*
|
|
|
|
* NOTE: unlike __rt_mutex_start_proxy_lock this _DOES_ remove the @waiter
|
|
|
|
* on failure.
|
|
|
|
*
|
|
|
|
* Returns:
|
|
|
|
* 0 - task blocked on lock
|
|
|
|
* 1 - acquired the lock for task, caller should wake it up
|
|
|
|
* <0 - error
|
|
|
|
*
|
|
|
|
* Special API call for PI-futex support.
|
|
|
|
*/
|
2021-08-16 05:27:58 +08:00
|
|
|
int __sched rt_mutex_start_proxy_lock(struct rt_mutex_base *lock,
|
2021-08-16 05:27:57 +08:00
|
|
|
struct rt_mutex_waiter *waiter,
|
|
|
|
struct task_struct *task)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
raw_spin_lock_irq(&lock->wait_lock);
|
|
|
|
ret = __rt_mutex_start_proxy_lock(lock, waiter, task);
|
|
|
|
if (unlikely(ret))
|
|
|
|
remove_waiter(lock, waiter);
|
|
|
|
raw_spin_unlock_irq(&lock->wait_lock);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rt_mutex_wait_proxy_lock() - Wait for lock acquisition
|
|
|
|
* @lock: the rt_mutex we were woken on
|
|
|
|
* @to: the timeout, null if none. hrtimer should already have
|
|
|
|
* been started.
|
|
|
|
* @waiter: the pre-initialized rt_mutex_waiter
|
|
|
|
*
|
|
|
|
* Wait for the lock acquisition started on our behalf by
|
|
|
|
* rt_mutex_start_proxy_lock(). Upon failure, the caller must call
|
|
|
|
* rt_mutex_cleanup_proxy_lock().
|
|
|
|
*
|
|
|
|
* Returns:
|
|
|
|
* 0 - success
|
|
|
|
* <0 - error, one of -EINTR, -ETIMEDOUT
|
|
|
|
*
|
|
|
|
* Special API call for PI-futex support
|
|
|
|
*/
|
2021-08-16 05:27:58 +08:00
|
|
|
int __sched rt_mutex_wait_proxy_lock(struct rt_mutex_base *lock,
|
2021-08-16 05:27:57 +08:00
|
|
|
struct hrtimer_sleeper *to,
|
|
|
|
struct rt_mutex_waiter *waiter)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
raw_spin_lock_irq(&lock->wait_lock);
|
|
|
|
/* sleep on the mutex */
|
|
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
2021-08-16 05:28:58 +08:00
|
|
|
ret = rt_mutex_slowlock_block(lock, NULL, TASK_INTERRUPTIBLE, to, waiter);
|
2021-08-16 05:27:57 +08:00
|
|
|
/*
|
|
|
|
* try_to_take_rt_mutex() sets the waiter bit unconditionally. We might
|
|
|
|
* have to fix that up.
|
|
|
|
*/
|
|
|
|
fixup_rt_mutex_waiters(lock);
|
|
|
|
raw_spin_unlock_irq(&lock->wait_lock);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* rt_mutex_cleanup_proxy_lock() - Cleanup failed lock acquisition
|
|
|
|
* @lock: the rt_mutex we were woken on
|
|
|
|
* @waiter: the pre-initialized rt_mutex_waiter
|
|
|
|
*
|
|
|
|
* Attempt to clean up after a failed __rt_mutex_start_proxy_lock() or
|
|
|
|
* rt_mutex_wait_proxy_lock().
|
|
|
|
*
|
|
|
|
* Unless we acquired the lock; we're still enqueued on the wait-list and can
|
|
|
|
* in fact still be granted ownership until we're removed. Therefore we can
|
|
|
|
* find we are in fact the owner and must disregard the
|
|
|
|
* rt_mutex_wait_proxy_lock() failure.
|
|
|
|
*
|
|
|
|
* Returns:
|
|
|
|
* true - did the cleanup, we done.
|
|
|
|
* false - we acquired the lock after rt_mutex_wait_proxy_lock() returned,
|
|
|
|
* caller should disregards its return value.
|
|
|
|
*
|
|
|
|
* Special API call for PI-futex support
|
|
|
|
*/
|
2021-08-16 05:27:58 +08:00
|
|
|
bool __sched rt_mutex_cleanup_proxy_lock(struct rt_mutex_base *lock,
|
2021-08-16 05:27:57 +08:00
|
|
|
struct rt_mutex_waiter *waiter)
|
|
|
|
{
|
|
|
|
bool cleanup = false;
|
|
|
|
|
|
|
|
raw_spin_lock_irq(&lock->wait_lock);
|
|
|
|
/*
|
|
|
|
* Do an unconditional try-lock, this deals with the lock stealing
|
|
|
|
* state where __rt_mutex_futex_unlock() -> mark_wakeup_next_waiter()
|
|
|
|
* sets a NULL owner.
|
|
|
|
*
|
|
|
|
* We're not interested in the return value, because the subsequent
|
|
|
|
* test on rt_mutex_owner() will infer that. If the trylock succeeded,
|
|
|
|
* we will own the lock and it will have removed the waiter. If we
|
|
|
|
* failed the trylock, we're still not owner and we need to remove
|
|
|
|
* ourselves.
|
|
|
|
*/
|
|
|
|
try_to_take_rt_mutex(lock, current, waiter);
|
|
|
|
/*
|
|
|
|
* Unless we're the owner; we're still enqueued on the wait_list.
|
|
|
|
* So check if we became owner, if not, take us off the wait_list.
|
|
|
|
*/
|
|
|
|
if (rt_mutex_owner(lock) != current) {
|
|
|
|
remove_waiter(lock, waiter);
|
|
|
|
cleanup = true;
|
|
|
|
}
|
|
|
|
/*
|
|
|
|
* try_to_take_rt_mutex() sets the waiter bit unconditionally. We might
|
|
|
|
* have to fix that up.
|
|
|
|
*/
|
|
|
|
fixup_rt_mutex_waiters(lock);
|
|
|
|
|
|
|
|
raw_spin_unlock_irq(&lock->wait_lock);
|
|
|
|
|
|
|
|
return cleanup;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Recheck the pi chain, in case we got a priority setting
|
|
|
|
*
|
|
|
|
* Called from sched_setscheduler
|
|
|
|
*/
|
|
|
|
void __sched rt_mutex_adjust_pi(struct task_struct *task)
|
|
|
|
{
|
|
|
|
struct rt_mutex_waiter *waiter;
|
2021-08-16 05:27:58 +08:00
|
|
|
struct rt_mutex_base *next_lock;
|
2021-08-16 05:27:57 +08:00
|
|
|
unsigned long flags;
|
|
|
|
|
|
|
|
raw_spin_lock_irqsave(&task->pi_lock, flags);
|
|
|
|
|
|
|
|
waiter = task->pi_blocked_on;
|
|
|
|
if (!waiter || rt_mutex_waiter_equal(waiter, task_to_waiter(task))) {
|
|
|
|
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
next_lock = waiter->lock;
|
|
|
|
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
|
|
|
|
|
|
|
|
/* gets dropped in rt_mutex_adjust_prio_chain()! */
|
|
|
|
get_task_struct(task);
|
|
|
|
|
|
|
|
rt_mutex_adjust_prio_chain(task, RT_MUTEX_MIN_CHAINWALK, NULL,
|
|
|
|
next_lock, NULL, task);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Performs the wakeup of the top-waiter and re-enables preemption.
|
|
|
|
*/
|
2021-08-16 05:28:09 +08:00
|
|
|
void __sched rt_mutex_postunlock(struct rt_wake_q_head *wqh)
|
2021-08-16 05:27:57 +08:00
|
|
|
{
|
2021-08-16 05:28:09 +08:00
|
|
|
rt_mutex_wake_up_q(wqh);
|
2021-08-16 05:27:57 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
#ifdef CONFIG_DEBUG_RT_MUTEXES
|
|
|
|
void rt_mutex_debug_task_free(struct task_struct *task)
|
|
|
|
{
|
|
|
|
DEBUG_LOCKS_WARN_ON(!RB_EMPTY_ROOT(&task->pi_waiters.rb_root));
|
|
|
|
DEBUG_LOCKS_WARN_ON(task->pi_blocked_on);
|
|
|
|
}
|
|
|
|
#endif
|
2021-08-16 05:29:01 +08:00
|
|
|
|
|
|
|
#ifdef CONFIG_PREEMPT_RT
|
|
|
|
/* 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_wait(&mutex->dep_map, name, key, 0, LD_WAIT_SLEEP);
|
|
|
|
}
|
|
|
|
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 */
|