[patch RT 2/4] rtmutex: Provide rt_mutex_lock_state()

Thomas Gleixner
2017-04-01T11:31:57Z

[-- Attachment #1: rtmutex-Provide-rt_mutex_lock_state-.patch --]
[-- Type: text/plain, Size: 3009 bytes --]

Allow rtmutex to be locked with arbitrary states. Preparatory patch for the
rt rwsem rework.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
include/linux/rtmutex.h | 1 +
kernel/locking/rtmutex.c | 44 +++++++++++++++++++++++++-------------------
2 files changed, 26 insertions(+), 19 deletions(-)

--- a/include/linux/rtmutex.h
+++ b/include/linux/rtmutex.h
@@ -105,6 +105,7 @@ extern void __rt_mutex_init(struct rt_mu
extern void rt_mutex_destroy(struct rt_mutex *lock);

extern void rt_mutex_lock(struct rt_mutex *lock);
+extern int rt_mutex_lock_state(struct rt_mutex *lock, int state);
extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
extern int rt_mutex_lock_killable(struct rt_mutex *lock);
extern int rt_mutex_timed_lock(struct rt_mutex *lock,
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -2011,21 +2011,32 @@ rt_mutex_fastunlock(struct rt_mutex *loc
}

/**
+ * rt_mutex_lock_state - lock a rt_mutex with a given state
+ *
+ * @lock: The rt_mutex to be locked
+ * @state: The state to set when blocking on the rt_mutex
+ */
+int __sched rt_mutex_lock_state(struct rt_mutex *lock, int state)
+{
+ might_sleep();
+
+ return rt_mutex_fastlock(lock, state, NULL, rt_mutex_slowlock);
+}
+
+/**
* rt_mutex_lock - lock a rt_mutex
*
* @lock: the rt_mutex to be locked
*/
void __sched rt_mutex_lock(struct rt_mutex *lock)
{
- might_sleep();
-
- rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, NULL, rt_mutex_slowlock);
+ rt_mutex_lock_state(lock, TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock);

/**
* rt_mutex_lock_interruptible - lock a rt_mutex interruptible
- *
+ **
* @lock: the rt_mutex to be locked
*
* Returns:
@@ -2034,20 +2045,10 @@ EXPORT_SYMBOL_GPL(rt_mutex_lock);
*/
int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock)
{
- might_sleep();
-
- return rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, NULL, rt_mutex_slowlock);
+ return rt_mutex_lock_state(lock, TASK_INTERRUPTIBLE);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);

-/*
- * Futex variant, must not use fastpath.
- */
-int __sched rt_mutex_futex_trylock(struct rt_mutex *lock)
-{
- return rt_mutex_slowtrylock(lock);
-}
-
/**
* rt_mutex_lock_killable - lock a rt_mutex killable
*
@@ -2057,16 +2058,21 @@ int __sched rt_mutex_futex_trylock(struc
* Returns:
* 0 on success
* -EINTR when interrupted by a signal
- * -EDEADLK when the lock would deadlock (when deadlock detection is on)
*/
int __sched rt_mutex_lock_killable(struct rt_mutex *lock)
{
- might_sleep();
-
- return rt_mutex_fastlock(lock, TASK_KILLABLE, NULL, rt_mutex_slowlock);
+ return rt_mutex_lock_state(lock, TASK_KILLABLE);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock_killable);

+/*
+ * Futex variant, must not use fastpath.
+ */
+int __sched rt_mutex_futex_trylock(struct rt_mutex *lock)
+{
+ return rt_mutex_slowtrylock(lock);
+}
+
/**
* rt_mutex_timed_lock - lock a rt_mutex interruptible
* the timeout structure is provided