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Diffstat (limited to 'kernel/locking/rtmutex_common.h')
-rw-r--r-- | kernel/locking/rtmutex_common.h | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/kernel/locking/rtmutex_common.h b/kernel/locking/rtmutex_common.h new file mode 100644 index 000000000..855212501 --- /dev/null +++ b/kernel/locking/rtmutex_common.h @@ -0,0 +1,141 @@ +/* + * RT Mutexes: blocking mutual exclusion locks with PI support + * + * started by Ingo Molnar and Thomas Gleixner: + * + * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> + * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com> + * + * This file contains the private data structure and API definitions. + */ + +#ifndef __KERNEL_RTMUTEX_COMMON_H +#define __KERNEL_RTMUTEX_COMMON_H + +#include <linux/rtmutex.h> + +/* + * The rtmutex in kernel tester is independent of rtmutex debugging. We + * call schedule_rt_mutex_test() instead of schedule() for the tasks which + * belong to the tester. That way we can delay the wakeup path of those + * threads to provoke lock stealing and testing of complex boosting scenarios. + */ +#ifdef CONFIG_RT_MUTEX_TESTER + +extern void schedule_rt_mutex_test(struct rt_mutex *lock); + +#define schedule_rt_mutex(_lock) \ + do { \ + if (!(current->flags & PF_MUTEX_TESTER)) \ + schedule(); \ + else \ + schedule_rt_mutex_test(_lock); \ + } while (0) + +#else +# define schedule_rt_mutex(_lock) schedule() +#endif + +/* + * This is the control structure for tasks blocked on a rt_mutex, + * which is allocated on the kernel stack on of the blocked task. + * + * @tree_entry: pi node to enqueue into the mutex waiters tree + * @pi_tree_entry: pi node to enqueue into the mutex owner waiters tree + * @task: task reference to the blocked task + */ +struct rt_mutex_waiter { + struct rb_node tree_entry; + struct rb_node pi_tree_entry; + struct task_struct *task; + struct rt_mutex *lock; +#ifdef CONFIG_DEBUG_RT_MUTEXES + unsigned long ip; + struct pid *deadlock_task_pid; + struct rt_mutex *deadlock_lock; +#endif + int prio; +}; + +/* + * Various helpers to access the waiters-tree: + */ +static inline int rt_mutex_has_waiters(struct rt_mutex *lock) +{ + return !RB_EMPTY_ROOT(&lock->waiters); +} + +static inline struct rt_mutex_waiter * +rt_mutex_top_waiter(struct rt_mutex *lock) +{ + struct rt_mutex_waiter *w; + + w = rb_entry(lock->waiters_leftmost, struct rt_mutex_waiter, + tree_entry); + BUG_ON(w->lock != lock); + + return w; +} + +static inline int task_has_pi_waiters(struct task_struct *p) +{ + return !RB_EMPTY_ROOT(&p->pi_waiters); +} + +static inline struct rt_mutex_waiter * +task_top_pi_waiter(struct task_struct *p) +{ + return rb_entry(p->pi_waiters_leftmost, struct rt_mutex_waiter, + pi_tree_entry); +} + +/* + * lock->owner state tracking: + */ +#define RT_MUTEX_HAS_WAITERS 1UL +#define RT_MUTEX_OWNER_MASKALL 1UL + +static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock) +{ + return (struct task_struct *) + ((unsigned long)lock->owner & ~RT_MUTEX_OWNER_MASKALL); +} + +/* + * Constants for rt mutex functions which have a selectable deadlock + * detection. + * + * RT_MUTEX_MIN_CHAINWALK: Stops the lock chain walk when there are + * no further PI adjustments to be made. + * + * RT_MUTEX_FULL_CHAINWALK: Invoke deadlock detection with a full + * walk of the lock chain. + */ +enum rtmutex_chainwalk { + RT_MUTEX_MIN_CHAINWALK, + RT_MUTEX_FULL_CHAINWALK, +}; + +/* + * PI-futex support (proxy locking functions, etc.): + */ +extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock); +extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock, + struct task_struct *proxy_owner); +extern void rt_mutex_proxy_unlock(struct rt_mutex *lock, + struct task_struct *proxy_owner); +extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock, + struct rt_mutex_waiter *waiter, + struct task_struct *task); +extern int rt_mutex_finish_proxy_lock(struct rt_mutex *lock, + struct hrtimer_sleeper *to, + struct rt_mutex_waiter *waiter); +extern int rt_mutex_timed_futex_lock(struct rt_mutex *l, struct hrtimer_sleeper *to); + +#ifdef CONFIG_DEBUG_RT_MUTEXES +# include "rtmutex-debug.h" +#else +# include "rtmutex.h" +#endif + +#endif |