/* * 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. * * @list_entry:		pi node to enqueue into the mutex waiters list * @pi_list_entry:	pi node to enqueue into the mutex owner waiters list * @task:		task reference to the blocked task */struct rt_mutex_waiter {	struct plist_node	list_entry;	struct plist_node	pi_list_entry;	struct task_struct	*task;	struct rt_mutex		*lock;#ifdef CONFIG_DEBUG_RT_MUTEXES	unsigned long		ip;	pid_t			deadlock_task_pid;	struct rt_mutex		*deadlock_lock;#endif}; /* * Various helpers to access the waiters-plist: */static inline int rt_mutex_has_waiters(struct rt_mutex *lock){	return !plist_head_empty(&lock->wait_list);} static inline struct rt_mutex_waiter *rt_mutex_top_waiter(struct rt_mutex *lock){	struct rt_mutex_waiter *w; 	w = plist_first_entry(&lock->wait_list, struct rt_mutex_waiter,			       list_entry);	BUG_ON(w->lock != lock); 	return w;} static inline int task_has_pi_waiters(struct task_struct *p){	return !plist_head_empty(&p->pi_waiters);} static inline struct rt_mutex_waiter *task_top_pi_waiter(struct task_struct *p){	return plist_first_entry(&p->pi_waiters, struct rt_mutex_waiter,				  pi_list_entry);} /* * lock->owner state tracking: */#define RT_MUTEX_OWNER_PENDING	1UL#define RT_MUTEX_HAS_WAITERS	2UL#define RT_MUTEX_OWNER_MASKALL	3UL static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock){	return (struct task_struct *)		((unsigned long)lock->owner & ~RT_MUTEX_OWNER_MASKALL);} static inline struct task_struct *rt_mutex_real_owner(struct rt_mutex *lock){ 	return (struct task_struct *)		((unsigned long)lock->owner & ~RT_MUTEX_HAS_WAITERS);} static inline unsigned long rt_mutex_owner_pending(struct rt_mutex *lock){	return (unsigned long)lock->owner & RT_MUTEX_OWNER_PENDING;} /* * We can speed up the acquire/release, if the architecture * supports cmpxchg and if there's no debugging state to be set up */#if defined(__HAVE_ARCH_CMPXCHG) && !defined(CONFIG_DEBUG_RT_MUTEXES)# define rt_mutex_cmpxchg(l,c,n)	(cmpxchg(&l->owner, c, n) == c)static inline void mark_rt_mutex_waiters(struct rt_mutex *lock){	unsigned long owner, *p = (unsigned long *) &lock->owner; 	do {		owner = *p;	} while (cmpxchg(p, owner, owner | RT_MUTEX_HAS_WAITERS) != owner);}#else# define rt_mutex_cmpxchg(l,c,n)	(0)static inline void mark_rt_mutex_waiters(struct rt_mutex *lock){	lock->owner = (struct task_struct *)			((unsigned long)lock->owner | RT_MUTEX_HAS_WAITERS);}#endif /* * 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 void rt_mutex_set_owner(struct rt_mutex *lock, struct task_struct *owner,			       unsigned long mask);extern void __rt_mutex_adjust_prio(struct task_struct *task);extern int rt_mutex_adjust_prio_chain(struct task_struct *task,				      int deadlock_detect,				      struct rt_mutex *orig_lock,				      struct rt_mutex_waiter *orig_waiter,				      struct task_struct *top_task);extern void remove_waiter(struct rt_mutex *lock,			  struct rt_mutex_waiter *waiter);#endif