/* * 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> /* * 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){	unsigned long owner = (unsigned long) READ_ONCE(lock->owner); 	return (struct task_struct *) (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);extern bool rt_mutex_futex_unlock(struct rt_mutex *lock,				  struct wake_q_head *wqh);extern void rt_mutex_adjust_prio(struct task_struct *task); #ifdef CONFIG_DEBUG_RT_MUTEXES# include "rtmutex-debug.h"#else# include "rtmutex.h"#endif #endif