[linux.git] / kernel / rtmutex_common.h

/*
 * 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 <[email protected]>
 *  Copyright (C) 2006, Timesys Corp., Thomas Gleixner <[email protected]>
 *
 * 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;
	struct pid		*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_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);
}

/*
 * 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,
				     int detect_deadlock);
extern int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
				      struct hrtimer_sleeper *to,
				      struct rt_mutex_waiter *waiter,
				      int detect_deadlock);

#ifdef CONFIG_DEBUG_RT_MUTEXES
# include "rtmutex-debug.h"
#else
# include "rtmutex.h"
#endif

#endif
Commit	Line	Data
23f78d4a IM	1	/*
	2	* RT Mutexes: blocking mutual exclusion locks with PI support
	3	*
	4	* started by Ingo Molnar and Thomas Gleixner:
	5	*
	6	* Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <[email protected]>
	7	* Copyright (C) 2006, Timesys Corp., Thomas Gleixner <[email protected]>
	8	*
	9	* This file contains the private data structure and API definitions.
	10	*/
	11
	12	#ifndef __KERNEL_RTMUTEX_COMMON_H
	13	#define __KERNEL_RTMUTEX_COMMON_H
	14
	15	#include <linux/rtmutex.h>
	16
61a87122 TG	17	/*
	18	* The rtmutex in kernel tester is independent of rtmutex debugging. We
	19	* call schedule_rt_mutex_test() instead of schedule() for the tasks which
	20	* belong to the tester. That way we can delay the wakeup path of those
	21	* threads to provoke lock stealing and testing of complex boosting scenarios.
	22	*/
	23	#ifdef CONFIG_RT_MUTEX_TESTER
	24
	25	extern void schedule_rt_mutex_test(struct rt_mutex *lock);
	26
	27	#define schedule_rt_mutex(_lock) \
	28	do { \
	29	if (!(current->flags & PF_MUTEX_TESTER)) \
	30	schedule(); \
	31	else \
	32	schedule_rt_mutex_test(_lock); \
	33	} while (0)
	34
	35	#else
	36	# define schedule_rt_mutex(_lock) schedule()
	37	#endif
	38
23f78d4a IM	39	/*
	40	* This is the control structure for tasks blocked on a rt_mutex,
	41	* which is allocated on the kernel stack on of the blocked task.
	42	*
	43	* @list_entry: pi node to enqueue into the mutex waiters list
	44	* @pi_list_entry: pi node to enqueue into the mutex owner waiters list
	45	* @task: task reference to the blocked task
	46	*/
	47	struct rt_mutex_waiter {
	48	struct plist_node list_entry;
	49	struct plist_node pi_list_entry;
	50	struct task_struct *task;
	51	struct rt_mutex *lock;
	52	#ifdef CONFIG_DEBUG_RT_MUTEXES
	53	unsigned long ip;
48d13e48	54	struct pid *deadlock_task_pid;
23f78d4a IM	55	struct rt_mutex *deadlock_lock;
	56	#endif
	57	};
	58
	59	/*
	60	* Various helpers to access the waiters-plist:
	61	*/
	62	static inline int rt_mutex_has_waiters(struct rt_mutex *lock)
	63	{
	64	return !plist_head_empty(&lock->wait_list);
	65	}
	66
	67	static inline struct rt_mutex_waiter *
	68	rt_mutex_top_waiter(struct rt_mutex *lock)
	69	{
	70	struct rt_mutex_waiter *w;
	71
	72	w = plist_first_entry(&lock->wait_list, struct rt_mutex_waiter,
	73	list_entry);
	74	BUG_ON(w->lock != lock);
	75
	76	return w;
	77	}
	78
	79	static inline int task_has_pi_waiters(struct task_struct *p)
	80	{
	81	return !plist_head_empty(&p->pi_waiters);
	82	}
	83
	84	static inline struct rt_mutex_waiter *
	85	task_top_pi_waiter(struct task_struct *p)
	86	{
	87	return plist_first_entry(&p->pi_waiters, struct rt_mutex_waiter,
	88	pi_list_entry);
	89	}
	90
	91	/*
	92	* lock->owner state tracking:
	93	*/
8161239a LJ	94	#define RT_MUTEX_HAS_WAITERS 1UL
8161239a LJ	95	#define RT_MUTEX_OWNER_MASKALL 1UL
23f78d4a IM	96
	97	static inline struct task_struct rt_mutex_owner(struct rt_mutex lock)
	98	{
	99	return (struct task_struct *)
	100	((unsigned long)lock->owner & ~RT_MUTEX_OWNER_MASKALL);
	101	}
	102
c87e2837 IM	103	/*
	104	* PI-futex support (proxy locking functions, etc.):
	105	*/
	106	extern struct task_struct rt_mutex_next_owner(struct rt_mutex lock);
	107	extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
	108	struct task_struct *proxy_owner);
	109	extern void rt_mutex_proxy_unlock(struct rt_mutex *lock,
	110	struct task_struct *proxy_owner);
8dac456a DH	111	extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
	112	struct rt_mutex_waiter *waiter,
	113	struct task_struct *task,
	114	int detect_deadlock);
	115	extern int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
	116	struct hrtimer_sleeper *to,
	117	struct rt_mutex_waiter *waiter,
	118	int detect_deadlock);
36cf3b5c TG	119
	120	#ifdef CONFIG_DEBUG_RT_MUTEXES
	121	# include "rtmutex-debug.h"
	122	#else
	123	# include "rtmutex.h"
	124	#endif
	125
23f78d4a	126	#endif