[linux-2.6-block.git] / include / linux / lockdep.h

/*
 * Runtime locking correctness validator
 *
 *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
 *
 * see Documentation/lockdep-design.txt for more details.
 */
#ifndef __LINUX_LOCKDEP_H
#define __LINUX_LOCKDEP_H

struct task_struct;
struct lockdep_map;

#ifdef CONFIG_LOCKDEP

#include <linux/linkage.h>
#include <linux/list.h>
#include <linux/debug_locks.h>
#include <linux/stacktrace.h>

/*
 * Lock-class usage-state bits:
 */
enum lock_usage_bit
{
	LOCK_USED = 0,
	LOCK_USED_IN_HARDIRQ,
	LOCK_USED_IN_SOFTIRQ,
	LOCK_ENABLED_SOFTIRQS,
	LOCK_ENABLED_HARDIRQS,
	LOCK_USED_IN_HARDIRQ_READ,
	LOCK_USED_IN_SOFTIRQ_READ,
	LOCK_ENABLED_SOFTIRQS_READ,
	LOCK_ENABLED_HARDIRQS_READ,
	LOCK_USAGE_STATES
};

/*
 * Usage-state bitmasks:
 */
#define LOCKF_USED			(1 << LOCK_USED)
#define LOCKF_USED_IN_HARDIRQ		(1 << LOCK_USED_IN_HARDIRQ)
#define LOCKF_USED_IN_SOFTIRQ		(1 << LOCK_USED_IN_SOFTIRQ)
#define LOCKF_ENABLED_HARDIRQS		(1 << LOCK_ENABLED_HARDIRQS)
#define LOCKF_ENABLED_SOFTIRQS		(1 << LOCK_ENABLED_SOFTIRQS)

#define LOCKF_ENABLED_IRQS (LOCKF_ENABLED_HARDIRQS | LOCKF_ENABLED_SOFTIRQS)
#define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ)

#define LOCKF_USED_IN_HARDIRQ_READ	(1 << LOCK_USED_IN_HARDIRQ_READ)
#define LOCKF_USED_IN_SOFTIRQ_READ	(1 << LOCK_USED_IN_SOFTIRQ_READ)
#define LOCKF_ENABLED_HARDIRQS_READ	(1 << LOCK_ENABLED_HARDIRQS_READ)
#define LOCKF_ENABLED_SOFTIRQS_READ	(1 << LOCK_ENABLED_SOFTIRQS_READ)

#define LOCKF_ENABLED_IRQS_READ \
		(LOCKF_ENABLED_HARDIRQS_READ | LOCKF_ENABLED_SOFTIRQS_READ)
#define LOCKF_USED_IN_IRQ_READ \
		(LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)

#define MAX_LOCKDEP_SUBCLASSES		8UL

/*
 * Lock-classes are keyed via unique addresses, by embedding the
 * lockclass-key into the kernel (or module) .data section. (For
 * static locks we use the lock address itself as the key.)
 */
struct lockdep_subclass_key {
	char __one_byte;
} __attribute__ ((__packed__));

struct lock_class_key {
	struct lockdep_subclass_key	subkeys[MAX_LOCKDEP_SUBCLASSES];
};

/*
 * The lock-class itself:
 */
struct lock_class {
	/*
	 * class-hash:
	 */
	struct list_head		hash_entry;

	/*
	 * global list of all lock-classes:
	 */
	struct list_head		lock_entry;

	struct lockdep_subclass_key	*key;
	unsigned int			subclass;

	/*
	 * IRQ/softirq usage tracking bits:
	 */
	unsigned long			usage_mask;
	struct stack_trace		usage_traces[LOCK_USAGE_STATES];

	/*
	 * These fields represent a directed graph of lock dependencies,
	 * to every node we attach a list of "forward" and a list of
	 * "backward" graph nodes.
	 */
	struct list_head		locks_after, locks_before;

	/*
	 * Generation counter, when doing certain classes of graph walking,
	 * to ensure that we check one node only once:
	 */
	unsigned int			version;

	/*
	 * Statistics counter:
	 */
	unsigned long			ops;

	const char			*name;
	int				name_version;

#ifdef CONFIG_LOCK_STAT
	unsigned long			contention_point[4];
#endif
};

#ifdef CONFIG_LOCK_STAT
struct lock_time {
	s64				min;
	s64				max;
	s64				total;
	unsigned long			nr;
};

enum bounce_type {
	bounce_acquired_write,
	bounce_acquired_read,
	bounce_contended_write,
	bounce_contended_read,
	nr_bounce_types,

	bounce_acquired = bounce_acquired_write,
	bounce_contended = bounce_contended_write,
};

struct lock_class_stats {
	unsigned long			contention_point[4];
	struct lock_time		read_waittime;
	struct lock_time		write_waittime;
	struct lock_time		read_holdtime;
	struct lock_time		write_holdtime;
	unsigned long			bounces[nr_bounce_types];
};

struct lock_class_stats lock_stats(struct lock_class *class);
void clear_lock_stats(struct lock_class *class);
#endif

/*
 * Map the lock object (the lock instance) to the lock-class object.
 * This is embedded into specific lock instances:
 */
struct lockdep_map {
	struct lock_class_key		*key;
	struct lock_class		*class_cache;
	const char			*name;
#ifdef CONFIG_LOCK_STAT
	int				cpu;
#endif
};

/*
 * Every lock has a list of other locks that were taken after it.
 * We only grow the list, never remove from it:
 */
struct lock_list {
	struct list_head		entry;
	struct lock_class		*class;
	struct stack_trace		trace;
	int				distance;
};

/*
 * We record lock dependency chains, so that we can cache them:
 */
struct lock_chain {
	struct list_head		entry;
	u64				chain_key;
};

struct held_lock {
	/*
	 * One-way hash of the dependency chain up to this point. We
	 * hash the hashes step by step as the dependency chain grows.
	 *
	 * We use it for dependency-caching and we skip detection
	 * passes and dependency-updates if there is a cache-hit, so
	 * it is absolutely critical for 100% coverage of the validator
	 * to have a unique key value for every unique dependency path
	 * that can occur in the system, to make a unique hash value
	 * as likely as possible - hence the 64-bit width.
	 *
	 * The task struct holds the current hash value (initialized
	 * with zero), here we store the previous hash value:
	 */
	u64				prev_chain_key;
	struct lock_class		*class;
	unsigned long			acquire_ip;
	struct lockdep_map		*instance;

#ifdef CONFIG_LOCK_STAT
	u64 				waittime_stamp;
	u64				holdtime_stamp;
#endif
	/*
	 * The lock-stack is unified in that the lock chains of interrupt
	 * contexts nest ontop of process context chains, but we 'separate'
	 * the hashes by starting with 0 if we cross into an interrupt
	 * context, and we also keep do not add cross-context lock
	 * dependencies - the lock usage graph walking covers that area
	 * anyway, and we'd just unnecessarily increase the number of
	 * dependencies otherwise. [Note: hardirq and softirq contexts
	 * are separated from each other too.]
	 *
	 * The following field is used to detect when we cross into an
	 * interrupt context:
	 */
	int				irq_context;
	int				trylock;
	int				read;
	int				check;
	int				hardirqs_off;
};

/*
 * Initialization, self-test and debugging-output methods:
 */
extern void lockdep_init(void);
extern void lockdep_info(void);
extern void lockdep_reset(void);
extern void lockdep_reset_lock(struct lockdep_map *lock);
extern void lockdep_free_key_range(void *start, unsigned long size);

extern void lockdep_off(void);
extern void lockdep_on(void);

/*
 * These methods are used by specific locking variants (spinlocks,
 * rwlocks, mutexes and rwsems) to pass init/acquire/release events
 * to lockdep:
 */

extern void lockdep_init_map(struct lockdep_map *lock, const char *name,
			     struct lock_class_key *key, int subclass);

/*
 * Reinitialize a lock key - for cases where there is special locking or
 * special initialization of locks so that the validator gets the scope
 * of dependencies wrong: they are either too broad (they need a class-split)
 * or they are too narrow (they suffer from a false class-split):
 */
#define lockdep_set_class(lock, key) \
		lockdep_init_map(&(lock)->dep_map, #key, key, 0)
#define lockdep_set_class_and_name(lock, key, name) \
		lockdep_init_map(&(lock)->dep_map, name, key, 0)
#define lockdep_set_class_and_subclass(lock, key, sub) \
		lockdep_init_map(&(lock)->dep_map, #key, key, sub)
#define lockdep_set_subclass(lock, sub)	\
		lockdep_init_map(&(lock)->dep_map, #lock, \
				 (lock)->dep_map.key, sub)

/*
 * Acquire a lock.
 *
 * Values for "read":
 *
 *   0: exclusive (write) acquire
 *   1: read-acquire (no recursion allowed)
 *   2: read-acquire with same-instance recursion allowed
 *
 * Values for check:
 *
 *   0: disabled
 *   1: simple checks (freeing, held-at-exit-time, etc.)
 *   2: full validation
 */
extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
			 int trylock, int read, int check, unsigned long ip);

extern void lock_release(struct lockdep_map *lock, int nested,
			 unsigned long ip);

# define INIT_LOCKDEP				.lockdep_recursion = 0,

#define lockdep_depth(tsk)	(debug_locks ? (tsk)->lockdep_depth : 0)

#else /* !LOCKDEP */

static inline void lockdep_off(void)
{
}

static inline void lockdep_on(void)
{
}

# define lock_acquire(l, s, t, r, c, i)		do { } while (0)
# define lock_release(l, n, i)			do { } while (0)
# define lockdep_init()				do { } while (0)
# define lockdep_info()				do { } while (0)
# define lockdep_init_map(lock, name, key, sub)	do { (void)(key); } while (0)
# define lockdep_set_class(lock, key)		do { (void)(key); } while (0)
# define lockdep_set_class_and_name(lock, key, name) \
		do { (void)(key); } while (0)
#define lockdep_set_class_and_subclass(lock, key, sub) \
		do { (void)(key); } while (0)
#define lockdep_set_subclass(lock, sub)		do { } while (0)

# define INIT_LOCKDEP
# define lockdep_reset()		do { debug_locks = 1; } while (0)
# define lockdep_free_key_range(start, size)	do { } while (0)
/*
 * The class key takes no space if lockdep is disabled:
 */
struct lock_class_key { };

#define lockdep_depth(tsk)	(0)

#endif /* !LOCKDEP */

#ifdef CONFIG_LOCK_STAT

extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
extern void lock_acquired(struct lockdep_map *lock);

#define LOCK_CONTENDED(_lock, try, lock)			\
do {								\
	if (!try(_lock)) {					\
		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
		lock(_lock);					\
	}							\
	lock_acquired(&(_lock)->dep_map);			\
} while (0)

#else /* CONFIG_LOCK_STAT */

#define lock_contended(lockdep_map, ip) do {} while (0)
#define lock_acquired(lockdep_map) do {} while (0)

#define LOCK_CONTENDED(_lock, try, lock) \
	lock(_lock)

#endif /* CONFIG_LOCK_STAT */

#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_GENERIC_HARDIRQS)
extern void early_init_irq_lock_class(void);
#else
static inline void early_init_irq_lock_class(void)
{
}
#endif

#ifdef CONFIG_TRACE_IRQFLAGS
extern void early_boot_irqs_off(void);
extern void early_boot_irqs_on(void);
extern void print_irqtrace_events(struct task_struct *curr);
#else
static inline void early_boot_irqs_off(void)
{
}
static inline void early_boot_irqs_on(void)
{
}
static inline void print_irqtrace_events(struct task_struct *curr)
{
}
#endif

/*
 * For trivial one-depth nesting of a lock-class, the following
 * global define can be used. (Subsystems with multiple levels
 * of nesting should define their own lock-nesting subclasses.)
 */
#define SINGLE_DEPTH_NESTING			1

/*
 * Map the dependency ops to NOP or to real lockdep ops, depending
 * on the per lock-class debug mode:
 */

#ifdef CONFIG_DEBUG_LOCK_ALLOC
# ifdef CONFIG_PROVE_LOCKING
#  define spin_acquire(l, s, t, i)		lock_acquire(l, s, t, 0, 2, i)
# else
#  define spin_acquire(l, s, t, i)		lock_acquire(l, s, t, 0, 1, i)
# endif
# define spin_release(l, n, i)			lock_release(l, n, i)
#else
# define spin_acquire(l, s, t, i)		do { } while (0)
# define spin_release(l, n, i)			do { } while (0)
#endif

#ifdef CONFIG_DEBUG_LOCK_ALLOC
# ifdef CONFIG_PROVE_LOCKING
#  define rwlock_acquire(l, s, t, i)		lock_acquire(l, s, t, 0, 2, i)
#  define rwlock_acquire_read(l, s, t, i)	lock_acquire(l, s, t, 2, 2, i)
# else
#  define rwlock_acquire(l, s, t, i)		lock_acquire(l, s, t, 0, 1, i)
#  define rwlock_acquire_read(l, s, t, i)	lock_acquire(l, s, t, 2, 1, i)
# endif
# define rwlock_release(l, n, i)		lock_release(l, n, i)
#else
# define rwlock_acquire(l, s, t, i)		do { } while (0)
# define rwlock_acquire_read(l, s, t, i)	do { } while (0)
# define rwlock_release(l, n, i)		do { } while (0)
#endif

#ifdef CONFIG_DEBUG_LOCK_ALLOC
# ifdef CONFIG_PROVE_LOCKING
#  define mutex_acquire(l, s, t, i)		lock_acquire(l, s, t, 0, 2, i)
# else
#  define mutex_acquire(l, s, t, i)		lock_acquire(l, s, t, 0, 1, i)
# endif
# define mutex_release(l, n, i)			lock_release(l, n, i)
#else
# define mutex_acquire(l, s, t, i)		do { } while (0)
# define mutex_release(l, n, i)			do { } while (0)
#endif

#ifdef CONFIG_DEBUG_LOCK_ALLOC
# ifdef CONFIG_PROVE_LOCKING
#  define rwsem_acquire(l, s, t, i)		lock_acquire(l, s, t, 0, 2, i)
#  define rwsem_acquire_read(l, s, t, i)	lock_acquire(l, s, t, 1, 2, i)
# else
#  define rwsem_acquire(l, s, t, i)		lock_acquire(l, s, t, 0, 1, i)
#  define rwsem_acquire_read(l, s, t, i)	lock_acquire(l, s, t, 1, 1, i)
# endif
# define rwsem_release(l, n, i)			lock_release(l, n, i)
#else
# define rwsem_acquire(l, s, t, i)		do { } while (0)
# define rwsem_acquire_read(l, s, t, i)		do { } while (0)
# define rwsem_release(l, n, i)			do { } while (0)
#endif

#endif /* __LINUX_LOCKDEP_H */
Commit	Line	Data
fbb9ce95 IM	1	/*
	2	* Runtime locking correctness validator
	3	*
4b32d0a4 PZ	4	* Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
4b32d0a4 PZ	5	* Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
fbb9ce95 IM	6	*
	7	* see Documentation/lockdep-design.txt for more details.
	8	*/
	9	#ifndef __LINUX_LOCKDEP_H
	10	#define __LINUX_LOCKDEP_H
	11
a1e96b03	12	struct task_struct;
f20786ff	13	struct lockdep_map;
a1e96b03	14
db0b0ead MT	15	#ifdef CONFIG_LOCKDEP
db0b0ead MT	16
fbb9ce95 IM	17	#include <linux/linkage.h>
	18	#include <linux/list.h>
	19	#include <linux/debug_locks.h>
	20	#include <linux/stacktrace.h>
	21
fbb9ce95 IM	22	/*
	23	* Lock-class usage-state bits:
	24	*/
	25	enum lock_usage_bit
	26	{
	27	LOCK_USED = 0,
	28	LOCK_USED_IN_HARDIRQ,
	29	LOCK_USED_IN_SOFTIRQ,
	30	LOCK_ENABLED_SOFTIRQS,
	31	LOCK_ENABLED_HARDIRQS,
	32	LOCK_USED_IN_HARDIRQ_READ,
	33	LOCK_USED_IN_SOFTIRQ_READ,
	34	LOCK_ENABLED_SOFTIRQS_READ,
	35	LOCK_ENABLED_HARDIRQS_READ,
	36	LOCK_USAGE_STATES
	37	};
	38
	39	/*
	40	* Usage-state bitmasks:
	41	*/
	42	#define LOCKF_USED (1 << LOCK_USED)
	43	#define LOCKF_USED_IN_HARDIRQ (1 << LOCK_USED_IN_HARDIRQ)
	44	#define LOCKF_USED_IN_SOFTIRQ (1 << LOCK_USED_IN_SOFTIRQ)
	45	#define LOCKF_ENABLED_HARDIRQS (1 << LOCK_ENABLED_HARDIRQS)
	46	#define LOCKF_ENABLED_SOFTIRQS (1 << LOCK_ENABLED_SOFTIRQS)
	47
	48	#define LOCKF_ENABLED_IRQS (LOCKF_ENABLED_HARDIRQS \| LOCKF_ENABLED_SOFTIRQS)
	49	#define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ \| LOCKF_USED_IN_SOFTIRQ)
	50
	51	#define LOCKF_USED_IN_HARDIRQ_READ (1 << LOCK_USED_IN_HARDIRQ_READ)
	52	#define LOCKF_USED_IN_SOFTIRQ_READ (1 << LOCK_USED_IN_SOFTIRQ_READ)
	53	#define LOCKF_ENABLED_HARDIRQS_READ (1 << LOCK_ENABLED_HARDIRQS_READ)
	54	#define LOCKF_ENABLED_SOFTIRQS_READ (1 << LOCK_ENABLED_SOFTIRQS_READ)
	55
	56	#define LOCKF_ENABLED_IRQS_READ \
	57	(LOCKF_ENABLED_HARDIRQS_READ \| LOCKF_ENABLED_SOFTIRQS_READ)
	58	#define LOCKF_USED_IN_IRQ_READ \
	59	(LOCKF_USED_IN_HARDIRQ_READ \| LOCKF_USED_IN_SOFTIRQ_READ)
	60
	61	#define MAX_LOCKDEP_SUBCLASSES 8UL
	62
	63	/*
	64	* Lock-classes are keyed via unique addresses, by embedding the
	65	* lockclass-key into the kernel (or module) .data section. (For
	66	* static locks we use the lock address itself as the key.)
	67	*/
	68	struct lockdep_subclass_key {
	69	char __one_byte;
	70	} __attribute__ ((__packed__));
	71
	72	struct lock_class_key {
	73	struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES];
	74	};
	75
	76	/*
	77	* The lock-class itself:
	78	*/
	79	struct lock_class {
	80	/*
	81	* class-hash:
	82	*/
	83	struct list_head hash_entry;
	84
	85	/*
86	* global list of all lock-classes:
87	*/
88	struct list_head lock_entry;
89
90	struct lockdep_subclass_key *key;
91	unsigned int subclass;
92
93	/*
94	* IRQ/softirq usage tracking bits:
95	*/
96	unsigned long usage_mask;
97	struct stack_trace usage_traces[LOCK_USAGE_STATES];
98
99	/*
100	* These fields represent a directed graph of lock dependencies,
101	* to every node we attach a list of "forward" and a list of
102	* "backward" graph nodes.
103	*/
104	struct list_head locks_after, locks_before;
105
106	/*
107	* Generation counter, when doing certain classes of graph walking,
108	* to ensure that we check one node only once:
109	*/
110	unsigned int version;
111
112	/*
113	* Statistics counter:
114	*/
115	unsigned long ops;
116
117	const char *name;
118	int name_version;
f20786ff PZ	119
	120	#ifdef CONFIG_LOCK_STAT
	121	unsigned long contention_point[4];
	122	#endif
	123	};
	124
	125	#ifdef CONFIG_LOCK_STAT
	126	struct lock_time {
	127	s64 min;
	128	s64 max;
	129	s64 total;
	130	unsigned long nr;
fbb9ce95 IM	131	};
fbb9ce95 IM	132
96645678 PZ	133	enum bounce_type {
	134	bounce_acquired_write,
	135	bounce_acquired_read,
	136	bounce_contended_write,
	137	bounce_contended_read,
	138	nr_bounce_types,
	139
	140	bounce_acquired = bounce_acquired_write,
	141	bounce_contended = bounce_contended_write,
	142	};
	143
f20786ff PZ	144	struct lock_class_stats {
	145	unsigned long contention_point[4];
	146	struct lock_time read_waittime;
	147	struct lock_time write_waittime;
	148	struct lock_time read_holdtime;
	149	struct lock_time write_holdtime;
96645678	150	unsigned long bounces[nr_bounce_types];
f20786ff PZ	151	};
	152
	153	struct lock_class_stats lock_stats(struct lock_class *class);
	154	void clear_lock_stats(struct lock_class *class);
	155	#endif
	156
fbb9ce95 IM	157	/*
	158	* Map the lock object (the lock instance) to the lock-class object.
	159	* This is embedded into specific lock instances:
	160	*/
	161	struct lockdep_map {
	162	struct lock_class_key *key;
d6d897ce	163	struct lock_class *class_cache;
fbb9ce95	164	const char *name;
96645678 PZ	165	#ifdef CONFIG_LOCK_STAT
	166	int cpu;
	167	#endif
fbb9ce95 IM	168	};
	169
	170	/*
	171	* Every lock has a list of other locks that were taken after it.
	172	* We only grow the list, never remove from it:
	173	*/
	174	struct lock_list {
	175	struct list_head entry;
	176	struct lock_class *class;
	177	struct stack_trace trace;
068135e6	178	int distance;
fbb9ce95 IM	179	};
	180
	181	/*
	182	* We record lock dependency chains, so that we can cache them:
	183	*/
	184	struct lock_chain {
	185	struct list_head entry;
	186	u64 chain_key;
	187	};
	188
	189	struct held_lock {
	190	/*
	191	* One-way hash of the dependency chain up to this point. We
	192	* hash the hashes step by step as the dependency chain grows.
	193	*
	194	* We use it for dependency-caching and we skip detection
	195	* passes and dependency-updates if there is a cache-hit, so
	196	* it is absolutely critical for 100% coverage of the validator
	197	* to have a unique key value for every unique dependency path
	198	* that can occur in the system, to make a unique hash value
	199	* as likely as possible - hence the 64-bit width.
	200	*
	201	* The task struct holds the current hash value (initialized
	202	* with zero), here we store the previous hash value:
	203	*/
	204	u64 prev_chain_key;
	205	struct lock_class *class;
	206	unsigned long acquire_ip;
	207	struct lockdep_map *instance;
	208
f20786ff PZ	209	#ifdef CONFIG_LOCK_STAT
	210	u64 waittime_stamp;
	211	u64 holdtime_stamp;
	212	#endif
fbb9ce95 IM	213	/*
	214	* The lock-stack is unified in that the lock chains of interrupt
	215	* contexts nest ontop of process context chains, but we 'separate'
	216	* the hashes by starting with 0 if we cross into an interrupt
	217	* context, and we also keep do not add cross-context lock
	218	* dependencies - the lock usage graph walking covers that area
	219	* anyway, and we'd just unnecessarily increase the number of
	220	* dependencies otherwise. [Note: hardirq and softirq contexts
	221	* are separated from each other too.]
	222	*
	223	* The following field is used to detect when we cross into an
	224	* interrupt context:
	225	*/
	226	int irq_context;
	227	int trylock;
	228	int read;
	229	int check;
	230	int hardirqs_off;
	231	};
	232
	233	/*
	234	* Initialization, self-test and debugging-output methods:
	235	*/
	236	extern void lockdep_init(void);
	237	extern void lockdep_info(void);
	238	extern void lockdep_reset(void);
	239	extern void lockdep_reset_lock(struct lockdep_map *lock);
	240	extern void lockdep_free_key_range(void *start, unsigned long size);
	241
	242	extern void lockdep_off(void);
	243	extern void lockdep_on(void);
fbb9ce95 IM	244
	245	/*
	246	* These methods are used by specific locking variants (spinlocks,
	247	* rwlocks, mutexes and rwsems) to pass init/acquire/release events
	248	* to lockdep:
	249	*/
	250
	251	extern void lockdep_init_map(struct lockdep_map lock, const char name,
4dfbb9d8	252	struct lock_class_key *key, int subclass);
fbb9ce95 IM	253
	254	/*
	255	* Reinitialize a lock key - for cases where there is special locking or
	256	* special initialization of locks so that the validator gets the scope
	257	* of dependencies wrong: they are either too broad (they need a class-split)
	258	* or they are too narrow (they suffer from a false class-split):
	259	*/
	260	#define lockdep_set_class(lock, key) \
4dfbb9d8	261	lockdep_init_map(&(lock)->dep_map, #key, key, 0)
fbb9ce95	262	#define lockdep_set_class_and_name(lock, key, name) \
4dfbb9d8 PZ	263	lockdep_init_map(&(lock)->dep_map, name, key, 0)
	264	#define lockdep_set_class_and_subclass(lock, key, sub) \
	265	lockdep_init_map(&(lock)->dep_map, #key, key, sub)
	266	#define lockdep_set_subclass(lock, sub) \
	267	lockdep_init_map(&(lock)->dep_map, #lock, \
	268	(lock)->dep_map.key, sub)
fbb9ce95 IM	269
	270	/*
	271	* Acquire a lock.
	272	*
	273	* Values for "read":
	274	*
	275	* 0: exclusive (write) acquire
	276	* 1: read-acquire (no recursion allowed)
	277	* 2: read-acquire with same-instance recursion allowed
	278	*
	279	* Values for check:
	280	*
	281	* 0: disabled
	282	* 1: simple checks (freeing, held-at-exit-time, etc.)
	283	* 2: full validation
	284	*/
	285	extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
	286	int trylock, int read, int check, unsigned long ip);
	287
	288	extern void lock_release(struct lockdep_map *lock, int nested,
	289	unsigned long ip);
	290
	291	# define INIT_LOCKDEP .lockdep_recursion = 0,
	292
e3a55fd1	293	#define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0)
d5abe669	294
fbb9ce95 IM	295	#else /* !LOCKDEP */
	296
	297	static inline void lockdep_off(void)
	298	{
	299	}
	300
	301	static inline void lockdep_on(void)
	302	{
	303	}
	304
fbb9ce95 IM	305	# define lock_acquire(l, s, t, r, c, i) do { } while (0)
	306	# define lock_release(l, n, i) do { } while (0)
	307	# define lockdep_init() do { } while (0)
	308	# define lockdep_info() do { } while (0)
4dfbb9d8	309	# define lockdep_init_map(lock, name, key, sub) do { (void)(key); } while (0)
fbb9ce95 IM	310	# define lockdep_set_class(lock, key) do { (void)(key); } while (0)
	311	# define lockdep_set_class_and_name(lock, key, name) \
	312	do { (void)(key); } while (0)
4dfbb9d8 PZ	313	#define lockdep_set_class_and_subclass(lock, key, sub) \
4dfbb9d8 PZ	314	do { (void)(key); } while (0)
07646e21 AM	315	#define lockdep_set_subclass(lock, sub) do { } while (0)
07646e21 AM	316
fbb9ce95 IM	317	# define INIT_LOCKDEP
	318	# define lockdep_reset() do { debug_locks = 1; } while (0)
	319	# define lockdep_free_key_range(start, size) do { } while (0)
	320	/*
	321	* The class key takes no space if lockdep is disabled:
	322	*/
	323	struct lock_class_key { };
d5abe669 PZ	324
	325	#define lockdep_depth(tsk) (0)
	326
fbb9ce95 IM	327	#endif /* !LOCKDEP */
fbb9ce95 IM	328
f20786ff PZ	329	#ifdef CONFIG_LOCK_STAT
	330
	331	extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
	332	extern void lock_acquired(struct lockdep_map *lock);
	333
	334	#define LOCK_CONTENDED(_lock, try, lock) \
	335	do { \
	336	if (!try(_lock)) { \
	337	lock_contended(&(_lock)->dep_map, _RET_IP_); \
	338	lock(_lock); \
f20786ff	339	} \
96645678	340	lock_acquired(&(_lock)->dep_map); \
f20786ff PZ	341	} while (0)
	342
	343	#else /* CONFIG_LOCK_STAT */
	344
	345	#define lock_contended(lockdep_map, ip) do {} while (0)
	346	#define lock_acquired(lockdep_map) do {} while (0)
	347
	348	#define LOCK_CONTENDED(_lock, try, lock) \
	349	lock(_lock)
	350
	351	#endif /* CONFIG_LOCK_STAT */
	352
243c7621 IM	353	#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_GENERIC_HARDIRQS)
	354	extern void early_init_irq_lock_class(void);
	355	#else
3117df04 IM	356	static inline void early_init_irq_lock_class(void)
	357	{
	358	}
243c7621 IM	359	#endif
243c7621 IM	360
fbb9ce95 IM	361	#ifdef CONFIG_TRACE_IRQFLAGS
	362	extern void early_boot_irqs_off(void);
	363	extern void early_boot_irqs_on(void);
3117df04	364	extern void print_irqtrace_events(struct task_struct *curr);
fbb9ce95	365	#else
3117df04 IM	366	static inline void early_boot_irqs_off(void)
	367	{
	368	}
	369	static inline void early_boot_irqs_on(void)
	370	{
	371	}
	372	static inline void print_irqtrace_events(struct task_struct *curr)
	373	{
	374	}
fbb9ce95 IM	375	#endif
	376
	377	/*
	378	* For trivial one-depth nesting of a lock-class, the following
	379	* global define can be used. (Subsystems with multiple levels
	380	* of nesting should define their own lock-nesting subclasses.)
	381	*/
	382	#define SINGLE_DEPTH_NESTING 1
	383
	384	/*
	385	* Map the dependency ops to NOP or to real lockdep ops, depending
	386	* on the per lock-class debug mode:
	387	*/
	388
	389	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	390	# ifdef CONFIG_PROVE_LOCKING
	391	# define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i)
	392	# else
	393	# define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i)
	394	# endif
	395	# define spin_release(l, n, i) lock_release(l, n, i)
	396	#else
	397	# define spin_acquire(l, s, t, i) do { } while (0)
	398	# define spin_release(l, n, i) do { } while (0)
	399	#endif
	400
	401	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	402	# ifdef CONFIG_PROVE_LOCKING
	403	# define rwlock_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i)
	404	# define rwlock_acquire_read(l, s, t, i) lock_acquire(l, s, t, 2, 2, i)
	405	# else
	406	# define rwlock_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i)
	407	# define rwlock_acquire_read(l, s, t, i) lock_acquire(l, s, t, 2, 1, i)
	408	# endif
	409	# define rwlock_release(l, n, i) lock_release(l, n, i)
	410	#else
	411	# define rwlock_acquire(l, s, t, i) do { } while (0)
	412	# define rwlock_acquire_read(l, s, t, i) do { } while (0)
	413	# define rwlock_release(l, n, i) do { } while (0)
	414	#endif
	415
	416	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	417	# ifdef CONFIG_PROVE_LOCKING
	418	# define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i)
	419	# else
	420	# define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i)
	421	# endif
	422	# define mutex_release(l, n, i) lock_release(l, n, i)
	423	#else
	424	# define mutex_acquire(l, s, t, i) do { } while (0)
	425	# define mutex_release(l, n, i) do { } while (0)
	426	#endif
	427
	428	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	429	# ifdef CONFIG_PROVE_LOCKING
	430	# define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i)
	431	# define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 2, i)
	432	# else
	433	# define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i)
	434	# define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 1, i)
	435	# endif
	436	# define rwsem_release(l, n, i) lock_release(l, n, i)
	437	#else
	438	# define rwsem_acquire(l, s, t, i) do { } while (0)
439	# define rwsem_acquire_read(l, s, t, i) do { } while (0)
440	# define rwsem_release(l, n, i) do { } while (0)
441	#endif
442
443	#endif /* __LINUX_LOCKDEP_H */