[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;
	unsigned int			dep_gen_id;

	/*
	 * 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 {
	u8				irq_context;
	u8				depth;
	u16				base;
	struct list_head		entry;
	u64				chain_key;
};

#define MAX_LOCKDEP_KEYS_BITS		13
/*
 * Subtract one because we offset hlock->class_idx by 1 in order
 * to make 0 mean no class. This avoids overflowing the class_idx
 * bitfield and hitting the BUG in hlock_class().
 */
#define MAX_LOCKDEP_KEYS		((1UL << MAX_LOCKDEP_KEYS_BITS) - 1)

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;
	unsigned long			acquire_ip;
	struct lockdep_map		*instance;
	struct lockdep_map		*nest_lock;
#ifdef CONFIG_LOCK_STAT
	u64 				waittime_stamp;
	u64				holdtime_stamp;
#endif
	unsigned int			class_idx:MAX_LOCKDEP_KEYS_BITS;
	/*
	 * 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:
	 */
	unsigned int irq_context:2; /* bit 0 - soft, bit 1 - hard */
	unsigned int trylock:1;
	unsigned int read:2;        /* see lock_acquire() comment */
	unsigned int check:2;       /* see lock_acquire() comment */
	unsigned int hardirqs_off:1;
};

/*
 * 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_sys_exit(void);

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);

/*
 * To initialize a lockdep_map statically use this macro.
 * Note that _name must not be NULL.
 */
#define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
	{ .name = (_name), .key = (void *)(_key), }

/*
 * 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,
			 struct lockdep_map *nest_lock, unsigned long ip);

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

extern void lock_set_subclass(struct lockdep_map *lock, unsigned int subclass,
			      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, n, i)	do { } while (0)
# define lock_release(l, n, i)			do { } while (0)
# define lock_set_subclass(l, s, 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)(name); (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); (void)(name); } 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)
# define lockdep_sys_exit() 			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, NULL, i)
#  define spin_acquire_nest(l, s, t, n, i)	lock_acquire(l, s, t, 0, 2, n, i)
# else
#  define spin_acquire(l, s, t, i)		lock_acquire(l, s, t, 0, 1, NULL, i)
#  define spin_acquire_nest(l, s, t, n, i)	lock_acquire(l, s, t, 0, 1, NULL, 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, NULL, i)
#  define rwlock_acquire_read(l, s, t, i)	lock_acquire(l, s, t, 2, 2, NULL, i)
# else
#  define rwlock_acquire(l, s, t, i)		lock_acquire(l, s, t, 0, 1, NULL, i)
#  define rwlock_acquire_read(l, s, t, i)	lock_acquire(l, s, t, 2, 1, NULL, 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, NULL, i)
# else
#  define mutex_acquire(l, s, t, i)		lock_acquire(l, s, t, 0, 1, NULL, 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, NULL, i)
#  define rwsem_acquire_read(l, s, t, i)	lock_acquire(l, s, t, 1, 2, NULL, i)
# else
#  define rwsem_acquire(l, s, t, i)		lock_acquire(l, s, t, 0, 1, NULL, i)
#  define rwsem_acquire_read(l, s, t, i)	lock_acquire(l, s, t, 1, 1, NULL, 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

#ifdef CONFIG_DEBUG_LOCK_ALLOC
# ifdef CONFIG_PROVE_LOCKING
#  define lock_map_acquire(l)		lock_acquire(l, 0, 0, 0, 2, NULL, _THIS_IP_)
# else
#  define lock_map_acquire(l)		lock_acquire(l, 0, 0, 0, 1, NULL, _THIS_IP_)
# endif
# define lock_map_release(l)			lock_release(l, 1, _THIS_IP_)
#else
# define lock_map_acquire(l)			do { } while (0)
# define lock_map_release(l)			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;
419ca3f1	92	unsigned int dep_gen_id;
fbb9ce95 IM	93
	94	/*
	95	* IRQ/softirq usage tracking bits:
	96	*/
	97	unsigned long usage_mask;
	98	struct stack_trace usage_traces[LOCK_USAGE_STATES];
	99
	100	/*
	101	* These fields represent a directed graph of lock dependencies,
	102	* to every node we attach a list of "forward" and a list of
	103	* "backward" graph nodes.
	104	*/
	105	struct list_head locks_after, locks_before;
	106
	107	/*
	108	* Generation counter, when doing certain classes of graph walking,
	109	* to ensure that we check one node only once:
	110	*/
	111	unsigned int version;
	112
	113	/*
	114	* Statistics counter:
	115	*/
	116	unsigned long ops;
	117
	118	const char *name;
	119	int name_version;
f20786ff PZ	120
	121	#ifdef CONFIG_LOCK_STAT
	122	unsigned long contention_point[4];
	123	#endif
	124	};
	125
	126	#ifdef CONFIG_LOCK_STAT
	127	struct lock_time {
	128	s64 min;
	129	s64 max;
	130	s64 total;
	131	unsigned long nr;
fbb9ce95 IM	132	};
fbb9ce95 IM	133
96645678 PZ	134	enum bounce_type {
	135	bounce_acquired_write,
	136	bounce_acquired_read,
	137	bounce_contended_write,
	138	bounce_contended_read,
	139	nr_bounce_types,
	140
	141	bounce_acquired = bounce_acquired_write,
	142	bounce_contended = bounce_contended_write,
	143	};
	144
f20786ff PZ	145	struct lock_class_stats {
	146	unsigned long contention_point[4];
	147	struct lock_time read_waittime;
	148	struct lock_time write_waittime;
	149	struct lock_time read_holdtime;
	150	struct lock_time write_holdtime;
96645678	151	unsigned long bounces[nr_bounce_types];
f20786ff PZ	152	};
	153
	154	struct lock_class_stats lock_stats(struct lock_class *class);
	155	void clear_lock_stats(struct lock_class *class);
	156	#endif
	157
fbb9ce95 IM	158	/*
	159	* Map the lock object (the lock instance) to the lock-class object.
	160	* This is embedded into specific lock instances:
	161	*/
	162	struct lockdep_map {
	163	struct lock_class_key *key;
d6d897ce	164	struct lock_class *class_cache;
fbb9ce95	165	const char *name;
96645678 PZ	166	#ifdef CONFIG_LOCK_STAT
	167	int cpu;
	168	#endif
fbb9ce95 IM	169	};
	170
	171	/*
	172	* Every lock has a list of other locks that were taken after it.
	173	* We only grow the list, never remove from it:
	174	*/
	175	struct lock_list {
	176	struct list_head entry;
	177	struct lock_class *class;
	178	struct stack_trace trace;
068135e6	179	int distance;
fbb9ce95 IM	180	};
	181
	182	/*
	183	* We record lock dependency chains, so that we can cache them:
	184	*/
	185	struct lock_chain {
443cd507 HY	186	u8 irq_context;
	187	u8 depth;
	188	u16 base;
fbb9ce95 IM	189	struct list_head entry;
	190	u64 chain_key;
	191	};
	192
e5f363e3	193	#define MAX_LOCKDEP_KEYS_BITS 13
b42e737e PZ	194	/*
	195	* Subtract one because we offset hlock->class_idx by 1 in order
	196	* to make 0 mean no class. This avoids overflowing the class_idx
	197	* bitfield and hitting the BUG in hlock_class().
	198	*/
	199	#define MAX_LOCKDEP_KEYS ((1UL << MAX_LOCKDEP_KEYS_BITS) - 1)
f82b217e	200
fbb9ce95 IM	201	struct held_lock {
	202	/*
	203	* One-way hash of the dependency chain up to this point. We
	204	* hash the hashes step by step as the dependency chain grows.
	205	*
	206	* We use it for dependency-caching and we skip detection
	207	* passes and dependency-updates if there is a cache-hit, so
	208	* it is absolutely critical for 100% coverage of the validator
	209	* to have a unique key value for every unique dependency path
	210	* that can occur in the system, to make a unique hash value
	211	* as likely as possible - hence the 64-bit width.
	212	*
	213	* The task struct holds the current hash value (initialized
	214	* with zero), here we store the previous hash value:
	215	*/
	216	u64 prev_chain_key;
fbb9ce95 IM	217	unsigned long acquire_ip;
fbb9ce95 IM	218	struct lockdep_map *instance;
7531e2f3	219	struct lockdep_map *nest_lock;
f20786ff PZ	220	#ifdef CONFIG_LOCK_STAT
	221	u64 waittime_stamp;
	222	u64 holdtime_stamp;
	223	#endif
f82b217e	224	unsigned int class_idx:MAX_LOCKDEP_KEYS_BITS;
fbb9ce95 IM	225	/*
	226	* The lock-stack is unified in that the lock chains of interrupt
	227	* contexts nest ontop of process context chains, but we 'separate'
	228	* the hashes by starting with 0 if we cross into an interrupt
	229	* context, and we also keep do not add cross-context lock
	230	* dependencies - the lock usage graph walking covers that area
	231	* anyway, and we'd just unnecessarily increase the number of
	232	* dependencies otherwise. [Note: hardirq and softirq contexts
	233	* are separated from each other too.]
	234	*
	235	* The following field is used to detect when we cross into an
	236	* interrupt context:
	237	*/
f82b217e DJ	238	unsigned int irq_context:2; /* bit 0 - soft, bit 1 - hard */
	239	unsigned int trylock:1;
	240	unsigned int read:2; /* see lock_acquire() comment */
	241	unsigned int check:2; /* see lock_acquire() comment */
	242	unsigned int hardirqs_off:1;
fbb9ce95 IM	243	};
	244
	245	/*
	246	* Initialization, self-test and debugging-output methods:
	247	*/
	248	extern void lockdep_init(void);
	249	extern void lockdep_info(void);
	250	extern void lockdep_reset(void);
	251	extern void lockdep_reset_lock(struct lockdep_map *lock);
	252	extern void lockdep_free_key_range(void *start, unsigned long size);
b351d164	253	extern void lockdep_sys_exit(void);
fbb9ce95 IM	254
	255	extern void lockdep_off(void);
	256	extern void lockdep_on(void);
fbb9ce95 IM	257
	258	/*
	259	* These methods are used by specific locking variants (spinlocks,
	260	* rwlocks, mutexes and rwsems) to pass init/acquire/release events
	261	* to lockdep:
	262	*/
	263
	264	extern void lockdep_init_map(struct lockdep_map lock, const char name,
4dfbb9d8	265	struct lock_class_key *key, int subclass);
fbb9ce95	266
851a67b8 PZ	267	/*
	268	* To initialize a lockdep_map statically use this macro.
	269	* Note that _name must not be NULL.
	270	*/
	271	#define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
	272	{ .name = (_name), .key = (void *)(_key), }
	273
fbb9ce95 IM	274	/*
	275	* Reinitialize a lock key - for cases where there is special locking or
	276	* special initialization of locks so that the validator gets the scope
	277	* of dependencies wrong: they are either too broad (they need a class-split)
	278	* or they are too narrow (they suffer from a false class-split):
	279	*/
	280	#define lockdep_set_class(lock, key) \
4dfbb9d8	281	lockdep_init_map(&(lock)->dep_map, #key, key, 0)
fbb9ce95	282	#define lockdep_set_class_and_name(lock, key, name) \
4dfbb9d8 PZ	283	lockdep_init_map(&(lock)->dep_map, name, key, 0)
	284	#define lockdep_set_class_and_subclass(lock, key, sub) \
	285	lockdep_init_map(&(lock)->dep_map, #key, key, sub)
	286	#define lockdep_set_subclass(lock, sub) \
	287	lockdep_init_map(&(lock)->dep_map, #lock, \
	288	(lock)->dep_map.key, sub)
fbb9ce95 IM	289
	290	/*
	291	* Acquire a lock.
	292	*
	293	* Values for "read":
	294	*
	295	* 0: exclusive (write) acquire
	296	* 1: read-acquire (no recursion allowed)
	297	* 2: read-acquire with same-instance recursion allowed
	298	*
	299	* Values for check:
	300	*
	301	* 0: disabled
	302	* 1: simple checks (freeing, held-at-exit-time, etc.)
	303	* 2: full validation
	304	*/
	305	extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
7531e2f3 PZ	306	int trylock, int read, int check,
7531e2f3 PZ	307	struct lockdep_map *nest_lock, unsigned long ip);
fbb9ce95 IM	308
	309	extern void lock_release(struct lockdep_map *lock, int nested,
	310	unsigned long ip);
	311
64aa348e PZ	312	extern void lock_set_subclass(struct lockdep_map *lock, unsigned int subclass,
	313	unsigned long ip);
	314
fbb9ce95 IM	315	# define INIT_LOCKDEP .lockdep_recursion = 0,
fbb9ce95 IM	316
e3a55fd1	317	#define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0)
d5abe669	318
fbb9ce95 IM	319	#else /* !LOCKDEP */
	320
	321	static inline void lockdep_off(void)
	322	{
	323	}
	324
	325	static inline void lockdep_on(void)
	326	{
	327	}
	328
7531e2f3	329	# define lock_acquire(l, s, t, r, c, n, i) do { } while (0)
fbb9ce95	330	# define lock_release(l, n, i) do { } while (0)
64aa348e	331	# define lock_set_subclass(l, s, i) do { } while (0)
fbb9ce95 IM	332	# define lockdep_init() do { } while (0)
fbb9ce95 IM	333	# define lockdep_info() do { } while (0)
e8f6fbf6 IM	334	# define lockdep_init_map(lock, name, key, sub) \
e8f6fbf6 IM	335	do { (void)(name); (void)(key); } while (0)
fbb9ce95 IM	336	# define lockdep_set_class(lock, key) do { (void)(key); } while (0)
fbb9ce95 IM	337	# define lockdep_set_class_and_name(lock, key, name) \
e8f6fbf6	338	do { (void)(key); (void)(name); } while (0)
4dfbb9d8 PZ	339	#define lockdep_set_class_and_subclass(lock, key, sub) \
4dfbb9d8 PZ	340	do { (void)(key); } while (0)
07646e21 AM	341	#define lockdep_set_subclass(lock, sub) do { } while (0)
07646e21 AM	342
fbb9ce95 IM	343	# define INIT_LOCKDEP
	344	# define lockdep_reset() do { debug_locks = 1; } while (0)
	345	# define lockdep_free_key_range(start, size) do { } while (0)
b351d164	346	# define lockdep_sys_exit() do { } while (0)
fbb9ce95 IM	347	/*
	348	* The class key takes no space if lockdep is disabled:
	349	*/
	350	struct lock_class_key { };
d5abe669 PZ	351
	352	#define lockdep_depth(tsk) (0)
	353
fbb9ce95 IM	354	#endif /* !LOCKDEP */
fbb9ce95 IM	355
f20786ff PZ	356	#ifdef CONFIG_LOCK_STAT
	357
	358	extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
	359	extern void lock_acquired(struct lockdep_map *lock);
	360
	361	#define LOCK_CONTENDED(_lock, try, lock) \
	362	do { \
	363	if (!try(_lock)) { \
	364	lock_contended(&(_lock)->dep_map, _RET_IP_); \
	365	lock(_lock); \
f20786ff	366	} \
96645678	367	lock_acquired(&(_lock)->dep_map); \
f20786ff PZ	368	} while (0)
	369
	370	#else /* CONFIG_LOCK_STAT */
	371
	372	#define lock_contended(lockdep_map, ip) do {} while (0)
	373	#define lock_acquired(lockdep_map) do {} while (0)
	374
	375	#define LOCK_CONTENDED(_lock, try, lock) \
	376	lock(_lock)
	377
	378	#endif /* CONFIG_LOCK_STAT */
	379
243c7621 IM	380	#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_GENERIC_HARDIRQS)
	381	extern void early_init_irq_lock_class(void);
	382	#else
3117df04 IM	383	static inline void early_init_irq_lock_class(void)
	384	{
	385	}
243c7621 IM	386	#endif
243c7621 IM	387
fbb9ce95 IM	388	#ifdef CONFIG_TRACE_IRQFLAGS
	389	extern void early_boot_irqs_off(void);
	390	extern void early_boot_irqs_on(void);
3117df04	391	extern void print_irqtrace_events(struct task_struct *curr);
fbb9ce95	392	#else
3117df04 IM	393	static inline void early_boot_irqs_off(void)
	394	{
	395	}
	396	static inline void early_boot_irqs_on(void)
	397	{
	398	}
	399	static inline void print_irqtrace_events(struct task_struct *curr)
	400	{
	401	}
fbb9ce95 IM	402	#endif
	403
	404	/*
	405	* For trivial one-depth nesting of a lock-class, the following
	406	* global define can be used. (Subsystems with multiple levels
	407	* of nesting should define their own lock-nesting subclasses.)
	408	*/
	409	#define SINGLE_DEPTH_NESTING 1
	410
	411	/*
	412	* Map the dependency ops to NOP or to real lockdep ops, depending
	413	* on the per lock-class debug mode:
	414	*/
	415
	416	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	417	# ifdef CONFIG_PROVE_LOCKING
7531e2f3	418	# define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, NULL, i)
b7d39aff	419	# define spin_acquire_nest(l, s, t, n, i) lock_acquire(l, s, t, 0, 2, n, i)
fbb9ce95	420	# else
7531e2f3	421	# define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, NULL, i)
b7d39aff	422	# define spin_acquire_nest(l, s, t, n, i) lock_acquire(l, s, t, 0, 1, NULL, i)
fbb9ce95 IM	423	# endif
	424	# define spin_release(l, n, i) lock_release(l, n, i)
	425	#else
	426	# define spin_acquire(l, s, t, i) do { } while (0)
	427	# define spin_release(l, n, i) do { } while (0)
	428	#endif
	429
	430	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	431	# ifdef CONFIG_PROVE_LOCKING
7531e2f3 PZ	432	# define rwlock_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, NULL, i)
7531e2f3 PZ	433	# define rwlock_acquire_read(l, s, t, i) lock_acquire(l, s, t, 2, 2, NULL, i)
fbb9ce95	434	# else
7531e2f3 PZ	435	# define rwlock_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, NULL, i)
7531e2f3 PZ	436	# define rwlock_acquire_read(l, s, t, i) lock_acquire(l, s, t, 2, 1, NULL, i)
fbb9ce95 IM	437	# endif
	438	# define rwlock_release(l, n, i) lock_release(l, n, i)
	439	#else
	440	# define rwlock_acquire(l, s, t, i) do { } while (0)
	441	# define rwlock_acquire_read(l, s, t, i) do { } while (0)
	442	# define rwlock_release(l, n, i) do { } while (0)
	443	#endif
	444
	445	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	446	# ifdef CONFIG_PROVE_LOCKING
7531e2f3	447	# define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, NULL, i)
fbb9ce95	448	# else
7531e2f3	449	# define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, NULL, i)
fbb9ce95 IM	450	# endif
	451	# define mutex_release(l, n, i) lock_release(l, n, i)
	452	#else
	453	# define mutex_acquire(l, s, t, i) do { } while (0)
	454	# define mutex_release(l, n, i) do { } while (0)
	455	#endif
	456
	457	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	458	# ifdef CONFIG_PROVE_LOCKING
7531e2f3 PZ	459	# define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, NULL, i)
7531e2f3 PZ	460	# define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 2, NULL, i)
fbb9ce95	461	# else
7531e2f3 PZ	462	# define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, NULL, i)
7531e2f3 PZ	463	# define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 1, NULL, i)
fbb9ce95 IM	464	# endif
	465	# define rwsem_release(l, n, i) lock_release(l, n, i)
	466	#else
	467	# define rwsem_acquire(l, s, t, i) do { } while (0)
	468	# define rwsem_acquire_read(l, s, t, i) do { } while (0)
	469	# define rwsem_release(l, n, i) do { } while (0)
	470	#endif
	471
4f3e7524 PZ	472	#ifdef CONFIG_DEBUG_LOCK_ALLOC
4f3e7524 PZ	473	# ifdef CONFIG_PROVE_LOCKING
3295f0ef	474	# define lock_map_acquire(l) lock_acquire(l, 0, 0, 0, 2, NULL, _THIS_IP_)
4f3e7524	475	# else
3295f0ef	476	# define lock_map_acquire(l) lock_acquire(l, 0, 0, 0, 1, NULL, _THIS_IP_)
4f3e7524	477	# endif
3295f0ef	478	# define lock_map_release(l) lock_release(l, 1, _THIS_IP_)
4f3e7524	479	#else
3295f0ef IM	480	# define lock_map_acquire(l) do { } while (0)
3295f0ef IM	481	# define lock_map_release(l) do { } while (0)
4f3e7524 PZ	482	#endif
4f3e7524 PZ	483
fbb9ce95	484	#endif /* __LINUX_LOCKDEP_H */