summaryrefslogtreecommitdiffstats
path: root/include/linux/lockdep.h
blob: a842551fe0449a38df5510a39d3fdc4760caa0ee (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Runtime locking correctness validator
 *
 *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
 *
 * see Documentation/locking/lockdep-design.txt for more details.
 */
#ifndef __LINUX_LOCKDEP_H
#define __LINUX_LOCKDEP_H

struct task_struct;
struct lockdep_map;

/* for sysctl */
extern int prove_locking;
extern int lock_stat;

#define MAX_LOCKDEP_SUBCLASSES		8UL

#include <linux/types.h>

#ifdef CONFIG_LOCKDEP

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

/*
 * We'd rather not expose kernel/lockdep_states.h this wide, but we do need
 * the total number of states... :-(
 */
#define XXX_LOCK_USAGE_STATES		(1+2*4)

/*
 * NR_LOCKDEP_CACHING_CLASSES ... Number of classes
 * cached in the instance of lockdep_map
 *
 * Currently main class (subclass == 0) and signle depth subclass
 * are cached in lockdep_map. This optimization is mainly targeting
 * on rq->lock. double_rq_lock() acquires this highly competitive with
 * single depth.
 */
#define NR_LOCKDEP_CACHING_CLASSES	2

/*
 * 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];
};

extern struct lock_class_key __lockdep_no_validate__;

#define LOCKSTAT_POINTS		4

/*
 * The lock-class itself:
 */
struct lock_class {
	/*
	 * class-hash:
	 */
	struct hlist_node		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[XXX_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[LOCKSTAT_POINTS];
	unsigned long			contending_point[LOCKSTAT_POINTS];
#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[LOCKSTAT_POINTS];
	unsigned long			contending_point[LOCKSTAT_POINTS];
	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[NR_LOCKDEP_CACHING_CLASSES];
	const char			*name;
#ifdef CONFIG_LOCK_STAT
	int				cpu;
	unsigned long			ip;
#endif
#ifdef CONFIG_LOCKDEP_CROSSRELEASE
	/*
	 * Whether it's a crosslock.
	 */
	int				cross;
#endif
};

static inline void lockdep_copy_map(struct lockdep_map *to,
				    struct lockdep_map *from)
{
	int i;

	*to = *from;
	/*
	 * Since the class cache can be modified concurrently we could observe
	 * half pointers (64bit arch using 32bit copy insns). Therefore clear
	 * the caches and take the performance hit.
	 *
	 * XXX it doesn't work well with lockdep_set_class_and_subclass(), since
	 *     that relies on cache abuse.
	 */
	for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++)
		to->class_cache[i] = NULL;
}

/*
 * 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;

	/*
	 * The parent field is used to implement breadth-first search, and the
	 * bit 0 is reused to indicate if the lock has been accessed in BFS.
	 */
	struct lock_list		*parent;
};

/*
 * We record lock dependency chains, so that we can cache them:
 */
struct lock_chain {
	/* see BUILD_BUG_ON()s in lookup_chain_cache() */
	unsigned int			irq_context :  2,
					depth       :  6,
					base	    : 24;
	/* 4 byte hole */
	struct hlist_node		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;						/* 16 bits */

	unsigned int read:2;        /* see lock_acquire() comment */
	unsigned int check:1;       /* see lock_acquire() comment */
	unsigned int hardirqs_off:1;
	unsigned int references:12;					/* 32 bits */
	unsigned int pin_count;
#ifdef CONFIG_LOCKDEP_CROSSRELEASE
	/*
	 * Generation id.
	 *
	 * A value of cross_gen_id will be stored when holding this,
	 * which is globally increased whenever each crosslock is held.
	 */
	unsigned int gen_id;
#endif
};

#ifdef CONFIG_LOCKDEP_CROSSRELEASE
#define MAX_XHLOCK_TRACE_ENTRIES 5

/*
 * This is for keeping locks waiting for commit so that true dependencies
 * can be added at commit step.
 */
struct hist_lock {
	/*
	 * Id for each entry in the ring buffer. This is used to
	 * decide whether the ring buffer was overwritten or not.
	 *
	 * For example,
	 *
	 *           |<----------- hist_lock ring buffer size ------->|
	 *           pppppppppppppppppppppiiiiiiiiiiiiiiiiiiiiiiiiiiiii
	 * wrapped > iiiiiiiiiiiiiiiiiiiiiiiiiii.......................
	 *
	 *           where 'p' represents an acquisition in process
	 *           context, 'i' represents an acquisition in irq
	 *           context.
	 *
	 * In this example, the ring buffer was overwritten by
	 * acquisitions in irq context, that should be detected on
	 * rollback or commit.
	 */
	unsigned int hist_id;

	/*
	 * Seperate stack_trace data. This will be used at commit step.
	 */
	struct stack_trace	trace;
	unsigned long		trace_entries[MAX_XHLOCK_TRACE_ENTRIES];

	/*
	 * Seperate hlock instance. This will be used at commit step.
	 *
	 * TODO: Use a smaller data structure containing only necessary
	 * data. However, we should make lockdep code able to handle the
	 * smaller one first.
	 */
	struct held_lock	hlock;
};

/*
 * To initialize a lock as crosslock, lockdep_init_map_crosslock() should
 * be called instead of lockdep_init_map().
 */
struct cross_lock {
	/*
	 * When more than one acquisition of crosslocks are overlapped,
	 * we have to perform commit for them based on cross_gen_id of
	 * the first acquisition, which allows us to add more true
	 * dependencies.
	 *
	 * Moreover, when no acquisition of a crosslock is in progress,
	 * we should not perform commit because the lock might not exist
	 * any more, which might cause incorrect memory access. So we
	 * have to track the number of acquisitions of a crosslock.
	 */
	int nr_acquire;

	/*
	 * Seperate hlock instance. This will be used at commit step.
	 *
	 * TODO: Use a smaller data structure containing only necessary
	 * data. However, we should make lockdep code able to handle the
	 * smaller one first.
	 */
	struct held_lock	hlock;
};

struct lockdep_map_cross {
	struct lockdep_map map;
	struct cross_lock xlock;
};
#endif

/*
 * Initialization, self-test and debugging-output methods:
 */
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 asmlinkage 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);

/*
 * 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)

#define lockdep_set_novalidate_class(lock) \
	lockdep_set_class_and_name(lock, &__lockdep_no_validate__, #lock)
/*
 * Compare locking classes
 */
#define lockdep_match_class(lock, key) lockdep_match_key(&(lock)->dep_map, key)

static inline int lockdep_match_key(struct lockdep_map *lock,
				    struct lock_class_key *key)
{
	return lock->key == key;
}

/*
 * 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: simple checks (freeing, held-at-exit-time, etc.)
 *   1: 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);

/*
 * Same "read" as for lock_acquire(), except -1 means any.
 */
extern int lock_is_held_type(struct lockdep_map *lock, int read);

static inline int lock_is_held(struct lockdep_map *lock)
{
	return lock_is_held_type(lock, -1);
}

#define lockdep_is_held(lock)		lock_is_held(&(lock)->dep_map)
#define lockdep_is_held_type(lock, r)	lock_is_held_type(&(lock)->dep_map, (r))

extern void lock_set_class(struct lockdep_map *lock, const char *name,
			   struct lock_class_key *key, unsigned int subclass,
			   unsigned long ip);

static inline void lock_set_subclass(struct lockdep_map *lock,
		unsigned int subclass, unsigned long ip)
{
	lock_set_class(lock, lock->name, lock->key, subclass, ip);
}

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

struct pin_cookie { unsigned int val; };

#define NIL_COOKIE (struct pin_cookie){ .val = 0U, }

extern struct pin_cookie lock_pin_lock(struct lockdep_map *lock);
extern void lock_repin_lock(struct lockdep_map *lock, struct pin_cookie);
extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);

# define INIT_LOCKDEP				.lockdep_recursion = 0,

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

#define lockdep_assert_held(l)	do {				\
		WARN_ON(debug_locks && !lockdep_is_held(l));	\
	} while (0)

#define lockdep_assert_held_exclusive(l)	do {			\
		WARN_ON(debug_locks && !lockdep_is_held_type(l, 0));	\
	} while (0)

#define lockdep_assert_held_read(l)	do {				\
		WARN_ON(debug_locks && !lockdep_is_held_type(l, 1));	\
	} while (0)

#define lockdep_assert_held_once(l)	do {				\
		WARN_ON_ONCE(debug_locks && !lockdep_is_held(l));	\
	} while (0)

#define lockdep_recursing(tsk)	((tsk)->lockdep_recursion)

#define lockdep_pin_lock(l)	lock_pin_lock(&(l)->dep_map)
#define lockdep_repin_lock(l,c)	lock_repin_lock(&(l)->dep_map, (c))
#define lockdep_unpin_lock(l,c)	lock_unpin_lock(&(l)->dep_map, (c))

#else /* !CONFIG_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_downgrade(l, i)			do { } while (0)
# define lock_set_class(l, n, k, s, i)		do { } while (0)
# define lock_set_subclass(l, s, i)		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 lockdep_set_novalidate_class(lock) do { } while (0)

/*
 * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP
 * case since the result is not well defined and the caller should rather
 * #ifdef the call himself.
 */

# 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 { };

/*
 * The lockdep_map takes no space if lockdep is disabled:
 */
struct lockdep_map { };

#define lockdep_depth(tsk)	(0)

#define lockdep_is_held_type(l, r)		(1)

#define lockdep_assert_held(l)			do { (void)(l); } while (0)
#define lockdep_assert_held_exclusive(l)	do { (void)(l); } while (0)
#define lockdep_assert_held_read(l)		do { (void)(l); } while (0)
#define lockdep_assert_held_once(l)		do { (void)(l); } while (0)

#define lockdep_recursing(tsk)			(0)

struct pin_cookie { };

#define NIL_COOKIE (struct pin_cookie){ }

#define lockdep_pin_lock(l)			({ struct pin_cookie cookie; cookie; })
#define lockdep_repin_lock(l, c)		do { (void)(l); (void)(c); } while (0)
#define lockdep_unpin_lock(l, c)		do { (void)(l); (void)(c); } while (0)

#endif /* !LOCKDEP */

enum xhlock_context_t {
	XHLOCK_HARD,
	XHLOCK_SOFT,
	XHLOCK_CTX_NR,
};

#ifdef CONFIG_LOCKDEP_CROSSRELEASE
extern void lockdep_init_map_crosslock(struct lockdep_map *lock,
				       const char *name,
				       struct lock_class_key *key,
				       int subclass);
extern void lock_commit_crosslock(struct lockdep_map *lock);

/*
 * What we essencially have to initialize is 'nr_acquire'. Other members
 * will be initialized in add_xlock().
 */
#define STATIC_CROSS_LOCK_INIT() \
	{ .nr_acquire = 0,}

#define STATIC_CROSS_LOCKDEP_MAP_INIT(_name, _key) \
	{ .map.name = (_name), .map.key = (void *)(_key), \
	  .map.cross = 1, .xlock = STATIC_CROSS_LOCK_INIT(), }

/*
 * 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), .cross = 0, }

extern void crossrelease_hist_start(enum xhlock_context_t c);
extern void crossrelease_hist_end(enum xhlock_context_t c);
extern void lockdep_invariant_state(bool force);
extern void lockdep_init_task(struct task_struct *task);
extern void lockdep_free_task(struct task_struct *task);
#else /* !CROSSRELEASE */
#define lockdep_init_map_crosslock(m, n, k, s) do {} while (0)
/*
 * 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), }

static inline void crossrelease_hist_start(enum xhlock_context_t c) {}
static inline void crossrelease_hist_end(enum xhlock_context_t c) {}
static inline void lockdep_invariant_state(bool force) {}
static inline void lockdep_init_task(struct task_struct *task) {}
static inline void lockdep_free_task(struct task_struct *task) {}
#endif /* CROSSRELEASE */

#ifdef CONFIG_LOCK_STAT

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

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

#define LOCK_CONTENDED_RETURN(_lock, try, lock)			\
({								\
	int ____err = 0;					\
	if (!try(_lock)) {					\
		lock_contended(&(_lock)->dep_map, _RET_IP_);	\
		____err = lock(_lock);				\
	}							\
	if (!____err)						\
		lock_acquired(&(_lock)->dep_map, _RET_IP_);	\
	____err;						\
})

#else /* CONFIG_LOCK_STAT */

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

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

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

#endif /* CONFIG_LOCK_STAT */

#ifdef CONFIG_LOCKDEP

/*
 * On lockdep we dont want the hand-coded irq-enable of
 * _raw_*_lock_flags() code, because lockdep assumes
 * that interrupts are not re-enabled during lock-acquire:
 */
#define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \
	LOCK_CONTENDED((_lock), (try), (lock))

#else /* CONFIG_LOCKDEP */

#define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \
	lockfl((_lock), (flags))

#endif /* CONFIG_LOCKDEP */

#ifdef CONFIG_TRACE_IRQFLAGS
extern void print_irqtrace_events(struct task_struct *curr);
#else
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:
 */

#define lock_acquire_exclusive(l, s, t, n, i)		lock_acquire(l, s, t, 0, 1, n, i)
#define lock_acquire_shared(l, s, t, n, i)		lock_acquire(l, s, t, 1, 1, n, i)
#define lock_acquire_shared_recursive(l, s, t, n, i)	lock_acquire(l, s, t, 2, 1, n, i)

#define spin_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
#define spin_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
#define spin_release(l, n, i)			lock_release(l, n, i)

#define rwlock_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
#define rwlock_acquire_read(l, s, t, i)		lock_acquire_shared_recursive(l, s, t, NULL, i)
#define rwlock_release(l, n, i)			lock_release(l, n, i)

#define seqcount_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
#define seqcount_acquire_read(l, s, t, i)	lock_acquire_shared_recursive(l, s, t, NULL, i)
#define seqcount_release(l, n, i)		lock_release(l, n, i)

#define mutex_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
#define mutex_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
#define mutex_release(l, n, i)			lock_release(l, n, i)

#define rwsem_acquire(l, s, t, i)		lock_acquire_exclusive(l, s, t, NULL, i)
#define rwsem_acquire_nest(l, s, t, n, i)	lock_acquire_exclusive(l, s, t, n, i)
#define rwsem_acquire_read(l, s, t, i)		lock_acquire_shared(l, s, t, NULL, i)
#define rwsem_release(l, n, i)			lock_release(l, n, i)

#define lock_map_acquire(l)			lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_)
#define lock_map_acquire_read(l)		lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_)
#define lock_map_acquire_tryread(l)		lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_)
#define lock_map_release(l)			lock_release(l, 1, _THIS_IP_)

#ifdef CONFIG_PROVE_LOCKING
# define might_lock(lock) 						\
do {									\
	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
	lock_acquire(&(lock)->dep_map, 0, 0, 0, 1, NULL, _THIS_IP_);	\
	lock_release(&(lock)->dep_map, 0, _THIS_IP_);			\
} while (0)
# define might_lock_read(lock) 						\
do {									\
	typecheck(struct lockdep_map *, &(lock)->dep_map);		\
	lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_);	\
	lock_release(&(lock)->dep_map, 0, _THIS_IP_);			\
} while (0)

#define lockdep_assert_irqs_enabled()	do {				\
		WARN_ONCE(debug_locks && !current->lockdep_recursion &&	\
			  !current->hardirqs_enabled,			\
			  "IRQs not enabled as expected\n");		\
	} while (0)

#define lockdep_assert_irqs_disabled()	do {				\
		WARN_ONCE(debug_locks && !current->lockdep_recursion &&	\
			  current->hardirqs_enabled,			\
			  "IRQs not disabled as expected\n");		\
	} while (0)

#else
# define might_lock(lock) do { } while (0)
# define might_lock_read(lock) do { } while (0)
# define lockdep_assert_irqs_enabled() do { } while (0)
# define lockdep_assert_irqs_disabled() do { } while (0)
#endif

#ifdef CONFIG_LOCKDEP
void lockdep_rcu_suspicious(const char *file, const int line, const char *s);
#else
static inline void
lockdep_rcu_suspicious(const char *file, const int line, const char *s)
{
}
#endif

#endif /* __LINUX_LOCKDEP_H */