[ALSA] Clean up duplicate includes in sound/core/
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / include / linux / lockdep.h
blobf6279f68a8270c143196c1c0c09afbea2cff02be
1 /*
2 * Runtime locking correctness validator
4 * Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
5 * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
7 * see Documentation/lockdep-design.txt for more details.
8 */
9 #ifndef __LINUX_LOCKDEP_H
10 #define __LINUX_LOCKDEP_H
12 struct task_struct;
13 struct lockdep_map;
15 #ifdef CONFIG_LOCKDEP
17 #include <linux/linkage.h>
18 #include <linux/list.h>
19 #include <linux/debug_locks.h>
20 #include <linux/stacktrace.h>
23 * Lock-class usage-state bits:
25 enum lock_usage_bit
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
40 * Usage-state bitmasks:
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)
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)
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)
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)
61 #define MAX_LOCKDEP_SUBCLASSES 8UL
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.)
68 struct lockdep_subclass_key {
69 char __one_byte;
70 } __attribute__ ((__packed__));
72 struct lock_class_key {
73 struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES];
77 * The lock-class itself:
79 struct lock_class {
81 * class-hash:
83 struct list_head hash_entry;
86 * global list of all lock-classes:
88 struct list_head lock_entry;
90 struct lockdep_subclass_key *key;
91 unsigned int subclass;
94 * IRQ/softirq usage tracking bits:
96 unsigned long usage_mask;
97 struct stack_trace usage_traces[LOCK_USAGE_STATES];
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.
104 struct list_head locks_after, locks_before;
107 * Generation counter, when doing certain classes of graph walking,
108 * to ensure that we check one node only once:
110 unsigned int version;
113 * Statistics counter:
115 unsigned long ops;
117 const char *name;
118 int name_version;
120 #ifdef CONFIG_LOCK_STAT
121 unsigned long contention_point[4];
122 #endif
125 #ifdef CONFIG_LOCK_STAT
126 struct lock_time {
127 s64 min;
128 s64 max;
129 s64 total;
130 unsigned long nr;
133 enum bounce_type {
134 bounce_acquired_write,
135 bounce_acquired_read,
136 bounce_contended_write,
137 bounce_contended_read,
138 nr_bounce_types,
140 bounce_acquired = bounce_acquired_write,
141 bounce_contended = bounce_contended_write,
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;
150 unsigned long bounces[nr_bounce_types];
153 struct lock_class_stats lock_stats(struct lock_class *class);
154 void clear_lock_stats(struct lock_class *class);
155 #endif
158 * Map the lock object (the lock instance) to the lock-class object.
159 * This is embedded into specific lock instances:
161 struct lockdep_map {
162 struct lock_class_key *key;
163 struct lock_class *class_cache;
164 const char *name;
165 #ifdef CONFIG_LOCK_STAT
166 int cpu;
167 #endif
171 * Every lock has a list of other locks that were taken after it.
172 * We only grow the list, never remove from it:
174 struct lock_list {
175 struct list_head entry;
176 struct lock_class *class;
177 struct stack_trace trace;
178 int distance;
182 * We record lock dependency chains, so that we can cache them:
184 struct lock_chain {
185 struct list_head entry;
186 u64 chain_key;
189 struct held_lock {
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.
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.
201 * The task struct holds the current hash value (initialized
202 * with zero), here we store the previous hash value:
204 u64 prev_chain_key;
205 struct lock_class *class;
206 unsigned long acquire_ip;
207 struct lockdep_map *instance;
209 #ifdef CONFIG_LOCK_STAT
210 u64 waittime_stamp;
211 u64 holdtime_stamp;
212 #endif
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.]
223 * The following field is used to detect when we cross into an
224 * interrupt context:
226 int irq_context;
227 int trylock;
228 int read;
229 int check;
230 int hardirqs_off;
234 * Initialization, self-test and debugging-output methods:
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 extern void lockdep_sys_exit(void);
243 extern void lockdep_off(void);
244 extern void lockdep_on(void);
247 * These methods are used by specific locking variants (spinlocks,
248 * rwlocks, mutexes and rwsems) to pass init/acquire/release events
249 * to lockdep:
252 extern void lockdep_init_map(struct lockdep_map *lock, const char *name,
253 struct lock_class_key *key, int subclass);
256 * To initialize a lockdep_map statically use this macro.
257 * Note that _name must not be NULL.
259 #define STATIC_LOCKDEP_MAP_INIT(_name, _key) \
260 { .name = (_name), .key = (void *)(_key), }
263 * Reinitialize a lock key - for cases where there is special locking or
264 * special initialization of locks so that the validator gets the scope
265 * of dependencies wrong: they are either too broad (they need a class-split)
266 * or they are too narrow (they suffer from a false class-split):
268 #define lockdep_set_class(lock, key) \
269 lockdep_init_map(&(lock)->dep_map, #key, key, 0)
270 #define lockdep_set_class_and_name(lock, key, name) \
271 lockdep_init_map(&(lock)->dep_map, name, key, 0)
272 #define lockdep_set_class_and_subclass(lock, key, sub) \
273 lockdep_init_map(&(lock)->dep_map, #key, key, sub)
274 #define lockdep_set_subclass(lock, sub) \
275 lockdep_init_map(&(lock)->dep_map, #lock, \
276 (lock)->dep_map.key, sub)
279 * Acquire a lock.
281 * Values for "read":
283 * 0: exclusive (write) acquire
284 * 1: read-acquire (no recursion allowed)
285 * 2: read-acquire with same-instance recursion allowed
287 * Values for check:
289 * 0: disabled
290 * 1: simple checks (freeing, held-at-exit-time, etc.)
291 * 2: full validation
293 extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
294 int trylock, int read, int check, unsigned long ip);
296 extern void lock_release(struct lockdep_map *lock, int nested,
297 unsigned long ip);
299 # define INIT_LOCKDEP .lockdep_recursion = 0,
301 #define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0)
303 #else /* !LOCKDEP */
305 static inline void lockdep_off(void)
309 static inline void lockdep_on(void)
313 # define lock_acquire(l, s, t, r, c, i) do { } while (0)
314 # define lock_release(l, n, i) do { } while (0)
315 # define lockdep_init() do { } while (0)
316 # define lockdep_info() do { } while (0)
317 # define lockdep_init_map(lock, name, key, sub) do { (void)(key); } while (0)
318 # define lockdep_set_class(lock, key) do { (void)(key); } while (0)
319 # define lockdep_set_class_and_name(lock, key, name) \
320 do { (void)(key); } while (0)
321 #define lockdep_set_class_and_subclass(lock, key, sub) \
322 do { (void)(key); } while (0)
323 #define lockdep_set_subclass(lock, sub) do { } while (0)
325 # define INIT_LOCKDEP
326 # define lockdep_reset() do { debug_locks = 1; } while (0)
327 # define lockdep_free_key_range(start, size) do { } while (0)
328 # define lockdep_sys_exit() do { } while (0)
330 * The class key takes no space if lockdep is disabled:
332 struct lock_class_key { };
334 #define lockdep_depth(tsk) (0)
336 #endif /* !LOCKDEP */
338 #ifdef CONFIG_LOCK_STAT
340 extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
341 extern void lock_acquired(struct lockdep_map *lock);
343 #define LOCK_CONTENDED(_lock, try, lock) \
344 do { \
345 if (!try(_lock)) { \
346 lock_contended(&(_lock)->dep_map, _RET_IP_); \
347 lock(_lock); \
349 lock_acquired(&(_lock)->dep_map); \
350 } while (0)
352 #else /* CONFIG_LOCK_STAT */
354 #define lock_contended(lockdep_map, ip) do {} while (0)
355 #define lock_acquired(lockdep_map) do {} while (0)
357 #define LOCK_CONTENDED(_lock, try, lock) \
358 lock(_lock)
360 #endif /* CONFIG_LOCK_STAT */
362 #if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_GENERIC_HARDIRQS)
363 extern void early_init_irq_lock_class(void);
364 #else
365 static inline void early_init_irq_lock_class(void)
368 #endif
370 #ifdef CONFIG_TRACE_IRQFLAGS
371 extern void early_boot_irqs_off(void);
372 extern void early_boot_irqs_on(void);
373 extern void print_irqtrace_events(struct task_struct *curr);
374 #else
375 static inline void early_boot_irqs_off(void)
378 static inline void early_boot_irqs_on(void)
381 static inline void print_irqtrace_events(struct task_struct *curr)
384 #endif
387 * For trivial one-depth nesting of a lock-class, the following
388 * global define can be used. (Subsystems with multiple levels
389 * of nesting should define their own lock-nesting subclasses.)
391 #define SINGLE_DEPTH_NESTING 1
394 * Map the dependency ops to NOP or to real lockdep ops, depending
395 * on the per lock-class debug mode:
398 #ifdef CONFIG_DEBUG_LOCK_ALLOC
399 # ifdef CONFIG_PROVE_LOCKING
400 # define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i)
401 # else
402 # define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i)
403 # endif
404 # define spin_release(l, n, i) lock_release(l, n, i)
405 #else
406 # define spin_acquire(l, s, t, i) do { } while (0)
407 # define spin_release(l, n, i) do { } while (0)
408 #endif
410 #ifdef CONFIG_DEBUG_LOCK_ALLOC
411 # ifdef CONFIG_PROVE_LOCKING
412 # define rwlock_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i)
413 # define rwlock_acquire_read(l, s, t, i) lock_acquire(l, s, t, 2, 2, i)
414 # else
415 # define rwlock_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i)
416 # define rwlock_acquire_read(l, s, t, i) lock_acquire(l, s, t, 2, 1, i)
417 # endif
418 # define rwlock_release(l, n, i) lock_release(l, n, i)
419 #else
420 # define rwlock_acquire(l, s, t, i) do { } while (0)
421 # define rwlock_acquire_read(l, s, t, i) do { } while (0)
422 # define rwlock_release(l, n, i) do { } while (0)
423 #endif
425 #ifdef CONFIG_DEBUG_LOCK_ALLOC
426 # ifdef CONFIG_PROVE_LOCKING
427 # define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i)
428 # else
429 # define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i)
430 # endif
431 # define mutex_release(l, n, i) lock_release(l, n, i)
432 #else
433 # define mutex_acquire(l, s, t, i) do { } while (0)
434 # define mutex_release(l, n, i) do { } while (0)
435 #endif
437 #ifdef CONFIG_DEBUG_LOCK_ALLOC
438 # ifdef CONFIG_PROVE_LOCKING
439 # define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i)
440 # define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 2, i)
441 # else
442 # define rwsem_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i)
443 # define rwsem_acquire_read(l, s, t, i) lock_acquire(l, s, t, 1, 1, i)
444 # endif
445 # define rwsem_release(l, n, i) lock_release(l, n, i)
446 #else
447 # define rwsem_acquire(l, s, t, i) do { } while (0)
448 # define rwsem_acquire_read(l, s, t, i) do { } while (0)
449 # define rwsem_release(l, n, i) do { } while (0)
450 #endif
452 #endif /* __LINUX_LOCKDEP_H */