datapath/linux-2.6/compat-2.6/include/linux/lockdep.h

   1 /*
   2  * Runtime locking correctness validator
   3  *
   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>
   6  *
   7  * see Documentation/lockdep-design.txt for more details.
   8  */
   9 #ifndef __LINUX_LOCKDEP_WRAPPER_H
  10 #define __LINUX_LOCKDEP_WRAPPER_H
  11
  12 #include_next <linux/lockdep.h>
  13
  14 #include <linux/version.h>
  15 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18)
  16
  17 struct task_struct;
  18 struct lockdep_map;
  19
  20 #ifdef CONFIG_LOCKDEP
  21
  22 #include <linux/linkage.h>
  23 #include <linux/list.h>
  24 #include <linux/debug_locks.h>
  25 #include <linux/stacktrace.h>
  26
  27 /*
  28  * Lock-class usage-state bits:
  29  */
  30 enum lock_usage_bit
  31 {
  32         LOCK_USED = 0,
  33         LOCK_USED_IN_HARDIRQ,
  34         LOCK_USED_IN_SOFTIRQ,
  35         LOCK_ENABLED_SOFTIRQS,
  36         LOCK_ENABLED_HARDIRQS,
  37         LOCK_USED_IN_HARDIRQ_READ,
  38         LOCK_USED_IN_SOFTIRQ_READ,
  39         LOCK_ENABLED_SOFTIRQS_READ,
  40         LOCK_ENABLED_HARDIRQS_READ,
  41         LOCK_USAGE_STATES
  42 };
  43
  44 /*
  45  * Usage-state bitmasks:
  46  */
  47 #define LOCKF_USED                      (1 << LOCK_USED)
  48 #define LOCKF_USED_IN_HARDIRQ           (1 << LOCK_USED_IN_HARDIRQ)
  49 #define LOCKF_USED_IN_SOFTIRQ           (1 << LOCK_USED_IN_SOFTIRQ)
  50 #define LOCKF_ENABLED_HARDIRQS          (1 << LOCK_ENABLED_HARDIRQS)
  51 #define LOCKF_ENABLED_SOFTIRQS          (1 << LOCK_ENABLED_SOFTIRQS)
  52
  53 #define LOCKF_ENABLED_IRQS (LOCKF_ENABLED_HARDIRQS | LOCKF_ENABLED_SOFTIRQS)
  54 #define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ)
  55
  56 #define LOCKF_USED_IN_HARDIRQ_READ      (1 << LOCK_USED_IN_HARDIRQ_READ)
  57 #define LOCKF_USED_IN_SOFTIRQ_READ      (1 << LOCK_USED_IN_SOFTIRQ_READ)
  58 #define LOCKF_ENABLED_HARDIRQS_READ     (1 << LOCK_ENABLED_HARDIRQS_READ)
  59 #define LOCKF_ENABLED_SOFTIRQS_READ     (1 << LOCK_ENABLED_SOFTIRQS_READ)
  60
  61 #define LOCKF_ENABLED_IRQS_READ \
  62                 (LOCKF_ENABLED_HARDIRQS_READ | LOCKF_ENABLED_SOFTIRQS_READ)
  63 #define LOCKF_USED_IN_IRQ_READ \
  64                 (LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)
  65
  66 #define MAX_LOCKDEP_SUBCLASSES          8UL
  67
  68 /*
  69  * Lock-classes are keyed via unique addresses, by embedding the
  70  * lockclass-key into the kernel (or module) .data section. (For
  71  * static locks we use the lock address itself as the key.)
  72  */
  73 struct lockdep_subclass_key {
  74         char __one_byte;
  75 } __attribute__ ((__packed__));
  76
  77 struct lock_class_key {
  78         struct lockdep_subclass_key     subkeys[MAX_LOCKDEP_SUBCLASSES];
  79 };
  80
  81 /*
  82  * The lock-class itself:
  83  */
  84 struct lock_class {
  85         /*
  86          * class-hash:
  87          */
  88         struct list_head                hash_entry;
  89
  90         /*
  91          * global list of all lock-classes:
  92          */
  93         struct list_head                lock_entry;
  94
  95         struct lockdep_subclass_key     *key;
  96         unsigned int                    subclass;
  97
  98         /*
  99          * IRQ/softirq usage tracking bits:
 100          */
 101         unsigned long                   usage_mask;
 102         struct stack_trace              usage_traces[LOCK_USAGE_STATES];
 103
 104         /*
 105          * These fields represent a directed graph of lock dependencies,
 106          * to every node we attach a list of "forward" and a list of
 107          * "backward" graph nodes.
 108          */
 109         struct list_head                locks_after, locks_before;
 110
 111         /*
 112          * Generation counter, when doing certain classes of graph walking,
 113          * to ensure that we check one node only once:
 114          */
 115         unsigned int                    version;
 116
 117         /*
 118          * Statistics counter:
 119          */
 120         unsigned long                   ops;
 121
 122         const char                      *name;
 123         int                             name_version;
 124
 125 #ifdef CONFIG_LOCK_STAT
 126         unsigned long                   contention_point[4];
 127 #endif
 128 };
 129
 130 #ifdef CONFIG_LOCK_STAT
 131 struct lock_time {
 132         s64                             min;
 133         s64                             max;
 134         s64                             total;
 135         unsigned long                   nr;
 136 };
 137
 138 enum bounce_type {
 139         bounce_acquired_write,
 140         bounce_acquired_read,
 141         bounce_contended_write,
 142         bounce_contended_read,
 143         nr_bounce_types,
 144
 145         bounce_acquired = bounce_acquired_write,
 146         bounce_contended = bounce_contended_write,
 147 };
 148
 149 struct lock_class_stats {
 150         unsigned long                   contention_point[4];
 151         struct lock_time                read_waittime;
 152         struct lock_time                write_waittime;
 153         struct lock_time                read_holdtime;
 154         struct lock_time                write_holdtime;
 155         unsigned long                   bounces[nr_bounce_types];
 156 };
 157
 158 struct lock_class_stats lock_stats(struct lock_class *class);
 159 void clear_lock_stats(struct lock_class *class);
 160 #endif
 161
 162 /*
 163  * Map the lock object (the lock instance) to the lock-class object.
 164  * This is embedded into specific lock instances:
 165  */
 166 struct lockdep_map {
 167         struct lock_class_key           *key;
 168         struct lock_class               *class_cache;
 169         const char                      *name;
 170 #ifdef CONFIG_LOCK_STAT
 171         int                             cpu;
 172 #endif
 173 };
 174
 175 /*
 176  * Every lock has a list of other locks that were taken after it.
 177  * We only grow the list, never remove from it:
 178  */
 179 struct lock_list {
 180         struct list_head                entry;
 181         struct lock_class               *class;
 182         struct stack_trace              trace;
 183         int                             distance;
 184 };
 185
 186 /*
 187  * We record lock dependency chains, so that we can cache them:
 188  */
 189 struct lock_chain {
 190         struct list_head                entry;
 191         u64                             chain_key;
 192 };
 193
 194 struct held_lock {
 195         /*
 196          * One-way hash of the dependency chain up to this point. We
 197          * hash the hashes step by step as the dependency chain grows.
 198          *
 199          * We use it for dependency-caching and we skip detection
 200          * passes and dependency-updates if there is a cache-hit, so
 201          * it is absolutely critical for 100% coverage of the validator
 202          * to have a unique key value for every unique dependency path
 203          * that can occur in the system, to make a unique hash value
 204          * as likely as possible - hence the 64-bit width.
 205          *
 206          * The task struct holds the current hash value (initialized
 207          * with zero), here we store the previous hash value:
 208          */
 209         u64                             prev_chain_key;
 210         struct lock_class               *class;
 211         unsigned long                   acquire_ip;
 212         struct lockdep_map              *instance;
 213
 214 #ifdef CONFIG_LOCK_STAT
 215         u64                             waittime_stamp;
 216         u64                             holdtime_stamp;
 217 #endif
 218         /*
 219          * The lock-stack is unified in that the lock chains of interrupt
 220          * contexts nest ontop of process context chains, but we 'separate'
 221          * the hashes by starting with 0 if we cross into an interrupt
 222          * context, and we also keep do not add cross-context lock
 223          * dependencies - the lock usage graph walking covers that area
 224          * anyway, and we'd just unnecessarily increase the number of
 225          * dependencies otherwise. [Note: hardirq and softirq contexts
 226          * are separated from each other too.]
 227          *
 228          * The following field is used to detect when we cross into an
 229          * interrupt context:
 230          */
 231         int                             irq_context;
 232         int                             trylock;
 233         int                             read;
 234         int                             check;
 235         int                             hardirqs_off;
 236 };
 237
 238 /*
 239  * Initialization, self-test and debugging-output methods:
 240  */
 241 extern void lockdep_init(void);
 242 extern void lockdep_info(void);
 243 extern void lockdep_reset(void);
 244 extern void lockdep_reset_lock(struct lockdep_map *lock);
 245 extern void lockdep_free_key_range(void *start, unsigned long size);
 246
 247 extern void lockdep_off(void);
 248 extern void lockdep_on(void);
 249
 250 /*
 251  * These methods are used by specific locking variants (spinlocks,
 252  * rwlocks, mutexes and rwsems) to pass init/acquire/release events
 253  * to lockdep:
 254  */
 255
 256 extern void lockdep_init_map(struct lockdep_map *lock, const char *name,
 257                         struct lock_class_key *key, int subclass);
 258
 259 /*
 260  * Reinitialize a lock key - for cases where there is special locking or
 261  * special initialization of locks so that the validator gets the scope
 262  * of dependencies wrong: they are either too broad (they need a class-split)
 263  * or they are too narrow (they suffer from a false class-split):
 264  */
 265 #define lockdep_set_class(lock, key) \
 266                 lockdep_init_map(&(lock)->dep_map, #key, key, 0)
 267 #define lockdep_set_class_and_name(lock, key, name) \
 268                 lockdep_init_map(&(lock)->dep_map, name, key, 0)
 269 #define lockdep_set_class_and_subclass(lock, key, sub) \
 270                 lockdep_init_map(&(lock)->dep_map, #key, key, sub)
 271 #define lockdep_set_subclass(lock, sub) \
 272                 lockdep_init_map(&(lock)->dep_map, #lock, \
 273                                  (lock)->dep_map.key, sub)
 274
 275 /*
 276  * Acquire a lock.
 277  *
 278  * Values for "read":
 279  *
 280  *   0: exclusive (write) acquire
 281  *   1: read-acquire (no recursion allowed)
 282  *   2: read-acquire with same-instance recursion allowed
 283  *
 284  * Values for check:
 285  *
 286  *   0: disabled
 287  *   1: simple checks (freeing, held-at-exit-time, etc.)
 288  *   2: full validation
 289  */
 290 extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 291                          int trylock, int read, int check, unsigned long ip);
 292
 293 extern void lock_release(struct lockdep_map *lock, int nested,
 294                          unsigned long ip);
 295
 296 # define INIT_LOCKDEP                           .lockdep_recursion = 0,
 297
 298 #define lockdep_depth(tsk)      (debug_locks ? (tsk)->lockdep_depth : 0)
 299
 300 #else /* !LOCKDEP */
 301
 302 static inline void lockdep_off(void)
 303 {
 304 }
 305
 306 static inline void lockdep_on(void)
 307 {
 308 }
 309
 310 # define lock_acquire(l, s, t, r, c, i)         do { } while (0)
 311 # define lock_release(l, n, i)                  do { } while (0)
 312 # define lockdep_init()                         do { } while (0)
 313 # define lockdep_info()                         do { } while (0)
 314 # define lockdep_init_map(lock, name, key, sub) do { (void)(key); } while (0)
 315 # define lockdep_set_class(lock, key)           do { (void)(key); } while (0)
 316 # define lockdep_set_class_and_name(lock, key, name) \
 317                 do { (void)(key); } while (0)
 318 #define lockdep_set_class_and_subclass(lock, key, sub) \
 319                 do { (void)(key); } while (0)
 320 #define lockdep_set_subclass(lock, sub)         do { } while (0)
 321
 322 # define INIT_LOCKDEP
 323 # define lockdep_reset()                do { debug_locks = 1; } while (0)
 324 # define lockdep_free_key_range(start, size)    do { } while (0)
 325 /*
 326  * The class key takes no space if lockdep is disabled:
 327  */
 328 struct lock_class_key { };
 329
 330 #define lockdep_depth(tsk)      (0)
 331
 332 #endif /* !LOCKDEP */
 333
 334 #ifdef CONFIG_LOCK_STAT
 335
 336 extern void lock_contended(struct lockdep_map *lock, unsigned long ip);
 337 extern void lock_acquired(struct lockdep_map *lock);
 338
 339 #define LOCK_CONTENDED(_lock, try, lock)                        \
 340 do {                                                            \
 341         if (!try(_lock)) {                                      \
 342                 lock_contended(&(_lock)->dep_map, _RET_IP_);    \
 343                 lock(_lock);                                    \
 344         }                                                       \
 345         lock_acquired(&(_lock)->dep_map);                       \
 346 } while (0)
 347
 348 #else /* CONFIG_LOCK_STAT */
 349
 350 #define lock_contended(lockdep_map, ip) do {} while (0)
 351 #define lock_acquired(lockdep_map) do {} while (0)
 352
 353 #define LOCK_CONTENDED(_lock, try, lock) \
 354         lock(_lock)
 355
 356 #endif /* CONFIG_LOCK_STAT */
 357
 358 #if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_GENERIC_HARDIRQS)
 359 extern void early_init_irq_lock_class(void);
 360 #else
 361 static inline void early_init_irq_lock_class(void)
 362 {
 363 }
 364 #endif
 365
 366 #ifdef CONFIG_TRACE_IRQFLAGS
 367 extern void early_boot_irqs_off(void);
 368 extern void early_boot_irqs_on(void);
 369 extern void print_irqtrace_events(struct task_struct *curr);
 370 #else
 371 static inline void early_boot_irqs_off(void)
 372 {
 373 }
 374 static inline void early_boot_irqs_on(void)
 375 {
 376 }
 377 static inline void print_irqtrace_events(struct task_struct *curr)
 378 {
 379 }
 380 #endif
 381
 382 /*
 383  * For trivial one-depth nesting of a lock-class, the following
 384  * global define can be used. (Subsystems with multiple levels
 385  * of nesting should define their own lock-nesting subclasses.)
 386  */
 387 #define SINGLE_DEPTH_NESTING                    1
 388
 389 /*
 390  * Map the dependency ops to NOP or to real lockdep ops, depending
 391  * on the per lock-class debug mode:
 392  */
 393
 394 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 395 # ifdef CONFIG_PROVE_LOCKING
 396 #  define spin_acquire(l, s, t, i)              lock_acquire(l, s, t, 0, 2, i)
 397 # else
 398 #  define spin_acquire(l, s, t, i)              lock_acquire(l, s, t, 0, 1, i)
 399 # endif
 400 # define spin_release(l, n, i)                  lock_release(l, n, i)
 401 #else
 402 # define spin_acquire(l, s, t, i)               do { } while (0)
 403 # define spin_release(l, n, i)                  do { } while (0)
 404 #endif
 405
 406 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 407 # ifdef CONFIG_PROVE_LOCKING
 408 #  define rwlock_acquire(l, s, t, i)            lock_acquire(l, s, t, 0, 2, i)
 409 #  define rwlock_acquire_read(l, s, t, i)       lock_acquire(l, s, t, 2, 2, i)
 410 # else
 411 #  define rwlock_acquire(l, s, t, i)            lock_acquire(l, s, t, 0, 1, i)
 412 #  define rwlock_acquire_read(l, s, t, i)       lock_acquire(l, s, t, 2, 1, i)
 413 # endif
 414 # define rwlock_release(l, n, i)                lock_release(l, n, i)
 415 #else
 416 # define rwlock_acquire(l, s, t, i)             do { } while (0)
 417 # define rwlock_acquire_read(l, s, t, i)        do { } while (0)
 418 # define rwlock_release(l, n, i)                do { } while (0)
 419 #endif
 420
 421 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 422 # ifdef CONFIG_PROVE_LOCKING
 423 #  define mutex_acquire(l, s, t, i)             lock_acquire(l, s, t, 0, 2, i)
 424 # else
 425 #  define mutex_acquire(l, s, t, i)             lock_acquire(l, s, t, 0, 1, i)
 426 # endif
 427 # define mutex_release(l, n, i)                 lock_release(l, n, i)
 428 #else
 429 # define mutex_acquire(l, s, t, i)              do { } while (0)
 430 # define mutex_release(l, n, i)                 do { } while (0)
 431 #endif
 432
 433 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 434 # ifdef CONFIG_PROVE_LOCKING
 435 #  define rwsem_acquire(l, s, t, i)             lock_acquire(l, s, t, 0, 2, i)
 436 #  define rwsem_acquire_read(l, s, t, i)        lock_acquire(l, s, t, 1, 2, i)
 437 # else
 438 #  define rwsem_acquire(l, s, t, i)             lock_acquire(l, s, t, 0, 1, i)
 439 #  define rwsem_acquire_read(l, s, t, i)        lock_acquire(l, s, t, 1, 1, i)
 440 # endif
 441 # define rwsem_release(l, n, i)                 lock_release(l, n, i)
 442 #else
 443 # define rwsem_acquire(l, s, t, i)              do { } while (0)
 444 # define rwsem_acquire_read(l, s, t, i)         do { } while (0)
 445 # define rwsem_release(l, n, i)                 do { } while (0)
 446 #endif
 447
 448 #endif /* linux kernel < 2.6.18 */
 449
 450 #endif /* __LINUX_LOCKDEP_WRAPPER_H */