include/linux/lockdep_types.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Runtime locking correctness validator
   4  *
   5  *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <[email protected]>
   6  *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
   7  *
   8  * see Documentation/locking/lockdep-design.rst for more details.
   9  */
  10 #ifndef __LINUX_LOCKDEP_TYPES_H
  11 #define __LINUX_LOCKDEP_TYPES_H
  12
  13 #include <linux/types.h>
  14
  15 #define MAX_LOCKDEP_SUBCLASSES          8UL
  16
  17 enum lockdep_wait_type {
  18         LD_WAIT_INV = 0,        /* not checked, catch all */
  19
  20         LD_WAIT_FREE,           /* wait free, rcu etc.. */
  21         LD_WAIT_SPIN,           /* spin loops, raw_spinlock_t etc.. */
  22
  23 #ifdef CONFIG_PROVE_RAW_LOCK_NESTING
  24         LD_WAIT_CONFIG,         /* preemptible in PREEMPT_RT, spinlock_t etc.. */
  25 #else
  26         LD_WAIT_CONFIG = LD_WAIT_SPIN,
  27 #endif
  28         LD_WAIT_SLEEP,          /* sleeping locks, mutex_t etc.. */
  29
  30         LD_WAIT_MAX,            /* must be last */
  31 };
  32
  33 enum lockdep_lock_type {
  34         LD_LOCK_NORMAL = 0,     /* normal, catch all */
  35         LD_LOCK_PERCPU,         /* percpu */
  36         LD_LOCK_MAX,
  37 };
  38
  39 #ifdef CONFIG_LOCKDEP
  40
  41 /*
  42  * We'd rather not expose kernel/lockdep_states.h this wide, but we do need
  43  * the total number of states... :-(
  44  *
  45  * XXX_LOCK_USAGE_STATES is the number of lines in lockdep_states.h, for each
  46  * of those we generates 4 states, Additionally we report on USED and USED_READ.
  47  */
  48 #define XXX_LOCK_USAGE_STATES           2
  49 #define LOCK_TRACE_STATES               (XXX_LOCK_USAGE_STATES*4 + 2)
  50
  51 /*
  52  * NR_LOCKDEP_CACHING_CLASSES ... Number of classes
  53  * cached in the instance of lockdep_map
  54  *
  55  * Currently main class (subclass == 0) and single depth subclass
  56  * are cached in lockdep_map. This optimization is mainly targeting
  57  * on rq->lock. double_rq_lock() acquires this highly competitive with
  58  * single depth.
  59  */
  60 #define NR_LOCKDEP_CACHING_CLASSES      2
  61
  62 /*
  63  * A lockdep key is associated with each lock object. For static locks we use
  64  * the lock address itself as the key. Dynamically allocated lock objects can
  65  * have a statically or dynamically allocated key. Dynamically allocated lock
  66  * keys must be registered before being used and must be unregistered before
  67  * the key memory is freed.
  68  */
  69 struct lockdep_subclass_key {
  70         char __one_byte;
  71 } __attribute__ ((__packed__));
  72
  73 /* hash_entry is used to keep track of dynamically allocated keys. */
  74 struct lock_class_key {
  75         union {
  76                 struct hlist_node               hash_entry;
  77                 struct lockdep_subclass_key     subkeys[MAX_LOCKDEP_SUBCLASSES];
  78         };
  79 };
  80
  81 extern struct lock_class_key __lockdep_no_validate__;
  82
  83 struct lock_trace;
  84
  85 #define LOCKSTAT_POINTS         4
  86
  87 /*
  88  * The lock-class itself. The order of the structure members matters.
  89  * reinit_class() zeroes the key member and all subsequent members.
  90  */
  91 struct lock_class {
  92         /*
  93          * class-hash:
  94          */
  95         struct hlist_node               hash_entry;
  96
  97         /*
  98          * Entry in all_lock_classes when in use. Entry in free_lock_classes
  99          * when not in use. Instances that are being freed are on one of the
 100          * zapped_classes lists.
 101          */
 102         struct list_head                lock_entry;
 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         const struct lockdep_subclass_key *key;
 112         unsigned int                    subclass;
 113         unsigned int                    dep_gen_id;
 114
 115         /*
 116          * IRQ/softirq usage tracking bits:
 117          */
 118         unsigned long                   usage_mask;
 119         const struct lock_trace         *usage_traces[LOCK_TRACE_STATES];
 120
 121         /*
 122          * Generation counter, when doing certain classes of graph walking,
 123          * to ensure that we check one node only once:
 124          */
 125         int                             name_version;
 126         const char                      *name;
 127
 128         u8                              wait_type_inner;
 129         u8                              wait_type_outer;
 130         u8                              lock_type;
 131         /* u8                           hole; */
 132
 133 #ifdef CONFIG_LOCK_STAT
 134         unsigned long                   contention_point[LOCKSTAT_POINTS];
 135         unsigned long                   contending_point[LOCKSTAT_POINTS];
 136 #endif
 137 } __no_randomize_layout;
 138
 139 #ifdef CONFIG_LOCK_STAT
 140 struct lock_time {
 141         s64                             min;
 142         s64                             max;
 143         s64                             total;
 144         unsigned long                   nr;
 145 };
 146
 147 enum bounce_type {
 148         bounce_acquired_write,
 149         bounce_acquired_read,
 150         bounce_contended_write,
 151         bounce_contended_read,
 152         nr_bounce_types,
 153
 154         bounce_acquired = bounce_acquired_write,
 155         bounce_contended = bounce_contended_write,
 156 };
 157
 158 struct lock_class_stats {
 159         unsigned long                   contention_point[LOCKSTAT_POINTS];
 160         unsigned long                   contending_point[LOCKSTAT_POINTS];
 161         struct lock_time                read_waittime;
 162         struct lock_time                write_waittime;
 163         struct lock_time                read_holdtime;
 164         struct lock_time                write_holdtime;
 165         unsigned long                   bounces[nr_bounce_types];
 166 };
 167
 168 struct lock_class_stats lock_stats(struct lock_class *class);
 169 void clear_lock_stats(struct lock_class *class);
 170 #endif
 171
 172 /*
 173  * Map the lock object (the lock instance) to the lock-class object.
 174  * This is embedded into specific lock instances:
 175  */
 176 struct lockdep_map {
 177         struct lock_class_key           *key;
 178         struct lock_class               *class_cache[NR_LOCKDEP_CACHING_CLASSES];
 179         const char                      *name;
 180         u8                              wait_type_outer; /* can be taken in this context */
 181         u8                              wait_type_inner; /* presents this context */
 182         u8                              lock_type;
 183         /* u8                           hole; */
 184 #ifdef CONFIG_LOCK_STAT
 185         int                             cpu;
 186         unsigned long                   ip;
 187 #endif
 188 };
 189
 190 struct pin_cookie { unsigned int val; };
 191
 192 #else /* !CONFIG_LOCKDEP */
 193
 194 /*
 195  * The class key takes no space if lockdep is disabled:
 196  */
 197 struct lock_class_key { };
 198
 199 /*
 200  * The lockdep_map takes no space if lockdep is disabled:
 201  */
 202 struct lockdep_map { };
 203
 204 struct pin_cookie { };
 205
 206 #endif /* !LOCKDEP */
 207
 208 #endif /* __LINUX_LOCKDEP_TYPES_H */