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 <mingo@redhat.com>
   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,         /* CONFIG_PREEMPT_LOCK, 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 #ifdef CONFIG_LOCKDEP
  34
  35 /*
  36  * We'd rather not expose kernel/lockdep_states.h this wide, but we do need
  37  * the total number of states... :-(
  38  */
  39 #define XXX_LOCK_USAGE_STATES           (1+2*4)
  40
  41 /*
  42  * NR_LOCKDEP_CACHING_CLASSES ... Number of classes
  43  * cached in the instance of lockdep_map
  44  *
  45  * Currently main class (subclass == 0) and signle depth subclass
  46  * are cached in lockdep_map. This optimization is mainly targeting
  47  * on rq->lock. double_rq_lock() acquires this highly competitive with
  48  * single depth.
  49  */
  50 #define NR_LOCKDEP_CACHING_CLASSES      2
  51
  52 /*
  53  * A lockdep key is associated with each lock object. For static locks we use
  54  * the lock address itself as the key. Dynamically allocated lock objects can
  55  * have a statically or dynamically allocated key. Dynamically allocated lock
  56  * keys must be registered before being used and must be unregistered before
  57  * the key memory is freed.
  58  */
  59 struct lockdep_subclass_key {
  60         char __one_byte;
  61 } __attribute__ ((__packed__));
  62
  63 /* hash_entry is used to keep track of dynamically allocated keys. */
  64 struct lock_class_key {
  65         union {
  66                 struct hlist_node               hash_entry;
  67                 struct lockdep_subclass_key     subkeys[MAX_LOCKDEP_SUBCLASSES];
  68         };
  69 };
  70
  71 extern struct lock_class_key __lockdep_no_validate__;
  72
  73 struct lock_trace;
  74
  75 #define LOCKSTAT_POINTS         4
  76
  77 /*
  78  * The lock-class itself. The order of the structure members matters.
  79  * reinit_class() zeroes the key member and all subsequent members.
  80  */
  81 struct lock_class {
  82         /*
  83          * class-hash:
  84          */
  85         struct hlist_node               hash_entry;
  86
  87         /*
  88          * Entry in all_lock_classes when in use. Entry in free_lock_classes
  89          * when not in use. Instances that are being freed are on one of the
  90          * zapped_classes lists.
  91          */
  92         struct list_head                lock_entry;
  93
  94         /*
  95          * These fields represent a directed graph of lock dependencies,
  96          * to every node we attach a list of "forward" and a list of
  97          * "backward" graph nodes.
  98          */
  99         struct list_head                locks_after, locks_before;
 100
 101         const struct lockdep_subclass_key *key;
 102         unsigned int                    subclass;
 103         unsigned int                    dep_gen_id;
 104
 105         /*
 106          * IRQ/softirq usage tracking bits:
 107          */
 108         unsigned long                   usage_mask;
 109         const struct lock_trace         *usage_traces[XXX_LOCK_USAGE_STATES];
 110
 111         /*
 112          * Generation counter, when doing certain classes of graph walking,
 113          * to ensure that we check one node only once:
 114          */
 115         int                             name_version;
 116         const char                      *name;
 117
 118         short                           wait_type_inner;
 119         short                           wait_type_outer;
 120
 121 #ifdef CONFIG_LOCK_STAT
 122         unsigned long                   contention_point[LOCKSTAT_POINTS];
 123         unsigned long                   contending_point[LOCKSTAT_POINTS];
 124 #endif
 125 } __no_randomize_layout;
 126
 127 #ifdef CONFIG_LOCK_STAT
 128 struct lock_time {
 129         s64                             min;
 130         s64                             max;
 131         s64                             total;
 132         unsigned long                   nr;
 133 };
 134
 135 enum bounce_type {
 136         bounce_acquired_write,
 137         bounce_acquired_read,
 138         bounce_contended_write,
 139         bounce_contended_read,
 140         nr_bounce_types,
 141
 142         bounce_acquired = bounce_acquired_write,
 143         bounce_contended = bounce_contended_write,
 144 };
 145
 146 struct lock_class_stats {
 147         unsigned long                   contention_point[LOCKSTAT_POINTS];
 148         unsigned long                   contending_point[LOCKSTAT_POINTS];
 149         struct lock_time                read_waittime;
 150         struct lock_time                write_waittime;
 151         struct lock_time                read_holdtime;
 152         struct lock_time                write_holdtime;
 153         unsigned long                   bounces[nr_bounce_types];
 154 };
 155
 156 struct lock_class_stats lock_stats(struct lock_class *class);
 157 void clear_lock_stats(struct lock_class *class);
 158 #endif
 159
 160 /*
 161  * Map the lock object (the lock instance) to the lock-class object.
 162  * This is embedded into specific lock instances:
 163  */
 164 struct lockdep_map {
 165         struct lock_class_key           *key;
 166         struct lock_class               *class_cache[NR_LOCKDEP_CACHING_CLASSES];
 167         const char                      *name;
 168         short                           wait_type_outer; /* can be taken in this context */
 169         short                           wait_type_inner; /* presents this context */
 170 #ifdef CONFIG_LOCK_STAT
 171         int                             cpu;
 172         unsigned long                   ip;
 173 #endif
 174 };
 175
 176 struct pin_cookie { unsigned int val; };
 177
 178 #else /* !CONFIG_LOCKDEP */
 179
 180 /*
 181  * The class key takes no space if lockdep is disabled:
 182  */
 183 struct lock_class_key { };
 184
 185 /*
 186  * The lockdep_map takes no space if lockdep is disabled:
 187  */
 188 struct lockdep_map { };
 189
 190 struct pin_cookie { };
 191
 192 #endif /* !LOCKDEP */
 193
 194 #endif /* __LINUX_LOCKDEP_TYPES_H */