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,         /* 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_WAIT_OVERRIDE,  /* annotation */
  37         LD_LOCK_MAX,
  38 };
  39
  40 #ifdef CONFIG_LOCKDEP
  41
  42 /*
  43  * We'd rather not expose kernel/lockdep_states.h this wide, but we do need
  44  * the total number of states... :-(
  45  *
  46  * XXX_LOCK_USAGE_STATES is the number of lines in lockdep_states.h, for each
  47  * of those we generates 4 states, Additionally we report on USED and USED_READ.
  48  */
  49 #define XXX_LOCK_USAGE_STATES           2
  50 #define LOCK_TRACE_STATES               (XXX_LOCK_USAGE_STATES*4 + 2)
  51
  52 /*
  53  * NR_LOCKDEP_CACHING_CLASSES ... Number of classes
  54  * cached in the instance of lockdep_map
  55  *
  56  * Currently main class (subclass == 0) and single depth subclass
  57  * are cached in lockdep_map. This optimization is mainly targeting
  58  * on rq->lock. double_rq_lock() acquires this highly competitive with
  59  * single depth.
  60  */
  61 #define NR_LOCKDEP_CACHING_CLASSES      2
  62
  63 /*
  64  * A lockdep key is associated with each lock object. For static locks we use
  65  * the lock address itself as the key. Dynamically allocated lock objects can
  66  * have a statically or dynamically allocated key. Dynamically allocated lock
  67  * keys must be registered before being used and must be unregistered before
  68  * the key memory is freed.
  69  */
  70 struct lockdep_subclass_key {
  71         char __one_byte;
  72 } __attribute__ ((__packed__));
  73
  74 /* hash_entry is used to keep track of dynamically allocated keys. */
  75 struct lock_class_key {
  76         union {
  77                 struct hlist_node               hash_entry;
  78                 struct lockdep_subclass_key     subkeys[MAX_LOCKDEP_SUBCLASSES];
  79         };
  80 };
  81
  82 extern struct lock_class_key __lockdep_no_validate__;
  83
  84 struct lock_trace;
  85
  86 #define LOCKSTAT_POINTS         4
  87
  88 struct lockdep_map;
  89 typedef int (*lock_cmp_fn)(const struct lockdep_map *a,
  90                            const struct lockdep_map *b);
  91 typedef void (*lock_print_fn)(const struct lockdep_map *map);
  92
  93 /*
  94  * The lock-class itself. The order of the structure members matters.
  95  * reinit_class() zeroes the key member and all subsequent members.
  96  */
  97 struct lock_class {
  98         /*
  99          * class-hash:
 100          */
 101         struct hlist_node               hash_entry;
 102
 103         /*
 104          * Entry in all_lock_classes when in use. Entry in free_lock_classes
 105          * when not in use. Instances that are being freed are on one of the
 106          * zapped_classes lists.
 107          */
 108         struct list_head                lock_entry;
 109
 110         /*
 111          * These fields represent a directed graph of lock dependencies,
 112          * to every node we attach a list of "forward" and a list of
 113          * "backward" graph nodes.
 114          */
 115         struct list_head                locks_after, locks_before;
 116
 117         const struct lockdep_subclass_key *key;
 118         lock_cmp_fn                     cmp_fn;
 119         lock_print_fn                   print_fn;
 120
 121         unsigned int                    subclass;
 122         unsigned int                    dep_gen_id;
 123
 124         /*
 125          * IRQ/softirq usage tracking bits:
 126          */
 127         unsigned long                   usage_mask;
 128         const struct lock_trace         *usage_traces[LOCK_TRACE_STATES];
 129
 130         /*
 131          * Generation counter, when doing certain classes of graph walking,
 132          * to ensure that we check one node only once:
 133          */
 134         int                             name_version;
 135         const char                      *name;
 136
 137         u8                              wait_type_inner;
 138         u8                              wait_type_outer;
 139         u8                              lock_type;
 140         /* u8                           hole; */
 141
 142 #ifdef CONFIG_LOCK_STAT
 143         unsigned long                   contention_point[LOCKSTAT_POINTS];
 144         unsigned long                   contending_point[LOCKSTAT_POINTS];
 145 #endif
 146 } __no_randomize_layout;
 147
 148 #ifdef CONFIG_LOCK_STAT
 149 struct lock_time {
 150         s64                             min;
 151         s64                             max;
 152         s64                             total;
 153         unsigned long                   nr;
 154 };
 155
 156 enum bounce_type {
 157         bounce_acquired_write,
 158         bounce_acquired_read,
 159         bounce_contended_write,
 160         bounce_contended_read,
 161         nr_bounce_types,
 162
 163         bounce_acquired = bounce_acquired_write,
 164         bounce_contended = bounce_contended_write,
 165 };
 166
 167 struct lock_class_stats {
 168         unsigned long                   contention_point[LOCKSTAT_POINTS];
 169         unsigned long                   contending_point[LOCKSTAT_POINTS];
 170         struct lock_time                read_waittime;
 171         struct lock_time                write_waittime;
 172         struct lock_time                read_holdtime;
 173         struct lock_time                write_holdtime;
 174         unsigned long                   bounces[nr_bounce_types];
 175 };
 176
 177 struct lock_class_stats lock_stats(struct lock_class *class);
 178 void clear_lock_stats(struct lock_class *class);
 179 #endif
 180
 181 /*
 182  * Map the lock object (the lock instance) to the lock-class object.
 183  * This is embedded into specific lock instances:
 184  */
 185 struct lockdep_map {
 186         struct lock_class_key           *key;
 187         struct lock_class               *class_cache[NR_LOCKDEP_CACHING_CLASSES];
 188         const char                      *name;
 189         u8                              wait_type_outer; /* can be taken in this context */
 190         u8                              wait_type_inner; /* presents this context */
 191         u8                              lock_type;
 192         /* u8                           hole; */
 193 #ifdef CONFIG_LOCK_STAT
 194         int                             cpu;
 195         unsigned long                   ip;
 196 #endif
 197 };
 198
 199 struct pin_cookie { unsigned int val; };
 200
 201 #else /* !CONFIG_LOCKDEP */
 202
 203 /*
 204  * The class key takes no space if lockdep is disabled:
 205  */
 206 struct lock_class_key { };
 207
 208 /*
 209  * The lockdep_map takes no space if lockdep is disabled:
 210  */
 211 struct lockdep_map { };
 212
 213 struct pin_cookie { };
 214
 215 #endif /* !LOCKDEP */
 216
 217 #endif /* __LINUX_LOCKDEP_TYPES_H */