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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
17enum 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
33enum 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 */
70struct lockdep_subclass_key {
71 char __one_byte;
72} __attribute__ ((__packed__));
73
74/* hash_entry is used to keep track of dynamically allocated keys. */
75struct lock_class_key {
76 union {
77 struct hlist_node hash_entry;
78 struct lockdep_subclass_key subkeys[MAX_LOCKDEP_SUBCLASSES];
79 };
80};
81
82extern struct lock_class_key __lockdep_no_validate__;
83
84struct lock_trace;
85
86#define LOCKSTAT_POINTS 4
87
88/*
89 * The lock-class itself. The order of the structure members matters.
90 * reinit_class() zeroes the key member and all subsequent members.
91 */
92struct lock_class {
93 /*
94 * class-hash:
95 */
96 struct hlist_node hash_entry;
97
98 /*
99 * Entry in all_lock_classes when in use. Entry in free_lock_classes
100 * when not in use. Instances that are being freed are on one of the
101 * zapped_classes lists.
102 */
103 struct list_head lock_entry;
104
105 /*
106 * These fields represent a directed graph of lock dependencies,
107 * to every node we attach a list of "forward" and a list of
108 * "backward" graph nodes.
109 */
110 struct list_head locks_after, locks_before;
111
112 const struct lockdep_subclass_key *key;
113 unsigned int subclass;
114 unsigned int dep_gen_id;
115
116 /*
117 * IRQ/softirq usage tracking bits:
118 */
119 unsigned long usage_mask;
120 const struct lock_trace *usage_traces[LOCK_TRACE_STATES];
121
122 /*
123 * Generation counter, when doing certain classes of graph walking,
124 * to ensure that we check one node only once:
125 */
126 int name_version;
127 const char *name;
128
129 u8 wait_type_inner;
130 u8 wait_type_outer;
131 u8 lock_type;
132 /* u8 hole; */
133
134#ifdef CONFIG_LOCK_STAT
135 unsigned long contention_point[LOCKSTAT_POINTS];
136 unsigned long contending_point[LOCKSTAT_POINTS];
137#endif
138} __no_randomize_layout;
139
140#ifdef CONFIG_LOCK_STAT
141struct lock_time {
142 s64 min;
143 s64 max;
144 s64 total;
145 unsigned long nr;
146};
147
148enum bounce_type {
149 bounce_acquired_write,
150 bounce_acquired_read,
151 bounce_contended_write,
152 bounce_contended_read,
153 nr_bounce_types,
154
155 bounce_acquired = bounce_acquired_write,
156 bounce_contended = bounce_contended_write,
157};
158
159struct lock_class_stats {
160 unsigned long contention_point[LOCKSTAT_POINTS];
161 unsigned long contending_point[LOCKSTAT_POINTS];
162 struct lock_time read_waittime;
163 struct lock_time write_waittime;
164 struct lock_time read_holdtime;
165 struct lock_time write_holdtime;
166 unsigned long bounces[nr_bounce_types];
167};
168
169struct lock_class_stats lock_stats(struct lock_class *class);
170void clear_lock_stats(struct lock_class *class);
171#endif
172
173/*
174 * Map the lock object (the lock instance) to the lock-class object.
175 * This is embedded into specific lock instances:
176 */
177struct lockdep_map {
178 struct lock_class_key *key;
179 struct lock_class *class_cache[NR_LOCKDEP_CACHING_CLASSES];
180 const char *name;
181 u8 wait_type_outer; /* can be taken in this context */
182 u8 wait_type_inner; /* presents this context */
183 u8 lock_type;
184 /* u8 hole; */
185#ifdef CONFIG_LOCK_STAT
186 int cpu;
187 unsigned long ip;
188#endif
189};
190
191struct pin_cookie { unsigned int val; };
192
193#else /* !CONFIG_LOCKDEP */
194
195/*
196 * The class key takes no space if lockdep is disabled:
197 */
198struct lock_class_key { };
199
200/*
201 * The lockdep_map takes no space if lockdep is disabled:
202 */
203struct lockdep_map { };
204
205struct pin_cookie { };
206
207#endif /* !LOCKDEP */
208
209#endif /* __LINUX_LOCKDEP_TYPES_H */