2 * kernel/lockdep_internals.h
4 * Runtime locking correctness validator
6 * lockdep subsystem internal functions and variables.
10 * Lock-class usage-state bits:
13 #define LOCKDEP_STATE(__STATE) \
14 LOCK_USED_IN_##__STATE, \
15 LOCK_USED_IN_##__STATE##_READ, \
16 LOCK_ENABLED_##__STATE, \
17 LOCK_ENABLED_##__STATE##_READ,
18 #include "lockdep_states.h"
25 * Usage-state bitmasks:
27 #define __LOCKF(__STATE) LOCKF_##__STATE = (1 << LOCK_##__STATE),
30 #define LOCKDEP_STATE(__STATE) \
31 __LOCKF(USED_IN_##__STATE) \
32 __LOCKF(USED_IN_##__STATE##_READ) \
33 __LOCKF(ENABLED_##__STATE) \
34 __LOCKF(ENABLED_##__STATE##_READ)
35 #include "lockdep_states.h"
40 #define LOCKF_ENABLED_IRQ (LOCKF_ENABLED_HARDIRQ | LOCKF_ENABLED_SOFTIRQ)
41 #define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ)
43 #define LOCKF_ENABLED_IRQ_READ \
44 (LOCKF_ENABLED_HARDIRQ_READ | LOCKF_ENABLED_SOFTIRQ_READ)
45 #define LOCKF_USED_IN_IRQ_READ \
46 (LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)
49 * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
52 * We use the per-lock dependency maps in two ways: we grow it by adding
53 * every to-be-taken lock to all currently held lock's own dependency
54 * table (if it's not there yet), and we check it for lock order
55 * conflicts and deadlocks.
57 #define MAX_LOCKDEP_ENTRIES 16384UL
59 #define MAX_LOCKDEP_CHAINS_BITS 15
60 #define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)
62 #define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
65 * Stack-trace: tightly packed array of stack backtrace
66 * addresses. Protected by the hash_lock.
68 #define MAX_STACK_TRACE_ENTRIES 262144UL
70 extern struct list_head all_lock_classes;
71 extern struct lock_chain lock_chains[];
73 #define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
75 extern void get_usage_chars(struct lock_class *class,
76 char usage[LOCK_USAGE_CHARS]);
78 extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str);
80 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
82 extern unsigned long nr_lock_classes;
83 extern unsigned long nr_list_entries;
84 extern unsigned long nr_lock_chains;
85 extern int nr_chain_hlocks;
86 extern unsigned long nr_stack_trace_entries;
88 extern unsigned int nr_hardirq_chains;
89 extern unsigned int nr_softirq_chains;
90 extern unsigned int nr_process_chains;
91 extern unsigned int max_lockdep_depth;
92 extern unsigned int max_recursion_depth;
94 #ifdef CONFIG_PROVE_LOCKING
95 extern unsigned long lockdep_count_forward_deps(struct lock_class *);
96 extern unsigned long lockdep_count_backward_deps(struct lock_class *);
98 static inline unsigned long
99 lockdep_count_forward_deps(struct lock_class *class)
103 static inline unsigned long
104 lockdep_count_backward_deps(struct lock_class *class)
110 #ifdef CONFIG_DEBUG_LOCKDEP
112 * Various lockdep statistics:
114 extern atomic_t chain_lookup_hits;
115 extern atomic_t chain_lookup_misses;
116 extern atomic_t hardirqs_on_events;
117 extern atomic_t hardirqs_off_events;
118 extern atomic_t redundant_hardirqs_on;
119 extern atomic_t redundant_hardirqs_off;
120 extern atomic_t softirqs_on_events;
121 extern atomic_t softirqs_off_events;
122 extern atomic_t redundant_softirqs_on;
123 extern atomic_t redundant_softirqs_off;
124 extern atomic_t nr_unused_locks;
125 extern atomic_t nr_cyclic_checks;
126 extern atomic_t nr_cyclic_check_recursions;
127 extern atomic_t nr_find_usage_forwards_checks;
128 extern atomic_t nr_find_usage_forwards_recursions;
129 extern atomic_t nr_find_usage_backwards_checks;
130 extern atomic_t nr_find_usage_backwards_recursions;
131 # define debug_atomic_inc(ptr) atomic_inc(ptr)
132 # define debug_atomic_dec(ptr) atomic_dec(ptr)
133 # define debug_atomic_read(ptr) atomic_read(ptr)
135 # define debug_atomic_inc(ptr) do { } while (0)
136 # define debug_atomic_dec(ptr) do { } while (0)
137 # define debug_atomic_read(ptr) 0
141 extern unsigned int max_bfs_queue_depth;
142 extern unsigned long nr_list_entries;
143 extern struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
144 extern unsigned long bfs_accessed[];
146 /*For good efficiency of modular, we use power of 2*/
147 #define MAX_CIRCULAR_QUE_SIZE 4096UL
149 /* The circular_queue and helpers is used to implement the
150 * breadth-first search(BFS)algorithem, by which we can build
151 * the shortest path from the next lock to be acquired to the
152 * previous held lock if there is a circular between them.
154 struct circular_queue{
155 unsigned long element[MAX_CIRCULAR_QUE_SIZE];
156 unsigned int front, rear;
159 static inline void __cq_init(struct circular_queue *cq)
161 cq->front = cq->rear = 0;
162 bitmap_zero(bfs_accessed, MAX_LOCKDEP_ENTRIES);
165 static inline int __cq_empty(struct circular_queue *cq)
167 return (cq->front == cq->rear);
170 static inline int __cq_full(struct circular_queue *cq)
172 return ((cq->rear + 1)&(MAX_CIRCULAR_QUE_SIZE-1)) == cq->front;
175 static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem)
180 cq->element[cq->rear] = elem;
181 cq->rear = (cq->rear + 1)&(MAX_CIRCULAR_QUE_SIZE-1);
185 static inline int __cq_dequeue(struct circular_queue *cq, unsigned long *elem)
190 *elem = cq->element[cq->front];
191 cq->front = (cq->front + 1)&(MAX_CIRCULAR_QUE_SIZE-1);
195 static inline unsigned int __cq_get_elem_count(struct circular_queue *cq)
197 return (cq->rear - cq->front)&(MAX_CIRCULAR_QUE_SIZE-1);
200 static inline void mark_lock_accessed(struct lock_list *lock,
201 struct lock_list *parent)
204 nr = lock - list_entries;
205 WARN_ON(nr >= nr_list_entries);
206 lock->parent = parent;
207 set_bit(nr, bfs_accessed);
210 static inline unsigned long lock_accessed(struct lock_list *lock)
213 nr = lock - list_entries;
214 WARN_ON(nr >= nr_list_entries);
215 return test_bit(nr, bfs_accessed);
218 static inline struct lock_list *get_lock_parent(struct lock_list *child)
220 return child->parent;
223 static inline int get_lock_depth(struct lock_list *child)
226 struct lock_list *parent;
228 while ((parent = get_lock_parent(child))) {