[mirror_ubuntu-zesty-kernel.git] / kernel / locking / lockdep_internals.h

/*
 * kernel/lockdep_internals.h
 *
 * Runtime locking correctness validator
 *
 * lockdep subsystem internal functions and variables.
 */

/*
 * Lock-class usage-state bits:
 */
enum lock_usage_bit {
#define LOCKDEP_STATE(__STATE)		\
	LOCK_USED_IN_##__STATE,		\
	LOCK_USED_IN_##__STATE##_READ,	\
	LOCK_ENABLED_##__STATE,		\
	LOCK_ENABLED_##__STATE##_READ,
#include "lockdep_states.h"
#undef LOCKDEP_STATE
	LOCK_USED,
	LOCK_USAGE_STATES
};

/*
 * Usage-state bitmasks:
 */
#define __LOCKF(__STATE)	LOCKF_##__STATE = (1 << LOCK_##__STATE),

enum {
#define LOCKDEP_STATE(__STATE)						\
	__LOCKF(USED_IN_##__STATE)					\
	__LOCKF(USED_IN_##__STATE##_READ)				\
	__LOCKF(ENABLED_##__STATE)					\
	__LOCKF(ENABLED_##__STATE##_READ)
#include "lockdep_states.h"
#undef LOCKDEP_STATE
	__LOCKF(USED)
};

#define LOCKF_ENABLED_IRQ (LOCKF_ENABLED_HARDIRQ | LOCKF_ENABLED_SOFTIRQ)
#define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ)

#define LOCKF_ENABLED_IRQ_READ \
		(LOCKF_ENABLED_HARDIRQ_READ | LOCKF_ENABLED_SOFTIRQ_READ)
#define LOCKF_USED_IN_IRQ_READ \
		(LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)

/*
 * CONFIG_PROVE_LOCKING_SMALL is defined for sparc. Sparc requires .text,
 * .data and .bss to fit in required 32MB limit for the kernel. With
 * PROVE_LOCKING we could go over this limit and cause system boot-up problems.
 * So, reduce the static allocations for lockdeps related structures so that
 * everything fits in current required size limit.
 */
#ifdef CONFIG_PROVE_LOCKING_SMALL
/*
 * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
 * we track.
 *
 * We use the per-lock dependency maps in two ways: we grow it by adding
 * every to-be-taken lock to all currently held lock's own dependency
 * table (if it's not there yet), and we check it for lock order
 * conflicts and deadlocks.
 */
#define MAX_LOCKDEP_ENTRIES	16384UL
#define MAX_LOCKDEP_CHAINS_BITS	15
#define MAX_STACK_TRACE_ENTRIES	262144UL
#else
#define MAX_LOCKDEP_ENTRIES	32768UL

#define MAX_LOCKDEP_CHAINS_BITS	16

/*
 * Stack-trace: tightly packed array of stack backtrace
 * addresses. Protected by the hash_lock.
 */
#define MAX_STACK_TRACE_ENTRIES	524288UL
#endif

#define MAX_LOCKDEP_CHAINS	(1UL << MAX_LOCKDEP_CHAINS_BITS)

#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)

extern struct list_head all_lock_classes;
extern struct lock_chain lock_chains[];

#define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)

extern void get_usage_chars(struct lock_class *class,
			    char usage[LOCK_USAGE_CHARS]);

extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str);

struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);

extern unsigned long nr_lock_classes;
extern unsigned long nr_list_entries;
extern unsigned long nr_lock_chains;
extern int nr_chain_hlocks;
extern unsigned long nr_stack_trace_entries;

extern unsigned int nr_hardirq_chains;
extern unsigned int nr_softirq_chains;
extern unsigned int nr_process_chains;
extern unsigned int max_lockdep_depth;
extern unsigned int max_recursion_depth;

extern unsigned int max_bfs_queue_depth;

#ifdef CONFIG_PROVE_LOCKING
extern unsigned long lockdep_count_forward_deps(struct lock_class *);
extern unsigned long lockdep_count_backward_deps(struct lock_class *);
#else
static inline unsigned long
lockdep_count_forward_deps(struct lock_class *class)
{
	return 0;
}
static inline unsigned long
lockdep_count_backward_deps(struct lock_class *class)
{
	return 0;
}
#endif

#ifdef CONFIG_DEBUG_LOCKDEP

#include <asm/local.h>
/*
 * Various lockdep statistics.
 * We want them per cpu as they are often accessed in fast path
 * and we want to avoid too much cache bouncing.
 */
struct lockdep_stats {
	int	chain_lookup_hits;
	int	chain_lookup_misses;
	int	hardirqs_on_events;
	int	hardirqs_off_events;
	int	redundant_hardirqs_on;
	int	redundant_hardirqs_off;
	int	softirqs_on_events;
	int	softirqs_off_events;
	int	redundant_softirqs_on;
	int	redundant_softirqs_off;
	int	nr_unused_locks;
	int	nr_cyclic_checks;
	int	nr_cyclic_check_recursions;
	int	nr_find_usage_forwards_checks;
	int	nr_find_usage_forwards_recursions;
	int	nr_find_usage_backwards_checks;
	int	nr_find_usage_backwards_recursions;
};

DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);

#define __debug_atomic_inc(ptr)					\
	this_cpu_inc(lockdep_stats.ptr);

#define debug_atomic_inc(ptr)			{		\
	WARN_ON_ONCE(!irqs_disabled());				\
	__this_cpu_inc(lockdep_stats.ptr);			\
}

#define debug_atomic_dec(ptr)			{		\
	WARN_ON_ONCE(!irqs_disabled());				\
	__this_cpu_dec(lockdep_stats.ptr);			\
}

#define debug_atomic_read(ptr)		({				\
	struct lockdep_stats *__cpu_lockdep_stats;			\
	unsigned long long __total = 0;					\
	int __cpu;							\
	for_each_possible_cpu(__cpu) {					\
		__cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu);	\
		__total += __cpu_lockdep_stats->ptr;			\
	}								\
	__total;							\
})
#else
# define __debug_atomic_inc(ptr)	do { } while (0)
# define debug_atomic_inc(ptr)		do { } while (0)
# define debug_atomic_dec(ptr)		do { } while (0)
# define debug_atomic_read(ptr)		0
#endif
Commit	Line	Data
fbb9ce95 IM	1	/*
	2	* kernel/lockdep_internals.h
	3	*
	4	* Runtime locking correctness validator
	5	*
	6	* lockdep subsystem internal functions and variables.
	7	*/
	8
9851673b PZ	9	/*
	10	* Lock-class usage-state bits:
	11	*/
	12	enum lock_usage_bit {
d7b1b021 PZ	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"
	19	#undef LOCKDEP_STATE
	20	LOCK_USED,
9851673b PZ	21	LOCK_USAGE_STATES
	22	};
	23
	24	/*
	25	* Usage-state bitmasks:
	26	*/
d7b1b021 PZ	27	#define __LOCKF(__STATE) LOCKF_##__STATE = (1 << LOCK_##__STATE),
	28
	29	enum {
	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"
	36	#undef LOCKDEP_STATE
	37	__LOCKF(USED)
	38	};
9851673b PZ	39
	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)
	42
9851673b PZ	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)
	47
e245d99e BM	48	/*
	49	* CONFIG_PROVE_LOCKING_SMALL is defined for sparc. Sparc requires .text,
	50	* .data and .bss to fit in required 32MB limit for the kernel. With
	51	* PROVE_LOCKING we could go over this limit and cause system boot-up problems.
	52	* So, reduce the static allocations for lockdeps related structures so that
	53	* everything fits in current required size limit.
	54	*/
	55	#ifdef CONFIG_PROVE_LOCKING_SMALL
fbb9ce95 IM	56	/*
	57	* MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
	58	* we track.
	59	*
	60	* We use the per-lock dependency maps in two ways: we grow it by adding
	61	* every to-be-taken lock to all currently held lock's own dependency
	62	* table (if it's not there yet), and we check it for lock order
	63	* conflicts and deadlocks.
	64	*/
e245d99e BM	65	#define MAX_LOCKDEP_ENTRIES 16384UL
	66	#define MAX_LOCKDEP_CHAINS_BITS 15
	67	#define MAX_STACK_TRACE_ENTRIES 262144UL
	68	#else
1413c038	69	#define MAX_LOCKDEP_ENTRIES 32768UL
fbb9ce95	70
1413c038	71	#define MAX_LOCKDEP_CHAINS_BITS 16
443cd507	72
fbb9ce95 IM	73	/*
	74	* Stack-trace: tightly packed array of stack backtrace
	75	* addresses. Protected by the hash_lock.
	76	*/
1413c038	77	#define MAX_STACK_TRACE_ENTRIES 524288UL
e245d99e BM	78	#endif
	79
	80	#define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)
	81
	82	#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
fbb9ce95 IM	83
fbb9ce95 IM	84	extern struct list_head all_lock_classes;
443cd507	85	extern struct lock_chain lock_chains[];
fbb9ce95	86
f510b233 PZ	87	#define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
	88
	89	extern void get_usage_chars(struct lock_class *class,
	90	char usage[LOCK_USAGE_CHARS]);
fbb9ce95 IM	91
	92	extern const char * __get_key_name(struct lockdep_subclass_key key, char str);
	93
443cd507 HY	94	struct lock_class lock_chain_get_class(struct lock_chain chain, int i);
443cd507 HY	95
fbb9ce95 IM	96	extern unsigned long nr_lock_classes;
	97	extern unsigned long nr_list_entries;
	98	extern unsigned long nr_lock_chains;
cd1a28e8	99	extern int nr_chain_hlocks;
fbb9ce95 IM	100	extern unsigned long nr_stack_trace_entries;
	101
	102	extern unsigned int nr_hardirq_chains;
	103	extern unsigned int nr_softirq_chains;
	104	extern unsigned int nr_process_chains;
	105	extern unsigned int max_lockdep_depth;
	106	extern unsigned int max_recursion_depth;
	107
af012961 PZ	108	extern unsigned int max_bfs_queue_depth;
af012961 PZ	109
d6672c50	110	#ifdef CONFIG_PROVE_LOCKING
419ca3f1 DM	111	extern unsigned long lockdep_count_forward_deps(struct lock_class *);
419ca3f1 DM	112	extern unsigned long lockdep_count_backward_deps(struct lock_class *);
d6672c50 IM	113	#else
	114	static inline unsigned long
	115	lockdep_count_forward_deps(struct lock_class *class)
	116	{
	117	return 0;
	118	}
	119	static inline unsigned long
	120	lockdep_count_backward_deps(struct lock_class *class)
	121	{
	122	return 0;
	123	}
	124	#endif
419ca3f1	125
fbb9ce95	126	#ifdef CONFIG_DEBUG_LOCKDEP
bd6d29c2 FW	127
bd6d29c2 FW	128	#include <asm/local.h>
fbb9ce95	129	/*
bd6d29c2 FW	130	* Various lockdep statistics.
	131	* We want them per cpu as they are often accessed in fast path
	132	* and we want to avoid too much cache bouncing.
fbb9ce95	133	*/
bd6d29c2 FW	134	struct lockdep_stats {
	135	int chain_lookup_hits;
	136	int chain_lookup_misses;
	137	int hardirqs_on_events;
	138	int hardirqs_off_events;
	139	int redundant_hardirqs_on;
	140	int redundant_hardirqs_off;
	141	int softirqs_on_events;
	142	int softirqs_off_events;
	143	int redundant_softirqs_on;
	144	int redundant_softirqs_off;
	145	int nr_unused_locks;
	146	int nr_cyclic_checks;
	147	int nr_cyclic_check_recursions;
	148	int nr_find_usage_forwards_checks;
	149	int nr_find_usage_forwards_recursions;
	150	int nr_find_usage_backwards_checks;
	151	int nr_find_usage_backwards_recursions;
	152	};
	153
	154	DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats);
	155
ba697f40 FW	156	#define __debug_atomic_inc(ptr) \
	157	this_cpu_inc(lockdep_stats.ptr);
	158
bd6d29c2	159	#define debug_atomic_inc(ptr) { \
bd6d29c2	160	WARN_ON_ONCE(!irqs_disabled()); \
54d47a2b	161	__this_cpu_inc(lockdep_stats.ptr); \
bd6d29c2 FW	162	}
	163
	164	#define debug_atomic_dec(ptr) { \
bd6d29c2	165	WARN_ON_ONCE(!irqs_disabled()); \
54d47a2b	166	__this_cpu_dec(lockdep_stats.ptr); \
bd6d29c2 FW	167	}
	168
	169	#define debug_atomic_read(ptr) ({ \
	170	struct lockdep_stats *__cpu_lockdep_stats; \
	171	unsigned long long __total = 0; \
	172	int __cpu; \
	173	for_each_possible_cpu(__cpu) { \
	174	__cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu); \
	175	__total += __cpu_lockdep_stats->ptr; \
	176	} \
	177	__total; \
	178	})
fbb9ce95	179	#else
ba697f40	180	# define __debug_atomic_inc(ptr) do { } while (0)
fbb9ce95 IM	181	# define debug_atomic_inc(ptr) do { } while (0)
	182	# define debug_atomic_dec(ptr) do { } while (0)
	183	# define debug_atomic_read(ptr) 0
	184	#endif