/* SPDX-License-Identifier: GPL-2.0 */
/*
 * 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_USED_READ,
        LOCK_USAGE_STATES,
};

/* states after LOCK_USED_READ are not traced and printed */
static_assert(LOCK_TRACE_STATES == LOCK_USAGE_STATES);

#define LOCK_USAGE_READ_MASK 1
#define LOCK_USAGE_DIR_MASK  2
#define LOCK_USAGE_STATE_MASK (~(LOCK_USAGE_READ_MASK | LOCK_USAGE_DIR_MASK))

/*
 * 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)
        __LOCKF(USED_READ)
};

enum {
#define LOCKDEP_STATE(__STATE)  LOCKF_ENABLED_##__STATE |
        LOCKF_ENABLED_IRQ =
#include "lockdep_states.h"
        0,
#undef LOCKDEP_STATE

#define LOCKDEP_STATE(__STATE)  LOCKF_USED_IN_##__STATE |
        LOCKF_USED_IN_IRQ =
#include "lockdep_states.h"
        0,
#undef LOCKDEP_STATE

#define LOCKDEP_STATE(__STATE)  LOCKF_ENABLED_##__STATE##_READ |
        LOCKF_ENABLED_IRQ_READ =
#include "lockdep_states.h"
        0,
#undef LOCKDEP_STATE

#define LOCKDEP_STATE(__STATE)  LOCKF_USED_IN_##__STATE##_READ |
        LOCKF_USED_IN_IRQ_READ =
#include "lockdep_states.h"
        0,
#undef LOCKDEP_STATE
};

#define LOCKF_ENABLED_IRQ_ALL (LOCKF_ENABLED_IRQ | LOCKF_ENABLED_IRQ_READ)
#define LOCKF_USED_IN_IRQ_ALL (LOCKF_USED_IN_IRQ | LOCKF_USED_IN_IRQ_READ)

#define LOCKF_IRQ (LOCKF_ENABLED_IRQ | LOCKF_USED_IN_IRQ)
#define LOCKF_IRQ_READ (LOCKF_ENABLED_IRQ_READ | LOCKF_USED_IN_IRQ_READ)

/*
 * CONFIG_LOCKDEP_SMALL is defined for sparc. Sparc requires .text,
 * .data and .bss to fit in required 32MB limit for the kernel. With
 * CONFIG_LOCKDEP 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_LOCKDEP_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
#define STACK_TRACE_HASH_SIZE   8192
#else
#define MAX_LOCKDEP_ENTRIES     (1UL << CONFIG_LOCKDEP_BITS)

#define MAX_LOCKDEP_CHAINS_BITS CONFIG_LOCKDEP_CHAINS_BITS

/*
 * Stack-trace: tightly packed array of stack backtrace
 * addresses. Protected by the hash_lock.
 */
#define MAX_STACK_TRACE_ENTRIES (1UL << CONFIG_LOCKDEP_STACK_TRACE_BITS)
#define STACK_TRACE_HASH_SIZE   (1 << CONFIG_LOCKDEP_STACK_TRACE_HASH_BITS)
#endif

/*
 * Bit definitions for lock_chain.irq_context
 */
#define LOCK_CHAIN_SOFTIRQ_CONTEXT      (1 << 0)
#define LOCK_CHAIN_HARDIRQ_CONTEXT      (1 << 1)

#define MAX_LOCKDEP_CHAINS      (1UL << MAX_LOCKDEP_CHAINS_BITS)

#define AVG_LOCKDEP_CHAIN_DEPTH         5
#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS * AVG_LOCKDEP_CHAIN_DEPTH)

extern struct lock_chain lock_chains[];

#define LOCK_USAGE_CHARS (2*XXX_LOCK_USAGE_STATES + 1)

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

extern const char *__get_key_name(const 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_zapped_classes;
extern unsigned long nr_zapped_lock_chains;
extern unsigned long nr_list_entries;
extern unsigned long nr_dynamic_keys;
long lockdep_next_lockchain(long i);
unsigned long lock_chain_count(void);
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 nr_free_chain_hlocks;
extern unsigned int nr_lost_chain_hlocks;
extern unsigned int nr_large_chain_blocks;

extern unsigned int max_lockdep_depth;
extern unsigned int max_bfs_queue_depth;
extern unsigned long max_lock_class_idx;

extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
extern unsigned long lock_classes_in_use[];

#ifdef CONFIG_PROVE_LOCKING
extern unsigned long lockdep_count_forward_deps(struct lock_class *);
extern unsigned long lockdep_count_backward_deps(struct lock_class *);
#ifdef CONFIG_TRACE_IRQFLAGS
u64 lockdep_stack_trace_count(void);
u64 lockdep_stack_hash_count(void);
#endif
#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 {
        unsigned long  chain_lookup_hits;
        unsigned int   chain_lookup_misses;
        unsigned long  hardirqs_on_events;
        unsigned long  hardirqs_off_events;
        unsigned long  redundant_hardirqs_on;
        unsigned long  redundant_hardirqs_off;
        unsigned long  softirqs_on_events;
        unsigned long  softirqs_off_events;
        unsigned long  redundant_softirqs_on;
        unsigned long  redundant_softirqs_off;
        int            nr_unused_locks;
        unsigned int   nr_redundant_checks;
        unsigned int   nr_redundant;
        unsigned int   nr_cyclic_checks;
        unsigned int   nr_find_usage_forwards_checks;
        unsigned int   nr_find_usage_backwards_checks;

        /*
         * Per lock class locking operation stat counts
         */
        unsigned long lock_class_ops[MAX_LOCKDEP_KEYS];
};

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;                                                        \
})

static inline void debug_class_ops_inc(struct lock_class *class)
{
        int idx;

        idx = class - lock_classes;
        __debug_atomic_inc(lock_class_ops[idx]);
}

static inline unsigned long debug_class_ops_read(struct lock_class *class)
{
        int idx, cpu;
        unsigned long ops = 0;

        idx = class - lock_classes;
        for_each_possible_cpu(cpu)
                ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu);
        return ops;
}

#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
# define debug_class_ops_inc(ptr)       do { } while (0)
#endif