/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Berkeley Software Design Inc's name may not be used to endorse or
 *    promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      from BSDI Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp
 */

#ifndef _SYS_LOCK_H_
#define _SYS_LOCK_H_

#include <sys/queue.h>
#include <sys/_lock.h>
#include <sys/ktr_class.h>

struct lock_list_entry;
struct thread;

/*
 * Lock classes.  Each lock has a class which describes characteristics
 * common to all types of locks of a given class.
 *
 * Spin locks in general must always protect against preemption, as it is
 * an error to perform any type of context switch while holding a spin lock.
 * Also, for an individual lock to be recursable, its class must allow
 * recursion and the lock itself must explicitly allow recursion.
 *
 * The 'lc_ddb_show' function pointer is used to dump class-specific
 * data for the 'show lock' DDB command.  The 'lc_lock' and
 * 'lc_unlock' function pointers are used in sleep(9) and cv_wait(9)
 * to lock and unlock locks while blocking on a sleep queue.  The
 * return value of 'lc_unlock' will be passed to 'lc_lock' on resume
 * to allow communication of state between the two routines.
 */

struct lock_class {
        const           char *lc_name;
        u_int           lc_flags;
        void            (*lc_assert)(const struct lock_object *lock, int what);
        void            (*lc_ddb_show)(const struct lock_object *lock);
        void            (*lc_lock)(struct lock_object *lock, uintptr_t how);
        int             (*lc_owner)(const struct lock_object *lock,
                            struct thread **owner);
        uintptr_t       (*lc_unlock)(struct lock_object *lock);
        int             (*lc_trylock)(struct lock_object *lock, uintptr_t how);
};

#define LC_SLEEPLOCK    0x00000001      /* Sleep lock. */
#define LC_SPINLOCK     0x00000002      /* Spin lock. */
#define LC_SLEEPABLE    0x00000004      /* Sleeping allowed with this lock. */
#define LC_RECURSABLE   0x00000008      /* Locks of this type may recurse. */
#define LC_UPGRADABLE   0x00000010      /* Upgrades and downgrades permitted. */

#define LO_CLASSFLAGS   0x0000ffff      /* Class specific flags. */
#define LO_INITIALIZED  0x00010000      /* Lock has been initialized. */
#define LO_WITNESS      0x00020000      /* Should witness monitor this lock. */
#define LO_QUIET        0x00040000      /* Don't log locking operations. */
#define LO_RECURSABLE   0x00080000      /* Lock may recurse. */
#define LO_SLEEPABLE    0x00100000      /* Lock may be held while sleeping. */
#define LO_UPGRADABLE   0x00200000      /* Lock may be upgraded/downgraded. */
#define LO_DUPOK        0x00400000      /* Don't check for duplicate acquires */
#define LO_IS_VNODE     0x00800000      /* Tell WITNESS about a VNODE lock */
#define LO_CLASSMASK    0x0f000000      /* Class index bitmask. */
#define LO_NOPROFILE    0x10000000      /* Don't profile this lock */
#define LO_NEW          0x20000000      /* Don't check for double-init */

/*
 * Lock classes are statically assigned an index into the gobal lock_classes
 * array.  Debugging code looks up the lock class for a given lock object
 * by indexing the array.
 */
#define LO_CLASSSHIFT           24
#define LO_CLASSINDEX(lock)     ((((lock)->lo_flags) & LO_CLASSMASK) >> LO_CLASSSHIFT)
#define LOCK_CLASS(lock)        (lock_classes[LO_CLASSINDEX((lock))])
#define LOCK_CLASS_MAX          (LO_CLASSMASK >> LO_CLASSSHIFT)

/*
 * Option flags passed to lock operations that witness also needs to know
 * about or that are generic across all locks.
 */
#define LOP_NEWORDER    0x00000001      /* Define a new lock order. */
#define LOP_QUIET       0x00000002      /* Don't log locking operations. */
#define LOP_TRYLOCK     0x00000004      /* Don't check lock order. */
#define LOP_EXCLUSIVE   0x00000008      /* Exclusive lock. */
#define LOP_DUPOK       0x00000010      /* Don't check for duplicate acquires */
#define LOP_NOSLEEP     0x00000020      /* Non-sleepable despite LO_SLEEPABLE */

/* Flags passed to witness_assert. */
#define LA_MASKASSERT   0x000000ff      /* Mask for witness defined asserts. */
#define LA_UNLOCKED     0x00000000      /* Lock is unlocked. */
#define LA_LOCKED       0x00000001      /* Lock is at least share locked. */
#define LA_SLOCKED      0x00000002      /* Lock is exactly share locked. */
#define LA_XLOCKED      0x00000004      /* Lock is exclusively locked. */
#define LA_RECURSED     0x00000008      /* Lock is recursed. */
#define LA_NOTRECURSED  0x00000010      /* Lock is not recursed. */

#ifdef _KERNEL
/*
 * Macros for KTR_LOCK tracing.
 *
 * opname  - name of this operation (LOCK/UNLOCK/SLOCK, etc.)
 * lo      - struct lock_object * for this lock
 * flags   - flags passed to the lock operation
 * recurse - this locks recursion level (or 0 if class is not recursable)
 * result  - result of a try lock operation
 * file    - file name
 * line    - line number
 */
#if LOCK_DEBUG > 0
#define LOCK_LOG_TEST(lo, flags)                                        \
        (((flags) & LOP_QUIET) == 0 && ((lo)->lo_flags & LO_QUIET) == 0)
#else
#define LOCK_LOG_TEST(lo, flags)        0
#endif

#define LOCK_LOG_LOCK(opname, lo, flags, recurse, file, line) do {      \
        if (LOCK_LOG_TEST((lo), (flags)))                               \
                CTR6(KTR_LOCK, opname " (%s) %s %p r = %d at %s:%d",    \
                    LOCK_CLASS(lo)->lc_name, (lo)->lo_name,             \
                    (lo), (u_int)(recurse), (file), (line));            \
} while (0)

#define LOCK_LOG_TRY(opname, lo, flags, result, file, line) do {        \
        if (LOCK_LOG_TEST((lo), (flags)))                               \
                CTR6(KTR_LOCK, "TRY_" opname " (%s) %s %p result=%d at %s:%d",\
                    LOCK_CLASS(lo)->lc_name, (lo)->lo_name,             \
                    (lo), (u_int)(result), (file), (line));             \
} while (0)

#define LOCK_LOG_INIT(lo, flags) do {                                   \
        if (LOCK_LOG_TEST((lo), (flags)))                               \
                CTR4(KTR_LOCK, "%s: %p (%s) %s", __func__, (lo),        \
                    LOCK_CLASS(lo)->lc_name, (lo)->lo_name);            \
} while (0)

#define LOCK_LOG_DESTROY(lo, flags)     LOCK_LOG_INIT(lo, flags)

#define lock_initialized(lo)    ((lo)->lo_flags & LO_INITIALIZED)

extern struct lock_class lock_class_mtx_sleep;
extern struct lock_class lock_class_mtx_spin;
extern struct lock_class lock_class_sx;
extern struct lock_class lock_class_rw;
extern struct lock_class lock_class_rm;
extern struct lock_class lock_class_rm_sleepable;
extern struct lock_class lock_class_lockmgr;

extern struct lock_class *lock_classes[];

struct lock_delay_config {
        u_short base;
        u_short max;
};

extern struct lock_delay_config locks_delay;
extern u_short locks_delay_retries;
extern u_short locks_delay_loops;

struct lock_delay_arg {
        struct lock_delay_config *config;
        u_int delay;
        u_int spin_cnt;
};

static inline void
lock_delay_arg_init(struct lock_delay_arg *la, struct lock_delay_config *lc)
{
        la->config = lc;
        la->delay = lc->base;
        la->spin_cnt = 0;
}

static inline void
lock_delay_arg_init_noadapt(struct lock_delay_arg *la)
{
        la->delay = 0;
        la->spin_cnt = 0;
}

#define lock_delay_spin(n)      do {    \
        u_int _i;                       \
                                        \
        for (_i = (n); _i > 0; _i--)    \
                cpu_spinwait();         \
} while (0)

#define LOCK_DELAY_SYSINIT(func) \
        SYSINIT(func##_ld, SI_SUB_LOCK, SI_ORDER_ANY, func, NULL)

#define LOCK_DELAY_SYSINIT_DEFAULT(lc) \
        SYSINIT(lock_delay_##lc##_ld, SI_SUB_LOCK, SI_ORDER_ANY, \
            lock_delay_default_init, &lc)

void    lock_init(struct lock_object *, struct lock_class *,
            const char *, const char *, int);
void    lock_destroy(struct lock_object *);
void    lock_delay(struct lock_delay_arg *);
void    lock_delay_default_init(struct lock_delay_config *);
void    spinlock_enter(void);
void    spinlock_exit(void);
void    witness_init(struct lock_object *, const char *);
void    witness_destroy(struct lock_object *);
int     witness_defineorder(struct lock_object *, struct lock_object *);
void    witness_checkorder(struct lock_object *, int, const char *, int,
            struct lock_object *);
void    witness_lock(struct lock_object *, int, const char *, int);
void    witness_upgrade(struct lock_object *, int, const char *, int);
void    witness_downgrade(struct lock_object *, int, const char *, int);
void    witness_unlock(struct lock_object *, int, const char *, int);
void    witness_save(struct lock_object *, const char **, int *);
void    witness_restore(struct lock_object *, const char *, int);
int     witness_list_locks(struct lock_list_entry **,
            int (*)(const char *, ...));
int     witness_warn(int, struct lock_object *, const char *, ...);
void    witness_assert(const struct lock_object *, int, const char *, int);
int     witness_is_owned(const struct lock_object *lock);
void    witness_display_spinlock(struct lock_object *, struct thread *,
            int (*)(const char *, ...));
int     witness_line(struct lock_object *);
void    witness_norelease(struct lock_object *);
void    witness_releaseok(struct lock_object *);
const char *witness_file(struct lock_object *);
void    witness_thread_exit(struct thread *);

#ifdef  WITNESS
int     witness_startup_count(void);
void    witness_startup(void *);

/* Flags for witness_warn(). */
#define WARN_GIANTOK    0x01    /* Giant is exempt from this check. */
#define WARN_PANIC      0x02    /* Panic if check fails. */
#define WARN_SLEEPOK    0x04    /* Sleepable locks are exempt from check. */

#define WITNESS_INIT(lock, type)                                        \
        witness_init((lock), (type))

#define WITNESS_DESTROY(lock)                                           \
        witness_destroy(lock)

#define WITNESS_CHECKORDER(lock, flags, file, line, interlock)          \
        witness_checkorder((lock), (flags), (file), (line), (interlock))

#define WITNESS_DEFINEORDER(lock1, lock2)                               \
        witness_defineorder((struct lock_object *)(lock1),              \
            (struct lock_object *)(lock2))

#define WITNESS_LOCK(lock, flags, file, line)                           \
        witness_lock((lock), (flags), (file), (line))

#define WITNESS_UPGRADE(lock, flags, file, line)                        \
        witness_upgrade((lock), (flags), (file), (line))

#define WITNESS_DOWNGRADE(lock, flags, file, line)                      \
        witness_downgrade((lock), (flags), (file), (line))

#define WITNESS_UNLOCK(lock, flags, file, line)                         \
        witness_unlock((lock), (flags), (file), (line))

#define WITNESS_CHECK(flags, lock, fmt, ...)                            \
        witness_warn((flags), (lock), (fmt), ## __VA_ARGS__)

#define WITNESS_WARN(flags, lock, fmt, ...)                             \
        witness_warn((flags), (lock), (fmt), ## __VA_ARGS__)

#define WITNESS_SAVE_DECL(n)                                            \
        const char * __CONCAT(n, __wf);                                 \
        int __CONCAT(n, __wl)

#define WITNESS_SAVE(lock, n)                                           \
        witness_save((lock), &__CONCAT(n, __wf), &__CONCAT(n, __wl))

#define WITNESS_RESTORE(lock, n)                                        \
        witness_restore((lock), __CONCAT(n, __wf), __CONCAT(n, __wl))

#define WITNESS_NORELEASE(lock)                                         \
        witness_norelease(&(lock)->lock_object)

#define WITNESS_RELEASEOK(lock)                                         \
        witness_releaseok(&(lock)->lock_object)

#define WITNESS_FILE(lock)                                              \
        witness_file(lock)

#define WITNESS_LINE(lock)                                              \
        witness_line(lock)

#else   /* WITNESS */
#define WITNESS_INIT(lock, type)                                (void)0
#define WITNESS_DESTROY(lock)                                   (void)0
#define WITNESS_DEFINEORDER(lock1, lock2)       0
#define WITNESS_CHECKORDER(lock, flags, file, line, interlock)  (void)0
#define WITNESS_LOCK(lock, flags, file, line)                   (void)0
#define WITNESS_UPGRADE(lock, flags, file, line)                (void)0
#define WITNESS_DOWNGRADE(lock, flags, file, line)              (void)0
#define WITNESS_UNLOCK(lock, flags, file, line)                 (void)0
#define WITNESS_CHECK(flags, lock, fmt, ...)    0
#define WITNESS_WARN(flags, lock, fmt, ...)                     (void)0
#define WITNESS_SAVE_DECL(n)                                    (void)0
#define WITNESS_SAVE(lock, n)                                   (void)0
#define WITNESS_RESTORE(lock, n)                                (void)0
#define WITNESS_NORELEASE(lock)                                 (void)0
#define WITNESS_RELEASEOK(lock)                                 (void)0
#define WITNESS_FILE(lock) ("?")
#define WITNESS_LINE(lock) (0)
#endif  /* WITNESS */

#endif  /* _KERNEL */
#endif  /* _SYS_LOCK_H_ */