/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2007 Stephan Uphoff <ups@FreeBSD.org>
 * 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. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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.
 */

#ifndef _SYS_RMLOCK_H_
#define _SYS_RMLOCK_H_

#include <sys/mutex.h>
#include <sys/sx.h>
#include <sys/_lock.h>
#include <sys/_rmlock.h>

#ifdef _KERNEL

/*
 * Flags passed to rm_init_flags(9).
 */
#define RM_NOWITNESS    0x00000001
#define RM_RECURSE      0x00000002
#define RM_SLEEPABLE    0x00000004
#define RM_NEW          0x00000008
#define RM_DUPOK        0x00000010

void    rm_init(struct rmlock *rm, const char *name);
void    rm_init_flags(struct rmlock *rm, const char *name, int opts);
void    rm_destroy(struct rmlock *rm);
int     rm_wowned(const struct rmlock *rm);
void    rm_sysinit(const void *arg);

void    _rm_wlock_debug(struct rmlock *rm, const char *file, int line);
void    _rm_wunlock_debug(struct rmlock *rm, const char *file, int line);
int     _rm_rlock_debug(struct rmlock *rm, struct rm_priotracker *tracker,
            int trylock, const char *file, int line);
void    _rm_runlock_debug(struct rmlock *rm,  struct rm_priotracker *tracker,
            const char *file, int line);

void    _rm_wlock(struct rmlock *rm);
void    _rm_wunlock(struct rmlock *rm);
int     _rm_rlock(struct rmlock *rm, struct rm_priotracker *tracker,
            int trylock);
void    _rm_runlock(struct rmlock *rm,  struct rm_priotracker *tracker);
#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
void    _rm_assert(const struct rmlock *rm, int what, const char *file,
            int line);
#endif

/*
 * Public interface for lock operations.
 */
#ifndef LOCK_DEBUG
#error LOCK_DEBUG not defined, include <sys/lock.h> before <sys/rmlock.h>
#endif

#if LOCK_DEBUG > 0
#define rm_wlock(rm)    _rm_wlock_debug((rm), LOCK_FILE, LOCK_LINE)
#define rm_wunlock(rm)  _rm_wunlock_debug((rm), LOCK_FILE, LOCK_LINE)
#define rm_rlock(rm,tracker)  \
    ((void)_rm_rlock_debug((rm),(tracker), 0, LOCK_FILE, LOCK_LINE ))
#define rm_try_rlock(rm,tracker)  \
    _rm_rlock_debug((rm),(tracker), 1, LOCK_FILE, LOCK_LINE )
#define rm_runlock(rm,tracker)  \
    _rm_runlock_debug((rm), (tracker), LOCK_FILE, LOCK_LINE )
#else
#define rm_wlock(rm)                    _rm_wlock((rm))
#define rm_wunlock(rm)                  _rm_wunlock((rm))
#define rm_rlock(rm,tracker)            ((void)_rm_rlock((rm),(tracker), 0))
#define rm_try_rlock(rm,tracker)        _rm_rlock((rm),(tracker), 1)
#define rm_runlock(rm,tracker)          _rm_runlock((rm), (tracker))
#endif
#define rm_sleep(chan, rm, pri, wmesg, timo)                            \
        _sleep((chan), &(rm)->lock_object, (pri), (wmesg),              \
            tick_sbt * (timo), 0, C_HARDCLOCK)

struct rm_args {
        struct rmlock   *ra_rm;
        const char      *ra_desc;
        int             ra_flags;
};

#define RM_SYSINIT_FLAGS(name, rm, desc, flags)                         \
        static struct rm_args name##_args = {                           \
                (rm),                                                   \
                (desc),                                                 \
                (flags),                                                \
        };                                                              \
        SYSINIT(name##_rm_sysinit, SI_SUB_LOCK, SI_ORDER_MIDDLE,        \
            rm_sysinit, &name##_args);                                  \
        SYSUNINIT(name##_rm_sysuninit, SI_SUB_LOCK, SI_ORDER_MIDDLE,    \
            rm_destroy, (rm))

#define RM_SYSINIT(name, rm, desc)      RM_SYSINIT_FLAGS(name, rm, desc, 0)

#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
#define RA_LOCKED               LA_LOCKED
#define RA_RLOCKED              LA_SLOCKED
#define RA_WLOCKED              LA_XLOCKED
#define RA_UNLOCKED             LA_UNLOCKED
#define RA_RECURSED             LA_RECURSED
#define RA_NOTRECURSED          LA_NOTRECURSED
#endif

#ifdef INVARIANTS
#define rm_assert(rm, what)     _rm_assert((rm), (what), LOCK_FILE, LOCK_LINE)
#else
#define rm_assert(rm, what)
#endif

void    rms_init(struct rmslock *rms, const char *name);
void    rms_destroy(struct rmslock *rms);
void    rms_rlock(struct rmslock *rms);
int     rms_try_rlock(struct rmslock *rms);
void    rms_runlock(struct rmslock *rms);
void    rms_wlock(struct rmslock *rms);
void    rms_wunlock(struct rmslock *rms);
void    rms_unlock(struct rmslock *rms);

static inline int
rms_wowned(struct rmslock *rms)
{

        return (rms->owner == curthread);
}

#ifdef INVARIANTS
#define rms_assert_rlock_ok(x)  \
        WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
#else
#define rms_assert_rlock_ok(x)
#endif

#ifdef INVARIANTS
/*
 * For assertion purposes.
 *
 * Main limitation is that we at best can tell there are readers, but not
 * whether curthread is one of them.
 */
static inline int
rms_rowned(struct rmslock *rms)
{

        return (rms->debug_readers > 0);
}

static inline int
rms_owned_any(struct rmslock *rms)
{

        if (rms_wowned(rms))
                return (1);

        return (rms_rowned(rms));
}
#endif

#endif /* _KERNEL */
#endif /* !_SYS_RMLOCK_H_ */