/*-
 * Copyright (c) 2010 Isilon Systems, Inc.
 * Copyright (c) 2010 iX Systems, Inc.
 * Copyright (c) 2010 Panasas, Inc.
 * Copyright (c) 2013-2017 Mellanox Technologies, Ltd.
 * 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 unmodified, 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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 _LINUXKPI_LINUX_SPINLOCK_H_
#define _LINUXKPI_LINUX_SPINLOCK_H_

#include <asm/atomic.h>
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/kdb.h>

#include <linux/cleanup.h>
#include <linux/compiler.h>
#include <linux/rwlock.h>
#include <linux/bottom_half.h>
#include <linux/lockdep.h>
#include <linux/preempt.h>

typedef struct mtx spinlock_t;

/*
 * By defining CONFIG_SPIN_SKIP LinuxKPI spinlocks and asserts will be
 * skipped during panic(). By default it is disabled due to
 * performance reasons.
 */
#ifdef CONFIG_SPIN_SKIP
#define SPIN_SKIP(void) unlikely(SCHEDULER_STOPPED() || kdb_active)
#else
#define SPIN_SKIP(void) 0
#endif

#define spin_lock(_l) do {                      \
        if (SPIN_SKIP())                        \
                break;                          \
        mtx_lock(_l);                           \
        local_bh_disable();                     \
} while (0)

#define spin_lock_bh(_l) do {                   \
        spin_lock(_l);                          \
        local_bh_disable();                     \
} while (0)

#define spin_lock_irq(_l) do {                  \
        spin_lock(_l);                          \
} while (0)

#define spin_unlock(_l) do {                    \
        if (SPIN_SKIP())                        \
                break;                          \
        local_bh_enable();                      \
        mtx_unlock(_l);                         \
} while (0)

#define spin_unlock_bh(_l) do {                 \
        local_bh_enable();                      \
        spin_unlock(_l);                        \
} while (0)

#define spin_unlock_irq(_l) do {                \
        spin_unlock(_l);                        \
} while (0)

#define spin_trylock(_l) ({                     \
        int __ret;                              \
        if (SPIN_SKIP()) {                      \
                __ret = 1;                      \
        } else {                                \
                __ret = mtx_trylock(_l);        \
                if (likely(__ret != 0))         \
                        local_bh_disable();     \
        }                                       \
        __ret;                                  \
})

#define spin_trylock_irq(_l)                    \
        spin_trylock(_l)

#define spin_trylock_irqsave(_l, flags) ({      \
        (flags) = 0;                            \
        spin_trylock(_l);                       \
})

#define spin_lock_nested(_l, _n) do {           \
        if (SPIN_SKIP())                        \
                break;                          \
        mtx_lock_flags(_l, MTX_DUPOK);          \
        local_bh_disable();                     \
} while (0)

#define spin_lock_irqsave(_l, flags) do {       \
        (flags) = 0;                            \
        spin_lock(_l);                          \
} while (0)

#define spin_lock_irqsave_nested(_l, flags, _n) do {    \
        (flags) = 0;                                    \
        spin_lock_nested(_l, _n);                       \
} while (0)

#define spin_unlock_irqrestore(_l, flags) do {          \
        (void)(flags);                                  \
        spin_unlock(_l);                                \
} while (0)

#ifdef WITNESS_ALL
/* NOTE: the maximum WITNESS name is 64 chars */
#define __spin_lock_name(name, file, line)              \
        (((const char *){file ":" #line "-" name}) +    \
        (sizeof(file) > 16 ? sizeof(file) - 16 : 0))
#else
#define __spin_lock_name(name, file, line)      name
#endif
#define _spin_lock_name(...)            __spin_lock_name(__VA_ARGS__)
#define spin_lock_name(name)            _spin_lock_name(name, __FILE__, __LINE__)

#define spin_lock_init(lock)    mtx_init(lock, spin_lock_name("lnxspin"), \
                                  NULL, MTX_DEF | MTX_NOWITNESS | MTX_NEW)

#define spin_lock_destroy(_l)   mtx_destroy(_l)

#define DEFINE_SPINLOCK(lock)                                   \
        spinlock_t lock;                                        \
        MTX_SYSINIT(lock, &lock, spin_lock_name("lnxspin"), MTX_DEF)

#define assert_spin_locked(_l) do {             \
        if (SPIN_SKIP())                        \
                break;                          \
        mtx_assert(_l, MA_OWNED);               \
} while (0)

#define local_irq_save(flags) do {              \
        (flags) = 0;                            \
} while (0)

#define local_irq_restore(flags) do {           \
        (void)(flags);                          \
} while (0)

#define atomic_dec_and_lock_irqsave(cnt, lock, flags) \
        _atomic_dec_and_lock_irqsave(cnt, lock, &(flags))
static inline int
_atomic_dec_and_lock_irqsave(atomic_t *cnt, spinlock_t *lock,
    unsigned long *flags)
{
        if (atomic_add_unless(cnt, -1, 1))
                return (0);

        spin_lock_irqsave(lock, *flags);
        if (atomic_dec_and_test(cnt))
                return (1);
        spin_unlock_irqrestore(lock, *flags);
        return (0);
}

/*
 * struct raw_spinlock
 */

typedef struct raw_spinlock {
        struct mtx      lock;
} raw_spinlock_t;

#define raw_spin_lock_init(rlock) \
        mtx_init(&(rlock)->lock, spin_lock_name("lnxspin_raw"), \
            NULL, MTX_DEF | MTX_NOWITNESS | MTX_NEW)

#define raw_spin_lock(rl)       spin_lock(&(rl)->lock)
#define raw_spin_trylock(rl)    spin_trylock(&(rl)->lock)
#define raw_spin_unlock(rl)     spin_unlock(&(rl)->lock)

#define raw_spin_lock_irqsave(rl, f)            spin_lock_irqsave(&(rl)->lock, (f))
#define raw_spin_trylock_irqsave(rl, f)         spin_trylock_irqsave(&(rl)->lock, (f))
#define raw_spin_unlock_irqrestore(rl, f)       spin_unlock_irqrestore(&(rl)->lock, (f))

/*
 * cleanup.h related pre-defined cases.
 */
DEFINE_LOCK_GUARD_1(spinlock_irqsave,
    spinlock_t,
    spin_lock_irqsave(_T->lock, _T->flags),
    spin_unlock_irqrestore(_T->lock, _T->flags),
    unsigned long flags)

#endif                                  /* _LINUXKPI_LINUX_SPINLOCK_H_ */