/*-
 * 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_WORKQUEUE_H_
#define _LINUXKPI_LINUX_WORKQUEUE_H_

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/slab.h>

#include <asm/atomic.h>

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/taskqueue.h>
#include <sys/mutex.h>

#define WORK_CPU_UNBOUND MAXCPU
#define WQ_UNBOUND (1 << 0)
#define WQ_HIGHPRI (1 << 1)

struct work_struct;
typedef void (*work_func_t)(struct work_struct *);

struct work_exec {
        TAILQ_ENTRY(work_exec) entry;
        struct work_struct *target;
};

struct workqueue_struct {
        struct taskqueue *taskqueue;
        struct mtx exec_mtx;
        TAILQ_HEAD(, work_exec) exec_head;
        atomic_t draining;
};

#define WQ_EXEC_LOCK(wq) mtx_lock(&(wq)->exec_mtx)
#define WQ_EXEC_UNLOCK(wq) mtx_unlock(&(wq)->exec_mtx)

struct work_struct {
        struct task work_task;
        struct workqueue_struct *work_queue;
        work_func_t func;
        atomic_t state;
};

struct rcu_work {
        struct work_struct work;
        struct rcu_head rcu;

        struct workqueue_struct *wq;
};

#define DECLARE_WORK(name, fn)                                          \
        struct work_struct name;                                        \
        static void name##_init(void *arg)                              \
        {                                                               \
                INIT_WORK(&name, fn);                                   \
        }                                                               \
        SYSINIT(name, SI_SUB_LOCK, SI_ORDER_SECOND, name##_init, NULL)

struct delayed_work {
        struct work_struct work;
        struct {
                struct callout callout;
                struct mtx mtx;
                unsigned long expires;
        } timer;
};

#define DECLARE_DELAYED_WORK(name, fn)                                  \
        struct delayed_work name;                                       \
        static void __linux_delayed_ ## name ## _init(void *arg)        \
        {                                                               \
                linux_init_delayed_work(&name, fn);                     \
        }                                                               \
        SYSINIT(name, SI_SUB_LOCK, SI_ORDER_SECOND,                     \
            __linux_delayed_ ## name##_init, NULL)

static inline struct delayed_work *
to_delayed_work(struct work_struct *work)
{
        return (container_of(work, struct delayed_work, work));
}

#define INIT_WORK(work, fn)                                             \
do {                                                                    \
        (work)->func = (fn);                                            \
        (work)->work_queue = NULL;                                      \
        atomic_set(&(work)->state, 0);                                  \
        TASK_INIT(&(work)->work_task, 0, linux_work_fn, (work));        \
} while (0)

#define INIT_RCU_WORK(_work, _fn) \
        INIT_WORK(&(_work)->work, (_fn))

#define INIT_WORK_ONSTACK(work, fn) \
        INIT_WORK(work, fn)

#define INIT_DELAYED_WORK(dwork, fn) \
        linux_init_delayed_work(dwork, fn)

#define INIT_DELAYED_WORK_ONSTACK(dwork, fn) \
        linux_init_delayed_work(dwork, fn)

#define INIT_DEFERRABLE_WORK(dwork, fn) \
        INIT_DELAYED_WORK(dwork, fn)

#define flush_scheduled_work() \
        taskqueue_drain_all(system_wq->taskqueue)

#define queue_work(wq, work) \
        linux_queue_work_on(WORK_CPU_UNBOUND, wq, work)

#define schedule_work(work) \
        linux_queue_work_on(WORK_CPU_UNBOUND, system_wq, work)

#define queue_delayed_work(wq, dwork, delay) \
        linux_queue_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay)

#define schedule_delayed_work_on(cpu, dwork, delay) \
        linux_queue_delayed_work_on(cpu, system_wq, dwork, delay)

#define queue_work_on(cpu, wq, work) \
        linux_queue_work_on(cpu, wq, work)

#define schedule_delayed_work(dwork, delay) \
        linux_queue_delayed_work_on(WORK_CPU_UNBOUND, system_wq, dwork, delay)

#define queue_delayed_work_on(cpu, wq, dwork, delay) \
        linux_queue_delayed_work_on(cpu, wq, dwork, delay)

#define create_singlethread_workqueue(name) \
        linux_create_workqueue_common(name, 1)

#define create_workqueue(name) \
        linux_create_workqueue_common(name, mp_ncpus)

#define alloc_ordered_workqueue(name, flags) \
        linux_create_workqueue_common(name, 1)

#define alloc_workqueue(name, flags, max_active) \
        linux_create_workqueue_common(name, max_active)

#define flush_workqueue(wq) \
        taskqueue_drain_all((wq)->taskqueue)

#define drain_workqueue(wq) do {                \
        atomic_inc(&(wq)->draining);            \
        taskqueue_drain_all((wq)->taskqueue);   \
        atomic_dec(&(wq)->draining);            \
} while (0)

#define mod_delayed_work(wq, dwork, delay) ({           \
        bool __retval;                                  \
        __retval = linux_cancel_delayed_work(dwork);    \
        linux_queue_delayed_work_on(WORK_CPU_UNBOUND,   \
            wq, dwork, delay);                          \
        __retval;                                       \
})

#define delayed_work_pending(dwork) \
        linux_work_pending(&(dwork)->work)

#define cancel_work(work) \
        linux_cancel_work(work)

#define cancel_delayed_work(dwork) \
        linux_cancel_delayed_work(dwork)

#define cancel_work_sync(work) \
        linux_cancel_work_sync(work)

#define cancel_delayed_work_sync(dwork) \
        linux_cancel_delayed_work_sync(dwork)

#define flush_work(work) \
        linux_flush_work(work)

#define queue_rcu_work(wq, rwork) \
        linux_queue_rcu_work(wq, rwork)

#define flush_rcu_work(rwork) \
        linux_flush_rcu_work(rwork)

#define flush_delayed_work(dwork) \
        linux_flush_delayed_work(dwork)

#define work_pending(work) \
        linux_work_pending(work)

#define work_busy(work) \
        linux_work_busy(work)

#define destroy_work_on_stack(work) \
        do { } while (0)

#define destroy_delayed_work_on_stack(dwork) \
        do { } while (0)

#define destroy_workqueue(wq) \
        linux_destroy_workqueue(wq)

#define current_work() \
        linux_current_work()

/* prototypes */

extern struct workqueue_struct *system_wq;
extern struct workqueue_struct *system_long_wq;
extern struct workqueue_struct *system_unbound_wq;
extern struct workqueue_struct *system_highpri_wq;
extern struct workqueue_struct *system_power_efficient_wq;

extern void linux_init_delayed_work(struct delayed_work *, work_func_t);
extern void linux_work_fn(void *, int);
extern void linux_delayed_work_fn(void *, int);
extern struct workqueue_struct *linux_create_workqueue_common(const char *, int);
extern void linux_destroy_workqueue(struct workqueue_struct *);
extern bool linux_queue_work_on(int cpu, struct workqueue_struct *, struct work_struct *);
extern bool linux_queue_delayed_work_on(int cpu, struct workqueue_struct *,
    struct delayed_work *, unsigned long delay);
extern bool linux_cancel_work(struct work_struct *);
extern bool linux_cancel_delayed_work(struct delayed_work *);
extern bool linux_cancel_work_sync(struct work_struct *);
extern bool linux_cancel_delayed_work_sync(struct delayed_work *);
extern bool linux_flush_work(struct work_struct *);
extern bool linux_flush_delayed_work(struct delayed_work *);
extern bool linux_work_pending(struct work_struct *);
extern bool linux_work_busy(struct work_struct *);
extern struct work_struct *linux_current_work(void);
extern bool linux_queue_rcu_work(struct workqueue_struct *wq, struct rcu_work *rwork);
extern bool linux_flush_rcu_work(struct rcu_work *rwork);

static inline bool
queue_work_node(int node __unused, struct workqueue_struct *wq, struct work_struct *work)
{
        return (queue_work(wq, work));
}

#endif                                  /* _LINUXKPI_LINUX_WORKQUEUE_H_ */