/*-
 * Copyright (c) 2015 François Tigeot
 * Copyright (c) 2016-2020 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_RCULIST_H_
#define _LINUXKPI_LINUX_RCULIST_H_

#include <linux/list.h>
#include <linux/rcupdate.h>

#define list_entry_rcu(ptr, type, member) \
        container_of(READ_ONCE(ptr), type, member)

#define list_next_rcu(head)     (*((struct list_head **)(&(head)->next)))
#define list_prev_rcu(head)     (*((struct list_head **)(&(head)->prev)))

#define list_for_each_entry_rcu(pos, head, member) \
        for (pos = list_entry_rcu((head)->next, typeof(*(pos)), member); \
             &(pos)->member != (head);                                  \
             pos = list_entry_rcu((pos)->member.next, typeof(*(pos)), member))

#define list_for_each_entry_from_rcu(pos, head, member) \
        for (; \
             &(pos)->member != (head);                                  \
             pos = list_entry_rcu((pos)->member.next, typeof(*(pos)), member))

#define list_for_each_entry_lockless(pos, head, member) \
        list_for_each_entry_rcu(pos, head, member)

static inline void
linux_list_add_rcu(struct list_head *new, struct list_head *prev,
    struct list_head *next)
{
        new->next = next;
        new->prev = prev;
        rcu_assign_pointer(list_next_rcu(prev), new);
        next->prev = new;
}

static inline void
list_add_rcu(struct list_head *new, struct list_head *head)
{
        linux_list_add_rcu(new, head, head->next);
}

static inline void
list_add_tail_rcu(struct list_head *new, struct list_head *head)
{
        linux_list_add_rcu(new, head->prev, head);
}

static inline void
__list_del_rcu(struct list_head *prev, struct list_head *next)
{
        next->prev = prev;
        rcu_assign_pointer(list_next_rcu(prev), next);
}

static inline void
__list_del_entry_rcu(struct list_head *entry)
{
        __list_del_rcu(entry->prev, entry->next);
}

static inline void
list_del_rcu(struct list_head *entry)
{
        __list_del_rcu(entry->prev, entry->next);
}

#define hlist_first_rcu(head)   (*((struct hlist_node **)(&(head)->first)))
#define hlist_next_rcu(node)    (*((struct hlist_node **)(&(node)->next)))
#define hlist_pprev_rcu(node)   (*((struct hlist_node **)((node)->pprev)))

static inline void
hlist_add_behind_rcu(struct hlist_node *n, struct hlist_node *prev)
{
        n->next = prev->next;
        n->pprev = &prev->next;
        rcu_assign_pointer(hlist_next_rcu(prev), n);
        if (n->next)
                n->next->pprev = &n->next;
}

#define hlist_for_each_entry_rcu(pos, head, member)                     \
        for (pos = hlist_entry_safe (rcu_dereference_raw(hlist_first_rcu(head)),\
                typeof(*(pos)), member);                                \
             (pos);                                                     \
             pos = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu( \
                        &(pos)->member)), typeof(*(pos)), member))

static inline void
hlist_del_rcu(struct hlist_node *n)
{
        struct hlist_node *next = n->next;
        struct hlist_node **pprev = n->pprev;

        WRITE_ONCE(*pprev, next);
        if (next)
                next->pprev = pprev;
}

static inline void
hlist_add_head_rcu(struct hlist_node *n, struct hlist_head *h)
{
        struct hlist_node *first = h->first;

        n->next = first;
        n->pprev = &h->first;
        rcu_assign_pointer(hlist_first_rcu(h), n);
        if (first)
                first->pprev = &n->next;
}

static inline void
hlist_del_init_rcu(struct hlist_node *n)
{
        if (!hlist_unhashed(n)) {
                hlist_del_rcu(n);
                n->pprev = NULL;
        }
}

#endif                                  /* _LINUXKPI_LINUX_RCULIST_H_ */