list.h

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/*-
 * Copyright (c) 2011 Felix Fietkau <nbd@openwrt.org>
 * Copyright (c) 2010 Isilon Systems, Inc.
 * Copyright (c) 2010 iX Systems, Inc.
 * Copyright (c) 2010 Panasas, 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 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 _LINUX_LIST_H_
#define _LINUX_LIST_H_
 
#include <stddef.h>
#include <stdbool.h>
 
#define prefetch(x)
 
#ifndef container_of
#define container_of(ptr, type, member)                                 \
        ({                                                              \
                const __typeof__(((type *) NULL)->member) *__mptr = (ptr);      \
                (type *) ((char *) __mptr - offsetof(type, member));    \
        })
#endif
 
#ifndef container_of_safe
#define container_of_safe(ptr, type, member)                                            \
        ({                                                                              \
                const __typeof__(((type *) NULL)->member) *__mptr = (ptr);              \
                __mptr ? (type *)((char *) __mptr - offsetof(type, member)) : NULL;     \
        })
#endif
 
struct list_head {
        struct list_head *next;
        struct list_head *prev;
};
 
#define LIST_HEAD_INIT(name) { &(name), &(name) }
#undef LIST_HEAD
#define LIST_HEAD(name) struct list_head name = LIST_HEAD_INIT(name)
 
static inline void
INIT_LIST_HEAD(struct list_head *list)
{
        list->next = list->prev = list;
}
 
static inline bool
list_empty(const struct list_head *head)
{
        return (head->next == head);
}
 
static inline bool
list_is_first(const struct list_head *list,
              const struct list_head *head)
{
        return list->prev == head;
}
 
static inline bool
list_is_last(const struct list_head *list,
             const struct list_head *head)
{
        return list->next == head;
}
 
static inline void
_list_del(struct list_head *entry)
{
        entry->next->prev = entry->prev;
        entry->prev->next = entry->next;
}
 
static inline void
list_del(struct list_head *entry)
{
        _list_del(entry);
        entry->next = entry->prev = NULL;
}
 
static inline void
_list_add(struct list_head *_new, struct list_head *prev,
    struct list_head *next)
{
 
        next->prev = _new;
        _new->next = next;
        _new->prev = prev;
        prev->next = _new;
}
 
static inline void
list_del_init(struct list_head *entry)
{
        _list_del(entry);
        INIT_LIST_HEAD(entry);
}
 
#define list_entry(ptr, type, field)    container_of(ptr, type, field)
#define list_first_entry(ptr, type, field)      list_entry((ptr)->next, type, field)
#define list_last_entry(ptr, type, field)       list_entry((ptr)->prev, type, field)
#define list_next_entry(pos, member)            list_entry((pos)->member.next, typeof(*(pos)), member)
#define list_entry_is_h(p, h, field)            (&p->field == (h))
 
#define list_for_each(p, head)                                          \
        for (p = (head)->next; p != (head); p = p->next)
 
#define list_for_each_safe(p, n, head)                                  \
        for (p = (head)->next, n = p->next; p != (head); p = n, n = p->next)
 
#define list_for_each_entry(p, h, field)                                \
        for (p = list_first_entry(h, __typeof__(*p), field); &p->field != (h); \
            p = list_entry(p->field.next, __typeof__(*p), field))
 
#define list_for_each_entry_continue(p, h, field)                       \
        for (p = list_next_entry(p, field);                             \
             !list_entry_is_h(p, h, field);                             \
             p = list_next_entry(p, field))
 
#define list_for_each_entry_continue_reverse(p, h, field)               \
        for (p = list_prev_entry(p, field);                             \
             !list_entry_is_h(p, h, field);                             \
             p = list_prev_entry(p, field))
 
#define list_for_each_entry_safe(p, n, h, field)                        \
        for (p = list_first_entry(h, __typeof__(*p), field),            \
            n = list_entry(p->field.next, __typeof__(*p), field); &p->field != (h);\
            p = n, n = list_entry(n->field.next, __typeof__(*n), field))
 
#define list_for_each_entry_reverse(p, h, field)                        \
        for (p = list_last_entry(h, __typeof__(*p), field); &p->field != (h); \
            p = list_entry(p->field.prev, __typeof__(*p), field))
 
#define list_for_each_prev(p, h) for (p = (h)->prev; p != (h); p = p->prev)
#define list_for_each_prev_safe(p, n, h) for (p = (h)->prev, n = p->prev; p != (h); p = n, n = p->prev)
 
static inline void
list_add(struct list_head *_new, struct list_head *head)
{
        _list_add(_new, head, head->next);
}
 
static inline void
list_add_tail(struct list_head *_new, struct list_head *head)
{
        _list_add(_new, head->prev, head);
}
 
static inline void
list_move(struct list_head *list, struct list_head *head)
{
        _list_del(list);
        list_add(list, head);
}
 
static inline void
list_move_tail(struct list_head *entry, struct list_head *head)
{
        _list_del(entry);
        list_add_tail(entry, head);
}
 
static inline void
_list_splice(const struct list_head *list, struct list_head *prev,
    struct list_head *next)
{
        struct list_head *first;
        struct list_head *last;
 
        if (list_empty(list))
                return;
 
        first = list->next;
        last = list->prev;
        first->prev = prev;
        prev->next = first;
        last->next = next;
        next->prev = last;
}
 
static inline void
list_splice(const struct list_head *list, struct list_head *head)
{
        _list_splice(list, head, head->next);
}
 
static inline void
list_splice_tail(struct list_head *list, struct list_head *head)
{
        _list_splice(list, head->prev, head);
}
 
static inline void
list_splice_init(struct list_head *list, struct list_head *head)
{
        _list_splice(list, head, head->next);
        INIT_LIST_HEAD(list);
}
 
static inline void
list_splice_tail_init(struct list_head *list, struct list_head *head)
{
        _list_splice(list, head->prev, head);
        INIT_LIST_HEAD(list);
}
 
#endif /* _LINUX_LIST_H_ */