linuxlist.h

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#ifndef _LINUX_LLIST_H
#define _LINUX_LLIST_H

#include <stddef.h>

#ifndef inline
#define inline __inline__
#endif

static inline void prefetch(const void *x) {;}

#define container_of(ptr, type, member) ({                      \
        const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
        (type *)( (char *)__mptr - offsetof(type,member) );})


/*
 * These are non-NULL pointers that will result in page faults
 * under normal circumstances, used to verify that nobody uses
 * non-initialized llist entries.
 */
#define LLIST_POISON1  ((void *) 0x00100100)
#define LLIST_POISON2  ((void *) 0x00200200)

/*
 * Simple doubly linked llist implementation.
 *
 * Some of the internal functions ("__xxx") are useful when
 * manipulating whole llists rather than single entries, as
 * sometimes we already know the next/prev entries and we can
 * generate better code by using them directly rather than
 * using the generic single-entry routines.
 */

struct llist_head {
        struct llist_head *next, *prev;
};

#define LLIST_HEAD_INIT(name) { &(name), &(name) }

#define LLIST_HEAD(name) \
        struct llist_head name = LLIST_HEAD_INIT(name)

#define INIT_LLIST_HEAD(ptr) do { \
        (ptr)->next = (ptr); (ptr)->prev = (ptr); \
} while (0)

/*
 * Insert a new entry between two known consecutive entries.
 *
 * This is only for internal llist manipulation where we know
 * the prev/next entries already!
 */
static inline void __llist_add(struct llist_head *new,
                                struct llist_head *prev,
                                struct llist_head *next)
{
        next->prev = new;
        new->next = next;
        new->prev = prev;
        prev->next = new;
}

static inline void llist_add(struct llist_head *new, struct llist_head *head)
{
        __llist_add(new, head, head->next);
}

static inline void llist_add_tail(struct llist_head *new, struct llist_head *head)
{
        __llist_add(new, head->prev, head);
}

/*
 * Delete a llist entry by making the prev/next entries
 * point to each other.
 *
 * This is only for internal llist manipulation where we know
 * the prev/next entries already!
 */
static inline void __llist_del(struct llist_head * prev, struct llist_head * next)
{
        next->prev = prev;
        prev->next = next;
}

static inline void llist_del(struct llist_head *entry)
{
        __llist_del(entry->prev, entry->next);
        entry->next = LLIST_POISON1;
        entry->prev = LLIST_POISON2;
}

static inline void llist_del_init(struct llist_head *entry)
{
        __llist_del(entry->prev, entry->next);
        INIT_LLIST_HEAD(entry);
}

static inline void llist_move(struct llist_head *llist, struct llist_head *head)
{
        __llist_del(llist->prev, llist->next);
        llist_add(llist, head);
}

static inline void llist_move_tail(struct llist_head *llist,
                                  struct llist_head *head)
{
        __llist_del(llist->prev, llist->next);
        llist_add_tail(llist, head);
}

static inline int llist_empty(const struct llist_head *head)
{
        return head->next == head;
}

static inline void __llist_splice(struct llist_head *llist,
                                 struct llist_head *head)
{
        struct llist_head *first = llist->next;
        struct llist_head *last = llist->prev;
        struct llist_head *at = head->next;

        first->prev = head;
        head->next = first;

        last->next = at;
        at->prev = last;
}

static inline void llist_splice(struct llist_head *llist, struct llist_head *head)
{
        if (!llist_empty(llist))
                __llist_splice(llist, head);
}

static inline void llist_splice_init(struct llist_head *llist,
                                    struct llist_head *head)
{
        if (!llist_empty(llist)) {
                __llist_splice(llist, head);
                INIT_LLIST_HEAD(llist);
        }
}

#define llist_entry(ptr, type, member) \
        container_of(ptr, type, member)

#define llist_for_each(pos, head) \
        for (pos = (head)->next, prefetch(pos->next); pos != (head); \
                pos = pos->next, prefetch(pos->next))

#define __llist_for_each(pos, head) \
        for (pos = (head)->next; pos != (head); pos = pos->next)

#define llist_for_each_prev(pos, head) \
        for (pos = (head)->prev, prefetch(pos->prev); pos != (head); \
                pos = pos->prev, prefetch(pos->prev))

#define llist_for_each_safe(pos, n, head) \
        for (pos = (head)->next, n = pos->next; pos != (head); \
                pos = n, n = pos->next)

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

#define llist_for_each_entry_reverse(pos, head, member)                 \
        for (pos = llist_entry((head)->prev, typeof(*pos), member),     \
                        prefetch(pos->member.prev);                     \
                &pos->member != (head);                                         \
                pos = llist_entry(pos->member.prev, typeof(*pos), member),      \
                        prefetch(pos->member.prev))

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

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

#define llist_for_each_rcu(pos, head) \
        for (pos = (head)->next, prefetch(pos->next); pos != (head); \
                pos = pos->next, ({ smp_read_barrier_depends(); 0;}), prefetch(pos->next))

#define __llist_for_each_rcu(pos, head) \
        for (pos = (head)->next; pos != (head); \
                pos = pos->next, ({ smp_read_barrier_depends(); 0;}))

#define llist_for_each_safe_rcu(pos, n, head) \
        for (pos = (head)->next, n = pos->next; pos != (head); \
                pos = n, ({ smp_read_barrier_depends(); 0;}), n = pos->next)

#define llist_for_each_entry_rcu(pos, head, member)                     \
        for (pos = llist_entry((head)->next, typeof(*pos), member),     \
                        prefetch(pos->member.next);                     \
                &pos->member != (head);                                         \
                pos = llist_entry(pos->member.next, typeof(*pos), member),      \
                        ({ smp_read_barrier_depends(); 0;}),            \
                        prefetch(pos->member.next))


#define llist_for_each_continue_rcu(pos, head) \
        for ((pos) = (pos)->next, prefetch((pos)->next); (pos) != (head); \
                (pos) = (pos)->next, ({ smp_read_barrier_depends(); 0;}), prefetch((pos)->next))


#endif

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