linux_list.h

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#ifndef _LINUX_LIST_H
#define _LINUX_LIST_H

#undef offsetof
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)

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

/*
 * Check at compile time that something is of a particular type.
 * Always evaluates to 1 so you may use it easily in comparisons.
 */
#define typecheck(type,x) \
({  type __dummy; \
    typeof(x) __dummy2; \
    (void)(&__dummy == &__dummy2); \
    1; \
})

#define prefetch(x)     1

/* empty define to make this work in userspace -HW */
#define smp_wmb()

/*
 * These are non-NULL pointers that will result in page faults
 * under normal circumstances, used to verify that nobody uses
 * non-initialized list entries.
 */
#define LIST_POISON1  ((void *) 0x00100100)
#define LIST_POISON2  ((void *) 0x00200200)

/*
 * Simple doubly linked list implementation.
 *
 * Some of the internal functions ("__xxx") are useful when
 * manipulating whole lists 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 list_head {
    struct list_head *next, *prev;
};

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

#define LIST_HEAD(name) \
    struct list_head name = LIST_HEAD_INIT(name)

#define INIT_LIST_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 list manipulation where we know
 * the prev/next entries already!
 */
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_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);
}

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

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

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

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

static inline void list_del(struct list_head *entry)
{
    __list_del(entry->prev, entry->next);
    entry->next = LIST_POISON1;
    entry->prev = LIST_POISON2;
}

static inline void list_del_rcu(struct list_head *entry)
{
    __list_del(entry->prev, entry->next);
    entry->prev = LIST_POISON2;
}

static inline void list_del_init(struct list_head *entry)
{
    __list_del(entry->prev, entry->next);
    INIT_LIST_HEAD(entry);
}

static inline void list_move(struct list_head *list, struct list_head *head)
{
        __list_del(list->prev, list->next);
        list_add(list, head);
}

static inline void list_move_tail(struct list_head *list,
                  struct list_head *head)
{
        __list_del(list->prev, list->next);
        list_add_tail(list, head);
}

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

static inline int list_empty_careful(const struct list_head *head)
{
    struct list_head *next = head->next;
    return (next == head) && (next == head->prev);
}

static inline void __list_splice(struct list_head *list,
                 struct list_head *head)
{
    struct list_head *first = list->next;
    struct list_head *last = list->prev;
    struct list_head *at = head->next;

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

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

static inline void list_splice(struct list_head *list, struct list_head *head)
{
    if (!list_empty(list))
        __list_splice(list, head);
}

static inline void list_splice_init(struct list_head *list,
                    struct list_head *head)
{
    if (!list_empty(list)) {
        __list_splice(list, head);
        INIT_LIST_HEAD(list);
    }
}

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

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

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

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

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

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

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

#define list_prepare_entry(pos, head, member) \
    ((pos) ? : list_entry(head, typeof(*pos), member))

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

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

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

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


#define list_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))

/*
 * Double linked lists with a single pointer list head.
 * Mostly useful for hash tables where the two pointer list head is
 * too wasteful.
 * You lose the ability to access the tail in O(1).
 */

struct hlist_head {
    struct hlist_node *first;
};

struct hlist_node {
    struct hlist_node *next, **pprev;
};

#define HLIST_HEAD_INIT { .first = NULL }
#define HLIST_HEAD(name) struct hlist_head name = {  .first = NULL }
#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
#define INIT_HLIST_NODE(ptr) ((ptr)->next = NULL, (ptr)->pprev = NULL)

static inline int hlist_unhashed(const struct hlist_node *h)
{
    return !h->pprev;
}

static inline int hlist_empty(const struct hlist_head *h)
{
    return !h->first;
}

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

static inline void hlist_del(struct hlist_node *n)
{
    __hlist_del(n);
    n->next = LIST_POISON1;
    n->pprev = LIST_POISON2;
}

static inline void hlist_del_rcu(struct hlist_node *n)
{
    __hlist_del(n);
    n->pprev = LIST_POISON2;
}

static inline void hlist_del_init(struct hlist_node *n)
{
    if (n->pprev)  {
        __hlist_del(n);
        INIT_HLIST_NODE(n);
    }
}

#define hlist_del_rcu_init hlist_del_init

static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
{
    struct hlist_node *first = h->first;
    n->next = first;
    if (first)
        first->pprev = &n->next;
    h->first = n;
    n->pprev = &h->first;
}


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;
    smp_wmb();
    if (first)
        first->pprev = &n->next;
    h->first = n;
}

/* next must be != NULL */
static inline void hlist_add_before(struct hlist_node *n,
                    struct hlist_node *next)
{
    n->pprev = next->pprev;
    n->next = next;
    next->pprev = &n->next;
    *(n->pprev) = n;
}

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

    if(next->next)
        next->next->pprev  = &next->next;
}

#define hlist_entry(ptr, type, member) container_of(ptr,type,member)

#define hlist_for_each(pos, head) \
    for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
         pos = pos->next)

#define hlist_for_each_safe(pos, n, head) \
    for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
         pos = n)

#define hlist_for_each_entry(tpos, pos, head, member)            \
    for (pos = (head)->first;                    \
         pos && ({ prefetch(pos->next); 1;}) &&          \
        ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
         pos = pos->next)

#define hlist_for_each_entry_continue(tpos, pos, member)         \
    for (pos = (pos)->next;                      \
         pos && ({ prefetch(pos->next); 1;}) &&          \
        ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
         pos = pos->next)

#define hlist_for_each_entry_from(tpos, pos, member)             \
    for (; pos && ({ prefetch(pos->next); 1;}) &&            \
        ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
         pos = pos->next)

#define hlist_for_each_entry_safe(tpos, pos, n, head, member)        \
    for (pos = (head)->first;                    \
         pos && ({ n = pos->next; 1; }) &&               \
        ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
         pos = n)

#define hlist_for_each_entry_rcu(tpos, pos, head, member)        \
    for (pos = (head)->first;                    \
         pos && ({ prefetch(pos->next); 1;}) &&          \
        ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
         pos = pos->next, ({ smp_read_barrier_depends(); 0; }) )

#endif