LXR linux/tools/usb/usbip/libsrc/list.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LIST_H
   3#define _LIST_H
   4
   5/* Stripped down implementation of linked list taken
   6 * from the Linux Kernel.
   7 */
   8
   9/*
  10 * Simple doubly linked list implementation.
  11 *
  12 * Some of the internal functions ("__xxx") are useful when
  13 * manipulating whole lists rather than single entries, as
  14 * sometimes we already know the next/prev entries and we can
  15 * generate better code by using them directly rather than
  16 * using the generic single-entry routines.
  17 */
  18
  19struct list_head {
  20        struct list_head *next, *prev;
  21};
  22
  23#define LIST_HEAD_INIT(name) { &(name), &(name) }
  24
  25#define LIST_HEAD(name) \
  26        struct list_head name = LIST_HEAD_INIT(name)
  27
  28static inline void INIT_LIST_HEAD(struct list_head *list)
  29{
  30        list->next = list;
  31        list->prev = list;
  32}
  33
  34/*
  35 * Insert a new entry between two known consecutive entries.
  36 *
  37 * This is only for internal list manipulation where we know
  38 * the prev/next entries already!
  39 */
  40static inline void __list_add(struct list_head *new,
  41                              struct list_head *prev,
  42                              struct list_head *next)
  43{
  44        next->prev = new;
  45        new->next = next;
  46        new->prev = prev;
  47        prev->next = new;
  48}
  49
  50/**
  51 * list_add - add a new entry
  52 * @new: new entry to be added
  53 * @head: list head to add it after
  54 *
  55 * Insert a new entry after the specified head.
  56 * This is good for implementing stacks.
  57 */
  58static inline void list_add(struct list_head *new, struct list_head *head)
  59{
  60        __list_add(new, head, head->next);
  61}
  62
  63/*
  64 * Delete a list entry by making the prev/next entries
  65 * point to each other.
  66 *
  67 * This is only for internal list manipulation where we know
  68 * the prev/next entries already!
  69 */
  70static inline void __list_del(struct list_head * prev, struct list_head * next)
  71{
  72        next->prev = prev;
  73        prev->next = next;
  74}
  75
  76#define POISON_POINTER_DELTA 0
  77#define LIST_POISON1  ((void *) 0x00100100 + POISON_POINTER_DELTA)
  78#define LIST_POISON2  ((void *) 0x00200200 + POISON_POINTER_DELTA)
  79
  80/**
  81 * list_del - deletes entry from list.
  82 * @entry: the element to delete from the list.
  83 * Note: list_empty() on entry does not return true after this, the entry is
  84 * in an undefined state.
  85 */
  86static inline void __list_del_entry(struct list_head *entry)
  87{
  88        __list_del(entry->prev, entry->next);
  89}
  90
  91static inline void list_del(struct list_head *entry)
  92{
  93        __list_del(entry->prev, entry->next);
  94        entry->next = LIST_POISON1;
  95        entry->prev = LIST_POISON2;
  96}
  97
  98/**
  99 * list_entry - get the struct for this entry
 100 * @ptr:        the &struct list_head pointer.
 101 * @type:       the type of the struct this is embedded in.
 102 * @member:     the name of the list_head within the struct.
 103 */
 104#define list_entry(ptr, type, member) \
 105        container_of(ptr, type, member)
 106/**
 107 * list_for_each        -       iterate over a list
 108 * @pos:        the &struct list_head to use as a loop cursor.
 109 * @head:       the head for your list.
 110 */
 111#define list_for_each(pos, head) \
 112        for (pos = (head)->next; pos != (head); pos = pos->next)
 113
 114/**
 115 * list_for_each_safe - iterate over a list safe against removal of list entry
 116 * @pos:        the &struct list_head to use as a loop cursor.
 117 * @n:          another &struct list_head to use as temporary storage
 118 * @head:       the head for your list.
 119 */
 120#define list_for_each_safe(pos, n, head) \
 121        for (pos = (head)->next, n = pos->next; pos != (head); \
 122                pos = n, n = pos->next)
 123
 124#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
 125
 126/**
 127 * container_of - cast a member of a structure out to the containing structure
 128 * @ptr:        the pointer to the member.
 129 * @type:       the type of the container struct this is embedded in.
 130 * @member:     the name of the member within the struct.
 131 *
 132 */
 133#define container_of(ptr, type, member) ({                      \
 134        const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 135        (type *)( (char *)__mptr - offsetof(type,member) );})
 136
 137#endif
 138