tools/usb/usbip/libsrc/list.h

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