include/list.h

   1 /**
   2  * @file list.h
   3  *
   4  * @brief Unearth list to the user space. Thxs to @e modinit tools!
   5  *
   6  * @author Yury GEORGIEVSKIY
   7  *
   8  * @date long time ago.
   9  *
  10  * Taken from Linux Kernel Source's list.h -- GPL.
  11  *
  12  * @version 1.0  ygeorige  30/06/2008  Creation date.
  13  */
  14
  15 #ifndef _MODINITTOOLS_LIST_H
  16 #define _MODINITTOOLS_LIST_H
  17
  18 #undef offsetof
  19 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
  20
  21 /**
  22  * container_of - cast a member of a structure out to the containing structure
  23  *
  24  * @ptr:        the pointer to the member.
  25  * @type:       the type of the container struct this is embedded in.
  26  * @member:     the name of the member within the struct.
  27  *
  28  */
  29 #define container_of(ptr, type, member) ({                      \
  30         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
  31         (type *)( (char *)__mptr - offsetof(type,member) );})
  32
  33 /*
  34  * Simple doubly linked list implementation.
  35  *
  36  * Some of the internal functions ("__xxx") are useful when
  37  * manipulating whole lists rather than single entries, as
  38  * sometimes we already know the next/prev entries and we can
  39  * generate better code by using them directly rather than
  40  * using the generic single-entry routines.
  41  */
  42
  43 struct list_head {
  44         struct list_head *next, *prev;
  45 };
  46
  47 #define LIST_HEAD_INIT(name) { &(name), &(name) }
  48
  49 #define LIST_HEAD(name) \
  50         struct list_head name = LIST_HEAD_INIT(name)
  51
  52 #define INIT_LIST_HEAD(ptr) do { \
  53         (ptr)->next = (ptr); (ptr)->prev = (ptr); \
  54 } while (0)
  55
  56 /*
  57  * Insert a new entry between two known consecutive entries.
  58  *
  59  * This is only for internal list manipulation where we know
  60  * the prev/next entries already!
  61  */
  62 static inline void __list_add(struct list_head *newl,
  63                               struct list_head *prev,
  64                               struct list_head *next)
  65 {
  66         next->prev = newl;
  67         newl->next = next;
  68         newl->prev = prev;
  69         prev->next = newl;
  70 }
  71
  72 /**
  73  * list_add - add a new entry
  74  * @new: new entry to be added
  75  * @head: list head to add it after
  76  *
  77  * Insert a new entry after the specified head.
  78  * This is good for implementing stacks.
  79  */
  80 static inline void list_add(struct list_head *newl, struct list_head *head)
  81 {
  82         __list_add(newl, head, head->next);
  83 }
  84
  85 /**
  86  * list_add_tail - add a new entry
  87  * @new: new entry to be added
  88  * @head: list head to add it before
  89  *
  90  * Insert a new entry before the specified head.
  91  * This is useful for implementing queues.
  92  */
  93 static inline void list_add_tail(struct list_head *newl, struct list_head *head)
  94 {
  95         __list_add(newl, head->prev, head);
  96 }
  97
  98 /*
  99  * Delete a list entry by making the prev/next entries
 100  * point to each other.
 101  *
 102  * This is only for internal list manipulation where we know
 103  * the prev/next entries already!
 104  */
 105 static inline void __list_del(struct list_head * prev, struct list_head * next)
 106 {
 107         next->prev = prev;
 108         prev->next = next;
 109 }
 110
 111 /**
 112  * list_del - deletes entry from list.
 113  * @entry: the element to delete from the list.
 114  * Note: list_empty on entry does not return true after this, the entry is
 115  * in an undefined state.
 116  */
 117 static inline void list_del(struct list_head *entry)
 118 {
 119         __list_del(entry->prev, entry->next);
 120 }
 121
 122 /**
 123  * list_del_init - deletes entry from list and reinitialize it.
 124  * @entry: the element to delete from the list.
 125  */
 126 static inline void list_del_init(struct list_head *entry)
 127 {
 128         __list_del(entry->prev, entry->next);
 129         INIT_LIST_HEAD(entry);
 130 }
 131
 132 /**
 133  * list_move - delete from one list and add as another's head
 134  * @list: the entry to move
 135  * @head: the head that will precede our entry
 136  */
 137 static inline void list_move(struct list_head *list, struct list_head *head)
 138 {
 139         __list_del(list->prev, list->next);
 140         list_add(list, head);
 141 }
 142
 143 /**
 144  * list_move_tail - delete from one list and add as another's tail
 145  * @list: the entry to move
 146  * @head: the head that will follow our entry
 147  */
 148 static inline void list_move_tail(struct list_head *list,
 149                                   struct list_head *head)
 150 {
 151         __list_del(list->prev, list->next);
 152         list_add_tail(list, head);
 153 }
 154
 155 /**
 156  * list_empty - tests whether a list is empty
 157  * @head: the list to test.
 158  */
 159 static inline int list_empty(struct list_head *head)
 160 {
 161         return head->next == head;
 162 }
 163
 164 static inline void __list_splice(struct list_head *list,
 165                                  struct list_head *head)
 166 {
 167         struct list_head *first = list->next;
 168         struct list_head *last = list->prev;
 169         struct list_head *at = head->next;
 170
 171         first->prev = head;
 172         head->next = first;
 173
 174         last->next = at;
 175         at->prev = last;
 176 }
 177
 178 /**
 179  * list_splice - join two lists
 180  * @list: the new list to add.
 181  * @head: the place to add it in the first list.
 182  */
 183 static inline void list_splice(struct list_head *list, struct list_head *head)
 184 {
 185         if (!list_empty(list))
 186                 __list_splice(list, head);
 187 }
 188
 189 /**
 190  * list_splice_init - join two lists and reinitialise the emptied list.
 191  * @list: the new list to add.
 192  * @head: the place to add it in the first list.
 193  *
 194  * The list at @list is reinitialised
 195  */
 196 static inline void list_splice_init(struct list_head *list, struct list_head *head)
 197 {
 198         if (!list_empty(list)) {
 199                 __list_splice(list, head);
 200                 INIT_LIST_HEAD(list);
 201         }
 202 }
 203
 204 /**
 205  * list_entry - get the struct for this entry
 206  * @ptr:        the &struct list_head pointer.
 207  * @type:       the type of the struct this is embedded in.
 208  * @member:     the name of the list_struct within the struct.
 209  */
 210 #define list_entry(ptr, type, member) \
 211         container_of(ptr, type, member)
 212
 213 /**
 214  * list_for_each        -       iterate over a list
 215  * @pos:        the &struct list_head to use as a loop counter.
 216  * @head:       the head for your list.
 217  */
 218 #define list_for_each(pos, head) \
 219         for (pos = (head)->next; pos != (head); pos = pos->next)
 220
 221 /**
 222  * list_for_each_prev   -       iterate over a list backwards
 223  * @pos:        the &struct list_head to use as a loop counter.
 224  * @head:       the head for your list.
 225  */
 226 #define list_for_each_prev(pos, head) \
 227         for (pos = (head)->prev; pos != (head); pos = pos->prev)
 228
 229 /**
 230  * list_for_each_safe - iterate over a list safe against removal of list entry
 231  * @pos:        the &struct list_head to use as a loop counter.
 232  * @n:          another &struct list_head to use as temporary storage
 233  * @head:       the head for your list.
 234  */
 235 #define list_for_each_safe(pos, n, head) \
 236         for (pos = (head)->next, n = pos->next; pos != (head); \
 237                 pos = n, n = pos->next)
 238
 239 /**
 240  * list_for_each_entry  -       iterate over list of given type
 241  * @pos:        the type * to use as a loop counter.
 242  * @head:       the head for your list.
 243  * @member:     the name of the list_struct within the struct.
 244  */
 245 #define list_for_each_entry(pos, head, member)                          \
 246         for (pos = list_entry((head)->next, typeof(*pos), member);      \
 247              &pos->member != (head);                                    \
 248              pos = list_entry(pos->member.next, typeof(*pos), member))
 249
 250 /**
 251  * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
 252  * @pos:        the type * to use as a loop cursor.
 253  * @n:          another type * to use as temporary storage
 254  * @head:       the head for your list.
 255  * @member:     the name of the list_struct within the struct.
 256  */
 257 #define list_for_each_entry_safe(pos, n, head, member)                  \
 258         for (pos = list_entry((head)->next, typeof(*pos), member),      \
 259                 n = list_entry(pos->member.next, typeof(*pos), member); \
 260              &pos->member != (head);                                    \
 261              pos = n, n = list_entry(n->member.next, typeof(*n), member))
 262
 263 /* Extra handy list definitions. (see the header for more detailes)
 264    In a separate file, because drivers also are using this marcoses */
 265 #include "list_extra.h"
 266
 267 #endif