list.h

   1 /*-
   2  * Copyright (c) 2011 Felix Fietkau <nbd@openwrt.org>
   3  * Copyright (c) 2010 Isilon Systems, Inc.
   4  * Copyright (c) 2010 iX Systems, Inc.
   5  * Copyright (c) 2010 Panasas, Inc.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice unmodified, this list of conditions, and the following
  13  *    disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29 #ifndef _LINUX_LIST_H_
  30 #define _LINUX_LIST_H_
  31
  32 #include <stddef.h>
  33 #include <stdbool.h>
  34
  35 #define prefetch(x)
  36
  37 #ifndef container_of
  38 #define container_of(ptr, type, member)                                 \
  39         ({                                                              \
  40                 const __typeof__(((type *) NULL)->member) *__mptr = (ptr);      \
  41                 (type *) ((char *) __mptr - offsetof(type, member));    \
  42         })
  43 #endif
  44
  45 #ifndef container_of_safe
  46 #define container_of_safe(ptr, type, member)                                            \
  47         ({                                                                              \
  48                 const __typeof__(((type *) NULL)->member) *__mptr = (ptr);              \
  49                 __mptr ? (type *)((char *) __mptr - offsetof(type, member)) : NULL;     \
  50         })
  51 #endif
  52
  53 struct list_head {
  54         struct list_head *next;
  55         struct list_head *prev;
  56 };
  57
  58 #define LIST_HEAD_INIT(name) { &(name), &(name) }
  59 #undef LIST_HEAD
  60 #define LIST_HEAD(name) struct list_head name = LIST_HEAD_INIT(name)
  61
  62 static inline void
  63 INIT_LIST_HEAD(struct list_head *list)
  64 {
  65         list->next = list->prev = list;
  66 }
  67
  68 static inline bool
  69 list_empty(const struct list_head *head)
  70 {
  71         return (head->next == head);
  72 }
  73
  74 static inline bool
  75 list_is_first(const struct list_head *list,
  76               const struct list_head *head)
  77 {
  78         return list->prev == head;
  79 }
  80
  81 static inline bool
  82 list_is_last(const struct list_head *list,
  83              const struct list_head *head)
  84 {
  85         return list->next == head;
  86 }
  87
  88 static inline void
  89 _list_del(struct list_head *entry)
  90 {
  91         entry->next->prev = entry->prev;
  92         entry->prev->next = entry->next;
  93 }
  94
  95 static inline void
  96 list_del(struct list_head *entry)
  97 {
  98         _list_del(entry);
  99         entry->next = entry->prev = NULL;
 100 }
 101
 102 static inline void
 103 _list_add(struct list_head *_new, struct list_head *prev,
 104     struct list_head *next)
 105 {
 106
 107         next->prev = _new;
 108         _new->next = next;
 109         _new->prev = prev;
 110         prev->next = _new;
 111 }
 112
 113 static inline void
 114 list_del_init(struct list_head *entry)
 115 {
 116         _list_del(entry);
 117         INIT_LIST_HEAD(entry);
 118 }
 119
 120 #define list_entry(ptr, type, field)    container_of(ptr, type, field)
 121 #define list_first_entry(ptr, type, field)      list_entry((ptr)->next, type, field)
 122 #define list_last_entry(ptr, type, field)       list_entry((ptr)->prev, type, field)
 123 #define list_next_entry(pos, member)            list_entry((pos)->member.next, typeof(*(pos)), member)
 124 #define list_entry_is_h(p, h, field)            (&p->field == (h))
 125
 126 #define list_for_each(p, head)                                          \
 127         for (p = (head)->next; p != (head); p = p->next)
 128
 129 #define list_for_each_safe(p, n, head)                                  \
 130         for (p = (head)->next, n = p->next; p != (head); p = n, n = p->next)
 131
 132 #define list_for_each_entry(p, h, field)                                \
 133         for (p = list_first_entry(h, __typeof__(*p), field); &p->field != (h); \
 134             p = list_entry(p->field.next, __typeof__(*p), field))
 135
 136 #define list_for_each_entry_continue(p, h, field)                       \
 137         for (p = list_next_entry(p, field);                             \
 138              !list_entry_is_h(p, h, field);                             \
 139              p = list_next_entry(p, field))
 140
 141 #define list_for_each_entry_continue_reverse(p, h, field)               \
 142         for (p = list_prev_entry(p, field);                             \
 143              !list_entry_is_h(p, h, field);                             \
 144              p = list_prev_entry(p, field))
 145
 146 #define list_for_each_entry_safe(p, n, h, field)                        \
 147         for (p = list_first_entry(h, __typeof__(*p), field),            \
 148             n = list_entry(p->field.next, __typeof__(*p), field); &p->field != (h);\
 149             p = n, n = list_entry(n->field.next, __typeof__(*n), field))
 150
 151 #define list_for_each_entry_reverse(p, h, field)                        \
 152         for (p = list_last_entry(h, __typeof__(*p), field); &p->field != (h); \
 153             p = list_entry(p->field.prev, __typeof__(*p), field))
 154
 155 #define list_for_each_prev(p, h) for (p = (h)->prev; p != (h); p = p->prev)
 156 #define list_for_each_prev_safe(p, n, h) for (p = (h)->prev, n = p->prev; p != (h); p = n, n = p->prev)
 157
 158 static inline void
 159 list_add(struct list_head *_new, struct list_head *head)
 160 {
 161         _list_add(_new, head, head->next);
 162 }
 163
 164 static inline void
 165 list_add_tail(struct list_head *_new, struct list_head *head)
 166 {
 167         _list_add(_new, head->prev, head);
 168 }
 169
 170 static inline void
 171 list_move(struct list_head *list, struct list_head *head)
 172 {
 173         _list_del(list);
 174         list_add(list, head);
 175 }
 176
 177 static inline void
 178 list_move_tail(struct list_head *entry, struct list_head *head)
 179 {
 180         _list_del(entry);
 181         list_add_tail(entry, head);
 182 }
 183
 184 static inline void
 185 _list_splice(const struct list_head *list, struct list_head *prev,
 186     struct list_head *next)
 187 {
 188         struct list_head *first;
 189         struct list_head *last;
 190
 191         if (list_empty(list))
 192                 return;
 193
 194         first = list->next;
 195         last = list->prev;
 196         first->prev = prev;
 197         prev->next = first;
 198         last->next = next;
 199         next->prev = last;
 200 }
 201
 202 static inline void
 203 list_splice(const struct list_head *list, struct list_head *head)
 204 {
 205         _list_splice(list, head, head->next);
 206 }
 207
 208 static inline void
 209 list_splice_tail(struct list_head *list, struct list_head *head)
 210 {
 211         _list_splice(list, head->prev, head);
 212 }
 213
 214 static inline void
 215 list_splice_init(struct list_head *list, struct list_head *head)
 216 {
 217         _list_splice(list, head, head->next);
 218         INIT_LIST_HEAD(list);
 219 }
 220
 221 static inline void
 222 list_splice_tail_init(struct list_head *list, struct list_head *head)
 223 {
 224         _list_splice(list, head->prev, head);
 225         INIT_LIST_HEAD(list);
 226 }
 227
 228 #endif /* _LINUX_LIST_H_ */