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Diffstat (limited to 'nvif/list.h')
-rw-r--r-- | nvif/list.h | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/nvif/list.h b/nvif/list.h new file mode 100644 index 000000000..8af5d144e --- /dev/null +++ b/nvif/list.h @@ -0,0 +1,353 @@ +/* + * Copyright © 2010 Intel Corporation + * Copyright © 2010 Francisco Jerez <currojerez@riseup.net> + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + * + */ + +/* Modified by Ben Skeggs <bskeggs@redhat.com> to match kernel list APIs */ + +#ifndef _XORG_LIST_H_ +#define _XORG_LIST_H_ + +/** + * @file Classic doubly-link circular list implementation. + * For real usage examples of the linked list, see the file test/list.c + * + * Example: + * We need to keep a list of struct foo in the parent struct bar, i.e. what + * we want is something like this. + * + * struct bar { + * ... + * struct foo *list_of_foos; -----> struct foo {}, struct foo {}, struct foo{} + * ... + * } + * + * We need one list head in bar and a list element in all list_of_foos (both are of + * data type 'struct list_head'). + * + * struct bar { + * ... + * struct list_head list_of_foos; + * ... + * } + * + * struct foo { + * ... + * struct list_head entry; + * ... + * } + * + * Now we initialize the list head: + * + * struct bar bar; + * ... + * INIT_LIST_HEAD(&bar.list_of_foos); + * + * Then we create the first element and add it to this list: + * + * struct foo *foo = malloc(...); + * .... + * list_add(&foo->entry, &bar.list_of_foos); + * + * Repeat the above for each element you want to add to the list. Deleting + * works with the element itself. + * list_del(&foo->entry); + * free(foo); + * + * Note: calling list_del(&bar.list_of_foos) will set bar.list_of_foos to an empty + * list again. + * + * Looping through the list requires a 'struct foo' as iterator and the + * name of the field the subnodes use. + * + * struct foo *iterator; + * list_for_each_entry(iterator, &bar.list_of_foos, entry) { + * if (iterator->something == ...) + * ... + * } + * + * Note: You must not call list_del() on the iterator if you continue the + * loop. You need to run the safe for-each loop instead: + * + * struct foo *iterator, *next; + * list_for_each_entry_safe(iterator, next, &bar.list_of_foos, entry) { + * if (...) + * list_del(&iterator->entry); + * } + * + */ + +/** + * The linkage struct for list nodes. This struct must be part of your + * to-be-linked struct. struct list_head is required for both the head of the + * list and for each list node. + * + * Position and name of the struct list_head field is irrelevant. + * There are no requirements that elements of a list are of the same type. + * There are no requirements for a list head, any struct list_head can be a list + * head. + */ +struct list_head { + struct list_head *next, *prev; +}; + +/** + * Initialize the list as an empty list. + * + * Example: + * INIT_LIST_HEAD(&bar->list_of_foos); + * + * @param The list to initialized. + */ +#define LIST_HEAD_INIT(name) { &(name), &(name) } + +#define LIST_HEAD(name) \ + struct list_head name = LIST_HEAD_INIT(name) + +static inline void +INIT_LIST_HEAD(struct list_head *list) +{ + list->next = list->prev = list; +} + +static inline void +__list_add(struct list_head *entry, + struct list_head *prev, struct list_head *next) +{ + next->prev = entry; + entry->next = next; + entry->prev = prev; + prev->next = entry; +} + +/** + * Insert a new element after the given list head. The new element does not + * need to be initialised as empty list. + * The list changes from: + * head → some element → ... + * to + * head → new element → older element → ... + * + * Example: + * struct foo *newfoo = malloc(...); + * list_add(&newfoo->entry, &bar->list_of_foos); + * + * @param entry The new element to prepend to the list. + * @param head The existing list. + */ +static inline void +list_add(struct list_head *entry, struct list_head *head) +{ + __list_add(entry, head, head->next); +} + +/** + * Append a new element to the end of the list given with this list head. + * + * The list changes from: + * head → some element → ... → lastelement + * to + * head → some element → ... → lastelement → new element + * + * Example: + * struct foo *newfoo = malloc(...); + * list_add_tail(&newfoo->entry, &bar->list_of_foos); + * + * @param entry The new element to prepend to the list. + * @param head The existing list. + */ +static inline void +list_add_tail(struct list_head *entry, struct list_head *head) +{ + __list_add(entry, head->prev, head); +} + +static inline void +__list_del(struct list_head *prev, struct list_head *next) +{ + next->prev = prev; + prev->next = next; +} + +/** + * Remove the element from the list it is in. Using this function will reset + * the pointers to/from this element so it is removed from the list. It does + * NOT free the element itself or manipulate it otherwise. + * + * Using list_del on a pure list head (like in the example at the top of + * this file) will NOT remove the first element from + * the list but rather reset the list as empty list. + * + * Example: + * list_del(&foo->entry); + * + * @param entry The element to remove. + */ +static inline void +list_del(struct list_head *entry) +{ + __list_del(entry->prev, entry->next); +} + +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_tail(struct list_head *list, + struct list_head *head) +{ + __list_del(list->prev, list->next); + list_add_tail(list, head); +} + +/** + * Check if the list is empty. + * + * Example: + * list_empty(&bar->list_of_foos); + * + * @return True if the list contains one or more elements or False otherwise. + */ +static inline bool +list_empty(struct list_head *head) +{ + return head->next == head; +} + +/** + * Returns a pointer to the container of this list element. + * + * Example: + * struct foo* f; + * f = container_of(&foo->entry, struct foo, entry); + * assert(f == foo); + * + * @param ptr Pointer to the struct list_head. + * @param type Data type of the list element. + * @param member Member name of the struct list_head field in the list element. + * @return A pointer to the data struct containing the list head. + */ +#ifndef container_of +#define container_of(ptr, type, member) \ + (type *)((char *)(ptr) - (char *) &((type *)0)->member) +#endif + +/** + * Alias of container_of + */ +#define list_entry(ptr, type, member) \ + container_of(ptr, type, member) + +/** + * Retrieve the first list entry for the given list pointer. + * + * Example: + * struct foo *first; + * first = list_first_entry(&bar->list_of_foos, struct foo, list_of_foos); + * + * @param ptr The list head + * @param type Data type of the list element to retrieve + * @param member Member name of the struct list_head field in the list element. + * @return A pointer to the first list element. + */ +#define list_first_entry(ptr, type, member) \ + list_entry((ptr)->next, type, member) + +/** + * Retrieve the last list entry for the given listpointer. + * + * Example: + * struct foo *first; + * first = list_last_entry(&bar->list_of_foos, struct foo, list_of_foos); + * + * @param ptr The list head + * @param type Data type of the list element to retrieve + * @param member Member name of the struct list_head field in the list element. + * @return A pointer to the last list element. + */ +#define list_last_entry(ptr, type, member) \ + list_entry((ptr)->prev, type, member) + +#define __container_of(ptr, sample, member) \ + (void *)container_of((ptr), typeof(*(sample)), member) + +/** + * Loop through the list given by head and set pos to struct in the list. + * + * Example: + * struct foo *iterator; + * list_for_each_entry(iterator, &bar->list_of_foos, entry) { + * [modify iterator] + * } + * + * This macro is not safe for node deletion. Use list_for_each_entry_safe + * instead. + * + * @param pos Iterator variable of the type of the list elements. + * @param head List head + * @param member Member name of the struct list_head in the list elements. + * + */ +#define list_for_each_entry(pos, head, member) \ + for (pos = __container_of((head)->next, pos, member); \ + &pos->member != (head); \ + pos = __container_of(pos->member.next, pos, member)) + +/** + * Loop through the list, keeping a backup pointer to the element. This + * macro allows for the deletion of a list element while looping through the + * list. + * + * See list_for_each_entry for more details. + */ +#define list_for_each_entry_safe(pos, tmp, head, member) \ + for (pos = __container_of((head)->next, pos, member), \ + tmp = __container_of(pos->member.next, pos, member); \ + &pos->member != (head); \ + pos = tmp, tmp = __container_of(pos->member.next, tmp, member)) + + +#define list_for_each_entry_reverse(pos, head, member) \ + for (pos = __container_of((head)->prev, pos, member); \ + &pos->member != (head); \ + pos = __container_of(pos->member.prev, pos, member)) + +#define list_for_each_entry_continue(pos, head, member) \ + for (pos = __container_of(pos->member.next, pos, member); \ + &pos->member != (head); \ + pos = __container_of(pos->member.next, pos, member)) + +#define list_for_each_entry_continue_reverse(pos, head, member) \ + for (pos = __container_of(pos->member.prev, pos, member); \ + &pos->member != (head); \ + pos = __container_of(pos->member.prev, pos, member)) + +#define list_for_each_entry_from(pos, head, member) \ + for (; \ + &pos->member != (head); \ + pos = __container_of(pos->member.next, pos, member)) + +#endif |