diff options
Diffstat (limited to 'linux/llist.c')
-rw-r--r-- | linux/llist.c | 92 |
1 files changed, 0 insertions, 92 deletions
diff --git a/linux/llist.c b/linux/llist.c deleted file mode 100644 index 611ce488..00000000 --- a/linux/llist.c +++ /dev/null @@ -1,92 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * Lock-less NULL terminated single linked list - * - * The basic atomic operation of this list is cmpxchg on long. On - * architectures that don't have NMI-safe cmpxchg implementation, the - * list can NOT be used in NMI handlers. So code that uses the list in - * an NMI handler should depend on CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG. - * - * Copyright 2010,2011 Intel Corp. - * Author: Huang Ying <ying.huang@intel.com> - */ -#include <linux/kernel.h> -#include <linux/export.h> -#include <linux/llist.h> - - -/** - * llist_add_batch - add several linked entries in batch - * @new_first: first entry in batch to be added - * @new_last: last entry in batch to be added - * @head: the head for your lock-less list - * - * Return whether list is empty before adding. - */ -bool llist_add_batch(struct llist_node *new_first, struct llist_node *new_last, - struct llist_head *head) -{ - struct llist_node *first; - - do { - new_last->next = first = READ_ONCE(head->first); - } while (cmpxchg(&head->first, first, new_first) != first); - - return !first; -} -EXPORT_SYMBOL_GPL(llist_add_batch); - -/** - * llist_del_first - delete the first entry of lock-less list - * @head: the head for your lock-less list - * - * If list is empty, return NULL, otherwise, return the first entry - * deleted, this is the newest added one. - * - * Only one llist_del_first user can be used simultaneously with - * multiple llist_add users without lock. Because otherwise - * llist_del_first, llist_add, llist_add (or llist_del_all, llist_add, - * llist_add) sequence in another user may change @head->first->next, - * but keep @head->first. If multiple consumers are needed, please - * use llist_del_all or use lock between consumers. - */ -struct llist_node *llist_del_first(struct llist_head *head) -{ - struct llist_node *entry, *old_entry, *next; - - entry = smp_load_acquire(&head->first); - for (;;) { - if (entry == NULL) - return NULL; - old_entry = entry; - next = READ_ONCE(entry->next); - entry = cmpxchg(&head->first, old_entry, next); - if (entry == old_entry) - break; - } - - return entry; -} -EXPORT_SYMBOL_GPL(llist_del_first); - -/** - * llist_reverse_order - reverse order of a llist chain - * @head: first item of the list to be reversed - * - * Reverse the order of a chain of llist entries and return the - * new first entry. - */ -struct llist_node *llist_reverse_order(struct llist_node *head) -{ - struct llist_node *new_head = NULL; - - while (head) { - struct llist_node *tmp = head; - head = head->next; - tmp->next = new_head; - new_head = tmp; - } - - return new_head; -} -EXPORT_SYMBOL_GPL(llist_reverse_order); |