include/linux/rculist_nulls.h

1 /* SPDX-License-Identifier: GPL-2.0 */
8  * RCU-protected list version
14  * hlist_nulls_del_init_rcu - deletes entry from hash list with re-initialization
28  * list-mutation primitive, such as hlist_nulls_add_head_rcu() or
30  * perfectly legal to run concurrently with the _rcu list-traversal
37 		WRITE_ONCE(n->pprev, NULL);  in hlist_nulls_del_init_rcu()
42  * hlist_nulls_first_rcu - returns the first element of the hash list.
46 	(*((struct hlist_nulls_node __rcu __force **)&(head)->first))
49  * hlist_nulls_next_rcu - returns the element of the list after @node.
53 	(*((struct hlist_nulls_node __rcu __force **)&(node)->next))
56  * hlist_nulls_del_rcu - deletes entry from hash list without re-initialization
68  * with another list-mutation primitive, such as hlist_nulls_add_head_rcu()
71  * the _rcu list-traversal primitives, such as
77 	WRITE_ONCE(n->pprev, LIST_POISON2);  in hlist_nulls_del_rcu()
91  * with another list-mutation primitive, such as hlist_nulls_add_head_rcu()
94  * the _rcu list-traversal primitives, such as
95  * hlist_nulls_for_each_entry_rcu(), used to prevent memory-consistency
97  * list-traversal primitive must be guarded by rcu_read_lock().
102 	struct hlist_nulls_node *first = h->first;  in hlist_nulls_add_head_rcu()
104 	WRITE_ONCE(n->next, first);  in hlist_nulls_add_head_rcu()
105 	WRITE_ONCE(n->pprev, &h->first);  in hlist_nulls_add_head_rcu()
108 		WRITE_ONCE(first->pprev, &n->next);  in hlist_nulls_add_head_rcu()
122  * with another list-mutation primitive, such as hlist_nulls_add_head_rcu()
125  * the _rcu list-traversal primitives, such as
126  * hlist_nulls_for_each_entry_rcu(), used to prevent memory-consistency
128  * list-traversal primitive must be guarded by rcu_read_lock().
136 	for (i = h->first; !is_a_nulls(i); i = i->next)  in hlist_nulls_add_tail_rcu()
140 		WRITE_ONCE(n->next, last->next);  in hlist_nulls_add_tail_rcu()
141 		n->pprev = &last->next;  in hlist_nulls_add_tail_rcu()
151 	n->pprev = &n->next;  in hlist_nulls_add_fake()
152 	n->next = (struct hlist_nulls_node *)NULLS_MARKER(NULL);  in hlist_nulls_add_fake()
156  * hlist_nulls_for_each_entry_rcu - iterate over rcu list of given type
164  * [1] Documentation/memory-barriers.txt around line 1533
175  * hlist_nulls_for_each_entry_safe -