1/* $NetBSD: llist.h,v 1.7 2022/04/09 23:43:55 riastradh Exp $ */ 2 3/*- 4 * Copyright (c) 2018 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Taylor R. Campbell. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#ifndef _LINUX_LLIST_H_ 33#define _LINUX_LLIST_H_ 34 35#include <sys/atomic.h> 36#include <sys/null.h> 37 38struct llist_head { 39 struct llist_node *first; 40}; 41 42struct llist_node { 43 struct llist_node *next; 44}; 45 46static inline void 47init_llist_head(struct llist_head *head) 48{ 49 50 head->first = NULL; 51} 52 53#define llist_entry(NODE, TYPE, FIELD) container_of(NODE, TYPE, FIELD) 54 55static inline bool 56llist_empty(struct llist_head *head) 57{ 58 bool empty; 59 60 empty = (atomic_load_acquire(&head->first) == NULL); 61 62 return empty; 63} 64 65static inline bool 66llist_add(struct llist_node *node, struct llist_head *head) 67{ 68 struct llist_node *first; 69 70 do { 71 first = head->first; 72 node->next = first; 73 membar_release(); 74 } while (atomic_cas_ptr(&head->first, first, node) != first); 75 76 return first == NULL; 77} 78 79static inline bool 80llist_add_batch(struct llist_node *first, struct llist_node *last, 81 struct llist_head *head) 82{ 83 struct llist_node *next; 84 85 do { 86 next = atomic_load_consume(&head->first); 87 last->next = next; 88 } while (atomic_cas_ptr(&head->first, next, first) != next); 89 90 return next == NULL; 91} 92 93static inline struct llist_node * 94llist_del_all(struct llist_head *head) 95{ 96 struct llist_node *first; 97 98 first = atomic_swap_ptr(&head->first, NULL); 99 membar_datadep_consumer(); 100 101 return first; 102} 103 104static inline struct llist_node * 105llist_del_first(struct llist_head *head) 106{ 107 struct llist_node *first; 108 109 do { 110 first = atomic_load_consume(&head->first); 111 if (first == NULL) 112 return NULL; 113 } while (atomic_cas_ptr(&head->first, first, first->next) 114 != first); 115 116 return first; 117} 118 119#define _llist_next(ENTRY, FIELD) \ 120({ \ 121 __typeof__((ENTRY)->FIELD.next) _NODE = \ 122 atomic_load_consume(&(ENTRY)->FIELD.next); \ 123 (_NODE == NULL ? NULL : \ 124 llist_entry(_NODE, __typeof__(*(ENTRY)), FIELD)); \ 125}) 126 127#define llist_for_each_safe(NODE, TMP, HEAD) \ 128 for ((NODE) = (HEAD); \ 129 (NODE) && ((TMP) = (NODE)->next, 1); \ 130 (NODE) = (TMP)) 131 132#define llist_for_each_entry(ENTRY, NODE, FIELD) \ 133 for ((ENTRY) = ((NODE) == NULL ? NULL : \ 134 (membar_datadep_consumer(), \ 135 llist_entry(NODE, typeof(*(ENTRY)), FIELD))); \ 136 (ENTRY) != NULL; \ 137 (ENTRY) = _llist_next(ENTRY, FIELD)) 138 139#define llist_for_each_entry_safe(ENTRY, TMP, NODE, FIELD) \ 140 for ((ENTRY) = ((NODE) == NULL ? NULL : \ 141 (membar_datadep_consumer(), \ 142 llist_entry(NODE, typeof(*(ENTRY)), FIELD))); \ 143 ((ENTRY) == NULL ? 0 : \ 144 ((TMP) = _llist_next(ENTRY, FIELD), 1)); \ 145 (ENTRY) = (TMP)) 146 147#endif /* _LINUX_LLIST_H_ */ 148