+#ifndef _KCOMPAT_HLIST_H
+#define _KCOMPAT_HLIST_H
+
+/*
+ * Kernel sourcecode compatible lightweight single pointer list head useful
+ * for implementing hash tables
+ *
+ * Copyright (C) 2009 Novell Inc.
+ *
+ * Author: Jan Blunck <jblunck@suse.de>
+ *
+ * Copyright (C) 2010-2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ */
+
+#include <stddef.h>
+
+struct cds_hlist_head {
+ struct cds_hlist_node *next;
+};
+
+struct cds_hlist_node {
+ struct cds_hlist_node *next, *prev;
+};
+
+/* Initialize a new list head. */
+static inline
+void CDS_INIT_HLIST_HEAD(struct cds_hlist_head *ptr)
+{
+ ptr->next = NULL;
+}
+
+#define CDS_HLIST_HEAD(name) \
+ struct cds_hlist_head name = { NULL }
+
+#define CDS_HLIST_HEAD_INIT(name) \
+ { .next = NULL }
+
+/* Get typed element from list at a given position. */
+#define cds_hlist_entry(ptr, type, member) \
+ ((type *) ((char *) (ptr) - (unsigned long) (&((type *) 0)->member)))
+
+/* Add new element at the head of the list. */
+static inline
+void cds_hlist_add_head(struct cds_hlist_node *newp,
+ struct cds_hlist_head *head)
+{
+ if (head->next)
+ head->next->prev = newp;
+ newp->next = head->next;
+ newp->prev = (struct cds_hlist_node *) head;
+ head->next = newp;
+}
+
+/* Remove element from list. */
+static inline
+void cds_hlist_del(struct cds_hlist_node *elem)
+{
+ if (elem->next)
+ elem->next->prev = elem->prev;
+ elem->prev->next = elem->next;
+}
+
+#define cds_hlist_for_each(pos, head) \
+ for (pos = (head)->next; pos != NULL; pos = pos->next)
+
+#define cds_hlist_for_each_safe(pos, p, head) \
+ for (pos = (head)->next; \
+ (pos != NULL) && (p = pos->next, 1); \
+ pos = p)
+
+/*
+ * cds_hlist_for_each_entry and cds_hlist_for_each_entry_safe take
+ * respectively 4 and 5 arguments, while the Linux kernel APIs take 3,
+ * and 4. We implement cds_hlist_for_each_entry_2() and
+ * cds_hlist_for_each_entry_safe_2() to follow the Linux kernel APIs.
+ */
+#define cds_hlist_for_each_entry(entry, pos, head, member) \
+ for (pos = (head)->next, \
+ entry = cds_hlist_entry(pos, __typeof__(*entry), member); \
+ pos != NULL; \
+ pos = pos->next, \
+ entry = cds_hlist_entry(pos, __typeof__(*entry), member))
+
+#define cds_hlist_for_each_entry_safe(entry, pos, p, head, member) \
+ for (pos = (head)->next, \
+ entry = cds_hlist_entry(pos, __typeof__(*entry), member); \
+ (pos != NULL) && (p = pos->next, 1); \
+ pos = p, \
+ entry = cds_hlist_entry(pos, __typeof__(*entry), member))
+
+#define cds_hlist_for_each_entry_2(entry, head, member) \
+ for (entry = ((head)->next == NULL ? NULL \
+ : cds_hlist_entry((head)->next, __typeof__(*entry), member)); \
+ entry != NULL; \
+ entry = (entry->member.next == NULL ? NULL \
+ : cds_hlist_entry(entry->member.next, __typeof__(*entry), member)))
+
+#define cds_hlist_for_each_entry_safe_2(entry, e, head, member) \
+ for (entry = ((head)->next == NULL ? NULL \
+ : cds_hlist_entry((head)->next, __typeof__(*entry), member)); \
+ (entry != NULL) && (e = (entry->member.next == NULL ? NULL \
+ : cds_hlist_entry(entry->member.next, \
+ __typeof__(*entry), member)), 1); \
+ entry = e)
+
+#endif /* _KCOMPAT_HLIST_H */