replace list.h with a BSD licensed variant (taken from FreeBSD SVN)

1 files changed, 141 insertions, 402 deletions

diff --git a/list.h b/list.h
index 76909c5..8425aff 100644
--- a/list.h
+++ b/list.h
@@ -1,465 +1,204 @@
-#ifndef _LINUX_LIST_H
-#define _LINUX_LIST_H
+/*-
+ * Copyright (c) 2011 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (c) 2010 Isilon Systems, Inc.
+ * Copyright (c) 2010 iX Systems, Inc.
+ * Copyright (c) 2010 Panasas, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice unmodified, this list of conditions, and the following
+ *    disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef _LINUX_LIST_H_
+#define _LINUX_LIST_H_
 
 #include <stddef.h>
-/**
- * container_of - cast a member of a structure out to the containing structure
- * @ptr:	the pointer to the member.
- * @type:	the type of the container struct this is embedded in.
- * @member:	the name of the member within the struct.
- *
- */
-#ifndef container_of
-#define container_of(ptr, type, member) (			\
-	(type *)( (char *)ptr - offsetof(type,member) ))
-#endif
+#include <stdbool.h>
 
+#define	prefetch(x)
 
-/*
- * Simple doubly linked list implementation.
- *
- * Some of the internal functions ("__xxx") are useful when
- * manipulating whole lists rather than single entries, as
- * sometimes we already know the next/prev entries and we can
- * generate better code by using them directly rather than
- * using the generic single-entry routines.
- */
+#ifndef container_of
+#define container_of(ptr, type, member) (           \
+    (type *)( (char *)ptr - offsetof(type,member) ))
+#endif
 
 struct list_head {
-	struct list_head *next, *prev;
+	struct list_head *next;
+	struct list_head *prev;
 };
 
 #define LIST_HEAD_INIT(name) { &(name), &(name) }
+#define LIST_HEAD(name)	struct list_head name = LIST_HEAD_INIT(name)
 
-#define LIST_HEAD(name) \
-	struct list_head name = LIST_HEAD_INIT(name)
-
-static inline void INIT_LIST_HEAD(struct list_head *list)
+static inline void
+INIT_LIST_HEAD(struct list_head *list)
 {
-	list->next = list;
-	list->prev = list;
+	list->next = list->prev = list;
 }
 
-/*
- * Insert a new entry between two known consecutive entries.
- *
- * This is only for internal list manipulation where we know
- * the prev/next entries already!
- */
-static inline void __list_add(struct list_head *_new,
-			      struct list_head *prev,
-			      struct list_head *next)
+static inline bool
+list_empty(const struct list_head *head)
 {
-	next->prev = _new;
-	_new->next = next;
-	_new->prev = prev;
-	prev->next = _new;
+	return (head->next == head);
 }
 
-/**
- * list_add - add a new entry
- * @_new: new entry to be added
- * @head: list head to add it after
- *
- * Insert a new entry after the specified head.
- * This is good for implementing stacks.
- */
-static inline void list_add(struct list_head *_new, struct list_head *head)
+static inline bool
+list_is_first(const struct list_head *list,
+	      const struct list_head *head)
 {
-	__list_add(_new, head, head->next);
+	return list->prev == head;
 }
 
-
-/**
- * list_add_tail - add a new entry
- * @_new: new entry to be added
- * @head: list head to add it before
- *
- * Insert a new entry before the specified head.
- * This is useful for implementing queues.
- */
-static inline void list_add_tail(struct list_head *_new, struct list_head *head)
+static inline bool
+list_is_last(const struct list_head *list,
+	     const struct list_head *head)
 {
-	__list_add(_new, head->prev, head);
+	return list->next == head;
 }
 
-
-/*
- * Delete a list entry by making the prev/next entries
- * point to each other.
- *
- * This is only for internal list manipulation where we know
- * the prev/next entries already!
- */
-static inline void __list_del(struct list_head * prev, struct list_head * next)
+static inline void
+_list_del(struct list_head *entry)
 {
-	next->prev = prev;
-	prev->next = next;
+	entry->next->prev = entry->prev;
+	entry->prev->next = entry->next;
 }
 
-/**
- * list_del - deletes entry from list.
- * @entry: the element to delete from the list.
- * Note: list_empty() on entry does not return true after this, the entry is
- * in an undefined state.
- */
-static inline void list_del(struct list_head *entry)
+static inline void
+list_del(struct list_head *entry)
 {
-	__list_del(entry->prev, entry->next);
-	entry->next = NULL;
-	entry->prev = NULL;
+	_list_del(entry);
+	entry->next = entry->prev = NULL;
 }
 
-/**
- * list_replace - replace old entry by new one
- * @old : the element to be replaced
- * @_new : the new element to insert
- *
- * If @old was empty, it will be overwritten.
- */
-static inline void list_replace(struct list_head *old,
-				struct list_head *_new)
+static inline void
+_list_add(struct list_head *_new, struct list_head *prev,
+    struct list_head *next)
 {
-	_new->next = old->next;
-	_new->next->prev = _new;
-	_new->prev = old->prev;
-	_new->prev->next = _new;
-}
 
-static inline void list_replace_init(struct list_head *old,
-					struct list_head *_new)
-{
-	list_replace(old, _new);
-	INIT_LIST_HEAD(old);
+	next->prev = _new;
+	_new->next = next;
+	_new->prev = prev;
+	prev->next = _new;
 }
 
-/**
- * list_del_init - deletes entry from list and reinitialize it.
- * @entry: the element to delete from the list.
- */
-static inline void list_del_init(struct list_head *entry)
+static inline void
+list_del_init(struct list_head *entry)
 {
-	__list_del(entry->prev, entry->next);
+	_list_del(entry);
 	INIT_LIST_HEAD(entry);
 }
 
-/**
- * list_move - delete from one list and add as another's head
- * @list: the entry to move
- * @head: the head that will precede our entry
- */
-static inline void list_move(struct list_head *list, struct list_head *head)
-{
-	__list_del(list->prev, list->next);
-	list_add(list, head);
-}
+#define	list_entry(ptr, type, field)	container_of(ptr, type, field)
+#define	list_first_entry(ptr, type, field)	list_entry((ptr)->next, type, field)
+#define	list_last_entry(ptr, type, field)	list_entry((ptr)->prev, type, field)
 
-/**
- * list_move_tail - delete from one list and add as another's tail
- * @list: the entry to move
- * @head: the head that will follow our 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);
-}
+#define	list_for_each(p, head)						\
+	for (p = (head)->next; p != (head); p = p->next)
 
-/**
- * list_is_first - tests whether @list is the first entry in list @head
- * @list: the entry to test
- * @head: the head of the list
- */
-static inline int list_is_first(const struct list_head *list,
-				const struct list_head *head)
+#define	list_for_each_safe(p, n, head)					\
+	for (p = (head)->next, n = p->next; p != (head); p = n, n = p->next)
+
+#define list_for_each_entry(p, h, field)				\
+	for (p = list_first_entry(h, typeof(*p), field); &p->field != (h); \
+	    p = list_entry(p->field.next, typeof(*p), field))
+
+#define list_for_each_entry_safe(p, n, h, field)			\
+	for (p = list_first_entry(h, typeof(*p), field),		\
+	    n = list_entry(p->field.next, typeof(*p), field); &p->field != (h);\
+	    p = n, n = list_entry(n->field.next, typeof(*n), field))
+
+#define	list_for_each_entry_reverse(p, h, field)			\
+	for (p = list_last_entry(h, typeof(*p), field); &p->field != (h); \
+	    p = list_entry(p->field.prev, typeof(*p), field))
+
+#define	list_for_each_prev(p, h) for (p = (h)->prev; p != (h); p = p->prev)
+#define	list_for_each_prev_safe(p, n, h) for (p = (h)->prev, n = p->prev; p != (h); p = n, n = p->prev)
+
+static inline void
+list_add(struct list_head *_new, struct list_head *head)
 {
-	return list->prev == head;
+	_list_add(_new, head, head->next);
 }
 
-/**
- * list_is_last - tests whether @list is the last entry in list @head
- * @list: the entry to test
- * @head: the head of the list
- */
-static inline int list_is_last(const struct list_head *list,
-				const struct list_head *head)
+static inline void
+list_add_tail(struct list_head *_new, struct list_head *head)
 {
-	return list->next == head;
+	_list_add(_new, head->prev, head);
 }
 
-/**
- * list_empty - tests whether a list is empty
- * @head: the list to test.
- */
-static inline int list_empty(const struct list_head *head)
+static inline void
+list_move(struct list_head *list, struct list_head *head)
 {
-	return head->next == head;
+	_list_del(list);
+	list_add(list, head);
 }
 
-/**
- * list_empty_careful - tests whether a list is empty and not being modified
- * @head: the list to test
- *
- * Description:
- * tests whether a list is empty _and_ checks that no other CPU might be
- * in the process of modifying either member (next or prev)
- *
- * NOTE: using list_empty_careful() without synchronization
- * can only be safe if the only activity that can happen
- * to the list entry is list_del_init(). Eg. it cannot be used
- * if another CPU could re-list_add() it.
- */
-static inline int list_empty_careful(const struct list_head *head)
+static inline void
+list_move_tail(struct list_head *entry, struct list_head *head)
 {
-	struct list_head *next = head->next;
-	return (next == head) && (next == head->prev);
+	_list_del(entry);
+	list_add_tail(entry, head);
 }
 
-static inline void __list_splice(struct list_head *list,
-				 struct list_head *head)
+static inline void
+_list_splice(const struct list_head *list, struct list_head *prev,
+    struct list_head *next)
 {
-	struct list_head *first = list->next;
-	struct list_head *last = list->prev;
-	struct list_head *at = head->next;
+	struct list_head *first;
+	struct list_head *last;
 
-	first->prev = head;
-	head->next = first;
+	if (list_empty(list))
+		return;
 
-	last->next = at;
-	at->prev = last;
+	first = list->next;
+	last = list->prev;
+	first->prev = prev;
+	prev->next = first;
+	last->next = next;
+	next->prev = last;
 }
 
-/**
- * list_splice - join two lists
- * @list: the new list to add.
- * @head: the place to add it in the first list.
- */
-static inline void list_splice(struct list_head *list, struct list_head *head)
+static inline void
+list_splice(const struct list_head *list, struct list_head *head)
 {
-	if (!list_empty(list))
-		__list_splice(list, head);
+	_list_splice(list, head, head->next);
 }
 
-/**
- * list_splice_init - join two lists and reinitialise the emptied list.
- * @list: the new list to add.
- * @head: the place to add it in the first list.
- *
- * The list at @list is reinitialised
- */
-static inline void list_splice_init(struct list_head *list,
-				    struct list_head *head)
+static inline void
+list_splice_tail(struct list_head *list, struct list_head *head)
 {
-	if (!list_empty(list)) {
-		__list_splice(list, head);
-		INIT_LIST_HEAD(list);
-	}
+	_list_splice(list, head->prev, head);
 }
 
-/**
- * list_entry - get the struct for this entry
- * @ptr:	the &struct list_head pointer.
- * @type:	the type of the struct this is embedded in.
- * @member:	the name of the list_struct within the struct.
- */
-#define list_entry(ptr, type, member) \
-	container_of(ptr, type, member)
-
-/**
- * list_first_entry - get the first element from a list
- * @ptr:	the list head to take the element from.
- * @type:	the type of the struct this is embedded in.
- * @member:	the name of the list_struct within the struct.
- *
- * Note, that list is expected to be not empty.
- */
-#define list_first_entry(ptr, type, member) \
-	list_entry((ptr)->next, type, member)
-
-/**
- * list_for_each	-	iterate over a list
- * @pos:	the &struct list_head to use as a loop cursor.
- * @head:	the head for your list.
- */
-#define list_for_each(pos, head) \
-	for (pos = (head)->next; pos != (head); \
-        	pos = pos->next)
-
-/**
- * __list_for_each	-	iterate over a list
- * @pos:	the &struct list_head to use as a loop cursor.
- * @head:	the head for your list.
- *
- * This variant differs from list_for_each() in that it's the
- * simplest possible list iteration code, no prefetching is done.
- * Use this for code that knows the list to be very short (empty
- * or 1 entry) most of the time.
- */
-#define __list_for_each(pos, head) \
-	for (pos = (head)->next; pos != (head); pos = pos->next)
+static inline void
+list_splice_init(struct list_head *list, struct list_head *head)
+{
+	_list_splice(list, head, head->next);
+	INIT_LIST_HEAD(list);
+}
 
-/**
- * list_for_each_prev	-	iterate over a list backwards
- * @pos:	the &struct list_head to use as a loop cursor.
- * @head:	the head for your list.
- */
-#define list_for_each_prev(pos, head) \
-	for (pos = (head)->prev; pos != (head); \
-        	pos = pos->prev)
-
-/**
- * list_for_each_safe - iterate over a list safe against removal of list entry
- * @pos:	the &struct list_head to use as a loop cursor.
- * @n:		another &struct list_head to use as temporary storage
- * @head:	the head for your list.
- */
-#define list_for_each_safe(pos, n, head) \
-	for (pos = (head)->next, n = pos->next; pos != (head); \
-		pos = n, n = pos->next)
-
-/**
- * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry
- * @pos:	the &struct list_head to use as a loop cursor.
- * @n:		another &struct list_head to use as temporary storage
- * @head:	the head for your list.
- */
-#define list_for_each_prev_safe(pos, n, head) \
-	for (pos = (head)->prev, n = pos->prev; \
-	     pos != (head); \
-	     pos = n, n = pos->prev)
-
-/**
- * list_for_each_entry	-	iterate over list of given type
- * @pos:	the type * to use as a loop cursor.
- * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
- */
-#define list_for_each_entry(pos, head, member)				\
-	for (pos = list_entry((head)->next, typeof(*pos), member);	\
-	     &pos->member != (head); 	\
-	     pos = list_entry(pos->member.next, typeof(*pos), member))
-
-/**
- * list_for_each_entry_reverse - iterate backwards over list of given type.
- * @pos:	the type * to use as a loop cursor.
- * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
- */
-#define list_for_each_entry_reverse(pos, head, member)			\
-	for (pos = list_entry((head)->prev, typeof(*pos), member);	\
-	     &pos->member != (head); 	\
-	     pos = list_entry(pos->member.prev, typeof(*pos), member))
-
-/**
- * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue()
- * @pos:	the type * to use as a start point
- * @head:	the head of the list
- * @member:	the name of the list_struct within the struct.
- *
- * Prepares a pos entry for use as a start point in list_for_each_entry_continue().
- */
-#define list_prepare_entry(pos, head, member) \
-	((pos) ? : list_entry(head, typeof(*pos), member))
-
-/**
- * list_for_each_entry_continue - continue iteration over list of given type
- * @pos:	the type * to use as a loop cursor.
- * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
- *
- * Continue to iterate over list of given type, continuing after
- * the current position.
- */
-#define list_for_each_entry_continue(pos, head, member) 		\
-	for (pos = list_entry(pos->member.next, typeof(*pos), member);	\
-	     &pos->member != (head);	\
-	     pos = list_entry(pos->member.next, typeof(*pos), member))
-
-/**
- * list_for_each_entry_continue_reverse - iterate backwards from the given point
- * @pos:	the type * to use as a loop cursor.
- * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
- *
- * Start to iterate over list of given type backwards, continuing after
- * the current position.
- */
-#define list_for_each_entry_continue_reverse(pos, head, member)		\
-	for (pos = list_entry(pos->member.prev, typeof(*pos), member);	\
-	     &pos->member != (head);	\
-	     pos = list_entry(pos->member.prev, typeof(*pos), member))
-
-/**
- * list_for_each_entry_from - iterate over list of given type from the current point
- * @pos:	the type * to use as a loop cursor.
- * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
- *
- * Iterate over list of given type, continuing from current position.
- */
-#define list_for_each_entry_from(pos, head, member) 			\
-	for (; &pos->member != (head);	\
-	     pos = list_entry(pos->member.next, typeof(*pos), member))
-
-/**
- * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
- * @pos:	the type * to use as a loop cursor.
- * @n:		another type * to use as temporary storage
- * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
- */
-#define list_for_each_entry_safe(pos, n, head, member)			\
-	for (pos = list_entry((head)->next, typeof(*pos), member),	\
-		n = list_entry(pos->member.next, typeof(*pos), member);	\
-	     &pos->member != (head); 					\
-	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
-
-/**
- * list_for_each_entry_safe_continue
- * @pos:	the type * to use as a loop cursor.
- * @n:		another type * to use as temporary storage
- * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
- *
- * Iterate over list of given type, continuing after current point,
- * safe against removal of list entry.
- */
-#define list_for_each_entry_safe_continue(pos, n, head, member) 		\
-	for (pos = list_entry(pos->member.next, typeof(*pos), member), 		\
-		n = list_entry(pos->member.next, typeof(*pos), member);		\
-	     &pos->member != (head);						\
-	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
-
-/**
- * list_for_each_entry_safe_from
- * @pos:	the type * to use as a loop cursor.
- * @n:		another type * to use as temporary storage
- * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
- *
- * Iterate over list of given type from current point, safe against
- * removal of list entry.
- */
-#define list_for_each_entry_safe_from(pos, n, head, member) 			\
-	for (n = list_entry(pos->member.next, typeof(*pos), member);		\
-	     &pos->member != (head);						\
-	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
-
-/**
- * list_for_each_entry_safe_reverse
- * @pos:	the type * to use as a loop cursor.
- * @n:		another type * to use as temporary storage
- * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
- *
- * Iterate backwards over list of given type, safe against removal
- * of list entry.
- */
-#define list_for_each_entry_safe_reverse(pos, n, head, member)		\
-	for (pos = list_entry((head)->prev, typeof(*pos), member),	\
-		n = list_entry(pos->member.prev, typeof(*pos), member);	\
-	     &pos->member != (head); 					\
-	     pos = n, n = list_entry(n->member.prev, typeof(*n), member))
+static inline void
+list_splice_tail_init(struct list_head *list, struct list_head *head)
+{
+	_list_splice(list, head->prev, head);
+	INIT_LIST_HEAD(list);
+}
 
-#endif
+#endif /* _LINUX_LIST_H_ */