#ifdef __KERNEL__
#include <linux/stddef.h>
+#include <linux/poison.h>
#include <linux/prefetch.h>
#include <asm/system.h>
/*
- * These are non-NULL pointers that will result in page faults
- * under normal circumstances, used to verify that nobody uses
- * non-initialized list entries.
- */
-#define LIST_POISON1 ((void *) 0x00100100)
-#define LIST_POISON2 ((void *) 0x00200200)
-
-/*
* Simple doubly linked list implementation.
*
* Some of the internal functions ("__xxx") are useful when
#define LIST_HEAD(name) \
struct list_head name = LIST_HEAD_INIT(name)
-#define INIT_LIST_HEAD(ptr) do { \
- (ptr)->next = (ptr); (ptr)->prev = (ptr); \
-} while (0)
+static inline void INIT_LIST_HEAD(struct list_head *list)
+{
+ list->next = list;
+ list->prev = list;
+}
/*
* Insert a new entry between two known consecutive entries.
entry->prev = LIST_POISON2;
}
+/**
+ * list_replace - replace old entry by new one
+ * @old : the element to be replaced
+ * @new : the new element to insert
+ * Note: if 'old' was empty, it will be overwritten.
+ */
+static inline void list_replace(struct list_head *old,
+ struct list_head *new)
+{
+ 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);
+}
+
/*
* list_replace_rcu - replace old entry by new one
* @old : the element to be replaced
* @new : the new element to insert
*
* The old entry will be replaced with the new entry atomically.
+ * Note: 'old' should not be empty.
*/
-static inline void list_replace_rcu(struct list_head *old, struct list_head *new){
+static inline void list_replace_rcu(struct list_head *old,
+ struct list_head *new)
+{
new->next = old->next;
new->prev = old->prev;
smp_wmb();
new->next->prev = new;
new->prev->next = new;
+ old->prev = LIST_POISON2;
}
/**
}
/**
+ * 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)
+{
+ return list->next == head;
+}
+
+/**
* list_empty - tests whether a list is empty
* @head: the list to test.
*/
}
/**
- * list_empty_careful - tests whether a list is
- * empty _and_ checks that no other CPU might be
- * in the process of still modifying either member
+ * 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.
- *
- * @head: the list to test.
*/
static inline int list_empty_careful(const struct list_head *head)
{
/**
* list_for_each - iterate over a list
- * @pos: the &struct list_head to use as a loop counter.
+ * @pos: the &struct list_head to use as a loop cursor.
* @head: the head for your list.
*/
#define list_for_each(pos, head) \
/**
* __list_for_each - iterate over a list
- * @pos: the &struct list_head to use as a loop counter.
+ * @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
/**
* list_for_each_prev - iterate over a list backwards
- * @pos: the &struct list_head to use as a loop counter.
+ * @pos: the &struct list_head to use as a loop cursor.
* @head: the head for your list.
*/
#define list_for_each_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 counter.
+ * 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.
*/
/**
* list_for_each_entry - iterate over list of given type
- * @pos: the type * to use as a loop counter.
+ * @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.
*/
/**
* list_for_each_entry_reverse - iterate backwards over list of given type.
- * @pos: the type * to use as a loop counter.
+ * @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.
*/
pos = list_entry(pos->member.prev, typeof(*pos), member))
/**
- * list_prepare_entry - prepare a pos entry for use as a start point in
- * list_for_each_entry_continue
+ * 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 - iterate over list of given type
- * continuing after existing point
- * @pos: the type * to use as a loop counter.
+ * 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 = list_entry(pos->member.next, 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 (; prefetch(pos->member.next), &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 counter.
+ * @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.
pos = n, n = list_entry(n->member.next, typeof(*n), member))
/**
- * list_for_each_entry_safe_continue - iterate over list of given type
- * continuing after existing point safe against removal of list entry
- * @pos: the type * to use as a loop counter.
+ * 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), \
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))
+
+/**
* list_for_each_rcu - iterate over an rcu-protected list
- * @pos: the &struct list_head to use as a loop counter.
+ * @pos: the &struct list_head to use as a loop cursor.
* @head: the head for your list.
*
* This list-traversal primitive may safely run concurrently with
pos = pos->next)
/**
- * list_for_each_safe_rcu - iterate over an rcu-protected list safe
- * against removal of list entry
- * @pos: the &struct list_head to use as a loop counter.
+ * list_for_each_safe_rcu
+ * @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.
*
+ * Iterate over an rcu-protected list, safe against removal of list entry.
+ *
* This list-traversal primitive may safely run concurrently with
* the _rcu list-mutation primitives such as list_add_rcu()
* as long as the traversal is guarded by rcu_read_lock().
/**
* list_for_each_entry_rcu - iterate over rcu list of given type
- * @pos: the type * to use as a loop counter.
+ * @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.
*
/**
- * list_for_each_continue_rcu - iterate over an rcu-protected list
- * continuing after existing point.
- * @pos: the &struct list_head to use as a loop counter.
+ * list_for_each_continue_rcu
+ * @pos: the &struct list_head to use as a loop cursor.
* @head: the head for your list.
*
+ * Iterate over an rcu-protected list, continuing after current point.
+ *
* This list-traversal primitive may safely run concurrently with
* the _rcu list-mutation primitives such as list_add_rcu()
* as long as the traversal is guarded by rcu_read_lock().
#define HLIST_HEAD_INIT { .first = NULL }
#define HLIST_HEAD(name) struct hlist_head name = { .first = NULL }
#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
-#define INIT_HLIST_NODE(ptr) ((ptr)->next = NULL, (ptr)->pprev = NULL)
+static inline void INIT_HLIST_NODE(struct hlist_node *h)
+{
+ h->next = NULL;
+ h->pprev = NULL;
+}
static inline int hlist_unhashed(const struct hlist_node *h)
{
static inline void hlist_del_init(struct hlist_node *n)
{
- if (n->pprev) {
+ if (!hlist_unhashed(n)) {
__hlist_del(n);
INIT_HLIST_NODE(n);
}
}
+/*
+ * hlist_replace_rcu - replace old entry by new one
+ * @old : the element to be replaced
+ * @new : the new element to insert
+ *
+ * The old entry will be replaced with the new entry atomically.
+ */
+static inline void hlist_replace_rcu(struct hlist_node *old,
+ struct hlist_node *new)
+{
+ struct hlist_node *next = old->next;
+
+ new->next = next;
+ new->pprev = old->pprev;
+ smp_wmb();
+ if (next)
+ new->next->pprev = &new->next;
+ *new->pprev = new;
+ old->pprev = LIST_POISON2;
+}
+
static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
{
struct hlist_node *first = h->first;
/**
- * hlist_add_head_rcu - adds the specified element to the specified hlist,
- * while permitting racing traversals.
+ * hlist_add_head_rcu
* @n: the element to add to the hash list.
* @h: the list to add to.
*
+ * Description:
+ * Adds the specified element to the specified hlist,
+ * while permitting racing traversals.
+ *
* The caller must take whatever precautions are necessary
* (such as holding appropriate locks) to avoid racing
* with another list-mutation primitive, such as hlist_add_head_rcu()
* or hlist_del_rcu(), running on this same list.
* However, it is perfectly legal to run concurrently with
* the _rcu list-traversal primitives, such as
- * hlist_for_each_rcu(), used to prevent memory-consistency
+ * hlist_for_each_entry_rcu(), used to prevent memory-consistency
* problems on Alpha CPUs. Regardless of the type of CPU, the
* list-traversal primitive must be guarded by rcu_read_lock().
*/
}
/**
- * hlist_add_before_rcu - adds the specified element to the specified hlist
- * before the specified node while permitting racing traversals.
+ * hlist_add_before_rcu
* @n: the new element to add to the hash list.
* @next: the existing element to add the new element before.
*
+ * Description:
+ * Adds the specified element to the specified hlist
+ * before the specified node while permitting racing traversals.
+ *
* The caller must take whatever precautions are necessary
* (such as holding appropriate locks) to avoid racing
* with another list-mutation primitive, such as hlist_add_head_rcu()
* or hlist_del_rcu(), running on this same list.
* However, it is perfectly legal to run concurrently with
* the _rcu list-traversal primitives, such as
- * hlist_for_each_rcu(), used to prevent memory-consistency
+ * hlist_for_each_entry_rcu(), used to prevent memory-consistency
* problems on Alpha CPUs.
*/
static inline void hlist_add_before_rcu(struct hlist_node *n,
}
/**
- * hlist_add_after_rcu - adds the specified element to the specified hlist
- * after the specified node while permitting racing traversals.
+ * hlist_add_after_rcu
* @prev: the existing element to add the new element after.
* @n: the new element to add to the hash list.
*
+ * Description:
+ * Adds the specified element to the specified hlist
+ * after the specified node while permitting racing traversals.
+ *
* The caller must take whatever precautions are necessary
* (such as holding appropriate locks) to avoid racing
* with another list-mutation primitive, such as hlist_add_head_rcu()
* or hlist_del_rcu(), running on this same list.
* However, it is perfectly legal to run concurrently with
* the _rcu list-traversal primitives, such as
- * hlist_for_each_rcu(), used to prevent memory-consistency
+ * hlist_for_each_entry_rcu(), used to prevent memory-consistency
* problems on Alpha CPUs.
*/
static inline void hlist_add_after_rcu(struct hlist_node *prev,
for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
pos = n)
-#define hlist_for_each_rcu(pos, head) \
- for ((pos) = (head)->first; \
- rcu_dereference((pos)) && ({ prefetch((pos)->next); 1; }); \
- (pos) = (pos)->next)
-
/**
* hlist_for_each_entry - iterate over list of given type
- * @tpos: the type * to use as a loop counter.
- * @pos: the &struct hlist_node to use as a loop counter.
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct hlist_node to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the hlist_node within the struct.
*/
pos = pos->next)
/**
- * hlist_for_each_entry_continue - iterate over a hlist continuing after existing point
- * @tpos: the type * to use as a loop counter.
- * @pos: the &struct hlist_node to use as a loop counter.
+ * hlist_for_each_entry_continue - iterate over a hlist continuing after current point
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct hlist_node to use as a loop cursor.
* @member: the name of the hlist_node within the struct.
*/
#define hlist_for_each_entry_continue(tpos, pos, member) \
pos = pos->next)
/**
- * hlist_for_each_entry_from - iterate over a hlist continuing from existing point
- * @tpos: the type * to use as a loop counter.
- * @pos: the &struct hlist_node to use as a loop counter.
+ * hlist_for_each_entry_from - iterate over a hlist continuing from current point
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct hlist_node to use as a loop cursor.
* @member: the name of the hlist_node within the struct.
*/
#define hlist_for_each_entry_from(tpos, pos, member) \
/**
* hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
- * @tpos: the type * to use as a loop counter.
- * @pos: the &struct hlist_node to use as a loop counter.
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct hlist_node to use as a loop cursor.
* @n: another &struct hlist_node to use as temporary storage
* @head: the head for your list.
* @member: the name of the hlist_node within the struct.
/**
* hlist_for_each_entry_rcu - iterate over rcu list of given type
- * @pos: the type * to use as a loop counter.
- * @pos: the &struct hlist_node to use as a loop counter.
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct hlist_node to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the hlist_node within the struct.
*