#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.
*
#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.
* This is only for internal list manipulation where we know
* the prev/next entries already!
*/
+#ifndef CONFIG_DEBUG_LIST
static inline void __list_add(struct list_head *new,
struct list_head *prev,
struct list_head *next)
new->prev = prev;
prev->next = new;
}
+#else
+extern void __list_add(struct list_head *new,
+ struct list_head *prev,
+ struct list_head *next);
+#endif
/**
* list_add - add a new entry
* Insert a new entry after the specified head.
* This is good for implementing stacks.
*/
+#ifndef CONFIG_DEBUG_LIST
static inline void list_add(struct list_head *new, struct list_head *head)
{
__list_add(new, head, head->next);
}
+#else
+extern void list_add(struct list_head *new, struct list_head *head);
+#endif
+
/**
* list_add_tail - add a new entry
* Note: list_empty on entry does not return true after this, the entry is
* in an undefined state.
*/
+#ifndef CONFIG_DEBUG_LIST
static inline void list_del(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
entry->next = LIST_POISON1;
entry->prev = LIST_POISON2;
}
+#else
+extern void list_del(struct list_head *entry);
+#endif
/**
* list_del_rcu - deletes entry from list without re-initialization
* list_for_each_entry_rcu().
*
* Note that the caller is not permitted to immediately free
- * the newly deleted entry. Instead, either synchronize_kernel()
+ * the newly deleted entry. Instead, either synchronize_rcu()
* or call_rcu() must be used to defer freeing until an RCU
* grace period has elapsed.
*/
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)
+{
+ new->next = old->next;
+ new->prev = old->prev;
+ smp_wmb();
+ new->next->prev = new;
+ new->prev->next = new;
+ old->prev = LIST_POISON2;
+}
+
/**
* list_del_init - deletes entry from list and reinitialize it.
* @entry: the element to delete from the list.
list_add_tail(list, head);
}
+/**
+ * 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) \
- for (pos = (head)->next, prefetch(pos->next); pos != (head); \
- pos = pos->next, prefetch(pos->next))
+ for (pos = (head)->next; prefetch(pos->next), pos != (head); \
+ pos = pos->next)
/**
* __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) \
- for (pos = (head)->prev, prefetch(pos->prev); pos != (head); \
- pos = pos->prev, prefetch(pos->prev))
+ for (pos = (head)->prev; prefetch(pos->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.
*/
#define list_for_each_entry(pos, head, member) \
- for (pos = list_entry((head)->next, typeof(*pos), member), \
- prefetch(pos->member.next); \
- &pos->member != (head); \
- pos = list_entry(pos->member.next, typeof(*pos), member), \
- prefetch(pos->member.next))
+ for (pos = list_entry((head)->next, typeof(*pos), member); \
+ prefetch(pos->member.next), &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 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.
*/
#define list_for_each_entry_reverse(pos, head, member) \
- for (pos = list_entry((head)->prev, typeof(*pos), member), \
- prefetch(pos->member.prev); \
- &pos->member != (head); \
- pos = list_entry(pos->member.prev, typeof(*pos), member), \
- prefetch(pos->member.prev))
+ for (pos = list_entry((head)->prev, typeof(*pos), member); \
+ prefetch(pos->member.prev), &pos->member != (head); \
+ 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), \
- prefetch(pos->member.next); \
- &pos->member != (head); \
- pos = list_entry(pos->member.next, typeof(*pos), member), \
- prefetch(pos->member.next))
+ for (pos = list_entry(pos->member.next, typeof(*pos), member); \
+ prefetch(pos->member.next), &pos->member != (head); \
+ 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->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))
+
/**
* 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
* as long as the traversal is guarded by rcu_read_lock().
*/
#define list_for_each_rcu(pos, head) \
- for (pos = (head)->next, prefetch(pos->next); pos != (head); \
- pos = pos->next, ({ smp_read_barrier_depends(); 0;}), prefetch(pos->next))
+ for (pos = (head)->next; \
+ prefetch(rcu_dereference(pos)->next), pos != (head); \
+ pos = pos->next)
#define __list_for_each_rcu(pos, head) \
- for (pos = (head)->next; pos != (head); \
- pos = pos->next, ({ smp_read_barrier_depends(); 0;}))
+ for (pos = (head)->next; \
+ rcu_dereference(pos) != (head); \
+ 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().
*/
#define list_for_each_safe_rcu(pos, n, head) \
- for (pos = (head)->next, n = pos->next; pos != (head); \
- pos = n, ({ smp_read_barrier_depends(); 0;}), n = pos->next)
+ for (pos = (head)->next; \
+ n = rcu_dereference(pos)->next, pos != (head); \
+ pos = n)
/**
* 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.
*
* the _rcu list-mutation primitives such as list_add_rcu()
* as long as the traversal is guarded by rcu_read_lock().
*/
-#define list_for_each_entry_rcu(pos, head, member) \
- for (pos = list_entry((head)->next, typeof(*pos), member), \
- prefetch(pos->member.next); \
- &pos->member != (head); \
- pos = list_entry(pos->member.next, typeof(*pos), member), \
- ({ smp_read_barrier_depends(); 0;}), \
- prefetch(pos->member.next))
+#define list_for_each_entry_rcu(pos, head, member) \
+ for (pos = list_entry((head)->next, typeof(*pos), member); \
+ prefetch(rcu_dereference(pos)->member.next), \
+ &pos->member != (head); \
+ pos = list_entry(pos->member.next, typeof(*pos), member))
/**
- * 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 list_for_each_continue_rcu(pos, head) \
- for ((pos) = (pos)->next, prefetch((pos)->next); (pos) != (head); \
- (pos) = (pos)->next, ({ smp_read_barrier_depends(); 0;}), prefetch((pos)->next))
+ for ((pos) = (pos)->next; \
+ prefetch(rcu_dereference((pos))->next), (pos) != (head); \
+ (pos) = (pos)->next)
/*
* Double linked lists with a single pointer list head.
#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);
}
}
-#define hlist_del_rcu_init hlist_del_init
+/*
+ * 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)
{
/**
- * 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_entry(), but only if smp_read_barrier_depends()
- * is 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().
- *
- * OK, so why don't we have an hlist_for_each_entry_rcu()???
+ * 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().
*/
static inline void hlist_add_head_rcu(struct hlist_node *n,
struct hlist_head *h)
next->next->pprev = &next->next;
}
+/**
+ * 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_entry_rcu(), used to prevent memory-consistency
+ * problems on Alpha CPUs.
+ */
+static inline void hlist_add_before_rcu(struct hlist_node *n,
+ struct hlist_node *next)
+{
+ n->pprev = next->pprev;
+ n->next = next;
+ smp_wmb();
+ next->pprev = &n->next;
+ *(n->pprev) = n;
+}
+
+/**
+ * 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_entry_rcu(), used to prevent memory-consistency
+ * problems on Alpha CPUs.
+ */
+static inline void hlist_add_after_rcu(struct hlist_node *prev,
+ struct hlist_node *n)
+{
+ n->next = prev->next;
+ n->pprev = &prev->next;
+ smp_wmb();
+ prev->next = n;
+ if (n->next)
+ n->next->pprev = &n->next;
+}
+
#define hlist_entry(ptr, type, member) container_of(ptr,type,member)
#define hlist_for_each(pos, head) \
/**
* 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.
*
* This list-traversal primitive may safely run concurrently with
- * the _rcu list-mutation primitives such as hlist_add_rcu()
+ * the _rcu list-mutation primitives such as hlist_add_head_rcu()
* as long as the traversal is guarded by rcu_read_lock().
*/
#define hlist_for_each_entry_rcu(tpos, pos, head, member) \
for (pos = (head)->first; \
- pos && ({ prefetch(pos->next); 1;}) && \
+ rcu_dereference(pos) && ({ prefetch(pos->next); 1;}) && \
({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = pos->next, ({ smp_read_barrier_depends(); 0; }) )
+ pos = pos->next)
#else
#warning "don't include kernel headers in userspace"
git://git.onelab.eu / linux-2.6.git / blobdiff