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Subject[PATCH tip/core/rcu 5/9] rcu: Add and update docbook header comments in list.h
Date
From: "Paul E. McKenney" <paulmck@kernel.org>

[ paulmck: Fix typo found by kbuild test robot. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
include/linux/list.h | 112 +++++++++++++++++++++++++++++++++++++++++++--------
1 file changed, 95 insertions(+), 17 deletions(-)

diff --git a/include/linux/list.h b/include/linux/list.h
index 61f5aaf..4f3b7f7 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -23,6 +23,13 @@
#define LIST_HEAD(name) \
struct list_head name = LIST_HEAD_INIT(name)

+/**
+ * INIT_LIST_HEAD - Initialize a list_head structure
+ * @list: list_head structure to be initialized.
+ *
+ * Initializes the list_head to point to itself. If it is a list header,
+ * the result is an empty list.
+ */
static inline void INIT_LIST_HEAD(struct list_head *list)
{
WRITE_ONCE(list->next, list);
@@ -120,12 +127,6 @@ static inline void __list_del_clearprev(struct list_head *entry)
entry->prev = NULL;
}

-/**
- * 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_entry(struct list_head *entry)
{
if (!__list_del_entry_valid(entry))
@@ -134,6 +135,12 @@ static inline void __list_del_entry(struct list_head *entry)
__list_del(entry->prev, 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)
{
__list_del_entry(entry);
@@ -157,8 +164,15 @@ static inline void list_replace(struct list_head *old,
new->prev->next = new;
}

+/**
+ * list_replace_init - replace old entry by new one and initialize the old 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_init(struct list_head *old,
- struct list_head *new)
+ struct list_head *new)
{
list_replace(old, new);
INIT_LIST_HEAD(old);
@@ -744,21 +758,36 @@ static inline void INIT_HLIST_NODE(struct hlist_node *h)
h->pprev = NULL;
}

+/**
+ * hlist_unhashed - Has node been removed from list and reinitialized?
+ * @h: Node to be checked
+ *
+ * Not that not all removal functions will leave a node in unhashed
+ * state. For example, hlist_nulls_del_init_rcu() does leave the
+ * node in unhashed state, but hlist_nulls_del() does not.
+ */
static inline int hlist_unhashed(const struct hlist_node *h)
{
return !h->pprev;
}

-/* This variant of hlist_unhashed() must be used in lockless contexts
- * to avoid potential load-tearing.
- * The READ_ONCE() is paired with the various WRITE_ONCE() in hlist
- * helpers that are defined below.
+/**
+ * hlist_unhashed_lockless - Version of hlist_unhashed for lockless use
+ * @h: Node to be checked
+ *
+ * This variant of hlist_unhashed() must be used in lockless contexts
+ * to avoid potential load-tearing. The READ_ONCE() is paired with the
+ * various WRITE_ONCE() in hlist helpers that are defined below.
*/
static inline int hlist_unhashed_lockless(const struct hlist_node *h)
{
return !READ_ONCE(h->pprev);
}

+/**
+ * hlist_empty - Is the specified hlist_head structure an empty hlist?
+ * @h: Structure to check.
+ */
static inline int hlist_empty(const struct hlist_head *h)
{
return !READ_ONCE(h->first);
@@ -774,6 +803,13 @@ static inline void __hlist_del(struct hlist_node *n)
WRITE_ONCE(next->pprev, pprev);
}

+/**
+ * hlist_del - Delete the specified hlist_node from its list
+ * @n: Node to delete.
+ *
+ * Note that this function leaves the node in hashed state. Use
+ * hlist_del_init() or similar instead to unhash @n.
+ */
static inline void hlist_del(struct hlist_node *n)
{
__hlist_del(n);
@@ -781,6 +817,12 @@ static inline void hlist_del(struct hlist_node *n)
n->pprev = LIST_POISON2;
}

+/**
+ * hlist_del_init - Delete the specified hlist_node from its list and initialize
+ * @n: Node to delete.
+ *
+ * Note that this function leaves the node in unhashed state.
+ */
static inline void hlist_del_init(struct hlist_node *n)
{
if (!hlist_unhashed(n)) {
@@ -789,6 +831,14 @@ static inline void hlist_del_init(struct hlist_node *n)
}
}

+/**
+ * hlist_add_head - add a new entry at the beginning of the hlist
+ * @n: new entry to be added
+ * @h: hlist head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ */
static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
{
struct hlist_node *first = h->first;
@@ -799,9 +849,13 @@ static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
WRITE_ONCE(n->pprev, &h->first);
}

-/* next must be != NULL */
+/**
+ * hlist_add_before - add a new entry before the one specified
+ * @n: new entry to be added
+ * @next: hlist node to add it before, which must be non-NULL
+ */
static inline void hlist_add_before(struct hlist_node *n,
- struct hlist_node *next)
+ struct hlist_node *next)
{
WRITE_ONCE(n->pprev, next->pprev);
WRITE_ONCE(n->next, next);
@@ -809,6 +863,11 @@ static inline void hlist_add_before(struct hlist_node *n,
WRITE_ONCE(*(n->pprev), n);
}

+/**
+ * hlist_add_behing - add a new entry after the one specified
+ * @n: new entry to be added
+ * @prev: hlist node to add it after, which must be non-NULL
+ */
static inline void hlist_add_behind(struct hlist_node *n,
struct hlist_node *prev)
{
@@ -820,20 +879,35 @@ static inline void hlist_add_behind(struct hlist_node *n,
WRITE_ONCE(n->next->pprev, &n->next);
}

-/* after that we'll appear to be on some hlist and hlist_del will work */
+/**
+ * hlist_add_fake - create a fake hlist consisting of a single headless node
+ * @n: Node to make a fake list out of
+ *
+ * This makes @n appear to be its own predecessor on a headless hlist.
+ * The point of this is to allow things like hlist_del() to work correctly
+ * in cases where there is no list.
+ */
static inline void hlist_add_fake(struct hlist_node *n)
{
n->pprev = &n->next;
}

+/**
+ * hlist_fake: Is this node a fake hlist?
+ * @h: Node to check for being a self-referential fake hlist.
+ */
static inline bool hlist_fake(struct hlist_node *h)
{
return h->pprev == &h->next;
}

-/*
+/**
+ * hlist_is_singular_node - is node the only element of the specified hlist?
+ * @n: Node to check for singularity.
+ * @h: Header for potentially singular list.
+ *
* Check whether the node is the only node of the head without
- * accessing head:
+ * accessing head, thus avoiding unnecessary cache misses.
*/
static inline bool
hlist_is_singular_node(struct hlist_node *n, struct hlist_head *h)
@@ -841,7 +915,11 @@ hlist_is_singular_node(struct hlist_node *n, struct hlist_head *h)
return !n->next && n->pprev == &h->first;
}

-/*
+/**
+ * hlist_move_list - Move an hlist
+ * @old: hlist_head for old list.
+ * @new: hlist_head for new list.
+ *
* Move a list from one list head to another. Fixup the pprev
* reference of the first entry if it exists.
*/
--
2.9.5
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