[PATCH 3/7]: net: Add new interfaces for SKB list light-weight init and splicing.
From: David Miller <davem@davemloft.net>
Date: 2008-09-23 02:12:48
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
net: Add new interfaces for SKB list light-weight init and splicing. This will be used by subsequent changesets. Signed-off-by: David S. Miller <davem@davemloft.net> --- include/linux/skbuff.h | 96 +++++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 94 insertions(+), 2 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index aa80ad9..027b061 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h@@ -660,6 +660,22 @@ static inline __u32 skb_queue_len(const struct sk_buff_head *list_) return list_->qlen; } +/** + * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head + * @list: queue to initialize + * + * This initializes only the list and queue length aspects of + * an sk_buff_head object. This allows to initialize the list + * aspects of an sk_buff_head without reinitializing things like + * the spinlock. It can also be used for on-stack sk_buff_head + * objects where the spinlock is known to not be used. + */ +static inline void __skb_queue_head_init(struct sk_buff_head *list) +{ + list->prev = list->next = (struct sk_buff *)list; + list->qlen = 0; +} + /* * This function creates a split out lock class for each invocation; * this is needed for now since a whole lot of users of the skb-queue
@@ -671,8 +687,7 @@ static inline __u32 skb_queue_len(const struct sk_buff_head *list_) static inline void skb_queue_head_init(struct sk_buff_head *list) { spin_lock_init(&list->lock); - list->prev = list->next = (struct sk_buff *)list; - list->qlen = 0; + __skb_queue_head_init(list); } static inline void skb_queue_head_init_class(struct sk_buff_head *list,
@@ -699,6 +714,83 @@ static inline void __skb_insert(struct sk_buff *newsk, list->qlen++; } +static inline void __skb_queue_splice(const struct sk_buff_head *list, + struct sk_buff *prev, + struct sk_buff *next) +{ + struct sk_buff *first = list->next; + struct sk_buff *last = list->prev; + + first->prev = prev; + prev->next = first; + + last->next = next; + next->prev = last; +} + +/** + * skb_queue_splice - join two skb lists, this is designed for stacks + * @list: the new list to add + * @head: the place to add it in the first list + */ +static inline void skb_queue_splice(const struct sk_buff_head *list, + struct sk_buff_head *head) +{ + if (!skb_queue_empty(list)) { + __skb_queue_splice(list, (struct sk_buff *) head, head->next); + head->qlen = list->qlen; + } +} + +/** + * skb_queue_splice - join two skb 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 skb_queue_splice_init(struct sk_buff_head *list, + struct sk_buff_head *head) +{ + if (!skb_queue_empty(list)) { + __skb_queue_splice(list, (struct sk_buff *) head, head->next); + head->qlen = list->qlen; + __skb_queue_head_init(list); + } +} + +/** + * skb_queue_splice_tail - join two skb lists, each list being a queue + * @list: the new list to add + * @head: the place to add it in the first list + */ +static inline void skb_queue_splice_tail(const struct sk_buff_head *list, + struct sk_buff_head *head) +{ + if (!skb_queue_empty(list)) { + __skb_queue_splice(list, head->prev, (struct sk_buff *) head); + head->qlen = list->qlen; + } +} + +/** + * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list + * @list: the new list to add + * @head: the place to add it in the first list + * + * Each of the lists is a queue. + * The list at @list is reinitialised + */ +static inline void skb_queue_splice_tail_init(struct sk_buff_head *list, + struct sk_buff_head *head) +{ + if (!skb_queue_empty(list)) { + __skb_queue_splice(list, head->prev, (struct sk_buff *) head); + head->qlen = list->qlen; + __skb_queue_head_init(list); + } +} + /** * __skb_queue_after - queue a buffer at the list head * @list: list to use
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1.5.6.5