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Commit 7d283aee authored by Luis R. Rodriguez's avatar Luis R. Rodriguez Committed by John W. Linville
Browse files

list.h: Add list_splice_tail() and list_splice_tail_init() 



If you are using linked lists for queues list_splice() will not do what
you would expect even if you use the elements passed reversed. We need
to handle these differently. We add list_splice_tail() and
list_splice_tail_init().

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent e6fce5b9

drivers/dma/ioat_dma.c

+1 −1
Original line number Diff line number Diff line
@@ -551,7 +551,7 @@ static dma_cookie_t ioat1_tx_submit(struct dma_async_tx_descriptor *tx) 
	/* write address into NextDescriptor field of last desc in chain */

	to_ioat_desc(ioat_chan->used_desc.prev)->hw->next =

							first->async_tx.phys;

	__list_splice(&new_chain, ioat_chan->used_desc.prev);

	list_splice_tail(&new_chain, &ioat_chan->used_desc);



	ioat_chan->dmacount += desc_count;

	ioat_chan->pending += desc_count;

drivers/usb/host/ehci-q.c

+1 −1
Original line number Diff line number Diff line
@@ -932,7 +932,7 @@ static struct ehci_qh *qh_append_tds ( 


			list_del (&qtd->qtd_list);

			list_add (&dummy->qtd_list, qtd_list);

			__list_splice (qtd_list, qh->qtd_list.prev);

			list_splice_tail(qtd_list, &qh->qtd_list);



			ehci_qtd_init(ehci, qtd, qtd->qtd_dma);

			qh->dummy = qtd;

include/linux/list.h

+38 −9
Original line number Diff line number Diff line
@@ -215,21 +215,21 @@ static inline int list_is_singular(const struct list_head *head) 
}



static inline void __list_splice(const struct list_head *list,

				 struct list_head *head)

				 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;



	first->prev = head;

	head->next = first;

	first->prev = prev;

	prev->next = first;



	last->next = at;

	at->prev = last;

	last->next = next;

	next->prev = last;

}



/**

 * list_splice - join two lists

 * list_splice - join two lists, this is designed for stacks

 * @list: the new list to add.

 * @head: the place to add it in the first list.

 */
@@ -237,7 +237,19 @@ 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_tail - join two 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 list_splice_tail(struct list_head *list,

				struct list_head *head)

{

	if (!list_empty(list))

		__list_splice(list, head->prev, head);

}



/**
@@ -251,7 +263,24 @@ static inline void list_splice_init(struct list_head *list, 
				    struct list_head *head)

{

	if (!list_empty(list)) {

		__list_splice(list, head);

		__list_splice(list, head, head->next);

		INIT_LIST_HEAD(list);

	}

}



/**

 * list_splice_tail_init - join two lists, each list being a queue, 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_tail_init(struct list_head *list,

					 struct list_head *head)

{

	if (!list_empty(list)) {

		__list_splice(list, head->prev, head);

		INIT_LIST_HEAD(list);

	}

}