diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/srcu.h | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/include/linux/srcu.h b/include/linux/srcu.h index 1a8a465a5650..d4dcaeb83e2b 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -18,6 +18,7 @@ #include <linux/mutex.h> #include <linux/rcupdate.h> +#include <linux/rculist.h> #include <linux/workqueue.h> #include <linux/rcu_segcblist.h> @@ -118,6 +119,41 @@ void cleanup_srcu_struct(struct srcu_struct *ssp); void synchronize_srcu(struct srcu_struct *ssp); void synchronize_srcu_atomic(struct srcu_struct *ssp); +/** + * list_splice_init_srcu - splice an SRCU-protected list into an existing list + * @list: the SRCU-protected list to splice + * @head: the place in the existing list to splice the first list into + * @ssp: the srcu_struct that readers of @list use + * + * Like list_splice_init_rcu(), but wait for the SRCU readers of @list + * instead of RCU ones, so that none of them can follow a next pointer + * onto @head. + * + * Note that this function blocks, and that the caller must prevent any + * other updates to @list. + */ +static inline void list_splice_init_srcu(struct list_head *list, + struct list_head *head, + struct srcu_struct *ssp) +{ + struct list_head *first = list->next; + struct list_head *last = list->prev; + struct list_head *next = head->next; + + if (list_empty(list)) + return; + + INIT_LIST_HEAD_RCU(list); + synchronize_srcu(ssp); + ASSERT_EXCLUSIVE_ACCESS(*first); + ASSERT_EXCLUSIVE_ACCESS(*last); + + last->next = next; + rcu_assign_pointer(list_next_rcu(head), first); + first->prev = head; + next->prev = last; +} + #define SRCU_GET_STATE_COMPLETED 0x1 /** |