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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 17:35:05 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 17:39:31 +0000 |
commit | 85c675d0d09a45a135bddd15d7b385f8758c32fb (patch) | |
tree | 76267dbc9b9a130337be3640948fe397b04ac629 /lib/llist.c | |
parent | Adding upstream version 6.6.15. (diff) | |
download | linux-85c675d0d09a45a135bddd15d7b385f8758c32fb.tar.xz linux-85c675d0d09a45a135bddd15d7b385f8758c32fb.zip |
Adding upstream version 6.7.7.upstream/6.7.7
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/llist.c')
-rw-r--r-- | lib/llist.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/lib/llist.c b/lib/llist.c index 6e668fa5a2..f21d0cfbba 100644 --- a/lib/llist.c +++ b/lib/llist.c @@ -66,6 +66,34 @@ struct llist_node *llist_del_first(struct llist_head *head) EXPORT_SYMBOL_GPL(llist_del_first); /** + * llist_del_first_this - delete given entry of lock-less list if it is first + * @head: the head for your lock-less list + * @this: a list entry. + * + * If head of the list is given entry, delete and return %true else + * return %false. + * + * Multiple callers can safely call this concurrently with multiple + * llist_add() callers, providing all the callers offer a different @this. + */ +bool llist_del_first_this(struct llist_head *head, + struct llist_node *this) +{ + struct llist_node *entry, *next; + + /* acquire ensures orderig wrt try_cmpxchg() is llist_del_first() */ + entry = smp_load_acquire(&head->first); + do { + if (entry != this) + return false; + next = READ_ONCE(entry->next); + } while (!try_cmpxchg(&head->first, &entry, next)); + + return true; +} +EXPORT_SYMBOL_GPL(llist_del_first_this); + +/** * llist_reverse_order - reverse order of a llist chain * @head: first item of the list to be reversed * |