list: add hlist_count_nodes()

Add a generic hlist_count_nodes() function and use it in two drivers.


This patch (of 3):

Add a function to count nodes in a hlist.  hlist_count_nodes() is similar
to list_count_nodes().

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Pierre Gondois <[email protected]>
Reviewed-by: Carlos Llamas <[email protected]>
Acked-by: Coly Li <[email protected]>
Acked-by: Marco Elver <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Cc: Arve Hjønnevåg <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jani Nikula <[email protected]>
Cc: Joel Fernandes (Google) <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Martijn Coenen <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Todd Kjos <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/list.h b/include/linux/list.h
index 059aa1fff41e..523b7c4d000a 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -1195,4 +1195,19 @@ static inline void hlist_splice_init(struct hlist_head *from,
 	     pos && ({ n = pos->member.next; 1; });			\
 	     pos = hlist_entry_safe(n, typeof(*pos), member))
 
+/**
+ * hlist_count_nodes - count nodes in the hlist
+ * @head:	the head for your hlist.
+ */
+static inline size_t hlist_count_nodes(struct hlist_head *head)
+{
+	struct hlist_node *pos;
+	size_t count = 0;
+
+	hlist_for_each(pos, head)
+		count++;
+
+	return count;
+}
+
 #endif