1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/s390/cio/idset.c b/drivers/s390/cio/idset.c
index 5c88faf5b897..4d10981c7cc1 100644
--- a/drivers/s390/cio/idset.c
+++ b/drivers/s390/cio/idset.c
@@ -120,3 +120,13 @@ int idset_is_empty(struct idset *set)
                 return 1;
         return 0;
 }
+
+void idset_add_set(struct idset *to, struct idset *from)
+{
+        unsigned long i, len;
+
+        len = min(__BITOPS_WORDS(to->num_ssid * to->num_id),
+                  __BITOPS_WORDS(from->num_ssid * from->num_id));
+        for (i = 0; i < len ; i++)
+                to->bitmap[i] |= from->bitmap[i];
+}