1 files changed, 16 insertions, 0 deletions

diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c
index 5d0f93cf358c..0daacb927be1 100644
--- a/block/blk-mq-cpumap.c
+++ b/block/blk-mq-cpumap.c
@@ -96,3 +96,19 @@ unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set)
         kfree(map);
         return NULL;
 }
+
+/*
+ * We have no quick way of doing reverse lookups. This is only used at
+ * queue init time, so runtime isn't important.
+ */
+int blk_mq_hw_queue_to_node(unsigned int *mq_map, unsigned int index)
+{
+        int i;
+
+        for_each_possible_cpu(i) {
+                if (index == mq_map[i])
+                        return cpu_to_node(i);
+        }
+
+        return NUMA_NO_NODE;
+}