diff --git a/block/blk-mq.c b/block/blk-mq.c
index d50b1d62a3d9..d98654869615 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -43,6 +43,7 @@
 #include "blk-ioprio.h"
 
 static DEFINE_PER_CPU(struct llist_head, blk_cpu_done);
+static DEFINE_PER_CPU(call_single_data_t, blk_cpu_csd);
 
 static void blk_mq_insert_request(struct request *rq, blk_insert_t flags);
 static void blk_mq_request_bypass_insert(struct request *rq,
@@ -1157,15 +1158,11 @@ static inline bool blk_mq_complete_need_ipi(struct request *rq)
 
 static void blk_mq_complete_send_ipi(struct request *rq)
 {
-	struct llist_head *list;
 	unsigned int cpu;
 
 	cpu = rq->mq_ctx->cpu;
-	list = &per_cpu(blk_cpu_done, cpu);
-	if (llist_add(&rq->ipi_list, list)) {
-		INIT_CSD(&rq->csd, __blk_mq_complete_request_remote, rq);
-		smp_call_function_single_async(cpu, &rq->csd);
-	}
+	if (llist_add(&rq->ipi_list, &per_cpu(blk_cpu_done, cpu)))
+		smp_call_function_single_async(cpu, &per_cpu(blk_cpu_csd, cpu));
 }
 
 static void blk_mq_raise_softirq(struct request *rq)
@@ -4829,6 +4826,9 @@ static int __init blk_mq_init(void)
 
 	for_each_possible_cpu(i)
 		init_llist_head(&per_cpu(blk_cpu_done, i));
+	for_each_possible_cpu(i)
+		INIT_CSD(&per_cpu(blk_cpu_csd, i),
+			 __blk_mq_complete_request_remote, NULL);
 	open_softirq(BLOCK_SOFTIRQ, blk_done_softirq);
 
 	cpuhp_setup_state_nocalls(CPUHP_BLOCK_SOFTIRQ_DEAD,
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index b96e00499f9e..67f810857634 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -182,10 +182,7 @@ struct request {
 		rq_end_io_fn		*saved_end_io;
 	} flush;
 
-	union {
-		struct __call_single_data csd;
-		u64 fifo_time;
-	};
+	u64 fifo_time;
 
 	/*
 	 * completion callback.