[PATCH V2 3/9] scsi: core: add helper of scsi_max_nr_hw_queues()

[Ming Lei <ming.lei@redhat.com>]

blk_mq_alloc_tag_set() may change nr_hw_queues for kdump kernel, so
driver has to take blk-mq max supported nr_hw_queues into account
when figuring out nr_hw_queues from hardware info, for avoiding
inconsistency between scsi driver and blk-mq.

Add helper of scsi_max_nr_hw_queues() for avoiding nr_hw_queues
inconsistency between scsi driver and blk-mq.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 include/scsi/scsi_host.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 70b7475dcf56..2273f855940f 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -803,6 +803,11 @@ extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
 void scsi_host_busy_iter(struct Scsi_Host *,
 			 bool (*fn)(struct scsi_cmnd *, void *), void *priv);
 
+static inline unsigned int scsi_max_nr_hw_queues(void)
+{
+	return blk_mq_max_nr_hw_queues();
+}
+
 struct class_container;
 
 /*
-- 
2.40.1