scsi: kill off the legacy IO path

This removes the legacy (non-mq) IO path for SCSI.

Cc: linux-scsi@vger.kernel.org
Acked-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

2 files changed, 7 insertions, 25 deletions

diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 5ea06d310a25..aa760df8c6b3 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -11,7 +11,6 @@
 #include <linux/blk-mq.h>
 #include <scsi/scsi.h>
 
-struct request_queue;
 struct block_device;
 struct completion;
 struct module;
@@ -22,7 +21,6 @@ struct scsi_target;
 struct Scsi_Host;
 struct scsi_host_cmd_pool;
 struct scsi_transport_template;
-struct blk_queue_tags;
 
 
 /*
@@ -547,14 +545,8 @@ struct Scsi_Host {
         struct scsi_host_template *hostt;
         struct scsi_transport_template *transportt;
 
-        /*
-         * Area to keep a shared tag map (if needed, will be
-         * NULL if not).
-         */
-        union {
-                struct blk_queue_tag    *bqt;
-                struct blk_mq_tag_set   tag_set;
-        };
+        /* Area to keep a shared tag map */
+        struct blk_mq_tag_set   tag_set;
 
         atomic_t host_busy;                /* commands actually active on low-level */
         atomic_t host_blocked;
@@ -648,7 +640,6 @@ struct Scsi_Host {
         /* The controller does not support WRITE SAME */
         unsigned no_write_same:1;
 
-        unsigned use_blk_mq:1;
         unsigned use_cmd_list:1;
 
         /* Host responded with short (<36 bytes) INQUIRY result */
@@ -742,11 +733,6 @@ static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
                 shost->tmf_in_progress;
 }
 
-static inline bool shost_use_blk_mq(struct Scsi_Host *shost)
-{
-        return shost->use_blk_mq;
-}
-
 extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
 extern void scsi_flush_work(struct Scsi_Host *);
 
diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index e192a0caa850..6053d46e794e 100644
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -23,19 +23,15 @@ static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost,
                 int tag)
 {
         struct request *req = NULL;
+        u16 hwq;
 
         if (tag == SCSI_NO_TAG)
                 return NULL;
 
-        if (shost_use_blk_mq(shost)) {
-                u16 hwq = blk_mq_unique_tag_to_hwq(tag);
-
-                if (hwq < shost->tag_set.nr_hw_queues) {
-                        req = blk_mq_tag_to_rq(shost->tag_set.tags[hwq],
-                                blk_mq_unique_tag_to_tag(tag));
-                }
-        } else {
-                req = blk_map_queue_find_tag(shost->bqt, tag);
+        hwq = blk_mq_unique_tag_to_hwq(tag);
+        if (hwq < shost->tag_set.nr_hw_queues) {
+                req = blk_mq_tag_to_rq(shost->tag_set.tags[hwq],
+                                        blk_mq_unique_tag_to_tag(tag));
         }
 
         if (!req)