scsi: core: Drop message byte helper

The message byte is now unused, so we can drop the helper to set the
message byte and the check for message bytes during error recovery.

Link: https://lore.kernel.org/r/20210427083046.31620-38-hare@suse.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

block/scsi_ioctl.c

@@ -254,7 +254,7 @@ static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
 	 */
 	hdr->status = req->result & 0xff;
 	hdr->masked_status = status_byte(req->result);
-	hdr->msg_status = msg_byte(req->result);
+	hdr->msg_status = COMMAND_COMPLETE;
 	hdr->host_status = host_byte(req->result);
 	hdr->driver_status = 0;
 	if (scsi_status_is_check_condition(hdr->status))

drivers/scsi/scsi_error.c

@@ -741,12 +741,6 @@ static enum scsi_disposition scsi_eh_completed_normally(struct scsi_cmnd *scmd)
 	if (host_byte(scmd->result) != DID_OK)
 		return FAILED;
 
-	/*
-	 * next, check the message byte.
-	 */
-	if (msg_byte(scmd->result) != COMMAND_COMPLETE)
-		return FAILED;
-
 	/*
 	 * now, check the status byte to see if this indicates
 	 * anything special.
@@ -1766,8 +1760,7 @@ int scsi_noretry_cmd(struct scsi_cmnd *scmd)
 	case DID_PARITY:
 		return (scmd->request->cmd_flags & REQ_FAILFAST_DEV);
 	case DID_ERROR:
-		if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
-		    status_byte(scmd->result) == RESERVATION_CONFLICT)
+		if (status_byte(scmd->result) == RESERVATION_CONFLICT)
 			return 0;
 		fallthrough;
 	case DID_SOFT_ERROR:
@@ -1883,8 +1876,7 @@ enum scsi_disposition scsi_decide_disposition(struct scsi_cmnd *scmd)
 		 */
 		return SUCCESS;
 	case DID_ERROR:
-		if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
-		    status_byte(scmd->result) == RESERVATION_CONFLICT)
+		if (status_byte(scmd->result) == RESERVATION_CONFLICT)
 			/*
 			 * execute reservation conflict processing code
 			 * lower down
@@ -1912,12 +1904,6 @@ enum scsi_disposition scsi_decide_disposition(struct scsi_cmnd *scmd)
 		return FAILED;
 	}
 
-	/*
-	 * next, check the message byte.
-	 */
-	if (msg_byte(scmd->result) != COMMAND_COMPLETE)
-		return FAILED;
-
 	/*
 	 * check the status byte to see if this indicates anything special.
 	 */

drivers/scsi/sg.c

@@ -1376,7 +1376,7 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
 
 		srp->header.status = 0xff & result;
 		srp->header.masked_status = status_byte(result);
-		srp->header.msg_status = msg_byte(result);
+		srp->header.msg_status = COMMAND_COMPLETE;
 		srp->header.host_status = host_byte(result);
 		srp->header.driver_status = driver_byte(result);
 		if ((sdp->sgdebug > 0) &&

drivers/xen/xen-scsiback.c

@@ -224,7 +224,7 @@ static void scsiback_print_status(char *sense_buffer, int errors,
 
 	pr_err("[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x\n",
 	       tpg->tport->tport_name, pending_req->v2p->lun,
-	       pending_req->cmnd[0], status_byte(errors), msg_byte(errors),
+	       pending_req->cmnd[0], status_byte(errors), COMMAND_COMPLETE,
 	       host_byte(errors));
 }
 

include/scsi/scsi.h

@@ -181,11 +181,10 @@ enum scsi_disposition {
  *  These are set by:
  *
  *      status byte = set from target device
- *      msg_byte    = return status from host adapter itself.
+ *      msg_byte    (unused)
  *      host_byte   = set by low-level driver to indicate status.
  */
 #define status_byte(result) (((result) >> 1) & 0x7f)
-#define msg_byte(result)    (((result) >> 8) & 0xff)
 #define host_byte(result)   (((result) >> 16) & 0xff)
 
 #define sense_class(sense)  (((sense) >> 4) & 0x7)

include/scsi/scsi_cmnd.h

@@ -320,11 +320,6 @@ static inline u8 get_status_byte(struct scsi_cmnd *cmd)
 	return cmd->result & 0xff;
 }
 
-static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
-{
-	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
-}
-
 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
 {
 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);