[libata scsi] add ata_scsi_set_sense helper

  - add extern ata_scsi_set_sense() to build SCSI
    fixed sense data and corresponding SCSI status
Signed-off-by: NDouglas Gilbert <dougg@torque.net>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

drivers/scsi/libata-scsi.c

@@ -1450,6 +1450,34 @@ unsigned int ata_scsiop_report_luns(struct ata_scsi_args *args, u8 *rbuf,
 	return 0;
 }
 
+/**
+ *	ata_scsi_set_sense - Set SCSI sense data and status
+ *	@cmd: SCSI request to be handled
+ *	@sk: SCSI-defined sense key
+ *	@asc: SCSI-defined additional sense code
+ *	@ascq: SCSI-defined additional sense code qualifier
+ *
+ *	Helper function that builds a valid fixed format, current
+ *	response code and the given sense key (sk), additional sense
+ *	code (asc) and additional sense code qualifier (ascq) with
+ *	a SCSI command status of %SAM_STAT_CHECK_CONDITION and
+ *	DRIVER_SENSE set in the upper bits of scsi_cmnd::result .
+ *
+ *	LOCKING:
+ *	Not required
+ */
+
+void ata_scsi_set_sense(struct scsi_cmnd *cmd, u8 sk, u8 asc, u8 ascq)
+{
+	cmd->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
+
+	cmd->sense_buffer[0] = 0x70;	/* fixed format, current */
+	cmd->sense_buffer[2] = sk;
+	cmd->sense_buffer[7] = 18 - 8;	/* additional sense length */
+	cmd->sense_buffer[12] = asc;
+	cmd->sense_buffer[13] = ascq;
+}
+
 /**
  *	ata_scsi_badcmd - End a SCSI request with an error
  *	@cmd: SCSI request to be handled

drivers/scsi/libata.h

@@ -80,6 +80,8 @@ extern unsigned int ata_scsiop_report_luns(struct ata_scsi_args *args, u8 *rbuf,
 extern void ata_scsi_badcmd(struct scsi_cmnd *cmd,
 			    void (*done)(struct scsi_cmnd *),
 			    u8 asc, u8 ascq);
+extern void ata_scsi_set_sense(struct scsi_cmnd *cmd,
+			       u8 sk, u8 asc, u8 ascq);
 extern void ata_scsi_rbuf_fill(struct ata_scsi_args *args,
                         unsigned int (*actor) (struct ata_scsi_args *args,
                                            u8 *rbuf, unsigned int buflen));