+/* standard prep_rq_fn that builds 10 byte cmds */
+static int ide_cdrom_prep_fs(struct request_queue *q, struct request *rq)
+{
+ int hard_sect = queue_logical_block_size(q);
+ long block = (long)blk_rq_pos(rq) / (hard_sect >> 9);
+ unsigned long blocks = blk_rq_sectors(rq) / (hard_sect >> 9);
+ struct scsi_request *req = scsi_req(rq);
+
+ if (rq_data_dir(rq) == READ)
+ req->cmd[0] = GPCMD_READ_10;
+ else
+ req->cmd[0] = GPCMD_WRITE_10;
+
+ /*
+ * fill in lba
+ */
+ req->cmd[2] = (block >> 24) & 0xff;
+ req->cmd[3] = (block >> 16) & 0xff;
+ req->cmd[4] = (block >> 8) & 0xff;
+ req->cmd[5] = block & 0xff;
+
+ /*
+ * and transfer length
+ */
+ req->cmd[7] = (blocks >> 8) & 0xff;
+ req->cmd[8] = blocks & 0xff;
+ req->cmd_len = 10;
+ return BLKPREP_OK;
+}
+
+/*
+ * Most of the SCSI commands are supported directly by ATAPI devices.
+ * This transform handles the few exceptions.
+ */
+static int ide_cdrom_prep_pc(struct request *rq)
+{
+ u8 *c = scsi_req(rq)->cmd;
+
+ /* transform 6-byte read/write commands to the 10-byte version */
+ if (c[0] == READ_6 || c[0] == WRITE_6) {
+ c[8] = c[4];
+ c[5] = c[3];
+ c[4] = c[2];
+ c[3] = c[1] & 0x1f;
+ c[2] = 0;
+ c[1] &= 0xe0;
+ c[0] += (READ_10 - READ_6);
+ scsi_req(rq)->cmd_len = 10;
+ return BLKPREP_OK;
+ }
+
+ /*
+ * it's silly to pretend we understand 6-byte sense commands, just
+ * reject with ILLEGAL_REQUEST and the caller should take the
+ * appropriate action
+ */
+ if (c[0] == MODE_SENSE || c[0] == MODE_SELECT) {
+ scsi_req(rq)->result = ILLEGAL_REQUEST;
+ return BLKPREP_KILL;
+ }
+
+ return BLKPREP_OK;
+}
+
+static int ide_cdrom_prep_fn(ide_drive_t *drive, struct request *rq)
+{
+ if (!blk_rq_is_passthrough(rq)) {
+ scsi_req_init(scsi_req(rq));
+
+ return ide_cdrom_prep_fs(drive->queue, rq);
+ } else if (blk_rq_is_scsi(rq))
+ return ide_cdrom_prep_pc(rq);
+
+ return 0;
+}
+