text: /*
   * ATAPI CD-ROM driver.
   *
   * Copyright (C) 1994-1996   Scott Snyder <snyder@fnald0.fnal.gov>
   * Copyright (C) 1996-1998   Erik Andersen <andersee@debian.org>
   * Copyright (C) 1998-2000   Jens Axboe <axboe@suse.de>
   * Copyright (C) 2005, 2007-2009  Bartlomiej Zolnierkiewicz
   *
   * May be copied or modified under the terms of the GNU General Public
   * License.  See linux/COPYING for more information.
   *
   * See Documentation/cdrom/ide-cd for usage information.
   *
   * Suggestions are welcome. Patches that work are more welcome though. ;-)
   *
   * Documentation:
   *	Mt. Fuji (SFF8090 version 4) and ATAPI (SFF-8020i rev 2.6) standards.
   *
   * For historical changelog please see:
   *	Documentation/ide/ChangeLog.ide-cd.1994-2004
   */
  
  #define DRV_NAME "ide-cd"
  #define PFX DRV_NAME ": "
  
  #define IDECD_VERSION "5.00"
  
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/sched/task_stack.h>
  #include <linux/delay.h>
  #include <linux/timer.h>
  #include <linux/seq_file.h>
  #include <linux/slab.h>
  #include <linux/interrupt.h>
  #include <linux/errno.h>
  #include <linux/cdrom.h>
  #include <linux/ide.h>
  #include <linux/completion.h>
  #include <linux/mutex.h>
  #include <linux/bcd.h>
  
  /* For SCSI -> ATAPI command conversion */
  #include <scsi/scsi.h>
  
  #include <linux/io.h>
  #include <asm/byteorder.h>
  #include <linux/uaccess.h>
  #include <asm/unaligned.h>
  
  #include "ide-cd.h"
  
  static DEFINE_MUTEX(ide_cd_mutex);
  static DEFINE_MUTEX(idecd_ref_mutex);
  
  static void ide_cd_release(struct device *);
  
  static struct cdrom_info *ide_cd_get(struct gendisk *disk)
  {
  	struct cdrom_info *cd = NULL;
  
  	mutex_lock(&idecd_ref_mutex);
  	cd = ide_drv_g(disk, cdrom_info);
  	if (cd) {
  		if (ide_device_get(cd->drive))
  			cd = NULL;
  		else
  			get_device(&cd->dev);
  
  	}
  	mutex_unlock(&idecd_ref_mutex);
  	return cd;
  }
  
  static void ide_cd_put(struct cdrom_info *cd)
  {
  	ide_drive_t *drive = cd->drive;
  
  	mutex_lock(&idecd_ref_mutex);
  	put_device(&cd->dev);
  	ide_device_put(drive);
  	mutex_unlock(&idecd_ref_mutex);
  }
  
  /*
   * Generic packet command support and error handling routines.
   */
  
  /* Mark that we've seen a media change and invalidate our internal buffers. */
  static void cdrom_saw_media_change(ide_drive_t *drive)
  {
  	drive->dev_flags |= IDE_DFLAG_MEDIA_CHANGED;
  	drive->atapi_flags &= ~IDE_AFLAG_TOC_VALID;
  }
  
  static int cdrom_log_sense(ide_drive_t *drive, struct request *rq)
  {
  	struct request_sense *sense = &drive->sense_data;
  	int log = 0;
  
  	if (!sense || !rq || (rq->rq_flags & RQF_QUIET))
  		return 0;
  
  	ide_debug_log(IDE_DBG_SENSE, "sense_key: 0x%x", sense->sense_key);
  
  	switch (sense->sense_key) {
  	case NO_SENSE:
  	case RECOVERED_ERROR:
  		break;
  	case NOT_READY:
  		/*
  		 * don't care about tray state messages for e.g. capacity
  		 * commands or in-progress or becoming ready
  		 */
  		if (sense->asc == 0x3a || sense->asc == 0x04)
  			break;
  		log = 1;
  		break;
  	case ILLEGAL_REQUEST:
  		/*
  		 * don't log START_STOP unit with LoEj set, since we cannot
  		 * reliably check if drive can auto-close
  		 */
  		if (scsi_req(rq)->cmd[0] == GPCMD_START_STOP_UNIT && sense->asc == 0x24)
  			break;
  		log = 1;
  		break;
  	case UNIT_ATTENTION:
  		/*
  		 * Make good and sure we've seen this potential media change.
  		 * Some drives (i.e. Creative) fail to present the correct sense
  		 * key in the error register.
  		 */
  		cdrom_saw_media_change(drive);
  		break;
  	default:
  		log = 1;
  		break;
  	}
  	return log;
  }
  
  static void cdrom_analyze_sense_data(ide_drive_t *drive,
  				     struct request *failed_command)
  {
  	struct request_sense *sense = &drive->sense_data;
  	struct cdrom_info *info = drive->driver_data;
  	unsigned long sector;
  	unsigned long bio_sectors;
  
  	ide_debug_log(IDE_DBG_SENSE, "error_code: 0x%x, sense_key: 0x%x",
  				     sense->error_code, sense->sense_key);
  
  	if (failed_command)
  		ide_debug_log(IDE_DBG_SENSE, "failed cmd: 0x%x",
  					     failed_command->cmd[0]);
  
  	if (!cdrom_log_sense(drive, failed_command))
  		return;
  
  	/*
  	 * If a read toc is executed for a CD-R or CD-RW medium where the first
  	 * toc has not been recorded yet, it will fail with 05/24/00 (which is a
  	 * confusing error)
  	 */
  	if (failed_command && scsi_req(failed_command)->cmd[0] == GPCMD_READ_TOC_PMA_ATIP)
  		if (sense->sense_key == 0x05 && sense->asc == 0x24)
  			return;
  
  	/* current error */
  	if (sense->error_code == 0x70) {
  		switch (sense->sense_key) {
  		case MEDIUM_ERROR:
  		case VOLUME_OVERFLOW:
  		case ILLEGAL_REQUEST:
  			if (!sense->valid)
  				break;
  			if (failed_command == NULL ||
  			    blk_rq_is_passthrough(failed_command))
  				break;
  			sector = (sense->information[0] << 24) |
  				 (sense->information[1] << 16) |
  				 (sense->information[2] <<  8) |
  				 (sense->information[3]);
  
  			if (queue_logical_block_size(drive->queue) == 2048)
  				/* device sector size is 2K */
  				sector <<= 2;
  
  			bio_sectors = max(bio_sectors(failed_command->bio), 4U);
  			sector &= ~(bio_sectors - 1);
  
  			/*
  			 * The SCSI specification allows for the value
  			 * returned by READ CAPACITY to be up to 75 2K
  			 * sectors past the last readable block.
  			 * Therefore, if we hit a medium error within the
  			 * last 75 2K sectors, we decrease the saved size
  			 * value.
  			 */
  			if (sector < get_capacity(info->disk) &&
  			    drive->probed_capacity - sector < 4 * 75)
  				set_capacity(info->disk, sector);
  		}
  	}
  
  	ide_cd_log_error(drive->name, failed_command, sense);
  }
  
  static void ide_cd_complete_failed_rq(ide_drive_t *drive, struct request *rq)
  {
  	/*
  	 * For ATA_PRIV_SENSE, "rq->special" points to the original
  	 * failed request.  Also, the sense data should be read
  	 * directly from rq which might be different from the original
  	 * sense buffer if it got copied during mapping.
  	 */
  	struct request *failed = (struct request *)rq->special;
  	void *sense = bio_data(rq->bio);
  
  	if (failed) {
  		/*
  		 * Sense is always read into drive->sense_data, copy back to the
  		 * original request.
  		 */
  		memcpy(scsi_req(failed)->sense, sense, 18);
  		scsi_req(failed)->sense_len = scsi_req(rq)->sense_len;
  		cdrom_analyze_sense_data(drive, failed);
  
  		if (ide_end_rq(drive, failed, BLK_STS_IOERR, blk_rq_bytes(failed)))
  			BUG();
  	} else
  		cdrom_analyze_sense_data(drive, NULL);
  }
  
  
  /*
   * Allow the drive 5 seconds to recover; some devices will return NOT_READY
   * while flushing data from cache.
   *
   * returns: 0 failed (write timeout expired)
   *	    1 success
   */
  static int ide_cd_breathe(ide_drive_t *drive, struct request *rq)
  {
  
  	struct cdrom_info *info = drive->driver_data;
  
  	if (!scsi_req(rq)->result)
  		info->write_timeout = jiffies +	ATAPI_WAIT_WRITE_BUSY;
  
  	scsi_req(rq)->result = 1;
  
  	if (time_after(jiffies, info->write_timeout))
  		return 0;
  	else {
  		/*
  		 * take a breather
  		 */
  		blk_delay_queue(drive->queue, 1);
  		return 1;
  	}
  }
  
  /**
   * Returns:
   * 0: if the request should be continued.
   * 1: if the request will be going through error recovery.
   * 2: if the request should be ended.
   */
  static int cdrom_decode_status(ide_drive_t *drive, u8 stat)
  {
  	ide_hwif_t *hwif = drive->hwif;
  	struct request *rq = hwif->rq;
  	int err, sense_key, do_end_request = 0;
  
  	/* get the IDE error register */
  	err = ide_read_error(drive);
  	sense_key = err >> 4;
  
  	ide_debug_log(IDE_DBG_RQ, "cmd: 0x%x, rq->cmd_type: 0x%x, err: 0x%x, "
  				  "stat 0x%x",
  				  rq->cmd[0], rq->cmd_type, err, stat);
  
  	if (ata_sense_request(rq)) {
  		/*
  		 * We got an error trying to get sense info from the drive
  		 * (probably while trying to recover from a former error).
  		 * Just give up.
  		 */
  		rq->rq_flags |= RQF_FAILED;
  		return 2;
  	}
  
  	/* if we have an error, pass CHECK_CONDITION as the SCSI status byte */
  	if (blk_rq_is_scsi(rq) && !scsi_req(rq)->result)
  		scsi_req(rq)->result = SAM_STAT_CHECK_CONDITION;
  
  	if (blk_noretry_request(rq))
  		do_end_request = 1;
  
  	switch (sense_key) {
  	case NOT_READY:
  		if (req_op(rq) == REQ_OP_WRITE) {
  			if (ide_cd_breathe(drive, rq))
  				return 1;
  		} else {
  			cdrom_saw_media_change(drive);
  
  			if (!blk_rq_is_passthrough(rq) &&
  			    !(rq->rq_flags & RQF_QUIET))
  				printk(KERN_ERR PFX "%s: tray open\n",
  					drive->name);
  		}
  		do_end_request = 1;
  		break;
  	case UNIT_ATTENTION:
  		cdrom_saw_media_change(drive);
  
  		if (blk_rq_is_passthrough(rq))
  			return 0;
  
  		/*
  		 * Arrange to retry the request but be sure to give up if we've
  		 * retried too many times.
  		 */
  		if (++scsi_req(rq)->result > ERROR_MAX)
  			do_end_request = 1;
  		break;
  	case ILLEGAL_REQUEST:
  		/*
  		 * Don't print error message for this condition -- SFF8090i
  		 * indicates that 5/24/00 is the correct response to a request
  		 * to close the tray if the drive doesn't have that capability.
  		 *
  		 * cdrom_log_sense() knows this!
  		 */
  		if (scsi_req(rq)->cmd[0] == GPCMD_START_STOP_UNIT)
  			break;
  		/* fall-through */
  	case DATA_PROTECT:
  		/*
  		 * No point in retrying after an illegal request or data
  		 * protect error.
  		 */
  		if (!(rq->rq_flags & RQF_QUIET))
  			ide_dump_status(drive, "command error", stat);
  		do_end_request = 1;
  		break;
  	case MEDIUM_ERROR:
  		/*
  		 * No point in re-trying a zillion times on a bad sector.
  		 * If we got here the error is not correctable.
  		 */
  		if (!(rq->rq_flags & RQF_QUIET))
  			ide_dump_status(drive, "media error "
  					"(bad sector)", stat);
  		do_end_request = 1;
  		break;
  	case BLANK_CHECK:
  		/* disk appears blank? */
  		if (!(rq->rq_flags & RQF_QUIET))
  			ide_dump_status(drive, "media error (blank)",
  					stat);
  		do_end_request = 1;
  		break;
  	default:
  		if (blk_rq_is_passthrough(rq))
  			break;
  		if (err & ~ATA_ABORTED) {
  			/* go to the default handler for other errors */
  			ide_error(drive, "cdrom_decode_status", stat);
  			return 1;
  		} else if (++scsi_req(rq)->result > ERROR_MAX)
  			/* we've racked up too many retries, abort */
  			do_end_request = 1;
  	}
  
  	if (blk_rq_is_passthrough(rq)) {
  		rq->rq_flags |= RQF_FAILED;
  		do_end_request = 1;
  	}
  
  	/*
  	 * End a request through request sense analysis when we have sense data.
  	 * We need this in order to perform end of media processing.
  	 */
  	if (do_end_request)
  		goto end_request;
  
  	/* if we got a CHECK_CONDITION status, queue a request sense command */
  	if (stat & ATA_ERR)
  		return ide_queue_sense_rq(drive, NULL) ? 2 : 1;
  	return 1;
  
  end_request:
  	if (stat & ATA_ERR) {
  		hwif->rq = NULL;
  		return ide_queue_sense_rq(drive, rq) ? 2 : 1;
  	} else
  		return 2;
  }
  
  static void ide_cd_request_sense_fixup(ide_drive_t *drive, struct ide_cmd *cmd)
  {
  	struct request *rq = cmd->rq;
  
  	ide_debug_log(IDE_DBG_FUNC, "rq->cmd[0]: 0x%x", rq->cmd[0]);
  
  	/*
  	 * Some of the trailing request sense fields are optional,
  	 * and some drives don't send them.  Sigh.
  	 */
  	if (scsi_req(rq)->cmd[0] == GPCMD_REQUEST_SENSE &&
  	    cmd->nleft > 0 && cmd->nleft <= 5)
  		cmd->nleft = 0;
  }
  
  int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd,
  		    int write, void *buffer, unsigned *bufflen,
  		    struct scsi_sense_hdr *sshdr, int timeout,
  		    req_flags_t rq_flags)
  {
  	struct cdrom_info *info = drive->driver_data;
  	struct scsi_sense_hdr local_sshdr;
  	int retries = 10;
  	bool failed;
  
  	ide_debug_log(IDE_DBG_PC, "cmd[0]: 0x%x, write: 0x%x, timeout: %d, "
  				  "rq_flags: 0x%x",
  				  cmd[0], write, timeout, rq_flags);
  
  	if (!sshdr)
  		sshdr = &local_sshdr;
  
  	/* start of retry loop */
  	do {
  		struct request *rq;
  		int error;
  		bool delay = false;
  
  		rq = blk_get_request(drive->queue,
  			write ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
  		memcpy(scsi_req(rq)->cmd, cmd, BLK_MAX_CDB);
  		ide_req(rq)->type = ATA_PRIV_PC;
  		rq->rq_flags |= rq_flags;
  		rq->timeout = timeout;
  		if (buffer) {
  			error = blk_rq_map_kern(drive->queue, rq, buffer,
  						*bufflen, GFP_NOIO);
  			if (error) {
  				blk_put_request(rq);
  				return error;
  			}
  		}
  
  		blk_execute_rq(drive->queue, info->disk, rq, 0);
  		error = scsi_req(rq)->result ? -EIO : 0;
  
  		if (buffer)
  			*bufflen = scsi_req(rq)->resid_len;
  		scsi_normalize_sense(scsi_req(rq)->sense,
  				     scsi_req(rq)->sense_len, sshdr);
  
  		/*
  		 * FIXME: we should probably abort/retry or something in case of
  		 * failure.
  		 */
  		failed = (rq->rq_flags & RQF_FAILED) != 0;
  		if (failed) {
  			/*
  			 * The request failed.  Retry if it was due to a unit
  			 * attention status (usually means media was changed).
  			 */
  			if (sshdr->sense_key == UNIT_ATTENTION)
  				cdrom_saw_media_change(drive);
  			else if (sshdr->sense_key == NOT_READY &&
  				 sshdr->asc == 4 && sshdr->ascq != 4) {
  				/*
  				 * The drive is in the process of loading
  				 * a disk.  Retry, but wait a little to give
  				 * the drive time to complete the load.
  				 */
  				delay = true;
  			} else {
  				/* otherwise, don't retry */
  				retries = 0;
  			}
  			--retries;
  		}
  		blk_put_request(rq);
  		if (delay)
  			ssleep(2);
  	} while (failed && retries >= 0);
  
  	/* return an error if the command failed */
  	return failed ? -EIO : 0;
  }
  
  /*
   * returns true if rq has been completed
   */
  static bool ide_cd_error_cmd(ide_drive_t *drive, struct ide_cmd *cmd)
  {
  	unsigned int nr_bytes = cmd->nbytes - cmd->nleft;
  
  	if (cmd->tf_flags & IDE_TFLAG_WRITE)
  		nr_bytes -= cmd->last_xfer_len;
  
  	if (nr_bytes > 0) {
  		ide_complete_rq(drive, BLK_STS_OK, nr_bytes);
  		return true;
  	}
  
  	return false;
  }
  
  static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive)
  {
  	ide_hwif_t *hwif = drive->hwif;
  	struct ide_cmd *cmd = &hwif->cmd;
  	struct request *rq = hwif->rq;
  	ide_expiry_t *expiry = NULL;
  	int dma_error = 0, dma, thislen, uptodate = 0;
  	int write = (rq_data_dir(rq) == WRITE) ? 1 : 0, rc = 0;
  	int sense = ata_sense_request(rq);
  	unsigned int timeout;
  	u16 len;
  	u8 ireason, stat;
  
  	ide_debug_log(IDE_DBG_PC, "cmd: 0x%x, write: 0x%x", rq->cmd[0], write);
  
  	/* check for errors */
  	dma = drive->dma;
  	if (dma) {
  		drive->dma = 0;
  		drive->waiting_for_dma = 0;
  		dma_error = hwif->dma_ops->dma_end(drive);
  		ide_dma_unmap_sg(drive, cmd);
  		if (dma_error) {
  			printk(KERN_ERR PFX "%s: DMA %s error\n", drive->name,
  					write ? "write" : "read");
  			ide_dma_off(drive);
  		}
  	}
  
  	/* check status */
  	stat = hwif->tp_ops->read_status(hwif);
  
  	if (!OK_STAT(stat, 0, BAD_R_STAT)) {
  		rc = cdrom_decode_status(drive, stat);
  		if (rc) {
  			if (rc == 2)
  				goto out_end;
  			return ide_stopped;
  		}
  	}
  
  	/* using dma, transfer is complete now */
  	if (dma) {
  		if (dma_error)
  			return ide_error(drive, "dma error", stat);
  		uptodate = 1;
  		goto out_end;
  	}
  
  	ide_read_bcount_and_ireason(drive, &len, &ireason);
  
  	thislen = !blk_rq_is_passthrough(rq) ? len : cmd->nleft;
  	if (thislen > len)
  		thislen = len;
  
  	ide_debug_log(IDE_DBG_PC, "DRQ: stat: 0x%x, thislen: %d",
  				  stat, thislen);
  
  	/* If DRQ is clear, the command has completed. */
  	if ((stat & ATA_DRQ) == 0) {
  		switch (req_op(rq)) {
  		default:
  			/*
  			 * If we're not done reading/writing, complain.
  			 * Otherwise, complete the command normally.
  			 */
  			uptodate = 1;
  			if (cmd->nleft > 0) {
  				printk(KERN_ERR PFX "%s: %s: data underrun "
  					"(%u bytes)\n", drive->name, __func__,
  					cmd->nleft);
  				if (!write)
  					rq->rq_flags |= RQF_FAILED;
  				uptodate = 0;
  			}
  			goto out_end;
  		case REQ_OP_DRV_IN:
  		case REQ_OP_DRV_OUT:
  			ide_cd_request_sense_fixup(drive, cmd);
  
  			uptodate = cmd->nleft ? 0 : 1;
  
  			/*
  			 * suck out the remaining bytes from the drive in an
  			 * attempt to complete the data xfer. (see BZ#13399)
  			 */
  			if (!(stat & ATA_ERR) && !uptodate && thislen) {
  				ide_pio_bytes(drive, cmd, write, thislen);
  				uptodate = cmd->nleft ? 0 : 1;
  			}
  
  			if (!uptodate)
  				rq->rq_flags |= RQF_FAILED;
  			goto out_end;
  		case REQ_OP_SCSI_IN:
  		case REQ_OP_SCSI_OUT:
  			goto out_end;
  		}
  	}
  
  	rc = ide_check_ireason(drive, rq, len, ireason, write);
  	if (rc)
  		goto out_end;
  
  	cmd->last_xfer_len = 0;
  
  	ide_debug_log(IDE_DBG_PC, "data transfer, rq->cmd_type: 0x%x, "
  				  "ireason: 0x%x",
  				  rq->cmd_type, ireason);
  
  	/* transfer data */
  	while (thislen > 0) {
  		int blen = min_t(int, thislen, cmd->nleft);
  
  		if (cmd->nleft == 0)
  			break;
  
  		ide_pio_bytes(drive, cmd, write, blen);
  		cmd->last_xfer_len += blen;
  
  		thislen -= blen;
  		len -= blen;
  
  		if (sense && write == 0)
  			scsi_req(rq)->sense_len += blen;
  	}
  
  	/* pad, if necessary */
  	if (len > 0) {
  		if (blk_rq_is_passthrough(rq) || write == 0)
  			ide_pad_transfer(drive, write, len);
  		else {
  			printk(KERN_ERR PFX "%s: confused, missing data\n",
  				drive->name);
  			blk_dump_rq_flags(rq, "cdrom_newpc_intr");
  		}
  	}
  
  	switch (req_op(rq)) {
  	case REQ_OP_SCSI_IN:
  	case REQ_OP_SCSI_OUT:
  		timeout = rq->timeout;
  		break;
  	case REQ_OP_DRV_IN:
  	case REQ_OP_DRV_OUT:
  		expiry = ide_cd_expiry;
  		/*FALLTHRU*/
  	default:
  		timeout = ATAPI_WAIT_PC;
  		break;
  	}
  
  	hwif->expiry = expiry;
  	ide_set_handler(drive, cdrom_newpc_intr, timeout);
  	return ide_started;
  
  out_end:
  	if (blk_rq_is_scsi(rq) && rc == 0) {
  		scsi_req(rq)->resid_len = 0;
  		blk_end_request_all(rq, BLK_STS_OK);
  		hwif->rq = NULL;
  	} else {
  		if (sense && uptodate)
  			ide_cd_complete_failed_rq(drive, rq);
  
  		if (!blk_rq_is_passthrough(rq)) {
  			if (cmd->nleft == 0)
  				uptodate = 1;
  		} else {
  			if (uptodate <= 0 && scsi_req(rq)->result == 0)
  				scsi_req(rq)->result = -EIO;
  		}
  
  		if (uptodate == 0 && rq->bio)
  			if (ide_cd_error_cmd(drive, cmd))
  				return ide_stopped;
  
  		/* make sure it's fully ended */
  		if (blk_rq_is_passthrough(rq)) {
  			scsi_req(rq)->resid_len -= cmd->nbytes - cmd->nleft;
  			if (uptodate == 0 && (cmd->tf_flags & IDE_TFLAG_WRITE))
  				scsi_req(rq)->resid_len += cmd->last_xfer_len;
  		}
  
  		ide_complete_rq(drive, uptodate ? BLK_STS_OK : BLK_STS_IOERR, blk_rq_bytes(rq));
  
  		if (sense && rc == 2)
  			ide_error(drive, "request sense failure", stat);
  	}
  	return ide_stopped;
  }
  
  static ide_startstop_t cdrom_start_rw(ide_drive_t *drive, struct request *rq)
  {
  	struct cdrom_info *cd = drive->driver_data;
  	struct request_queue *q = drive->queue;
  	int write = rq_data_dir(rq) == WRITE;
  	unsigned short sectors_per_frame =
  		queue_logical_block_size(q) >> SECTOR_SHIFT;
  
  	ide_debug_log(IDE_DBG_RQ, "rq->cmd[0]: 0x%x, rq->cmd_flags: 0x%x, "
  				  "secs_per_frame: %u",
  				  rq->cmd[0], rq->cmd_flags, sectors_per_frame);
  
  	if (write) {
  		/* disk has become write protected */
  		if (get_disk_ro(cd->disk))
  			return ide_stopped;
  	} else {
  		/*
  		 * We may be retrying this request after an error.  Fix up any
  		 * weirdness which might be present in the request packet.
  		 */
  		q->prep_rq_fn(q, rq);
  	}
  
  	/* fs requests *must* be hardware frame aligned */
  	if ((blk_rq_sectors(rq) & (sectors_per_frame - 1)) ||
  	    (blk_rq_pos(rq) & (sectors_per_frame - 1)))
  		return ide_stopped;
  
  	/* use DMA, if possible */
  	drive->dma = !!(drive->dev_flags & IDE_DFLAG_USING_DMA);
  
  	if (write)
  		cd->devinfo.media_written = 1;
  
  	rq->timeout = ATAPI_WAIT_PC;
  
  	return ide_started;
  }
  
  static void cdrom_do_block_pc(ide_drive_t *drive, struct request *rq)
  {
  
  	ide_debug_log(IDE_DBG_PC, "rq->cmd[0]: 0x%x, rq->cmd_type: 0x%x",
  				  rq->cmd[0], rq->cmd_type);
  
  	if (blk_rq_is_scsi(rq))
  		rq->rq_flags |= RQF_QUIET;
  	else
  		rq->rq_flags &= ~RQF_FAILED;
  
  	drive->dma = 0;
  
  	/* sg request */
  	if (rq->bio) {
  		struct request_queue *q = drive->queue;
  		char *buf = bio_data(rq->bio);
  		unsigned int alignment;
  
  		drive->dma = !!(drive->dev_flags & IDE_DFLAG_USING_DMA);
  
  		/*
  		 * check if dma is safe
  		 *
  		 * NOTE! The "len" and "addr" checks should possibly have
  		 * separate masks.
  		 */
  		alignment = queue_dma_alignment(q) | q->dma_pad_mask;
  		if ((unsigned long)buf & alignment
  		    || blk_rq_bytes(rq) & q->dma_pad_mask
  		    || object_is_on_stack(buf))
  			drive->dma = 0;
  	}
  }
  
  static ide_startstop_t ide_cd_do_request(ide_drive_t *drive, struct request *rq,
  					sector_t block)
  {
  	struct ide_cmd cmd;
  	int uptodate = 0;
  	unsigned int nsectors;
  
  	ide_debug_log(IDE_DBG_RQ, "cmd: 0x%x, block: %llu",
  				  rq->cmd[0], (unsigned long long)block);
  
  	if (drive->debug_mask & IDE_DBG_RQ)
  		blk_dump_rq_flags(rq, "ide_cd_do_request");
  
  	switch (req_op(rq)) {
  	default:
  		if (cdrom_start_rw(drive, rq) == ide_stopped)
  			goto out_end;
  		break;
  	case REQ_OP_SCSI_IN:
  	case REQ_OP_SCSI_OUT:
  	handle_pc:
  		if (!rq->timeout)
  			rq->timeout = ATAPI_WAIT_PC;
  		cdrom_do_block_pc(drive, rq);
  		break;
  	case REQ_OP_DRV_IN:
  	case REQ_OP_DRV_OUT:
  		switch (ide_req(rq)->type) {
  		case ATA_PRIV_MISC:
  			/* right now this can only be a reset... */
  			uptodate = 1;
  			goto out_end;
  		case ATA_PRIV_SENSE:
  		case ATA_PRIV_PC:
  			goto handle_pc;
  		default:
  			BUG();
  		}
  	}
  
  	/* prepare sense request for this command */
  	ide_prep_sense(drive, rq);
  
  	memset(&cmd, 0, sizeof(cmd));
  
  	if (rq_data_dir(rq))
  		cmd.tf_flags |= IDE_TFLAG_WRITE;
  
  	cmd.rq = rq;
  
  	if (!blk_rq_is_passthrough(rq) || blk_rq_bytes(rq)) {
  		ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
  		ide_map_sg(drive, &cmd);
  	}
  
  	return ide_issue_pc(drive, &cmd);
  out_end:
  	nsectors = blk_rq_sectors(rq);
  
  	if (nsectors == 0)
  		nsectors = 1;
  
  	ide_complete_rq(drive, uptodate ? BLK_STS_OK : BLK_STS_IOERR, nsectors << 9);
  
  	return ide_stopped;
  }
  
  /*
   * Ioctl handling.
   *
   * Routines which queue packet commands take as a final argument a pointer to a
   * request_sense struct. If execution of the command results in an error with a
   * CHECK CONDITION status, this structure will be filled with the results of the
   * subsequent request sense command. The pointer can also be NULL, in which case
   * no sense information is returned.
   */
  static void msf_from_bcd(struct atapi_msf *msf)
  {
  	msf->minute = bcd2bin(msf->minute);
  	msf->second = bcd2bin(msf->second);
  	msf->frame  = bcd2bin(msf->frame);
  }
  
  int cdrom_check_status(ide_drive_t *drive, struct scsi_sense_hdr *sshdr)
  {
  	struct cdrom_info *info = drive->driver_data;
  	struct cdrom_device_info *cdi;
  	unsigned char cmd[BLK_MAX_CDB];
  
  	ide_debug_log(IDE_DBG_FUNC, "enter");
  
  	if (!info)
  		return -EIO;
  
  	cdi = &info->devinfo;
  
  	memset(cmd, 0, BLK_MAX_CDB);
  	cmd[0] = GPCMD_TEST_UNIT_READY;
  
  	/*
  	 * Sanyo 3 CD changer uses byte 7 of TEST_UNIT_READY to switch CDs
  	 * instead of supporting the LOAD_UNLOAD opcode.
  	 */
  	cmd[7] = cdi->sanyo_slot % 3;
  
  	return ide_cd_queue_pc(drive, cmd, 0, NULL, NULL, sshdr, 0, RQF_QUIET);
  }
  
  static int cdrom_read_capacity(ide_drive_t *drive, unsigned long *capacity,
  			       unsigned long *sectors_per_frame)
  {
  	struct {
  		__be32 lba;
  		__be32 blocklen;
  	} capbuf;
  
  	int stat;
  	unsigned char cmd[BLK_MAX_CDB];
  	unsigned len = sizeof(capbuf);
  	u32 blocklen;
  
  	ide_debug_log(IDE_DBG_FUNC, "enter");
  
  	memset(cmd, 0, BLK_MAX_CDB);
  	cmd[0] = GPCMD_READ_CDVD_CAPACITY;
  
  	stat = ide_cd_queue_pc(drive, cmd, 0, &capbuf, &len, NULL, 0,
  			       RQF_QUIET);
  	if (stat)
  		return stat;
  
  	/*
  	 * Sanity check the given block size, in so far as making
  	 * sure the sectors_per_frame we give to the caller won't
  	 * end up being bogus.
  	 */
  	blocklen = be32_to_cpu(capbuf.blocklen);
  	blocklen = (blocklen >> SECTOR_SHIFT) << SECTOR_SHIFT;
  	switch (blocklen) {
  	case 512:
  	case 1024:
  	case 2048:
  	case 4096:
  		break;
  	default:
  		printk_once(KERN_ERR PFX "%s: weird block size %u; "
  				"setting default block size to 2048\n",
  				drive->name, blocklen);
  		blocklen = 2048;
  		break;
  	}
  
  	*capacity = 1 + be32_to_cpu(capbuf.lba);
  	*sectors_per_frame = blocklen >> SECTOR_SHIFT;
  
  	ide_debug_log(IDE_DBG_PROBE, "cap: %lu, sectors_per_frame: %lu",
  				     *capacity, *sectors_per_frame);
  
  	return 0;
  }
  
  static int cdrom_read_tocentry(ide_drive_t *drive, int trackno, int msf_flag,
  				int format, char *buf, int buflen)
  {
  	unsigned char cmd[BLK_MAX_CDB];
  
  	ide_debug_log(IDE_DBG_FUNC, "enter");
  
  	memset(cmd, 0, BLK_MAX_CDB);
  
  	cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
  	cmd[6] = trackno;
  	cmd[7] = (buflen >> 8);
  	cmd[8] = (buflen & 0xff);
  	cmd[9] = (format << 6);
  
  	if (msf_flag)
  		cmd[1] = 2;
  
  	return ide_cd_queue_pc(drive, cmd, 0, buf, &buflen, NULL, 0, RQF_QUIET);
  }
  
  /* Try to read the entire TOC for the disk into our internal buffer. */
  int ide_cd_read_toc(ide_drive_t *drive)
  {
  	int stat, ntracks, i;
  	struct cdrom_info *info = drive->driver_data;
  	struct cdrom_device_info *cdi = &info->devinfo;
  	struct atapi_toc *toc = info->toc;
  	struct {
  		struct atapi_toc_header hdr;
  		struct atapi_toc_entry  ent;
  	} ms_tmp;
  	long last_written;
  	unsigned long sectors_per_frame = SECTORS_PER_FRAME;
  
  	ide_debug_log(IDE_DBG_FUNC, "enter");
  
  	if (toc == NULL) {
  		/* try to allocate space */
  		toc = kmalloc(sizeof(struct atapi_toc), GFP_KERNEL);
  		if (toc == NULL) {
  			printk(KERN_ERR PFX "%s: No cdrom TOC buffer!\n",
  					drive->name);
  			return -ENOMEM;
  		}
  		info->toc = toc;
  	}
  
  	/*
  	 * Check to see if the existing data is still valid. If it is,
  	 * just return.
  	 */
  	(void) cdrom_check_status(drive, NULL);
  
  	if (drive->atapi_flags & IDE_AFLAG_TOC_VALID)
  		return 0;
  
  	/* try to get the total cdrom capacity and sector size */
  	stat = cdrom_read_capacity(drive, &toc->capacity, &sectors_per_frame);
  	if (stat)
  		toc->capacity = 0x1fffff;
  
  	set_capacity(info->disk, toc->capacity * sectors_per_frame);
  	/* save a private copy of the TOC capacity for error handling */
  	drive->probed_capacity = toc->capacity * sectors_per_frame;
  
  	blk_queue_logical_block_size(drive->queue,
  				     sectors_per_frame << SECTOR_SHIFT);
  
  	/* first read just the header, so we know how long the TOC is */
  	stat = cdrom_read_tocentry(drive, 0, 1, 0, (char *) &toc->hdr,
  				    sizeof(struct atapi_toc_header));
  	if (stat)
  		return stat;
  
  	if (drive->atapi_flags & IDE_AFLAG_TOCTRACKS_AS_BCD) {
  		toc->hdr.first_track = bcd2bin(toc->hdr.first_track);
  		toc->hdr.last_track  = bcd2bin(toc->hdr.last_track);
  	}
  
  	ntracks = toc->hdr.last_track - toc->hdr.first_track + 1;
  	if (ntracks <= 0)
  		return -EIO;
  	if (ntracks > MAX_TRACKS)
  		ntracks = MAX_TRACKS;
  
  	/* now read the whole schmeer */
  	stat = cdrom_read_tocentry(drive, toc->hdr.first_track, 1, 0,
  				  (char *)&toc->hdr,
  				   sizeof(struct atapi_toc_header) +
  				   (ntracks + 1) *
  				   sizeof(struct atapi_toc_entry));
  
  	if (stat && toc->hdr.first_track > 1) {
  		/*
  		 * Cds with CDI tracks only don't have any TOC entries, despite
  		 * of this the returned values are
  		 * first_track == last_track = number of CDI tracks + 1,
  		 * so that this case is indistinguishable from the same layout
  		 * plus an additional audio track. If we get an error for the
  		 * regular case, we assume a CDI without additional audio
  		 * tracks. In this case the readable TOC is empty (CDI tracks
  		 * are not included) and only holds the Leadout entry.
  		 *
  		 * Heiko Eißfeldt.
  		 */
  		ntracks = 0;
  		stat = cdrom_read_tocentry(drive, CDROM_LEADOUT, 1, 0,
  					   (char *)&toc->hdr,
  					   sizeof(struct atapi_toc_header) +
  					   (ntracks + 1) *
  					   sizeof(struct atapi_toc_entry));
  		if (stat)
  			return stat;
  
  		if (drive->atapi_flags & IDE_AFLAG_TOCTRACKS_AS_BCD) {
  			toc->hdr.first_track = (u8)bin2bcd(CDROM_LEADOUT);
  			toc->hdr.last_track = (u8)bin2bcd(CDROM_LEADOUT);
  		} else {
  			toc->hdr.first_track = CDROM_LEADOUT;
  			toc->hdr.last_track = CDROM_LEADOUT;
  		}
  	}
  
  	if (stat)
  		return stat;
  
  	toc->hdr.toc_length = be16_to_cpu(toc->hdr.toc_length);
  
  	if (drive->atapi_flags & IDE_AFLAG_TOCTRACKS_AS_BCD) {
  		toc->hdr.first_track = bcd2bin(toc->hdr.first_track);
  		toc->hdr.last_track  = bcd2bin(toc->hdr.last_track);
  	}
  
  	for (i = 0; i <= ntracks; i++) {
  		if (drive->atapi_flags & IDE_AFLAG_TOCADDR_AS_BCD) {
  			if (drive->atapi_flags & IDE_AFLAG_TOCTRACKS_AS_BCD)
  				toc->ent[i].track = bcd2bin(toc->ent[i].track);
  			msf_from_bcd(&toc->ent[i].addr.msf);
  		}
  		toc->ent[i].addr.lba = msf_to_lba(toc->ent[i].addr.msf.minute,
  						  toc->ent[i].addr.msf.second,
  						  toc->ent[i].addr.msf.frame);
  	}
  
  	if (toc->hdr.first_track != CDROM_LEADOUT) {
  		/* read the multisession information */
  		stat = cdrom_read_tocentry(drive, 0, 0, 1, (char *)&ms_tmp,
  					   sizeof(ms_tmp));
  		if (stat)
  			return stat;
  
  		toc->last_session_lba = be32_to_cpu(ms_tmp.ent.addr.lba);
  	} else {
  		ms_tmp.hdr.last_track = CDROM_LEADOUT;
  		ms_tmp.hdr.first_track = ms_tmp.hdr.last_track;
  		toc->last_session_lba = msf_to_lba(0, 2, 0); /* 0m 2s 0f */
  	}
  
  	if (drive->atapi_flags & IDE_AFLAG_TOCADDR_AS_BCD) {
  		/* re-read multisession information using MSF format */
  		stat = cdrom_read_tocentry(drive, 0, 1, 1, (char *)&ms_tmp,
  					   sizeof(ms_tmp));
  		if (stat)
  			return stat;
  
  		msf_from_bcd(&ms_tmp.ent.addr.msf);
  		toc->last_session_lba = msf_to_lba(ms_tmp.ent.addr.msf.minute,
  						   ms_tmp.ent.addr.msf.second,
  						   ms_tmp.ent.addr.msf.frame);
  	}
  
  	toc->xa_flag = (ms_tmp.hdr.first_track != ms_tmp.hdr.last_track);
  
  	/* now try to get the total cdrom capacity */
  	stat = cdrom_get_last_written(cdi, &last_written);
  	if (!stat && (last_written > toc->capacity)) {
  		toc->capacity = last_written;
  		set_capacity(info->disk, toc->capacity * sectors_per_frame);
  		drive->probed_capacity = toc->capacity * sectors_per_frame;
  	}
  
  	/* Remember that we've read this stuff. */
  	drive->atapi_flags |= IDE_AFLAG_TOC_VALID;
  
  	return 0;
  }
  
  int ide_cdrom_get_capabilities(ide_drive_t *drive, u8 *buf)
  {
  	struct cdrom_info *info = drive->driver_data;
  	struct cdrom_device_info *cdi = &info->devinfo;
  	struct packet_command cgc;
  	int stat, attempts = 3, size = ATAPI_CAPABILITIES_PAGE_SIZE;
  
  	ide_debug_log(IDE_DBG_FUNC, "enter");
  
  	if ((drive->atapi_flags & IDE_AFLAG_FULL_CAPS_PAGE) == 0)
  		size -= ATAPI_CAPABILITIES_PAGE_PAD_SIZE;
  
  	init_cdrom_command(&cgc, buf, size, CGC_DATA_UNKNOWN);
  	do {
  		/* we seem to get stat=0x01,err=0x00 the first time (??) */
  		stat = cdrom_mode_sense(cdi, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
  		if (!stat)
  			break;
  	} while (--attempts);
  	return stat;
  }
  
  void ide_cdrom_update_speed(ide_drive_t *drive, u8 *buf)
  {
  	struct cdrom_info *cd = drive->driver_data;
  	u16 curspeed, maxspeed;
  
  	ide_debug_log(IDE_DBG_FUNC, "enter");
  
  	if (drive->atapi_flags & IDE_AFLAG_LE_SPEED_FIELDS) {
  		curspeed = le16_to_cpup((__le16 *)&buf[8 + 14]);
  		maxspeed = le16_to_cpup((__le16 *)&buf[8 + 8]);
  	} else {
  		curspeed = be16_to_cpup((__be16 *)&buf[8 + 14]);
  		maxspeed = be16_to_cpup((__be16 *)&buf[8 + 8]);
  	}
  
  	ide_debug_log(IDE_DBG_PROBE, "curspeed: %u, maxspeed: %u",
  				     curspeed, maxspeed);
  
  	cd->current_speed = DIV_ROUND_CLOSEST(curspeed, 176);
  	cd->max_speed = DIV_ROUND_CLOSEST(maxspeed, 176);
  }
  
  #define IDE_CD_CAPABILITIES \
  	(CDC_CLOSE_TRAY | CDC_OPEN_TRAY | CDC_LOCK | CDC_SELECT_SPEED | \
  	 CDC_SELECT_DISC | CDC_MULTI_SESSION | CDC_MCN | CDC_MEDIA_CHANGED | \
  	 CDC_PLAY_AUDIO | CDC_RESET | CDC_DRIVE_STATUS | CDC_CD_R | \
  	 CDC_CD_RW | CDC_DVD | CDC_DVD_R | CDC_DVD_RAM | CDC_GENERIC_PACKET | \
  	 CDC_MO_DRIVE | CDC_MRW | CDC_MRW_W | CDC_RAM)
  
  static const struct cdrom_device_ops ide_cdrom_dops = {
  	.open			= ide_cdrom_open_real,
  	.release		= ide_cdrom_release_real,
  	.drive_status		= ide_cdrom_drive_status,
  	.check_events		= ide_cdrom_check_events_real,
  	.tray_move		= ide_cdrom_tray_move,
  	.lock_door		= ide_cdrom_lock_door,
  	.select_speed		= ide_cdrom_select_speed,
  	.get_last_session	= ide_cdrom_get_last_session,
  	.get_mcn		= ide_cdrom_get_mcn,
  	.reset			= ide_cdrom_reset,
  	.audio_ioctl		= ide_cdrom_audio_ioctl,
  	.capability		= IDE_CD_CAPABILITIES,
  	.generic_packet		= ide_cdrom_packet,
  };
  
  static int ide_cdrom_register(ide_drive_t *drive, int nslots)
  {
  	struct cdrom_info *info = drive->driver_data;
  	struct cdrom_device_info *devinfo = &info->devinfo;
  
  	ide_debug_log(IDE_DBG_PROBE, "nslots: %d", nslots);
  
  	devinfo->ops = &ide_cdrom_dops;
  	devinfo->speed = info->current_speed;
  	devinfo->capacity = nslots;
  	devinfo->handle = drive;
  	strcpy(devinfo->name, drive->name);
  
  	if (drive->atapi_flags & IDE_AFLAG_NO_SPEED_SELECT)
  		devinfo->mask |= CDC_SELECT_SPEED;
  
  	devinfo->disk = info->disk;
  	return register_cdrom(devinfo);
  }
  
  static int ide_cdrom_probe_capabilities(ide_drive_t *drive)
  {
  	struct cdrom_info *cd = drive->driver_data;
  	struct cdrom_device_info *cdi = &cd->devinfo;
  	u8 buf[ATAPI_CAPABILITIES_PAGE_SIZE];
  	mechtype_t mechtype;
  	int nslots = 1;
  
  	ide_debug_log(IDE_DBG_PROBE, "media: 0x%x, atapi_flags: 0x%lx",
  				     drive->media, drive->atapi_flags);
  
  	cdi->mask = (CDC_CD_R | CDC_CD_RW | CDC_DVD | CDC_DVD_R |
  		     CDC_DVD_RAM | CDC_SELECT_DISC | CDC_PLAY_AUDIO |
  		     CDC_MO_DRIVE | CDC_RAM);
  
  	if (drive->media == ide_optical) {
  		cdi->mask &= ~(CDC_MO_DRIVE | CDC_RAM);
  		printk(KERN_ERR PFX "%s: ATAPI magneto-optical drive\n",
  				drive->name);
  		return nslots;
  	}
  
  	if (drive->atapi_flags & IDE_AFLAG_PRE_ATAPI12) {
  		drive->atapi_flags &= ~IDE_AFLAG_NO_EJECT;
  		cdi->mask &= ~CDC_PLAY_AUDIO;
  		return nslots;
  	}
  
  	/*
  	 * We have to cheat a little here. the packet will eventually be queued
  	 * with ide_cdrom_packet(), which extracts the drive from cdi->handle.
  	 * Since this device hasn't been registered with the Uniform layer yet,
  	 * it can't do this. Same goes for cdi->ops.
  	 */
  	cdi->handle = drive;
  	cdi->ops = &ide_cdrom_dops;
  
  	if (ide_cdrom_get_capabilities(drive, buf))
  		return 0;
  
  	if ((buf[8 + 6] & 0x01) == 0)
  		drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
  	if (buf[8 + 6] & 0x08)
  		drive->atapi_flags &= ~IDE_AFLAG_NO_EJECT;
  	if (buf[8 + 3] & 0x01)
  		cdi->mask &= ~CDC_CD_R;
  	if (buf[8 + 3] & 0x02)
  		cdi->mask &= ~(CDC_CD_RW | CDC_RAM);
  	if (buf[8 + 2] & 0x38)
  		cdi->mask &= ~CDC_DVD;
  	if (buf[8 + 3] & 0x20)
  		cdi->mask &= ~(CDC_DVD_RAM | CDC_RAM);
  	if (buf[8 + 3] & 0x10)
  		cdi->mask &= ~CDC_DVD_R;
  	if ((buf[8 + 4] & 0x01) || (drive->atapi_flags & IDE_AFLAG_PLAY_AUDIO_OK))
  		cdi->mask &= ~CDC_PLAY_AUDIO;
  
  	mechtype = buf[8 + 6] >> 5;
  	if (mechtype == mechtype_caddy ||
  	    mechtype == mechtype_popup ||
  	    (drive->atapi_flags & IDE_AFLAG_NO_AUTOCLOSE))
  		cdi->mask |= CDC_CLOSE_TRAY;
  
  	if (cdi->sanyo_slot > 0) {
  		cdi->mask &= ~CDC_SELECT_DISC;
  		nslots = 3;
  	} else if (mechtype == mechtype_individual_changer ||
  		   mechtype == mechtype_cartridge_changer) {
  		nslots = cdrom_number_of_slots(cdi);
  		if (nslots > 1)
  			cdi->mask &= ~CDC_SELECT_DISC;
  	}
  
  	ide_cdrom_update_speed(drive, buf);
  
  	printk(KERN_INFO PFX "%s: ATAPI", drive->name);
  
  	/* don't print speed if the drive reported 0 */
  	if (cd->max_speed)
  		printk(KERN_CONT " %dX", cd->max_speed);
  
  	printk(KERN_CONT " %s", (cdi->mask & CDC_DVD) ? "CD-ROM" : "DVD-ROM");
  
  	if ((cdi->mask & CDC_DVD_R) == 0 || (cdi->mask & CDC_DVD_RAM) == 0)
  		printk(KERN_CONT " DVD%s%s",
  				 (cdi->mask & CDC_DVD_R) ? "" : "-R",
  				 (cdi->mask & CDC_DVD_RAM) ? "" : "/RAM");
  
  	if ((cdi->mask & CDC_CD_R) == 0 || (cdi->mask & CDC_CD_RW) == 0)
  		printk(KERN_CONT " CD%s%s",
  				 (cdi->mask & CDC_CD_R) ? "" : "-R",
  				 (cdi->mask & CDC_CD_RW) ? "" : "/RW");
  
  	if ((cdi->mask & CDC_SELECT_DISC) == 0)
  		printk(KERN_CONT " changer w/%d slots", nslots);
  	else
  		printk(KERN_CONT " drive");
  
  	printk(KERN_CONT ", %dkB Cache\n",
  			 be16_to_cpup((__be16 *)&buf[8 + 12]));
  
  	return nslots;
  }
  
  /* 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);
  
  	q->initialize_rq_fn(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(struct request_queue *q, struct request *rq)
  {
  	if (!blk_rq_is_passthrough(rq))
  		return ide_cdrom_prep_fs(q, rq);
  	else if (blk_rq_is_scsi(rq))
  		return ide_cdrom_prep_pc(rq);
  
  	return 0;
  }
  
  struct cd_list_entry {
  	const char	*id_model;
  	const char	*id_firmware;
  	unsigned int	cd_flags;
  };
  
  #ifdef CONFIG_IDE_PROC_FS
  static sector_t ide_cdrom_capacity(ide_drive_t *drive)
  {
  	unsigned long capacity, sectors_per_frame;
  
  	if (cdrom_read_capacity(drive, &capacity, &sectors_per_frame))
  		return 0;
  
  	return capacity * sectors_per_frame;
  }
  
  static int idecd_capacity_proc_show(struct seq_file *m, void *v)
  {
  	ide_drive_t *drive = m->private;
  
  	seq_printf(m, "%llu\n", (long long)ide_cdrom_capacity(drive));
  	return 0;
  }
  
  static ide_proc_entry_t idecd_proc[] = {
  	{ "capacity", S_IFREG|S_IRUGO, idecd_capacity_proc_show },
  	{}
  };
  
  static ide_proc_entry_t *ide_cd_proc_entries(ide_drive_t *drive)
  {
  	return idecd_proc;
  }
  
  static const struct ide_proc_devset *ide_cd_proc_devsets(ide_drive_t *drive)
  {
  	return NULL;
  }
  #endif
  
  static const struct cd_list_entry ide_cd_quirks_list[] = {
  	/* SCR-3231 doesn't support the SET_CD_SPEED command. */
  	{ "SAMSUNG CD-ROM SCR-3231", NULL,   IDE_AFLAG_NO_SPEED_SELECT	     },
  	/* Old NEC260 (not R) was released before ATAPI 1.2 spec. */
  	{ "NEC CD-ROM DRIVE:260",    "1.01", IDE_AFLAG_TOCADDR_AS_BCD |
  					     IDE_AFLAG_PRE_ATAPI12,	     },
  	/* Vertos 300, some versions of this drive like to talk BCD. */
  	{ "V003S0DS",		     NULL,   IDE_AFLAG_VERTOS_300_SSD,	     },
  	/* Vertos 600 ESD. */
  	{ "V006E0DS",		     NULL,   IDE_AFLAG_VERTOS_600_ESD,	     },
  	/*
  	 * Sanyo 3 CD changer uses a non-standard command for CD changing
  	 * (by default standard ATAPI support for CD changers is used).
  	 */
  	{ "CD-ROM CDR-C3 G",	     NULL,   IDE_AFLAG_SANYO_3CD	     },
  	{ "CD-ROM CDR-C3G",	     NULL,   IDE_AFLAG_SANYO_3CD	     },
  	{ "CD-ROM CDR_C36",	     NULL,   IDE_AFLAG_SANYO_3CD	     },
  	/* Stingray 8X CD-ROM. */
  	{ "STINGRAY 8422 IDE 8X CD-ROM 7-27-95", NULL, IDE_AFLAG_PRE_ATAPI12 },
  	/*
  	 * ACER 50X CD-ROM and WPI 32X CD-ROM require the full spec length
  	 * mode sense page capabilities size, but older drives break.
  	 */
  	{ "ATAPI CD ROM DRIVE 50X MAX",	NULL,	IDE_AFLAG_FULL_CAPS_PAGE     },
  	{ "WPI CDS-32X",		NULL,	IDE_AFLAG_FULL_CAPS_PAGE     },
  	/* ACER/AOpen 24X CD-ROM has the speed fields byte-swapped. */
  	{ "",			     "241N", IDE_AFLAG_LE_SPEED_FIELDS       },
  	/*
  	 * Some drives used by Apple don't advertise audio play
  	 * but they do support reading TOC & audio datas.
  	 */
  	{ "MATSHITADVD-ROM SR-8187", NULL,   IDE_AFLAG_PLAY_AUDIO_OK	     },
  	{ "MATSHITADVD-ROM SR-8186", NULL,   IDE_AFLAG_PLAY_AUDIO_OK	     },
  	{ "MATSHITADVD-ROM SR-8176", NULL,   IDE_AFLAG_PLAY_AUDIO_OK	     },
  	{ "MATSHITADVD-ROM SR-8174", NULL,   IDE_AFLAG_PLAY_AUDIO_OK	     },
  	{ "Optiarc DVD RW AD-5200A", NULL,   IDE_AFLAG_PLAY_AUDIO_OK	     },
  	{ "Optiarc DVD RW AD-7200A", NULL,   IDE_AFLAG_PLAY_AUDIO_OK	     },
  	{ "Optiarc DVD RW AD-7543A", NULL,   IDE_AFLAG_NO_AUTOCLOSE	     },
  	{ "TEAC CD-ROM CD-224E",     NULL,   IDE_AFLAG_NO_AUTOCLOSE	     },
  	{ NULL, NULL, 0 }
  };
  
  static unsigned int ide_cd_flags(u16 *id)
  {
  	const struct cd_list_entry *cle = ide_cd_quirks_list;
  
  	while (cle->id_model) {
  		if (strcmp(cle->id_model, (char *)&id[ATA_ID_PROD]) == 0 &&
  		    (cle->id_firmware == NULL ||
  		     strstr((char *)&id[ATA_ID_FW_REV], cle->id_firmware)))
  			return cle->cd_flags;
  		cle++;
  	}
  
  	return 0;
  }
  
  static int ide_cdrom_setup(ide_drive_t *drive)
  {
  	struct cdrom_info *cd = drive->driver_data;
  	struct cdrom_device_info *cdi = &cd->devinfo;
  	struct request_queue *q = drive->queue;
  	u16 *id = drive->id;
  	char *fw_rev = (char *)&id[ATA_ID_FW_REV];
  	int nslots;
  
  	ide_debug_log(IDE_DBG_PROBE, "enter");
  
  	blk_queue_prep_rq(q, ide_cdrom_prep_fn);
  	blk_queue_dma_alignment(q, 31);
  	blk_queue_update_dma_pad(q, 15);
  
  	drive->dev_flags |= IDE_DFLAG_MEDIA_CHANGED;
  	drive->atapi_flags = IDE_AFLAG_NO_EJECT | ide_cd_flags(id);
  
  	if ((drive->atapi_flags & IDE_AFLAG_VERTOS_300_SSD) &&
  	    fw_rev[4] == '1' && fw_rev[6] <= '2')
  		drive->atapi_flags |= (IDE_AFLAG_TOCTRACKS_AS_BCD |
  				     IDE_AFLAG_TOCADDR_AS_BCD);
  	else if ((drive->atapi_flags & IDE_AFLAG_VERTOS_600_ESD) &&
  		 fw_rev[4] == '1' && fw_rev[6] <= '2')
  		drive->atapi_flags |= IDE_AFLAG_TOCTRACKS_AS_BCD;
  	else if (drive->atapi_flags & IDE_AFLAG_SANYO_3CD)
  		/* 3 => use CD in slot 0 */
  		cdi->sanyo_slot = 3;
  
  	nslots = ide_cdrom_probe_capabilities(drive);
  
  	blk_queue_logical_block_size(q, CD_FRAMESIZE);
  
  	if (ide_cdrom_register(drive, nslots)) {
  		printk(KERN_ERR PFX "%s: %s failed to register device with the"
  				" cdrom driver.\n", drive->name, __func__);
  		cd->devinfo.handle = NULL;
  		return 1;
  	}
  
  	ide_proc_register_driver(drive, cd->driver);
  	return 0;
  }
  
  static void ide_cd_remove(ide_drive_t *drive)
  {
  	struct cdrom_info *info = drive->driver_data;
  
  	ide_debug_log(IDE_DBG_FUNC, "enter");
  
  	ide_proc_unregister_driver(drive, info->driver);
  	device_del(&info->dev);
  	del_gendisk(info->disk);
  
  	mutex_lock(&idecd_ref_mutex);
  	put_device(&info->dev);
  	mutex_unlock(&idecd_ref_mutex);
  }
  
  static void ide_cd_release(struct device *dev)
  {
  	struct cdrom_info *info = to_ide_drv(dev, cdrom_info);
  	struct cdrom_device_info *devinfo = &info->devinfo;
  	ide_drive_t *drive = info->drive;
  	struct gendisk *g = info->disk;
  
  	ide_debug_log(IDE_DBG_FUNC, "enter");
  
  	kfree(info->toc);
  	if (devinfo->handle == drive)
  		unregister_cdrom(devinfo);
  	drive->driver_data = NULL;
  	blk_queue_prep_rq(drive->queue, NULL);
  	g->private_data = NULL;
  	put_disk(g);
  	kfree(info);
  }
  
  static int ide_cd_probe(ide_drive_t *);
  
  static struct ide_driver ide_cdrom_driver = {
  	.gen_driver = {
  		.owner		= THIS_MODULE,
  		.name		= "ide-cdrom",
  		.bus		= &ide_bus_type,
  	},
  	.probe			= ide_cd_probe,
  	.remove			= ide_cd_remove,
  	.version		= IDECD_VERSION,
  	.do_request		= ide_cd_do_request,
  #ifdef CONFIG_IDE_PROC_FS
  	.proc_entries		= ide_cd_proc_entries,
  	.proc_devsets		= ide_cd_proc_devsets,
  #endif
  };
  
  static int idecd_open(struct block_device *bdev, fmode_t mode)
  {
  	struct cdrom_info *info;
  	int rc = -ENXIO;
  
  	check_disk_change(bdev);
  
  	mutex_lock(&ide_cd_mutex);
  	info = ide_cd_get(bdev->bd_disk);
  	if (!info)
  		goto out;
  
  	rc = cdrom_open(&info->devinfo, bdev, mode);
  	if (rc < 0)
  		ide_cd_put(info);
  out:
  	mutex_unlock(&ide_cd_mutex);
  	return rc;
  }
  
  static void idecd_release(struct gendisk *disk, fmode_t mode)
  {
  	struct cdrom_info *info = ide_drv_g(disk, cdrom_info);
  
  	mutex_lock(&ide_cd_mutex);
  	cdrom_release(&info->devinfo, mode);
  
  	ide_cd_put(info);
  	mutex_unlock(&ide_cd_mutex);
  }
  
  static int idecd_set_spindown(struct cdrom_device_info *cdi, unsigned long arg)
  {
  	struct packet_command cgc;
  	char buffer[16];
  	int stat;
  	char spindown;
  
  	if (copy_from_user(&spindown, (void __user *)arg, sizeof(char)))
  		return -EFAULT;
  
  	init_cdrom_command(&cgc, buffer, sizeof(buffer), CGC_DATA_UNKNOWN);
  
  	stat = cdrom_mode_sense(cdi, &cgc, GPMODE_CDROM_PAGE, 0);
  	if (stat)
  		return stat;
  
  	buffer[11] = (buffer[11] & 0xf0) | (spindown & 0x0f);
  	return cdrom_mode_select(cdi, &cgc);
  }
  
  static int idecd_get_spindown(struct cdrom_device_info *cdi, unsigned long arg)
  {
  	struct packet_command cgc;
  	char buffer[16];
  	int stat;
  	char spindown;
  
  	init_cdrom_command(&cgc, buffer, sizeof(buffer), CGC_DATA_UNKNOWN);
  
  	stat = cdrom_mode_sense(cdi, &cgc, GPMODE_CDROM_PAGE, 0);
  	if (stat)
  		return stat;
  
  	spindown = buffer[11] & 0x0f;
  	if (copy_to_user((void __user *)arg, &spindown, sizeof(char)))
  		return -EFAULT;
  	return 0;
  }
  
  static int idecd_locked_ioctl(struct block_device *bdev, fmode_t mode,
  			unsigned int cmd, unsigned long arg)
  {
  	struct cdrom_info *info = ide_drv_g(bdev->bd_disk, cdrom_info);
  	int err;
  
  	switch (cmd) {
  	case CDROMSETSPINDOWN:
  		return idecd_set_spindown(&info->devinfo, arg);
  	case CDROMGETSPINDOWN:
  		return idecd_get_spindown(&info->devinfo, arg);
  	default:
  		break;
  	}
  
  	err = generic_ide_ioctl(info->drive, bdev, cmd, arg);
  	if (err == -EINVAL)
  		err = cdrom_ioctl(&info->devinfo, bdev, mode, cmd, arg);
  
  	return err;
  }
  
  static int idecd_ioctl(struct block_device *bdev, fmode_t mode,
  			     unsigned int cmd, unsigned long arg)
  {
  	int ret;
  
  	mutex_lock(&ide_cd_mutex);
  	ret = idecd_locked_ioctl(bdev, mode, cmd, arg);
  	mutex_unlock(&ide_cd_mutex);
  
  	return ret;
  }
  
  
  static unsigned int idecd_check_events(struct gendisk *disk,
  				       unsigned int clearing)
  {
  	struct cdrom_info *info = ide_drv_g(disk, cdrom_info);
  	return cdrom_check_events(&info->devinfo, clearing);
  }
  
  static int idecd_revalidate_disk(struct gendisk *disk)
  {
  	struct cdrom_info *info = ide_drv_g(disk, cdrom_info);
  
  	ide_cd_read_toc(info->drive);
  
  	return  0;
  }
  
  static const struct block_device_operations idecd_ops = {
  	.owner			= THIS_MODULE,
  	.open			= idecd_open,
  	.release		= idecd_release,
  	.ioctl			= idecd_ioctl,
  	.check_events		= idecd_check_events,
  	.revalidate_disk	= idecd_revalidate_disk
  };
  
  /* module options */
  static unsigned long debug_mask;
  module_param(debug_mask, ulong, 0644);
  
  MODULE_DESCRIPTION("ATAPI CD-ROM Driver");
  
  static int ide_cd_probe(ide_drive_t *drive)
  {
  	struct cdrom_info *info;
  	struct gendisk *g;
  
  	ide_debug_log(IDE_DBG_PROBE, "driver_req: %s, media: 0x%x",
  				     drive->driver_req, drive->media);
  
  	if (!strstr("ide-cdrom", drive->driver_req))
  		goto failed;
  
  	if (drive->media != ide_cdrom && drive->media != ide_optical)
  		goto failed;
  
  	drive->debug_mask = debug_mask;
  	drive->irq_handler = cdrom_newpc_intr;
  
  	info = kzalloc(sizeof(struct cdrom_info), GFP_KERNEL);
  	if (info == NULL) {
  		printk(KERN_ERR PFX "%s: Can't allocate a cdrom structure\n",
  				drive->name);
  		goto failed;
  	}
  
  	g = alloc_disk(1 << PARTN_BITS);
  	if (!g)
  		goto out_free_cd;
  
  	ide_init_disk(g, drive);
  
  	info->dev.parent = &drive->gendev;
  	info->dev.release = ide_cd_release;
  	dev_set_name(&info->dev, "%s", dev_name(&drive->gendev));
  
  	if (device_register(&info->dev))
  		goto out_free_disk;
  
  	info->drive = drive;
  	info->driver = &ide_cdrom_driver;
  	info->disk = g;
  
  	g->private_data = &info->driver;
  
  	drive->driver_data = info;
  
  	g->minors = 1;
  	g->flags = GENHD_FL_CD | GENHD_FL_REMOVABLE;
  	if (ide_cdrom_setup(drive)) {
  		put_device(&info->dev);
  		goto failed;
  	}
  
  	ide_cd_read_toc(drive);
  	g->fops = &idecd_ops;
  	g->flags |= GENHD_FL_REMOVABLE | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
  	device_add_disk(&drive->gendev, g);
  	return 0;
  
  out_free_disk:
  	put_disk(g);
  out_free_cd:
  	kfree(info);
  failed:
  	return -ENODEV;
  }
  
  static void __exit ide_cdrom_exit(void)
  {
  	driver_unregister(&ide_cdrom_driver.gen_driver);
  }
  
  static int __init ide_cdrom_init(void)
  {
  	printk(KERN_INFO DRV_NAME " driver " IDECD_VERSION "\n");
  	return driver_register(&ide_cdrom_driver.gen_driver);
  }
  
  MODULE_ALIAS("ide:*m-cdrom*");
  MODULE_ALIAS("ide-cd");
  module_init(ide_cdrom_init);
  module_exit(ide_cdrom_exit);
  MODULE_LICENSE("GPL");
  