ide: destroy DMA mappings after ending DMA (v2)

[safe/jmp/linux-2.6] / drivers / ide / ide-cd.c

/*
 * 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/delay.h>
#include <linux/timer.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/irq.h>
#include <linux/io.h>
#include <asm/byteorder.h>
#include <linux/uaccess.h>
#include <asm/unaligned.h>

#include "ide-cd.h"

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)
{
        int log = 0;

        ide_debug_log(IDE_DBG_SENSE, "sense_key: 0x%x", sense->sense_key);

        if (!sense || !rq || (rq->cmd_flags & REQ_QUIET))
                return 0;

        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 (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)
{
        unsigned long sector;
        unsigned long bio_sectors;
        struct cdrom_info *info = drive->driver_data;

        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, sense))
                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 && 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_fs_request(failed_command))
                                break;
                        sector = (sense->information[0] << 24) |
                                 (sense->information[1] << 16) |
                                 (sense->information[2] <<  8) |
                                 (sense->information[3]);

                        if (drive->queue->hardsect_size == 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 cdrom_queue_request_sense(ide_drive_t *drive, void *sense,
                                      struct request *failed_command)
{
        struct cdrom_info *info         = drive->driver_data;
        struct request *rq              = &drive->request_sense_rq;

        ide_debug_log(IDE_DBG_SENSE, "enter");

        if (sense == NULL)
                sense = &info->sense_data;

        /* stuff the sense request in front of our current request */
        blk_rq_init(NULL, rq);
        rq->cmd_type = REQ_TYPE_ATA_PC;
        rq->rq_disk = info->disk;

        rq->data = sense;
        rq->cmd[0] = GPCMD_REQUEST_SENSE;
        rq->cmd[4] = 18;
        rq->data_len = 18;

        rq->cmd_type = REQ_TYPE_SENSE;
        rq->cmd_flags |= REQ_PREEMPT;

        /* NOTE! Save the failed command in "rq->buffer" */
        rq->buffer = (void *) failed_command;

        if (failed_command)
                ide_debug_log(IDE_DBG_SENSE, "failed_cmd: 0x%x",
                                             failed_command->cmd[0]);

        drive->hwif->rq = NULL;

        elv_add_request(drive->queue, rq, ELEVATOR_INSERT_FRONT, 0);
}

static void ide_cd_complete_failed_rq(ide_drive_t *drive, struct request *rq)
{
        /*
         * For REQ_TYPE_SENSE, "rq->buffer" points to the original
         * failed request
         */
        struct request *failed = (struct request *)rq->buffer;
        struct cdrom_info *info = drive->driver_data;
        void *sense = &info->sense_data;

        if (failed) {
                if (failed->sense) {
                        sense = failed->sense;
                        failed->sense_len = rq->sense_len;
                }
                cdrom_analyze_sense_data(drive, failed, sense);

                if (ide_end_rq(drive, failed, -EIO, blk_rq_bytes(failed)))
                        BUG();
        } else
                cdrom_analyze_sense_data(drive, NULL, sense);
}

/*
 * 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, int good_stat, int *stat_ret)
{
        ide_hwif_t *hwif = drive->hwif;
        struct request *rq = hwif->rq;
        int stat, err, sense_key;

        /* check for errors */
        stat = hwif->tp_ops->read_status(hwif);

        if (stat_ret)
                *stat_ret = stat;

        if (OK_STAT(stat, good_stat, BAD_R_STAT))
                return 0;

        /* get the IDE error register */
        err = ide_read_error(drive);
        sense_key = err >> 4;

        ide_debug_log(IDE_DBG_RQ, "stat: 0x%x, good_stat: 0x%x, cmd[0]: 0x%x, "
                                  "rq->cmd_type: 0x%x, err: 0x%x",
                                  stat, good_stat, rq->cmd[0], rq->cmd_type,
                                  err);

        if (blk_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->cmd_flags |= REQ_FAILED;
                return 2;
        } else if (blk_pc_request(rq) || rq->cmd_type == REQ_TYPE_ATA_PC) {
                /* All other functions, except for READ. */

                /*
                 * if we have an error, pass back CHECK_CONDITION as the
                 * scsi status byte
                 */
                if (blk_pc_request(rq) && !rq->errors)
                        rq->errors = SAM_STAT_CHECK_CONDITION;

                /* check for tray open */
                if (sense_key == NOT_READY) {
                        cdrom_saw_media_change(drive);
                } else if (sense_key == UNIT_ATTENTION) {
                        /* check for media change */
                        cdrom_saw_media_change(drive);
                        return 0;
                } else if (sense_key == ILLEGAL_REQUEST &&
                           rq->cmd[0] == GPCMD_START_STOP_UNIT) {
                        /*
                         * 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!
                         */
                } else if (!(rq->cmd_flags & REQ_QUIET)) {
                        /* otherwise, print an error */
                        ide_dump_status(drive, "packet command error", stat);
                }

                rq->cmd_flags |= REQ_FAILED;

                /*
                 * instead of playing games with moving completions around,
                 * remove failed request completely and end it when the
                 * request sense has completed
                 */
                goto end_request;

        } else if (blk_fs_request(rq)) {
                int do_end_request = 0;

                /* handle errors from READ and WRITE requests */

                if (blk_noretry_request(rq))
                        do_end_request = 1;

                if (sense_key == NOT_READY) {
                        /* tray open */
                        if (rq_data_dir(rq) == READ) {
                                cdrom_saw_media_change(drive);

                                /* fail the request */
                                printk(KERN_ERR PFX "%s: tray open\n",
                                                drive->name);
                                do_end_request = 1;
                        } else {
                                struct cdrom_info *info = drive->driver_data;

                                /*
                                 * Allow the drive 5 seconds to recover, some
                                 * devices will return this error while flushing
                                 * data from cache.
                                 */
                                if (!rq->errors)
                                        info->write_timeout = jiffies +
                                                        ATAPI_WAIT_WRITE_BUSY;
                                rq->errors = 1;
                                if (time_after(jiffies, info->write_timeout))
                                        do_end_request = 1;
                                else {
                                        struct request_queue *q = drive->queue;
                                        unsigned long flags;

                                        /*
                                         * take a breather relying on the unplug
                                         * timer to kick us again
                                         */
                                        spin_lock_irqsave(q->queue_lock, flags);
                                        blk_plug_device(q);
                                        spin_unlock_irqrestore(q->queue_lock, flags);

                                        return 1;
                                }
                        }
                } else if (sense_key == UNIT_ATTENTION) {
                        /* media change */
                        cdrom_saw_media_change(drive);

                        /*
                         * Arrange to retry the request but be sure to give up
                         * if we've retried too many times.
                         */
                        if (++rq->errors > ERROR_MAX)
                                do_end_request = 1;
                } else if (sense_key == ILLEGAL_REQUEST ||
                           sense_key == DATA_PROTECT) {
                        /*
                         * No point in retrying after an illegal request or data
                         * protect error.
                         */
                        ide_dump_status(drive, "command error", stat);
                        do_end_request = 1;
                } else if (sense_key == MEDIUM_ERROR) {
                        /*
                         * No point in re-trying a zillion times on a bad
                         * sector. If we got here the error is not correctable.
                         */
                        ide_dump_status(drive, "media error (bad sector)",
                                        stat);
                        do_end_request = 1;
                } else if (sense_key == BLANK_CHECK) {
                        /* disk appears blank ?? */
                        ide_dump_status(drive, "media error (blank)", stat);
                        do_end_request = 1;
                } else if ((err & ~ATA_ABORTED) != 0) {
                        /* go to the default handler for other errors */
                        ide_error(drive, "cdrom_decode_status", stat);
                        return 1;
                } else if ((++rq->errors > ERROR_MAX)) {
                        /* we've racked up too many retries, abort */
                        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)
                        cdrom_queue_request_sense(drive, NULL, NULL);
                return 1;
        } else {
                blk_dump_rq_flags(rq, PFX "bad rq");
                return 2;
        }

end_request:
        if (stat & ATA_ERR) {
                struct request_queue *q = drive->queue;
                unsigned long flags;

                spin_lock_irqsave(q->queue_lock, flags);
                blkdev_dequeue_request(rq);
                spin_unlock_irqrestore(q->queue_lock, flags);

                hwif->rq = NULL;

                cdrom_queue_request_sense(drive, rq->sense, rq);
                return 1;
        } else
                return 2;
}

/*
 * Check the contents of the interrupt reason register from the cdrom
 * and attempt to recover if there are problems.  Returns  0 if everything's
 * ok; nonzero if the request has been terminated.
 */
static int ide_cd_check_ireason(ide_drive_t *drive, struct request *rq,
                                int len, int ireason, int rw)
{
        ide_hwif_t *hwif = drive->hwif;

        ide_debug_log(IDE_DBG_FUNC, "ireason: 0x%x, rw: 0x%x", ireason, rw);

        /*
         * ireason == 0: the drive wants to receive data from us
         * ireason == 2: the drive is expecting to transfer data to us
         */
        if (ireason == (!rw << 1))
                return 0;
        else if (ireason == (rw << 1)) {

                /* whoops... */
                printk(KERN_ERR PFX "%s: %s: wrong transfer direction!\n",
                                drive->name, __func__);

                ide_pad_transfer(drive, rw, len);
        } else  if (rw == 0 && ireason == 1) {
                /*
                 * Some drives (ASUS) seem to tell us that status info is
                 * available.  Just get it and ignore.
                 */
                (void)hwif->tp_ops->read_status(hwif);
                return 0;
        } else {
                /* drive wants a command packet, or invalid ireason... */
                printk(KERN_ERR PFX "%s: %s: bad interrupt reason 0x%02x\n",
                                drive->name, __func__, ireason);
        }

        if (rq->cmd_type == REQ_TYPE_ATA_PC)
                rq->cmd_flags |= REQ_FAILED;

        return -1;
}

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 (rq->cmd[0] == GPCMD_REQUEST_SENSE &&
            cmd->nleft > 0 && cmd->nleft <= 5) {
                unsigned int ofs = cmd->nbytes - cmd->nleft;

                while (cmd->nleft > 0) {
                        *((u8 *)rq->data + ofs++) = 0;
                        cmd->nleft--;
                }
        }
}

int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd,
                    int write, void *buffer, unsigned *bufflen,
                    struct request_sense *sense, int timeout,
                    unsigned int cmd_flags)
{
        struct cdrom_info *info = drive->driver_data;
        struct request_sense local_sense;
        int retries = 10;
        unsigned int flags = 0;

        if (!sense)
                sense = &local_sense;

        ide_debug_log(IDE_DBG_PC, "cmd[0]: 0x%x, write: 0x%x, timeout: %d, "
                                  "cmd_flags: 0x%x",
                                  cmd[0], write, timeout, cmd_flags);

        /* start of retry loop */
        do {
                struct request *rq;
                int error;

                rq = blk_get_request(drive->queue, write, __GFP_WAIT);

                memcpy(rq->cmd, cmd, BLK_MAX_CDB);
                rq->cmd_type = REQ_TYPE_ATA_PC;
                rq->sense = sense;
                rq->cmd_flags |= cmd_flags;
                rq->timeout = timeout;
                if (buffer) {
                        rq->data = buffer;
                        rq->data_len = *bufflen;
                }

                error = blk_execute_rq(drive->queue, info->disk, rq, 0);

                if (buffer)
                        *bufflen = rq->data_len;

                flags = rq->cmd_flags;
                blk_put_request(rq);

                /*
                 * FIXME: we should probably abort/retry or something in case of
                 * failure.
                 */
                if (flags & REQ_FAILED) {
                        /*
                         * The request failed.  Retry if it was due to a unit
                         * attention status (usually means media was changed).
                         */
                        struct request_sense *reqbuf = sense;

                        if (reqbuf->sense_key == UNIT_ATTENTION)
                                cdrom_saw_media_change(drive);
                        else if (reqbuf->sense_key == NOT_READY &&
                                 reqbuf->asc == 4 && reqbuf->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.
                                 */
                                ssleep(2);
                        } else {
                                /* otherwise, don't retry */
                                retries = 0;
                        }
                        --retries;
                }

                /* end of retry loop */
        } while ((flags & REQ_FAILED) && retries >= 0);

        /* return an error if the command failed */
        return (flags & REQ_FAILED) ? -EIO : 0;
}

static void 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, 0, nr_bytes);
}

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, stat, thislen, uptodate = 0;
        int write = (rq_data_dir(rq) == WRITE) ? 1 : 0, rc, nsectors;
        int sense = blk_sense_request(rq);
        unsigned int timeout;
        u16 len;
        u8 ireason;

        ide_debug_log(IDE_DBG_PC, "cmd[0]: 0x%x, write: 0x%x",
                                  rq->cmd[0], write);

        /* check for errors */
        dma = drive->dma;
        if (dma) {
                drive->dma = 0;
                dma_error = hwif->dma_ops->dma_end(drive);
                ide_destroy_dmatable(drive);
                if (dma_error) {
                        printk(KERN_ERR PFX "%s: DMA %s error\n", drive->name,
                                        write ? "write" : "read");
                        ide_dma_off(drive);
                }
        }

        rc = cdrom_decode_status(drive, 0, &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_fs_request(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) {
                if (blk_fs_request(rq)) {
                        /*
                         * 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->cmd_flags |= REQ_FAILED;
                                uptodate = 0;
                        }
                } else if (!blk_pc_request(rq)) {
                        ide_cd_request_sense_fixup(drive, cmd);
                        /* complain if we still have data left to transfer */
                        uptodate = cmd->nleft ? 0 : 1;
                        if (uptodate == 0)
                                rq->cmd_flags |= REQ_FAILED;
                }
                goto out_end;
        }

        /* check which way to transfer data */
        rc = ide_cd_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)
                        rq->sense_len += blen;
        }

        /* pad, if necessary */
        if (len > 0) {
                if (blk_fs_request(rq) == 0 || 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");
                }
        }

        if (blk_pc_request(rq)) {
                timeout = rq->timeout;
        } else {
                timeout = ATAPI_WAIT_PC;
                if (!blk_fs_request(rq))
                        expiry = ide_cd_expiry;
        }

        hwif->expiry = expiry;
        ide_set_handler(drive, cdrom_newpc_intr, timeout);
        return ide_started;

out_end:
        if (blk_pc_request(rq) && rc == 0) {
                unsigned int dlen = rq->data_len;

                rq->data_len = 0;

                if (blk_end_request(rq, 0, dlen))
                        BUG();

                hwif->rq = NULL;
        } else {
                if (sense && uptodate)
                        ide_cd_complete_failed_rq(drive, rq);

                if (blk_fs_request(rq)) {
                        if (cmd->nleft == 0)
                                uptodate = 1;
                } else {
                        if (uptodate <= 0 && rq->errors == 0)
                                rq->errors = -EIO;
                }

                if (uptodate == 0)
                        ide_cd_error_cmd(drive, cmd);

                /* make sure it's fully ended */
                if (blk_pc_request(rq))
                        nsectors = (rq->data_len + 511) >> 9;
                else
                        nsectors = rq->hard_nr_sectors;

                if (nsectors == 0)
                        nsectors = 1;

                if (blk_fs_request(rq) == 0) {
                        rq->data_len -= (cmd->nbytes - cmd->nleft);
                        if (uptodate == 0 && (cmd->tf_flags & IDE_TFLAG_WRITE))
                                rq->data_len += cmd->last_xfer_len;
                }

                ide_complete_rq(drive, uptodate ? 0 : -EIO, nsectors << 9);

                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_hardsect_size(q) >> SECTOR_BITS;

        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 ((rq->nr_sectors & (sectors_per_frame - 1)) ||
            (rq->sector & (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_pc_request(rq))
                rq->cmd_flags |= REQ_QUIET;
        else
                rq->cmd_flags &= ~REQ_FAILED;

        drive->dma = 0;

        /* sg request */
        if (rq->bio || ((rq->cmd_type == REQ_TYPE_ATA_PC) && rq->data_len)) {
                struct request_queue *q = drive->queue;
                unsigned int alignment;
                char *buf;

                if (rq->bio)
                        buf = bio_data(rq->bio);
                else
                        buf = rq->data;

                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
                    || rq->data_len & 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, 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");

        if (blk_fs_request(rq)) {
                if (cdrom_start_rw(drive, rq) == ide_stopped)
                        goto out_end;
        } else if (blk_sense_request(rq) || blk_pc_request(rq) ||
                   rq->cmd_type == REQ_TYPE_ATA_PC) {
                if (!rq->timeout)
                        rq->timeout = ATAPI_WAIT_PC;

                cdrom_do_block_pc(drive, rq);
        } else if (blk_special_request(rq)) {
                /* right now this can only be a reset... */
                uptodate = 1;
                goto out_end;
        } else {
                blk_dump_rq_flags(rq, DRV_NAME " bad flags");
                if (rq->errors == 0)
                        rq->errors = -EIO;
                goto out_end;
        }

        memset(&cmd, 0, sizeof(cmd));

        if (rq_data_dir(rq))
                cmd.tf_flags |= IDE_TFLAG_WRITE;

        cmd.rq = rq;

        if (blk_fs_request(rq) || rq->data_len) {
                ide_init_sg_cmd(&cmd, blk_fs_request(rq) ? (rq->nr_sectors << 9)
                                                         : rq->data_len);
                ide_map_sg(drive, &cmd);
        }

        return ide_issue_pc(drive, &cmd);
out_end:
        nsectors = rq->hard_nr_sectors;

        if (nsectors == 0)
                nsectors = 1;

        ide_complete_rq(drive, uptodate ? 0 : -EIO, 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 request_sense *sense)
{
        struct cdrom_info *info = drive->driver_data;
        struct cdrom_device_info *cdi = &info->devinfo;
        unsigned char cmd[BLK_MAX_CDB];

        ide_debug_log(IDE_DBG_FUNC, "enter");

        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, sense, 0, REQ_QUIET);
}

static int cdrom_read_capacity(ide_drive_t *drive, unsigned long *capacity,
                               unsigned long *sectors_per_frame,
                               struct request_sense *sense)
{
        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, sense, 0,
                               REQ_QUIET);
        if (stat)
                return stat;

        /*
         * Sanity check the given block size
         */
        blocklen = be32_to_cpu(capbuf.blocklen);
        switch (blocklen) {
        case 512:
        case 1024:
        case 2048:
        case 4096:
                break;
        default:
                printk(KERN_ERR PFX "%s: weird block size %u\n",
                                drive->name, blocklen);
                printk(KERN_ERR PFX "%s: default to 2kb block size\n",
                                drive->name);
                blocklen = 2048;
                break;
        }

        *capacity = 1 + be32_to_cpu(capbuf.lba);
        *sectors_per_frame = blocklen >> SECTOR_BITS;

        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,
                                struct request_sense *sense)
{
        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, sense, 0, REQ_QUIET);
}

/* Try to read the entire TOC for the disk into our internal buffer. */
int ide_cd_read_toc(ide_drive_t *drive, struct request_sense *sense)
{
        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, sense);

        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,
                                   sense);
        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_hardsect_size(drive->queue,
                                sectors_per_frame << SECTOR_BITS);

        /* 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), sense);
        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), sense);

        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),
                                           sense);
                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), sense);
                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), sense);
                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 = (curspeed + (176/2)) / 176;
        cd->max_speed = (maxspeed + (176/2)) / 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 struct cdrom_device_ops ide_cdrom_dops = {
        .open                   = ide_cdrom_open_real,
        .release                = ide_cdrom_release_real,
        .drive_status           = ide_cdrom_drive_status,
        .media_changed          = ide_cdrom_check_media_change_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_hardsect_size(q);
        long block = (long)rq->hard_sector / (hard_sect >> 9);
        unsigned long blocks = rq->hard_nr_sectors / (hard_sect >> 9);

        memset(rq->cmd, 0, BLK_MAX_CDB);

        if (rq_data_dir(rq) == READ)
                rq->cmd[0] = GPCMD_READ_10;
        else
                rq->cmd[0] = GPCMD_WRITE_10;

        /*
         * fill in lba
         */
        rq->cmd[2] = (block >> 24) & 0xff;
        rq->cmd[3] = (block >> 16) & 0xff;
        rq->cmd[4] = (block >>  8) & 0xff;
        rq->cmd[5] = block & 0xff;

        /*
         * and transfer length
         */
        rq->cmd[7] = (blocks >> 8) & 0xff;
        rq->cmd[8] = blocks & 0xff;
        rq->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 = 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);
                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) {
                rq->errors = ILLEGAL_REQUEST;
                return BLKPREP_KILL;
        }

        return BLKPREP_OK;
}

static int ide_cdrom_prep_fn(struct request_queue *q, struct request *rq)
{
        if (blk_fs_request(rq))
                return ide_cdrom_prep_fs(q, rq);
        else if (blk_pc_request(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, NULL))
                return 0;

        return capacity * sectors_per_frame;
}

static int proc_idecd_read_capacity(char *page, char **start, off_t off,
                                        int count, int *eof, void *data)
{
        ide_drive_t *drive = data;
        int len;

        len = sprintf(page, "%llu\n", (long long)ide_cdrom_capacity(drive));
        PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
}

static ide_proc_entry_t idecd_proc[] = {
        { "capacity", S_IFREG|S_IRUGO, proc_idecd_read_capacity, NULL },
        { NULL, 0, NULL, NULL }
};

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);

        q->unplug_delay = max((1 * HZ) / 1000, 1);

        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_hardsect_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 = ide_cd_get(bdev->bd_disk);
        int rc = -ENOMEM;

        if (!info)
                return -ENXIO;

        rc = cdrom_open(&info->devinfo, bdev, mode);

        if (rc < 0)
                ide_cd_put(info);

        return rc;
}

static int idecd_release(struct gendisk *disk, fmode_t mode)
{
        struct cdrom_info *info = ide_drv_g(disk, cdrom_info);

        cdrom_release(&info->devinfo, mode);

        ide_cd_put(info);

        return 0;
}

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_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_media_changed(struct gendisk *disk)
{
        struct cdrom_info *info = ide_drv_g(disk, cdrom_info);
        return cdrom_media_changed(&info->devinfo);
}

static int idecd_revalidate_disk(struct gendisk *disk)
{
        struct cdrom_info *info = ide_drv_g(disk, cdrom_info);
        struct request_sense sense;

        ide_cd_read_toc(info->drive, &sense);

        return  0;
}

static struct block_device_operations idecd_ops = {
        .owner                  = THIS_MODULE,
        .open                   = idecd_open,
        .release                = idecd_release,
        .locked_ioctl           = idecd_ioctl,
        .media_changed          = idecd_media_changed,
        .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;
        struct request_sense sense;

        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, 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->driverfs_dev = &drive->gendev;
        g->flags = GENHD_FL_CD | GENHD_FL_REMOVABLE;
        if (ide_cdrom_setup(drive)) {
                put_device(&info->dev);
                goto failed;
        }

        ide_cd_read_toc(drive, &sense);
        g->fops = &idecd_ops;
        g->flags |= GENHD_FL_REMOVABLE;
        add_disk(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");