FreeBSD/Linux Kernel Cross Reference
sys/cam/scsi/scsi_cd.c

     /*-
      * Copyright (c) 1997 Justin T. Gibbs.
      * Copyright (c) 1997, 1998, 1999, 2000, 2001, 2002, 2003 Kenneth D. Merry.
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions, and the following disclaimer,
     *    without modification, immediately at the beginning of the file.
     * 2. The name of the author may not be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
     * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */
    
    /*-
     * Portions of this driver taken from the original FreeBSD cd driver.
     * Written by Julian Elischer (julian@tfs.com)
     * for TRW Financial Systems for use under the MACH(2.5) operating system.
     *
     * TRW Financial Systems, in accordance with their agreement with Carnegie
     * Mellon University, makes this software available to CMU to distribute
     * or use in any manner that they see fit as long as this message is kept with
     * the software. For this reason TFS also grants any other persons or
     * organisations permission to use or modify this software.
     *
     * TFS supplies this software to be publicly redistributed
     * on the understanding that TFS is not responsible for the correct
     * functioning of this software in any circumstances.
     *
     * Ported to run under 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
     *
     *      from: cd.c,v 1.83 1997/05/04 15:24:22 joerg Exp $
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/8.3/sys/cam/scsi/scsi_cd.c 230015 2012-01-12 15:02:51Z mav $");
    
    #include "opt_cd.h"
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/bio.h>
    #include <sys/conf.h>
    #include <sys/disk.h>
    #include <sys/malloc.h>
    #include <sys/cdio.h>
    #include <sys/cdrio.h>
    #include <sys/dvdio.h>
    #include <sys/devicestat.h>
    #include <sys/sysctl.h>
    #include <sys/taskqueue.h>
    #include <geom/geom_disk.h>
    
    #include <cam/cam.h>
    #include <cam/cam_ccb.h>
    #include <cam/cam_periph.h>
    #include <cam/cam_xpt_periph.h>
    #include <cam/cam_queue.h>
    #include <cam/cam_sim.h>
    
    #include <cam/scsi/scsi_message.h>
    #include <cam/scsi/scsi_da.h>
    #include <cam/scsi/scsi_cd.h>
    
    #define LEADOUT         0xaa            /* leadout toc entry */
    
    struct cd_params {
            u_int32_t blksize;
            u_long    disksize;
    };
    
    typedef enum {
            CD_Q_NONE               = 0x00,
            CD_Q_NO_TOUCH           = 0x01,
            CD_Q_BCD_TRACKS         = 0x02,
            CD_Q_NO_CHANGER         = 0x04,
            CD_Q_CHANGER            = 0x08,
            CD_Q_10_BYTE_ONLY       = 0x10
    } cd_quirks;
    
    typedef enum {
            CD_FLAG_INVALID         = 0x0001,
            CD_FLAG_NEW_DISC        = 0x0002,
            CD_FLAG_DISC_LOCKED     = 0x0004,
            CD_FLAG_DISC_REMOVABLE  = 0x0008,
           CD_FLAG_TAGGED_QUEUING  = 0x0010,
           CD_FLAG_CHANGER         = 0x0040,
           CD_FLAG_ACTIVE          = 0x0080,
           CD_FLAG_SCHED_ON_COMP   = 0x0100,
           CD_FLAG_RETRY_UA        = 0x0200,
           CD_FLAG_VALID_MEDIA     = 0x0400,
           CD_FLAG_VALID_TOC       = 0x0800,
           CD_FLAG_SCTX_INIT       = 0x1000,
           CD_FLAG_OPEN            = 0x2000
   } cd_flags;
   
   typedef enum {
           CD_CCB_PROBE            = 0x01,
           CD_CCB_BUFFER_IO        = 0x02,
           CD_CCB_WAITING          = 0x03,
           CD_CCB_TYPE_MASK        = 0x0F,
           CD_CCB_RETRY_UA         = 0x10
   } cd_ccb_state;
   
   typedef enum {
           CHANGER_TIMEOUT_SCHED           = 0x01,
           CHANGER_SHORT_TMOUT_SCHED       = 0x02,
           CHANGER_MANUAL_CALL             = 0x04,
           CHANGER_NEED_TIMEOUT            = 0x08
   } cd_changer_flags;
   
   #define ccb_state ppriv_field0
   #define ccb_bp ppriv_ptr1
   
   struct cd_tocdata {
           struct ioc_toc_header header;
           struct cd_toc_entry entries[100];
   };
   
   struct cd_toc_single {
           struct ioc_toc_header header;
           struct cd_toc_entry entry;
   };
   
   typedef enum {
           CD_STATE_PROBE,
           CD_STATE_NORMAL
   } cd_state;
   
   struct cd_softc {
           cam_pinfo               pinfo;
           cd_state                state;
           volatile cd_flags       flags;
           struct bio_queue_head   bio_queue;
           LIST_HEAD(, ccb_hdr)    pending_ccbs;
           struct cd_params        params;
           union ccb               saved_ccb;
           cd_quirks               quirks;
           STAILQ_ENTRY(cd_softc)  changer_links;
           struct cdchanger        *changer;
           int                     bufs_left;
           struct cam_periph       *periph;
           int                     minimum_command_size;
           int                     outstanding_cmds;
           struct task             sysctl_task;
           struct sysctl_ctx_list  sysctl_ctx;
           struct sysctl_oid       *sysctl_tree;
           STAILQ_HEAD(, cd_mode_params)   mode_queue;
           struct cd_tocdata       toc;
           struct disk             *disk;
   };
   
   struct cd_page_sizes {
           int page;
           int page_size;
   };
   
   static struct cd_page_sizes cd_page_size_table[] =
   {
           { AUDIO_PAGE, sizeof(struct cd_audio_page)}
   };
   
   struct cd_quirk_entry {
           struct scsi_inquiry_pattern inq_pat;
           cd_quirks quirks;
   };
   
   /*
    * The changer quirk entries aren't strictly necessary.  Basically, what
    * they do is tell cdregister() up front that a device is a changer.
    * Otherwise, it will figure that fact out once it sees a LUN on the device
    * that is greater than 0.  If it is known up front that a device is a changer,
    * all I/O to the device will go through the changer scheduling routines, as
    * opposed to the "normal" CD code.
    *
    * NOTE ON 10_BYTE_ONLY quirks:  Any 10_BYTE_ONLY quirks MUST be because
    * your device hangs when it gets a 10 byte command.  Adding a quirk just
    * to get rid of the informative diagnostic message is not acceptable.  All
    * 10_BYTE_ONLY quirks must be documented in full in a PR (which should be
    * referenced in a comment along with the quirk) , and must be approved by
    * ken@FreeBSD.org.  Any quirks added that don't adhere to this policy may
    * be removed until the submitter can explain why they are needed.
    * 10_BYTE_ONLY quirks will be removed (as they will no longer be necessary)
    * when the CAM_NEW_TRAN_CODE work is done.
    */
   static struct cd_quirk_entry cd_quirk_table[] =
   {
           {
                   { T_CDROM, SIP_MEDIA_REMOVABLE, "NRC", "MBR-7", "*"},
                    /*quirks*/ CD_Q_CHANGER
           },
           {
                   { T_CDROM, SIP_MEDIA_REMOVABLE, "PIONEER", "CD-ROM DRM*",
                     "*"}, /* quirks */ CD_Q_CHANGER
           },
           {
                   { T_CDROM, SIP_MEDIA_REMOVABLE, "NAKAMICH", "MJ-*", "*"},
                    /* quirks */ CD_Q_CHANGER
           },
           {
                   { T_CDROM, SIP_MEDIA_REMOVABLE, "CHINON", "CD-ROM CDS-535","*"},
                   /* quirks */ CD_Q_BCD_TRACKS
           }
   };
   
   static  disk_open_t     cdopen;
   static  disk_close_t    cdclose;
   static  disk_ioctl_t    cdioctl;
   static  disk_strategy_t cdstrategy;
   
   static  periph_init_t   cdinit;
   static  periph_ctor_t   cdregister;
   static  periph_dtor_t   cdcleanup;
   static  periph_start_t  cdstart;
   static  periph_oninv_t  cdoninvalidate;
   static  void            cdasync(void *callback_arg, u_int32_t code,
                                   struct cam_path *path, void *arg);
   static  int             cdcmdsizesysctl(SYSCTL_HANDLER_ARGS);
   static  void            cdshorttimeout(void *arg);
   static  void            cdschedule(struct cam_periph *periph, int priority);
   static  void            cdrunchangerqueue(void *arg);
   static  void            cdchangerschedule(struct cd_softc *softc);
   static  int             cdrunccb(union ccb *ccb,
                                    int (*error_routine)(union ccb *ccb,
                                                         u_int32_t cam_flags,
                                                         u_int32_t sense_flags),
                                    u_int32_t cam_flags, u_int32_t sense_flags);
   static  union ccb       *cdgetccb(struct cam_periph *periph,
                                     u_int32_t priority);
   static  void            cddone(struct cam_periph *periph,
                                  union ccb *start_ccb);
   static  union cd_pages  *cdgetpage(struct cd_mode_params *mode_params);
   static  int             cdgetpagesize(int page_num);
   static  void            cdprevent(struct cam_periph *periph, int action);
   static  int             cdcheckmedia(struct cam_periph *periph);
   static  int             cdsize(struct cam_periph *periph, u_int32_t *size);
   static  int             cd6byteworkaround(union ccb *ccb);
   static  int             cderror(union ccb *ccb, u_int32_t cam_flags,
                                   u_int32_t sense_flags);
   static  int             cdreadtoc(struct cam_periph *periph, u_int32_t mode, 
                                     u_int32_t start, u_int8_t *data, 
                                     u_int32_t len, u_int32_t sense_flags);
   static  int             cdgetmode(struct cam_periph *periph, 
                                     struct cd_mode_params *data, u_int32_t page);
   static  int             cdsetmode(struct cam_periph *periph,
                                     struct cd_mode_params *data);
   static  int             cdplay(struct cam_periph *periph, u_int32_t blk, 
                                  u_int32_t len);
   static  int             cdreadsubchannel(struct cam_periph *periph, 
                                            u_int32_t mode, u_int32_t format, 
                                            int track, 
                                            struct cd_sub_channel_info *data, 
                                            u_int32_t len);
   static  int             cdplaymsf(struct cam_periph *periph, u_int32_t startm, 
                                     u_int32_t starts, u_int32_t startf, 
                                     u_int32_t endm, u_int32_t ends, 
                                     u_int32_t endf);
   static  int             cdplaytracks(struct cam_periph *periph, 
                                        u_int32_t strack, u_int32_t sindex,
                                        u_int32_t etrack, u_int32_t eindex);
   static  int             cdpause(struct cam_periph *periph, u_int32_t go);
   static  int             cdstopunit(struct cam_periph *periph, u_int32_t eject);
   static  int             cdstartunit(struct cam_periph *periph, int load);
   static  int             cdsetspeed(struct cam_periph *periph,
                                      u_int32_t rdspeed, u_int32_t wrspeed);
   static  int             cdreportkey(struct cam_periph *periph,
                                       struct dvd_authinfo *authinfo);
   static  int             cdsendkey(struct cam_periph *periph,
                                     struct dvd_authinfo *authinfo);
   static  int             cdreaddvdstructure(struct cam_periph *periph,
                                              struct dvd_struct *dvdstruct);
   
   static struct periph_driver cddriver =
   {
           cdinit, "cd",
           TAILQ_HEAD_INITIALIZER(cddriver.units), /* generation */ 0
   };
   
   PERIPHDRIVER_DECLARE(cd, cddriver);
   
   #ifndef CD_DEFAULT_RETRY
   #define CD_DEFAULT_RETRY        4
   #endif
   #ifndef CHANGER_MIN_BUSY_SECONDS
   #define CHANGER_MIN_BUSY_SECONDS        5
   #endif
   #ifndef CHANGER_MAX_BUSY_SECONDS
   #define CHANGER_MAX_BUSY_SECONDS        15
   #endif
   
   static int cd_retry_count = CD_DEFAULT_RETRY;
   static int changer_min_busy_seconds = CHANGER_MIN_BUSY_SECONDS;
   static int changer_max_busy_seconds = CHANGER_MAX_BUSY_SECONDS;
   
   SYSCTL_NODE(_kern_cam, OID_AUTO, cd, CTLFLAG_RD, 0, "CAM CDROM driver");
   SYSCTL_NODE(_kern_cam_cd, OID_AUTO, changer, CTLFLAG_RD, 0, "CD Changer");
   SYSCTL_INT(_kern_cam_cd, OID_AUTO, retry_count, CTLFLAG_RW,
              &cd_retry_count, 0, "Normal I/O retry count");
   TUNABLE_INT("kern.cam.cd.retry_count", &cd_retry_count);
   SYSCTL_INT(_kern_cam_cd_changer, OID_AUTO, min_busy_seconds, CTLFLAG_RW,
              &changer_min_busy_seconds, 0, "Minimum changer scheduling quantum");
   TUNABLE_INT("kern.cam.cd.changer.min_busy_seconds", &changer_min_busy_seconds);
   SYSCTL_INT(_kern_cam_cd_changer, OID_AUTO, max_busy_seconds, CTLFLAG_RW,
              &changer_max_busy_seconds, 0, "Maximum changer scheduling quantum");
   TUNABLE_INT("kern.cam.cd.changer.max_busy_seconds", &changer_max_busy_seconds);
   
   struct cdchanger {
           path_id_t                        path_id;
           target_id_t                      target_id;
           int                              num_devices;
           struct camq                      devq;
           struct timeval                   start_time;
           struct cd_softc                  *cur_device;
           struct callout                   short_handle;
           struct callout                   long_handle;
           volatile cd_changer_flags        flags;
           STAILQ_ENTRY(cdchanger)          changer_links;
           STAILQ_HEAD(chdevlist, cd_softc) chluns;
   };
   
   static struct mtx changerq_mtx;
   static STAILQ_HEAD(changerlist, cdchanger) changerq;
   static int num_changers;
   
   MALLOC_DEFINE(M_SCSICD, "scsi_cd", "scsi_cd buffers");
   
   static void
   cdinit(void)
   {
           cam_status status;
   
           mtx_init(&changerq_mtx, "cdchangerq", "SCSI CD Changer List", MTX_DEF);
           STAILQ_INIT(&changerq);
   
           /*
            * Install a global async callback.  This callback will
            * receive async callbacks like "new device found".
            */
           status = xpt_register_async(AC_FOUND_DEVICE, cdasync, NULL, NULL);
   
           if (status != CAM_REQ_CMP) {
                   printf("cd: Failed to attach master async callback "
                          "due to status 0x%x!\n", status);
           }
   }
   
   static void
   cdoninvalidate(struct cam_periph *periph)
   {
           struct cd_softc *softc;
   
           softc = (struct cd_softc *)periph->softc;
   
           /*
            * De-register any async callbacks.
            */
           xpt_register_async(0, cdasync, periph, periph->path);
   
           softc->flags |= CD_FLAG_INVALID;
   
           /*
            * Return all queued I/O with ENXIO.
            * XXX Handle any transactions queued to the card
            *     with XPT_ABORT_CCB.
            */
           bioq_flush(&softc->bio_queue, NULL, ENXIO);
   
           /*
            * If this device is part of a changer, and it was scheduled
            * to run, remove it from the run queue since we just nuked
            * all of its scheduled I/O.
            */
           if ((softc->flags & CD_FLAG_CHANGER)
            && (softc->pinfo.index != CAM_UNQUEUED_INDEX))
                   camq_remove(&softc->changer->devq, softc->pinfo.index);
   
           disk_gone(softc->disk);
           xpt_print(periph->path, "lost device\n");
   }
   
   static void
   cdcleanup(struct cam_periph *periph)
   {
           struct cd_softc *softc;
   
           softc = (struct cd_softc *)periph->softc;
   
           xpt_print(periph->path, "removing device entry\n");
   
           /*
            * In the queued, non-active case, the device in question
            * has already been removed from the changer run queue.  Since this
            * device is active, we need to de-activate it, and schedule
            * another device to run.  (if there is another one to run)
            */
           if ((softc->flags & CD_FLAG_CHANGER)
            && (softc->flags & CD_FLAG_ACTIVE)) {
   
                   /*
                    * The purpose of the short timeout is soley to determine
                    * whether the current device has finished or not.  Well,
                    * since we're removing the active device, we know that it
                    * is finished.  So, get rid of the short timeout.
                    * Otherwise, if we're in the time period before the short
                    * timeout fires, and there are no other devices in the
                    * queue to run, there won't be any other device put in the
                    * active slot.  i.e., when we call cdrunchangerqueue()
                    * below, it won't do anything.  Then, when the short
                    * timeout fires, it'll look at the "current device", which
                    * we are free below, and possibly panic the kernel on a
                    * bogus pointer reference.
                    *
                    * The long timeout doesn't really matter, since we
                    * decrement the qfrozen_cnt to indicate that there is
                    * nothing in the active slot now.  Therefore, there won't
                    * be any bogus pointer references there.
                    */
                   if (softc->changer->flags & CHANGER_SHORT_TMOUT_SCHED) {
                           callout_stop(&softc->changer->short_handle);
                           softc->changer->flags &= ~CHANGER_SHORT_TMOUT_SCHED;
                   }
                   softc->changer->devq.qfrozen_cnt[0]--;
                   softc->changer->flags |= CHANGER_MANUAL_CALL;
                   cdrunchangerqueue(softc->changer);
           }
   
           /*
            * If we're removing the last device on the changer, go ahead and
            * remove the changer device structure.
            */
           if ((softc->flags & CD_FLAG_CHANGER)
            && (--softc->changer->num_devices == 0)) {
   
                   /*
                    * Theoretically, there shouldn't be any timeouts left, but
                    * I'm not completely sure that that will be the case.  So,
                    * it won't hurt to check and see if there are any left.
                    */
                   if (softc->changer->flags & CHANGER_TIMEOUT_SCHED) {
                           callout_stop(&softc->changer->long_handle);
                           softc->changer->flags &= ~CHANGER_TIMEOUT_SCHED;
                   }
   
                   if (softc->changer->flags & CHANGER_SHORT_TMOUT_SCHED) {
                           callout_stop(&softc->changer->short_handle);
                           softc->changer->flags &= ~CHANGER_SHORT_TMOUT_SCHED;
                   }
   
                   mtx_lock(&changerq_mtx);
                   STAILQ_REMOVE(&changerq, softc->changer, cdchanger,
                                 changer_links);
                   num_changers--;
                   mtx_unlock(&changerq_mtx);
                   xpt_print(periph->path, "removing changer entry\n");
                   free(softc->changer, M_DEVBUF);
           }
           cam_periph_unlock(periph);
           if ((softc->flags & CD_FLAG_SCTX_INIT) != 0
               && sysctl_ctx_free(&softc->sysctl_ctx) != 0) {
                   xpt_print(periph->path, "can't remove sysctl context\n");
           }
   
           disk_destroy(softc->disk);
           free(softc, M_DEVBUF);
           cam_periph_lock(periph);
   }
   
   static void
   cdasync(void *callback_arg, u_int32_t code,
           struct cam_path *path, void *arg)
   {
           struct cam_periph *periph;
   
           periph = (struct cam_periph *)callback_arg;
           switch (code) {
           case AC_FOUND_DEVICE:
           {
                   struct ccb_getdev *cgd;
                   cam_status status;
   
                   cgd = (struct ccb_getdev *)arg;
                   if (cgd == NULL)
                           break;
   
                   if (cgd->protocol != PROTO_SCSI)
                           break;
   
                   if (SID_TYPE(&cgd->inq_data) != T_CDROM
                       && SID_TYPE(&cgd->inq_data) != T_WORM)
                           break;
   
                   /*
                    * Allocate a peripheral instance for
                    * this device and start the probe
                    * process.
                    */
                   status = cam_periph_alloc(cdregister, cdoninvalidate,
                                             cdcleanup, cdstart,
                                             "cd", CAM_PERIPH_BIO,
                                             cgd->ccb_h.path, cdasync,
                                             AC_FOUND_DEVICE, cgd);
   
                   if (status != CAM_REQ_CMP
                    && status != CAM_REQ_INPROG)
                           printf("cdasync: Unable to attach new device "
                                  "due to status 0x%x\n", status);
   
                   break;
           }
           case AC_SENT_BDR:
           case AC_BUS_RESET:
           {
                   struct cd_softc *softc;
                   struct ccb_hdr *ccbh;
   
                   softc = (struct cd_softc *)periph->softc;
                   /*
                    * Don't fail on the expected unit attention
                    * that will occur.
                    */
                   softc->flags |= CD_FLAG_RETRY_UA;
                   LIST_FOREACH(ccbh, &softc->pending_ccbs, periph_links.le)
                           ccbh->ccb_state |= CD_CCB_RETRY_UA;
                   /* FALLTHROUGH */
           }
           default:
                   cam_periph_async(periph, code, path, arg);
                   break;
           }
   }
   
   static void
   cdsysctlinit(void *context, int pending)
   {
           struct cam_periph *periph;
           struct cd_softc *softc;
           char tmpstr[80], tmpstr2[80];
   
           periph = (struct cam_periph *)context;
           if (cam_periph_acquire(periph) != CAM_REQ_CMP)
                   return;
   
           softc = (struct cd_softc *)periph->softc;
           snprintf(tmpstr, sizeof(tmpstr), "CAM CD unit %d", periph->unit_number);
           snprintf(tmpstr2, sizeof(tmpstr2), "%d", periph->unit_number);
   
           sysctl_ctx_init(&softc->sysctl_ctx);
           softc->flags |= CD_FLAG_SCTX_INIT;
           softc->sysctl_tree = SYSCTL_ADD_NODE(&softc->sysctl_ctx,
                   SYSCTL_STATIC_CHILDREN(_kern_cam_cd), OID_AUTO,
                   tmpstr2, CTLFLAG_RD, 0, tmpstr);
   
           if (softc->sysctl_tree == NULL) {
                   printf("cdsysctlinit: unable to allocate sysctl tree\n");
                   cam_periph_release(periph);
                   return;
           }
   
           /*
            * Now register the sysctl handler, so the user can the value on
            * the fly.
            */
           SYSCTL_ADD_PROC(&softc->sysctl_ctx,SYSCTL_CHILDREN(softc->sysctl_tree),
                   OID_AUTO, "minimum_cmd_size", CTLTYPE_INT | CTLFLAG_RW,
                   &softc->minimum_command_size, 0, cdcmdsizesysctl, "I",
                   "Minimum CDB size");
   
           cam_periph_release(periph);
   }
   
   /*
    * We have a handler function for this so we can check the values when the
    * user sets them, instead of every time we look at them.
    */
   static int
   cdcmdsizesysctl(SYSCTL_HANDLER_ARGS)
   {
           int error, value;
   
           value = *(int *)arg1;
   
           error = sysctl_handle_int(oidp, &value, 0, req);
   
           if ((error != 0)
            || (req->newptr == NULL))
                   return (error);
   
           /*
            * The only real values we can have here are 6 or 10.  I don't
            * really forsee having 12 be an option at any time in the future.
            * So if the user sets something less than or equal to 6, we'll set
            * it to 6.  If he sets something greater than 6, we'll set it to 10.
            *
            * I suppose we could just return an error here for the wrong values,
            * but I don't think it's necessary to do so, as long as we can
            * determine the user's intent without too much trouble.
            */
           if (value < 6)
                   value = 6;
           else if (value > 6)
                   value = 10;
   
           *(int *)arg1 = value;
   
           return (0);
   }
   
   static cam_status
   cdregister(struct cam_periph *periph, void *arg)
   {
           struct cd_softc *softc;
           struct ccb_pathinq cpi;
           struct ccb_getdev *cgd;
           char tmpstr[80];
           caddr_t match;
   
           cgd = (struct ccb_getdev *)arg;
           if (periph == NULL) {
                   printf("cdregister: periph was NULL!!\n");
                   return(CAM_REQ_CMP_ERR);
           }
           if (cgd == NULL) {
                   printf("cdregister: no getdev CCB, can't register device\n");
                   return(CAM_REQ_CMP_ERR);
           }
   
           softc = (struct cd_softc *)malloc(sizeof(*softc),M_DEVBUF,
               M_NOWAIT | M_ZERO);
           if (softc == NULL) {
                   printf("cdregister: Unable to probe new device. "
                          "Unable to allocate softc\n");                           
                   return(CAM_REQ_CMP_ERR);
           }
   
           LIST_INIT(&softc->pending_ccbs);
           STAILQ_INIT(&softc->mode_queue);
           softc->state = CD_STATE_PROBE;
           bioq_init(&softc->bio_queue);
           if (SID_IS_REMOVABLE(&cgd->inq_data))
                   softc->flags |= CD_FLAG_DISC_REMOVABLE;
           if ((cgd->inq_data.flags & SID_CmdQue) != 0)
                   softc->flags |= CD_FLAG_TAGGED_QUEUING;
   
           periph->softc = softc;
           softc->periph = periph;
   
           /*
            * See if this device has any quirks.
            */
           match = cam_quirkmatch((caddr_t)&cgd->inq_data,
                                  (caddr_t)cd_quirk_table,
                                  sizeof(cd_quirk_table)/sizeof(*cd_quirk_table),
                                  sizeof(*cd_quirk_table), scsi_inquiry_match);
   
           if (match != NULL)
                   softc->quirks = ((struct cd_quirk_entry *)match)->quirks;
           else
                   softc->quirks = CD_Q_NONE;
   
           /* Check if the SIM does not want 6 byte commands */
           bzero(&cpi, sizeof(cpi));
           xpt_setup_ccb(&cpi.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
           cpi.ccb_h.func_code = XPT_PATH_INQ;
           xpt_action((union ccb *)&cpi);
           if (cpi.ccb_h.status == CAM_REQ_CMP && (cpi.hba_misc & PIM_NO_6_BYTE))
                   softc->quirks |= CD_Q_10_BYTE_ONLY;
   
           TASK_INIT(&softc->sysctl_task, 0, cdsysctlinit, periph);
   
           /* The default is 6 byte commands, unless quirked otherwise */
           if (softc->quirks & CD_Q_10_BYTE_ONLY)
                   softc->minimum_command_size = 10;
           else
                   softc->minimum_command_size = 6;
   
           (void)cam_periph_hold(periph, PRIBIO);
           cam_periph_unlock(periph);
           /*
            * Load the user's default, if any.
            */
           snprintf(tmpstr, sizeof(tmpstr), "kern.cam.cd.%d.minimum_cmd_size",
                    periph->unit_number);
           TUNABLE_INT_FETCH(tmpstr, &softc->minimum_command_size);
   
           /* 6 and 10 are the only permissible values here. */
           if (softc->minimum_command_size < 6)
                   softc->minimum_command_size = 6;
           else if (softc->minimum_command_size > 6)
                   softc->minimum_command_size = 10;
   
           /*
            * We need to register the statistics structure for this device,
            * but we don't have the blocksize yet for it.  So, we register
            * the structure and indicate that we don't have the blocksize
            * yet.  Unlike other SCSI peripheral drivers, we explicitly set
            * the device type here to be CDROM, rather than just ORing in
            * the device type.  This is because this driver can attach to either
            * CDROM or WORM devices, and we want this peripheral driver to
            * show up in the devstat list as a CD peripheral driver, not a
            * WORM peripheral driver.  WORM drives will also have the WORM
            * driver attached to them.
            */
           softc->disk = disk_alloc();
           softc->disk->d_devstat = devstat_new_entry("cd",
                             periph->unit_number, 0,
                             DEVSTAT_BS_UNAVAILABLE,
                             DEVSTAT_TYPE_CDROM |
                             XPORT_DEVSTAT_TYPE(cpi.transport),
                             DEVSTAT_PRIORITY_CD);
           softc->disk->d_open = cdopen;
           softc->disk->d_close = cdclose;
           softc->disk->d_strategy = cdstrategy;
           softc->disk->d_ioctl = cdioctl;
           softc->disk->d_name = "cd";
           softc->disk->d_unit = periph->unit_number;
           softc->disk->d_drv1 = periph;
           if (cpi.maxio == 0)
                   softc->disk->d_maxsize = DFLTPHYS;      /* traditional default */
           else if (cpi.maxio > MAXPHYS)
                   softc->disk->d_maxsize = MAXPHYS;       /* for safety */
           else
                   softc->disk->d_maxsize = cpi.maxio;
           softc->disk->d_flags = 0;
           disk_create(softc->disk, DISK_VERSION);
           cam_periph_lock(periph);
           cam_periph_unhold(periph);
   
           /*
            * Add an async callback so that we get
            * notified if this device goes away.
            */
           xpt_register_async(AC_SENT_BDR | AC_BUS_RESET | AC_LOST_DEVICE,
                              cdasync, periph, periph->path);
   
           /*
            * If the target lun is greater than 0, we most likely have a CD
            * changer device.  Check the quirk entries as well, though, just
            * in case someone has a CD tower with one lun per drive or
            * something like that.  Also, if we know up front that a
            * particular device is a changer, we can mark it as such starting
            * with lun 0, instead of lun 1.  It shouldn't be necessary to have
            * a quirk entry to define something as a changer, however.
            */
           if (((cgd->ccb_h.target_lun > 0)
             && ((softc->quirks & CD_Q_NO_CHANGER) == 0))
            || ((softc->quirks & CD_Q_CHANGER) != 0)) {
                   struct cdchanger *nchanger;
                   struct cam_periph *nperiph;
                   struct cam_path *path;
                   cam_status status;
                   int found;
   
                   /* Set the changer flag in the current device's softc */
                   softc->flags |= CD_FLAG_CHANGER;
   
                   /*
                    * Now, look around for an existing changer device with the
                    * same path and target ID as the current device.
                    */
                   mtx_lock(&changerq_mtx);
                   for (found = 0,
                        nchanger = (struct cdchanger *)STAILQ_FIRST(&changerq);
                        nchanger != NULL;
                        nchanger = STAILQ_NEXT(nchanger, changer_links)){
                           if ((nchanger->path_id == cgd->ccb_h.path_id) 
                            && (nchanger->target_id == cgd->ccb_h.target_id)) {
                                   found = 1;
                                   break;
                           }
                   }
                   mtx_unlock(&changerq_mtx);
   
                   /*
                    * If we found a matching entry, just add this device to
                    * the list of devices on this changer.
                    */
                   if (found == 1) {
                           struct chdevlist *chlunhead;
   
                           chlunhead = &nchanger->chluns;
   
                           /*
                            * XXX KDM look at consolidating this code with the
                            * code below in a separate function.
                            */
   
                           /*
                            * Create a path with lun id 0, and see if we can
                            * find a matching device
                            */
                           status = xpt_create_path(&path, /*periph*/ periph,
                                                    cgd->ccb_h.path_id,
                                                    cgd->ccb_h.target_id, 0);
   
                           if ((status == CAM_REQ_CMP)
                            && ((nperiph = cam_periph_find(path, "cd")) != NULL)){
                                   struct cd_softc *nsoftc;
   
                                   nsoftc = (struct cd_softc *)nperiph->softc;
   
                                   if ((nsoftc->flags & CD_FLAG_CHANGER) == 0){
                                           nsoftc->flags |= CD_FLAG_CHANGER;
                                           nchanger->num_devices++;
                                           if (camq_resize(&nchanger->devq,
                                              nchanger->num_devices)!=CAM_REQ_CMP){
                                                   printf("cdregister: "
                                                          "camq_resize "
                                                          "failed, changer "
                                                          "support may "
                                                          "be messed up\n");
                                           }
                                           nsoftc->changer = nchanger;
                                           nsoftc->pinfo.index =CAM_UNQUEUED_INDEX;
   
                                           STAILQ_INSERT_TAIL(&nchanger->chluns,
                                                             nsoftc,changer_links);
                                   }
                                   xpt_free_path(path);
                           } else if (status == CAM_REQ_CMP)
                                   xpt_free_path(path);
                           else {
                                   printf("cdregister: unable to allocate path\n"
                                          "cdregister: changer support may be "
                                          "broken\n");
                           }
   
                           nchanger->num_devices++;
   
                           softc->changer = nchanger;
                           softc->pinfo.index = CAM_UNQUEUED_INDEX;
   
                           if (camq_resize(&nchanger->devq,
                               nchanger->num_devices) != CAM_REQ_CMP) {
                                   printf("cdregister: camq_resize "
                                          "failed, changer support may "
                                          "be messed up\n");
                           }
   
                           STAILQ_INSERT_TAIL(chlunhead, softc, changer_links);
                   }
                   /*
                    * In this case, we don't already have an entry for this
                    * particular changer, so we need to create one, add it to
                    * the queue, and queue this device on the list for this
                    * changer.  Before we queue this device, however, we need
                    * to search for lun id 0 on this target, and add it to the
                    * queue first, if it exists.  (and if it hasn't already
                    * been marked as part of the changer.)
                    */
                   else {
                           nchanger = malloc(sizeof(struct cdchanger),
                                   M_DEVBUF, M_NOWAIT | M_ZERO);
                           if (nchanger == NULL) {
                                   softc->flags &= ~CD_FLAG_CHANGER;
                                   printf("cdregister: unable to malloc "
                                          "changer structure\ncdregister: "
                                          "changer support disabled\n");
   
                                   /*
                                    * Yes, gotos can be gross but in this case
                                    * I think it's justified..
                                    */
                                   goto cdregisterexit;
                           }
                           if (camq_init(&nchanger->devq, 1) != 0) {
                                   softc->flags &= ~CD_FLAG_CHANGER;
                                   printf("cdregister: changer support "
                                          "disabled\n");
                                   goto cdregisterexit;
                           }
   
                           nchanger->path_id = cgd->ccb_h.path_id;
                           nchanger->target_id = cgd->ccb_h.target_id;
   
                           /* this is superfluous, but it makes things clearer */
                           nchanger->num_devices = 0;
   
                           STAILQ_INIT(&nchanger->chluns);
   
                           callout_init_mtx(&nchanger->long_handle,
                               periph->sim->mtx, 0);
                           callout_init_mtx(&nchanger->short_handle,
                               periph->sim->mtx, 0);
   
                           mtx_lock(&changerq_mtx);
                           num_changers++;
                           STAILQ_INSERT_TAIL(&changerq, nchanger,
                                              changer_links);
                           mtx_unlock(&changerq_mtx);
                           
                           /*
                            * Create a path with lun id 0, and see if we can
                            * find a matching device
                            */
                           status = xpt_create_path(&path, /*periph*/ periph,
                                                    cgd->ccb_h.path_id,
                                                    cgd->ccb_h.target_id, 0);
   
                           /*
                            * If we were able to allocate the path, and if we
                            * find a matching device and it isn't already
                            * marked as part of a changer, then we add it to
                            * the current changer.
                            */
                           if ((status == CAM_REQ_CMP)
                            && ((nperiph = cam_periph_find(path, "cd")) != NULL)
                            && ((((struct cd_softc *)periph->softc)->flags &
                                  CD_FLAG_CHANGER) == 0)) {
                                   struct cd_softc *nsoftc;
   
                                   nsoftc = (struct cd_softc *)nperiph->softc;
   
                                   nsoftc->flags |= CD_FLAG_CHANGER;
                                   nchanger->num_devices++;
                                   if (camq_resize(&nchanger->devq,
                                       nchanger->num_devices) != CAM_REQ_CMP) {
                                           printf("cdregister: camq_resize "
                                                  "failed, changer support may "
                                                  "be messed up\n");
                                   }
                                   nsoftc->changer = nchanger;
                                   nsoftc->pinfo.index = CAM_UNQUEUED_INDEX;
   
                                   STAILQ_INSERT_TAIL(&nchanger->chluns,
                                                      nsoftc, changer_links);
                                   xpt_free_path(path);
                           } else if (status == CAM_REQ_CMP)
                                   xpt_free_path(path);
                           else {
                                   printf("cdregister: unable to allocate path\n"
                                          "cdregister: changer support may be "
                                          "broken\n");
                           }
   
                           softc->changer = nchanger;
                           softc->pinfo.index = CAM_UNQUEUED_INDEX;
                           nchanger->num_devices++;
                           if (camq_resize(&nchanger->devq,
                               nchanger->num_devices) != CAM_REQ_CMP) {
                                   printf("cdregister: camq_resize "
                                          "failed, changer support may "
                                          "be messed up\n");
                           }
                           STAILQ_INSERT_TAIL(&nchanger->chluns, softc,
                                              changer_links);
                   }
           }
   
   cdregisterexit:
   
           /*
            * Refcount and block open attempts until we are setup
            * Can't block
            */
           (void)cam_periph_hold(periph, PRIBIO);
   
           if ((softc->flags & CD_FLAG_CHANGER) == 0)
                   xpt_schedule(periph, CAM_PRIORITY_DEV);
           else
                   cdschedule(periph, CAM_PRIORITY_DEV);
   
           return(CAM_REQ_CMP);
   }
   
   static int
   cdopen(struct disk *dp)
   {
           struct cam_periph *periph;
           struct cd_softc *softc;
           int error;
   
           periph = (struct cam_periph *)dp->d_drv1;
           if (periph == NULL)
                   return (ENXIO);
   
           softc = (struct cd_softc *)periph->softc;
   
           if (cam_periph_acquire(periph) != CAM_REQ_CMP)
                   return(ENXIO);
   
           cam_periph_lock(periph);
   
           if (softc->flags & CD_FLAG_INVALID) {
                   cam_periph_unlock(periph);
                   cam_periph_release(periph);
                  return(ENXIO);
          }
  
          if ((error = cam_periph_hold(periph, PRIBIO | PCATCH)) != 0) {
                  cam_periph_unlock(periph);
                  cam_periph_release(periph);
                  return (error);
          }
  
          /*
           * Check for media, and set the appropriate flags.  We don't bail
           * if we don't have media, but then we don't allow anything but the
           * CDIOCEJECT/CDIOCCLOSE ioctls if there is no media.
           */
          cdcheckmedia(periph);
  
          CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("leaving cdopen\n"));
          cam_periph_unhold(periph);
  
          /* Closes aren't symmetrical with opens, so fix up the refcounting. */
          if ((softc->flags & CD_FLAG_OPEN) == 0) {
                  softc->flags |= CD_FLAG_OPEN;
                  cam_periph_unlock(periph);
          } else {
                  cam_periph_unlock(periph);
                  cam_periph_release(periph);
          }
  
          return (0);
  }
  
  static int
  cdclose(struct disk *dp)
  {
          struct  cam_periph *periph;
          struct  cd_softc *softc;
  
          periph = (struct cam_periph *)dp->d_drv1;
          if (periph == NULL)
                  return (ENXIO); 
  
          softc = (struct cd_softc *)periph->softc;
  
          cam_periph_lock(periph);
          cam_periph_hold(periph, PRIBIO);
  
          if ((softc->flags & CD_FLAG_DISC_REMOVABLE) != 0)
                  cdprevent(periph, PR_ALLOW);
  
          /*
           * Since we're closing this CD, mark the blocksize as unavailable.
           * It will be marked as available when the CD is opened again.
           */
          softc->disk->d_devstat->flags |= DEVSTAT_BS_UNAVAILABLE;
  
          /*
           * We'll check the media and toc again at the next open().
           */
          softc->flags &= ~(CD_FLAG_VALID_MEDIA|CD_FLAG_VALID_TOC|CD_FLAG_OPEN);
  
          cam_periph_unhold(periph);
          cam_periph_unlock(periph);
          cam_periph_release(periph);
  
          return (0);
  }
  
  static void
  cdshorttimeout(void *arg)
  {
          struct cdchanger *changer;
  
          changer = (struct cdchanger *)arg;
  
          /* Always clear the short timeout flag, since that's what we're in */
          changer->flags &= ~CHANGER_SHORT_TMOUT_SCHED;
  
          /*
           * Check to see if there is any more pending or outstanding I/O for
           * this device.  If not, move it out of the active slot.
           */
          if ((bioq_first(&changer->cur_device->bio_queue) == NULL)
           && (changer->cur_device->outstanding_cmds == 0)) {
                  changer->flags |= CHANGER_MANUAL_CALL;
                  cdrunchangerqueue(changer);
          }
  }
  
  /*
   * This is a wrapper for xpt_schedule.  It only applies to changers.
   */
  static void
  cdschedule(struct cam_periph *periph, int priority)
  {
          struct cd_softc *softc;
  
          softc = (struct cd_softc *)periph->softc;
  
          /*
           * If this device isn't currently queued, and if it isn't
           * the active device, then we queue this device and run the
           * changer queue if there is no timeout scheduled to do it.
           * If this device is the active device, just schedule it
           * to run again.  If this device is queued, there should be
           * a timeout in place already that will make sure it runs.
           */
          if ((softc->pinfo.index == CAM_UNQUEUED_INDEX) 
           && ((softc->flags & CD_FLAG_ACTIVE) == 0)) {
                  /*
                   * We don't do anything with the priority here.
                   * This is strictly a fifo queue.
                   */
                  softc->pinfo.priority = CAM_PRIORITY_NORMAL;
                  softc->pinfo.generation = ++softc->changer->devq.generation;
                  camq_insert(&softc->changer->devq, (cam_pinfo *)softc);
  
                  /*
                   * Since we just put a device in the changer queue,
                   * check and see if there is a timeout scheduled for
                   * this changer.  If so, let the timeout handle
                   * switching this device into the active slot.  If
                   * not, manually call the timeout routine to
                   * bootstrap things.
                   */
                  if (((softc->changer->flags & CHANGER_TIMEOUT_SCHED)==0)
                   && ((softc->changer->flags & CHANGER_NEED_TIMEOUT)==0)
                   && ((softc->changer->flags & CHANGER_SHORT_TMOUT_SCHED)==0)){
                          softc->changer->flags |= CHANGER_MANUAL_CALL;
                          cdrunchangerqueue(softc->changer);
                  }
          } else if ((softc->flags & CD_FLAG_ACTIVE)
                  && ((softc->flags & CD_FLAG_SCHED_ON_COMP) == 0))
                  xpt_schedule(periph, priority);
  }
  
  static void
  cdrunchangerqueue(void *arg)
  {
          struct cd_softc *softc;
          struct cdchanger *changer;
          int called_from_timeout;
  
          changer = (struct cdchanger *)arg;
  
          /*
           * If we have NOT been called from cdstrategy() or cddone(), and
           * instead from a timeout routine, go ahead and clear the
           * timeout flag.
           */
          if ((changer->flags & CHANGER_MANUAL_CALL) == 0) {
                  changer->flags &= ~CHANGER_TIMEOUT_SCHED;
                  called_from_timeout = 1;
          } else
                  called_from_timeout = 0;
  
          /* Always clear the manual call flag */
          changer->flags &= ~CHANGER_MANUAL_CALL;
  
          /* nothing to do if the queue is empty */
          if (changer->devq.entries <= 0) {
                  return;
          }
  
          /*
           * If the changer queue is frozen, that means we have an active
           * device.
           */
          if (changer->devq.qfrozen_cnt[0] > 0) {
  
                  /*
                   * We always need to reset the frozen count and clear the
                   * active flag.
                   */
                  changer->devq.qfrozen_cnt[0]--;
                  changer->cur_device->flags &= ~CD_FLAG_ACTIVE;
                  changer->cur_device->flags &= ~CD_FLAG_SCHED_ON_COMP;
  
                  if (changer->cur_device->outstanding_cmds > 0) {
                          changer->cur_device->flags |= CD_FLAG_SCHED_ON_COMP;
                          changer->cur_device->bufs_left = 
                                  changer->cur_device->outstanding_cmds;
                          if (called_from_timeout) {
                                  callout_reset(&changer->long_handle,
                                      changer_max_busy_seconds * hz,
                                      cdrunchangerqueue, changer);
                                  changer->flags |= CHANGER_TIMEOUT_SCHED;
                          }
                          return;
                  }
  
                  /*
                   * Check to see whether the current device has any I/O left
                   * to do.  If so, requeue it at the end of the queue.  If
                   * not, there is no need to requeue it.
                   */
                  if (bioq_first(&changer->cur_device->bio_queue) != NULL) {
  
                          changer->cur_device->pinfo.generation =
                                  ++changer->devq.generation;
                          camq_insert(&changer->devq,
                                  (cam_pinfo *)changer->cur_device);
                  } 
          }
  
          softc = (struct cd_softc *)camq_remove(&changer->devq, CAMQ_HEAD);
  
          changer->cur_device = softc;
  
          changer->devq.qfrozen_cnt[0]++;
          softc->flags |= CD_FLAG_ACTIVE;
  
          /* Just in case this device is waiting */
          wakeup(&softc->changer);
          xpt_schedule(softc->periph, CAM_PRIORITY_NORMAL);
  
          /*
           * Get rid of any pending timeouts, and set a flag to schedule new
           * ones so this device gets its full time quantum.
           */
          if (changer->flags & CHANGER_TIMEOUT_SCHED) {
                  callout_stop(&changer->long_handle);
                  changer->flags &= ~CHANGER_TIMEOUT_SCHED;
          }
  
          if (changer->flags & CHANGER_SHORT_TMOUT_SCHED) {
                  callout_stop(&changer->short_handle);
                  changer->flags &= ~CHANGER_SHORT_TMOUT_SCHED;
          }
  
          /*
           * We need to schedule timeouts, but we only do this after the
           * first transaction has completed.  This eliminates the changer
           * switch time.
           */
          changer->flags |= CHANGER_NEED_TIMEOUT;
  }
  
  static void
  cdchangerschedule(struct cd_softc *softc)
  {
          struct cdchanger *changer;
  
          changer = softc->changer;
  
          /*
           * If this is a changer, and this is the current device,
           * and this device has at least the minimum time quantum to
           * run, see if we can switch it out.
           */
          if ((softc->flags & CD_FLAG_ACTIVE) 
           && ((changer->flags & CHANGER_SHORT_TMOUT_SCHED) == 0)
           && ((changer->flags & CHANGER_NEED_TIMEOUT) == 0)) {
                  /*
                   * We try three things here.  The first is that we
                   * check to see whether the schedule on completion
                   * flag is set.  If it is, we decrement the number
                   * of buffers left, and if it's zero, we reschedule.
                   * Next, we check to see whether the pending buffer
                   * queue is empty and whether there are no
                   * outstanding transactions.  If so, we reschedule.
                   * Next, we see if the pending buffer queue is empty.
                   * If it is, we set the number of buffers left to
                   * the current active buffer count and set the
                   * schedule on complete flag.
                   */
                  if (softc->flags & CD_FLAG_SCHED_ON_COMP) {
                          if (--softc->bufs_left == 0) {
                                  softc->changer->flags |=
                                          CHANGER_MANUAL_CALL;
                                  softc->flags &= ~CD_FLAG_SCHED_ON_COMP;
                                  cdrunchangerqueue(softc->changer);
                          }
                  } else if ((bioq_first(&softc->bio_queue) == NULL)
                          && (softc->outstanding_cmds == 0)) {
                          softc->changer->flags |= CHANGER_MANUAL_CALL;
                          cdrunchangerqueue(softc->changer);
                  }
          } else if ((softc->changer->flags & CHANGER_NEED_TIMEOUT) 
                  && (softc->flags & CD_FLAG_ACTIVE)) {
  
                  /*
                   * Now that the first transaction to this
                   * particular device has completed, we can go ahead
                   * and schedule our timeouts.
                   */
                  if ((changer->flags & CHANGER_TIMEOUT_SCHED) == 0) {
                          callout_reset(&changer->long_handle,
                              changer_max_busy_seconds * hz,
                              cdrunchangerqueue, changer);
                          changer->flags |= CHANGER_TIMEOUT_SCHED;
                  } else
                          printf("cdchangerschedule: already have a long"
                                 " timeout!\n");
  
                  if ((changer->flags & CHANGER_SHORT_TMOUT_SCHED) == 0) {
                          callout_reset(&changer->short_handle,
                              changer_min_busy_seconds * hz,
                              cdshorttimeout, changer);
                          changer->flags |= CHANGER_SHORT_TMOUT_SCHED;
                  } else
                          printf("cdchangerschedule: already have a short "
                                 "timeout!\n");
  
                  /*
                   * We just scheduled timeouts, no need to schedule
                   * more.
                   */
                  changer->flags &= ~CHANGER_NEED_TIMEOUT;
  
          }
  }
  
  static int
  cdrunccb(union ccb *ccb, int (*error_routine)(union ccb *ccb,
                                                u_int32_t cam_flags,
                                                u_int32_t sense_flags),
           u_int32_t cam_flags, u_int32_t sense_flags)
  {
          struct cd_softc *softc;
          struct cam_periph *periph;
          int error;
  
          periph = xpt_path_periph(ccb->ccb_h.path);
          softc = (struct cd_softc *)periph->softc;
  
          error = cam_periph_runccb(ccb, error_routine, cam_flags, sense_flags,
                                    softc->disk->d_devstat);
  
          if (softc->flags & CD_FLAG_CHANGER)
                  cdchangerschedule(softc);
  
          return(error);
  }
  
  static union ccb *
  cdgetccb(struct cam_periph *periph, u_int32_t priority)
  {
          struct cd_softc *softc;
  
          softc = (struct cd_softc *)periph->softc;
  
          if (softc->flags & CD_FLAG_CHANGER) {
                  /*
                   * This should work the first time this device is woken up,
                   * but just in case it doesn't, we use a while loop.
                   */
                  while ((softc->flags & CD_FLAG_ACTIVE) == 0) {
                          /*
                           * If this changer isn't already queued, queue it up.
                           */
                          if (softc->pinfo.index == CAM_UNQUEUED_INDEX) {
                                  softc->pinfo.priority = CAM_PRIORITY_NORMAL;
                                  softc->pinfo.generation =
                                          ++softc->changer->devq.generation;
                                  camq_insert(&softc->changer->devq,
                                              (cam_pinfo *)softc);
                          }
                          if (((softc->changer->flags & CHANGER_TIMEOUT_SCHED)==0)
                           && ((softc->changer->flags & CHANGER_NEED_TIMEOUT)==0)
                           && ((softc->changer->flags
                                & CHANGER_SHORT_TMOUT_SCHED)==0)) {
                                  softc->changer->flags |= CHANGER_MANUAL_CALL;
                                  cdrunchangerqueue(softc->changer);
                          } else
                                  msleep(&softc->changer, periph->sim->mtx,
                                      PRIBIO, "cgticb", 0);
                  }
          }
          return(cam_periph_getccb(periph, priority));
  }
  
  
  /*
   * Actually translate the requested transfer into one the physical driver
   * can understand.  The transfer is described by a buf and will include
   * only one physical transfer.
   */
  static void
  cdstrategy(struct bio *bp)
  {
          struct cam_periph *periph;
          struct cd_softc *softc;
  
          periph = (struct cam_periph *)bp->bio_disk->d_drv1;
          if (periph == NULL) {
                  biofinish(bp, NULL, ENXIO);
                  return;
          }
  
          cam_periph_lock(periph);
          CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("entering cdstrategy\n"));
  
          softc = (struct cd_softc *)periph->softc;
  
          /*
           * If the device has been made invalid, error out
           */
          if ((softc->flags & CD_FLAG_INVALID)) {
                  cam_periph_unlock(periph);
                  biofinish(bp, NULL, ENXIO);
                  return;
          }
  
          /*
           * If we don't have valid media, look for it before trying to
           * schedule the I/O.
           */
          if ((softc->flags & CD_FLAG_VALID_MEDIA) == 0) {
                  int error;
  
                  error = cdcheckmedia(periph);
                  if (error != 0) {
                          cam_periph_unlock(periph);
                          biofinish(bp, NULL, error);
                          return;
                  }
          }
  
          /*
           * Place it in the queue of disk activities for this disk
           */
          bioq_disksort(&softc->bio_queue, bp);
  
          /*
           * Schedule ourselves for performing the work.  We do things
           * differently for changers.
           */
          if ((softc->flags & CD_FLAG_CHANGER) == 0)
                  xpt_schedule(periph, CAM_PRIORITY_NORMAL);
          else
                  cdschedule(periph, CAM_PRIORITY_NORMAL);
  
          cam_periph_unlock(periph);
          return;
  }
  
  static void
  cdstart(struct cam_periph *periph, union ccb *start_ccb)
  {
          struct cd_softc *softc;
          struct bio *bp;
          struct ccb_scsiio *csio;
          struct scsi_read_capacity_data *rcap;
  
          softc = (struct cd_softc *)periph->softc;
  
          CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("entering cdstart\n"));
  
          switch (softc->state) {
          case CD_STATE_NORMAL:
          {
                  bp = bioq_first(&softc->bio_queue);
                  if (periph->immediate_priority <= periph->pinfo.priority) {
                          start_ccb->ccb_h.ccb_state = CD_CCB_WAITING;
  
                          SLIST_INSERT_HEAD(&periph->ccb_list, &start_ccb->ccb_h,
                                            periph_links.sle);
                          periph->immediate_priority = CAM_PRIORITY_NONE;
                          wakeup(&periph->ccb_list);
                  } else if (bp == NULL) {
                          xpt_release_ccb(start_ccb);
                  } else {
                          bioq_remove(&softc->bio_queue, bp);
  
                          scsi_read_write(&start_ccb->csio,
                                          /*retries*/ cd_retry_count,
                                          /* cbfcnp */ cddone,
                                          MSG_SIMPLE_Q_TAG,
                                          /* read */bp->bio_cmd == BIO_READ,
                                          /* byte2 */ 0,
                                          /* minimum_cmd_size */ 10,
                                          /* lba */ bp->bio_offset /
                                            softc->params.blksize,
                                          bp->bio_bcount / softc->params.blksize,
                                          /* data_ptr */ bp->bio_data,
                                          /* dxfer_len */ bp->bio_bcount,
                                          /* sense_len */ SSD_FULL_SIZE,
                                          /* timeout */ 30000);
                          /* Use READ CD command for audio tracks. */
                          if (softc->params.blksize == 2352) {
                                  start_ccb->csio.cdb_io.cdb_bytes[0] = READ_CD;
                                  start_ccb->csio.cdb_io.cdb_bytes[9] = 0xf8;
                                  start_ccb->csio.cdb_io.cdb_bytes[10] = 0;
                                  start_ccb->csio.cdb_io.cdb_bytes[11] = 0;
                                  start_ccb->csio.cdb_len = 12;
                          }
                          start_ccb->ccb_h.ccb_state = CD_CCB_BUFFER_IO;
  
                          
                          LIST_INSERT_HEAD(&softc->pending_ccbs,
                                           &start_ccb->ccb_h, periph_links.le);
                          softc->outstanding_cmds++;
  
                          /* We expect a unit attention from this device */
                          if ((softc->flags & CD_FLAG_RETRY_UA) != 0) {
                                  start_ccb->ccb_h.ccb_state |= CD_CCB_RETRY_UA;
                                  softc->flags &= ~CD_FLAG_RETRY_UA;
                          }
  
                          start_ccb->ccb_h.ccb_bp = bp;
                          bp = bioq_first(&softc->bio_queue);
  
                          xpt_action(start_ccb);
                  }
                  if (bp != NULL) {
                          /* Have more work to do, so ensure we stay scheduled */
                          xpt_schedule(periph, CAM_PRIORITY_NORMAL);
                  }
                  break;
          }
          case CD_STATE_PROBE:
          {
  
                  rcap = (struct scsi_read_capacity_data *)malloc(sizeof(*rcap),
                      M_SCSICD, M_NOWAIT | M_ZERO);
                  if (rcap == NULL) {
                          xpt_print(periph->path,
                              "cdstart: Couldn't malloc read_capacity data\n");
                          /* cd_free_periph??? */
                          break;
                  }
                  csio = &start_ccb->csio;
                  scsi_read_capacity(csio,
                                     /*retries*/ cd_retry_count,
                                     cddone,
                                     MSG_SIMPLE_Q_TAG,
                                     rcap,
                                     SSD_FULL_SIZE,
                                     /*timeout*/20000);
                  start_ccb->ccb_h.ccb_bp = NULL;
                  start_ccb->ccb_h.ccb_state = CD_CCB_PROBE;
                  xpt_action(start_ccb);
                  break;
          }
          }
  }
  
  static void
  cddone(struct cam_periph *periph, union ccb *done_ccb)
  { 
          struct cd_softc *softc;
          struct ccb_scsiio *csio;
  
          CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("entering cddone\n"));
  
          softc = (struct cd_softc *)periph->softc;
          csio = &done_ccb->csio;
  
          switch (csio->ccb_h.ccb_state & CD_CCB_TYPE_MASK) {
          case CD_CCB_BUFFER_IO:
          {
                  struct bio      *bp;
                  int             error;
  
                  bp = (struct bio *)done_ccb->ccb_h.ccb_bp;
                  error = 0;
  
                  if ((done_ccb->ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_CMP) {
                          int sf;
  
                          if ((done_ccb->ccb_h.ccb_state & CD_CCB_RETRY_UA) != 0)
                                  sf = SF_RETRY_UA;
                          else
                                  sf = 0;
  
                          error = cderror(done_ccb, CAM_RETRY_SELTO, sf);
                          if (error == ERESTART) {
                                  /*
                                   * A retry was scheuled, so
                                   * just return.
                                   */
                                  return;
                          }
                  }
  
                  if (error != 0) {
                          xpt_print(periph->path,
                              "cddone: got error %#x back\n", error);
                          bioq_flush(&softc->bio_queue, NULL, EIO);
                          bp->bio_resid = bp->bio_bcount;
                          bp->bio_error = error;
                          bp->bio_flags |= BIO_ERROR;
                          if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0)
                                  cam_release_devq(done_ccb->ccb_h.path,
                                           /*relsim_flags*/0,
                                           /*reduction*/0,
                                           /*timeout*/0,
                                           /*getcount_only*/0);
  
                  } else {
                          bp->bio_resid = csio->resid;
                          bp->bio_error = 0;
                          if (bp->bio_resid != 0) {
                                  /*
                                   * Short transfer ??? 
                                   * XXX: not sure this is correct for partial
                                   * transfers at EOM
                                   */
                                  bp->bio_flags |= BIO_ERROR;
                          }
                  }
  
                  LIST_REMOVE(&done_ccb->ccb_h, periph_links.le);
                  softc->outstanding_cmds--;
  
                  if (softc->flags & CD_FLAG_CHANGER)
                          cdchangerschedule(softc);
  
                  biofinish(bp, NULL, 0);
                  break;
          }
          case CD_CCB_PROBE:
          {
                  struct     scsi_read_capacity_data *rdcap;
                  char       announce_buf[120]; /*
                                                 * Currently (9/30/97) the 
                                                 * longest possible announce 
                                                 * buffer is 108 bytes, for the 
                                                 * first error case below.  
                                                 * That is 39 bytes for the 
                                                 * basic string, 16 bytes for the
                                                 * biggest sense key (hardware 
                                                 * error), 52 bytes for the
                                                 * text of the largest sense 
                                                 * qualifier valid for a CDROM,
                                                 * (0x72, 0x03 or 0x04,
                                                 * 0x03), and one byte for the
                                                 * null terminating character.
                                                 * To allow for longer strings, 
                                                 * the announce buffer is 120
                                                 * bytes.
                                                 */
                  struct     cd_params *cdp;
  
                  cdp = &softc->params;
  
                  rdcap = (struct scsi_read_capacity_data *)csio->data_ptr;
                  
                  cdp->disksize = scsi_4btoul (rdcap->addr) + 1;
                  cdp->blksize = scsi_4btoul (rdcap->length);
  
                  if ((csio->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_CMP) {
  
                          snprintf(announce_buf, sizeof(announce_buf),
                                  "cd present [%lu x %lu byte records]",
                                  cdp->disksize, (u_long)cdp->blksize);
  
                  } else {
                          int     error;
                          /*
                           * Retry any UNIT ATTENTION type errors.  They
                           * are expected at boot.
                           */
                          error = cderror(done_ccb, CAM_RETRY_SELTO,
                                          SF_RETRY_UA | SF_NO_PRINT);
                          if (error == ERESTART) {
                                  /*
                                   * A retry was scheuled, so
                                   * just return.
                                   */
                                  return;
                          } else if (error != 0) {
  
                                  struct scsi_sense_data *sense;
                                  int asc, ascq;
                                  int sense_key, error_code;
                                  int have_sense;
                                  cam_status status;
                                  struct ccb_getdev cgd;
  
                                  /* Don't wedge this device's queue */
                                  if ((done_ccb->ccb_h.status & CAM_DEV_QFRZN) != 0)
                                          cam_release_devq(done_ccb->ccb_h.path,
                                                   /*relsim_flags*/0,
                                                   /*reduction*/0,
                                                   /*timeout*/0,
                                                   /*getcount_only*/0);
  
                                  status = done_ccb->ccb_h.status;
  
                                  xpt_setup_ccb(&cgd.ccb_h, 
                                                done_ccb->ccb_h.path,
                                                CAM_PRIORITY_NORMAL);
                                  cgd.ccb_h.func_code = XPT_GDEV_TYPE;
                                  xpt_action((union ccb *)&cgd);
  
                                  if (((csio->ccb_h.flags & CAM_SENSE_PHYS) != 0)
                                   || ((csio->ccb_h.flags & CAM_SENSE_PTR) != 0)
                                   || ((status & CAM_AUTOSNS_VALID) == 0))
                                          have_sense = FALSE;
                                  else
                                          have_sense = TRUE;
  
                                  if (have_sense) {
                                          sense = &csio->sense_data;
                                          scsi_extract_sense(sense, &error_code,
                                                             &sense_key, 
                                                             &asc, &ascq);
                                  }
                                  /*
                                   * Attach to anything that claims to be a
                                   * CDROM or WORM device, as long as it
                                   * doesn't return a "Logical unit not
                                   * supported" (0x25) error.
                                   */
                                  if ((have_sense) && (asc != 0x25)
                                   && (error_code == SSD_CURRENT_ERROR)) {
                                          const char *sense_key_desc;
                                          const char *asc_desc;
  
                                          scsi_sense_desc(sense_key, asc, ascq,
                                                          &cgd.inq_data,
                                                          &sense_key_desc,
                                                          &asc_desc);
                                          snprintf(announce_buf,
                                              sizeof(announce_buf),
                                                  "Attempt to query device "
                                                  "size failed: %s, %s",
                                                  sense_key_desc,
                                                  asc_desc);
                                  } else if ((have_sense == 0) 
                                        && ((status & CAM_STATUS_MASK) ==
                                             CAM_SCSI_STATUS_ERROR)
                                        && (csio->scsi_status ==
                                            SCSI_STATUS_BUSY)) {
                                          snprintf(announce_buf,
                                              sizeof(announce_buf),
                                              "Attempt to query device "
                                              "size failed: SCSI Status: %s",
                                              scsi_status_string(csio));
                                  } else if (SID_TYPE(&cgd.inq_data) == T_CDROM) {
                                          /*
                                           * We only print out an error for
                                           * CDROM type devices.  For WORM
                                           * devices, we don't print out an
                                           * error since a few WORM devices
                                           * don't support CDROM commands.
                                           * If we have sense information, go
                                           * ahead and print it out.
                                           * Otherwise, just say that we 
                                           * couldn't attach.
                                           */
  
                                          /*
                                           * Just print out the error, not
                                           * the full probe message, when we
                                           * don't attach.
                                           */
                                          if (have_sense)
                                                  scsi_sense_print(
                                                          &done_ccb->csio);
                                          else {
                                                  xpt_print(periph->path,
                                                      "got CAM status %#x\n",
                                                      done_ccb->ccb_h.status);
                                          }
                                          xpt_print(periph->path, "fatal error, "
                                              "failed to attach to device\n");
                                          /*
                                           * Invalidate this peripheral.
                                           */
                                          cam_periph_invalidate(periph);
  
                                          announce_buf[0] = '\0';
                                  } else {
  
                                          /*
                                           * Invalidate this peripheral.
                                           */
                                          cam_periph_invalidate(periph);
                                          announce_buf[0] = '\0';
                                  }
                          }
                  }
                  free(rdcap, M_SCSICD);
                  if (announce_buf[0] != '\0') {
                          xpt_announce_periph(periph, announce_buf);
                          if (softc->flags & CD_FLAG_CHANGER)
                                  cdchangerschedule(softc);
                          /*
                           * Create our sysctl variables, now that we know
                           * we have successfully attached.
                           */
                          taskqueue_enqueue(taskqueue_thread,&softc->sysctl_task);
                  }
                  softc->state = CD_STATE_NORMAL;         
                  /*
                   * Since our peripheral may be invalidated by an error
                   * above or an external event, we must release our CCB
                   * before releasing the probe lock on the peripheral.
                   * The peripheral will only go away once the last lock
                   * is removed, and we need it around for the CCB release
                   * operation.
                   */
                  xpt_release_ccb(done_ccb);
                  cam_periph_unhold(periph);
                  return;
          }
          case CD_CCB_WAITING:
          {
                  /* Caller will release the CCB */
                  CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, 
                            ("trying to wakeup ccbwait\n"));
  
                  wakeup(&done_ccb->ccb_h.cbfcnp);
                  return;
          }
          default:
                  break;
          }
          xpt_release_ccb(done_ccb);
  }
  
  static union cd_pages *
  cdgetpage(struct cd_mode_params *mode_params)
  {
          union cd_pages *page;
  
          if (mode_params->cdb_size == 10)
                  page = (union cd_pages *)find_mode_page_10(
                          (struct scsi_mode_header_10 *)mode_params->mode_buf);
          else
                  page = (union cd_pages *)find_mode_page_6(
                          (struct scsi_mode_header_6 *)mode_params->mode_buf);
  
          return (page);
  }
  
  static int
  cdgetpagesize(int page_num)
  {
          int i;
  
          for (i = 0; i < (sizeof(cd_page_size_table)/
               sizeof(cd_page_size_table[0])); i++) {
                  if (cd_page_size_table[i].page == page_num)
                          return (cd_page_size_table[i].page_size);
          }
  
          return (-1);
  }
  
  static int
  cdioctl(struct disk *dp, u_long cmd, void *addr, int flag, struct thread *td)
  {
  
          struct  cam_periph *periph;
          struct  cd_softc *softc;
          int     nocopyout, error = 0;
  
          periph = (struct cam_periph *)dp->d_drv1;
          if (periph == NULL)
                  return(ENXIO);  
  
          cam_periph_lock(periph);
          CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("entering cdioctl\n"));
  
          softc = (struct cd_softc *)periph->softc;
  
          CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, 
                    ("trying to do ioctl %#lx\n", cmd));
  
          if ((error = cam_periph_hold(periph, PRIBIO | PCATCH)) != 0) {
                  cam_periph_unlock(periph);
                  cam_periph_release(periph);
                  return (error);
          }
  
          /*
           * If we don't have media loaded, check for it.  If still don't
           * have media loaded, we can only do a load or eject.
           *
           * We only care whether media is loaded if this is a cd-specific ioctl
           * (thus the IOCGROUP check below).  Note that this will break if
           * anyone adds any ioctls into the switch statement below that don't
           * have their ioctl group set to 'c'.
           */
          if (((softc->flags & CD_FLAG_VALID_MEDIA) == 0)
           && ((cmd != CDIOCCLOSE)
            && (cmd != CDIOCEJECT))
           && (IOCGROUP(cmd) == 'c')) {
                  error = cdcheckmedia(periph);
                  if (error != 0) {
                          cam_periph_unhold(periph);
                          cam_periph_unlock(periph);
                          return (error);
                  }
          }
          /*
           * Drop the lock here so later mallocs can use WAITOK.  The periph
           * is essentially locked still with the cam_periph_hold call above.
           */
          cam_periph_unlock(periph);
  
          nocopyout = 0;
          switch (cmd) {
  
          case CDIOCPLAYTRACKS:
                  {
                          struct ioc_play_track *args
                              = (struct ioc_play_track *) addr;
                          struct cd_mode_params params;
                          union cd_pages *page;
  
                          params.alloc_len = sizeof(union cd_mode_data_6_10);
                          params.mode_buf = malloc(params.alloc_len, M_SCSICD,
                                                   M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOCPLAYTRACKS\n"));
  
                          error = cdgetmode(periph, &params, AUDIO_PAGE);
                          if (error) {
                                  free(params.mode_buf, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          page = cdgetpage(&params);
  
                          page->audio.flags &= ~CD_PA_SOTC;
                          page->audio.flags |= CD_PA_IMMED;
                          error = cdsetmode(periph, &params);
                          free(params.mode_buf, M_SCSICD);
                          if (error) {
                                  cam_periph_unlock(periph);
                                  break;
                          }
  
                          /*
                           * This was originally implemented with the PLAY
                           * AUDIO TRACK INDEX command, but that command was
                           * deprecated after SCSI-2.  Most (all?) SCSI CDROM
                           * drives support it but ATAPI and ATAPI-derivative
                           * drives don't seem to support it.  So we keep a
                           * cache of the table of contents and translate
                           * track numbers to MSF format.
                           */
                          if (softc->flags & CD_FLAG_VALID_TOC) {
                                  union msf_lba *sentry, *eentry;
                                  int st, et;
  
                                  if (args->end_track <
                                      softc->toc.header.ending_track + 1)
                                          args->end_track++;
                                  if (args->end_track >
                                      softc->toc.header.ending_track + 1)
                                          args->end_track =
                                              softc->toc.header.ending_track + 1;
                                  st = args->start_track -
                                          softc->toc.header.starting_track;
                                  et = args->end_track -
                                          softc->toc.header.starting_track;
                                  if ((st < 0)
                                   || (et < 0)
                                   || (st > (softc->toc.header.ending_track -
                                       softc->toc.header.starting_track))) {
                                          error = EINVAL;
                                          break;
                                  }
                                  sentry = &softc->toc.entries[st].addr;
                                  eentry = &softc->toc.entries[et].addr;
                                  error = cdplaymsf(periph,
                                                    sentry->msf.minute,
                                                    sentry->msf.second,
                                                    sentry->msf.frame,
                                                    eentry->msf.minute,
                                                    eentry->msf.second,
                                                    eentry->msf.frame);
                          } else {
                                  /*
                                   * If we don't have a valid TOC, try the
                                   * play track index command.  It is part of
                                   * the SCSI-2 spec, but was removed in the
                                   * MMC specs.  ATAPI and ATAPI-derived
                                   * drives don't support it.
                                   */
                                  if (softc->quirks & CD_Q_BCD_TRACKS) {
                                          args->start_track =
                                                  bin2bcd(args->start_track);
                                          args->end_track =
                                                  bin2bcd(args->end_track);
                                  }
                                  error = cdplaytracks(periph,
                                                       args->start_track,
                                                       args->start_index,
                                                       args->end_track,
                                                       args->end_index);
                          }
                          cam_periph_unlock(periph);
                  }
                  break;
          case CDIOCPLAYMSF:
                  {
                          struct ioc_play_msf *args
                                  = (struct ioc_play_msf *) addr;
                          struct cd_mode_params params;
                          union cd_pages *page;
  
                          params.alloc_len = sizeof(union cd_mode_data_6_10);
                          params.mode_buf = malloc(params.alloc_len, M_SCSICD,
                                                   M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOCPLAYMSF\n"));
  
                          error = cdgetmode(periph, &params, AUDIO_PAGE);
                          if (error) {
                                  free(params.mode_buf, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          page = cdgetpage(&params);
  
                          page->audio.flags &= ~CD_PA_SOTC;
                          page->audio.flags |= CD_PA_IMMED;
                          error = cdsetmode(periph, &params);
                          free(params.mode_buf, M_SCSICD);
                          if (error) {
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          error = cdplaymsf(periph,
                                            args->start_m,
                                            args->start_s,
                                            args->start_f,
                                            args->end_m,
                                            args->end_s,
                                            args->end_f);
                          cam_periph_unlock(periph);
                  }
                  break;
          case CDIOCPLAYBLOCKS:
                  {
                          struct ioc_play_blocks *args
                                  = (struct ioc_play_blocks *) addr;
                          struct cd_mode_params params;
                          union cd_pages *page;
  
                          params.alloc_len = sizeof(union cd_mode_data_6_10);
                          params.mode_buf = malloc(params.alloc_len, M_SCSICD,
                                                   M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOCPLAYBLOCKS\n"));
  
  
                          error = cdgetmode(periph, &params, AUDIO_PAGE);
                          if (error) {
                                  free(params.mode_buf, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          page = cdgetpage(&params);
  
                          page->audio.flags &= ~CD_PA_SOTC;
                          page->audio.flags |= CD_PA_IMMED;
                          error = cdsetmode(periph, &params);
                          free(params.mode_buf, M_SCSICD);
                          if (error) {
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          error = cdplay(periph, args->blk, args->len);
                          cam_periph_unlock(periph);
                  }
                  break;
          case CDIOCREADSUBCHANNEL_SYSSPACE:
                  nocopyout = 1;
                  /* Fallthrough */
          case CDIOCREADSUBCHANNEL:
                  {
                          struct ioc_read_subchannel *args
                                  = (struct ioc_read_subchannel *) addr;
                          struct cd_sub_channel_info *data;
                          u_int32_t len = args->data_len;
  
                          data = malloc(sizeof(struct cd_sub_channel_info), 
                                        M_SCSICD, M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOCREADSUBCHANNEL\n"));
  
                          if ((len > sizeof(struct cd_sub_channel_info)) ||
                              (len < sizeof(struct cd_sub_channel_header))) {
                                  printf(
                                          "scsi_cd: cdioctl: "
                                          "cdioreadsubchannel: error, len=%d\n",
                                          len);
                                  error = EINVAL;
                                  free(data, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
  
                          if (softc->quirks & CD_Q_BCD_TRACKS)
                                  args->track = bin2bcd(args->track);
  
                          error = cdreadsubchannel(periph, args->address_format,
                                  args->data_format, args->track, data, len);
  
                          if (error) {
                                  free(data, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          if (softc->quirks & CD_Q_BCD_TRACKS)
                                  data->what.track_info.track_number =
                                      bcd2bin(data->what.track_info.track_number);
                          len = min(len, ((data->header.data_len[0] << 8) +
                                  data->header.data_len[1] +
                                  sizeof(struct cd_sub_channel_header)));
                          cam_periph_unlock(periph);
                          if (nocopyout == 0) {
                                  if (copyout(data, args->data, len) != 0) {
                                          error = EFAULT;
                                  }
                          } else {
                                  bcopy(data, args->data, len);
                          }
                          free(data, M_SCSICD);
                  }
                  break;
  
          case CDIOREADTOCHEADER:
                  {
                          struct ioc_toc_header *th;
  
                          th = malloc(sizeof(struct ioc_toc_header), M_SCSICD,
                                      M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOREADTOCHEADER\n"));
  
                          error = cdreadtoc(periph, 0, 0, (u_int8_t *)th, 
                                            sizeof (*th), /*sense_flags*/SF_NO_PRINT);
                          if (error) {
                                  free(th, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          if (softc->quirks & CD_Q_BCD_TRACKS) {
                                  /* we are going to have to convert the BCD
                                   * encoding on the cd to what is expected
                                   */
                                  th->starting_track = 
                                          bcd2bin(th->starting_track);
                                  th->ending_track = bcd2bin(th->ending_track);
                          }
                          th->len = ntohs(th->len);
                          bcopy(th, addr, sizeof(*th));
                          free(th, M_SCSICD);
                          cam_periph_unlock(periph);
                  }
                  break;
          case CDIOREADTOCENTRYS:
                  {
                          struct cd_tocdata *data;
                          struct cd_toc_single *lead;
                          struct ioc_read_toc_entry *te =
                                  (struct ioc_read_toc_entry *) addr;
                          struct ioc_toc_header *th;
                          u_int32_t len, readlen, idx, num;
                          u_int32_t starting_track = te->starting_track;
  
                          data = malloc(sizeof(*data), M_SCSICD, M_WAITOK | M_ZERO);
                          lead = malloc(sizeof(*lead), M_SCSICD, M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOREADTOCENTRYS\n"));
  
                          if (te->data_len < sizeof(struct cd_toc_entry)
                           || (te->data_len % sizeof(struct cd_toc_entry)) != 0
                           || (te->address_format != CD_MSF_FORMAT
                            && te->address_format != CD_LBA_FORMAT)) {
                                  error = EINVAL;
                                  printf("scsi_cd: error in readtocentries, "
                                         "returning EINVAL\n");
                                  free(data, M_SCSICD);
                                  free(lead, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
  
                          th = &data->header;
                          error = cdreadtoc(periph, 0, 0, (u_int8_t *)th, 
                                            sizeof (*th), /*sense_flags*/0);
                          if (error) {
                                  free(data, M_SCSICD);
                                  free(lead, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
  
                          if (softc->quirks & CD_Q_BCD_TRACKS) {
                                  /* we are going to have to convert the BCD
                                   * encoding on the cd to what is expected
                                   */
                                  th->starting_track =
                                      bcd2bin(th->starting_track);
                                  th->ending_track = bcd2bin(th->ending_track);
                          }
  
                          if (starting_track == 0)
                                  starting_track = th->starting_track;
                          else if (starting_track == LEADOUT)
                                  starting_track = th->ending_track + 1;
                          else if (starting_track < th->starting_track ||
                                   starting_track > th->ending_track + 1) {
                                  printf("scsi_cd: error in readtocentries, "
                                         "returning EINVAL\n");
                                  free(data, M_SCSICD);
                                  free(lead, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  error = EINVAL;
                                  break;
                          }
  
                          /* calculate reading length without leadout entry */
                          readlen = (th->ending_track - starting_track + 1) *
                                    sizeof(struct cd_toc_entry);
  
                          /* and with leadout entry */
                          len = readlen + sizeof(struct cd_toc_entry);
                          if (te->data_len < len) {
                                  len = te->data_len;
                                  if (readlen > len)
                                          readlen = len;
                          }
                          if (len > sizeof(data->entries)) {
                                  printf("scsi_cd: error in readtocentries, "
                                         "returning EINVAL\n");
                                  error = EINVAL;
                                  free(data, M_SCSICD);
                                  free(lead, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          num = len / sizeof(struct cd_toc_entry);
  
                          if (readlen > 0) {
                                  error = cdreadtoc(periph, te->address_format,
                                                    starting_track,
                                                    (u_int8_t *)data,
                                                    readlen + sizeof (*th),
                                                    /*sense_flags*/0);
                                  if (error) {
                                          free(data, M_SCSICD);
                                          free(lead, M_SCSICD);
                                          cam_periph_unlock(periph);
                                          break;
                                  }
                          }
  
                          /* make leadout entry if needed */
                          idx = starting_track + num - 1;
                          if (softc->quirks & CD_Q_BCD_TRACKS)
                                  th->ending_track = bcd2bin(th->ending_track);
                          if (idx == th->ending_track + 1) {
                                  error = cdreadtoc(periph, te->address_format,
                                                    LEADOUT, (u_int8_t *)lead,
                                                    sizeof(*lead),
                                                    /*sense_flags*/0);
                                  if (error) {
                                          free(data, M_SCSICD);
                                          free(lead, M_SCSICD);
                                          cam_periph_unlock(periph);
                                          break;
                                  }
                                  data->entries[idx - starting_track] = 
                                          lead->entry;
                          }
                          if (softc->quirks & CD_Q_BCD_TRACKS) {
                                  for (idx = 0; idx < num - 1; idx++) {
                                          data->entries[idx].track =
                                              bcd2bin(data->entries[idx].track);
                                  }
                          }
  
                          cam_periph_unlock(periph);
                          error = copyout(data->entries, te->data, len);
                          free(data, M_SCSICD);
                          free(lead, M_SCSICD);
                  }
                  break;
          case CDIOREADTOCENTRY:
                  {
                          struct cd_toc_single *data;
                          struct ioc_read_toc_single_entry *te =
                                  (struct ioc_read_toc_single_entry *) addr;
                          struct ioc_toc_header *th;
                          u_int32_t track;
  
                          data = malloc(sizeof(*data), M_SCSICD, M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOREADTOCENTRY\n"));
  
                          if (te->address_format != CD_MSF_FORMAT
                              && te->address_format != CD_LBA_FORMAT) {
                                  printf("error in readtocentry, "
                                         " returning EINVAL\n");
                                  free(data, M_SCSICD);
                                  error = EINVAL;
                                  cam_periph_unlock(periph);
                                  break;
                          }
  
                          th = &data->header;
                          error = cdreadtoc(periph, 0, 0, (u_int8_t *)th,
                                            sizeof (*th), /*sense_flags*/0);
                          if (error) {
                                  free(data, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
  
                          if (softc->quirks & CD_Q_BCD_TRACKS) {
                                  /* we are going to have to convert the BCD
                                   * encoding on the cd to what is expected
                                   */
                                  th->starting_track =
                                      bcd2bin(th->starting_track);
                                  th->ending_track = bcd2bin(th->ending_track);
                          }
                          track = te->track;
                          if (track == 0)
                                  track = th->starting_track;
                          else if (track == LEADOUT)
                                  /* OK */;
                          else if (track < th->starting_track ||
                                   track > th->ending_track + 1) {
                                  printf("error in readtocentry, "
                                         " returning EINVAL\n");
                                  free(data, M_SCSICD);
                                  error = EINVAL;
                                  cam_periph_unlock(periph);
                                  break;
                          }
  
                          error = cdreadtoc(periph, te->address_format, track,
                                            (u_int8_t *)data, sizeof(*data),
                                            /*sense_flags*/0);
                          if (error) {
                                  free(data, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
  
                          if (softc->quirks & CD_Q_BCD_TRACKS)
                                  data->entry.track = bcd2bin(data->entry.track);
                          bcopy(&data->entry, &te->entry,
                                sizeof(struct cd_toc_entry));
                          free(data, M_SCSICD);
                          cam_periph_unlock(periph);
                  }
                  break;
          case CDIOCSETPATCH:
                  {
                          struct ioc_patch *arg = (struct ioc_patch *)addr;
                          struct cd_mode_params params;
                          union cd_pages *page;
  
                          params.alloc_len = sizeof(union cd_mode_data_6_10);
                          params.mode_buf = malloc(params.alloc_len, M_SCSICD, 
                                                   M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOCSETPATCH\n"));
  
                          error = cdgetmode(periph, &params, AUDIO_PAGE);
                          if (error) {
                                  free(params.mode_buf, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          page = cdgetpage(&params);
  
                          page->audio.port[LEFT_PORT].channels = 
                                  arg->patch[0];
                          page->audio.port[RIGHT_PORT].channels = 
                                  arg->patch[1];
                          page->audio.port[2].channels = arg->patch[2];
                          page->audio.port[3].channels = arg->patch[3];
                          error = cdsetmode(periph, &params);
                          free(params.mode_buf, M_SCSICD);
                          cam_periph_unlock(periph);
                  }
                  break;
          case CDIOCGETVOL:
                  {
                          struct ioc_vol *arg = (struct ioc_vol *) addr;
                          struct cd_mode_params params;
                          union cd_pages *page;
  
                          params.alloc_len = sizeof(union cd_mode_data_6_10);
                          params.mode_buf = malloc(params.alloc_len, M_SCSICD, 
                                                   M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOCGETVOL\n"));
  
                          error = cdgetmode(periph, &params, AUDIO_PAGE);
                          if (error) {
                                  free(params.mode_buf, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          page = cdgetpage(&params);
  
                          arg->vol[LEFT_PORT] = 
                                  page->audio.port[LEFT_PORT].volume;
                          arg->vol[RIGHT_PORT] = 
                                  page->audio.port[RIGHT_PORT].volume;
                          arg->vol[2] = page->audio.port[2].volume;
                          arg->vol[3] = page->audio.port[3].volume;
                          free(params.mode_buf, M_SCSICD);
                          cam_periph_unlock(periph);
                  }
                  break;
          case CDIOCSETVOL:
                  {
                          struct ioc_vol *arg = (struct ioc_vol *) addr;
                          struct cd_mode_params params;
                          union cd_pages *page;
  
                          params.alloc_len = sizeof(union cd_mode_data_6_10);
                          params.mode_buf = malloc(params.alloc_len, M_SCSICD, 
                                                   M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOCSETVOL\n"));
  
                          error = cdgetmode(periph, &params, AUDIO_PAGE);
                          if (error) {
                                  free(params.mode_buf, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          page = cdgetpage(&params);
  
                          page->audio.port[LEFT_PORT].channels = CHANNEL_0;
                          page->audio.port[LEFT_PORT].volume = 
                                  arg->vol[LEFT_PORT];
                          page->audio.port[RIGHT_PORT].channels = CHANNEL_1;
                          page->audio.port[RIGHT_PORT].volume = 
                                  arg->vol[RIGHT_PORT];
                          page->audio.port[2].volume = arg->vol[2];
                          page->audio.port[3].volume = arg->vol[3];
                          error = cdsetmode(periph, &params);
                          cam_periph_unlock(periph);
                          free(params.mode_buf, M_SCSICD);
                  }
                  break;
          case CDIOCSETMONO:
                  {
                          struct cd_mode_params params;
                          union cd_pages *page;
  
                          params.alloc_len = sizeof(union cd_mode_data_6_10);
                          params.mode_buf = malloc(params.alloc_len, M_SCSICD,
                                                   M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOCSETMONO\n"));
  
                          error = cdgetmode(periph, &params, AUDIO_PAGE);
                          if (error) {
                                  free(params.mode_buf, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          page = cdgetpage(&params);
  
                          page->audio.port[LEFT_PORT].channels = 
                                  LEFT_CHANNEL | RIGHT_CHANNEL;
                          page->audio.port[RIGHT_PORT].channels = 
                                  LEFT_CHANNEL | RIGHT_CHANNEL;
                          page->audio.port[2].channels = 0;
                          page->audio.port[3].channels = 0;
                          error = cdsetmode(periph, &params);
                          cam_periph_unlock(periph);
                          free(params.mode_buf, M_SCSICD);
                  }
                  break;
          case CDIOCSETSTEREO:
                  {
                          struct cd_mode_params params;
                          union cd_pages *page;
  
                          params.alloc_len = sizeof(union cd_mode_data_6_10);
                          params.mode_buf = malloc(params.alloc_len, M_SCSICD,
                                                   M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOCSETSTEREO\n"));
  
                          error = cdgetmode(periph, &params, AUDIO_PAGE);
                          if (error) {
                                  free(params.mode_buf, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          page = cdgetpage(&params);
  
                          page->audio.port[LEFT_PORT].channels = 
                                  LEFT_CHANNEL;
                          page->audio.port[RIGHT_PORT].channels = 
                                  RIGHT_CHANNEL;
                          page->audio.port[2].channels = 0;
                          page->audio.port[3].channels = 0;
                          error = cdsetmode(periph, &params);
                          free(params.mode_buf, M_SCSICD);
                          cam_periph_unlock(periph);
                  }
                  break;
          case CDIOCSETMUTE:
                  {
                          struct cd_mode_params params;
                          union cd_pages *page;
  
                          params.alloc_len = sizeof(union cd_mode_data_6_10);
                          params.mode_buf = malloc(params.alloc_len, M_SCSICD,
                                                   M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOCSETMUTE\n"));
  
                          error = cdgetmode(periph, &params, AUDIO_PAGE);
                          if (error) {
                                  free(params.mode_buf, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          page = cdgetpage(&params);
  
                          page->audio.port[LEFT_PORT].channels = 0;
                          page->audio.port[RIGHT_PORT].channels = 0;
                          page->audio.port[2].channels = 0;
                          page->audio.port[3].channels = 0;
                          error = cdsetmode(periph, &params);
                          free(params.mode_buf, M_SCSICD);
                          cam_periph_unlock(periph);
                  }
                  break;
          case CDIOCSETLEFT:
                  {
                          struct cd_mode_params params;
                          union cd_pages *page;
  
                          params.alloc_len = sizeof(union cd_mode_data_6_10);
                          params.mode_buf = malloc(params.alloc_len, M_SCSICD,
                                                   M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOCSETLEFT\n"));
  
                          error = cdgetmode(periph, &params, AUDIO_PAGE);
                          if (error) {
                                  free(params.mode_buf, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          page = cdgetpage(&params);
  
                          page->audio.port[LEFT_PORT].channels = LEFT_CHANNEL;
                          page->audio.port[RIGHT_PORT].channels = LEFT_CHANNEL;
                          page->audio.port[2].channels = 0;
                          page->audio.port[3].channels = 0;
                          error = cdsetmode(periph, &params);
                          free(params.mode_buf, M_SCSICD);
                          cam_periph_unlock(periph);
                  }
                  break;
          case CDIOCSETRIGHT:
                  {
                          struct cd_mode_params params;
                          union cd_pages *page;
  
                          params.alloc_len = sizeof(union cd_mode_data_6_10);
                          params.mode_buf = malloc(params.alloc_len, M_SCSICD,
                                                   M_WAITOK | M_ZERO);
  
                          cam_periph_lock(periph);
                          CAM_DEBUG(periph->path, CAM_DEBUG_SUBTRACE, 
                                    ("trying to do CDIOCSETRIGHT\n"));
  
                          error = cdgetmode(periph, &params, AUDIO_PAGE);
                          if (error) {
                                  free(params.mode_buf, M_SCSICD);
                                  cam_periph_unlock(periph);
                                  break;
                          }
                          page = cdgetpage(&params);
  
                          page->audio.port[LEFT_PORT].channels = RIGHT_CHANNEL;
                          page->audio.port[RIGHT_PORT].channels = RIGHT_CHANNEL;
                          page->audio.port[2].channels = 0;
                          page->audio.port[3].channels = 0;
                          error = cdsetmode(periph, &params);
                          free(params.mode_buf, M_SCSICD);
                          cam_periph_unlock(periph);
                  }
                  break;
          case CDIOCRESUME:
                  cam_periph_lock(periph);
                  error = cdpause(periph, 1);
                  cam_periph_unlock(periph);
                  break;
          case CDIOCPAUSE:
                  cam_periph_lock(periph);
                  error = cdpause(periph, 0);
                  cam_periph_unlock(periph);
                  break;
          case CDIOCSTART:
                  cam_periph_lock(periph);
                  error = cdstartunit(periph, 0);
                  cam_periph_unlock(periph);
                  break;
          case CDIOCCLOSE:
                  cam_periph_lock(periph);
                  error = cdstartunit(periph, 1);
                  cam_periph_unlock(periph);
                  break;
          case CDIOCSTOP:
                  cam_periph_lock(periph);
                  error = cdstopunit(periph, 0);
                  cam_periph_unlock(periph);
                  break;
          case CDIOCEJECT:
                  cam_periph_lock(periph);
                  error = cdstopunit(periph, 1);
                  cam_periph_unlock(periph);
                  break;
          case CDIOCALLOW:
                  cam_periph_lock(periph);
                  cdprevent(periph, PR_ALLOW);
                  cam_periph_unlock(periph);
                  break;
          case CDIOCPREVENT:
                  cam_periph_lock(periph);
                  cdprevent(periph, PR_PREVENT);
                  cam_periph_unlock(periph);
                  break;
          case CDIOCSETDEBUG:
                  /* sc_link->flags |= (SDEV_DB1 | SDEV_DB2); */
                  error = ENOTTY;
                  break;
          case CDIOCCLRDEBUG:
                  /* sc_link->flags &= ~(SDEV_DB1 | SDEV_DB2); */
                  error = ENOTTY;
                  break;
          case CDIOCRESET:
                  /* return (cd_reset(periph)); */
                  error = ENOTTY;
                  break;
          case CDRIOCREADSPEED:
                  cam_periph_lock(periph);
                  error = cdsetspeed(periph, *(u_int32_t *)addr, CDR_MAX_SPEED);
                  cam_periph_unlock(periph);
                  break;
          case CDRIOCWRITESPEED:
                  cam_periph_lock(periph);
                  error = cdsetspeed(periph, CDR_MAX_SPEED, *(u_int32_t *)addr);
                  cam_periph_unlock(periph);
                  break;
          case CDRIOCGETBLOCKSIZE:
                  *(int *)addr = softc->params.blksize;
                  break;
          case CDRIOCSETBLOCKSIZE:
                  if (*(int *)addr <= 0) {
                          error = EINVAL;
                          break;
                  }
                  softc->disk->d_sectorsize = softc->params.blksize = *(int *)addr;
                  break;
          case DVDIOCSENDKEY:
          case DVDIOCREPORTKEY: {
                  struct dvd_authinfo *authinfo;
  
                  authinfo = (struct dvd_authinfo *)addr;
  
                  if (cmd == DVDIOCREPORTKEY)
                          error = cdreportkey(periph, authinfo);
                  else
                          error = cdsendkey(periph, authinfo);
                  break;
                  }
          case DVDIOCREADSTRUCTURE: {
                  struct dvd_struct *dvdstruct;
  
                  dvdstruct = (struct dvd_struct *)addr;
  
                  error = cdreaddvdstructure(periph, dvdstruct);
  
                  break;
          }
          default:
                  cam_periph_lock(periph);
                  error = cam_periph_ioctl(periph, cmd, addr, cderror);
                  cam_periph_unlock(periph);
                  break;
          }
  
          cam_periph_lock(periph);
          cam_periph_unhold(periph);
          
          CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("leaving cdioctl\n"));
          if (error && bootverbose) {
                  printf("scsi_cd.c::ioctl cmd=%08lx error=%d\n", cmd, error);
          }
          cam_periph_unlock(periph);
  
          return (error);
  }
  
  static void
  cdprevent(struct cam_periph *periph, int action)
  {
          union   ccb *ccb;
          struct  cd_softc *softc;
          int     error;
  
          CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("entering cdprevent\n"));
  
          softc = (struct cd_softc *)periph->softc;
          
          if (((action == PR_ALLOW)
            && (softc->flags & CD_FLAG_DISC_LOCKED) == 0)
           || ((action == PR_PREVENT)
            && (softc->flags & CD_FLAG_DISC_LOCKED) != 0)) {
                  return;
          }
              
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
  
          scsi_prevent(&ccb->csio, 
                       /*retries*/ cd_retry_count,
                       cddone,
                       MSG_SIMPLE_Q_TAG,
                       action,
                       SSD_FULL_SIZE,
                       /* timeout */60000);
          
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                          /*sense_flags*/SF_RETRY_UA|SF_NO_PRINT);
  
          xpt_release_ccb(ccb);
  
          if (error == 0) {
                  if (action == PR_ALLOW)
                          softc->flags &= ~CD_FLAG_DISC_LOCKED;
                  else
                          softc->flags |= CD_FLAG_DISC_LOCKED;
          }
  }
  
  /*
   * XXX: the disk media and sector size is only really able to change
   * XXX: while the device is closed.
   */
  static int
  cdcheckmedia(struct cam_periph *periph)
  {
          struct cd_softc *softc;
          struct ioc_toc_header *toch;
          struct cd_toc_single leadout;
          u_int32_t size, toclen;
          int error, num_entries, cdindex;
  
          softc = (struct cd_softc *)periph->softc;
  
          cdprevent(periph, PR_PREVENT);
          softc->disk->d_sectorsize = 2048;
          softc->disk->d_mediasize = 0;
  
          /*
           * Get the disc size and block size.  If we can't get it, we don't
           * have media, most likely.
           */
          if ((error = cdsize(periph, &size)) != 0) {
                  softc->flags &= ~(CD_FLAG_VALID_MEDIA|CD_FLAG_VALID_TOC);
                  cdprevent(periph, PR_ALLOW);
                  return (error);
          } else {
                  softc->flags |= CD_FLAG_VALID_MEDIA;
                  softc->disk->d_sectorsize = softc->params.blksize;
                  softc->disk->d_mediasize =
                      (off_t)softc->params.blksize * softc->params.disksize;
          }
  
          /*
           * Now we check the table of contents.  This (currently) is only
           * used for the CDIOCPLAYTRACKS ioctl.  It may be used later to do
           * things like present a separate entry in /dev for each track,
           * like that acd(4) driver does.
           */
          bzero(&softc->toc, sizeof(softc->toc));
          toch = &softc->toc.header;
          /*
           * We will get errors here for media that doesn't have a table of
           * contents.  According to the MMC-3 spec: "When a Read TOC/PMA/ATIP
           * command is presented for a DDCD/CD-R/RW media, where the first TOC
           * has not been recorded (no complete session) and the Format codes
           * 0000b, 0001b, or 0010b are specified, this command shall be rejected
           * with an INVALID FIELD IN CDB.  Devices that are not capable of
           * reading an incomplete session on DDC/CD-R/RW media shall report
           * CANNOT READ MEDIUM - INCOMPATIBLE FORMAT."
           *
           * So this isn't fatal if we can't read the table of contents, it
           * just means that the user won't be able to issue the play tracks
           * ioctl, and likely lots of other stuff won't work either.  They
           * need to burn the CD before we can do a whole lot with it.  So
           * we don't print anything here if we get an error back.
           */
          error = cdreadtoc(periph, 0, 0, (u_int8_t *)toch, sizeof(*toch),
                            SF_NO_PRINT);
          /*
           * Errors in reading the table of contents aren't fatal, we just
           * won't have a valid table of contents cached.
           */
          if (error != 0) {
                  error = 0;
                  bzero(&softc->toc, sizeof(softc->toc));
                  goto bailout;
          }
  
          if (softc->quirks & CD_Q_BCD_TRACKS) {
                  toch->starting_track = bcd2bin(toch->starting_track);
                  toch->ending_track = bcd2bin(toch->ending_track);
          }
  
          /* Number of TOC entries, plus leadout */
          num_entries = (toch->ending_track - toch->starting_track) + 2;
  
          if (num_entries <= 0)
                  goto bailout;
  
          toclen = num_entries * sizeof(struct cd_toc_entry);
  
          error = cdreadtoc(periph, CD_MSF_FORMAT, toch->starting_track,
                            (u_int8_t *)&softc->toc, toclen + sizeof(*toch),
                            SF_NO_PRINT);
          if (error != 0) {
                  error = 0;
                  bzero(&softc->toc, sizeof(softc->toc));
                  goto bailout;
          }
  
          if (softc->quirks & CD_Q_BCD_TRACKS) {
                  toch->starting_track = bcd2bin(toch->starting_track);
                  toch->ending_track = bcd2bin(toch->ending_track);
          }
          /*
           * XXX KDM is this necessary?  Probably only if the drive doesn't
           * return leadout information with the table of contents.
           */
          cdindex = toch->starting_track + num_entries -1;
          if (cdindex == toch->ending_track + 1) {
  
                  error = cdreadtoc(periph, CD_MSF_FORMAT, LEADOUT, 
                                    (u_int8_t *)&leadout, sizeof(leadout),
                                    SF_NO_PRINT);
                  if (error != 0) {
                          error = 0;
                          goto bailout;
                  }
                  softc->toc.entries[cdindex - toch->starting_track] =
                          leadout.entry;
          }
          if (softc->quirks & CD_Q_BCD_TRACKS) {
                  for (cdindex = 0; cdindex < num_entries - 1; cdindex++) {
                          softc->toc.entries[cdindex].track =
                                  bcd2bin(softc->toc.entries[cdindex].track);
                  }
          }
  
          softc->flags |= CD_FLAG_VALID_TOC;
  
          /* If the first track is audio, correct sector size. */
          if ((softc->toc.entries[0].control & 4) == 0) {
                  softc->disk->d_sectorsize = softc->params.blksize = 2352;
                  softc->disk->d_mediasize =
                      (off_t)softc->params.blksize * softc->params.disksize;
          }
  
  bailout:
  
          /*
           * We unconditionally (re)set the blocksize each time the
           * CD device is opened.  This is because the CD can change,
           * and therefore the blocksize might change.
           * XXX problems here if some slice or partition is still
           * open with the old size?
           */
          if ((softc->disk->d_devstat->flags & DEVSTAT_BS_UNAVAILABLE) != 0)
                  softc->disk->d_devstat->flags &= ~DEVSTAT_BS_UNAVAILABLE;
          softc->disk->d_devstat->block_size = softc->params.blksize;
  
          return (error);
  }
  
  static int
  cdsize(struct cam_periph *periph, u_int32_t *size)
  {
          struct cd_softc *softc;
          union ccb *ccb;
          struct scsi_read_capacity_data *rcap_buf;
          int error;
  
          CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("entering cdsize\n"));
  
          softc = (struct cd_softc *)periph->softc;
               
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
  
          /* XXX Should be M_WAITOK */
          rcap_buf = malloc(sizeof(struct scsi_read_capacity_data), 
                            M_SCSICD, M_NOWAIT | M_ZERO);
          if (rcap_buf == NULL)
                  return (ENOMEM);
  
          scsi_read_capacity(&ccb->csio, 
                             /*retries*/ cd_retry_count,
                             cddone,
                             MSG_SIMPLE_Q_TAG,
                             rcap_buf,
                             SSD_FULL_SIZE,
                             /* timeout */20000);
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA|SF_NO_PRINT);
  
          xpt_release_ccb(ccb);
  
          softc->params.disksize = scsi_4btoul(rcap_buf->addr) + 1;
          softc->params.blksize  = scsi_4btoul(rcap_buf->length);
          /* Make sure we got at least some block size. */
          if (error == 0 && softc->params.blksize == 0)
                  error = EIO;
          /*
           * SCSI-3 mandates that the reported blocksize shall be 2048.
           * Older drives sometimes report funny values, trim it down to
           * 2048, or other parts of the kernel will get confused.
           *
           * XXX we leave drives alone that might report 512 bytes, as
           * well as drives reporting more weird sizes like perhaps 4K.
           */
          if (softc->params.blksize > 2048 && softc->params.blksize <= 2352)
                  softc->params.blksize = 2048;
  
          free(rcap_buf, M_SCSICD);
          *size = softc->params.disksize;
  
          return (error);
  
  }
  
  static int
  cd6byteworkaround(union ccb *ccb)
  {
          u_int8_t *cdb;
          struct cam_periph *periph;
          struct cd_softc *softc;
          struct cd_mode_params *params;
          int frozen, found;
  
          periph = xpt_path_periph(ccb->ccb_h.path);
          softc = (struct cd_softc *)periph->softc;
  
          cdb = ccb->csio.cdb_io.cdb_bytes;
  
          if ((ccb->ccb_h.flags & CAM_CDB_POINTER)
           || ((cdb[0] != MODE_SENSE_6)
            && (cdb[0] != MODE_SELECT_6)))
                  return (0);
  
          /*
           * Because there is no convenient place to stash the overall
           * cd_mode_params structure pointer, we have to grab it like this.
           * This means that ALL MODE_SENSE and MODE_SELECT requests in the
           * cd(4) driver MUST go through cdgetmode() and cdsetmode()!
           *
           * XXX It would be nice if, at some point, we could increase the
           * number of available peripheral private pointers.  Both pointers
           * are currently used in most every peripheral driver.
           */
          found = 0;
  
          STAILQ_FOREACH(params, &softc->mode_queue, links) {
                  if (params->mode_buf == ccb->csio.data_ptr) {
                          found = 1;
                          break;
                  }
          }
  
          /*
           * This shouldn't happen.  All mode sense and mode select
           * operations in the cd(4) driver MUST go through cdgetmode() and
           * cdsetmode()!
           */
          if (found == 0) {
                  xpt_print(periph->path,
                      "mode buffer not found in mode queue!\n");
                  return (0);
          }
  
          params->cdb_size = 10;
          softc->minimum_command_size = 10;
          xpt_print(ccb->ccb_h.path,
              "%s(6) failed, increasing minimum CDB size to 10 bytes\n",
              (cdb[0] == MODE_SENSE_6) ? "MODE_SENSE" : "MODE_SELECT");
  
          if (cdb[0] == MODE_SENSE_6) {
                  struct scsi_mode_sense_10 ms10;
                  struct scsi_mode_sense_6 *ms6;
                  int len;
  
                  ms6 = (struct scsi_mode_sense_6 *)cdb;
  
                  bzero(&ms10, sizeof(ms10));
                  ms10.opcode = MODE_SENSE_10;
                  ms10.byte2 = ms6->byte2;
                  ms10.page = ms6->page;
  
                  /*
                   * 10 byte mode header, block descriptor,
                   * sizeof(union cd_pages)
                   */
                  len = sizeof(struct cd_mode_data_10);
                  ccb->csio.dxfer_len = len;
  
                  scsi_ulto2b(len, ms10.length);
                  ms10.control = ms6->control;
                  bcopy(&ms10, cdb, 10);
                  ccb->csio.cdb_len = 10;
          } else {
                  struct scsi_mode_select_10 ms10;
                  struct scsi_mode_select_6 *ms6;
                  struct scsi_mode_header_6 *header6;
                  struct scsi_mode_header_10 *header10;
                  struct scsi_mode_page_header *page_header;
                  int blk_desc_len, page_num, page_size, len;
  
                  ms6 = (struct scsi_mode_select_6 *)cdb;
  
                  bzero(&ms10, sizeof(ms10));
                  ms10.opcode = MODE_SELECT_10;
                  ms10.byte2 = ms6->byte2;
  
                  header6 = (struct scsi_mode_header_6 *)params->mode_buf;
                  header10 = (struct scsi_mode_header_10 *)params->mode_buf;
  
                  page_header = find_mode_page_6(header6);
                  page_num = page_header->page_code;
  
                  blk_desc_len = header6->blk_desc_len;
  
                  page_size = cdgetpagesize(page_num);
  
                  if (page_size != (page_header->page_length +
                      sizeof(*page_header)))
                          page_size = page_header->page_length +
                                  sizeof(*page_header);
  
                  len = sizeof(*header10) + blk_desc_len + page_size;
  
                  len = min(params->alloc_len, len);
  
                  /*
                   * Since the 6 byte parameter header is shorter than the 10
                   * byte parameter header, we need to copy the actual mode
                   * page data, and the block descriptor, if any, so things wind
                   * up in the right place.  The regions will overlap, but
                   * bcopy() does the right thing.
                   */
                  bcopy(params->mode_buf + sizeof(*header6),
                        params->mode_buf + sizeof(*header10),
                        len - sizeof(*header10));
  
                  /* Make sure these fields are set correctly. */
                  scsi_ulto2b(0, header10->data_length);
                  header10->medium_type = 0;
                  scsi_ulto2b(blk_desc_len, header10->blk_desc_len);
  
                  ccb->csio.dxfer_len = len;
  
                  scsi_ulto2b(len, ms10.length);
                  ms10.control = ms6->control;
                  bcopy(&ms10, cdb, 10);
                  ccb->csio.cdb_len = 10;
          }
  
          frozen = (ccb->ccb_h.status & CAM_DEV_QFRZN) != 0;
          ccb->ccb_h.status = CAM_REQUEUE_REQ;
          xpt_action(ccb);
          if (frozen) {
                  cam_release_devq(ccb->ccb_h.path,
                                   /*relsim_flags*/0,
                                   /*openings*/0,
                                   /*timeout*/0,
                                   /*getcount_only*/0);
          }
  
          return (ERESTART);
  }
  
  static int
  cderror(union ccb *ccb, u_int32_t cam_flags, u_int32_t sense_flags)
  {
          struct cd_softc *softc;
          struct cam_periph *periph;
          int error;
  
          periph = xpt_path_periph(ccb->ccb_h.path);
          softc = (struct cd_softc *)periph->softc;
  
          error = 0;
  
          /*
           * We use a status of CAM_REQ_INVALID as shorthand -- if a 6 byte
           * CDB comes back with this particular error, try transforming it
           * into the 10 byte version.
           */
          if ((ccb->ccb_h.status & CAM_STATUS_MASK) == CAM_REQ_INVALID) {
                  error = cd6byteworkaround(ccb);
          } else if (((ccb->ccb_h.status & CAM_STATUS_MASK) ==
                       CAM_SCSI_STATUS_ERROR)
           && (ccb->ccb_h.status & CAM_AUTOSNS_VALID)
           && (ccb->csio.scsi_status == SCSI_STATUS_CHECK_COND)
           && ((ccb->ccb_h.flags & CAM_SENSE_PHYS) == 0)
           && ((ccb->ccb_h.flags & CAM_SENSE_PTR) == 0)) {
                  int sense_key, error_code, asc, ascq;
  
                  scsi_extract_sense(&ccb->csio.sense_data,
                                     &error_code, &sense_key, &asc, &ascq);
                  if (sense_key == SSD_KEY_ILLEGAL_REQUEST)
                          error = cd6byteworkaround(ccb);
          }
  
          if (error == ERESTART)
                  return (error);
  
          /*
           * XXX
           * Until we have a better way of doing pack validation,
           * don't treat UAs as errors.
           */
          sense_flags |= SF_RETRY_UA;
          return (cam_periph_error(ccb, cam_flags, sense_flags, 
                                   &softc->saved_ccb));
  }
  
  /*
   * Read table of contents
   */
  static int 
  cdreadtoc(struct cam_periph *periph, u_int32_t mode, u_int32_t start, 
            u_int8_t *data, u_int32_t len, u_int32_t sense_flags)
  {
          struct scsi_read_toc *scsi_cmd;
          u_int32_t ntoc;
          struct ccb_scsiio *csio;
          union ccb *ccb;
          int error;
  
          ntoc = len;
          error = 0;
  
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
  
          csio = &ccb->csio;
  
          cam_fill_csio(csio, 
                        /* retries */ cd_retry_count, 
                        /* cbfcnp */ cddone, 
                        /* flags */ CAM_DIR_IN,
                        /* tag_action */ MSG_SIMPLE_Q_TAG,
                        /* data_ptr */ data,
                        /* dxfer_len */ len,
                        /* sense_len */ SSD_FULL_SIZE,
                        sizeof(struct scsi_read_toc),
                        /* timeout */ 50000);
  
          scsi_cmd = (struct scsi_read_toc *)&csio->cdb_io.cdb_bytes;
          bzero (scsi_cmd, sizeof(*scsi_cmd));
  
          if (mode == CD_MSF_FORMAT)
                  scsi_cmd->byte2 |= CD_MSF;
          scsi_cmd->from_track = start;
          /* scsi_ulto2b(ntoc, (u_int8_t *)scsi_cmd->data_len); */
          scsi_cmd->data_len[0] = (ntoc) >> 8;
          scsi_cmd->data_len[1] = (ntoc) & 0xff;
  
          scsi_cmd->op_code = READ_TOC;
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA | sense_flags);
  
          xpt_release_ccb(ccb);
  
          return(error);
  }
  
  static int
  cdreadsubchannel(struct cam_periph *periph, u_int32_t mode, 
                   u_int32_t format, int track, 
                   struct cd_sub_channel_info *data, u_int32_t len) 
  {
          struct scsi_read_subchannel *scsi_cmd;
          struct ccb_scsiio *csio;
          union ccb *ccb;
          int error;
  
          error = 0;
  
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
  
          csio = &ccb->csio;
  
          cam_fill_csio(csio, 
                        /* retries */ cd_retry_count, 
                        /* cbfcnp */ cddone, 
                        /* flags */ CAM_DIR_IN,
                        /* tag_action */ MSG_SIMPLE_Q_TAG,
                        /* data_ptr */ (u_int8_t *)data,
                        /* dxfer_len */ len,
                        /* sense_len */ SSD_FULL_SIZE,
                        sizeof(struct scsi_read_subchannel),
                        /* timeout */ 50000);
  
          scsi_cmd = (struct scsi_read_subchannel *)&csio->cdb_io.cdb_bytes;
          bzero (scsi_cmd, sizeof(*scsi_cmd));
  
          scsi_cmd->op_code = READ_SUBCHANNEL;
          if (mode == CD_MSF_FORMAT)
                  scsi_cmd->byte1 |= CD_MSF;
          scsi_cmd->byte2 = SRS_SUBQ;
          scsi_cmd->subchan_format = format;
          scsi_cmd->track = track;
          scsi_ulto2b(len, (u_int8_t *)scsi_cmd->data_len);
          scsi_cmd->control = 0;
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA);
  
          xpt_release_ccb(ccb);
  
          return(error);
  }
  
  
  /*
   * All MODE_SENSE requests in the cd(4) driver MUST go through this
   * routine.  See comments in cd6byteworkaround() for details.
   */
  static int
  cdgetmode(struct cam_periph *periph, struct cd_mode_params *data,
            u_int32_t page)
  {
          struct ccb_scsiio *csio;
          struct cd_softc *softc;
          union ccb *ccb;
          int param_len;
          int error;
  
          softc = (struct cd_softc *)periph->softc;
  
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
  
          csio = &ccb->csio;
  
          data->cdb_size = softc->minimum_command_size;
          if (data->cdb_size < 10)
                  param_len = sizeof(struct cd_mode_data);
          else
                  param_len = sizeof(struct cd_mode_data_10);
  
          /* Don't say we've got more room than we actually allocated */
          param_len = min(param_len, data->alloc_len);
  
          scsi_mode_sense_len(csio,
                              /* retries */ cd_retry_count,
                              /* cbfcnp */ cddone,
                              /* tag_action */ MSG_SIMPLE_Q_TAG,
                              /* dbd */ 0,
                              /* page_code */ SMS_PAGE_CTRL_CURRENT,
                              /* page */ page,
                              /* param_buf */ data->mode_buf,
                              /* param_len */ param_len,
                              /* minimum_cmd_size */ softc->minimum_command_size,
                              /* sense_len */ SSD_FULL_SIZE,
                              /* timeout */ 50000);
  
          /*
           * It would be nice not to have to do this, but there's no
           * available pointer in the CCB that would allow us to stuff the
           * mode params structure in there and retrieve it in
           * cd6byteworkaround(), so we can set the cdb size.  The cdb size
           * lets the caller know what CDB size we ended up using, so they
           * can find the actual mode page offset.
           */
          STAILQ_INSERT_TAIL(&softc->mode_queue, data, links);
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA);
  
          xpt_release_ccb(ccb);
  
          STAILQ_REMOVE(&softc->mode_queue, data, cd_mode_params, links);
  
          /*
           * This is a bit of belt-and-suspenders checking, but if we run
           * into a situation where the target sends back multiple block
           * descriptors, we might not have enough space in the buffer to
           * see the whole mode page.  Better to return an error than
           * potentially access memory beyond our malloced region.
           */
          if (error == 0) {
                  u_int32_t data_len;
  
                  if (data->cdb_size == 10) {
                          struct scsi_mode_header_10 *hdr10;
  
                          hdr10 = (struct scsi_mode_header_10 *)data->mode_buf;
                          data_len = scsi_2btoul(hdr10->data_length);
                          data_len += sizeof(hdr10->data_length);
                  } else {
                          struct scsi_mode_header_6 *hdr6;
  
                          hdr6 = (struct scsi_mode_header_6 *)data->mode_buf;
                          data_len = hdr6->data_length;
                          data_len += sizeof(hdr6->data_length);
                  }
  
                  /*
                   * Complain if there is more mode data available than we
                   * allocated space for.  This could potentially happen if
                   * we miscalculated the page length for some reason, if the
                   * drive returns multiple block descriptors, or if it sets
                   * the data length incorrectly.
                   */
                  if (data_len > data->alloc_len) {
                          xpt_print(periph->path, "allocated modepage %d length "
                              "%d < returned length %d\n", page, data->alloc_len,
                              data_len);
                          error = ENOSPC;
                  }
          }
          return (error);
  }
  
  /*
   * All MODE_SELECT requests in the cd(4) driver MUST go through this
   * routine.  See comments in cd6byteworkaround() for details.
   */
  static int
  cdsetmode(struct cam_periph *periph, struct cd_mode_params *data)
  {
          struct ccb_scsiio *csio;
          struct cd_softc *softc;
          union ccb *ccb;
          int cdb_size, param_len;
          int error;
  
          softc = (struct cd_softc *)periph->softc;
  
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
  
          csio = &ccb->csio;
  
          error = 0;
  
          /*
           * If the data is formatted for the 10 byte version of the mode
           * select parameter list, we need to use the 10 byte CDB.
           * Otherwise, we use whatever the stored minimum command size.
           */
          if (data->cdb_size == 10)
                  cdb_size = data->cdb_size;
          else
                  cdb_size = softc->minimum_command_size;
  
          if (cdb_size >= 10) {
                  struct scsi_mode_header_10 *mode_header;
                  u_int32_t data_len;
  
                  mode_header = (struct scsi_mode_header_10 *)data->mode_buf;
  
                  data_len = scsi_2btoul(mode_header->data_length);
  
                  scsi_ulto2b(0, mode_header->data_length);
                  /*
                   * SONY drives do not allow a mode select with a medium_type
                   * value that has just been returned by a mode sense; use a
                   * medium_type of 0 (Default) instead.
                   */
                  mode_header->medium_type = 0;
  
                  /*
                   * Pass back whatever the drive passed to us, plus the size
                   * of the data length field.
                   */
                  param_len = data_len + sizeof(mode_header->data_length);
  
          } else {
                  struct scsi_mode_header_6 *mode_header;
  
                  mode_header = (struct scsi_mode_header_6 *)data->mode_buf;
  
                  param_len = mode_header->data_length + 1;
  
                  mode_header->data_length = 0;
                  /*
                   * SONY drives do not allow a mode select with a medium_type
                   * value that has just been returned by a mode sense; use a
                   * medium_type of 0 (Default) instead.
                   */
                  mode_header->medium_type = 0;
          }
  
          /* Don't say we've got more room than we actually allocated */
          param_len = min(param_len, data->alloc_len);
  
          scsi_mode_select_len(csio,
                               /* retries */ cd_retry_count,
                               /* cbfcnp */ cddone,
                               /* tag_action */ MSG_SIMPLE_Q_TAG,
                               /* scsi_page_fmt */ 1,
                               /* save_pages */ 0,
                               /* param_buf */ data->mode_buf,
                               /* param_len */ param_len,
                               /* minimum_cmd_size */ cdb_size,
                               /* sense_len */ SSD_FULL_SIZE,
                               /* timeout */ 50000);
  
          /* See comments in cdgetmode() and cd6byteworkaround(). */
          STAILQ_INSERT_TAIL(&softc->mode_queue, data, links);
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA);
  
          xpt_release_ccb(ccb);
  
          STAILQ_REMOVE(&softc->mode_queue, data, cd_mode_params, links);
  
          return (error);
  }
  
  
  static int 
  cdplay(struct cam_periph *periph, u_int32_t blk, u_int32_t len)
  {
          struct ccb_scsiio *csio;
          union ccb *ccb;
          int error;
          u_int8_t cdb_len;
  
          error = 0;
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
          csio = &ccb->csio;
          /*
           * Use the smallest possible command to perform the operation.
           */
          if ((len & 0xffff0000) == 0) {
                  /*
                   * We can fit in a 10 byte cdb.
                   */
                  struct scsi_play_10 *scsi_cmd;
  
                  scsi_cmd = (struct scsi_play_10 *)&csio->cdb_io.cdb_bytes;
                  bzero (scsi_cmd, sizeof(*scsi_cmd));
                  scsi_cmd->op_code = PLAY_10;
                  scsi_ulto4b(blk, (u_int8_t *)scsi_cmd->blk_addr);
                  scsi_ulto2b(len, (u_int8_t *)scsi_cmd->xfer_len);
                  cdb_len = sizeof(*scsi_cmd);
          } else  {
                  struct scsi_play_12 *scsi_cmd;
  
                  scsi_cmd = (struct scsi_play_12 *)&csio->cdb_io.cdb_bytes;
                  bzero (scsi_cmd, sizeof(*scsi_cmd));
                  scsi_cmd->op_code = PLAY_12;
                  scsi_ulto4b(blk, (u_int8_t *)scsi_cmd->blk_addr);
                  scsi_ulto4b(len, (u_int8_t *)scsi_cmd->xfer_len);
                  cdb_len = sizeof(*scsi_cmd);
          }
          cam_fill_csio(csio,
                        /*retries*/ cd_retry_count,
                        cddone,
                        /*flags*/CAM_DIR_NONE,
                        MSG_SIMPLE_Q_TAG,
                        /*dataptr*/NULL,
                        /*datalen*/0,
                        /*sense_len*/SSD_FULL_SIZE,
                        cdb_len,
                        /*timeout*/50 * 1000);
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA);
  
          xpt_release_ccb(ccb);
  
          return(error);
  }
  
  static int
  cdplaymsf(struct cam_periph *periph, u_int32_t startm, u_int32_t starts,
            u_int32_t startf, u_int32_t endm, u_int32_t ends, u_int32_t endf)
  {
          struct scsi_play_msf *scsi_cmd;
          struct ccb_scsiio *csio;
          union ccb *ccb;
          int error;
  
          error = 0;
  
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
  
          csio = &ccb->csio;
  
          cam_fill_csio(csio, 
                        /* retries */ cd_retry_count, 
                        /* cbfcnp */ cddone, 
                        /* flags */ CAM_DIR_NONE,
                        /* tag_action */ MSG_SIMPLE_Q_TAG,
                        /* data_ptr */ NULL,
                        /* dxfer_len */ 0,
                        /* sense_len */ SSD_FULL_SIZE,
                        sizeof(struct scsi_play_msf),
                        /* timeout */ 50000);
  
          scsi_cmd = (struct scsi_play_msf *)&csio->cdb_io.cdb_bytes;
          bzero (scsi_cmd, sizeof(*scsi_cmd));
  
          scsi_cmd->op_code = PLAY_MSF;
          scsi_cmd->start_m = startm;
          scsi_cmd->start_s = starts;
          scsi_cmd->start_f = startf;
          scsi_cmd->end_m = endm;
          scsi_cmd->end_s = ends;
          scsi_cmd->end_f = endf; 
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA);
          
          xpt_release_ccb(ccb);
  
          return(error);
  }
  
  
  static int
  cdplaytracks(struct cam_periph *periph, u_int32_t strack, u_int32_t sindex,
               u_int32_t etrack, u_int32_t eindex)
  {
          struct scsi_play_track *scsi_cmd;
          struct ccb_scsiio *csio;
          union ccb *ccb;
          int error;
  
          error = 0;
  
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
  
          csio = &ccb->csio;
  
          cam_fill_csio(csio, 
                        /* retries */ cd_retry_count, 
                        /* cbfcnp */ cddone, 
                        /* flags */ CAM_DIR_NONE,
                        /* tag_action */ MSG_SIMPLE_Q_TAG,
                        /* data_ptr */ NULL,
                        /* dxfer_len */ 0,
                        /* sense_len */ SSD_FULL_SIZE,
                        sizeof(struct scsi_play_track),
                        /* timeout */ 50000);
  
          scsi_cmd = (struct scsi_play_track *)&csio->cdb_io.cdb_bytes;
          bzero (scsi_cmd, sizeof(*scsi_cmd));
  
          scsi_cmd->op_code = PLAY_TRACK;
          scsi_cmd->start_track = strack;
          scsi_cmd->start_index = sindex;
          scsi_cmd->end_track = etrack;
          scsi_cmd->end_index = eindex;
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA);
  
          xpt_release_ccb(ccb);
  
          return(error);
  }
  
  static int
  cdpause(struct cam_periph *periph, u_int32_t go)
  {
          struct scsi_pause *scsi_cmd;
          struct ccb_scsiio *csio;
          union ccb *ccb;
          int error;
  
          error = 0;
  
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
  
          csio = &ccb->csio;
  
          cam_fill_csio(csio, 
                        /* retries */ cd_retry_count, 
                        /* cbfcnp */ cddone, 
                        /* flags */ CAM_DIR_NONE,
                        /* tag_action */ MSG_SIMPLE_Q_TAG,
                        /* data_ptr */ NULL,
                        /* dxfer_len */ 0,
                        /* sense_len */ SSD_FULL_SIZE,
                        sizeof(struct scsi_pause),
                        /* timeout */ 50000);
  
          scsi_cmd = (struct scsi_pause *)&csio->cdb_io.cdb_bytes;
          bzero (scsi_cmd, sizeof(*scsi_cmd));
  
          scsi_cmd->op_code = PAUSE;
          scsi_cmd->resume = go;
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA);
  
          xpt_release_ccb(ccb);
  
          return(error);
  }
  
  static int
  cdstartunit(struct cam_periph *periph, int load)
  {
          union ccb *ccb;
          int error;
  
          error = 0;
  
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
  
          scsi_start_stop(&ccb->csio,
                          /* retries */ cd_retry_count,
                          /* cbfcnp */ cddone,
                          /* tag_action */ MSG_SIMPLE_Q_TAG,
                          /* start */ TRUE,
                          /* load_eject */ load,
                          /* immediate */ FALSE,
                          /* sense_len */ SSD_FULL_SIZE,
                          /* timeout */ 50000);
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA);
  
          xpt_release_ccb(ccb);
  
          return(error);
  }
  
  static int
  cdstopunit(struct cam_periph *periph, u_int32_t eject)
  {
          union ccb *ccb;
          int error;
  
          error = 0;
  
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
  
          scsi_start_stop(&ccb->csio,
                          /* retries */ cd_retry_count,
                          /* cbfcnp */ cddone,
                          /* tag_action */ MSG_SIMPLE_Q_TAG,
                          /* start */ FALSE,
                          /* load_eject */ eject,
                          /* immediate */ FALSE,
                          /* sense_len */ SSD_FULL_SIZE,
                          /* timeout */ 50000);
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA);
  
          xpt_release_ccb(ccb);
  
          return(error);
  }
  
  static int
  cdsetspeed(struct cam_periph *periph, u_int32_t rdspeed, u_int32_t wrspeed)
  {
          struct scsi_set_speed *scsi_cmd;
          struct ccb_scsiio *csio;
          union ccb *ccb;
          int error;
  
          error = 0;
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
          csio = &ccb->csio;
  
          /* Preserve old behavior: units in multiples of CDROM speed */
          if (rdspeed < 177)
                  rdspeed *= 177;
          if (wrspeed < 177)
                  wrspeed *= 177;
  
          cam_fill_csio(csio,
                        /* retries */ cd_retry_count,
                        /* cbfcnp */ cddone,
                        /* flags */ CAM_DIR_NONE,
                        /* tag_action */ MSG_SIMPLE_Q_TAG,
                        /* data_ptr */ NULL,
                        /* dxfer_len */ 0,
                        /* sense_len */ SSD_FULL_SIZE,
                        sizeof(struct scsi_set_speed),
                        /* timeout */ 50000);
  
          scsi_cmd = (struct scsi_set_speed *)&csio->cdb_io.cdb_bytes;
          bzero(scsi_cmd, sizeof(*scsi_cmd));
  
          scsi_cmd->opcode = SET_CD_SPEED;
          scsi_ulto2b(rdspeed, scsi_cmd->readspeed);
          scsi_ulto2b(wrspeed, scsi_cmd->writespeed);
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA);
  
          xpt_release_ccb(ccb);
  
          return(error);
  }
  
  static int
  cdreportkey(struct cam_periph *periph, struct dvd_authinfo *authinfo)
  {
          union ccb *ccb;
          u_int8_t *databuf;
          u_int32_t lba;
          int error;
          int length;
  
          error = 0;
          databuf = NULL;
          lba = 0;
  
          switch (authinfo->format) {
          case DVD_REPORT_AGID:
                  length = sizeof(struct scsi_report_key_data_agid);
                  break;
          case DVD_REPORT_CHALLENGE:
                  length = sizeof(struct scsi_report_key_data_challenge);
                  break;
          case DVD_REPORT_KEY1:
                  length = sizeof(struct scsi_report_key_data_key1_key2);
                  break;
          case DVD_REPORT_TITLE_KEY:
                  length = sizeof(struct scsi_report_key_data_title);
                  /* The lba field is only set for the title key */
                  lba = authinfo->lba;
                  break;
          case DVD_REPORT_ASF:
                  length = sizeof(struct scsi_report_key_data_asf);
                  break;
          case DVD_REPORT_RPC:
                  length = sizeof(struct scsi_report_key_data_rpc);
                  break;
          case DVD_INVALIDATE_AGID:
                  length = 0;
                  break;
          default:
                  return (EINVAL);
          }
  
          if (length != 0) {
                  databuf = malloc(length, M_DEVBUF, M_WAITOK | M_ZERO);
          } else
                  databuf = NULL;
  
          cam_periph_lock(periph);
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
  
          scsi_report_key(&ccb->csio,
                          /* retries */ cd_retry_count,
                          /* cbfcnp */ cddone,
                          /* tag_action */ MSG_SIMPLE_Q_TAG,
                          /* lba */ lba,
                          /* agid */ authinfo->agid,
                          /* key_format */ authinfo->format,
                          /* data_ptr */ databuf,
                          /* dxfer_len */ length,
                          /* sense_len */ SSD_FULL_SIZE,
                          /* timeout */ 50000);
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA);
  
          if (error != 0)
                  goto bailout;
  
          if (ccb->csio.resid != 0) {
                  xpt_print(periph->path, "warning, residual for report key "
                      "command is %d\n", ccb->csio.resid);
          }
  
          switch(authinfo->format) {
          case DVD_REPORT_AGID: {
                  struct scsi_report_key_data_agid *agid_data;
  
                  agid_data = (struct scsi_report_key_data_agid *)databuf;
  
                  authinfo->agid = (agid_data->agid & RKD_AGID_MASK) >>
                          RKD_AGID_SHIFT;
                  break;
          }
          case DVD_REPORT_CHALLENGE: {
                  struct scsi_report_key_data_challenge *chal_data;
  
                  chal_data = (struct scsi_report_key_data_challenge *)databuf;
  
                  bcopy(chal_data->challenge_key, authinfo->keychal,
                        min(sizeof(chal_data->challenge_key),
                            sizeof(authinfo->keychal)));
                  break;
          }
          case DVD_REPORT_KEY1: {
                  struct scsi_report_key_data_key1_key2 *key1_data;
  
                  key1_data = (struct scsi_report_key_data_key1_key2 *)databuf;
  
                  bcopy(key1_data->key1, authinfo->keychal,
                        min(sizeof(key1_data->key1), sizeof(authinfo->keychal)));
                  break;
          }
          case DVD_REPORT_TITLE_KEY: {
                  struct scsi_report_key_data_title *title_data;
  
                  title_data = (struct scsi_report_key_data_title *)databuf;
  
                  authinfo->cpm = (title_data->byte0 & RKD_TITLE_CPM) >>
                          RKD_TITLE_CPM_SHIFT;
                  authinfo->cp_sec = (title_data->byte0 & RKD_TITLE_CP_SEC) >>
                          RKD_TITLE_CP_SEC_SHIFT;
                  authinfo->cgms = (title_data->byte0 & RKD_TITLE_CMGS_MASK) >>
                          RKD_TITLE_CMGS_SHIFT;
                  bcopy(title_data->title_key, authinfo->keychal,
                        min(sizeof(title_data->title_key),
                            sizeof(authinfo->keychal)));
                  break;
          }
          case DVD_REPORT_ASF: {
                  struct scsi_report_key_data_asf *asf_data;
  
                  asf_data = (struct scsi_report_key_data_asf *)databuf;
  
                  authinfo->asf = asf_data->success & RKD_ASF_SUCCESS;
                  break;
          }
          case DVD_REPORT_RPC: {
                  struct scsi_report_key_data_rpc *rpc_data;
  
                  rpc_data = (struct scsi_report_key_data_rpc *)databuf;
  
                  authinfo->reg_type = (rpc_data->byte4 & RKD_RPC_TYPE_MASK) >>
                          RKD_RPC_TYPE_SHIFT;
                  authinfo->vend_rsts =
                          (rpc_data->byte4 & RKD_RPC_VENDOR_RESET_MASK) >>
                          RKD_RPC_VENDOR_RESET_SHIFT;
                  authinfo->user_rsts = rpc_data->byte4 & RKD_RPC_USER_RESET_MASK;
                  authinfo->region = rpc_data->region_mask;
                  authinfo->rpc_scheme = rpc_data->rpc_scheme1;
                  break;
          }
          case DVD_INVALIDATE_AGID:
                  break;
          default:
                  /* This should be impossible, since we checked above */
                  error = EINVAL;
                  goto bailout;
                  break; /* NOTREACHED */
          }
  
  bailout:
          xpt_release_ccb(ccb);
          cam_periph_unlock(periph);
  
          if (databuf != NULL)
                  free(databuf, M_DEVBUF);
  
          return(error);
  }
  
  static int
  cdsendkey(struct cam_periph *periph, struct dvd_authinfo *authinfo)
  {
          union ccb *ccb;
          u_int8_t *databuf;
          int length;
          int error;
  
          error = 0;
          databuf = NULL;
  
          switch(authinfo->format) {
          case DVD_SEND_CHALLENGE: {
                  struct scsi_report_key_data_challenge *challenge_data;
  
                  length = sizeof(*challenge_data);
  
                  challenge_data = malloc(length, M_DEVBUF, M_WAITOK | M_ZERO);
  
                  databuf = (u_int8_t *)challenge_data;
  
                  scsi_ulto2b(length - sizeof(challenge_data->data_len),
                              challenge_data->data_len);
  
                  bcopy(authinfo->keychal, challenge_data->challenge_key,
                        min(sizeof(authinfo->keychal),
                            sizeof(challenge_data->challenge_key)));
                  break;
          }
          case DVD_SEND_KEY2: {
                  struct scsi_report_key_data_key1_key2 *key2_data;
  
                  length = sizeof(*key2_data);
  
                  key2_data = malloc(length, M_DEVBUF, M_WAITOK | M_ZERO);
  
                  databuf = (u_int8_t *)key2_data;
  
                  scsi_ulto2b(length - sizeof(key2_data->data_len),
                              key2_data->data_len);
  
                  bcopy(authinfo->keychal, key2_data->key1,
                        min(sizeof(authinfo->keychal), sizeof(key2_data->key1)));
  
                  break;
          }
          case DVD_SEND_RPC: {
                  struct scsi_send_key_data_rpc *rpc_data;
  
                  length = sizeof(*rpc_data);
  
                  rpc_data = malloc(length, M_DEVBUF, M_WAITOK | M_ZERO);
  
                  databuf = (u_int8_t *)rpc_data;
  
                  scsi_ulto2b(length - sizeof(rpc_data->data_len),
                              rpc_data->data_len);
  
                  rpc_data->region_code = authinfo->region;
                  break;
          }
          default:
                  return (EINVAL);
          }
  
          cam_periph_lock(periph);
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
  
          scsi_send_key(&ccb->csio,
                        /* retries */ cd_retry_count,
                        /* cbfcnp */ cddone,
                        /* tag_action */ MSG_SIMPLE_Q_TAG,
                        /* agid */ authinfo->agid,
                        /* key_format */ authinfo->format,
                        /* data_ptr */ databuf,
                        /* dxfer_len */ length,
                        /* sense_len */ SSD_FULL_SIZE,
                        /* timeout */ 50000);
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA);
  
          xpt_release_ccb(ccb);
          cam_periph_unlock(periph);
  
          if (databuf != NULL)
                  free(databuf, M_DEVBUF);
  
          return(error);
  }
  
  static int
  cdreaddvdstructure(struct cam_periph *periph, struct dvd_struct *dvdstruct)
  {
          union ccb *ccb;
          u_int8_t *databuf;
          u_int32_t address;
          int error;
          int length;
  
          error = 0;
          databuf = NULL;
          /* The address is reserved for many of the formats */
          address = 0;
  
          switch(dvdstruct->format) {
          case DVD_STRUCT_PHYSICAL:
                  length = sizeof(struct scsi_read_dvd_struct_data_physical);
                  break;
          case DVD_STRUCT_COPYRIGHT:
                  length = sizeof(struct scsi_read_dvd_struct_data_copyright);
                  break;
          case DVD_STRUCT_DISCKEY:
                  length = sizeof(struct scsi_read_dvd_struct_data_disc_key);
                  break;
          case DVD_STRUCT_BCA:
                  length = sizeof(struct scsi_read_dvd_struct_data_bca);
                  break;
          case DVD_STRUCT_MANUFACT:
                  length = sizeof(struct scsi_read_dvd_struct_data_manufacturer);
                  break;
          case DVD_STRUCT_CMI:
                  return (ENODEV);
          case DVD_STRUCT_PROTDISCID:
                  length = sizeof(struct scsi_read_dvd_struct_data_prot_discid);
                  break;
          case DVD_STRUCT_DISCKEYBLOCK:
                  length = sizeof(struct scsi_read_dvd_struct_data_disc_key_blk);
                  break;
          case DVD_STRUCT_DDS:
                  length = sizeof(struct scsi_read_dvd_struct_data_dds);
                  break;
          case DVD_STRUCT_MEDIUM_STAT:
                  length = sizeof(struct scsi_read_dvd_struct_data_medium_status);
                  break;
          case DVD_STRUCT_SPARE_AREA:
                  length = sizeof(struct scsi_read_dvd_struct_data_spare_area);
                  break;
          case DVD_STRUCT_RMD_LAST:
                  return (ENODEV);
          case DVD_STRUCT_RMD_RMA:
                  return (ENODEV);
          case DVD_STRUCT_PRERECORDED:
                  length = sizeof(struct scsi_read_dvd_struct_data_leadin);
                  break;
          case DVD_STRUCT_UNIQUEID:
                  length = sizeof(struct scsi_read_dvd_struct_data_disc_id);
                  break;
          case DVD_STRUCT_DCB:
                  return (ENODEV);
          case DVD_STRUCT_LIST:
                  /*
                   * This is the maximum allocation length for the READ DVD
                   * STRUCTURE command.  There's nothing in the MMC3 spec
                   * that indicates a limit in the amount of data that can
                   * be returned from this call, other than the limits
                   * imposed by the 2-byte length variables.
                   */
                  length = 65535;
                  break;
          default:
                  return (EINVAL);
          }
  
          if (length != 0) {
                  databuf = malloc(length, M_DEVBUF, M_WAITOK | M_ZERO);
          } else
                  databuf = NULL;
  
          cam_periph_lock(periph);
          ccb = cdgetccb(periph, CAM_PRIORITY_NORMAL);
  
          scsi_read_dvd_structure(&ccb->csio,
                                  /* retries */ cd_retry_count,
                                  /* cbfcnp */ cddone,
                                  /* tag_action */ MSG_SIMPLE_Q_TAG,
                                  /* lba */ address,
                                  /* layer_number */ dvdstruct->layer_num,
                                  /* key_format */ dvdstruct->format,
                                  /* agid */ dvdstruct->agid,
                                  /* data_ptr */ databuf,
                                  /* dxfer_len */ length,
                                  /* sense_len */ SSD_FULL_SIZE,
                                  /* timeout */ 50000);
  
          error = cdrunccb(ccb, cderror, /*cam_flags*/CAM_RETRY_SELTO,
                           /*sense_flags*/SF_RETRY_UA);
  
          if (error != 0)
                  goto bailout;
  
          switch(dvdstruct->format) {
          case DVD_STRUCT_PHYSICAL: {
                  struct scsi_read_dvd_struct_data_layer_desc *inlayer;
                  struct dvd_layer *outlayer;
                  struct scsi_read_dvd_struct_data_physical *phys_data;
  
                  phys_data =
                          (struct scsi_read_dvd_struct_data_physical *)databuf;
                  inlayer = &phys_data->layer_desc;
                  outlayer = (struct dvd_layer *)&dvdstruct->data;
  
                  dvdstruct->length = sizeof(*inlayer);
  
                  outlayer->book_type = (inlayer->book_type_version &
                          RDSD_BOOK_TYPE_MASK) >> RDSD_BOOK_TYPE_SHIFT;
                  outlayer->book_version = (inlayer->book_type_version &
                          RDSD_BOOK_VERSION_MASK);
                  outlayer->disc_size = (inlayer->disc_size_max_rate &
                          RDSD_DISC_SIZE_MASK) >> RDSD_DISC_SIZE_SHIFT;
                  outlayer->max_rate = (inlayer->disc_size_max_rate &
                          RDSD_MAX_RATE_MASK);
                  outlayer->nlayers = (inlayer->layer_info &
                          RDSD_NUM_LAYERS_MASK) >> RDSD_NUM_LAYERS_SHIFT;
                  outlayer->track_path = (inlayer->layer_info &
                          RDSD_TRACK_PATH_MASK) >> RDSD_TRACK_PATH_SHIFT;
                  outlayer->layer_type = (inlayer->layer_info &
                          RDSD_LAYER_TYPE_MASK);
                  outlayer->linear_density = (inlayer->density &
                          RDSD_LIN_DENSITY_MASK) >> RDSD_LIN_DENSITY_SHIFT;
                  outlayer->track_density = (inlayer->density &
                          RDSD_TRACK_DENSITY_MASK);
                  outlayer->bca = (inlayer->bca & RDSD_BCA_MASK) >>
                          RDSD_BCA_SHIFT;
                  outlayer->start_sector = scsi_3btoul(inlayer->main_data_start);
                  outlayer->end_sector = scsi_3btoul(inlayer->main_data_end);
                  outlayer->end_sector_l0 =
                          scsi_3btoul(inlayer->end_sector_layer0);
                  break;
          }
          case DVD_STRUCT_COPYRIGHT: {
                  struct scsi_read_dvd_struct_data_copyright *copy_data;
  
                  copy_data = (struct scsi_read_dvd_struct_data_copyright *)
                          databuf;
  
                  dvdstruct->cpst = copy_data->cps_type;
                  dvdstruct->rmi = copy_data->region_info;
                  dvdstruct->length = 0;
  
                  break;
          }
          default:
                  /*
                   * Tell the user what the overall length is, no matter
                   * what we can actually fit in the data buffer.
                   */
                  dvdstruct->length = length - ccb->csio.resid - 
                          sizeof(struct scsi_read_dvd_struct_data_header);
  
                  /*
                   * But only actually copy out the smaller of what we read
                   * in or what the structure can take.
                   */
                  bcopy(databuf + sizeof(struct scsi_read_dvd_struct_data_header),
                        dvdstruct->data,
                        min(sizeof(dvdstruct->data), dvdstruct->length));
                  break;
          }
  
  bailout:
          xpt_release_ccb(ccb);
          cam_periph_unlock(periph);
  
          if (databuf != NULL)
                  free(databuf, M_DEVBUF);
  
          return(error);
  }
  
  void
  scsi_report_key(struct ccb_scsiio *csio, u_int32_t retries,
                  void (*cbfcnp)(struct cam_periph *, union ccb *),
                  u_int8_t tag_action, u_int32_t lba, u_int8_t agid,
                  u_int8_t key_format, u_int8_t *data_ptr, u_int32_t dxfer_len,
                  u_int8_t sense_len, u_int32_t timeout)
  {
          struct scsi_report_key *scsi_cmd;
  
          scsi_cmd = (struct scsi_report_key *)&csio->cdb_io.cdb_bytes;
          bzero(scsi_cmd, sizeof(*scsi_cmd));
          scsi_cmd->opcode = REPORT_KEY;
          scsi_ulto4b(lba, scsi_cmd->lba);
          scsi_ulto2b(dxfer_len, scsi_cmd->alloc_len);
          scsi_cmd->agid_keyformat = (agid << RK_KF_AGID_SHIFT) |
                  (key_format & RK_KF_KEYFORMAT_MASK);
  
          cam_fill_csio(csio,
                        retries,
                        cbfcnp,
                        /*flags*/ (dxfer_len == 0) ? CAM_DIR_NONE : CAM_DIR_IN,
                        tag_action,
                        /*data_ptr*/ data_ptr,
                        /*dxfer_len*/ dxfer_len,
                        sense_len,
                        sizeof(*scsi_cmd),
                        timeout);
  }
  
  void
  scsi_send_key(struct ccb_scsiio *csio, u_int32_t retries,
                void (*cbfcnp)(struct cam_periph *, union ccb *),
                u_int8_t tag_action, u_int8_t agid, u_int8_t key_format,
                u_int8_t *data_ptr, u_int32_t dxfer_len, u_int8_t sense_len,
                u_int32_t timeout)
  {
          struct scsi_send_key *scsi_cmd;
  
          scsi_cmd = (struct scsi_send_key *)&csio->cdb_io.cdb_bytes;
          bzero(scsi_cmd, sizeof(*scsi_cmd));
          scsi_cmd->opcode = SEND_KEY;
  
          scsi_ulto2b(dxfer_len, scsi_cmd->param_len);
          scsi_cmd->agid_keyformat = (agid << RK_KF_AGID_SHIFT) |
                  (key_format & RK_KF_KEYFORMAT_MASK);
  
          cam_fill_csio(csio,
                        retries,
                        cbfcnp,
                        /*flags*/ CAM_DIR_OUT,
                        tag_action,
                        /*data_ptr*/ data_ptr,
                        /*dxfer_len*/ dxfer_len,
                        sense_len,
                        sizeof(*scsi_cmd),
                        timeout);
  }
  
  
  void
  scsi_read_dvd_structure(struct ccb_scsiio *csio, u_int32_t retries,
                          void (*cbfcnp)(struct cam_periph *, union ccb *),
                          u_int8_t tag_action, u_int32_t address,
                          u_int8_t layer_number, u_int8_t format, u_int8_t agid,
                          u_int8_t *data_ptr, u_int32_t dxfer_len,
                          u_int8_t sense_len, u_int32_t timeout)
  {
          struct scsi_read_dvd_structure *scsi_cmd;
  
          scsi_cmd = (struct scsi_read_dvd_structure *)&csio->cdb_io.cdb_bytes;
          bzero(scsi_cmd, sizeof(*scsi_cmd));
          scsi_cmd->opcode = READ_DVD_STRUCTURE;
  
          scsi_ulto4b(address, scsi_cmd->address);
          scsi_cmd->layer_number = layer_number;
          scsi_cmd->format = format;
          scsi_ulto2b(dxfer_len, scsi_cmd->alloc_len);
          /* The AGID is the top two bits of this byte */
          scsi_cmd->agid = agid << 6;
  
          cam_fill_csio(csio,
                        retries,
                        cbfcnp,
                        /*flags*/ CAM_DIR_IN,
                        tag_action,
                        /*data_ptr*/ data_ptr,
                        /*dxfer_len*/ dxfer_len,
                        sense_len,
                        sizeof(*scsi_cmd),
                        timeout);
  }