cdrom.c

cdrom device drive for linux.

/* linux/drivers/cdrom/cdrom.c. 
   Copyright (c) 1996, 1997 David A. van Leeuwen.
   Copyright (c) 1997, 1998 Erik Andersen <[e-mail]>
   Copyright (c) 1998, 1999 Jens Axboe <[e-mail]>

   May be copied or modified under the terms of the GNU General Public
   License.  See linux/COPYING for more information.

   Uniform CD-ROM driver for Linux.
   See Documentation/cdrom/cdrom-standard.tex for usage information.

   The routines in the file provide a uniform interface between the
   software that uses CD-ROMs and the various low-level drivers that
   actually talk to the hardware. Suggestions are welcome.
   Patches that work are more welcome though.  ;-)

 To Do List:
 ----------------------------------

 -- Modify sysctl/proc interface. I plan on having one directory per
 drive, with entries for outputing general drive information, and sysctl
 based tunable parameters such as whether the tray should auto-close for
 that drive. Suggestions (or patches) for this welcome!


 Revision History
 ----------------------------------
 1.00  Date Unknown -- David van Leeuwen <[e-mail]>
 -- Initial version by David A. van Leeuwen. I don't have a detailed
  changelog for the 1.x series, David?

2.00  Dec  2, 1997 -- Erik Andersen <[e-mail]>
  -- New maintainer! As David A. van Leeuwen has been too busy to activly
  maintain and improve this driver, I am now carrying on the torch. If
  you have a problem with this driver, please feel free to contact me.

  -- Added (rudimentary) sysctl interface. I realize this is really weak
  right now, and is _very_ badly implemented. It will be improved...

  -- Modified CDROM_DISC_STATUS so that it is now incorporated into
  the Uniform CD-ROM driver via the cdrom_count_tracks function.
  The cdrom_count_tracks function helps resolve some of the false
  assumptions of the CDROM_DISC_STATUS ioctl, and is also used to check
  for the correct media type when mounting or playing audio from a CD.

  -- Remove the calls to verify_area and only use the copy_from_user and
  copy_to_user stuff, since these calls now provide their own memory
  checking with the 2.1.x kernels.

  -- Major update to return codes so that errors from low-level drivers
  are passed on through (thanks to Gerd Knorr for pointing out this
  problem).

  -- Made it so if a function isn't implemented in a low-level driver,
  ENOSYS is now returned instead of EINVAL.

  -- Simplified some complex logic so that the source code is easier to read.

  -- Other stuff I probably forgot to mention (lots of changes).

2.01 to 2.11 Dec 1997-Jan 1998
  -- TO-DO!  Write changelogs for 2.01 to 2.12.

2.12  Jan  24, 1998 -- Erik Andersen <[e-mail]>
  -- Fixed a bug in the IOCTL_IN and IOCTL_OUT macros.  It turns out that
  copy_*_user does not return EFAULT on error, but instead returns the number 
  of bytes not copied.  I was returning whatever non-zero stuff came back from 
  the copy_*_user functions directly, which would result in strange errors.

2.13  July 17, 1998 -- Erik Andersen <[e-mail]>
  -- Fixed a bug in CDROM_SELECT_SPEED where you couldn't lower the speed
  of the drive.  Thanks to Tobias Ringstr|m <[e-mail]> for pointing
  this out and providing a simple fix.
  -- Fixed the procfs-unload-module bug with the fill_inode procfs callback.
  thanks to Andrea Arcangeli
  -- Fixed it so that the /proc entry now also shows up when cdrom is
  compiled into the kernel.  Before it only worked when loaded as a module.

  2.14 August 17, 1998 -- Erik Andersen <[e-mail]>
  -- Fixed a bug in cdrom_media_changed and handling of reporting that
  the media had changed for devices that _don't_ implement media_changed.  
  Thanks to Grant R. Guenther <[e-mail]> for spotting this bug.
  -- Made a few things more pedanticly correct.

2.50 Oct 19, 1998 - Jens Axboe <[e-mail]>
  -- New maintainers! Erik was too busy to continue the work on the driver,
  so now Chris Zwilling <[e-mail]> and Jens Axboe <[e-mail]>
  will do their best to follow in his footsteps
  
  2.51 Dec 20, 1998 - Jens Axboe <[e-mail]>
  -- Check if drive is capable of doing what we ask before blindly changing
  cdi->options in various ioctl.
  -- Added version to proc entry.
  
  2.52 Jan 16, 1999 - Jens Axboe <[e-mail]>
  -- Fixed an error in open_for_data where we would sometimes not return
  the correct error value. Thanks Huba Gaspar <[e-mail]>.
  -- Fixed module usage count - usage was based on /proc/sys/dev
  instead of /proc/sys/dev/cdrom. This could lead to an oops when other
  modules had entries in dev. Feb 02 - real bug was in sysctl.c where
  dev would be removed even though it was used. cdrom.c just illuminated
  that bug.
  
  2.53 Feb 22, 1999 - Jens Axboe <[e-mail]>
  -- Fixup of several ioctl calls, in particular CDROM_SET_OPTIONS has
  been "rewritten" because capabilities and options aren't in sync. They
  should be...
  -- Added CDROM_LOCKDOOR ioctl. Locks the door and keeps it that way.
  -- Added CDROM_RESET ioctl.
  -- Added CDROM_DEBUG ioctl. Enable debug messages on-the-fly.
  -- Added CDROM_GET_CAPABILITY ioctl. This relieves userspace programs
  from parsing /proc/sys/dev/cdrom/info.
  
  2.54 Mar 15, 1999 - Jens Axboe <[e-mail]>
  -- Check capability mask from low level driver when counting tracks as
  per suggestion from Corey J. Scotts <[e-mail]>.
  
  2.55 Apr 25, 1999 - Jens Axboe <[e-mail]>
  -- autoclose was mistakenly checked against CDC_OPEN_TRAY instead of
  CDC_CLOSE_TRAY.
  -- proc info didn't mask against capabilities mask.
  
  3.00 Aug 5, 1999 - Jens Axboe <[e-mail]>
  -- Unified audio ioctl handling across CD-ROM drivers. A lot of the
  code was duplicated before. Drives that support the generic packet
  interface are now being fed packets from here instead.
  -- First attempt at adding support for MMC2 commands - for DVD and
  CD-R(W) drives. Only the DVD parts are in now - the interface used is
  the same as for the audio ioctls.
  -- ioctl cleanups. if a drive couldn't play audio, it didn't get
  a change to perform device specific ioctls as well.
  -- Defined CDROM_CAN(CDC_XXX) for checking the capabilities.
  -- Put in sysctl files for autoclose, autoeject, check_media, debug,
  and lock.
  -- /proc/sys/dev/cdrom/info has been updated to also contain info about
  CD-Rx and DVD capabilities.
  -- Now default to checking media type.
  -- CDROM_SEND_PACKET ioctl added. The infrastructure was in place for
  doing this anyway, with the generic_packet addition.
  
  3.01 Aug 6, 1999 - Jens Axboe <[e-mail]>
  -- Fix up the sysctl handling so that the option flags get set
  correctly.
  -- Fix up ioctl handling so the device specific ones actually get
  called :).
  
  3.02 Aug 8, 1999 - Jens Axboe <[e-mail]>
  -- Fixed volume control on SCSI drives (or others with longer audio
  page).
  -- Fixed a couple of DVD minors. Thanks to Andrew T. Veliath
  <[e-mail]> for telling me and for having defined the various
  DVD structures and ioctls in the first place! He designed the original
  DVD patches for ide-cd and while I rearranged and unified them, the
  interface is still the same.
  
  3.03 Sep 1, 1999 - Jens Axboe <[e-mail]>
  -- Moved the rest of the audio ioctls from the CD-ROM drivers here. Only
  CDROMREADTOCENTRY and CDROMREADTOCHDR are left.
  -- Moved the CDROMREADxxx ioctls in here.
  -- Defined the cdrom_get_last_written and cdrom_get_next_block as ioctls
  and exported functions.
  -- Erik Andersen <[e-mail]> modified all SCMD_ commands
  to now read GPCMD_ for the new generic packet interface. All low level
  drivers are updated as well.
  -- Various other cleanups.

  3.04 Sep 12, 1999 - Jens Axboe <[e-mail]>
  -- Fixed a couple of possible memory leaks (if an operation failed and
  we didn't free the buffer before returning the error).
  -- Integrated Uniform CD Changer handling from Richard Sharman
  <[e-mail]>.
  -- Defined CD_DVD and CD_CHANGER log levels.
  -- Fixed the CDROMREADxxx ioctls.
  -- CDROMPLAYTRKIND uses the GPCMD_PLAY_AUDIO_MSF command - too few
  drives supported it. We loose the index part, however.
  -- Small modifications to accomodate opens of /dev/hdc1, required
  for ide-cd to handle multisession discs.
  -- Export cdrom_mode_sense and cdrom_mode_select.
  -- init_cdrom_command() for setting up a cgc command.
  
  3.05 Oct 24, 1999 - Jens Axboe <[e-mail]>
  -- Changed the interface for CDROM_SEND_PACKET. Before it was virtually
  impossible to send the drive data in a sensible way.
  -- Lowered stack usage in mmc_ioctl(), dvd_read_disckey(), and
  dvd_read_manufact.
  -- Added setup of write mode for packet writing.
  -- Fixed CDDA ripping with cdda2wav - accept much larger requests of
  number of frames and split the reads in blocks of 8.

  3.06 Dec 13, 1999 - Jens Axboe <[e-mail]>
  -- Added support for changing the region of DVD drives.
  -- Added sense data to generic command.

  3.07 Feb 2, 2000 - Jens Axboe <[e-mail]>
  -- Do same "read header length" trick in cdrom_get_disc_info() as
  we do in cdrom_get_track_info() -- some drive don't obey specs and
  fail if they can't supply the full Mt Fuji size table.
  -- Deleted stuff related to setting up write modes. It has a different
  home now.
  -- Clear header length in mode_select unconditionally.
  -- Removed the register_disk() that was added, not needed here.

  3.08 May 1, 2000 - Jens Axboe <[e-mail]>
  -- Fix direction flag in setup_send_key and setup_report_key. This
  gave some SCSI adapters problems.
  -- Always return -EROFS for write opens
  -- Convert to module_init/module_exit style init and remove some
  of the #ifdef MODULE stuff
  -- Fix several dvd errors - DVD_LU_SEND_ASF should pass agid,
  DVD_HOST_SEND_RPC_STATE did not set buffer size in cdb, and
  dvd_do_auth passed uninitialized data to drive because init_cdrom_command
  did not clear a 0 sized buffer.
  
  3.09 May 12, 2000 - Jens Axboe <[e-mail]>
  -- Fix Video-CD on SCSI drives that don't support READ_CD command. In
  that case switch block size and issue plain READ_10 again, then switch
  back.

  3.10 Jun 10, 2000 - Jens Axboe <[e-mail]>
  -- Fix volume control on CD's - old SCSI-II drives now use their own
  code, as doing MODE6 stuff in here is really not my intention.
  -- Use READ_DISC_INFO for more reliable end-of-disc.

  3.11 Jun 12, 2000 - Jens Axboe <[e-mail]>
  -- Fix bug in getting rpc phase 2 region info.
  -- Reinstate "correct" CDROMPLAYTRKIND

   3.12 Oct 18, 2000 - Jens Axboe <[e-mail]>
  -- Use quiet bit on packet commands not known to work

-------------------------------------------------------------------------*/

#define REVISION "Revision: 3.12"
#define VERSION "Id: cdrom.c 3.12 2000/10/18"

/* I use an error-log mask to give fine grain control over the type of
   messages dumped to the system logs.  The available masks include: */
#define CD_NOTHING      0x0
#define CD_WARNING	0x1
#define CD_REG_UNREG	0x2
#define CD_DO_IOCTL	0x4
#define CD_OPEN		0x8
#define CD_CLOSE	0x10
#define CD_COUNT_TRACKS 0x20
#define CD_CHANGER	0x40
#define CD_DVD		0x80

/* Define this to remove _all_ the debugging messages */
/* #define ERRLOGMASK CD_NOTHING */
#define ERRLOGMASK (CD_WARNING)
/* #define ERRLOGMASK (CD_WARNING|CD_OPEN|CD_COUNT_TRACKS|CD_CLOSE) */
/* #define ERRLOGMASK (CD_WARNING|CD_REG_UNREG|CD_DO_IOCTL|CD_OPEN|CD_CLOSE|CD_COUNT_TRACKS) */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/major.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h> 
#include <linux/cdrom.h>
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/init.h>

#include <asm/fcntl.h>
#include <asm/segment.h>
#include <asm/uaccess.h>

/* used to tell the module to turn on full debugging messages */
static int debug;
/* used to keep tray locked at all times */
static int keeplocked;
/* default compatibility mode */
static int autoclose=1;
static int autoeject;
static int lockdoor = 1;
/* will we ever get to use this... sigh. */
static int check_media_type;
MODULE_PARM(debug, "i");
MODULE_PARM(autoclose, "i");
MODULE_PARM(autoeject, "i");
MODULE_PARM(lockdoor, "i");
MODULE_PARM(check_media_type, "i");

#if (ERRLOGMASK!=CD_NOTHING)
#define cdinfo(type, fmt, args...) \
        if ((ERRLOGMASK & type) || debug==1 ) \
            printk(KERN_INFO "cdrom: " fmt, ## args)
#else
#define cdinfo(type, fmt, args...) 
#endif

/* These are used to simplify getting data in from and back to user land */
#define IOCTL_IN(arg, type, in)					\
	if (copy_from_user(&(in), (type *) (arg), sizeof (in)))	\
		return -EFAULT;

#define IOCTL_OUT(arg, type, out) \
	if (copy_to_user((type *) (arg), &(out), sizeof (out)))	\
		return -EFAULT;

/* The (cdo->capability & ~cdi->mask & CDC_XXX) construct was used in
   a lot of places. This macro makes the code more clear. */
#define CDROM_CAN(type) (cdi->ops->capability & ~cdi->mask & (type))

/* used in the audio ioctls */
#define CHECKAUDIO if ((ret=check_for_audio_disc(cdi, cdo))) return ret

/* Not-exported routines. */
static int open_for_data(struct cdrom_device_info * cdi);
static int check_for_audio_disc(struct cdrom_device_info * cdi,
			 struct cdrom_device_ops * cdo);
static void sanitize_format(union cdrom_addr *addr, 
		u_char * curr, u_char requested);
static int mmc_ioctl(struct cdrom_device_info *cdi, unsigned int cmd,
		     unsigned long arg);

int cdrom_get_last_written(kdev_t dev, long *last_written);
int cdrom_get_next_writable(kdev_t dev, long *next_writable);

#ifdef CONFIG_SYSCTL
static void cdrom_sysctl_register(void);
#endif /* CONFIG_SYSCTL */ 
static struct cdrom_device_info *topCdromPtr;
static devfs_handle_t devfs_handle;
static struct unique_numspace cdrom_numspace = UNIQUE_NUMBERSPACE_INITIALISER;

/* This macro makes sure we don't have to check on cdrom_device_ops
 * existence in the run-time routines below. Change_capability is a
 * hack to have the capability flags defined const, while we can still
 * change it here without gcc complaining at every line.
 */
#define ENSURE(call, bits) if (cdo->call == NULL) *change_capability &= ~(bits)

int register_cdrom(struct cdrom_device_info *cdi)
{
	static char banner_printed;
	int major = MAJOR(cdi->dev);
        struct cdrom_device_ops *cdo = cdi->ops;
        int *change_capability = (int *)&cdo->capability; /* hack */

	cdinfo(CD_OPEN, "entering register_cdrom\n"); 

	if (major < 0 || major >= MAX_BLKDEV)
		return -1;
	if (cdo->open == NULL || cdo->release == NULL)
		return -2;
	if ( !banner_printed ) {
		printk(KERN_INFO "Uniform CD-ROM driver " REVISION "\n");
		banner_printed = 1;
#ifdef CONFIG_SYSCTL
		cdrom_sysctl_register();
#endif /* CONFIG_SYSCTL */ 
	}
	ENSURE(drive_status, CDC_DRIVE_STATUS );
	ENSURE(media_changed, CDC_MEDIA_CHANGED);
	ENSURE(tray_move, CDC_CLOSE_TRAY | CDC_OPEN_TRAY);
	ENSURE(lock_door, CDC_LOCK);
	ENSURE(select_speed, CDC_SELECT_SPEED);
	ENSURE(get_last_session, CDC_MULTI_SESSION);
	ENSURE(get_mcn, CDC_MCN);
	ENSURE(reset, CDC_RESET);
	ENSURE(audio_ioctl, CDC_PLAY_AUDIO);
	ENSURE(dev_ioctl, CDC_IOCTLS);
	ENSURE(generic_packet, CDC_GENERIC_PACKET);
	cdi->mc_flags = 0;
	cdo->n_minors = 0;
        cdi->options = CDO_USE_FFLAGS;
	
	if (autoclose==1 && CDROM_CAN(CDC_CLOSE_TRAY))
		cdi->options |= (int) CDO_AUTO_CLOSE;
	if (autoeject==1 && CDROM_CAN(CDC_OPEN_TRAY))
		cdi->options |= (int) CDO_AUTO_EJECT;
	if (lockdoor==1)
		cdi->options |= (int) CDO_LOCK;
	if (check_media_type==1)
		cdi->options |= (int) CDO_CHECK_TYPE;

	if (!devfs_handle)
		devfs_handle = devfs_mk_dir (NULL, "cdroms", NULL);
	cdi->number = devfs_alloc_unique_number (&cdrom_numspace);
	if (cdi->de) {
		int pos;
		devfs_handle_t slave;
		char rname[64];

		pos = devfs_generate_path (cdi->de, rname + 3,
					   sizeof rname - 3);
		if (pos >= 0) {
			char vname[16];
			sprintf (vname, "cdrom%d", cdi->number);
			strncpy (rname + pos, "../", 3);
			devfs_mk_symlink (devfs_handle, vname,
					  DEVFS_FL_DEFAULT,
					  rname + pos, &slave, NULL);
			devfs_auto_unregister (cdi->de, slave);
		}
	}
	cdinfo(CD_REG_UNREG, "drive \"/dev/%s\" registered\n", cdi->name);
	cdi->next = topCdromPtr; 	
	topCdromPtr = cdi;
	return 0;
}
#undef ENSURE

int unregister_cdrom(struct cdrom_device_info *unreg)
{
	struct cdrom_device_info *cdi, *prev;
	int major = MAJOR(unreg->dev);

	cdinfo(CD_OPEN, "entering unregister_cdrom\n"); 

	if (major < 0 || major >= MAX_BLKDEV)
		return -1;

	prev = NULL;