docs: Move the user-space ioctl() docs to userspace-api

This is strictly user-space material at this point, so put it with the
other user-space API documentation.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

5 files changed, 2983 insertions, 0 deletions

diff --git a/Documentation/userspace-api/ioctl/cdrom.rst b/Documentation/userspace-api/ioctl/cdrom.rst
new file mode 100644
index 000000000000..3b4c0506de46
--- /dev/null
+++ b/Documentation/userspace-api/ioctl/cdrom.rst
@@ -0,0 +1,1233 @@
+============================
+Summary of CDROM ioctl calls
+============================
+
+- Edward A. Falk <efalk@google.com>
+
+November, 2004
+
+This document attempts to describe the ioctl(2) calls supported by
+the CDROM layer.  These are by-and-large implemented (as of Linux 2.6)
+in drivers/cdrom/cdrom.c and drivers/block/scsi_ioctl.c
+
+ioctl values are listed in <linux/cdrom.h>.  As of this writing, they
+are as follows:
+
+	======================	===============================================
+	CDROMPAUSE		Pause Audio Operation
+	CDROMRESUME		Resume paused Audio Operation
+	CDROMPLAYMSF		Play Audio MSF (struct cdrom_msf)
+	CDROMPLAYTRKIND		Play Audio Track/index (struct cdrom_ti)
+	CDROMREADTOCHDR		Read TOC header (struct cdrom_tochdr)
+	CDROMREADTOCENTRY	Read TOC entry (struct cdrom_tocentry)
+	CDROMSTOP		Stop the cdrom drive
+	CDROMSTART		Start the cdrom drive
+	CDROMEJECT		Ejects the cdrom media
+	CDROMVOLCTRL		Control output volume (struct cdrom_volctrl)
+	CDROMSUBCHNL		Read subchannel data (struct cdrom_subchnl)
+	CDROMREADMODE2		Read CDROM mode 2 data (2336 Bytes)
+				(struct cdrom_read)
+	CDROMREADMODE1		Read CDROM mode 1 data (2048 Bytes)
+				(struct cdrom_read)
+	CDROMREADAUDIO		(struct cdrom_read_audio)
+	CDROMEJECT_SW		enable(1)/disable(0) auto-ejecting
+	CDROMMULTISESSION	Obtain the start-of-last-session
+				address of multi session disks
+				(struct cdrom_multisession)
+	CDROM_GET_MCN		Obtain the "Universal Product Code"
+				if available (struct cdrom_mcn)
+	CDROM_GET_UPC		Deprecated, use CDROM_GET_MCN instead.
+	CDROMRESET		hard-reset the drive
+	CDROMVOLREAD		Get the drive's volume setting
+				(struct cdrom_volctrl)
+	CDROMREADRAW		read data in raw mode (2352 Bytes)
+				(struct cdrom_read)
+	CDROMREADCOOKED		read data in cooked mode
+	CDROMSEEK		seek msf address
+	CDROMPLAYBLK		scsi-cd only, (struct cdrom_blk)
+	CDROMREADALL		read all 2646 bytes
+	CDROMGETSPINDOWN	return 4-bit spindown value
+	CDROMSETSPINDOWN	set 4-bit spindown value
+	CDROMCLOSETRAY		pendant of CDROMEJECT
+	CDROM_SET_OPTIONS	Set behavior options
+	CDROM_CLEAR_OPTIONS	Clear behavior options
+	CDROM_SELECT_SPEED	Set the CD-ROM speed
+	CDROM_SELECT_DISC	Select disc (for juke-boxes)
+	CDROM_MEDIA_CHANGED	Check is media changed
+	CDROM_DRIVE_STATUS	Get tray position, etc.
+	CDROM_DISC_STATUS	Get disc type, etc.
+	CDROM_CHANGER_NSLOTS	Get number of slots
+	CDROM_LOCKDOOR		lock or unlock door
+	CDROM_DEBUG		Turn debug messages on/off
+	CDROM_GET_CAPABILITY	get capabilities
+	CDROMAUDIOBUFSIZ	set the audio buffer size
+	DVD_READ_STRUCT		Read structure
+	DVD_WRITE_STRUCT	Write structure
+	DVD_AUTH		Authentication
+	CDROM_SEND_PACKET	send a packet to the drive
+	CDROM_NEXT_WRITABLE	get next writable block
+	CDROM_LAST_WRITTEN	get last block written on disc
+	======================	===============================================
+
+
+The information that follows was determined from reading kernel source
+code.  It is likely that some corrections will be made over time.
+
+------------------------------------------------------------------------------
+
+General:
+
+	Unless otherwise specified, all ioctl calls return 0 on success
+	and -1 with errno set to an appropriate value on error.  (Some
+	ioctls return non-negative data values.)
+
+	Unless otherwise specified, all ioctl calls return -1 and set
+	errno to EFAULT on a failed attempt to copy data to or from user
+	address space.
+
+	Individual drivers may return error codes not listed here.
+
+	Unless otherwise specified, all data structures and constants
+	are defined in <linux/cdrom.h>
+
+------------------------------------------------------------------------------
+
+
+CDROMPAUSE
+	Pause Audio Operation
+
+
+	usage::
+
+	  ioctl(fd, CDROMPAUSE, 0);
+
+
+	inputs:
+		none
+
+
+	outputs:
+		none
+
+
+	error return:
+	  - ENOSYS	cd drive not audio-capable.
+
+
+CDROMRESUME
+	Resume paused Audio Operation
+
+
+	usage::
+
+	  ioctl(fd, CDROMRESUME, 0);
+
+
+	inputs:
+		none
+
+
+	outputs:
+		none
+
+
+	error return:
+	  - ENOSYS	cd drive not audio-capable.
+
+
+CDROMPLAYMSF
+	Play Audio MSF
+
+	(struct cdrom_msf)
+
+
+	usage::
+
+	  struct cdrom_msf msf;
+
+	  ioctl(fd, CDROMPLAYMSF, &msf);
+
+	inputs:
+		cdrom_msf structure, describing a segment of music to play
+
+
+	outputs:
+		none
+
+
+	error return:
+	  - ENOSYS	cd drive not audio-capable.
+
+	notes:
+		- MSF stands for minutes-seconds-frames
+		- LBA stands for logical block address
+		- Segment is described as start and end times, where each time
+		  is described as minutes:seconds:frames.
+		  A frame is 1/75 of a second.
+
+
+CDROMPLAYTRKIND
+	Play Audio Track/index
+
+	(struct cdrom_ti)
+
+
+	usage::
+
+	  struct cdrom_ti ti;
+
+	  ioctl(fd, CDROMPLAYTRKIND, &ti);
+
+	inputs:
+		cdrom_ti structure, describing a segment of music to play
+
+
+	outputs:
+		none
+
+
+	error return:
+	  - ENOSYS	cd drive not audio-capable.
+
+	notes:
+		- Segment is described as start and end times, where each time
+		  is described as a track and an index.
+
+
+
+CDROMREADTOCHDR
+	Read TOC header
+
+	(struct cdrom_tochdr)
+
+
+	usage::
+
+	  cdrom_tochdr header;
+
+	  ioctl(fd, CDROMREADTOCHDR, &header);
+
+	inputs:
+		cdrom_tochdr structure
+
+
+	outputs:
+		cdrom_tochdr structure
+
+
+	error return:
+	  - ENOSYS	cd drive not audio-capable.
+
+
+
+CDROMREADTOCENTRY
+	Read TOC entry
+
+	(struct cdrom_tocentry)
+
+
+	usage::
+
+	  struct cdrom_tocentry entry;
+
+	  ioctl(fd, CDROMREADTOCENTRY, &entry);
+
+	inputs:
+		cdrom_tocentry structure
+
+
+	outputs:
+		cdrom_tocentry structure
+
+
+	error return:
+	  - ENOSYS	cd drive not audio-capable.
+	  - EINVAL	entry.cdte_format not CDROM_MSF or CDROM_LBA
+	  - EINVAL	requested track out of bounds
+	  - EIO		I/O error reading TOC
+
+	notes:
+		- TOC stands for Table Of Contents
+		- MSF stands for minutes-seconds-frames
+		- LBA stands for logical block address
+
+
+
+CDROMSTOP
+	Stop the cdrom drive
+
+
+	usage::
+
+	  ioctl(fd, CDROMSTOP, 0);
+
+
+	inputs:
+		none
+
+
+	outputs:
+		none
+
+
+	error return:
+	  - ENOSYS	cd drive not audio-capable.
+
+	notes:
+	  - Exact interpretation of this ioctl depends on the device,
+	    but most seem to spin the drive down.
+
+
+CDROMSTART
+	Start the cdrom drive
+
+
+	usage::
+
+	  ioctl(fd, CDROMSTART, 0);
+
+
+	inputs:
+		none
+
+
+	outputs:
+		none
+
+
+	error return:
+	  - ENOSYS	cd drive not audio-capable.
+
+	notes:
+	  - Exact interpretation of this ioctl depends on the device,
+	    but most seem to spin the drive up and/or close the tray.
+	    Other devices ignore the ioctl completely.
+
+
+CDROMEJECT
+	- Ejects the cdrom media
+
+
+	usage::
+
+	  ioctl(fd, CDROMEJECT, 0);
+
+
+	inputs:
+		none
+
+
+	outputs:
+		none
+
+
+	error returns:
+	  - ENOSYS	cd drive not capable of ejecting
+	  - EBUSY	other processes are accessing drive, or door is locked
+
+	notes:
+		- See CDROM_LOCKDOOR, below.
+
+
+
+
+CDROMCLOSETRAY
+	pendant of CDROMEJECT
+
+
+	usage::
+
+	  ioctl(fd, CDROMCLOSETRAY, 0);
+
+
+	inputs:
+		none
+
+
+	outputs:
+		none
+
+
+	error returns:
+	  - ENOSYS	cd drive not capable of closing the tray
+	  - EBUSY	other processes are accessing drive, or door is locked
+
+	notes:
+		- See CDROM_LOCKDOOR, below.
+
+
+
+
+CDROMVOLCTRL
+	Control output volume (struct cdrom_volctrl)
+
+
+	usage::
+
+	  struct cdrom_volctrl volume;
+
+	  ioctl(fd, CDROMVOLCTRL, &volume);
+
+	inputs:
+		cdrom_volctrl structure containing volumes for up to 4
+		channels.
+
+	outputs:
+		none
+
+
+	error return:
+	  - ENOSYS	cd drive not audio-capable.
+
+
+
+CDROMVOLREAD
+	Get the drive's volume setting
+
+	(struct cdrom_volctrl)
+
+
+	usage::
+
+	  struct cdrom_volctrl volume;
+
+	  ioctl(fd, CDROMVOLREAD, &volume);
+
+	inputs:
+		none
+
+
+	outputs:
+		The current volume settings.
+
+
+	error return:
+	  - ENOSYS	cd drive not audio-capable.
+
+
+
+CDROMSUBCHNL
+	Read subchannel data
+
+	(struct cdrom_subchnl)
+
+
+	usage::
+
+	  struct cdrom_subchnl q;
+
+	  ioctl(fd, CDROMSUBCHNL, &q);
+
+	inputs:
+		cdrom_subchnl structure
+
+
+	outputs:
+		cdrom_subchnl structure
+
+
+	error return:
+	  - ENOSYS	cd drive not audio-capable.
+	  - EINVAL	format not CDROM_MSF or CDROM_LBA
+
+	notes:
+		- Format is converted to CDROM_MSF or CDROM_LBA
+		  as per user request on return
+
+
+
+CDROMREADRAW
+	read data in raw mode (2352 Bytes)
+
+	(struct cdrom_read)
+
+	usage::
+
+	  union {
+
+	    struct cdrom_msf msf;		/* input */
+	    char buffer[CD_FRAMESIZE_RAW];	/* return */
+	  } arg;
+	  ioctl(fd, CDROMREADRAW, &arg);
+
+	inputs:
+		cdrom_msf structure indicating an address to read.
+
+		Only the start values are significant.
+
+	outputs:
+		Data written to address provided by user.
+
+
+	error return:
+	  - EINVAL	address less than 0, or msf less than 0:2:0
+	  - ENOMEM	out of memory
+
+	notes:
+		- As of 2.6.8.1, comments in <linux/cdrom.h> indicate that this
+		  ioctl accepts a cdrom_read structure, but actual source code
+		  reads a cdrom_msf structure and writes a buffer of data to
+		  the same address.
+
+		- MSF values are converted to LBA values via this formula::
+
+		    lba = (((m * CD_SECS) + s) * CD_FRAMES + f) - CD_MSF_OFFSET;
+
+
+
+
+CDROMREADMODE1
+	Read CDROM mode 1 data (2048 Bytes)
+
+	(struct cdrom_read)
+
+	notes:
+		Identical to CDROMREADRAW except that block size is
+		CD_FRAMESIZE (2048) bytes
+
+
+
+CDROMREADMODE2
+	Read CDROM mode 2 data (2336 Bytes)
+
+	(struct cdrom_read)
+
+	notes:
+		Identical to CDROMREADRAW except that block size is
+		CD_FRAMESIZE_RAW0 (2336) bytes
+
+
+
+CDROMREADAUDIO
+	(struct cdrom_read_audio)
+
+	usage::
+
+	  struct cdrom_read_audio ra;
+
+	  ioctl(fd, CDROMREADAUDIO, &ra);
+
+	inputs:
+		cdrom_read_audio structure containing read start
+		point and length
+
+	outputs:
+		audio data, returned to buffer indicated by ra
+
+
+	error return:
+	  - EINVAL	format not CDROM_MSF or CDROM_LBA
+	  - EINVAL	nframes not in range [1 75]
+	  - ENXIO	drive has no queue (probably means invalid fd)
+	  - ENOMEM	out of memory
+
+
+CDROMEJECT_SW
+	enable(1)/disable(0) auto-ejecting
+
+
+	usage::
+
+	  int val;
+
+	  ioctl(fd, CDROMEJECT_SW, val);
+
+	inputs:
+		Flag specifying auto-eject flag.
+
+
+	outputs:
+		none
+
+
+	error return:
+	  - ENOSYS	Drive is not capable of ejecting.
+	  - EBUSY	Door is locked
+
+
+
+
+CDROMMULTISESSION
+	Obtain the start-of-last-session address of multi session disks
+
+	(struct cdrom_multisession)
+
+	usage::
+
+	  struct cdrom_multisession ms_info;
+
+	  ioctl(fd, CDROMMULTISESSION, &ms_info);
+
+	inputs:
+		cdrom_multisession structure containing desired
+
+	  format.
+
+	outputs:
+		cdrom_multisession structure is filled with last_session
+		information.
+
+	error return:
+	  - EINVAL	format not CDROM_MSF or CDROM_LBA
+
+
+CDROM_GET_MCN
+	Obtain the "Universal Product Code"
+	if available
+
+	(struct cdrom_mcn)
+
+
+	usage::
+
+	  struct cdrom_mcn mcn;
+
+	  ioctl(fd, CDROM_GET_MCN, &mcn);
+
+	inputs:
+		none
+
+
+	outputs:
+		Universal Product Code
+
+
+	error return:
+	  - ENOSYS	Drive is not capable of reading MCN data.
+
+	notes:
+		- Source code comments state::
+
+		    The following function is implemented, although very few
+		    audio discs give Universal Product Code information, which
+		    should just be the Medium Catalog Number on the box.  Note,
+		    that the way the code is written on the CD is /not/ uniform
+		    across all discs!
+
+
+
+
+CDROM_GET_UPC
+	CDROM_GET_MCN  (deprecated)
+
+
+	Not implemented, as of 2.6.8.1
+
+
+
+CDROMRESET
+	hard-reset the drive
+
+
+	usage::
+
+	  ioctl(fd, CDROMRESET, 0);
+
+
+	inputs:
+		none
+
+
+	outputs:
+		none
+
+
+	error return:
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  - ENOSYS	Drive is not capable of resetting.
+
+
+
+
+CDROMREADCOOKED
+	read data in cooked mode
+
+
+	usage::
+
+	  u8 buffer[CD_FRAMESIZE]
+
+	  ioctl(fd, CDROMREADCOOKED, buffer);
+
+	inputs:
+		none
+
+
+	outputs:
+		2048 bytes of data, "cooked" mode.
+
+
+	notes:
+		Not implemented on all drives.
+
+
+
+
+
+CDROMREADALL
+	read all 2646 bytes
+
+
+	Same as CDROMREADCOOKED, but reads 2646 bytes.
+
+
+
+CDROMSEEK
+	seek msf address
+
+
+	usage::
+
+	  struct cdrom_msf msf;
+
+	  ioctl(fd, CDROMSEEK, &msf);
+
+	inputs:
+		MSF address to seek to.
+
+
+	outputs:
+		none
+
+
+
+
+CDROMPLAYBLK
+	scsi-cd only
+
+	(struct cdrom_blk)
+
+
+	usage::
+
+	  struct cdrom_blk blk;
+
+	  ioctl(fd, CDROMPLAYBLK, &blk);
+
+	inputs:
+		Region to play
+
+
+	outputs:
+		none
+
+
+
+
+CDROMGETSPINDOWN
+	usage::
+
+	  char spindown;
+
+	  ioctl(fd, CDROMGETSPINDOWN, &spindown);
+
+	inputs:
+		none
+
+
+	outputs:
+		The value of the current 4-bit spindown value.
+
+
+
+
+
+CDROMSETSPINDOWN
+	usage::
+
+	  char spindown
+
+	  ioctl(fd, CDROMSETSPINDOWN, &spindown);
+
+	inputs:
+		4-bit value used to control spindown (TODO: more detail here)
+
+
+	outputs:
+		none
+
+
+
+
+
+
+CDROM_SET_OPTIONS
+	Set behavior options
+
+
+	usage::
+
+	  int options;
+
+	  ioctl(fd, CDROM_SET_OPTIONS, options);
+
+	inputs:
+		New values for drive options.  The logical 'or' of:
+
+	    ==============      ==================================
+	    CDO_AUTO_CLOSE	close tray on first open(2)
+	    CDO_AUTO_EJECT	open tray on last release
+	    CDO_USE_FFLAGS	use O_NONBLOCK information on open
+	    CDO_LOCK		lock tray on open files
+	    CDO_CHECK_TYPE	check type on open for data
+	    ==============      ==================================
+
+	outputs:
+		Returns the resulting options settings in the
+		ioctl return value.  Returns -1 on error.
+
+	error return:
+	  - ENOSYS	selected option(s) not supported by drive.
+
+
+
+
+CDROM_CLEAR_OPTIONS
+	Clear behavior options
+
+
+	Same as CDROM_SET_OPTIONS, except that selected options are
+	turned off.
+
+
+
+CDROM_SELECT_SPEED
+	Set the CD-ROM speed
+
+
+	usage::
+
+	  int speed;
+
+	  ioctl(fd, CDROM_SELECT_SPEED, speed);
+
+	inputs:
+		New drive speed.
+
+
+	outputs:
+		none
+
+
+	error return:
+	  - ENOSYS	speed selection not supported by drive.
+
+
+
+CDROM_SELECT_DISC
+	Select disc (for juke-boxes)
+
+
+	usage::
+
+	  int disk;
+
+	  ioctl(fd, CDROM_SELECT_DISC, disk);
+
+	inputs:
+		Disk to load into drive.
+
+
+	outputs:
+		none
+
+
+	error return:
+	  - EINVAL	Disk number beyond capacity of drive
+
+
+
+CDROM_MEDIA_CHANGED
+	Check is media changed
+
+
+	usage::
+
+	  int slot;
+
+	  ioctl(fd, CDROM_MEDIA_CHANGED, slot);
+
+	inputs:
+		Slot number to be tested, always zero except for jukeboxes.
+
+		May also be special values CDSL_NONE or CDSL_CURRENT
+
+	outputs:
+		Ioctl return value is 0 or 1 depending on whether the media
+
+	  has been changed, or -1 on error.
+
+	error returns:
+	  - ENOSYS	Drive can't detect media change
+	  - EINVAL	Slot number beyond capacity of drive
+	  - ENOMEM	Out of memory
+
+
+
+CDROM_DRIVE_STATUS
+	Get tray position, etc.
+
+
+	usage::
+
+	  int slot;
+
+	  ioctl(fd, CDROM_DRIVE_STATUS, slot);
+
+	inputs:
+		Slot number to be tested, always zero except for jukeboxes.
+
+		May also be special values CDSL_NONE or CDSL_CURRENT
+
+	outputs:
+		Ioctl return value will be one of the following values
+
+	  from <linux/cdrom.h>:
+
+	    =================== ==========================
+	    CDS_NO_INFO		Information not available.
+	    CDS_NO_DISC
+	    CDS_TRAY_OPEN
+	    CDS_DRIVE_NOT_READY
+	    CDS_DISC_OK
+	    -1			error
+	    =================== ==========================
+
+	error returns:
+	  - ENOSYS	Drive can't detect drive status
+	  - EINVAL	Slot number beyond capacity of drive
+	  - ENOMEM	Out of memory
+
+
+
+
+CDROM_DISC_STATUS
+	Get disc type, etc.
+
+
+	usage::
+
+	  ioctl(fd, CDROM_DISC_STATUS, 0);
+
+
+	inputs:
+		none
+
+
+	outputs:
+		Ioctl return value will be one of the following values
+
+	  from <linux/cdrom.h>:
+
+	    - CDS_NO_INFO
+	    - CDS_AUDIO
+	    - CDS_MIXED
+	    - CDS_XA_2_2
+	    - CDS_XA_2_1
+	    - CDS_DATA_1
+
+	error returns:
+		none at present
+
+	notes:
+	    - Source code comments state::
+
+
+		Ok, this is where problems start.  The current interface for
+		the CDROM_DISC_STATUS ioctl is flawed.  It makes the false
+		assumption that CDs are all CDS_DATA_1 or all CDS_AUDIO, etc.
+		Unfortunately, while this is often the case, it is also
+		very common for CDs to have some tracks with data, and some
+		tracks with audio.	Just because I feel like it, I declare
+		the following to be the best way to cope.  If the CD has
+		ANY data tracks on it, it will be returned as a data CD.
+		If it has any XA tracks, I will return it as that.	Now I
+		could simplify this interface by combining these returns with
+		the above, but this more clearly demonstrates the problem
+		with the current interface.  Too bad this wasn't designed
+		to use bitmasks...	       -Erik
+
+		Well, now we have the option CDS_MIXED: a mixed-type CD.
+		User level programmers might feel the ioctl is not very
+		useful.
+				---david
+
+
+
+
+CDROM_CHANGER_NSLOTS
+	Get number of slots
+
+
+	usage::
+
+	  ioctl(fd, CDROM_CHANGER_NSLOTS, 0);
+
+
+	inputs:
+		none
+
+
+	outputs:
+		The ioctl return value will be the number of slots in a
+		CD changer.  Typically 1 for non-multi-disk devices.
+
+	error returns:
+		none
+
+
+
+CDROM_LOCKDOOR
+	lock or unlock door
+
+
+	usage::
+
+	  int lock;
+
+	  ioctl(fd, CDROM_LOCKDOOR, lock);
+
+	inputs:
+		Door lock flag, 1=lock, 0=unlock
+
+
+	outputs:
+		none
+
+
+	error returns:
+	  - EDRIVE_CANT_DO_THIS
+
+				Door lock function not supported.
+	  - EBUSY
+
+				Attempt to unlock when multiple users
+				have the drive open and not CAP_SYS_ADMIN
+
+	notes:
+		As of 2.6.8.1, the lock flag is a global lock, meaning that
+		all CD drives will be locked or unlocked together.  This is
+		probably a bug.
+
+		The EDRIVE_CANT_DO_THIS value is defined in <linux/cdrom.h>
+		and is currently (2.6.8.1) the same as EOPNOTSUPP
+
+
+
+CDROM_DEBUG
+	Turn debug messages on/off
+
+
+	usage::
+
+	  int debug;
+
+	  ioctl(fd, CDROM_DEBUG, debug);
+
+	inputs:
+		Cdrom debug flag, 0=disable, 1=enable
+
+
+	outputs:
+		The ioctl return value will be the new debug flag.
+
+
+	error return:
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+
+
+
+CDROM_GET_CAPABILITY
+	get capabilities
+
+
+	usage::
+
+	  ioctl(fd, CDROM_GET_CAPABILITY, 0);
+
+
+	inputs:
+		none
+
+
+	outputs:
+		The ioctl return value is the current device capability
+		flags.  See CDC_CLOSE_TRAY, CDC_OPEN_TRAY, etc.
+
+
+
+CDROMAUDIOBUFSIZ
+	set the audio buffer size
+
+
+	usage::
+
+	  int arg;
+
+	  ioctl(fd, CDROMAUDIOBUFSIZ, val);
+
+	inputs:
+		New audio buffer size
+
+
+	outputs:
+		The ioctl return value is the new audio buffer size, or -1
+		on error.
+
+	error return:
+	  - ENOSYS	Not supported by this driver.
+
+	notes:
+		Not supported by all drivers.
+
+
+
+
+DVD_READ_STRUCT			Read structure
+
+	usage::
+
+	  dvd_struct s;
+
+	  ioctl(fd, DVD_READ_STRUCT, &s);
+
+	inputs:
+		dvd_struct structure, containing:
+
+	    =================== ==========================================
+	    type		specifies the information desired, one of
+				DVD_STRUCT_PHYSICAL, DVD_STRUCT_COPYRIGHT,
+				DVD_STRUCT_DISCKEY, DVD_STRUCT_BCA,
+				DVD_STRUCT_MANUFACT
+	    physical.layer_num	desired layer, indexed from 0
+	    copyright.layer_num	desired layer, indexed from 0
+	    disckey.agid
+	    =================== ==========================================
+
+	outputs:
+		dvd_struct structure, containing:
+
+	    =================== ================================
+	    physical		for type == DVD_STRUCT_PHYSICAL
+	    copyright		for type == DVD_STRUCT_COPYRIGHT
+	    disckey.value	for type == DVD_STRUCT_DISCKEY
+	    bca.{len,value}	for type == DVD_STRUCT_BCA
+	    manufact.{len,valu}	for type == DVD_STRUCT_MANUFACT
+	    =================== ================================
+
+	error returns:
+	  - EINVAL	physical.layer_num exceeds number of layers
+	  - EIO		Received invalid response from drive
+
+
+
+DVD_WRITE_STRUCT		Write structure
+
+	Not implemented, as of 2.6.8.1
+
+
+
+DVD_AUTH			Authentication
+
+	usage::
+
+	  dvd_authinfo ai;
+
+	  ioctl(fd, DVD_AUTH, &ai);
+
+	inputs:
+		dvd_authinfo structure.  See <linux/cdrom.h>
+
+
+	outputs:
+		dvd_authinfo structure.
+
+
+	error return:
+	  - ENOTTY	ai.type not recognized.
+
+
+
+CDROM_SEND_PACKET
+	send a packet to the drive
+
+
+	usage::
+
+	  struct cdrom_generic_command cgc;
+
+	  ioctl(fd, CDROM_SEND_PACKET, &cgc);
+
+	inputs:
+		cdrom_generic_command structure containing the packet to send.
+
+
+	outputs:
+		none
+
+	  cdrom_generic_command structure containing results.
+
+	error return:
+	  - EIO
+
+			command failed.
+	  - EPERM
+
+			Operation not permitted, either because a
+			write command was attempted on a drive which
+			is opened read-only, or because the command
+			requires CAP_SYS_RAWIO
+	  - EINVAL
+
+			cgc.data_direction not set
+
+
+
+CDROM_NEXT_WRITABLE
+	get next writable block
+
+
+	usage::
+
+	  long next;
+
+	  ioctl(fd, CDROM_NEXT_WRITABLE, &next);
+
+	inputs:
+		none
+
+
+	outputs:
+		The next writable block.
+
+
+	notes:
+		If the device does not support this ioctl directly, the
+
+	  ioctl will return CDROM_LAST_WRITTEN + 7.
+
+
+
+CDROM_LAST_WRITTEN
+	get last block written on disc
+
+
+	usage::
+
+	  long last;
+
+	  ioctl(fd, CDROM_LAST_WRITTEN, &last);
+
+	inputs:
+		none
+
+
+	outputs:
+		The last block written on disc
+
+
+	notes:
+		If the device does not support this ioctl directly, the
+		result is derived from the disc's table of contents.  If the
+		table of contents can't be read, this ioctl returns an
+		error.
diff --git a/Documentation/userspace-api/ioctl/hdio.rst b/Documentation/userspace-api/ioctl/hdio.rst
new file mode 100644
index 000000000000..e822e3dff176
--- /dev/null
+++ b/Documentation/userspace-api/ioctl/hdio.rst
@@ -0,0 +1,1342 @@
+==============================
+Summary of `HDIO_` ioctl calls
+==============================
+
+- Edward A. Falk <efalk@google.com>
+
+November, 2004
+
+This document attempts to describe the ioctl(2) calls supported by
+the HD/IDE layer.  These are by-and-large implemented (as of Linux 2.6)
+in drivers/ide/ide.c and drivers/block/scsi_ioctl.c
+
+ioctl values are listed in <linux/hdreg.h>.  As of this writing, they
+are as follows:
+
+    ioctls that pass argument pointers to user space:
+
+	=======================	=======================================
+	HDIO_GETGEO		get device geometry
+	HDIO_GET_UNMASKINTR	get current unmask setting
+	HDIO_GET_MULTCOUNT	get current IDE blockmode setting
+	HDIO_GET_QDMA		get use-qdma flag
+	HDIO_SET_XFER		set transfer rate via proc
+	HDIO_OBSOLETE_IDENTITY	OBSOLETE, DO NOT USE
+	HDIO_GET_KEEPSETTINGS	get keep-settings-on-reset flag
+	HDIO_GET_32BIT		get current io_32bit setting
+	HDIO_GET_NOWERR		get ignore-write-error flag
+	HDIO_GET_DMA		get use-dma flag
+	HDIO_GET_NICE		get nice flags
+	HDIO_GET_IDENTITY	get IDE identification info
+	HDIO_GET_WCACHE		get write cache mode on|off
+	HDIO_GET_ACOUSTIC	get acoustic value
+	HDIO_GET_ADDRESS	get sector addressing mode
+	HDIO_GET_BUSSTATE	get the bus state of the hwif
+	HDIO_TRISTATE_HWIF	execute a channel tristate
+	HDIO_DRIVE_RESET	execute a device reset
+	HDIO_DRIVE_TASKFILE	execute raw taskfile
+	HDIO_DRIVE_TASK		execute task and special drive command
+	HDIO_DRIVE_CMD		execute a special drive command
+	HDIO_DRIVE_CMD_AEB	HDIO_DRIVE_TASK
+	=======================	=======================================
+
+    ioctls that pass non-pointer values:
+
+	=======================	=======================================
+	HDIO_SET_MULTCOUNT	change IDE blockmode
+	HDIO_SET_UNMASKINTR	permit other irqs during I/O
+	HDIO_SET_KEEPSETTINGS	keep ioctl settings on reset
+	HDIO_SET_32BIT		change io_32bit flags
+	HDIO_SET_NOWERR		change ignore-write-error flag
+	HDIO_SET_DMA		change use-dma flag
+	HDIO_SET_PIO_MODE	reconfig interface to new speed
+	HDIO_SCAN_HWIF		register and (re)scan interface
+	HDIO_SET_NICE		set nice flags
+	HDIO_UNREGISTER_HWIF	unregister interface
+	HDIO_SET_WCACHE		change write cache enable-disable
+	HDIO_SET_ACOUSTIC	change acoustic behavior
+	HDIO_SET_BUSSTATE	set the bus state of the hwif
+	HDIO_SET_QDMA		change use-qdma flag
+	HDIO_SET_ADDRESS	change lba addressing modes
+
+	HDIO_SET_IDE_SCSI	Set scsi emulation mode on/off
+	HDIO_SET_SCSI_IDE	not implemented yet
+	=======================	=======================================
+
+
+The information that follows was determined from reading kernel source
+code.  It is likely that some corrections will be made over time.
+
+------------------------------------------------------------------------------
+
+General:
+
+	Unless otherwise specified, all ioctl calls return 0 on success
+	and -1 with errno set to an appropriate value on error.
+
+	Unless otherwise specified, all ioctl calls return -1 and set
+	errno to EFAULT on a failed attempt to copy data to or from user
+	address space.
+
+	Unless otherwise specified, all data structures and constants
+	are defined in <linux/hdreg.h>
+
+------------------------------------------------------------------------------
+
+HDIO_GETGEO
+	get device geometry
+
+
+	usage::
+
+	  struct hd_geometry geom;
+
+	  ioctl(fd, HDIO_GETGEO, &geom);
+
+
+	inputs:
+		none
+
+
+
+	outputs:
+		hd_geometry structure containing:
+
+
+	    =========	==================================
+	    heads	number of heads
+	    sectors	number of sectors/track
+	    cylinders	number of cylinders, mod 65536
+	    start	starting sector of this partition.
+	    =========	==================================
+
+
+	error returns:
+	  - EINVAL
+
+			if the device is not a disk drive or floppy drive,
+			or if the user passes a null pointer
+
+
+	notes:
+		Not particularly useful with modern disk drives, whose geometry
+		is a polite fiction anyway.  Modern drives are addressed
+		purely by sector number nowadays (lba addressing), and the
+		drive geometry is an abstraction which is actually subject
+		to change.  Currently (as of Nov 2004), the geometry values
+		are the "bios" values -- presumably the values the drive had
+		when Linux first booted.
+
+		In addition, the cylinders field of the hd_geometry is an
+		unsigned short, meaning that on most architectures, this
+		ioctl will not return a meaningful value on drives with more
+		than 65535 tracks.
+
+		The start field is unsigned long, meaning that it will not
+		contain a meaningful value for disks over 219 Gb in size.
+
+
+
+
+HDIO_GET_UNMASKINTR
+	get current unmask setting
+
+
+	usage::
+
+	  long val;
+
+	  ioctl(fd, HDIO_GET_UNMASKINTR, &val);
+
+	inputs:
+		none
+
+
+
+	outputs:
+		The value of the drive's current unmask setting
+
+
+
+
+
+HDIO_SET_UNMASKINTR
+	permit other irqs during I/O
+
+
+	usage::
+
+	  unsigned long val;
+
+	  ioctl(fd, HDIO_SET_UNMASKINTR, val);
+
+	inputs:
+		New value for unmask flag
+
+
+
+	outputs:
+		none
+
+
+
+	error return:
+	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  - EINVAL	value out of range [0 1]
+	  - EBUSY	Controller busy
+
+
+
+
+HDIO_GET_MULTCOUNT
+	get current IDE blockmode setting
+
+
+	usage::
+
+	  long val;
+
+	  ioctl(fd, HDIO_GET_MULTCOUNT, &val);
+
+	inputs:
+		none
+
+
+
+	outputs:
+		The value of the current IDE block mode setting.  This
+		controls how many sectors the drive will transfer per
+		interrupt.
+
+
+
+HDIO_SET_MULTCOUNT
+	change IDE blockmode
+
+
+	usage::
+
+	  int val;
+
+	  ioctl(fd, HDIO_SET_MULTCOUNT, val);
+
+	inputs:
+		New value for IDE block mode setting.  This controls how many
+		sectors the drive will transfer per interrupt.
+
+	outputs:
+		none
+
+
+
+	error return:
+	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  - EINVAL	value out of range supported by disk.
+	  - EBUSY	Controller busy or blockmode already set.
+	  - EIO		Drive did not accept new block mode.
+
+	notes:
+	  Source code comments read::
+
+	    This is tightly woven into the driver->do_special cannot
+	    touch.  DON'T do it again until a total personality rewrite
+	    is committed.
+
+	  If blockmode has already been set, this ioctl will fail with
+	  -EBUSY
+
+
+
+HDIO_GET_QDMA
+	get use-qdma flag
+
+
+	Not implemented, as of 2.6.8.1
+
+
+
+HDIO_SET_XFER
+	set transfer rate via proc
+
+
+	Not implemented, as of 2.6.8.1
+
+
+
+HDIO_OBSOLETE_IDENTITY
+	OBSOLETE, DO NOT USE
+
+
+	Same as HDIO_GET_IDENTITY (see below), except that it only
+	returns the first 142 bytes of drive identity information.
+
+
+
+HDIO_GET_IDENTITY
+	get IDE identification info
+
+
+	usage::
+
+	  unsigned char identity[512];
+
+	  ioctl(fd, HDIO_GET_IDENTITY, identity);
+
+	inputs:
+		none
+
+
+
+	outputs:
+		ATA drive identity information.  For full description, see
+		the IDENTIFY DEVICE and IDENTIFY PACKET DEVICE commands in
+		the ATA specification.
+
+	error returns:
+	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
+	  - ENOMSG	IDENTIFY DEVICE information not available
+
+	notes:
+		Returns information that was obtained when the drive was
+		probed.  Some of this information is subject to change, and
+		this ioctl does not re-probe the drive to update the
+		information.
+
+		This information is also available from /proc/ide/hdX/identify
+
+
+
+HDIO_GET_KEEPSETTINGS
+	get keep-settings-on-reset flag
+
+
+	usage::
+
+	  long val;
+
+	  ioctl(fd, HDIO_GET_KEEPSETTINGS, &val);
+
+	inputs:
+		none
+
+
+
+	outputs:
+		The value of the current "keep settings" flag
+
+
+
+	notes:
+		When set, indicates that kernel should restore settings
+		after a drive reset.
+
+
+
+HDIO_SET_KEEPSETTINGS
+	keep ioctl settings on reset
+
+
+	usage::
+
+	  long val;
+
+	  ioctl(fd, HDIO_SET_KEEPSETTINGS, val);
+
+	inputs:
+		New value for keep_settings flag
+
+
+
+	outputs:
+		none
+
+
+
+	error return:
+	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  - EINVAL	value out of range [0 1]
+	  - EBUSY		Controller busy
+
+
+
+HDIO_GET_32BIT
+	get current io_32bit setting
+
+
+	usage::
+
+	  long val;
+
+	  ioctl(fd, HDIO_GET_32BIT, &val);
+
+	inputs:
+		none
+
+
+
+	outputs:
+		The value of the current io_32bit setting
+
+
+
+	notes:
+		0=16-bit, 1=32-bit, 2,3 = 32bit+sync
+
+
+
+
+
+HDIO_GET_NOWERR
+	get ignore-write-error flag
+
+
+	usage::
+
+	  long val;
+
+	  ioctl(fd, HDIO_GET_NOWERR, &val);
+
+	inputs:
+		none
+
+
+
+	outputs:
+		The value of the current ignore-write-error flag
+
+
+
+
+
+HDIO_GET_DMA
+	get use-dma flag
+
+
+	usage::
+
+	  long val;
+
+	  ioctl(fd, HDIO_GET_DMA, &val);
+
+	inputs:
+		none
+
+
+
+	outputs:
+		The value of the current use-dma flag
+
+
+
+
+
+HDIO_GET_NICE
+	get nice flags
+
+
+	usage::
+
+	  long nice;
+
+	  ioctl(fd, HDIO_GET_NICE, &nice);
+
+	inputs:
+		none
+
+
+
+	outputs:
+		The drive's "nice" values.
+
+
+
+	notes:
+		Per-drive flags which determine when the system will give more
+		bandwidth to other devices sharing the same IDE bus.
+
+		See <linux/hdreg.h>, near symbol IDE_NICE_DSC_OVERLAP.
+
+
+
+
+HDIO_SET_NICE
+	set nice flags
+
+
+	usage::
+
+	  unsigned long nice;
+
+	  ...
+	  ioctl(fd, HDIO_SET_NICE, nice);
+
+	inputs:
+		bitmask of nice flags.
+
+
+
+	outputs:
+		none
+
+
+
+	error returns:
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  - EPERM	Flags other than DSC_OVERLAP and NICE_1 set.
+	  - EPERM	DSC_OVERLAP specified but not supported by drive
+
+	notes:
+		This ioctl sets the DSC_OVERLAP and NICE_1 flags from values
+		provided by the user.
+
+		Nice flags are listed in <linux/hdreg.h>, starting with
+		IDE_NICE_DSC_OVERLAP.  These values represent shifts.
+
+
+
+
+
+HDIO_GET_WCACHE
+	get write cache mode on|off
+
+
+	usage::
+
+	  long val;
+
+	  ioctl(fd, HDIO_GET_WCACHE, &val);
+
+	inputs:
+		none
+
+
+
+	outputs:
+		The value of the current write cache mode
+
+
+
+
+
+HDIO_GET_ACOUSTIC
+	get acoustic value
+
+
+	usage::
+
+	  long val;
+
+	  ioctl(fd, HDIO_GET_ACOUSTIC, &val);
+
+	inputs:
+		none
+
+
+
+	outputs:
+		The value of the current acoustic settings
+
+
+
+	notes:
+		See HDIO_SET_ACOUSTIC
+
+
+
+
+
+HDIO_GET_ADDRESS
+	usage::
+
+
+	  long val;
+
+	  ioctl(fd, HDIO_GET_ADDRESS, &val);
+
+	inputs:
+		none
+
+
+
+	outputs:
+		The value of the current addressing mode:
+
+	    =  ===================
+	    0  28-bit
+	    1  48-bit
+	    2  48-bit doing 28-bit
+	    3  64-bit
+	    =  ===================
+
+
+
+HDIO_GET_BUSSTATE
+	get the bus state of the hwif
+
+
+	usage::
+
+	  long state;
+
+	  ioctl(fd, HDIO_SCAN_HWIF, &state);
+
+	inputs:
+		none
+
+
+
+	outputs:
+		Current power state of the IDE bus.  One of BUSSTATE_OFF,
+		BUSSTATE_ON, or BUSSTATE_TRISTATE
+
+	error returns:
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+
+
+
+
+HDIO_SET_BUSSTATE
+	set the bus state of the hwif
+
+
+	usage::
+
+	  int state;
+
+	  ...
+	  ioctl(fd, HDIO_SCAN_HWIF, state);
+
+	inputs:
+		Desired IDE power state.  One of BUSSTATE_OFF, BUSSTATE_ON,
+		or BUSSTATE_TRISTATE
+
+	outputs:
+		none
+
+
+
+	error returns:
+	  - EACCES	Access denied:  requires CAP_SYS_RAWIO
+	  - EOPNOTSUPP	Hardware interface does not support bus power control
+
+
+
+
+HDIO_TRISTATE_HWIF
+	execute a channel tristate
+
+
+	Not implemented, as of 2.6.8.1.  See HDIO_SET_BUSSTATE
+
+
+
+HDIO_DRIVE_RESET
+	execute a device reset
+
+
+	usage::
+
+	  int args[3]
+
+	  ...
+	  ioctl(fd, HDIO_DRIVE_RESET, args);
+
+	inputs:
+		none
+
+
+
+	outputs:
+		none
+
+
+
+	error returns:
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  - ENXIO	No such device:	phy dead or ctl_addr == 0
+	  - EIO		I/O error:	reset timed out or hardware error
+
+	notes:
+
+	  - Execute a reset on the device as soon as the current IO
+	    operation has completed.
+
+	  - Executes an ATAPI soft reset if applicable, otherwise
+	    executes an ATA soft reset on the controller.
+
+
+
+HDIO_DRIVE_TASKFILE
+	execute raw taskfile
+
+
+	Note:
+		If you don't have a copy of the ANSI ATA specification
+		handy, you should probably ignore this ioctl.
+
+	- Execute an ATA disk command directly by writing the "taskfile"
+	  registers of the drive.  Requires ADMIN and RAWIO access
+	  privileges.
+
+	usage::
+
+	  struct {
+
+	    ide_task_request_t req_task;
+	    u8 outbuf[OUTPUT_SIZE];
+	    u8 inbuf[INPUT_SIZE];
+	  } task;
+	  memset(&task.req_task, 0, sizeof(task.req_task));
+	  task.req_task.out_size = sizeof(task.outbuf);
+	  task.req_task.in_size = sizeof(task.inbuf);
+	  ...
+	  ioctl(fd, HDIO_DRIVE_TASKFILE, &task);
+	  ...
+
+	inputs:
+
+	  (See below for details on memory area passed to ioctl.)
+
+	  ============	===================================================
+	  io_ports[8]	values to be written to taskfile registers
+	  hob_ports[8]	high-order bytes, for extended commands.
+	  out_flags	flags indicating which registers are valid
+	  in_flags	flags indicating which registers should be returned
+	  data_phase	see below
+	  req_cmd	command type to be executed
+	  out_size	size of output buffer
+	  outbuf	buffer of data to be transmitted to disk
+	  inbuf		buffer of data to be received from disk (see [1])
+	  ============	===================================================
+
+	outputs:
+
+	  ===========	====================================================
+	  io_ports[]	values returned in the taskfile registers
+	  hob_ports[]	high-order bytes, for extended commands.
+	  out_flags	flags indicating which registers are valid (see [2])
+	  in_flags	flags indicating which registers should be returned
+	  outbuf	buffer of data to be transmitted to disk (see [1])
+	  inbuf		buffer of data to be received from disk
+	  ===========	====================================================
+
+	error returns:
+	  - EACCES	CAP_SYS_ADMIN or CAP_SYS_RAWIO privilege not set.
+	  - ENOMSG	Device is not a disk drive.
+	  - ENOMEM	Unable to allocate memory for task
+	  - EFAULT	req_cmd == TASKFILE_IN_OUT (not implemented as of 2.6.8)
+	  - EPERM
+
+			req_cmd == TASKFILE_MULTI_OUT and drive
+			multi-count not yet set.
+	  - EIO		Drive failed the command.
+
+	notes:
+
+	  [1] READ THE FOLLOWING NOTES *CAREFULLY*.  THIS IOCTL IS
+	  FULL OF GOTCHAS.  Extreme caution should be used with using
+	  this ioctl.  A mistake can easily corrupt data or hang the
+	  system.
+
+	  [2] Both the input and output buffers are copied from the
+	  user and written back to the user, even when not used.
+
+	  [3] If one or more bits are set in out_flags and in_flags is
+	  zero, the following values are used for in_flags.all and
+	  written back into in_flags on completion.
+
+	   * IDE_TASKFILE_STD_IN_FLAGS | (IDE_HOB_STD_IN_FLAGS << 8)
+	     if LBA48 addressing is enabled for the drive
+	   * IDE_TASKFILE_STD_IN_FLAGS
+	     if CHS/LBA28
+
+	  The association between in_flags.all and each enable
+	  bitfield flips depending on endianness; fortunately, TASKFILE
+	  only uses inflags.b.data bit and ignores all other bits.
+	  The end result is that, on any endian machines, it has no
+	  effect other than modifying in_flags on completion.
+
+	  [4] The default value of SELECT is (0xa0|DEV_bit|LBA_bit)
+	  except for four drives per port chipsets.  For four drives
+	  per port chipsets, it's (0xa0|DEV_bit|LBA_bit) for the first
+	  pair and (0x80|DEV_bit|LBA_bit) for the second pair.
+
+	  [5] The argument to the ioctl is a pointer to a region of
+	  memory containing a ide_task_request_t structure, followed
+	  by an optional buffer of data to be transmitted to the
+	  drive, followed by an optional buffer to receive data from
+	  the drive.
+
+	  Command is passed to the disk drive via the ide_task_request_t
+	  structure, which contains these fields:
+
+	    ============	===============================================
+	    io_ports[8]		values for the taskfile registers
+	    hob_ports[8]	high-order bytes, for extended commands
+	    out_flags		flags indicating which entries in the
+				io_ports[] and hob_ports[] arrays
+				contain valid values.  Type ide_reg_valid_t.
+	    in_flags		flags indicating which entries in the
+				io_ports[] and hob_ports[] arrays
+				are expected to contain valid values
+				on return.
+	    data_phase		See below
+	    req_cmd		Command type, see below
+	    out_size		output (user->drive) buffer size, bytes
+	    in_size		input (drive->user) buffer size, bytes
+	    ============	===============================================
+
+	  When out_flags is zero, the following registers are loaded.
+
+	    ============	===============================================
+	    HOB_FEATURE		If the drive supports LBA48
+	    HOB_NSECTOR		If the drive supports LBA48
+	    HOB_SECTOR		If the drive supports LBA48
+	    HOB_LCYL		If the drive supports LBA48
+	    HOB_HCYL		If the drive supports LBA48
+	    FEATURE
+	    NSECTOR
+	    SECTOR
+	    LCYL
+	    HCYL
+	    SELECT		First, masked with 0xE0 if LBA48, 0xEF
+				otherwise; then, or'ed with the default
+				value of SELECT.
+	    ============	===============================================
+
+	  If any bit in out_flags is set, the following registers are loaded.
+
+	    ============	===============================================
+	    HOB_DATA		If out_flags.b.data is set.  HOB_DATA will
+				travel on DD8-DD15 on little endian machines
+				and on DD0-DD7 on big endian machines.
+	    DATA		If out_flags.b.data is set.  DATA will
+				travel on DD0-DD7 on little endian machines
+				and on DD8-DD15 on big endian machines.
+	    HOB_NSECTOR		If out_flags.b.nsector_hob is set
+	    HOB_SECTOR		If out_flags.b.sector_hob is set
+	    HOB_LCYL		If out_flags.b.lcyl_hob is set
+	    HOB_HCYL		If out_flags.b.hcyl_hob is set
+	    FEATURE		If out_flags.b.feature is set
+	    NSECTOR		If out_flags.b.nsector is set
+	    SECTOR		If out_flags.b.sector is set
+	    LCYL		If out_flags.b.lcyl is set
+	    HCYL		If out_flags.b.hcyl is set
+	    SELECT		Or'ed with the default value of SELECT and
+				loaded regardless of out_flags.b.select.
+	    ============	===============================================
+
+	  Taskfile registers are read back from the drive into
+	  {io|hob}_ports[] after the command completes iff one of the
+	  following conditions is met; otherwise, the original values
+	  will be written back, unchanged.
+
+	    1. The drive fails the command (EIO).
+	    2. One or more than one bits are set in out_flags.
+	    3. The requested data_phase is TASKFILE_NO_DATA.
+
+	    ============	===============================================
+	    HOB_DATA		If in_flags.b.data is set.  It will contain
+				DD8-DD15 on little endian machines and
+				DD0-DD7 on big endian machines.
+	    DATA		If in_flags.b.data is set.  It will contain
+				DD0-DD7 on little endian machines and
+				DD8-DD15 on big endian machines.
+	    HOB_FEATURE		If the drive supports LBA48
+	    HOB_NSECTOR		If the drive supports LBA48
+	    HOB_SECTOR		If the drive supports LBA48
+	    HOB_LCYL		If the drive supports LBA48
+	    HOB_HCYL		If the drive supports LBA48
+	    NSECTOR
+	    SECTOR
+	    LCYL
+	    HCYL
+	    ============	===============================================
+
+	  The data_phase field describes the data transfer to be
+	  performed.  Value is one of:
+
+	    ===================        ========================================
+	    TASKFILE_IN
+	    TASKFILE_MULTI_IN
+	    TASKFILE_OUT
+	    TASKFILE_MULTI_OUT
+	    TASKFILE_IN_OUT
+	    TASKFILE_IN_DMA
+	    TASKFILE_IN_DMAQ		== IN_DMA (queueing not supported)
+	    TASKFILE_OUT_DMA
+	    TASKFILE_OUT_DMAQ		== OUT_DMA (queueing not supported)
+	    TASKFILE_P_IN		unimplemented
+	    TASKFILE_P_IN_DMA		unimplemented
+	    TASKFILE_P_IN_DMAQ		unimplemented
+	    TASKFILE_P_OUT		unimplemented
+	    TASKFILE_P_OUT_DMA		unimplemented
+	    TASKFILE_P_OUT_DMAQ		unimplemented
+	    ===================        ========================================
+
+	  The req_cmd field classifies the command type.  It may be
+	  one of:
+
+	    ========================    =======================================
+	    IDE_DRIVE_TASK_NO_DATA
+	    IDE_DRIVE_TASK_SET_XFER	unimplemented
+	    IDE_DRIVE_TASK_IN
+	    IDE_DRIVE_TASK_OUT		unimplemented
+	    IDE_DRIVE_TASK_RAW_WRITE
+	    ========================    =======================================
+
+	  [6] Do not access {in|out}_flags->all except for resetting
+	  all the bits.  Always access individual bit fields.  ->all
+	  value will flip depending on endianness.  For the same
+	  reason, do not use IDE_{TASKFILE|HOB}_STD_{OUT|IN}_FLAGS
+	  constants defined in hdreg.h.
+
+
+
+HDIO_DRIVE_CMD
+	execute a special drive command
+
+
+	Note:  If you don't have a copy of the ANSI ATA specification
+	handy, you should probably ignore this ioctl.
+
+	usage::
+
+	  u8 args[4+XFER_SIZE];
+
+	  ...
+	  ioctl(fd, HDIO_DRIVE_CMD, args);
+
+	inputs:
+	    Commands other than WIN_SMART:
+
+	    =======     =======
+	    args[0]	COMMAND
+	    args[1]	NSECTOR
+	    args[2]	FEATURE
+	    args[3]	NSECTOR
+	    =======     =======
+
+	    WIN_SMART:
+
+	    =======     =======
+	    args[0]	COMMAND
+	    args[1]	SECTOR
+	    args[2]	FEATURE
+	    args[3]	NSECTOR
+	    =======     =======
+
+	outputs:
+		args[] buffer is filled with register values followed by any
+
+
+	  data returned by the disk.
+
+	    ========	====================================================
+	    args[0]	status
+	    args[1]	error
+	    args[2]	NSECTOR
+	    args[3]	undefined
+	    args[4+]	NSECTOR * 512 bytes of data returned by the command.
+	    ========	====================================================
+
+	error returns:
+	  - EACCES	Access denied:  requires CAP_SYS_RAWIO
+	  - ENOMEM	Unable to allocate memory for task
+	  - EIO		Drive reports error
+
+	notes:
+
+	  [1] For commands other than WIN_SMART, args[1] should equal
+	  args[3].  SECTOR, LCYL and HCYL are undefined.  For
+	  WIN_SMART, 0x4f and 0xc2 are loaded into LCYL and HCYL
+	  respectively.  In both cases SELECT will contain the default
+	  value for the drive.  Please refer to HDIO_DRIVE_TASKFILE
+	  notes for the default value of SELECT.
+
+	  [2] If NSECTOR value is greater than zero and the drive sets
+	  DRQ when interrupting for the command, NSECTOR * 512 bytes
+	  are read from the device into the area following NSECTOR.
+	  In the above example, the area would be
+	  args[4..4+XFER_SIZE].  16bit PIO is used regardless of
+	  HDIO_SET_32BIT setting.
+
+	  [3] If COMMAND == WIN_SETFEATURES && FEATURE == SETFEATURES_XFER
+	  && NSECTOR >= XFER_SW_DMA_0 && the drive supports any DMA
+	  mode, IDE driver will try to tune the transfer mode of the
+	  drive accordingly.
+
+
+
+HDIO_DRIVE_TASK
+	execute task and special drive command
+
+
+	Note:  If you don't have a copy of the ANSI ATA specification
+	handy, you should probably ignore this ioctl.
+
+	usage::
+
+	  u8 args[7];
+
+	  ...
+	  ioctl(fd, HDIO_DRIVE_TASK, args);
+
+	inputs:
+	    Taskfile register values:
+
+	    =======	=======
+	    args[0]	COMMAND
+	    args[1]	FEATURE
+	    args[2]	NSECTOR
+	    args[3]	SECTOR
+	    args[4]	LCYL
+	    args[5]	HCYL
+	    args[6]	SELECT
+	    =======	=======
+
+	outputs:
+	    Taskfile register values:
+
+
+	    =======	=======
+	    args[0]	status
+	    args[1]	error
+	    args[2]	NSECTOR
+	    args[3]	SECTOR
+	    args[4]	LCYL
+	    args[5]	HCYL
+	    args[6]	SELECT
+	    =======	=======
+
+	error returns:
+	  - EACCES	Access denied:  requires CAP_SYS_RAWIO
+	  - ENOMEM	Unable to allocate memory for task
+	  - ENOMSG	Device is not a disk drive.
+	  - EIO		Drive failed the command.
+
+	notes:
+
+	  [1] DEV bit (0x10) of SELECT register is ignored and the
+	  appropriate value for the drive is used.  All other bits
+	  are used unaltered.
+
+
+
+HDIO_DRIVE_CMD_AEB
+	HDIO_DRIVE_TASK
+
+
+	Not implemented, as of 2.6.8.1
+
+
+
+HDIO_SET_32BIT
+	change io_32bit flags
+
+
+	usage::
+
+	  int val;
+
+	  ioctl(fd, HDIO_SET_32BIT, val);
+
+	inputs:
+		New value for io_32bit flag
+
+
+
+	outputs:
+		none
+
+
+
+	error return:
+	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  - EINVAL	value out of range [0 3]
+	  - EBUSY	Controller busy
+
+
+
+
+HDIO_SET_NOWERR
+	change ignore-write-error flag
+
+
+	usage::
+
+	  int val;
+
+	  ioctl(fd, HDIO_SET_NOWERR, val);
+
+	inputs:
+		New value for ignore-write-error flag.  Used for ignoring
+
+
+	  WRERR_STAT
+
+	outputs:
+		none
+
+
+
+	error return:
+	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  - EINVAL	value out of range [0 1]
+	  - EBUSY		Controller busy
+
+
+
+HDIO_SET_DMA
+	change use-dma flag
+
+
+	usage::
+
+	  long val;
+
+	  ioctl(fd, HDIO_SET_DMA, val);
+
+	inputs:
+		New value for use-dma flag
+
+
+
+	outputs:
+		none
+
+
+
+	error return:
+	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  - EINVAL	value out of range [0 1]
+	  - EBUSY	Controller busy
+
+
+
+HDIO_SET_PIO_MODE
+	reconfig interface to new speed
+
+
+	usage::
+
+	  long val;
+
+	  ioctl(fd, HDIO_SET_PIO_MODE, val);
+
+	inputs:
+		New interface speed.
+
+
+
+	outputs:
+		none
+
+
+
+	error return:
+	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  - EINVAL	value out of range [0 255]
+	  - EBUSY	Controller busy
+
+
+
+HDIO_SCAN_HWIF
+	register and (re)scan interface
+
+
+	usage::
+
+	  int args[3]
+
+	  ...
+	  ioctl(fd, HDIO_SCAN_HWIF, args);
+
+	inputs:
+
+	  =======	=========================
+	  args[0]	io address to probe
+
+
+	  args[1]	control address to probe
+	  args[2]	irq number
+	  =======	=========================
+
+	outputs:
+		none
+
+
+
+	error returns:
+	  - EACCES	Access denied:  requires CAP_SYS_RAWIO
+	  - EIO		Probe failed.
+
+	notes:
+		This ioctl initializes the addresses and irq for a disk
+		controller, probes for drives, and creates /proc/ide
+		interfaces as appropriate.
+
+
+
+HDIO_UNREGISTER_HWIF
+	unregister interface
+
+
+	usage::
+
+	  int index;
+
+	  ioctl(fd, HDIO_UNREGISTER_HWIF, index);
+
+	inputs:
+		index		index of hardware interface to unregister
+
+
+
+	outputs:
+		none
+
+
+
+	error returns:
+	  - EACCES	Access denied:  requires CAP_SYS_RAWIO
+
+	notes:
+		This ioctl removes a hardware interface from the kernel.
+
+		Currently (2.6.8) this ioctl silently fails if any drive on
+		the interface is busy.
+
+
+
+HDIO_SET_WCACHE
+	change write cache enable-disable
+
+
+	usage::
+
+	  int val;
+
+	  ioctl(fd, HDIO_SET_WCACHE, val);
+
+	inputs:
+		New value for write cache enable
+
+
+
+	outputs:
+		none
+
+
+
+	error return:
+	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  - EINVAL	value out of range [0 1]
+	  - EBUSY	Controller busy
+
+
+
+HDIO_SET_ACOUSTIC
+	change acoustic behavior
+
+
+	usage::
+
+	  int val;
+
+	  ioctl(fd, HDIO_SET_ACOUSTIC, val);
+
+	inputs:
+		New value for drive acoustic settings
+
+
+
+	outputs:
+		none
+
+
+
+	error return:
+	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  - EINVAL	value out of range [0 254]
+	  - EBUSY	Controller busy
+
+
+
+HDIO_SET_QDMA
+	change use-qdma flag
+
+
+	Not implemented, as of 2.6.8.1
+
+
+
+HDIO_SET_ADDRESS
+	change lba addressing modes
+
+
+	usage::
+
+	  int val;
+
+	  ioctl(fd, HDIO_SET_ADDRESS, val);
+
+	inputs:
+		New value for addressing mode
+
+	    =   ===================
+	    0   28-bit
+	    1   48-bit
+	    2   48-bit doing 28-bit
+	    =   ===================
+
+	outputs:
+		none
+
+
+
+	error return:
+	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  - EINVAL	value out of range [0 2]
+	  - EBUSY		Controller busy
+	  - EIO		Drive does not support lba48 mode.
+
+
+HDIO_SET_IDE_SCSI
+	usage::
+
+
+	  long val;
+
+	  ioctl(fd, HDIO_SET_IDE_SCSI, val);
+
+	inputs:
+		New value for scsi emulation mode (?)
+
+
+
+	outputs:
+		none
+
+
+
+	error return:
+	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
+	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  - EINVAL	value out of range [0 1]
+	  - EBUSY	Controller busy
+
+
+
+HDIO_SET_SCSI_IDE
+	Not implemented, as of 2.6.8.1
diff --git a/Documentation/userspace-api/ioctl/index.rst b/Documentation/userspace-api/ioctl/index.rst
new file mode 100644
index 000000000000..475675eae086
--- /dev/null
+++ b/Documentation/userspace-api/ioctl/index.rst
@@ -0,0 +1,15 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+======
+IOCTLs
+======
+
+.. toctree::
+   :maxdepth: 1
+
+   ioctl-number
+
+   ioctl-decoding
+
+   cdrom
+   hdio
diff --git a/Documentation/userspace-api/ioctl/ioctl-decoding.rst b/Documentation/userspace-api/ioctl/ioctl-decoding.rst
new file mode 100644
index 000000000000..380d6bb3e3ea
--- /dev/null
+++ b/Documentation/userspace-api/ioctl/ioctl-decoding.rst
@@ -0,0 +1,31 @@
+==============================
+Decoding an IOCTL Magic Number
+==============================
+
+To decode a hex IOCTL code:
+
+Most architectures use this generic format, but check
+include/ARCH/ioctl.h for specifics, e.g. powerpc
+uses 3 bits to encode read/write and 13 bits for size.
+
+ ====== ==================================
+ bits   meaning
+ ====== ==================================
+ 31-30	00 - no parameters: uses _IO macro
+	10 - read: _IOR
+	01 - write: _IOW
+	11 - read/write: _IOWR
+
+ 29-16	size of arguments
+
+ 15-8	ascii character supposedly
+	unique to each driver
+
+ 7-0	function #
+ ====== ==================================
+
+
+So for example 0x82187201 is a read with arg length of 0x218,
+character 'r' function 1. Grepping the source reveals this is::
+
+	#define VFAT_IOCTL_READDIR_BOTH         _IOR('r', 1, struct dirent [2])
diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
new file mode 100644
index 000000000000..bef79cd4c6b4
--- /dev/null
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -0,0 +1,362 @@
+=============
+Ioctl Numbers
+=============
+
+19 October 1999
+
+Michael Elizabeth Chastain
+<mec@shout.net>
+
+If you are adding new ioctl's to the kernel, you should use the _IO
+macros defined in <linux/ioctl.h>:
+
+    ====== == ============================================
+    _IO    an ioctl with no parameters
+    _IOW   an ioctl with write parameters (copy_from_user)
+    _IOR   an ioctl with read parameters  (copy_to_user)
+    _IOWR  an ioctl with both write and read parameters.
+    ====== == ============================================
+
+'Write' and 'read' are from the user's point of view, just like the
+system calls 'write' and 'read'.  For example, a SET_FOO ioctl would
+be _IOW, although the kernel would actually read data from user space;
+a GET_FOO ioctl would be _IOR, although the kernel would actually write
+data to user space.
+
+The first argument to _IO, _IOW, _IOR, or _IOWR is an identifying letter
+or number from the table below.  Because of the large number of drivers,
+many drivers share a partial letter with other drivers.
+
+If you are writing a driver for a new device and need a letter, pick an
+unused block with enough room for expansion: 32 to 256 ioctl commands.
+You can register the block by patching this file and submitting the
+patch to Linus Torvalds.  Or you can e-mail me at <mec@shout.net> and
+I'll register one for you.
+
+The second argument to _IO, _IOW, _IOR, or _IOWR is a sequence number
+to distinguish ioctls from each other.  The third argument to _IOW,
+_IOR, or _IOWR is the type of the data going into the kernel or coming
+out of the kernel (e.g.  'int' or 'struct foo').  NOTE!  Do NOT use
+sizeof(arg) as the third argument as this results in your ioctl thinking
+it passes an argument of type size_t.
+
+Some devices use their major number as the identifier; this is OK, as
+long as it is unique.  Some devices are irregular and don't follow any
+convention at all.
+
+Following this convention is good because:
+
+(1) Keeping the ioctl's globally unique helps error checking:
+    if a program calls an ioctl on the wrong device, it will get an
+    error rather than some unexpected behaviour.
+
+(2) The 'strace' build procedure automatically finds ioctl numbers
+    defined with _IO, _IOW, _IOR, or _IOWR.
+
+(3) 'strace' can decode numbers back into useful names when the
+    numbers are unique.
+
+(4) People looking for ioctls can grep for them more easily when
+    this convention is used to define the ioctl numbers.
+
+(5) When following the convention, the driver code can use generic
+    code to copy the parameters between user and kernel space.
+
+This table lists ioctls visible from user land for Linux/x86.  It contains
+most drivers up to 2.6.31, but I know I am missing some.  There has been
+no attempt to list non-X86 architectures or ioctls from drivers/staging/.
+
+====  =====  ======================================================= ================================================================
+Code  Seq#    Include File                                           Comments
+      (hex)
+====  =====  ======================================================= ================================================================
+0x00  00-1F  linux/fs.h                                              conflict!
+0x00  00-1F  scsi/scsi_ioctl.h                                       conflict!
+0x00  00-1F  linux/fb.h                                              conflict!
+0x00  00-1F  linux/wavefront.h                                       conflict!
+0x02  all    linux/fd.h
+0x03  all    linux/hdreg.h
+0x04  D2-DC  linux/umsdos_fs.h                                       Dead since 2.6.11, but don't reuse these.
+0x06  all    linux/lp.h
+0x09  all    linux/raid/md_u.h
+0x10  00-0F  drivers/char/s390/vmcp.h
+0x10  10-1F  arch/s390/include/uapi/sclp_ctl.h
+0x10  20-2F  arch/s390/include/uapi/asm/hypfs.h
+0x12  all    linux/fs.h
+             linux/blkpg.h
+0x1b  all                                                            InfiniBand Subsystem
+                                                                     <http://infiniband.sourceforge.net/>
+0x20  all    drivers/cdrom/cm206.h
+0x22  all    scsi/sg.h
+'!'   00-1F  uapi/linux/seccomp.h
+'#'   00-3F                                                          IEEE 1394 Subsystem
+                                                                     Block for the entire subsystem
+'$'   00-0F  linux/perf_counter.h, linux/perf_event.h
+'%'   00-0F  include/uapi/linux/stm.h                                System Trace Module subsystem
+                                                                     <mailto:alexander.shishkin@linux.intel.com>
+'&'   00-07  drivers/firewire/nosy-user.h
+'1'   00-1F  linux/timepps.h                                         PPS kit from Ulrich Windl
+                                                                     <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/>
+'2'   01-04  linux/i2o.h
+'3'   00-0F  drivers/s390/char/raw3270.h                             conflict!
+'3'   00-1F  linux/suspend_ioctls.h,                                 conflict!
+             kernel/power/user.c
+'8'   all                                                            SNP8023 advanced NIC card
+                                                                     <mailto:mcr@solidum.com>
+';'   64-7F  linux/vfio.h
+'@'   00-0F  linux/radeonfb.h                                        conflict!
+'@'   00-0F  drivers/video/aty/aty128fb.c                            conflict!
+'A'   00-1F  linux/apm_bios.h                                        conflict!
+'A'   00-0F  linux/agpgart.h,                                        conflict!
+             drivers/char/agp/compat_ioctl.h
+'A'   00-7F  sound/asound.h                                          conflict!
+'B'   00-1F  linux/cciss_ioctl.h                                     conflict!
+'B'   00-0F  include/linux/pmu.h                                     conflict!
+'B'   C0-FF  advanced bbus                                           <mailto:maassen@uni-freiburg.de>
+'C'   all    linux/soundcard.h                                       conflict!
+'C'   01-2F  linux/capi.h                                            conflict!
+'C'   F0-FF  drivers/net/wan/cosa.h                                  conflict!
+'D'   all    arch/s390/include/asm/dasd.h
+'D'   40-5F  drivers/scsi/dpt/dtpi_ioctl.h
+'D'   05     drivers/scsi/pmcraid.h
+'E'   all    linux/input.h                                           conflict!
+'E'   00-0F  xen/evtchn.h                                            conflict!
+'F'   all    linux/fb.h                                              conflict!
+'F'   01-02  drivers/scsi/pmcraid.h                                  conflict!
+'F'   20     drivers/video/fsl-diu-fb.h                              conflict!
+'F'   20     drivers/video/intelfb/intelfb.h                         conflict!
+'F'   20     linux/ivtvfb.h                                          conflict!
+'F'   20     linux/matroxfb.h                                        conflict!
+'F'   20     drivers/video/aty/atyfb_base.c                          conflict!
+'F'   00-0F  video/da8xx-fb.h                                        conflict!
+'F'   80-8F  linux/arcfb.h                                           conflict!
+'F'   DD     video/sstfb.h                                           conflict!
+'G'   00-3F  drivers/misc/sgi-gru/grulib.h                           conflict!
+'G'   00-0F  linux/gigaset_dev.h                                     conflict!
+'H'   00-7F  linux/hiddev.h                                          conflict!
+'H'   00-0F  linux/hidraw.h                                          conflict!
+'H'   01     linux/mei.h                                             conflict!
+'H'   02     linux/mei.h                                             conflict!
+'H'   03     linux/mei.h                                             conflict!
+'H'   00-0F  sound/asound.h                                          conflict!
+'H'   20-40  sound/asound_fm.h                                       conflict!
+'H'   80-8F  sound/sfnt_info.h                                       conflict!
+'H'   10-8F  sound/emu10k1.h                                         conflict!
+'H'   10-1F  sound/sb16_csp.h                                        conflict!
+'H'   10-1F  sound/hda_hwdep.h                                       conflict!
+'H'   40-4F  sound/hdspm.h                                           conflict!
+'H'   40-4F  sound/hdsp.h                                            conflict!
+'H'   90     sound/usb/usx2y/usb_stream.h
+'H'   A0     uapi/linux/usb/cdc-wdm.h
+'H'   C0-F0  net/bluetooth/hci.h                                     conflict!
+'H'   C0-DF  net/bluetooth/hidp/hidp.h                               conflict!
+'H'   C0-DF  net/bluetooth/cmtp/cmtp.h                               conflict!
+'H'   C0-DF  net/bluetooth/bnep/bnep.h                               conflict!
+'H'   F1     linux/hid-roccat.h                                      <mailto:erazor_de@users.sourceforge.net>
+'H'   F8-FA  sound/firewire.h
+'I'   all    linux/isdn.h                                            conflict!
+'I'   00-0F  drivers/isdn/divert/isdn_divert.h                       conflict!
+'I'   40-4F  linux/mISDNif.h                                         conflict!
+'J'   00-1F  drivers/scsi/gdth_ioctl.h
+'K'   all    linux/kd.h
+'L'   00-1F  linux/loop.h                                            conflict!
+'L'   10-1F  drivers/scsi/mpt3sas/mpt3sas_ctl.h                      conflict!
+'L'   20-2F  linux/lightnvm.h
+'L'   E0-FF  linux/ppdd.h                                            encrypted disk device driver
+                                                                     <http://linux01.gwdg.de/~alatham/ppdd.html>
+'M'   all    linux/soundcard.h                                       conflict!
+'M'   01-16  mtd/mtd-abi.h                                           conflict!
+      and    drivers/mtd/mtdchar.c
+'M'   01-03  drivers/scsi/megaraid/megaraid_sas.h
+'M'   00-0F  drivers/video/fsl-diu-fb.h                              conflict!
+'N'   00-1F  drivers/usb/scanner.h
+'N'   40-7F  drivers/block/nvme.c
+'O'   00-06  mtd/ubi-user.h                                          UBI
+'P'   all    linux/soundcard.h                                       conflict!
+'P'   60-6F  sound/sscape_ioctl.h                                    conflict!
+'P'   00-0F  drivers/usb/class/usblp.c                               conflict!
+'P'   01-09  drivers/misc/pci_endpoint_test.c                        conflict!
+'Q'   all    linux/soundcard.h
+'R'   00-1F  linux/random.h                                          conflict!
+'R'   01     linux/rfkill.h                                          conflict!
+'R'   C0-DF  net/bluetooth/rfcomm.h
+'S'   all    linux/cdrom.h                                           conflict!
+'S'   80-81  scsi/scsi_ioctl.h                                       conflict!
+'S'   82-FF  scsi/scsi.h                                             conflict!
+'S'   00-7F  sound/asequencer.h                                      conflict!
+'T'   all    linux/soundcard.h                                       conflict!
+'T'   00-AF  sound/asound.h                                          conflict!
+'T'   all    arch/x86/include/asm/ioctls.h                           conflict!
+'T'   C0-DF  linux/if_tun.h                                          conflict!
+'U'   all    sound/asound.h                                          conflict!
+'U'   00-CF  linux/uinput.h                                          conflict!
+'U'   00-EF  linux/usbdevice_fs.h
+'U'   C0-CF  drivers/bluetooth/hci_uart.h
+'V'   all    linux/vt.h                                              conflict!
+'V'   all    linux/videodev2.h                                       conflict!
+'V'   C0     linux/ivtvfb.h                                          conflict!
+'V'   C0     linux/ivtv.h                                            conflict!
+'V'   C0     media/davinci/vpfe_capture.h                            conflict!
+'V'   C0     media/si4713.h                                          conflict!
+'W'   00-1F  linux/watchdog.h                                        conflict!
+'W'   00-1F  linux/wanrouter.h                                       conflict! (pre 3.9)
+'W'   00-3F  sound/asound.h                                          conflict!
+'W'   40-5F  drivers/pci/switch/switchtec.c
+'X'   all    fs/xfs/xfs_fs.h,                                        conflict!
+             fs/xfs/linux-2.6/xfs_ioctl32.h,
+             include/linux/falloc.h,
+             linux/fs.h,
+'X'   all    fs/ocfs2/ocfs_fs.h                                      conflict!
+'X'   01     linux/pktcdvd.h                                         conflict!
+'Y'   all    linux/cyclades.h
+'Z'   14-15  drivers/message/fusion/mptctl.h
+'['   00-3F  linux/usb/tmc.h                                         USB Test and Measurement Devices
+                                                                     <mailto:gregkh@linuxfoundation.org>
+'a'   all    linux/atm*.h, linux/sonet.h                             ATM on linux
+                                                                     <http://lrcwww.epfl.ch/>
+'a'   00-0F  drivers/crypto/qat/qat_common/adf_cfg_common.h          conflict! qat driver
+'b'   00-FF                                                          conflict! bit3 vme host bridge
+                                                                     <mailto:natalia@nikhefk.nikhef.nl>
+'c'   all    linux/cm4000_cs.h                                       conflict!
+'c'   00-7F  linux/comstats.h                                        conflict!
+'c'   00-7F  linux/coda.h                                            conflict!
+'c'   00-1F  linux/chio.h                                            conflict!
+'c'   80-9F  arch/s390/include/asm/chsc.h                            conflict!
+'c'   A0-AF  arch/x86/include/asm/msr.h conflict!
+'d'   00-FF  linux/char/drm/drm.h                                    conflict!
+'d'   02-40  pcmcia/ds.h                                             conflict!
+'d'   F0-FF  linux/digi1.h
+'e'   all    linux/digi1.h                                           conflict!
+'f'   00-1F  linux/ext2_fs.h                                         conflict!
+'f'   00-1F  linux/ext3_fs.h                                         conflict!
+'f'   00-0F  fs/jfs/jfs_dinode.h                                     conflict!
+'f'   00-0F  fs/ext4/ext4.h                                          conflict!
+'f'   00-0F  linux/fs.h                                              conflict!
+'f'   00-0F  fs/ocfs2/ocfs2_fs.h                                     conflict!
+'f'   81-8F  linux/fsverity.h
+'g'   00-0F  linux/usb/gadgetfs.h
+'g'   20-2F  linux/usb/g_printer.h
+'h'   00-7F                                                          conflict! Charon filesystem
+                                                                     <mailto:zapman@interlan.net>
+'h'   00-1F  linux/hpet.h                                            conflict!
+'h'   80-8F  fs/hfsplus/ioctl.c
+'i'   00-3F  linux/i2o-dev.h                                         conflict!
+'i'   0B-1F  linux/ipmi.h                                            conflict!
+'i'   80-8F  linux/i8k.h
+'j'   00-3F  linux/joystick.h
+'k'   00-0F  linux/spi/spidev.h                                      conflict!
+'k'   00-05  video/kyro.h                                            conflict!
+'k'   10-17  linux/hsi/hsi_char.h                                    HSI character device
+'l'   00-3F  linux/tcfs_fs.h                                         transparent cryptographic file system
+                                                                     <http://web.archive.org/web/%2A/http://mikonos.dia.unisa.it/tcfs>
+'l'   40-7F  linux/udf_fs_i.h                                        in development:
+                                                                     <http://sourceforge.net/projects/linux-udf/>
+'m'   00-09  linux/mmtimer.h                                         conflict!
+'m'   all    linux/mtio.h                                            conflict!
+'m'   all    linux/soundcard.h                                       conflict!
+'m'   all    linux/synclink.h                                        conflict!
+'m'   00-19  drivers/message/fusion/mptctl.h                         conflict!
+'m'   00     drivers/scsi/megaraid/megaraid_ioctl.h                  conflict!
+'n'   00-7F  linux/ncp_fs.h and fs/ncpfs/ioctl.c
+'n'   80-8F  uapi/linux/nilfs2_api.h                                 NILFS2
+'n'   E0-FF  linux/matroxfb.h                                        matroxfb
+'o'   00-1F  fs/ocfs2/ocfs2_fs.h                                     OCFS2
+'o'   00-03  mtd/ubi-user.h                                          conflict! (OCFS2 and UBI overlaps)
+'o'   40-41  mtd/ubi-user.h                                          UBI
+'o'   01-A1  `linux/dvb/*.h`                                         DVB
+'p'   00-0F  linux/phantom.h                                         conflict! (OpenHaptics needs this)
+'p'   00-1F  linux/rtc.h                                             conflict!
+'p'   00-3F  linux/mc146818rtc.h                                     conflict!
+'p'   40-7F  linux/nvram.h
+'p'   80-9F  linux/ppdev.h                                           user-space parport
+                                                                     <mailto:tim@cyberelk.net>
+'p'   A1-A5  linux/pps.h                                             LinuxPPS
+                                                                     <mailto:giometti@linux.it>
+'q'   00-1F  linux/serio.h
+'q'   80-FF  linux/telephony.h                                       Internet PhoneJACK, Internet LineJACK
+             linux/ixjuser.h                                         <http://web.archive.org/web/%2A/http://www.quicknet.net>
+'r'   00-1F  linux/msdos_fs.h and fs/fat/dir.c
+'s'   all    linux/cdk.h
+'t'   00-7F  linux/ppp-ioctl.h
+'t'   80-8F  linux/isdn_ppp.h
+'t'   90-91  linux/toshiba.h                                         toshiba and toshiba_acpi SMM
+'u'   00-1F  linux/smb_fs.h                                          gone
+'u'   20-3F  linux/uvcvideo.h                                        USB video class host driver
+'u'   40-4f  linux/udmabuf.h                                         userspace dma-buf misc device
+'v'   00-1F  linux/ext2_fs.h                                         conflict!
+'v'   00-1F  linux/fs.h                                              conflict!
+'v'   00-0F  linux/sonypi.h                                          conflict!
+'v'   00-0F  media/v4l2-subdev.h                                     conflict!
+'v'   C0-FF  linux/meye.h                                            conflict!
+'w'   all                                                            CERN SCI driver
+'y'   00-1F                                                          packet based user level communications
+                                                                     <mailto:zapman@interlan.net>
+'z'   00-3F                                                          CAN bus card conflict!
+                                                                     <mailto:hdstich@connectu.ulm.circular.de>
+'z'   40-7F                                                          CAN bus card conflict!
+                                                                     <mailto:oe@port.de>
+'z'   10-4F  drivers/s390/crypto/zcrypt_api.h                        conflict!
+'|'   00-7F  linux/media.h
+0x80  00-1F  linux/fb.h
+0x89  00-06  arch/x86/include/asm/sockios.h
+0x89  0B-DF  linux/sockios.h
+0x89  E0-EF  linux/sockios.h                                         SIOCPROTOPRIVATE range
+0x89  E0-EF  linux/dn.h                                              PROTOPRIVATE range
+0x89  F0-FF  linux/sockios.h                                         SIOCDEVPRIVATE range
+0x8B  all    linux/wireless.h
+0x8C  00-3F                                                          WiNRADiO driver
+                                                                     <http://www.winradio.com.au/>
+0x90  00     drivers/cdrom/sbpcd.h
+0x92  00-0F  drivers/usb/mon/mon_bin.c
+0x93  60-7F  linux/auto_fs.h
+0x94  all    fs/btrfs/ioctl.h                                        Btrfs filesystem
+             and linux/fs.h                                          some lifted to vfs/generic
+0x97  00-7F  fs/ceph/ioctl.h                                         Ceph file system
+0x99  00-0F                                                          537-Addinboard driver
+                                                                     <mailto:buk@buks.ipn.de>
+0xA0  all    linux/sdp/sdp.h                                         Industrial Device Project
+                                                                     <mailto:kenji@bitgate.com>
+0xA1  0      linux/vtpm_proxy.h                                      TPM Emulator Proxy Driver
+0xA3  80-8F                                                          Port ACL  in development:
+                                                                     <mailto:tlewis@mindspring.com>
+0xA3  90-9F  linux/dtlk.h
+0xA4  00-1F  uapi/linux/tee.h                                        Generic TEE subsystem
+0xAA  00-3F  linux/uapi/linux/userfaultfd.h
+0xAB  00-1F  linux/nbd.h
+0xAC  00-1F  linux/raw.h
+0xAD  00                                                             Netfilter device in development:
+                                                                     <mailto:rusty@rustcorp.com.au>
+0xAE  all    linux/kvm.h                                             Kernel-based Virtual Machine
+                                                                     <mailto:kvm@vger.kernel.org>
+0xAF  00-1F  linux/fsl_hypervisor.h                                  Freescale hypervisor
+0xB0  all                                                            RATIO devices in development:
+                                                                     <mailto:vgo@ratio.de>
+0xB1  00-1F                                                          PPPoX
+                                                                     <mailto:mostrows@styx.uwaterloo.ca>
+0xB3  00     linux/mmc/ioctl.h
+0xB4  00-0F  linux/gpio.h                                            <mailto:linux-gpio@vger.kernel.org>
+0xB5  00-0F  uapi/linux/rpmsg.h                                      <mailto:linux-remoteproc@vger.kernel.org>
+0xB6  all    linux/fpga-dfl.h
+0xC0  00-0F  linux/usb/iowarrior.h
+0xCA  00-0F  uapi/misc/cxl.h
+0xCA  10-2F  uapi/misc/ocxl.h
+0xCA  80-BF  uapi/scsi/cxlflash_ioctl.h
+0xCB  00-1F                                                          CBM serial IEC bus in development:
+                                                                     <mailto:michael.klein@puffin.lb.shuttle.de>
+0xCC  00-0F  drivers/misc/ibmvmc.h                                   pseries VMC driver
+0xCD  01     linux/reiserfs_fs.h
+0xCF  02     fs/cifs/ioctl.c
+0xDB  00-0F  drivers/char/mwave/mwavepub.h
+0xDD  00-3F                                                          ZFCP device driver see drivers/s390/scsi/
+                                                                     <mailto:aherrman@de.ibm.com>
+0xE5  00-3F  linux/fuse.h
+0xEC  00-01  drivers/platform/chrome/cros_ec_dev.h                   ChromeOS EC driver
+0xF3  00-3F  drivers/usb/misc/sisusbvga/sisusb.h                     sisfb (in development)
+                                                                     <mailto:thomas@winischhofer.net>
+0xF4  00-1F  video/mbxfb.h                                           mbxfb
+                                                                     <mailto:raph@8d.com>
+0xF6  all                                                            LTTng Linux Trace Toolkit Next Generation
+                                                                     <mailto:mathieu.desnoyers@efficios.com>
+0xFD  all    linux/dm-ioctl.h
+0xFE  all    linux/isst_if.h
+====  =====  ======================================================= ================================================================