Commit 17935c9f authored by Edward Falk's avatar Edward Falk Committed by Linus Torvalds

[PATCH] Documentation for IDE and CDROM ioctls

I've written two document files, and packaged them as a patch.

Two things caught my eye while I was writing this up:

The header comments for CDROMREADRAW, CDROMREADMODE1, and CDROMREADMODE2
disagree with the actual source code.  The header comments imply that a
cdrom_read structure is used to pass data, but the source code actually
reads a cdrom_msf structure and then overwrites it with raw data.  I'm not
sure if there's a bug in the header comments, in the driver source, or I
misread something.

The CDROM_LOCKDOOR ioctl seems to lock/unlock all doors on all drives,
because it uses a global variable.
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 41beabcb
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 CDROM_GET_MCN (deprecated)
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
CDROMSETSPINDOWN
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.
Unless otherwise specified, all ioctl calls return 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:
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
notes:
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.
CDROMSTART Start the cdrom drive
usage:
ioctl(fd, CDROMSTART, 0);
inputs: none
outputs: none
error return:
ENOSYS cd drive not audio-capable.
CDROMEJECT Ejects the cdrom media
usage:
ioctl(fd, CDROMEJECT, 0);
inputs: none
outputs: none
error return:
ENOSYS cd drive not capable of ejecting
EBUSY other processes have drive open or door is locked
CDROMCLOSETRAY pendant of CDROMEJECT
usage:
ioctl(fd, CDROMEJECT, 0);
inputs: none
outputs: none
error return:
ENOSYS cd drive not capable of ejecting
EBUSY other processes have drive open or door is locked
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 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
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.
Unfortunatly, 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 Recieved 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.
CDROM_LAST_WRITTEN get last block written on disc
usage:
long last;
ioctl(fd, CDROM_NEXT_WRITABLE, &last);
inputs: none
outputs:
The last block written on disc
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
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
HDIO_SET_SCSI_IDE
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 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:
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 can not
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:
int nice;
...
ioctl(fd, HDIO_SET_NICE, nice);
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_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.
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
notes:
Aborts any current command, prevent anything else from being
queued, execute a reset on the device, and issue BLKRRPART
ioctl on the block device.
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.
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[] values to be written to taskfile registers
hob_ports[] values to be written to taskfile registers
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
outputs:
io_ports[] values returned in the taskfile registers
hob_ports[] values returned in the taskfile registers
out_flags flags indicating which registers are valid
in_flags flags indicating which registers should be returned
outbuf buffer of data to be transmitted to disk
inbuf buffer of data to be received from disk
error returns:
EACCES CAP_SYS_ADMIN or CAP_SYS_RAWIO privelege 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.
notes:
Execute an ATA disk command directly by writing the "taskfile"
registers of the drive. Requires ADMIN and RAWIO access
privileges.
Extreme caution should be used with using this ioctl. A
mistake can easily corrupt data or hang the system.
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.
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
Unused fields of io_ports[] and hob_ports[] should be set to
zero.
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
TASKFILE_OUT_DMA
TASKFILE_OUT_DMAQ
TASKFILE_P_IN
TASKFILE_P_IN_DMA
TASKFILE_P_IN_DMAQ
TASKFILE_P_OUT
TASKFILE_P_OUT_DMA
TASKFILE_P_OUT_DMAQ
The req_cmd field classifies the command type. It may be
one of:
IDE_DRIVE_TASK_NO_DATA
IDE_DRIVE_TASK_SET_XFER
IDE_DRIVE_TASK_IN
IDE_DRIVE_TASK_OUT
IDE_DRIVE_TASK_RAW_WRITE
Currently (2.6.8), both the input and output buffers are
copied from the user and written back to the user, even when
not used.
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:
Taskfile register values:
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
error returns:
EACCES Access denied: requires CAP_SYS_RAWIO
ENOMEM Unable to allocate memory for task
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
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 appropiate.
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
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