--- /dev/null
+=================================
+(How to avoid) Botching up ioctls
+=================================
+
+From: http://blog.ffwll.ch/2013/11/botching-up-ioctls.html
+
+By: Daniel Vetter, Copyright © 2013 Intel Corporation
+
+One clear insight kernel graphics hackers gained in the past few years is that
+trying to come up with a unified interface to manage the execution units and
+memory on completely different GPUs is a futile effort. So nowadays every
+driver has its own set of ioctls to allocate memory and submit work to the GPU.
+Which is nice, since there's no more insanity in the form of fake-generic, but
+actually only used once interfaces. But the clear downside is that there's much
+more potential to screw things up.
+
+To avoid repeating all the same mistakes again I've written up some of the
+lessons learned while botching the job for the drm/i915 driver. Most of these
+only cover technicalities and not the big-picture issues like what the command
+submission ioctl exactly should look like. Learning these lessons is probably
+something every GPU driver has to do on its own.
+
+
+Prerequisites
+-------------
+
+First the prerequisites. Without these you have already failed, because you
+will need to add a 32-bit compat layer:
+
+ * Only use fixed sized integers. To avoid conflicts with typedefs in userspace
+ the kernel has special types like __u32, __s64. Use them.
+
+ * Align everything to the natural size and use explicit padding. 32-bit
+ platforms don't necessarily align 64-bit values to 64-bit boundaries, but
+ 64-bit platforms do. So we always need padding to the natural size to get
+ this right.
+
+ * Pad the entire struct to a multiple of 64-bits if the structure contains
+ 64-bit types - the structure size will otherwise differ on 32-bit versus
+ 64-bit. Having a different structure size hurts when passing arrays of
+ structures to the kernel, or if the kernel checks the structure size, which
+ e.g. the drm core does.
+
+ * Pointers are __u64, cast from/to a uintprt_t on the userspace side and
+ from/to a void __user * in the kernel. Try really hard not to delay this
+ conversion or worse, fiddle the raw __u64 through your code since that
+ diminishes the checking tools like sparse can provide. The macro
+ u64_to_user_ptr can be used in the kernel to avoid warnings about integers
+ and pointres of different sizes.
+
+
+Basics
+------
+
+With the joys of writing a compat layer avoided we can take a look at the basic
+fumbles. Neglecting these will make backward and forward compatibility a real
+pain. And since getting things wrong on the first attempt is guaranteed you
+will have a second iteration or at least an extension for any given interface.
+
+ * Have a clear way for userspace to figure out whether your new ioctl or ioctl
+ extension is supported on a given kernel. If you can't rely on old kernels
+ rejecting the new flags/modes or ioctls (since doing that was botched in the
+ past) then you need a driver feature flag or revision number somewhere.
+
+ * Have a plan for extending ioctls with new flags or new fields at the end of
+ the structure. The drm core checks the passed-in size for each ioctl call
+ and zero-extends any mismatches between kernel and userspace. That helps,
+ but isn't a complete solution since newer userspace on older kernels won't
+ notice that the newly added fields at the end get ignored. So this still
+ needs a new driver feature flags.
+
+ * Check all unused fields and flags and all the padding for whether it's 0,
+ and reject the ioctl if that's not the case. Otherwise your nice plan for
+ future extensions is going right down the gutters since someone will submit
+ an ioctl struct with random stack garbage in the yet unused parts. Which
+ then bakes in the ABI that those fields can never be used for anything else
+ but garbage. This is also the reason why you must explicitly pad all
+ structures, even if you never use them in an array - the padding the compiler
+ might insert could contain garbage.
+
+ * Have simple testcases for all of the above.
+
+
+Fun with Error Paths
+--------------------
+
+Nowadays we don't have any excuse left any more for drm drivers being neat
+little root exploits. This means we both need full input validation and solid
+error handling paths - GPUs will die eventually in the oddmost corner cases
+anyway:
+
+ * The ioctl must check for array overflows. Also it needs to check for
+ over/underflows and clamping issues of integer values in general. The usual
+ example is sprite positioning values fed directly into the hardware with the
+ hardware just having 12 bits or so. Works nicely until some odd display
+ server doesn't bother with clamping itself and the cursor wraps around the
+ screen.
+
+ * Have simple testcases for every input validation failure case in your ioctl.
+ Check that the error code matches your expectations. And finally make sure
+ that you only test for one single error path in each subtest by submitting
+ otherwise perfectly valid data. Without this an earlier check might reject
+ the ioctl already and shadow the codepath you actually want to test, hiding
+ bugs and regressions.
+
+ * Make all your ioctls restartable. First X really loves signals and second
+ this will allow you to test 90% of all error handling paths by just
+ interrupting your main test suite constantly with signals. Thanks to X's
+ love for signal you'll get an excellent base coverage of all your error
+ paths pretty much for free for graphics drivers. Also, be consistent with
+ how you handle ioctl restarting - e.g. drm has a tiny drmIoctl helper in its
+ userspace library. The i915 driver botched this with the set_tiling ioctl,
+ now we're stuck forever with some arcane semantics in both the kernel and
+ userspace.
+
+ * If you can't make a given codepath restartable make a stuck task at least
+ killable. GPUs just die and your users won't like you more if you hang their
+ entire box (by means of an unkillable X process). If the state recovery is
+ still too tricky have a timeout or hangcheck safety net as a last-ditch
+ effort in case the hardware has gone bananas.
+
+ * Have testcases for the really tricky corner cases in your error recovery code
+ - it's way too easy to create a deadlock between your hangcheck code and
+ waiters.
+
+
+Time, Waiting and Missing it
+----------------------------
+
+GPUs do most everything asynchronously, so we have a need to time operations and
+wait for outstanding ones. This is really tricky business; at the moment none of
+the ioctls supported by the drm/i915 get this fully right, which means there's
+still tons more lessons to learn here.
+
+ * Use CLOCK_MONOTONIC as your reference time, always. It's what alsa, drm and
+ v4l use by default nowadays. But let userspace know which timestamps are
+ derived from different clock domains like your main system clock (provided
+ by the kernel) or some independent hardware counter somewhere else. Clocks
+ will mismatch if you look close enough, but if performance measuring tools
+ have this information they can at least compensate. If your userspace can
+ get at the raw values of some clocks (e.g. through in-command-stream
+ performance counter sampling instructions) consider exposing those also.
+
+ * Use __s64 seconds plus __u64 nanoseconds to specify time. It's not the most
+ convenient time specification, but it's mostly the standard.
+
+ * Check that input time values are normalized and reject them if not. Note
+ that the kernel native struct ktime has a signed integer for both seconds
+ and nanoseconds, so beware here.
+
+ * For timeouts, use absolute times. If you're a good fellow and made your
+ ioctl restartable relative timeouts tend to be too coarse and can
+ indefinitely extend your wait time due to rounding on each restart.
+ Especially if your reference clock is something really slow like the display
+ frame counter. With a spec lawyer hat on this isn't a bug since timeouts can
+ always be extended - but users will surely hate you if their neat animations
+ starts to stutter due to this.
+
+ * Consider ditching any synchronous wait ioctls with timeouts and just deliver
+ an asynchronous event on a pollable file descriptor. It fits much better
+ into event driven applications' main loop.
+
+ * Have testcases for corner-cases, especially whether the return values for
+ already-completed events, successful waits and timed-out waits are all sane
+ and suiting to your needs.
+
+
+Leaking Resources, Not
+----------------------
+
+A full-blown drm driver essentially implements a little OS, but specialized to
+the given GPU platforms. This means a driver needs to expose tons of handles
+for different objects and other resources to userspace. Doing that right
+entails its own little set of pitfalls:
+
+ * Always attach the lifetime of your dynamically created resources to the
+ lifetime of a file descriptor. Consider using a 1:1 mapping if your resource
+ needs to be shared across processes - fd-passing over unix domain sockets
+ also simplifies lifetime management for userspace.
+
+ * Always have O_CLOEXEC support.
+
+ * Ensure that you have sufficient insulation between different clients. By
+ default pick a private per-fd namespace which forces any sharing to be done
+ explicitly. Only go with a more global per-device namespace if the objects
+ are truly device-unique. One counterexample in the drm modeset interfaces is
+ that the per-device modeset objects like connectors share a namespace with
+ framebuffer objects, which mostly are not shared at all. A separate
+ namespace, private by default, for framebuffers would have been more
+ suitable.
+
+ * Think about uniqueness requirements for userspace handles. E.g. for most drm
+ drivers it's a userspace bug to submit the same object twice in the same
+ command submission ioctl. But then if objects are shareable userspace needs
+ to know whether it has seen an imported object from a different process
+ already or not. I haven't tried this myself yet due to lack of a new class
+ of objects, but consider using inode numbers on your shared file descriptors
+ as unique identifiers - it's how real files are told apart, too.
+ Unfortunately this requires a full-blown virtual filesystem in the kernel.
+
+
+Last, but not Least
+-------------------
+
+Not every problem needs a new ioctl:
+
+ * Think hard whether you really want a driver-private interface. Of course
+ it's much quicker to push a driver-private interface than engaging in
+ lengthy discussions for a more generic solution. And occasionally doing a
+ private interface to spearhead a new concept is what's required. But in the
+ end, once the generic interface comes around you'll end up maintainer two
+ interfaces. Indefinitely.
+
+ * Consider other interfaces than ioctls. A sysfs attribute is much better for
+ per-device settings, or for child objects with fairly static lifetimes (like
+ output connectors in drm with all the detection override attributes). Or
+ maybe only your testsuite needs this interface, and then debugfs with its
+ disclaimer of not having a stable ABI would be better.
+
+Finally, the name of the game is to get it right on the first attempt, since if
+your driver proves popular and your hardware platforms long-lived then you'll
+be stuck with a given ioctl essentially forever. You can try to deprecate
+horrible ioctls on newer iterations of your hardware, but generally it takes
+years to accomplish this. And then again years until the last user able to
+complain about regressions disappears, too.
+++ /dev/null
-(How to avoid) Botching up ioctls
-=================================
-
-From: http://blog.ffwll.ch/2013/11/botching-up-ioctls.html
-
-By: Daniel Vetter, Copyright © 2013 Intel Corporation
-
-One clear insight kernel graphics hackers gained in the past few years is that
-trying to come up with a unified interface to manage the execution units and
-memory on completely different GPUs is a futile effort. So nowadays every
-driver has its own set of ioctls to allocate memory and submit work to the GPU.
-Which is nice, since there's no more insanity in the form of fake-generic, but
-actually only used once interfaces. But the clear downside is that there's much
-more potential to screw things up.
-
-To avoid repeating all the same mistakes again I've written up some of the
-lessons learned while botching the job for the drm/i915 driver. Most of these
-only cover technicalities and not the big-picture issues like what the command
-submission ioctl exactly should look like. Learning these lessons is probably
-something every GPU driver has to do on its own.
-
-
-Prerequisites
--------------
-
-First the prerequisites. Without these you have already failed, because you
-will need to add a 32-bit compat layer:
-
- * Only use fixed sized integers. To avoid conflicts with typedefs in userspace
- the kernel has special types like __u32, __s64. Use them.
-
- * Align everything to the natural size and use explicit padding. 32-bit
- platforms don't necessarily align 64-bit values to 64-bit boundaries, but
- 64-bit platforms do. So we always need padding to the natural size to get
- this right.
-
- * Pad the entire struct to a multiple of 64-bits if the structure contains
- 64-bit types - the structure size will otherwise differ on 32-bit versus
- 64-bit. Having a different structure size hurts when passing arrays of
- structures to the kernel, or if the kernel checks the structure size, which
- e.g. the drm core does.
-
- * Pointers are __u64, cast from/to a uintprt_t on the userspace side and
- from/to a void __user * in the kernel. Try really hard not to delay this
- conversion or worse, fiddle the raw __u64 through your code since that
- diminishes the checking tools like sparse can provide. The macro
- u64_to_user_ptr can be used in the kernel to avoid warnings about integers
- and pointres of different sizes.
-
-
-Basics
-------
-
-With the joys of writing a compat layer avoided we can take a look at the basic
-fumbles. Neglecting these will make backward and forward compatibility a real
-pain. And since getting things wrong on the first attempt is guaranteed you
-will have a second iteration or at least an extension for any given interface.
-
- * Have a clear way for userspace to figure out whether your new ioctl or ioctl
- extension is supported on a given kernel. If you can't rely on old kernels
- rejecting the new flags/modes or ioctls (since doing that was botched in the
- past) then you need a driver feature flag or revision number somewhere.
-
- * Have a plan for extending ioctls with new flags or new fields at the end of
- the structure. The drm core checks the passed-in size for each ioctl call
- and zero-extends any mismatches between kernel and userspace. That helps,
- but isn't a complete solution since newer userspace on older kernels won't
- notice that the newly added fields at the end get ignored. So this still
- needs a new driver feature flags.
-
- * Check all unused fields and flags and all the padding for whether it's 0,
- and reject the ioctl if that's not the case. Otherwise your nice plan for
- future extensions is going right down the gutters since someone will submit
- an ioctl struct with random stack garbage in the yet unused parts. Which
- then bakes in the ABI that those fields can never be used for anything else
- but garbage. This is also the reason why you must explicitly pad all
- structures, even if you never use them in an array - the padding the compiler
- might insert could contain garbage.
-
- * Have simple testcases for all of the above.
-
-
-Fun with Error Paths
---------------------
-
-Nowadays we don't have any excuse left any more for drm drivers being neat
-little root exploits. This means we both need full input validation and solid
-error handling paths - GPUs will die eventually in the oddmost corner cases
-anyway:
-
- * The ioctl must check for array overflows. Also it needs to check for
- over/underflows and clamping issues of integer values in general. The usual
- example is sprite positioning values fed directly into the hardware with the
- hardware just having 12 bits or so. Works nicely until some odd display
- server doesn't bother with clamping itself and the cursor wraps around the
- screen.
-
- * Have simple testcases for every input validation failure case in your ioctl.
- Check that the error code matches your expectations. And finally make sure
- that you only test for one single error path in each subtest by submitting
- otherwise perfectly valid data. Without this an earlier check might reject
- the ioctl already and shadow the codepath you actually want to test, hiding
- bugs and regressions.
-
- * Make all your ioctls restartable. First X really loves signals and second
- this will allow you to test 90% of all error handling paths by just
- interrupting your main test suite constantly with signals. Thanks to X's
- love for signal you'll get an excellent base coverage of all your error
- paths pretty much for free for graphics drivers. Also, be consistent with
- how you handle ioctl restarting - e.g. drm has a tiny drmIoctl helper in its
- userspace library. The i915 driver botched this with the set_tiling ioctl,
- now we're stuck forever with some arcane semantics in both the kernel and
- userspace.
-
- * If you can't make a given codepath restartable make a stuck task at least
- killable. GPUs just die and your users won't like you more if you hang their
- entire box (by means of an unkillable X process). If the state recovery is
- still too tricky have a timeout or hangcheck safety net as a last-ditch
- effort in case the hardware has gone bananas.
-
- * Have testcases for the really tricky corner cases in your error recovery code
- - it's way too easy to create a deadlock between your hangcheck code and
- waiters.
-
-
-Time, Waiting and Missing it
-----------------------------
-
-GPUs do most everything asynchronously, so we have a need to time operations and
-wait for outstanding ones. This is really tricky business; at the moment none of
-the ioctls supported by the drm/i915 get this fully right, which means there's
-still tons more lessons to learn here.
-
- * Use CLOCK_MONOTONIC as your reference time, always. It's what alsa, drm and
- v4l use by default nowadays. But let userspace know which timestamps are
- derived from different clock domains like your main system clock (provided
- by the kernel) or some independent hardware counter somewhere else. Clocks
- will mismatch if you look close enough, but if performance measuring tools
- have this information they can at least compensate. If your userspace can
- get at the raw values of some clocks (e.g. through in-command-stream
- performance counter sampling instructions) consider exposing those also.
-
- * Use __s64 seconds plus __u64 nanoseconds to specify time. It's not the most
- convenient time specification, but it's mostly the standard.
-
- * Check that input time values are normalized and reject them if not. Note
- that the kernel native struct ktime has a signed integer for both seconds
- and nanoseconds, so beware here.
-
- * For timeouts, use absolute times. If you're a good fellow and made your
- ioctl restartable relative timeouts tend to be too coarse and can
- indefinitely extend your wait time due to rounding on each restart.
- Especially if your reference clock is something really slow like the display
- frame counter. With a spec lawyer hat on this isn't a bug since timeouts can
- always be extended - but users will surely hate you if their neat animations
- starts to stutter due to this.
-
- * Consider ditching any synchronous wait ioctls with timeouts and just deliver
- an asynchronous event on a pollable file descriptor. It fits much better
- into event driven applications' main loop.
-
- * Have testcases for corner-cases, especially whether the return values for
- already-completed events, successful waits and timed-out waits are all sane
- and suiting to your needs.
-
-
-Leaking Resources, Not
-----------------------
-
-A full-blown drm driver essentially implements a little OS, but specialized to
-the given GPU platforms. This means a driver needs to expose tons of handles
-for different objects and other resources to userspace. Doing that right
-entails its own little set of pitfalls:
-
- * Always attach the lifetime of your dynamically created resources to the
- lifetime of a file descriptor. Consider using a 1:1 mapping if your resource
- needs to be shared across processes - fd-passing over unix domain sockets
- also simplifies lifetime management for userspace.
-
- * Always have O_CLOEXEC support.
-
- * Ensure that you have sufficient insulation between different clients. By
- default pick a private per-fd namespace which forces any sharing to be done
- explicitly. Only go with a more global per-device namespace if the objects
- are truly device-unique. One counterexample in the drm modeset interfaces is
- that the per-device modeset objects like connectors share a namespace with
- framebuffer objects, which mostly are not shared at all. A separate
- namespace, private by default, for framebuffers would have been more
- suitable.
-
- * Think about uniqueness requirements for userspace handles. E.g. for most drm
- drivers it's a userspace bug to submit the same object twice in the same
- command submission ioctl. But then if objects are shareable userspace needs
- to know whether it has seen an imported object from a different process
- already or not. I haven't tried this myself yet due to lack of a new class
- of objects, but consider using inode numbers on your shared file descriptors
- as unique identifiers - it's how real files are told apart, too.
- Unfortunately this requires a full-blown virtual filesystem in the kernel.
-
-
-Last, but not Least
--------------------
-
-Not every problem needs a new ioctl:
-
- * Think hard whether you really want a driver-private interface. Of course
- it's much quicker to push a driver-private interface than engaging in
- lengthy discussions for a more generic solution. And occasionally doing a
- private interface to spearhead a new concept is what's required. But in the
- end, once the generic interface comes around you'll end up maintainer two
- interfaces. Indefinitely.
-
- * Consider other interfaces than ioctls. A sysfs attribute is much better for
- per-device settings, or for child objects with fairly static lifetimes (like
- output connectors in drm with all the detection override attributes). Or
- maybe only your testsuite needs this interface, and then debugfs with its
- disclaimer of not having a stable ABI would be better.
-
-Finally, the name of the game is to get it right on the first attempt, since if
-your driver proves popular and your hardware platforms long-lived then you'll
-be stuck with a given ioctl essentially forever. You can try to deprecate
-horrible ioctls on newer iterations of your hardware, but generally it takes
-years to accomplish this. And then again years until the last user able to
-complain about regressions disappears, too.
--- /dev/null
+============================
+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.
+++ /dev/null
- 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.
--- /dev/null
+==============================
+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
+++ /dev/null
- 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
-
-
--- /dev/null
+:orphan:
+
+======
+IOCTLs
+======
+
+.. toctree::
+ :maxdepth: 1
+
+ ioctl-number
+
+ botching-up-ioctls
+ ioctl-decoding
+
+ cdrom
+ hdio
--- /dev/null
+==============================
+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])
+++ /dev/null
-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])
* };
*
* Please make sure that you follow all the best practices from
- * ``Documentation/ioctl/botching-up-ioctls.txt``. Note that drm_ioctl()
+ * ``Documentation/ioctl/botching-up-ioctls.rst``. Note that drm_ioctl()
* automatically zero-extends structures, hence make sure you can add more stuff
* at the end, i.e. don't put a variable sized array there.
*
projects / openwrt / staging / blogic.git / commitdiff