linux-stable/Documentation/ioctl/ioctl-number.txt
Bjørn Mork 3edce1cf81 USB: cdc-wdm: implement IOCTL_WDM_MAX_COMMAND
Userspace applications need to know the maximum supported message
size.

The cdc-wdm driver translates between a character device stream
and a message based protocol.  Each message is transported as a
usb control message with no further encapsulation or syncronization.
Each read or write on the character device should translate to
exactly one usb control message to ensure that message boundaries
are kept intact.  That means that the userspace application must
know the maximum message size supported by the device and driver,
making this size a vital part of the cdc-wdm character device API.

CDC WDM and CDC MBIM functions export the maximum supported
message size through CDC functional descriptors.  The cdc-wdm and
cdc_mbim drivers will parse these descriptors and use the value
chosen by the device.  The only current way for a userspace
application to retrive the value is by duplicating the descriptor
parsing. This is an unnecessary complex task, and application
writers are likely to postpone it, using a fixed value and adding
a "todo" item.

QMI functions have no way to tell the host what message size they
support.  The qmi_wwan driver use a fixed value based on protocol
recommendations and observed device behaviour.  Userspace
applications must know and hard code the same value.  This scheme
will break if we ever encounter a QMI device needing a device
specific message size quirk.  We are currently unable to support
such a device because using a non default size would break the
implicit userspace API.

The message size is currently a hidden attribute of the cdc-wdm
userspace API.  Retrieving it is unnecessarily complex, increasing
the possibility of drivers and applications using different limits.
The resulting errors are hard to debug, and can only be replicated
on identical hardware.

Exporting the maximum message size from the driver simplifies the
task for the userspace application, and creates a unified
information source independent of device and function class. It also
serves to document that the message size is part of the cdc-wdm
userspace API.

This proposed API extension has been presented for the authors of
userspace applications and libraries using the current API: libmbim,
libqmi, uqmi, oFono and ModemManager.  The replies were:

Aleksander Morgado:
 "We do really need max message size for MBIM; and as you say, it may be
  good to have the max message size info also for QMI, so the new ioctl
  seems a good addition. So +1 from my side, for what it's worth."

Dan Williams:
 "Yeah, +1 here.  I'd prefer the sysfs file, but the fact that that
  doesn't work for fd passing pretty much kills it."

No negative replies are so far received.

Cc: Aleksander Morgado <aleksander@lanedo.com>
Cc: Dan Williams <dcbw@redhat.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Acked-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-25 13:32:20 -07:00

325 lines
12 KiB
Text

Ioctl Numbers
19 October 1999
Michael Elizabeth Chastain
<mec@shout.net>
If you are adding new ioctl's to the kernel, you should use the _IO
macros defined in <linux/ioctl.h>:
_IO an ioctl with no parameters
_IOW an ioctl with write parameters (copy_from_user)
_IOR an ioctl with read parameters (copy_to_user)
_IOWR an ioctl with both write and read parameters.
'Write' and 'read' are from the user's point of view, just like the
system calls 'write' and 'read'. For example, a SET_FOO ioctl would
be _IOW, although the kernel would actually read data from user space;
a GET_FOO ioctl would be _IOR, although the kernel would actually write
data to user space.
The first argument to _IO, _IOW, _IOR, or _IOWR is an identifying letter
or number from the table below. Because of the large number of drivers,
many drivers share a partial letter with other drivers.
If you are writing a driver for a new device and need a letter, pick an
unused block with enough room for expansion: 32 to 256 ioctl commands.
You can register the block by patching this file and submitting the
patch to Linus Torvalds. Or you can e-mail me at <mec@shout.net> and
I'll register one for you.
The second argument to _IO, _IOW, _IOR, or _IOWR is a sequence number
to distinguish ioctls from each other. The third argument to _IOW,
_IOR, or _IOWR is the type of the data going into the kernel or coming
out of the kernel (e.g. 'int' or 'struct foo'). NOTE! Do NOT use
sizeof(arg) as the third argument as this results in your ioctl thinking
it passes an argument of type size_t.
Some devices use their major number as the identifier; this is OK, as
long as it is unique. Some devices are irregular and don't follow any
convention at all.
Following this convention is good because:
(1) Keeping the ioctl's globally unique helps error checking:
if a program calls an ioctl on the wrong device, it will get an
error rather than some unexpected behaviour.
(2) The 'strace' build procedure automatically finds ioctl numbers
defined with _IO, _IOW, _IOR, or _IOWR.
(3) 'strace' can decode numbers back into useful names when the
numbers are unique.
(4) People looking for ioctls can grep for them more easily when
this convention is used to define the ioctl numbers.
(5) When following the convention, the driver code can use generic
code to copy the parameters between user and kernel space.
This table lists ioctls visible from user land for Linux/x86. It contains
most drivers up to 2.6.31, but I know I am missing some. There has been
no attempt to list non-X86 architectures or ioctls from drivers/staging/.
Code Seq#(hex) Include File Comments
========================================================
0x00 00-1F linux/fs.h conflict!
0x00 00-1F scsi/scsi_ioctl.h conflict!
0x00 00-1F linux/fb.h conflict!
0x00 00-1F linux/wavefront.h conflict!
0x02 all linux/fd.h
0x03 all linux/hdreg.h
0x04 D2-DC linux/umsdos_fs.h Dead since 2.6.11, but don't reuse these.
0x06 all linux/lp.h
0x09 all linux/raid/md_u.h
0x10 00-0F drivers/char/s390/vmcp.h
0x12 all linux/fs.h
linux/blkpg.h
0x1b all InfiniBand Subsystem <http://infiniband.sourceforge.net/>
0x20 all drivers/cdrom/cm206.h
0x22 all scsi/sg.h
'#' 00-3F IEEE 1394 Subsystem Block for the entire subsystem
'$' 00-0F linux/perf_counter.h, linux/perf_event.h
'&' 00-07 drivers/firewire/nosy-user.h
'1' 00-1F <linux/timepps.h> PPS kit from Ulrich Windl
<ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/>
'2' 01-04 linux/i2o.h
'3' 00-0F drivers/s390/char/raw3270.h conflict!
'3' 00-1F linux/suspend_ioctls.h conflict!
and kernel/power/user.c
'8' all SNP8023 advanced NIC card
<mailto:mcr@solidum.com>
';' 64-7F linux/vfio.h
'@' 00-0F linux/radeonfb.h conflict!
'@' 00-0F drivers/video/aty/aty128fb.c conflict!
'A' 00-1F linux/apm_bios.h conflict!
'A' 00-0F linux/agpgart.h conflict!
and drivers/char/agp/compat_ioctl.h
'A' 00-7F sound/asound.h conflict!
'B' 00-1F linux/cciss_ioctl.h conflict!
'B' 00-0F include/linux/pmu.h conflict!
'B' C0-FF advanced bbus
<mailto:maassen@uni-freiburg.de>
'C' all linux/soundcard.h conflict!
'C' 01-2F linux/capi.h conflict!
'C' F0-FF drivers/net/wan/cosa.h conflict!
'D' all arch/s390/include/asm/dasd.h
'D' 40-5F drivers/scsi/dpt/dtpi_ioctl.h
'D' 05 drivers/scsi/pmcraid.h
'E' all linux/input.h conflict!
'E' 00-0F xen/evtchn.h conflict!
'F' all linux/fb.h conflict!
'F' 01-02 drivers/scsi/pmcraid.h conflict!
'F' 20 drivers/video/fsl-diu-fb.h conflict!
'F' 20 drivers/video/intelfb/intelfb.h conflict!
'F' 20 linux/ivtvfb.h conflict!
'F' 20 linux/matroxfb.h conflict!
'F' 20 drivers/video/aty/atyfb_base.c conflict!
'F' 00-0F video/da8xx-fb.h conflict!
'F' 80-8F linux/arcfb.h conflict!
'F' DD video/sstfb.h conflict!
'G' 00-3F drivers/misc/sgi-gru/grulib.h conflict!
'G' 00-0F linux/gigaset_dev.h conflict!
'H' 00-7F linux/hiddev.h conflict!
'H' 00-0F linux/hidraw.h conflict!
'H' 01 linux/mei.h conflict!
'H' 00-0F sound/asound.h conflict!
'H' 20-40 sound/asound_fm.h conflict!
'H' 80-8F sound/sfnt_info.h conflict!
'H' 10-8F sound/emu10k1.h conflict!
'H' 10-1F sound/sb16_csp.h conflict!
'H' 10-1F sound/hda_hwdep.h conflict!
'H' 40-4F sound/hdspm.h conflict!
'H' 40-4F sound/hdsp.h conflict!
'H' 90 sound/usb/usx2y/usb_stream.h
'H' A0 uapi/linux/usb/cdc-wdm.h
'H' C0-F0 net/bluetooth/hci.h conflict!
'H' C0-DF net/bluetooth/hidp/hidp.h conflict!
'H' C0-DF net/bluetooth/cmtp/cmtp.h conflict!
'H' C0-DF net/bluetooth/bnep/bnep.h conflict!
'H' F1 linux/hid-roccat.h <mailto:erazor_de@users.sourceforge.net>
'I' all linux/isdn.h conflict!
'I' 00-0F drivers/isdn/divert/isdn_divert.h conflict!
'I' 40-4F linux/mISDNif.h conflict!
'J' 00-1F drivers/scsi/gdth_ioctl.h
'K' all linux/kd.h
'L' 00-1F linux/loop.h conflict!
'L' 10-1F drivers/scsi/mpt2sas/mpt2sas_ctl.h conflict!
'L' E0-FF linux/ppdd.h encrypted disk device driver
<http://linux01.gwdg.de/~alatham/ppdd.html>
'M' all linux/soundcard.h conflict!
'M' 01-16 mtd/mtd-abi.h conflict!
and drivers/mtd/mtdchar.c
'M' 01-03 drivers/scsi/megaraid/megaraid_sas.h
'M' 00-0F drivers/video/fsl-diu-fb.h conflict!
'N' 00-1F drivers/usb/scanner.h
'N' 40-7F drivers/block/nvme.c
'O' 00-06 mtd/ubi-user.h UBI
'P' all linux/soundcard.h conflict!
'P' 60-6F sound/sscape_ioctl.h conflict!
'P' 00-0F drivers/usb/class/usblp.c conflict!
'Q' all linux/soundcard.h
'R' 00-1F linux/random.h conflict!
'R' 01 linux/rfkill.h conflict!
'R' C0-DF net/bluetooth/rfcomm.h
'S' all linux/cdrom.h conflict!
'S' 80-81 scsi/scsi_ioctl.h conflict!
'S' 82-FF scsi/scsi.h conflict!
'S' 00-7F sound/asequencer.h conflict!
'T' all linux/soundcard.h conflict!
'T' 00-AF sound/asound.h conflict!
'T' all arch/x86/include/asm/ioctls.h conflict!
'T' C0-DF linux/if_tun.h conflict!
'U' all sound/asound.h conflict!
'U' 00-CF linux/uinput.h conflict!
'U' 00-EF linux/usbdevice_fs.h
'U' C0-CF drivers/bluetooth/hci_uart.h
'V' all linux/vt.h conflict!
'V' all linux/videodev2.h conflict!
'V' C0 linux/ivtvfb.h conflict!
'V' C0 linux/ivtv.h conflict!
'V' C0 media/davinci/vpfe_capture.h conflict!
'V' C0 media/si4713.h conflict!
'W' 00-1F linux/watchdog.h conflict!
'W' 00-1F linux/wanrouter.h conflict! (pre 3.9)
'W' 00-3F sound/asound.h conflict!
'X' all fs/xfs/xfs_fs.h conflict!
and fs/xfs/linux-2.6/xfs_ioctl32.h
and include/linux/falloc.h
and linux/fs.h
'X' all fs/ocfs2/ocfs_fs.h conflict!
'X' 01 linux/pktcdvd.h conflict!
'Y' all linux/cyclades.h
'Z' 14-15 drivers/message/fusion/mptctl.h
'[' 00-07 linux/usb/tmc.h USB Test and Measurement Devices
<mailto:gregkh@linuxfoundation.org>
'a' all linux/atm*.h, linux/sonet.h ATM on linux
<http://lrcwww.epfl.ch/>
'b' 00-FF conflict! bit3 vme host bridge
<mailto:natalia@nikhefk.nikhef.nl>
'c' all linux/cm4000_cs.h conflict!
'c' 00-7F linux/comstats.h conflict!
'c' 00-7F linux/coda.h conflict!
'c' 00-1F linux/chio.h conflict!
'c' 80-9F arch/s390/include/asm/chsc.h conflict!
'c' A0-AF arch/x86/include/asm/msr.h conflict!
'd' 00-FF linux/char/drm/drm/h conflict!
'd' 02-40 pcmcia/ds.h conflict!
'd' F0-FF linux/digi1.h
'e' all linux/digi1.h conflict!
'e' 00-1F drivers/net/irda/irtty-sir.h conflict!
'f' 00-1F linux/ext2_fs.h conflict!
'f' 00-1F linux/ext3_fs.h conflict!
'f' 00-0F fs/jfs/jfs_dinode.h conflict!
'f' 00-0F fs/ext4/ext4.h conflict!
'f' 00-0F linux/fs.h conflict!
'f' 00-0F fs/ocfs2/ocfs2_fs.h conflict!
'g' 00-0F linux/usb/gadgetfs.h
'g' 20-2F linux/usb/g_printer.h
'h' 00-7F conflict! Charon filesystem
<mailto:zapman@interlan.net>
'h' 00-1F linux/hpet.h conflict!
'h' 80-8F fs/hfsplus/ioctl.c
'i' 00-3F linux/i2o-dev.h conflict!
'i' 0B-1F linux/ipmi.h conflict!
'i' 80-8F linux/i8k.h
'j' 00-3F linux/joystick.h
'k' 00-0F linux/spi/spidev.h conflict!
'k' 00-05 video/kyro.h conflict!
'k' 10-17 linux/hsi/hsi_char.h HSI character device
'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system
<http://web.archive.org/web/*/http://mikonos.dia.unisa.it/tcfs>
'l' 40-7F linux/udf_fs_i.h in development:
<http://sourceforge.net/projects/linux-udf/>
'm' 00-09 linux/mmtimer.h conflict!
'm' all linux/mtio.h conflict!
'm' all linux/soundcard.h conflict!
'm' all linux/synclink.h conflict!
'm' 00-19 drivers/message/fusion/mptctl.h conflict!
'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict!
'm' 00-1F net/irda/irmod.h conflict!
'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c
'n' 80-8F linux/nilfs2_fs.h NILFS2
'n' E0-FF linux/matroxfb.h matroxfb
'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2
'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps)
'o' 40-41 mtd/ubi-user.h UBI
'o' 01-A1 linux/dvb/*.h DVB
'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this)
'p' 00-1F linux/rtc.h conflict!
'p' 00-3F linux/mc146818rtc.h conflict!
'p' 40-7F linux/nvram.h
'p' 80-9F linux/ppdev.h user-space parport
<mailto:tim@cyberelk.net>
'p' A1-A5 linux/pps.h LinuxPPS
<mailto:giometti@linux.it>
'q' 00-1F linux/serio.h
'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK
linux/ixjuser.h <http://web.archive.org/web/*/http://www.quicknet.net>
'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c
's' all linux/cdk.h
't' 00-7F linux/ppp-ioctl.h
't' 80-8F linux/isdn_ppp.h
't' 90 linux/toshiba.h
'u' 00-1F linux/smb_fs.h gone
'u' 20-3F linux/uvcvideo.h USB video class host driver
'v' 00-1F linux/ext2_fs.h conflict!
'v' 00-1F linux/fs.h conflict!
'v' 00-0F linux/sonypi.h conflict!
'v' C0-FF linux/meye.h conflict!
'w' all CERN SCI driver
'y' 00-1F packet based user level communications
<mailto:zapman@interlan.net>
'z' 00-3F CAN bus card conflict!
<mailto:hdstich@connectu.ulm.circular.de>
'z' 40-7F CAN bus card conflict!
<mailto:oe@port.de>
'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict!
'|' 00-7F linux/media.h
0x80 00-1F linux/fb.h
0x89 00-06 arch/x86/include/asm/sockios.h
0x89 0B-DF linux/sockios.h
0x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range
0x89 E0-EF linux/dn.h PROTOPRIVATE range
0x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range
0x8B all linux/wireless.h
0x8C 00-3F WiNRADiO driver
<http://www.winradio.com.au/>
0x90 00 drivers/cdrom/sbpcd.h
0x92 00-0F drivers/usb/mon/mon_bin.c
0x93 60-7F linux/auto_fs.h
0x94 all fs/btrfs/ioctl.h
0x97 00-7F fs/ceph/ioctl.h Ceph file system
0x99 00-0F 537-Addinboard driver
<mailto:buk@buks.ipn.de>
0xA0 all linux/sdp/sdp.h Industrial Device Project
<mailto:kenji@bitgate.com>
0xA2 00-0F arch/tile/include/asm/hardwall.h
0xA3 80-8F Port ACL in development:
<mailto:tlewis@mindspring.com>
0xA3 90-9F linux/dtlk.h
0xAB 00-1F linux/nbd.h
0xAC 00-1F linux/raw.h
0xAD 00 Netfilter device in development:
<mailto:rusty@rustcorp.com.au>
0xAE all linux/kvm.h Kernel-based Virtual Machine
<mailto:kvm@vger.kernel.org>
0xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor
0xB0 all RATIO devices in development:
<mailto:vgo@ratio.de>
0xB1 00-1F PPPoX <mailto:mostrows@styx.uwaterloo.ca>
0xB3 00 linux/mmc/ioctl.h
0xC0 00-0F linux/usb/iowarrior.h
0xCB 00-1F CBM serial IEC bus in development:
<mailto:michael.klein@puffin.lb.shuttle.de>
0xCD 01 linux/reiserfs_fs.h
0xCF 02 fs/cifs/ioctl.c
0xDB 00-0F drivers/char/mwave/mwavepub.h
0xDD 00-3F ZFCP device driver see drivers/s390/scsi/
<mailto:aherrman@de.ibm.com>
0xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development)
<mailto:thomas@winischhofer.net>
0xF4 00-1F video/mbxfb.h mbxfb
<mailto:raph@8d.com>
0xF6 all LTTng Linux Trace Toolkit Next Generation
<mailto:mathieu.desnoyers@efficios.com>
0xFD all linux/dm-ioctl.h