Documentation/ioctl/ioctl-number.txt

   1 Ioctl Numbers
   2 19 October 1999
   3 Michael Elizabeth Chastain
   4 <mec@shout.net>
   5
   6 If you are adding new ioctl's to the kernel, you should use the _IO
   7 macros defined in <linux/ioctl.h>:
   8
   9     _IO    an ioctl with no parameters
  10     _IOW   an ioctl with write parameters (copy_from_user)
  11     _IOR   an ioctl with read parameters  (copy_to_user)
  12     _IOWR  an ioctl with both write and read parameters.
  13
  14 'Write' and 'read' are from the user's point of view, just like the
  15 system calls 'write' and 'read'.  For example, a SET_FOO ioctl would
  16 be _IOW, although the kernel would actually read data from user space;
  17 a GET_FOO ioctl would be _IOR, although the kernel would actually write
  18 data to user space.
  19
  20 The first argument to _IO, _IOW, _IOR, or _IOWR is an identifying letter
  21 or number from the table below.  Because of the large number of drivers,
  22 many drivers share a partial letter with other drivers.
  23
  24 If you are writing a driver for a new device and need a letter, pick an
  25 unused block with enough room for expansion: 32 to 256 ioctl commands.
  26 You can register the block by patching this file and submitting the
  27 patch to Linus Torvalds.  Or you can e-mail me at <mec@shout.net> and
  28 I'll register one for you.
  29
  30 The second argument to _IO, _IOW, _IOR, or _IOWR is a sequence number
  31 to distinguish ioctls from each other.  The third argument to _IOW,
  32 _IOR, or _IOWR is the type of the data going into the kernel or coming
  33 out of the kernel (e.g.  'int' or 'struct foo').  NOTE!  Do NOT use
  34 sizeof(arg) as the third argument as this results in your ioctl thinking
  35 it passes an argument of type size_t.
  36
  37 Some devices use their major number as the identifier; this is OK, as
  38 long as it is unique.  Some devices are irregular and don't follow any
  39 convention at all.
  40
  41 Following this convention is good because:
  42
  43 (1) Keeping the ioctl's globally unique helps error checking:
  44     if a program calls an ioctl on the wrong device, it will get an
  45     error rather than some unexpected behaviour.
  46
  47 (2) The 'strace' build procedure automatically finds ioctl numbers
  48     defined with _IO, _IOW, _IOR, or _IOWR.
  49
  50 (3) 'strace' can decode numbers back into useful names when the
  51     numbers are unique.
  52
  53 (4) People looking for ioctls can grep for them more easily when
  54     this convention is used to define the ioctl numbers.
  55
  56 (5) When following the convention, the driver code can use generic
  57     code to copy the parameters between user and kernel space.
  58
  59 This table lists ioctls visible from user land for Linux/x86.  It contains
  60 most drivers up to 2.6.31, but I know I am missing some.  There has been
  61 no attempt to list non-X86 architectures or ioctls from drivers/staging/.
  62
  63 Code  Seq#(hex) Include File            Comments
  64 ========================================================
  65 0x00    00-1F   linux/fs.h              conflict!
  66 0x00    00-1F   scsi/scsi_ioctl.h       conflict!
  67 0x00    00-1F   linux/fb.h              conflict!
  68 0x00    00-1F   linux/wavefront.h       conflict!
  69 0x02    all     linux/fd.h
  70 0x03    all     linux/hdreg.h
  71 0x04    D2-DC   linux/umsdos_fs.h       Dead since 2.6.11, but don't reuse these.
  72 0x06    all     linux/lp.h
  73 0x09    all     linux/raid/md_u.h
  74 0x10    00-0F   drivers/char/s390/vmcp.h
  75 0x10    10-1F   arch/s390/include/uapi/sclp_ctl.h
  76 0x10    20-2F   arch/s390/include/uapi/asm/hypfs.h
  77 0x12    all     linux/fs.h
  78                 linux/blkpg.h
  79 0x1b    all     InfiniBand Subsystem    <http://infiniband.sourceforge.net/>
  80 0x20    all     drivers/cdrom/cm206.h
  81 0x22    all     scsi/sg.h
  82 '#'     00-3F   IEEE 1394 Subsystem     Block for the entire subsystem
  83 '$'     00-0F   linux/perf_counter.h, linux/perf_event.h
  84 '&'     00-07   drivers/firewire/nosy-user.h
  85 '1'     00-1F   <linux/timepps.h>       PPS kit from Ulrich Windl
  86                                         <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/>
  87 '2'     01-04   linux/i2o.h
  88 '3'     00-0F   drivers/s390/char/raw3270.h     conflict!
  89 '3'     00-1F   linux/suspend_ioctls.h  conflict!
  90                 and kernel/power/user.c
  91 '8'     all                             SNP8023 advanced NIC card
  92                                         <mailto:mcr@solidum.com>
  93 ';'     64-7F   linux/vfio.h
  94 '@'     00-0F   linux/radeonfb.h        conflict!
  95 '@'     00-0F   drivers/video/aty/aty128fb.c    conflict!
  96 'A'     00-1F   linux/apm_bios.h        conflict!
  97 'A'     00-0F   linux/agpgart.h         conflict!
  98                 and drivers/char/agp/compat_ioctl.h
  99 'A'     00-7F   sound/asound.h          conflict!
 100 'B'     00-1F   linux/cciss_ioctl.h     conflict!
 101 'B'     00-0F   include/linux/pmu.h     conflict!
 102 'B'     C0-FF                           advanced bbus
 103                                         <mailto:maassen@uni-freiburg.de>
 104 'C'     all     linux/soundcard.h       conflict!
 105 'C'     01-2F   linux/capi.h            conflict!
 106 'C'     F0-FF   drivers/net/wan/cosa.h  conflict!
 107 'D'     all     arch/s390/include/asm/dasd.h
 108 'D'     40-5F   drivers/scsi/dpt/dtpi_ioctl.h
 109 'D'     05      drivers/scsi/pmcraid.h
 110 'E'     all     linux/input.h           conflict!
 111 'E'     00-0F   xen/evtchn.h            conflict!
 112 'F'     all     linux/fb.h              conflict!
 113 'F'     01-02   drivers/scsi/pmcraid.h  conflict!
 114 'F'     20      drivers/video/fsl-diu-fb.h      conflict!
 115 'F'     20      drivers/video/intelfb/intelfb.h conflict!
 116 'F'     20      linux/ivtvfb.h          conflict!
 117 'F'     20      linux/matroxfb.h        conflict!
 118 'F'     20      drivers/video/aty/atyfb_base.c  conflict!
 119 'F'     00-0F   video/da8xx-fb.h        conflict!
 120 'F'     80-8F   linux/arcfb.h           conflict!
 121 'F'     DD      video/sstfb.h           conflict!
 122 'G'     00-3F   drivers/misc/sgi-gru/grulib.h   conflict!
 123 'G'     00-0F   linux/gigaset_dev.h     conflict!
 124 'H'     00-7F   linux/hiddev.h          conflict!
 125 'H'     00-0F   linux/hidraw.h          conflict!
 126 'H'     01      linux/mei.h             conflict!
 127 'H'     02      linux/mei.h             conflict!
 128 'H'     03      linux/mei.h             conflict!
 129 'H'     00-0F   sound/asound.h          conflict!
 130 'H'     20-40   sound/asound_fm.h       conflict!
 131 'H'     80-8F   sound/sfnt_info.h       conflict!
 132 'H'     10-8F   sound/emu10k1.h         conflict!
 133 'H'     10-1F   sound/sb16_csp.h        conflict!
 134 'H'     10-1F   sound/hda_hwdep.h       conflict!
 135 'H'     40-4F   sound/hdspm.h           conflict!
 136 'H'     40-4F   sound/hdsp.h            conflict!
 137 'H'     90      sound/usb/usx2y/usb_stream.h
 138 'H'     A0      uapi/linux/usb/cdc-wdm.h
 139 'H'     C0-F0   net/bluetooth/hci.h     conflict!
 140 'H'     C0-DF   net/bluetooth/hidp/hidp.h       conflict!
 141 'H'     C0-DF   net/bluetooth/cmtp/cmtp.h       conflict!
 142 'H'     C0-DF   net/bluetooth/bnep/bnep.h       conflict!
 143 'H'     F1      linux/hid-roccat.h      <mailto:erazor_de@users.sourceforge.net>
 144 'H'     F8-FA   sound/firewire.h
 145 'I'     all     linux/isdn.h            conflict!
 146 'I'     00-0F   drivers/isdn/divert/isdn_divert.h       conflict!
 147 'I'     40-4F   linux/mISDNif.h         conflict!
 148 'J'     00-1F   drivers/scsi/gdth_ioctl.h
 149 'K'     all     linux/kd.h
 150 'L'     00-1F   linux/loop.h            conflict!
 151 'L'     10-1F   drivers/scsi/mpt2sas/mpt2sas_ctl.h      conflict!
 152 'L'     20-2F   linux/lightnvm.h
 153 'L'     E0-FF   linux/ppdd.h            encrypted disk device driver
 154                                         <http://linux01.gwdg.de/~alatham/ppdd.html>
 155 'M'     all     linux/soundcard.h       conflict!
 156 'M'     01-16   mtd/mtd-abi.h           conflict!
 157                 and drivers/mtd/mtdchar.c
 158 'M'     01-03   drivers/scsi/megaraid/megaraid_sas.h
 159 'M'     00-0F   drivers/video/fsl-diu-fb.h      conflict!
 160 'N'     00-1F   drivers/usb/scanner.h
 161 'N'     40-7F   drivers/block/nvme.c
 162 'O'     00-06   mtd/ubi-user.h          UBI
 163 'P'     all     linux/soundcard.h       conflict!
 164 'P'     60-6F   sound/sscape_ioctl.h    conflict!
 165 'P'     00-0F   drivers/usb/class/usblp.c       conflict!
 166 'Q'     all     linux/soundcard.h
 167 'R'     00-1F   linux/random.h          conflict!
 168 'R'     01      linux/rfkill.h          conflict!
 169 'R'     C0-DF   net/bluetooth/rfcomm.h
 170 'S'     all     linux/cdrom.h           conflict!
 171 'S'     80-81   scsi/scsi_ioctl.h       conflict!
 172 'S'     82-FF   scsi/scsi.h             conflict!
 173 'S'     00-7F   sound/asequencer.h      conflict!
 174 'T'     all     linux/soundcard.h       conflict!
 175 'T'     00-AF   sound/asound.h          conflict!
 176 'T'     all     arch/x86/include/asm/ioctls.h   conflict!
 177 'T'     C0-DF   linux/if_tun.h          conflict!
 178 'U'     all     sound/asound.h          conflict!
 179 'U'     00-CF   linux/uinput.h          conflict!
 180 'U'     00-EF   linux/usbdevice_fs.h
 181 'U'     C0-CF   drivers/bluetooth/hci_uart.h
 182 'V'     all     linux/vt.h              conflict!
 183 'V'     all     linux/videodev2.h       conflict!
 184 'V'     C0      linux/ivtvfb.h          conflict!
 185 'V'     C0      linux/ivtv.h            conflict!
 186 'V'     C0      media/davinci/vpfe_capture.h    conflict!
 187 'V'     C0      media/si4713.h          conflict!
 188 'W'     00-1F   linux/watchdog.h        conflict!
 189 'W'     00-1F   linux/wanrouter.h       conflict!               (pre 3.9)
 190 'W'     00-3F   sound/asound.h          conflict!
 191 'X'     all     fs/xfs/xfs_fs.h         conflict!
 192                 and fs/xfs/linux-2.6/xfs_ioctl32.h
 193                 and include/linux/falloc.h
 194                 and linux/fs.h
 195 'X'     all     fs/ocfs2/ocfs_fs.h      conflict!
 196 'X'     01      linux/pktcdvd.h         conflict!
 197 'Y'     all     linux/cyclades.h
 198 'Z'     14-15   drivers/message/fusion/mptctl.h
 199 '['     00-07   linux/usb/tmc.h         USB Test and Measurement Devices
 200                                         <mailto:gregkh@linuxfoundation.org>
 201 'a'     all     linux/atm*.h, linux/sonet.h     ATM on linux
 202                                         <http://lrcwww.epfl.ch/>
 203 'a'     00-0F   drivers/crypto/qat/qat_common/adf_cfg_common.h  conflict! qat driver
 204 'b'     00-FF                           conflict! bit3 vme host bridge
 205                                         <mailto:natalia@nikhefk.nikhef.nl>
 206 'c'     all     linux/cm4000_cs.h       conflict!
 207 'c'     00-7F   linux/comstats.h        conflict!
 208 'c'     00-7F   linux/coda.h            conflict!
 209 'c'     00-1F   linux/chio.h            conflict!
 210 'c'     80-9F   arch/s390/include/asm/chsc.h    conflict!
 211 'c'     A0-AF   arch/x86/include/asm/msr.h      conflict!
 212 'd'     00-FF   linux/char/drm/drm/h    conflict!
 213 'd'     02-40   pcmcia/ds.h             conflict!
 214 'd'     F0-FF   linux/digi1.h
 215 'e'     all     linux/digi1.h           conflict!
 216 'e'     00-1F   drivers/net/irda/irtty-sir.h    conflict!
 217 'f'     00-1F   linux/ext2_fs.h         conflict!
 218 'f'     00-1F   linux/ext3_fs.h         conflict!
 219 'f'     00-0F   fs/jfs/jfs_dinode.h     conflict!
 220 'f'     00-0F   fs/ext4/ext4.h          conflict!
 221 'f'     00-0F   linux/fs.h              conflict!
 222 'f'     00-0F   fs/ocfs2/ocfs2_fs.h     conflict!
 223 'g'     00-0F   linux/usb/gadgetfs.h
 224 'g'     20-2F   linux/usb/g_printer.h
 225 'h'     00-7F                           conflict! Charon filesystem
 226                                         <mailto:zapman@interlan.net>
 227 'h'     00-1F   linux/hpet.h            conflict!
 228 'h'     80-8F   fs/hfsplus/ioctl.c
 229 'i'     00-3F   linux/i2o-dev.h         conflict!
 230 'i'     0B-1F   linux/ipmi.h            conflict!
 231 'i'     80-8F   linux/i8k.h
 232 'j'     00-3F   linux/joystick.h
 233 'k'     00-0F   linux/spi/spidev.h      conflict!
 234 'k'     00-05   video/kyro.h            conflict!
 235 'k'     10-17   linux/hsi/hsi_char.h    HSI character device
 236 'l'     00-3F   linux/tcfs_fs.h         transparent cryptographic file system
 237                                         <http://web.archive.org/web/*/http://mikonos.dia.unisa.it/tcfs>
 238 'l'     40-7F   linux/udf_fs_i.h        in development:
 239                                         <http://sourceforge.net/projects/linux-udf/>
 240 'm'     00-09   linux/mmtimer.h         conflict!
 241 'm'     all     linux/mtio.h            conflict!
 242 'm'     all     linux/soundcard.h       conflict!
 243 'm'     all     linux/synclink.h        conflict!
 244 'm'     00-19   drivers/message/fusion/mptctl.h conflict!
 245 'm'     00      drivers/scsi/megaraid/megaraid_ioctl.h  conflict!
 246 'm'     00-1F   net/irda/irmod.h        conflict!
 247 'n'     00-7F   linux/ncp_fs.h and fs/ncpfs/ioctl.c
 248 'n'     80-8F   linux/nilfs2_fs.h       NILFS2
 249 'n'     E0-FF   linux/matroxfb.h        matroxfb
 250 'o'     00-1F   fs/ocfs2/ocfs2_fs.h     OCFS2
 251 'o'     00-03   mtd/ubi-user.h          conflict! (OCFS2 and UBI overlaps)
 252 'o'     40-41   mtd/ubi-user.h          UBI
 253 'o'     01-A1   linux/dvb/*.h           DVB
 254 'p'     00-0F   linux/phantom.h         conflict! (OpenHaptics needs this)
 255 'p'     00-1F   linux/rtc.h             conflict!
 256 'p'     00-3F   linux/mc146818rtc.h     conflict!
 257 'p'     40-7F   linux/nvram.h
 258 'p'     80-9F   linux/ppdev.h           user-space parport
 259                                         <mailto:tim@cyberelk.net>
 260 'p'     A1-A5   linux/pps.h             LinuxPPS
 261                                         <mailto:giometti@linux.it>
 262 'q'     00-1F   linux/serio.h
 263 'q'     80-FF   linux/telephony.h       Internet PhoneJACK, Internet LineJACK
 264                 linux/ixjuser.h         <http://web.archive.org/web/*/http://www.quicknet.net>
 265 'r'     00-1F   linux/msdos_fs.h and fs/fat/dir.c
 266 's'     all     linux/cdk.h
 267 't'     00-7F   linux/ppp-ioctl.h
 268 't'     80-8F   linux/isdn_ppp.h
 269 't'     90-91   linux/toshiba.h         toshiba and toshiba_acpi SMM
 270 'u'     00-1F   linux/smb_fs.h          gone
 271 'u'     20-3F   linux/uvcvideo.h        USB video class host driver
 272 'v'     00-1F   linux/ext2_fs.h         conflict!
 273 'v'     00-1F   linux/fs.h              conflict!
 274 'v'     00-0F   linux/sonypi.h          conflict!
 275 'v'     C0-FF   linux/meye.h            conflict!
 276 'w'     all                             CERN SCI driver
 277 'y'     00-1F                           packet based user level communications
 278                                         <mailto:zapman@interlan.net>
 279 'z'     00-3F                           CAN bus card    conflict!
 280                                         <mailto:hdstich@connectu.ulm.circular.de>
 281 'z'     40-7F                           CAN bus card    conflict!
 282                                         <mailto:oe@port.de>
 283 'z'     10-4F   drivers/s390/crypto/zcrypt_api.h        conflict!
 284 '|'     00-7F   linux/media.h
 285 0x80    00-1F   linux/fb.h
 286 0x89    00-06   arch/x86/include/asm/sockios.h
 287 0x89    0B-DF   linux/sockios.h
 288 0x89    E0-EF   linux/sockios.h         SIOCPROTOPRIVATE range
 289 0x89    E0-EF   linux/dn.h              PROTOPRIVATE range
 290 0x89    F0-FF   linux/sockios.h         SIOCDEVPRIVATE range
 291 0x8B    all     linux/wireless.h
 292 0x8C    00-3F                           WiNRADiO driver
 293                                         <http://www.winradio.com.au/>
 294 0x90    00      drivers/cdrom/sbpcd.h
 295 0x92    00-0F   drivers/usb/mon/mon_bin.c
 296 0x93    60-7F   linux/auto_fs.h
 297 0x94    all     fs/btrfs/ioctl.h
 298 0x97    00-7F   fs/ceph/ioctl.h         Ceph file system
 299 0x99    00-0F                           537-Addinboard driver
 300                                         <mailto:buk@buks.ipn.de>
 301 0xA0    all     linux/sdp/sdp.h         Industrial Device Project
 302                                         <mailto:kenji@bitgate.com>
 303 0xA2    00-0F   arch/tile/include/asm/hardwall.h
 304 0xA3    80-8F   Port ACL                in development:
 305                                         <mailto:tlewis@mindspring.com>
 306 0xA3    90-9F   linux/dtlk.h
 307 0xAA    00-3F   linux/uapi/linux/userfaultfd.h
 308 0xAB    00-1F   linux/nbd.h
 309 0xAC    00-1F   linux/raw.h
 310 0xAD    00      Netfilter device        in development:
 311                                         <mailto:rusty@rustcorp.com.au>
 312 0xAE    all     linux/kvm.h             Kernel-based Virtual Machine
 313                                         <mailto:kvm@vger.kernel.org>
 314 0xAF    00-1F   linux/fsl_hypervisor.h  Freescale hypervisor
 315 0xB0    all     RATIO devices           in development:
 316                                         <mailto:vgo@ratio.de>
 317 0xB1    00-1F   PPPoX                   <mailto:mostrows@styx.uwaterloo.ca>
 318 0xB3    00      linux/mmc/ioctl.h
 319 0xC0    00-0F   linux/usb/iowarrior.h
 320 0xCA    00-0F   uapi/misc/cxl.h
 321 0xCA    80-8F   uapi/scsi/cxlflash_ioctl.h
 322 0xCB    00-1F   CBM serial IEC bus      in development:
 323                                         <mailto:michael.klein@puffin.lb.shuttle.de>
 324 0xCD    01      linux/reiserfs_fs.h
 325 0xCF    02      fs/cifs/ioctl.c
 326 0xDB    00-0F   drivers/char/mwave/mwavepub.h
 327 0xDD    00-3F   ZFCP device driver      see drivers/s390/scsi/
 328                                         <mailto:aherrman@de.ibm.com>
 329 0xE5    00-3F   linux/fuse.h
 330 0xEC    00-01   drivers/platform/chrome/cros_ec_dev.h   ChromeOS EC driver
 331 0xF3    00-3F   drivers/usb/misc/sisusbvga/sisusb.h     sisfb (in development)
 332                                         <mailto:thomas@winischhofer.net>
 333 0xF4    00-1F   video/mbxfb.h           mbxfb
 334                                         <mailto:raph@8d.com>
 335 0xF6    all     LTTng                   Linux Trace Toolkit Next Generation
 336                                         <mailto:mathieu.desnoyers@efficios.com>
 337 0xFD    all     linux/dm-ioctl.h