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 '%'     00-0F   include/uapi/linux/stm.h
  85                                         System Trace Module subsystem
  86                                         <mailto:alexander.shishkin@linux.intel.com>
  87 '&'     00-07   drivers/firewire/nosy-user.h
  88 '1'     00-1F   <linux/timepps.h>       PPS kit from Ulrich Windl
  89                                         <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/>
  90 '2'     01-04   linux/i2o.h
  91 '3'     00-0F   drivers/s390/char/raw3270.h     conflict!
  92 '3'     00-1F   linux/suspend_ioctls.h  conflict!
  93                 and kernel/power/user.c
  94 '8'     all                             SNP8023 advanced NIC card
  95                                         <mailto:mcr@solidum.com>
  96 ';'     64-7F   linux/vfio.h
  97 '@'     00-0F   linux/radeonfb.h        conflict!
  98 '@'     00-0F   drivers/video/aty/aty128fb.c    conflict!
  99 'A'     00-1F   linux/apm_bios.h        conflict!
 100 'A'     00-0F   linux/agpgart.h         conflict!
 101                 and drivers/char/agp/compat_ioctl.h
 102 'A'     00-7F   sound/asound.h          conflict!
 103 'B'     00-1F   linux/cciss_ioctl.h     conflict!
 104 'B'     00-0F   include/linux/pmu.h     conflict!
 105 'B'     C0-FF                           advanced bbus
 106                                         <mailto:maassen@uni-freiburg.de>
 107 'C'     all     linux/soundcard.h       conflict!
 108 'C'     01-2F   linux/capi.h            conflict!
 109 'C'     F0-FF   drivers/net/wan/cosa.h  conflict!
 110 'D'     all     arch/s390/include/asm/dasd.h
 111 'D'     40-5F   drivers/scsi/dpt/dtpi_ioctl.h
 112 'D'     05      drivers/scsi/pmcraid.h
 113 'E'     all     linux/input.h           conflict!
 114 'E'     00-0F   xen/evtchn.h            conflict!
 115 'F'     all     linux/fb.h              conflict!
 116 'F'     01-02   drivers/scsi/pmcraid.h  conflict!
 117 'F'     20      drivers/video/fsl-diu-fb.h      conflict!
 118 'F'     20      drivers/video/intelfb/intelfb.h conflict!
 119 'F'     20      linux/ivtvfb.h          conflict!
 120 'F'     20      linux/matroxfb.h        conflict!
 121 'F'     20      drivers/video/aty/atyfb_base.c  conflict!
 122 'F'     00-0F   video/da8xx-fb.h        conflict!
 123 'F'     80-8F   linux/arcfb.h           conflict!
 124 'F'     DD      video/sstfb.h           conflict!
 125 'G'     00-3F   drivers/misc/sgi-gru/grulib.h   conflict!
 126 'G'     00-0F   linux/gigaset_dev.h     conflict!
 127 'H'     00-7F   linux/hiddev.h          conflict!
 128 'H'     00-0F   linux/hidraw.h          conflict!
 129 'H'     01      linux/mei.h             conflict!
 130 'H'     02      linux/mei.h             conflict!
 131 'H'     03      linux/mei.h             conflict!
 132 'H'     00-0F   sound/asound.h          conflict!
 133 'H'     20-40   sound/asound_fm.h       conflict!
 134 'H'     80-8F   sound/sfnt_info.h       conflict!
 135 'H'     10-8F   sound/emu10k1.h         conflict!
 136 'H'     10-1F   sound/sb16_csp.h        conflict!
 137 'H'     10-1F   sound/hda_hwdep.h       conflict!
 138 'H'     40-4F   sound/hdspm.h           conflict!
 139 'H'     40-4F   sound/hdsp.h            conflict!
 140 'H'     90      sound/usb/usx2y/usb_stream.h
 141 'H'     A0      uapi/linux/usb/cdc-wdm.h
 142 'H'     C0-F0   net/bluetooth/hci.h     conflict!
 143 'H'     C0-DF   net/bluetooth/hidp/hidp.h       conflict!
 144 'H'     C0-DF   net/bluetooth/cmtp/cmtp.h       conflict!
 145 'H'     C0-DF   net/bluetooth/bnep/bnep.h       conflict!
 146 'H'     F1      linux/hid-roccat.h      <mailto:erazor_de@users.sourceforge.net>
 147 'H'     F8-FA   sound/firewire.h
 148 'I'     all     linux/isdn.h            conflict!
 149 'I'     00-0F   drivers/isdn/divert/isdn_divert.h       conflict!
 150 'I'     40-4F   linux/mISDNif.h         conflict!
 151 'J'     00-1F   drivers/scsi/gdth_ioctl.h
 152 'K'     all     linux/kd.h
 153 'L'     00-1F   linux/loop.h            conflict!
 154 'L'     10-1F   drivers/scsi/mpt2sas/mpt2sas_ctl.h      conflict!
 155 'L'     20-2F   linux/lightnvm.h
 156 'L'     E0-FF   linux/ppdd.h            encrypted disk device driver
 157                                         <http://linux01.gwdg.de/~alatham/ppdd.html>
 158 'M'     all     linux/soundcard.h       conflict!
 159 'M'     01-16   mtd/mtd-abi.h           conflict!
 160                 and drivers/mtd/mtdchar.c
 161 'M'     01-03   drivers/scsi/megaraid/megaraid_sas.h
 162 'M'     00-0F   drivers/video/fsl-diu-fb.h      conflict!
 163 'N'     00-1F   drivers/usb/scanner.h
 164 'N'     40-7F   drivers/block/nvme.c
 165 'O'     00-06   mtd/ubi-user.h          UBI
 166 'P'     all     linux/soundcard.h       conflict!
 167 'P'     60-6F   sound/sscape_ioctl.h    conflict!
 168 'P'     00-0F   drivers/usb/class/usblp.c       conflict!
 169 'Q'     all     linux/soundcard.h
 170 'R'     00-1F   linux/random.h          conflict!
 171 'R'     01      linux/rfkill.h          conflict!
 172 'R'     C0-DF   net/bluetooth/rfcomm.h
 173 'S'     all     linux/cdrom.h           conflict!
 174 'S'     80-81   scsi/scsi_ioctl.h       conflict!
 175 'S'     82-FF   scsi/scsi.h             conflict!
 176 'S'     00-7F   sound/asequencer.h      conflict!
 177 'T'     all     linux/soundcard.h       conflict!
 178 'T'     00-AF   sound/asound.h          conflict!
 179 'T'     all     arch/x86/include/asm/ioctls.h   conflict!
 180 'T'     C0-DF   linux/if_tun.h          conflict!
 181 'U'     all     sound/asound.h          conflict!
 182 'U'     00-CF   linux/uinput.h          conflict!
 183 'U'     00-EF   linux/usbdevice_fs.h
 184 'U'     C0-CF   drivers/bluetooth/hci_uart.h
 185 'V'     all     linux/vt.h              conflict!
 186 'V'     all     linux/videodev2.h       conflict!
 187 'V'     C0      linux/ivtvfb.h          conflict!
 188 'V'     C0      linux/ivtv.h            conflict!
 189 'V'     C0      media/davinci/vpfe_capture.h    conflict!
 190 'V'     C0      media/si4713.h          conflict!
 191 'W'     00-1F   linux/watchdog.h        conflict!
 192 'W'     00-1F   linux/wanrouter.h       conflict!               (pre 3.9)
 193 'W'     00-3F   sound/asound.h          conflict!
 194 'X'     all     fs/xfs/xfs_fs.h         conflict!
 195                 and fs/xfs/linux-2.6/xfs_ioctl32.h
 196                 and include/linux/falloc.h
 197                 and linux/fs.h
 198 'X'     all     fs/ocfs2/ocfs_fs.h      conflict!
 199 'X'     01      linux/pktcdvd.h         conflict!
 200 'Y'     all     linux/cyclades.h
 201 'Z'     14-15   drivers/message/fusion/mptctl.h
 202 '['     00-07   linux/usb/tmc.h         USB Test and Measurement Devices
 203                                         <mailto:gregkh@linuxfoundation.org>
 204 'a'     all     linux/atm*.h, linux/sonet.h     ATM on linux
 205                                         <http://lrcwww.epfl.ch/>
 206 'a'     00-0F   drivers/crypto/qat/qat_common/adf_cfg_common.h  conflict! qat driver
 207 'b'     00-FF                           conflict! bit3 vme host bridge
 208                                         <mailto:natalia@nikhefk.nikhef.nl>
 209 'c'     all     linux/cm4000_cs.h       conflict!
 210 'c'     00-7F   linux/comstats.h        conflict!
 211 'c'     00-7F   linux/coda.h            conflict!
 212 'c'     00-1F   linux/chio.h            conflict!
 213 'c'     80-9F   arch/s390/include/asm/chsc.h    conflict!
 214 'c'     A0-AF   arch/x86/include/asm/msr.h      conflict!
 215 'd'     00-FF   linux/char/drm/drm/h    conflict!
 216 'd'     02-40   pcmcia/ds.h             conflict!
 217 'd'     F0-FF   linux/digi1.h
 218 'e'     all     linux/digi1.h           conflict!
 219 'e'     00-1F   drivers/net/irda/irtty-sir.h    conflict!
 220 'f'     00-1F   linux/ext2_fs.h         conflict!
 221 'f'     00-1F   linux/ext3_fs.h         conflict!
 222 'f'     00-0F   fs/jfs/jfs_dinode.h     conflict!
 223 'f'     00-0F   fs/ext4/ext4.h          conflict!
 224 'f'     00-0F   linux/fs.h              conflict!
 225 'f'     00-0F   fs/ocfs2/ocfs2_fs.h     conflict!
 226 'g'     00-0F   linux/usb/gadgetfs.h
 227 'g'     20-2F   linux/usb/g_printer.h
 228 'h'     00-7F                           conflict! Charon filesystem
 229                                         <mailto:zapman@interlan.net>
 230 'h'     00-1F   linux/hpet.h            conflict!
 231 'h'     80-8F   fs/hfsplus/ioctl.c
 232 'i'     00-3F   linux/i2o-dev.h         conflict!
 233 'i'     0B-1F   linux/ipmi.h            conflict!
 234 'i'     80-8F   linux/i8k.h
 235 'j'     00-3F   linux/joystick.h
 236 'k'     00-0F   linux/spi/spidev.h      conflict!
 237 'k'     00-05   video/kyro.h            conflict!
 238 'k'     10-17   linux/hsi/hsi_char.h    HSI character device
 239 'l'     00-3F   linux/tcfs_fs.h         transparent cryptographic file system
 240                                         <http://web.archive.org/web/*/http://mikonos.dia.unisa.it/tcfs>
 241 'l'     40-7F   linux/udf_fs_i.h        in development:
 242                                         <http://sourceforge.net/projects/linux-udf/>
 243 'm'     00-09   linux/mmtimer.h         conflict!
 244 'm'     all     linux/mtio.h            conflict!
 245 'm'     all     linux/soundcard.h       conflict!
 246 'm'     all     linux/synclink.h        conflict!
 247 'm'     00-19   drivers/message/fusion/mptctl.h conflict!
 248 'm'     00      drivers/scsi/megaraid/megaraid_ioctl.h  conflict!
 249 'm'     00-1F   net/irda/irmod.h        conflict!
 250 'n'     00-7F   linux/ncp_fs.h and fs/ncpfs/ioctl.c
 251 'n'     80-8F   uapi/linux/nilfs2_api.h NILFS2
 252 'n'     E0-FF   linux/matroxfb.h        matroxfb
 253 'o'     00-1F   fs/ocfs2/ocfs2_fs.h     OCFS2
 254 'o'     00-03   mtd/ubi-user.h          conflict! (OCFS2 and UBI overlaps)
 255 'o'     40-41   mtd/ubi-user.h          UBI
 256 'o'     01-A1   linux/dvb/*.h           DVB
 257 'p'     00-0F   linux/phantom.h         conflict! (OpenHaptics needs this)
 258 'p'     00-1F   linux/rtc.h             conflict!
 259 'p'     00-3F   linux/mc146818rtc.h     conflict!
 260 'p'     40-7F   linux/nvram.h
 261 'p'     80-9F   linux/ppdev.h           user-space parport
 262                                         <mailto:tim@cyberelk.net>
 263 'p'     A1-A5   linux/pps.h             LinuxPPS
 264                                         <mailto:giometti@linux.it>
 265 'q'     00-1F   linux/serio.h
 266 'q'     80-FF   linux/telephony.h       Internet PhoneJACK, Internet LineJACK
 267                 linux/ixjuser.h         <http://web.archive.org/web/*/http://www.quicknet.net>
 268 'r'     00-1F   linux/msdos_fs.h and fs/fat/dir.c
 269 's'     all     linux/cdk.h
 270 't'     00-7F   linux/ppp-ioctl.h
 271 't'     80-8F   linux/isdn_ppp.h
 272 't'     90-91   linux/toshiba.h         toshiba and toshiba_acpi SMM
 273 'u'     00-1F   linux/smb_fs.h          gone
 274 'u'     20-3F   linux/uvcvideo.h        USB video class host driver
 275 'v'     00-1F   linux/ext2_fs.h         conflict!
 276 'v'     00-1F   linux/fs.h              conflict!
 277 'v'     00-0F   linux/sonypi.h          conflict!
 278 'v'     C0-FF   linux/meye.h            conflict!
 279 'w'     all                             CERN SCI driver
 280 'y'     00-1F                           packet based user level communications
 281                                         <mailto:zapman@interlan.net>
 282 'z'     00-3F                           CAN bus card    conflict!
 283                                         <mailto:hdstich@connectu.ulm.circular.de>
 284 'z'     40-7F                           CAN bus card    conflict!
 285                                         <mailto:oe@port.de>
 286 'z'     10-4F   drivers/s390/crypto/zcrypt_api.h        conflict!
 287 '|'     00-7F   linux/media.h
 288 0x80    00-1F   linux/fb.h
 289 0x89    00-06   arch/x86/include/asm/sockios.h
 290 0x89    0B-DF   linux/sockios.h
 291 0x89    E0-EF   linux/sockios.h         SIOCPROTOPRIVATE range
 292 0x89    E0-EF   linux/dn.h              PROTOPRIVATE range
 293 0x89    F0-FF   linux/sockios.h         SIOCDEVPRIVATE range
 294 0x8B    all     linux/wireless.h
 295 0x8C    00-3F                           WiNRADiO driver
 296                                         <http://www.winradio.com.au/>
 297 0x90    00      drivers/cdrom/sbpcd.h
 298 0x92    00-0F   drivers/usb/mon/mon_bin.c
 299 0x93    60-7F   linux/auto_fs.h
 300 0x94    all     fs/btrfs/ioctl.h
 301 0x97    00-7F   fs/ceph/ioctl.h         Ceph file system
 302 0x99    00-0F                           537-Addinboard driver
 303                                         <mailto:buk@buks.ipn.de>
 304 0xA0    all     linux/sdp/sdp.h         Industrial Device Project
 305                                         <mailto:kenji@bitgate.com>
 306 0xA1    0       linux/vtpm_proxy.h      TPM Emulator Proxy Driver
 307 0xA2    00-0F   arch/tile/include/asm/hardwall.h
 308 0xA3    80-8F   Port ACL                in development:
 309                                         <mailto:tlewis@mindspring.com>
 310 0xA3    90-9F   linux/dtlk.h
 311 0xAA    00-3F   linux/uapi/linux/userfaultfd.h
 312 0xAB    00-1F   linux/nbd.h
 313 0xAC    00-1F   linux/raw.h
 314 0xAD    00      Netfilter device        in development:
 315                                         <mailto:rusty@rustcorp.com.au>
 316 0xAE    all     linux/kvm.h             Kernel-based Virtual Machine
 317                                         <mailto:kvm@vger.kernel.org>
 318 0xAF    00-1F   linux/fsl_hypervisor.h  Freescale hypervisor
 319 0xB0    all     RATIO devices           in development:
 320                                         <mailto:vgo@ratio.de>
 321 0xB1    00-1F   PPPoX                   <mailto:mostrows@styx.uwaterloo.ca>
 322 0xB3    00      linux/mmc/ioctl.h
 323 0xB4    00-0F   linux/gpio.h            <mailto:linux-gpio@vger.kernel.org>
 324 0xC0    00-0F   linux/usb/iowarrior.h
 325 0xCA    00-0F   uapi/misc/cxl.h
 326 0xCA    80-BF   uapi/scsi/cxlflash_ioctl.h
 327 0xCB    00-1F   CBM serial IEC bus      in development:
 328                                         <mailto:michael.klein@puffin.lb.shuttle.de>
 329 0xCD    01      linux/reiserfs_fs.h
 330 0xCF    02      fs/cifs/ioctl.c
 331 0xDB    00-0F   drivers/char/mwave/mwavepub.h
 332 0xDD    00-3F   ZFCP device driver      see drivers/s390/scsi/
 333                                         <mailto:aherrman@de.ibm.com>
 334 0xE5    00-3F   linux/fuse.h
 335 0xEC    00-01   drivers/platform/chrome/cros_ec_dev.h   ChromeOS EC driver
 336 0xF3    00-3F   drivers/usb/misc/sisusbvga/sisusb.h     sisfb (in development)
 337                                         <mailto:thomas@winischhofer.net>
 338 0xF4    00-1F   video/mbxfb.h           mbxfb
 339                                         <mailto:raph@8d.com>
 340 0xF6    all     LTTng                   Linux Trace Toolkit Next Generation
 341                                         <mailto:mathieu.desnoyers@efficios.com>
 342 0xFD    all     linux/dm-ioctl.h