Documentation/userspace-api/ioctl/ioctl-number.rst

   1 =============
   2 Ioctl Numbers
   3 =============
   4
   5 19 October 1999
   6
   7 Michael Elizabeth Chastain
   8 <mec@shout.net>
   9
  10 If you are adding new ioctl's to the kernel, you should use the _IO
  11 macros defined in <linux/ioctl.h>:
  12
  13     ====== == ============================================
  14     _IO    an ioctl with no parameters
  15     _IOW   an ioctl with write parameters (copy_from_user)
  16     _IOR   an ioctl with read parameters  (copy_to_user)
  17     _IOWR  an ioctl with both write and read parameters.
  18     ====== == ============================================
  19
  20 'Write' and 'read' are from the user's point of view, just like the
  21 system calls 'write' and 'read'.  For example, a SET_FOO ioctl would
  22 be _IOW, although the kernel would actually read data from user space;
  23 a GET_FOO ioctl would be _IOR, although the kernel would actually write
  24 data to user space.
  25
  26 The first argument to _IO, _IOW, _IOR, or _IOWR is an identifying letter
  27 or number from the table below.  Because of the large number of drivers,
  28 many drivers share a partial letter with other drivers.
  29
  30 If you are writing a driver for a new device and need a letter, pick an
  31 unused block with enough room for expansion: 32 to 256 ioctl commands.
  32 You can register the block by patching this file and submitting the
  33 patch to Linus Torvalds.  Or you can e-mail me at <mec@shout.net> and
  34 I'll register one for you.
  35
  36 The second argument to _IO, _IOW, _IOR, or _IOWR is a sequence number
  37 to distinguish ioctls from each other.  The third argument to _IOW,
  38 _IOR, or _IOWR is the type of the data going into the kernel or coming
  39 out of the kernel (e.g.  'int' or 'struct foo').  NOTE!  Do NOT use
  40 sizeof(arg) as the third argument as this results in your ioctl thinking
  41 it passes an argument of type size_t.
  42
  43 Some devices use their major number as the identifier; this is OK, as
  44 long as it is unique.  Some devices are irregular and don't follow any
  45 convention at all.
  46
  47 Following this convention is good because:
  48
  49 (1) Keeping the ioctl's globally unique helps error checking:
  50     if a program calls an ioctl on the wrong device, it will get an
  51     error rather than some unexpected behaviour.
  52
  53 (2) The 'strace' build procedure automatically finds ioctl numbers
  54     defined with _IO, _IOW, _IOR, or _IOWR.
  55
  56 (3) 'strace' can decode numbers back into useful names when the
  57     numbers are unique.
  58
  59 (4) People looking for ioctls can grep for them more easily when
  60     this convention is used to define the ioctl numbers.
  61
  62 (5) When following the convention, the driver code can use generic
  63     code to copy the parameters between user and kernel space.
  64
  65 This table lists ioctls visible from user land for Linux/x86.  It contains
  66 most drivers up to 2.6.31, but I know I am missing some.  There has been
  67 no attempt to list non-X86 architectures or ioctls from drivers/staging/.
  68
  69 ====  =====  ======================================================= ================================================================
  70 Code  Seq#    Include File                                           Comments
  71       (hex)
  72 ====  =====  ======================================================= ================================================================
  73 0x00  00-1F  linux/fs.h                                              conflict!
  74 0x00  00-1F  scsi/scsi_ioctl.h                                       conflict!
  75 0x00  00-1F  linux/fb.h                                              conflict!
  76 0x00  00-1F  linux/wavefront.h                                       conflict!
  77 0x02  all    linux/fd.h
  78 0x03  all    linux/hdreg.h
  79 0x04  D2-DC  linux/umsdos_fs.h                                       Dead since 2.6.11, but don't reuse these.
  80 0x06  all    linux/lp.h
  81 0x09  all    linux/raid/md_u.h
  82 0x10  00-0F  drivers/char/s390/vmcp.h
  83 0x10  10-1F  arch/s390/include/uapi/sclp_ctl.h
  84 0x10  20-2F  arch/s390/include/uapi/asm/hypfs.h
  85 0x12  all    linux/fs.h
  86              linux/blkpg.h
  87 0x1b  all                                                            InfiniBand Subsystem
  88                                                                      <http://infiniband.sourceforge.net/>
  89 0x20  all    drivers/cdrom/cm206.h
  90 0x22  all    scsi/sg.h
  91 '!'   00-1F  uapi/linux/seccomp.h
  92 '#'   00-3F                                                          IEEE 1394 Subsystem
  93                                                                      Block for the entire subsystem
  94 '$'   00-0F  linux/perf_counter.h, linux/perf_event.h
  95 '%'   00-0F  include/uapi/linux/stm.h                                System Trace Module subsystem
  96                                                                      <mailto:alexander.shishkin@linux.intel.com>
  97 '&'   00-07  drivers/firewire/nosy-user.h
  98 '1'   00-1F  linux/timepps.h                                         PPS kit from Ulrich Windl
  99                                                                      <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/>
 100 '2'   01-04  linux/i2o.h
 101 '3'   00-0F  drivers/s390/char/raw3270.h                             conflict!
 102 '3'   00-1F  linux/suspend_ioctls.h,                                 conflict!
 103              kernel/power/user.c
 104 '8'   all                                                            SNP8023 advanced NIC card
 105                                                                      <mailto:mcr@solidum.com>
 106 ';'   64-7F  linux/vfio.h
 107 '@'   00-0F  linux/radeonfb.h                                        conflict!
 108 '@'   00-0F  drivers/video/aty/aty128fb.c                            conflict!
 109 'A'   00-1F  linux/apm_bios.h                                        conflict!
 110 'A'   00-0F  linux/agpgart.h,                                        conflict!
 111              drivers/char/agp/compat_ioctl.h
 112 'A'   00-7F  sound/asound.h                                          conflict!
 113 'B'   00-1F  linux/cciss_ioctl.h                                     conflict!
 114 'B'   00-0F  include/linux/pmu.h                                     conflict!
 115 'B'   C0-FF  advanced bbus                                           <mailto:maassen@uni-freiburg.de>
 116 'C'   all    linux/soundcard.h                                       conflict!
 117 'C'   01-2F  linux/capi.h                                            conflict!
 118 'C'   F0-FF  drivers/net/wan/cosa.h                                  conflict!
 119 'D'   all    arch/s390/include/asm/dasd.h
 120 'D'   40-5F  drivers/scsi/dpt/dtpi_ioctl.h
 121 'D'   05     drivers/scsi/pmcraid.h
 122 'E'   all    linux/input.h                                           conflict!
 123 'E'   00-0F  xen/evtchn.h                                            conflict!
 124 'F'   all    linux/fb.h                                              conflict!
 125 'F'   01-02  drivers/scsi/pmcraid.h                                  conflict!
 126 'F'   20     drivers/video/fsl-diu-fb.h                              conflict!
 127 'F'   20     drivers/video/intelfb/intelfb.h                         conflict!
 128 'F'   20     linux/ivtvfb.h                                          conflict!
 129 'F'   20     linux/matroxfb.h                                        conflict!
 130 'F'   20     drivers/video/aty/atyfb_base.c                          conflict!
 131 'F'   00-0F  video/da8xx-fb.h                                        conflict!
 132 'F'   80-8F  linux/arcfb.h                                           conflict!
 133 'F'   DD     video/sstfb.h                                           conflict!
 134 'G'   00-3F  drivers/misc/sgi-gru/grulib.h                           conflict!
 135 'H'   00-7F  linux/hiddev.h                                          conflict!
 136 'H'   00-0F  linux/hidraw.h                                          conflict!
 137 'H'   01     linux/mei.h                                             conflict!
 138 'H'   02     linux/mei.h                                             conflict!
 139 'H'   03     linux/mei.h                                             conflict!
 140 'H'   00-0F  sound/asound.h                                          conflict!
 141 'H'   20-40  sound/asound_fm.h                                       conflict!
 142 'H'   80-8F  sound/sfnt_info.h                                       conflict!
 143 'H'   10-8F  sound/emu10k1.h                                         conflict!
 144 'H'   10-1F  sound/sb16_csp.h                                        conflict!
 145 'H'   10-1F  sound/hda_hwdep.h                                       conflict!
 146 'H'   40-4F  sound/hdspm.h                                           conflict!
 147 'H'   40-4F  sound/hdsp.h                                            conflict!
 148 'H'   90     sound/usb/usx2y/usb_stream.h
 149 'H'   00-0F  uapi/misc/habanalabs.h                                  conflict!
 150 'H'   A0     uapi/linux/usb/cdc-wdm.h
 151 'H'   C0-F0  net/bluetooth/hci.h                                     conflict!
 152 'H'   C0-DF  net/bluetooth/hidp/hidp.h                               conflict!
 153 'H'   C0-DF  net/bluetooth/cmtp/cmtp.h                               conflict!
 154 'H'   C0-DF  net/bluetooth/bnep/bnep.h                               conflict!
 155 'H'   F1     linux/hid-roccat.h                                      <mailto:erazor_de@users.sourceforge.net>
 156 'H'   F8-FA  sound/firewire.h
 157 'I'   all    linux/isdn.h                                            conflict!
 158 'I'   00-0F  drivers/isdn/divert/isdn_divert.h                       conflict!
 159 'I'   40-4F  linux/mISDNif.h                                         conflict!
 160 'J'   00-1F  drivers/scsi/gdth_ioctl.h
 161 'K'   all    linux/kd.h
 162 'L'   00-1F  linux/loop.h                                            conflict!
 163 'L'   10-1F  drivers/scsi/mpt3sas/mpt3sas_ctl.h                      conflict!
 164 'L'   20-2F  linux/lightnvm.h
 165 'L'   E0-FF  linux/ppdd.h                                            encrypted disk device driver
 166                                                                      <http://linux01.gwdg.de/~alatham/ppdd.html>
 167 'M'   all    linux/soundcard.h                                       conflict!
 168 'M'   01-16  mtd/mtd-abi.h                                           conflict!
 169       and    drivers/mtd/mtdchar.c
 170 'M'   01-03  drivers/scsi/megaraid/megaraid_sas.h
 171 'M'   00-0F  drivers/video/fsl-diu-fb.h                              conflict!
 172 'N'   00-1F  drivers/usb/scanner.h
 173 'N'   40-7F  drivers/block/nvme.c
 174 'O'   00-06  mtd/ubi-user.h                                          UBI
 175 'P'   all    linux/soundcard.h                                       conflict!
 176 'P'   60-6F  sound/sscape_ioctl.h                                    conflict!
 177 'P'   00-0F  drivers/usb/class/usblp.c                               conflict!
 178 'P'   01-09  drivers/misc/pci_endpoint_test.c                        conflict!
 179 'Q'   all    linux/soundcard.h
 180 'R'   00-1F  linux/random.h                                          conflict!
 181 'R'   01     linux/rfkill.h                                          conflict!
 182 'R'   C0-DF  net/bluetooth/rfcomm.h
 183 'S'   all    linux/cdrom.h                                           conflict!
 184 'S'   80-81  scsi/scsi_ioctl.h                                       conflict!
 185 'S'   82-FF  scsi/scsi.h                                             conflict!
 186 'S'   00-7F  sound/asequencer.h                                      conflict!
 187 'T'   all    linux/soundcard.h                                       conflict!
 188 'T'   00-AF  sound/asound.h                                          conflict!
 189 'T'   all    arch/x86/include/asm/ioctls.h                           conflict!
 190 'T'   C0-DF  linux/if_tun.h                                          conflict!
 191 'U'   all    sound/asound.h                                          conflict!
 192 'U'   00-CF  linux/uinput.h                                          conflict!
 193 'U'   00-EF  linux/usbdevice_fs.h
 194 'U'   C0-CF  drivers/bluetooth/hci_uart.h
 195 'V'   all    linux/vt.h                                              conflict!
 196 'V'   all    linux/videodev2.h                                       conflict!
 197 'V'   C0     linux/ivtvfb.h                                          conflict!
 198 'V'   C0     linux/ivtv.h                                            conflict!
 199 'V'   C0     media/davinci/vpfe_capture.h                            conflict!
 200 'V'   C0     media/si4713.h                                          conflict!
 201 'W'   00-1F  linux/watchdog.h                                        conflict!
 202 'W'   00-1F  linux/wanrouter.h                                       conflict! (pre 3.9)
 203 'W'   00-3F  sound/asound.h                                          conflict!
 204 'W'   40-5F  drivers/pci/switch/switchtec.c
 205 'W'   60-61  linux/watch_queue.h
 206 'X'   all    fs/xfs/xfs_fs.h,                                        conflict!
 207              fs/xfs/linux-2.6/xfs_ioctl32.h,
 208              include/linux/falloc.h,
 209              linux/fs.h,
 210 'X'   all    fs/ocfs2/ocfs_fs.h                                      conflict!
 211 'X'   01     linux/pktcdvd.h                                         conflict!
 212 'Y'   all    linux/cyclades.h
 213 'Z'   14-15  drivers/message/fusion/mptctl.h
 214 '['   00-3F  linux/usb/tmc.h                                         USB Test and Measurement Devices
 215                                                                      <mailto:gregkh@linuxfoundation.org>
 216 'a'   all    linux/atm*.h, linux/sonet.h                             ATM on linux
 217                                                                      <http://lrcwww.epfl.ch/>
 218 'a'   00-0F  drivers/crypto/qat/qat_common/adf_cfg_common.h          conflict! qat driver
 219 'b'   00-FF                                                          conflict! bit3 vme host bridge
 220                                                                      <mailto:natalia@nikhefk.nikhef.nl>
 221 'c'   all    linux/cm4000_cs.h                                       conflict!
 222 'c'   00-7F  linux/comstats.h                                        conflict!
 223 'c'   00-7F  linux/coda.h                                            conflict!
 224 'c'   00-1F  linux/chio.h                                            conflict!
 225 'c'   80-9F  arch/s390/include/asm/chsc.h                            conflict!
 226 'c'   A0-AF  arch/x86/include/asm/msr.h conflict!
 227 'd'   00-FF  linux/char/drm/drm.h                                    conflict!
 228 'd'   02-40  pcmcia/ds.h                                             conflict!
 229 'd'   F0-FF  linux/digi1.h
 230 'e'   all    linux/digi1.h                                           conflict!
 231 'f'   00-1F  linux/ext2_fs.h                                         conflict!
 232 'f'   00-1F  linux/ext3_fs.h                                         conflict!
 233 'f'   00-0F  fs/jfs/jfs_dinode.h                                     conflict!
 234 'f'   00-0F  fs/ext4/ext4.h                                          conflict!
 235 'f'   00-0F  linux/fs.h                                              conflict!
 236 'f'   00-0F  fs/ocfs2/ocfs2_fs.h                                     conflict!
 237 'f'   13-27  linux/fscrypt.h
 238 'f'   81-8F  linux/fsverity.h
 239 'g'   00-0F  linux/usb/gadgetfs.h
 240 'g'   20-2F  linux/usb/g_printer.h
 241 'h'   00-7F                                                          conflict! Charon filesystem
 242                                                                      <mailto:zapman@interlan.net>
 243 'h'   00-1F  linux/hpet.h                                            conflict!
 244 'h'   80-8F  fs/hfsplus/ioctl.c
 245 'i'   00-3F  linux/i2o-dev.h                                         conflict!
 246 'i'   0B-1F  linux/ipmi.h                                            conflict!
 247 'i'   80-8F  linux/i8k.h
 248 'j'   00-3F  linux/joystick.h
 249 'k'   00-0F  linux/spi/spidev.h                                      conflict!
 250 'k'   00-05  video/kyro.h                                            conflict!
 251 'k'   10-17  linux/hsi/hsi_char.h                                    HSI character device
 252 'l'   00-3F  linux/tcfs_fs.h                                         transparent cryptographic file system
 253                                                                      <http://web.archive.org/web/%2A/http://mikonos.dia.unisa.it/tcfs>
 254 'l'   40-7F  linux/udf_fs_i.h                                        in development:
 255                                                                      <http://sourceforge.net/projects/linux-udf/>
 256 'm'   00-09  linux/mmtimer.h                                         conflict!
 257 'm'   all    linux/mtio.h                                            conflict!
 258 'm'   all    linux/soundcard.h                                       conflict!
 259 'm'   all    linux/synclink.h                                        conflict!
 260 'm'   00-19  drivers/message/fusion/mptctl.h                         conflict!
 261 'm'   00     drivers/scsi/megaraid/megaraid_ioctl.h                  conflict!
 262 'n'   00-7F  linux/ncp_fs.h and fs/ncpfs/ioctl.c
 263 'n'   80-8F  uapi/linux/nilfs2_api.h                                 NILFS2
 264 'n'   E0-FF  linux/matroxfb.h                                        matroxfb
 265 'o'   00-1F  fs/ocfs2/ocfs2_fs.h                                     OCFS2
 266 'o'   00-03  mtd/ubi-user.h                                          conflict! (OCFS2 and UBI overlaps)
 267 'o'   40-41  mtd/ubi-user.h                                          UBI
 268 'o'   01-A1  `linux/dvb/*.h`                                         DVB
 269 'p'   00-0F  linux/phantom.h                                         conflict! (OpenHaptics needs this)
 270 'p'   00-1F  linux/rtc.h                                             conflict!
 271 'p'   40-7F  linux/nvram.h
 272 'p'   80-9F  linux/ppdev.h                                           user-space parport
 273                                                                      <mailto:tim@cyberelk.net>
 274 'p'   A1-A5  linux/pps.h                                             LinuxPPS
 275                                                                      <mailto:giometti@linux.it>
 276 'q'   00-1F  linux/serio.h
 277 'q'   80-FF  linux/telephony.h                                       Internet PhoneJACK, Internet LineJACK
 278              linux/ixjuser.h                                         <http://web.archive.org/web/%2A/http://www.quicknet.net>
 279 'r'   00-1F  linux/msdos_fs.h and fs/fat/dir.c
 280 's'   all    linux/cdk.h
 281 't'   00-7F  linux/ppp-ioctl.h
 282 't'   80-8F  linux/isdn_ppp.h
 283 't'   90-91  linux/toshiba.h                                         toshiba and toshiba_acpi SMM
 284 'u'   00-1F  linux/smb_fs.h                                          gone
 285 'u'   20-3F  linux/uvcvideo.h                                        USB video class host driver
 286 'u'   40-4f  linux/udmabuf.h                                         userspace dma-buf misc device
 287 'v'   00-1F  linux/ext2_fs.h                                         conflict!
 288 'v'   00-1F  linux/fs.h                                              conflict!
 289 'v'   00-0F  linux/sonypi.h                                          conflict!
 290 'v'   00-0F  media/v4l2-subdev.h                                     conflict!
 291 'v'   20-27  arch/powerpc/include/uapi/asm/vas-api.h                 VAS API
 292 'v'   C0-FF  linux/meye.h                                            conflict!
 293 'w'   all                                                            CERN SCI driver
 294 'y'   00-1F                                                          packet based user level communications
 295                                                                      <mailto:zapman@interlan.net>
 296 'z'   00-3F                                                          CAN bus card conflict!
 297                                                                      <mailto:hdstich@connectu.ulm.circular.de>
 298 'z'   40-7F                                                          CAN bus card conflict!
 299                                                                      <mailto:oe@port.de>
 300 'z'   10-4F  drivers/s390/crypto/zcrypt_api.h                        conflict!
 301 '|'   00-7F  linux/media.h
 302 0x80  00-1F  linux/fb.h
 303 0x89  00-06  arch/x86/include/asm/sockios.h
 304 0x89  0B-DF  linux/sockios.h
 305 0x89  E0-EF  linux/sockios.h                                         SIOCPROTOPRIVATE range
 306 0x89  E0-EF  linux/dn.h                                              PROTOPRIVATE range
 307 0x89  F0-FF  linux/sockios.h                                         SIOCDEVPRIVATE range
 308 0x8B  all    linux/wireless.h
 309 0x8C  00-3F                                                          WiNRADiO driver
 310                                                                      <http://www.winradio.com.au/>
 311 0x90  00     drivers/cdrom/sbpcd.h
 312 0x92  00-0F  drivers/usb/mon/mon_bin.c
 313 0x93  60-7F  linux/auto_fs.h
 314 0x94  all    fs/btrfs/ioctl.h                                        Btrfs filesystem
 315              and linux/fs.h                                          some lifted to vfs/generic
 316 0x97  00-7F  fs/ceph/ioctl.h                                         Ceph file system
 317 0x99  00-0F                                                          537-Addinboard driver
 318                                                                      <mailto:buk@buks.ipn.de>
 319 0xA0  all    linux/sdp/sdp.h                                         Industrial Device Project
 320                                                                      <mailto:kenji@bitgate.com>
 321 0xA1  0      linux/vtpm_proxy.h                                      TPM Emulator Proxy Driver
 322 0xA3  80-8F                                                          Port ACL  in development:
 323                                                                      <mailto:tlewis@mindspring.com>
 324 0xA3  90-9F  linux/dtlk.h
 325 0xA4  00-1F  uapi/linux/tee.h                                        Generic TEE subsystem
 326 0xA4  00-1F  uapi/asm/sgx.h                                          <mailto:linux-sgx@vger.kernel.org>
 327 0xAA  00-3F  linux/uapi/linux/userfaultfd.h
 328 0xAB  00-1F  linux/nbd.h
 329 0xAC  00-1F  linux/raw.h
 330 0xAD  00                                                             Netfilter device in development:
 331                                                                      <mailto:rusty@rustcorp.com.au>
 332 0xAE  00-1F  linux/kvm.h                                             Kernel-based Virtual Machine
 333                                                                      <mailto:kvm@vger.kernel.org>
 334 0xAE  40-FF  linux/kvm.h                                             Kernel-based Virtual Machine
 335                                                                      <mailto:kvm@vger.kernel.org>
 336 0xAE  20-3F  linux/nitro_enclaves.h                                  Nitro Enclaves
 337 0xAF  00-1F  linux/fsl_hypervisor.h                                  Freescale hypervisor
 338 0xB0  all                                                            RATIO devices in development:
 339                                                                      <mailto:vgo@ratio.de>
 340 0xB1  00-1F                                                          PPPoX
 341                                                                      <mailto:mostrows@styx.uwaterloo.ca>
 342 0xB3  00     linux/mmc/ioctl.h
 343 0xB4  00-0F  linux/gpio.h                                            <mailto:linux-gpio@vger.kernel.org>
 344 0xB5  00-0F  uapi/linux/rpmsg.h                                      <mailto:linux-remoteproc@vger.kernel.org>
 345 0xB6  all    linux/fpga-dfl.h
 346 0xB7  all    uapi/linux/remoteproc_cdev.h                            <mailto:linux-remoteproc@vger.kernel.org>
 347 0xC0  00-0F  linux/usb/iowarrior.h
 348 0xCA  00-0F  uapi/misc/cxl.h
 349 0xCA  10-2F  uapi/misc/ocxl.h
 350 0xCA  80-BF  uapi/scsi/cxlflash_ioctl.h
 351 0xCB  00-1F                                                          CBM serial IEC bus in development:
 352                                                                      <mailto:michael.klein@puffin.lb.shuttle.de>
 353 0xCC  00-0F  drivers/misc/ibmvmc.h                                   pseries VMC driver
 354 0xCD  01     linux/reiserfs_fs.h
 355 0xCF  02     fs/cifs/ioctl.c
 356 0xDB  00-0F  drivers/char/mwave/mwavepub.h
 357 0xDD  00-3F                                                          ZFCP device driver see drivers/s390/scsi/
 358                                                                      <mailto:aherrman@de.ibm.com>
 359 0xE5  00-3F  linux/fuse.h
 360 0xEC  00-01  drivers/platform/chrome/cros_ec_dev.h                   ChromeOS EC driver
 361 0xF3  00-3F  drivers/usb/misc/sisusbvga/sisusb.h                     sisfb (in development)
 362                                                                      <mailto:thomas@winischhofer.net>
 363 0xF6  all                                                            LTTng Linux Trace Toolkit Next Generation
 364                                                                      <mailto:mathieu.desnoyers@efficios.com>
 365 0xFD  all    linux/dm-ioctl.h
 366 0xFE  all    linux/isst_if.h
 367 ====  =====  ======================================================= ================================================================