1============= 2Ioctl Numbers 3============= 4 519 October 1999 6 7Michael Elizabeth Chastain 8<mec@shout.net> 9 10If you are adding new ioctl's to the kernel, you should use the _IO 11macros 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 21system calls 'write' and 'read'. For example, a SET_FOO ioctl would 22be _IOW, although the kernel would actually read data from user space; 23a GET_FOO ioctl would be _IOR, although the kernel would actually write 24data to user space. 25 26The first argument to _IO, _IOW, _IOR, or _IOWR is an identifying letter 27or number from the table below. Because of the large number of drivers, 28many drivers share a partial letter with other drivers. 29 30If you are writing a driver for a new device and need a letter, pick an 31unused block with enough room for expansion: 32 to 256 ioctl commands. 32You can register the block by patching this file and submitting the 33patch to Linus Torvalds. Or you can e-mail me at <mec@shout.net> and 34I'll register one for you. 35 36The second argument to _IO, _IOW, _IOR, or _IOWR is a sequence number 37to 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 39out of the kernel (e.g. 'int' or 'struct foo'). NOTE! Do NOT use 40sizeof(arg) as the third argument as this results in your ioctl thinking 41it passes an argument of type size_t. 42 43Some devices use their major number as the identifier; this is OK, as 44long as it is unique. Some devices are irregular and don't follow any 45convention at all. 46 47Following 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 65This table lists ioctls visible from user land for Linux/x86. It contains 66most drivers up to 2.6.31, but I know I am missing some. There has been 67no attempt to list non-X86 architectures or ioctls from drivers/staging/. 68 69==== ===== ======================================================= ================================================================ 70Code Seq# Include File Comments 71 (hex) 72==== ===== ======================================================= ================================================================ 730x00 00-1F linux/fs.h conflict! 740x00 00-1F scsi/scsi_ioctl.h conflict! 750x00 00-1F linux/fb.h conflict! 760x00 00-1F linux/wavefront.h conflict! 770x02 all linux/fd.h 780x03 all linux/hdreg.h 790x04 D2-DC linux/umsdos_fs.h Dead since 2.6.11, but don't reuse these. 800x06 all linux/lp.h 810x09 all linux/raid/md_u.h 820x10 00-0F drivers/char/s390/vmcp.h 830x10 10-1F arch/s390/include/uapi/sclp_ctl.h 840x10 20-2F arch/s390/include/uapi/asm/hypfs.h 850x12 all linux/fs.h 86 linux/blkpg.h 870x1b all InfiniBand Subsystem 88 <http://infiniband.sourceforge.net/> 890x20 all drivers/cdrom/cm206.h 900x22 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'G' 00-0F linux/gigaset_dev.h conflict! 136'H' 00-7F linux/hiddev.h conflict! 137'H' 00-0F linux/hidraw.h conflict! 138'H' 01 linux/mei.h conflict! 139'H' 02 linux/mei.h conflict! 140'H' 03 linux/mei.h conflict! 141'H' 00-0F sound/asound.h conflict! 142'H' 20-40 sound/asound_fm.h conflict! 143'H' 80-8F sound/sfnt_info.h conflict! 144'H' 10-8F sound/emu10k1.h conflict! 145'H' 10-1F sound/sb16_csp.h conflict! 146'H' 10-1F sound/hda_hwdep.h conflict! 147'H' 40-4F sound/hdspm.h conflict! 148'H' 40-4F sound/hdsp.h conflict! 149'H' 90 sound/usb/usx2y/usb_stream.h 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'X' all fs/xfs/xfs_fs.h, conflict! 206 fs/xfs/linux-2.6/xfs_ioctl32.h, 207 include/linux/falloc.h, 208 linux/fs.h, 209'X' all fs/ocfs2/ocfs_fs.h conflict! 210'X' 01 linux/pktcdvd.h conflict! 211'Y' all linux/cyclades.h 212'Z' 14-15 drivers/message/fusion/mptctl.h 213'[' 00-3F linux/usb/tmc.h USB Test and Measurement Devices 214 <mailto:gregkh@linuxfoundation.org> 215'a' all linux/atm*.h, linux/sonet.h ATM on linux 216 <http://lrcwww.epfl.ch/> 217'a' 00-0F drivers/crypto/qat/qat_common/adf_cfg_common.h conflict! qat driver 218'b' 00-FF conflict! bit3 vme host bridge 219 <mailto:natalia@nikhefk.nikhef.nl> 220'c' all linux/cm4000_cs.h conflict! 221'c' 00-7F linux/comstats.h conflict! 222'c' 00-7F linux/coda.h conflict! 223'c' 00-1F linux/chio.h conflict! 224'c' 80-9F arch/s390/include/asm/chsc.h conflict! 225'c' A0-AF arch/x86/include/asm/msr.h conflict! 226'd' 00-FF linux/char/drm/drm.h conflict! 227'd' 02-40 pcmcia/ds.h conflict! 228'd' F0-FF linux/digi1.h 229'e' all linux/digi1.h conflict! 230'f' 00-1F linux/ext2_fs.h conflict! 231'f' 00-1F linux/ext3_fs.h conflict! 232'f' 00-0F fs/jfs/jfs_dinode.h conflict! 233'f' 00-0F fs/ext4/ext4.h conflict! 234'f' 00-0F linux/fs.h conflict! 235'f' 00-0F fs/ocfs2/ocfs2_fs.h conflict! 236'f' 13-27 linux/fscrypt.h 237'f' 81-8F linux/fsverity.h 238'g' 00-0F linux/usb/gadgetfs.h 239'g' 20-2F linux/usb/g_printer.h 240'h' 00-7F conflict! Charon filesystem 241 <mailto:zapman@interlan.net> 242'h' 00-1F linux/hpet.h conflict! 243'h' 80-8F fs/hfsplus/ioctl.c 244'i' 00-3F linux/i2o-dev.h conflict! 245'i' 0B-1F linux/ipmi.h conflict! 246'i' 80-8F linux/i8k.h 247'j' 00-3F linux/joystick.h 248'k' 00-0F linux/spi/spidev.h conflict! 249'k' 00-05 video/kyro.h conflict! 250'k' 10-17 linux/hsi/hsi_char.h HSI character device 251'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system 252 <http://web.archive.org/web/%2A/http://mikonos.dia.unisa.it/tcfs> 253'l' 40-7F linux/udf_fs_i.h in development: 254 <http://sourceforge.net/projects/linux-udf/> 255'm' 00-09 linux/mmtimer.h conflict! 256'm' all linux/mtio.h conflict! 257'm' all linux/soundcard.h conflict! 258'm' all linux/synclink.h conflict! 259'm' 00-19 drivers/message/fusion/mptctl.h conflict! 260'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict! 261'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c 262'n' 80-8F uapi/linux/nilfs2_api.h NILFS2 263'n' E0-FF linux/matroxfb.h matroxfb 264'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2 265'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps) 266'o' 40-41 mtd/ubi-user.h UBI 267'o' 01-A1 `linux/dvb/*.h` DVB 268'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this) 269'p' 00-1F linux/rtc.h conflict! 270'p' 00-3F linux/mc146818rtc.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' C0-FF linux/meye.h conflict! 292'w' all CERN SCI driver 293'y' 00-1F packet based user level communications 294 <mailto:zapman@interlan.net> 295'z' 00-3F CAN bus card conflict! 296 <mailto:hdstich@connectu.ulm.circular.de> 297'z' 40-7F CAN bus card conflict! 298 <mailto:oe@port.de> 299'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict! 300'|' 00-7F linux/media.h 3010x80 00-1F linux/fb.h 3020x89 00-06 arch/x86/include/asm/sockios.h 3030x89 0B-DF linux/sockios.h 3040x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range 3050x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range 3060x8B all linux/wireless.h 3070x8C 00-3F WiNRADiO driver 308 <http://www.winradio.com.au/> 3090x90 00 drivers/cdrom/sbpcd.h 3100x92 00-0F drivers/usb/mon/mon_bin.c 3110x93 60-7F linux/auto_fs.h 3120x94 all fs/btrfs/ioctl.h Btrfs filesystem 313 and linux/fs.h some lifted to vfs/generic 3140x97 00-7F fs/ceph/ioctl.h Ceph file system 3150x99 00-0F 537-Addinboard driver 316 <mailto:buk@buks.ipn.de> 3170xA0 all linux/sdp/sdp.h Industrial Device Project 318 <mailto:kenji@bitgate.com> 3190xA1 0 linux/vtpm_proxy.h TPM Emulator Proxy Driver 3200xA3 80-8F Port ACL in development: 321 <mailto:tlewis@mindspring.com> 3220xA3 90-9F linux/dtlk.h 3230xA4 00-1F uapi/linux/tee.h Generic TEE subsystem 3240xAA 00-3F linux/uapi/linux/userfaultfd.h 3250xAB 00-1F linux/nbd.h 3260xAC 00-1F linux/raw.h 3270xAD 00 Netfilter device in development: 328 <mailto:rusty@rustcorp.com.au> 3290xAE all linux/kvm.h Kernel-based Virtual Machine 330 <mailto:kvm@vger.kernel.org> 3310xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor 3320xB0 all RATIO devices in development: 333 <mailto:vgo@ratio.de> 3340xB1 00-1F PPPoX 335 <mailto:mostrows@styx.uwaterloo.ca> 3360xB3 00 linux/mmc/ioctl.h 3370xB4 00-0F linux/gpio.h <mailto:linux-gpio@vger.kernel.org> 3380xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc@vger.kernel.org> 3390xB6 all linux/fpga-dfl.h 3400xC0 00-0F linux/usb/iowarrior.h 3410xCA 00-0F uapi/misc/cxl.h 3420xCA 10-2F uapi/misc/ocxl.h 3430xCA 80-BF uapi/scsi/cxlflash_ioctl.h 3440xCB 00-1F CBM serial IEC bus in development: 345 <mailto:michael.klein@puffin.lb.shuttle.de> 3460xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver 3470xCD 01 linux/reiserfs_fs.h 3480xCF 02 fs/cifs/ioctl.c 3490xDB 00-0F drivers/char/mwave/mwavepub.h 3500xDD 00-3F ZFCP device driver see drivers/s390/scsi/ 351 <mailto:aherrman@de.ibm.com> 3520xE5 00-3F linux/fuse.h 3530xEC 00-01 drivers/platform/chrome/cros_ec_dev.h ChromeOS EC driver 3540xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development) 355 <mailto:thomas@winischhofer.net> 3560xF4 00-1F video/mbxfb.h mbxfb 357 <mailto:raph@8d.com> 3580xF6 all LTTng Linux Trace Toolkit Next Generation 359 <mailto:mathieu.desnoyers@efficios.com> 3600xFD all linux/dm-ioctl.h 3610xFE all linux/isst_if.h 362==== ===== ======================================================= ================================================================ 363