1Ioctl Numbers 219 October 1999 3Michael Elizabeth Chastain 4<mec@shout.net> 5 6If you are adding new ioctl's to the kernel, you should use the _IO 7macros 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 15system calls 'write' and 'read'. For example, a SET_FOO ioctl would 16be _IOW, although the kernel would actually read data from user space; 17a GET_FOO ioctl would be _IOR, although the kernel would actually write 18data to user space. 19 20The first argument to _IO, _IOW, _IOR, or _IOWR is an identifying letter 21or number from the table below. Because of the large number of drivers, 22many drivers share a partial letter with other drivers. 23 24If you are writing a driver for a new device and need a letter, pick an 25unused block with enough room for expansion: 32 to 256 ioctl commands. 26You can register the block by patching this file and submitting the 27patch to Linus Torvalds. Or you can e-mail me at <mec@shout.net> and 28I'll register one for you. 29 30The second argument to _IO, _IOW, _IOR, or _IOWR is a sequence number 31to 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 33out of the kernel (e.g. 'int' or 'struct foo'). NOTE! Do NOT use 34sizeof(arg) as the third argument as this results in your ioctl thinking 35it passes an argument of type size_t. 36 37Some devices use their major number as the identifier; this is OK, as 38long as it is unique. Some devices are irregular and don't follow any 39convention at all. 40 41Following 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 59This table lists ioctls visible from user land for Linux/x86. It contains 60most drivers up to 2.6.31, but I know I am missing some. There has been 61no attempt to list non-X86 architectures or ioctls from drivers/staging/. 62 63Code Seq#(hex) Include File Comments 64======================================================== 650x00 00-1F linux/fs.h conflict! 660x00 00-1F scsi/scsi_ioctl.h conflict! 670x00 00-1F linux/fb.h conflict! 680x00 00-1F linux/wavefront.h conflict! 690x02 all linux/fd.h 700x03 all linux/hdreg.h 710x04 D2-DC linux/umsdos_fs.h Dead since 2.6.11, but don't reuse these. 720x06 all linux/lp.h 730x09 all linux/raid/md_u.h 740x10 00-0F drivers/char/s390/vmcp.h 750x10 10-1F arch/s390/include/uapi/sclp_ctl.h 760x10 20-2F arch/s390/include/uapi/asm/hypfs.h 770x12 all linux/fs.h 78 linux/blkpg.h 790x1b all InfiniBand Subsystem <http://infiniband.sourceforge.net/> 800x20 all drivers/cdrom/cm206.h 810x22 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'W' 40-5F drivers/pci/switch/switchtec.c 195'X' all fs/xfs/xfs_fs.h conflict! 196 and fs/xfs/linux-2.6/xfs_ioctl32.h 197 and include/linux/falloc.h 198 and linux/fs.h 199'X' all fs/ocfs2/ocfs_fs.h conflict! 200'X' 01 linux/pktcdvd.h conflict! 201'Y' all linux/cyclades.h 202'Z' 14-15 drivers/message/fusion/mptctl.h 203'[' 00-07 linux/usb/tmc.h USB Test and Measurement Devices 204 <mailto:gregkh@linuxfoundation.org> 205'a' all linux/atm*.h, linux/sonet.h ATM on linux 206 <http://lrcwww.epfl.ch/> 207'a' 00-0F drivers/crypto/qat/qat_common/adf_cfg_common.h conflict! qat driver 208'b' 00-FF conflict! bit3 vme host bridge 209 <mailto:natalia@nikhefk.nikhef.nl> 210'c' all linux/cm4000_cs.h conflict! 211'c' 00-7F linux/comstats.h conflict! 212'c' 00-7F linux/coda.h conflict! 213'c' 00-1F linux/chio.h conflict! 214'c' 80-9F arch/s390/include/asm/chsc.h conflict! 215'c' A0-AF arch/x86/include/asm/msr.h conflict! 216'd' 00-FF linux/char/drm/drm.h conflict! 217'd' 02-40 pcmcia/ds.h conflict! 218'd' F0-FF linux/digi1.h 219'e' all linux/digi1.h conflict! 220'e' 00-1F drivers/net/irda/irtty-sir.h conflict! 221'f' 00-1F linux/ext2_fs.h conflict! 222'f' 00-1F linux/ext3_fs.h conflict! 223'f' 00-0F fs/jfs/jfs_dinode.h conflict! 224'f' 00-0F fs/ext4/ext4.h conflict! 225'f' 00-0F linux/fs.h conflict! 226'f' 00-0F fs/ocfs2/ocfs2_fs.h conflict! 227'g' 00-0F linux/usb/gadgetfs.h 228'g' 20-2F linux/usb/g_printer.h 229'h' 00-7F conflict! Charon filesystem 230 <mailto:zapman@interlan.net> 231'h' 00-1F linux/hpet.h conflict! 232'h' 80-8F fs/hfsplus/ioctl.c 233'i' 00-3F linux/i2o-dev.h conflict! 234'i' 0B-1F linux/ipmi.h conflict! 235'i' 80-8F linux/i8k.h 236'j' 00-3F linux/joystick.h 237'k' 00-0F linux/spi/spidev.h conflict! 238'k' 00-05 video/kyro.h conflict! 239'k' 10-17 linux/hsi/hsi_char.h HSI character device 240'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system 241 <http://web.archive.org/web/*/http://mikonos.dia.unisa.it/tcfs> 242'l' 40-7F linux/udf_fs_i.h in development: 243 <http://sourceforge.net/projects/linux-udf/> 244'm' 00-09 linux/mmtimer.h conflict! 245'm' all linux/mtio.h conflict! 246'm' all linux/soundcard.h conflict! 247'm' all linux/synclink.h conflict! 248'm' 00-19 drivers/message/fusion/mptctl.h conflict! 249'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict! 250'm' 00-1F net/irda/irmod.h conflict! 251'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c 252'n' 80-8F uapi/linux/nilfs2_api.h NILFS2 253'n' E0-FF linux/matroxfb.h matroxfb 254'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2 255'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps) 256'o' 40-41 mtd/ubi-user.h UBI 257'o' 01-A1 linux/dvb/*.h DVB 258'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this) 259'p' 00-1F linux/rtc.h conflict! 260'p' 00-3F linux/mc146818rtc.h conflict! 261'p' 40-7F linux/nvram.h 262'p' 80-9F linux/ppdev.h user-space parport 263 <mailto:tim@cyberelk.net> 264'p' A1-A5 linux/pps.h LinuxPPS 265 <mailto:giometti@linux.it> 266'q' 00-1F linux/serio.h 267'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK 268 linux/ixjuser.h <http://web.archive.org/web/*/http://www.quicknet.net> 269'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c 270's' all linux/cdk.h 271't' 00-7F linux/ppp-ioctl.h 272't' 80-8F linux/isdn_ppp.h 273't' 90-91 linux/toshiba.h toshiba and toshiba_acpi SMM 274'u' 00-1F linux/smb_fs.h gone 275'u' 20-3F linux/uvcvideo.h USB video class host driver 276'v' 00-1F linux/ext2_fs.h conflict! 277'v' 00-1F linux/fs.h conflict! 278'v' 00-0F linux/sonypi.h conflict! 279'v' C0-FF linux/meye.h conflict! 280'w' all CERN SCI driver 281'y' 00-1F packet based user level communications 282 <mailto:zapman@interlan.net> 283'z' 00-3F CAN bus card conflict! 284 <mailto:hdstich@connectu.ulm.circular.de> 285'z' 40-7F CAN bus card conflict! 286 <mailto:oe@port.de> 287'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict! 288'|' 00-7F linux/media.h 2890x80 00-1F linux/fb.h 2900x89 00-06 arch/x86/include/asm/sockios.h 2910x89 0B-DF linux/sockios.h 2920x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range 2930x89 E0-EF linux/dn.h PROTOPRIVATE range 2940x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range 2950x8B all linux/wireless.h 2960x8C 00-3F WiNRADiO driver 297 <http://www.winradio.com.au/> 2980x90 00 drivers/cdrom/sbpcd.h 2990x92 00-0F drivers/usb/mon/mon_bin.c 3000x93 60-7F linux/auto_fs.h 3010x94 all fs/btrfs/ioctl.h 3020x97 00-7F fs/ceph/ioctl.h Ceph file system 3030x99 00-0F 537-Addinboard driver 304 <mailto:buk@buks.ipn.de> 3050xA0 all linux/sdp/sdp.h Industrial Device Project 306 <mailto:kenji@bitgate.com> 3070xA1 0 linux/vtpm_proxy.h TPM Emulator Proxy Driver 3080xA2 00-0F arch/tile/include/asm/hardwall.h 3090xA3 80-8F Port ACL in development: 310 <mailto:tlewis@mindspring.com> 3110xA3 90-9F linux/dtlk.h 3120xA4 00-1F uapi/linux/tee.h Generic TEE subsystem 3130xAA 00-3F linux/uapi/linux/userfaultfd.h 3140xAB 00-1F linux/nbd.h 3150xAC 00-1F linux/raw.h 3160xAD 00 Netfilter device in development: 317 <mailto:rusty@rustcorp.com.au> 3180xAE all linux/kvm.h Kernel-based Virtual Machine 319 <mailto:kvm@vger.kernel.org> 3200xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor 3210xB0 all RATIO devices in development: 322 <mailto:vgo@ratio.de> 3230xB1 00-1F PPPoX <mailto:mostrows@styx.uwaterloo.ca> 3240xB3 00 linux/mmc/ioctl.h 3250xB4 00-0F linux/gpio.h <mailto:linux-gpio@vger.kernel.org> 3260xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc@vger.kernel.org> 3270xC0 00-0F linux/usb/iowarrior.h 3280xCA 00-0F uapi/misc/cxl.h 3290xCA 80-BF uapi/scsi/cxlflash_ioctl.h 3300xCB 00-1F CBM serial IEC bus in development: 331 <mailto:michael.klein@puffin.lb.shuttle.de> 3320xCD 01 linux/reiserfs_fs.h 3330xCF 02 fs/cifs/ioctl.c 3340xDB 00-0F drivers/char/mwave/mwavepub.h 3350xDD 00-3F ZFCP device driver see drivers/s390/scsi/ 336 <mailto:aherrman@de.ibm.com> 3370xE5 00-3F linux/fuse.h 3380xEC 00-01 drivers/platform/chrome/cros_ec_dev.h ChromeOS EC driver 3390xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development) 340 <mailto:thomas@winischhofer.net> 3410xF4 00-1F video/mbxfb.h mbxfb 342 <mailto:raph@8d.com> 3430xF6 all LTTng Linux Trace Toolkit Next Generation 344 <mailto:mathieu.desnoyers@efficios.com> 3450xFD all linux/dm-ioctl.h 346