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 750x12 all linux/fs.h 76 linux/blkpg.h 770x1b all InfiniBand Subsystem <http://infiniband.sourceforge.net/> 780x20 all drivers/cdrom/cm206.h 790x22 all scsi/sg.h 80'#' 00-3F IEEE 1394 Subsystem Block for the entire subsystem 81'$' 00-0F linux/perf_counter.h, linux/perf_event.h 82'&' 00-07 drivers/firewire/nosy-user.h 83'1' 00-1F <linux/timepps.h> PPS kit from Ulrich Windl 84 <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/> 85'2' 01-04 linux/i2o.h 86'3' 00-0F drivers/s390/char/raw3270.h conflict! 87'3' 00-1F linux/suspend_ioctls.h conflict! 88 and kernel/power/user.c 89'8' all SNP8023 advanced NIC card 90 <mailto:mcr@solidum.com> 91'@' 00-0F linux/radeonfb.h conflict! 92'@' 00-0F drivers/video/aty/aty128fb.c conflict! 93'A' 00-1F linux/apm_bios.h conflict! 94'A' 00-0F linux/agpgart.h conflict! 95 and drivers/char/agp/compat_ioctl.h 96'A' 00-7F sound/asound.h conflict! 97'B' 00-1F linux/cciss_ioctl.h conflict! 98'B' 00-0F include/linux/pmu.h conflict! 99'B' C0-FF advanced bbus 100 <mailto:maassen@uni-freiburg.de> 101'C' all linux/soundcard.h conflict! 102'C' 01-2F linux/capi.h conflict! 103'C' F0-FF drivers/net/wan/cosa.h conflict! 104'D' all arch/s390/include/asm/dasd.h 105'D' 40-5F drivers/scsi/dpt/dtpi_ioctl.h 106'D' 05 drivers/scsi/pmcraid.h 107'E' all linux/input.h conflict! 108'E' 00-0F xen/evtchn.h conflict! 109'F' all linux/fb.h conflict! 110'F' 01-02 drivers/scsi/pmcraid.h conflict! 111'F' 20 drivers/video/fsl-diu-fb.h conflict! 112'F' 20 drivers/video/intelfb/intelfb.h conflict! 113'F' 20 linux/ivtvfb.h conflict! 114'F' 20 linux/matroxfb.h conflict! 115'F' 20 drivers/video/aty/atyfb_base.c conflict! 116'F' 00-0F video/da8xx-fb.h conflict! 117'F' 80-8F linux/arcfb.h conflict! 118'F' DD video/sstfb.h conflict! 119'G' 00-3F drivers/misc/sgi-gru/grulib.h conflict! 120'G' 00-0F linux/gigaset_dev.h conflict! 121'H' 00-7F linux/hiddev.h conflict! 122'H' 00-0F linux/hidraw.h conflict! 123'H' 00-0F sound/asound.h conflict! 124'H' 20-40 sound/asound_fm.h conflict! 125'H' 80-8F sound/sfnt_info.h conflict! 126'H' 10-8F sound/emu10k1.h conflict! 127'H' 10-1F sound/sb16_csp.h conflict! 128'H' 10-1F sound/hda_hwdep.h conflict! 129'H' 40-4F sound/hdspm.h conflict! 130'H' 40-4F sound/hdsp.h conflict! 131'H' 90 sound/usb/usx2y/usb_stream.h 132'H' C0-F0 net/bluetooth/hci.h conflict! 133'H' C0-DF net/bluetooth/hidp/hidp.h conflict! 134'H' C0-DF net/bluetooth/cmtp/cmtp.h conflict! 135'H' C0-DF net/bluetooth/bnep/bnep.h conflict! 136'H' F1 linux/hid-roccat.h <mailto:erazor_de@users.sourceforge.net> 137'I' all linux/isdn.h conflict! 138'I' 00-0F drivers/isdn/divert/isdn_divert.h conflict! 139'I' 40-4F linux/mISDNif.h conflict! 140'J' 00-1F drivers/scsi/gdth_ioctl.h 141'K' all linux/kd.h 142'L' 00-1F linux/loop.h conflict! 143'L' 10-1F drivers/scsi/mpt2sas/mpt2sas_ctl.h conflict! 144'L' E0-FF linux/ppdd.h encrypted disk device driver 145 <http://linux01.gwdg.de/~alatham/ppdd.html> 146'M' all linux/soundcard.h conflict! 147'M' 01-16 mtd/mtd-abi.h conflict! 148 and drivers/mtd/mtdchar.c 149'M' 01-03 drivers/scsi/megaraid/megaraid_sas.h 150'M' 00-0F drivers/video/fsl-diu-fb.h conflict! 151'N' 00-1F drivers/usb/scanner.h 152'N' 40-7F drivers/block/nvme.c 153'O' 00-06 mtd/ubi-user.h UBI 154'P' all linux/soundcard.h conflict! 155'P' 60-6F sound/sscape_ioctl.h conflict! 156'P' 00-0F drivers/usb/class/usblp.c conflict! 157'Q' all linux/soundcard.h 158'R' 00-1F linux/random.h conflict! 159'R' 01 linux/rfkill.h conflict! 160'R' C0-DF net/bluetooth/rfcomm.h 161'S' all linux/cdrom.h conflict! 162'S' 80-81 scsi/scsi_ioctl.h conflict! 163'S' 82-FF scsi/scsi.h conflict! 164'S' 00-7F sound/asequencer.h conflict! 165'T' all linux/soundcard.h conflict! 166'T' 00-AF sound/asound.h conflict! 167'T' all arch/x86/include/asm/ioctls.h conflict! 168'T' C0-DF linux/if_tun.h conflict! 169'U' all sound/asound.h conflict! 170'U' 00-CF linux/uinput.h conflict! 171'U' 00-EF linux/usbdevice_fs.h 172'U' C0-CF drivers/bluetooth/hci_uart.h 173'V' all linux/vt.h conflict! 174'V' all linux/videodev2.h conflict! 175'V' C0 linux/ivtvfb.h conflict! 176'V' C0 linux/ivtv.h conflict! 177'V' C0 media/davinci/vpfe_capture.h conflict! 178'V' C0 media/si4713.h conflict! 179'V' C0-CF drivers/media/video/mxb.h conflict! 180'W' 00-1F linux/watchdog.h conflict! 181'W' 00-1F linux/wanrouter.h conflict! 182'W' 00-3F sound/asound.h conflict! 183'X' all fs/xfs/xfs_fs.h conflict! 184 and fs/xfs/linux-2.6/xfs_ioctl32.h 185 and include/linux/falloc.h 186 and linux/fs.h 187'X' all fs/ocfs2/ocfs_fs.h conflict! 188'X' 01 linux/pktcdvd.h conflict! 189'Y' all linux/cyclades.h 190'Z' 14-15 drivers/message/fusion/mptctl.h 191'[' 00-07 linux/usb/tmc.h USB Test and Measurement Devices 192 <mailto:gregkh@suse.de> 193'a' all linux/atm*.h, linux/sonet.h ATM on linux 194 <http://lrcwww.epfl.ch/> 195'b' 00-FF conflict! bit3 vme host bridge 196 <mailto:natalia@nikhefk.nikhef.nl> 197'c' all linux/cm4000_cs.h conflict! 198'c' 00-7F linux/comstats.h conflict! 199'c' 00-7F linux/coda.h conflict! 200'c' 00-1F linux/chio.h conflict! 201'c' 80-9F arch/s390/include/asm/chsc.h conflict! 202'c' A0-AF arch/x86/include/asm/msr.h conflict! 203'd' 00-FF linux/char/drm/drm/h conflict! 204'd' 02-40 pcmcia/ds.h conflict! 205'd' 10-3F drivers/media/video/dabusb.h conflict! 206'd' C0-CF drivers/media/video/saa7191.h conflict! 207'd' F0-FF linux/digi1.h 208'e' all linux/digi1.h conflict! 209'e' 00-1F drivers/net/irda/irtty-sir.h conflict! 210'f' 00-1F linux/ext2_fs.h conflict! 211'f' 00-1F linux/ext3_fs.h conflict! 212'f' 00-0F fs/jfs/jfs_dinode.h conflict! 213'f' 00-0F fs/ext4/ext4.h conflict! 214'f' 00-0F linux/fs.h conflict! 215'f' 00-0F fs/ocfs2/ocfs2_fs.h conflict! 216'g' 00-0F linux/usb/gadgetfs.h 217'g' 20-2F linux/usb/g_printer.h 218'h' 00-7F conflict! Charon filesystem 219 <mailto:zapman@interlan.net> 220'h' 00-1F linux/hpet.h conflict! 221'i' 00-3F linux/i2o-dev.h conflict! 222'i' 0B-1F linux/ipmi.h conflict! 223'i' 80-8F linux/i8k.h 224'j' 00-3F linux/joystick.h 225'k' 00-0F linux/spi/spidev.h conflict! 226'k' 00-05 video/kyro.h conflict! 227'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system 228 <http://web.archive.org/web/*/http://mikonos.dia.unisa.it/tcfs> 229'l' 40-7F linux/udf_fs_i.h in development: 230 <http://sourceforge.net/projects/linux-udf/> 231'm' 00-09 linux/mmtimer.h conflict! 232'm' all linux/mtio.h conflict! 233'm' all linux/soundcard.h conflict! 234'm' all linux/synclink.h conflict! 235'm' 00-19 drivers/message/fusion/mptctl.h conflict! 236'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict! 237'm' 00-1F net/irda/irmod.h conflict! 238'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c 239'n' 80-8F linux/nilfs2_fs.h NILFS2 240'n' E0-FF linux/matroxfb.h matroxfb 241'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2 242'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps) 243'o' 40-41 mtd/ubi-user.h UBI 244'o' 01-A1 linux/dvb/*.h DVB 245'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this) 246'p' 00-1F linux/rtc.h conflict! 247'p' 00-3F linux/mc146818rtc.h conflict! 248'p' 40-7F linux/nvram.h 249'p' 80-9F linux/ppdev.h user-space parport 250 <mailto:tim@cyberelk.net> 251'p' A1-A5 linux/pps.h LinuxPPS 252 <mailto:giometti@linux.it> 253'q' 00-1F linux/serio.h 254'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK 255 linux/ixjuser.h <http://web.archive.org/web/*/http://www.quicknet.net> 256'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c 257's' all linux/cdk.h 258't' 00-7F linux/if_ppp.h 259't' 80-8F linux/isdn_ppp.h 260't' 90 linux/toshiba.h 261'u' 00-1F linux/smb_fs.h gone 262'u' 20-3F linux/uvcvideo.h USB video class host driver 263'v' 00-1F linux/ext2_fs.h conflict! 264'v' 00-1F linux/fs.h conflict! 265'v' 00-0F linux/sonypi.h conflict! 266'v' C0-DF media/pwc-ioctl.h conflict! 267'v' C0-FF linux/meye.h conflict! 268'v' D0-DF drivers/media/video/cpia2/cpia2dev.h conflict! 269'w' all CERN SCI driver 270'y' 00-1F packet based user level communications 271 <mailto:zapman@interlan.net> 272'z' 00-3F CAN bus card conflict! 273 <mailto:hdstich@connectu.ulm.circular.de> 274'z' 40-7F CAN bus card conflict! 275 <mailto:oe@port.de> 276'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict! 277'|' 00-7F linux/media.h 2780x80 00-1F linux/fb.h 2790x89 00-06 arch/x86/include/asm/sockios.h 2800x89 0B-DF linux/sockios.h 2810x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range 2820x89 E0-EF linux/dn.h PROTOPRIVATE range 2830x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range 2840x8B all linux/wireless.h 2850x8C 00-3F WiNRADiO driver 286 <http://www.winradio.com.au/> 2870x90 00 drivers/cdrom/sbpcd.h 2880x92 00-0F drivers/usb/mon/mon_bin.c 2890x93 60-7F linux/auto_fs.h 2900x94 all fs/btrfs/ioctl.h 2910x97 00-7F fs/ceph/ioctl.h Ceph file system 2920x99 00-0F 537-Addinboard driver 293 <mailto:buk@buks.ipn.de> 2940xA0 all linux/sdp/sdp.h Industrial Device Project 295 <mailto:kenji@bitgate.com> 2960xA2 00-0F arch/tile/include/asm/hardwall.h 2970xA3 80-8F Port ACL in development: 298 <mailto:tlewis@mindspring.com> 2990xA3 90-9F linux/dtlk.h 3000xAB 00-1F linux/nbd.h 3010xAC 00-1F linux/raw.h 3020xAD 00 Netfilter device in development: 303 <mailto:rusty@rustcorp.com.au> 3040xAE all linux/kvm.h Kernel-based Virtual Machine 305 <mailto:kvm@vger.kernel.org> 3060xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor 3070xB0 all RATIO devices in development: 308 <mailto:vgo@ratio.de> 3090xB1 00-1F PPPoX <mailto:mostrows@styx.uwaterloo.ca> 3100xB3 00 linux/mmc/ioctl.h 3110xC0 00-0F linux/usb/iowarrior.h 3120xCB 00-1F CBM serial IEC bus in development: 313 <mailto:michael.klein@puffin.lb.shuttle.de> 3140xCD 01 linux/reiserfs_fs.h 3150xCF 02 fs/cifs/ioctl.c 3160xDB 00-0F drivers/char/mwave/mwavepub.h 3170xDD 00-3F ZFCP device driver see drivers/s390/scsi/ 318 <mailto:aherrman@de.ibm.com> 3190xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development) 320 <mailto:thomas@winischhofer.net> 3210xF4 00-1F video/mbxfb.h mbxfb 322 <mailto:raph@8d.com> 3230xF6 all LTTng Linux Trace Toolkit Next Generation 324 <mailto:mathieu.desnoyers@efficios.com> 3250xFD all linux/dm-ioctl.h 326