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'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'K' all linux/kd.h 161'L' 00-1F linux/loop.h conflict! 162'L' 10-1F drivers/scsi/mpt3sas/mpt3sas_ctl.h conflict! 163'L' 20-2F linux/lightnvm.h 164'L' E0-FF linux/ppdd.h encrypted disk device driver 165 <http://linux01.gwdg.de/~alatham/ppdd.html> 166'M' all linux/soundcard.h conflict! 167'M' 01-16 mtd/mtd-abi.h conflict! 168 and drivers/mtd/mtdchar.c 169'M' 01-03 drivers/scsi/megaraid/megaraid_sas.h 170'M' 00-0F drivers/video/fsl-diu-fb.h conflict! 171'N' 00-1F drivers/usb/scanner.h 172'N' 40-7F drivers/block/nvme.c 173'O' 00-06 mtd/ubi-user.h UBI 174'P' all linux/soundcard.h conflict! 175'P' 60-6F sound/sscape_ioctl.h conflict! 176'P' 00-0F drivers/usb/class/usblp.c conflict! 177'P' 01-09 drivers/misc/pci_endpoint_test.c conflict! 178'Q' all linux/soundcard.h 179'R' 00-1F linux/random.h conflict! 180'R' 01 linux/rfkill.h conflict! 181'R' C0-DF net/bluetooth/rfcomm.h 182'R' E0 uapi/linux/fsl_mc.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'i' 90-9F `linux/iio/*.h` IIO 249'j' 00-3F linux/joystick.h 250'k' 00-0F linux/spi/spidev.h conflict! 251'k' 00-05 video/kyro.h conflict! 252'k' 10-17 linux/hsi/hsi_char.h HSI character device 253'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system 254 <http://web.archive.org/web/%2A/http://mikonos.dia.unisa.it/tcfs> 255'l' 40-7F linux/udf_fs_i.h in development: 256 <http://sourceforge.net/projects/linux-udf/> 257'm' 00-09 linux/mmtimer.h conflict! 258'm' all linux/mtio.h conflict! 259'm' all linux/soundcard.h conflict! 260'm' all linux/synclink.h conflict! 261'm' 00-19 drivers/message/fusion/mptctl.h conflict! 262'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict! 263'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c 264'n' 80-8F uapi/linux/nilfs2_api.h NILFS2 265'n' E0-FF linux/matroxfb.h matroxfb 266'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2 267'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps) 268'o' 40-41 mtd/ubi-user.h UBI 269'o' 01-A1 `linux/dvb/*.h` DVB 270'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this) 271'p' 00-1F linux/rtc.h conflict! 272'p' 40-7F linux/nvram.h 273'p' 80-9F linux/ppdev.h user-space parport 274 <mailto:tim@cyberelk.net> 275'p' A1-A5 linux/pps.h LinuxPPS 276 <mailto:giometti@linux.it> 277'q' 00-1F linux/serio.h 278'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK 279 linux/ixjuser.h <http://web.archive.org/web/%2A/http://www.quicknet.net> 280'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c 281's' all linux/cdk.h 282't' 00-7F linux/ppp-ioctl.h 283't' 80-8F linux/isdn_ppp.h 284't' 90-91 linux/toshiba.h toshiba and toshiba_acpi SMM 285'u' 00-1F linux/smb_fs.h gone 286'u' 20-3F linux/uvcvideo.h USB video class host driver 287'u' 40-4f linux/udmabuf.h userspace dma-buf misc device 288'v' 00-1F linux/ext2_fs.h conflict! 289'v' 00-1F linux/fs.h conflict! 290'v' 00-0F linux/sonypi.h conflict! 291'v' 00-0F media/v4l2-subdev.h conflict! 292'v' 20-27 arch/powerpc/include/uapi/asm/vas-api.h VAS API 293'v' C0-FF linux/meye.h conflict! 294'w' all CERN SCI driver 295'y' 00-1F packet based user level communications 296 <mailto:zapman@interlan.net> 297'z' 00-3F CAN bus card conflict! 298 <mailto:hdstich@connectu.ulm.circular.de> 299'z' 40-7F CAN bus card conflict! 300 <mailto:oe@port.de> 301'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict! 302'|' 00-7F linux/media.h 3030x80 00-1F linux/fb.h 3040x89 00-06 arch/x86/include/asm/sockios.h 3050x89 0B-DF linux/sockios.h 3060x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range 3070x89 E0-EF linux/dn.h PROTOPRIVATE range 3080x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range 3090x8B all linux/wireless.h 3100x8C 00-3F WiNRADiO driver 311 <http://www.winradio.com.au/> 3120x90 00 drivers/cdrom/sbpcd.h 3130x92 00-0F drivers/usb/mon/mon_bin.c 3140x93 60-7F linux/auto_fs.h 3150x94 all fs/btrfs/ioctl.h Btrfs filesystem 316 and linux/fs.h some lifted to vfs/generic 3170x97 00-7F fs/ceph/ioctl.h Ceph file system 3180x99 00-0F 537-Addinboard driver 319 <mailto:buk@buks.ipn.de> 3200xA0 all linux/sdp/sdp.h Industrial Device Project 321 <mailto:kenji@bitgate.com> 3220xA1 0 linux/vtpm_proxy.h TPM Emulator Proxy Driver 3230xA2 all uapi/linux/acrn.h ACRN hypervisor 3240xA3 80-8F Port ACL in development: 325 <mailto:tlewis@mindspring.com> 3260xA3 90-9F linux/dtlk.h 3270xA4 00-1F uapi/linux/tee.h Generic TEE subsystem 3280xA4 00-1F uapi/asm/sgx.h <mailto:linux-sgx@vger.kernel.org> 3290xA5 01 linux/surface_aggregator/cdev.h Microsoft Surface Platform System Aggregator 330 <mailto:luzmaximilian@gmail.com> 3310xAA 00-3F linux/uapi/linux/userfaultfd.h 3320xAB 00-1F linux/nbd.h 3330xAC 00-1F linux/raw.h 3340xAD 00 Netfilter device in development: 335 <mailto:rusty@rustcorp.com.au> 3360xAE 00-1F linux/kvm.h Kernel-based Virtual Machine 337 <mailto:kvm@vger.kernel.org> 3380xAE 40-FF linux/kvm.h Kernel-based Virtual Machine 339 <mailto:kvm@vger.kernel.org> 3400xAE 20-3F linux/nitro_enclaves.h Nitro Enclaves 3410xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor 3420xB0 all RATIO devices in development: 343 <mailto:vgo@ratio.de> 3440xB1 00-1F PPPoX 345 <mailto:mostrows@styx.uwaterloo.ca> 3460xB3 00 linux/mmc/ioctl.h 3470xB4 00-0F linux/gpio.h <mailto:linux-gpio@vger.kernel.org> 3480xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc@vger.kernel.org> 3490xB6 all linux/fpga-dfl.h 3500xB7 all uapi/linux/remoteproc_cdev.h <mailto:linux-remoteproc@vger.kernel.org> 3510xC0 00-0F linux/usb/iowarrior.h 3520xCA 00-0F uapi/misc/cxl.h 3530xCA 10-2F uapi/misc/ocxl.h 3540xCA 80-BF uapi/scsi/cxlflash_ioctl.h 3550xCB 00-1F CBM serial IEC bus in development: 356 <mailto:michael.klein@puffin.lb.shuttle.de> 3570xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver 3580xCD 01 linux/reiserfs_fs.h 3590xCE 01-02 uapi/linux/cxl_mem.h Compute Express Link Memory Devices 3600xCF 02 fs/cifs/ioctl.c 3610xDB 00-0F drivers/char/mwave/mwavepub.h 3620xDD 00-3F ZFCP device driver see drivers/s390/scsi/ 363 <mailto:aherrman@de.ibm.com> 3640xE5 00-3F linux/fuse.h 3650xEC 00-01 drivers/platform/chrome/cros_ec_dev.h ChromeOS EC driver 3660xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development) 367 <mailto:thomas@winischhofer.net> 3680xF6 all LTTng Linux Trace Toolkit Next Generation 369 <mailto:mathieu.desnoyers@efficios.com> 3700xFD all linux/dm-ioctl.h 3710xFE all linux/isst_if.h 372==== ===== ======================================================= ================================================================ 373