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 910x3E 00-0F linux/counter.h <mailto:linux-iio@vger.kernel.org> 92'!' 00-1F uapi/linux/seccomp.h 93'#' 00-3F IEEE 1394 Subsystem 94 Block for the entire subsystem 95'$' 00-0F linux/perf_counter.h, linux/perf_event.h 96'%' 00-0F include/uapi/linux/stm.h System Trace Module subsystem 97 <mailto:alexander.shishkin@linux.intel.com> 98'&' 00-07 drivers/firewire/nosy-user.h 99'1' 00-1F linux/timepps.h PPS kit from Ulrich Windl 100 <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/> 101'2' 01-04 linux/i2o.h 102'3' 00-0F drivers/s390/char/raw3270.h conflict! 103'3' 00-1F linux/suspend_ioctls.h, conflict! 104 kernel/power/user.c 105'8' all SNP8023 advanced NIC card 106 <mailto:mcr@solidum.com> 107';' 64-7F linux/vfio.h 108';' 80-FF linux/iommufd.h 109'=' 00-3f uapi/linux/ptp_clock.h <mailto:richardcochran@gmail.com> 110'@' 00-0F linux/radeonfb.h conflict! 111'@' 00-0F drivers/video/aty/aty128fb.c conflict! 112'A' 00-1F linux/apm_bios.h conflict! 113'A' 00-0F linux/agpgart.h, conflict! 114 drivers/char/agp/compat_ioctl.h 115'A' 00-7F sound/asound.h conflict! 116'B' 00-1F linux/cciss_ioctl.h conflict! 117'B' 00-0F include/linux/pmu.h conflict! 118'B' C0-FF advanced bbus <mailto:maassen@uni-freiburg.de> 119'B' 00-0F xen/xenbus_dev.h conflict! 120'C' all linux/soundcard.h conflict! 121'C' 01-2F linux/capi.h conflict! 122'C' F0-FF drivers/net/wan/cosa.h conflict! 123'D' all arch/s390/include/asm/dasd.h 124'D' 40-5F drivers/scsi/dpt/dtpi_ioctl.h Dead since 2022 125'D' 05 drivers/scsi/pmcraid.h 126'E' all linux/input.h conflict! 127'E' 00-0F xen/evtchn.h conflict! 128'F' all linux/fb.h conflict! 129'F' 01-02 drivers/scsi/pmcraid.h conflict! 130'F' 20 drivers/video/fsl-diu-fb.h conflict! 131'F' 20 drivers/video/intelfb/intelfb.h conflict! 132'F' 20 linux/ivtvfb.h conflict! 133'F' 20 linux/matroxfb.h conflict! 134'F' 20 drivers/video/aty/atyfb_base.c conflict! 135'F' 00-0F video/da8xx-fb.h conflict! 136'F' 80-8F linux/arcfb.h conflict! 137'F' DD video/sstfb.h conflict! 138'G' 00-3F drivers/misc/sgi-gru/grulib.h conflict! 139'G' 00-0F xen/gntalloc.h, xen/gntdev.h conflict! 140'H' 00-7F linux/hiddev.h conflict! 141'H' 00-0F linux/hidraw.h conflict! 142'H' 01 linux/mei.h conflict! 143'H' 02 linux/mei.h conflict! 144'H' 03 linux/mei.h conflict! 145'H' 00-0F sound/asound.h conflict! 146'H' 20-40 sound/asound_fm.h conflict! 147'H' 80-8F sound/sfnt_info.h conflict! 148'H' 10-8F sound/emu10k1.h conflict! 149'H' 10-1F sound/sb16_csp.h conflict! 150'H' 10-1F sound/hda_hwdep.h conflict! 151'H' 40-4F sound/hdspm.h conflict! 152'H' 40-4F sound/hdsp.h conflict! 153'H' 90 sound/usb/usx2y/usb_stream.h 154'H' 00-0F uapi/misc/habanalabs.h conflict! 155'H' A0 uapi/linux/usb/cdc-wdm.h 156'H' C0-F0 net/bluetooth/hci.h conflict! 157'H' C0-DF net/bluetooth/hidp/hidp.h conflict! 158'H' C0-DF net/bluetooth/cmtp/cmtp.h conflict! 159'H' C0-DF net/bluetooth/bnep/bnep.h conflict! 160'H' F1 linux/hid-roccat.h <mailto:erazor_de@users.sourceforge.net> 161'H' F8-FA sound/firewire.h 162'I' all linux/isdn.h conflict! 163'I' 00-0F drivers/isdn/divert/isdn_divert.h conflict! 164'I' 40-4F linux/mISDNif.h conflict! 165'K' all linux/kd.h 166'L' 00-1F linux/loop.h conflict! 167'L' 10-1F drivers/scsi/mpt3sas/mpt3sas_ctl.h conflict! 168'L' E0-FF linux/ppdd.h encrypted disk device driver 169 <http://linux01.gwdg.de/~alatham/ppdd.html> 170'M' all linux/soundcard.h conflict! 171'M' 01-16 mtd/mtd-abi.h conflict! 172 and drivers/mtd/mtdchar.c 173'M' 01-03 drivers/scsi/megaraid/megaraid_sas.h 174'M' 00-0F drivers/video/fsl-diu-fb.h conflict! 175'N' 00-1F drivers/usb/scanner.h 176'N' 40-7F drivers/block/nvme.c 177'O' 00-06 mtd/ubi-user.h UBI 178'P' all linux/soundcard.h conflict! 179'P' 60-6F sound/sscape_ioctl.h conflict! 180'P' 00-0F drivers/usb/class/usblp.c conflict! 181'P' 01-09 drivers/misc/pci_endpoint_test.c conflict! 182'P' 00-0F xen/privcmd.h conflict! 183'Q' all linux/soundcard.h 184'R' 00-1F linux/random.h conflict! 185'R' 01 linux/rfkill.h conflict! 186'R' C0-DF net/bluetooth/rfcomm.h 187'R' E0 uapi/linux/fsl_mc.h 188'S' all linux/cdrom.h conflict! 189'S' 80-81 scsi/scsi_ioctl.h conflict! 190'S' 82-FF scsi/scsi.h conflict! 191'S' 00-7F sound/asequencer.h conflict! 192'T' all linux/soundcard.h conflict! 193'T' 00-AF sound/asound.h conflict! 194'T' all arch/x86/include/asm/ioctls.h conflict! 195'T' C0-DF linux/if_tun.h conflict! 196'U' all sound/asound.h conflict! 197'U' 00-CF linux/uinput.h conflict! 198'U' 00-EF linux/usbdevice_fs.h 199'U' C0-CF drivers/bluetooth/hci_uart.h 200'V' all linux/vt.h conflict! 201'V' all linux/videodev2.h conflict! 202'V' C0 linux/ivtvfb.h conflict! 203'V' C0 linux/ivtv.h conflict! 204'V' C0 media/si4713.h conflict! 205'W' 00-1F linux/watchdog.h conflict! 206'W' 00-1F linux/wanrouter.h conflict! (pre 3.9) 207'W' 00-3F sound/asound.h conflict! 208'W' 40-5F drivers/pci/switch/switchtec.c 209'W' 60-61 linux/watch_queue.h 210'X' all fs/xfs/xfs_fs.h, conflict! 211 fs/xfs/linux-2.6/xfs_ioctl32.h, 212 include/linux/falloc.h, 213 linux/fs.h, 214'X' all fs/ocfs2/ocfs_fs.h conflict! 215'X' 01 linux/pktcdvd.h conflict! 216'Z' 14-15 drivers/message/fusion/mptctl.h 217'[' 00-3F linux/usb/tmc.h USB Test and Measurement Devices 218 <mailto:gregkh@linuxfoundation.org> 219'a' all linux/atm*.h, linux/sonet.h ATM on linux 220 <http://lrcwww.epfl.ch/> 221'a' 00-0F drivers/crypto/qat/qat_common/adf_cfg_common.h conflict! qat driver 222'b' 00-FF conflict! bit3 vme host bridge 223 <mailto:natalia@nikhefk.nikhef.nl> 224'b' 00-0F linux/dma-buf.h conflict! 225'c' 00-7F linux/comstats.h conflict! 226'c' 00-7F linux/coda.h conflict! 227'c' 00-1F linux/chio.h conflict! 228'c' 80-9F arch/s390/include/asm/chsc.h conflict! 229'c' A0-AF arch/x86/include/asm/msr.h conflict! 230'd' 00-FF linux/char/drm/drm.h conflict! 231'd' 02-40 pcmcia/ds.h conflict! 232'd' F0-FF linux/digi1.h 233'e' all linux/digi1.h conflict! 234'f' 00-1F linux/ext2_fs.h conflict! 235'f' 00-1F linux/ext3_fs.h conflict! 236'f' 00-0F fs/jfs/jfs_dinode.h conflict! 237'f' 00-0F fs/ext4/ext4.h conflict! 238'f' 00-0F linux/fs.h conflict! 239'f' 00-0F fs/ocfs2/ocfs2_fs.h conflict! 240'f' 13-27 linux/fscrypt.h 241'f' 81-8F linux/fsverity.h 242'g' 00-0F linux/usb/gadgetfs.h 243'g' 20-2F linux/usb/g_printer.h 244'h' 00-7F conflict! Charon filesystem 245 <mailto:zapman@interlan.net> 246'h' 00-1F linux/hpet.h conflict! 247'h' 80-8F fs/hfsplus/ioctl.c 248'i' 00-3F linux/i2o-dev.h conflict! 249'i' 0B-1F linux/ipmi.h conflict! 250'i' 80-8F linux/i8k.h 251'i' 90-9F `linux/iio/*.h` IIO 252'j' 00-3F linux/joystick.h 253'k' 00-0F linux/spi/spidev.h conflict! 254'k' 00-05 video/kyro.h conflict! 255'k' 10-17 linux/hsi/hsi_char.h HSI character device 256'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system 257 <http://web.archive.org/web/%2A/http://mikonos.dia.unisa.it/tcfs> 258'l' 40-7F linux/udf_fs_i.h in development: 259 <https://github.com/pali/udftools> 260'm' 00-09 linux/mmtimer.h conflict! 261'm' all linux/mtio.h conflict! 262'm' all linux/soundcard.h conflict! 263'm' all linux/synclink.h conflict! 264'm' 00-19 drivers/message/fusion/mptctl.h conflict! 265'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict! 266'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c 267'n' 80-8F uapi/linux/nilfs2_api.h NILFS2 268'n' E0-FF linux/matroxfb.h matroxfb 269'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2 270'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps) 271'o' 40-41 mtd/ubi-user.h UBI 272'o' 01-A1 `linux/dvb/*.h` DVB 273'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this) 274'p' 00-1F linux/rtc.h conflict! 275'p' 40-7F linux/nvram.h 276'p' 80-9F linux/ppdev.h user-space parport 277 <mailto:tim@cyberelk.net> 278'p' A1-A5 linux/pps.h LinuxPPS 279 <mailto:giometti@linux.it> 280'q' 00-1F linux/serio.h 281'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK 282 linux/ixjuser.h <http://web.archive.org/web/%2A/http://www.quicknet.net> 283'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c 284's' all linux/cdk.h 285't' 00-7F linux/ppp-ioctl.h 286't' 80-8F linux/isdn_ppp.h 287't' 90-91 linux/toshiba.h toshiba and toshiba_acpi SMM 288'u' 00-1F linux/smb_fs.h gone 289'u' 20-3F linux/uvcvideo.h USB video class host driver 290'u' 40-4f linux/udmabuf.h userspace dma-buf misc device 291'v' 00-1F linux/ext2_fs.h conflict! 292'v' 00-1F linux/fs.h conflict! 293'v' 00-0F linux/sonypi.h conflict! 294'v' 00-0F media/v4l2-subdev.h conflict! 295'v' 20-27 arch/powerpc/include/uapi/asm/vas-api.h VAS API 296'v' C0-FF linux/meye.h conflict! 297'w' all CERN SCI driver 298'y' 00-1F packet based user level communications 299 <mailto:zapman@interlan.net> 300'z' 00-3F CAN bus card conflict! 301 <mailto:hdstich@connectu.ulm.circular.de> 302'z' 40-7F CAN bus card conflict! 303 <mailto:oe@port.de> 304'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict! 305'|' 00-7F linux/media.h 3060x80 00-1F linux/fb.h 3070x81 00-1F linux/vduse.h 3080x89 00-06 arch/x86/include/asm/sockios.h 3090x89 0B-DF linux/sockios.h 3100x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range 3110x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range 3120x8B all linux/wireless.h 3130x8C 00-3F WiNRADiO driver 314 <http://www.winradio.com.au/> 3150x90 00 drivers/cdrom/sbpcd.h 3160x92 00-0F drivers/usb/mon/mon_bin.c 3170x93 60-7F linux/auto_fs.h 3180x94 all fs/btrfs/ioctl.h Btrfs filesystem 319 and linux/fs.h some lifted to vfs/generic 3200x97 00-7F fs/ceph/ioctl.h Ceph file system 3210x99 00-0F 537-Addinboard driver 322 <mailto:buk@buks.ipn.de> 3230xA0 all linux/sdp/sdp.h Industrial Device Project 324 <mailto:kenji@bitgate.com> 3250xA1 0 linux/vtpm_proxy.h TPM Emulator Proxy Driver 3260xA2 all uapi/linux/acrn.h ACRN hypervisor 3270xA3 80-8F Port ACL in development: 328 <mailto:tlewis@mindspring.com> 3290xA3 90-9F linux/dtlk.h 3300xA4 00-1F uapi/linux/tee.h Generic TEE subsystem 3310xA4 00-1F uapi/asm/sgx.h <mailto:linux-sgx@vger.kernel.org> 3320xA5 01-05 linux/surface_aggregator/cdev.h Microsoft Surface Platform System Aggregator 333 <mailto:luzmaximilian@gmail.com> 3340xA5 20-2F linux/surface_aggregator/dtx.h Microsoft Surface DTX driver 335 <mailto:luzmaximilian@gmail.com> 3360xAA 00-3F linux/uapi/linux/userfaultfd.h 3370xAB 00-1F linux/nbd.h 3380xAC 00-1F linux/raw.h 3390xAD 00 Netfilter device in development: 340 <mailto:rusty@rustcorp.com.au> 3410xAE 00-1F linux/kvm.h Kernel-based Virtual Machine 342 <mailto:kvm@vger.kernel.org> 3430xAE 40-FF linux/kvm.h Kernel-based Virtual Machine 344 <mailto:kvm@vger.kernel.org> 3450xAE 20-3F linux/nitro_enclaves.h Nitro Enclaves 3460xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor 3470xB0 all RATIO devices in development: 348 <mailto:vgo@ratio.de> 3490xB1 00-1F PPPoX 350 <mailto:mostrows@styx.uwaterloo.ca> 3510xB3 00 linux/mmc/ioctl.h 3520xB4 00-0F linux/gpio.h <mailto:linux-gpio@vger.kernel.org> 3530xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc@vger.kernel.org> 3540xB6 all linux/fpga-dfl.h 3550xB7 all uapi/linux/remoteproc_cdev.h <mailto:linux-remoteproc@vger.kernel.org> 3560xB7 all uapi/linux/nsfs.h <mailto:Andrei Vagin <avagin@openvz.org>> 3570xC0 00-0F linux/usb/iowarrior.h 3580xCA 00-0F uapi/misc/cxl.h 3590xCA 10-2F uapi/misc/ocxl.h 3600xCA 80-BF uapi/scsi/cxlflash_ioctl.h 3610xCB 00-1F CBM serial IEC bus in development: 362 <mailto:michael.klein@puffin.lb.shuttle.de> 3630xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver 3640xCD 01 linux/reiserfs_fs.h 3650xCE 01-02 uapi/linux/cxl_mem.h Compute Express Link Memory Devices 3660xCF 02 fs/smb/client/cifs_ioctl.h 3670xDB 00-0F drivers/char/mwave/mwavepub.h 3680xDD 00-3F ZFCP device driver see drivers/s390/scsi/ 369 <mailto:aherrman@de.ibm.com> 3700xE5 00-3F linux/fuse.h 3710xEC 00-01 drivers/platform/chrome/cros_ec_dev.h ChromeOS EC driver 3720xEE 00-09 uapi/linux/pfrut.h Platform Firmware Runtime Update and Telemetry 3730xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development) 374 <mailto:thomas@winischhofer.net> 3750xF6 all LTTng Linux Trace Toolkit Next Generation 376 <mailto:mathieu.desnoyers@efficios.com> 3770xF8 all arch/x86/include/uapi/asm/amd_hsmp.h AMD HSMP EPYC system management interface driver 378 <mailto:nchatrad@amd.com> 3790xFD all linux/dm-ioctl.h 3800xFE all linux/isst_if.h 381==== ===== ======================================================= ================================================================ 382