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'j' 00-3F linux/joystick.h 249'k' 00-0F linux/spi/spidev.h conflict! 250'k' 00-05 video/kyro.h conflict! 251'k' 10-17 linux/hsi/hsi_char.h HSI character device 252'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system 253 <http://web.archive.org/web/%2A/http://mikonos.dia.unisa.it/tcfs> 254'l' 40-7F linux/udf_fs_i.h in development: 255 <http://sourceforge.net/projects/linux-udf/> 256'm' 00-09 linux/mmtimer.h conflict! 257'm' all linux/mtio.h conflict! 258'm' all linux/soundcard.h conflict! 259'm' all linux/synclink.h conflict! 260'm' 00-19 drivers/message/fusion/mptctl.h conflict! 261'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict! 262'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c 263'n' 80-8F uapi/linux/nilfs2_api.h NILFS2 264'n' E0-FF linux/matroxfb.h matroxfb 265'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2 266'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps) 267'o' 40-41 mtd/ubi-user.h UBI 268'o' 01-A1 `linux/dvb/*.h` DVB 269'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this) 270'p' 00-1F linux/rtc.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' 20-27 arch/powerpc/include/uapi/asm/vas-api.h VAS API 292'v' C0-FF linux/meye.h conflict! 293'w' all CERN SCI driver 294'y' 00-1F packet based user level communications 295 <mailto:zapman@interlan.net> 296'z' 00-3F CAN bus card conflict! 297 <mailto:hdstich@connectu.ulm.circular.de> 298'z' 40-7F CAN bus card conflict! 299 <mailto:oe@port.de> 300'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict! 301'|' 00-7F linux/media.h 3020x80 00-1F linux/fb.h 3030x89 00-06 arch/x86/include/asm/sockios.h 3040x89 0B-DF linux/sockios.h 3050x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range 3060x89 E0-EF linux/dn.h PROTOPRIVATE range 3070x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range 3080x8B all linux/wireless.h 3090x8C 00-3F WiNRADiO driver 310 <http://www.winradio.com.au/> 3110x90 00 drivers/cdrom/sbpcd.h 3120x92 00-0F drivers/usb/mon/mon_bin.c 3130x93 60-7F linux/auto_fs.h 3140x94 all fs/btrfs/ioctl.h Btrfs filesystem 315 and linux/fs.h some lifted to vfs/generic 3160x97 00-7F fs/ceph/ioctl.h Ceph file system 3170x99 00-0F 537-Addinboard driver 318 <mailto:buk@buks.ipn.de> 3190xA0 all linux/sdp/sdp.h Industrial Device Project 320 <mailto:kenji@bitgate.com> 3210xA1 0 linux/vtpm_proxy.h TPM Emulator Proxy Driver 3220xA2 all uapi/linux/acrn.h ACRN hypervisor 3230xA3 80-8F Port ACL in development: 324 <mailto:tlewis@mindspring.com> 3250xA3 90-9F linux/dtlk.h 3260xA4 00-1F uapi/linux/tee.h Generic TEE subsystem 3270xA4 00-1F uapi/asm/sgx.h <mailto:linux-sgx@vger.kernel.org> 3280xA5 01 linux/surface_aggregator/cdev.h Microsoft Surface Platform System Aggregator 329 <mailto:luzmaximilian@gmail.com> 3300xAA 00-3F linux/uapi/linux/userfaultfd.h 3310xAB 00-1F linux/nbd.h 3320xAC 00-1F linux/raw.h 3330xAD 00 Netfilter device in development: 334 <mailto:rusty@rustcorp.com.au> 3350xAE 00-1F linux/kvm.h Kernel-based Virtual Machine 336 <mailto:kvm@vger.kernel.org> 3370xAE 40-FF linux/kvm.h Kernel-based Virtual Machine 338 <mailto:kvm@vger.kernel.org> 3390xAE 20-3F linux/nitro_enclaves.h Nitro Enclaves 3400xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor 3410xB0 all RATIO devices in development: 342 <mailto:vgo@ratio.de> 3430xB1 00-1F PPPoX 344 <mailto:mostrows@styx.uwaterloo.ca> 3450xB3 00 linux/mmc/ioctl.h 3460xB4 00-0F linux/gpio.h <mailto:linux-gpio@vger.kernel.org> 3470xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc@vger.kernel.org> 3480xB6 all linux/fpga-dfl.h 3490xB7 all uapi/linux/remoteproc_cdev.h <mailto:linux-remoteproc@vger.kernel.org> 3500xC0 00-0F linux/usb/iowarrior.h 3510xCA 00-0F uapi/misc/cxl.h 3520xCA 10-2F uapi/misc/ocxl.h 3530xCA 80-BF uapi/scsi/cxlflash_ioctl.h 3540xCB 00-1F CBM serial IEC bus in development: 355 <mailto:michael.klein@puffin.lb.shuttle.de> 3560xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver 3570xCD 01 linux/reiserfs_fs.h 3580xCE 01-02 uapi/linux/cxl_mem.h Compute Express Link Memory Devices 3590xCF 02 fs/cifs/ioctl.c 3600xDB 00-0F drivers/char/mwave/mwavepub.h 3610xDD 00-3F ZFCP device driver see drivers/s390/scsi/ 362 <mailto:aherrman@de.ibm.com> 3630xE5 00-3F linux/fuse.h 3640xEC 00-01 drivers/platform/chrome/cros_ec_dev.h ChromeOS EC driver 3650xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development) 366 <mailto:thomas@winischhofer.net> 3670xF6 all LTTng Linux Trace Toolkit Next Generation 368 <mailto:mathieu.desnoyers@efficios.com> 3690xFD all linux/dm-ioctl.h 3700xFE all linux/isst_if.h 371==== ===== ======================================================= ================================================================ 372