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/davinci/vpfe_capture.h conflict! 205'V' C0 media/si4713.h conflict! 206'W' 00-1F linux/watchdog.h conflict! 207'W' 00-1F linux/wanrouter.h conflict! (pre 3.9) 208'W' 00-3F sound/asound.h conflict! 209'W' 40-5F drivers/pci/switch/switchtec.c 210'W' 60-61 linux/watch_queue.h 211'X' all fs/xfs/xfs_fs.h, conflict! 212 fs/xfs/linux-2.6/xfs_ioctl32.h, 213 include/linux/falloc.h, 214 linux/fs.h, 215'X' all fs/ocfs2/ocfs_fs.h conflict! 216'X' 01 linux/pktcdvd.h conflict! 217'Z' 14-15 drivers/message/fusion/mptctl.h 218'[' 00-3F linux/usb/tmc.h USB Test and Measurement Devices 219 <mailto:gregkh@linuxfoundation.org> 220'a' all linux/atm*.h, linux/sonet.h ATM on linux 221 <http://lrcwww.epfl.ch/> 222'a' 00-0F drivers/crypto/qat/qat_common/adf_cfg_common.h conflict! qat driver 223'b' 00-FF conflict! bit3 vme host bridge 224 <mailto:natalia@nikhefk.nikhef.nl> 225'b' 00-0F linux/dma-buf.h conflict! 226'c' all linux/cm4000_cs.h conflict! 227'c' 00-7F linux/comstats.h conflict! 228'c' 00-7F linux/coda.h conflict! 229'c' 00-1F linux/chio.h conflict! 230'c' 80-9F arch/s390/include/asm/chsc.h conflict! 231'c' A0-AF arch/x86/include/asm/msr.h conflict! 232'd' 00-FF linux/char/drm/drm.h conflict! 233'd' 02-40 pcmcia/ds.h conflict! 234'd' F0-FF linux/digi1.h 235'e' all linux/digi1.h conflict! 236'f' 00-1F linux/ext2_fs.h conflict! 237'f' 00-1F linux/ext3_fs.h conflict! 238'f' 00-0F fs/jfs/jfs_dinode.h conflict! 239'f' 00-0F fs/ext4/ext4.h conflict! 240'f' 00-0F linux/fs.h conflict! 241'f' 00-0F fs/ocfs2/ocfs2_fs.h conflict! 242'f' 13-27 linux/fscrypt.h 243'f' 81-8F linux/fsverity.h 244'g' 00-0F linux/usb/gadgetfs.h 245'g' 20-2F linux/usb/g_printer.h 246'h' 00-7F conflict! Charon filesystem 247 <mailto:zapman@interlan.net> 248'h' 00-1F linux/hpet.h conflict! 249'h' 80-8F fs/hfsplus/ioctl.c 250'i' 00-3F linux/i2o-dev.h conflict! 251'i' 0B-1F linux/ipmi.h conflict! 252'i' 80-8F linux/i8k.h 253'i' 90-9F `linux/iio/*.h` IIO 254'j' 00-3F linux/joystick.h 255'k' 00-0F linux/spi/spidev.h conflict! 256'k' 00-05 video/kyro.h conflict! 257'k' 10-17 linux/hsi/hsi_char.h HSI character device 258'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system 259 <http://web.archive.org/web/%2A/http://mikonos.dia.unisa.it/tcfs> 260'l' 40-7F linux/udf_fs_i.h in development: 261 <https://github.com/pali/udftools> 262'm' 00-09 linux/mmtimer.h conflict! 263'm' all linux/mtio.h conflict! 264'm' all linux/soundcard.h conflict! 265'm' all linux/synclink.h conflict! 266'm' 00-19 drivers/message/fusion/mptctl.h conflict! 267'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict! 268'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c 269'n' 80-8F uapi/linux/nilfs2_api.h NILFS2 270'n' E0-FF linux/matroxfb.h matroxfb 271'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2 272'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps) 273'o' 40-41 mtd/ubi-user.h UBI 274'o' 01-A1 `linux/dvb/*.h` DVB 275'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this) 276'p' 00-1F linux/rtc.h conflict! 277'p' 40-7F linux/nvram.h 278'p' 80-9F linux/ppdev.h user-space parport 279 <mailto:tim@cyberelk.net> 280'p' A1-A5 linux/pps.h LinuxPPS 281 <mailto:giometti@linux.it> 282'q' 00-1F linux/serio.h 283'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK 284 linux/ixjuser.h <http://web.archive.org/web/%2A/http://www.quicknet.net> 285'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c 286's' all linux/cdk.h 287't' 00-7F linux/ppp-ioctl.h 288't' 80-8F linux/isdn_ppp.h 289't' 90-91 linux/toshiba.h toshiba and toshiba_acpi SMM 290'u' 00-1F linux/smb_fs.h gone 291'u' 20-3F linux/uvcvideo.h USB video class host driver 292'u' 40-4f linux/udmabuf.h userspace dma-buf misc device 293'v' 00-1F linux/ext2_fs.h conflict! 294'v' 00-1F linux/fs.h conflict! 295'v' 00-0F linux/sonypi.h conflict! 296'v' 00-0F media/v4l2-subdev.h conflict! 297'v' 20-27 arch/powerpc/include/uapi/asm/vas-api.h VAS API 298'v' C0-FF linux/meye.h conflict! 299'w' all CERN SCI driver 300'y' 00-1F packet based user level communications 301 <mailto:zapman@interlan.net> 302'z' 00-3F CAN bus card conflict! 303 <mailto:hdstich@connectu.ulm.circular.de> 304'z' 40-7F CAN bus card conflict! 305 <mailto:oe@port.de> 306'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict! 307'|' 00-7F linux/media.h 3080x80 00-1F linux/fb.h 3090x81 00-1F linux/vduse.h 3100x89 00-06 arch/x86/include/asm/sockios.h 3110x89 0B-DF linux/sockios.h 3120x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range 3130x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range 3140x8B all linux/wireless.h 3150x8C 00-3F WiNRADiO driver 316 <http://www.winradio.com.au/> 3170x90 00 drivers/cdrom/sbpcd.h 3180x92 00-0F drivers/usb/mon/mon_bin.c 3190x93 60-7F linux/auto_fs.h 3200x94 all fs/btrfs/ioctl.h Btrfs filesystem 321 and linux/fs.h some lifted to vfs/generic 3220x97 00-7F fs/ceph/ioctl.h Ceph file system 3230x99 00-0F 537-Addinboard driver 324 <mailto:buk@buks.ipn.de> 3250xA0 all linux/sdp/sdp.h Industrial Device Project 326 <mailto:kenji@bitgate.com> 3270xA1 0 linux/vtpm_proxy.h TPM Emulator Proxy Driver 3280xA2 all uapi/linux/acrn.h ACRN hypervisor 3290xA3 80-8F Port ACL in development: 330 <mailto:tlewis@mindspring.com> 3310xA3 90-9F linux/dtlk.h 3320xA4 00-1F uapi/linux/tee.h Generic TEE subsystem 3330xA4 00-1F uapi/asm/sgx.h <mailto:linux-sgx@vger.kernel.org> 3340xA5 01-05 linux/surface_aggregator/cdev.h Microsoft Surface Platform System Aggregator 335 <mailto:luzmaximilian@gmail.com> 3360xA5 20-2F linux/surface_aggregator/dtx.h Microsoft Surface DTX driver 337 <mailto:luzmaximilian@gmail.com> 3380xAA 00-3F linux/uapi/linux/userfaultfd.h 3390xAB 00-1F linux/nbd.h 3400xAC 00-1F linux/raw.h 3410xAD 00 Netfilter device in development: 342 <mailto:rusty@rustcorp.com.au> 3430xAE 00-1F linux/kvm.h Kernel-based Virtual Machine 344 <mailto:kvm@vger.kernel.org> 3450xAE 40-FF linux/kvm.h Kernel-based Virtual Machine 346 <mailto:kvm@vger.kernel.org> 3470xAE 20-3F linux/nitro_enclaves.h Nitro Enclaves 3480xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor 3490xB0 all RATIO devices in development: 350 <mailto:vgo@ratio.de> 3510xB1 00-1F PPPoX 352 <mailto:mostrows@styx.uwaterloo.ca> 3530xB3 00 linux/mmc/ioctl.h 3540xB4 00-0F linux/gpio.h <mailto:linux-gpio@vger.kernel.org> 3550xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc@vger.kernel.org> 3560xB6 all linux/fpga-dfl.h 3570xB7 all uapi/linux/remoteproc_cdev.h <mailto:linux-remoteproc@vger.kernel.org> 3580xB7 all uapi/linux/nsfs.h <mailto:Andrei Vagin <avagin@openvz.org>> 3590xC0 00-0F linux/usb/iowarrior.h 3600xCA 00-0F uapi/misc/cxl.h 3610xCA 10-2F uapi/misc/ocxl.h 3620xCA 80-BF uapi/scsi/cxlflash_ioctl.h 3630xCB 00-1F CBM serial IEC bus in development: 364 <mailto:michael.klein@puffin.lb.shuttle.de> 3650xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver 3660xCD 01 linux/reiserfs_fs.h 3670xCE 01-02 uapi/linux/cxl_mem.h Compute Express Link Memory Devices 3680xCF 02 fs/cifs/ioctl.c 3690xDB 00-0F drivers/char/mwave/mwavepub.h 3700xDD 00-3F ZFCP device driver see drivers/s390/scsi/ 371 <mailto:aherrman@de.ibm.com> 3720xE5 00-3F linux/fuse.h 3730xEC 00-01 drivers/platform/chrome/cros_ec_dev.h ChromeOS EC driver 3740xEE 00-09 uapi/linux/pfrut.h Platform Firmware Runtime Update and Telemetry 3750xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development) 376 <mailto:thomas@winischhofer.net> 3770xF6 all LTTng Linux Trace Toolkit Next Generation 378 <mailto:mathieu.desnoyers@efficios.com> 3790xF8 all arch/x86/include/uapi/asm/amd_hsmp.h AMD HSMP EPYC system management interface driver 380 <mailto:nchatrad@amd.com> 3810xFD all linux/dm-ioctl.h 3820xFE all linux/isst_if.h 383==== ===== ======================================================= ================================================================ 384