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 810x07 9F-D0 linux/vmw_vmci_defs.h, uapi/linux/vm_sockets.h 820x09 all linux/raid/md_u.h 830x10 00-0F drivers/char/s390/vmcp.h 840x10 10-1F arch/s390/include/uapi/sclp_ctl.h 850x10 20-2F arch/s390/include/uapi/asm/hypfs.h 860x12 all linux/fs.h BLK* ioctls 87 linux/blkpg.h 88 linux/blkzoned.h 89 linux/blk-crypto.h 900x15 all linux/fs.h FS_IOC_* ioctls 910x1b all InfiniBand Subsystem 92 <http://infiniband.sourceforge.net/> 930x20 all drivers/cdrom/cm206.h 940x22 all scsi/sg.h 950x3E 00-0F linux/counter.h <mailto:linux-iio@vger.kernel.org> 96'!' 00-1F uapi/linux/seccomp.h 97'#' 00-3F IEEE 1394 Subsystem 98 Block for the entire subsystem 99'$' 00-0F linux/perf_counter.h, linux/perf_event.h 100'%' 00-0F include/uapi/linux/stm.h System Trace Module subsystem 101 <mailto:alexander.shishkin@linux.intel.com> 102'&' 00-07 drivers/firewire/nosy-user.h 103'*' 00-1F uapi/linux/user_events.h User Events Subsystem 104 <mailto:linux-trace-kernel@vger.kernel.org> 105'1' 00-1F linux/timepps.h PPS kit from Ulrich Windl 106 <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/> 107'2' 01-04 linux/i2o.h 108'3' 00-0F drivers/s390/char/raw3270.h conflict! 109'3' 00-1F linux/suspend_ioctls.h, conflict! 110 kernel/power/user.c 111'8' all SNP8023 advanced NIC card 112 <mailto:mcr@solidum.com> 113';' 64-7F linux/vfio.h 114';' 80-FF linux/iommufd.h 115'=' 00-3f uapi/linux/ptp_clock.h <mailto:richardcochran@gmail.com> 116'@' 00-0F linux/radeonfb.h conflict! 117'@' 00-0F drivers/video/aty/aty128fb.c conflict! 118'A' 00-1F linux/apm_bios.h conflict! 119'A' 00-0F linux/agpgart.h, conflict! 120 drivers/char/agp/compat_ioctl.h 121'A' 00-7F sound/asound.h conflict! 122'B' 00-1F linux/cciss_ioctl.h conflict! 123'B' 00-0F include/linux/pmu.h conflict! 124'B' C0-FF advanced bbus <mailto:maassen@uni-freiburg.de> 125'B' 00-0F xen/xenbus_dev.h conflict! 126'C' all linux/soundcard.h conflict! 127'C' 01-2F linux/capi.h conflict! 128'C' F0-FF drivers/net/wan/cosa.h conflict! 129'D' all arch/s390/include/asm/dasd.h 130'D' 40-5F drivers/scsi/dpt/dtpi_ioctl.h Dead since 2022 131'D' 05 drivers/scsi/pmcraid.h 132'E' all linux/input.h conflict! 133'E' 00-0F xen/evtchn.h conflict! 134'F' all linux/fb.h conflict! 135'F' 01-02 drivers/scsi/pmcraid.h conflict! 136'F' 20 drivers/video/fsl-diu-fb.h conflict! 137'F' 20 linux/ivtvfb.h conflict! 138'F' 20 linux/matroxfb.h conflict! 139'F' 20 drivers/video/aty/atyfb_base.c conflict! 140'F' 00-0F video/da8xx-fb.h conflict! 141'F' 80-8F linux/arcfb.h conflict! 142'F' DD video/sstfb.h conflict! 143'G' 00-3F drivers/misc/sgi-gru/grulib.h conflict! 144'G' 00-0F xen/gntalloc.h, xen/gntdev.h conflict! 145'H' 00-7F linux/hiddev.h conflict! 146'H' 00-0F linux/hidraw.h conflict! 147'H' 01 linux/mei.h conflict! 148'H' 02 linux/mei.h conflict! 149'H' 03 linux/mei.h conflict! 150'H' 00-0F sound/asound.h conflict! 151'H' 20-40 sound/asound_fm.h conflict! 152'H' 80-8F sound/sfnt_info.h conflict! 153'H' 10-8F sound/emu10k1.h conflict! 154'H' 10-1F sound/sb16_csp.h conflict! 155'H' 10-1F sound/hda_hwdep.h conflict! 156'H' 40-4F sound/hdspm.h conflict! 157'H' 40-4F sound/hdsp.h conflict! 158'H' 90 sound/usb/usx2y/usb_stream.h 159'H' 00-0F uapi/misc/habanalabs.h conflict! 160'H' A0 uapi/linux/usb/cdc-wdm.h 161'H' C0-F0 net/bluetooth/hci.h conflict! 162'H' C0-DF net/bluetooth/hidp/hidp.h conflict! 163'H' C0-DF net/bluetooth/cmtp/cmtp.h conflict! 164'H' C0-DF net/bluetooth/bnep/bnep.h conflict! 165'H' F1 linux/hid-roccat.h <mailto:erazor_de@users.sourceforge.net> 166'H' F8-FA sound/firewire.h 167'I' all linux/isdn.h conflict! 168'I' 00-0F drivers/isdn/divert/isdn_divert.h conflict! 169'I' 40-4F linux/mISDNif.h conflict! 170'K' all linux/kd.h 171'L' 00-1F linux/loop.h conflict! 172'L' 10-1F drivers/scsi/mpt3sas/mpt3sas_ctl.h conflict! 173'L' E0-FF linux/ppdd.h encrypted disk device driver 174 <http://linux01.gwdg.de/~alatham/ppdd.html> 175'M' all linux/soundcard.h conflict! 176'M' 01-16 mtd/mtd-abi.h conflict! 177 and drivers/mtd/mtdchar.c 178'M' 01-03 drivers/scsi/megaraid/megaraid_sas.h 179'M' 00-0F drivers/video/fsl-diu-fb.h conflict! 180'N' 00-1F drivers/usb/scanner.h 181'N' 40-7F drivers/block/nvme.c 182'N' 80-8F uapi/linux/ntsync.h NT synchronization primitives 183 <mailto:wine-devel@winehq.org> 184'O' 00-06 mtd/ubi-user.h UBI 185'P' all linux/soundcard.h conflict! 186'P' 60-6F sound/sscape_ioctl.h conflict! 187'P' 00-0F drivers/usb/class/usblp.c conflict! 188'P' 01-09 drivers/misc/pci_endpoint_test.c conflict! 189'P' 00-0F xen/privcmd.h conflict! 190'P' 00-05 linux/tps6594_pfsm.h conflict! 191'Q' all linux/soundcard.h 192'R' 00-1F linux/random.h conflict! 193'R' 01 linux/rfkill.h conflict! 194'R' 20-2F linux/trace_mmap.h 195'R' C0-DF net/bluetooth/rfcomm.h 196'R' E0 uapi/linux/fsl_mc.h 197'S' all linux/cdrom.h conflict! 198'S' 80-81 scsi/scsi_ioctl.h conflict! 199'S' 82-FF scsi/scsi.h conflict! 200'S' 00-7F sound/asequencer.h conflict! 201'T' all linux/soundcard.h conflict! 202'T' 00-AF sound/asound.h conflict! 203'T' all arch/x86/include/asm/ioctls.h conflict! 204'T' C0-DF linux/if_tun.h conflict! 205'U' all sound/asound.h conflict! 206'U' 00-CF linux/uinput.h conflict! 207'U' 00-EF linux/usbdevice_fs.h 208'U' C0-CF drivers/bluetooth/hci_uart.h 209'V' all linux/vt.h conflict! 210'V' all linux/videodev2.h conflict! 211'V' C0 linux/ivtvfb.h conflict! 212'V' C0 linux/ivtv.h conflict! 213'V' C0 media/si4713.h conflict! 214'W' 00-1F linux/watchdog.h conflict! 215'W' 00-1F linux/wanrouter.h conflict! (pre 3.9) 216'W' 00-3F sound/asound.h conflict! 217'W' 40-5F drivers/pci/switch/switchtec.c 218'W' 60-61 linux/watch_queue.h 219'X' all fs/xfs/xfs_fs.h, conflict! 220 fs/xfs/linux-2.6/xfs_ioctl32.h, 221 include/linux/falloc.h, 222 linux/fs.h, 223'X' all fs/ocfs2/ocfs_fs.h conflict! 224'X' 01 linux/pktcdvd.h conflict! 225'Z' 14-15 drivers/message/fusion/mptctl.h 226'[' 00-3F linux/usb/tmc.h USB Test and Measurement Devices 227 <mailto:gregkh@linuxfoundation.org> 228'a' all linux/atm*.h, linux/sonet.h ATM on linux 229 <http://lrcwww.epfl.ch/> 230'a' 00-0F drivers/crypto/qat/qat_common/adf_cfg_common.h conflict! qat driver 231'b' 00-FF conflict! bit3 vme host bridge 232 <mailto:natalia@nikhefk.nikhef.nl> 233'b' 00-0F linux/dma-buf.h conflict! 234'c' 00-7F linux/comstats.h conflict! 235'c' 00-7F linux/coda.h conflict! 236'c' 00-1F linux/chio.h conflict! 237'c' 80-9F arch/s390/include/asm/chsc.h conflict! 238'c' A0-AF arch/x86/include/asm/msr.h conflict! 239'd' 00-FF linux/char/drm/drm.h conflict! 240'd' 02-40 pcmcia/ds.h conflict! 241'd' F0-FF linux/digi1.h 242'e' all linux/digi1.h conflict! 243'f' 00-1F linux/ext2_fs.h conflict! 244'f' 00-1F linux/ext3_fs.h conflict! 245'f' 00-0F fs/jfs/jfs_dinode.h conflict! 246'f' 00-0F fs/ext4/ext4.h conflict! 247'f' 00-0F linux/fs.h conflict! 248'f' 00-0F fs/ocfs2/ocfs2_fs.h conflict! 249'f' 13-27 linux/fscrypt.h 250'f' 81-8F linux/fsverity.h 251'g' 00-0F linux/usb/gadgetfs.h 252'g' 20-2F linux/usb/g_printer.h 253'h' 00-7F conflict! Charon filesystem 254 <mailto:zapman@interlan.net> 255'h' 00-1F linux/hpet.h conflict! 256'h' 80-8F fs/hfsplus/ioctl.c 257'i' 00-3F linux/i2o-dev.h conflict! 258'i' 0B-1F linux/ipmi.h conflict! 259'i' 80-8F linux/i8k.h 260'i' 90-9F `linux/iio/*.h` IIO 261'j' 00-3F linux/joystick.h 262'k' 00-0F linux/spi/spidev.h conflict! 263'k' 00-05 video/kyro.h conflict! 264'k' 10-17 linux/hsi/hsi_char.h HSI character device 265'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system 266 <http://web.archive.org/web/%2A/http://mikonos.dia.unisa.it/tcfs> 267'l' 40-7F linux/udf_fs_i.h in development: 268 <https://github.com/pali/udftools> 269'm' 00-09 linux/mmtimer.h conflict! 270'm' all linux/mtio.h conflict! 271'm' all linux/soundcard.h conflict! 272'm' all linux/synclink.h conflict! 273'm' 00-19 drivers/message/fusion/mptctl.h conflict! 274'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict! 275'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c 276'n' 80-8F uapi/linux/nilfs2_api.h NILFS2 277'n' E0-FF linux/matroxfb.h matroxfb 278'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2 279'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps) 280'o' 40-41 mtd/ubi-user.h UBI 281'o' 01-A1 `linux/dvb/*.h` DVB 282'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this) 283'p' 00-1F linux/rtc.h conflict! 284'p' 40-7F linux/nvram.h 285'p' 80-9F linux/ppdev.h user-space parport 286 <mailto:tim@cyberelk.net> 287'p' A1-A5 linux/pps.h LinuxPPS 288'p' B1-B3 linux/pps_gen.h LinuxPPS 289 <mailto:giometti@linux.it> 290'q' 00-1F linux/serio.h 291'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK 292 linux/ixjuser.h <http://web.archive.org/web/%2A/http://www.quicknet.net> 293'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c 294's' all linux/cdk.h 295't' 00-7F linux/ppp-ioctl.h 296't' 80-8F linux/isdn_ppp.h 297't' 90-91 linux/toshiba.h toshiba and toshiba_acpi SMM 298'u' 00-1F linux/smb_fs.h gone 299'u' 00-2F linux/ublk_cmd.h conflict! 300'u' 20-3F linux/uvcvideo.h USB video class host driver 301'u' 40-4f linux/udmabuf.h userspace dma-buf misc device 302'v' 00-1F linux/ext2_fs.h conflict! 303'v' 00-1F linux/fs.h conflict! 304'v' 00-0F linux/sonypi.h conflict! 305'v' 00-0F media/v4l2-subdev.h conflict! 306'v' 20-27 arch/powerpc/include/uapi/asm/vas-api.h VAS API 307'v' C0-FF linux/meye.h conflict! 308'w' all CERN SCI driver 309'y' 00-1F packet based user level communications 310 <mailto:zapman@interlan.net> 311'z' 00-3F CAN bus card conflict! 312 <mailto:hdstich@connectu.ulm.circular.de> 313'z' 40-7F CAN bus card conflict! 314 <mailto:oe@port.de> 315'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict! 316'|' 00-7F linux/media.h 317'|' 80-9F samples/ Any sample and example drivers 3180x80 00-1F linux/fb.h 3190x81 00-1F linux/vduse.h 3200x89 00-06 arch/x86/include/asm/sockios.h 3210x89 0B-DF linux/sockios.h 3220x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range 3230x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range 3240x8A 00-1F linux/eventpoll.h 3250x8B all linux/wireless.h 3260x8C 00-3F WiNRADiO driver 327 <http://www.winradio.com.au/> 3280x90 00 drivers/cdrom/sbpcd.h 3290x92 00-0F drivers/usb/mon/mon_bin.c 3300x93 60-7F linux/auto_fs.h 3310x94 all fs/btrfs/ioctl.h Btrfs filesystem 332 and linux/fs.h some lifted to vfs/generic 3330x97 00-7F fs/ceph/ioctl.h Ceph file system 3340x99 00-0F 537-Addinboard driver 335 <mailto:buk@buks.ipn.de> 3360x9A 00-0F include/uapi/fwctl/fwctl.h 3370xA0 all linux/sdp/sdp.h Industrial Device Project 338 <mailto:kenji@bitgate.com> 3390xA1 0 linux/vtpm_proxy.h TPM Emulator Proxy Driver 3400xA2 all uapi/linux/acrn.h ACRN hypervisor 3410xA3 80-8F Port ACL in development: 342 <mailto:tlewis@mindspring.com> 3430xA3 90-9F linux/dtlk.h 3440xA4 00-1F uapi/linux/tee.h Generic TEE subsystem 3450xA4 00-1F uapi/asm/sgx.h <mailto:linux-sgx@vger.kernel.org> 3460xA5 01-05 linux/surface_aggregator/cdev.h Microsoft Surface Platform System Aggregator 347 <mailto:luzmaximilian@gmail.com> 3480xA5 20-2F linux/surface_aggregator/dtx.h Microsoft Surface DTX driver 349 <mailto:luzmaximilian@gmail.com> 3500xAA 00-3F linux/uapi/linux/userfaultfd.h 3510xAB 00-1F linux/nbd.h 3520xAC 00-1F linux/raw.h 3530xAD 00 Netfilter device in development: 354 <mailto:rusty@rustcorp.com.au> 3550xAE 00-1F linux/kvm.h Kernel-based Virtual Machine 356 <mailto:kvm@vger.kernel.org> 3570xAE 40-FF linux/kvm.h Kernel-based Virtual Machine 358 <mailto:kvm@vger.kernel.org> 3590xAE 20-3F linux/nitro_enclaves.h Nitro Enclaves 3600xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor 3610xB0 all RATIO devices in development: 362 <mailto:vgo@ratio.de> 3630xB1 00-1F PPPoX 364 <mailto:mostrows@styx.uwaterloo.ca> 3650xB2 00 arch/powerpc/include/uapi/asm/papr-vpd.h powerpc/pseries VPD API 366 <mailto:linuxppc-dev> 3670xB2 01-02 arch/powerpc/include/uapi/asm/papr-sysparm.h powerpc/pseries system parameter API 368 <mailto:linuxppc-dev> 3690xB3 00 linux/mmc/ioctl.h 3700xB4 00-0F linux/gpio.h <mailto:linux-gpio@vger.kernel.org> 3710xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc@vger.kernel.org> 3720xB6 all linux/fpga-dfl.h 3730xB7 all uapi/linux/remoteproc_cdev.h <mailto:linux-remoteproc@vger.kernel.org> 3740xB7 all uapi/linux/nsfs.h <mailto:Andrei Vagin <avagin@openvz.org>> 3750xB8 01-02 uapi/misc/mrvl_cn10k_dpi.h Marvell CN10K DPI driver 3760xB8 all uapi/linux/mshv.h Microsoft Hyper-V /dev/mshv driver 377 <mailto:linux-hyperv@vger.kernel.org> 3780xC0 00-0F linux/usb/iowarrior.h 3790xCA 00-0F uapi/misc/cxl.h Dead since 6.15 3800xCA 10-2F uapi/misc/ocxl.h 3810xCA 80-BF uapi/scsi/cxlflash_ioctl.h Dead since 6.15 3820xCB 00-1F CBM serial IEC bus in development: 383 <mailto:michael.klein@puffin.lb.shuttle.de> 3840xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver 3850xCD 01 linux/reiserfs_fs.h Dead since 6.13 3860xCE 01-02 uapi/linux/cxl_mem.h Compute Express Link Memory Devices 3870xCF 02 fs/smb/client/cifs_ioctl.h 3880xDB 00-0F drivers/char/mwave/mwavepub.h 3890xDD 00-3F ZFCP device driver see drivers/s390/scsi/ 390 <mailto:aherrman@de.ibm.com> 3910xE5 00-3F linux/fuse.h 3920xEC 00-01 drivers/platform/chrome/cros_ec_dev.h ChromeOS EC driver 3930xEE 00-09 uapi/linux/pfrut.h Platform Firmware Runtime Update and Telemetry 3940xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development) 395 <mailto:thomas@winischhofer.net> 3960xF6 all LTTng Linux Trace Toolkit Next Generation 397 <mailto:mathieu.desnoyers@efficios.com> 3980xF8 all arch/x86/include/uapi/asm/amd_hsmp.h AMD HSMP EPYC system management interface driver 399 <mailto:nchatrad@amd.com> 4000xFD all linux/dm-ioctl.h 4010xFE all linux/isst_if.h 402==== ===== ======================================================= ================================================================ 403