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 BLK* ioctls 86 linux/blkpg.h 870x15 all linux/fs.h FS_IOC_* ioctls 880x1b all InfiniBand Subsystem 89 <http://infiniband.sourceforge.net/> 900x20 all drivers/cdrom/cm206.h 910x22 all scsi/sg.h 920x3E 00-0F linux/counter.h <mailto:linux-iio@vger.kernel.org> 93'!' 00-1F uapi/linux/seccomp.h 94'#' 00-3F IEEE 1394 Subsystem 95 Block for the entire subsystem 96'$' 00-0F linux/perf_counter.h, linux/perf_event.h 97'%' 00-0F include/uapi/linux/stm.h System Trace Module subsystem 98 <mailto:alexander.shishkin@linux.intel.com> 99'&' 00-07 drivers/firewire/nosy-user.h 100'1' 00-1F linux/timepps.h PPS kit from Ulrich Windl 101 <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/> 102'2' 01-04 linux/i2o.h 103'3' 00-0F drivers/s390/char/raw3270.h conflict! 104'3' 00-1F linux/suspend_ioctls.h, conflict! 105 kernel/power/user.c 106'8' all SNP8023 advanced NIC card 107 <mailto:mcr@solidum.com> 108';' 64-7F linux/vfio.h 109';' 80-FF linux/iommufd.h 110'=' 00-3f uapi/linux/ptp_clock.h <mailto:richardcochran@gmail.com> 111'@' 00-0F linux/radeonfb.h conflict! 112'@' 00-0F drivers/video/aty/aty128fb.c conflict! 113'A' 00-1F linux/apm_bios.h conflict! 114'A' 00-0F linux/agpgart.h, conflict! 115 drivers/char/agp/compat_ioctl.h 116'A' 00-7F sound/asound.h conflict! 117'B' 00-1F linux/cciss_ioctl.h conflict! 118'B' 00-0F include/linux/pmu.h conflict! 119'B' C0-FF advanced bbus <mailto:maassen@uni-freiburg.de> 120'B' 00-0F xen/xenbus_dev.h conflict! 121'C' all linux/soundcard.h conflict! 122'C' 01-2F linux/capi.h conflict! 123'C' F0-FF drivers/net/wan/cosa.h conflict! 124'D' all arch/s390/include/asm/dasd.h 125'D' 40-5F drivers/scsi/dpt/dtpi_ioctl.h Dead since 2022 126'D' 05 drivers/scsi/pmcraid.h 127'E' all linux/input.h conflict! 128'E' 00-0F xen/evtchn.h conflict! 129'F' all linux/fb.h conflict! 130'F' 01-02 drivers/scsi/pmcraid.h conflict! 131'F' 20 drivers/video/fsl-diu-fb.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'N' 80-8F uapi/linux/ntsync.h NT synchronization primitives 178 <mailto:wine-devel@winehq.org> 179'O' 00-06 mtd/ubi-user.h UBI 180'P' all linux/soundcard.h conflict! 181'P' 60-6F sound/sscape_ioctl.h conflict! 182'P' 00-0F drivers/usb/class/usblp.c conflict! 183'P' 01-09 drivers/misc/pci_endpoint_test.c conflict! 184'P' 00-0F xen/privcmd.h conflict! 185'P' 00-05 linux/tps6594_pfsm.h conflict! 186'Q' all linux/soundcard.h 187'R' 00-1F linux/random.h conflict! 188'R' 01 linux/rfkill.h conflict! 189'R' 20-2F linux/trace_mmap.h 190'R' C0-DF net/bluetooth/rfcomm.h 191'R' E0 uapi/linux/fsl_mc.h 192'S' all linux/cdrom.h conflict! 193'S' 80-81 scsi/scsi_ioctl.h conflict! 194'S' 82-FF scsi/scsi.h conflict! 195'S' 00-7F sound/asequencer.h conflict! 196'T' all linux/soundcard.h conflict! 197'T' 00-AF sound/asound.h conflict! 198'T' all arch/x86/include/asm/ioctls.h conflict! 199'T' C0-DF linux/if_tun.h conflict! 200'U' all sound/asound.h conflict! 201'U' 00-CF linux/uinput.h conflict! 202'U' 00-EF linux/usbdevice_fs.h 203'U' C0-CF drivers/bluetooth/hci_uart.h 204'V' all linux/vt.h conflict! 205'V' all linux/videodev2.h conflict! 206'V' C0 linux/ivtvfb.h conflict! 207'V' C0 linux/ivtv.h conflict! 208'V' C0 media/si4713.h conflict! 209'W' 00-1F linux/watchdog.h conflict! 210'W' 00-1F linux/wanrouter.h conflict! (pre 3.9) 211'W' 00-3F sound/asound.h conflict! 212'W' 40-5F drivers/pci/switch/switchtec.c 213'W' 60-61 linux/watch_queue.h 214'X' all fs/xfs/xfs_fs.h, conflict! 215 fs/xfs/linux-2.6/xfs_ioctl32.h, 216 include/linux/falloc.h, 217 linux/fs.h, 218'X' all fs/ocfs2/ocfs_fs.h conflict! 219'X' 01 linux/pktcdvd.h conflict! 220'Z' 14-15 drivers/message/fusion/mptctl.h 221'[' 00-3F linux/usb/tmc.h USB Test and Measurement Devices 222 <mailto:gregkh@linuxfoundation.org> 223'a' all linux/atm*.h, linux/sonet.h ATM on linux 224 <http://lrcwww.epfl.ch/> 225'a' 00-0F drivers/crypto/qat/qat_common/adf_cfg_common.h conflict! qat driver 226'b' 00-FF conflict! bit3 vme host bridge 227 <mailto:natalia@nikhefk.nikhef.nl> 228'b' 00-0F linux/dma-buf.h conflict! 229'c' 00-7F linux/comstats.h conflict! 230'c' 00-7F linux/coda.h conflict! 231'c' 00-1F linux/chio.h conflict! 232'c' 80-9F arch/s390/include/asm/chsc.h conflict! 233'c' A0-AF arch/x86/include/asm/msr.h conflict! 234'd' 00-FF linux/char/drm/drm.h conflict! 235'd' 02-40 pcmcia/ds.h conflict! 236'd' F0-FF linux/digi1.h 237'e' all linux/digi1.h conflict! 238'f' 00-1F linux/ext2_fs.h conflict! 239'f' 00-1F linux/ext3_fs.h conflict! 240'f' 00-0F fs/jfs/jfs_dinode.h conflict! 241'f' 00-0F fs/ext4/ext4.h conflict! 242'f' 00-0F linux/fs.h conflict! 243'f' 00-0F fs/ocfs2/ocfs2_fs.h conflict! 244'f' 13-27 linux/fscrypt.h 245'f' 81-8F linux/fsverity.h 246'g' 00-0F linux/usb/gadgetfs.h 247'g' 20-2F linux/usb/g_printer.h 248'h' 00-7F conflict! Charon filesystem 249 <mailto:zapman@interlan.net> 250'h' 00-1F linux/hpet.h conflict! 251'h' 80-8F fs/hfsplus/ioctl.c 252'i' 00-3F linux/i2o-dev.h conflict! 253'i' 0B-1F linux/ipmi.h conflict! 254'i' 80-8F linux/i8k.h 255'i' 90-9F `linux/iio/*.h` IIO 256'j' 00-3F linux/joystick.h 257'k' 00-0F linux/spi/spidev.h conflict! 258'k' 00-05 video/kyro.h conflict! 259'k' 10-17 linux/hsi/hsi_char.h HSI character device 260'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system 261 <http://web.archive.org/web/%2A/http://mikonos.dia.unisa.it/tcfs> 262'l' 40-7F linux/udf_fs_i.h in development: 263 <https://github.com/pali/udftools> 264'm' 00-09 linux/mmtimer.h conflict! 265'm' all linux/mtio.h conflict! 266'm' all linux/soundcard.h conflict! 267'm' all linux/synclink.h conflict! 268'm' 00-19 drivers/message/fusion/mptctl.h conflict! 269'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict! 270'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c 271'n' 80-8F uapi/linux/nilfs2_api.h NILFS2 272'n' E0-FF linux/matroxfb.h matroxfb 273'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2 274'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps) 275'o' 40-41 mtd/ubi-user.h UBI 276'o' 01-A1 `linux/dvb/*.h` DVB 277'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this) 278'p' 00-1F linux/rtc.h conflict! 279'p' 40-7F linux/nvram.h 280'p' 80-9F linux/ppdev.h user-space parport 281 <mailto:tim@cyberelk.net> 282'p' A1-A5 linux/pps.h LinuxPPS 283 <mailto:giometti@linux.it> 284'q' 00-1F linux/serio.h 285'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK 286 linux/ixjuser.h <http://web.archive.org/web/%2A/http://www.quicknet.net> 287'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c 288's' all linux/cdk.h 289't' 00-7F linux/ppp-ioctl.h 290't' 80-8F linux/isdn_ppp.h 291't' 90-91 linux/toshiba.h toshiba and toshiba_acpi SMM 292'u' 00-1F linux/smb_fs.h gone 293'u' 20-3F linux/uvcvideo.h USB video class host driver 294'u' 40-4f linux/udmabuf.h userspace dma-buf misc device 295'v' 00-1F linux/ext2_fs.h conflict! 296'v' 00-1F linux/fs.h conflict! 297'v' 00-0F linux/sonypi.h conflict! 298'v' 00-0F media/v4l2-subdev.h conflict! 299'v' 20-27 arch/powerpc/include/uapi/asm/vas-api.h VAS API 300'v' C0-FF linux/meye.h conflict! 301'w' all CERN SCI driver 302'y' 00-1F packet based user level communications 303 <mailto:zapman@interlan.net> 304'z' 00-3F CAN bus card conflict! 305 <mailto:hdstich@connectu.ulm.circular.de> 306'z' 40-7F CAN bus card conflict! 307 <mailto:oe@port.de> 308'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict! 309'|' 00-7F linux/media.h 3100x80 00-1F linux/fb.h 3110x81 00-1F linux/vduse.h 3120x89 00-06 arch/x86/include/asm/sockios.h 3130x89 0B-DF linux/sockios.h 3140x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range 3150x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range 3160x8A 00-1F linux/eventpoll.h 3170x8B all linux/wireless.h 3180x8C 00-3F WiNRADiO driver 319 <http://www.winradio.com.au/> 3200x90 00 drivers/cdrom/sbpcd.h 3210x92 00-0F drivers/usb/mon/mon_bin.c 3220x93 60-7F linux/auto_fs.h 3230x94 all fs/btrfs/ioctl.h Btrfs filesystem 324 and linux/fs.h some lifted to vfs/generic 3250x97 00-7F fs/ceph/ioctl.h Ceph file system 3260x99 00-0F 537-Addinboard driver 327 <mailto:buk@buks.ipn.de> 3280xA0 all linux/sdp/sdp.h Industrial Device Project 329 <mailto:kenji@bitgate.com> 3300xA1 0 linux/vtpm_proxy.h TPM Emulator Proxy Driver 3310xA2 all uapi/linux/acrn.h ACRN hypervisor 3320xA3 80-8F Port ACL in development: 333 <mailto:tlewis@mindspring.com> 3340xA3 90-9F linux/dtlk.h 3350xA4 00-1F uapi/linux/tee.h Generic TEE subsystem 3360xA4 00-1F uapi/asm/sgx.h <mailto:linux-sgx@vger.kernel.org> 3370xA5 01-05 linux/surface_aggregator/cdev.h Microsoft Surface Platform System Aggregator 338 <mailto:luzmaximilian@gmail.com> 3390xA5 20-2F linux/surface_aggregator/dtx.h Microsoft Surface DTX driver 340 <mailto:luzmaximilian@gmail.com> 3410xAA 00-3F linux/uapi/linux/userfaultfd.h 3420xAB 00-1F linux/nbd.h 3430xAC 00-1F linux/raw.h 3440xAD 00 Netfilter device in development: 345 <mailto:rusty@rustcorp.com.au> 3460xAE 00-1F linux/kvm.h Kernel-based Virtual Machine 347 <mailto:kvm@vger.kernel.org> 3480xAE 40-FF linux/kvm.h Kernel-based Virtual Machine 349 <mailto:kvm@vger.kernel.org> 3500xAE 20-3F linux/nitro_enclaves.h Nitro Enclaves 3510xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor 3520xB0 all RATIO devices in development: 353 <mailto:vgo@ratio.de> 3540xB1 00-1F PPPoX 355 <mailto:mostrows@styx.uwaterloo.ca> 3560xB2 00 arch/powerpc/include/uapi/asm/papr-vpd.h powerpc/pseries VPD API 357 <mailto:linuxppc-dev> 3580xB2 01-02 arch/powerpc/include/uapi/asm/papr-sysparm.h powerpc/pseries system parameter API 359 <mailto:linuxppc-dev> 3600xB3 00 linux/mmc/ioctl.h 3610xB4 00-0F linux/gpio.h <mailto:linux-gpio@vger.kernel.org> 3620xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc@vger.kernel.org> 3630xB6 all linux/fpga-dfl.h 3640xB7 all uapi/linux/remoteproc_cdev.h <mailto:linux-remoteproc@vger.kernel.org> 3650xB7 all uapi/linux/nsfs.h <mailto:Andrei Vagin <avagin@openvz.org>> 3660xC0 00-0F linux/usb/iowarrior.h 3670xCA 00-0F uapi/misc/cxl.h 3680xCA 10-2F uapi/misc/ocxl.h 3690xCA 80-BF uapi/scsi/cxlflash_ioctl.h 3700xCB 00-1F CBM serial IEC bus in development: 371 <mailto:michael.klein@puffin.lb.shuttle.de> 3720xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver 3730xCD 01 linux/reiserfs_fs.h 3740xCE 01-02 uapi/linux/cxl_mem.h Compute Express Link Memory Devices 3750xCF 02 fs/smb/client/cifs_ioctl.h 3760xDB 00-0F drivers/char/mwave/mwavepub.h 3770xDD 00-3F ZFCP device driver see drivers/s390/scsi/ 378 <mailto:aherrman@de.ibm.com> 3790xE5 00-3F linux/fuse.h 3800xEC 00-01 drivers/platform/chrome/cros_ec_dev.h ChromeOS EC driver 3810xEE 00-09 uapi/linux/pfrut.h Platform Firmware Runtime Update and Telemetry 3820xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development) 383 <mailto:thomas@winischhofer.net> 3840xF6 all LTTng Linux Trace Toolkit Next Generation 385 <mailto:mathieu.desnoyers@efficios.com> 3860xF8 all arch/x86/include/uapi/asm/amd_hsmp.h AMD HSMP EPYC system management interface driver 387 <mailto:nchatrad@amd.com> 3880xFD all linux/dm-ioctl.h 3890xFE all linux/isst_if.h 390==== ===== ======================================================= ================================================================ 391