1============= 2Ioctl Numbers 3============= 4 519 October 1999 6 7Michael Elizabeth Chastain 8<[email protected]> 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 <[email protected]> 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:[email protected]> 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:[email protected]> 99'&' 00-07 drivers/firewire/nosy-user.h 100'*' 00-1F uapi/linux/user_events.h User Events Subsystem 101 <mailto:[email protected]> 102'1' 00-1F linux/timepps.h PPS kit from Ulrich Windl 103 <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/> 104'2' 01-04 linux/i2o.h 105'3' 00-0F drivers/s390/char/raw3270.h conflict! 106'3' 00-1F linux/suspend_ioctls.h, conflict! 107 kernel/power/user.c 108'8' all SNP8023 advanced NIC card 109 <mailto:[email protected]> 110';' 64-7F linux/vfio.h 111';' 80-FF linux/iommufd.h 112'=' 00-3f uapi/linux/ptp_clock.h <mailto:[email protected]> 113'@' 00-0F linux/radeonfb.h conflict! 114'@' 00-0F drivers/video/aty/aty128fb.c conflict! 115'A' 00-1F linux/apm_bios.h conflict! 116'A' 00-0F linux/agpgart.h, conflict! 117 drivers/char/agp/compat_ioctl.h 118'A' 00-7F sound/asound.h conflict! 119'B' 00-1F linux/cciss_ioctl.h conflict! 120'B' 00-0F include/linux/pmu.h conflict! 121'B' C0-FF advanced bbus <mailto:[email protected]> 122'B' 00-0F xen/xenbus_dev.h conflict! 123'C' all linux/soundcard.h conflict! 124'C' 01-2F linux/capi.h conflict! 125'C' F0-FF drivers/net/wan/cosa.h conflict! 126'D' all arch/s390/include/asm/dasd.h 127'D' 40-5F drivers/scsi/dpt/dtpi_ioctl.h Dead since 2022 128'D' 05 drivers/scsi/pmcraid.h 129'E' all linux/input.h conflict! 130'E' 00-0F xen/evtchn.h conflict! 131'F' all linux/fb.h conflict! 132'F' 01-02 drivers/scsi/pmcraid.h conflict! 133'F' 20 drivers/video/fsl-diu-fb.h conflict! 134'F' 20 linux/ivtvfb.h conflict! 135'F' 20 linux/matroxfb.h conflict! 136'F' 20 drivers/video/aty/atyfb_base.c conflict! 137'F' 00-0F video/da8xx-fb.h conflict! 138'F' 80-8F linux/arcfb.h conflict! 139'F' DD video/sstfb.h conflict! 140'G' 00-3F drivers/misc/sgi-gru/grulib.h conflict! 141'G' 00-0F xen/gntalloc.h, xen/gntdev.h conflict! 142'H' 00-7F linux/hiddev.h conflict! 143'H' 00-0F linux/hidraw.h conflict! 144'H' 01 linux/mei.h conflict! 145'H' 02 linux/mei.h conflict! 146'H' 03 linux/mei.h conflict! 147'H' 00-0F sound/asound.h conflict! 148'H' 20-40 sound/asound_fm.h conflict! 149'H' 80-8F sound/sfnt_info.h conflict! 150'H' 10-8F sound/emu10k1.h conflict! 151'H' 10-1F sound/sb16_csp.h conflict! 152'H' 10-1F sound/hda_hwdep.h conflict! 153'H' 40-4F sound/hdspm.h conflict! 154'H' 40-4F sound/hdsp.h conflict! 155'H' 90 sound/usb/usx2y/usb_stream.h 156'H' 00-0F uapi/misc/habanalabs.h conflict! 157'H' A0 uapi/linux/usb/cdc-wdm.h 158'H' C0-F0 net/bluetooth/hci.h conflict! 159'H' C0-DF net/bluetooth/hidp/hidp.h conflict! 160'H' C0-DF net/bluetooth/cmtp/cmtp.h conflict! 161'H' C0-DF net/bluetooth/bnep/bnep.h conflict! 162'H' F1 linux/hid-roccat.h <mailto:[email protected]> 163'H' F8-FA sound/firewire.h 164'I' all linux/isdn.h conflict! 165'I' 00-0F drivers/isdn/divert/isdn_divert.h conflict! 166'I' 40-4F linux/mISDNif.h conflict! 167'K' all linux/kd.h 168'L' 00-1F linux/loop.h conflict! 169'L' 10-1F drivers/scsi/mpt3sas/mpt3sas_ctl.h conflict! 170'L' E0-FF linux/ppdd.h encrypted disk device driver 171 <http://linux01.gwdg.de/~alatham/ppdd.html> 172'M' all linux/soundcard.h conflict! 173'M' 01-16 mtd/mtd-abi.h conflict! 174 and drivers/mtd/mtdchar.c 175'M' 01-03 drivers/scsi/megaraid/megaraid_sas.h 176'M' 00-0F drivers/video/fsl-diu-fb.h conflict! 177'N' 00-1F drivers/usb/scanner.h 178'N' 40-7F drivers/block/nvme.c 179'N' 80-8F uapi/linux/ntsync.h NT synchronization primitives 180 <mailto:[email protected]> 181'O' 00-06 mtd/ubi-user.h UBI 182'P' all linux/soundcard.h conflict! 183'P' 60-6F sound/sscape_ioctl.h conflict! 184'P' 00-0F drivers/usb/class/usblp.c conflict! 185'P' 01-09 drivers/misc/pci_endpoint_test.c conflict! 186'P' 00-0F xen/privcmd.h conflict! 187'P' 00-05 linux/tps6594_pfsm.h conflict! 188'Q' all linux/soundcard.h 189'R' 00-1F linux/random.h conflict! 190'R' 01 linux/rfkill.h conflict! 191'R' 20-2F linux/trace_mmap.h 192'R' C0-DF net/bluetooth/rfcomm.h 193'R' E0 uapi/linux/fsl_mc.h 194'S' all linux/cdrom.h conflict! 195'S' 80-81 scsi/scsi_ioctl.h conflict! 196'S' 82-FF scsi/scsi.h conflict! 197'S' 00-7F sound/asequencer.h conflict! 198'T' all linux/soundcard.h conflict! 199'T' 00-AF sound/asound.h conflict! 200'T' all arch/x86/include/asm/ioctls.h conflict! 201'T' C0-DF linux/if_tun.h conflict! 202'U' all sound/asound.h conflict! 203'U' 00-CF linux/uinput.h conflict! 204'U' 00-EF linux/usbdevice_fs.h 205'U' C0-CF drivers/bluetooth/hci_uart.h 206'V' all linux/vt.h conflict! 207'V' all linux/videodev2.h conflict! 208'V' C0 linux/ivtvfb.h conflict! 209'V' C0 linux/ivtv.h conflict! 210'V' C0 media/si4713.h conflict! 211'W' 00-1F linux/watchdog.h conflict! 212'W' 00-1F linux/wanrouter.h conflict! (pre 3.9) 213'W' 00-3F sound/asound.h conflict! 214'W' 40-5F drivers/pci/switch/switchtec.c 215'W' 60-61 linux/watch_queue.h 216'X' all fs/xfs/xfs_fs.h, conflict! 217 fs/xfs/linux-2.6/xfs_ioctl32.h, 218 include/linux/falloc.h, 219 linux/fs.h, 220'X' all fs/ocfs2/ocfs_fs.h conflict! 221'X' 01 linux/pktcdvd.h conflict! 222'Z' 14-15 drivers/message/fusion/mptctl.h 223'[' 00-3F linux/usb/tmc.h USB Test and Measurement Devices 224 <mailto:[email protected]> 225'a' all linux/atm*.h, linux/sonet.h ATM on linux 226 <http://lrcwww.epfl.ch/> 227'a' 00-0F drivers/crypto/qat/qat_common/adf_cfg_common.h conflict! qat driver 228'b' 00-FF conflict! bit3 vme host bridge 229 <mailto:[email protected]> 230'b' 00-0F linux/dma-buf.h conflict! 231'c' 00-7F linux/comstats.h conflict! 232'c' 00-7F linux/coda.h conflict! 233'c' 00-1F linux/chio.h conflict! 234'c' 80-9F arch/s390/include/asm/chsc.h conflict! 235'c' A0-AF arch/x86/include/asm/msr.h conflict! 236'd' 00-FF linux/char/drm/drm.h conflict! 237'd' 02-40 pcmcia/ds.h conflict! 238'd' F0-FF linux/digi1.h 239'e' all linux/digi1.h conflict! 240'f' 00-1F linux/ext2_fs.h conflict! 241'f' 00-1F linux/ext3_fs.h conflict! 242'f' 00-0F fs/jfs/jfs_dinode.h conflict! 243'f' 00-0F fs/ext4/ext4.h conflict! 244'f' 00-0F linux/fs.h conflict! 245'f' 00-0F fs/ocfs2/ocfs2_fs.h conflict! 246'f' 13-27 linux/fscrypt.h 247'f' 81-8F linux/fsverity.h 248'g' 00-0F linux/usb/gadgetfs.h 249'g' 20-2F linux/usb/g_printer.h 250'h' 00-7F conflict! Charon filesystem 251 <mailto:[email protected]> 252'h' 00-1F linux/hpet.h conflict! 253'h' 80-8F fs/hfsplus/ioctl.c 254'i' 00-3F linux/i2o-dev.h conflict! 255'i' 0B-1F linux/ipmi.h conflict! 256'i' 80-8F linux/i8k.h 257'i' 90-9F `linux/iio/*.h` IIO 258'j' 00-3F linux/joystick.h 259'k' 00-0F linux/spi/spidev.h conflict! 260'k' 00-05 video/kyro.h conflict! 261'k' 10-17 linux/hsi/hsi_char.h HSI character device 262'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system 263 <http://web.archive.org/web/%2A/http://mikonos.dia.unisa.it/tcfs> 264'l' 40-7F linux/udf_fs_i.h in development: 265 <https://github.com/pali/udftools> 266'm' 00-09 linux/mmtimer.h conflict! 267'm' all linux/mtio.h conflict! 268'm' all linux/soundcard.h conflict! 269'm' all linux/synclink.h conflict! 270'm' 00-19 drivers/message/fusion/mptctl.h conflict! 271'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict! 272'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c 273'n' 80-8F uapi/linux/nilfs2_api.h NILFS2 274'n' E0-FF linux/matroxfb.h matroxfb 275'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2 276'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps) 277'o' 40-41 mtd/ubi-user.h UBI 278'o' 01-A1 `linux/dvb/*.h` DVB 279'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this) 280'p' 00-1F linux/rtc.h conflict! 281'p' 40-7F linux/nvram.h 282'p' 80-9F linux/ppdev.h user-space parport 283 <mailto:[email protected]> 284'p' A1-A5 linux/pps.h LinuxPPS 285 <mailto:[email protected]> 286'q' 00-1F linux/serio.h 287'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK 288 linux/ixjuser.h <http://web.archive.org/web/%2A/http://www.quicknet.net> 289'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c 290's' all linux/cdk.h 291't' 00-7F linux/ppp-ioctl.h 292't' 80-8F linux/isdn_ppp.h 293't' 90-91 linux/toshiba.h toshiba and toshiba_acpi SMM 294'u' 00-1F linux/smb_fs.h gone 295'u' 20-3F linux/uvcvideo.h USB video class host driver 296'u' 40-4f linux/udmabuf.h userspace dma-buf misc device 297'v' 00-1F linux/ext2_fs.h conflict! 298'v' 00-1F linux/fs.h conflict! 299'v' 00-0F linux/sonypi.h conflict! 300'v' 00-0F media/v4l2-subdev.h conflict! 301'v' 20-27 arch/powerpc/include/uapi/asm/vas-api.h VAS API 302'v' C0-FF linux/meye.h conflict! 303'w' all CERN SCI driver 304'y' 00-1F packet based user level communications 305 <mailto:[email protected]> 306'z' 00-3F CAN bus card conflict! 307 <mailto:[email protected]> 308'z' 40-7F CAN bus card conflict! 309 <mailto:[email protected]> 310'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict! 311'|' 00-7F linux/media.h 3120x80 00-1F linux/fb.h 3130x81 00-1F linux/vduse.h 3140x89 00-06 arch/x86/include/asm/sockios.h 3150x89 0B-DF linux/sockios.h 3160x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range 3170x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range 3180x8A 00-1F linux/eventpoll.h 3190x8B all linux/wireless.h 3200x8C 00-3F WiNRADiO driver 321 <http://www.winradio.com.au/> 3220x90 00 drivers/cdrom/sbpcd.h 3230x92 00-0F drivers/usb/mon/mon_bin.c 3240x93 60-7F linux/auto_fs.h 3250x94 all fs/btrfs/ioctl.h Btrfs filesystem 326 and linux/fs.h some lifted to vfs/generic 3270x97 00-7F fs/ceph/ioctl.h Ceph file system 3280x99 00-0F 537-Addinboard driver 329 <mailto:[email protected]> 3300xA0 all linux/sdp/sdp.h Industrial Device Project 331 <mailto:[email protected]> 3320xA1 0 linux/vtpm_proxy.h TPM Emulator Proxy Driver 3330xA2 all uapi/linux/acrn.h ACRN hypervisor 3340xA3 80-8F Port ACL in development: 335 <mailto:[email protected]> 3360xA3 90-9F linux/dtlk.h 3370xA4 00-1F uapi/linux/tee.h Generic TEE subsystem 3380xA4 00-1F uapi/asm/sgx.h <mailto:[email protected]> 3390xA5 01-05 linux/surface_aggregator/cdev.h Microsoft Surface Platform System Aggregator 340 <mailto:[email protected]> 3410xA5 20-2F linux/surface_aggregator/dtx.h Microsoft Surface DTX driver 342 <mailto:[email protected]> 3430xAA 00-3F linux/uapi/linux/userfaultfd.h 3440xAB 00-1F linux/nbd.h 3450xAC 00-1F linux/raw.h 3460xAD 00 Netfilter device in development: 347 <mailto:[email protected]> 3480xAE 00-1F linux/kvm.h Kernel-based Virtual Machine 349 <mailto:[email protected]> 3500xAE 40-FF linux/kvm.h Kernel-based Virtual Machine 351 <mailto:[email protected]> 3520xAE 20-3F linux/nitro_enclaves.h Nitro Enclaves 3530xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor 3540xB0 all RATIO devices in development: 355 <mailto:[email protected]> 3560xB1 00-1F PPPoX 357 <mailto:[email protected]> 3580xB2 00 arch/powerpc/include/uapi/asm/papr-vpd.h powerpc/pseries VPD API 359 <mailto:linuxppc-dev> 3600xB2 01-02 arch/powerpc/include/uapi/asm/papr-sysparm.h powerpc/pseries system parameter API 361 <mailto:linuxppc-dev> 3620xB3 00 linux/mmc/ioctl.h 3630xB4 00-0F linux/gpio.h <mailto:[email protected]> 3640xB5 00-0F uapi/linux/rpmsg.h <mailto:[email protected]> 3650xB6 all linux/fpga-dfl.h 3660xB7 all uapi/linux/remoteproc_cdev.h <mailto:[email protected]> 3670xB7 all uapi/linux/nsfs.h <mailto:Andrei Vagin <[email protected]>> 3680xB8 01-02 uapi/misc/mrvl_cn10k_dpi.h Marvell CN10K DPI driver 3690xC0 00-0F linux/usb/iowarrior.h 3700xCA 00-0F uapi/misc/cxl.h 3710xCA 10-2F uapi/misc/ocxl.h 3720xCA 80-BF uapi/scsi/cxlflash_ioctl.h 3730xCB 00-1F CBM serial IEC bus in development: 374 <mailto:[email protected]> 3750xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver 3760xCD 01 linux/reiserfs_fs.h 3770xCE 01-02 uapi/linux/cxl_mem.h Compute Express Link Memory Devices 3780xCF 02 fs/smb/client/cifs_ioctl.h 3790xDB 00-0F drivers/char/mwave/mwavepub.h 3800xDD 00-3F ZFCP device driver see drivers/s390/scsi/ 381 <mailto:[email protected]> 3820xE5 00-3F linux/fuse.h 3830xEC 00-01 drivers/platform/chrome/cros_ec_dev.h ChromeOS EC driver 3840xEE 00-09 uapi/linux/pfrut.h Platform Firmware Runtime Update and Telemetry 3850xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development) 386 <mailto:[email protected]> 3870xF6 all LTTng Linux Trace Toolkit Next Generation 388 <mailto:[email protected]> 3890xF8 all arch/x86/include/uapi/asm/amd_hsmp.h AMD HSMP EPYC system management interface driver 390 <mailto:[email protected]> 3910xFD all linux/dm-ioctl.h 3920xFE all linux/isst_if.h 393==== ===== ======================================================= ================================================================ 394