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 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 880x15 all linux/fs.h FS_IOC_* ioctls 890x1b all InfiniBand Subsystem 90 <http://infiniband.sourceforge.net/> 910x20 all drivers/cdrom/cm206.h 920x22 all scsi/sg.h 930x3E 00-0F linux/counter.h <mailto:[email protected]> 94'!' 00-1F uapi/linux/seccomp.h 95'#' 00-3F IEEE 1394 Subsystem 96 Block for the entire subsystem 97'$' 00-0F linux/perf_counter.h, linux/perf_event.h 98'%' 00-0F include/uapi/linux/stm.h System Trace Module subsystem 99 <mailto:[email protected]> 100'&' 00-07 drivers/firewire/nosy-user.h 101'*' 00-1F uapi/linux/user_events.h User Events Subsystem 102 <mailto:[email protected]> 103'1' 00-1F linux/timepps.h PPS kit from Ulrich Windl 104 <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/> 105'2' 01-04 linux/i2o.h 106'3' 00-0F drivers/s390/char/raw3270.h conflict! 107'3' 00-1F linux/suspend_ioctls.h, conflict! 108 kernel/power/user.c 109'8' all SNP8023 advanced NIC card 110 <mailto:[email protected]> 111';' 64-7F linux/vfio.h 112';' 80-FF linux/iommufd.h 113'=' 00-3f uapi/linux/ptp_clock.h <mailto:[email protected]> 114'@' 00-0F linux/radeonfb.h conflict! 115'@' 00-0F drivers/video/aty/aty128fb.c conflict! 116'A' 00-1F linux/apm_bios.h conflict! 117'A' 00-0F linux/agpgart.h, conflict! 118 drivers/char/agp/compat_ioctl.h 119'A' 00-7F sound/asound.h conflict! 120'B' 00-1F linux/cciss_ioctl.h conflict! 121'B' 00-0F include/linux/pmu.h conflict! 122'B' C0-FF advanced bbus <mailto:[email protected]> 123'B' 00-0F xen/xenbus_dev.h conflict! 124'C' all linux/soundcard.h conflict! 125'C' 01-2F linux/capi.h conflict! 126'C' F0-FF drivers/net/wan/cosa.h conflict! 127'D' all arch/s390/include/asm/dasd.h 128'D' 40-5F drivers/scsi/dpt/dtpi_ioctl.h Dead since 2022 129'D' 05 drivers/scsi/pmcraid.h 130'E' all linux/input.h conflict! 131'E' 00-0F xen/evtchn.h conflict! 132'F' all linux/fb.h conflict! 133'F' 01-02 drivers/scsi/pmcraid.h conflict! 134'F' 20 drivers/video/fsl-diu-fb.h conflict! 135'F' 20 linux/ivtvfb.h conflict! 136'F' 20 linux/matroxfb.h conflict! 137'F' 20 drivers/video/aty/atyfb_base.c conflict! 138'F' 00-0F video/da8xx-fb.h conflict! 139'F' 80-8F linux/arcfb.h conflict! 140'F' DD video/sstfb.h conflict! 141'G' 00-3F drivers/misc/sgi-gru/grulib.h conflict! 142'G' 00-0F xen/gntalloc.h, xen/gntdev.h conflict! 143'H' 00-7F linux/hiddev.h conflict! 144'H' 00-0F linux/hidraw.h conflict! 145'H' 01 linux/mei.h conflict! 146'H' 02 linux/mei.h conflict! 147'H' 03 linux/mei.h conflict! 148'H' 00-0F sound/asound.h conflict! 149'H' 20-40 sound/asound_fm.h conflict! 150'H' 80-8F sound/sfnt_info.h conflict! 151'H' 10-8F sound/emu10k1.h conflict! 152'H' 10-1F sound/sb16_csp.h conflict! 153'H' 10-1F sound/hda_hwdep.h conflict! 154'H' 40-4F sound/hdspm.h conflict! 155'H' 40-4F sound/hdsp.h conflict! 156'H' 90 sound/usb/usx2y/usb_stream.h 157'H' 00-0F uapi/misc/habanalabs.h conflict! 158'H' A0 uapi/linux/usb/cdc-wdm.h 159'H' C0-F0 net/bluetooth/hci.h conflict! 160'H' C0-DF net/bluetooth/hidp/hidp.h conflict! 161'H' C0-DF net/bluetooth/cmtp/cmtp.h conflict! 162'H' C0-DF net/bluetooth/bnep/bnep.h conflict! 163'H' F1 linux/hid-roccat.h <mailto:[email protected]> 164'H' F8-FA sound/firewire.h 165'I' all linux/isdn.h conflict! 166'I' 00-0F drivers/isdn/divert/isdn_divert.h conflict! 167'I' 40-4F linux/mISDNif.h conflict! 168'K' all linux/kd.h 169'L' 00-1F linux/loop.h conflict! 170'L' 10-1F drivers/scsi/mpt3sas/mpt3sas_ctl.h conflict! 171'L' E0-FF linux/ppdd.h encrypted disk device driver 172 <http://linux01.gwdg.de/~alatham/ppdd.html> 173'M' all linux/soundcard.h conflict! 174'M' 01-16 mtd/mtd-abi.h conflict! 175 and drivers/mtd/mtdchar.c 176'M' 01-03 drivers/scsi/megaraid/megaraid_sas.h 177'M' 00-0F drivers/video/fsl-diu-fb.h conflict! 178'N' 00-1F drivers/usb/scanner.h 179'N' 40-7F drivers/block/nvme.c 180'N' 80-8F uapi/linux/ntsync.h NT synchronization primitives 181 <mailto:[email protected]> 182'O' 00-06 mtd/ubi-user.h UBI 183'P' all linux/soundcard.h conflict! 184'P' 60-6F sound/sscape_ioctl.h conflict! 185'P' 00-0F drivers/usb/class/usblp.c conflict! 186'P' 01-09 drivers/misc/pci_endpoint_test.c conflict! 187'P' 00-0F xen/privcmd.h conflict! 188'P' 00-05 linux/tps6594_pfsm.h conflict! 189'Q' all linux/soundcard.h 190'R' 00-1F linux/random.h conflict! 191'R' 01 linux/rfkill.h conflict! 192'R' 20-2F linux/trace_mmap.h 193'R' C0-DF net/bluetooth/rfcomm.h 194'R' E0 uapi/linux/fsl_mc.h 195'S' all linux/cdrom.h conflict! 196'S' 80-81 scsi/scsi_ioctl.h conflict! 197'S' 82-FF scsi/scsi.h conflict! 198'S' 00-7F sound/asequencer.h conflict! 199'T' all linux/soundcard.h conflict! 200'T' 00-AF sound/asound.h conflict! 201'T' all arch/x86/include/asm/ioctls.h conflict! 202'T' C0-DF linux/if_tun.h conflict! 203'U' all sound/asound.h conflict! 204'U' 00-CF linux/uinput.h conflict! 205'U' 00-EF linux/usbdevice_fs.h 206'U' C0-CF drivers/bluetooth/hci_uart.h 207'V' all linux/vt.h conflict! 208'V' all linux/videodev2.h conflict! 209'V' C0 linux/ivtvfb.h conflict! 210'V' C0 linux/ivtv.h conflict! 211'V' C0 media/si4713.h conflict! 212'W' 00-1F linux/watchdog.h conflict! 213'W' 00-1F linux/wanrouter.h conflict! (pre 3.9) 214'W' 00-3F sound/asound.h conflict! 215'W' 40-5F drivers/pci/switch/switchtec.c 216'W' 60-61 linux/watch_queue.h 217'X' all fs/xfs/xfs_fs.h, conflict! 218 fs/xfs/linux-2.6/xfs_ioctl32.h, 219 include/linux/falloc.h, 220 linux/fs.h, 221'X' all fs/ocfs2/ocfs_fs.h conflict! 222'X' 01 linux/pktcdvd.h conflict! 223'Z' 14-15 drivers/message/fusion/mptctl.h 224'[' 00-3F linux/usb/tmc.h USB Test and Measurement Devices 225 <mailto:[email protected]> 226'a' all linux/atm*.h, linux/sonet.h ATM on linux 227 <http://lrcwww.epfl.ch/> 228'a' 00-0F drivers/crypto/qat/qat_common/adf_cfg_common.h conflict! qat driver 229'b' 00-FF conflict! bit3 vme host bridge 230 <mailto:[email protected]> 231'b' 00-0F linux/dma-buf.h conflict! 232'c' 00-7F linux/comstats.h conflict! 233'c' 00-7F linux/coda.h conflict! 234'c' 00-1F linux/chio.h conflict! 235'c' 80-9F arch/s390/include/asm/chsc.h conflict! 236'c' A0-AF arch/x86/include/asm/msr.h conflict! 237'd' 00-FF linux/char/drm/drm.h conflict! 238'd' 02-40 pcmcia/ds.h conflict! 239'd' F0-FF linux/digi1.h 240'e' all linux/digi1.h conflict! 241'f' 00-1F linux/ext2_fs.h conflict! 242'f' 00-1F linux/ext3_fs.h conflict! 243'f' 00-0F fs/jfs/jfs_dinode.h conflict! 244'f' 00-0F fs/ext4/ext4.h conflict! 245'f' 00-0F linux/fs.h conflict! 246'f' 00-0F fs/ocfs2/ocfs2_fs.h conflict! 247'f' 13-27 linux/fscrypt.h 248'f' 81-8F linux/fsverity.h 249'g' 00-0F linux/usb/gadgetfs.h 250'g' 20-2F linux/usb/g_printer.h 251'h' 00-7F conflict! Charon filesystem 252 <mailto:[email protected]> 253'h' 00-1F linux/hpet.h conflict! 254'h' 80-8F fs/hfsplus/ioctl.c 255'i' 00-3F linux/i2o-dev.h conflict! 256'i' 0B-1F linux/ipmi.h conflict! 257'i' 80-8F linux/i8k.h 258'i' 90-9F `linux/iio/*.h` IIO 259'j' 00-3F linux/joystick.h 260'k' 00-0F linux/spi/spidev.h conflict! 261'k' 00-05 video/kyro.h conflict! 262'k' 10-17 linux/hsi/hsi_char.h HSI character device 263'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system 264 <http://web.archive.org/web/%2A/http://mikonos.dia.unisa.it/tcfs> 265'l' 40-7F linux/udf_fs_i.h in development: 266 <https://github.com/pali/udftools> 267'm' 00-09 linux/mmtimer.h conflict! 268'm' all linux/mtio.h conflict! 269'm' all linux/soundcard.h conflict! 270'm' all linux/synclink.h conflict! 271'm' 00-19 drivers/message/fusion/mptctl.h conflict! 272'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict! 273'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c 274'n' 80-8F uapi/linux/nilfs2_api.h NILFS2 275'n' E0-FF linux/matroxfb.h matroxfb 276'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2 277'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps) 278'o' 40-41 mtd/ubi-user.h UBI 279'o' 01-A1 `linux/dvb/*.h` DVB 280'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this) 281'p' 00-1F linux/rtc.h conflict! 282'p' 40-7F linux/nvram.h 283'p' 80-9F linux/ppdev.h user-space parport 284 <mailto:[email protected]> 285'p' A1-A5 linux/pps.h LinuxPPS 286'p' B1-B3 linux/pps_gen.h LinuxPPS 287 <mailto:[email protected]> 288'q' 00-1F linux/serio.h 289'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK 290 linux/ixjuser.h <http://web.archive.org/web/%2A/http://www.quicknet.net> 291'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c 292's' all linux/cdk.h 293't' 00-7F linux/ppp-ioctl.h 294't' 80-8F linux/isdn_ppp.h 295't' 90-91 linux/toshiba.h toshiba and toshiba_acpi SMM 296'u' 00-1F linux/smb_fs.h gone 297'u' 00-2F linux/ublk_cmd.h conflict! 298'u' 20-3F linux/uvcvideo.h USB video class host driver 299'u' 40-4f linux/udmabuf.h userspace dma-buf misc device 300'v' 00-1F linux/ext2_fs.h conflict! 301'v' 00-1F linux/fs.h conflict! 302'v' 00-0F linux/sonypi.h conflict! 303'v' 00-0F media/v4l2-subdev.h conflict! 304'v' 20-27 arch/powerpc/include/uapi/asm/vas-api.h VAS API 305'v' C0-FF linux/meye.h conflict! 306'w' all CERN SCI driver 307'y' 00-1F packet based user level communications 308 <mailto:[email protected]> 309'z' 00-3F CAN bus card conflict! 310 <mailto:[email protected]> 311'z' 40-7F CAN bus card conflict! 312 <mailto:[email protected]> 313'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict! 314'|' 00-7F linux/media.h 315'|' 80-9F samples/ Any sample and example drivers 3160x80 00-1F linux/fb.h 3170x81 00-1F linux/vduse.h 3180x89 00-06 arch/x86/include/asm/sockios.h 3190x89 0B-DF linux/sockios.h 3200x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range 3210x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range 3220x8A 00-1F linux/eventpoll.h 3230x8B all linux/wireless.h 3240x8C 00-3F WiNRADiO driver 325 <http://www.winradio.com.au/> 3260x90 00 drivers/cdrom/sbpcd.h 3270x92 00-0F drivers/usb/mon/mon_bin.c 3280x93 60-7F linux/auto_fs.h 3290x94 all fs/btrfs/ioctl.h Btrfs filesystem 330 and linux/fs.h some lifted to vfs/generic 3310x97 00-7F fs/ceph/ioctl.h Ceph file system 3320x99 00-0F 537-Addinboard driver 333 <mailto:[email protected]> 3340xA0 all linux/sdp/sdp.h Industrial Device Project 335 <mailto:[email protected]> 3360xA1 0 linux/vtpm_proxy.h TPM Emulator Proxy Driver 3370xA2 all uapi/linux/acrn.h ACRN hypervisor 3380xA3 80-8F Port ACL in development: 339 <mailto:[email protected]> 3400xA3 90-9F linux/dtlk.h 3410xA4 00-1F uapi/linux/tee.h Generic TEE subsystem 3420xA4 00-1F uapi/asm/sgx.h <mailto:[email protected]> 3430xA5 01-05 linux/surface_aggregator/cdev.h Microsoft Surface Platform System Aggregator 344 <mailto:[email protected]> 3450xA5 20-2F linux/surface_aggregator/dtx.h Microsoft Surface DTX driver 346 <mailto:[email protected]> 3470xAA 00-3F linux/uapi/linux/userfaultfd.h 3480xAB 00-1F linux/nbd.h 3490xAC 00-1F linux/raw.h 3500xAD 00 Netfilter device in development: 351 <mailto:[email protected]> 3520xAE 00-1F linux/kvm.h Kernel-based Virtual Machine 353 <mailto:[email protected]> 3540xAE 40-FF linux/kvm.h Kernel-based Virtual Machine 355 <mailto:[email protected]> 3560xAE 20-3F linux/nitro_enclaves.h Nitro Enclaves 3570xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor 3580xB0 all RATIO devices in development: 359 <mailto:[email protected]> 3600xB1 00-1F PPPoX 361 <mailto:[email protected]> 3620xB2 00 arch/powerpc/include/uapi/asm/papr-vpd.h powerpc/pseries VPD API 363 <mailto:linuxppc-dev> 3640xB2 01-02 arch/powerpc/include/uapi/asm/papr-sysparm.h powerpc/pseries system parameter API 365 <mailto:linuxppc-dev> 3660xB3 00 linux/mmc/ioctl.h 3670xB4 00-0F linux/gpio.h <mailto:[email protected]> 3680xB5 00-0F uapi/linux/rpmsg.h <mailto:[email protected]> 3690xB6 all linux/fpga-dfl.h 3700xB7 all uapi/linux/remoteproc_cdev.h <mailto:[email protected]> 3710xB7 all uapi/linux/nsfs.h <mailto:Andrei Vagin <[email protected]>> 3720xB8 01-02 uapi/misc/mrvl_cn10k_dpi.h Marvell CN10K DPI driver 3730xC0 00-0F linux/usb/iowarrior.h 3740xCA 00-0F uapi/misc/cxl.h 3750xCA 10-2F uapi/misc/ocxl.h 3760xCA 80-BF uapi/scsi/cxlflash_ioctl.h 3770xCB 00-1F CBM serial IEC bus in development: 378 <mailto:[email protected]> 3790xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver 3800xCD 01 linux/reiserfs_fs.h Dead since 6.13 3810xCE 01-02 uapi/linux/cxl_mem.h Compute Express Link Memory Devices 3820xCF 02 fs/smb/client/cifs_ioctl.h 3830xDB 00-0F drivers/char/mwave/mwavepub.h 3840xDD 00-3F ZFCP device driver see drivers/s390/scsi/ 385 <mailto:[email protected]> 3860xE5 00-3F linux/fuse.h 3870xEC 00-01 drivers/platform/chrome/cros_ec_dev.h ChromeOS EC driver 3880xEE 00-09 uapi/linux/pfrut.h Platform Firmware Runtime Update and Telemetry 3890xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development) 390 <mailto:[email protected]> 3910xF6 all LTTng Linux Trace Toolkit Next Generation 392 <mailto:[email protected]> 3930xF8 all arch/x86/include/uapi/asm/amd_hsmp.h AMD HSMP EPYC system management interface driver 394 <mailto:[email protected]> 3950xFD all linux/dm-ioctl.h 3960xFE all linux/isst_if.h 397==== ===== ======================================================= ================================================================ 398