tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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==== ===== ======================================================= ================================================================