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
86             linux/blkpg.h
870x1b  all                                                            InfiniBand Subsystem
88                                                                     <http://infiniband.sourceforge.net/>
890x20  all    drivers/cdrom/cm206.h
900x22  all    scsi/sg.h
910x3E  00-0F  linux/counter.h                                         <mailto:linux-iio@vger.kernel.org>
92'!'   00-1F  uapi/linux/seccomp.h
93'#'   00-3F                                                          IEEE 1394 Subsystem
94                                                                     Block for the entire subsystem
95'$'   00-0F  linux/perf_counter.h, linux/perf_event.h
96'%'   00-0F  include/uapi/linux/stm.h                                System Trace Module subsystem
97                                                                     <mailto:alexander.shishkin@linux.intel.com>
98'&'   00-07  drivers/firewire/nosy-user.h
99'1'   00-1F  linux/timepps.h                                         PPS kit from Ulrich Windl
100                                                                     <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/>
101'2'   01-04  linux/i2o.h
102'3'   00-0F  drivers/s390/char/raw3270.h                             conflict!
103'3'   00-1F  linux/suspend_ioctls.h,                                 conflict!
104             kernel/power/user.c
105'8'   all                                                            SNP8023 advanced NIC card
106                                                                     <mailto:mcr@solidum.com>
107';'   64-7F  linux/vfio.h
108'='   00-3f  uapi/linux/ptp_clock.h                                  <mailto:richardcochran@gmail.com>
109'@'   00-0F  linux/radeonfb.h                                        conflict!
110'@'   00-0F  drivers/video/aty/aty128fb.c                            conflict!
111'A'   00-1F  linux/apm_bios.h                                        conflict!
112'A'   00-0F  linux/agpgart.h,                                        conflict!
113             drivers/char/agp/compat_ioctl.h
114'A'   00-7F  sound/asound.h                                          conflict!
115'B'   00-1F  linux/cciss_ioctl.h                                     conflict!
116'B'   00-0F  include/linux/pmu.h                                     conflict!
117'B'   C0-FF  advanced bbus                                           <mailto:maassen@uni-freiburg.de>
118'B'   00-0F  xen/xenbus_dev.h                                        conflict!
119'C'   all    linux/soundcard.h                                       conflict!
120'C'   01-2F  linux/capi.h                                            conflict!
121'C'   F0-FF  drivers/net/wan/cosa.h                                  conflict!
122'D'   all    arch/s390/include/asm/dasd.h
123'D'   40-5F  drivers/scsi/dpt/dtpi_ioctl.h                           Dead since 2022
124'D'   05     drivers/scsi/pmcraid.h
125'E'   all    linux/input.h                                           conflict!
126'E'   00-0F  xen/evtchn.h                                            conflict!
127'F'   all    linux/fb.h                                              conflict!
128'F'   01-02  drivers/scsi/pmcraid.h                                  conflict!
129'F'   20     drivers/video/fsl-diu-fb.h                              conflict!
130'F'   20     drivers/video/intelfb/intelfb.h                         conflict!
131'F'   20     linux/ivtvfb.h                                          conflict!
132'F'   20     linux/matroxfb.h                                        conflict!
133'F'   20     drivers/video/aty/atyfb_base.c                          conflict!
134'F'   00-0F  video/da8xx-fb.h                                        conflict!
135'F'   80-8F  linux/arcfb.h                                           conflict!
136'F'   DD     video/sstfb.h                                           conflict!
137'G'   00-3F  drivers/misc/sgi-gru/grulib.h                           conflict!
138'G'   00-0F  xen/gntalloc.h, xen/gntdev.h                            conflict!
139'H'   00-7F  linux/hiddev.h                                          conflict!
140'H'   00-0F  linux/hidraw.h                                          conflict!
141'H'   01     linux/mei.h                                             conflict!
142'H'   02     linux/mei.h                                             conflict!
143'H'   03     linux/mei.h                                             conflict!
144'H'   00-0F  sound/asound.h                                          conflict!
145'H'   20-40  sound/asound_fm.h                                       conflict!
146'H'   80-8F  sound/sfnt_info.h                                       conflict!
147'H'   10-8F  sound/emu10k1.h                                         conflict!
148'H'   10-1F  sound/sb16_csp.h                                        conflict!
149'H'   10-1F  sound/hda_hwdep.h                                       conflict!
150'H'   40-4F  sound/hdspm.h                                           conflict!
151'H'   40-4F  sound/hdsp.h                                            conflict!
152'H'   90     sound/usb/usx2y/usb_stream.h
153'H'   00-0F  uapi/misc/habanalabs.h                                  conflict!
154'H'   A0     uapi/linux/usb/cdc-wdm.h
155'H'   C0-F0  net/bluetooth/hci.h                                     conflict!
156'H'   C0-DF  net/bluetooth/hidp/hidp.h                               conflict!
157'H'   C0-DF  net/bluetooth/cmtp/cmtp.h                               conflict!
158'H'   C0-DF  net/bluetooth/bnep/bnep.h                               conflict!
159'H'   F1     linux/hid-roccat.h                                      <mailto:erazor_de@users.sourceforge.net>
160'H'   F8-FA  sound/firewire.h
161'I'   all    linux/isdn.h                                            conflict!
162'I'   00-0F  drivers/isdn/divert/isdn_divert.h                       conflict!
163'I'   40-4F  linux/mISDNif.h                                         conflict!
164'K'   all    linux/kd.h
165'L'   00-1F  linux/loop.h                                            conflict!
166'L'   10-1F  drivers/scsi/mpt3sas/mpt3sas_ctl.h                      conflict!
167'L'   E0-FF  linux/ppdd.h                                            encrypted disk device driver
168                                                                     <http://linux01.gwdg.de/~alatham/ppdd.html>
169'M'   all    linux/soundcard.h                                       conflict!
170'M'   01-16  mtd/mtd-abi.h                                           conflict!
171      and    drivers/mtd/mtdchar.c
172'M'   01-03  drivers/scsi/megaraid/megaraid_sas.h
173'M'   00-0F  drivers/video/fsl-diu-fb.h                              conflict!
174'N'   00-1F  drivers/usb/scanner.h
175'N'   40-7F  drivers/block/nvme.c
176'O'   00-06  mtd/ubi-user.h                                          UBI
177'P'   all    linux/soundcard.h                                       conflict!
178'P'   60-6F  sound/sscape_ioctl.h                                    conflict!
179'P'   00-0F  drivers/usb/class/usblp.c                               conflict!
180'P'   01-09  drivers/misc/pci_endpoint_test.c                        conflict!
181'P'   00-0F  xen/privcmd.h                                           conflict!
182'Q'   all    linux/soundcard.h
183'R'   00-1F  linux/random.h                                          conflict!
184'R'   01     linux/rfkill.h                                          conflict!
185'R'   C0-DF  net/bluetooth/rfcomm.h
186'R'   E0     uapi/linux/fsl_mc.h
187'S'   all    linux/cdrom.h                                           conflict!
188'S'   80-81  scsi/scsi_ioctl.h                                       conflict!
189'S'   82-FF  scsi/scsi.h                                             conflict!
190'S'   00-7F  sound/asequencer.h                                      conflict!
191'T'   all    linux/soundcard.h                                       conflict!
192'T'   00-AF  sound/asound.h                                          conflict!
193'T'   all    arch/x86/include/asm/ioctls.h                           conflict!
194'T'   C0-DF  linux/if_tun.h                                          conflict!
195'U'   all    sound/asound.h                                          conflict!
196'U'   00-CF  linux/uinput.h                                          conflict!
197'U'   00-EF  linux/usbdevice_fs.h
198'U'   C0-CF  drivers/bluetooth/hci_uart.h
199'V'   all    linux/vt.h                                              conflict!
200'V'   all    linux/videodev2.h                                       conflict!
201'V'   C0     linux/ivtvfb.h                                          conflict!
202'V'   C0     linux/ivtv.h                                            conflict!
203'V'   C0     media/davinci/vpfe_capture.h                            conflict!
204'V'   C0     media/si4713.h                                          conflict!
205'W'   00-1F  linux/watchdog.h                                        conflict!
206'W'   00-1F  linux/wanrouter.h                                       conflict! (pre 3.9)
207'W'   00-3F  sound/asound.h                                          conflict!
208'W'   40-5F  drivers/pci/switch/switchtec.c
209'W'   60-61  linux/watch_queue.h
210'X'   all    fs/xfs/xfs_fs.h,                                        conflict!
211             fs/xfs/linux-2.6/xfs_ioctl32.h,
212             include/linux/falloc.h,
213             linux/fs.h,
214'X'   all    fs/ocfs2/ocfs_fs.h                                      conflict!
215'X'   01     linux/pktcdvd.h                                         conflict!
216'Z'   14-15  drivers/message/fusion/mptctl.h
217'['   00-3F  linux/usb/tmc.h                                         USB Test and Measurement Devices
218                                                                     <mailto:gregkh@linuxfoundation.org>
219'a'   all    linux/atm*.h, linux/sonet.h                             ATM on linux
220                                                                     <http://lrcwww.epfl.ch/>
221'a'   00-0F  drivers/crypto/qat/qat_common/adf_cfg_common.h          conflict! qat driver
222'b'   00-FF                                                          conflict! bit3 vme host bridge
223                                                                     <mailto:natalia@nikhefk.nikhef.nl>
224'c'   all    linux/cm4000_cs.h                                       conflict!
225'c'   00-7F  linux/comstats.h                                        conflict!
226'c'   00-7F  linux/coda.h                                            conflict!
227'c'   00-1F  linux/chio.h                                            conflict!
228'c'   80-9F  arch/s390/include/asm/chsc.h                            conflict!
229'c'   A0-AF  arch/x86/include/asm/msr.h conflict!
230'd'   00-FF  linux/char/drm/drm.h                                    conflict!
231'd'   02-40  pcmcia/ds.h                                             conflict!
232'd'   F0-FF  linux/digi1.h
233'e'   all    linux/digi1.h                                           conflict!
234'f'   00-1F  linux/ext2_fs.h                                         conflict!
235'f'   00-1F  linux/ext3_fs.h                                         conflict!
236'f'   00-0F  fs/jfs/jfs_dinode.h                                     conflict!
237'f'   00-0F  fs/ext4/ext4.h                                          conflict!
238'f'   00-0F  linux/fs.h                                              conflict!
239'f'   00-0F  fs/ocfs2/ocfs2_fs.h                                     conflict!
240'f'   13-27  linux/fscrypt.h
241'f'   81-8F  linux/fsverity.h
242'g'   00-0F  linux/usb/gadgetfs.h
243'g'   20-2F  linux/usb/g_printer.h
244'h'   00-7F                                                          conflict! Charon filesystem
245                                                                     <mailto:zapman@interlan.net>
246'h'   00-1F  linux/hpet.h                                            conflict!
247'h'   80-8F  fs/hfsplus/ioctl.c
248'i'   00-3F  linux/i2o-dev.h                                         conflict!
249'i'   0B-1F  linux/ipmi.h                                            conflict!
250'i'   80-8F  linux/i8k.h
251'i'   90-9F  `linux/iio/*.h`                                         IIO
252'j'   00-3F  linux/joystick.h
253'k'   00-0F  linux/spi/spidev.h                                      conflict!
254'k'   00-05  video/kyro.h                                            conflict!
255'k'   10-17  linux/hsi/hsi_char.h                                    HSI character device
256'l'   00-3F  linux/tcfs_fs.h                                         transparent cryptographic file system
257                                                                     <http://web.archive.org/web/%2A/http://mikonos.dia.unisa.it/tcfs>
258'l'   40-7F  linux/udf_fs_i.h                                        in development:
259                                                                     <https://github.com/pali/udftools>
260'm'   00-09  linux/mmtimer.h                                         conflict!
261'm'   all    linux/mtio.h                                            conflict!
262'm'   all    linux/soundcard.h                                       conflict!
263'm'   all    linux/synclink.h                                        conflict!
264'm'   00-19  drivers/message/fusion/mptctl.h                         conflict!
265'm'   00     drivers/scsi/megaraid/megaraid_ioctl.h                  conflict!
266'n'   00-7F  linux/ncp_fs.h and fs/ncpfs/ioctl.c
267'n'   80-8F  uapi/linux/nilfs2_api.h                                 NILFS2
268'n'   E0-FF  linux/matroxfb.h                                        matroxfb
269'o'   00-1F  fs/ocfs2/ocfs2_fs.h                                     OCFS2
270'o'   00-03  mtd/ubi-user.h                                          conflict! (OCFS2 and UBI overlaps)
271'o'   40-41  mtd/ubi-user.h                                          UBI
272'o'   01-A1  `linux/dvb/*.h`                                         DVB
273'p'   00-0F  linux/phantom.h                                         conflict! (OpenHaptics needs this)
274'p'   00-1F  linux/rtc.h                                             conflict!
275'p'   40-7F  linux/nvram.h
276'p'   80-9F  linux/ppdev.h                                           user-space parport
277                                                                     <mailto:tim@cyberelk.net>
278'p'   A1-A5  linux/pps.h                                             LinuxPPS
279                                                                     <mailto:giometti@linux.it>
280'q'   00-1F  linux/serio.h
281'q'   80-FF  linux/telephony.h                                       Internet PhoneJACK, Internet LineJACK
282             linux/ixjuser.h                                         <http://web.archive.org/web/%2A/http://www.quicknet.net>
283'r'   00-1F  linux/msdos_fs.h and fs/fat/dir.c
284's'   all    linux/cdk.h
285't'   00-7F  linux/ppp-ioctl.h
286't'   80-8F  linux/isdn_ppp.h
287't'   90-91  linux/toshiba.h                                         toshiba and toshiba_acpi SMM
288'u'   00-1F  linux/smb_fs.h                                          gone
289'u'   20-3F  linux/uvcvideo.h                                        USB video class host driver
290'u'   40-4f  linux/udmabuf.h                                         userspace dma-buf misc device
291'v'   00-1F  linux/ext2_fs.h                                         conflict!
292'v'   00-1F  linux/fs.h                                              conflict!
293'v'   00-0F  linux/sonypi.h                                          conflict!
294'v'   00-0F  media/v4l2-subdev.h                                     conflict!
295'v'   20-27  arch/powerpc/include/uapi/asm/vas-api.h		     VAS API
296'v'   C0-FF  linux/meye.h                                            conflict!
297'w'   all                                                            CERN SCI driver
298'y'   00-1F                                                          packet based user level communications
299                                                                     <mailto:zapman@interlan.net>
300'z'   00-3F                                                          CAN bus card conflict!
301                                                                     <mailto:hdstich@connectu.ulm.circular.de>
302'z'   40-7F                                                          CAN bus card conflict!
303                                                                     <mailto:oe@port.de>
304'z'   10-4F  drivers/s390/crypto/zcrypt_api.h                        conflict!
305'|'   00-7F  linux/media.h
3060x80  00-1F  linux/fb.h
3070x81  00-1F  linux/vduse.h
3080x89  00-06  arch/x86/include/asm/sockios.h
3090x89  0B-DF  linux/sockios.h
3100x89  E0-EF  linux/sockios.h                                         SIOCPROTOPRIVATE range
3110x89  F0-FF  linux/sockios.h                                         SIOCDEVPRIVATE range
3120x8B  all    linux/wireless.h
3130x8C  00-3F                                                          WiNRADiO driver
314                                                                     <http://www.winradio.com.au/>
3150x90  00     drivers/cdrom/sbpcd.h
3160x92  00-0F  drivers/usb/mon/mon_bin.c
3170x93  60-7F  linux/auto_fs.h
3180x94  all    fs/btrfs/ioctl.h                                        Btrfs filesystem
319             and linux/fs.h                                          some lifted to vfs/generic
3200x97  00-7F  fs/ceph/ioctl.h                                         Ceph file system
3210x99  00-0F                                                          537-Addinboard driver
322                                                                     <mailto:buk@buks.ipn.de>
3230xA0  all    linux/sdp/sdp.h                                         Industrial Device Project
324                                                                     <mailto:kenji@bitgate.com>
3250xA1  0      linux/vtpm_proxy.h                                      TPM Emulator Proxy Driver
3260xA2  all    uapi/linux/acrn.h                                       ACRN hypervisor
3270xA3  80-8F                                                          Port ACL  in development:
328                                                                     <mailto:tlewis@mindspring.com>
3290xA3  90-9F  linux/dtlk.h
3300xA4  00-1F  uapi/linux/tee.h                                        Generic TEE subsystem
3310xA4  00-1F  uapi/asm/sgx.h                                          <mailto:linux-sgx@vger.kernel.org>
3320xA5  01-05  linux/surface_aggregator/cdev.h                         Microsoft Surface Platform System Aggregator
333                                                                     <mailto:luzmaximilian@gmail.com>
3340xA5  20-2F  linux/surface_aggregator/dtx.h                          Microsoft Surface DTX driver
335                                                                     <mailto:luzmaximilian@gmail.com>
3360xAA  00-3F  linux/uapi/linux/userfaultfd.h
3370xAB  00-1F  linux/nbd.h
3380xAC  00-1F  linux/raw.h
3390xAD  00                                                             Netfilter device in development:
340                                                                     <mailto:rusty@rustcorp.com.au>
3410xAE  00-1F  linux/kvm.h                                             Kernel-based Virtual Machine
342                                                                     <mailto:kvm@vger.kernel.org>
3430xAE  40-FF  linux/kvm.h                                             Kernel-based Virtual Machine
344                                                                     <mailto:kvm@vger.kernel.org>
3450xAE  20-3F  linux/nitro_enclaves.h                                  Nitro Enclaves
3460xAF  00-1F  linux/fsl_hypervisor.h                                  Freescale hypervisor
3470xB0  all                                                            RATIO devices in development:
348                                                                     <mailto:vgo@ratio.de>
3490xB1  00-1F                                                          PPPoX
350                                                                     <mailto:mostrows@styx.uwaterloo.ca>
3510xB3  00     linux/mmc/ioctl.h
3520xB4  00-0F  linux/gpio.h                                            <mailto:linux-gpio@vger.kernel.org>
3530xB5  00-0F  uapi/linux/rpmsg.h                                      <mailto:linux-remoteproc@vger.kernel.org>
3540xB6  all    linux/fpga-dfl.h
3550xB7  all    uapi/linux/remoteproc_cdev.h                            <mailto:linux-remoteproc@vger.kernel.org>
3560xB7  all    uapi/linux/nsfs.h                                       <mailto:Andrei Vagin <avagin@openvz.org>>
3570xC0  00-0F  linux/usb/iowarrior.h
3580xCA  00-0F  uapi/misc/cxl.h
3590xCA  10-2F  uapi/misc/ocxl.h
3600xCA  80-BF  uapi/scsi/cxlflash_ioctl.h
3610xCB  00-1F                                                          CBM serial IEC bus in development:
362                                                                     <mailto:michael.klein@puffin.lb.shuttle.de>
3630xCC  00-0F  drivers/misc/ibmvmc.h                                   pseries VMC driver
3640xCD  01     linux/reiserfs_fs.h
3650xCE  01-02  uapi/linux/cxl_mem.h                                    Compute Express Link Memory Devices
3660xCF  02     fs/cifs/ioctl.c
3670xDB  00-0F  drivers/char/mwave/mwavepub.h
3680xDD  00-3F                                                          ZFCP device driver see drivers/s390/scsi/
369                                                                     <mailto:aherrman@de.ibm.com>
3700xE5  00-3F  linux/fuse.h
3710xEC  00-01  drivers/platform/chrome/cros_ec_dev.h                   ChromeOS EC driver
3720xEE  00-09  uapi/linux/pfrut.h                                      Platform Firmware Runtime Update and Telemetry
3730xF3  00-3F  drivers/usb/misc/sisusbvga/sisusb.h                     sisfb (in development)
374                                                                     <mailto:thomas@winischhofer.net>
3750xF6  all                                                            LTTng Linux Trace Toolkit Next Generation
376                                                                     <mailto:mathieu.desnoyers@efficios.com>
3770xF8  all    arch/x86/include/uapi/asm/amd_hsmp.h                    AMD HSMP EPYC system management interface driver
378                                                                     <mailto:nchatrad@amd.com>
3790xFD  all    linux/dm-ioctl.h
3800xFE  all    linux/isst_if.h
381====  =====  ======================================================= ================================================================
382