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';'   80-FF  linux/iommufd.h
109'='   00-3f  uapi/linux/ptp_clock.h                                  <mailto:richardcochran@gmail.com>
110'@'   00-0F  linux/radeonfb.h                                        conflict!
111'@'   00-0F  drivers/video/aty/aty128fb.c                            conflict!
112'A'   00-1F  linux/apm_bios.h                                        conflict!
113'A'   00-0F  linux/agpgart.h,                                        conflict!
114             drivers/char/agp/compat_ioctl.h
115'A'   00-7F  sound/asound.h                                          conflict!
116'B'   00-1F  linux/cciss_ioctl.h                                     conflict!
117'B'   00-0F  include/linux/pmu.h                                     conflict!
118'B'   C0-FF  advanced bbus                                           <mailto:maassen@uni-freiburg.de>
119'B'   00-0F  xen/xenbus_dev.h                                        conflict!
120'C'   all    linux/soundcard.h                                       conflict!
121'C'   01-2F  linux/capi.h                                            conflict!
122'C'   F0-FF  drivers/net/wan/cosa.h                                  conflict!
123'D'   all    arch/s390/include/asm/dasd.h
124'D'   40-5F  drivers/scsi/dpt/dtpi_ioctl.h                           Dead since 2022
125'D'   05     drivers/scsi/pmcraid.h
126'E'   all    linux/input.h                                           conflict!
127'E'   00-0F  xen/evtchn.h                                            conflict!
128'F'   all    linux/fb.h                                              conflict!
129'F'   01-02  drivers/scsi/pmcraid.h                                  conflict!
130'F'   20     drivers/video/fsl-diu-fb.h                              conflict!
131'F'   20     drivers/video/intelfb/intelfb.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'O'   00-06  mtd/ubi-user.h                                          UBI
178'P'   all    linux/soundcard.h                                       conflict!
179'P'   60-6F  sound/sscape_ioctl.h                                    conflict!
180'P'   00-0F  drivers/usb/class/usblp.c                               conflict!
181'P'   01-09  drivers/misc/pci_endpoint_test.c                        conflict!
182'P'   00-0F  xen/privcmd.h                                           conflict!
183'Q'   all    linux/soundcard.h
184'R'   00-1F  linux/random.h                                          conflict!
185'R'   01     linux/rfkill.h                                          conflict!
186'R'   C0-DF  net/bluetooth/rfcomm.h
187'R'   E0     uapi/linux/fsl_mc.h
188'S'   all    linux/cdrom.h                                           conflict!
189'S'   80-81  scsi/scsi_ioctl.h                                       conflict!
190'S'   82-FF  scsi/scsi.h                                             conflict!
191'S'   00-7F  sound/asequencer.h                                      conflict!
192'T'   all    linux/soundcard.h                                       conflict!
193'T'   00-AF  sound/asound.h                                          conflict!
194'T'   all    arch/x86/include/asm/ioctls.h                           conflict!
195'T'   C0-DF  linux/if_tun.h                                          conflict!
196'U'   all    sound/asound.h                                          conflict!
197'U'   00-CF  linux/uinput.h                                          conflict!
198'U'   00-EF  linux/usbdevice_fs.h
199'U'   C0-CF  drivers/bluetooth/hci_uart.h
200'V'   all    linux/vt.h                                              conflict!
201'V'   all    linux/videodev2.h                                       conflict!
202'V'   C0     linux/ivtvfb.h                                          conflict!
203'V'   C0     linux/ivtv.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'b'   00-0F  linux/dma-buf.h                                         conflict!
225'c'   all    linux/cm4000_cs.h                                       conflict!
226'c'   00-7F  linux/comstats.h                                        conflict!
227'c'   00-7F  linux/coda.h                                            conflict!
228'c'   00-1F  linux/chio.h                                            conflict!
229'c'   80-9F  arch/s390/include/asm/chsc.h                            conflict!
230'c'   A0-AF  arch/x86/include/asm/msr.h conflict!
231'd'   00-FF  linux/char/drm/drm.h                                    conflict!
232'd'   02-40  pcmcia/ds.h                                             conflict!
233'd'   F0-FF  linux/digi1.h
234'e'   all    linux/digi1.h                                           conflict!
235'f'   00-1F  linux/ext2_fs.h                                         conflict!
236'f'   00-1F  linux/ext3_fs.h                                         conflict!
237'f'   00-0F  fs/jfs/jfs_dinode.h                                     conflict!
238'f'   00-0F  fs/ext4/ext4.h                                          conflict!
239'f'   00-0F  linux/fs.h                                              conflict!
240'f'   00-0F  fs/ocfs2/ocfs2_fs.h                                     conflict!
241'f'   13-27  linux/fscrypt.h
242'f'   81-8F  linux/fsverity.h
243'g'   00-0F  linux/usb/gadgetfs.h
244'g'   20-2F  linux/usb/g_printer.h
245'h'   00-7F                                                          conflict! Charon filesystem
246                                                                     <mailto:zapman@interlan.net>
247'h'   00-1F  linux/hpet.h                                            conflict!
248'h'   80-8F  fs/hfsplus/ioctl.c
249'i'   00-3F  linux/i2o-dev.h                                         conflict!
250'i'   0B-1F  linux/ipmi.h                                            conflict!
251'i'   80-8F  linux/i8k.h
252'i'   90-9F  `linux/iio/*.h`                                         IIO
253'j'   00-3F  linux/joystick.h
254'k'   00-0F  linux/spi/spidev.h                                      conflict!
255'k'   00-05  video/kyro.h                                            conflict!
256'k'   10-17  linux/hsi/hsi_char.h                                    HSI character device
257'l'   00-3F  linux/tcfs_fs.h                                         transparent cryptographic file system
258                                                                     <http://web.archive.org/web/%2A/http://mikonos.dia.unisa.it/tcfs>
259'l'   40-7F  linux/udf_fs_i.h                                        in development:
260                                                                     <https://github.com/pali/udftools>
261'm'   00-09  linux/mmtimer.h                                         conflict!
262'm'   all    linux/mtio.h                                            conflict!
263'm'   all    linux/soundcard.h                                       conflict!
264'm'   all    linux/synclink.h                                        conflict!
265'm'   00-19  drivers/message/fusion/mptctl.h                         conflict!
266'm'   00     drivers/scsi/megaraid/megaraid_ioctl.h                  conflict!
267'n'   00-7F  linux/ncp_fs.h and fs/ncpfs/ioctl.c
268'n'   80-8F  uapi/linux/nilfs2_api.h                                 NILFS2
269'n'   E0-FF  linux/matroxfb.h                                        matroxfb
270'o'   00-1F  fs/ocfs2/ocfs2_fs.h                                     OCFS2
271'o'   00-03  mtd/ubi-user.h                                          conflict! (OCFS2 and UBI overlaps)
272'o'   40-41  mtd/ubi-user.h                                          UBI
273'o'   01-A1  `linux/dvb/*.h`                                         DVB
274'p'   00-0F  linux/phantom.h                                         conflict! (OpenHaptics needs this)
275'p'   00-1F  linux/rtc.h                                             conflict!
276'p'   40-7F  linux/nvram.h
277'p'   80-9F  linux/ppdev.h                                           user-space parport
278                                                                     <mailto:tim@cyberelk.net>
279'p'   A1-A5  linux/pps.h                                             LinuxPPS
280                                                                     <mailto:giometti@linux.it>
281'q'   00-1F  linux/serio.h
282'q'   80-FF  linux/telephony.h                                       Internet PhoneJACK, Internet LineJACK
283             linux/ixjuser.h                                         <http://web.archive.org/web/%2A/http://www.quicknet.net>
284'r'   00-1F  linux/msdos_fs.h and fs/fat/dir.c
285's'   all    linux/cdk.h
286't'   00-7F  linux/ppp-ioctl.h
287't'   80-8F  linux/isdn_ppp.h
288't'   90-91  linux/toshiba.h                                         toshiba and toshiba_acpi SMM
289'u'   00-1F  linux/smb_fs.h                                          gone
290'u'   20-3F  linux/uvcvideo.h                                        USB video class host driver
291'u'   40-4f  linux/udmabuf.h                                         userspace dma-buf misc device
292'v'   00-1F  linux/ext2_fs.h                                         conflict!
293'v'   00-1F  linux/fs.h                                              conflict!
294'v'   00-0F  linux/sonypi.h                                          conflict!
295'v'   00-0F  media/v4l2-subdev.h                                     conflict!
296'v'   20-27  arch/powerpc/include/uapi/asm/vas-api.h		     VAS API
297'v'   C0-FF  linux/meye.h                                            conflict!
298'w'   all                                                            CERN SCI driver
299'y'   00-1F                                                          packet based user level communications
300                                                                     <mailto:zapman@interlan.net>
301'z'   00-3F                                                          CAN bus card conflict!
302                                                                     <mailto:hdstich@connectu.ulm.circular.de>
303'z'   40-7F                                                          CAN bus card conflict!
304                                                                     <mailto:oe@port.de>
305'z'   10-4F  drivers/s390/crypto/zcrypt_api.h                        conflict!
306'|'   00-7F  linux/media.h
3070x80  00-1F  linux/fb.h
3080x81  00-1F  linux/vduse.h
3090x89  00-06  arch/x86/include/asm/sockios.h
3100x89  0B-DF  linux/sockios.h
3110x89  E0-EF  linux/sockios.h                                         SIOCPROTOPRIVATE range
3120x89  F0-FF  linux/sockios.h                                         SIOCDEVPRIVATE range
3130x8B  all    linux/wireless.h
3140x8C  00-3F                                                          WiNRADiO driver
315                                                                     <http://www.winradio.com.au/>
3160x90  00     drivers/cdrom/sbpcd.h
3170x92  00-0F  drivers/usb/mon/mon_bin.c
3180x93  60-7F  linux/auto_fs.h
3190x94  all    fs/btrfs/ioctl.h                                        Btrfs filesystem
320             and linux/fs.h                                          some lifted to vfs/generic
3210x97  00-7F  fs/ceph/ioctl.h                                         Ceph file system
3220x99  00-0F                                                          537-Addinboard driver
323                                                                     <mailto:buk@buks.ipn.de>
3240xA0  all    linux/sdp/sdp.h                                         Industrial Device Project
325                                                                     <mailto:kenji@bitgate.com>
3260xA1  0      linux/vtpm_proxy.h                                      TPM Emulator Proxy Driver
3270xA2  all    uapi/linux/acrn.h                                       ACRN hypervisor
3280xA3  80-8F                                                          Port ACL  in development:
329                                                                     <mailto:tlewis@mindspring.com>
3300xA3  90-9F  linux/dtlk.h
3310xA4  00-1F  uapi/linux/tee.h                                        Generic TEE subsystem
3320xA4  00-1F  uapi/asm/sgx.h                                          <mailto:linux-sgx@vger.kernel.org>
3330xA5  01-05  linux/surface_aggregator/cdev.h                         Microsoft Surface Platform System Aggregator
334                                                                     <mailto:luzmaximilian@gmail.com>
3350xA5  20-2F  linux/surface_aggregator/dtx.h                          Microsoft Surface DTX driver
336                                                                     <mailto:luzmaximilian@gmail.com>
3370xAA  00-3F  linux/uapi/linux/userfaultfd.h
3380xAB  00-1F  linux/nbd.h
3390xAC  00-1F  linux/raw.h
3400xAD  00                                                             Netfilter device in development:
341                                                                     <mailto:rusty@rustcorp.com.au>
3420xAE  00-1F  linux/kvm.h                                             Kernel-based Virtual Machine
343                                                                     <mailto:kvm@vger.kernel.org>
3440xAE  40-FF  linux/kvm.h                                             Kernel-based Virtual Machine
345                                                                     <mailto:kvm@vger.kernel.org>
3460xAE  20-3F  linux/nitro_enclaves.h                                  Nitro Enclaves
3470xAF  00-1F  linux/fsl_hypervisor.h                                  Freescale hypervisor
3480xB0  all                                                            RATIO devices in development:
349                                                                     <mailto:vgo@ratio.de>
3500xB1  00-1F                                                          PPPoX
351                                                                     <mailto:mostrows@styx.uwaterloo.ca>
3520xB3  00     linux/mmc/ioctl.h
3530xB4  00-0F  linux/gpio.h                                            <mailto:linux-gpio@vger.kernel.org>
3540xB5  00-0F  uapi/linux/rpmsg.h                                      <mailto:linux-remoteproc@vger.kernel.org>
3550xB6  all    linux/fpga-dfl.h
3560xB7  all    uapi/linux/remoteproc_cdev.h                            <mailto:linux-remoteproc@vger.kernel.org>
3570xB7  all    uapi/linux/nsfs.h                                       <mailto:Andrei Vagin <avagin@openvz.org>>
3580xC0  00-0F  linux/usb/iowarrior.h
3590xCA  00-0F  uapi/misc/cxl.h
3600xCA  10-2F  uapi/misc/ocxl.h
3610xCA  80-BF  uapi/scsi/cxlflash_ioctl.h
3620xCB  00-1F                                                          CBM serial IEC bus in development:
363                                                                     <mailto:michael.klein@puffin.lb.shuttle.de>
3640xCC  00-0F  drivers/misc/ibmvmc.h                                   pseries VMC driver
3650xCD  01     linux/reiserfs_fs.h
3660xCE  01-02  uapi/linux/cxl_mem.h                                    Compute Express Link Memory Devices
3670xCF  02     fs/cifs/ioctl.c
3680xDB  00-0F  drivers/char/mwave/mwavepub.h
3690xDD  00-3F                                                          ZFCP device driver see drivers/s390/scsi/
370                                                                     <mailto:aherrman@de.ibm.com>
3710xE5  00-3F  linux/fuse.h
3720xEC  00-01  drivers/platform/chrome/cros_ec_dev.h                   ChromeOS EC driver
3730xEE  00-09  uapi/linux/pfrut.h                                      Platform Firmware Runtime Update and Telemetry
3740xF3  00-3F  drivers/usb/misc/sisusbvga/sisusb.h                     sisfb (in development)
375                                                                     <mailto:thomas@winischhofer.net>
3760xF6  all                                                            LTTng Linux Trace Toolkit Next Generation
377                                                                     <mailto:mathieu.desnoyers@efficios.com>
3780xF8  all    arch/x86/include/uapi/asm/amd_hsmp.h                    AMD HSMP EPYC system management interface driver
379                                                                     <mailto:nchatrad@amd.com>
3800xFD  all    linux/dm-ioctl.h
3810xFE  all    linux/isst_if.h
382====  =====  ======================================================= ================================================================
383