3 Michael Elizabeth Chastain
6 If you are adding new ioctl's to the kernel, you should use the _IO
7 macros defined in <linux/ioctl.h>:
9 _IO an ioctl with no parameters
10 _IOW an ioctl with write parameters (copy_from_user)
11 _IOR an ioctl with read parameters (copy_to_user)
12 _IOWR an ioctl with both write and read parameters.
14 'Write' and 'read' are from the user's point of view, just like the
15 system calls 'write' and 'read'. For example, a SET_FOO ioctl would
16 be _IOW, although the kernel would actually read data from user space;
17 a GET_FOO ioctl would be _IOR, although the kernel would actually write
20 The first argument to _IO, _IOW, _IOR, or _IOWR is an identifying letter
21 or number from the table below. Because of the large number of drivers,
22 many drivers share a partial letter with other drivers.
24 If you are writing a driver for a new device and need a letter, pick an
25 unused block with enough room for expansion: 32 to 256 ioctl commands.
26 You can register the block by patching this file and submitting the
27 patch to Linus Torvalds. Or you can e-mail me at <mec@shout.net> and
28 I'll register one for you.
30 The second argument to _IO, _IOW, _IOR, or _IOWR is a sequence number
31 to distinguish ioctls from each other. The third argument to _IOW,
32 _IOR, or _IOWR is the type of the data going into the kernel or coming
33 out of the kernel (e.g. 'int' or 'struct foo'). NOTE! Do NOT use
34 sizeof(arg) as the third argument as this results in your ioctl thinking
35 it passes an argument of type size_t.
37 Some devices use their major number as the identifier; this is OK, as
38 long as it is unique. Some devices are irregular and don't follow any
41 Following this convention is good because:
43 (1) Keeping the ioctl's globally unique helps error checking:
44 if a program calls an ioctl on the wrong device, it will get an
45 error rather than some unexpected behaviour.
47 (2) The 'strace' build procedure automatically finds ioctl numbers
48 defined with _IO, _IOW, _IOR, or _IOWR.
50 (3) 'strace' can decode numbers back into useful names when the
53 (4) People looking for ioctls can grep for them more easily when
54 this convention is used to define the ioctl numbers.
56 (5) When following the convention, the driver code can use generic
57 code to copy the parameters between user and kernel space.
59 This table lists ioctls visible from user land for Linux/x86. It contains
60 most drivers up to 2.6.31, but I know I am missing some. There has been
61 no attempt to list non-X86 architectures or ioctls from drivers/staging/.
63 Code Seq#(hex) Include File Comments
64 ========================================================
65 0x00 00-1F linux/fs.h conflict!
66 0x00 00-1F scsi/scsi_ioctl.h conflict!
67 0x00 00-1F linux/fb.h conflict!
68 0x00 00-1F linux/wavefront.h conflict!
70 0x03 all linux/hdreg.h
71 0x04 D2-DC linux/umsdos_fs.h Dead since 2.6.11, but don't reuse these.
73 0x09 all linux/raid/md_u.h
74 0x10 00-0F drivers/char/s390/vmcp.h
75 0x10 10-1F arch/s390/include/uapi/sclp_ctl.h
76 0x10 20-2F arch/s390/include/uapi/asm/hypfs.h
79 0x1b all InfiniBand Subsystem <http://infiniband.sourceforge.net/>
80 0x20 all drivers/cdrom/cm206.h
82 '!' 00-1F uapi/linux/seccomp.h
83 '#' 00-3F IEEE 1394 Subsystem Block for the entire subsystem
84 '$' 00-0F linux/perf_counter.h, linux/perf_event.h
85 '%' 00-0F include/uapi/linux/stm.h
86 System Trace Module subsystem
87 <mailto:alexander.shishkin@linux.intel.com>
88 '&' 00-07 drivers/firewire/nosy-user.h
89 '1' 00-1F <linux/timepps.h> PPS kit from Ulrich Windl
90 <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/>
92 '3' 00-0F drivers/s390/char/raw3270.h conflict!
93 '3' 00-1F linux/suspend_ioctls.h conflict!
94 and kernel/power/user.c
95 '8' all SNP8023 advanced NIC card
96 <mailto:mcr@solidum.com>
97 ';' 64-7F linux/vfio.h
98 '@' 00-0F linux/radeonfb.h conflict!
99 '@' 00-0F drivers/video/aty/aty128fb.c conflict!
100 'A' 00-1F linux/apm_bios.h conflict!
101 'A' 00-0F linux/agpgart.h conflict!
102 and drivers/char/agp/compat_ioctl.h
103 'A' 00-7F sound/asound.h conflict!
104 'B' 00-1F linux/cciss_ioctl.h conflict!
105 'B' 00-0F include/linux/pmu.h conflict!
106 'B' C0-FF advanced bbus
107 <mailto:maassen@uni-freiburg.de>
108 'C' all linux/soundcard.h conflict!
109 'C' 01-2F linux/capi.h conflict!
110 'C' F0-FF drivers/net/wan/cosa.h conflict!
111 'D' all arch/s390/include/asm/dasd.h
112 'D' 40-5F drivers/scsi/dpt/dtpi_ioctl.h
113 'D' 05 drivers/scsi/pmcraid.h
114 'E' all linux/input.h conflict!
115 'E' 00-0F xen/evtchn.h conflict!
116 'F' all linux/fb.h conflict!
117 'F' 01-02 drivers/scsi/pmcraid.h conflict!
118 'F' 20 drivers/video/fsl-diu-fb.h conflict!
119 'F' 20 drivers/video/intelfb/intelfb.h conflict!
120 'F' 20 linux/ivtvfb.h conflict!
121 'F' 20 linux/matroxfb.h conflict!
122 'F' 20 drivers/video/aty/atyfb_base.c conflict!
123 'F' 00-0F video/da8xx-fb.h conflict!
124 'F' 80-8F linux/arcfb.h conflict!
125 'F' DD video/sstfb.h conflict!
126 'G' 00-3F drivers/misc/sgi-gru/grulib.h conflict!
127 'G' 00-0F linux/gigaset_dev.h conflict!
128 'H' 00-7F linux/hiddev.h conflict!
129 'H' 00-0F linux/hidraw.h conflict!
130 'H' 01 linux/mei.h conflict!
131 'H' 02 linux/mei.h conflict!
132 'H' 03 linux/mei.h conflict!
133 'H' 00-0F sound/asound.h conflict!
134 'H' 20-40 sound/asound_fm.h conflict!
135 'H' 80-8F sound/sfnt_info.h conflict!
136 'H' 10-8F sound/emu10k1.h conflict!
137 'H' 10-1F sound/sb16_csp.h conflict!
138 'H' 10-1F sound/hda_hwdep.h conflict!
139 'H' 40-4F sound/hdspm.h conflict!
140 'H' 40-4F sound/hdsp.h conflict!
141 'H' 90 sound/usb/usx2y/usb_stream.h
142 'H' A0 uapi/linux/usb/cdc-wdm.h
143 'H' C0-F0 net/bluetooth/hci.h conflict!
144 'H' C0-DF net/bluetooth/hidp/hidp.h conflict!
145 'H' C0-DF net/bluetooth/cmtp/cmtp.h conflict!
146 'H' C0-DF net/bluetooth/bnep/bnep.h conflict!
147 'H' F1 linux/hid-roccat.h <mailto:erazor_de@users.sourceforge.net>
148 'H' F8-FA sound/firewire.h
149 'I' all linux/isdn.h conflict!
150 'I' 00-0F drivers/isdn/divert/isdn_divert.h conflict!
151 'I' 40-4F linux/mISDNif.h conflict!
152 'J' 00-1F drivers/scsi/gdth_ioctl.h
154 'L' 00-1F linux/loop.h conflict!
155 'L' 10-1F drivers/scsi/mpt3sas/mpt3sas_ctl.h conflict!
156 'L' 20-2F linux/lightnvm.h
157 'L' E0-FF linux/ppdd.h encrypted disk device driver
158 <http://linux01.gwdg.de/~alatham/ppdd.html>
159 'M' all linux/soundcard.h conflict!
160 'M' 01-16 mtd/mtd-abi.h conflict!
161 and drivers/mtd/mtdchar.c
162 'M' 01-03 drivers/scsi/megaraid/megaraid_sas.h
163 'M' 00-0F drivers/video/fsl-diu-fb.h conflict!
164 'N' 00-1F drivers/usb/scanner.h
165 'N' 40-7F drivers/block/nvme.c
166 'O' 00-06 mtd/ubi-user.h UBI
167 'P' all linux/soundcard.h conflict!
168 'P' 60-6F sound/sscape_ioctl.h conflict!
169 'P' 00-0F drivers/usb/class/usblp.c conflict!
170 'P' 01-09 drivers/misc/pci_endpoint_test.c conflict!
171 'Q' all linux/soundcard.h
172 'R' 00-1F linux/random.h conflict!
173 'R' 01 linux/rfkill.h conflict!
174 'R' C0-DF net/bluetooth/rfcomm.h
175 'S' all linux/cdrom.h conflict!
176 'S' 80-81 scsi/scsi_ioctl.h conflict!
177 'S' 82-FF scsi/scsi.h conflict!
178 'S' 00-7F sound/asequencer.h conflict!
179 'T' all linux/soundcard.h conflict!
180 'T' 00-AF sound/asound.h conflict!
181 'T' all arch/x86/include/asm/ioctls.h conflict!
182 'T' C0-DF linux/if_tun.h conflict!
183 'U' all sound/asound.h conflict!
184 'U' 00-CF linux/uinput.h conflict!
185 'U' 00-EF linux/usbdevice_fs.h
186 'U' C0-CF drivers/bluetooth/hci_uart.h
187 'V' all linux/vt.h conflict!
188 'V' all linux/videodev2.h conflict!
189 'V' C0 linux/ivtvfb.h conflict!
190 'V' C0 linux/ivtv.h conflict!
191 'V' C0 media/davinci/vpfe_capture.h conflict!
192 'V' C0 media/si4713.h conflict!
193 'W' 00-1F linux/watchdog.h conflict!
194 'W' 00-1F linux/wanrouter.h conflict! (pre 3.9)
195 'W' 00-3F sound/asound.h conflict!
196 'W' 40-5F drivers/pci/switch/switchtec.c
197 'X' all fs/xfs/xfs_fs.h conflict!
198 and fs/xfs/linux-2.6/xfs_ioctl32.h
199 and include/linux/falloc.h
201 'X' all fs/ocfs2/ocfs_fs.h conflict!
202 'X' 01 linux/pktcdvd.h conflict!
203 'Y' all linux/cyclades.h
204 'Z' 14-15 drivers/message/fusion/mptctl.h
205 '[' 00-3F linux/usb/tmc.h USB Test and Measurement Devices
206 <mailto:gregkh@linuxfoundation.org>
207 'a' all linux/atm*.h, linux/sonet.h ATM on linux
208 <http://lrcwww.epfl.ch/>
209 'a' 00-0F drivers/crypto/qat/qat_common/adf_cfg_common.h conflict! qat driver
210 'b' 00-FF conflict! bit3 vme host bridge
211 <mailto:natalia@nikhefk.nikhef.nl>
212 'c' all linux/cm4000_cs.h conflict!
213 'c' 00-7F linux/comstats.h conflict!
214 'c' 00-7F linux/coda.h conflict!
215 'c' 00-1F linux/chio.h conflict!
216 'c' 80-9F arch/s390/include/asm/chsc.h conflict!
217 'c' A0-AF arch/x86/include/asm/msr.h conflict!
218 'd' 00-FF linux/char/drm/drm.h conflict!
219 'd' 02-40 pcmcia/ds.h conflict!
220 'd' F0-FF linux/digi1.h
221 'e' all linux/digi1.h conflict!
222 'f' 00-1F linux/ext2_fs.h conflict!
223 'f' 00-1F linux/ext3_fs.h conflict!
224 'f' 00-0F fs/jfs/jfs_dinode.h conflict!
225 'f' 00-0F fs/ext4/ext4.h conflict!
226 'f' 00-0F linux/fs.h conflict!
227 'f' 00-0F fs/ocfs2/ocfs2_fs.h conflict!
228 'g' 00-0F linux/usb/gadgetfs.h
229 'g' 20-2F linux/usb/g_printer.h
230 'h' 00-7F conflict! Charon filesystem
231 <mailto:zapman@interlan.net>
232 'h' 00-1F linux/hpet.h conflict!
233 'h' 80-8F fs/hfsplus/ioctl.c
234 'i' 00-3F linux/i2o-dev.h conflict!
235 'i' 0B-1F linux/ipmi.h conflict!
236 'i' 80-8F linux/i8k.h
237 'j' 00-3F linux/joystick.h
238 'k' 00-0F linux/spi/spidev.h conflict!
239 'k' 00-05 video/kyro.h conflict!
240 'k' 10-17 linux/hsi/hsi_char.h HSI character device
241 'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system
242 <http://web.archive.org/web/*/http://mikonos.dia.unisa.it/tcfs>
243 'l' 40-7F linux/udf_fs_i.h in development:
244 <http://sourceforge.net/projects/linux-udf/>
245 'm' 00-09 linux/mmtimer.h conflict!
246 'm' all linux/mtio.h conflict!
247 'm' all linux/soundcard.h conflict!
248 'm' all linux/synclink.h conflict!
249 'm' 00-19 drivers/message/fusion/mptctl.h conflict!
250 'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict!
251 'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c
252 'n' 80-8F uapi/linux/nilfs2_api.h NILFS2
253 'n' E0-FF linux/matroxfb.h matroxfb
254 'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2
255 'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps)
256 'o' 40-41 mtd/ubi-user.h UBI
257 'o' 01-A1 linux/dvb/*.h DVB
258 'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this)
259 'p' 00-1F linux/rtc.h conflict!
260 'p' 00-3F linux/mc146818rtc.h conflict!
261 'p' 40-7F linux/nvram.h
262 'p' 80-9F linux/ppdev.h user-space parport
263 <mailto:tim@cyberelk.net>
264 'p' A1-A5 linux/pps.h LinuxPPS
265 <mailto:giometti@linux.it>
266 'q' 00-1F linux/serio.h
267 'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK
268 linux/ixjuser.h <http://web.archive.org/web/*/http://www.quicknet.net>
269 'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c
271 't' 00-7F linux/ppp-ioctl.h
272 't' 80-8F linux/isdn_ppp.h
273 't' 90-91 linux/toshiba.h toshiba and toshiba_acpi SMM
274 'u' 00-1F linux/smb_fs.h gone
275 'u' 20-3F linux/uvcvideo.h USB video class host driver
276 'u' 40-4f linux/udmabuf.h userspace dma-buf misc device
277 'v' 00-1F linux/ext2_fs.h conflict!
278 'v' 00-1F linux/fs.h conflict!
279 'v' 00-0F linux/sonypi.h conflict!
280 'v' 00-0F media/v4l2-subdev.h conflict!
281 'v' C0-FF linux/meye.h conflict!
282 'w' all CERN SCI driver
283 'y' 00-1F packet based user level communications
284 <mailto:zapman@interlan.net>
285 'z' 00-3F CAN bus card conflict!
286 <mailto:hdstich@connectu.ulm.circular.de>
287 'z' 40-7F CAN bus card conflict!
289 'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict!
290 '|' 00-7F linux/media.h
291 0x80 00-1F linux/fb.h
292 0x89 00-06 arch/x86/include/asm/sockios.h
293 0x89 0B-DF linux/sockios.h
294 0x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range
295 0x89 E0-EF linux/dn.h PROTOPRIVATE range
296 0x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range
297 0x8B all linux/wireless.h
298 0x8C 00-3F WiNRADiO driver
299 <http://www.winradio.com.au/>
300 0x90 00 drivers/cdrom/sbpcd.h
301 0x92 00-0F drivers/usb/mon/mon_bin.c
302 0x93 60-7F linux/auto_fs.h
303 0x94 all fs/btrfs/ioctl.h Btrfs filesystem
304 and linux/fs.h some lifted to vfs/generic
305 0x97 00-7F fs/ceph/ioctl.h Ceph file system
306 0x99 00-0F 537-Addinboard driver
307 <mailto:buk@buks.ipn.de>
308 0xA0 all linux/sdp/sdp.h Industrial Device Project
309 <mailto:kenji@bitgate.com>
310 0xA1 0 linux/vtpm_proxy.h TPM Emulator Proxy Driver
311 0xA3 80-8F Port ACL in development:
312 <mailto:tlewis@mindspring.com>
313 0xA3 90-9F linux/dtlk.h
314 0xA4 00-1F uapi/linux/tee.h Generic TEE subsystem
315 0xAA 00-3F linux/uapi/linux/userfaultfd.h
316 0xAB 00-1F linux/nbd.h
317 0xAC 00-1F linux/raw.h
318 0xAD 00 Netfilter device in development:
319 <mailto:rusty@rustcorp.com.au>
320 0xAE all linux/kvm.h Kernel-based Virtual Machine
321 <mailto:kvm@vger.kernel.org>
322 0xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor
323 0xB0 all RATIO devices in development:
324 <mailto:vgo@ratio.de>
325 0xB1 00-1F PPPoX <mailto:mostrows@styx.uwaterloo.ca>
326 0xB3 00 linux/mmc/ioctl.h
327 0xB4 00-0F linux/gpio.h <mailto:linux-gpio@vger.kernel.org>
328 0xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc@vger.kernel.org>
329 0xB6 all linux/fpga-dfl.h
330 0xC0 00-0F linux/usb/iowarrior.h
331 0xCA 00-0F uapi/misc/cxl.h
332 0xCA 10-2F uapi/misc/ocxl.h
333 0xCA 80-BF uapi/scsi/cxlflash_ioctl.h
334 0xCB 00-1F CBM serial IEC bus in development:
335 <mailto:michael.klein@puffin.lb.shuttle.de>
336 0xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver
337 0xCD 01 linux/reiserfs_fs.h
338 0xCF 02 fs/cifs/ioctl.c
339 0xDB 00-0F drivers/char/mwave/mwavepub.h
340 0xDD 00-3F ZFCP device driver see drivers/s390/scsi/
341 <mailto:aherrman@de.ibm.com>
342 0xE5 00-3F linux/fuse.h
343 0xEC 00-01 drivers/platform/chrome/cros_ec_dev.h ChromeOS EC driver
344 0xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development)
345 <mailto:thomas@winischhofer.net>
346 0xF4 00-1F video/mbxfb.h mbxfb
348 0xF6 all LTTng Linux Trace Toolkit Next Generation
349 <mailto:mathieu.desnoyers@efficios.com>
350 0xFD all linux/dm-ioctl.h
git.samba.org / sfrench / cifs-2.6.git / blob