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 '#' 00-3F IEEE 1394 Subsystem Block for the entire subsystem
83 '$' 00-0F linux/perf_counter.h, linux/perf_event.h
84 '%' 00-0F include/uapi/linux/stm.h
85 System Trace Module subsystem
86 <mailto:alexander.shishkin@linux.intel.com>
87 '&' 00-07 drivers/firewire/nosy-user.h
88 '1' 00-1F <linux/timepps.h> PPS kit from Ulrich Windl
89 <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/>
91 '3' 00-0F drivers/s390/char/raw3270.h conflict!
92 '3' 00-1F linux/suspend_ioctls.h conflict!
93 and kernel/power/user.c
94 '8' all SNP8023 advanced NIC card
95 <mailto:mcr@solidum.com>
96 ';' 64-7F linux/vfio.h
97 '@' 00-0F linux/radeonfb.h conflict!
98 '@' 00-0F drivers/video/aty/aty128fb.c conflict!
99 'A' 00-1F linux/apm_bios.h conflict!
100 'A' 00-0F linux/agpgart.h conflict!
101 and drivers/char/agp/compat_ioctl.h
102 'A' 00-7F sound/asound.h conflict!
103 'B' 00-1F linux/cciss_ioctl.h conflict!
104 'B' 00-0F include/linux/pmu.h conflict!
105 'B' C0-FF advanced bbus
106 <mailto:maassen@uni-freiburg.de>
107 'C' all linux/soundcard.h conflict!
108 'C' 01-2F linux/capi.h conflict!
109 'C' F0-FF drivers/net/wan/cosa.h conflict!
110 'D' all arch/s390/include/asm/dasd.h
111 'D' 40-5F drivers/scsi/dpt/dtpi_ioctl.h
112 'D' 05 drivers/scsi/pmcraid.h
113 'E' all linux/input.h conflict!
114 'E' 00-0F xen/evtchn.h conflict!
115 'F' all linux/fb.h conflict!
116 'F' 01-02 drivers/scsi/pmcraid.h conflict!
117 'F' 20 drivers/video/fsl-diu-fb.h conflict!
118 'F' 20 drivers/video/intelfb/intelfb.h conflict!
119 'F' 20 linux/ivtvfb.h conflict!
120 'F' 20 linux/matroxfb.h conflict!
121 'F' 20 drivers/video/aty/atyfb_base.c conflict!
122 'F' 00-0F video/da8xx-fb.h conflict!
123 'F' 80-8F linux/arcfb.h conflict!
124 'F' DD video/sstfb.h conflict!
125 'G' 00-3F drivers/misc/sgi-gru/grulib.h conflict!
126 'G' 00-0F linux/gigaset_dev.h conflict!
127 'H' 00-7F linux/hiddev.h conflict!
128 'H' 00-0F linux/hidraw.h conflict!
129 'H' 01 linux/mei.h conflict!
130 'H' 02 linux/mei.h conflict!
131 'H' 03 linux/mei.h conflict!
132 'H' 00-0F sound/asound.h conflict!
133 'H' 20-40 sound/asound_fm.h conflict!
134 'H' 80-8F sound/sfnt_info.h conflict!
135 'H' 10-8F sound/emu10k1.h conflict!
136 'H' 10-1F sound/sb16_csp.h conflict!
137 'H' 10-1F sound/hda_hwdep.h conflict!
138 'H' 40-4F sound/hdspm.h conflict!
139 'H' 40-4F sound/hdsp.h conflict!
140 'H' 90 sound/usb/usx2y/usb_stream.h
141 'H' A0 uapi/linux/usb/cdc-wdm.h
142 'H' C0-F0 net/bluetooth/hci.h conflict!
143 'H' C0-DF net/bluetooth/hidp/hidp.h conflict!
144 'H' C0-DF net/bluetooth/cmtp/cmtp.h conflict!
145 'H' C0-DF net/bluetooth/bnep/bnep.h conflict!
146 'H' F1 linux/hid-roccat.h <mailto:erazor_de@users.sourceforge.net>
147 'H' F8-FA sound/firewire.h
148 'I' all linux/isdn.h conflict!
149 'I' 00-0F drivers/isdn/divert/isdn_divert.h conflict!
150 'I' 40-4F linux/mISDNif.h conflict!
151 'J' 00-1F drivers/scsi/gdth_ioctl.h
153 'L' 00-1F linux/loop.h conflict!
154 'L' 10-1F drivers/scsi/mpt3sas/mpt3sas_ctl.h conflict!
155 'L' 20-2F linux/lightnvm.h
156 'L' E0-FF linux/ppdd.h encrypted disk device driver
157 <http://linux01.gwdg.de/~alatham/ppdd.html>
158 'M' all linux/soundcard.h conflict!
159 'M' 01-16 mtd/mtd-abi.h conflict!
160 and drivers/mtd/mtdchar.c
161 'M' 01-03 drivers/scsi/megaraid/megaraid_sas.h
162 'M' 00-0F drivers/video/fsl-diu-fb.h conflict!
163 'N' 00-1F drivers/usb/scanner.h
164 'N' 40-7F drivers/block/nvme.c
165 'O' 00-06 mtd/ubi-user.h UBI
166 'P' all linux/soundcard.h conflict!
167 'P' 60-6F sound/sscape_ioctl.h conflict!
168 'P' 00-0F drivers/usb/class/usblp.c conflict!
169 'P' 01-09 drivers/misc/pci_endpoint_test.c conflict!
170 'Q' all linux/soundcard.h
171 'R' 00-1F linux/random.h conflict!
172 'R' 01 linux/rfkill.h conflict!
173 'R' C0-DF net/bluetooth/rfcomm.h
174 'S' all linux/cdrom.h conflict!
175 'S' 80-81 scsi/scsi_ioctl.h conflict!
176 'S' 82-FF scsi/scsi.h conflict!
177 'S' 00-7F sound/asequencer.h conflict!
178 'T' all linux/soundcard.h conflict!
179 'T' 00-AF sound/asound.h conflict!
180 'T' all arch/x86/include/asm/ioctls.h conflict!
181 'T' C0-DF linux/if_tun.h conflict!
182 'U' all sound/asound.h conflict!
183 'U' 00-CF linux/uinput.h conflict!
184 'U' 00-EF linux/usbdevice_fs.h
185 'U' C0-CF drivers/bluetooth/hci_uart.h
186 'V' all linux/vt.h conflict!
187 'V' all linux/videodev2.h conflict!
188 'V' C0 linux/ivtvfb.h conflict!
189 'V' C0 linux/ivtv.h conflict!
190 'V' C0 media/davinci/vpfe_capture.h conflict!
191 'V' C0 media/si4713.h conflict!
192 'W' 00-1F linux/watchdog.h conflict!
193 'W' 00-1F linux/wanrouter.h conflict! (pre 3.9)
194 'W' 00-3F sound/asound.h conflict!
195 'W' 40-5F drivers/pci/switch/switchtec.c
196 'X' all fs/xfs/xfs_fs.h conflict!
197 and fs/xfs/linux-2.6/xfs_ioctl32.h
198 and include/linux/falloc.h
200 'X' all fs/ocfs2/ocfs_fs.h conflict!
201 'X' 01 linux/pktcdvd.h conflict!
202 'Y' all linux/cyclades.h
203 'Z' 14-15 drivers/message/fusion/mptctl.h
204 '[' 00-3F linux/usb/tmc.h USB Test and Measurement Devices
205 <mailto:gregkh@linuxfoundation.org>
206 'a' all linux/atm*.h, linux/sonet.h ATM on linux
207 <http://lrcwww.epfl.ch/>
208 'a' 00-0F drivers/crypto/qat/qat_common/adf_cfg_common.h conflict! qat driver
209 'b' 00-FF conflict! bit3 vme host bridge
210 <mailto:natalia@nikhefk.nikhef.nl>
211 'c' all linux/cm4000_cs.h conflict!
212 'c' 00-7F linux/comstats.h conflict!
213 'c' 00-7F linux/coda.h conflict!
214 'c' 00-1F linux/chio.h conflict!
215 'c' 80-9F arch/s390/include/asm/chsc.h conflict!
216 'c' A0-AF arch/x86/include/asm/msr.h conflict!
217 'd' 00-FF linux/char/drm/drm.h conflict!
218 'd' 02-40 pcmcia/ds.h conflict!
219 'd' F0-FF linux/digi1.h
220 'e' all linux/digi1.h conflict!
221 'f' 00-1F linux/ext2_fs.h conflict!
222 'f' 00-1F linux/ext3_fs.h conflict!
223 'f' 00-0F fs/jfs/jfs_dinode.h conflict!
224 'f' 00-0F fs/ext4/ext4.h conflict!
225 'f' 00-0F linux/fs.h conflict!
226 'f' 00-0F fs/ocfs2/ocfs2_fs.h conflict!
227 'g' 00-0F linux/usb/gadgetfs.h
228 'g' 20-2F linux/usb/g_printer.h
229 'h' 00-7F conflict! Charon filesystem
230 <mailto:zapman@interlan.net>
231 'h' 00-1F linux/hpet.h conflict!
232 'h' 80-8F fs/hfsplus/ioctl.c
233 'i' 00-3F linux/i2o-dev.h conflict!
234 'i' 0B-1F linux/ipmi.h conflict!
235 'i' 80-8F linux/i8k.h
236 'j' 00-3F linux/joystick.h
237 'k' 00-0F linux/spi/spidev.h conflict!
238 'k' 00-05 video/kyro.h conflict!
239 'k' 10-17 linux/hsi/hsi_char.h HSI character device
240 'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system
241 <http://web.archive.org/web/*/http://mikonos.dia.unisa.it/tcfs>
242 'l' 40-7F linux/udf_fs_i.h in development:
243 <http://sourceforge.net/projects/linux-udf/>
244 'm' 00-09 linux/mmtimer.h conflict!
245 'm' all linux/mtio.h conflict!
246 'm' all linux/soundcard.h conflict!
247 'm' all linux/synclink.h conflict!
248 'm' 00-19 drivers/message/fusion/mptctl.h conflict!
249 'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict!
250 'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c
251 'n' 80-8F uapi/linux/nilfs2_api.h NILFS2
252 'n' E0-FF linux/matroxfb.h matroxfb
253 'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2
254 'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps)
255 'o' 40-41 mtd/ubi-user.h UBI
256 'o' 01-A1 linux/dvb/*.h DVB
257 'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this)
258 'p' 00-1F linux/rtc.h conflict!
259 'p' 00-3F linux/mc146818rtc.h conflict!
260 'p' 40-7F linux/nvram.h
261 'p' 80-9F linux/ppdev.h user-space parport
262 <mailto:tim@cyberelk.net>
263 'p' A1-A5 linux/pps.h LinuxPPS
264 <mailto:giometti@linux.it>
265 'q' 00-1F linux/serio.h
266 'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK
267 linux/ixjuser.h <http://web.archive.org/web/*/http://www.quicknet.net>
268 'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c
270 't' 00-7F linux/ppp-ioctl.h
271 't' 80-8F linux/isdn_ppp.h
272 't' 90-91 linux/toshiba.h toshiba and toshiba_acpi SMM
273 'u' 00-1F linux/smb_fs.h gone
274 'u' 20-3F linux/uvcvideo.h USB video class host driver
275 'u' 40-4f linux/udmabuf.h userspace dma-buf misc device
276 'v' 00-1F linux/ext2_fs.h conflict!
277 'v' 00-1F linux/fs.h conflict!
278 'v' 00-0F linux/sonypi.h conflict!
279 'v' 00-0F media/v4l2-subdev.h conflict!
280 'v' C0-FF linux/meye.h conflict!
281 'w' all CERN SCI driver
282 'y' 00-1F packet based user level communications
283 <mailto:zapman@interlan.net>
284 'z' 00-3F CAN bus card conflict!
285 <mailto:hdstich@connectu.ulm.circular.de>
286 'z' 40-7F CAN bus card conflict!
288 'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict!
289 '|' 00-7F linux/media.h
290 0x80 00-1F linux/fb.h
291 0x89 00-06 arch/x86/include/asm/sockios.h
292 0x89 0B-DF linux/sockios.h
293 0x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range
294 0x89 E0-EF linux/dn.h PROTOPRIVATE range
295 0x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range
296 0x8B all linux/wireless.h
297 0x8C 00-3F WiNRADiO driver
298 <http://www.winradio.com.au/>
299 0x90 00 drivers/cdrom/sbpcd.h
300 0x92 00-0F drivers/usb/mon/mon_bin.c
301 0x93 60-7F linux/auto_fs.h
302 0x94 all fs/btrfs/ioctl.h Btrfs filesystem
303 and linux/fs.h some lifted to vfs/generic
304 0x97 00-7F fs/ceph/ioctl.h Ceph file system
305 0x99 00-0F 537-Addinboard driver
306 <mailto:buk@buks.ipn.de>
307 0xA0 all linux/sdp/sdp.h Industrial Device Project
308 <mailto:kenji@bitgate.com>
309 0xA1 0 linux/vtpm_proxy.h TPM Emulator Proxy Driver
310 0xA3 80-8F Port ACL in development:
311 <mailto:tlewis@mindspring.com>
312 0xA3 90-9F linux/dtlk.h
313 0xA4 00-1F uapi/linux/tee.h Generic TEE subsystem
314 0xAA 00-3F linux/uapi/linux/userfaultfd.h
315 0xAB 00-1F linux/nbd.h
316 0xAC 00-1F linux/raw.h
317 0xAD 00 Netfilter device in development:
318 <mailto:rusty@rustcorp.com.au>
319 0xAE all linux/kvm.h Kernel-based Virtual Machine
320 <mailto:kvm@vger.kernel.org>
321 0xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor
322 0xB0 all RATIO devices in development:
323 <mailto:vgo@ratio.de>
324 0xB1 00-1F PPPoX <mailto:mostrows@styx.uwaterloo.ca>
325 0xB3 00 linux/mmc/ioctl.h
326 0xB4 00-0F linux/gpio.h <mailto:linux-gpio@vger.kernel.org>
327 0xB5 00-0F uapi/linux/rpmsg.h <mailto:linux-remoteproc@vger.kernel.org>
328 0xB6 all linux/fpga-dfl.h
329 0xC0 00-0F linux/usb/iowarrior.h
330 0xCA 00-0F uapi/misc/cxl.h
331 0xCA 10-2F uapi/misc/ocxl.h
332 0xCA 80-BF uapi/scsi/cxlflash_ioctl.h
333 0xCB 00-1F CBM serial IEC bus in development:
334 <mailto:michael.klein@puffin.lb.shuttle.de>
335 0xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver
336 0xCD 01 linux/reiserfs_fs.h
337 0xCF 02 fs/cifs/ioctl.c
338 0xDB 00-0F drivers/char/mwave/mwavepub.h
339 0xDD 00-3F ZFCP device driver see drivers/s390/scsi/
340 <mailto:aherrman@de.ibm.com>
341 0xE5 00-3F linux/fuse.h
342 0xEC 00-01 drivers/platform/chrome/cros_ec_dev.h ChromeOS EC driver
343 0xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development)
344 <mailto:thomas@winischhofer.net>
345 0xF4 00-1F video/mbxfb.h mbxfb
347 0xF6 all LTTng Linux Trace Toolkit Next Generation
348 <mailto:mathieu.desnoyers@efficios.com>
349 0xFD all linux/dm-ioctl.h
git.samba.org / sfrench / cifs-2.6.git / blob