1		Summary of HDIO_ ioctl calls.
2		============================
3
4		Edward A. Falk <efalk@google.com>
5
6		November, 2004
7
8This document attempts to describe the ioctl(2) calls supported by
9the HD/IDE layer.  These are by-and-large implemented (as of Linux 2.6)
10in drivers/ide/ide.c and drivers/block/scsi_ioctl.c
11
12ioctl values are listed in <linux/hdreg.h>.  As of this writing, they
13are as follows:
14
15    ioctls that pass argument pointers to user space:
16
17	HDIO_GETGEO		get device geometry
18	HDIO_GET_UNMASKINTR	get current unmask setting
19	HDIO_GET_MULTCOUNT	get current IDE blockmode setting
20	HDIO_GET_QDMA		get use-qdma flag
21	HDIO_SET_XFER		set transfer rate via proc
22	HDIO_OBSOLETE_IDENTITY	OBSOLETE, DO NOT USE
23	HDIO_GET_KEEPSETTINGS	get keep-settings-on-reset flag
24	HDIO_GET_32BIT		get current io_32bit setting
25	HDIO_GET_NOWERR		get ignore-write-error flag
26	HDIO_GET_DMA		get use-dma flag
27	HDIO_GET_NICE		get nice flags
28	HDIO_GET_IDENTITY	get IDE identification info
29	HDIO_GET_WCACHE		get write cache mode on|off
30	HDIO_GET_ACOUSTIC	get acoustic value
31	HDIO_GET_ADDRESS	get sector addressing mode
32	HDIO_GET_BUSSTATE	get the bus state of the hwif
33	HDIO_TRISTATE_HWIF	execute a channel tristate
34	HDIO_DRIVE_RESET	execute a device reset
35	HDIO_DRIVE_TASKFILE	execute raw taskfile
36	HDIO_DRIVE_TASK		execute task and special drive command
37	HDIO_DRIVE_CMD		execute a special drive command
38	HDIO_DRIVE_CMD_AEB	HDIO_DRIVE_TASK
39
40    ioctls that pass non-pointer values:
41
42	HDIO_SET_MULTCOUNT	change IDE blockmode
43	HDIO_SET_UNMASKINTR	permit other irqs during I/O
44	HDIO_SET_KEEPSETTINGS	keep ioctl settings on reset
45	HDIO_SET_32BIT		change io_32bit flags
46	HDIO_SET_NOWERR		change ignore-write-error flag
47	HDIO_SET_DMA		change use-dma flag
48	HDIO_SET_PIO_MODE	reconfig interface to new speed
49	HDIO_SCAN_HWIF		register and (re)scan interface
50	HDIO_SET_NICE		set nice flags
51	HDIO_UNREGISTER_HWIF	unregister interface
52	HDIO_SET_WCACHE		change write cache enable-disable
53	HDIO_SET_ACOUSTIC	change acoustic behavior
54	HDIO_SET_BUSSTATE	set the bus state of the hwif
55	HDIO_SET_QDMA		change use-qdma flag
56	HDIO_SET_ADDRESS	change lba addressing modes
57
58	HDIO_SET_IDE_SCSI	Set scsi emulation mode on/off
59	HDIO_SET_SCSI_IDE	not implemented yet
60
61
62The information that follows was determined from reading kernel source
63code.  It is likely that some corrections will be made over time.
64
65
66
67
68
69
70
71General:
72
73	Unless otherwise specified, all ioctl calls return 0 on success
74	and -1 with errno set to an appropriate value on error.
75
76	Unless otherwise specified, all ioctl calls return -1 and set
77	errno to EFAULT on a failed attempt to copy data to or from user
78	address space.
79
80	Unless otherwise specified, all data structures and constants
81	are defined in <linux/hdreg.h>
82
83
84
85HDIO_GETGEO			get device geometry
86
87	usage:
88
89	  struct hd_geometry geom;
90	  ioctl(fd, HDIO_GETGEO, &geom);
91
92
93	inputs:		none
94
95	outputs:
96
97	  hd_geometry structure containing:
98
99	    heads	number of heads
100	    sectors	number of sectors/track
101	    cylinders	number of cylinders, mod 65536
102	    start	starting sector of this partition.
103
104
105	error returns:
106	  EINVAL	if the device is not a disk drive or floppy drive,
107	  		or if the user passes a null pointer
108
109
110	notes:
111
112	  Not particularly useful with modern disk drives, whose geometry
113	  is a polite fiction anyway.  Modern drives are addressed
114	  purely by sector number nowadays (lba addressing), and the
115	  drive geometry is an abstraction which is actually subject
116	  to change.  Currently (as of Nov 2004), the geometry values
117	  are the "bios" values -- presumably the values the drive had
118	  when Linux first booted.
119
120	  In addition, the cylinders field of the hd_geometry is an
121	  unsigned short, meaning that on most architectures, this
122	  ioctl will not return a meaningful value on drives with more
123	  than 65535 tracks.
124
125	  The start field is unsigned long, meaning that it will not
126	  contain a meaningful value for disks over 219 Gb in size.
127
128
129
130
131HDIO_GET_UNMASKINTR		get current unmask setting
132
133	usage:
134
135	  long val;
136	  ioctl(fd, HDIO_GET_UNMASKINTR, &val);
137
138	inputs:		none
139
140	outputs:
141	  The value of the drive's current unmask setting
142
143
144
145HDIO_SET_UNMASKINTR		permit other irqs during I/O
146
147	usage:
148
149	  unsigned long val;
150	  ioctl(fd, HDIO_SET_UNMASKINTR, val);
151
152	inputs:
153	  New value for unmask flag
154
155	outputs:	none
156
157	error return:
158	  EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
159	  EACCES	Access denied:  requires CAP_SYS_ADMIN
160	  EINVAL	value out of range [0 1]
161	  EBUSY		Controller busy
162
163
164
165
166HDIO_GET_MULTCOUNT		get current IDE blockmode setting
167
168	usage:
169
170	  long val;
171	  ioctl(fd, HDIO_GET_MULTCOUNT, &val);
172
173	inputs:		none
174
175	outputs:
176	  The value of the current IDE block mode setting.  This
177	  controls how many sectors the drive will transfer per
178	  interrupt.
179
180
181
182HDIO_SET_MULTCOUNT		change IDE blockmode
183
184	usage:
185
186	  int val;
187	  ioctl(fd, HDIO_SET_MULTCOUNT, val);
188
189	inputs:
190	  New value for IDE block mode setting.  This controls how many
191	  sectors the drive will transfer per interrupt.
192
193	outputs:	none
194
195	error return:
196	  EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
197	  EACCES	Access denied:  requires CAP_SYS_ADMIN
198	  EINVAL	value out of range supported by disk.
199	  EBUSY		Controller busy or blockmode already set.
200	  EIO		Drive did not accept new block mode.
201
202	notes:
203
204	  Source code comments read:
205
206	    This is tightly woven into the driver->do_special cannot
207	    touch.  DON'T do it again until a total personality rewrite
208	    is committed.
209
210	  If blockmode has already been set, this ioctl will fail with
211	  EBUSY
212
213
214
215HDIO_GET_QDMA			get use-qdma flag
216
217	Not implemented, as of 2.6.8.1
218
219
220
221HDIO_SET_XFER			set transfer rate via proc
222
223	Not implemented, as of 2.6.8.1
224
225
226
227HDIO_OBSOLETE_IDENTITY		OBSOLETE, DO NOT USE
228
229	Same as HDIO_GET_IDENTITY (see below), except that it only
230	returns the first 142 bytes of drive identity information.
231
232
233
234HDIO_GET_IDENTITY		get IDE identification info
235
236	usage:
237
238	  unsigned char identity[512];
239	  ioctl(fd, HDIO_GET_IDENTITY, identity);
240
241	inputs:		none
242
243	outputs:
244
245	  ATA drive identity information.  For full description, see
246	  the IDENTIFY DEVICE and IDENTIFY PACKET DEVICE commands in
247	  the ATA specification.
248
249	error returns:
250	  EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
251	  ENOMSG	IDENTIFY DEVICE information not available
252
253	notes:
254
255	  Returns information that was obtained when the drive was
256	  probed.  Some of this information is subject to change, and
257	  this ioctl does not re-probe the drive to update the
258	  information.
259
260	  This information is also available from /proc/ide/hdX/identify
261
262
263
264HDIO_GET_KEEPSETTINGS		get keep-settings-on-reset flag
265
266	usage:
267
268	  long val;
269	  ioctl(fd, HDIO_GET_KEEPSETTINGS, &val);
270
271	inputs:		none
272
273	outputs:
274	  The value of the current "keep settings" flag
275
276	notes:
277
278	  When set, indicates that kernel should restore settings
279	  after a drive reset.
280
281
282
283HDIO_SET_KEEPSETTINGS		keep ioctl settings on reset
284
285	usage:
286
287	  long val;
288	  ioctl(fd, HDIO_SET_KEEPSETTINGS, val);
289
290	inputs:
291	  New value for keep_settings flag
292
293	outputs:	none
294
295	error return:
296	  EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
297	  EACCES	Access denied:  requires CAP_SYS_ADMIN
298	  EINVAL	value out of range [0 1]
299	  EBUSY		Controller busy
300
301
302
303HDIO_GET_32BIT			get current io_32bit setting
304
305	usage:
306
307	  long val;
308	  ioctl(fd, HDIO_GET_32BIT, &val);
309
310	inputs:		none
311
312	outputs:
313	  The value of the current io_32bit setting
314
315	notes:
316
317	  0=16-bit, 1=32-bit, 2,3 = 32bit+sync
318
319
320
321HDIO_GET_NOWERR			get ignore-write-error flag
322
323	usage:
324
325	  long val;
326	  ioctl(fd, HDIO_GET_NOWERR, &val);
327
328	inputs:		none
329
330	outputs:
331	  The value of the current ignore-write-error flag
332
333
334
335HDIO_GET_DMA			get use-dma flag
336
337	usage:
338
339	  long val;
340	  ioctl(fd, HDIO_GET_DMA, &val);
341
342	inputs:		none
343
344	outputs:
345	  The value of the current use-dma flag
346
347
348
349HDIO_GET_NICE			get nice flags
350
351	usage:
352
353	  long nice;
354	  ioctl(fd, HDIO_GET_NICE, &nice);
355
356	inputs:		none
357
358	outputs:
359
360	  The drive's "nice" values.
361
362	notes:
363
364	  Per-drive flags which determine when the system will give more
365	  bandwidth to other devices sharing the same IDE bus.
366	  See <linux/hdreg.h>, near symbol IDE_NICE_DSC_OVERLAP.
367
368
369
370
371HDIO_SET_NICE			set nice flags
372
373	usage:
374
375	  unsigned long nice;
376	  ...
377	  ioctl(fd, HDIO_SET_NICE, nice);
378
379	inputs:
380	  bitmask of nice flags.
381
382	outputs:	none
383
384	error returns:
385	  EACCES	Access denied:  requires CAP_SYS_ADMIN
386	  EPERM		Flags other than DSC_OVERLAP and NICE_1 set.
387	  EPERM		DSC_OVERLAP specified but not supported by drive
388
389	notes:
390
391	  This ioctl sets the DSC_OVERLAP and NICE_1 flags from values
392	  provided by the user.
393
394	  Nice flags are listed in <linux/hdreg.h>, starting with
395	  IDE_NICE_DSC_OVERLAP.  These values represent shifts.
396
397
398
399
400
401HDIO_GET_WCACHE			get write cache mode on|off
402
403	usage:
404
405	  long val;
406	  ioctl(fd, HDIO_GET_WCACHE, &val);
407
408	inputs:		none
409
410	outputs:
411	  The value of the current write cache mode
412
413
414
415HDIO_GET_ACOUSTIC		get acoustic value
416
417	usage:
418
419	  long val;
420	  ioctl(fd, HDIO_GET_ACOUSTIC, &val);
421
422	inputs:		none
423
424	outputs:
425	  The value of the current acoustic settings
426
427	notes:
428
429	  See HDIO_SET_ACOUSTIC
430
431
432
433HDIO_GET_ADDRESS
434
435	usage:
436
437	  long val;
438	  ioctl(fd, HDIO_GET_ADDRESS, &val);
439
440	inputs:		none
441
442	outputs:
443	  The value of the current addressing mode:
444	    0 = 28-bit
445	    1 = 48-bit
446	    2 = 48-bit doing 28-bit
447	    3 = 64-bit
448
449
450
451HDIO_GET_BUSSTATE		get the bus state of the hwif
452
453	usage:
454
455	  long state;
456	  ioctl(fd, HDIO_SCAN_HWIF, &state);
457
458	inputs:		none
459
460	outputs:
461	  Current power state of the IDE bus.  One of BUSSTATE_OFF,
462	  BUSSTATE_ON, or BUSSTATE_TRISTATE
463
464	error returns:
465	  EACCES	Access denied:  requires CAP_SYS_ADMIN
466
467
468
469
470HDIO_SET_BUSSTATE		set the bus state of the hwif
471
472	usage:
473
474	  int state;
475	  ...
476	  ioctl(fd, HDIO_SCAN_HWIF, state);
477
478	inputs:
479	  Desired IDE power state.  One of BUSSTATE_OFF, BUSSTATE_ON,
480	  or BUSSTATE_TRISTATE
481
482	outputs:	none
483
484	error returns:
485	  EACCES	Access denied:  requires CAP_SYS_RAWIO
486	  EOPNOTSUPP	Hardware interface does not support bus power control
487
488
489
490
491HDIO_TRISTATE_HWIF		execute a channel tristate
492
493	Not implemented, as of 2.6.8.1.  See HDIO_SET_BUSSTATE
494
495
496
497HDIO_DRIVE_RESET		execute a device reset
498
499	usage:
500
501	  int args[3]
502	  ...
503	  ioctl(fd, HDIO_DRIVE_RESET, args);
504
505	inputs:		none
506
507	outputs:	none
508
509	error returns:
510	  EACCES	Access denied:  requires CAP_SYS_ADMIN
511	  ENXIO		No such device:	phy dead or ctl_addr == 0
512	  EIO		I/O error:	reset timed out or hardware error
513
514	notes:
515
516	  Execute a reset on the device as soon as the current IO
517	  operation has completed.
518
519	  Executes an ATAPI soft reset if applicable, otherwise
520	  executes an ATA soft reset on the controller.
521
522
523
524HDIO_DRIVE_TASKFILE		execute raw taskfile
525
526	Note:  If you don't have a copy of the ANSI ATA specification
527	handy, you should probably ignore this ioctl.
528
529	Execute an ATA disk command directly by writing the "taskfile"
530	registers of the drive.  Requires ADMIN and RAWIO access
531	privileges.
532
533	usage:
534
535	  struct {
536	    ide_task_request_t req_task;
537	    u8 outbuf[OUTPUT_SIZE];
538	    u8 inbuf[INPUT_SIZE];
539	  } task;
540	  memset(&task.req_task, 0, sizeof(task.req_task));
541	  task.req_task.out_size = sizeof(task.outbuf);
542	  task.req_task.in_size = sizeof(task.inbuf);
543	  ...
544	  ioctl(fd, HDIO_DRIVE_TASKFILE, &task);
545	  ...
546
547	inputs:
548
549	  (See below for details on memory area passed to ioctl.)
550
551	  io_ports[8]	values to be written to taskfile registers
552	  hob_ports[8]	high-order bytes, for extended commands.
553	  out_flags	flags indicating which registers are valid
554	  in_flags	flags indicating which registers should be returned
555	  data_phase	see below
556	  req_cmd	command type to be executed
557	  out_size	size of output buffer
558	  outbuf	buffer of data to be transmitted to disk
559	  inbuf		buffer of data to be received from disk (see [1])
560
561	outputs:
562
563	  io_ports[]	values returned in the taskfile registers
564	  hob_ports[]	high-order bytes, for extended commands.
565	  out_flags	flags indicating which registers are valid (see [2])
566	  in_flags	flags indicating which registers should be returned
567	  outbuf	buffer of data to be transmitted to disk (see [1])
568	  inbuf		buffer of data to be received from disk
569
570	error returns:
571	  EACCES	CAP_SYS_ADMIN or CAP_SYS_RAWIO privilege not set.
572	  ENOMSG	Device is not a disk drive.
573	  ENOMEM	Unable to allocate memory for task
574	  EFAULT	req_cmd == TASKFILE_IN_OUT (not implemented as of 2.6.8)
575	  EPERM		req_cmd == TASKFILE_MULTI_OUT and drive
576	  		multi-count not yet set.
577	  EIO		Drive failed the command.
578
579	notes:
580
581	  [1] READ THE FOLLOWING NOTES *CAREFULLY*.  THIS IOCTL IS
582	  FULL OF GOTCHAS.  Extreme caution should be used with using
583	  this ioctl.  A mistake can easily corrupt data or hang the
584	  system.
585
586	  [2] Both the input and output buffers are copied from the
587	  user and written back to the user, even when not used.
588
589	  [3] If one or more bits are set in out_flags and in_flags is
590	  zero, the following values are used for in_flags.all and
591	  written back into in_flags on completion.
592
593	   * IDE_TASKFILE_STD_IN_FLAGS | (IDE_HOB_STD_IN_FLAGS << 8)
594	     if LBA48 addressing is enabled for the drive
595	   * IDE_TASKFILE_STD_IN_FLAGS
596	     if CHS/LBA28
597
598	  The association between in_flags.all and each enable
599	  bitfield flips depending on endianess; fortunately, TASKFILE
600	  only uses inflags.b.data bit and ignores all other bits.
601	  The end result is that, on any endian machines, it has no
602	  effect other than modifying in_flags on completion.
603
604	  [4] The default value of SELECT is (0xa0|DEV_bit|LBA_bit)
605	  except for four drives per port chipsets.  For four drives
606	  per port chipsets, it's (0xa0|DEV_bit|LBA_bit) for the first
607	  pair and (0x80|DEV_bit|LBA_bit) for the second pair.
608
609	  [5] The argument to the ioctl is a pointer to a region of
610	  memory containing a ide_task_request_t structure, followed
611	  by an optional buffer of data to be transmitted to the
612	  drive, followed by an optional buffer to receive data from
613	  the drive.
614
615	  Command is passed to the disk drive via the ide_task_request_t
616	  structure, which contains these fields:
617
618	    io_ports[8]		values for the taskfile registers
619	    hob_ports[8]	high-order bytes, for extended commands
620	    out_flags		flags indicating which entries in the
621	    			io_ports[] and hob_ports[] arrays
622				contain valid values.  Type ide_reg_valid_t.
623	    in_flags		flags indicating which entries in the
624	    			io_ports[] and hob_ports[] arrays
625				are expected to contain valid values
626				on return.
627	    data_phase		See below
628	    req_cmd		Command type, see below
629	    out_size		output (user->drive) buffer size, bytes
630	    in_size		input (drive->user) buffer size, bytes
631
632	  When out_flags is zero, the following registers are loaded.
633
634	    HOB_FEATURE		If the drive supports LBA48
635	    HOB_NSECTOR		If the drive supports LBA48
636	    HOB_SECTOR		If the drive supports LBA48
637	    HOB_LCYL		If the drive supports LBA48
638	    HOB_HCYL		If the drive supports LBA48
639	    FEATURE
640	    NSECTOR
641	    SECTOR
642	    LCYL
643	    HCYL
644	    SELECT		First, masked with 0xE0 if LBA48, 0xEF
645				otherwise; then, or'ed with the default
646				value of SELECT.
647
648	  If any bit in out_flags is set, the following registers are loaded.
649
650	    HOB_DATA		If out_flags.b.data is set.  HOB_DATA will
651				travel on DD8-DD15 on little endian machines
652				and on DD0-DD7 on big endian machines.
653	    DATA		If out_flags.b.data is set.  DATA will
654				travel on DD0-DD7 on little endian machines
655				and on DD8-DD15 on big endian machines.
656	    HOB_NSECTOR		If out_flags.b.nsector_hob is set
657	    HOB_SECTOR		If out_flags.b.sector_hob is set
658	    HOB_LCYL		If out_flags.b.lcyl_hob is set
659	    HOB_HCYL		If out_flags.b.hcyl_hob is set
660	    FEATURE		If out_flags.b.feature is set
661	    NSECTOR		If out_flags.b.nsector is set
662	    SECTOR		If out_flags.b.sector is set
663	    LCYL		If out_flags.b.lcyl is set
664	    HCYL		If out_flags.b.hcyl is set
665	    SELECT		Or'ed with the default value of SELECT and
666				loaded regardless of out_flags.b.select.
667
668	  Taskfile registers are read back from the drive into
669	  {io|hob}_ports[] after the command completes iff one of the
670	  following conditions is met; otherwise, the original values
671	  will be written back, unchanged.
672
673	    1. The drive fails the command (EIO).
674	    2. One or more than one bits are set in out_flags.
675	    3. The requested data_phase is TASKFILE_NO_DATA.
676
677	    HOB_DATA		If in_flags.b.data is set.  It will contain
678				DD8-DD15 on little endian machines and
679				DD0-DD7 on big endian machines.
680	    DATA		If in_flags.b.data is set.  It will contain
681				DD0-DD7 on little endian machines and
682				DD8-DD15 on big endian machines.
683	    HOB_FEATURE		If the drive supports LBA48
684	    HOB_NSECTOR		If the drive supports LBA48
685	    HOB_SECTOR		If the drive supports LBA48
686	    HOB_LCYL		If the drive supports LBA48
687	    HOB_HCYL		If the drive supports LBA48
688	    NSECTOR
689	    SECTOR
690	    LCYL
691	    HCYL
692
693	  The data_phase field describes the data transfer to be
694	  performed.  Value is one of:
695
696	    TASKFILE_IN
697	    TASKFILE_MULTI_IN
698	    TASKFILE_OUT
699	    TASKFILE_MULTI_OUT
700	    TASKFILE_IN_OUT
701	    TASKFILE_IN_DMA
702	    TASKFILE_IN_DMAQ		== IN_DMA (queueing not supported)
703	    TASKFILE_OUT_DMA
704	    TASKFILE_OUT_DMAQ		== OUT_DMA (queueing not supported)
705	    TASKFILE_P_IN		unimplemented
706	    TASKFILE_P_IN_DMA		unimplemented
707	    TASKFILE_P_IN_DMAQ		unimplemented
708	    TASKFILE_P_OUT		unimplemented
709	    TASKFILE_P_OUT_DMA		unimplemented
710	    TASKFILE_P_OUT_DMAQ		unimplemented
711
712	  The req_cmd field classifies the command type.  It may be
713	  one of:
714
715	    IDE_DRIVE_TASK_NO_DATA
716	    IDE_DRIVE_TASK_SET_XFER	unimplemented
717	    IDE_DRIVE_TASK_IN
718	    IDE_DRIVE_TASK_OUT		unimplemented
719	    IDE_DRIVE_TASK_RAW_WRITE
720
721	  [6] Do not access {in|out}_flags->all except for resetting
722	  all the bits.  Always access individual bit fields.  ->all
723	  value will flip depending on endianess.  For the same
724	  reason, do not use IDE_{TASKFILE|HOB}_STD_{OUT|IN}_FLAGS
725	  constants defined in hdreg.h.
726
727
728
729HDIO_DRIVE_CMD			execute a special drive command
730
731	Note:  If you don't have a copy of the ANSI ATA specification
732	handy, you should probably ignore this ioctl.
733
734	usage:
735
736	  u8 args[4+XFER_SIZE];
737	  ...
738	  ioctl(fd, HDIO_DRIVE_CMD, args);
739
740	inputs:
741
742	  Commands other than WIN_SMART
743	    args[0]	COMMAND
744	    args[1]	NSECTOR
745	    args[2]	FEATURE
746	    args[3]	NSECTOR
747
748	  WIN_SMART
749	    args[0]	COMMAND
750	    args[1]	SECTOR
751	    args[2]	FEATURE
752	    args[3]	NSECTOR
753
754	outputs:
755
756	  args[] buffer is filled with register values followed by any
757	  data returned by the disk.
758	    args[0]	status
759	    args[1]	error
760	    args[2]	NSECTOR
761	    args[3]	undefined
762	    args[4+]	NSECTOR * 512 bytes of data returned by the command.
763
764	error returns:
765	  EACCES	Access denied:  requires CAP_SYS_RAWIO
766	  ENOMEM	Unable to allocate memory for task
767	  EIO		Drive reports error
768
769	notes:
770
771	  [1] For commands other than WIN_SMART, args[1] should equal
772	  args[3].  SECTOR, LCYL and HCYL are undefined.  For
773	  WIN_SMART, 0x4f and 0xc2 are loaded into LCYL and HCYL
774	  respectively.  In both cases SELECT will contain the default
775	  value for the drive.  Please refer to HDIO_DRIVE_TASKFILE
776	  notes for the default value of SELECT.
777
778	  [2] If NSECTOR value is greater than zero and the drive sets
779	  DRQ when interrupting for the command, NSECTOR * 512 bytes
780	  are read from the device into the area following NSECTOR.
781	  In the above example, the area would be
782	  args[4..4+XFER_SIZE].  16bit PIO is used regardless of
783	  HDIO_SET_32BIT setting.
784
785	  [3] If COMMAND == WIN_SETFEATURES && FEATURE == SETFEATURES_XFER
786	  && NSECTOR >= XFER_SW_DMA_0 && the drive supports any DMA
787	  mode, IDE driver will try to tune the transfer mode of the
788	  drive accordingly.
789
790
791
792HDIO_DRIVE_TASK			execute task and special drive command
793
794	Note:  If you don't have a copy of the ANSI ATA specification
795	handy, you should probably ignore this ioctl.
796
797	usage:
798
799	  u8 args[7];
800	  ...
801	  ioctl(fd, HDIO_DRIVE_TASK, args);
802
803	inputs:
804
805	  Taskfile register values:
806	    args[0]	COMMAND
807	    args[1]	FEATURE
808	    args[2]	NSECTOR
809	    args[3]	SECTOR
810	    args[4]	LCYL
811	    args[5]	HCYL
812	    args[6]	SELECT
813
814	outputs:
815
816	  Taskfile register values:
817	    args[0]	status
818	    args[1]	error
819	    args[2]	NSECTOR
820	    args[3]	SECTOR
821	    args[4]	LCYL
822	    args[5]	HCYL
823	    args[6]	SELECT
824
825	error returns:
826	  EACCES	Access denied:  requires CAP_SYS_RAWIO
827	  ENOMEM	Unable to allocate memory for task
828	  ENOMSG	Device is not a disk drive.
829	  EIO		Drive failed the command.
830
831	notes:
832
833	  [1] DEV bit (0x10) of SELECT register is ignored and the
834	  appropriate value for the drive is used.  All other bits
835	  are used unaltered.
836
837
838
839HDIO_DRIVE_CMD_AEB		HDIO_DRIVE_TASK
840
841	Not implemented, as of 2.6.8.1
842
843
844
845HDIO_SET_32BIT			change io_32bit flags
846
847	usage:
848
849	  int val;
850	  ioctl(fd, HDIO_SET_32BIT, val);
851
852	inputs:
853	  New value for io_32bit flag
854
855	outputs:	none
856
857	error return:
858	  EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
859	  EACCES	Access denied:  requires CAP_SYS_ADMIN
860	  EINVAL	value out of range [0 3]
861	  EBUSY		Controller busy
862
863
864
865
866HDIO_SET_NOWERR			change ignore-write-error flag
867
868	usage:
869
870	  int val;
871	  ioctl(fd, HDIO_SET_NOWERR, val);
872
873	inputs:
874	  New value for ignore-write-error flag.  Used for ignoring
875	  WRERR_STAT
876
877	outputs:	none
878
879	error return:
880	  EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
881	  EACCES	Access denied:  requires CAP_SYS_ADMIN
882	  EINVAL	value out of range [0 1]
883	  EBUSY		Controller busy
884
885
886
887HDIO_SET_DMA			change use-dma flag
888
889	usage:
890
891	  long val;
892	  ioctl(fd, HDIO_SET_DMA, val);
893
894	inputs:
895	  New value for use-dma flag
896
897	outputs:	none
898
899	error return:
900	  EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
901	  EACCES	Access denied:  requires CAP_SYS_ADMIN
902	  EINVAL	value out of range [0 1]
903	  EBUSY		Controller busy
904
905
906
907HDIO_SET_PIO_MODE		reconfig interface to new speed
908
909	usage:
910
911	  long val;
912	  ioctl(fd, HDIO_SET_PIO_MODE, val);
913
914	inputs:
915	  New interface speed.
916
917	outputs:	none
918
919	error return:
920	  EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
921	  EACCES	Access denied:  requires CAP_SYS_ADMIN
922	  EINVAL	value out of range [0 255]
923	  EBUSY		Controller busy
924
925
926
927HDIO_SCAN_HWIF			register and (re)scan interface
928
929	usage:
930
931	  int args[3]
932	  ...
933	  ioctl(fd, HDIO_SCAN_HWIF, args);
934
935	inputs:
936	  args[0]	io address to probe
937	  args[1]	control address to probe
938	  args[2]	irq number
939
940	outputs:	none
941
942	error returns:
943	  EACCES	Access denied:  requires CAP_SYS_RAWIO
944	  EIO		Probe failed.
945
946	notes:
947
948	  This ioctl initializes the addresses and irq for a disk
949	  controller, probes for drives, and creates /proc/ide
950	  interfaces as appropriate.
951
952
953
954HDIO_UNREGISTER_HWIF		unregister interface
955
956	usage:
957
958	  int index;
959	  ioctl(fd, HDIO_UNREGISTER_HWIF, index);
960
961	inputs:
962	  index		index of hardware interface to unregister
963
964	outputs:	none
965
966	error returns:
967	  EACCES	Access denied:  requires CAP_SYS_RAWIO
968
969	notes:
970
971	  This ioctl removes a hardware interface from the kernel.
972
973	  Currently (2.6.8) this ioctl silently fails if any drive on
974	  the interface is busy.
975
976
977
978HDIO_SET_WCACHE			change write cache enable-disable
979
980	usage:
981
982	  int val;
983	  ioctl(fd, HDIO_SET_WCACHE, val);
984
985	inputs:
986	  New value for write cache enable
987
988	outputs:	none
989
990	error return:
991	  EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
992	  EACCES	Access denied:  requires CAP_SYS_ADMIN
993	  EINVAL	value out of range [0 1]
994	  EBUSY		Controller busy
995
996
997
998HDIO_SET_ACOUSTIC		change acoustic behavior
999
1000	usage:
1001
1002	  int val;
1003	  ioctl(fd, HDIO_SET_ACOUSTIC, val);
1004
1005	inputs:
1006	  New value for drive acoustic settings
1007
1008	outputs:	none
1009
1010	error return:
1011	  EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
1012	  EACCES	Access denied:  requires CAP_SYS_ADMIN
1013	  EINVAL	value out of range [0 254]
1014	  EBUSY		Controller busy
1015
1016
1017
1018HDIO_SET_QDMA			change use-qdma flag
1019
1020	Not implemented, as of 2.6.8.1
1021
1022
1023
1024HDIO_SET_ADDRESS		change lba addressing modes
1025
1026	usage:
1027
1028	  int val;
1029	  ioctl(fd, HDIO_SET_ADDRESS, val);
1030
1031	inputs:
1032	  New value for addressing mode
1033	    0 = 28-bit
1034	    1 = 48-bit
1035	    2 = 48-bit doing 28-bit
1036
1037	outputs:	none
1038
1039	error return:
1040	  EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
1041	  EACCES	Access denied:  requires CAP_SYS_ADMIN
1042	  EINVAL	value out of range [0 2]
1043	  EBUSY		Controller busy
1044	  EIO		Drive does not support lba48 mode.
1045
1046
1047HDIO_SET_IDE_SCSI
1048
1049	usage:
1050
1051	  long val;
1052	  ioctl(fd, HDIO_SET_IDE_SCSI, val);
1053
1054	inputs:
1055	  New value for scsi emulation mode (?)
1056
1057	outputs:	none
1058
1059	error return:
1060	  EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
1061	  EACCES	Access denied:  requires CAP_SYS_ADMIN
1062	  EINVAL	value out of range [0 1]
1063	  EBUSY		Controller busy
1064
1065
1066
1067HDIO_SET_SCSI_IDE
1068
1069	Not implemented, as of 2.6.8.1
1070
1071
1072