1==============================
2Summary of `HDIO_` ioctl calls
3==============================
4
5- Edward A. Falk <efalk@google.com>
6
7November, 2004
8
9This document attempts to describe the ioctl(2) calls supported by
10the HD/IDE layer.  These are by-and-large implemented (as of Linux 2.6)
11in drivers/ide/ide.c and drivers/block/scsi_ioctl.c
12
13ioctl values are listed in <linux/hdreg.h>.  As of this writing, they
14are as follows:
15
16    ioctls that pass argument pointers to user space:
17
18	=======================	=======================================
19	HDIO_GETGEO		get device geometry
20	HDIO_GET_UNMASKINTR	get current unmask setting
21	HDIO_GET_MULTCOUNT	get current IDE blockmode setting
22	HDIO_GET_QDMA		get use-qdma flag
23	HDIO_SET_XFER		set transfer rate via proc
24	HDIO_OBSOLETE_IDENTITY	OBSOLETE, DO NOT USE
25	HDIO_GET_KEEPSETTINGS	get keep-settings-on-reset flag
26	HDIO_GET_32BIT		get current io_32bit setting
27	HDIO_GET_NOWERR		get ignore-write-error flag
28	HDIO_GET_DMA		get use-dma flag
29	HDIO_GET_NICE		get nice flags
30	HDIO_GET_IDENTITY	get IDE identification info
31	HDIO_GET_WCACHE		get write cache mode on|off
32	HDIO_GET_ACOUSTIC	get acoustic value
33	HDIO_GET_ADDRESS	get sector addressing mode
34	HDIO_GET_BUSSTATE	get the bus state of the hwif
35	HDIO_TRISTATE_HWIF	execute a channel tristate
36	HDIO_DRIVE_RESET	execute a device reset
37	HDIO_DRIVE_TASKFILE	execute raw taskfile
38	HDIO_DRIVE_TASK		execute task and special drive command
39	HDIO_DRIVE_CMD		execute a special drive command
40	HDIO_DRIVE_CMD_AEB	HDIO_DRIVE_TASK
41	=======================	=======================================
42
43    ioctls that pass non-pointer values:
44
45	=======================	=======================================
46	HDIO_SET_MULTCOUNT	change IDE blockmode
47	HDIO_SET_UNMASKINTR	permit other irqs during I/O
48	HDIO_SET_KEEPSETTINGS	keep ioctl settings on reset
49	HDIO_SET_32BIT		change io_32bit flags
50	HDIO_SET_NOWERR		change ignore-write-error flag
51	HDIO_SET_DMA		change use-dma flag
52	HDIO_SET_PIO_MODE	reconfig interface to new speed
53	HDIO_SCAN_HWIF		register and (re)scan interface
54	HDIO_SET_NICE		set nice flags
55	HDIO_UNREGISTER_HWIF	unregister interface
56	HDIO_SET_WCACHE		change write cache enable-disable
57	HDIO_SET_ACOUSTIC	change acoustic behavior
58	HDIO_SET_BUSSTATE	set the bus state of the hwif
59	HDIO_SET_QDMA		change use-qdma flag
60	HDIO_SET_ADDRESS	change lba addressing modes
61
62	HDIO_SET_IDE_SCSI	Set scsi emulation mode on/off
63	HDIO_SET_SCSI_IDE	not implemented yet
64	=======================	=======================================
65
66
67The information that follows was determined from reading kernel source
68code.  It is likely that some corrections will be made over time.
69
70------------------------------------------------------------------------------
71
72General:
73
74	Unless otherwise specified, all ioctl calls return 0 on success
75	and -1 with errno set to an appropriate value on error.
76
77	Unless otherwise specified, all ioctl calls return -1 and set
78	errno to EFAULT on a failed attempt to copy data to or from user
79	address space.
80
81	Unless otherwise specified, all data structures and constants
82	are defined in <linux/hdreg.h>
83
84------------------------------------------------------------------------------
85
86HDIO_GETGEO
87	get device geometry
88
89
90	usage::
91
92	  struct hd_geometry geom;
93
94	  ioctl(fd, HDIO_GETGEO, &geom);
95
96
97	inputs:
98		none
99
100
101
102	outputs:
103		hd_geometry structure containing:
104
105
106	    =========	==================================
107	    heads	number of heads
108	    sectors	number of sectors/track
109	    cylinders	number of cylinders, mod 65536
110	    start	starting sector of this partition.
111	    =========	==================================
112
113
114	error returns:
115	  - EINVAL
116
117			if the device is not a disk drive or floppy drive,
118			or if the user passes a null pointer
119
120
121	notes:
122		Not particularly useful with modern disk drives, whose geometry
123		is a polite fiction anyway.  Modern drives are addressed
124		purely by sector number nowadays (lba addressing), and the
125		drive geometry is an abstraction which is actually subject
126		to change.  Currently (as of Nov 2004), the geometry values
127		are the "bios" values -- presumably the values the drive had
128		when Linux first booted.
129
130		In addition, the cylinders field of the hd_geometry is an
131		unsigned short, meaning that on most architectures, this
132		ioctl will not return a meaningful value on drives with more
133		than 65535 tracks.
134
135		The start field is unsigned long, meaning that it will not
136		contain a meaningful value for disks over 219 Gb in size.
137
138
139
140
141HDIO_GET_UNMASKINTR
142	get current unmask setting
143
144
145	usage::
146
147	  long val;
148
149	  ioctl(fd, HDIO_GET_UNMASKINTR, &val);
150
151	inputs:
152		none
153
154
155
156	outputs:
157		The value of the drive's current unmask setting
158
159
160
161
162
163HDIO_SET_UNMASKINTR
164	permit other irqs during I/O
165
166
167	usage::
168
169	  unsigned long val;
170
171	  ioctl(fd, HDIO_SET_UNMASKINTR, val);
172
173	inputs:
174		New value for unmask flag
175
176
177
178	outputs:
179		none
180
181
182
183	error return:
184	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
185	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
186	  - EINVAL	value out of range [0 1]
187	  - EBUSY	Controller busy
188
189
190
191
192HDIO_GET_MULTCOUNT
193	get current IDE blockmode setting
194
195
196	usage::
197
198	  long val;
199
200	  ioctl(fd, HDIO_GET_MULTCOUNT, &val);
201
202	inputs:
203		none
204
205
206
207	outputs:
208		The value of the current IDE block mode setting.  This
209		controls how many sectors the drive will transfer per
210		interrupt.
211
212
213
214HDIO_SET_MULTCOUNT
215	change IDE blockmode
216
217
218	usage::
219
220	  int val;
221
222	  ioctl(fd, HDIO_SET_MULTCOUNT, val);
223
224	inputs:
225		New value for IDE block mode setting.  This controls how many
226		sectors the drive will transfer per interrupt.
227
228	outputs:
229		none
230
231
232
233	error return:
234	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
235	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
236	  - EINVAL	value out of range supported by disk.
237	  - EBUSY	Controller busy or blockmode already set.
238	  - EIO		Drive did not accept new block mode.
239
240	notes:
241	  Source code comments read::
242
243	    This is tightly woven into the driver->do_special cannot
244	    touch.  DON'T do it again until a total personality rewrite
245	    is committed.
246
247	  If blockmode has already been set, this ioctl will fail with
248	  -EBUSY
249
250
251
252HDIO_GET_QDMA
253	get use-qdma flag
254
255
256	Not implemented, as of 2.6.8.1
257
258
259
260HDIO_SET_XFER
261	set transfer rate via proc
262
263
264	Not implemented, as of 2.6.8.1
265
266
267
268HDIO_OBSOLETE_IDENTITY
269	OBSOLETE, DO NOT USE
270
271
272	Same as HDIO_GET_IDENTITY (see below), except that it only
273	returns the first 142 bytes of drive identity information.
274
275
276
277HDIO_GET_IDENTITY
278	get IDE identification info
279
280
281	usage::
282
283	  unsigned char identity[512];
284
285	  ioctl(fd, HDIO_GET_IDENTITY, identity);
286
287	inputs:
288		none
289
290
291
292	outputs:
293		ATA drive identity information.  For full description, see
294		the IDENTIFY DEVICE and IDENTIFY PACKET DEVICE commands in
295		the ATA specification.
296
297	error returns:
298	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
299	  - ENOMSG	IDENTIFY DEVICE information not available
300
301	notes:
302		Returns information that was obtained when the drive was
303		probed.  Some of this information is subject to change, and
304		this ioctl does not re-probe the drive to update the
305		information.
306
307		This information is also available from /proc/ide/hdX/identify
308
309
310
311HDIO_GET_KEEPSETTINGS
312	get keep-settings-on-reset flag
313
314
315	usage::
316
317	  long val;
318
319	  ioctl(fd, HDIO_GET_KEEPSETTINGS, &val);
320
321	inputs:
322		none
323
324
325
326	outputs:
327		The value of the current "keep settings" flag
328
329
330
331	notes:
332		When set, indicates that kernel should restore settings
333		after a drive reset.
334
335
336
337HDIO_SET_KEEPSETTINGS
338	keep ioctl settings on reset
339
340
341	usage::
342
343	  long val;
344
345	  ioctl(fd, HDIO_SET_KEEPSETTINGS, val);
346
347	inputs:
348		New value for keep_settings flag
349
350
351
352	outputs:
353		none
354
355
356
357	error return:
358	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
359	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
360	  - EINVAL	value out of range [0 1]
361	  - EBUSY		Controller busy
362
363
364
365HDIO_GET_32BIT
366	get current io_32bit setting
367
368
369	usage::
370
371	  long val;
372
373	  ioctl(fd, HDIO_GET_32BIT, &val);
374
375	inputs:
376		none
377
378
379
380	outputs:
381		The value of the current io_32bit setting
382
383
384
385	notes:
386		0=16-bit, 1=32-bit, 2,3 = 32bit+sync
387
388
389
390
391
392HDIO_GET_NOWERR
393	get ignore-write-error flag
394
395
396	usage::
397
398	  long val;
399
400	  ioctl(fd, HDIO_GET_NOWERR, &val);
401
402	inputs:
403		none
404
405
406
407	outputs:
408		The value of the current ignore-write-error flag
409
410
411
412
413
414HDIO_GET_DMA
415	get use-dma flag
416
417
418	usage::
419
420	  long val;
421
422	  ioctl(fd, HDIO_GET_DMA, &val);
423
424	inputs:
425		none
426
427
428
429	outputs:
430		The value of the current use-dma flag
431
432
433
434
435
436HDIO_GET_NICE
437	get nice flags
438
439
440	usage::
441
442	  long nice;
443
444	  ioctl(fd, HDIO_GET_NICE, &nice);
445
446	inputs:
447		none
448
449
450
451	outputs:
452		The drive's "nice" values.
453
454
455
456	notes:
457		Per-drive flags which determine when the system will give more
458		bandwidth to other devices sharing the same IDE bus.
459
460		See <linux/hdreg.h>, near symbol IDE_NICE_DSC_OVERLAP.
461
462
463
464
465HDIO_SET_NICE
466	set nice flags
467
468
469	usage::
470
471	  unsigned long nice;
472
473	  ...
474	  ioctl(fd, HDIO_SET_NICE, nice);
475
476	inputs:
477		bitmask of nice flags.
478
479
480
481	outputs:
482		none
483
484
485
486	error returns:
487	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
488	  - EPERM	Flags other than DSC_OVERLAP and NICE_1 set.
489	  - EPERM	DSC_OVERLAP specified but not supported by drive
490
491	notes:
492		This ioctl sets the DSC_OVERLAP and NICE_1 flags from values
493		provided by the user.
494
495		Nice flags are listed in <linux/hdreg.h>, starting with
496		IDE_NICE_DSC_OVERLAP.  These values represent shifts.
497
498
499
500
501
502HDIO_GET_WCACHE
503	get write cache mode on|off
504
505
506	usage::
507
508	  long val;
509
510	  ioctl(fd, HDIO_GET_WCACHE, &val);
511
512	inputs:
513		none
514
515
516
517	outputs:
518		The value of the current write cache mode
519
520
521
522
523
524HDIO_GET_ACOUSTIC
525	get acoustic value
526
527
528	usage::
529
530	  long val;
531
532	  ioctl(fd, HDIO_GET_ACOUSTIC, &val);
533
534	inputs:
535		none
536
537
538
539	outputs:
540		The value of the current acoustic settings
541
542
543
544	notes:
545		See HDIO_SET_ACOUSTIC
546
547
548
549
550
551HDIO_GET_ADDRESS
552	usage::
553
554
555	  long val;
556
557	  ioctl(fd, HDIO_GET_ADDRESS, &val);
558
559	inputs:
560		none
561
562
563
564	outputs:
565		The value of the current addressing mode:
566
567	    =  ===================
568	    0  28-bit
569	    1  48-bit
570	    2  48-bit doing 28-bit
571	    3  64-bit
572	    =  ===================
573
574
575
576HDIO_GET_BUSSTATE
577	get the bus state of the hwif
578
579
580	usage::
581
582	  long state;
583
584	  ioctl(fd, HDIO_SCAN_HWIF, &state);
585
586	inputs:
587		none
588
589
590
591	outputs:
592		Current power state of the IDE bus.  One of BUSSTATE_OFF,
593		BUSSTATE_ON, or BUSSTATE_TRISTATE
594
595	error returns:
596	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
597
598
599
600
601HDIO_SET_BUSSTATE
602	set the bus state of the hwif
603
604
605	usage::
606
607	  int state;
608
609	  ...
610	  ioctl(fd, HDIO_SCAN_HWIF, state);
611
612	inputs:
613		Desired IDE power state.  One of BUSSTATE_OFF, BUSSTATE_ON,
614		or BUSSTATE_TRISTATE
615
616	outputs:
617		none
618
619
620
621	error returns:
622	  - EACCES	Access denied:  requires CAP_SYS_RAWIO
623	  - EOPNOTSUPP	Hardware interface does not support bus power control
624
625
626
627
628HDIO_TRISTATE_HWIF
629	execute a channel tristate
630
631
632	Not implemented, as of 2.6.8.1.  See HDIO_SET_BUSSTATE
633
634
635
636HDIO_DRIVE_RESET
637	execute a device reset
638
639
640	usage::
641
642	  int args[3]
643
644	  ...
645	  ioctl(fd, HDIO_DRIVE_RESET, args);
646
647	inputs:
648		none
649
650
651
652	outputs:
653		none
654
655
656
657	error returns:
658	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
659	  - ENXIO	No such device:	phy dead or ctl_addr == 0
660	  - EIO		I/O error:	reset timed out or hardware error
661
662	notes:
663
664	  - Execute a reset on the device as soon as the current IO
665	    operation has completed.
666
667	  - Executes an ATAPI soft reset if applicable, otherwise
668	    executes an ATA soft reset on the controller.
669
670
671
672HDIO_DRIVE_TASKFILE
673	execute raw taskfile
674
675
676	Note:
677		If you don't have a copy of the ANSI ATA specification
678		handy, you should probably ignore this ioctl.
679
680	- Execute an ATA disk command directly by writing the "taskfile"
681	  registers of the drive.  Requires ADMIN and RAWIO access
682	  privileges.
683
684	usage::
685
686	  struct {
687
688	    ide_task_request_t req_task;
689	    u8 outbuf[OUTPUT_SIZE];
690	    u8 inbuf[INPUT_SIZE];
691	  } task;
692	  memset(&task.req_task, 0, sizeof(task.req_task));
693	  task.req_task.out_size = sizeof(task.outbuf);
694	  task.req_task.in_size = sizeof(task.inbuf);
695	  ...
696	  ioctl(fd, HDIO_DRIVE_TASKFILE, &task);
697	  ...
698
699	inputs:
700
701	  (See below for details on memory area passed to ioctl.)
702
703	  ============	===================================================
704	  io_ports[8]	values to be written to taskfile registers
705	  hob_ports[8]	high-order bytes, for extended commands.
706	  out_flags	flags indicating which registers are valid
707	  in_flags	flags indicating which registers should be returned
708	  data_phase	see below
709	  req_cmd	command type to be executed
710	  out_size	size of output buffer
711	  outbuf	buffer of data to be transmitted to disk
712	  inbuf		buffer of data to be received from disk (see [1])
713	  ============	===================================================
714
715	outputs:
716
717	  ===========	====================================================
718	  io_ports[]	values returned in the taskfile registers
719	  hob_ports[]	high-order bytes, for extended commands.
720	  out_flags	flags indicating which registers are valid (see [2])
721	  in_flags	flags indicating which registers should be returned
722	  outbuf	buffer of data to be transmitted to disk (see [1])
723	  inbuf		buffer of data to be received from disk
724	  ===========	====================================================
725
726	error returns:
727	  - EACCES	CAP_SYS_ADMIN or CAP_SYS_RAWIO privilege not set.
728	  - ENOMSG	Device is not a disk drive.
729	  - ENOMEM	Unable to allocate memory for task
730	  - EFAULT	req_cmd == TASKFILE_IN_OUT (not implemented as of 2.6.8)
731	  - EPERM
732
733			req_cmd == TASKFILE_MULTI_OUT and drive
734			multi-count not yet set.
735	  - EIO		Drive failed the command.
736
737	notes:
738
739	  [1] READ THE FOLLOWING NOTES *CAREFULLY*.  THIS IOCTL IS
740	  FULL OF GOTCHAS.  Extreme caution should be used with using
741	  this ioctl.  A mistake can easily corrupt data or hang the
742	  system.
743
744	  [2] Both the input and output buffers are copied from the
745	  user and written back to the user, even when not used.
746
747	  [3] If one or more bits are set in out_flags and in_flags is
748	  zero, the following values are used for in_flags.all and
749	  written back into in_flags on completion.
750
751	   * IDE_TASKFILE_STD_IN_FLAGS | (IDE_HOB_STD_IN_FLAGS << 8)
752	     if LBA48 addressing is enabled for the drive
753	   * IDE_TASKFILE_STD_IN_FLAGS
754	     if CHS/LBA28
755
756	  The association between in_flags.all and each enable
757	  bitfield flips depending on endianness; fortunately, TASKFILE
758	  only uses inflags.b.data bit and ignores all other bits.
759	  The end result is that, on any endian machines, it has no
760	  effect other than modifying in_flags on completion.
761
762	  [4] The default value of SELECT is (0xa0|DEV_bit|LBA_bit)
763	  except for four drives per port chipsets.  For four drives
764	  per port chipsets, it's (0xa0|DEV_bit|LBA_bit) for the first
765	  pair and (0x80|DEV_bit|LBA_bit) for the second pair.
766
767	  [5] The argument to the ioctl is a pointer to a region of
768	  memory containing a ide_task_request_t structure, followed
769	  by an optional buffer of data to be transmitted to the
770	  drive, followed by an optional buffer to receive data from
771	  the drive.
772
773	  Command is passed to the disk drive via the ide_task_request_t
774	  structure, which contains these fields:
775
776	    ============	===============================================
777	    io_ports[8]		values for the taskfile registers
778	    hob_ports[8]	high-order bytes, for extended commands
779	    out_flags		flags indicating which entries in the
780				io_ports[] and hob_ports[] arrays
781				contain valid values.  Type ide_reg_valid_t.
782	    in_flags		flags indicating which entries in the
783				io_ports[] and hob_ports[] arrays
784				are expected to contain valid values
785				on return.
786	    data_phase		See below
787	    req_cmd		Command type, see below
788	    out_size		output (user->drive) buffer size, bytes
789	    in_size		input (drive->user) buffer size, bytes
790	    ============	===============================================
791
792	  When out_flags is zero, the following registers are loaded.
793
794	    ============	===============================================
795	    HOB_FEATURE		If the drive supports LBA48
796	    HOB_NSECTOR		If the drive supports LBA48
797	    HOB_SECTOR		If the drive supports LBA48
798	    HOB_LCYL		If the drive supports LBA48
799	    HOB_HCYL		If the drive supports LBA48
800	    FEATURE
801	    NSECTOR
802	    SECTOR
803	    LCYL
804	    HCYL
805	    SELECT		First, masked with 0xE0 if LBA48, 0xEF
806				otherwise; then, or'ed with the default
807				value of SELECT.
808	    ============	===============================================
809
810	  If any bit in out_flags is set, the following registers are loaded.
811
812	    ============	===============================================
813	    HOB_DATA		If out_flags.b.data is set.  HOB_DATA will
814				travel on DD8-DD15 on little endian machines
815				and on DD0-DD7 on big endian machines.
816	    DATA		If out_flags.b.data is set.  DATA will
817				travel on DD0-DD7 on little endian machines
818				and on DD8-DD15 on big endian machines.
819	    HOB_NSECTOR		If out_flags.b.nsector_hob is set
820	    HOB_SECTOR		If out_flags.b.sector_hob is set
821	    HOB_LCYL		If out_flags.b.lcyl_hob is set
822	    HOB_HCYL		If out_flags.b.hcyl_hob is set
823	    FEATURE		If out_flags.b.feature is set
824	    NSECTOR		If out_flags.b.nsector is set
825	    SECTOR		If out_flags.b.sector is set
826	    LCYL		If out_flags.b.lcyl is set
827	    HCYL		If out_flags.b.hcyl is set
828	    SELECT		Or'ed with the default value of SELECT and
829				loaded regardless of out_flags.b.select.
830	    ============	===============================================
831
832	  Taskfile registers are read back from the drive into
833	  {io|hob}_ports[] after the command completes iff one of the
834	  following conditions is met; otherwise, the original values
835	  will be written back, unchanged.
836
837	    1. The drive fails the command (EIO).
838	    2. One or more than one bits are set in out_flags.
839	    3. The requested data_phase is TASKFILE_NO_DATA.
840
841	    ============	===============================================
842	    HOB_DATA		If in_flags.b.data is set.  It will contain
843				DD8-DD15 on little endian machines and
844				DD0-DD7 on big endian machines.
845	    DATA		If in_flags.b.data is set.  It will contain
846				DD0-DD7 on little endian machines and
847				DD8-DD15 on big endian machines.
848	    HOB_FEATURE		If the drive supports LBA48
849	    HOB_NSECTOR		If the drive supports LBA48
850	    HOB_SECTOR		If the drive supports LBA48
851	    HOB_LCYL		If the drive supports LBA48
852	    HOB_HCYL		If the drive supports LBA48
853	    NSECTOR
854	    SECTOR
855	    LCYL
856	    HCYL
857	    ============	===============================================
858
859	  The data_phase field describes the data transfer to be
860	  performed.  Value is one of:
861
862	    ===================        ========================================
863	    TASKFILE_IN
864	    TASKFILE_MULTI_IN
865	    TASKFILE_OUT
866	    TASKFILE_MULTI_OUT
867	    TASKFILE_IN_OUT
868	    TASKFILE_IN_DMA
869	    TASKFILE_IN_DMAQ		== IN_DMA (queueing not supported)
870	    TASKFILE_OUT_DMA
871	    TASKFILE_OUT_DMAQ		== OUT_DMA (queueing not supported)
872	    TASKFILE_P_IN		unimplemented
873	    TASKFILE_P_IN_DMA		unimplemented
874	    TASKFILE_P_IN_DMAQ		unimplemented
875	    TASKFILE_P_OUT		unimplemented
876	    TASKFILE_P_OUT_DMA		unimplemented
877	    TASKFILE_P_OUT_DMAQ		unimplemented
878	    ===================        ========================================
879
880	  The req_cmd field classifies the command type.  It may be
881	  one of:
882
883	    ========================    =======================================
884	    IDE_DRIVE_TASK_NO_DATA
885	    IDE_DRIVE_TASK_SET_XFER	unimplemented
886	    IDE_DRIVE_TASK_IN
887	    IDE_DRIVE_TASK_OUT		unimplemented
888	    IDE_DRIVE_TASK_RAW_WRITE
889	    ========================    =======================================
890
891	  [6] Do not access {in|out}_flags->all except for resetting
892	  all the bits.  Always access individual bit fields.  ->all
893	  value will flip depending on endianness.  For the same
894	  reason, do not use IDE_{TASKFILE|HOB}_STD_{OUT|IN}_FLAGS
895	  constants defined in hdreg.h.
896
897
898
899HDIO_DRIVE_CMD
900	execute a special drive command
901
902
903	Note:  If you don't have a copy of the ANSI ATA specification
904	handy, you should probably ignore this ioctl.
905
906	usage::
907
908	  u8 args[4+XFER_SIZE];
909
910	  ...
911	  ioctl(fd, HDIO_DRIVE_CMD, args);
912
913	inputs:
914	    Commands other than WIN_SMART:
915
916	    =======     =======
917	    args[0]	COMMAND
918	    args[1]	NSECTOR
919	    args[2]	FEATURE
920	    args[3]	NSECTOR
921	    =======     =======
922
923	    WIN_SMART:
924
925	    =======     =======
926	    args[0]	COMMAND
927	    args[1]	SECTOR
928	    args[2]	FEATURE
929	    args[3]	NSECTOR
930	    =======     =======
931
932	outputs:
933		args[] buffer is filled with register values followed by any
934
935
936	  data returned by the disk.
937
938	    ========	====================================================
939	    args[0]	status
940	    args[1]	error
941	    args[2]	NSECTOR
942	    args[3]	undefined
943	    args[4+]	NSECTOR * 512 bytes of data returned by the command.
944	    ========	====================================================
945
946	error returns:
947	  - EACCES	Access denied:  requires CAP_SYS_RAWIO
948	  - ENOMEM	Unable to allocate memory for task
949	  - EIO		Drive reports error
950
951	notes:
952
953	  [1] For commands other than WIN_SMART, args[1] should equal
954	  args[3].  SECTOR, LCYL and HCYL are undefined.  For
955	  WIN_SMART, 0x4f and 0xc2 are loaded into LCYL and HCYL
956	  respectively.  In both cases SELECT will contain the default
957	  value for the drive.  Please refer to HDIO_DRIVE_TASKFILE
958	  notes for the default value of SELECT.
959
960	  [2] If NSECTOR value is greater than zero and the drive sets
961	  DRQ when interrupting for the command, NSECTOR * 512 bytes
962	  are read from the device into the area following NSECTOR.
963	  In the above example, the area would be
964	  args[4..4+XFER_SIZE].  16bit PIO is used regardless of
965	  HDIO_SET_32BIT setting.
966
967	  [3] If COMMAND == WIN_SETFEATURES && FEATURE == SETFEATURES_XFER
968	  && NSECTOR >= XFER_SW_DMA_0 && the drive supports any DMA
969	  mode, IDE driver will try to tune the transfer mode of the
970	  drive accordingly.
971
972
973
974HDIO_DRIVE_TASK
975	execute task and special drive command
976
977
978	Note:  If you don't have a copy of the ANSI ATA specification
979	handy, you should probably ignore this ioctl.
980
981	usage::
982
983	  u8 args[7];
984
985	  ...
986	  ioctl(fd, HDIO_DRIVE_TASK, args);
987
988	inputs:
989	    Taskfile register values:
990
991	    =======	=======
992	    args[0]	COMMAND
993	    args[1]	FEATURE
994	    args[2]	NSECTOR
995	    args[3]	SECTOR
996	    args[4]	LCYL
997	    args[5]	HCYL
998	    args[6]	SELECT
999	    =======	=======
1000
1001	outputs:
1002	    Taskfile register values:
1003
1004
1005	    =======	=======
1006	    args[0]	status
1007	    args[1]	error
1008	    args[2]	NSECTOR
1009	    args[3]	SECTOR
1010	    args[4]	LCYL
1011	    args[5]	HCYL
1012	    args[6]	SELECT
1013	    =======	=======
1014
1015	error returns:
1016	  - EACCES	Access denied:  requires CAP_SYS_RAWIO
1017	  - ENOMEM	Unable to allocate memory for task
1018	  - ENOMSG	Device is not a disk drive.
1019	  - EIO		Drive failed the command.
1020
1021	notes:
1022
1023	  [1] DEV bit (0x10) of SELECT register is ignored and the
1024	  appropriate value for the drive is used.  All other bits
1025	  are used unaltered.
1026
1027
1028
1029HDIO_DRIVE_CMD_AEB
1030	HDIO_DRIVE_TASK
1031
1032
1033	Not implemented, as of 2.6.8.1
1034
1035
1036
1037HDIO_SET_32BIT
1038	change io_32bit flags
1039
1040
1041	usage::
1042
1043	  int val;
1044
1045	  ioctl(fd, HDIO_SET_32BIT, val);
1046
1047	inputs:
1048		New value for io_32bit flag
1049
1050
1051
1052	outputs:
1053		none
1054
1055
1056
1057	error return:
1058	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
1059	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
1060	  - EINVAL	value out of range [0 3]
1061	  - EBUSY	Controller busy
1062
1063
1064
1065
1066HDIO_SET_NOWERR
1067	change ignore-write-error flag
1068
1069
1070	usage::
1071
1072	  int val;
1073
1074	  ioctl(fd, HDIO_SET_NOWERR, val);
1075
1076	inputs:
1077		New value for ignore-write-error flag.  Used for ignoring
1078
1079
1080	  WRERR_STAT
1081
1082	outputs:
1083		none
1084
1085
1086
1087	error return:
1088	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
1089	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
1090	  - EINVAL	value out of range [0 1]
1091	  - EBUSY		Controller busy
1092
1093
1094
1095HDIO_SET_DMA
1096	change use-dma flag
1097
1098
1099	usage::
1100
1101	  long val;
1102
1103	  ioctl(fd, HDIO_SET_DMA, val);
1104
1105	inputs:
1106		New value for use-dma flag
1107
1108
1109
1110	outputs:
1111		none
1112
1113
1114
1115	error return:
1116	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
1117	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
1118	  - EINVAL	value out of range [0 1]
1119	  - EBUSY	Controller busy
1120
1121
1122
1123HDIO_SET_PIO_MODE
1124	reconfig interface to new speed
1125
1126
1127	usage::
1128
1129	  long val;
1130
1131	  ioctl(fd, HDIO_SET_PIO_MODE, val);
1132
1133	inputs:
1134		New interface speed.
1135
1136
1137
1138	outputs:
1139		none
1140
1141
1142
1143	error return:
1144	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
1145	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
1146	  - EINVAL	value out of range [0 255]
1147	  - EBUSY	Controller busy
1148
1149
1150
1151HDIO_SCAN_HWIF
1152	register and (re)scan interface
1153
1154
1155	usage::
1156
1157	  int args[3]
1158
1159	  ...
1160	  ioctl(fd, HDIO_SCAN_HWIF, args);
1161
1162	inputs:
1163
1164	  =======	=========================
1165	  args[0]	io address to probe
1166
1167
1168	  args[1]	control address to probe
1169	  args[2]	irq number
1170	  =======	=========================
1171
1172	outputs:
1173		none
1174
1175
1176
1177	error returns:
1178	  - EACCES	Access denied:  requires CAP_SYS_RAWIO
1179	  - EIO		Probe failed.
1180
1181	notes:
1182		This ioctl initializes the addresses and irq for a disk
1183		controller, probes for drives, and creates /proc/ide
1184		interfaces as appropriate.
1185
1186
1187
1188HDIO_UNREGISTER_HWIF
1189	unregister interface
1190
1191
1192	usage::
1193
1194	  int index;
1195
1196	  ioctl(fd, HDIO_UNREGISTER_HWIF, index);
1197
1198	inputs:
1199		index		index of hardware interface to unregister
1200
1201
1202
1203	outputs:
1204		none
1205
1206
1207
1208	error returns:
1209	  - EACCES	Access denied:  requires CAP_SYS_RAWIO
1210
1211	notes:
1212		This ioctl removes a hardware interface from the kernel.
1213
1214		Currently (2.6.8) this ioctl silently fails if any drive on
1215		the interface is busy.
1216
1217
1218
1219HDIO_SET_WCACHE
1220	change write cache enable-disable
1221
1222
1223	usage::
1224
1225	  int val;
1226
1227	  ioctl(fd, HDIO_SET_WCACHE, val);
1228
1229	inputs:
1230		New value for write cache enable
1231
1232
1233
1234	outputs:
1235		none
1236
1237
1238
1239	error return:
1240	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
1241	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
1242	  - EINVAL	value out of range [0 1]
1243	  - EBUSY	Controller busy
1244
1245
1246
1247HDIO_SET_ACOUSTIC
1248	change acoustic behavior
1249
1250
1251	usage::
1252
1253	  int val;
1254
1255	  ioctl(fd, HDIO_SET_ACOUSTIC, val);
1256
1257	inputs:
1258		New value for drive acoustic settings
1259
1260
1261
1262	outputs:
1263		none
1264
1265
1266
1267	error return:
1268	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
1269	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
1270	  - EINVAL	value out of range [0 254]
1271	  - EBUSY	Controller busy
1272
1273
1274
1275HDIO_SET_QDMA
1276	change use-qdma flag
1277
1278
1279	Not implemented, as of 2.6.8.1
1280
1281
1282
1283HDIO_SET_ADDRESS
1284	change lba addressing modes
1285
1286
1287	usage::
1288
1289	  int val;
1290
1291	  ioctl(fd, HDIO_SET_ADDRESS, val);
1292
1293	inputs:
1294		New value for addressing mode
1295
1296	    =   ===================
1297	    0   28-bit
1298	    1   48-bit
1299	    2   48-bit doing 28-bit
1300	    =   ===================
1301
1302	outputs:
1303		none
1304
1305
1306
1307	error return:
1308	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
1309	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
1310	  - EINVAL	value out of range [0 2]
1311	  - EBUSY		Controller busy
1312	  - EIO		Drive does not support lba48 mode.
1313
1314
1315HDIO_SET_IDE_SCSI
1316	usage::
1317
1318
1319	  long val;
1320
1321	  ioctl(fd, HDIO_SET_IDE_SCSI, val);
1322
1323	inputs:
1324		New value for scsi emulation mode (?)
1325
1326
1327
1328	outputs:
1329		none
1330
1331
1332
1333	error return:
1334	  - EINVAL	(bdev != bdev->bd_contains) (not sure what this means)
1335	  - EACCES	Access denied:  requires CAP_SYS_ADMIN
1336	  - EINVAL	value out of range [0 1]
1337	  - EBUSY	Controller busy
1338
1339
1340
1341HDIO_SET_SCSI_IDE
1342	Not implemented, as of 2.6.8.1
1343