aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/s390/char/tape_std.c
blob: 03f07e5dd6e9ebe9699ae7306d585101f0db38ec (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
/*
 *  drivers/s390/char/tape_std.c
 *    standard tape device functions for ibm tapes.
 *
 *  S390 and zSeries version
 *    Copyright (C) 2001,2002 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author(s): Carsten Otte <cotte@de.ibm.com>
 *		 Michael Holzheu <holzheu@de.ibm.com>
 *		 Tuan Ngo-Anh <ngoanh@de.ibm.com>
 *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
 *		 Stefan Bader <shbader@de.ibm.com>
 */

#define KMSG_COMPONENT "tape"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/bio.h>
#include <linux/timer.h>

#include <asm/types.h>
#include <asm/idals.h>
#include <asm/ebcdic.h>
#include <asm/tape390.h>

#define TAPE_DBF_AREA	tape_core_dbf

#include "tape.h"
#include "tape_std.h"

/*
 * tape_std_assign
 */
static void
tape_std_assign_timeout(unsigned long data)
{
	struct tape_request *	request;
	struct tape_device *	device;
	int rc;

	request = (struct tape_request *) data;
	device = request->device;
	BUG_ON(!device);

	DBF_EVENT(3, "%08x: Assignment timeout. Device busy.\n",
			device->cdev_id);
	rc = tape_cancel_io(device, request);
	if(rc)
		DBF_EVENT(3, "(%s): Assign timeout: Cancel failed with rc = %i\n",
			dev_name(&device->cdev->dev), rc);
}

int
tape_std_assign(struct tape_device *device)
{
	int                  rc;
	struct timer_list    timeout;
	struct tape_request *request;

	request = tape_alloc_request(2, 11);
	if (IS_ERR(request))
		return PTR_ERR(request);

	request->op = TO_ASSIGN;
	tape_ccw_cc(request->cpaddr, ASSIGN, 11, request->cpdata);
	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);

	/*
	 * The assign command sometimes blocks if the device is assigned
	 * to another host (actually this shouldn't happen but it does).
	 * So we set up a timeout for this call.
	 */
	init_timer_on_stack(&timeout);
	timeout.function = tape_std_assign_timeout;
	timeout.data     = (unsigned long) request;
	timeout.expires  = jiffies + 2 * HZ;
	add_timer(&timeout);

	rc = tape_do_io_interruptible(device, request);

	del_timer(&timeout);

	if (rc != 0) {
		DBF_EVENT(3, "%08x: assign failed - device might be busy\n",
			device->cdev_id);
	} else {
		DBF_EVENT(3, "%08x: Tape assigned\n", device->cdev_id);
	}
	tape_free_request(request);
	return rc;
}

/*
 * tape_std_unassign
 */
int
tape_std_unassign (struct tape_device *device)
{
	int                  rc;
	struct tape_request *request;

	if (device->tape_state == TS_NOT_OPER) {
		DBF_EVENT(3, "(%08x): Can't unassign device\n",
			device->cdev_id);
		return -EIO;
	}

	request = tape_alloc_request(2, 11);
	if (IS_ERR(request))
		return PTR_ERR(request);

	request->op = TO_UNASSIGN;
	tape_ccw_cc(request->cpaddr, UNASSIGN, 11, request->cpdata);
	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);

	if ((rc = tape_do_io(device, request)) != 0) {
		DBF_EVENT(3, "%08x: Unassign failed\n", device->cdev_id);
	} else {
		DBF_EVENT(3, "%08x: Tape unassigned\n", device->cdev_id);
	}
	tape_free_request(request);
	return rc;
}

/*
 * TAPE390_DISPLAY: Show a string on the tape display.
 */
int
tape_std_display(struct tape_device *device, struct display_struct *disp)
{
	struct tape_request *request;
	int rc;

	request = tape_alloc_request(2, 17);
	if (IS_ERR(request)) {
		DBF_EVENT(3, "TAPE: load display failed\n");
		return PTR_ERR(request);
	}
	request->op = TO_DIS;

	*(unsigned char *) request->cpdata = disp->cntrl;
	DBF_EVENT(5, "TAPE: display cntrl=%04x\n", disp->cntrl);
	memcpy(((unsigned char *) request->cpdata) + 1, disp->message1, 8);
	memcpy(((unsigned char *) request->cpdata) + 9, disp->message2, 8);
	ASCEBC(((unsigned char*) request->cpdata) + 1, 16);

	tape_ccw_cc(request->cpaddr, LOAD_DISPLAY, 17, request->cpdata);
	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);

	rc = tape_do_io_interruptible(device, request);
	tape_free_request(request);
	return rc;
}

/*
 * Read block id.
 */
int
tape_std_read_block_id(struct tape_device *device, __u64 *id)
{
	struct tape_request *request;
	int rc;

	request = tape_alloc_request(3, 8);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_RBI;
	/* setup ccws */
	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
	tape_ccw_cc(request->cpaddr + 1, READ_BLOCK_ID, 8, request->cpdata);
	tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
	/* execute it */
	rc = tape_do_io(device, request);
	if (rc == 0)
		/* Get result from read buffer. */
		*id = *(__u64 *) request->cpdata;
	tape_free_request(request);
	return rc;
}

int
tape_std_terminate_write(struct tape_device *device)
{
	int rc;

	if(device->required_tapemarks == 0)
		return 0;

	DBF_LH(5, "tape%d: terminate write %dxEOF\n", device->first_minor,
		device->required_tapemarks);

	rc = tape_mtop(device, MTWEOF, device->required_tapemarks);
	if (rc)
		return rc;

	device->required_tapemarks = 0;
	return tape_mtop(device, MTBSR, 1);
}

/*
 * MTLOAD: Loads the tape.
 * The default implementation just wait until the tape medium state changes
 * to MS_LOADED.
 */
int
tape_std_mtload(struct tape_device *device, int count)
{
	return wait_event_interruptible(device->state_change_wq,
		(device->medium_state == MS_LOADED));
}

/*
 * MTSETBLK: Set block size.
 */
int
tape_std_mtsetblk(struct tape_device *device, int count)
{
	struct idal_buffer *new;

	DBF_LH(6, "tape_std_mtsetblk(%d)\n", count);
	if (count <= 0) {
		/*
		 * Just set block_size to 0. tapechar_read/tapechar_write
		 * will realloc the idal buffer if a bigger one than the
		 * current is needed.
		 */
		device->char_data.block_size = 0;
		return 0;
	}
	if (device->char_data.idal_buf != NULL &&
	    device->char_data.idal_buf->size == count)
		/* We already have a idal buffer of that size. */
		return 0;

	if (count > MAX_BLOCKSIZE) {
		DBF_EVENT(3, "Invalid block size (%d > %d) given.\n",
			count, MAX_BLOCKSIZE);
		return -EINVAL;
	}

	/* Allocate a new idal buffer. */
	new = idal_buffer_alloc(count, 0);
	if (IS_ERR(new))
		return -ENOMEM;
	if (device->char_data.idal_buf != NULL)
		idal_buffer_free(device->char_data.idal_buf);
	device->char_data.idal_buf = new;
	device->char_data.block_size = count;

	DBF_LH(6, "new blocksize is %d\n", device->char_data.block_size);

	return 0;
}

/*
 * MTRESET: Set block size to 0.
 */
int
tape_std_mtreset(struct tape_device *device, int count)
{
	DBF_EVENT(6, "TCHAR:devreset:\n");
	device->char_data.block_size = 0;
	return 0;
}

/*
 * MTFSF: Forward space over 'count' file marks. The tape is positioned
 * at the EOT (End of Tape) side of the file mark.
 */
int
tape_std_mtfsf(struct tape_device *device, int mt_count)
{
	struct tape_request *request;
	struct ccw1 *ccw;

	request = tape_alloc_request(mt_count + 2, 0);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_FSF;
	/* setup ccws */
	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
			  device->modeset_byte);
	ccw = tape_ccw_repeat(ccw, FORSPACEFILE, mt_count);
	ccw = tape_ccw_end(ccw, NOP, 0, NULL);

	/* execute it */
	return tape_do_io_free(device, request);
}

/*
 * MTFSR: Forward space over 'count' tape blocks (blocksize is set
 * via MTSETBLK.
 */
int
tape_std_mtfsr(struct tape_device *device, int mt_count)
{
	struct tape_request *request;
	struct ccw1 *ccw;
	int rc;

	request = tape_alloc_request(mt_count + 2, 0);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_FSB;
	/* setup ccws */
	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
			  device->modeset_byte);
	ccw = tape_ccw_repeat(ccw, FORSPACEBLOCK, mt_count);
	ccw = tape_ccw_end(ccw, NOP, 0, NULL);

	/* execute it */
	rc = tape_do_io(device, request);
	if (rc == 0 && request->rescnt > 0) {
		DBF_LH(3, "FSR over tapemark\n");
		rc = 1;
	}
	tape_free_request(request);

	return rc;
}

/*
 * MTBSR: Backward space over 'count' tape blocks.
 * (blocksize is set via MTSETBLK.
 */
int
tape_std_mtbsr(struct tape_device *device, int mt_count)
{
	struct tape_request *request;
	struct ccw1 *ccw;
	int rc;

	request = tape_alloc_request(mt_count + 2, 0);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_BSB;
	/* setup ccws */
	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
			  device->modeset_byte);
	ccw = tape_ccw_repeat(ccw, BACKSPACEBLOCK, mt_count);
	ccw = tape_ccw_end(ccw, NOP, 0, NULL);

	/* execute it */
	rc = tape_do_io(device, request);
	if (rc == 0 && request->rescnt > 0) {
		DBF_LH(3, "BSR over tapemark\n");
		rc = 1;
	}
	tape_free_request(request);

	return rc;
}

/*
 * MTWEOF: Write 'count' file marks at the current position.
 */
int
tape_std_mtweof(struct tape_device *device, int mt_count)
{
	struct tape_request *request;
	struct ccw1 *ccw;

	request = tape_alloc_request(mt_count + 2, 0);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_WTM;
	/* setup ccws */
	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
			  device->modeset_byte);
	ccw = tape_ccw_repeat(ccw, WRITETAPEMARK, mt_count);
	ccw = tape_ccw_end(ccw, NOP, 0, NULL);

	/* execute it */
	return tape_do_io_free(device, request);
}

/*
 * MTBSFM: Backward space over 'count' file marks.
 * The tape is positioned at the BOT (Begin Of Tape) side of the
 * last skipped file mark.
 */
int
tape_std_mtbsfm(struct tape_device *device, int mt_count)
{
	struct tape_request *request;
	struct ccw1 *ccw;

	request = tape_alloc_request(mt_count + 2, 0);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_BSF;
	/* setup ccws */
	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
			  device->modeset_byte);
	ccw = tape_ccw_repeat(ccw, BACKSPACEFILE, mt_count);
	ccw = tape_ccw_end(ccw, NOP, 0, NULL);

	/* execute it */
	return tape_do_io_free(device, request);
}

/*
 * MTBSF: Backward space over 'count' file marks. The tape is positioned at
 * the EOT (End of Tape) side of the last skipped file mark.
 */
int
tape_std_mtbsf(struct tape_device *device, int mt_count)
{
	struct tape_request *request;
	struct ccw1 *ccw;
	int rc;

	request = tape_alloc_request(mt_count + 2, 0);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_BSF;
	/* setup ccws */
	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
			  device->modeset_byte);
	ccw = tape_ccw_repeat(ccw, BACKSPACEFILE, mt_count);
	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
	/* execute it */
	rc = tape_do_io_free(device, request);
	if (rc == 0) {
		rc = tape_mtop(device, MTFSR, 1);
		if (rc > 0)
			rc = 0;
	}
	return rc;
}

/*
 * MTFSFM: Forward space over 'count' file marks.
 * The tape is positioned at the BOT (Begin Of Tape) side
 * of the last skipped file mark.
 */
int
tape_std_mtfsfm(struct tape_device *device, int mt_count)
{
	struct tape_request *request;
	struct ccw1 *ccw;
	int rc;

	request = tape_alloc_request(mt_count + 2, 0);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_FSF;
	/* setup ccws */
	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
			  device->modeset_byte);
	ccw = tape_ccw_repeat(ccw, FORSPACEFILE, mt_count);
	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
	/* execute it */
	rc = tape_do_io_free(device, request);
	if (rc == 0) {
		rc = tape_mtop(device, MTBSR, 1);
		if (rc > 0)
			rc = 0;
	}

	return rc;
}

/*
 * MTREW: Rewind the tape.
 */
int
tape_std_mtrew(struct tape_device *device, int mt_count)
{
	struct tape_request *request;

	request = tape_alloc_request(3, 0);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_REW;
	/* setup ccws */
	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
		    device->modeset_byte);
	tape_ccw_cc(request->cpaddr + 1, REWIND, 0, NULL);
	tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);

	/* execute it */
	return tape_do_io_free(device, request);
}

/*
 * MTOFFL: Rewind the tape and put the drive off-line.
 * Implement 'rewind unload'
 */
int
tape_std_mtoffl(struct tape_device *device, int mt_count)
{
	struct tape_request *request;

	request = tape_alloc_request(3, 0);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_RUN;
	/* setup ccws */
	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
	tape_ccw_cc(request->cpaddr + 1, REWIND_UNLOAD, 0, NULL);
	tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);

	/* execute it */
	return tape_do_io_free(device, request);
}

/*
 * MTNOP: 'No operation'.
 */
int
tape_std_mtnop(struct tape_device *device, int mt_count)
{
	struct tape_request *request;

	request = tape_alloc_request(2, 0);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_NOP;
	/* setup ccws */
	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
	/* execute it */
	return tape_do_io_free(device, request);
}

/*
 * MTEOM: positions at the end of the portion of the tape already used
 * for recordind data. MTEOM positions after the last file mark, ready for
 * appending another file.
 */
int
tape_std_mteom(struct tape_device *device, int mt_count)
{
	int rc;

	/*
	 * Seek from the beginning of tape (rewind).
	 */
	if ((rc = tape_mtop(device, MTREW, 1)) < 0)
		return rc;

	/*
	 * The logical end of volume is given by two sewuential tapemarks.
	 * Look for this by skipping to the next file (over one tapemark)
	 * and then test for another one (fsr returns 1 if a tapemark was
	 * encountered).
	 */
	do {
		if ((rc = tape_mtop(device, MTFSF, 1)) < 0)
			return rc;
		if ((rc = tape_mtop(device, MTFSR, 1)) < 0)
			return rc;
	} while (rc == 0);

	return tape_mtop(device, MTBSR, 1);
}

/*
 * MTRETEN: Retension the tape, i.e. forward space to end of tape and rewind.
 */
int
tape_std_mtreten(struct tape_device *device, int mt_count)
{
	struct tape_request *request;
	int rc;

	request = tape_alloc_request(4, 0);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_FSF;
	/* setup ccws */
	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
	tape_ccw_cc(request->cpaddr + 1,FORSPACEFILE, 0, NULL);
	tape_ccw_cc(request->cpaddr + 2, NOP, 0, NULL);
	tape_ccw_end(request->cpaddr + 3, CCW_CMD_TIC, 0, request->cpaddr);
	/* execute it, MTRETEN rc gets ignored */
	rc = tape_do_io_interruptible(device, request);
	tape_free_request(request);
	return tape_mtop(device, MTREW, 1);
}

/*
 * MTERASE: erases the tape.
 */
int
tape_std_mterase(struct tape_device *device, int mt_count)
{
	struct tape_request *request;

	request = tape_alloc_request(6, 0);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_DSE;
	/* setup ccws */
	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
	tape_ccw_cc(request->cpaddr + 1, REWIND, 0, NULL);
	tape_ccw_cc(request->cpaddr + 2, ERASE_GAP, 0, NULL);
	tape_ccw_cc(request->cpaddr + 3, DATA_SEC_ERASE, 0, NULL);
	tape_ccw_cc(request->cpaddr + 4, REWIND, 0, NULL);
	tape_ccw_end(request->cpaddr + 5, NOP, 0, NULL);

	/* execute it */
	return tape_do_io_free(device, request);
}

/*
 * MTUNLOAD: Rewind the tape and unload it.
 */
int
tape_std_mtunload(struct tape_device *device, int mt_count)
{
	return tape_mtop(device, MTOFFL, mt_count);
}

/*
 * MTCOMPRESSION: used to enable compression.
 * Sets the IDRC on/off.
 */
int
tape_std_mtcompression(struct tape_device *device, int mt_count)
{
	struct tape_request *request;

	if (mt_count < 0 || mt_count > 1) {
		DBF_EXCEPTION(6, "xcom parm\n");
		return -EINVAL;
	}
	request = tape_alloc_request(2, 0);
	if (IS_ERR(request))
		return PTR_ERR(request);
	request->op = TO_NOP;
	/* setup ccws */
	if (mt_count == 0)
		*device->modeset_byte &= ~0x08;
	else
		*device->modeset_byte |= 0x08;
	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
	/* execute it */
	return tape_do_io_free(device, request);
}

/*
 * Read Block
 */
struct tape_request *
tape_std_read_block(struct tape_device *device, size_t count)
{
	struct tape_request *request;

	/*
	 * We have to alloc 4 ccws in order to be able to transform request
	 * into a read backward request in error case.
	 */
	request = tape_alloc_request(4, 0);
	if (IS_ERR(request)) {
		DBF_EXCEPTION(6, "xrbl fail");
		return request;
	}
	request->op = TO_RFO;
	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
	tape_ccw_end_idal(request->cpaddr + 1, READ_FORWARD,
			  device->char_data.idal_buf);
	DBF_EVENT(6, "xrbl ccwg\n");
	return request;
}

/*
 * Read Block backward transformation function.
 */
void
tape_std_read_backward(struct tape_device *device, struct tape_request *request)
{
	/*
	 * We have allocated 4 ccws in tape_std_read, so we can now
	 * transform the request to a read backward, followed by a
	 * forward space block.
	 */
	request->op = TO_RBA;
	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
	tape_ccw_cc_idal(request->cpaddr + 1, READ_BACKWARD,
			 device->char_data.idal_buf);
	tape_ccw_cc(request->cpaddr + 2, FORSPACEBLOCK, 0, NULL);
	tape_ccw_end(request->cpaddr + 3, NOP, 0, NULL);
	DBF_EVENT(6, "xrop ccwg");}

/*
 * Write Block
 */
struct tape_request *
tape_std_write_block(struct tape_device *device, size_t count)
{
	struct tape_request *request;

	request = tape_alloc_request(2, 0);
	if (IS_ERR(request)) {
		DBF_EXCEPTION(6, "xwbl fail\n");
		return request;
	}
	request->op = TO_WRI;
	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
	tape_ccw_end_idal(request->cpaddr + 1, WRITE_CMD,
			  device->char_data.idal_buf);
	DBF_EVENT(6, "xwbl ccwg\n");
	return request;
}

/*
 * This routine is called by frontend after an ENOSP on write
 */
void
tape_std_process_eov(struct tape_device *device)
{
	/*
	 * End of volume: We have to backspace the last written record, then
	 * we TRY to write a tapemark and then backspace over the written TM
	 */
	if (tape_mtop(device, MTBSR, 1) == 0 &&
	    tape_mtop(device, MTWEOF, 1) == 0) {
		tape_mtop(device, MTBSR, 1);
	}
}

EXPORT_SYMBOL(tape_std_assign);
EXPORT_SYMBOL(tape_std_unassign);
EXPORT_SYMBOL(tape_std_display);
EXPORT_SYMBOL(tape_std_read_block_id);
EXPORT_SYMBOL(tape_std_mtload);
EXPORT_SYMBOL(tape_std_mtsetblk);
EXPORT_SYMBOL(tape_std_mtreset);
EXPORT_SYMBOL(tape_std_mtfsf);
EXPORT_SYMBOL(tape_std_mtfsr);
EXPORT_SYMBOL(tape_std_mtbsr);
EXPORT_SYMBOL(tape_std_mtweof);
EXPORT_SYMBOL(tape_std_mtbsfm);
EXPORT_SYMBOL(tape_std_mtbsf);
EXPORT_SYMBOL(tape_std_mtfsfm);
EXPORT_SYMBOL(tape_std_mtrew);
EXPORT_SYMBOL(tape_std_mtoffl);
EXPORT_SYMBOL(tape_std_mtnop);
EXPORT_SYMBOL(tape_std_mteom);
EXPORT_SYMBOL(tape_std_mtreten);
EXPORT_SYMBOL(tape_std_mterase);
EXPORT_SYMBOL(tape_std_mtunload);
EXPORT_SYMBOL(tape_std_mtcompression);
EXPORT_SYMBOL(tape_std_read_block);
EXPORT_SYMBOL(tape_std_read_backward);
EXPORT_SYMBOL(tape_std_write_block);
EXPORT_SYMBOL(tape_std_process_eov);