xref: /openbmc/linux/drivers/s390/char/tape_std.c (revision 588b48ca) 
1 /*
2  *    standard tape device functions for ibm tapes.
3  *
4  *  S390 and zSeries version
5  *    Copyright IBM Corp. 2001, 2002
6  *    Author(s): Carsten Otte <cotte@de.ibm.com>
7  *		 Michael Holzheu <holzheu@de.ibm.com>
8  *		 Tuan Ngo-Anh <ngoanh@de.ibm.com>
9  *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
10  *		 Stefan Bader <shbader@de.ibm.com>
11  */
12 
13 #define KMSG_COMPONENT "tape"
14 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15 
16 #include <linux/stddef.h>
17 #include <linux/kernel.h>
18 #include <linux/bio.h>
19 #include <linux/timer.h>
20 
21 #include <asm/types.h>
22 #include <asm/idals.h>
23 #include <asm/ebcdic.h>
24 #include <asm/tape390.h>
25 
26 #define TAPE_DBF_AREA	tape_core_dbf
27 
28 #include "tape.h"
29 #include "tape_std.h"
30 
31 /*
32  * tape_std_assign
33  */
34 static void
35 tape_std_assign_timeout(unsigned long data)
36 {
37 	struct tape_request *	request;
38 	struct tape_device *	device;
39 	int rc;
40 
41 	request = (struct tape_request *) data;
42 	device = request->device;
43 	BUG_ON(!device);
44 
45 	DBF_EVENT(3, "%08x: Assignment timeout. Device busy.\n",
46 			device->cdev_id);
47 	rc = tape_cancel_io(device, request);
48 	if(rc)
49 		DBF_EVENT(3, "(%08x): Assign timeout: Cancel failed with rc = "
50 			  "%i\n", device->cdev_id, rc);
51 }
52 
53 int
54 tape_std_assign(struct tape_device *device)
55 {
56 	int                  rc;
57 	struct timer_list    timeout;
58 	struct tape_request *request;
59 
60 	request = tape_alloc_request(2, 11);
61 	if (IS_ERR(request))
62 		return PTR_ERR(request);
63 
64 	request->op = TO_ASSIGN;
65 	tape_ccw_cc(request->cpaddr, ASSIGN, 11, request->cpdata);
66 	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
67 
68 	/*
69 	 * The assign command sometimes blocks if the device is assigned
70 	 * to another host (actually this shouldn't happen but it does).
71 	 * So we set up a timeout for this call.
72 	 */
73 	init_timer_on_stack(&timeout);
74 	timeout.function = tape_std_assign_timeout;
75 	timeout.data     = (unsigned long) request;
76 	timeout.expires  = jiffies + 2 * HZ;
77 	add_timer(&timeout);
78 
79 	rc = tape_do_io_interruptible(device, request);
80 
81 	del_timer_sync(&timeout);
82 	destroy_timer_on_stack(&timeout);
83 
84 	if (rc != 0) {
85 		DBF_EVENT(3, "%08x: assign failed - device might be busy\n",
86 			device->cdev_id);
87 	} else {
88 		DBF_EVENT(3, "%08x: Tape assigned\n", device->cdev_id);
89 	}
90 	tape_free_request(request);
91 	return rc;
92 }
93 
94 /*
95  * tape_std_unassign
96  */
97 int
98 tape_std_unassign (struct tape_device *device)
99 {
100 	int                  rc;
101 	struct tape_request *request;
102 
103 	if (device->tape_state == TS_NOT_OPER) {
104 		DBF_EVENT(3, "(%08x): Can't unassign device\n",
105 			device->cdev_id);
106 		return -EIO;
107 	}
108 
109 	request = tape_alloc_request(2, 11);
110 	if (IS_ERR(request))
111 		return PTR_ERR(request);
112 
113 	request->op = TO_UNASSIGN;
114 	tape_ccw_cc(request->cpaddr, UNASSIGN, 11, request->cpdata);
115 	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
116 
117 	if ((rc = tape_do_io(device, request)) != 0) {
118 		DBF_EVENT(3, "%08x: Unassign failed\n", device->cdev_id);
119 	} else {
120 		DBF_EVENT(3, "%08x: Tape unassigned\n", device->cdev_id);
121 	}
122 	tape_free_request(request);
123 	return rc;
124 }
125 
126 /*
127  * TAPE390_DISPLAY: Show a string on the tape display.
128  */
129 int
130 tape_std_display(struct tape_device *device, struct display_struct *disp)
131 {
132 	struct tape_request *request;
133 	int rc;
134 
135 	request = tape_alloc_request(2, 17);
136 	if (IS_ERR(request)) {
137 		DBF_EVENT(3, "TAPE: load display failed\n");
138 		return PTR_ERR(request);
139 	}
140 	request->op = TO_DIS;
141 
142 	*(unsigned char *) request->cpdata = disp->cntrl;
143 	DBF_EVENT(5, "TAPE: display cntrl=%04x\n", disp->cntrl);
144 	memcpy(((unsigned char *) request->cpdata) + 1, disp->message1, 8);
145 	memcpy(((unsigned char *) request->cpdata) + 9, disp->message2, 8);
146 	ASCEBC(((unsigned char*) request->cpdata) + 1, 16);
147 
148 	tape_ccw_cc(request->cpaddr, LOAD_DISPLAY, 17, request->cpdata);
149 	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
150 
151 	rc = tape_do_io_interruptible(device, request);
152 	tape_free_request(request);
153 	return rc;
154 }
155 
156 /*
157  * Read block id.
158  */
159 int
160 tape_std_read_block_id(struct tape_device *device, __u64 *id)
161 {
162 	struct tape_request *request;
163 	int rc;
164 
165 	request = tape_alloc_request(3, 8);
166 	if (IS_ERR(request))
167 		return PTR_ERR(request);
168 	request->op = TO_RBI;
169 	/* setup ccws */
170 	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
171 	tape_ccw_cc(request->cpaddr + 1, READ_BLOCK_ID, 8, request->cpdata);
172 	tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
173 	/* execute it */
174 	rc = tape_do_io(device, request);
175 	if (rc == 0)
176 		/* Get result from read buffer. */
177 		*id = *(__u64 *) request->cpdata;
178 	tape_free_request(request);
179 	return rc;
180 }
181 
182 int
183 tape_std_terminate_write(struct tape_device *device)
184 {
185 	int rc;
186 
187 	if(device->required_tapemarks == 0)
188 		return 0;
189 
190 	DBF_LH(5, "tape%d: terminate write %dxEOF\n", device->first_minor,
191 		device->required_tapemarks);
192 
193 	rc = tape_mtop(device, MTWEOF, device->required_tapemarks);
194 	if (rc)
195 		return rc;
196 
197 	device->required_tapemarks = 0;
198 	return tape_mtop(device, MTBSR, 1);
199 }
200 
201 /*
202  * MTLOAD: Loads the tape.
203  * The default implementation just wait until the tape medium state changes
204  * to MS_LOADED.
205  */
206 int
207 tape_std_mtload(struct tape_device *device, int count)
208 {
209 	return wait_event_interruptible(device->state_change_wq,
210 		(device->medium_state == MS_LOADED));
211 }
212 
213 /*
214  * MTSETBLK: Set block size.
215  */
216 int
217 tape_std_mtsetblk(struct tape_device *device, int count)
218 {
219 	struct idal_buffer *new;
220 
221 	DBF_LH(6, "tape_std_mtsetblk(%d)\n", count);
222 	if (count <= 0) {
223 		/*
224 		 * Just set block_size to 0. tapechar_read/tapechar_write
225 		 * will realloc the idal buffer if a bigger one than the
226 		 * current is needed.
227 		 */
228 		device->char_data.block_size = 0;
229 		return 0;
230 	}
231 	if (device->char_data.idal_buf != NULL &&
232 	    device->char_data.idal_buf->size == count)
233 		/* We already have a idal buffer of that size. */
234 		return 0;
235 
236 	if (count > MAX_BLOCKSIZE) {
237 		DBF_EVENT(3, "Invalid block size (%d > %d) given.\n",
238 			count, MAX_BLOCKSIZE);
239 		return -EINVAL;
240 	}
241 
242 	/* Allocate a new idal buffer. */
243 	new = idal_buffer_alloc(count, 0);
244 	if (IS_ERR(new))
245 		return -ENOMEM;
246 	if (device->char_data.idal_buf != NULL)
247 		idal_buffer_free(device->char_data.idal_buf);
248 	device->char_data.idal_buf = new;
249 	device->char_data.block_size = count;
250 
251 	DBF_LH(6, "new blocksize is %d\n", device->char_data.block_size);
252 
253 	return 0;
254 }
255 
256 /*
257  * MTRESET: Set block size to 0.
258  */
259 int
260 tape_std_mtreset(struct tape_device *device, int count)
261 {
262 	DBF_EVENT(6, "TCHAR:devreset:\n");
263 	device->char_data.block_size = 0;
264 	return 0;
265 }
266 
267 /*
268  * MTFSF: Forward space over 'count' file marks. The tape is positioned
269  * at the EOT (End of Tape) side of the file mark.
270  */
271 int
272 tape_std_mtfsf(struct tape_device *device, int mt_count)
273 {
274 	struct tape_request *request;
275 	struct ccw1 *ccw;
276 
277 	request = tape_alloc_request(mt_count + 2, 0);
278 	if (IS_ERR(request))
279 		return PTR_ERR(request);
280 	request->op = TO_FSF;
281 	/* setup ccws */
282 	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
283 			  device->modeset_byte);
284 	ccw = tape_ccw_repeat(ccw, FORSPACEFILE, mt_count);
285 	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
286 
287 	/* execute it */
288 	return tape_do_io_free(device, request);
289 }
290 
291 /*
292  * MTFSR: Forward space over 'count' tape blocks (blocksize is set
293  * via MTSETBLK.
294  */
295 int
296 tape_std_mtfsr(struct tape_device *device, int mt_count)
297 {
298 	struct tape_request *request;
299 	struct ccw1 *ccw;
300 	int rc;
301 
302 	request = tape_alloc_request(mt_count + 2, 0);
303 	if (IS_ERR(request))
304 		return PTR_ERR(request);
305 	request->op = TO_FSB;
306 	/* setup ccws */
307 	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
308 			  device->modeset_byte);
309 	ccw = tape_ccw_repeat(ccw, FORSPACEBLOCK, mt_count);
310 	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
311 
312 	/* execute it */
313 	rc = tape_do_io(device, request);
314 	if (rc == 0 && request->rescnt > 0) {
315 		DBF_LH(3, "FSR over tapemark\n");
316 		rc = 1;
317 	}
318 	tape_free_request(request);
319 
320 	return rc;
321 }
322 
323 /*
324  * MTBSR: Backward space over 'count' tape blocks.
325  * (blocksize is set via MTSETBLK.
326  */
327 int
328 tape_std_mtbsr(struct tape_device *device, int mt_count)
329 {
330 	struct tape_request *request;
331 	struct ccw1 *ccw;
332 	int rc;
333 
334 	request = tape_alloc_request(mt_count + 2, 0);
335 	if (IS_ERR(request))
336 		return PTR_ERR(request);
337 	request->op = TO_BSB;
338 	/* setup ccws */
339 	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
340 			  device->modeset_byte);
341 	ccw = tape_ccw_repeat(ccw, BACKSPACEBLOCK, mt_count);
342 	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
343 
344 	/* execute it */
345 	rc = tape_do_io(device, request);
346 	if (rc == 0 && request->rescnt > 0) {
347 		DBF_LH(3, "BSR over tapemark\n");
348 		rc = 1;
349 	}
350 	tape_free_request(request);
351 
352 	return rc;
353 }
354 
355 /*
356  * MTWEOF: Write 'count' file marks at the current position.
357  */
358 int
359 tape_std_mtweof(struct tape_device *device, int mt_count)
360 {
361 	struct tape_request *request;
362 	struct ccw1 *ccw;
363 
364 	request = tape_alloc_request(mt_count + 2, 0);
365 	if (IS_ERR(request))
366 		return PTR_ERR(request);
367 	request->op = TO_WTM;
368 	/* setup ccws */
369 	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
370 			  device->modeset_byte);
371 	ccw = tape_ccw_repeat(ccw, WRITETAPEMARK, mt_count);
372 	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
373 
374 	/* execute it */
375 	return tape_do_io_free(device, request);
376 }
377 
378 /*
379  * MTBSFM: Backward space over 'count' file marks.
380  * The tape is positioned at the BOT (Begin Of Tape) side of the
381  * last skipped file mark.
382  */
383 int
384 tape_std_mtbsfm(struct tape_device *device, int mt_count)
385 {
386 	struct tape_request *request;
387 	struct ccw1 *ccw;
388 
389 	request = tape_alloc_request(mt_count + 2, 0);
390 	if (IS_ERR(request))
391 		return PTR_ERR(request);
392 	request->op = TO_BSF;
393 	/* setup ccws */
394 	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
395 			  device->modeset_byte);
396 	ccw = tape_ccw_repeat(ccw, BACKSPACEFILE, mt_count);
397 	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
398 
399 	/* execute it */
400 	return tape_do_io_free(device, request);
401 }
402 
403 /*
404  * MTBSF: Backward space over 'count' file marks. The tape is positioned at
405  * the EOT (End of Tape) side of the last skipped file mark.
406  */
407 int
408 tape_std_mtbsf(struct tape_device *device, int mt_count)
409 {
410 	struct tape_request *request;
411 	struct ccw1 *ccw;
412 	int rc;
413 
414 	request = tape_alloc_request(mt_count + 2, 0);
415 	if (IS_ERR(request))
416 		return PTR_ERR(request);
417 	request->op = TO_BSF;
418 	/* setup ccws */
419 	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
420 			  device->modeset_byte);
421 	ccw = tape_ccw_repeat(ccw, BACKSPACEFILE, mt_count);
422 	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
423 	/* execute it */
424 	rc = tape_do_io_free(device, request);
425 	if (rc == 0) {
426 		rc = tape_mtop(device, MTFSR, 1);
427 		if (rc > 0)
428 			rc = 0;
429 	}
430 	return rc;
431 }
432 
433 /*
434  * MTFSFM: Forward space over 'count' file marks.
435  * The tape is positioned at the BOT (Begin Of Tape) side
436  * of the last skipped file mark.
437  */
438 int
439 tape_std_mtfsfm(struct tape_device *device, int mt_count)
440 {
441 	struct tape_request *request;
442 	struct ccw1 *ccw;
443 	int rc;
444 
445 	request = tape_alloc_request(mt_count + 2, 0);
446 	if (IS_ERR(request))
447 		return PTR_ERR(request);
448 	request->op = TO_FSF;
449 	/* setup ccws */
450 	ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
451 			  device->modeset_byte);
452 	ccw = tape_ccw_repeat(ccw, FORSPACEFILE, mt_count);
453 	ccw = tape_ccw_end(ccw, NOP, 0, NULL);
454 	/* execute it */
455 	rc = tape_do_io_free(device, request);
456 	if (rc == 0) {
457 		rc = tape_mtop(device, MTBSR, 1);
458 		if (rc > 0)
459 			rc = 0;
460 	}
461 
462 	return rc;
463 }
464 
465 /*
466  * MTREW: Rewind the tape.
467  */
468 int
469 tape_std_mtrew(struct tape_device *device, int mt_count)
470 {
471 	struct tape_request *request;
472 
473 	request = tape_alloc_request(3, 0);
474 	if (IS_ERR(request))
475 		return PTR_ERR(request);
476 	request->op = TO_REW;
477 	/* setup ccws */
478 	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
479 		    device->modeset_byte);
480 	tape_ccw_cc(request->cpaddr + 1, REWIND, 0, NULL);
481 	tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
482 
483 	/* execute it */
484 	return tape_do_io_free(device, request);
485 }
486 
487 /*
488  * MTOFFL: Rewind the tape and put the drive off-line.
489  * Implement 'rewind unload'
490  */
491 int
492 tape_std_mtoffl(struct tape_device *device, int mt_count)
493 {
494 	struct tape_request *request;
495 
496 	request = tape_alloc_request(3, 0);
497 	if (IS_ERR(request))
498 		return PTR_ERR(request);
499 	request->op = TO_RUN;
500 	/* setup ccws */
501 	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
502 	tape_ccw_cc(request->cpaddr + 1, REWIND_UNLOAD, 0, NULL);
503 	tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
504 
505 	/* execute it */
506 	return tape_do_io_free(device, request);
507 }
508 
509 /*
510  * MTNOP: 'No operation'.
511  */
512 int
513 tape_std_mtnop(struct tape_device *device, int mt_count)
514 {
515 	struct tape_request *request;
516 
517 	request = tape_alloc_request(2, 0);
518 	if (IS_ERR(request))
519 		return PTR_ERR(request);
520 	request->op = TO_NOP;
521 	/* setup ccws */
522 	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
523 	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
524 	/* execute it */
525 	return tape_do_io_free(device, request);
526 }
527 
528 /*
529  * MTEOM: positions at the end of the portion of the tape already used
530  * for recordind data. MTEOM positions after the last file mark, ready for
531  * appending another file.
532  */
533 int
534 tape_std_mteom(struct tape_device *device, int mt_count)
535 {
536 	int rc;
537 
538 	/*
539 	 * Seek from the beginning of tape (rewind).
540 	 */
541 	if ((rc = tape_mtop(device, MTREW, 1)) < 0)
542 		return rc;
543 
544 	/*
545 	 * The logical end of volume is given by two sewuential tapemarks.
546 	 * Look for this by skipping to the next file (over one tapemark)
547 	 * and then test for another one (fsr returns 1 if a tapemark was
548 	 * encountered).
549 	 */
550 	do {
551 		if ((rc = tape_mtop(device, MTFSF, 1)) < 0)
552 			return rc;
553 		if ((rc = tape_mtop(device, MTFSR, 1)) < 0)
554 			return rc;
555 	} while (rc == 0);
556 
557 	return tape_mtop(device, MTBSR, 1);
558 }
559 
560 /*
561  * MTRETEN: Retension the tape, i.e. forward space to end of tape and rewind.
562  */
563 int
564 tape_std_mtreten(struct tape_device *device, int mt_count)
565 {
566 	struct tape_request *request;
567 
568 	request = tape_alloc_request(4, 0);
569 	if (IS_ERR(request))
570 		return PTR_ERR(request);
571 	request->op = TO_FSF;
572 	/* setup ccws */
573 	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
574 	tape_ccw_cc(request->cpaddr + 1,FORSPACEFILE, 0, NULL);
575 	tape_ccw_cc(request->cpaddr + 2, NOP, 0, NULL);
576 	tape_ccw_end(request->cpaddr + 3, CCW_CMD_TIC, 0, request->cpaddr);
577 	/* execute it, MTRETEN rc gets ignored */
578 	tape_do_io_interruptible(device, request);
579 	tape_free_request(request);
580 	return tape_mtop(device, MTREW, 1);
581 }
582 
583 /*
584  * MTERASE: erases the tape.
585  */
586 int
587 tape_std_mterase(struct tape_device *device, int mt_count)
588 {
589 	struct tape_request *request;
590 
591 	request = tape_alloc_request(6, 0);
592 	if (IS_ERR(request))
593 		return PTR_ERR(request);
594 	request->op = TO_DSE;
595 	/* setup ccws */
596 	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
597 	tape_ccw_cc(request->cpaddr + 1, REWIND, 0, NULL);
598 	tape_ccw_cc(request->cpaddr + 2, ERASE_GAP, 0, NULL);
599 	tape_ccw_cc(request->cpaddr + 3, DATA_SEC_ERASE, 0, NULL);
600 	tape_ccw_cc(request->cpaddr + 4, REWIND, 0, NULL);
601 	tape_ccw_end(request->cpaddr + 5, NOP, 0, NULL);
602 
603 	/* execute it */
604 	return tape_do_io_free(device, request);
605 }
606 
607 /*
608  * MTUNLOAD: Rewind the tape and unload it.
609  */
610 int
611 tape_std_mtunload(struct tape_device *device, int mt_count)
612 {
613 	return tape_mtop(device, MTOFFL, mt_count);
614 }
615 
616 /*
617  * MTCOMPRESSION: used to enable compression.
618  * Sets the IDRC on/off.
619  */
620 int
621 tape_std_mtcompression(struct tape_device *device, int mt_count)
622 {
623 	struct tape_request *request;
624 
625 	if (mt_count < 0 || mt_count > 1) {
626 		DBF_EXCEPTION(6, "xcom parm\n");
627 		return -EINVAL;
628 	}
629 	request = tape_alloc_request(2, 0);
630 	if (IS_ERR(request))
631 		return PTR_ERR(request);
632 	request->op = TO_NOP;
633 	/* setup ccws */
634 	if (mt_count == 0)
635 		*device->modeset_byte &= ~0x08;
636 	else
637 		*device->modeset_byte |= 0x08;
638 	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
639 	tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
640 	/* execute it */
641 	return tape_do_io_free(device, request);
642 }
643 
644 /*
645  * Read Block
646  */
647 struct tape_request *
648 tape_std_read_block(struct tape_device *device, size_t count)
649 {
650 	struct tape_request *request;
651 
652 	/*
653 	 * We have to alloc 4 ccws in order to be able to transform request
654 	 * into a read backward request in error case.
655 	 */
656 	request = tape_alloc_request(4, 0);
657 	if (IS_ERR(request)) {
658 		DBF_EXCEPTION(6, "xrbl fail");
659 		return request;
660 	}
661 	request->op = TO_RFO;
662 	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
663 	tape_ccw_end_idal(request->cpaddr + 1, READ_FORWARD,
664 			  device->char_data.idal_buf);
665 	DBF_EVENT(6, "xrbl ccwg\n");
666 	return request;
667 }
668 
669 /*
670  * Read Block backward transformation function.
671  */
672 void
673 tape_std_read_backward(struct tape_device *device, struct tape_request *request)
674 {
675 	/*
676 	 * We have allocated 4 ccws in tape_std_read, so we can now
677 	 * transform the request to a read backward, followed by a
678 	 * forward space block.
679 	 */
680 	request->op = TO_RBA;
681 	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
682 	tape_ccw_cc_idal(request->cpaddr + 1, READ_BACKWARD,
683 			 device->char_data.idal_buf);
684 	tape_ccw_cc(request->cpaddr + 2, FORSPACEBLOCK, 0, NULL);
685 	tape_ccw_end(request->cpaddr + 3, NOP, 0, NULL);
686 	DBF_EVENT(6, "xrop ccwg");}
687 
688 /*
689  * Write Block
690  */
691 struct tape_request *
692 tape_std_write_block(struct tape_device *device, size_t count)
693 {
694 	struct tape_request *request;
695 
696 	request = tape_alloc_request(2, 0);
697 	if (IS_ERR(request)) {
698 		DBF_EXCEPTION(6, "xwbl fail\n");
699 		return request;
700 	}
701 	request->op = TO_WRI;
702 	tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
703 	tape_ccw_end_idal(request->cpaddr + 1, WRITE_CMD,
704 			  device->char_data.idal_buf);
705 	DBF_EVENT(6, "xwbl ccwg\n");
706 	return request;
707 }
708 
709 /*
710  * This routine is called by frontend after an ENOSP on write
711  */
712 void
713 tape_std_process_eov(struct tape_device *device)
714 {
715 	/*
716 	 * End of volume: We have to backspace the last written record, then
717 	 * we TRY to write a tapemark and then backspace over the written TM
718 	 */
719 	if (tape_mtop(device, MTBSR, 1) == 0 &&
720 	    tape_mtop(device, MTWEOF, 1) == 0) {
721 		tape_mtop(device, MTBSR, 1);
722 	}
723 }
724 
725 EXPORT_SYMBOL(tape_std_assign);
726 EXPORT_SYMBOL(tape_std_unassign);
727 EXPORT_SYMBOL(tape_std_display);
728 EXPORT_SYMBOL(tape_std_read_block_id);
729 EXPORT_SYMBOL(tape_std_mtload);
730 EXPORT_SYMBOL(tape_std_mtsetblk);
731 EXPORT_SYMBOL(tape_std_mtreset);
732 EXPORT_SYMBOL(tape_std_mtfsf);
733 EXPORT_SYMBOL(tape_std_mtfsr);
734 EXPORT_SYMBOL(tape_std_mtbsr);
735 EXPORT_SYMBOL(tape_std_mtweof);
736 EXPORT_SYMBOL(tape_std_mtbsfm);
737 EXPORT_SYMBOL(tape_std_mtbsf);
738 EXPORT_SYMBOL(tape_std_mtfsfm);
739 EXPORT_SYMBOL(tape_std_mtrew);
740 EXPORT_SYMBOL(tape_std_mtoffl);
741 EXPORT_SYMBOL(tape_std_mtnop);
742 EXPORT_SYMBOL(tape_std_mteom);
743 EXPORT_SYMBOL(tape_std_mtreten);
744 EXPORT_SYMBOL(tape_std_mterase);
745 EXPORT_SYMBOL(tape_std_mtunload);
746 EXPORT_SYMBOL(tape_std_mtcompression);
747 EXPORT_SYMBOL(tape_std_read_block);
748 EXPORT_SYMBOL(tape_std_read_backward);
749 EXPORT_SYMBOL(tape_std_write_block);
750 EXPORT_SYMBOL(tape_std_process_eov);
751