1 /*
2  * Author(s)......: Horst  Hummel    <Horst.Hummel@de.ibm.com>
3  *		    Holger Smolinski <Holger.Smolinski@de.ibm.com>
4  * Bugreports.to..: <Linux390@de.ibm.com>
5  * Copyright IBM Corp. 2000, 2001
6  *
7  */
8 
9 #define KMSG_COMPONENT "dasd-eckd"
10 
11 #include <linux/timer.h>
12 #include <asm/idals.h>
13 
14 #define PRINTK_HEADER "dasd_erp(3990): "
15 
16 #include "dasd_int.h"
17 #include "dasd_eckd.h"
18 
19 
20 struct DCTL_data {
21 	unsigned char subcommand;  /* e.g Inhibit Write, Enable Write,... */
22 	unsigned char modifier;	   /* Subcommand modifier */
23 	unsigned short res;	   /* reserved */
24 } __attribute__ ((packed));
25 
26 /*
27  *****************************************************************************
28  * SECTION ERP HANDLING
29  *****************************************************************************
30  */
31 /*
32  *****************************************************************************
33  * 24 and 32 byte sense ERP functions
34  *****************************************************************************
35  */
36 
37 /*
38  * DASD_3990_ERP_CLEANUP
39  *
40  * DESCRIPTION
41  *   Removes the already build but not necessary ERP request and sets
42  *   the status of the original cqr / erp to the given (final) status
43  *
44  *  PARAMETER
45  *   erp		request to be blocked
46  *   final_status	either DASD_CQR_DONE or DASD_CQR_FAILED
47  *
48  * RETURN VALUES
49  *   cqr		original cqr
50  */
51 static struct dasd_ccw_req *
52 dasd_3990_erp_cleanup(struct dasd_ccw_req * erp, char final_status)
53 {
54 	struct dasd_ccw_req *cqr = erp->refers;
55 
56 	dasd_free_erp_request(erp, erp->memdev);
57 	cqr->status = final_status;
58 	return cqr;
59 
60 }				/* end dasd_3990_erp_cleanup */
61 
62 /*
63  * DASD_3990_ERP_BLOCK_QUEUE
64  *
65  * DESCRIPTION
66  *   Block the given device request queue to prevent from further
67  *   processing until the started timer has expired or an related
68  *   interrupt was received.
69  */
70 static void dasd_3990_erp_block_queue(struct dasd_ccw_req *erp, int expires)
71 {
72 
73 	struct dasd_device *device = erp->startdev;
74 	unsigned long flags;
75 
76 	DBF_DEV_EVENT(DBF_INFO, device,
77 		    "blocking request queue for %is", expires/HZ);
78 
79 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
80 	dasd_device_set_stop_bits(device, DASD_STOPPED_PENDING);
81 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
82 	erp->status = DASD_CQR_FILLED;
83 	if (erp->block)
84 		dasd_block_set_timer(erp->block, expires);
85 	else
86 		dasd_device_set_timer(device, expires);
87 }
88 
89 /*
90  * DASD_3990_ERP_INT_REQ
91  *
92  * DESCRIPTION
93  *   Handles 'Intervention Required' error.
94  *   This means either device offline or not installed.
95  *
96  * PARAMETER
97  *   erp		current erp
98  * RETURN VALUES
99  *   erp		modified erp
100  */
101 static struct dasd_ccw_req *
102 dasd_3990_erp_int_req(struct dasd_ccw_req * erp)
103 {
104 
105 	struct dasd_device *device = erp->startdev;
106 
107 	/* first time set initial retry counter and erp_function */
108 	/* and retry once without blocking queue		 */
109 	/* (this enables easier enqueing of the cqr)		 */
110 	if (erp->function != dasd_3990_erp_int_req) {
111 
112 		erp->retries = 256;
113 		erp->function = dasd_3990_erp_int_req;
114 
115 	} else {
116 
117 		/* issue a message and wait for 'device ready' interrupt */
118 		dev_err(&device->cdev->dev,
119 			    "is offline or not installed - "
120 			    "INTERVENTION REQUIRED!!\n");
121 
122 		dasd_3990_erp_block_queue(erp, 60*HZ);
123 	}
124 
125 	return erp;
126 
127 }				/* end dasd_3990_erp_int_req */
128 
129 /*
130  * DASD_3990_ERP_ALTERNATE_PATH
131  *
132  * DESCRIPTION
133  *   Repeat the operation on a different channel path.
134  *   If all alternate paths have been tried, the request is posted with a
135  *   permanent error.
136  *
137  *  PARAMETER
138  *   erp		pointer to the current ERP
139  *
140  * RETURN VALUES
141  *   erp		modified pointer to the ERP
142  */
143 static void
144 dasd_3990_erp_alternate_path(struct dasd_ccw_req * erp)
145 {
146 	struct dasd_device *device = erp->startdev;
147 	__u8 opm;
148 	unsigned long flags;
149 
150 	/* try alternate valid path */
151 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
152 	opm = ccw_device_get_path_mask(device->cdev);
153 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
154 	if (erp->lpm == 0)
155 		erp->lpm = dasd_path_get_opm(device) &
156 			~(erp->irb.esw.esw0.sublog.lpum);
157 	else
158 		erp->lpm &= ~(erp->irb.esw.esw0.sublog.lpum);
159 
160 	if ((erp->lpm & opm) != 0x00) {
161 
162 		DBF_DEV_EVENT(DBF_WARNING, device,
163 			    "try alternate lpm=%x (lpum=%x / opm=%x)",
164 			    erp->lpm, erp->irb.esw.esw0.sublog.lpum, opm);
165 
166 		/* reset status to submit the request again... */
167 		erp->status = DASD_CQR_FILLED;
168 		erp->retries = 10;
169 	} else {
170 		dev_err(&device->cdev->dev,
171 			"The DASD cannot be reached on any path (lpum=%x"
172 			"/opm=%x)\n", erp->irb.esw.esw0.sublog.lpum, opm);
173 
174 		/* post request with permanent error */
175 		erp->status = DASD_CQR_FAILED;
176 	}
177 }				/* end dasd_3990_erp_alternate_path */
178 
179 /*
180  * DASD_3990_ERP_DCTL
181  *
182  * DESCRIPTION
183  *   Setup cqr to do the Diagnostic Control (DCTL) command with an
184  *   Inhibit Write subcommand (0x20) and the given modifier.
185  *
186  *  PARAMETER
187  *   erp		pointer to the current (failed) ERP
188  *   modifier		subcommand modifier
189  *
190  * RETURN VALUES
191  *   dctl_cqr		pointer to NEW dctl_cqr
192  *
193  */
194 static struct dasd_ccw_req *
195 dasd_3990_erp_DCTL(struct dasd_ccw_req * erp, char modifier)
196 {
197 
198 	struct dasd_device *device = erp->startdev;
199 	struct DCTL_data *DCTL_data;
200 	struct ccw1 *ccw;
201 	struct dasd_ccw_req *dctl_cqr;
202 
203 	dctl_cqr = dasd_alloc_erp_request((char *) &erp->magic, 1,
204 					  sizeof(struct DCTL_data),
205 					  device);
206 	if (IS_ERR(dctl_cqr)) {
207 		dev_err(&device->cdev->dev,
208 			    "Unable to allocate DCTL-CQR\n");
209 		erp->status = DASD_CQR_FAILED;
210 		return erp;
211 	}
212 
213 	DCTL_data = dctl_cqr->data;
214 
215 	DCTL_data->subcommand = 0x02;	/* Inhibit Write */
216 	DCTL_data->modifier = modifier;
217 
218 	ccw = dctl_cqr->cpaddr;
219 	memset(ccw, 0, sizeof(struct ccw1));
220 	ccw->cmd_code = CCW_CMD_DCTL;
221 	ccw->count = 4;
222 	ccw->cda = (__u32)(addr_t) DCTL_data;
223 	dctl_cqr->flags = erp->flags;
224 	dctl_cqr->function = dasd_3990_erp_DCTL;
225 	dctl_cqr->refers = erp;
226 	dctl_cqr->startdev = device;
227 	dctl_cqr->memdev = device;
228 	dctl_cqr->magic = erp->magic;
229 	dctl_cqr->expires = 5 * 60 * HZ;
230 	dctl_cqr->retries = 2;
231 
232 	dctl_cqr->buildclk = get_tod_clock();
233 
234 	dctl_cqr->status = DASD_CQR_FILLED;
235 
236 	return dctl_cqr;
237 
238 }				/* end dasd_3990_erp_DCTL */
239 
240 /*
241  * DASD_3990_ERP_ACTION_1
242  *
243  * DESCRIPTION
244  *   Setup ERP to do the ERP action 1 (see Reference manual).
245  *   Repeat the operation on a different channel path.
246  *   As deviation from the recommended recovery action, we reset the path mask
247  *   after we have tried each path and go through all paths a second time.
248  *   This will cover situations where only one path at a time is actually down,
249  *   but all paths fail and recover just with the same sequence and timing as
250  *   we try to use them (flapping links).
251  *   If all alternate paths have been tried twice, the request is posted with
252  *   a permanent error.
253  *
254  *  PARAMETER
255  *   erp		pointer to the current ERP
256  *
257  * RETURN VALUES
258  *   erp		pointer to the ERP
259  *
260  */
261 static struct dasd_ccw_req *dasd_3990_erp_action_1_sec(struct dasd_ccw_req *erp)
262 {
263 	erp->function = dasd_3990_erp_action_1_sec;
264 	dasd_3990_erp_alternate_path(erp);
265 	return erp;
266 }
267 
268 static struct dasd_ccw_req *dasd_3990_erp_action_1(struct dasd_ccw_req *erp)
269 {
270 	erp->function = dasd_3990_erp_action_1;
271 	dasd_3990_erp_alternate_path(erp);
272 	if (erp->status == DASD_CQR_FAILED &&
273 	    !test_bit(DASD_CQR_VERIFY_PATH, &erp->flags)) {
274 		erp->status = DASD_CQR_FILLED;
275 		erp->retries = 10;
276 		erp->lpm = dasd_path_get_opm(erp->startdev);
277 		erp->function = dasd_3990_erp_action_1_sec;
278 	}
279 	return erp;
280 }				/* end dasd_3990_erp_action_1(b) */
281 
282 /*
283  * DASD_3990_ERP_ACTION_4
284  *
285  * DESCRIPTION
286  *   Setup ERP to do the ERP action 4 (see Reference manual).
287  *   Set the current request to PENDING to block the CQR queue for that device
288  *   until the state change interrupt appears.
289  *   Use a timer (20 seconds) to retry the cqr if the interrupt is still
290  *   missing.
291  *
292  *  PARAMETER
293  *   sense		sense data of the actual error
294  *   erp		pointer to the current ERP
295  *
296  * RETURN VALUES
297  *   erp		pointer to the ERP
298  *
299  */
300 static struct dasd_ccw_req *
301 dasd_3990_erp_action_4(struct dasd_ccw_req * erp, char *sense)
302 {
303 
304 	struct dasd_device *device = erp->startdev;
305 
306 	/* first time set initial retry counter and erp_function    */
307 	/* and retry once without waiting for state change pending  */
308 	/* interrupt (this enables easier enqueing of the cqr)	    */
309 	if (erp->function != dasd_3990_erp_action_4) {
310 
311 		DBF_DEV_EVENT(DBF_INFO, device, "%s",
312 			    "dasd_3990_erp_action_4: first time retry");
313 
314 		erp->retries = 256;
315 		erp->function = dasd_3990_erp_action_4;
316 
317 	} else {
318 		if (sense && (sense[25] == 0x1D)) { /* state change pending */
319 
320 			DBF_DEV_EVENT(DBF_INFO, device,
321 				    "waiting for state change pending "
322 				    "interrupt, %d retries left",
323 				    erp->retries);
324 
325 			dasd_3990_erp_block_queue(erp, 30*HZ);
326 
327 		} else if (sense && (sense[25] == 0x1E)) {	/* busy */
328 			DBF_DEV_EVENT(DBF_INFO, device,
329 				    "busy - redriving request later, "
330 				    "%d retries left",
331 				    erp->retries);
332                         dasd_3990_erp_block_queue(erp, HZ);
333 		} else {
334 			/* no state change pending - retry */
335 			DBF_DEV_EVENT(DBF_INFO, device,
336 				     "redriving request immediately, "
337 				     "%d retries left",
338 				     erp->retries);
339 			erp->status = DASD_CQR_FILLED;
340 		}
341 	}
342 
343 	return erp;
344 
345 }				/* end dasd_3990_erp_action_4 */
346 
347 /*
348  *****************************************************************************
349  * 24 byte sense ERP functions (only)
350  *****************************************************************************
351  */
352 
353 /*
354  * DASD_3990_ERP_ACTION_5
355  *
356  * DESCRIPTION
357  *   Setup ERP to do the ERP action 5 (see Reference manual).
358  *   NOTE: Further handling is done in xxx_further_erp after the retries.
359  *
360  *  PARAMETER
361  *   erp		pointer to the current ERP
362  *
363  * RETURN VALUES
364  *   erp		pointer to the ERP
365  *
366  */
367 static struct dasd_ccw_req *
368 dasd_3990_erp_action_5(struct dasd_ccw_req * erp)
369 {
370 
371 	/* first of all retry */
372 	erp->retries = 10;
373 	erp->function = dasd_3990_erp_action_5;
374 
375 	return erp;
376 
377 }				/* end dasd_3990_erp_action_5 */
378 
379 /*
380  * DASD_3990_HANDLE_ENV_DATA
381  *
382  * DESCRIPTION
383  *   Handles 24 byte 'Environmental data present'.
384  *   Does a analysis of the sense data (message Format)
385  *   and prints the error messages.
386  *
387  * PARAMETER
388  *   sense		current sense data
389  *
390  * RETURN VALUES
391  *   void
392  */
393 static void
394 dasd_3990_handle_env_data(struct dasd_ccw_req * erp, char *sense)
395 {
396 
397 	struct dasd_device *device = erp->startdev;
398 	char msg_format = (sense[7] & 0xF0);
399 	char msg_no = (sense[7] & 0x0F);
400 	char errorstring[ERRORLENGTH];
401 
402 	switch (msg_format) {
403 	case 0x00:		/* Format 0 - Program or System Checks */
404 
405 		if (sense[1] & 0x10) {	/* check message to operator bit */
406 
407 			switch (msg_no) {
408 			case 0x00:	/* No Message */
409 				break;
410 			case 0x01:
411 				dev_warn(&device->cdev->dev,
412 					    "FORMAT 0 - Invalid Command\n");
413 				break;
414 			case 0x02:
415 				dev_warn(&device->cdev->dev,
416 					    "FORMAT 0 - Invalid Command "
417 					    "Sequence\n");
418 				break;
419 			case 0x03:
420 				dev_warn(&device->cdev->dev,
421 					    "FORMAT 0 - CCW Count less than "
422 					    "required\n");
423 				break;
424 			case 0x04:
425 				dev_warn(&device->cdev->dev,
426 					    "FORMAT 0 - Invalid Parameter\n");
427 				break;
428 			case 0x05:
429 				dev_warn(&device->cdev->dev,
430 					    "FORMAT 0 - Diagnostic of Special"
431 					    " Command Violates File Mask\n");
432 				break;
433 			case 0x07:
434 				dev_warn(&device->cdev->dev,
435 					    "FORMAT 0 - Channel Returned with "
436 					    "Incorrect retry CCW\n");
437 				break;
438 			case 0x08:
439 				dev_warn(&device->cdev->dev,
440 					    "FORMAT 0 - Reset Notification\n");
441 				break;
442 			case 0x09:
443 				dev_warn(&device->cdev->dev,
444 					 "FORMAT 0 - Storage Path Restart\n");
445 				break;
446 			case 0x0A:
447 				dev_warn(&device->cdev->dev,
448 					    "FORMAT 0 - Channel requested "
449 					    "... %02x\n", sense[8]);
450 				break;
451 			case 0x0B:
452 				dev_warn(&device->cdev->dev,
453 					    "FORMAT 0 - Invalid Defective/"
454 					    "Alternate Track Pointer\n");
455 				break;
456 			case 0x0C:
457 				dev_warn(&device->cdev->dev,
458 					    "FORMAT 0 - DPS Installation "
459 					    "Check\n");
460 				break;
461 			case 0x0E:
462 				dev_warn(&device->cdev->dev,
463 					    "FORMAT 0 - Command Invalid on "
464 					    "Secondary Address\n");
465 				break;
466 			case 0x0F:
467 				dev_warn(&device->cdev->dev,
468 					    "FORMAT 0 - Status Not As "
469 					    "Required: reason %02x\n",
470 					 sense[8]);
471 				break;
472 			default:
473 				dev_warn(&device->cdev->dev,
474 					    "FORMAT 0 - Reserved\n");
475 			}
476 		} else {
477 			switch (msg_no) {
478 			case 0x00:	/* No Message */
479 				break;
480 			case 0x01:
481 				dev_warn(&device->cdev->dev,
482 					 "FORMAT 0 - Device Error "
483 					 "Source\n");
484 				break;
485 			case 0x02:
486 				dev_warn(&device->cdev->dev,
487 					    "FORMAT 0 - Reserved\n");
488 				break;
489 			case 0x03:
490 				dev_warn(&device->cdev->dev,
491 					    "FORMAT 0 - Device Fenced - "
492 					    "device = %02x\n", sense[4]);
493 				break;
494 			case 0x04:
495 				dev_warn(&device->cdev->dev,
496 					    "FORMAT 0 - Data Pinned for "
497 					    "Device\n");
498 				break;
499 			default:
500 				dev_warn(&device->cdev->dev,
501 					    "FORMAT 0 - Reserved\n");
502 			}
503 		}
504 		break;
505 
506 	case 0x10:		/* Format 1 - Device Equipment Checks */
507 		switch (msg_no) {
508 		case 0x00:	/* No Message */
509 			break;
510 		case 0x01:
511 			dev_warn(&device->cdev->dev,
512 				    "FORMAT 1 - Device Status 1 not as "
513 				    "expected\n");
514 			break;
515 		case 0x03:
516 			dev_warn(&device->cdev->dev,
517 				    "FORMAT 1 - Index missing\n");
518 			break;
519 		case 0x04:
520 			dev_warn(&device->cdev->dev,
521 				 "FORMAT 1 - Interruption cannot be "
522 				 "reset\n");
523 			break;
524 		case 0x05:
525 			dev_warn(&device->cdev->dev,
526 				    "FORMAT 1 - Device did not respond to "
527 				    "selection\n");
528 			break;
529 		case 0x06:
530 			dev_warn(&device->cdev->dev,
531 				    "FORMAT 1 - Device check-2 error or Set "
532 				    "Sector is not complete\n");
533 			break;
534 		case 0x07:
535 			dev_warn(&device->cdev->dev,
536 				    "FORMAT 1 - Head address does not "
537 				    "compare\n");
538 			break;
539 		case 0x08:
540 			dev_warn(&device->cdev->dev,
541 				    "FORMAT 1 - Device status 1 not valid\n");
542 			break;
543 		case 0x09:
544 			dev_warn(&device->cdev->dev,
545 				    "FORMAT 1 - Device not ready\n");
546 			break;
547 		case 0x0A:
548 			dev_warn(&device->cdev->dev,
549 				    "FORMAT 1 - Track physical address did "
550 				    "not compare\n");
551 			break;
552 		case 0x0B:
553 			dev_warn(&device->cdev->dev,
554 				    "FORMAT 1 - Missing device address bit\n");
555 			break;
556 		case 0x0C:
557 			dev_warn(&device->cdev->dev,
558 				    "FORMAT 1 - Drive motor switch is off\n");
559 			break;
560 		case 0x0D:
561 			dev_warn(&device->cdev->dev,
562 				    "FORMAT 1 - Seek incomplete\n");
563 			break;
564 		case 0x0E:
565 			dev_warn(&device->cdev->dev,
566 				    "FORMAT 1 - Cylinder address did not "
567 				    "compare\n");
568 			break;
569 		case 0x0F:
570 			dev_warn(&device->cdev->dev,
571 				    "FORMAT 1 - Offset active cannot be "
572 				    "reset\n");
573 			break;
574 		default:
575 			dev_warn(&device->cdev->dev,
576 				    "FORMAT 1 - Reserved\n");
577 		}
578 		break;
579 
580 	case 0x20:		/* Format 2 - 3990 Equipment Checks */
581 		switch (msg_no) {
582 		case 0x08:
583 			dev_warn(&device->cdev->dev,
584 				    "FORMAT 2 - 3990 check-2 error\n");
585 			break;
586 		case 0x0E:
587 			dev_warn(&device->cdev->dev,
588 				    "FORMAT 2 - Support facility errors\n");
589 			break;
590 		case 0x0F:
591 			dev_warn(&device->cdev->dev,
592 				 "FORMAT 2 - Microcode detected error "
593 				 "%02x\n",
594 				 sense[8]);
595 			break;
596 		default:
597 			dev_warn(&device->cdev->dev,
598 				    "FORMAT 2 - Reserved\n");
599 		}
600 		break;
601 
602 	case 0x30:		/* Format 3 - 3990 Control Checks */
603 		switch (msg_no) {
604 		case 0x0F:
605 			dev_warn(&device->cdev->dev,
606 				    "FORMAT 3 - Allegiance terminated\n");
607 			break;
608 		default:
609 			dev_warn(&device->cdev->dev,
610 				    "FORMAT 3 - Reserved\n");
611 		}
612 		break;
613 
614 	case 0x40:		/* Format 4 - Data Checks */
615 		switch (msg_no) {
616 		case 0x00:
617 			dev_warn(&device->cdev->dev,
618 				    "FORMAT 4 - Home address area error\n");
619 			break;
620 		case 0x01:
621 			dev_warn(&device->cdev->dev,
622 				    "FORMAT 4 - Count area error\n");
623 			break;
624 		case 0x02:
625 			dev_warn(&device->cdev->dev,
626 				    "FORMAT 4 - Key area error\n");
627 			break;
628 		case 0x03:
629 			dev_warn(&device->cdev->dev,
630 				    "FORMAT 4 - Data area error\n");
631 			break;
632 		case 0x04:
633 			dev_warn(&device->cdev->dev,
634 				    "FORMAT 4 - No sync byte in home address "
635 				    "area\n");
636 			break;
637 		case 0x05:
638 			dev_warn(&device->cdev->dev,
639 				    "FORMAT 4 - No sync byte in count address "
640 				    "area\n");
641 			break;
642 		case 0x06:
643 			dev_warn(&device->cdev->dev,
644 				    "FORMAT 4 - No sync byte in key area\n");
645 			break;
646 		case 0x07:
647 			dev_warn(&device->cdev->dev,
648 				    "FORMAT 4 - No sync byte in data area\n");
649 			break;
650 		case 0x08:
651 			dev_warn(&device->cdev->dev,
652 				    "FORMAT 4 - Home address area error; "
653 				    "offset active\n");
654 			break;
655 		case 0x09:
656 			dev_warn(&device->cdev->dev,
657 				    "FORMAT 4 - Count area error; offset "
658 				    "active\n");
659 			break;
660 		case 0x0A:
661 			dev_warn(&device->cdev->dev,
662 				    "FORMAT 4 - Key area error; offset "
663 				    "active\n");
664 			break;
665 		case 0x0B:
666 			dev_warn(&device->cdev->dev,
667 				    "FORMAT 4 - Data area error; "
668 				    "offset active\n");
669 			break;
670 		case 0x0C:
671 			dev_warn(&device->cdev->dev,
672 				    "FORMAT 4 - No sync byte in home "
673 				    "address area; offset active\n");
674 			break;
675 		case 0x0D:
676 			dev_warn(&device->cdev->dev,
677 				    "FORMAT 4 - No sync byte in count "
678 				    "address area; offset active\n");
679 			break;
680 		case 0x0E:
681 			dev_warn(&device->cdev->dev,
682 				    "FORMAT 4 - No sync byte in key area; "
683 				    "offset active\n");
684 			break;
685 		case 0x0F:
686 			dev_warn(&device->cdev->dev,
687 				    "FORMAT 4 - No sync byte in data area; "
688 				    "offset active\n");
689 			break;
690 		default:
691 			dev_warn(&device->cdev->dev,
692 				    "FORMAT 4 - Reserved\n");
693 		}
694 		break;
695 
696 	case 0x50:  /* Format 5 - Data Check with displacement information */
697 		switch (msg_no) {
698 		case 0x00:
699 			dev_warn(&device->cdev->dev,
700 				    "FORMAT 5 - Data Check in the "
701 				    "home address area\n");
702 			break;
703 		case 0x01:
704 			dev_warn(&device->cdev->dev,
705 				 "FORMAT 5 - Data Check in the count "
706 				 "area\n");
707 			break;
708 		case 0x02:
709 			dev_warn(&device->cdev->dev,
710 				    "FORMAT 5 - Data Check in the key area\n");
711 			break;
712 		case 0x03:
713 			dev_warn(&device->cdev->dev,
714 				 "FORMAT 5 - Data Check in the data "
715 				 "area\n");
716 			break;
717 		case 0x08:
718 			dev_warn(&device->cdev->dev,
719 				    "FORMAT 5 - Data Check in the "
720 				    "home address area; offset active\n");
721 			break;
722 		case 0x09:
723 			dev_warn(&device->cdev->dev,
724 				    "FORMAT 5 - Data Check in the count area; "
725 				    "offset active\n");
726 			break;
727 		case 0x0A:
728 			dev_warn(&device->cdev->dev,
729 				    "FORMAT 5 - Data Check in the key area; "
730 				    "offset active\n");
731 			break;
732 		case 0x0B:
733 			dev_warn(&device->cdev->dev,
734 				    "FORMAT 5 - Data Check in the data area; "
735 				    "offset active\n");
736 			break;
737 		default:
738 			dev_warn(&device->cdev->dev,
739 				    "FORMAT 5 - Reserved\n");
740 		}
741 		break;
742 
743 	case 0x60:  /* Format 6 - Usage Statistics/Overrun Errors */
744 		switch (msg_no) {
745 		case 0x00:
746 			dev_warn(&device->cdev->dev,
747 				    "FORMAT 6 - Overrun on channel A\n");
748 			break;
749 		case 0x01:
750 			dev_warn(&device->cdev->dev,
751 				    "FORMAT 6 - Overrun on channel B\n");
752 			break;
753 		case 0x02:
754 			dev_warn(&device->cdev->dev,
755 				    "FORMAT 6 - Overrun on channel C\n");
756 			break;
757 		case 0x03:
758 			dev_warn(&device->cdev->dev,
759 				    "FORMAT 6 - Overrun on channel D\n");
760 			break;
761 		case 0x04:
762 			dev_warn(&device->cdev->dev,
763 				    "FORMAT 6 - Overrun on channel E\n");
764 			break;
765 		case 0x05:
766 			dev_warn(&device->cdev->dev,
767 				    "FORMAT 6 - Overrun on channel F\n");
768 			break;
769 		case 0x06:
770 			dev_warn(&device->cdev->dev,
771 				    "FORMAT 6 - Overrun on channel G\n");
772 			break;
773 		case 0x07:
774 			dev_warn(&device->cdev->dev,
775 				    "FORMAT 6 - Overrun on channel H\n");
776 			break;
777 		default:
778 			dev_warn(&device->cdev->dev,
779 				    "FORMAT 6 - Reserved\n");
780 		}
781 		break;
782 
783 	case 0x70:  /* Format 7 - Device Connection Control Checks */
784 		switch (msg_no) {
785 		case 0x00:
786 			dev_warn(&device->cdev->dev,
787 				    "FORMAT 7 - RCC initiated by a connection "
788 				    "check alert\n");
789 			break;
790 		case 0x01:
791 			dev_warn(&device->cdev->dev,
792 				    "FORMAT 7 - RCC 1 sequence not "
793 				    "successful\n");
794 			break;
795 		case 0x02:
796 			dev_warn(&device->cdev->dev,
797 				    "FORMAT 7 - RCC 1 and RCC 2 sequences not "
798 				    "successful\n");
799 			break;
800 		case 0x03:
801 			dev_warn(&device->cdev->dev,
802 				    "FORMAT 7 - Invalid tag-in during "
803 				    "selection sequence\n");
804 			break;
805 		case 0x04:
806 			dev_warn(&device->cdev->dev,
807 				    "FORMAT 7 - extra RCC required\n");
808 			break;
809 		case 0x05:
810 			dev_warn(&device->cdev->dev,
811 				    "FORMAT 7 - Invalid DCC selection "
812 				    "response or timeout\n");
813 			break;
814 		case 0x06:
815 			dev_warn(&device->cdev->dev,
816 				    "FORMAT 7 - Missing end operation; device "
817 				    "transfer complete\n");
818 			break;
819 		case 0x07:
820 			dev_warn(&device->cdev->dev,
821 				    "FORMAT 7 - Missing end operation; device "
822 				    "transfer incomplete\n");
823 			break;
824 		case 0x08:
825 			dev_warn(&device->cdev->dev,
826 				    "FORMAT 7 - Invalid tag-in for an "
827 				    "immediate command sequence\n");
828 			break;
829 		case 0x09:
830 			dev_warn(&device->cdev->dev,
831 				    "FORMAT 7 - Invalid tag-in for an "
832 				    "extended command sequence\n");
833 			break;
834 		case 0x0A:
835 			dev_warn(&device->cdev->dev,
836 				    "FORMAT 7 - 3990 microcode time out when "
837 				    "stopping selection\n");
838 			break;
839 		case 0x0B:
840 			dev_warn(&device->cdev->dev,
841 				    "FORMAT 7 - No response to selection "
842 				    "after a poll interruption\n");
843 			break;
844 		case 0x0C:
845 			dev_warn(&device->cdev->dev,
846 				    "FORMAT 7 - Permanent path error (DASD "
847 				    "controller not available)\n");
848 			break;
849 		case 0x0D:
850 			dev_warn(&device->cdev->dev,
851 				    "FORMAT 7 - DASD controller not available"
852 				    " on disconnected command chain\n");
853 			break;
854 		default:
855 			dev_warn(&device->cdev->dev,
856 				    "FORMAT 7 - Reserved\n");
857 		}
858 		break;
859 
860 	case 0x80:  /* Format 8 - Additional Device Equipment Checks */
861 		switch (msg_no) {
862 		case 0x00:	/* No Message */
863 		case 0x01:
864 			dev_warn(&device->cdev->dev,
865 				    "FORMAT 8 - Error correction code "
866 				    "hardware fault\n");
867 			break;
868 		case 0x03:
869 			dev_warn(&device->cdev->dev,
870 				    "FORMAT 8 - Unexpected end operation "
871 				    "response code\n");
872 			break;
873 		case 0x04:
874 			dev_warn(&device->cdev->dev,
875 				    "FORMAT 8 - End operation with transfer "
876 				    "count not zero\n");
877 			break;
878 		case 0x05:
879 			dev_warn(&device->cdev->dev,
880 				    "FORMAT 8 - End operation with transfer "
881 				    "count zero\n");
882 			break;
883 		case 0x06:
884 			dev_warn(&device->cdev->dev,
885 				    "FORMAT 8 - DPS checks after a system "
886 				    "reset or selective reset\n");
887 			break;
888 		case 0x07:
889 			dev_warn(&device->cdev->dev,
890 				    "FORMAT 8 - DPS cannot be filled\n");
891 			break;
892 		case 0x08:
893 			dev_warn(&device->cdev->dev,
894 				    "FORMAT 8 - Short busy time-out during "
895 				    "device selection\n");
896 			break;
897 		case 0x09:
898 			dev_warn(&device->cdev->dev,
899 				    "FORMAT 8 - DASD controller failed to "
900 				    "set or reset the long busy latch\n");
901 			break;
902 		case 0x0A:
903 			dev_warn(&device->cdev->dev,
904 				    "FORMAT 8 - No interruption from device "
905 				    "during a command chain\n");
906 			break;
907 		default:
908 			dev_warn(&device->cdev->dev,
909 				    "FORMAT 8 - Reserved\n");
910 		}
911 		break;
912 
913 	case 0x90:  /* Format 9 - Device Read, Write, and Seek Checks */
914 		switch (msg_no) {
915 		case 0x00:
916 			break;	/* No Message */
917 		case 0x06:
918 			dev_warn(&device->cdev->dev,
919 				    "FORMAT 9 - Device check-2 error\n");
920 			break;
921 		case 0x07:
922 			dev_warn(&device->cdev->dev,
923 				 "FORMAT 9 - Head address did not "
924 				 "compare\n");
925 			break;
926 		case 0x0A:
927 			dev_warn(&device->cdev->dev,
928 				    "FORMAT 9 - Track physical address did "
929 				    "not compare while oriented\n");
930 			break;
931 		case 0x0E:
932 			dev_warn(&device->cdev->dev,
933 				    "FORMAT 9 - Cylinder address did not "
934 				    "compare\n");
935 			break;
936 		default:
937 			dev_warn(&device->cdev->dev,
938 				    "FORMAT 9 - Reserved\n");
939 		}
940 		break;
941 
942 	case 0xF0:		/* Format F - Cache Storage Checks */
943 		switch (msg_no) {
944 		case 0x00:
945 			dev_warn(&device->cdev->dev,
946 				    "FORMAT F - Operation Terminated\n");
947 			break;
948 		case 0x01:
949 			dev_warn(&device->cdev->dev,
950 				    "FORMAT F - Subsystem Processing Error\n");
951 			break;
952 		case 0x02:
953 			dev_warn(&device->cdev->dev,
954 				    "FORMAT F - Cache or nonvolatile storage "
955 				    "equipment failure\n");
956 			break;
957 		case 0x04:
958 			dev_warn(&device->cdev->dev,
959 				    "FORMAT F - Caching terminated\n");
960 			break;
961 		case 0x06:
962 			dev_warn(&device->cdev->dev,
963 				    "FORMAT F - Cache fast write access not "
964 				    "authorized\n");
965 			break;
966 		case 0x07:
967 			dev_warn(&device->cdev->dev,
968 				    "FORMAT F - Track format incorrect\n");
969 			break;
970 		case 0x09:
971 			dev_warn(&device->cdev->dev,
972 				    "FORMAT F - Caching reinitiated\n");
973 			break;
974 		case 0x0A:
975 			dev_warn(&device->cdev->dev,
976 				    "FORMAT F - Nonvolatile storage "
977 				    "terminated\n");
978 			break;
979 		case 0x0B:
980 			dev_warn(&device->cdev->dev,
981 				    "FORMAT F - Volume is suspended duplex\n");
982 			/* call extended error reporting (EER) */
983 			dasd_eer_write(device, erp->refers,
984 				       DASD_EER_PPRCSUSPEND);
985 			break;
986 		case 0x0C:
987 			dev_warn(&device->cdev->dev,
988 				    "FORMAT F - Subsystem status cannot be "
989 				    "determined\n");
990 			break;
991 		case 0x0D:
992 			dev_warn(&device->cdev->dev,
993 				    "FORMAT F - Caching status reset to "
994 				    "default\n");
995 			break;
996 		case 0x0E:
997 			dev_warn(&device->cdev->dev,
998 				    "FORMAT F - DASD Fast Write inhibited\n");
999 			break;
1000 		default:
1001 			dev_warn(&device->cdev->dev,
1002 				    "FORMAT F - Reserved\n");
1003 		}
1004 		break;
1005 
1006 	default:	/* unknown message format - should not happen
1007 			   internal error 03 - unknown message format */
1008 		snprintf(errorstring, ERRORLENGTH, "03 %x02", msg_format);
1009 		dev_err(&device->cdev->dev,
1010 			 "An error occurred in the DASD device driver, "
1011 			 "reason=%s\n", errorstring);
1012 		break;
1013 	}			/* end switch message format */
1014 
1015 }				/* end dasd_3990_handle_env_data */
1016 
1017 /*
1018  * DASD_3990_ERP_COM_REJ
1019  *
1020  * DESCRIPTION
1021  *   Handles 24 byte 'Command Reject' error.
1022  *
1023  * PARAMETER
1024  *   erp		current erp_head
1025  *   sense		current sense data
1026  *
1027  * RETURN VALUES
1028  *   erp		'new' erp_head - pointer to new ERP
1029  */
1030 static struct dasd_ccw_req *
1031 dasd_3990_erp_com_rej(struct dasd_ccw_req * erp, char *sense)
1032 {
1033 
1034 	struct dasd_device *device = erp->startdev;
1035 
1036 	erp->function = dasd_3990_erp_com_rej;
1037 
1038 	/* env data present (ACTION 10 - retry should work) */
1039 	if (sense[2] & SNS2_ENV_DATA_PRESENT) {
1040 
1041 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1042 			    "Command Reject - environmental data present");
1043 
1044 		dasd_3990_handle_env_data(erp, sense);
1045 
1046 		erp->retries = 5;
1047 
1048 	} else if (sense[1] & SNS1_WRITE_INHIBITED) {
1049 		dev_err(&device->cdev->dev, "An I/O request was rejected"
1050 			" because writing is inhibited\n");
1051 		erp = dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
1052 	} else {
1053 		/* fatal error -  set status to FAILED
1054 		   internal error 09 - Command Reject */
1055 		dev_err(&device->cdev->dev, "An error occurred in the DASD "
1056 			"device driver, reason=%s\n", "09");
1057 
1058 		erp = dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
1059 	}
1060 
1061 	return erp;
1062 
1063 }				/* end dasd_3990_erp_com_rej */
1064 
1065 /*
1066  * DASD_3990_ERP_BUS_OUT
1067  *
1068  * DESCRIPTION
1069  *   Handles 24 byte 'Bus Out Parity Check' error.
1070  *
1071  * PARAMETER
1072  *   erp		current erp_head
1073  * RETURN VALUES
1074  *   erp		new erp_head - pointer to new ERP
1075  */
1076 static struct dasd_ccw_req *
1077 dasd_3990_erp_bus_out(struct dasd_ccw_req * erp)
1078 {
1079 
1080 	struct dasd_device *device = erp->startdev;
1081 
1082 	/* first time set initial retry counter and erp_function */
1083 	/* and retry once without blocking queue		 */
1084 	/* (this enables easier enqueing of the cqr)		 */
1085 	if (erp->function != dasd_3990_erp_bus_out) {
1086 		erp->retries = 256;
1087 		erp->function = dasd_3990_erp_bus_out;
1088 
1089 	} else {
1090 
1091 		/* issue a message and wait for 'device ready' interrupt */
1092 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1093 			    "bus out parity error or BOPC requested by "
1094 			    "channel");
1095 
1096 		dasd_3990_erp_block_queue(erp, 60*HZ);
1097 
1098 	}
1099 
1100 	return erp;
1101 
1102 }				/* end dasd_3990_erp_bus_out */
1103 
1104 /*
1105  * DASD_3990_ERP_EQUIP_CHECK
1106  *
1107  * DESCRIPTION
1108  *   Handles 24 byte 'Equipment Check' error.
1109  *
1110  * PARAMETER
1111  *   erp		current erp_head
1112  * RETURN VALUES
1113  *   erp		new erp_head - pointer to new ERP
1114  */
1115 static struct dasd_ccw_req *
1116 dasd_3990_erp_equip_check(struct dasd_ccw_req * erp, char *sense)
1117 {
1118 
1119 	struct dasd_device *device = erp->startdev;
1120 
1121 	erp->function = dasd_3990_erp_equip_check;
1122 
1123 	if (sense[1] & SNS1_WRITE_INHIBITED) {
1124 		dev_info(&device->cdev->dev,
1125 			    "Write inhibited path encountered\n");
1126 
1127 		/* vary path offline
1128 		   internal error 04 - Path should be varied off-line.*/
1129 		dev_err(&device->cdev->dev, "An error occurred in the DASD "
1130 			"device driver, reason=%s\n", "04");
1131 
1132 		erp = dasd_3990_erp_action_1(erp);
1133 
1134 	} else if (sense[2] & SNS2_ENV_DATA_PRESENT) {
1135 
1136 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1137 			    "Equipment Check - " "environmental data present");
1138 
1139 		dasd_3990_handle_env_data(erp, sense);
1140 
1141 		erp = dasd_3990_erp_action_4(erp, sense);
1142 
1143 	} else if (sense[1] & SNS1_PERM_ERR) {
1144 
1145 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1146 			    "Equipment Check - retry exhausted or "
1147 			    "undesirable");
1148 
1149 		erp = dasd_3990_erp_action_1(erp);
1150 
1151 	} else {
1152 		/* all other equipment checks - Action 5 */
1153 		/* rest is done when retries == 0 */
1154 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1155 			    "Equipment check or processing error");
1156 
1157 		erp = dasd_3990_erp_action_5(erp);
1158 	}
1159 	return erp;
1160 
1161 }				/* end dasd_3990_erp_equip_check */
1162 
1163 /*
1164  * DASD_3990_ERP_DATA_CHECK
1165  *
1166  * DESCRIPTION
1167  *   Handles 24 byte 'Data Check' error.
1168  *
1169  * PARAMETER
1170  *   erp		current erp_head
1171  * RETURN VALUES
1172  *   erp		new erp_head - pointer to new ERP
1173  */
1174 static struct dasd_ccw_req *
1175 dasd_3990_erp_data_check(struct dasd_ccw_req * erp, char *sense)
1176 {
1177 
1178 	struct dasd_device *device = erp->startdev;
1179 
1180 	erp->function = dasd_3990_erp_data_check;
1181 
1182 	if (sense[2] & SNS2_CORRECTABLE) {	/* correctable data check */
1183 
1184 		/* issue message that the data has been corrected */
1185 		dev_emerg(&device->cdev->dev,
1186 			    "Data recovered during retry with PCI "
1187 			    "fetch mode active\n");
1188 
1189 		/* not possible to handle this situation in Linux */
1190 		panic("No way to inform application about the possibly "
1191 		      "incorrect data");
1192 
1193 	} else if (sense[2] & SNS2_ENV_DATA_PRESENT) {
1194 
1195 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1196 			    "Uncorrectable data check recovered secondary "
1197 			    "addr of duplex pair");
1198 
1199 		erp = dasd_3990_erp_action_4(erp, sense);
1200 
1201 	} else if (sense[1] & SNS1_PERM_ERR) {
1202 
1203 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1204 			    "Uncorrectable data check with internal "
1205 			    "retry exhausted");
1206 
1207 		erp = dasd_3990_erp_action_1(erp);
1208 
1209 	} else {
1210 		/* all other data checks */
1211 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1212 			    "Uncorrectable data check with retry count "
1213 			    "exhausted...");
1214 
1215 		erp = dasd_3990_erp_action_5(erp);
1216 	}
1217 
1218 	return erp;
1219 
1220 }				/* end dasd_3990_erp_data_check */
1221 
1222 /*
1223  * DASD_3990_ERP_OVERRUN
1224  *
1225  * DESCRIPTION
1226  *   Handles 24 byte 'Overrun' error.
1227  *
1228  * PARAMETER
1229  *   erp		current erp_head
1230  * RETURN VALUES
1231  *   erp		new erp_head - pointer to new ERP
1232  */
1233 static struct dasd_ccw_req *
1234 dasd_3990_erp_overrun(struct dasd_ccw_req * erp, char *sense)
1235 {
1236 
1237 	struct dasd_device *device = erp->startdev;
1238 
1239 	erp->function = dasd_3990_erp_overrun;
1240 
1241 	DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1242 		    "Overrun - service overrun or overrun"
1243 		    " error requested by channel");
1244 
1245 	erp = dasd_3990_erp_action_5(erp);
1246 
1247 	return erp;
1248 
1249 }				/* end dasd_3990_erp_overrun */
1250 
1251 /*
1252  * DASD_3990_ERP_INV_FORMAT
1253  *
1254  * DESCRIPTION
1255  *   Handles 24 byte 'Invalid Track Format' error.
1256  *
1257  * PARAMETER
1258  *   erp		current erp_head
1259  * RETURN VALUES
1260  *   erp		new erp_head - pointer to new ERP
1261  */
1262 static struct dasd_ccw_req *
1263 dasd_3990_erp_inv_format(struct dasd_ccw_req * erp, char *sense)
1264 {
1265 
1266 	struct dasd_device *device = erp->startdev;
1267 
1268 	erp->function = dasd_3990_erp_inv_format;
1269 
1270 	if (sense[2] & SNS2_ENV_DATA_PRESENT) {
1271 
1272 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1273 			    "Track format error when destaging or "
1274 			    "staging data");
1275 
1276 		dasd_3990_handle_env_data(erp, sense);
1277 
1278 		erp = dasd_3990_erp_action_4(erp, sense);
1279 
1280 	} else {
1281 		/* internal error 06 - The track format is not valid*/
1282 		dev_err(&device->cdev->dev,
1283 			"An error occurred in the DASD device driver, "
1284 			"reason=%s\n", "06");
1285 
1286 		erp = dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
1287 	}
1288 
1289 	return erp;
1290 
1291 }				/* end dasd_3990_erp_inv_format */
1292 
1293 /*
1294  * DASD_3990_ERP_EOC
1295  *
1296  * DESCRIPTION
1297  *   Handles 24 byte 'End-of-Cylinder' error.
1298  *
1299  * PARAMETER
1300  *   erp		already added default erp
1301  * RETURN VALUES
1302  *   erp		pointer to original (failed) cqr.
1303  */
1304 static struct dasd_ccw_req *
1305 dasd_3990_erp_EOC(struct dasd_ccw_req * default_erp, char *sense)
1306 {
1307 
1308 	struct dasd_device *device = default_erp->startdev;
1309 
1310 	dev_err(&device->cdev->dev,
1311 		"The cylinder data for accessing the DASD is inconsistent\n");
1312 
1313 	/* implement action 7 - BUG */
1314 	return dasd_3990_erp_cleanup(default_erp, DASD_CQR_FAILED);
1315 
1316 }				/* end dasd_3990_erp_EOC */
1317 
1318 /*
1319  * DASD_3990_ERP_ENV_DATA
1320  *
1321  * DESCRIPTION
1322  *   Handles 24 byte 'Environmental-Data Present' error.
1323  *
1324  * PARAMETER
1325  *   erp		current erp_head
1326  * RETURN VALUES
1327  *   erp		new erp_head - pointer to new ERP
1328  */
1329 static struct dasd_ccw_req *
1330 dasd_3990_erp_env_data(struct dasd_ccw_req * erp, char *sense)
1331 {
1332 
1333 	struct dasd_device *device = erp->startdev;
1334 
1335 	erp->function = dasd_3990_erp_env_data;
1336 
1337 	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "Environmental data present");
1338 
1339 	dasd_3990_handle_env_data(erp, sense);
1340 
1341 	/* don't retry on disabled interface */
1342 	if (sense[7] != 0x0F) {
1343 		erp = dasd_3990_erp_action_4(erp, sense);
1344 	} else {
1345 		erp->status = DASD_CQR_FILLED;
1346 	}
1347 
1348 	return erp;
1349 
1350 }				/* end dasd_3990_erp_env_data */
1351 
1352 /*
1353  * DASD_3990_ERP_NO_REC
1354  *
1355  * DESCRIPTION
1356  *   Handles 24 byte 'No Record Found' error.
1357  *
1358  * PARAMETER
1359  *   erp		already added default ERP
1360  *
1361  * RETURN VALUES
1362  *   erp		new erp_head - pointer to new ERP
1363  */
1364 static struct dasd_ccw_req *
1365 dasd_3990_erp_no_rec(struct dasd_ccw_req * default_erp, char *sense)
1366 {
1367 
1368 	struct dasd_device *device = default_erp->startdev;
1369 
1370 	/*
1371 	 * In some cases the 'No Record Found' error might be expected and
1372 	 * log messages shouldn't be written then.
1373 	 * Check if the according suppress bit is set.
1374 	 */
1375 	if (!test_bit(DASD_CQR_SUPPRESS_NRF, &default_erp->flags))
1376 		dev_err(&device->cdev->dev,
1377 			"The specified record was not found\n");
1378 
1379 	return dasd_3990_erp_cleanup(default_erp, DASD_CQR_FAILED);
1380 
1381 }				/* end dasd_3990_erp_no_rec */
1382 
1383 /*
1384  * DASD_3990_ERP_FILE_PROT
1385  *
1386  * DESCRIPTION
1387  *   Handles 24 byte 'File Protected' error.
1388  *   Note: Seek related recovery is not implemented because
1389  *	   wee don't use the seek command yet.
1390  *
1391  * PARAMETER
1392  *   erp		current erp_head
1393  * RETURN VALUES
1394  *   erp		new erp_head - pointer to new ERP
1395  */
1396 static struct dasd_ccw_req *
1397 dasd_3990_erp_file_prot(struct dasd_ccw_req * erp)
1398 {
1399 
1400 	struct dasd_device *device = erp->startdev;
1401 
1402 	/*
1403 	 * In some cases the 'File Protected' error might be expected and
1404 	 * log messages shouldn't be written then.
1405 	 * Check if the according suppress bit is set.
1406 	 */
1407 	if (!test_bit(DASD_CQR_SUPPRESS_FP, &erp->flags))
1408 		dev_err(&device->cdev->dev,
1409 			"Accessing the DASD failed because of a hardware error\n");
1410 
1411 	return dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
1412 
1413 }				/* end dasd_3990_erp_file_prot */
1414 
1415 /*
1416  * DASD_3990_ERP_INSPECT_ALIAS
1417  *
1418  * DESCRIPTION
1419  *   Checks if the original request was started on an alias device.
1420  *   If yes, it modifies the original and the erp request so that
1421  *   the erp request can be started on a base device.
1422  *
1423  * PARAMETER
1424  *   erp		pointer to the currently created default ERP
1425  *
1426  * RETURN VALUES
1427  *   erp		pointer to the modified ERP, or NULL
1428  */
1429 
1430 static struct dasd_ccw_req *dasd_3990_erp_inspect_alias(
1431 						struct dasd_ccw_req *erp)
1432 {
1433 	struct dasd_ccw_req *cqr = erp->refers;
1434 	char *sense;
1435 
1436 	if (cqr->block &&
1437 	    (cqr->block->base != cqr->startdev)) {
1438 
1439 		sense = dasd_get_sense(&erp->refers->irb);
1440 		/*
1441 		 * dynamic pav may have changed base alias mapping
1442 		 */
1443 		if (!test_bit(DASD_FLAG_OFFLINE, &cqr->startdev->flags) && sense
1444 		    && (sense[0] == 0x10) && (sense[7] == 0x0F)
1445 		    && (sense[8] == 0x67)) {
1446 			/*
1447 			 * remove device from alias handling to prevent new
1448 			 * requests from being scheduled on the
1449 			 * wrong alias device
1450 			 */
1451 			dasd_alias_remove_device(cqr->startdev);
1452 
1453 			/* schedule worker to reload device */
1454 			dasd_reload_device(cqr->startdev);
1455 		}
1456 
1457 		if (cqr->startdev->features & DASD_FEATURE_ERPLOG) {
1458 			DBF_DEV_EVENT(DBF_ERR, cqr->startdev,
1459 				    "ERP on alias device for request %p,"
1460 				    " recover on base device %s", cqr,
1461 				    dev_name(&cqr->block->base->cdev->dev));
1462 		}
1463 		dasd_eckd_reset_ccw_to_base_io(cqr);
1464 		erp->startdev = cqr->block->base;
1465 		erp->function = dasd_3990_erp_inspect_alias;
1466 		return erp;
1467 	} else
1468 		return NULL;
1469 }
1470 
1471 
1472 /*
1473  * DASD_3990_ERP_INSPECT_24
1474  *
1475  * DESCRIPTION
1476  *   Does a detailed inspection of the 24 byte sense data
1477  *   and sets up a related error recovery action.
1478  *
1479  * PARAMETER
1480  *   sense		sense data of the actual error
1481  *   erp		pointer to the currently created default ERP
1482  *
1483  * RETURN VALUES
1484  *   erp		pointer to the (addtitional) ERP
1485  */
1486 static struct dasd_ccw_req *
1487 dasd_3990_erp_inspect_24(struct dasd_ccw_req * erp, char *sense)
1488 {
1489 
1490 	struct dasd_ccw_req *erp_filled = NULL;
1491 
1492 	/* Check sense for ....	   */
1493 	/* 'Command Reject'	   */
1494 	if ((erp_filled == NULL) && (sense[0] & SNS0_CMD_REJECT)) {
1495 		erp_filled = dasd_3990_erp_com_rej(erp, sense);
1496 	}
1497 	/* 'Intervention Required' */
1498 	if ((erp_filled == NULL) && (sense[0] & SNS0_INTERVENTION_REQ)) {
1499 		erp_filled = dasd_3990_erp_int_req(erp);
1500 	}
1501 	/* 'Bus Out Parity Check'  */
1502 	if ((erp_filled == NULL) && (sense[0] & SNS0_BUS_OUT_CHECK)) {
1503 		erp_filled = dasd_3990_erp_bus_out(erp);
1504 	}
1505 	/* 'Equipment Check'	   */
1506 	if ((erp_filled == NULL) && (sense[0] & SNS0_EQUIPMENT_CHECK)) {
1507 		erp_filled = dasd_3990_erp_equip_check(erp, sense);
1508 	}
1509 	/* 'Data Check'		   */
1510 	if ((erp_filled == NULL) && (sense[0] & SNS0_DATA_CHECK)) {
1511 		erp_filled = dasd_3990_erp_data_check(erp, sense);
1512 	}
1513 	/* 'Overrun'		   */
1514 	if ((erp_filled == NULL) && (sense[0] & SNS0_OVERRUN)) {
1515 		erp_filled = dasd_3990_erp_overrun(erp, sense);
1516 	}
1517 	/* 'Invalid Track Format'  */
1518 	if ((erp_filled == NULL) && (sense[1] & SNS1_INV_TRACK_FORMAT)) {
1519 		erp_filled = dasd_3990_erp_inv_format(erp, sense);
1520 	}
1521 	/* 'End-of-Cylinder'	   */
1522 	if ((erp_filled == NULL) && (sense[1] & SNS1_EOC)) {
1523 		erp_filled = dasd_3990_erp_EOC(erp, sense);
1524 	}
1525 	/* 'Environmental Data'	   */
1526 	if ((erp_filled == NULL) && (sense[2] & SNS2_ENV_DATA_PRESENT)) {
1527 		erp_filled = dasd_3990_erp_env_data(erp, sense);
1528 	}
1529 	/* 'No Record Found'	   */
1530 	if ((erp_filled == NULL) && (sense[1] & SNS1_NO_REC_FOUND)) {
1531 		erp_filled = dasd_3990_erp_no_rec(erp, sense);
1532 	}
1533 	/* 'File Protected'	   */
1534 	if ((erp_filled == NULL) && (sense[1] & SNS1_FILE_PROTECTED)) {
1535 		erp_filled = dasd_3990_erp_file_prot(erp);
1536 	}
1537 	/* other (unknown) error - do default ERP */
1538 	if (erp_filled == NULL) {
1539 
1540 		erp_filled = erp;
1541 	}
1542 
1543 	return erp_filled;
1544 
1545 }				/* END dasd_3990_erp_inspect_24 */
1546 
1547 /*
1548  *****************************************************************************
1549  * 32 byte sense ERP functions (only)
1550  *****************************************************************************
1551  */
1552 
1553 /*
1554  * DASD_3990_ERPACTION_10_32
1555  *
1556  * DESCRIPTION
1557  *   Handles 32 byte 'Action 10' of Single Program Action Codes.
1558  *   Just retry and if retry doesn't work, return with error.
1559  *
1560  * PARAMETER
1561  *   erp		current erp_head
1562  *   sense		current sense data
1563  * RETURN VALUES
1564  *   erp		modified erp_head
1565  */
1566 static struct dasd_ccw_req *
1567 dasd_3990_erp_action_10_32(struct dasd_ccw_req * erp, char *sense)
1568 {
1569 
1570 	struct dasd_device *device = erp->startdev;
1571 
1572 	erp->retries = 256;
1573 	erp->function = dasd_3990_erp_action_10_32;
1574 
1575 	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "Perform logging requested");
1576 
1577 	return erp;
1578 
1579 }				/* end dasd_3990_erp_action_10_32 */
1580 
1581 /*
1582  * DASD_3990_ERP_ACTION_1B_32
1583  *
1584  * DESCRIPTION
1585  *   Handles 32 byte 'Action 1B' of Single Program Action Codes.
1586  *   A write operation could not be finished because of an unexpected
1587  *   condition.
1588  *   The already created 'default erp' is used to get the link to
1589  *   the erp chain, but it can not be used for this recovery
1590  *   action because it contains no DE/LO data space.
1591  *
1592  * PARAMETER
1593  *   default_erp	already added default erp.
1594  *   sense		current sense data
1595  *
1596  * RETURN VALUES
1597  *   erp		new erp or
1598  *			default_erp in case of imprecise ending or error
1599  */
1600 static struct dasd_ccw_req *
1601 dasd_3990_erp_action_1B_32(struct dasd_ccw_req * default_erp, char *sense)
1602 {
1603 
1604 	struct dasd_device *device = default_erp->startdev;
1605 	__u32 cpa = 0;
1606 	struct dasd_ccw_req *cqr;
1607 	struct dasd_ccw_req *erp;
1608 	struct DE_eckd_data *DE_data;
1609 	struct PFX_eckd_data *PFX_data;
1610 	char *LO_data;		/* LO_eckd_data_t */
1611 	struct ccw1 *ccw, *oldccw;
1612 
1613 	DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1614 		    "Write not finished because of unexpected condition");
1615 
1616 	default_erp->function = dasd_3990_erp_action_1B_32;
1617 
1618 	/* determine the original cqr */
1619 	cqr = default_erp;
1620 
1621 	while (cqr->refers != NULL) {
1622 		cqr = cqr->refers;
1623 	}
1624 
1625 	if (scsw_is_tm(&cqr->irb.scsw)) {
1626 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1627 			      "32 bit sense, action 1B is not defined"
1628 			      " in transport mode - just retry");
1629 		return default_erp;
1630 	}
1631 
1632 	/* for imprecise ending just do default erp */
1633 	if (sense[1] & 0x01) {
1634 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1635 			    "Imprecise ending is set - just retry");
1636 
1637 		return default_erp;
1638 	}
1639 
1640 	/* determine the address of the CCW to be restarted */
1641 	/* Imprecise ending is not set -> addr from IRB-SCSW */
1642 	cpa = default_erp->refers->irb.scsw.cmd.cpa;
1643 
1644 	if (cpa == 0) {
1645 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1646 			    "Unable to determine address of the CCW "
1647 			    "to be restarted");
1648 
1649 		return dasd_3990_erp_cleanup(default_erp, DASD_CQR_FAILED);
1650 	}
1651 
1652 	/* Build new ERP request including DE/LO */
1653 	erp = dasd_alloc_erp_request((char *) &cqr->magic,
1654 				     2 + 1,/* DE/LO + TIC */
1655 				     sizeof(struct DE_eckd_data) +
1656 				     sizeof(struct LO_eckd_data), device);
1657 
1658 	if (IS_ERR(erp)) {
1659 		/* internal error 01 - Unable to allocate ERP */
1660 		dev_err(&device->cdev->dev, "An error occurred in the DASD "
1661 			"device driver, reason=%s\n", "01");
1662 		return dasd_3990_erp_cleanup(default_erp, DASD_CQR_FAILED);
1663 	}
1664 
1665 	/* use original DE */
1666 	DE_data = erp->data;
1667 	oldccw = cqr->cpaddr;
1668 	if (oldccw->cmd_code == DASD_ECKD_CCW_PFX) {
1669 		PFX_data = cqr->data;
1670 		memcpy(DE_data, &PFX_data->define_extent,
1671 		       sizeof(struct DE_eckd_data));
1672 	} else
1673 		memcpy(DE_data, cqr->data, sizeof(struct DE_eckd_data));
1674 
1675 	/* create LO */
1676 	LO_data = erp->data + sizeof(struct DE_eckd_data);
1677 
1678 	if ((sense[3] == 0x01) && (LO_data[1] & 0x01)) {
1679 		/* should not */
1680 		return dasd_3990_erp_cleanup(default_erp, DASD_CQR_FAILED);
1681 	}
1682 
1683 	if ((sense[7] & 0x3F) == 0x01) {
1684 		/* operation code is WRITE DATA -> data area orientation */
1685 		LO_data[0] = 0x81;
1686 
1687 	} else if ((sense[7] & 0x3F) == 0x03) {
1688 		/* operation code is FORMAT WRITE -> index orientation */
1689 		LO_data[0] = 0xC3;
1690 
1691 	} else {
1692 		LO_data[0] = sense[7];	/* operation */
1693 	}
1694 
1695 	LO_data[1] = sense[8];	/* auxiliary */
1696 	LO_data[2] = sense[9];
1697 	LO_data[3] = sense[3];	/* count */
1698 	LO_data[4] = sense[29];	/* seek_addr.cyl */
1699 	LO_data[5] = sense[30];	/* seek_addr.cyl 2nd byte */
1700 	LO_data[7] = sense[31];	/* seek_addr.head 2nd byte */
1701 
1702 	memcpy(&(LO_data[8]), &(sense[11]), 8);
1703 
1704 	/* create DE ccw */
1705 	ccw = erp->cpaddr;
1706 	memset(ccw, 0, sizeof(struct ccw1));
1707 	ccw->cmd_code = DASD_ECKD_CCW_DEFINE_EXTENT;
1708 	ccw->flags = CCW_FLAG_CC;
1709 	ccw->count = 16;
1710 	ccw->cda = (__u32)(addr_t) DE_data;
1711 
1712 	/* create LO ccw */
1713 	ccw++;
1714 	memset(ccw, 0, sizeof(struct ccw1));
1715 	ccw->cmd_code = DASD_ECKD_CCW_LOCATE_RECORD;
1716 	ccw->flags = CCW_FLAG_CC;
1717 	ccw->count = 16;
1718 	ccw->cda = (__u32)(addr_t) LO_data;
1719 
1720 	/* TIC to the failed ccw */
1721 	ccw++;
1722 	ccw->cmd_code = CCW_CMD_TIC;
1723 	ccw->cda = cpa;
1724 
1725 	/* fill erp related fields */
1726 	erp->flags = default_erp->flags;
1727 	erp->function = dasd_3990_erp_action_1B_32;
1728 	erp->refers = default_erp->refers;
1729 	erp->startdev = device;
1730 	erp->memdev = device;
1731 	erp->magic = default_erp->magic;
1732 	erp->expires = default_erp->expires;
1733 	erp->retries = 256;
1734 	erp->buildclk = get_tod_clock();
1735 	erp->status = DASD_CQR_FILLED;
1736 
1737 	/* remove the default erp */
1738 	dasd_free_erp_request(default_erp, device);
1739 
1740 	return erp;
1741 
1742 }				/* end dasd_3990_erp_action_1B_32 */
1743 
1744 /*
1745  * DASD_3990_UPDATE_1B
1746  *
1747  * DESCRIPTION
1748  *   Handles the update to the 32 byte 'Action 1B' of Single Program
1749  *   Action Codes in case the first action was not successful.
1750  *   The already created 'previous_erp' is the currently not successful
1751  *   ERP.
1752  *
1753  * PARAMETER
1754  *   previous_erp	already created previous erp.
1755  *   sense		current sense data
1756  * RETURN VALUES
1757  *   erp		modified erp
1758  */
1759 static struct dasd_ccw_req *
1760 dasd_3990_update_1B(struct dasd_ccw_req * previous_erp, char *sense)
1761 {
1762 
1763 	struct dasd_device *device = previous_erp->startdev;
1764 	__u32 cpa = 0;
1765 	struct dasd_ccw_req *cqr;
1766 	struct dasd_ccw_req *erp;
1767 	char *LO_data;		/* struct LO_eckd_data */
1768 	struct ccw1 *ccw;
1769 
1770 	DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1771 		    "Write not finished because of unexpected condition"
1772 		    " - follow on");
1773 
1774 	/* determine the original cqr */
1775 	cqr = previous_erp;
1776 
1777 	while (cqr->refers != NULL) {
1778 		cqr = cqr->refers;
1779 	}
1780 
1781 	if (scsw_is_tm(&cqr->irb.scsw)) {
1782 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1783 			      "32 bit sense, action 1B, update,"
1784 			      " in transport mode - just retry");
1785 		return previous_erp;
1786 	}
1787 
1788 	/* for imprecise ending just do default erp */
1789 	if (sense[1] & 0x01) {
1790 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1791 			    "Imprecise ending is set - just retry");
1792 
1793 		previous_erp->status = DASD_CQR_FILLED;
1794 
1795 		return previous_erp;
1796 	}
1797 
1798 	/* determine the address of the CCW to be restarted */
1799 	/* Imprecise ending is not set -> addr from IRB-SCSW */
1800 	cpa = previous_erp->irb.scsw.cmd.cpa;
1801 
1802 	if (cpa == 0) {
1803 		/* internal error 02 -
1804 		   Unable to determine address of the CCW to be restarted */
1805 		dev_err(&device->cdev->dev, "An error occurred in the DASD "
1806 			"device driver, reason=%s\n", "02");
1807 
1808 		previous_erp->status = DASD_CQR_FAILED;
1809 
1810 		return previous_erp;
1811 	}
1812 
1813 	erp = previous_erp;
1814 
1815 	/* update the LO with the new returned sense data  */
1816 	LO_data = erp->data + sizeof(struct DE_eckd_data);
1817 
1818 	if ((sense[3] == 0x01) && (LO_data[1] & 0x01)) {
1819 		/* should not happen */
1820 		previous_erp->status = DASD_CQR_FAILED;
1821 
1822 		return previous_erp;
1823 	}
1824 
1825 	if ((sense[7] & 0x3F) == 0x01) {
1826 		/* operation code is WRITE DATA -> data area orientation */
1827 		LO_data[0] = 0x81;
1828 
1829 	} else if ((sense[7] & 0x3F) == 0x03) {
1830 		/* operation code is FORMAT WRITE -> index orientation */
1831 		LO_data[0] = 0xC3;
1832 
1833 	} else {
1834 		LO_data[0] = sense[7];	/* operation */
1835 	}
1836 
1837 	LO_data[1] = sense[8];	/* auxiliary */
1838 	LO_data[2] = sense[9];
1839 	LO_data[3] = sense[3];	/* count */
1840 	LO_data[4] = sense[29];	/* seek_addr.cyl */
1841 	LO_data[5] = sense[30];	/* seek_addr.cyl 2nd byte */
1842 	LO_data[7] = sense[31];	/* seek_addr.head 2nd byte */
1843 
1844 	memcpy(&(LO_data[8]), &(sense[11]), 8);
1845 
1846 	/* TIC to the failed ccw */
1847 	ccw = erp->cpaddr;	/* addr of DE ccw */
1848 	ccw++;			/* addr of LE ccw */
1849 	ccw++;			/* addr of TIC ccw */
1850 	ccw->cda = cpa;
1851 
1852 	erp->status = DASD_CQR_FILLED;
1853 
1854 	return erp;
1855 
1856 }				/* end dasd_3990_update_1B */
1857 
1858 /*
1859  * DASD_3990_ERP_COMPOUND_RETRY
1860  *
1861  * DESCRIPTION
1862  *   Handles the compound ERP action retry code.
1863  *   NOTE: At least one retry is done even if zero is specified
1864  *	   by the sense data. This makes enqueueing of the request
1865  *	   easier.
1866  *
1867  * PARAMETER
1868  *   sense		sense data of the actual error
1869  *   erp		pointer to the currently created ERP
1870  *
1871  * RETURN VALUES
1872  *   erp		modified ERP pointer
1873  *
1874  */
1875 static void
1876 dasd_3990_erp_compound_retry(struct dasd_ccw_req * erp, char *sense)
1877 {
1878 
1879 	switch (sense[25] & 0x03) {
1880 	case 0x00:		/* no not retry */
1881 		erp->retries = 1;
1882 		break;
1883 
1884 	case 0x01:		/* retry 2 times */
1885 		erp->retries = 2;
1886 		break;
1887 
1888 	case 0x02:		/* retry 10 times */
1889 		erp->retries = 10;
1890 		break;
1891 
1892 	case 0x03:		/* retry 256 times */
1893 		erp->retries = 256;
1894 		break;
1895 
1896 	default:
1897 		BUG();
1898 	}
1899 
1900 	erp->function = dasd_3990_erp_compound_retry;
1901 
1902 }				/* end dasd_3990_erp_compound_retry */
1903 
1904 /*
1905  * DASD_3990_ERP_COMPOUND_PATH
1906  *
1907  * DESCRIPTION
1908  *   Handles the compound ERP action for retry on alternate
1909  *   channel path.
1910  *
1911  * PARAMETER
1912  *   sense		sense data of the actual error
1913  *   erp		pointer to the currently created ERP
1914  *
1915  * RETURN VALUES
1916  *   erp		modified ERP pointer
1917  *
1918  */
1919 static void
1920 dasd_3990_erp_compound_path(struct dasd_ccw_req * erp, char *sense)
1921 {
1922 	if (sense[25] & DASD_SENSE_BIT_3) {
1923 		dasd_3990_erp_alternate_path(erp);
1924 
1925 		if (erp->status == DASD_CQR_FAILED &&
1926 		    !test_bit(DASD_CQR_VERIFY_PATH, &erp->flags)) {
1927 			/* reset the lpm and the status to be able to
1928 			 * try further actions. */
1929 			erp->lpm = dasd_path_get_opm(erp->startdev);
1930 			erp->status = DASD_CQR_NEED_ERP;
1931 		}
1932 	}
1933 
1934 	erp->function = dasd_3990_erp_compound_path;
1935 
1936 }				/* end dasd_3990_erp_compound_path */
1937 
1938 /*
1939  * DASD_3990_ERP_COMPOUND_CODE
1940  *
1941  * DESCRIPTION
1942  *   Handles the compound ERP action for retry code.
1943  *
1944  * PARAMETER
1945  *   sense		sense data of the actual error
1946  *   erp		pointer to the currently created ERP
1947  *
1948  * RETURN VALUES
1949  *   erp		NEW ERP pointer
1950  *
1951  */
1952 static struct dasd_ccw_req *
1953 dasd_3990_erp_compound_code(struct dasd_ccw_req * erp, char *sense)
1954 {
1955 
1956 	if (sense[25] & DASD_SENSE_BIT_2) {
1957 
1958 		switch (sense[28]) {
1959 		case 0x17:
1960 			/* issue a Diagnostic Control command with an
1961 			 * Inhibit Write subcommand and controller modifier */
1962 			erp = dasd_3990_erp_DCTL(erp, 0x20);
1963 			break;
1964 
1965 		case 0x25:
1966 			/* wait for 5 seconds and retry again */
1967 			erp->retries = 1;
1968 
1969 			dasd_3990_erp_block_queue (erp, 5*HZ);
1970 			break;
1971 
1972 		default:
1973 			/* should not happen - continue */
1974 			break;
1975 		}
1976 	}
1977 
1978 	erp->function = dasd_3990_erp_compound_code;
1979 
1980 	return erp;
1981 
1982 }				/* end dasd_3990_erp_compound_code */
1983 
1984 /*
1985  * DASD_3990_ERP_COMPOUND_CONFIG
1986  *
1987  * DESCRIPTION
1988  *   Handles the compound ERP action for configruation
1989  *   dependent error.
1990  *   Note: duplex handling is not implemented (yet).
1991  *
1992  * PARAMETER
1993  *   sense		sense data of the actual error
1994  *   erp		pointer to the currently created ERP
1995  *
1996  * RETURN VALUES
1997  *   erp		modified ERP pointer
1998  *
1999  */
2000 static void
2001 dasd_3990_erp_compound_config(struct dasd_ccw_req * erp, char *sense)
2002 {
2003 
2004 	if ((sense[25] & DASD_SENSE_BIT_1) && (sense[26] & DASD_SENSE_BIT_2)) {
2005 
2006 		/* set to suspended duplex state then restart
2007 		   internal error 05 - Set device to suspended duplex state
2008 		   should be done */
2009 		struct dasd_device *device = erp->startdev;
2010 		dev_err(&device->cdev->dev,
2011 			"An error occurred in the DASD device driver, "
2012 			"reason=%s\n", "05");
2013 
2014 	}
2015 
2016 	erp->function = dasd_3990_erp_compound_config;
2017 
2018 }				/* end dasd_3990_erp_compound_config */
2019 
2020 /*
2021  * DASD_3990_ERP_COMPOUND
2022  *
2023  * DESCRIPTION
2024  *   Does the further compound program action if
2025  *   compound retry was not successful.
2026  *
2027  * PARAMETER
2028  *   sense		sense data of the actual error
2029  *   erp		pointer to the current (failed) ERP
2030  *
2031  * RETURN VALUES
2032  *   erp		(additional) ERP pointer
2033  *
2034  */
2035 static struct dasd_ccw_req *
2036 dasd_3990_erp_compound(struct dasd_ccw_req * erp, char *sense)
2037 {
2038 
2039 	if ((erp->function == dasd_3990_erp_compound_retry) &&
2040 	    (erp->status == DASD_CQR_NEED_ERP)) {
2041 
2042 		dasd_3990_erp_compound_path(erp, sense);
2043 	}
2044 
2045 	if ((erp->function == dasd_3990_erp_compound_path) &&
2046 	    (erp->status == DASD_CQR_NEED_ERP)) {
2047 
2048 		erp = dasd_3990_erp_compound_code(erp, sense);
2049 	}
2050 
2051 	if ((erp->function == dasd_3990_erp_compound_code) &&
2052 	    (erp->status == DASD_CQR_NEED_ERP)) {
2053 
2054 		dasd_3990_erp_compound_config(erp, sense);
2055 	}
2056 
2057 	/* if no compound action ERP specified, the request failed */
2058 	if (erp->status == DASD_CQR_NEED_ERP)
2059 		erp->status = DASD_CQR_FAILED;
2060 
2061 	return erp;
2062 
2063 }				/* end dasd_3990_erp_compound */
2064 
2065 /*
2066  *DASD_3990_ERP_HANDLE_SIM
2067  *
2068  *DESCRIPTION
2069  *  inspects the SIM SENSE data and starts an appropriate action
2070  *
2071  * PARAMETER
2072  *   sense	   sense data of the actual error
2073  *
2074  * RETURN VALUES
2075  *   none
2076  */
2077 void
2078 dasd_3990_erp_handle_sim(struct dasd_device *device, char *sense)
2079 {
2080 	/* print message according to log or message to operator mode */
2081 	if ((sense[24] & DASD_SIM_MSG_TO_OP) || (sense[1] & 0x10)) {
2082 		/* print SIM SRC from RefCode */
2083 		dev_err(&device->cdev->dev, "SIM - SRC: "
2084 			    "%02x%02x%02x%02x\n", sense[22],
2085 			    sense[23], sense[11], sense[12]);
2086 	} else if (sense[24] & DASD_SIM_LOG) {
2087 		/* print SIM SRC Refcode */
2088 		dev_warn(&device->cdev->dev, "log SIM - SRC: "
2089 			    "%02x%02x%02x%02x\n", sense[22],
2090 			    sense[23], sense[11], sense[12]);
2091 	}
2092 }
2093 
2094 /*
2095  * DASD_3990_ERP_INSPECT_32
2096  *
2097  * DESCRIPTION
2098  *   Does a detailed inspection of the 32 byte sense data
2099  *   and sets up a related error recovery action.
2100  *
2101  * PARAMETER
2102  *   sense		sense data of the actual error
2103  *   erp		pointer to the currently created default ERP
2104  *
2105  * RETURN VALUES
2106  *   erp_filled		pointer to the ERP
2107  *
2108  */
2109 static struct dasd_ccw_req *
2110 dasd_3990_erp_inspect_32(struct dasd_ccw_req * erp, char *sense)
2111 {
2112 
2113 	struct dasd_device *device = erp->startdev;
2114 
2115 	erp->function = dasd_3990_erp_inspect_32;
2116 
2117 	/* check for SIM sense data */
2118 	if ((sense[6] & DASD_SIM_SENSE) == DASD_SIM_SENSE)
2119 		dasd_3990_erp_handle_sim(device, sense);
2120 
2121 	if (sense[25] & DASD_SENSE_BIT_0) {
2122 
2123 		/* compound program action codes (byte25 bit 0 == '1') */
2124 		dasd_3990_erp_compound_retry(erp, sense);
2125 
2126 	} else {
2127 
2128 		/* single program action codes (byte25 bit 0 == '0') */
2129 		switch (sense[25]) {
2130 
2131 		case 0x00:	/* success - use default ERP for retries */
2132 			DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
2133 				    "ERP called for successful request"
2134 				    " - just retry");
2135 			break;
2136 
2137 		case 0x01:	/* fatal error */
2138 			dev_err(&device->cdev->dev,
2139 				    "ERP failed for the DASD\n");
2140 
2141 			erp = dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
2142 			break;
2143 
2144 		case 0x02:	/* intervention required */
2145 		case 0x03:	/* intervention required during dual copy */
2146 			erp = dasd_3990_erp_int_req(erp);
2147 			break;
2148 
2149 		case 0x0F:  /* length mismatch during update write command
2150 			       internal error 08 - update write command error*/
2151 			dev_err(&device->cdev->dev, "An error occurred in the "
2152 				"DASD device driver, reason=%s\n", "08");
2153 
2154 			erp = dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
2155 			break;
2156 
2157 		case 0x10:  /* logging required for other channel program */
2158 			erp = dasd_3990_erp_action_10_32(erp, sense);
2159 			break;
2160 
2161 		case 0x15:	/* next track outside defined extend
2162 				   internal error 07 - The next track is not
2163 				   within the defined storage extent */
2164 			dev_err(&device->cdev->dev,
2165 				"An error occurred in the DASD device driver, "
2166 				"reason=%s\n", "07");
2167 
2168 			erp = dasd_3990_erp_cleanup(erp, DASD_CQR_FAILED);
2169 			break;
2170 
2171 		case 0x1B:	/* unexpected condition during write */
2172 
2173 			erp = dasd_3990_erp_action_1B_32(erp, sense);
2174 			break;
2175 
2176 		case 0x1C:	/* invalid data */
2177 			dev_emerg(&device->cdev->dev,
2178 				    "Data recovered during retry with PCI "
2179 				    "fetch mode active\n");
2180 
2181 			/* not possible to handle this situation in Linux */
2182 			panic
2183 			    ("Invalid data - No way to inform application "
2184 			     "about the possibly incorrect data");
2185 			break;
2186 
2187 		case 0x1D:	/* state-change pending */
2188 			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
2189 				    "A State change pending condition exists "
2190 				    "for the subsystem or device");
2191 
2192 			erp = dasd_3990_erp_action_4(erp, sense);
2193 			break;
2194 
2195 		case 0x1E:	/* busy */
2196 			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
2197 				    "Busy condition exists "
2198 				    "for the subsystem or device");
2199                         erp = dasd_3990_erp_action_4(erp, sense);
2200 			break;
2201 
2202 		default:	/* all others errors - default erp  */
2203 			break;
2204 		}
2205 	}
2206 
2207 	return erp;
2208 
2209 }				/* end dasd_3990_erp_inspect_32 */
2210 
2211 static void dasd_3990_erp_disable_path(struct dasd_device *device, __u8 lpum)
2212 {
2213 	int pos = pathmask_to_pos(lpum);
2214 
2215 	/* no remaining path, cannot disable */
2216 	if (!(dasd_path_get_opm(device) & ~lpum))
2217 		return;
2218 
2219 	dev_err(&device->cdev->dev,
2220 		"Path %x.%02x (pathmask %02x) is disabled - IFCC threshold exceeded\n",
2221 		device->path[pos].cssid, device->path[pos].chpid, lpum);
2222 	dasd_path_remove_opm(device, lpum);
2223 	dasd_path_add_ifccpm(device, lpum);
2224 	device->path[pos].errorclk = 0;
2225 	atomic_set(&device->path[pos].error_count, 0);
2226 }
2227 
2228 static void dasd_3990_erp_account_error(struct dasd_ccw_req *erp)
2229 {
2230 	struct dasd_device *device = erp->startdev;
2231 	__u8 lpum = erp->refers->irb.esw.esw1.lpum;
2232 	int pos = pathmask_to_pos(lpum);
2233 	unsigned long long clk;
2234 
2235 	if (!device->path_thrhld)
2236 		return;
2237 
2238 	clk = get_tod_clock();
2239 	/*
2240 	 * check if the last error is longer ago than the timeout,
2241 	 * if so reset error state
2242 	 */
2243 	if ((tod_to_ns(clk - device->path[pos].errorclk) / NSEC_PER_SEC)
2244 	    >= device->path_interval) {
2245 		atomic_set(&device->path[pos].error_count, 0);
2246 		device->path[pos].errorclk = 0;
2247 	}
2248 	atomic_inc(&device->path[pos].error_count);
2249 	device->path[pos].errorclk = clk;
2250 	/* threshold exceeded disable path if possible */
2251 	if (atomic_read(&device->path[pos].error_count) >=
2252 	    device->path_thrhld)
2253 		dasd_3990_erp_disable_path(device, lpum);
2254 }
2255 
2256 /*
2257  *****************************************************************************
2258  * main ERP control functions (24 and 32 byte sense)
2259  *****************************************************************************
2260  */
2261 
2262 /*
2263  * DASD_3990_ERP_CONTROL_CHECK
2264  *
2265  * DESCRIPTION
2266  *   Does a generic inspection if a control check occurred and sets up
2267  *   the related error recovery procedure
2268  *
2269  * PARAMETER
2270  *   erp		pointer to the currently created default ERP
2271  *
2272  * RETURN VALUES
2273  *   erp_filled		pointer to the erp
2274  */
2275 
2276 static struct dasd_ccw_req *
2277 dasd_3990_erp_control_check(struct dasd_ccw_req *erp)
2278 {
2279 	struct dasd_device *device = erp->startdev;
2280 
2281 	if (scsw_cstat(&erp->refers->irb.scsw) & (SCHN_STAT_INTF_CTRL_CHK
2282 					   | SCHN_STAT_CHN_CTRL_CHK)) {
2283 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
2284 			    "channel or interface control check");
2285 		dasd_3990_erp_account_error(erp);
2286 		erp = dasd_3990_erp_action_4(erp, NULL);
2287 	}
2288 	return erp;
2289 }
2290 
2291 /*
2292  * DASD_3990_ERP_INSPECT
2293  *
2294  * DESCRIPTION
2295  *   Does a detailed inspection for sense data by calling either
2296  *   the 24-byte or the 32-byte inspection routine.
2297  *
2298  * PARAMETER
2299  *   erp		pointer to the currently created default ERP
2300  * RETURN VALUES
2301  *   erp_new		contens was possibly modified
2302  */
2303 static struct dasd_ccw_req *
2304 dasd_3990_erp_inspect(struct dasd_ccw_req *erp)
2305 {
2306 
2307 	struct dasd_ccw_req *erp_new = NULL;
2308 	char *sense;
2309 
2310 	/* if this problem occurred on an alias retry on base */
2311 	erp_new = dasd_3990_erp_inspect_alias(erp);
2312 	if (erp_new)
2313 		return erp_new;
2314 
2315 	/* sense data are located in the refers record of the
2316 	 * already set up new ERP !
2317 	 * check if concurrent sens is available
2318 	 */
2319 	sense = dasd_get_sense(&erp->refers->irb);
2320 	if (!sense)
2321 		erp_new = dasd_3990_erp_control_check(erp);
2322 	/* distinguish between 24 and 32 byte sense data */
2323 	else if (sense[27] & DASD_SENSE_BIT_0) {
2324 
2325 		/* inspect the 24 byte sense data */
2326 		erp_new = dasd_3990_erp_inspect_24(erp, sense);
2327 
2328 	} else {
2329 
2330 		/* inspect the 32 byte sense data */
2331 		erp_new = dasd_3990_erp_inspect_32(erp, sense);
2332 
2333 	}	/* end distinguish between 24 and 32 byte sense data */
2334 
2335 	return erp_new;
2336 }
2337 
2338 /*
2339  * DASD_3990_ERP_ADD_ERP
2340  *
2341  * DESCRIPTION
2342  *   This function adds an additional request block (ERP) to the head of
2343  *   the given cqr (or erp).
2344  *   For a command mode cqr the erp is initialized as an default erp
2345  *   (retry TIC).
2346  *   For transport mode we make a copy of the original TCW (points to
2347  *   the original TCCB, TIDALs, etc.) but give it a fresh
2348  *   TSB so the original sense data will not be changed.
2349  *
2350  * PARAMETER
2351  *   cqr		head of the current ERP-chain (or single cqr if
2352  *			first error)
2353  * RETURN VALUES
2354  *   erp		pointer to new ERP-chain head
2355  */
2356 static struct dasd_ccw_req *dasd_3990_erp_add_erp(struct dasd_ccw_req *cqr)
2357 {
2358 
2359 	struct dasd_device *device = cqr->startdev;
2360 	struct ccw1 *ccw;
2361 	struct dasd_ccw_req *erp;
2362 	int cplength, datasize;
2363 	struct tcw *tcw;
2364 	struct tsb *tsb;
2365 
2366 	if (cqr->cpmode == 1) {
2367 		cplength = 0;
2368 		/* TCW needs to be 64 byte aligned, so leave enough room */
2369 		datasize = 64 + sizeof(struct tcw) + sizeof(struct tsb);
2370 	} else {
2371 		cplength = 2;
2372 		datasize = 0;
2373 	}
2374 
2375 	/* allocate additional request block */
2376 	erp = dasd_alloc_erp_request((char *) &cqr->magic,
2377 				     cplength, datasize, device);
2378 	if (IS_ERR(erp)) {
2379                 if (cqr->retries <= 0) {
2380 			DBF_DEV_EVENT(DBF_ERR, device, "%s",
2381 				    "Unable to allocate ERP request");
2382 			cqr->status = DASD_CQR_FAILED;
2383 			cqr->stopclk = get_tod_clock();
2384 		} else {
2385 			DBF_DEV_EVENT(DBF_ERR, device,
2386                                      "Unable to allocate ERP request "
2387 				     "(%i retries left)",
2388                                      cqr->retries);
2389 			dasd_block_set_timer(device->block, (HZ << 3));
2390                 }
2391 		return erp;
2392 	}
2393 
2394 	ccw = cqr->cpaddr;
2395 	if (cqr->cpmode == 1) {
2396 		/* make a shallow copy of the original tcw but set new tsb */
2397 		erp->cpmode = 1;
2398 		erp->cpaddr = PTR_ALIGN(erp->data, 64);
2399 		tcw = erp->cpaddr;
2400 		tsb = (struct tsb *) &tcw[1];
2401 		*tcw = *((struct tcw *)cqr->cpaddr);
2402 		tcw->tsb = (long)tsb;
2403 	} else if (ccw->cmd_code == DASD_ECKD_CCW_PSF) {
2404 		/* PSF cannot be chained from NOOP/TIC */
2405 		erp->cpaddr = cqr->cpaddr;
2406 	} else {
2407 		/* initialize request with default TIC to current ERP/CQR */
2408 		ccw = erp->cpaddr;
2409 		ccw->cmd_code = CCW_CMD_NOOP;
2410 		ccw->flags = CCW_FLAG_CC;
2411 		ccw++;
2412 		ccw->cmd_code = CCW_CMD_TIC;
2413 		ccw->cda      = (long)(cqr->cpaddr);
2414 	}
2415 
2416 	erp->flags = cqr->flags;
2417 	erp->function = dasd_3990_erp_add_erp;
2418 	erp->refers   = cqr;
2419 	erp->startdev = device;
2420 	erp->memdev   = device;
2421 	erp->block    = cqr->block;
2422 	erp->magic    = cqr->magic;
2423 	erp->expires  = cqr->expires;
2424 	erp->retries  = 256;
2425 	erp->buildclk = get_tod_clock();
2426 	erp->status = DASD_CQR_FILLED;
2427 
2428 	return erp;
2429 }
2430 
2431 /*
2432  * DASD_3990_ERP_ADDITIONAL_ERP
2433  *
2434  * DESCRIPTION
2435  *   An additional ERP is needed to handle the current error.
2436  *   Add ERP to the head of the ERP-chain containing the ERP processing
2437  *   determined based on the sense data.
2438  *
2439  * PARAMETER
2440  *   cqr		head of the current ERP-chain (or single cqr if
2441  *			first error)
2442  *
2443  * RETURN VALUES
2444  *   erp		pointer to new ERP-chain head
2445  */
2446 static struct dasd_ccw_req *
2447 dasd_3990_erp_additional_erp(struct dasd_ccw_req * cqr)
2448 {
2449 
2450 	struct dasd_ccw_req *erp = NULL;
2451 
2452 	/* add erp and initialize with default TIC */
2453 	erp = dasd_3990_erp_add_erp(cqr);
2454 
2455 	if (IS_ERR(erp))
2456 		return erp;
2457 
2458 	/* inspect sense, determine specific ERP if possible */
2459 	if (erp != cqr) {
2460 
2461 		erp = dasd_3990_erp_inspect(erp);
2462 	}
2463 
2464 	return erp;
2465 
2466 }				/* end dasd_3990_erp_additional_erp */
2467 
2468 /*
2469  * DASD_3990_ERP_ERROR_MATCH
2470  *
2471  * DESCRIPTION
2472  *   Check if the device status of the given cqr is the same.
2473  *   This means that the failed CCW and the relevant sense data
2474  *   must match.
2475  *   I don't distinguish between 24 and 32 byte sense because in case of
2476  *   24 byte sense byte 25 and 27 is set as well.
2477  *
2478  * PARAMETER
2479  *   cqr1		first cqr, which will be compared with the
2480  *   cqr2		second cqr.
2481  *
2482  * RETURN VALUES
2483  *   match		'boolean' for match found
2484  *			returns 1 if match found, otherwise 0.
2485  */
2486 static int dasd_3990_erp_error_match(struct dasd_ccw_req *cqr1,
2487 				     struct dasd_ccw_req *cqr2)
2488 {
2489 	char *sense1, *sense2;
2490 
2491 	if (cqr1->startdev != cqr2->startdev)
2492 		return 0;
2493 
2494 	sense1 = dasd_get_sense(&cqr1->irb);
2495 	sense2 = dasd_get_sense(&cqr2->irb);
2496 
2497 	/* one request has sense data, the other not -> no match, return 0 */
2498 	if (!sense1 != !sense2)
2499 		return 0;
2500 	/* no sense data in both cases -> check cstat for IFCC */
2501 	if (!sense1 && !sense2)	{
2502 		if ((scsw_cstat(&cqr1->irb.scsw) & (SCHN_STAT_INTF_CTRL_CHK |
2503 						    SCHN_STAT_CHN_CTRL_CHK)) ==
2504 		    (scsw_cstat(&cqr2->irb.scsw) & (SCHN_STAT_INTF_CTRL_CHK |
2505 						    SCHN_STAT_CHN_CTRL_CHK)))
2506 			return 1; /* match with ifcc*/
2507 	}
2508 	/* check sense data; byte 0-2,25,27 */
2509 	if (!(sense1 && sense2 &&
2510 	      (memcmp(sense1, sense2, 3) == 0) &&
2511 	      (sense1[27] == sense2[27]) &&
2512 	      (sense1[25] == sense2[25]))) {
2513 
2514 		return 0;	/* sense doesn't match */
2515 	}
2516 
2517 	return 1;		/* match */
2518 
2519 }				/* end dasd_3990_erp_error_match */
2520 
2521 /*
2522  * DASD_3990_ERP_IN_ERP
2523  *
2524  * DESCRIPTION
2525  *   check if the current error already happened before.
2526  *   quick exit if current cqr is not an ERP (cqr->refers=NULL)
2527  *
2528  * PARAMETER
2529  *   cqr		failed cqr (either original cqr or already an erp)
2530  *
2531  * RETURN VALUES
2532  *   erp		erp-pointer to the already defined error
2533  *			recovery procedure OR
2534  *			NULL if a 'new' error occurred.
2535  */
2536 static struct dasd_ccw_req *
2537 dasd_3990_erp_in_erp(struct dasd_ccw_req *cqr)
2538 {
2539 
2540 	struct dasd_ccw_req *erp_head = cqr,	/* save erp chain head */
2541 	*erp_match = NULL;	/* save erp chain head */
2542 	int match = 0;		/* 'boolean' for matching error found */
2543 
2544 	if (cqr->refers == NULL) {	/* return if not in erp */
2545 		return NULL;
2546 	}
2547 
2548 	/* check the erp/cqr chain for current error */
2549 	do {
2550 		match = dasd_3990_erp_error_match(erp_head, cqr->refers);
2551 		erp_match = cqr;	/* save possible matching erp  */
2552 		cqr = cqr->refers;	/* check next erp/cqr in queue */
2553 
2554 	} while ((cqr->refers != NULL) && (!match));
2555 
2556 	if (!match) {
2557 		return NULL;	/* no match was found */
2558 	}
2559 
2560 	return erp_match;	/* return address of matching erp */
2561 
2562 }				/* END dasd_3990_erp_in_erp */
2563 
2564 /*
2565  * DASD_3990_ERP_FURTHER_ERP (24 & 32 byte sense)
2566  *
2567  * DESCRIPTION
2568  *   No retry is left for the current ERP. Check what has to be done
2569  *   with the ERP.
2570  *     - do further defined ERP action or
2571  *     - wait for interrupt or
2572  *     - exit with permanent error
2573  *
2574  * PARAMETER
2575  *   erp		ERP which is in progress with no retry left
2576  *
2577  * RETURN VALUES
2578  *   erp		modified/additional ERP
2579  */
2580 static struct dasd_ccw_req *
2581 dasd_3990_erp_further_erp(struct dasd_ccw_req *erp)
2582 {
2583 
2584 	struct dasd_device *device = erp->startdev;
2585 	char *sense = dasd_get_sense(&erp->irb);
2586 
2587 	/* check for 24 byte sense ERP */
2588 	if ((erp->function == dasd_3990_erp_bus_out) ||
2589 	    (erp->function == dasd_3990_erp_action_1) ||
2590 	    (erp->function == dasd_3990_erp_action_4)) {
2591 
2592 		erp = dasd_3990_erp_action_1(erp);
2593 
2594 	} else if (erp->function == dasd_3990_erp_action_1_sec) {
2595 		erp = dasd_3990_erp_action_1_sec(erp);
2596 	} else if (erp->function == dasd_3990_erp_action_5) {
2597 
2598 		/* retries have not been successful */
2599 		/* prepare erp for retry on different channel path */
2600 		erp = dasd_3990_erp_action_1(erp);
2601 
2602 		if (sense && !(sense[2] & DASD_SENSE_BIT_0)) {
2603 
2604 			/* issue a Diagnostic Control command with an
2605 			 * Inhibit Write subcommand */
2606 
2607 			switch (sense[25]) {
2608 			case 0x17:
2609 			case 0x57:{	/* controller */
2610 					erp = dasd_3990_erp_DCTL(erp, 0x20);
2611 					break;
2612 				}
2613 			case 0x18:
2614 			case 0x58:{	/* channel path */
2615 					erp = dasd_3990_erp_DCTL(erp, 0x40);
2616 					break;
2617 				}
2618 			case 0x19:
2619 			case 0x59:{	/* storage director */
2620 					erp = dasd_3990_erp_DCTL(erp, 0x80);
2621 					break;
2622 				}
2623 			default:
2624 				DBF_DEV_EVENT(DBF_WARNING, device,
2625 					    "invalid subcommand modifier 0x%x "
2626 					    "for Diagnostic Control Command",
2627 					    sense[25]);
2628 			}
2629 		}
2630 
2631 		/* check for 32 byte sense ERP */
2632 	} else if (sense &&
2633 		   ((erp->function == dasd_3990_erp_compound_retry) ||
2634 		    (erp->function == dasd_3990_erp_compound_path) ||
2635 		    (erp->function == dasd_3990_erp_compound_code) ||
2636 		    (erp->function == dasd_3990_erp_compound_config))) {
2637 
2638 		erp = dasd_3990_erp_compound(erp, sense);
2639 
2640 	} else {
2641 		/*
2642 		 * No retry left and no additional special handling
2643 		 * necessary
2644 		 */
2645 		dev_err(&device->cdev->dev,
2646 			"ERP %p has run out of retries and failed\n", erp);
2647 
2648 		erp->status = DASD_CQR_FAILED;
2649 	}
2650 
2651 	return erp;
2652 
2653 }				/* end dasd_3990_erp_further_erp */
2654 
2655 /*
2656  * DASD_3990_ERP_HANDLE_MATCH_ERP
2657  *
2658  * DESCRIPTION
2659  *   An error occurred again and an ERP has been detected which is already
2660  *   used to handle this error (e.g. retries).
2661  *   All prior ERP's are asumed to be successful and therefore removed
2662  *   from queue.
2663  *   If retry counter of matching erp is already 0, it is checked if further
2664  *   action is needed (besides retry) or if the ERP has failed.
2665  *
2666  * PARAMETER
2667  *   erp_head		first ERP in ERP-chain
2668  *   erp		ERP that handles the actual error.
2669  *			(matching erp)
2670  *
2671  * RETURN VALUES
2672  *   erp		modified/additional ERP
2673  */
2674 static struct dasd_ccw_req *
2675 dasd_3990_erp_handle_match_erp(struct dasd_ccw_req *erp_head,
2676 			       struct dasd_ccw_req *erp)
2677 {
2678 
2679 	struct dasd_device *device = erp_head->startdev;
2680 	struct dasd_ccw_req *erp_done = erp_head;	/* finished req */
2681 	struct dasd_ccw_req *erp_free = NULL;	/* req to be freed */
2682 
2683 	/* loop over successful ERPs and remove them from chanq */
2684 	while (erp_done != erp) {
2685 
2686 		if (erp_done == NULL)	/* end of chain reached */
2687 			panic(PRINTK_HEADER "Programming error in ERP! The "
2688 			      "original request was lost\n");
2689 
2690 		/* remove the request from the device queue */
2691 		list_del(&erp_done->blocklist);
2692 
2693 		erp_free = erp_done;
2694 		erp_done = erp_done->refers;
2695 
2696 		/* free the finished erp request */
2697 		dasd_free_erp_request(erp_free, erp_free->memdev);
2698 
2699 	}			/* end while */
2700 
2701 	if (erp->retries > 0) {
2702 
2703 		char *sense = dasd_get_sense(&erp->refers->irb);
2704 
2705 		/* check for special retries */
2706 		if (sense && erp->function == dasd_3990_erp_action_4) {
2707 
2708 			erp = dasd_3990_erp_action_4(erp, sense);
2709 
2710 		} else if (sense &&
2711 			   erp->function == dasd_3990_erp_action_1B_32) {
2712 
2713 			erp = dasd_3990_update_1B(erp, sense);
2714 
2715 		} else if (sense && erp->function == dasd_3990_erp_int_req) {
2716 
2717 			erp = dasd_3990_erp_int_req(erp);
2718 
2719 		} else {
2720 			/* simple retry	  */
2721 			DBF_DEV_EVENT(DBF_DEBUG, device,
2722 				    "%i retries left for erp %p",
2723 				    erp->retries, erp);
2724 
2725 			/* handle the request again... */
2726 			erp->status = DASD_CQR_FILLED;
2727 		}
2728 
2729 	} else {
2730 		/* no retry left - check for further necessary action	 */
2731 		/* if no further actions, handle rest as permanent error */
2732 		erp = dasd_3990_erp_further_erp(erp);
2733 	}
2734 
2735 	return erp;
2736 
2737 }				/* end dasd_3990_erp_handle_match_erp */
2738 
2739 /*
2740  * DASD_3990_ERP_ACTION
2741  *
2742  * DESCRIPTION
2743  *   control routine for 3990 erp actions.
2744  *   Has to be called with the queue lock (namely the s390_irq_lock) acquired.
2745  *
2746  * PARAMETER
2747  *   cqr		failed cqr (either original cqr or already an erp)
2748  *
2749  * RETURN VALUES
2750  *   erp		erp-pointer to the head of the ERP action chain.
2751  *			This means:
2752  *			 - either a ptr to an additional ERP cqr or
2753  *			 - the original given cqr (which's status might
2754  *			   be modified)
2755  */
2756 struct dasd_ccw_req *
2757 dasd_3990_erp_action(struct dasd_ccw_req * cqr)
2758 {
2759 	struct dasd_ccw_req *erp = NULL;
2760 	struct dasd_device *device = cqr->startdev;
2761 	struct dasd_ccw_req *temp_erp = NULL;
2762 
2763 	if (device->features & DASD_FEATURE_ERPLOG) {
2764 		/* print current erp_chain */
2765 		dev_err(&device->cdev->dev,
2766 			    "ERP chain at BEGINNING of ERP-ACTION\n");
2767 		for (temp_erp = cqr;
2768 		     temp_erp != NULL; temp_erp = temp_erp->refers) {
2769 
2770 			dev_err(&device->cdev->dev,
2771 				    "ERP %p (%02x) refers to %p\n",
2772 				    temp_erp, temp_erp->status,
2773 				    temp_erp->refers);
2774 		}
2775 	}
2776 
2777 	/* double-check if current erp/cqr was successful */
2778 	if ((scsw_cstat(&cqr->irb.scsw) == 0x00) &&
2779 	    (scsw_dstat(&cqr->irb.scsw) ==
2780 	     (DEV_STAT_CHN_END | DEV_STAT_DEV_END))) {
2781 
2782 		DBF_DEV_EVENT(DBF_DEBUG, device,
2783 			    "ERP called for successful request %p"
2784 			    " - NO ERP necessary", cqr);
2785 
2786 		cqr->status = DASD_CQR_DONE;
2787 
2788 		return cqr;
2789 	}
2790 
2791 	/* check if error happened before */
2792 	erp = dasd_3990_erp_in_erp(cqr);
2793 
2794 	if (erp == NULL) {
2795 		/* no matching erp found - set up erp */
2796 		erp = dasd_3990_erp_additional_erp(cqr);
2797 		if (IS_ERR(erp))
2798 			return erp;
2799 	} else {
2800 		/* matching erp found - set all leading erp's to DONE */
2801 		erp = dasd_3990_erp_handle_match_erp(cqr, erp);
2802 	}
2803 
2804 	if (device->features & DASD_FEATURE_ERPLOG) {
2805 		/* print current erp_chain */
2806 		dev_err(&device->cdev->dev,
2807 			    "ERP chain at END of ERP-ACTION\n");
2808 		for (temp_erp = erp;
2809 		     temp_erp != NULL; temp_erp = temp_erp->refers) {
2810 
2811 			dev_err(&device->cdev->dev,
2812 				    "ERP %p (%02x) refers to %p\n",
2813 				    temp_erp, temp_erp->status,
2814 				    temp_erp->refers);
2815 		}
2816 	}
2817 
2818 	/* enqueue ERP request if it's a new one */
2819 	if (list_empty(&erp->blocklist)) {
2820 		cqr->status = DASD_CQR_IN_ERP;
2821 		/* add erp request before the cqr */
2822 		list_add_tail(&erp->blocklist, &cqr->blocklist);
2823 	}
2824 
2825 
2826 
2827 	return erp;
2828 
2829 }				/* end dasd_3990_erp_action */
2830