summaryrefslogtreecommitdiffstats
path: root/drivers/s390/cio/device_pgid.c
blob: c52449a1f9fce93f2af14456c88cb7dc7e390d96 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
/*
 * drivers/s390/cio/device_pgid.c
 *
 *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
 *			 IBM Corporation
 *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
 *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
 *
 * Path Group ID functions.
 */

#include <linux/module.h>
#include <linux/init.h>

#include <asm/ccwdev.h>
#include <asm/cio.h>
#include <asm/delay.h>
#include <asm/lowcore.h>

#include "cio.h"
#include "cio_debug.h"
#include "css.h"
#include "device.h"
#include "ioasm.h"
#include "io_sch.h"

/*
 * Helper function called from interrupt context to decide whether an
 * operation should be tried again.
 */
static int __ccw_device_should_retry(struct scsw *scsw)
{
	/* CC is only valid if start function bit is set. */
	if ((scsw->fctl & SCSW_FCTL_START_FUNC) && scsw->cc == 1)
		return 1;
	/* No more activity. For sense and set PGID we stubbornly try again. */
	if (!scsw->actl)
		return 1;
	return 0;
}

/*
 * Start Sense Path Group ID helper function. Used in ccw_device_recog
 * and ccw_device_sense_pgid.
 */
static int
__ccw_device_sense_pgid_start(struct ccw_device *cdev)
{
	struct subchannel *sch;
	struct ccw1 *ccw;
	int ret;
	int i;

	sch = to_subchannel(cdev->dev.parent);
	/* Return if we already checked on all paths. */
	if (cdev->private->imask == 0)
		return (sch->lpm == 0) ? -ENODEV : -EACCES;
	i = 8 - ffs(cdev->private->imask);

	/* Setup sense path group id channel program. */
	ccw = cdev->private->iccws;
	ccw->cmd_code = CCW_CMD_SENSE_PGID;
	ccw->count = sizeof (struct pgid);
	ccw->flags = CCW_FLAG_SLI;

	/* Reset device status. */
	memset(&cdev->private->irb, 0, sizeof(struct irb));
	/* Try on every path. */
	ret = -ENODEV;
	while (cdev->private->imask != 0) {
		/* Try every path multiple times. */
		ccw->cda = (__u32) __pa (&cdev->private->pgid[i]);
		if (cdev->private->iretry > 0) {
			cdev->private->iretry--;
			/* Reset internal retry indication. */
			cdev->private->flags.intretry = 0;
			ret = cio_start (sch, cdev->private->iccws, 
					 cdev->private->imask);
			/* ret is 0, -EBUSY, -EACCES or -ENODEV */
			if (ret != -EACCES)
				return ret;
			CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel "
				      "0.%x.%04x, lpm %02X, became 'not "
				      "operational'\n",
				      cdev->private->dev_id.devno,
				      sch->schid.ssid,
				      sch->schid.sch_no, cdev->private->imask);

		}
		cdev->private->imask >>= 1;
		cdev->private->iretry = 5;
		i++;
	}

	return ret;
}

void
ccw_device_sense_pgid_start(struct ccw_device *cdev)
{
	int ret;

	/* Set a timeout of 60s */
	ccw_device_set_timeout(cdev, 60*HZ);

	cdev->private->state = DEV_STATE_SENSE_PGID;
	cdev->private->imask = 0x80;
	cdev->private->iretry = 5;
	memset (&cdev->private->pgid, 0, sizeof (cdev->private->pgid));
	ret = __ccw_device_sense_pgid_start(cdev);
	if (ret && ret != -EBUSY)
		ccw_device_sense_pgid_done(cdev, ret);
}

/*
 * Called from interrupt context to check if a valid answer
 * to Sense Path Group ID was received.
 */
static int
__ccw_device_check_sense_pgid(struct ccw_device *cdev)
{
	struct subchannel *sch;
	struct irb *irb;
	int i;

	sch = to_subchannel(cdev->dev.parent);
	irb = &cdev->private->irb;
	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
		/* Retry Sense PGID if requested. */
		if (cdev->private->flags.intretry) {
			cdev->private->flags.intretry = 0;
			return -EAGAIN;
		}
		return -ETIME;
	}
	if (irb->esw.esw0.erw.cons &&
	    (irb->ecw[0]&(SNS0_CMD_REJECT|SNS0_INTERVENTION_REQ))) {
		/*
		 * If the device doesn't support the Sense Path Group ID
		 *  command further retries wouldn't help ...
		 */
		return -EOPNOTSUPP;
	}
	if (irb->esw.esw0.erw.cons) {
		CIO_MSG_EVENT(2, "SNID - device 0.%x.%04x, unit check, "
			      "lpum %02X, cnt %02d, sns : "
			      "%02X%02X%02X%02X %02X%02X%02X%02X ...\n",
			      cdev->private->dev_id.ssid,
			      cdev->private->dev_id.devno,
			      irb->esw.esw0.sublog.lpum,
			      irb->esw.esw0.erw.scnt,
			      irb->ecw[0], irb->ecw[1],
			      irb->ecw[2], irb->ecw[3],
			      irb->ecw[4], irb->ecw[5],
			      irb->ecw[6], irb->ecw[7]);
		return -EAGAIN;
	}
	if (irb->scsw.cc == 3) {
		u8 lpm;

		lpm = to_io_private(sch)->orb.lpm;
		CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x,"
			      " lpm %02X, became 'not operational'\n",
			      cdev->private->dev_id.devno, sch->schid.ssid,
			      sch->schid.sch_no, lpm);
		return -EACCES;
	}
	i = 8 - ffs(cdev->private->imask);
	if (cdev->private->pgid[i].inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
		CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
			      "is reserved by someone else\n",
			      cdev->private->dev_id.devno, sch->schid.ssid,
			      sch->schid.sch_no);
		return -EUSERS;
	}
	return 0;
}

/*
 * Got interrupt for Sense Path Group ID.
 */
void
ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct subchannel *sch;
	struct irb *irb;
	int ret;

	irb = (struct irb *) __LC_IRB;

	if (irb->scsw.stctl ==
	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
		if (__ccw_device_should_retry(&irb->scsw)) {
			ret = __ccw_device_sense_pgid_start(cdev);
			if (ret && ret != -EBUSY)
				ccw_device_sense_pgid_done(cdev, ret);
		}
		return;
	}
	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
		return;
	sch = to_subchannel(cdev->dev.parent);
	ret = __ccw_device_check_sense_pgid(cdev);
	memset(&cdev->private->irb, 0, sizeof(struct irb));
	switch (ret) {
	/* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
	case -EOPNOTSUPP:	/* Sense Path Group ID not supported */
		ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
		break;
	case -ETIME:		/* Sense path group id stopped by timeout. */
		ccw_device_sense_pgid_done(cdev, -ETIME);
		break;
	case -EACCES:		/* channel is not operational. */
		sch->lpm &= ~cdev->private->imask;
		/* Fall through. */
	case 0:			/* Sense Path Group ID successful. */
		cdev->private->imask >>= 1;
		cdev->private->iretry = 5;
		/* Fall through. */
	case -EAGAIN:		/* Try again. */
		ret = __ccw_device_sense_pgid_start(cdev);
		if (ret != 0 && ret != -EBUSY)
			ccw_device_sense_pgid_done(cdev, ret);
		break;
	case -EUSERS:		/* device is reserved for someone else. */
		ccw_device_sense_pgid_done(cdev, -EUSERS);
		break;
	}
}

/*
 * Path Group ID helper function.
 */
static int
__ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
{
	struct subchannel *sch;
	struct ccw1 *ccw;
	int ret;

	sch = to_subchannel(cdev->dev.parent);

	/* Setup sense path group id channel program. */
	cdev->private->pgid[0].inf.fc = func;
	ccw = cdev->private->iccws;
	if (!cdev->private->flags.pgid_single) {
		cdev->private->pgid[0].inf.fc |= SPID_FUNC_MULTI_PATH;
		ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
		ccw->cda = 0;
		ccw->count = 0;
		ccw->flags = CCW_FLAG_SLI | CCW_FLAG_CC;
		ccw++;
	} else
		cdev->private->pgid[0].inf.fc |= SPID_FUNC_SINGLE_PATH;

	ccw->cmd_code = CCW_CMD_SET_PGID;
	ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
	ccw->count = sizeof (struct pgid);
	ccw->flags = CCW_FLAG_SLI;

	/* Reset device status. */
	memset(&cdev->private->irb, 0, sizeof(struct irb));

	/* Try multiple times. */
	ret = -EACCES;
	if (cdev->private->iretry > 0) {
		cdev->private->iretry--;
		/* Reset internal retry indication. */
		cdev->private->flags.intretry = 0;
		ret = cio_start (sch, cdev->private->iccws,
				 cdev->private->imask);
		/* We expect an interrupt in case of success or busy
		 * indication. */
		if ((ret == 0) || (ret == -EBUSY))
			return ret;
	}
	/* PGID command failed on this path. */
	CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
		      "0.%x.%04x, lpm %02X, became 'not operational'\n",
		      cdev->private->dev_id.devno, sch->schid.ssid,
		      sch->schid.sch_no, cdev->private->imask);
	return ret;
}

/*
 * Helper function to send a nop ccw down a path.
 */
static int __ccw_device_do_nop(struct ccw_device *cdev)
{
	struct subchannel *sch;
	struct ccw1 *ccw;
	int ret;

	sch = to_subchannel(cdev->dev.parent);

	/* Setup nop channel program. */
	ccw = cdev->private->iccws;
	ccw->cmd_code = CCW_CMD_NOOP;
	ccw->cda = 0;
	ccw->count = 0;
	ccw->flags = CCW_FLAG_SLI;

	/* Reset device status. */
	memset(&cdev->private->irb, 0, sizeof(struct irb));

	/* Try multiple times. */
	ret = -EACCES;
	if (cdev->private->iretry > 0) {
		cdev->private->iretry--;
		/* Reset internal retry indication. */
		cdev->private->flags.intretry = 0;
		ret = cio_start (sch, cdev->private->iccws,
				 cdev->private->imask);
		/* We expect an interrupt in case of success or busy
		 * indication. */
		if ((ret == 0) || (ret == -EBUSY))
			return ret;
	}
	/* nop command failed on this path. */
	CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel "
		      "0.%x.%04x, lpm %02X, became 'not operational'\n",
		      cdev->private->dev_id.devno, sch->schid.ssid,
		      sch->schid.sch_no, cdev->private->imask);
	return ret;
}


/*
 * Called from interrupt context to check if a valid answer
 * to Set Path Group ID was received.
 */
static int
__ccw_device_check_pgid(struct ccw_device *cdev)
{
	struct subchannel *sch;
	struct irb *irb;

	sch = to_subchannel(cdev->dev.parent);
	irb = &cdev->private->irb;
	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
		/* Retry Set PGID if requested. */
		if (cdev->private->flags.intretry) {
			cdev->private->flags.intretry = 0;
			return -EAGAIN;
		}
		return -ETIME;
	}
	if (irb->esw.esw0.erw.cons) {
		if (irb->ecw[0] & SNS0_CMD_REJECT)
			return -EOPNOTSUPP;
		/* Hmm, whatever happened, try again. */
		CIO_MSG_EVENT(2, "SPID - device 0.%x.%04x, unit check, "
			      "cnt %02d, "
			      "sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
			      cdev->private->dev_id.ssid,
			      cdev->private->dev_id.devno,
			      irb->esw.esw0.erw.scnt,
			      irb->ecw[0], irb->ecw[1],
			      irb->ecw[2], irb->ecw[3],
			      irb->ecw[4], irb->ecw[5],
			      irb->ecw[6], irb->ecw[7]);
		return -EAGAIN;
	}
	if (irb->scsw.cc == 3) {
		CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel 0.%x.%04x,"
			      " lpm %02X, became 'not operational'\n",
			      cdev->private->dev_id.devno, sch->schid.ssid,
			      sch->schid.sch_no, cdev->private->imask);
		return -EACCES;
	}
	return 0;
}

/*
 * Called from interrupt context to check the path status after a nop has
 * been send.
 */
static int __ccw_device_check_nop(struct ccw_device *cdev)
{
	struct subchannel *sch;
	struct irb *irb;

	sch = to_subchannel(cdev->dev.parent);
	irb = &cdev->private->irb;
	if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
		/* Retry NOP if requested. */
		if (cdev->private->flags.intretry) {
			cdev->private->flags.intretry = 0;
			return -EAGAIN;
		}
		return -ETIME;
	}
	if (irb->scsw.cc == 3) {
		CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel 0.%x.%04x,"
			      " lpm %02X, became 'not operational'\n",
			      cdev->private->dev_id.devno, sch->schid.ssid,
			      sch->schid.sch_no, cdev->private->imask);
		return -EACCES;
	}
	return 0;
}

static void
__ccw_device_verify_start(struct ccw_device *cdev)
{
	struct subchannel *sch;
	__u8 func;
	int ret;

	sch = to_subchannel(cdev->dev.parent);
	/* Repeat for all paths. */
	for (; cdev->private->imask; cdev->private->imask >>= 1,
				     cdev->private->iretry = 5) {
		if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)
			/* Path not available, try next. */
			continue;
		if (cdev->private->options.pgroup) {
			if (sch->opm & cdev->private->imask)
				func = SPID_FUNC_ESTABLISH;
			else
				func = SPID_FUNC_RESIGN;
			ret = __ccw_device_do_pgid(cdev, func);
		} else
			ret = __ccw_device_do_nop(cdev);
		/* We expect an interrupt in case of success or busy
		 * indication. */
		if (ret == 0 || ret == -EBUSY)
			return;
		/* Permanent path failure, try next. */
	}
	/* Done with all paths. */
	ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);
}
		
/*
 * Got interrupt for Set Path Group ID.
 */
void
ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct subchannel *sch;
	struct irb *irb;
	int ret;

	irb = (struct irb *) __LC_IRB;

	if (irb->scsw.stctl ==
	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
		if (__ccw_device_should_retry(&irb->scsw))
			__ccw_device_verify_start(cdev);
		return;
	}
	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
		return;
	sch = to_subchannel(cdev->dev.parent);
	if (cdev->private->options.pgroup)
		ret = __ccw_device_check_pgid(cdev);
	else
		ret = __ccw_device_check_nop(cdev);
	memset(&cdev->private->irb, 0, sizeof(struct irb));

	switch (ret) {
	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
	case 0:
		/* Path verification ccw finished successfully, update lpm. */
		sch->vpm |= sch->opm & cdev->private->imask;
		/* Go on with next path. */
		cdev->private->imask >>= 1;
		cdev->private->iretry = 5;
		__ccw_device_verify_start(cdev);
		break;
	case -EOPNOTSUPP:
		/*
		 * One of those strange devices which claim to be able
		 * to do multipathing but not for Set Path Group ID.
		 */
		if (cdev->private->flags.pgid_single)
			cdev->private->options.pgroup = 0;
		else
			cdev->private->flags.pgid_single = 1;
		/* Retry */
		sch->vpm = 0;
		cdev->private->imask = 0x80;
		cdev->private->iretry = 5;
		/* fall through. */
	case -EAGAIN:		/* Try again. */
		__ccw_device_verify_start(cdev);
		break;
	case -ETIME:		/* Set path group id stopped by timeout. */
		ccw_device_verify_done(cdev, -ETIME);
		break;
	case -EACCES:		/* channel is not operational. */
		cdev->private->imask >>= 1;
		cdev->private->iretry = 5;
		__ccw_device_verify_start(cdev);
		break;
	}
}

void
ccw_device_verify_start(struct ccw_device *cdev)
{
	struct subchannel *sch = to_subchannel(cdev->dev.parent);

	cdev->private->flags.pgid_single = 0;
	cdev->private->imask = 0x80;
	cdev->private->iretry = 5;

	/* Start with empty vpm. */
	sch->vpm = 0;

	/* Get current pam. */
	if (stsch(sch->schid, &sch->schib)) {
		ccw_device_verify_done(cdev, -ENODEV);
		return;
	}
	/* After 60s path verification is considered to have failed. */
	ccw_device_set_timeout(cdev, 60*HZ);
	__ccw_device_verify_start(cdev);
}

static void
__ccw_device_disband_start(struct ccw_device *cdev)
{
	struct subchannel *sch;
	int ret;

	sch = to_subchannel(cdev->dev.parent);
	while (cdev->private->imask != 0) {
		if (sch->lpm & cdev->private->imask) {
			ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
			if (ret == 0)
				return;
		}
		cdev->private->iretry = 5;
		cdev->private->imask >>= 1;
	}
	ccw_device_disband_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
}

/*
 * Got interrupt for Unset Path Group ID.
 */
void
ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
{
	struct subchannel *sch;
	struct irb *irb;
	int ret;

	irb = (struct irb *) __LC_IRB;

	if (irb->scsw.stctl ==
	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
		if (__ccw_device_should_retry(&irb->scsw))
			__ccw_device_disband_start(cdev);
		return;
	}
	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
		return;
	sch = to_subchannel(cdev->dev.parent);
	ret = __ccw_device_check_pgid(cdev);
	memset(&cdev->private->irb, 0, sizeof(struct irb));
	switch (ret) {
	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
	case 0:			/* disband successful. */
		ccw_device_disband_done(cdev, ret);
		break;
	case -EOPNOTSUPP:
		/*
		 * One of those strange devices which claim to be able
		 * to do multipathing but not for Unset Path Group ID.
		 */
		cdev->private->flags.pgid_single = 1;
		/* fall through. */
	case -EAGAIN:		/* Try again. */
		__ccw_device_disband_start(cdev);
		break;
	case -ETIME:		/* Set path group id stopped by timeout. */
		ccw_device_disband_done(cdev, -ETIME);
		break;
	case -EACCES:		/* channel is not operational. */
		cdev->private->imask >>= 1;
		cdev->private->iretry = 5;
		__ccw_device_disband_start(cdev);
		break;
	}
}

void
ccw_device_disband_start(struct ccw_device *cdev)
{
	/* After 60s disbanding is considered to have failed. */
	ccw_device_set_timeout(cdev, 60*HZ);

	cdev->private->flags.pgid_single = 0;
	cdev->private->iretry = 5;
	cdev->private->imask = 0x80;
	__ccw_device_disband_start(cdev);
}
OpenPOWER on IntegriCloud