xref: /openbmc/linux/drivers/s390/cio/device_pgid.c (revision 9ac8d3fb) 
1 /*
2  * drivers/s390/cio/device_pgid.c
3  *
4  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
5  *			 IBM Corporation
6  *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
7  *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
8  *
9  * Path Group ID functions.
10  */
11 
12 #include <linux/module.h>
13 #include <linux/init.h>
14 
15 #include <asm/ccwdev.h>
16 #include <asm/cio.h>
17 #include <asm/delay.h>
18 #include <asm/lowcore.h>
19 
20 #include "cio.h"
21 #include "cio_debug.h"
22 #include "css.h"
23 #include "device.h"
24 #include "ioasm.h"
25 #include "io_sch.h"
26 
27 /*
28  * Helper function called from interrupt context to decide whether an
29  * operation should be tried again.
30  */
31 static int __ccw_device_should_retry(union scsw *scsw)
32 {
33 	/* CC is only valid if start function bit is set. */
34 	if ((scsw->cmd.fctl & SCSW_FCTL_START_FUNC) && scsw->cmd.cc == 1)
35 		return 1;
36 	/* No more activity. For sense and set PGID we stubbornly try again. */
37 	if (!scsw->cmd.actl)
38 		return 1;
39 	return 0;
40 }
41 
42 /*
43  * Start Sense Path Group ID helper function. Used in ccw_device_recog
44  * and ccw_device_sense_pgid.
45  */
46 static int
47 __ccw_device_sense_pgid_start(struct ccw_device *cdev)
48 {
49 	struct subchannel *sch;
50 	struct ccw1 *ccw;
51 	int ret;
52 	int i;
53 
54 	sch = to_subchannel(cdev->dev.parent);
55 	/* Return if we already checked on all paths. */
56 	if (cdev->private->imask == 0)
57 		return (sch->lpm == 0) ? -ENODEV : -EACCES;
58 	i = 8 - ffs(cdev->private->imask);
59 
60 	/* Setup sense path group id channel program. */
61 	ccw = cdev->private->iccws;
62 	ccw->cmd_code = CCW_CMD_SENSE_PGID;
63 	ccw->count = sizeof (struct pgid);
64 	ccw->flags = CCW_FLAG_SLI;
65 
66 	/* Reset device status. */
67 	memset(&cdev->private->irb, 0, sizeof(struct irb));
68 	/* Try on every path. */
69 	ret = -ENODEV;
70 	while (cdev->private->imask != 0) {
71 		/* Try every path multiple times. */
72 		ccw->cda = (__u32) __pa (&cdev->private->pgid[i]);
73 		if (cdev->private->iretry > 0) {
74 			cdev->private->iretry--;
75 			/* Reset internal retry indication. */
76 			cdev->private->flags.intretry = 0;
77 			ret = cio_start (sch, cdev->private->iccws,
78 					 cdev->private->imask);
79 			/* ret is 0, -EBUSY, -EACCES or -ENODEV */
80 			if (ret != -EACCES)
81 				return ret;
82 			CIO_MSG_EVENT(3, "SNID - Device %04x on Subchannel "
83 				      "0.%x.%04x, lpm %02X, became 'not "
84 				      "operational'\n",
85 				      cdev->private->dev_id.devno,
86 				      sch->schid.ssid,
87 				      sch->schid.sch_no, cdev->private->imask);
88 
89 		}
90 		cdev->private->imask >>= 1;
91 		cdev->private->iretry = 5;
92 		i++;
93 	}
94 
95 	return ret;
96 }
97 
98 void
99 ccw_device_sense_pgid_start(struct ccw_device *cdev)
100 {
101 	int ret;
102 
103 	/* Set a timeout of 60s */
104 	ccw_device_set_timeout(cdev, 60*HZ);
105 
106 	cdev->private->state = DEV_STATE_SENSE_PGID;
107 	cdev->private->imask = 0x80;
108 	cdev->private->iretry = 5;
109 	memset (&cdev->private->pgid, 0, sizeof (cdev->private->pgid));
110 	ret = __ccw_device_sense_pgid_start(cdev);
111 	if (ret && ret != -EBUSY)
112 		ccw_device_sense_pgid_done(cdev, ret);
113 }
114 
115 /*
116  * Called from interrupt context to check if a valid answer
117  * to Sense Path Group ID was received.
118  */
119 static int
120 __ccw_device_check_sense_pgid(struct ccw_device *cdev)
121 {
122 	struct subchannel *sch;
123 	struct irb *irb;
124 	int i;
125 
126 	sch = to_subchannel(cdev->dev.parent);
127 	irb = &cdev->private->irb;
128 	if (irb->scsw.cmd.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
129 		/* Retry Sense PGID if requested. */
130 		if (cdev->private->flags.intretry) {
131 			cdev->private->flags.intretry = 0;
132 			return -EAGAIN;
133 		}
134 		return -ETIME;
135 	}
136 	if (irb->esw.esw0.erw.cons &&
137 	    (irb->ecw[0]&(SNS0_CMD_REJECT|SNS0_INTERVENTION_REQ))) {
138 		/*
139 		 * If the device doesn't support the Sense Path Group ID
140 		 *  command further retries wouldn't help ...
141 		 */
142 		return -EOPNOTSUPP;
143 	}
144 	if (irb->esw.esw0.erw.cons) {
145 		CIO_MSG_EVENT(2, "SNID - device 0.%x.%04x, unit check, "
146 			      "lpum %02X, cnt %02d, sns : "
147 			      "%02X%02X%02X%02X %02X%02X%02X%02X ...\n",
148 			      cdev->private->dev_id.ssid,
149 			      cdev->private->dev_id.devno,
150 			      irb->esw.esw0.sublog.lpum,
151 			      irb->esw.esw0.erw.scnt,
152 			      irb->ecw[0], irb->ecw[1],
153 			      irb->ecw[2], irb->ecw[3],
154 			      irb->ecw[4], irb->ecw[5],
155 			      irb->ecw[6], irb->ecw[7]);
156 		return -EAGAIN;
157 	}
158 	if (irb->scsw.cmd.cc == 3) {
159 		u8 lpm;
160 
161 		lpm = to_io_private(sch)->orb.cmd.lpm;
162 		CIO_MSG_EVENT(3, "SNID - Device %04x on Subchannel 0.%x.%04x,"
163 			      " lpm %02X, became 'not operational'\n",
164 			      cdev->private->dev_id.devno, sch->schid.ssid,
165 			      sch->schid.sch_no, lpm);
166 		return -EACCES;
167 	}
168 	i = 8 - ffs(cdev->private->imask);
169 	if (cdev->private->pgid[i].inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
170 		CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
171 			      "is reserved by someone else\n",
172 			      cdev->private->dev_id.devno, sch->schid.ssid,
173 			      sch->schid.sch_no);
174 		return -EUSERS;
175 	}
176 	return 0;
177 }
178 
179 /*
180  * Got interrupt for Sense Path Group ID.
181  */
182 void
183 ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
184 {
185 	struct subchannel *sch;
186 	struct irb *irb;
187 	int ret;
188 
189 	irb = (struct irb *) __LC_IRB;
190 
191 	if (irb->scsw.cmd.stctl ==
192 	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
193 		if (__ccw_device_should_retry(&irb->scsw)) {
194 			ret = __ccw_device_sense_pgid_start(cdev);
195 			if (ret && ret != -EBUSY)
196 				ccw_device_sense_pgid_done(cdev, ret);
197 		}
198 		return;
199 	}
200 	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
201 		return;
202 	sch = to_subchannel(cdev->dev.parent);
203 	ret = __ccw_device_check_sense_pgid(cdev);
204 	memset(&cdev->private->irb, 0, sizeof(struct irb));
205 	switch (ret) {
206 	/* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
207 	case -EOPNOTSUPP:	/* Sense Path Group ID not supported */
208 		ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
209 		break;
210 	case -ETIME:		/* Sense path group id stopped by timeout. */
211 		ccw_device_sense_pgid_done(cdev, -ETIME);
212 		break;
213 	case -EACCES:		/* channel is not operational. */
214 		sch->lpm &= ~cdev->private->imask;
215 		/* Fall through. */
216 	case 0:			/* Sense Path Group ID successful. */
217 		cdev->private->imask >>= 1;
218 		cdev->private->iretry = 5;
219 		/* Fall through. */
220 	case -EAGAIN:		/* Try again. */
221 		ret = __ccw_device_sense_pgid_start(cdev);
222 		if (ret != 0 && ret != -EBUSY)
223 			ccw_device_sense_pgid_done(cdev, ret);
224 		break;
225 	case -EUSERS:		/* device is reserved for someone else. */
226 		ccw_device_sense_pgid_done(cdev, -EUSERS);
227 		break;
228 	}
229 }
230 
231 /*
232  * Path Group ID helper function.
233  */
234 static int
235 __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
236 {
237 	struct subchannel *sch;
238 	struct ccw1 *ccw;
239 	int ret;
240 
241 	sch = to_subchannel(cdev->dev.parent);
242 
243 	/* Setup sense path group id channel program. */
244 	cdev->private->pgid[0].inf.fc = func;
245 	ccw = cdev->private->iccws;
246 	if (cdev->private->flags.pgid_single)
247 		cdev->private->pgid[0].inf.fc |= SPID_FUNC_SINGLE_PATH;
248 	else
249 		cdev->private->pgid[0].inf.fc |= SPID_FUNC_MULTI_PATH;
250 	ccw->cmd_code = CCW_CMD_SET_PGID;
251 	ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
252 	ccw->count = sizeof (struct pgid);
253 	ccw->flags = CCW_FLAG_SLI;
254 
255 	/* Reset device status. */
256 	memset(&cdev->private->irb, 0, sizeof(struct irb));
257 
258 	/* Try multiple times. */
259 	ret = -EACCES;
260 	if (cdev->private->iretry > 0) {
261 		cdev->private->iretry--;
262 		/* Reset internal retry indication. */
263 		cdev->private->flags.intretry = 0;
264 		ret = cio_start (sch, cdev->private->iccws,
265 				 cdev->private->imask);
266 		/* We expect an interrupt in case of success or busy
267 		 * indication. */
268 		if ((ret == 0) || (ret == -EBUSY))
269 			return ret;
270 	}
271 	/* PGID command failed on this path. */
272 	CIO_MSG_EVENT(3, "SPID - Device %04x on Subchannel "
273 		      "0.%x.%04x, lpm %02X, became 'not operational'\n",
274 		      cdev->private->dev_id.devno, sch->schid.ssid,
275 		      sch->schid.sch_no, cdev->private->imask);
276 	return ret;
277 }
278 
279 /*
280  * Helper function to send a nop ccw down a path.
281  */
282 static int __ccw_device_do_nop(struct ccw_device *cdev)
283 {
284 	struct subchannel *sch;
285 	struct ccw1 *ccw;
286 	int ret;
287 
288 	sch = to_subchannel(cdev->dev.parent);
289 
290 	/* Setup nop channel program. */
291 	ccw = cdev->private->iccws;
292 	ccw->cmd_code = CCW_CMD_NOOP;
293 	ccw->cda = 0;
294 	ccw->count = 0;
295 	ccw->flags = CCW_FLAG_SLI;
296 
297 	/* Reset device status. */
298 	memset(&cdev->private->irb, 0, sizeof(struct irb));
299 
300 	/* Try multiple times. */
301 	ret = -EACCES;
302 	if (cdev->private->iretry > 0) {
303 		cdev->private->iretry--;
304 		/* Reset internal retry indication. */
305 		cdev->private->flags.intretry = 0;
306 		ret = cio_start (sch, cdev->private->iccws,
307 				 cdev->private->imask);
308 		/* We expect an interrupt in case of success or busy
309 		 * indication. */
310 		if ((ret == 0) || (ret == -EBUSY))
311 			return ret;
312 	}
313 	/* nop command failed on this path. */
314 	CIO_MSG_EVENT(3, "NOP - Device %04x on Subchannel "
315 		      "0.%x.%04x, lpm %02X, became 'not operational'\n",
316 		      cdev->private->dev_id.devno, sch->schid.ssid,
317 		      sch->schid.sch_no, cdev->private->imask);
318 	return ret;
319 }
320 
321 
322 /*
323  * Called from interrupt context to check if a valid answer
324  * to Set Path Group ID was received.
325  */
326 static int
327 __ccw_device_check_pgid(struct ccw_device *cdev)
328 {
329 	struct subchannel *sch;
330 	struct irb *irb;
331 
332 	sch = to_subchannel(cdev->dev.parent);
333 	irb = &cdev->private->irb;
334 	if (irb->scsw.cmd.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
335 		/* Retry Set PGID if requested. */
336 		if (cdev->private->flags.intretry) {
337 			cdev->private->flags.intretry = 0;
338 			return -EAGAIN;
339 		}
340 		return -ETIME;
341 	}
342 	if (irb->esw.esw0.erw.cons) {
343 		if (irb->ecw[0] & SNS0_CMD_REJECT)
344 			return -EOPNOTSUPP;
345 		/* Hmm, whatever happened, try again. */
346 		CIO_MSG_EVENT(2, "SPID - device 0.%x.%04x, unit check, "
347 			      "cnt %02d, "
348 			      "sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
349 			      cdev->private->dev_id.ssid,
350 			      cdev->private->dev_id.devno,
351 			      irb->esw.esw0.erw.scnt,
352 			      irb->ecw[0], irb->ecw[1],
353 			      irb->ecw[2], irb->ecw[3],
354 			      irb->ecw[4], irb->ecw[5],
355 			      irb->ecw[6], irb->ecw[7]);
356 		return -EAGAIN;
357 	}
358 	if (irb->scsw.cmd.cc == 3) {
359 		CIO_MSG_EVENT(3, "SPID - Device %04x on Subchannel 0.%x.%04x,"
360 			      " lpm %02X, became 'not operational'\n",
361 			      cdev->private->dev_id.devno, sch->schid.ssid,
362 			      sch->schid.sch_no, cdev->private->imask);
363 		return -EACCES;
364 	}
365 	return 0;
366 }
367 
368 /*
369  * Called from interrupt context to check the path status after a nop has
370  * been send.
371  */
372 static int __ccw_device_check_nop(struct ccw_device *cdev)
373 {
374 	struct subchannel *sch;
375 	struct irb *irb;
376 
377 	sch = to_subchannel(cdev->dev.parent);
378 	irb = &cdev->private->irb;
379 	if (irb->scsw.cmd.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
380 		/* Retry NOP if requested. */
381 		if (cdev->private->flags.intretry) {
382 			cdev->private->flags.intretry = 0;
383 			return -EAGAIN;
384 		}
385 		return -ETIME;
386 	}
387 	if (irb->scsw.cmd.cc == 3) {
388 		CIO_MSG_EVENT(3, "NOP - Device %04x on Subchannel 0.%x.%04x,"
389 			      " lpm %02X, became 'not operational'\n",
390 			      cdev->private->dev_id.devno, sch->schid.ssid,
391 			      sch->schid.sch_no, cdev->private->imask);
392 		return -EACCES;
393 	}
394 	return 0;
395 }
396 
397 static void
398 __ccw_device_verify_start(struct ccw_device *cdev)
399 {
400 	struct subchannel *sch;
401 	__u8 func;
402 	int ret;
403 
404 	sch = to_subchannel(cdev->dev.parent);
405 	/* Repeat for all paths. */
406 	for (; cdev->private->imask; cdev->private->imask >>= 1,
407 				     cdev->private->iretry = 5) {
408 		if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)
409 			/* Path not available, try next. */
410 			continue;
411 		if (cdev->private->options.pgroup) {
412 			if (sch->opm & cdev->private->imask)
413 				func = SPID_FUNC_ESTABLISH;
414 			else
415 				func = SPID_FUNC_RESIGN;
416 			ret = __ccw_device_do_pgid(cdev, func);
417 		} else
418 			ret = __ccw_device_do_nop(cdev);
419 		/* We expect an interrupt in case of success or busy
420 		 * indication. */
421 		if (ret == 0 || ret == -EBUSY)
422 			return;
423 		/* Permanent path failure, try next. */
424 	}
425 	/* Done with all paths. */
426 	ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);
427 }
428 
429 /*
430  * Got interrupt for Set Path Group ID.
431  */
432 void
433 ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
434 {
435 	struct subchannel *sch;
436 	struct irb *irb;
437 	int ret;
438 
439 	irb = (struct irb *) __LC_IRB;
440 
441 	if (irb->scsw.cmd.stctl ==
442 	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
443 		if (__ccw_device_should_retry(&irb->scsw))
444 			__ccw_device_verify_start(cdev);
445 		return;
446 	}
447 	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
448 		return;
449 	sch = to_subchannel(cdev->dev.parent);
450 	if (cdev->private->options.pgroup)
451 		ret = __ccw_device_check_pgid(cdev);
452 	else
453 		ret = __ccw_device_check_nop(cdev);
454 	memset(&cdev->private->irb, 0, sizeof(struct irb));
455 
456 	switch (ret) {
457 	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
458 	case 0:
459 		/* Path verification ccw finished successfully, update lpm. */
460 		sch->vpm |= sch->opm & cdev->private->imask;
461 		/* Go on with next path. */
462 		cdev->private->imask >>= 1;
463 		cdev->private->iretry = 5;
464 		__ccw_device_verify_start(cdev);
465 		break;
466 	case -EOPNOTSUPP:
467 		/*
468 		 * One of those strange devices which claim to be able
469 		 * to do multipathing but not for Set Path Group ID.
470 		 */
471 		if (cdev->private->flags.pgid_single)
472 			cdev->private->options.pgroup = 0;
473 		else
474 			cdev->private->flags.pgid_single = 1;
475 		/* Retry */
476 		sch->vpm = 0;
477 		cdev->private->imask = 0x80;
478 		cdev->private->iretry = 5;
479 		/* fall through. */
480 	case -EAGAIN:		/* Try again. */
481 		__ccw_device_verify_start(cdev);
482 		break;
483 	case -ETIME:		/* Set path group id stopped by timeout. */
484 		ccw_device_verify_done(cdev, -ETIME);
485 		break;
486 	case -EACCES:		/* channel is not operational. */
487 		cdev->private->imask >>= 1;
488 		cdev->private->iretry = 5;
489 		__ccw_device_verify_start(cdev);
490 		break;
491 	}
492 }
493 
494 void
495 ccw_device_verify_start(struct ccw_device *cdev)
496 {
497 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
498 
499 	cdev->private->flags.pgid_single = 0;
500 	cdev->private->imask = 0x80;
501 	cdev->private->iretry = 5;
502 
503 	/* Start with empty vpm. */
504 	sch->vpm = 0;
505 
506 	/* Get current pam. */
507 	if (stsch(sch->schid, &sch->schib)) {
508 		ccw_device_verify_done(cdev, -ENODEV);
509 		return;
510 	}
511 	/* After 60s path verification is considered to have failed. */
512 	ccw_device_set_timeout(cdev, 60*HZ);
513 	__ccw_device_verify_start(cdev);
514 }
515 
516 static void
517 __ccw_device_disband_start(struct ccw_device *cdev)
518 {
519 	struct subchannel *sch;
520 	int ret;
521 
522 	sch = to_subchannel(cdev->dev.parent);
523 	while (cdev->private->imask != 0) {
524 		if (sch->lpm & cdev->private->imask) {
525 			ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
526 			if (ret == 0)
527 				return;
528 		}
529 		cdev->private->iretry = 5;
530 		cdev->private->imask >>= 1;
531 	}
532 	ccw_device_disband_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
533 }
534 
535 /*
536  * Got interrupt for Unset Path Group ID.
537  */
538 void
539 ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
540 {
541 	struct subchannel *sch;
542 	struct irb *irb;
543 	int ret;
544 
545 	irb = (struct irb *) __LC_IRB;
546 
547 	if (irb->scsw.cmd.stctl ==
548 	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
549 		if (__ccw_device_should_retry(&irb->scsw))
550 			__ccw_device_disband_start(cdev);
551 		return;
552 	}
553 	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
554 		return;
555 	sch = to_subchannel(cdev->dev.parent);
556 	ret = __ccw_device_check_pgid(cdev);
557 	memset(&cdev->private->irb, 0, sizeof(struct irb));
558 	switch (ret) {
559 	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
560 	case 0:			/* disband successful. */
561 		ccw_device_disband_done(cdev, ret);
562 		break;
563 	case -EOPNOTSUPP:
564 		/*
565 		 * One of those strange devices which claim to be able
566 		 * to do multipathing but not for Unset Path Group ID.
567 		 */
568 		cdev->private->flags.pgid_single = 1;
569 		/* fall through. */
570 	case -EAGAIN:		/* Try again. */
571 		__ccw_device_disband_start(cdev);
572 		break;
573 	case -ETIME:		/* Set path group id stopped by timeout. */
574 		ccw_device_disband_done(cdev, -ETIME);
575 		break;
576 	case -EACCES:		/* channel is not operational. */
577 		cdev->private->imask >>= 1;
578 		cdev->private->iretry = 5;
579 		__ccw_device_disband_start(cdev);
580 		break;
581 	}
582 }
583 
584 void
585 ccw_device_disband_start(struct ccw_device *cdev)
586 {
587 	/* After 60s disbanding is considered to have failed. */
588 	ccw_device_set_timeout(cdev, 60*HZ);
589 
590 	cdev->private->flags.pgid_single = 0;
591 	cdev->private->iretry = 5;
592 	cdev->private->imask = 0x80;
593 	__ccw_device_disband_start(cdev);
594 }
595