xref: /openbmc/linux/drivers/s390/cio/device_fsm.c (revision 7aacf86b)
1 /*
2  * finite state machine for device handling
3  *
4  *    Copyright IBM Corp. 2002, 2008
5  *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
6  *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
7  */
8 
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/jiffies.h>
12 #include <linux/string.h>
13 
14 #include <asm/ccwdev.h>
15 #include <asm/cio.h>
16 #include <asm/chpid.h>
17 
18 #include "cio.h"
19 #include "cio_debug.h"
20 #include "css.h"
21 #include "device.h"
22 #include "chsc.h"
23 #include "ioasm.h"
24 #include "chp.h"
25 
26 static int timeout_log_enabled;
27 
28 static int __init ccw_timeout_log_setup(char *unused)
29 {
30 	timeout_log_enabled = 1;
31 	return 1;
32 }
33 
34 __setup("ccw_timeout_log", ccw_timeout_log_setup);
35 
36 static void ccw_timeout_log(struct ccw_device *cdev)
37 {
38 	struct schib schib;
39 	struct subchannel *sch;
40 	struct io_subchannel_private *private;
41 	union orb *orb;
42 	int cc;
43 
44 	sch = to_subchannel(cdev->dev.parent);
45 	private = to_io_private(sch);
46 	orb = &private->orb;
47 	cc = stsch(sch->schid, &schib);
48 
49 	printk(KERN_WARNING "cio: ccw device timeout occurred at %llx, "
50 	       "device information:\n", get_tod_clock());
51 	printk(KERN_WARNING "cio: orb:\n");
52 	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
53 		       orb, sizeof(*orb), 0);
54 	printk(KERN_WARNING "cio: ccw device bus id: %s\n",
55 	       dev_name(&cdev->dev));
56 	printk(KERN_WARNING "cio: subchannel bus id: %s\n",
57 	       dev_name(&sch->dev));
58 	printk(KERN_WARNING "cio: subchannel lpm: %02x, opm: %02x, "
59 	       "vpm: %02x\n", sch->lpm, sch->opm, sch->vpm);
60 
61 	if (orb->tm.b) {
62 		printk(KERN_WARNING "cio: orb indicates transport mode\n");
63 		printk(KERN_WARNING "cio: last tcw:\n");
64 		print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
65 			       (void *)(addr_t)orb->tm.tcw,
66 			       sizeof(struct tcw), 0);
67 	} else {
68 		printk(KERN_WARNING "cio: orb indicates command mode\n");
69 		if ((void *)(addr_t)orb->cmd.cpa == &private->sense_ccw ||
70 		    (void *)(addr_t)orb->cmd.cpa == cdev->private->iccws)
71 			printk(KERN_WARNING "cio: last channel program "
72 			       "(intern):\n");
73 		else
74 			printk(KERN_WARNING "cio: last channel program:\n");
75 
76 		print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
77 			       (void *)(addr_t)orb->cmd.cpa,
78 			       sizeof(struct ccw1), 0);
79 	}
80 	printk(KERN_WARNING "cio: ccw device state: %d\n",
81 	       cdev->private->state);
82 	printk(KERN_WARNING "cio: store subchannel returned: cc=%d\n", cc);
83 	printk(KERN_WARNING "cio: schib:\n");
84 	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
85 		       &schib, sizeof(schib), 0);
86 	printk(KERN_WARNING "cio: ccw device flags:\n");
87 	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
88 		       &cdev->private->flags, sizeof(cdev->private->flags), 0);
89 }
90 
91 /*
92  * Timeout function. It just triggers a DEV_EVENT_TIMEOUT.
93  */
94 static void
95 ccw_device_timeout(unsigned long data)
96 {
97 	struct ccw_device *cdev;
98 
99 	cdev = (struct ccw_device *) data;
100 	spin_lock_irq(cdev->ccwlock);
101 	if (timeout_log_enabled)
102 		ccw_timeout_log(cdev);
103 	dev_fsm_event(cdev, DEV_EVENT_TIMEOUT);
104 	spin_unlock_irq(cdev->ccwlock);
105 }
106 
107 /*
108  * Set timeout
109  */
110 void
111 ccw_device_set_timeout(struct ccw_device *cdev, int expires)
112 {
113 	if (expires == 0) {
114 		del_timer(&cdev->private->timer);
115 		return;
116 	}
117 	if (timer_pending(&cdev->private->timer)) {
118 		if (mod_timer(&cdev->private->timer, jiffies + expires))
119 			return;
120 	}
121 	cdev->private->timer.function = ccw_device_timeout;
122 	cdev->private->timer.data = (unsigned long) cdev;
123 	cdev->private->timer.expires = jiffies + expires;
124 	add_timer(&cdev->private->timer);
125 }
126 
127 int
128 ccw_device_cancel_halt_clear(struct ccw_device *cdev)
129 {
130 	struct subchannel *sch;
131 	int ret;
132 
133 	sch = to_subchannel(cdev->dev.parent);
134 	ret = cio_cancel_halt_clear(sch, &cdev->private->iretry);
135 
136 	if (ret == -EIO)
137 		CIO_MSG_EVENT(0, "0.%x.%04x: could not stop I/O\n",
138 			      cdev->private->dev_id.ssid,
139 			      cdev->private->dev_id.devno);
140 
141 	return ret;
142 }
143 
144 void ccw_device_update_sense_data(struct ccw_device *cdev)
145 {
146 	memset(&cdev->id, 0, sizeof(cdev->id));
147 	cdev->id.cu_type   = cdev->private->senseid.cu_type;
148 	cdev->id.cu_model  = cdev->private->senseid.cu_model;
149 	cdev->id.dev_type  = cdev->private->senseid.dev_type;
150 	cdev->id.dev_model = cdev->private->senseid.dev_model;
151 }
152 
153 int ccw_device_test_sense_data(struct ccw_device *cdev)
154 {
155 	return cdev->id.cu_type == cdev->private->senseid.cu_type &&
156 		cdev->id.cu_model == cdev->private->senseid.cu_model &&
157 		cdev->id.dev_type == cdev->private->senseid.dev_type &&
158 		cdev->id.dev_model == cdev->private->senseid.dev_model;
159 }
160 
161 /*
162  * The machine won't give us any notification by machine check if a chpid has
163  * been varied online on the SE so we have to find out by magic (i. e. driving
164  * the channel subsystem to device selection and updating our path masks).
165  */
166 static void
167 __recover_lost_chpids(struct subchannel *sch, int old_lpm)
168 {
169 	int mask, i;
170 	struct chp_id chpid;
171 
172 	chp_id_init(&chpid);
173 	for (i = 0; i<8; i++) {
174 		mask = 0x80 >> i;
175 		if (!(sch->lpm & mask))
176 			continue;
177 		if (old_lpm & mask)
178 			continue;
179 		chpid.id = sch->schib.pmcw.chpid[i];
180 		if (!chp_is_registered(chpid))
181 			css_schedule_eval_all();
182 	}
183 }
184 
185 /*
186  * Stop device recognition.
187  */
188 static void
189 ccw_device_recog_done(struct ccw_device *cdev, int state)
190 {
191 	struct subchannel *sch;
192 	int old_lpm;
193 
194 	sch = to_subchannel(cdev->dev.parent);
195 
196 	if (cio_disable_subchannel(sch))
197 		state = DEV_STATE_NOT_OPER;
198 	/*
199 	 * Now that we tried recognition, we have performed device selection
200 	 * through ssch() and the path information is up to date.
201 	 */
202 	old_lpm = sch->lpm;
203 
204 	/* Check since device may again have become not operational. */
205 	if (cio_update_schib(sch))
206 		state = DEV_STATE_NOT_OPER;
207 	else
208 		sch->lpm = sch->schib.pmcw.pam & sch->opm;
209 
210 	if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID)
211 		/* Force reprobe on all chpids. */
212 		old_lpm = 0;
213 	if (sch->lpm != old_lpm)
214 		__recover_lost_chpids(sch, old_lpm);
215 	if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID &&
216 	    (state == DEV_STATE_NOT_OPER || state == DEV_STATE_BOXED)) {
217 		cdev->private->flags.recog_done = 1;
218 		cdev->private->state = DEV_STATE_DISCONNECTED;
219 		wake_up(&cdev->private->wait_q);
220 		return;
221 	}
222 	if (cdev->private->flags.resuming) {
223 		cdev->private->state = state;
224 		cdev->private->flags.recog_done = 1;
225 		wake_up(&cdev->private->wait_q);
226 		return;
227 	}
228 	switch (state) {
229 	case DEV_STATE_NOT_OPER:
230 		break;
231 	case DEV_STATE_OFFLINE:
232 		if (!cdev->online) {
233 			ccw_device_update_sense_data(cdev);
234 			break;
235 		}
236 		cdev->private->state = DEV_STATE_OFFLINE;
237 		cdev->private->flags.recog_done = 1;
238 		if (ccw_device_test_sense_data(cdev)) {
239 			cdev->private->flags.donotify = 1;
240 			ccw_device_online(cdev);
241 			wake_up(&cdev->private->wait_q);
242 		} else {
243 			ccw_device_update_sense_data(cdev);
244 			ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
245 		}
246 		return;
247 	case DEV_STATE_BOXED:
248 		if (cdev->id.cu_type != 0) { /* device was recognized before */
249 			cdev->private->flags.recog_done = 1;
250 			cdev->private->state = DEV_STATE_BOXED;
251 			wake_up(&cdev->private->wait_q);
252 			return;
253 		}
254 		break;
255 	}
256 	cdev->private->state = state;
257 	io_subchannel_recog_done(cdev);
258 	wake_up(&cdev->private->wait_q);
259 }
260 
261 /*
262  * Function called from device_id.c after sense id has completed.
263  */
264 void
265 ccw_device_sense_id_done(struct ccw_device *cdev, int err)
266 {
267 	switch (err) {
268 	case 0:
269 		ccw_device_recog_done(cdev, DEV_STATE_OFFLINE);
270 		break;
271 	case -ETIME:		/* Sense id stopped by timeout. */
272 		ccw_device_recog_done(cdev, DEV_STATE_BOXED);
273 		break;
274 	default:
275 		ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
276 		break;
277 	}
278 }
279 
280 /**
281   * ccw_device_notify() - inform the device's driver about an event
282   * @cdev: device for which an event occurred
283   * @event: event that occurred
284   *
285   * Returns:
286   *   -%EINVAL if the device is offline or has no driver.
287   *   -%EOPNOTSUPP if the device's driver has no notifier registered.
288   *   %NOTIFY_OK if the driver wants to keep the device.
289   *   %NOTIFY_BAD if the driver doesn't want to keep the device.
290   */
291 int ccw_device_notify(struct ccw_device *cdev, int event)
292 {
293 	int ret = -EINVAL;
294 
295 	if (!cdev->drv)
296 		goto out;
297 	if (!cdev->online)
298 		goto out;
299 	CIO_MSG_EVENT(2, "notify called for 0.%x.%04x, event=%d\n",
300 		      cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
301 		      event);
302 	if (!cdev->drv->notify) {
303 		ret = -EOPNOTSUPP;
304 		goto out;
305 	}
306 	if (cdev->drv->notify(cdev, event))
307 		ret = NOTIFY_OK;
308 	else
309 		ret = NOTIFY_BAD;
310 out:
311 	return ret;
312 }
313 
314 static void ccw_device_oper_notify(struct ccw_device *cdev)
315 {
316 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
317 
318 	if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_OK) {
319 		/* Reenable channel measurements, if needed. */
320 		ccw_device_sched_todo(cdev, CDEV_TODO_ENABLE_CMF);
321 		/* Save indication for new paths. */
322 		cdev->private->path_new_mask = sch->vpm;
323 		return;
324 	}
325 	/* Driver doesn't want device back. */
326 	ccw_device_set_notoper(cdev);
327 	ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
328 }
329 
330 /*
331  * Finished with online/offline processing.
332  */
333 static void
334 ccw_device_done(struct ccw_device *cdev, int state)
335 {
336 	struct subchannel *sch;
337 
338 	sch = to_subchannel(cdev->dev.parent);
339 
340 	ccw_device_set_timeout(cdev, 0);
341 
342 	if (state != DEV_STATE_ONLINE)
343 		cio_disable_subchannel(sch);
344 
345 	/* Reset device status. */
346 	memset(&cdev->private->irb, 0, sizeof(struct irb));
347 
348 	cdev->private->state = state;
349 
350 	switch (state) {
351 	case DEV_STATE_BOXED:
352 		CIO_MSG_EVENT(0, "Boxed device %04x on subchannel %04x\n",
353 			      cdev->private->dev_id.devno, sch->schid.sch_no);
354 		if (cdev->online &&
355 		    ccw_device_notify(cdev, CIO_BOXED) != NOTIFY_OK)
356 			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
357 		cdev->private->flags.donotify = 0;
358 		break;
359 	case DEV_STATE_NOT_OPER:
360 		CIO_MSG_EVENT(0, "Device %04x gone on subchannel %04x\n",
361 			      cdev->private->dev_id.devno, sch->schid.sch_no);
362 		if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
363 			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
364 		else
365 			ccw_device_set_disconnected(cdev);
366 		cdev->private->flags.donotify = 0;
367 		break;
368 	case DEV_STATE_DISCONNECTED:
369 		CIO_MSG_EVENT(0, "Disconnected device %04x on subchannel "
370 			      "%04x\n", cdev->private->dev_id.devno,
371 			      sch->schid.sch_no);
372 		if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK) {
373 			cdev->private->state = DEV_STATE_NOT_OPER;
374 			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
375 		} else
376 			ccw_device_set_disconnected(cdev);
377 		cdev->private->flags.donotify = 0;
378 		break;
379 	default:
380 		break;
381 	}
382 
383 	if (cdev->private->flags.donotify) {
384 		cdev->private->flags.donotify = 0;
385 		ccw_device_oper_notify(cdev);
386 	}
387 	wake_up(&cdev->private->wait_q);
388 }
389 
390 /*
391  * Start device recognition.
392  */
393 void ccw_device_recognition(struct ccw_device *cdev)
394 {
395 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
396 
397 	/*
398 	 * We used to start here with a sense pgid to find out whether a device
399 	 * is locked by someone else. Unfortunately, the sense pgid command
400 	 * code has other meanings on devices predating the path grouping
401 	 * algorithm, so we start with sense id and box the device after an
402 	 * timeout (or if sense pgid during path verification detects the device
403 	 * is locked, as may happen on newer devices).
404 	 */
405 	cdev->private->flags.recog_done = 0;
406 	cdev->private->state = DEV_STATE_SENSE_ID;
407 	if (cio_enable_subchannel(sch, (u32) (addr_t) sch)) {
408 		ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
409 		return;
410 	}
411 	ccw_device_sense_id_start(cdev);
412 }
413 
414 /*
415  * Handle events for states that use the ccw request infrastructure.
416  */
417 static void ccw_device_request_event(struct ccw_device *cdev, enum dev_event e)
418 {
419 	switch (e) {
420 	case DEV_EVENT_NOTOPER:
421 		ccw_request_notoper(cdev);
422 		break;
423 	case DEV_EVENT_INTERRUPT:
424 		ccw_request_handler(cdev);
425 		break;
426 	case DEV_EVENT_TIMEOUT:
427 		ccw_request_timeout(cdev);
428 		break;
429 	default:
430 		break;
431 	}
432 }
433 
434 static void ccw_device_report_path_events(struct ccw_device *cdev)
435 {
436 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
437 	int path_event[8];
438 	int chp, mask;
439 
440 	for (chp = 0, mask = 0x80; chp < 8; chp++, mask >>= 1) {
441 		path_event[chp] = PE_NONE;
442 		if (mask & cdev->private->path_gone_mask & ~(sch->vpm))
443 			path_event[chp] |= PE_PATH_GONE;
444 		if (mask & cdev->private->path_new_mask & sch->vpm)
445 			path_event[chp] |= PE_PATH_AVAILABLE;
446 		if (mask & cdev->private->pgid_reset_mask & sch->vpm)
447 			path_event[chp] |= PE_PATHGROUP_ESTABLISHED;
448 	}
449 	if (cdev->online && cdev->drv->path_event)
450 		cdev->drv->path_event(cdev, path_event);
451 }
452 
453 static void ccw_device_reset_path_events(struct ccw_device *cdev)
454 {
455 	cdev->private->path_gone_mask = 0;
456 	cdev->private->path_new_mask = 0;
457 	cdev->private->pgid_reset_mask = 0;
458 }
459 
460 static void create_fake_irb(struct irb *irb, int type)
461 {
462 	memset(irb, 0, sizeof(*irb));
463 	if (type == FAKE_CMD_IRB) {
464 		struct cmd_scsw *scsw = &irb->scsw.cmd;
465 		scsw->cc = 1;
466 		scsw->fctl = SCSW_FCTL_START_FUNC;
467 		scsw->actl = SCSW_ACTL_START_PEND;
468 		scsw->stctl = SCSW_STCTL_STATUS_PEND;
469 	} else if (type == FAKE_TM_IRB) {
470 		struct tm_scsw *scsw = &irb->scsw.tm;
471 		scsw->x = 1;
472 		scsw->cc = 1;
473 		scsw->fctl = SCSW_FCTL_START_FUNC;
474 		scsw->actl = SCSW_ACTL_START_PEND;
475 		scsw->stctl = SCSW_STCTL_STATUS_PEND;
476 	}
477 }
478 
479 void ccw_device_verify_done(struct ccw_device *cdev, int err)
480 {
481 	struct subchannel *sch;
482 
483 	sch = to_subchannel(cdev->dev.parent);
484 	/* Update schib - pom may have changed. */
485 	if (cio_update_schib(sch)) {
486 		err = -ENODEV;
487 		goto callback;
488 	}
489 	/* Update lpm with verified path mask. */
490 	sch->lpm = sch->vpm;
491 	/* Repeat path verification? */
492 	if (cdev->private->flags.doverify) {
493 		ccw_device_verify_start(cdev);
494 		return;
495 	}
496 callback:
497 	switch (err) {
498 	case 0:
499 		ccw_device_done(cdev, DEV_STATE_ONLINE);
500 		/* Deliver fake irb to device driver, if needed. */
501 		if (cdev->private->flags.fake_irb) {
502 			create_fake_irb(&cdev->private->irb,
503 					cdev->private->flags.fake_irb);
504 			cdev->private->flags.fake_irb = 0;
505 			if (cdev->handler)
506 				cdev->handler(cdev, cdev->private->intparm,
507 					      &cdev->private->irb);
508 			memset(&cdev->private->irb, 0, sizeof(struct irb));
509 		}
510 		ccw_device_report_path_events(cdev);
511 		break;
512 	case -ETIME:
513 	case -EUSERS:
514 		/* Reset oper notify indication after verify error. */
515 		cdev->private->flags.donotify = 0;
516 		ccw_device_done(cdev, DEV_STATE_BOXED);
517 		break;
518 	case -EACCES:
519 		/* Reset oper notify indication after verify error. */
520 		cdev->private->flags.donotify = 0;
521 		ccw_device_done(cdev, DEV_STATE_DISCONNECTED);
522 		break;
523 	default:
524 		/* Reset oper notify indication after verify error. */
525 		cdev->private->flags.donotify = 0;
526 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
527 		break;
528 	}
529 	ccw_device_reset_path_events(cdev);
530 }
531 
532 /*
533  * Get device online.
534  */
535 int
536 ccw_device_online(struct ccw_device *cdev)
537 {
538 	struct subchannel *sch;
539 	int ret;
540 
541 	if ((cdev->private->state != DEV_STATE_OFFLINE) &&
542 	    (cdev->private->state != DEV_STATE_BOXED))
543 		return -EINVAL;
544 	sch = to_subchannel(cdev->dev.parent);
545 	ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
546 	if (ret != 0) {
547 		/* Couldn't enable the subchannel for i/o. Sick device. */
548 		if (ret == -ENODEV)
549 			dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
550 		return ret;
551 	}
552 	/* Start initial path verification. */
553 	cdev->private->state = DEV_STATE_VERIFY;
554 	ccw_device_verify_start(cdev);
555 	return 0;
556 }
557 
558 void
559 ccw_device_disband_done(struct ccw_device *cdev, int err)
560 {
561 	switch (err) {
562 	case 0:
563 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
564 		break;
565 	case -ETIME:
566 		ccw_device_done(cdev, DEV_STATE_BOXED);
567 		break;
568 	default:
569 		cdev->private->flags.donotify = 0;
570 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
571 		break;
572 	}
573 }
574 
575 /*
576  * Shutdown device.
577  */
578 int
579 ccw_device_offline(struct ccw_device *cdev)
580 {
581 	struct subchannel *sch;
582 
583 	/* Allow ccw_device_offline while disconnected. */
584 	if (cdev->private->state == DEV_STATE_DISCONNECTED ||
585 	    cdev->private->state == DEV_STATE_NOT_OPER) {
586 		cdev->private->flags.donotify = 0;
587 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
588 		return 0;
589 	}
590 	if (cdev->private->state == DEV_STATE_BOXED) {
591 		ccw_device_done(cdev, DEV_STATE_BOXED);
592 		return 0;
593 	}
594 	if (ccw_device_is_orphan(cdev)) {
595 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
596 		return 0;
597 	}
598 	sch = to_subchannel(cdev->dev.parent);
599 	if (cio_update_schib(sch))
600 		return -ENODEV;
601 	if (scsw_actl(&sch->schib.scsw) != 0)
602 		return -EBUSY;
603 	if (cdev->private->state != DEV_STATE_ONLINE)
604 		return -EINVAL;
605 	/* Are we doing path grouping? */
606 	if (!cdev->private->flags.pgroup) {
607 		/* No, set state offline immediately. */
608 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
609 		return 0;
610 	}
611 	/* Start Set Path Group commands. */
612 	cdev->private->state = DEV_STATE_DISBAND_PGID;
613 	ccw_device_disband_start(cdev);
614 	return 0;
615 }
616 
617 /*
618  * Handle not operational event in non-special state.
619  */
620 static void ccw_device_generic_notoper(struct ccw_device *cdev,
621 				       enum dev_event dev_event)
622 {
623 	if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
624 		ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
625 	else
626 		ccw_device_set_disconnected(cdev);
627 }
628 
629 /*
630  * Handle path verification event in offline state.
631  */
632 static void ccw_device_offline_verify(struct ccw_device *cdev,
633 				      enum dev_event dev_event)
634 {
635 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
636 
637 	css_schedule_eval(sch->schid);
638 }
639 
640 /*
641  * Handle path verification event.
642  */
643 static void
644 ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
645 {
646 	struct subchannel *sch;
647 
648 	if (cdev->private->state == DEV_STATE_W4SENSE) {
649 		cdev->private->flags.doverify = 1;
650 		return;
651 	}
652 	sch = to_subchannel(cdev->dev.parent);
653 	/*
654 	 * Since we might not just be coming from an interrupt from the
655 	 * subchannel we have to update the schib.
656 	 */
657 	if (cio_update_schib(sch)) {
658 		ccw_device_verify_done(cdev, -ENODEV);
659 		return;
660 	}
661 
662 	if (scsw_actl(&sch->schib.scsw) != 0 ||
663 	    (scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_STATUS_PEND) ||
664 	    (scsw_stctl(&cdev->private->irb.scsw) & SCSW_STCTL_STATUS_PEND)) {
665 		/*
666 		 * No final status yet or final status not yet delivered
667 		 * to the device driver. Can't do path verification now,
668 		 * delay until final status was delivered.
669 		 */
670 		cdev->private->flags.doverify = 1;
671 		return;
672 	}
673 	/* Device is idle, we can do the path verification. */
674 	cdev->private->state = DEV_STATE_VERIFY;
675 	ccw_device_verify_start(cdev);
676 }
677 
678 /*
679  * Handle path verification event in boxed state.
680  */
681 static void ccw_device_boxed_verify(struct ccw_device *cdev,
682 				    enum dev_event dev_event)
683 {
684 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
685 
686 	if (cdev->online) {
687 		if (cio_enable_subchannel(sch, (u32) (addr_t) sch))
688 			ccw_device_done(cdev, DEV_STATE_NOT_OPER);
689 		else
690 			ccw_device_online_verify(cdev, dev_event);
691 	} else
692 		css_schedule_eval(sch->schid);
693 }
694 
695 /*
696  * Pass interrupt to device driver.
697  */
698 static int ccw_device_call_handler(struct ccw_device *cdev)
699 {
700 	unsigned int stctl;
701 	int ending_status;
702 
703 	/*
704 	 * we allow for the device action handler if .
705 	 *  - we received ending status
706 	 *  - the action handler requested to see all interrupts
707 	 *  - we received an intermediate status
708 	 *  - fast notification was requested (primary status)
709 	 *  - unsolicited interrupts
710 	 */
711 	stctl = scsw_stctl(&cdev->private->irb.scsw);
712 	ending_status = (stctl & SCSW_STCTL_SEC_STATUS) ||
713 		(stctl == (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)) ||
714 		(stctl == SCSW_STCTL_STATUS_PEND);
715 	if (!ending_status &&
716 	    !cdev->private->options.repall &&
717 	    !(stctl & SCSW_STCTL_INTER_STATUS) &&
718 	    !(cdev->private->options.fast &&
719 	      (stctl & SCSW_STCTL_PRIM_STATUS)))
720 		return 0;
721 
722 	if (ending_status)
723 		ccw_device_set_timeout(cdev, 0);
724 
725 	if (cdev->handler)
726 		cdev->handler(cdev, cdev->private->intparm,
727 			      &cdev->private->irb);
728 
729 	memset(&cdev->private->irb, 0, sizeof(struct irb));
730 	return 1;
731 }
732 
733 /*
734  * Got an interrupt for a normal io (state online).
735  */
736 static void
737 ccw_device_irq(struct ccw_device *cdev, enum dev_event dev_event)
738 {
739 	struct irb *irb;
740 	int is_cmd;
741 
742 	irb = this_cpu_ptr(&cio_irb);
743 	is_cmd = !scsw_is_tm(&irb->scsw);
744 	/* Check for unsolicited interrupt. */
745 	if (!scsw_is_solicited(&irb->scsw)) {
746 		if (is_cmd && (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) &&
747 		    !irb->esw.esw0.erw.cons) {
748 			/* Unit check but no sense data. Need basic sense. */
749 			if (ccw_device_do_sense(cdev, irb) != 0)
750 				goto call_handler_unsol;
751 			memcpy(&cdev->private->irb, irb, sizeof(struct irb));
752 			cdev->private->state = DEV_STATE_W4SENSE;
753 			cdev->private->intparm = 0;
754 			return;
755 		}
756 call_handler_unsol:
757 		if (cdev->handler)
758 			cdev->handler (cdev, 0, irb);
759 		if (cdev->private->flags.doverify)
760 			ccw_device_online_verify(cdev, 0);
761 		return;
762 	}
763 	/* Accumulate status and find out if a basic sense is needed. */
764 	ccw_device_accumulate_irb(cdev, irb);
765 	if (is_cmd && cdev->private->flags.dosense) {
766 		if (ccw_device_do_sense(cdev, irb) == 0) {
767 			cdev->private->state = DEV_STATE_W4SENSE;
768 		}
769 		return;
770 	}
771 	/* Call the handler. */
772 	if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
773 		/* Start delayed path verification. */
774 		ccw_device_online_verify(cdev, 0);
775 }
776 
777 /*
778  * Got an timeout in online state.
779  */
780 static void
781 ccw_device_online_timeout(struct ccw_device *cdev, enum dev_event dev_event)
782 {
783 	int ret;
784 
785 	ccw_device_set_timeout(cdev, 0);
786 	cdev->private->iretry = 255;
787 	ret = ccw_device_cancel_halt_clear(cdev);
788 	if (ret == -EBUSY) {
789 		ccw_device_set_timeout(cdev, 3*HZ);
790 		cdev->private->state = DEV_STATE_TIMEOUT_KILL;
791 		return;
792 	}
793 	if (ret)
794 		dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
795 	else if (cdev->handler)
796 		cdev->handler(cdev, cdev->private->intparm,
797 			      ERR_PTR(-ETIMEDOUT));
798 }
799 
800 /*
801  * Got an interrupt for a basic sense.
802  */
803 static void
804 ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
805 {
806 	struct irb *irb;
807 
808 	irb = this_cpu_ptr(&cio_irb);
809 	/* Check for unsolicited interrupt. */
810 	if (scsw_stctl(&irb->scsw) ==
811 	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
812 		if (scsw_cc(&irb->scsw) == 1)
813 			/* Basic sense hasn't started. Try again. */
814 			ccw_device_do_sense(cdev, irb);
815 		else {
816 			CIO_MSG_EVENT(0, "0.%x.%04x: unsolicited "
817 				      "interrupt during w4sense...\n",
818 				      cdev->private->dev_id.ssid,
819 				      cdev->private->dev_id.devno);
820 			if (cdev->handler)
821 				cdev->handler (cdev, 0, irb);
822 		}
823 		return;
824 	}
825 	/*
826 	 * Check if a halt or clear has been issued in the meanwhile. If yes,
827 	 * only deliver the halt/clear interrupt to the device driver as if it
828 	 * had killed the original request.
829 	 */
830 	if (scsw_fctl(&irb->scsw) &
831 	    (SCSW_FCTL_CLEAR_FUNC | SCSW_FCTL_HALT_FUNC)) {
832 		cdev->private->flags.dosense = 0;
833 		memset(&cdev->private->irb, 0, sizeof(struct irb));
834 		ccw_device_accumulate_irb(cdev, irb);
835 		goto call_handler;
836 	}
837 	/* Add basic sense info to irb. */
838 	ccw_device_accumulate_basic_sense(cdev, irb);
839 	if (cdev->private->flags.dosense) {
840 		/* Another basic sense is needed. */
841 		ccw_device_do_sense(cdev, irb);
842 		return;
843 	}
844 call_handler:
845 	cdev->private->state = DEV_STATE_ONLINE;
846 	/* In case sensing interfered with setting the device online */
847 	wake_up(&cdev->private->wait_q);
848 	/* Call the handler. */
849 	if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
850 		/* Start delayed path verification. */
851 		ccw_device_online_verify(cdev, 0);
852 }
853 
854 static void
855 ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
856 {
857 	ccw_device_set_timeout(cdev, 0);
858 	/* Start delayed path verification. */
859 	ccw_device_online_verify(cdev, 0);
860 	/* OK, i/o is dead now. Call interrupt handler. */
861 	if (cdev->handler)
862 		cdev->handler(cdev, cdev->private->intparm,
863 			      ERR_PTR(-EIO));
864 }
865 
866 static void
867 ccw_device_killing_timeout(struct ccw_device *cdev, enum dev_event dev_event)
868 {
869 	int ret;
870 
871 	ret = ccw_device_cancel_halt_clear(cdev);
872 	if (ret == -EBUSY) {
873 		ccw_device_set_timeout(cdev, 3*HZ);
874 		return;
875 	}
876 	/* Start delayed path verification. */
877 	ccw_device_online_verify(cdev, 0);
878 	if (cdev->handler)
879 		cdev->handler(cdev, cdev->private->intparm,
880 			      ERR_PTR(-EIO));
881 }
882 
883 void ccw_device_kill_io(struct ccw_device *cdev)
884 {
885 	int ret;
886 
887 	cdev->private->iretry = 255;
888 	ret = ccw_device_cancel_halt_clear(cdev);
889 	if (ret == -EBUSY) {
890 		ccw_device_set_timeout(cdev, 3*HZ);
891 		cdev->private->state = DEV_STATE_TIMEOUT_KILL;
892 		return;
893 	}
894 	/* Start delayed path verification. */
895 	ccw_device_online_verify(cdev, 0);
896 	if (cdev->handler)
897 		cdev->handler(cdev, cdev->private->intparm,
898 			      ERR_PTR(-EIO));
899 }
900 
901 static void
902 ccw_device_delay_verify(struct ccw_device *cdev, enum dev_event dev_event)
903 {
904 	/* Start verification after current task finished. */
905 	cdev->private->flags.doverify = 1;
906 }
907 
908 static void
909 ccw_device_start_id(struct ccw_device *cdev, enum dev_event dev_event)
910 {
911 	struct subchannel *sch;
912 
913 	sch = to_subchannel(cdev->dev.parent);
914 	if (cio_enable_subchannel(sch, (u32)(addr_t)sch) != 0)
915 		/* Couldn't enable the subchannel for i/o. Sick device. */
916 		return;
917 	cdev->private->state = DEV_STATE_DISCONNECTED_SENSE_ID;
918 	ccw_device_sense_id_start(cdev);
919 }
920 
921 void ccw_device_trigger_reprobe(struct ccw_device *cdev)
922 {
923 	struct subchannel *sch;
924 
925 	if (cdev->private->state != DEV_STATE_DISCONNECTED)
926 		return;
927 
928 	sch = to_subchannel(cdev->dev.parent);
929 	/* Update some values. */
930 	if (cio_update_schib(sch))
931 		return;
932 	/*
933 	 * The pim, pam, pom values may not be accurate, but they are the best
934 	 * we have before performing device selection :/
935 	 */
936 	sch->lpm = sch->schib.pmcw.pam & sch->opm;
937 	/*
938 	 * Use the initial configuration since we can't be shure that the old
939 	 * paths are valid.
940 	 */
941 	io_subchannel_init_config(sch);
942 	if (cio_commit_config(sch))
943 		return;
944 
945 	/* We should also udate ssd info, but this has to wait. */
946 	/* Check if this is another device which appeared on the same sch. */
947 	if (sch->schib.pmcw.dev != cdev->private->dev_id.devno)
948 		css_schedule_eval(sch->schid);
949 	else
950 		ccw_device_start_id(cdev, 0);
951 }
952 
953 static void ccw_device_disabled_irq(struct ccw_device *cdev,
954 				    enum dev_event dev_event)
955 {
956 	struct subchannel *sch;
957 
958 	sch = to_subchannel(cdev->dev.parent);
959 	/*
960 	 * An interrupt in a disabled state means a previous disable was not
961 	 * successful - should not happen, but we try to disable again.
962 	 */
963 	cio_disable_subchannel(sch);
964 }
965 
966 static void
967 ccw_device_change_cmfstate(struct ccw_device *cdev, enum dev_event dev_event)
968 {
969 	retry_set_schib(cdev);
970 	cdev->private->state = DEV_STATE_ONLINE;
971 	dev_fsm_event(cdev, dev_event);
972 }
973 
974 static void ccw_device_update_cmfblock(struct ccw_device *cdev,
975 				       enum dev_event dev_event)
976 {
977 	cmf_retry_copy_block(cdev);
978 	cdev->private->state = DEV_STATE_ONLINE;
979 	dev_fsm_event(cdev, dev_event);
980 }
981 
982 static void
983 ccw_device_quiesce_done(struct ccw_device *cdev, enum dev_event dev_event)
984 {
985 	ccw_device_set_timeout(cdev, 0);
986 	cdev->private->state = DEV_STATE_NOT_OPER;
987 	wake_up(&cdev->private->wait_q);
988 }
989 
990 static void
991 ccw_device_quiesce_timeout(struct ccw_device *cdev, enum dev_event dev_event)
992 {
993 	int ret;
994 
995 	ret = ccw_device_cancel_halt_clear(cdev);
996 	if (ret == -EBUSY) {
997 		ccw_device_set_timeout(cdev, HZ/10);
998 	} else {
999 		cdev->private->state = DEV_STATE_NOT_OPER;
1000 		wake_up(&cdev->private->wait_q);
1001 	}
1002 }
1003 
1004 /*
1005  * No operation action. This is used e.g. to ignore a timeout event in
1006  * state offline.
1007  */
1008 static void
1009 ccw_device_nop(struct ccw_device *cdev, enum dev_event dev_event)
1010 {
1011 }
1012 
1013 /*
1014  * device statemachine
1015  */
1016 fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
1017 	[DEV_STATE_NOT_OPER] = {
1018 		[DEV_EVENT_NOTOPER]	= ccw_device_nop,
1019 		[DEV_EVENT_INTERRUPT]	= ccw_device_disabled_irq,
1020 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1021 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1022 	},
1023 	[DEV_STATE_SENSE_ID] = {
1024 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1025 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1026 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1027 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1028 	},
1029 	[DEV_STATE_OFFLINE] = {
1030 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1031 		[DEV_EVENT_INTERRUPT]	= ccw_device_disabled_irq,
1032 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1033 		[DEV_EVENT_VERIFY]	= ccw_device_offline_verify,
1034 	},
1035 	[DEV_STATE_VERIFY] = {
1036 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1037 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1038 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1039 		[DEV_EVENT_VERIFY]	= ccw_device_delay_verify,
1040 	},
1041 	[DEV_STATE_ONLINE] = {
1042 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1043 		[DEV_EVENT_INTERRUPT]	= ccw_device_irq,
1044 		[DEV_EVENT_TIMEOUT]	= ccw_device_online_timeout,
1045 		[DEV_EVENT_VERIFY]	= ccw_device_online_verify,
1046 	},
1047 	[DEV_STATE_W4SENSE] = {
1048 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1049 		[DEV_EVENT_INTERRUPT]	= ccw_device_w4sense,
1050 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1051 		[DEV_EVENT_VERIFY]	= ccw_device_online_verify,
1052 	},
1053 	[DEV_STATE_DISBAND_PGID] = {
1054 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1055 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1056 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1057 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1058 	},
1059 	[DEV_STATE_BOXED] = {
1060 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1061 		[DEV_EVENT_INTERRUPT]	= ccw_device_nop,
1062 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1063 		[DEV_EVENT_VERIFY]	= ccw_device_boxed_verify,
1064 	},
1065 	/* states to wait for i/o completion before doing something */
1066 	[DEV_STATE_TIMEOUT_KILL] = {
1067 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1068 		[DEV_EVENT_INTERRUPT]	= ccw_device_killing_irq,
1069 		[DEV_EVENT_TIMEOUT]	= ccw_device_killing_timeout,
1070 		[DEV_EVENT_VERIFY]	= ccw_device_nop, //FIXME
1071 	},
1072 	[DEV_STATE_QUIESCE] = {
1073 		[DEV_EVENT_NOTOPER]	= ccw_device_quiesce_done,
1074 		[DEV_EVENT_INTERRUPT]	= ccw_device_quiesce_done,
1075 		[DEV_EVENT_TIMEOUT]	= ccw_device_quiesce_timeout,
1076 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1077 	},
1078 	/* special states for devices gone not operational */
1079 	[DEV_STATE_DISCONNECTED] = {
1080 		[DEV_EVENT_NOTOPER]	= ccw_device_nop,
1081 		[DEV_EVENT_INTERRUPT]	= ccw_device_start_id,
1082 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1083 		[DEV_EVENT_VERIFY]	= ccw_device_start_id,
1084 	},
1085 	[DEV_STATE_DISCONNECTED_SENSE_ID] = {
1086 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1087 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1088 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1089 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1090 	},
1091 	[DEV_STATE_CMFCHANGE] = {
1092 		[DEV_EVENT_NOTOPER]	= ccw_device_change_cmfstate,
1093 		[DEV_EVENT_INTERRUPT]	= ccw_device_change_cmfstate,
1094 		[DEV_EVENT_TIMEOUT]	= ccw_device_change_cmfstate,
1095 		[DEV_EVENT_VERIFY]	= ccw_device_change_cmfstate,
1096 	},
1097 	[DEV_STATE_CMFUPDATE] = {
1098 		[DEV_EVENT_NOTOPER]	= ccw_device_update_cmfblock,
1099 		[DEV_EVENT_INTERRUPT]	= ccw_device_update_cmfblock,
1100 		[DEV_EVENT_TIMEOUT]	= ccw_device_update_cmfblock,
1101 		[DEV_EVENT_VERIFY]	= ccw_device_update_cmfblock,
1102 	},
1103 	[DEV_STATE_STEAL_LOCK] = {
1104 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1105 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1106 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1107 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1108 	},
1109 };
1110 
1111 EXPORT_SYMBOL_GPL(ccw_device_set_timeout);
1112