xref: /openbmc/linux/drivers/s390/cio/device_fsm.c (revision 63dc02bd)
1 /*
2  * drivers/s390/cio/device_fsm.c
3  * finite state machine for device handling
4  *
5  *    Copyright IBM Corp. 2002,2008
6  *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
7  *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
8  */
9 
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/jiffies.h>
13 #include <linux/string.h>
14 
15 #include <asm/ccwdev.h>
16 #include <asm/cio.h>
17 #include <asm/chpid.h>
18 
19 #include "cio.h"
20 #include "cio_debug.h"
21 #include "css.h"
22 #include "device.h"
23 #include "chsc.h"
24 #include "ioasm.h"
25 #include "chp.h"
26 
27 static int timeout_log_enabled;
28 
29 static int __init ccw_timeout_log_setup(char *unused)
30 {
31 	timeout_log_enabled = 1;
32 	return 1;
33 }
34 
35 __setup("ccw_timeout_log", ccw_timeout_log_setup);
36 
37 static void ccw_timeout_log(struct ccw_device *cdev)
38 {
39 	struct schib schib;
40 	struct subchannel *sch;
41 	struct io_subchannel_private *private;
42 	union orb *orb;
43 	int cc;
44 
45 	sch = to_subchannel(cdev->dev.parent);
46 	private = to_io_private(sch);
47 	orb = &private->orb;
48 	cc = stsch_err(sch->schid, &schib);
49 
50 	printk(KERN_WARNING "cio: ccw device timeout occurred at %llx, "
51 	       "device information:\n", get_clock());
52 	printk(KERN_WARNING "cio: orb:\n");
53 	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
54 		       orb, sizeof(*orb), 0);
55 	printk(KERN_WARNING "cio: ccw device bus id: %s\n",
56 	       dev_name(&cdev->dev));
57 	printk(KERN_WARNING "cio: subchannel bus id: %s\n",
58 	       dev_name(&sch->dev));
59 	printk(KERN_WARNING "cio: subchannel lpm: %02x, opm: %02x, "
60 	       "vpm: %02x\n", sch->lpm, sch->opm, sch->vpm);
61 
62 	if (orb->tm.b) {
63 		printk(KERN_WARNING "cio: orb indicates transport mode\n");
64 		printk(KERN_WARNING "cio: last tcw:\n");
65 		print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
66 			       (void *)(addr_t)orb->tm.tcw,
67 			       sizeof(struct tcw), 0);
68 	} else {
69 		printk(KERN_WARNING "cio: orb indicates command mode\n");
70 		if ((void *)(addr_t)orb->cmd.cpa == &private->sense_ccw ||
71 		    (void *)(addr_t)orb->cmd.cpa == cdev->private->iccws)
72 			printk(KERN_WARNING "cio: last channel program "
73 			       "(intern):\n");
74 		else
75 			printk(KERN_WARNING "cio: last channel program:\n");
76 
77 		print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
78 			       (void *)(addr_t)orb->cmd.cpa,
79 			       sizeof(struct ccw1), 0);
80 	}
81 	printk(KERN_WARNING "cio: ccw device state: %d\n",
82 	       cdev->private->state);
83 	printk(KERN_WARNING "cio: store subchannel returned: cc=%d\n", cc);
84 	printk(KERN_WARNING "cio: schib:\n");
85 	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
86 		       &schib, sizeof(schib), 0);
87 	printk(KERN_WARNING "cio: ccw device flags:\n");
88 	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
89 		       &cdev->private->flags, sizeof(cdev->private->flags), 0);
90 }
91 
92 /*
93  * Timeout function. It just triggers a DEV_EVENT_TIMEOUT.
94  */
95 static void
96 ccw_device_timeout(unsigned long data)
97 {
98 	struct ccw_device *cdev;
99 
100 	cdev = (struct ccw_device *) data;
101 	spin_lock_irq(cdev->ccwlock);
102 	if (timeout_log_enabled)
103 		ccw_timeout_log(cdev);
104 	dev_fsm_event(cdev, DEV_EVENT_TIMEOUT);
105 	spin_unlock_irq(cdev->ccwlock);
106 }
107 
108 /*
109  * Set timeout
110  */
111 void
112 ccw_device_set_timeout(struct ccw_device *cdev, int expires)
113 {
114 	if (expires == 0) {
115 		del_timer(&cdev->private->timer);
116 		return;
117 	}
118 	if (timer_pending(&cdev->private->timer)) {
119 		if (mod_timer(&cdev->private->timer, jiffies + expires))
120 			return;
121 	}
122 	cdev->private->timer.function = ccw_device_timeout;
123 	cdev->private->timer.data = (unsigned long) cdev;
124 	cdev->private->timer.expires = jiffies + expires;
125 	add_timer(&cdev->private->timer);
126 }
127 
128 /*
129  * Cancel running i/o. This is called repeatedly since halt/clear are
130  * asynchronous operations. We do one try with cio_cancel, two tries
131  * with cio_halt, 255 tries with cio_clear. If everythings fails panic.
132  * Returns 0 if device now idle, -ENODEV for device not operational and
133  * -EBUSY if an interrupt is expected (either from halt/clear or from a
134  * status pending).
135  */
136 int
137 ccw_device_cancel_halt_clear(struct ccw_device *cdev)
138 {
139 	struct subchannel *sch;
140 	int ret;
141 
142 	sch = to_subchannel(cdev->dev.parent);
143 	if (cio_update_schib(sch))
144 		return -ENODEV;
145 	if (!sch->schib.pmcw.ena)
146 		/* Not operational -> done. */
147 		return 0;
148 	/* Stage 1: cancel io. */
149 	if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_HALT_PEND) &&
150 	    !(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
151 		if (!scsw_is_tm(&sch->schib.scsw)) {
152 			ret = cio_cancel(sch);
153 			if (ret != -EINVAL)
154 				return ret;
155 		}
156 		/* cancel io unsuccessful or not applicable (transport mode).
157 		 * Continue with asynchronous instructions. */
158 		cdev->private->iretry = 3;	/* 3 halt retries. */
159 	}
160 	if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
161 		/* Stage 2: halt io. */
162 		if (cdev->private->iretry) {
163 			cdev->private->iretry--;
164 			ret = cio_halt(sch);
165 			if (ret != -EBUSY)
166 				return (ret == 0) ? -EBUSY : ret;
167 		}
168 		/* halt io unsuccessful. */
169 		cdev->private->iretry = 255;	/* 255 clear retries. */
170 	}
171 	/* Stage 3: clear io. */
172 	if (cdev->private->iretry) {
173 		cdev->private->iretry--;
174 		ret = cio_clear (sch);
175 		return (ret == 0) ? -EBUSY : ret;
176 	}
177 	/* Function was unsuccessful */
178 	CIO_MSG_EVENT(0, "0.%x.%04x: could not stop I/O\n",
179 		      cdev->private->dev_id.ssid, cdev->private->dev_id.devno);
180 	return -EIO;
181 }
182 
183 void ccw_device_update_sense_data(struct ccw_device *cdev)
184 {
185 	memset(&cdev->id, 0, sizeof(cdev->id));
186 	cdev->id.cu_type   = cdev->private->senseid.cu_type;
187 	cdev->id.cu_model  = cdev->private->senseid.cu_model;
188 	cdev->id.dev_type  = cdev->private->senseid.dev_type;
189 	cdev->id.dev_model = cdev->private->senseid.dev_model;
190 }
191 
192 int ccw_device_test_sense_data(struct ccw_device *cdev)
193 {
194 	return cdev->id.cu_type == cdev->private->senseid.cu_type &&
195 		cdev->id.cu_model == cdev->private->senseid.cu_model &&
196 		cdev->id.dev_type == cdev->private->senseid.dev_type &&
197 		cdev->id.dev_model == cdev->private->senseid.dev_model;
198 }
199 
200 /*
201  * The machine won't give us any notification by machine check if a chpid has
202  * been varied online on the SE so we have to find out by magic (i. e. driving
203  * the channel subsystem to device selection and updating our path masks).
204  */
205 static void
206 __recover_lost_chpids(struct subchannel *sch, int old_lpm)
207 {
208 	int mask, i;
209 	struct chp_id chpid;
210 
211 	chp_id_init(&chpid);
212 	for (i = 0; i<8; i++) {
213 		mask = 0x80 >> i;
214 		if (!(sch->lpm & mask))
215 			continue;
216 		if (old_lpm & mask)
217 			continue;
218 		chpid.id = sch->schib.pmcw.chpid[i];
219 		if (!chp_is_registered(chpid))
220 			css_schedule_eval_all();
221 	}
222 }
223 
224 /*
225  * Stop device recognition.
226  */
227 static void
228 ccw_device_recog_done(struct ccw_device *cdev, int state)
229 {
230 	struct subchannel *sch;
231 	int old_lpm;
232 
233 	sch = to_subchannel(cdev->dev.parent);
234 
235 	if (cio_disable_subchannel(sch))
236 		state = DEV_STATE_NOT_OPER;
237 	/*
238 	 * Now that we tried recognition, we have performed device selection
239 	 * through ssch() and the path information is up to date.
240 	 */
241 	old_lpm = sch->lpm;
242 
243 	/* Check since device may again have become not operational. */
244 	if (cio_update_schib(sch))
245 		state = DEV_STATE_NOT_OPER;
246 	else
247 		sch->lpm = sch->schib.pmcw.pam & sch->opm;
248 
249 	if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID)
250 		/* Force reprobe on all chpids. */
251 		old_lpm = 0;
252 	if (sch->lpm != old_lpm)
253 		__recover_lost_chpids(sch, old_lpm);
254 	if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID &&
255 	    (state == DEV_STATE_NOT_OPER || state == DEV_STATE_BOXED)) {
256 		cdev->private->flags.recog_done = 1;
257 		cdev->private->state = DEV_STATE_DISCONNECTED;
258 		wake_up(&cdev->private->wait_q);
259 		return;
260 	}
261 	if (cdev->private->flags.resuming) {
262 		cdev->private->state = state;
263 		cdev->private->flags.recog_done = 1;
264 		wake_up(&cdev->private->wait_q);
265 		return;
266 	}
267 	switch (state) {
268 	case DEV_STATE_NOT_OPER:
269 		break;
270 	case DEV_STATE_OFFLINE:
271 		if (!cdev->online) {
272 			ccw_device_update_sense_data(cdev);
273 			break;
274 		}
275 		cdev->private->state = DEV_STATE_OFFLINE;
276 		cdev->private->flags.recog_done = 1;
277 		if (ccw_device_test_sense_data(cdev)) {
278 			cdev->private->flags.donotify = 1;
279 			ccw_device_online(cdev);
280 			wake_up(&cdev->private->wait_q);
281 		} else {
282 			ccw_device_update_sense_data(cdev);
283 			ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
284 		}
285 		return;
286 	case DEV_STATE_BOXED:
287 		if (cdev->id.cu_type != 0) { /* device was recognized before */
288 			cdev->private->flags.recog_done = 1;
289 			cdev->private->state = DEV_STATE_BOXED;
290 			wake_up(&cdev->private->wait_q);
291 			return;
292 		}
293 		break;
294 	}
295 	cdev->private->state = state;
296 	io_subchannel_recog_done(cdev);
297 	wake_up(&cdev->private->wait_q);
298 }
299 
300 /*
301  * Function called from device_id.c after sense id has completed.
302  */
303 void
304 ccw_device_sense_id_done(struct ccw_device *cdev, int err)
305 {
306 	switch (err) {
307 	case 0:
308 		ccw_device_recog_done(cdev, DEV_STATE_OFFLINE);
309 		break;
310 	case -ETIME:		/* Sense id stopped by timeout. */
311 		ccw_device_recog_done(cdev, DEV_STATE_BOXED);
312 		break;
313 	default:
314 		ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
315 		break;
316 	}
317 }
318 
319 /**
320   * ccw_device_notify() - inform the device's driver about an event
321   * @cdev: device for which an event occurred
322   * @event: event that occurred
323   *
324   * Returns:
325   *   -%EINVAL if the device is offline or has no driver.
326   *   -%EOPNOTSUPP if the device's driver has no notifier registered.
327   *   %NOTIFY_OK if the driver wants to keep the device.
328   *   %NOTIFY_BAD if the driver doesn't want to keep the device.
329   */
330 int ccw_device_notify(struct ccw_device *cdev, int event)
331 {
332 	int ret = -EINVAL;
333 
334 	if (!cdev->drv)
335 		goto out;
336 	if (!cdev->online)
337 		goto out;
338 	CIO_MSG_EVENT(2, "notify called for 0.%x.%04x, event=%d\n",
339 		      cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
340 		      event);
341 	if (!cdev->drv->notify) {
342 		ret = -EOPNOTSUPP;
343 		goto out;
344 	}
345 	if (cdev->drv->notify(cdev, event))
346 		ret = NOTIFY_OK;
347 	else
348 		ret = NOTIFY_BAD;
349 out:
350 	return ret;
351 }
352 
353 static void ccw_device_oper_notify(struct ccw_device *cdev)
354 {
355 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
356 
357 	if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_OK) {
358 		/* Reenable channel measurements, if needed. */
359 		ccw_device_sched_todo(cdev, CDEV_TODO_ENABLE_CMF);
360 		/* Save indication for new paths. */
361 		cdev->private->path_new_mask = sch->vpm;
362 		return;
363 	}
364 	/* Driver doesn't want device back. */
365 	ccw_device_set_notoper(cdev);
366 	ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
367 }
368 
369 /*
370  * Finished with online/offline processing.
371  */
372 static void
373 ccw_device_done(struct ccw_device *cdev, int state)
374 {
375 	struct subchannel *sch;
376 
377 	sch = to_subchannel(cdev->dev.parent);
378 
379 	ccw_device_set_timeout(cdev, 0);
380 
381 	if (state != DEV_STATE_ONLINE)
382 		cio_disable_subchannel(sch);
383 
384 	/* Reset device status. */
385 	memset(&cdev->private->irb, 0, sizeof(struct irb));
386 
387 	cdev->private->state = state;
388 
389 	switch (state) {
390 	case DEV_STATE_BOXED:
391 		CIO_MSG_EVENT(0, "Boxed device %04x on subchannel %04x\n",
392 			      cdev->private->dev_id.devno, sch->schid.sch_no);
393 		if (cdev->online &&
394 		    ccw_device_notify(cdev, CIO_BOXED) != NOTIFY_OK)
395 			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
396 		cdev->private->flags.donotify = 0;
397 		break;
398 	case DEV_STATE_NOT_OPER:
399 		CIO_MSG_EVENT(0, "Device %04x gone on subchannel %04x\n",
400 			      cdev->private->dev_id.devno, sch->schid.sch_no);
401 		if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
402 			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
403 		else
404 			ccw_device_set_disconnected(cdev);
405 		cdev->private->flags.donotify = 0;
406 		break;
407 	case DEV_STATE_DISCONNECTED:
408 		CIO_MSG_EVENT(0, "Disconnected device %04x on subchannel "
409 			      "%04x\n", cdev->private->dev_id.devno,
410 			      sch->schid.sch_no);
411 		if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK) {
412 			cdev->private->state = DEV_STATE_NOT_OPER;
413 			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
414 		} else
415 			ccw_device_set_disconnected(cdev);
416 		cdev->private->flags.donotify = 0;
417 		break;
418 	default:
419 		break;
420 	}
421 
422 	if (cdev->private->flags.donotify) {
423 		cdev->private->flags.donotify = 0;
424 		ccw_device_oper_notify(cdev);
425 	}
426 	wake_up(&cdev->private->wait_q);
427 }
428 
429 /*
430  * Start device recognition.
431  */
432 void ccw_device_recognition(struct ccw_device *cdev)
433 {
434 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
435 
436 	/*
437 	 * We used to start here with a sense pgid to find out whether a device
438 	 * is locked by someone else. Unfortunately, the sense pgid command
439 	 * code has other meanings on devices predating the path grouping
440 	 * algorithm, so we start with sense id and box the device after an
441 	 * timeout (or if sense pgid during path verification detects the device
442 	 * is locked, as may happen on newer devices).
443 	 */
444 	cdev->private->flags.recog_done = 0;
445 	cdev->private->state = DEV_STATE_SENSE_ID;
446 	if (cio_enable_subchannel(sch, (u32) (addr_t) sch)) {
447 		ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
448 		return;
449 	}
450 	ccw_device_sense_id_start(cdev);
451 }
452 
453 /*
454  * Handle events for states that use the ccw request infrastructure.
455  */
456 static void ccw_device_request_event(struct ccw_device *cdev, enum dev_event e)
457 {
458 	switch (e) {
459 	case DEV_EVENT_NOTOPER:
460 		ccw_request_notoper(cdev);
461 		break;
462 	case DEV_EVENT_INTERRUPT:
463 		ccw_request_handler(cdev);
464 		break;
465 	case DEV_EVENT_TIMEOUT:
466 		ccw_request_timeout(cdev);
467 		break;
468 	default:
469 		break;
470 	}
471 }
472 
473 static void ccw_device_report_path_events(struct ccw_device *cdev)
474 {
475 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
476 	int path_event[8];
477 	int chp, mask;
478 
479 	for (chp = 0, mask = 0x80; chp < 8; chp++, mask >>= 1) {
480 		path_event[chp] = PE_NONE;
481 		if (mask & cdev->private->path_gone_mask & ~(sch->vpm))
482 			path_event[chp] |= PE_PATH_GONE;
483 		if (mask & cdev->private->path_new_mask & sch->vpm)
484 			path_event[chp] |= PE_PATH_AVAILABLE;
485 		if (mask & cdev->private->pgid_reset_mask & sch->vpm)
486 			path_event[chp] |= PE_PATHGROUP_ESTABLISHED;
487 	}
488 	if (cdev->online && cdev->drv->path_event)
489 		cdev->drv->path_event(cdev, path_event);
490 }
491 
492 static void ccw_device_reset_path_events(struct ccw_device *cdev)
493 {
494 	cdev->private->path_gone_mask = 0;
495 	cdev->private->path_new_mask = 0;
496 	cdev->private->pgid_reset_mask = 0;
497 }
498 
499 static void create_fake_irb(struct irb *irb, int type)
500 {
501 	memset(irb, 0, sizeof(*irb));
502 	if (type == FAKE_CMD_IRB) {
503 		struct cmd_scsw *scsw = &irb->scsw.cmd;
504 		scsw->cc = 1;
505 		scsw->fctl = SCSW_FCTL_START_FUNC;
506 		scsw->actl = SCSW_ACTL_START_PEND;
507 		scsw->stctl = SCSW_STCTL_STATUS_PEND;
508 	} else if (type == FAKE_TM_IRB) {
509 		struct tm_scsw *scsw = &irb->scsw.tm;
510 		scsw->x = 1;
511 		scsw->cc = 1;
512 		scsw->fctl = SCSW_FCTL_START_FUNC;
513 		scsw->actl = SCSW_ACTL_START_PEND;
514 		scsw->stctl = SCSW_STCTL_STATUS_PEND;
515 	}
516 }
517 
518 void ccw_device_verify_done(struct ccw_device *cdev, int err)
519 {
520 	struct subchannel *sch;
521 
522 	sch = to_subchannel(cdev->dev.parent);
523 	/* Update schib - pom may have changed. */
524 	if (cio_update_schib(sch)) {
525 		err = -ENODEV;
526 		goto callback;
527 	}
528 	/* Update lpm with verified path mask. */
529 	sch->lpm = sch->vpm;
530 	/* Repeat path verification? */
531 	if (cdev->private->flags.doverify) {
532 		ccw_device_verify_start(cdev);
533 		return;
534 	}
535 callback:
536 	switch (err) {
537 	case 0:
538 		ccw_device_done(cdev, DEV_STATE_ONLINE);
539 		/* Deliver fake irb to device driver, if needed. */
540 		if (cdev->private->flags.fake_irb) {
541 			create_fake_irb(&cdev->private->irb,
542 					cdev->private->flags.fake_irb);
543 			cdev->private->flags.fake_irb = 0;
544 			if (cdev->handler)
545 				cdev->handler(cdev, cdev->private->intparm,
546 					      &cdev->private->irb);
547 			memset(&cdev->private->irb, 0, sizeof(struct irb));
548 		}
549 		ccw_device_report_path_events(cdev);
550 		break;
551 	case -ETIME:
552 	case -EUSERS:
553 		/* Reset oper notify indication after verify error. */
554 		cdev->private->flags.donotify = 0;
555 		ccw_device_done(cdev, DEV_STATE_BOXED);
556 		break;
557 	case -EACCES:
558 		/* Reset oper notify indication after verify error. */
559 		cdev->private->flags.donotify = 0;
560 		ccw_device_done(cdev, DEV_STATE_DISCONNECTED);
561 		break;
562 	default:
563 		/* Reset oper notify indication after verify error. */
564 		cdev->private->flags.donotify = 0;
565 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
566 		break;
567 	}
568 	ccw_device_reset_path_events(cdev);
569 }
570 
571 /*
572  * Get device online.
573  */
574 int
575 ccw_device_online(struct ccw_device *cdev)
576 {
577 	struct subchannel *sch;
578 	int ret;
579 
580 	if ((cdev->private->state != DEV_STATE_OFFLINE) &&
581 	    (cdev->private->state != DEV_STATE_BOXED))
582 		return -EINVAL;
583 	sch = to_subchannel(cdev->dev.parent);
584 	ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
585 	if (ret != 0) {
586 		/* Couldn't enable the subchannel for i/o. Sick device. */
587 		if (ret == -ENODEV)
588 			dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
589 		return ret;
590 	}
591 	/* Start initial path verification. */
592 	cdev->private->state = DEV_STATE_VERIFY;
593 	ccw_device_verify_start(cdev);
594 	return 0;
595 }
596 
597 void
598 ccw_device_disband_done(struct ccw_device *cdev, int err)
599 {
600 	switch (err) {
601 	case 0:
602 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
603 		break;
604 	case -ETIME:
605 		ccw_device_done(cdev, DEV_STATE_BOXED);
606 		break;
607 	default:
608 		cdev->private->flags.donotify = 0;
609 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
610 		break;
611 	}
612 }
613 
614 /*
615  * Shutdown device.
616  */
617 int
618 ccw_device_offline(struct ccw_device *cdev)
619 {
620 	struct subchannel *sch;
621 
622 	/* Allow ccw_device_offline while disconnected. */
623 	if (cdev->private->state == DEV_STATE_DISCONNECTED ||
624 	    cdev->private->state == DEV_STATE_NOT_OPER) {
625 		cdev->private->flags.donotify = 0;
626 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
627 		return 0;
628 	}
629 	if (cdev->private->state == DEV_STATE_BOXED) {
630 		ccw_device_done(cdev, DEV_STATE_BOXED);
631 		return 0;
632 	}
633 	if (ccw_device_is_orphan(cdev)) {
634 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
635 		return 0;
636 	}
637 	sch = to_subchannel(cdev->dev.parent);
638 	if (cio_update_schib(sch))
639 		return -ENODEV;
640 	if (scsw_actl(&sch->schib.scsw) != 0)
641 		return -EBUSY;
642 	if (cdev->private->state != DEV_STATE_ONLINE)
643 		return -EINVAL;
644 	/* Are we doing path grouping? */
645 	if (!cdev->private->flags.pgroup) {
646 		/* No, set state offline immediately. */
647 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
648 		return 0;
649 	}
650 	/* Start Set Path Group commands. */
651 	cdev->private->state = DEV_STATE_DISBAND_PGID;
652 	ccw_device_disband_start(cdev);
653 	return 0;
654 }
655 
656 /*
657  * Handle not operational event in non-special state.
658  */
659 static void ccw_device_generic_notoper(struct ccw_device *cdev,
660 				       enum dev_event dev_event)
661 {
662 	if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
663 		ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
664 	else
665 		ccw_device_set_disconnected(cdev);
666 }
667 
668 /*
669  * Handle path verification event in offline state.
670  */
671 static void ccw_device_offline_verify(struct ccw_device *cdev,
672 				      enum dev_event dev_event)
673 {
674 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
675 
676 	css_schedule_eval(sch->schid);
677 }
678 
679 /*
680  * Handle path verification event.
681  */
682 static void
683 ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
684 {
685 	struct subchannel *sch;
686 
687 	if (cdev->private->state == DEV_STATE_W4SENSE) {
688 		cdev->private->flags.doverify = 1;
689 		return;
690 	}
691 	sch = to_subchannel(cdev->dev.parent);
692 	/*
693 	 * Since we might not just be coming from an interrupt from the
694 	 * subchannel we have to update the schib.
695 	 */
696 	if (cio_update_schib(sch)) {
697 		ccw_device_verify_done(cdev, -ENODEV);
698 		return;
699 	}
700 
701 	if (scsw_actl(&sch->schib.scsw) != 0 ||
702 	    (scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_STATUS_PEND) ||
703 	    (scsw_stctl(&cdev->private->irb.scsw) & SCSW_STCTL_STATUS_PEND)) {
704 		/*
705 		 * No final status yet or final status not yet delivered
706 		 * to the device driver. Can't do path verification now,
707 		 * delay until final status was delivered.
708 		 */
709 		cdev->private->flags.doverify = 1;
710 		return;
711 	}
712 	/* Device is idle, we can do the path verification. */
713 	cdev->private->state = DEV_STATE_VERIFY;
714 	ccw_device_verify_start(cdev);
715 }
716 
717 /*
718  * Handle path verification event in boxed state.
719  */
720 static void ccw_device_boxed_verify(struct ccw_device *cdev,
721 				    enum dev_event dev_event)
722 {
723 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
724 
725 	if (cdev->online) {
726 		if (cio_enable_subchannel(sch, (u32) (addr_t) sch))
727 			ccw_device_done(cdev, DEV_STATE_NOT_OPER);
728 		else
729 			ccw_device_online_verify(cdev, dev_event);
730 	} else
731 		css_schedule_eval(sch->schid);
732 }
733 
734 /*
735  * Got an interrupt for a normal io (state online).
736  */
737 static void
738 ccw_device_irq(struct ccw_device *cdev, enum dev_event dev_event)
739 {
740 	struct irb *irb;
741 	int is_cmd;
742 
743 	irb = (struct irb *)&S390_lowcore.irb;
744 	is_cmd = !scsw_is_tm(&irb->scsw);
745 	/* Check for unsolicited interrupt. */
746 	if (!scsw_is_solicited(&irb->scsw)) {
747 		if (is_cmd && (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) &&
748 		    !irb->esw.esw0.erw.cons) {
749 			/* Unit check but no sense data. Need basic sense. */
750 			if (ccw_device_do_sense(cdev, irb) != 0)
751 				goto call_handler_unsol;
752 			memcpy(&cdev->private->irb, irb, sizeof(struct irb));
753 			cdev->private->state = DEV_STATE_W4SENSE;
754 			cdev->private->intparm = 0;
755 			return;
756 		}
757 call_handler_unsol:
758 		if (cdev->handler)
759 			cdev->handler (cdev, 0, irb);
760 		if (cdev->private->flags.doverify)
761 			ccw_device_online_verify(cdev, 0);
762 		return;
763 	}
764 	/* Accumulate status and find out if a basic sense is needed. */
765 	ccw_device_accumulate_irb(cdev, irb);
766 	if (is_cmd && cdev->private->flags.dosense) {
767 		if (ccw_device_do_sense(cdev, irb) == 0) {
768 			cdev->private->state = DEV_STATE_W4SENSE;
769 		}
770 		return;
771 	}
772 	/* Call the handler. */
773 	if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
774 		/* Start delayed path verification. */
775 		ccw_device_online_verify(cdev, 0);
776 }
777 
778 /*
779  * Got an timeout in online state.
780  */
781 static void
782 ccw_device_online_timeout(struct ccw_device *cdev, enum dev_event dev_event)
783 {
784 	int ret;
785 
786 	ccw_device_set_timeout(cdev, 0);
787 	cdev->private->iretry = 255;
788 	ret = ccw_device_cancel_halt_clear(cdev);
789 	if (ret == -EBUSY) {
790 		ccw_device_set_timeout(cdev, 3*HZ);
791 		cdev->private->state = DEV_STATE_TIMEOUT_KILL;
792 		return;
793 	}
794 	if (ret)
795 		dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
796 	else if (cdev->handler)
797 		cdev->handler(cdev, cdev->private->intparm,
798 			      ERR_PTR(-ETIMEDOUT));
799 }
800 
801 /*
802  * Got an interrupt for a basic sense.
803  */
804 static void
805 ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
806 {
807 	struct irb *irb;
808 
809 	irb = (struct irb *)&S390_lowcore.irb;
810 	/* Check for unsolicited interrupt. */
811 	if (scsw_stctl(&irb->scsw) ==
812 	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
813 		if (scsw_cc(&irb->scsw) == 1)
814 			/* Basic sense hasn't started. Try again. */
815 			ccw_device_do_sense(cdev, irb);
816 		else {
817 			CIO_MSG_EVENT(0, "0.%x.%04x: unsolicited "
818 				      "interrupt during w4sense...\n",
819 				      cdev->private->dev_id.ssid,
820 				      cdev->private->dev_id.devno);
821 			if (cdev->handler)
822 				cdev->handler (cdev, 0, irb);
823 		}
824 		return;
825 	}
826 	/*
827 	 * Check if a halt or clear has been issued in the meanwhile. If yes,
828 	 * only deliver the halt/clear interrupt to the device driver as if it
829 	 * had killed the original request.
830 	 */
831 	if (scsw_fctl(&irb->scsw) &
832 	    (SCSW_FCTL_CLEAR_FUNC | SCSW_FCTL_HALT_FUNC)) {
833 		cdev->private->flags.dosense = 0;
834 		memset(&cdev->private->irb, 0, sizeof(struct irb));
835 		ccw_device_accumulate_irb(cdev, irb);
836 		goto call_handler;
837 	}
838 	/* Add basic sense info to irb. */
839 	ccw_device_accumulate_basic_sense(cdev, irb);
840 	if (cdev->private->flags.dosense) {
841 		/* Another basic sense is needed. */
842 		ccw_device_do_sense(cdev, irb);
843 		return;
844 	}
845 call_handler:
846 	cdev->private->state = DEV_STATE_ONLINE;
847 	/* In case sensing interfered with setting the device online */
848 	wake_up(&cdev->private->wait_q);
849 	/* Call the handler. */
850 	if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
851 		/* Start delayed path verification. */
852 		ccw_device_online_verify(cdev, 0);
853 }
854 
855 static void
856 ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
857 {
858 	ccw_device_set_timeout(cdev, 0);
859 	/* Start delayed path verification. */
860 	ccw_device_online_verify(cdev, 0);
861 	/* OK, i/o is dead now. Call interrupt handler. */
862 	if (cdev->handler)
863 		cdev->handler(cdev, cdev->private->intparm,
864 			      ERR_PTR(-EIO));
865 }
866 
867 static void
868 ccw_device_killing_timeout(struct ccw_device *cdev, enum dev_event dev_event)
869 {
870 	int ret;
871 
872 	ret = ccw_device_cancel_halt_clear(cdev);
873 	if (ret == -EBUSY) {
874 		ccw_device_set_timeout(cdev, 3*HZ);
875 		return;
876 	}
877 	/* Start delayed path verification. */
878 	ccw_device_online_verify(cdev, 0);
879 	if (cdev->handler)
880 		cdev->handler(cdev, cdev->private->intparm,
881 			      ERR_PTR(-EIO));
882 }
883 
884 void ccw_device_kill_io(struct ccw_device *cdev)
885 {
886 	int ret;
887 
888 	cdev->private->iretry = 255;
889 	ret = ccw_device_cancel_halt_clear(cdev);
890 	if (ret == -EBUSY) {
891 		ccw_device_set_timeout(cdev, 3*HZ);
892 		cdev->private->state = DEV_STATE_TIMEOUT_KILL;
893 		return;
894 	}
895 	/* Start delayed path verification. */
896 	ccw_device_online_verify(cdev, 0);
897 	if (cdev->handler)
898 		cdev->handler(cdev, cdev->private->intparm,
899 			      ERR_PTR(-EIO));
900 }
901 
902 static void
903 ccw_device_delay_verify(struct ccw_device *cdev, enum dev_event dev_event)
904 {
905 	/* Start verification after current task finished. */
906 	cdev->private->flags.doverify = 1;
907 }
908 
909 static void
910 ccw_device_start_id(struct ccw_device *cdev, enum dev_event dev_event)
911 {
912 	struct subchannel *sch;
913 
914 	sch = to_subchannel(cdev->dev.parent);
915 	if (cio_enable_subchannel(sch, (u32)(addr_t)sch) != 0)
916 		/* Couldn't enable the subchannel for i/o. Sick device. */
917 		return;
918 	cdev->private->state = DEV_STATE_DISCONNECTED_SENSE_ID;
919 	ccw_device_sense_id_start(cdev);
920 }
921 
922 void ccw_device_trigger_reprobe(struct ccw_device *cdev)
923 {
924 	struct subchannel *sch;
925 
926 	if (cdev->private->state != DEV_STATE_DISCONNECTED)
927 		return;
928 
929 	sch = to_subchannel(cdev->dev.parent);
930 	/* Update some values. */
931 	if (cio_update_schib(sch))
932 		return;
933 	/*
934 	 * The pim, pam, pom values may not be accurate, but they are the best
935 	 * we have before performing device selection :/
936 	 */
937 	sch->lpm = sch->schib.pmcw.pam & sch->opm;
938 	/*
939 	 * Use the initial configuration since we can't be shure that the old
940 	 * paths are valid.
941 	 */
942 	io_subchannel_init_config(sch);
943 	if (cio_commit_config(sch))
944 		return;
945 
946 	/* We should also udate ssd info, but this has to wait. */
947 	/* Check if this is another device which appeared on the same sch. */
948 	if (sch->schib.pmcw.dev != cdev->private->dev_id.devno)
949 		css_schedule_eval(sch->schid);
950 	else
951 		ccw_device_start_id(cdev, 0);
952 }
953 
954 static void ccw_device_disabled_irq(struct ccw_device *cdev,
955 				    enum dev_event dev_event)
956 {
957 	struct subchannel *sch;
958 
959 	sch = to_subchannel(cdev->dev.parent);
960 	/*
961 	 * An interrupt in a disabled state means a previous disable was not
962 	 * successful - should not happen, but we try to disable again.
963 	 */
964 	cio_disable_subchannel(sch);
965 }
966 
967 static void
968 ccw_device_change_cmfstate(struct ccw_device *cdev, enum dev_event dev_event)
969 {
970 	retry_set_schib(cdev);
971 	cdev->private->state = DEV_STATE_ONLINE;
972 	dev_fsm_event(cdev, dev_event);
973 }
974 
975 static void ccw_device_update_cmfblock(struct ccw_device *cdev,
976 				       enum dev_event dev_event)
977 {
978 	cmf_retry_copy_block(cdev);
979 	cdev->private->state = DEV_STATE_ONLINE;
980 	dev_fsm_event(cdev, dev_event);
981 }
982 
983 static void
984 ccw_device_quiesce_done(struct ccw_device *cdev, enum dev_event dev_event)
985 {
986 	ccw_device_set_timeout(cdev, 0);
987 	cdev->private->state = DEV_STATE_NOT_OPER;
988 	wake_up(&cdev->private->wait_q);
989 }
990 
991 static void
992 ccw_device_quiesce_timeout(struct ccw_device *cdev, enum dev_event dev_event)
993 {
994 	int ret;
995 
996 	ret = ccw_device_cancel_halt_clear(cdev);
997 	if (ret == -EBUSY) {
998 		ccw_device_set_timeout(cdev, HZ/10);
999 	} else {
1000 		cdev->private->state = DEV_STATE_NOT_OPER;
1001 		wake_up(&cdev->private->wait_q);
1002 	}
1003 }
1004 
1005 /*
1006  * No operation action. This is used e.g. to ignore a timeout event in
1007  * state offline.
1008  */
1009 static void
1010 ccw_device_nop(struct ccw_device *cdev, enum dev_event dev_event)
1011 {
1012 }
1013 
1014 /*
1015  * device statemachine
1016  */
1017 fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
1018 	[DEV_STATE_NOT_OPER] = {
1019 		[DEV_EVENT_NOTOPER]	= ccw_device_nop,
1020 		[DEV_EVENT_INTERRUPT]	= ccw_device_disabled_irq,
1021 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1022 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1023 	},
1024 	[DEV_STATE_SENSE_PGID] = {
1025 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1026 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1027 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1028 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1029 	},
1030 	[DEV_STATE_SENSE_ID] = {
1031 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1032 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1033 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1034 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1035 	},
1036 	[DEV_STATE_OFFLINE] = {
1037 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1038 		[DEV_EVENT_INTERRUPT]	= ccw_device_disabled_irq,
1039 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1040 		[DEV_EVENT_VERIFY]	= ccw_device_offline_verify,
1041 	},
1042 	[DEV_STATE_VERIFY] = {
1043 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1044 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1045 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1046 		[DEV_EVENT_VERIFY]	= ccw_device_delay_verify,
1047 	},
1048 	[DEV_STATE_ONLINE] = {
1049 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1050 		[DEV_EVENT_INTERRUPT]	= ccw_device_irq,
1051 		[DEV_EVENT_TIMEOUT]	= ccw_device_online_timeout,
1052 		[DEV_EVENT_VERIFY]	= ccw_device_online_verify,
1053 	},
1054 	[DEV_STATE_W4SENSE] = {
1055 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1056 		[DEV_EVENT_INTERRUPT]	= ccw_device_w4sense,
1057 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1058 		[DEV_EVENT_VERIFY]	= ccw_device_online_verify,
1059 	},
1060 	[DEV_STATE_DISBAND_PGID] = {
1061 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1062 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1063 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1064 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1065 	},
1066 	[DEV_STATE_BOXED] = {
1067 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1068 		[DEV_EVENT_INTERRUPT]	= ccw_device_nop,
1069 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1070 		[DEV_EVENT_VERIFY]	= ccw_device_boxed_verify,
1071 	},
1072 	/* states to wait for i/o completion before doing something */
1073 	[DEV_STATE_TIMEOUT_KILL] = {
1074 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1075 		[DEV_EVENT_INTERRUPT]	= ccw_device_killing_irq,
1076 		[DEV_EVENT_TIMEOUT]	= ccw_device_killing_timeout,
1077 		[DEV_EVENT_VERIFY]	= ccw_device_nop, //FIXME
1078 	},
1079 	[DEV_STATE_QUIESCE] = {
1080 		[DEV_EVENT_NOTOPER]	= ccw_device_quiesce_done,
1081 		[DEV_EVENT_INTERRUPT]	= ccw_device_quiesce_done,
1082 		[DEV_EVENT_TIMEOUT]	= ccw_device_quiesce_timeout,
1083 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1084 	},
1085 	/* special states for devices gone not operational */
1086 	[DEV_STATE_DISCONNECTED] = {
1087 		[DEV_EVENT_NOTOPER]	= ccw_device_nop,
1088 		[DEV_EVENT_INTERRUPT]	= ccw_device_start_id,
1089 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1090 		[DEV_EVENT_VERIFY]	= ccw_device_start_id,
1091 	},
1092 	[DEV_STATE_DISCONNECTED_SENSE_ID] = {
1093 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1094 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1095 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1096 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1097 	},
1098 	[DEV_STATE_CMFCHANGE] = {
1099 		[DEV_EVENT_NOTOPER]	= ccw_device_change_cmfstate,
1100 		[DEV_EVENT_INTERRUPT]	= ccw_device_change_cmfstate,
1101 		[DEV_EVENT_TIMEOUT]	= ccw_device_change_cmfstate,
1102 		[DEV_EVENT_VERIFY]	= ccw_device_change_cmfstate,
1103 	},
1104 	[DEV_STATE_CMFUPDATE] = {
1105 		[DEV_EVENT_NOTOPER]	= ccw_device_update_cmfblock,
1106 		[DEV_EVENT_INTERRUPT]	= ccw_device_update_cmfblock,
1107 		[DEV_EVENT_TIMEOUT]	= ccw_device_update_cmfblock,
1108 		[DEV_EVENT_VERIFY]	= ccw_device_update_cmfblock,
1109 	},
1110 	[DEV_STATE_STEAL_LOCK] = {
1111 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1112 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1113 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1114 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1115 	},
1116 };
1117 
1118 EXPORT_SYMBOL_GPL(ccw_device_set_timeout);
1119