xref: /openbmc/linux/drivers/s390/cio/device_fsm.c (revision 8730046c)
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 /*
128  * Cancel running i/o. This is called repeatedly since halt/clear are
129  * asynchronous operations. We do one try with cio_cancel, two tries
130  * with cio_halt, 255 tries with cio_clear. If everythings fails panic.
131  * Returns 0 if device now idle, -ENODEV for device not operational and
132  * -EBUSY if an interrupt is expected (either from halt/clear or from a
133  * status pending).
134  */
135 int
136 ccw_device_cancel_halt_clear(struct ccw_device *cdev)
137 {
138 	struct subchannel *sch;
139 	int ret;
140 
141 	sch = to_subchannel(cdev->dev.parent);
142 	if (cio_update_schib(sch))
143 		return -ENODEV;
144 	if (!sch->schib.pmcw.ena)
145 		/* Not operational -> done. */
146 		return 0;
147 	/* Stage 1: cancel io. */
148 	if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_HALT_PEND) &&
149 	    !(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
150 		if (!scsw_is_tm(&sch->schib.scsw)) {
151 			ret = cio_cancel(sch);
152 			if (ret != -EINVAL)
153 				return ret;
154 		}
155 		/* cancel io unsuccessful or not applicable (transport mode).
156 		 * Continue with asynchronous instructions. */
157 		cdev->private->iretry = 3;	/* 3 halt retries. */
158 	}
159 	if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
160 		/* Stage 2: halt io. */
161 		if (cdev->private->iretry) {
162 			cdev->private->iretry--;
163 			ret = cio_halt(sch);
164 			if (ret != -EBUSY)
165 				return (ret == 0) ? -EBUSY : ret;
166 		}
167 		/* halt io unsuccessful. */
168 		cdev->private->iretry = 255;	/* 255 clear retries. */
169 	}
170 	/* Stage 3: clear io. */
171 	if (cdev->private->iretry) {
172 		cdev->private->iretry--;
173 		ret = cio_clear (sch);
174 		return (ret == 0) ? -EBUSY : ret;
175 	}
176 	/* Function was unsuccessful */
177 	CIO_MSG_EVENT(0, "0.%x.%04x: could not stop I/O\n",
178 		      cdev->private->dev_id.ssid, cdev->private->dev_id.devno);
179 	return -EIO;
180 }
181 
182 void ccw_device_update_sense_data(struct ccw_device *cdev)
183 {
184 	memset(&cdev->id, 0, sizeof(cdev->id));
185 	cdev->id.cu_type   = cdev->private->senseid.cu_type;
186 	cdev->id.cu_model  = cdev->private->senseid.cu_model;
187 	cdev->id.dev_type  = cdev->private->senseid.dev_type;
188 	cdev->id.dev_model = cdev->private->senseid.dev_model;
189 }
190 
191 int ccw_device_test_sense_data(struct ccw_device *cdev)
192 {
193 	return cdev->id.cu_type == cdev->private->senseid.cu_type &&
194 		cdev->id.cu_model == cdev->private->senseid.cu_model &&
195 		cdev->id.dev_type == cdev->private->senseid.dev_type &&
196 		cdev->id.dev_model == cdev->private->senseid.dev_model;
197 }
198 
199 /*
200  * The machine won't give us any notification by machine check if a chpid has
201  * been varied online on the SE so we have to find out by magic (i. e. driving
202  * the channel subsystem to device selection and updating our path masks).
203  */
204 static void
205 __recover_lost_chpids(struct subchannel *sch, int old_lpm)
206 {
207 	int mask, i;
208 	struct chp_id chpid;
209 
210 	chp_id_init(&chpid);
211 	for (i = 0; i<8; i++) {
212 		mask = 0x80 >> i;
213 		if (!(sch->lpm & mask))
214 			continue;
215 		if (old_lpm & mask)
216 			continue;
217 		chpid.id = sch->schib.pmcw.chpid[i];
218 		if (!chp_is_registered(chpid))
219 			css_schedule_eval_all();
220 	}
221 }
222 
223 /*
224  * Stop device recognition.
225  */
226 static void
227 ccw_device_recog_done(struct ccw_device *cdev, int state)
228 {
229 	struct subchannel *sch;
230 	int old_lpm;
231 
232 	sch = to_subchannel(cdev->dev.parent);
233 
234 	if (cio_disable_subchannel(sch))
235 		state = DEV_STATE_NOT_OPER;
236 	/*
237 	 * Now that we tried recognition, we have performed device selection
238 	 * through ssch() and the path information is up to date.
239 	 */
240 	old_lpm = sch->lpm;
241 
242 	/* Check since device may again have become not operational. */
243 	if (cio_update_schib(sch))
244 		state = DEV_STATE_NOT_OPER;
245 	else
246 		sch->lpm = sch->schib.pmcw.pam & sch->opm;
247 
248 	if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID)
249 		/* Force reprobe on all chpids. */
250 		old_lpm = 0;
251 	if (sch->lpm != old_lpm)
252 		__recover_lost_chpids(sch, old_lpm);
253 	if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID &&
254 	    (state == DEV_STATE_NOT_OPER || state == DEV_STATE_BOXED)) {
255 		cdev->private->flags.recog_done = 1;
256 		cdev->private->state = DEV_STATE_DISCONNECTED;
257 		wake_up(&cdev->private->wait_q);
258 		return;
259 	}
260 	if (cdev->private->flags.resuming) {
261 		cdev->private->state = state;
262 		cdev->private->flags.recog_done = 1;
263 		wake_up(&cdev->private->wait_q);
264 		return;
265 	}
266 	switch (state) {
267 	case DEV_STATE_NOT_OPER:
268 		break;
269 	case DEV_STATE_OFFLINE:
270 		if (!cdev->online) {
271 			ccw_device_update_sense_data(cdev);
272 			break;
273 		}
274 		cdev->private->state = DEV_STATE_OFFLINE;
275 		cdev->private->flags.recog_done = 1;
276 		if (ccw_device_test_sense_data(cdev)) {
277 			cdev->private->flags.donotify = 1;
278 			ccw_device_online(cdev);
279 			wake_up(&cdev->private->wait_q);
280 		} else {
281 			ccw_device_update_sense_data(cdev);
282 			ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
283 		}
284 		return;
285 	case DEV_STATE_BOXED:
286 		if (cdev->id.cu_type != 0) { /* device was recognized before */
287 			cdev->private->flags.recog_done = 1;
288 			cdev->private->state = DEV_STATE_BOXED;
289 			wake_up(&cdev->private->wait_q);
290 			return;
291 		}
292 		break;
293 	}
294 	cdev->private->state = state;
295 	io_subchannel_recog_done(cdev);
296 	wake_up(&cdev->private->wait_q);
297 }
298 
299 /*
300  * Function called from device_id.c after sense id has completed.
301  */
302 void
303 ccw_device_sense_id_done(struct ccw_device *cdev, int err)
304 {
305 	switch (err) {
306 	case 0:
307 		ccw_device_recog_done(cdev, DEV_STATE_OFFLINE);
308 		break;
309 	case -ETIME:		/* Sense id stopped by timeout. */
310 		ccw_device_recog_done(cdev, DEV_STATE_BOXED);
311 		break;
312 	default:
313 		ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
314 		break;
315 	}
316 }
317 
318 /**
319   * ccw_device_notify() - inform the device's driver about an event
320   * @cdev: device for which an event occurred
321   * @event: event that occurred
322   *
323   * Returns:
324   *   -%EINVAL if the device is offline or has no driver.
325   *   -%EOPNOTSUPP if the device's driver has no notifier registered.
326   *   %NOTIFY_OK if the driver wants to keep the device.
327   *   %NOTIFY_BAD if the driver doesn't want to keep the device.
328   */
329 int ccw_device_notify(struct ccw_device *cdev, int event)
330 {
331 	int ret = -EINVAL;
332 
333 	if (!cdev->drv)
334 		goto out;
335 	if (!cdev->online)
336 		goto out;
337 	CIO_MSG_EVENT(2, "notify called for 0.%x.%04x, event=%d\n",
338 		      cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
339 		      event);
340 	if (!cdev->drv->notify) {
341 		ret = -EOPNOTSUPP;
342 		goto out;
343 	}
344 	if (cdev->drv->notify(cdev, event))
345 		ret = NOTIFY_OK;
346 	else
347 		ret = NOTIFY_BAD;
348 out:
349 	return ret;
350 }
351 
352 static void ccw_device_oper_notify(struct ccw_device *cdev)
353 {
354 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
355 
356 	if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_OK) {
357 		/* Reenable channel measurements, if needed. */
358 		ccw_device_sched_todo(cdev, CDEV_TODO_ENABLE_CMF);
359 		/* Save indication for new paths. */
360 		cdev->private->path_new_mask = sch->vpm;
361 		return;
362 	}
363 	/* Driver doesn't want device back. */
364 	ccw_device_set_notoper(cdev);
365 	ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
366 }
367 
368 /*
369  * Finished with online/offline processing.
370  */
371 static void
372 ccw_device_done(struct ccw_device *cdev, int state)
373 {
374 	struct subchannel *sch;
375 
376 	sch = to_subchannel(cdev->dev.parent);
377 
378 	ccw_device_set_timeout(cdev, 0);
379 
380 	if (state != DEV_STATE_ONLINE)
381 		cio_disable_subchannel(sch);
382 
383 	/* Reset device status. */
384 	memset(&cdev->private->irb, 0, sizeof(struct irb));
385 
386 	cdev->private->state = state;
387 
388 	switch (state) {
389 	case DEV_STATE_BOXED:
390 		CIO_MSG_EVENT(0, "Boxed device %04x on subchannel %04x\n",
391 			      cdev->private->dev_id.devno, sch->schid.sch_no);
392 		if (cdev->online &&
393 		    ccw_device_notify(cdev, CIO_BOXED) != NOTIFY_OK)
394 			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
395 		cdev->private->flags.donotify = 0;
396 		break;
397 	case DEV_STATE_NOT_OPER:
398 		CIO_MSG_EVENT(0, "Device %04x gone on subchannel %04x\n",
399 			      cdev->private->dev_id.devno, sch->schid.sch_no);
400 		if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
401 			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
402 		else
403 			ccw_device_set_disconnected(cdev);
404 		cdev->private->flags.donotify = 0;
405 		break;
406 	case DEV_STATE_DISCONNECTED:
407 		CIO_MSG_EVENT(0, "Disconnected device %04x on subchannel "
408 			      "%04x\n", cdev->private->dev_id.devno,
409 			      sch->schid.sch_no);
410 		if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK) {
411 			cdev->private->state = DEV_STATE_NOT_OPER;
412 			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
413 		} else
414 			ccw_device_set_disconnected(cdev);
415 		cdev->private->flags.donotify = 0;
416 		break;
417 	default:
418 		break;
419 	}
420 
421 	if (cdev->private->flags.donotify) {
422 		cdev->private->flags.donotify = 0;
423 		ccw_device_oper_notify(cdev);
424 	}
425 	wake_up(&cdev->private->wait_q);
426 }
427 
428 /*
429  * Start device recognition.
430  */
431 void ccw_device_recognition(struct ccw_device *cdev)
432 {
433 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
434 
435 	/*
436 	 * We used to start here with a sense pgid to find out whether a device
437 	 * is locked by someone else. Unfortunately, the sense pgid command
438 	 * code has other meanings on devices predating the path grouping
439 	 * algorithm, so we start with sense id and box the device after an
440 	 * timeout (or if sense pgid during path verification detects the device
441 	 * is locked, as may happen on newer devices).
442 	 */
443 	cdev->private->flags.recog_done = 0;
444 	cdev->private->state = DEV_STATE_SENSE_ID;
445 	if (cio_enable_subchannel(sch, (u32) (addr_t) sch)) {
446 		ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
447 		return;
448 	}
449 	ccw_device_sense_id_start(cdev);
450 }
451 
452 /*
453  * Handle events for states that use the ccw request infrastructure.
454  */
455 static void ccw_device_request_event(struct ccw_device *cdev, enum dev_event e)
456 {
457 	switch (e) {
458 	case DEV_EVENT_NOTOPER:
459 		ccw_request_notoper(cdev);
460 		break;
461 	case DEV_EVENT_INTERRUPT:
462 		ccw_request_handler(cdev);
463 		break;
464 	case DEV_EVENT_TIMEOUT:
465 		ccw_request_timeout(cdev);
466 		break;
467 	default:
468 		break;
469 	}
470 }
471 
472 static void ccw_device_report_path_events(struct ccw_device *cdev)
473 {
474 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
475 	int path_event[8];
476 	int chp, mask;
477 
478 	for (chp = 0, mask = 0x80; chp < 8; chp++, mask >>= 1) {
479 		path_event[chp] = PE_NONE;
480 		if (mask & cdev->private->path_gone_mask & ~(sch->vpm))
481 			path_event[chp] |= PE_PATH_GONE;
482 		if (mask & cdev->private->path_new_mask & sch->vpm)
483 			path_event[chp] |= PE_PATH_AVAILABLE;
484 		if (mask & cdev->private->pgid_reset_mask & sch->vpm)
485 			path_event[chp] |= PE_PATHGROUP_ESTABLISHED;
486 	}
487 	if (cdev->online && cdev->drv->path_event)
488 		cdev->drv->path_event(cdev, path_event);
489 }
490 
491 static void ccw_device_reset_path_events(struct ccw_device *cdev)
492 {
493 	cdev->private->path_gone_mask = 0;
494 	cdev->private->path_new_mask = 0;
495 	cdev->private->pgid_reset_mask = 0;
496 }
497 
498 static void create_fake_irb(struct irb *irb, int type)
499 {
500 	memset(irb, 0, sizeof(*irb));
501 	if (type == FAKE_CMD_IRB) {
502 		struct cmd_scsw *scsw = &irb->scsw.cmd;
503 		scsw->cc = 1;
504 		scsw->fctl = SCSW_FCTL_START_FUNC;
505 		scsw->actl = SCSW_ACTL_START_PEND;
506 		scsw->stctl = SCSW_STCTL_STATUS_PEND;
507 	} else if (type == FAKE_TM_IRB) {
508 		struct tm_scsw *scsw = &irb->scsw.tm;
509 		scsw->x = 1;
510 		scsw->cc = 1;
511 		scsw->fctl = SCSW_FCTL_START_FUNC;
512 		scsw->actl = SCSW_ACTL_START_PEND;
513 		scsw->stctl = SCSW_STCTL_STATUS_PEND;
514 	}
515 }
516 
517 void ccw_device_verify_done(struct ccw_device *cdev, int err)
518 {
519 	struct subchannel *sch;
520 
521 	sch = to_subchannel(cdev->dev.parent);
522 	/* Update schib - pom may have changed. */
523 	if (cio_update_schib(sch)) {
524 		err = -ENODEV;
525 		goto callback;
526 	}
527 	/* Update lpm with verified path mask. */
528 	sch->lpm = sch->vpm;
529 	/* Repeat path verification? */
530 	if (cdev->private->flags.doverify) {
531 		ccw_device_verify_start(cdev);
532 		return;
533 	}
534 callback:
535 	switch (err) {
536 	case 0:
537 		ccw_device_done(cdev, DEV_STATE_ONLINE);
538 		/* Deliver fake irb to device driver, if needed. */
539 		if (cdev->private->flags.fake_irb) {
540 			create_fake_irb(&cdev->private->irb,
541 					cdev->private->flags.fake_irb);
542 			cdev->private->flags.fake_irb = 0;
543 			if (cdev->handler)
544 				cdev->handler(cdev, cdev->private->intparm,
545 					      &cdev->private->irb);
546 			memset(&cdev->private->irb, 0, sizeof(struct irb));
547 		}
548 		ccw_device_report_path_events(cdev);
549 		break;
550 	case -ETIME:
551 	case -EUSERS:
552 		/* Reset oper notify indication after verify error. */
553 		cdev->private->flags.donotify = 0;
554 		ccw_device_done(cdev, DEV_STATE_BOXED);
555 		break;
556 	case -EACCES:
557 		/* Reset oper notify indication after verify error. */
558 		cdev->private->flags.donotify = 0;
559 		ccw_device_done(cdev, DEV_STATE_DISCONNECTED);
560 		break;
561 	default:
562 		/* Reset oper notify indication after verify error. */
563 		cdev->private->flags.donotify = 0;
564 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
565 		break;
566 	}
567 	ccw_device_reset_path_events(cdev);
568 }
569 
570 /*
571  * Get device online.
572  */
573 int
574 ccw_device_online(struct ccw_device *cdev)
575 {
576 	struct subchannel *sch;
577 	int ret;
578 
579 	if ((cdev->private->state != DEV_STATE_OFFLINE) &&
580 	    (cdev->private->state != DEV_STATE_BOXED))
581 		return -EINVAL;
582 	sch = to_subchannel(cdev->dev.parent);
583 	ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
584 	if (ret != 0) {
585 		/* Couldn't enable the subchannel for i/o. Sick device. */
586 		if (ret == -ENODEV)
587 			dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
588 		return ret;
589 	}
590 	/* Start initial path verification. */
591 	cdev->private->state = DEV_STATE_VERIFY;
592 	ccw_device_verify_start(cdev);
593 	return 0;
594 }
595 
596 void
597 ccw_device_disband_done(struct ccw_device *cdev, int err)
598 {
599 	switch (err) {
600 	case 0:
601 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
602 		break;
603 	case -ETIME:
604 		ccw_device_done(cdev, DEV_STATE_BOXED);
605 		break;
606 	default:
607 		cdev->private->flags.donotify = 0;
608 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
609 		break;
610 	}
611 }
612 
613 /*
614  * Shutdown device.
615  */
616 int
617 ccw_device_offline(struct ccw_device *cdev)
618 {
619 	struct subchannel *sch;
620 
621 	/* Allow ccw_device_offline while disconnected. */
622 	if (cdev->private->state == DEV_STATE_DISCONNECTED ||
623 	    cdev->private->state == DEV_STATE_NOT_OPER) {
624 		cdev->private->flags.donotify = 0;
625 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
626 		return 0;
627 	}
628 	if (cdev->private->state == DEV_STATE_BOXED) {
629 		ccw_device_done(cdev, DEV_STATE_BOXED);
630 		return 0;
631 	}
632 	if (ccw_device_is_orphan(cdev)) {
633 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
634 		return 0;
635 	}
636 	sch = to_subchannel(cdev->dev.parent);
637 	if (cio_update_schib(sch))
638 		return -ENODEV;
639 	if (scsw_actl(&sch->schib.scsw) != 0)
640 		return -EBUSY;
641 	if (cdev->private->state != DEV_STATE_ONLINE)
642 		return -EINVAL;
643 	/* Are we doing path grouping? */
644 	if (!cdev->private->flags.pgroup) {
645 		/* No, set state offline immediately. */
646 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
647 		return 0;
648 	}
649 	/* Start Set Path Group commands. */
650 	cdev->private->state = DEV_STATE_DISBAND_PGID;
651 	ccw_device_disband_start(cdev);
652 	return 0;
653 }
654 
655 /*
656  * Handle not operational event in non-special state.
657  */
658 static void ccw_device_generic_notoper(struct ccw_device *cdev,
659 				       enum dev_event dev_event)
660 {
661 	if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
662 		ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
663 	else
664 		ccw_device_set_disconnected(cdev);
665 }
666 
667 /*
668  * Handle path verification event in offline state.
669  */
670 static void ccw_device_offline_verify(struct ccw_device *cdev,
671 				      enum dev_event dev_event)
672 {
673 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
674 
675 	css_schedule_eval(sch->schid);
676 }
677 
678 /*
679  * Handle path verification event.
680  */
681 static void
682 ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
683 {
684 	struct subchannel *sch;
685 
686 	if (cdev->private->state == DEV_STATE_W4SENSE) {
687 		cdev->private->flags.doverify = 1;
688 		return;
689 	}
690 	sch = to_subchannel(cdev->dev.parent);
691 	/*
692 	 * Since we might not just be coming from an interrupt from the
693 	 * subchannel we have to update the schib.
694 	 */
695 	if (cio_update_schib(sch)) {
696 		ccw_device_verify_done(cdev, -ENODEV);
697 		return;
698 	}
699 
700 	if (scsw_actl(&sch->schib.scsw) != 0 ||
701 	    (scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_STATUS_PEND) ||
702 	    (scsw_stctl(&cdev->private->irb.scsw) & SCSW_STCTL_STATUS_PEND)) {
703 		/*
704 		 * No final status yet or final status not yet delivered
705 		 * to the device driver. Can't do path verification now,
706 		 * delay until final status was delivered.
707 		 */
708 		cdev->private->flags.doverify = 1;
709 		return;
710 	}
711 	/* Device is idle, we can do the path verification. */
712 	cdev->private->state = DEV_STATE_VERIFY;
713 	ccw_device_verify_start(cdev);
714 }
715 
716 /*
717  * Handle path verification event in boxed state.
718  */
719 static void ccw_device_boxed_verify(struct ccw_device *cdev,
720 				    enum dev_event dev_event)
721 {
722 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
723 
724 	if (cdev->online) {
725 		if (cio_enable_subchannel(sch, (u32) (addr_t) sch))
726 			ccw_device_done(cdev, DEV_STATE_NOT_OPER);
727 		else
728 			ccw_device_online_verify(cdev, dev_event);
729 	} else
730 		css_schedule_eval(sch->schid);
731 }
732 
733 /*
734  * Pass interrupt to device driver.
735  */
736 static int ccw_device_call_handler(struct ccw_device *cdev)
737 {
738 	unsigned int stctl;
739 	int ending_status;
740 
741 	/*
742 	 * we allow for the device action handler if .
743 	 *  - we received ending status
744 	 *  - the action handler requested to see all interrupts
745 	 *  - we received an intermediate status
746 	 *  - fast notification was requested (primary status)
747 	 *  - unsolicited interrupts
748 	 */
749 	stctl = scsw_stctl(&cdev->private->irb.scsw);
750 	ending_status = (stctl & SCSW_STCTL_SEC_STATUS) ||
751 		(stctl == (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)) ||
752 		(stctl == SCSW_STCTL_STATUS_PEND);
753 	if (!ending_status &&
754 	    !cdev->private->options.repall &&
755 	    !(stctl & SCSW_STCTL_INTER_STATUS) &&
756 	    !(cdev->private->options.fast &&
757 	      (stctl & SCSW_STCTL_PRIM_STATUS)))
758 		return 0;
759 
760 	if (ending_status)
761 		ccw_device_set_timeout(cdev, 0);
762 
763 	if (cdev->handler)
764 		cdev->handler(cdev, cdev->private->intparm,
765 			      &cdev->private->irb);
766 
767 	memset(&cdev->private->irb, 0, sizeof(struct irb));
768 	return 1;
769 }
770 
771 /*
772  * Got an interrupt for a normal io (state online).
773  */
774 static void
775 ccw_device_irq(struct ccw_device *cdev, enum dev_event dev_event)
776 {
777 	struct irb *irb;
778 	int is_cmd;
779 
780 	irb = this_cpu_ptr(&cio_irb);
781 	is_cmd = !scsw_is_tm(&irb->scsw);
782 	/* Check for unsolicited interrupt. */
783 	if (!scsw_is_solicited(&irb->scsw)) {
784 		if (is_cmd && (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) &&
785 		    !irb->esw.esw0.erw.cons) {
786 			/* Unit check but no sense data. Need basic sense. */
787 			if (ccw_device_do_sense(cdev, irb) != 0)
788 				goto call_handler_unsol;
789 			memcpy(&cdev->private->irb, irb, sizeof(struct irb));
790 			cdev->private->state = DEV_STATE_W4SENSE;
791 			cdev->private->intparm = 0;
792 			return;
793 		}
794 call_handler_unsol:
795 		if (cdev->handler)
796 			cdev->handler (cdev, 0, irb);
797 		if (cdev->private->flags.doverify)
798 			ccw_device_online_verify(cdev, 0);
799 		return;
800 	}
801 	/* Accumulate status and find out if a basic sense is needed. */
802 	ccw_device_accumulate_irb(cdev, irb);
803 	if (is_cmd && cdev->private->flags.dosense) {
804 		if (ccw_device_do_sense(cdev, irb) == 0) {
805 			cdev->private->state = DEV_STATE_W4SENSE;
806 		}
807 		return;
808 	}
809 	/* Call the handler. */
810 	if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
811 		/* Start delayed path verification. */
812 		ccw_device_online_verify(cdev, 0);
813 }
814 
815 /*
816  * Got an timeout in online state.
817  */
818 static void
819 ccw_device_online_timeout(struct ccw_device *cdev, enum dev_event dev_event)
820 {
821 	int ret;
822 
823 	ccw_device_set_timeout(cdev, 0);
824 	cdev->private->iretry = 255;
825 	ret = ccw_device_cancel_halt_clear(cdev);
826 	if (ret == -EBUSY) {
827 		ccw_device_set_timeout(cdev, 3*HZ);
828 		cdev->private->state = DEV_STATE_TIMEOUT_KILL;
829 		return;
830 	}
831 	if (ret)
832 		dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
833 	else if (cdev->handler)
834 		cdev->handler(cdev, cdev->private->intparm,
835 			      ERR_PTR(-ETIMEDOUT));
836 }
837 
838 /*
839  * Got an interrupt for a basic sense.
840  */
841 static void
842 ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
843 {
844 	struct irb *irb;
845 
846 	irb = this_cpu_ptr(&cio_irb);
847 	/* Check for unsolicited interrupt. */
848 	if (scsw_stctl(&irb->scsw) ==
849 	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
850 		if (scsw_cc(&irb->scsw) == 1)
851 			/* Basic sense hasn't started. Try again. */
852 			ccw_device_do_sense(cdev, irb);
853 		else {
854 			CIO_MSG_EVENT(0, "0.%x.%04x: unsolicited "
855 				      "interrupt during w4sense...\n",
856 				      cdev->private->dev_id.ssid,
857 				      cdev->private->dev_id.devno);
858 			if (cdev->handler)
859 				cdev->handler (cdev, 0, irb);
860 		}
861 		return;
862 	}
863 	/*
864 	 * Check if a halt or clear has been issued in the meanwhile. If yes,
865 	 * only deliver the halt/clear interrupt to the device driver as if it
866 	 * had killed the original request.
867 	 */
868 	if (scsw_fctl(&irb->scsw) &
869 	    (SCSW_FCTL_CLEAR_FUNC | SCSW_FCTL_HALT_FUNC)) {
870 		cdev->private->flags.dosense = 0;
871 		memset(&cdev->private->irb, 0, sizeof(struct irb));
872 		ccw_device_accumulate_irb(cdev, irb);
873 		goto call_handler;
874 	}
875 	/* Add basic sense info to irb. */
876 	ccw_device_accumulate_basic_sense(cdev, irb);
877 	if (cdev->private->flags.dosense) {
878 		/* Another basic sense is needed. */
879 		ccw_device_do_sense(cdev, irb);
880 		return;
881 	}
882 call_handler:
883 	cdev->private->state = DEV_STATE_ONLINE;
884 	/* In case sensing interfered with setting the device online */
885 	wake_up(&cdev->private->wait_q);
886 	/* Call the handler. */
887 	if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
888 		/* Start delayed path verification. */
889 		ccw_device_online_verify(cdev, 0);
890 }
891 
892 static void
893 ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
894 {
895 	ccw_device_set_timeout(cdev, 0);
896 	/* Start delayed path verification. */
897 	ccw_device_online_verify(cdev, 0);
898 	/* OK, i/o is dead now. Call interrupt handler. */
899 	if (cdev->handler)
900 		cdev->handler(cdev, cdev->private->intparm,
901 			      ERR_PTR(-EIO));
902 }
903 
904 static void
905 ccw_device_killing_timeout(struct ccw_device *cdev, enum dev_event dev_event)
906 {
907 	int ret;
908 
909 	ret = ccw_device_cancel_halt_clear(cdev);
910 	if (ret == -EBUSY) {
911 		ccw_device_set_timeout(cdev, 3*HZ);
912 		return;
913 	}
914 	/* Start delayed path verification. */
915 	ccw_device_online_verify(cdev, 0);
916 	if (cdev->handler)
917 		cdev->handler(cdev, cdev->private->intparm,
918 			      ERR_PTR(-EIO));
919 }
920 
921 void ccw_device_kill_io(struct ccw_device *cdev)
922 {
923 	int ret;
924 
925 	cdev->private->iretry = 255;
926 	ret = ccw_device_cancel_halt_clear(cdev);
927 	if (ret == -EBUSY) {
928 		ccw_device_set_timeout(cdev, 3*HZ);
929 		cdev->private->state = DEV_STATE_TIMEOUT_KILL;
930 		return;
931 	}
932 	/* Start delayed path verification. */
933 	ccw_device_online_verify(cdev, 0);
934 	if (cdev->handler)
935 		cdev->handler(cdev, cdev->private->intparm,
936 			      ERR_PTR(-EIO));
937 }
938 
939 static void
940 ccw_device_delay_verify(struct ccw_device *cdev, enum dev_event dev_event)
941 {
942 	/* Start verification after current task finished. */
943 	cdev->private->flags.doverify = 1;
944 }
945 
946 static void
947 ccw_device_start_id(struct ccw_device *cdev, enum dev_event dev_event)
948 {
949 	struct subchannel *sch;
950 
951 	sch = to_subchannel(cdev->dev.parent);
952 	if (cio_enable_subchannel(sch, (u32)(addr_t)sch) != 0)
953 		/* Couldn't enable the subchannel for i/o. Sick device. */
954 		return;
955 	cdev->private->state = DEV_STATE_DISCONNECTED_SENSE_ID;
956 	ccw_device_sense_id_start(cdev);
957 }
958 
959 void ccw_device_trigger_reprobe(struct ccw_device *cdev)
960 {
961 	struct subchannel *sch;
962 
963 	if (cdev->private->state != DEV_STATE_DISCONNECTED)
964 		return;
965 
966 	sch = to_subchannel(cdev->dev.parent);
967 	/* Update some values. */
968 	if (cio_update_schib(sch))
969 		return;
970 	/*
971 	 * The pim, pam, pom values may not be accurate, but they are the best
972 	 * we have before performing device selection :/
973 	 */
974 	sch->lpm = sch->schib.pmcw.pam & sch->opm;
975 	/*
976 	 * Use the initial configuration since we can't be shure that the old
977 	 * paths are valid.
978 	 */
979 	io_subchannel_init_config(sch);
980 	if (cio_commit_config(sch))
981 		return;
982 
983 	/* We should also udate ssd info, but this has to wait. */
984 	/* Check if this is another device which appeared on the same sch. */
985 	if (sch->schib.pmcw.dev != cdev->private->dev_id.devno)
986 		css_schedule_eval(sch->schid);
987 	else
988 		ccw_device_start_id(cdev, 0);
989 }
990 
991 static void ccw_device_disabled_irq(struct ccw_device *cdev,
992 				    enum dev_event dev_event)
993 {
994 	struct subchannel *sch;
995 
996 	sch = to_subchannel(cdev->dev.parent);
997 	/*
998 	 * An interrupt in a disabled state means a previous disable was not
999 	 * successful - should not happen, but we try to disable again.
1000 	 */
1001 	cio_disable_subchannel(sch);
1002 }
1003 
1004 static void
1005 ccw_device_change_cmfstate(struct ccw_device *cdev, enum dev_event dev_event)
1006 {
1007 	retry_set_schib(cdev);
1008 	cdev->private->state = DEV_STATE_ONLINE;
1009 	dev_fsm_event(cdev, dev_event);
1010 }
1011 
1012 static void ccw_device_update_cmfblock(struct ccw_device *cdev,
1013 				       enum dev_event dev_event)
1014 {
1015 	cmf_retry_copy_block(cdev);
1016 	cdev->private->state = DEV_STATE_ONLINE;
1017 	dev_fsm_event(cdev, dev_event);
1018 }
1019 
1020 static void
1021 ccw_device_quiesce_done(struct ccw_device *cdev, enum dev_event dev_event)
1022 {
1023 	ccw_device_set_timeout(cdev, 0);
1024 	cdev->private->state = DEV_STATE_NOT_OPER;
1025 	wake_up(&cdev->private->wait_q);
1026 }
1027 
1028 static void
1029 ccw_device_quiesce_timeout(struct ccw_device *cdev, enum dev_event dev_event)
1030 {
1031 	int ret;
1032 
1033 	ret = ccw_device_cancel_halt_clear(cdev);
1034 	if (ret == -EBUSY) {
1035 		ccw_device_set_timeout(cdev, HZ/10);
1036 	} else {
1037 		cdev->private->state = DEV_STATE_NOT_OPER;
1038 		wake_up(&cdev->private->wait_q);
1039 	}
1040 }
1041 
1042 /*
1043  * No operation action. This is used e.g. to ignore a timeout event in
1044  * state offline.
1045  */
1046 static void
1047 ccw_device_nop(struct ccw_device *cdev, enum dev_event dev_event)
1048 {
1049 }
1050 
1051 /*
1052  * device statemachine
1053  */
1054 fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
1055 	[DEV_STATE_NOT_OPER] = {
1056 		[DEV_EVENT_NOTOPER]	= ccw_device_nop,
1057 		[DEV_EVENT_INTERRUPT]	= ccw_device_disabled_irq,
1058 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1059 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1060 	},
1061 	[DEV_STATE_SENSE_ID] = {
1062 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1063 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1064 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1065 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1066 	},
1067 	[DEV_STATE_OFFLINE] = {
1068 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1069 		[DEV_EVENT_INTERRUPT]	= ccw_device_disabled_irq,
1070 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1071 		[DEV_EVENT_VERIFY]	= ccw_device_offline_verify,
1072 	},
1073 	[DEV_STATE_VERIFY] = {
1074 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1075 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1076 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1077 		[DEV_EVENT_VERIFY]	= ccw_device_delay_verify,
1078 	},
1079 	[DEV_STATE_ONLINE] = {
1080 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1081 		[DEV_EVENT_INTERRUPT]	= ccw_device_irq,
1082 		[DEV_EVENT_TIMEOUT]	= ccw_device_online_timeout,
1083 		[DEV_EVENT_VERIFY]	= ccw_device_online_verify,
1084 	},
1085 	[DEV_STATE_W4SENSE] = {
1086 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1087 		[DEV_EVENT_INTERRUPT]	= ccw_device_w4sense,
1088 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1089 		[DEV_EVENT_VERIFY]	= ccw_device_online_verify,
1090 	},
1091 	[DEV_STATE_DISBAND_PGID] = {
1092 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1093 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1094 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1095 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1096 	},
1097 	[DEV_STATE_BOXED] = {
1098 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1099 		[DEV_EVENT_INTERRUPT]	= ccw_device_nop,
1100 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1101 		[DEV_EVENT_VERIFY]	= ccw_device_boxed_verify,
1102 	},
1103 	/* states to wait for i/o completion before doing something */
1104 	[DEV_STATE_TIMEOUT_KILL] = {
1105 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1106 		[DEV_EVENT_INTERRUPT]	= ccw_device_killing_irq,
1107 		[DEV_EVENT_TIMEOUT]	= ccw_device_killing_timeout,
1108 		[DEV_EVENT_VERIFY]	= ccw_device_nop, //FIXME
1109 	},
1110 	[DEV_STATE_QUIESCE] = {
1111 		[DEV_EVENT_NOTOPER]	= ccw_device_quiesce_done,
1112 		[DEV_EVENT_INTERRUPT]	= ccw_device_quiesce_done,
1113 		[DEV_EVENT_TIMEOUT]	= ccw_device_quiesce_timeout,
1114 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1115 	},
1116 	/* special states for devices gone not operational */
1117 	[DEV_STATE_DISCONNECTED] = {
1118 		[DEV_EVENT_NOTOPER]	= ccw_device_nop,
1119 		[DEV_EVENT_INTERRUPT]	= ccw_device_start_id,
1120 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1121 		[DEV_EVENT_VERIFY]	= ccw_device_start_id,
1122 	},
1123 	[DEV_STATE_DISCONNECTED_SENSE_ID] = {
1124 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1125 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1126 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1127 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1128 	},
1129 	[DEV_STATE_CMFCHANGE] = {
1130 		[DEV_EVENT_NOTOPER]	= ccw_device_change_cmfstate,
1131 		[DEV_EVENT_INTERRUPT]	= ccw_device_change_cmfstate,
1132 		[DEV_EVENT_TIMEOUT]	= ccw_device_change_cmfstate,
1133 		[DEV_EVENT_VERIFY]	= ccw_device_change_cmfstate,
1134 	},
1135 	[DEV_STATE_CMFUPDATE] = {
1136 		[DEV_EVENT_NOTOPER]	= ccw_device_update_cmfblock,
1137 		[DEV_EVENT_INTERRUPT]	= ccw_device_update_cmfblock,
1138 		[DEV_EVENT_TIMEOUT]	= ccw_device_update_cmfblock,
1139 		[DEV_EVENT_VERIFY]	= ccw_device_update_cmfblock,
1140 	},
1141 	[DEV_STATE_STEAL_LOCK] = {
1142 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1143 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1144 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1145 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1146 	},
1147 };
1148 
1149 EXPORT_SYMBOL_GPL(ccw_device_set_timeout);
1150