xref: /linux/drivers/s390/cio/device_fsm.c (revision 25eabb13c7d67ae32298015c5e28d00f604f412c)
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 static void ccw_device_handle_broken_paths(struct ccw_device *cdev)
480 {
481 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
482 	u8 broken_paths = (sch->schib.pmcw.pam & sch->opm) ^ sch->vpm;
483 
484 	if (broken_paths && (cdev->private->path_broken_mask != broken_paths))
485 		ccw_device_schedule_recovery();
486 
487 	cdev->private->path_broken_mask = broken_paths;
488 }
489 
490 void ccw_device_verify_done(struct ccw_device *cdev, int err)
491 {
492 	struct subchannel *sch;
493 
494 	sch = to_subchannel(cdev->dev.parent);
495 	/* Update schib - pom may have changed. */
496 	if (cio_update_schib(sch)) {
497 		err = -ENODEV;
498 		goto callback;
499 	}
500 	/* Update lpm with verified path mask. */
501 	sch->lpm = sch->vpm;
502 	/* Repeat path verification? */
503 	if (cdev->private->flags.doverify) {
504 		ccw_device_verify_start(cdev);
505 		return;
506 	}
507 callback:
508 	switch (err) {
509 	case 0:
510 		ccw_device_done(cdev, DEV_STATE_ONLINE);
511 		/* Deliver fake irb to device driver, if needed. */
512 		if (cdev->private->flags.fake_irb) {
513 			create_fake_irb(&cdev->private->irb,
514 					cdev->private->flags.fake_irb);
515 			cdev->private->flags.fake_irb = 0;
516 			if (cdev->handler)
517 				cdev->handler(cdev, cdev->private->intparm,
518 					      &cdev->private->irb);
519 			memset(&cdev->private->irb, 0, sizeof(struct irb));
520 		}
521 		ccw_device_report_path_events(cdev);
522 		ccw_device_handle_broken_paths(cdev);
523 		break;
524 	case -ETIME:
525 	case -EUSERS:
526 		/* Reset oper notify indication after verify error. */
527 		cdev->private->flags.donotify = 0;
528 		ccw_device_done(cdev, DEV_STATE_BOXED);
529 		break;
530 	case -EACCES:
531 		/* Reset oper notify indication after verify error. */
532 		cdev->private->flags.donotify = 0;
533 		ccw_device_done(cdev, DEV_STATE_DISCONNECTED);
534 		break;
535 	default:
536 		/* Reset oper notify indication after verify error. */
537 		cdev->private->flags.donotify = 0;
538 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
539 		break;
540 	}
541 	ccw_device_reset_path_events(cdev);
542 }
543 
544 /*
545  * Get device online.
546  */
547 int
548 ccw_device_online(struct ccw_device *cdev)
549 {
550 	struct subchannel *sch;
551 	int ret;
552 
553 	if ((cdev->private->state != DEV_STATE_OFFLINE) &&
554 	    (cdev->private->state != DEV_STATE_BOXED))
555 		return -EINVAL;
556 	sch = to_subchannel(cdev->dev.parent);
557 	ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
558 	if (ret != 0) {
559 		/* Couldn't enable the subchannel for i/o. Sick device. */
560 		if (ret == -ENODEV)
561 			dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
562 		return ret;
563 	}
564 	/* Start initial path verification. */
565 	cdev->private->state = DEV_STATE_VERIFY;
566 	ccw_device_verify_start(cdev);
567 	return 0;
568 }
569 
570 void
571 ccw_device_disband_done(struct ccw_device *cdev, int err)
572 {
573 	switch (err) {
574 	case 0:
575 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
576 		break;
577 	case -ETIME:
578 		ccw_device_done(cdev, DEV_STATE_BOXED);
579 		break;
580 	default:
581 		cdev->private->flags.donotify = 0;
582 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
583 		break;
584 	}
585 }
586 
587 /*
588  * Shutdown device.
589  */
590 int
591 ccw_device_offline(struct ccw_device *cdev)
592 {
593 	struct subchannel *sch;
594 
595 	/* Allow ccw_device_offline while disconnected. */
596 	if (cdev->private->state == DEV_STATE_DISCONNECTED ||
597 	    cdev->private->state == DEV_STATE_NOT_OPER) {
598 		cdev->private->flags.donotify = 0;
599 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
600 		return 0;
601 	}
602 	if (cdev->private->state == DEV_STATE_BOXED) {
603 		ccw_device_done(cdev, DEV_STATE_BOXED);
604 		return 0;
605 	}
606 	if (ccw_device_is_orphan(cdev)) {
607 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
608 		return 0;
609 	}
610 	sch = to_subchannel(cdev->dev.parent);
611 	if (cio_update_schib(sch))
612 		return -ENODEV;
613 	if (scsw_actl(&sch->schib.scsw) != 0)
614 		return -EBUSY;
615 	if (cdev->private->state != DEV_STATE_ONLINE)
616 		return -EINVAL;
617 	/* Are we doing path grouping? */
618 	if (!cdev->private->flags.pgroup) {
619 		/* No, set state offline immediately. */
620 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
621 		return 0;
622 	}
623 	/* Start Set Path Group commands. */
624 	cdev->private->state = DEV_STATE_DISBAND_PGID;
625 	ccw_device_disband_start(cdev);
626 	return 0;
627 }
628 
629 /*
630  * Handle not operational event in non-special state.
631  */
632 static void ccw_device_generic_notoper(struct ccw_device *cdev,
633 				       enum dev_event dev_event)
634 {
635 	if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
636 		ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
637 	else
638 		ccw_device_set_disconnected(cdev);
639 }
640 
641 /*
642  * Handle path verification event in offline state.
643  */
644 static void ccw_device_offline_verify(struct ccw_device *cdev,
645 				      enum dev_event dev_event)
646 {
647 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
648 
649 	css_schedule_eval(sch->schid);
650 }
651 
652 /*
653  * Handle path verification event.
654  */
655 static void
656 ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
657 {
658 	struct subchannel *sch;
659 
660 	if (cdev->private->state == DEV_STATE_W4SENSE) {
661 		cdev->private->flags.doverify = 1;
662 		return;
663 	}
664 	sch = to_subchannel(cdev->dev.parent);
665 	/*
666 	 * Since we might not just be coming from an interrupt from the
667 	 * subchannel we have to update the schib.
668 	 */
669 	if (cio_update_schib(sch)) {
670 		ccw_device_verify_done(cdev, -ENODEV);
671 		return;
672 	}
673 
674 	if (scsw_actl(&sch->schib.scsw) != 0 ||
675 	    (scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_STATUS_PEND) ||
676 	    (scsw_stctl(&cdev->private->irb.scsw) & SCSW_STCTL_STATUS_PEND)) {
677 		/*
678 		 * No final status yet or final status not yet delivered
679 		 * to the device driver. Can't do path verification now,
680 		 * delay until final status was delivered.
681 		 */
682 		cdev->private->flags.doverify = 1;
683 		return;
684 	}
685 	/* Device is idle, we can do the path verification. */
686 	cdev->private->state = DEV_STATE_VERIFY;
687 	ccw_device_verify_start(cdev);
688 }
689 
690 /*
691  * Handle path verification event in boxed state.
692  */
693 static void ccw_device_boxed_verify(struct ccw_device *cdev,
694 				    enum dev_event dev_event)
695 {
696 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
697 
698 	if (cdev->online) {
699 		if (cio_enable_subchannel(sch, (u32) (addr_t) sch))
700 			ccw_device_done(cdev, DEV_STATE_NOT_OPER);
701 		else
702 			ccw_device_online_verify(cdev, dev_event);
703 	} else
704 		css_schedule_eval(sch->schid);
705 }
706 
707 /*
708  * Pass interrupt to device driver.
709  */
710 static int ccw_device_call_handler(struct ccw_device *cdev)
711 {
712 	unsigned int stctl;
713 	int ending_status;
714 
715 	/*
716 	 * we allow for the device action handler if .
717 	 *  - we received ending status
718 	 *  - the action handler requested to see all interrupts
719 	 *  - we received an intermediate status
720 	 *  - fast notification was requested (primary status)
721 	 *  - unsolicited interrupts
722 	 */
723 	stctl = scsw_stctl(&cdev->private->irb.scsw);
724 	ending_status = (stctl & SCSW_STCTL_SEC_STATUS) ||
725 		(stctl == (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)) ||
726 		(stctl == SCSW_STCTL_STATUS_PEND);
727 	if (!ending_status &&
728 	    !cdev->private->options.repall &&
729 	    !(stctl & SCSW_STCTL_INTER_STATUS) &&
730 	    !(cdev->private->options.fast &&
731 	      (stctl & SCSW_STCTL_PRIM_STATUS)))
732 		return 0;
733 
734 	if (ending_status)
735 		ccw_device_set_timeout(cdev, 0);
736 
737 	if (cdev->handler)
738 		cdev->handler(cdev, cdev->private->intparm,
739 			      &cdev->private->irb);
740 
741 	memset(&cdev->private->irb, 0, sizeof(struct irb));
742 	return 1;
743 }
744 
745 /*
746  * Got an interrupt for a normal io (state online).
747  */
748 static void
749 ccw_device_irq(struct ccw_device *cdev, enum dev_event dev_event)
750 {
751 	struct irb *irb;
752 	int is_cmd;
753 
754 	irb = this_cpu_ptr(&cio_irb);
755 	is_cmd = !scsw_is_tm(&irb->scsw);
756 	/* Check for unsolicited interrupt. */
757 	if (!scsw_is_solicited(&irb->scsw)) {
758 		if (is_cmd && (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) &&
759 		    !irb->esw.esw0.erw.cons) {
760 			/* Unit check but no sense data. Need basic sense. */
761 			if (ccw_device_do_sense(cdev, irb) != 0)
762 				goto call_handler_unsol;
763 			memcpy(&cdev->private->irb, irb, sizeof(struct irb));
764 			cdev->private->state = DEV_STATE_W4SENSE;
765 			cdev->private->intparm = 0;
766 			return;
767 		}
768 call_handler_unsol:
769 		if (cdev->handler)
770 			cdev->handler (cdev, 0, irb);
771 		if (cdev->private->flags.doverify)
772 			ccw_device_online_verify(cdev, 0);
773 		return;
774 	}
775 	/* Accumulate status and find out if a basic sense is needed. */
776 	ccw_device_accumulate_irb(cdev, irb);
777 	if (is_cmd && cdev->private->flags.dosense) {
778 		if (ccw_device_do_sense(cdev, irb) == 0) {
779 			cdev->private->state = DEV_STATE_W4SENSE;
780 		}
781 		return;
782 	}
783 	/* Call the handler. */
784 	if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
785 		/* Start delayed path verification. */
786 		ccw_device_online_verify(cdev, 0);
787 }
788 
789 /*
790  * Got an timeout in online state.
791  */
792 static void
793 ccw_device_online_timeout(struct ccw_device *cdev, enum dev_event dev_event)
794 {
795 	int ret;
796 
797 	ccw_device_set_timeout(cdev, 0);
798 	cdev->private->iretry = 255;
799 	ret = ccw_device_cancel_halt_clear(cdev);
800 	if (ret == -EBUSY) {
801 		ccw_device_set_timeout(cdev, 3*HZ);
802 		cdev->private->state = DEV_STATE_TIMEOUT_KILL;
803 		return;
804 	}
805 	if (ret)
806 		dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
807 	else if (cdev->handler)
808 		cdev->handler(cdev, cdev->private->intparm,
809 			      ERR_PTR(-ETIMEDOUT));
810 }
811 
812 /*
813  * Got an interrupt for a basic sense.
814  */
815 static void
816 ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
817 {
818 	struct irb *irb;
819 
820 	irb = this_cpu_ptr(&cio_irb);
821 	/* Check for unsolicited interrupt. */
822 	if (scsw_stctl(&irb->scsw) ==
823 	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
824 		if (scsw_cc(&irb->scsw) == 1)
825 			/* Basic sense hasn't started. Try again. */
826 			ccw_device_do_sense(cdev, irb);
827 		else {
828 			CIO_MSG_EVENT(0, "0.%x.%04x: unsolicited "
829 				      "interrupt during w4sense...\n",
830 				      cdev->private->dev_id.ssid,
831 				      cdev->private->dev_id.devno);
832 			if (cdev->handler)
833 				cdev->handler (cdev, 0, irb);
834 		}
835 		return;
836 	}
837 	/*
838 	 * Check if a halt or clear has been issued in the meanwhile. If yes,
839 	 * only deliver the halt/clear interrupt to the device driver as if it
840 	 * had killed the original request.
841 	 */
842 	if (scsw_fctl(&irb->scsw) &
843 	    (SCSW_FCTL_CLEAR_FUNC | SCSW_FCTL_HALT_FUNC)) {
844 		cdev->private->flags.dosense = 0;
845 		memset(&cdev->private->irb, 0, sizeof(struct irb));
846 		ccw_device_accumulate_irb(cdev, irb);
847 		goto call_handler;
848 	}
849 	/* Add basic sense info to irb. */
850 	ccw_device_accumulate_basic_sense(cdev, irb);
851 	if (cdev->private->flags.dosense) {
852 		/* Another basic sense is needed. */
853 		ccw_device_do_sense(cdev, irb);
854 		return;
855 	}
856 call_handler:
857 	cdev->private->state = DEV_STATE_ONLINE;
858 	/* In case sensing interfered with setting the device online */
859 	wake_up(&cdev->private->wait_q);
860 	/* Call the handler. */
861 	if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
862 		/* Start delayed path verification. */
863 		ccw_device_online_verify(cdev, 0);
864 }
865 
866 static void
867 ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
868 {
869 	ccw_device_set_timeout(cdev, 0);
870 	/* Start delayed path verification. */
871 	ccw_device_online_verify(cdev, 0);
872 	/* OK, i/o is dead now. Call interrupt handler. */
873 	if (cdev->handler)
874 		cdev->handler(cdev, cdev->private->intparm,
875 			      ERR_PTR(-EIO));
876 }
877 
878 static void
879 ccw_device_killing_timeout(struct ccw_device *cdev, enum dev_event dev_event)
880 {
881 	int ret;
882 
883 	ret = ccw_device_cancel_halt_clear(cdev);
884 	if (ret == -EBUSY) {
885 		ccw_device_set_timeout(cdev, 3*HZ);
886 		return;
887 	}
888 	/* Start delayed path verification. */
889 	ccw_device_online_verify(cdev, 0);
890 	if (cdev->handler)
891 		cdev->handler(cdev, cdev->private->intparm,
892 			      ERR_PTR(-EIO));
893 }
894 
895 void ccw_device_kill_io(struct ccw_device *cdev)
896 {
897 	int ret;
898 
899 	cdev->private->iretry = 255;
900 	ret = ccw_device_cancel_halt_clear(cdev);
901 	if (ret == -EBUSY) {
902 		ccw_device_set_timeout(cdev, 3*HZ);
903 		cdev->private->state = DEV_STATE_TIMEOUT_KILL;
904 		return;
905 	}
906 	/* Start delayed path verification. */
907 	ccw_device_online_verify(cdev, 0);
908 	if (cdev->handler)
909 		cdev->handler(cdev, cdev->private->intparm,
910 			      ERR_PTR(-EIO));
911 }
912 
913 static void
914 ccw_device_delay_verify(struct ccw_device *cdev, enum dev_event dev_event)
915 {
916 	/* Start verification after current task finished. */
917 	cdev->private->flags.doverify = 1;
918 }
919 
920 static void
921 ccw_device_start_id(struct ccw_device *cdev, enum dev_event dev_event)
922 {
923 	struct subchannel *sch;
924 
925 	sch = to_subchannel(cdev->dev.parent);
926 	if (cio_enable_subchannel(sch, (u32)(addr_t)sch) != 0)
927 		/* Couldn't enable the subchannel for i/o. Sick device. */
928 		return;
929 	cdev->private->state = DEV_STATE_DISCONNECTED_SENSE_ID;
930 	ccw_device_sense_id_start(cdev);
931 }
932 
933 void ccw_device_trigger_reprobe(struct ccw_device *cdev)
934 {
935 	struct subchannel *sch;
936 
937 	if (cdev->private->state != DEV_STATE_DISCONNECTED)
938 		return;
939 
940 	sch = to_subchannel(cdev->dev.parent);
941 	/* Update some values. */
942 	if (cio_update_schib(sch))
943 		return;
944 	/*
945 	 * The pim, pam, pom values may not be accurate, but they are the best
946 	 * we have before performing device selection :/
947 	 */
948 	sch->lpm = sch->schib.pmcw.pam & sch->opm;
949 	/*
950 	 * Use the initial configuration since we can't be shure that the old
951 	 * paths are valid.
952 	 */
953 	io_subchannel_init_config(sch);
954 	if (cio_commit_config(sch))
955 		return;
956 
957 	/* We should also udate ssd info, but this has to wait. */
958 	/* Check if this is another device which appeared on the same sch. */
959 	if (sch->schib.pmcw.dev != cdev->private->dev_id.devno)
960 		css_schedule_eval(sch->schid);
961 	else
962 		ccw_device_start_id(cdev, 0);
963 }
964 
965 static void ccw_device_disabled_irq(struct ccw_device *cdev,
966 				    enum dev_event dev_event)
967 {
968 	struct subchannel *sch;
969 
970 	sch = to_subchannel(cdev->dev.parent);
971 	/*
972 	 * An interrupt in a disabled state means a previous disable was not
973 	 * successful - should not happen, but we try to disable again.
974 	 */
975 	cio_disable_subchannel(sch);
976 }
977 
978 static void
979 ccw_device_change_cmfstate(struct ccw_device *cdev, enum dev_event dev_event)
980 {
981 	retry_set_schib(cdev);
982 	cdev->private->state = DEV_STATE_ONLINE;
983 	dev_fsm_event(cdev, dev_event);
984 }
985 
986 static void ccw_device_update_cmfblock(struct ccw_device *cdev,
987 				       enum dev_event dev_event)
988 {
989 	cmf_retry_copy_block(cdev);
990 	cdev->private->state = DEV_STATE_ONLINE;
991 	dev_fsm_event(cdev, dev_event);
992 }
993 
994 static void
995 ccw_device_quiesce_done(struct ccw_device *cdev, enum dev_event dev_event)
996 {
997 	ccw_device_set_timeout(cdev, 0);
998 	cdev->private->state = DEV_STATE_NOT_OPER;
999 	wake_up(&cdev->private->wait_q);
1000 }
1001 
1002 static void
1003 ccw_device_quiesce_timeout(struct ccw_device *cdev, enum dev_event dev_event)
1004 {
1005 	int ret;
1006 
1007 	ret = ccw_device_cancel_halt_clear(cdev);
1008 	if (ret == -EBUSY) {
1009 		ccw_device_set_timeout(cdev, HZ/10);
1010 	} else {
1011 		cdev->private->state = DEV_STATE_NOT_OPER;
1012 		wake_up(&cdev->private->wait_q);
1013 	}
1014 }
1015 
1016 /*
1017  * No operation action. This is used e.g. to ignore a timeout event in
1018  * state offline.
1019  */
1020 static void
1021 ccw_device_nop(struct ccw_device *cdev, enum dev_event dev_event)
1022 {
1023 }
1024 
1025 /*
1026  * device statemachine
1027  */
1028 fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
1029 	[DEV_STATE_NOT_OPER] = {
1030 		[DEV_EVENT_NOTOPER]	= ccw_device_nop,
1031 		[DEV_EVENT_INTERRUPT]	= ccw_device_disabled_irq,
1032 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1033 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1034 	},
1035 	[DEV_STATE_SENSE_ID] = {
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_nop,
1040 	},
1041 	[DEV_STATE_OFFLINE] = {
1042 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1043 		[DEV_EVENT_INTERRUPT]	= ccw_device_disabled_irq,
1044 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1045 		[DEV_EVENT_VERIFY]	= ccw_device_offline_verify,
1046 	},
1047 	[DEV_STATE_VERIFY] = {
1048 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1049 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1050 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1051 		[DEV_EVENT_VERIFY]	= ccw_device_delay_verify,
1052 	},
1053 	[DEV_STATE_ONLINE] = {
1054 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1055 		[DEV_EVENT_INTERRUPT]	= ccw_device_irq,
1056 		[DEV_EVENT_TIMEOUT]	= ccw_device_online_timeout,
1057 		[DEV_EVENT_VERIFY]	= ccw_device_online_verify,
1058 	},
1059 	[DEV_STATE_W4SENSE] = {
1060 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1061 		[DEV_EVENT_INTERRUPT]	= ccw_device_w4sense,
1062 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1063 		[DEV_EVENT_VERIFY]	= ccw_device_online_verify,
1064 	},
1065 	[DEV_STATE_DISBAND_PGID] = {
1066 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1067 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1068 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1069 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1070 	},
1071 	[DEV_STATE_BOXED] = {
1072 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1073 		[DEV_EVENT_INTERRUPT]	= ccw_device_nop,
1074 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1075 		[DEV_EVENT_VERIFY]	= ccw_device_boxed_verify,
1076 	},
1077 	/* states to wait for i/o completion before doing something */
1078 	[DEV_STATE_TIMEOUT_KILL] = {
1079 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
1080 		[DEV_EVENT_INTERRUPT]	= ccw_device_killing_irq,
1081 		[DEV_EVENT_TIMEOUT]	= ccw_device_killing_timeout,
1082 		[DEV_EVENT_VERIFY]	= ccw_device_nop, //FIXME
1083 	},
1084 	[DEV_STATE_QUIESCE] = {
1085 		[DEV_EVENT_NOTOPER]	= ccw_device_quiesce_done,
1086 		[DEV_EVENT_INTERRUPT]	= ccw_device_quiesce_done,
1087 		[DEV_EVENT_TIMEOUT]	= ccw_device_quiesce_timeout,
1088 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1089 	},
1090 	/* special states for devices gone not operational */
1091 	[DEV_STATE_DISCONNECTED] = {
1092 		[DEV_EVENT_NOTOPER]	= ccw_device_nop,
1093 		[DEV_EVENT_INTERRUPT]	= ccw_device_start_id,
1094 		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
1095 		[DEV_EVENT_VERIFY]	= ccw_device_start_id,
1096 	},
1097 	[DEV_STATE_DISCONNECTED_SENSE_ID] = {
1098 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1099 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1100 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1101 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1102 	},
1103 	[DEV_STATE_CMFCHANGE] = {
1104 		[DEV_EVENT_NOTOPER]	= ccw_device_change_cmfstate,
1105 		[DEV_EVENT_INTERRUPT]	= ccw_device_change_cmfstate,
1106 		[DEV_EVENT_TIMEOUT]	= ccw_device_change_cmfstate,
1107 		[DEV_EVENT_VERIFY]	= ccw_device_change_cmfstate,
1108 	},
1109 	[DEV_STATE_CMFUPDATE] = {
1110 		[DEV_EVENT_NOTOPER]	= ccw_device_update_cmfblock,
1111 		[DEV_EVENT_INTERRUPT]	= ccw_device_update_cmfblock,
1112 		[DEV_EVENT_TIMEOUT]	= ccw_device_update_cmfblock,
1113 		[DEV_EVENT_VERIFY]	= ccw_device_update_cmfblock,
1114 	},
1115 	[DEV_STATE_STEAL_LOCK] = {
1116 		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
1117 		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
1118 		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
1119 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
1120 	},
1121 };
1122 
1123 EXPORT_SYMBOL_GPL(ccw_device_set_timeout);
1124