xref: /openbmc/linux/drivers/s390/cio/device_fsm.c (revision 078b39c9)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
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/io.h>
13 #include <linux/jiffies.h>
14 #include <linux/string.h>
15 
16 #include <asm/ccwdev.h>
17 #include <asm/cio.h>
18 #include <asm/chpid.h>
19 
20 #include "cio.h"
21 #include "cio_debug.h"
22 #include "css.h"
23 #include "device.h"
24 #include "chsc.h"
25 #include "ioasm.h"
26 #include "chp.h"
27 
28 static int timeout_log_enabled;
29 
30 static int __init ccw_timeout_log_setup(char *unused)
31 {
32 	timeout_log_enabled = 1;
33 	return 1;
34 }
35 
36 __setup("ccw_timeout_log", ccw_timeout_log_setup);
37 
38 static void ccw_timeout_log(struct ccw_device *cdev)
39 {
40 	struct schib schib;
41 	struct subchannel *sch;
42 	struct io_subchannel_private *private;
43 	union orb *orb;
44 	int cc;
45 
46 	sch = to_subchannel(cdev->dev.parent);
47 	private = to_io_private(sch);
48 	orb = &private->orb;
49 	cc = stsch(sch->schid, &schib);
50 
51 	printk(KERN_WARNING "cio: ccw device timeout occurred at %lx, "
52 	       "device information:\n", get_tod_clock());
53 	printk(KERN_WARNING "cio: orb:\n");
54 	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
55 		       orb, sizeof(*orb), 0);
56 	printk(KERN_WARNING "cio: ccw device bus id: %s\n",
57 	       dev_name(&cdev->dev));
58 	printk(KERN_WARNING "cio: subchannel bus id: %s\n",
59 	       dev_name(&sch->dev));
60 	printk(KERN_WARNING "cio: subchannel lpm: %02x, opm: %02x, "
61 	       "vpm: %02x\n", sch->lpm, sch->opm, sch->vpm);
62 
63 	if (orb->tm.b) {
64 		printk(KERN_WARNING "cio: orb indicates transport mode\n");
65 		printk(KERN_WARNING "cio: last tcw:\n");
66 		print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
67 			       phys_to_virt(orb->tm.tcw),
68 			       sizeof(struct tcw), 0);
69 	} else {
70 		printk(KERN_WARNING "cio: orb indicates command mode\n");
71 		if ((void *)(addr_t)orb->cmd.cpa ==
72 		    &private->dma_area->sense_ccw ||
73 		    (void *)(addr_t)orb->cmd.cpa ==
74 		    cdev->private->dma_area->iccws)
75 			printk(KERN_WARNING "cio: last channel program "
76 			       "(intern):\n");
77 		else
78 			printk(KERN_WARNING "cio: last channel program:\n");
79 
80 		print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
81 			       phys_to_virt(orb->cmd.cpa),
82 			       sizeof(struct ccw1), 0);
83 	}
84 	printk(KERN_WARNING "cio: ccw device state: %d\n",
85 	       cdev->private->state);
86 	printk(KERN_WARNING "cio: store subchannel returned: cc=%d\n", cc);
87 	printk(KERN_WARNING "cio: schib:\n");
88 	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
89 		       &schib, sizeof(schib), 0);
90 	printk(KERN_WARNING "cio: ccw device flags:\n");
91 	print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
92 		       &cdev->private->flags, sizeof(cdev->private->flags), 0);
93 }
94 
95 /*
96  * Timeout function. It just triggers a DEV_EVENT_TIMEOUT.
97  */
98 void
99 ccw_device_timeout(struct timer_list *t)
100 {
101 	struct ccw_device_private *priv = from_timer(priv, t, timer);
102 	struct ccw_device *cdev = priv->cdev;
103 
104 	spin_lock_irq(cdev->ccwlock);
105 	if (timeout_log_enabled)
106 		ccw_timeout_log(cdev);
107 	dev_fsm_event(cdev, DEV_EVENT_TIMEOUT);
108 	spin_unlock_irq(cdev->ccwlock);
109 }
110 
111 /*
112  * Set timeout
113  */
114 void
115 ccw_device_set_timeout(struct ccw_device *cdev, int expires)
116 {
117 	if (expires == 0)
118 		del_timer(&cdev->private->timer);
119 	else
120 		mod_timer(&cdev->private->timer, jiffies + expires);
121 }
122 
123 int
124 ccw_device_cancel_halt_clear(struct ccw_device *cdev)
125 {
126 	struct subchannel *sch;
127 	int ret;
128 
129 	sch = to_subchannel(cdev->dev.parent);
130 	ret = cio_cancel_halt_clear(sch, &cdev->private->iretry);
131 
132 	if (ret == -EIO)
133 		CIO_MSG_EVENT(0, "0.%x.%04x: could not stop I/O\n",
134 			      cdev->private->dev_id.ssid,
135 			      cdev->private->dev_id.devno);
136 
137 	return ret;
138 }
139 
140 void ccw_device_update_sense_data(struct ccw_device *cdev)
141 {
142 	memset(&cdev->id, 0, sizeof(cdev->id));
143 	cdev->id.cu_type = cdev->private->dma_area->senseid.cu_type;
144 	cdev->id.cu_model = cdev->private->dma_area->senseid.cu_model;
145 	cdev->id.dev_type = cdev->private->dma_area->senseid.dev_type;
146 	cdev->id.dev_model = cdev->private->dma_area->senseid.dev_model;
147 }
148 
149 int ccw_device_test_sense_data(struct ccw_device *cdev)
150 {
151 	return cdev->id.cu_type ==
152 		cdev->private->dma_area->senseid.cu_type &&
153 		cdev->id.cu_model ==
154 		cdev->private->dma_area->senseid.cu_model &&
155 		cdev->id.dev_type ==
156 		cdev->private->dma_area->senseid.dev_type &&
157 		cdev->id.dev_model ==
158 		cdev->private->dma_area->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 	switch (state) {
223 	case DEV_STATE_NOT_OPER:
224 		break;
225 	case DEV_STATE_OFFLINE:
226 		if (!cdev->online) {
227 			ccw_device_update_sense_data(cdev);
228 			break;
229 		}
230 		cdev->private->state = DEV_STATE_OFFLINE;
231 		cdev->private->flags.recog_done = 1;
232 		if (ccw_device_test_sense_data(cdev)) {
233 			cdev->private->flags.donotify = 1;
234 			ccw_device_online(cdev);
235 			wake_up(&cdev->private->wait_q);
236 		} else {
237 			ccw_device_update_sense_data(cdev);
238 			ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
239 		}
240 		return;
241 	case DEV_STATE_BOXED:
242 		if (cdev->id.cu_type != 0) { /* device was recognized before */
243 			cdev->private->flags.recog_done = 1;
244 			cdev->private->state = DEV_STATE_BOXED;
245 			wake_up(&cdev->private->wait_q);
246 			return;
247 		}
248 		break;
249 	}
250 	cdev->private->state = state;
251 	io_subchannel_recog_done(cdev);
252 	wake_up(&cdev->private->wait_q);
253 }
254 
255 /*
256  * Function called from device_id.c after sense id has completed.
257  */
258 void
259 ccw_device_sense_id_done(struct ccw_device *cdev, int err)
260 {
261 	switch (err) {
262 	case 0:
263 		ccw_device_recog_done(cdev, DEV_STATE_OFFLINE);
264 		break;
265 	case -ETIME:		/* Sense id stopped by timeout. */
266 		ccw_device_recog_done(cdev, DEV_STATE_BOXED);
267 		break;
268 	default:
269 		ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
270 		break;
271 	}
272 }
273 
274 /**
275   * ccw_device_notify() - inform the device's driver about an event
276   * @cdev: device for which an event occurred
277   * @event: event that occurred
278   *
279   * Returns:
280   *   -%EINVAL if the device is offline or has no driver.
281   *   -%EOPNOTSUPP if the device's driver has no notifier registered.
282   *   %NOTIFY_OK if the driver wants to keep the device.
283   *   %NOTIFY_BAD if the driver doesn't want to keep the device.
284   */
285 int ccw_device_notify(struct ccw_device *cdev, int event)
286 {
287 	int ret = -EINVAL;
288 
289 	if (!cdev->drv)
290 		goto out;
291 	if (!cdev->online)
292 		goto out;
293 	CIO_MSG_EVENT(2, "notify called for 0.%x.%04x, event=%d\n",
294 		      cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
295 		      event);
296 	if (!cdev->drv->notify) {
297 		ret = -EOPNOTSUPP;
298 		goto out;
299 	}
300 	if (cdev->drv->notify(cdev, event))
301 		ret = NOTIFY_OK;
302 	else
303 		ret = NOTIFY_BAD;
304 out:
305 	return ret;
306 }
307 
308 static void ccw_device_oper_notify(struct ccw_device *cdev)
309 {
310 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
311 
312 	if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_OK) {
313 		/* Re-enable channel measurements, if needed. */
314 		ccw_device_sched_todo(cdev, CDEV_TODO_ENABLE_CMF);
315 		/* Save indication for new paths. */
316 		cdev->private->path_new_mask = sch->vpm;
317 		return;
318 	}
319 	/* Driver doesn't want device back. */
320 	ccw_device_set_notoper(cdev);
321 	ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
322 }
323 
324 /*
325  * Finished with online/offline processing.
326  */
327 static void
328 ccw_device_done(struct ccw_device *cdev, int state)
329 {
330 	struct subchannel *sch;
331 
332 	sch = to_subchannel(cdev->dev.parent);
333 
334 	ccw_device_set_timeout(cdev, 0);
335 
336 	if (state != DEV_STATE_ONLINE)
337 		cio_disable_subchannel(sch);
338 
339 	/* Reset device status. */
340 	memset(&cdev->private->dma_area->irb, 0, sizeof(struct irb));
341 
342 	cdev->private->state = state;
343 
344 	switch (state) {
345 	case DEV_STATE_BOXED:
346 		CIO_MSG_EVENT(0, "Boxed device %04x on subchannel %04x\n",
347 			      cdev->private->dev_id.devno, sch->schid.sch_no);
348 		if (cdev->online &&
349 		    ccw_device_notify(cdev, CIO_BOXED) != NOTIFY_OK)
350 			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
351 		cdev->private->flags.donotify = 0;
352 		break;
353 	case DEV_STATE_NOT_OPER:
354 		CIO_MSG_EVENT(0, "Device %04x gone on subchannel %04x\n",
355 			      cdev->private->dev_id.devno, sch->schid.sch_no);
356 		if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
357 			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
358 		else
359 			ccw_device_set_disconnected(cdev);
360 		cdev->private->flags.donotify = 0;
361 		break;
362 	case DEV_STATE_DISCONNECTED:
363 		CIO_MSG_EVENT(0, "Disconnected device %04x on subchannel "
364 			      "%04x\n", cdev->private->dev_id.devno,
365 			      sch->schid.sch_no);
366 		if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK) {
367 			cdev->private->state = DEV_STATE_NOT_OPER;
368 			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
369 		} else
370 			ccw_device_set_disconnected(cdev);
371 		cdev->private->flags.donotify = 0;
372 		break;
373 	default:
374 		break;
375 	}
376 
377 	if (cdev->private->flags.donotify) {
378 		cdev->private->flags.donotify = 0;
379 		ccw_device_oper_notify(cdev);
380 	}
381 	wake_up(&cdev->private->wait_q);
382 }
383 
384 /*
385  * Start device recognition.
386  */
387 void ccw_device_recognition(struct ccw_device *cdev)
388 {
389 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
390 
391 	/*
392 	 * We used to start here with a sense pgid to find out whether a device
393 	 * is locked by someone else. Unfortunately, the sense pgid command
394 	 * code has other meanings on devices predating the path grouping
395 	 * algorithm, so we start with sense id and box the device after an
396 	 * timeout (or if sense pgid during path verification detects the device
397 	 * is locked, as may happen on newer devices).
398 	 */
399 	cdev->private->flags.recog_done = 0;
400 	cdev->private->state = DEV_STATE_SENSE_ID;
401 	if (cio_enable_subchannel(sch, (u32)virt_to_phys(sch))) {
402 		ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
403 		return;
404 	}
405 	ccw_device_sense_id_start(cdev);
406 }
407 
408 /*
409  * Handle events for states that use the ccw request infrastructure.
410  */
411 static void ccw_device_request_event(struct ccw_device *cdev, enum dev_event e)
412 {
413 	switch (e) {
414 	case DEV_EVENT_NOTOPER:
415 		ccw_request_notoper(cdev);
416 		break;
417 	case DEV_EVENT_INTERRUPT:
418 		ccw_request_handler(cdev);
419 		break;
420 	case DEV_EVENT_TIMEOUT:
421 		ccw_request_timeout(cdev);
422 		break;
423 	default:
424 		break;
425 	}
426 }
427 
428 static void ccw_device_report_path_events(struct ccw_device *cdev)
429 {
430 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
431 	int path_event[8];
432 	int chp, mask;
433 
434 	for (chp = 0, mask = 0x80; chp < 8; chp++, mask >>= 1) {
435 		path_event[chp] = PE_NONE;
436 		if (mask & cdev->private->path_gone_mask & ~(sch->vpm))
437 			path_event[chp] |= PE_PATH_GONE;
438 		if (mask & cdev->private->path_new_mask & sch->vpm)
439 			path_event[chp] |= PE_PATH_AVAILABLE;
440 		if (mask & cdev->private->pgid_reset_mask & sch->vpm)
441 			path_event[chp] |= PE_PATHGROUP_ESTABLISHED;
442 	}
443 	if (cdev->online && cdev->drv->path_event)
444 		cdev->drv->path_event(cdev, path_event);
445 }
446 
447 static void ccw_device_reset_path_events(struct ccw_device *cdev)
448 {
449 	cdev->private->path_gone_mask = 0;
450 	cdev->private->path_new_mask = 0;
451 	cdev->private->pgid_reset_mask = 0;
452 }
453 
454 static void create_fake_irb(struct irb *irb, int type)
455 {
456 	memset(irb, 0, sizeof(*irb));
457 	if (type == FAKE_CMD_IRB) {
458 		struct cmd_scsw *scsw = &irb->scsw.cmd;
459 		scsw->cc = 1;
460 		scsw->fctl = SCSW_FCTL_START_FUNC;
461 		scsw->actl = SCSW_ACTL_START_PEND;
462 		scsw->stctl = SCSW_STCTL_STATUS_PEND;
463 	} else if (type == FAKE_TM_IRB) {
464 		struct tm_scsw *scsw = &irb->scsw.tm;
465 		scsw->x = 1;
466 		scsw->cc = 1;
467 		scsw->fctl = SCSW_FCTL_START_FUNC;
468 		scsw->actl = SCSW_ACTL_START_PEND;
469 		scsw->stctl = SCSW_STCTL_STATUS_PEND;
470 	}
471 }
472 
473 static void ccw_device_handle_broken_paths(struct ccw_device *cdev)
474 {
475 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
476 	u8 broken_paths = (sch->schib.pmcw.pam & sch->opm) ^ sch->vpm;
477 
478 	if (broken_paths && (cdev->private->path_broken_mask != broken_paths))
479 		ccw_device_schedule_recovery();
480 
481 	cdev->private->path_broken_mask = broken_paths;
482 }
483 
484 void ccw_device_verify_done(struct ccw_device *cdev, int err)
485 {
486 	struct subchannel *sch;
487 
488 	sch = to_subchannel(cdev->dev.parent);
489 	/* Update schib - pom may have changed. */
490 	if (cio_update_schib(sch)) {
491 		err = -ENODEV;
492 		goto callback;
493 	}
494 	/* Update lpm with verified path mask. */
495 	sch->lpm = sch->vpm;
496 	/* Repeat path verification? */
497 	if (cdev->private->flags.doverify) {
498 		ccw_device_verify_start(cdev);
499 		return;
500 	}
501 callback:
502 	switch (err) {
503 	case 0:
504 		ccw_device_done(cdev, DEV_STATE_ONLINE);
505 		/* Deliver fake irb to device driver, if needed. */
506 		if (cdev->private->flags.fake_irb) {
507 			create_fake_irb(&cdev->private->dma_area->irb,
508 					cdev->private->flags.fake_irb);
509 			cdev->private->flags.fake_irb = 0;
510 			if (cdev->handler)
511 				cdev->handler(cdev, cdev->private->intparm,
512 					      &cdev->private->dma_area->irb);
513 			memset(&cdev->private->dma_area->irb, 0,
514 			       sizeof(struct irb));
515 		}
516 		ccw_device_report_path_events(cdev);
517 		ccw_device_handle_broken_paths(cdev);
518 		break;
519 	case -ETIME:
520 	case -EUSERS:
521 		/* Reset oper notify indication after verify error. */
522 		cdev->private->flags.donotify = 0;
523 		ccw_device_done(cdev, DEV_STATE_BOXED);
524 		break;
525 	case -EACCES:
526 		/* Reset oper notify indication after verify error. */
527 		cdev->private->flags.donotify = 0;
528 		ccw_device_done(cdev, DEV_STATE_DISCONNECTED);
529 		break;
530 	default:
531 		/* Reset oper notify indication after verify error. */
532 		cdev->private->flags.donotify = 0;
533 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
534 		break;
535 	}
536 	ccw_device_reset_path_events(cdev);
537 }
538 
539 /*
540  * Get device online.
541  */
542 int
543 ccw_device_online(struct ccw_device *cdev)
544 {
545 	struct subchannel *sch;
546 	int ret;
547 
548 	if ((cdev->private->state != DEV_STATE_OFFLINE) &&
549 	    (cdev->private->state != DEV_STATE_BOXED))
550 		return -EINVAL;
551 	sch = to_subchannel(cdev->dev.parent);
552 	ret = cio_enable_subchannel(sch, (u32)virt_to_phys(sch));
553 	if (ret != 0) {
554 		/* Couldn't enable the subchannel for i/o. Sick device. */
555 		if (ret == -ENODEV)
556 			dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
557 		return ret;
558 	}
559 	/* Start initial path verification. */
560 	cdev->private->state = DEV_STATE_VERIFY;
561 	ccw_device_verify_start(cdev);
562 	return 0;
563 }
564 
565 void
566 ccw_device_disband_done(struct ccw_device *cdev, int err)
567 {
568 	switch (err) {
569 	case 0:
570 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
571 		break;
572 	case -ETIME:
573 		ccw_device_done(cdev, DEV_STATE_BOXED);
574 		break;
575 	default:
576 		cdev->private->flags.donotify = 0;
577 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
578 		break;
579 	}
580 }
581 
582 /*
583  * Shutdown device.
584  */
585 int
586 ccw_device_offline(struct ccw_device *cdev)
587 {
588 	struct subchannel *sch;
589 
590 	/* Allow ccw_device_offline while disconnected. */
591 	if (cdev->private->state == DEV_STATE_DISCONNECTED ||
592 	    cdev->private->state == DEV_STATE_NOT_OPER) {
593 		cdev->private->flags.donotify = 0;
594 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
595 		return 0;
596 	}
597 	if (cdev->private->state == DEV_STATE_BOXED) {
598 		ccw_device_done(cdev, DEV_STATE_BOXED);
599 		return 0;
600 	}
601 	if (ccw_device_is_orphan(cdev)) {
602 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
603 		return 0;
604 	}
605 	sch = to_subchannel(cdev->dev.parent);
606 	if (cio_update_schib(sch))
607 		return -ENODEV;
608 	if (scsw_actl(&sch->schib.scsw) != 0)
609 		return -EBUSY;
610 	if (cdev->private->state != DEV_STATE_ONLINE)
611 		return -EINVAL;
612 	/* Are we doing path grouping? */
613 	if (!cdev->private->flags.pgroup) {
614 		/* No, set state offline immediately. */
615 		ccw_device_done(cdev, DEV_STATE_OFFLINE);
616 		return 0;
617 	}
618 	/* Start Set Path Group commands. */
619 	cdev->private->state = DEV_STATE_DISBAND_PGID;
620 	ccw_device_disband_start(cdev);
621 	return 0;
622 }
623 
624 /*
625  * Handle not operational event in non-special state.
626  */
627 static void ccw_device_generic_notoper(struct ccw_device *cdev,
628 				       enum dev_event dev_event)
629 {
630 	if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
631 		ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
632 	else
633 		ccw_device_set_disconnected(cdev);
634 }
635 
636 /*
637  * Handle path verification event in offline state.
638  */
639 static void ccw_device_offline_verify(struct ccw_device *cdev,
640 				      enum dev_event dev_event)
641 {
642 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
643 
644 	css_schedule_eval(sch->schid);
645 }
646 
647 /*
648  * Handle path verification event.
649  */
650 static void
651 ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
652 {
653 	struct subchannel *sch;
654 
655 	if (cdev->private->state == DEV_STATE_W4SENSE) {
656 		cdev->private->flags.doverify = 1;
657 		return;
658 	}
659 	sch = to_subchannel(cdev->dev.parent);
660 	/*
661 	 * Since we might not just be coming from an interrupt from the
662 	 * subchannel we have to update the schib.
663 	 */
664 	if (cio_update_schib(sch)) {
665 		ccw_device_verify_done(cdev, -ENODEV);
666 		return;
667 	}
668 
669 	if (scsw_actl(&sch->schib.scsw) != 0 ||
670 	    (scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_STATUS_PEND) ||
671 	    (scsw_stctl(&cdev->private->dma_area->irb.scsw) &
672 	     SCSW_STCTL_STATUS_PEND)) {
673 		/*
674 		 * No final status yet or final status not yet delivered
675 		 * to the device driver. Can't do path verification now,
676 		 * delay until final status was delivered.
677 		 */
678 		cdev->private->flags.doverify = 1;
679 		return;
680 	}
681 	/* Device is idle, we can do the path verification. */
682 	cdev->private->state = DEV_STATE_VERIFY;
683 	ccw_device_verify_start(cdev);
684 }
685 
686 /*
687  * Handle path verification event in boxed state.
688  */
689 static void ccw_device_boxed_verify(struct ccw_device *cdev,
690 				    enum dev_event dev_event)
691 {
692 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
693 
694 	if (cdev->online) {
695 		if (cio_enable_subchannel(sch, (u32)virt_to_phys(sch)))
696 			ccw_device_done(cdev, DEV_STATE_NOT_OPER);
697 		else
698 			ccw_device_online_verify(cdev, dev_event);
699 	} else
700 		css_schedule_eval(sch->schid);
701 }
702 
703 /*
704  * Pass interrupt to device driver.
705  */
706 static int ccw_device_call_handler(struct ccw_device *cdev)
707 {
708 	unsigned int stctl;
709 	int ending_status;
710 
711 	/*
712 	 * we allow for the device action handler if .
713 	 *  - we received ending status
714 	 *  - the action handler requested to see all interrupts
715 	 *  - we received an intermediate status
716 	 *  - fast notification was requested (primary status)
717 	 *  - unsolicited interrupts
718 	 */
719 	stctl = scsw_stctl(&cdev->private->dma_area->irb.scsw);
720 	ending_status = (stctl & SCSW_STCTL_SEC_STATUS) ||
721 		(stctl == (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)) ||
722 		(stctl == SCSW_STCTL_STATUS_PEND);
723 	if (!ending_status &&
724 	    !cdev->private->options.repall &&
725 	    !(stctl & SCSW_STCTL_INTER_STATUS) &&
726 	    !(cdev->private->options.fast &&
727 	      (stctl & SCSW_STCTL_PRIM_STATUS)))
728 		return 0;
729 
730 	if (ending_status)
731 		ccw_device_set_timeout(cdev, 0);
732 
733 	if (cdev->handler)
734 		cdev->handler(cdev, cdev->private->intparm,
735 			      &cdev->private->dma_area->irb);
736 
737 	memset(&cdev->private->dma_area->irb, 0, sizeof(struct irb));
738 	return 1;
739 }
740 
741 /*
742  * Got an interrupt for a normal io (state online).
743  */
744 static void
745 ccw_device_irq(struct ccw_device *cdev, enum dev_event dev_event)
746 {
747 	struct irb *irb;
748 	int is_cmd;
749 
750 	irb = this_cpu_ptr(&cio_irb);
751 	is_cmd = !scsw_is_tm(&irb->scsw);
752 	/* Check for unsolicited interrupt. */
753 	if (!scsw_is_solicited(&irb->scsw)) {
754 		if (is_cmd && (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) &&
755 		    !irb->esw.esw0.erw.cons) {
756 			/* Unit check but no sense data. Need basic sense. */
757 			if (ccw_device_do_sense(cdev, irb) != 0)
758 				goto call_handler_unsol;
759 			memcpy(&cdev->private->dma_area->irb, irb,
760 			       sizeof(struct irb));
761 			cdev->private->state = DEV_STATE_W4SENSE;
762 			cdev->private->intparm = 0;
763 			return;
764 		}
765 call_handler_unsol:
766 		if (cdev->handler)
767 			cdev->handler (cdev, 0, irb);
768 		if (cdev->private->flags.doverify)
769 			ccw_device_online_verify(cdev, 0);
770 		return;
771 	}
772 	/* Accumulate status and find out if a basic sense is needed. */
773 	ccw_device_accumulate_irb(cdev, irb);
774 	if (is_cmd && cdev->private->flags.dosense) {
775 		if (ccw_device_do_sense(cdev, irb) == 0) {
776 			cdev->private->state = DEV_STATE_W4SENSE;
777 		}
778 		return;
779 	}
780 	/* Call the handler. */
781 	if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
782 		/* Start delayed path verification. */
783 		ccw_device_online_verify(cdev, 0);
784 }
785 
786 /*
787  * Got an timeout in online state.
788  */
789 static void
790 ccw_device_online_timeout(struct ccw_device *cdev, enum dev_event dev_event)
791 {
792 	int ret;
793 
794 	ccw_device_set_timeout(cdev, 0);
795 	cdev->private->iretry = 255;
796 	cdev->private->async_kill_io_rc = -ETIMEDOUT;
797 	ret = ccw_device_cancel_halt_clear(cdev);
798 	if (ret == -EBUSY) {
799 		ccw_device_set_timeout(cdev, 3*HZ);
800 		cdev->private->state = DEV_STATE_TIMEOUT_KILL;
801 		return;
802 	}
803 	if (ret)
804 		dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
805 	else if (cdev->handler)
806 		cdev->handler(cdev, cdev->private->intparm,
807 			      ERR_PTR(-ETIMEDOUT));
808 }
809 
810 /*
811  * Got an interrupt for a basic sense.
812  */
813 static void
814 ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
815 {
816 	struct irb *irb;
817 
818 	irb = this_cpu_ptr(&cio_irb);
819 	/* Check for unsolicited interrupt. */
820 	if (scsw_stctl(&irb->scsw) ==
821 	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
822 		if (scsw_cc(&irb->scsw) == 1)
823 			/* Basic sense hasn't started. Try again. */
824 			ccw_device_do_sense(cdev, irb);
825 		else {
826 			CIO_MSG_EVENT(0, "0.%x.%04x: unsolicited "
827 				      "interrupt during w4sense...\n",
828 				      cdev->private->dev_id.ssid,
829 				      cdev->private->dev_id.devno);
830 			if (cdev->handler)
831 				cdev->handler (cdev, 0, irb);
832 		}
833 		return;
834 	}
835 	/*
836 	 * Check if a halt or clear has been issued in the meanwhile. If yes,
837 	 * only deliver the halt/clear interrupt to the device driver as if it
838 	 * had killed the original request.
839 	 */
840 	if (scsw_fctl(&irb->scsw) &
841 	    (SCSW_FCTL_CLEAR_FUNC | SCSW_FCTL_HALT_FUNC)) {
842 		cdev->private->flags.dosense = 0;
843 		memset(&cdev->private->dma_area->irb, 0, sizeof(struct irb));
844 		ccw_device_accumulate_irb(cdev, irb);
845 		goto call_handler;
846 	}
847 	/* Add basic sense info to irb. */
848 	ccw_device_accumulate_basic_sense(cdev, irb);
849 	if (cdev->private->flags.dosense) {
850 		/* Another basic sense is needed. */
851 		ccw_device_do_sense(cdev, irb);
852 		return;
853 	}
854 call_handler:
855 	cdev->private->state = DEV_STATE_ONLINE;
856 	/* In case sensing interfered with setting the device online */
857 	wake_up(&cdev->private->wait_q);
858 	/* Call the handler. */
859 	if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
860 		/* Start delayed path verification. */
861 		ccw_device_online_verify(cdev, 0);
862 }
863 
864 static void
865 ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
866 {
867 	ccw_device_set_timeout(cdev, 0);
868 	/* Start delayed path verification. */
869 	ccw_device_online_verify(cdev, 0);
870 	/* OK, i/o is dead now. Call interrupt handler. */
871 	if (cdev->handler)
872 		cdev->handler(cdev, cdev->private->intparm,
873 			      ERR_PTR(cdev->private->async_kill_io_rc));
874 }
875 
876 static void
877 ccw_device_killing_timeout(struct ccw_device *cdev, enum dev_event dev_event)
878 {
879 	int ret;
880 
881 	ret = ccw_device_cancel_halt_clear(cdev);
882 	if (ret == -EBUSY) {
883 		ccw_device_set_timeout(cdev, 3*HZ);
884 		return;
885 	}
886 	/* Start delayed path verification. */
887 	ccw_device_online_verify(cdev, 0);
888 	if (cdev->handler)
889 		cdev->handler(cdev, cdev->private->intparm,
890 			      ERR_PTR(cdev->private->async_kill_io_rc));
891 }
892 
893 void ccw_device_kill_io(struct ccw_device *cdev)
894 {
895 	int ret;
896 
897 	ccw_device_set_timeout(cdev, 0);
898 	cdev->private->iretry = 255;
899 	cdev->private->async_kill_io_rc = -EIO;
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)virt_to_phys(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 sure 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