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