drivers/s390/cio/device_fsm.c

   1 /*
   2  * drivers/s390/cio/device_fsm.c
   3  * finite state machine for device handling
   4  *
   5  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
   6  *                       IBM Corporation
   7  *    Author(s): Cornelia Huck(cohuck@de.ibm.com)
   8  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/config.h>
  13 #include <linux/init.h>
  14
  15 #include <asm/ccwdev.h>
  16 #include <asm/qdio.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 "qdio.h"
  25
  26 int
  27 device_is_disconnected(struct subchannel *sch)
  28 {
  29         struct ccw_device *cdev;
  30
  31         if (!sch->dev.driver_data)
  32                 return 0;
  33         cdev = sch->dev.driver_data;
  34         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
  35                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
  36 }
  37
  38 void
  39 device_set_disconnected(struct subchannel *sch)
  40 {
  41         struct ccw_device *cdev;
  42
  43         if (!sch->dev.driver_data)
  44                 return;
  45         cdev = sch->dev.driver_data;
  46         ccw_device_set_timeout(cdev, 0);
  47         cdev->private->state = DEV_STATE_DISCONNECTED;
  48 }
  49
  50 void
  51 device_set_waiting(struct subchannel *sch)
  52 {
  53         struct ccw_device *cdev;
  54
  55         if (!sch->dev.driver_data)
  56                 return;
  57         cdev = sch->dev.driver_data;
  58         ccw_device_set_timeout(cdev, 10*HZ);
  59         cdev->private->state = DEV_STATE_WAIT4IO;
  60 }
  61
  62 /*
  63  * Timeout function. It just triggers a DEV_EVENT_TIMEOUT.
  64  */
  65 static void
  66 ccw_device_timeout(unsigned long data)
  67 {
  68         struct ccw_device *cdev;
  69
  70         cdev = (struct ccw_device *) data;
  71         spin_lock_irq(cdev->ccwlock);
  72         dev_fsm_event(cdev, DEV_EVENT_TIMEOUT);
  73         spin_unlock_irq(cdev->ccwlock);
  74 }
  75
  76 /*
  77  * Set timeout
  78  */
  79 void
  80 ccw_device_set_timeout(struct ccw_device *cdev, int expires)
  81 {
  82         if (expires == 0) {
  83                 del_timer(&cdev->private->timer);
  84                 return;
  85         }
  86         if (timer_pending(&cdev->private->timer)) {
  87                 if (mod_timer(&cdev->private->timer, jiffies + expires))
  88                         return;
  89         }
  90         cdev->private->timer.function = ccw_device_timeout;
  91         cdev->private->timer.data = (unsigned long) cdev;
  92         cdev->private->timer.expires = jiffies + expires;
  93         add_timer(&cdev->private->timer);
  94 }
  95
  96 /*
  97  * Cancel running i/o. This is called repeatedly since halt/clear are
  98  * asynchronous operations. We do one try with cio_cancel, two tries
  99  * with cio_halt, 255 tries with cio_clear. If everythings fails panic.
 100  * Returns 0 if device now idle, -ENODEV for device not operational and
 101  * -EBUSY if an interrupt is expected (either from halt/clear or from a
 102  * status pending).
 103  */
 104 int
 105 ccw_device_cancel_halt_clear(struct ccw_device *cdev)
 106 {
 107         struct subchannel *sch;
 108         int ret;
 109
 110         sch = to_subchannel(cdev->dev.parent);
 111         ret = stsch(sch->irq, &sch->schib);
 112         if (ret || !sch->schib.pmcw.dnv)
 113                 return -ENODEV;
 114         if (!sch->schib.pmcw.ena || sch->schib.scsw.actl == 0)
 115                 /* Not operational or no activity -> done. */
 116                 return 0;
 117         /* Stage 1: cancel io. */
 118         if (!(sch->schib.scsw.actl & SCSW_ACTL_HALT_PEND) &&
 119             !(sch->schib.scsw.actl & SCSW_ACTL_CLEAR_PEND)) {
 120                 ret = cio_cancel(sch);
 121                 if (ret != -EINVAL)
 122                         return ret;
 123                 /* cancel io unsuccessful. From now on it is asynchronous. */
 124                 cdev->private->iretry = 3;      /* 3 halt retries. */
 125         }
 126         if (!(sch->schib.scsw.actl & SCSW_ACTL_CLEAR_PEND)) {
 127                 /* Stage 2: halt io. */
 128                 if (cdev->private->iretry) {
 129                         cdev->private->iretry--;
 130                         ret = cio_halt(sch);
 131                         return (ret == 0) ? -EBUSY : ret;
 132                 }
 133                 /* halt io unsuccessful. */
 134                 cdev->private->iretry = 255;    /* 255 clear retries. */
 135         }
 136         /* Stage 3: clear io. */
 137         if (cdev->private->iretry) {
 138                 cdev->private->iretry--;
 139                 ret = cio_clear (sch);
 140                 return (ret == 0) ? -EBUSY : ret;
 141         }
 142         panic("Can't stop i/o on subchannel.\n");
 143 }
 144
 145 static void
 146 ccw_device_handle_oper(struct ccw_device *cdev)
 147 {
 148         struct subchannel *sch;
 149
 150         sch = to_subchannel(cdev->dev.parent);
 151         cdev->private->flags.recog_done = 1;
 152         /*
 153          * Check if cu type and device type still match. If
 154          * not, it is certainly another device and we have to
 155          * de- and re-register. Also check here for non-matching devno.
 156          */
 157         if (cdev->id.cu_type != cdev->private->senseid.cu_type ||
 158             cdev->id.cu_model != cdev->private->senseid.cu_model ||
 159             cdev->id.dev_type != cdev->private->senseid.dev_type ||
 160             cdev->id.dev_model != cdev->private->senseid.dev_model ||
 161             cdev->private->devno != sch->schib.pmcw.dev) {
 162                 PREPARE_WORK(&cdev->private->kick_work,
 163                              ccw_device_do_unreg_rereg, (void *)cdev);
 164                 queue_work(ccw_device_work, &cdev->private->kick_work);
 165                 return;
 166         }
 167         cdev->private->flags.donotify = 1;
 168 }
 169
 170 /*
 171  * The machine won't give us any notification by machine check if a chpid has
 172  * been varied online on the SE so we have to find out by magic (i. e. driving
 173  * the channel subsystem to device selection and updating our path masks).
 174  */
 175 static inline void
 176 __recover_lost_chpids(struct subchannel *sch, int old_lpm)
 177 {
 178         int mask, i;
 179
 180         for (i = 0; i<8; i++) {
 181                 mask = 0x80 >> i;
 182                 if (!(sch->lpm & mask))
 183                         continue;
 184                 if (old_lpm & mask)
 185                         continue;
 186                 chpid_is_actually_online(sch->schib.pmcw.chpid[i]);
 187         }
 188 }
 189
 190 /*
 191  * Stop device recognition.
 192  */
 193 static void
 194 ccw_device_recog_done(struct ccw_device *cdev, int state)
 195 {
 196         struct subchannel *sch;
 197         int notify, old_lpm;
 198
 199         sch = to_subchannel(cdev->dev.parent);
 200
 201         ccw_device_set_timeout(cdev, 0);
 202         cio_disable_subchannel(sch);
 203         /*
 204          * Now that we tried recognition, we have performed device selection
 205          * through ssch() and the path information is up to date.
 206          */
 207         old_lpm = sch->lpm;
 208         stsch(sch->irq, &sch->schib);
 209         sch->lpm = sch->schib.pmcw.pim &
 210                 sch->schib.pmcw.pam &
 211                 sch->schib.pmcw.pom &
 212                 sch->opm;
 213         if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID)
 214                 /* Force reprobe on all chpids. */
 215                 old_lpm = 0;
 216         if (sch->lpm != old_lpm)
 217                 __recover_lost_chpids(sch, old_lpm);
 218         if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID) {
 219                 if (state == DEV_STATE_NOT_OPER) {
 220                         cdev->private->flags.recog_done = 1;
 221                         cdev->private->state = DEV_STATE_DISCONNECTED;
 222                         return;
 223                 }
 224                 /* Boxed devices don't need extra treatment. */
 225         }
 226         notify = 0;
 227         switch (state) {
 228         case DEV_STATE_NOT_OPER:
 229                 CIO_DEBUG(KERN_WARNING, 2,
 230                           "SenseID : unknown device %04x on subchannel %04x\n",
 231                           cdev->private->devno, sch->irq);
 232                 break;
 233         case DEV_STATE_OFFLINE:
 234                 if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID) {
 235                         ccw_device_handle_oper(cdev);
 236                         notify = 1;
 237                 }
 238                 /* fill out sense information */
 239                 cdev->id = (struct ccw_device_id) {
 240                         .cu_type   = cdev->private->senseid.cu_type,
 241                         .cu_model  = cdev->private->senseid.cu_model,
 242                         .dev_type  = cdev->private->senseid.dev_type,
 243                         .dev_model = cdev->private->senseid.dev_model,
 244                 };
 245                 if (notify) {
 246                         /* Get device online again. */
 247                         ccw_device_online(cdev);
 248                         wake_up(&cdev->private->wait_q);
 249                         return;
 250                 }
 251                 /* Issue device info message. */
 252                 CIO_DEBUG(KERN_INFO, 2, "SenseID : device %04x reports: "
 253                           "CU  Type/Mod = %04X/%02X, Dev Type/Mod = "
 254                           "%04X/%02X\n", cdev->private->devno,
 255                           cdev->id.cu_type, cdev->id.cu_model,
 256                           cdev->id.dev_type, cdev->id.dev_model);
 257                 break;
 258         case DEV_STATE_BOXED:
 259                 CIO_DEBUG(KERN_WARNING, 2,
 260                           "SenseID : boxed device %04x on subchannel %04x\n",
 261                           cdev->private->devno, sch->irq);
 262                 break;
 263         }
 264         cdev->private->state = state;
 265         io_subchannel_recog_done(cdev);
 266         if (state != DEV_STATE_NOT_OPER)
 267                 wake_up(&cdev->private->wait_q);
 268 }
 269
 270 /*
 271  * Function called from device_id.c after sense id has completed.
 272  */
 273 void
 274 ccw_device_sense_id_done(struct ccw_device *cdev, int err)
 275 {
 276         switch (err) {
 277         case 0:
 278                 ccw_device_recog_done(cdev, DEV_STATE_OFFLINE);
 279                 break;
 280         case -ETIME:            /* Sense id stopped by timeout. */
 281                 ccw_device_recog_done(cdev, DEV_STATE_BOXED);
 282                 break;
 283         default:
 284                 ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
 285                 break;
 286         }
 287 }
 288
 289 static void
 290 ccw_device_oper_notify(void *data)
 291 {
 292         struct ccw_device *cdev;
 293         struct subchannel *sch;
 294         int ret;
 295
 296         cdev = (struct ccw_device *)data;
 297         sch = to_subchannel(cdev->dev.parent);
 298         ret = (sch->driver && sch->driver->notify) ?
 299                 sch->driver->notify(&sch->dev, CIO_OPER) : 0;
 300         if (!ret)
 301                 /* Driver doesn't want device back. */
 302                 ccw_device_do_unreg_rereg((void *)cdev);
 303         else
 304                 wake_up(&cdev->private->wait_q);
 305 }
 306
 307 /*
 308  * Finished with online/offline processing.
 309  */
 310 static void
 311 ccw_device_done(struct ccw_device *cdev, int state)
 312 {
 313         struct subchannel *sch;
 314
 315         sch = to_subchannel(cdev->dev.parent);
 316
 317         if (state != DEV_STATE_ONLINE)
 318                 cio_disable_subchannel(sch);
 319
 320         /* Reset device status. */
 321         memset(&cdev->private->irb, 0, sizeof(struct irb));
 322
 323         cdev->private->state = state;
 324
 325
 326         if (state == DEV_STATE_BOXED)
 327                 CIO_DEBUG(KERN_WARNING, 2,
 328                           "Boxed device %04x on subchannel %04x\n",
 329                           cdev->private->devno, sch->irq);
 330
 331         if (cdev->private->flags.donotify) {
 332                 cdev->private->flags.donotify = 0;
 333                 PREPARE_WORK(&cdev->private->kick_work, ccw_device_oper_notify,
 334                              (void *)cdev);
 335                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 336         }
 337         wake_up(&cdev->private->wait_q);
 338
 339         if (css_init_done && state != DEV_STATE_ONLINE)
 340                 put_device (&cdev->dev);
 341 }
 342
 343 /*
 344  * Function called from device_pgid.c after sense path ground has completed.
 345  */
 346 void
 347 ccw_device_sense_pgid_done(struct ccw_device *cdev, int err)
 348 {
 349         struct subchannel *sch;
 350
 351         sch = to_subchannel(cdev->dev.parent);
 352         switch (err) {
 353         case 0:
 354                 /* Start Path Group verification. */
 355                 sch->vpm = 0;   /* Start with no path groups set. */
 356                 cdev->private->state = DEV_STATE_VERIFY;
 357                 ccw_device_verify_start(cdev);
 358                 break;
 359         case -ETIME:            /* Sense path group id stopped by timeout. */
 360         case -EUSERS:           /* device is reserved for someone else. */
 361                 ccw_device_done(cdev, DEV_STATE_BOXED);
 362                 break;
 363         case -EOPNOTSUPP: /* path grouping not supported, just set online. */
 364                 cdev->private->options.pgroup = 0;
 365                 ccw_device_done(cdev, DEV_STATE_ONLINE);
 366                 break;
 367         default:
 368                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 369                 break;
 370         }
 371 }
 372
 373 /*
 374  * Start device recognition.
 375  */
 376 int
 377 ccw_device_recognition(struct ccw_device *cdev)
 378 {
 379         struct subchannel *sch;
 380         int ret;
 381
 382         if ((cdev->private->state != DEV_STATE_NOT_OPER) &&
 383             (cdev->private->state != DEV_STATE_BOXED))
 384                 return -EINVAL;
 385         sch = to_subchannel(cdev->dev.parent);
 386         ret = cio_enable_subchannel(sch, sch->schib.pmcw.isc);
 387         if (ret != 0)
 388                 /* Couldn't enable the subchannel for i/o. Sick device. */
 389                 return ret;
 390
 391         /* After 60s the device recognition is considered to have failed. */
 392         ccw_device_set_timeout(cdev, 60*HZ);
 393
 394         /*
 395          * We used to start here with a sense pgid to find out whether a device
 396          * is locked by someone else. Unfortunately, the sense pgid command
 397          * code has other meanings on devices predating the path grouping
 398          * algorithm, so we start with sense id and box the device after an
 399          * timeout (or if sense pgid during path verification detects the device
 400          * is locked, as may happen on newer devices).
 401          */
 402         cdev->private->flags.recog_done = 0;
 403         cdev->private->state = DEV_STATE_SENSE_ID;
 404         ccw_device_sense_id_start(cdev);
 405         return 0;
 406 }
 407
 408 /*
 409  * Handle timeout in device recognition.
 410  */
 411 static void
 412 ccw_device_recog_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 413 {
 414         int ret;
 415
 416         ret = ccw_device_cancel_halt_clear(cdev);
 417         switch (ret) {
 418         case 0:
 419                 ccw_device_recog_done(cdev, DEV_STATE_BOXED);
 420                 break;
 421         case -ENODEV:
 422                 ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
 423                 break;
 424         default:
 425                 ccw_device_set_timeout(cdev, 3*HZ);
 426         }
 427 }
 428
 429
 430 static void
 431 ccw_device_nopath_notify(void *data)
 432 {
 433         struct ccw_device *cdev;
 434         struct subchannel *sch;
 435         int ret;
 436
 437         cdev = (struct ccw_device *)data;
 438         sch = to_subchannel(cdev->dev.parent);
 439         /* Extra sanity. */
 440         if (sch->lpm)
 441                 return;
 442         ret = (sch->driver && sch->driver->notify) ?
 443                 sch->driver->notify(&sch->dev, CIO_NO_PATH) : 0;
 444         if (!ret) {
 445                 if (get_device(&sch->dev)) {
 446                         /* Driver doesn't want to keep device. */
 447                         cio_disable_subchannel(sch);
 448                         if (get_device(&cdev->dev)) {
 449                                 PREPARE_WORK(&cdev->private->kick_work,
 450                                              ccw_device_call_sch_unregister,
 451                                              (void *)cdev);
 452                                 queue_work(ccw_device_work,
 453                                            &cdev->private->kick_work);
 454                         }
 455                 }
 456         } else {
 457                 cio_disable_subchannel(sch);
 458                 ccw_device_set_timeout(cdev, 0);
 459                 cdev->private->state = DEV_STATE_DISCONNECTED;
 460                 wake_up(&cdev->private->wait_q);
 461         }
 462 }
 463
 464 void
 465 ccw_device_verify_done(struct ccw_device *cdev, int err)
 466 {
 467         cdev->private->flags.doverify = 0;
 468         switch (err) {
 469         case -EOPNOTSUPP: /* path grouping not supported, just set online. */
 470                 cdev->private->options.pgroup = 0;
 471         case 0:
 472                 ccw_device_done(cdev, DEV_STATE_ONLINE);
 473                 break;
 474         case -ETIME:
 475                 ccw_device_done(cdev, DEV_STATE_BOXED);
 476                 break;
 477         default:
 478                 PREPARE_WORK(&cdev->private->kick_work,
 479                              ccw_device_nopath_notify, (void *)cdev);
 480                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 481                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 482                 break;
 483         }
 484 }
 485
 486 /*
 487  * Get device online.
 488  */
 489 int
 490 ccw_device_online(struct ccw_device *cdev)
 491 {
 492         struct subchannel *sch;
 493         int ret;
 494
 495         if ((cdev->private->state != DEV_STATE_OFFLINE) &&
 496             (cdev->private->state != DEV_STATE_BOXED))
 497                 return -EINVAL;
 498         sch = to_subchannel(cdev->dev.parent);
 499         if (css_init_done && !get_device(&cdev->dev))
 500                 return -ENODEV;
 501         ret = cio_enable_subchannel(sch, sch->schib.pmcw.isc);
 502         if (ret != 0) {
 503                 /* Couldn't enable the subchannel for i/o. Sick device. */
 504                 if (ret == -ENODEV)
 505                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 506                 return ret;
 507         }
 508         /* Do we want to do path grouping? */
 509         if (!cdev->private->options.pgroup) {
 510                 /* No, set state online immediately. */
 511                 ccw_device_done(cdev, DEV_STATE_ONLINE);
 512                 return 0;
 513         }
 514         /* Do a SensePGID first. */
 515         cdev->private->state = DEV_STATE_SENSE_PGID;
 516         ccw_device_sense_pgid_start(cdev);
 517         return 0;
 518 }
 519
 520 void
 521 ccw_device_disband_done(struct ccw_device *cdev, int err)
 522 {
 523         switch (err) {
 524         case 0:
 525                 ccw_device_done(cdev, DEV_STATE_OFFLINE);
 526                 break;
 527         case -ETIME:
 528                 ccw_device_done(cdev, DEV_STATE_BOXED);
 529                 break;
 530         default:
 531                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 532                 break;
 533         }
 534 }
 535
 536 /*
 537  * Shutdown device.
 538  */
 539 int
 540 ccw_device_offline(struct ccw_device *cdev)
 541 {
 542         struct subchannel *sch;
 543
 544         sch = to_subchannel(cdev->dev.parent);
 545         if (cdev->private->state != DEV_STATE_ONLINE) {
 546                 if (sch->schib.scsw.actl != 0)
 547                         return -EBUSY;
 548                 return -EINVAL;
 549         }
 550         if (sch->schib.scsw.actl != 0)
 551                 return -EBUSY;
 552         /* Are we doing path grouping? */
 553         if (!cdev->private->options.pgroup) {
 554                 /* No, set state offline immediately. */
 555                 ccw_device_done(cdev, DEV_STATE_OFFLINE);
 556                 return 0;
 557         }
 558         /* Start Set Path Group commands. */
 559         cdev->private->state = DEV_STATE_DISBAND_PGID;
 560         ccw_device_disband_start(cdev);
 561         return 0;
 562 }
 563
 564 /*
 565  * Handle timeout in device online/offline process.
 566  */
 567 static void
 568 ccw_device_onoff_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 569 {
 570         int ret;
 571
 572         ret = ccw_device_cancel_halt_clear(cdev);
 573         switch (ret) {
 574         case 0:
 575                 ccw_device_done(cdev, DEV_STATE_BOXED);
 576                 break;
 577         case -ENODEV:
 578                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 579                 break;
 580         default:
 581                 ccw_device_set_timeout(cdev, 3*HZ);
 582         }
 583 }
 584
 585 /*
 586  * Handle not oper event in device recognition.
 587  */
 588 static void
 589 ccw_device_recog_notoper(struct ccw_device *cdev, enum dev_event dev_event)
 590 {
 591         ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
 592 }
 593
 594 /*
 595  * Handle not operational event while offline.
 596  */
 597 static void
 598 ccw_device_offline_notoper(struct ccw_device *cdev, enum dev_event dev_event)
 599 {
 600         struct subchannel *sch;
 601
 602         cdev->private->state = DEV_STATE_NOT_OPER;
 603         sch = to_subchannel(cdev->dev.parent);
 604         device_unregister(&sch->dev);
 605         sch->schib.pmcw.intparm = 0;
 606         cio_modify(sch);
 607         wake_up(&cdev->private->wait_q);
 608 }
 609
 610 /*
 611  * Handle not operational event while online.
 612  */
 613 static void
 614 ccw_device_online_notoper(struct ccw_device *cdev, enum dev_event dev_event)
 615 {
 616         struct subchannel *sch;
 617
 618         sch = to_subchannel(cdev->dev.parent);
 619         if (sch->driver->notify &&
 620             sch->driver->notify(&sch->dev, sch->lpm ? CIO_GONE : CIO_NO_PATH)) {
 621                         ccw_device_set_timeout(cdev, 0);
 622                         cdev->private->state = DEV_STATE_DISCONNECTED;
 623                         wake_up(&cdev->private->wait_q);
 624                         return;
 625         }
 626         cdev->private->state = DEV_STATE_NOT_OPER;
 627         cio_disable_subchannel(sch);
 628         if (sch->schib.scsw.actl != 0) {
 629                 // FIXME: not-oper indication to device driver ?
 630                 ccw_device_call_handler(cdev);
 631         }
 632         device_unregister(&sch->dev);
 633         sch->schib.pmcw.intparm = 0;
 634         cio_modify(sch);
 635         wake_up(&cdev->private->wait_q);
 636 }
 637
 638 /*
 639  * Handle path verification event.
 640  */
 641 static void
 642 ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
 643 {
 644         struct subchannel *sch;
 645
 646         if (!cdev->private->options.pgroup)
 647                 return;
 648         if (cdev->private->state == DEV_STATE_W4SENSE) {
 649                 cdev->private->flags.doverify = 1;
 650                 return;
 651         }
 652         sch = to_subchannel(cdev->dev.parent);
 653         if (sch->schib.scsw.actl != 0 ||
 654             (cdev->private->irb.scsw.stctl & SCSW_STCTL_STATUS_PEND)) {
 655                 /*
 656                  * No final status yet or final status not yet delivered
 657                  * to the device driver. Can't do path verfication now,
 658                  * delay until final status was delivered.
 659                  */
 660                 cdev->private->flags.doverify = 1;
 661                 return;
 662         }
 663         /* Device is idle, we can do the path verification. */
 664         cdev->private->state = DEV_STATE_VERIFY;
 665         ccw_device_verify_start(cdev);
 666 }
 667
 668 /*
 669  * Got an interrupt for a normal io (state online).
 670  */
 671 static void
 672 ccw_device_irq(struct ccw_device *cdev, enum dev_event dev_event)
 673 {
 674         struct irb *irb;
 675
 676         irb = (struct irb *) __LC_IRB;
 677         /* Check for unsolicited interrupt. */
 678         if ((irb->scsw.stctl ==
 679                         (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS))
 680             && (!irb->scsw.cc)) {
 681                 if ((irb->scsw.dstat & DEV_STAT_UNIT_CHECK) &&
 682                     !irb->esw.esw0.erw.cons) {
 683                         /* Unit check but no sense data. Need basic sense. */
 684                         if (ccw_device_do_sense(cdev, irb) != 0)
 685                                 goto call_handler_unsol;
 686                         memcpy(irb, &cdev->private->irb, sizeof(struct irb));
 687                         cdev->private->state = DEV_STATE_W4SENSE;
 688                         cdev->private->intparm = 0;
 689                         return;
 690                 }
 691 call_handler_unsol:
 692                 if (cdev->handler)
 693                         cdev->handler (cdev, 0, irb);
 694                 return;
 695         }
 696         /* Accumulate status and find out if a basic sense is needed. */
 697         ccw_device_accumulate_irb(cdev, irb);
 698         if (cdev->private->flags.dosense) {
 699                 if (ccw_device_do_sense(cdev, irb) == 0) {
 700                         cdev->private->state = DEV_STATE_W4SENSE;
 701                 }
 702                 return;
 703         }
 704         /* Call the handler. */
 705         if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
 706                 /* Start delayed path verification. */
 707                 ccw_device_online_verify(cdev, 0);
 708 }
 709
 710 /*
 711  * Got an timeout in online state.
 712  */
 713 static void
 714 ccw_device_online_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 715 {
 716         int ret;
 717
 718         ccw_device_set_timeout(cdev, 0);
 719         ret = ccw_device_cancel_halt_clear(cdev);
 720         if (ret == -EBUSY) {
 721                 ccw_device_set_timeout(cdev, 3*HZ);
 722                 cdev->private->state = DEV_STATE_TIMEOUT_KILL;
 723                 return;
 724         }
 725         if (ret == -ENODEV) {
 726                 struct subchannel *sch;
 727
 728                 sch = to_subchannel(cdev->dev.parent);
 729                 if (!sch->lpm) {
 730                         PREPARE_WORK(&cdev->private->kick_work,
 731                                      ccw_device_nopath_notify, (void *)cdev);
 732                         queue_work(ccw_device_notify_work,
 733                                    &cdev->private->kick_work);
 734                 } else
 735                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 736         } else if (cdev->handler)
 737                 cdev->handler(cdev, cdev->private->intparm,
 738                               ERR_PTR(-ETIMEDOUT));
 739 }
 740
 741 /*
 742  * Got an interrupt for a basic sense.
 743  */
 744 void
 745 ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
 746 {
 747         struct irb *irb;
 748
 749         irb = (struct irb *) __LC_IRB;
 750         /* Check for unsolicited interrupt. */
 751         if (irb->scsw.stctl ==
 752                         (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 753                 if (irb->scsw.cc == 1)
 754                         /* Basic sense hasn't started. Try again. */
 755                         ccw_device_do_sense(cdev, irb);
 756                 else {
 757                         printk("Huh? %s(%s): unsolicited interrupt...\n",
 758                                __FUNCTION__, cdev->dev.bus_id);
 759                         if (cdev->handler)
 760                                 cdev->handler (cdev, 0, irb);
 761                 }
 762                 return;
 763         }
 764         /* Add basic sense info to irb. */
 765         ccw_device_accumulate_basic_sense(cdev, irb);
 766         if (cdev->private->flags.dosense) {
 767                 /* Another basic sense is needed. */
 768                 ccw_device_do_sense(cdev, irb);
 769                 return;
 770         }
 771         cdev->private->state = DEV_STATE_ONLINE;
 772         /* Call the handler. */
 773         if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
 774                 /* Start delayed path verification. */
 775                 ccw_device_online_verify(cdev, 0);
 776 }
 777
 778 static void
 779 ccw_device_clear_verify(struct ccw_device *cdev, enum dev_event dev_event)
 780 {
 781         struct irb *irb;
 782
 783         irb = (struct irb *) __LC_IRB;
 784         /* Accumulate status. We don't do basic sense. */
 785         ccw_device_accumulate_irb(cdev, irb);
 786         /* Try to start delayed device verification. */
 787         ccw_device_online_verify(cdev, 0);
 788         /* Note: Don't call handler for cio initiated clear! */
 789 }
 790
 791 static void
 792 ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
 793 {
 794         struct subchannel *sch;
 795
 796         sch = to_subchannel(cdev->dev.parent);
 797         ccw_device_set_timeout(cdev, 0);
 798         /* OK, i/o is dead now. Call interrupt handler. */
 799         cdev->private->state = DEV_STATE_ONLINE;
 800         if (cdev->handler)
 801                 cdev->handler(cdev, cdev->private->intparm,
 802                               ERR_PTR(-ETIMEDOUT));
 803         if (!sch->lpm) {
 804                 PREPARE_WORK(&cdev->private->kick_work,
 805                              ccw_device_nopath_notify, (void *)cdev);
 806                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 807         } else if (cdev->private->flags.doverify)
 808                 /* Start delayed path verification. */
 809                 ccw_device_online_verify(cdev, 0);
 810 }
 811
 812 static void
 813 ccw_device_killing_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 814 {
 815         int ret;
 816
 817         ret = ccw_device_cancel_halt_clear(cdev);
 818         if (ret == -EBUSY) {
 819                 ccw_device_set_timeout(cdev, 3*HZ);
 820                 return;
 821         }
 822         if (ret == -ENODEV) {
 823                 struct subchannel *sch;
 824
 825                 sch = to_subchannel(cdev->dev.parent);
 826                 if (!sch->lpm) {
 827                         PREPARE_WORK(&cdev->private->kick_work,
 828                                      ccw_device_nopath_notify, (void *)cdev);
 829                         queue_work(ccw_device_notify_work,
 830                                    &cdev->private->kick_work);
 831                 } else
 832                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 833                 return;
 834         }
 835         //FIXME: Can we get here?
 836         cdev->private->state = DEV_STATE_ONLINE;
 837         if (cdev->handler)
 838                 cdev->handler(cdev, cdev->private->intparm,
 839                               ERR_PTR(-ETIMEDOUT));
 840 }
 841
 842 static void
 843 ccw_device_wait4io_irq(struct ccw_device *cdev, enum dev_event dev_event)
 844 {
 845         struct irb *irb;
 846         struct subchannel *sch;
 847
 848         irb = (struct irb *) __LC_IRB;
 849         /*
 850          * Accumulate status and find out if a basic sense is needed.
 851          * This is fine since we have already adapted the lpm.
 852          */
 853         ccw_device_accumulate_irb(cdev, irb);
 854         if (cdev->private->flags.dosense) {
 855                 if (ccw_device_do_sense(cdev, irb) == 0) {
 856                         cdev->private->state = DEV_STATE_W4SENSE;
 857                 }
 858                 return;
 859         }
 860
 861         /* Iff device is idle, reset timeout. */
 862         sch = to_subchannel(cdev->dev.parent);
 863         if (!stsch(sch->irq, &sch->schib))
 864                 if (sch->schib.scsw.actl == 0)
 865                         ccw_device_set_timeout(cdev, 0);
 866         /* Call the handler. */
 867         ccw_device_call_handler(cdev);
 868         if (!sch->lpm) {
 869                 PREPARE_WORK(&cdev->private->kick_work,
 870                              ccw_device_nopath_notify, (void *)cdev);
 871                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 872         } else if (cdev->private->flags.doverify)
 873                 ccw_device_online_verify(cdev, 0);
 874 }
 875
 876 static void
 877 ccw_device_wait4io_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 878 {
 879         int ret;
 880         struct subchannel *sch;
 881
 882         sch = to_subchannel(cdev->dev.parent);
 883         ccw_device_set_timeout(cdev, 0);
 884         ret = ccw_device_cancel_halt_clear(cdev);
 885         if (ret == -EBUSY) {
 886                 ccw_device_set_timeout(cdev, 3*HZ);
 887                 cdev->private->state = DEV_STATE_TIMEOUT_KILL;
 888                 return;
 889         }
 890         if (ret == -ENODEV) {
 891                 if (!sch->lpm) {
 892                         PREPARE_WORK(&cdev->private->kick_work,
 893                                      ccw_device_nopath_notify, (void *)cdev);
 894                         queue_work(ccw_device_notify_work,
 895                                    &cdev->private->kick_work);
 896                 } else
 897                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 898                 return;
 899         }
 900         if (cdev->handler)
 901                 cdev->handler(cdev, cdev->private->intparm,
 902                               ERR_PTR(-ETIMEDOUT));
 903         if (!sch->lpm) {
 904                 PREPARE_WORK(&cdev->private->kick_work,
 905                              ccw_device_nopath_notify, (void *)cdev);
 906                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 907         } else if (cdev->private->flags.doverify)
 908                 /* Start delayed path verification. */
 909                 ccw_device_online_verify(cdev, 0);
 910 }
 911
 912 static void
 913 ccw_device_wait4io_verify(struct ccw_device *cdev, enum dev_event dev_event)
 914 {
 915         /* When the I/O has terminated, we have to start verification. */
 916         if (cdev->private->options.pgroup)
 917                 cdev->private->flags.doverify = 1;
 918 }
 919
 920 static void
 921 ccw_device_stlck_done(struct ccw_device *cdev, enum dev_event dev_event)
 922 {
 923         struct irb *irb;
 924
 925         switch (dev_event) {
 926         case DEV_EVENT_INTERRUPT:
 927                 irb = (struct irb *) __LC_IRB;
 928                 /* Check for unsolicited interrupt. */
 929                 if ((irb->scsw.stctl ==
 930                      (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) &&
 931                     (!irb->scsw.cc))
 932                         /* FIXME: we should restart stlck here, but this
 933                          * is extremely unlikely ... */
 934                         goto out_wakeup;
 935
 936                 ccw_device_accumulate_irb(cdev, irb);
 937                 /* We don't care about basic sense etc. */
 938                 break;
 939         default: /* timeout */
 940                 break;
 941         }
 942 out_wakeup:
 943         wake_up(&cdev->private->wait_q);
 944 }
 945
 946 static void
 947 ccw_device_start_id(struct ccw_device *cdev, enum dev_event dev_event)
 948 {
 949         struct subchannel *sch;
 950
 951         sch = to_subchannel(cdev->dev.parent);
 952         if (cio_enable_subchannel(sch, sch->schib.pmcw.isc) != 0)
 953                 /* Couldn't enable the subchannel for i/o. Sick device. */
 954                 return;
 955
 956         /* After 60s the device recognition is considered to have failed. */
 957         ccw_device_set_timeout(cdev, 60*HZ);
 958
 959         cdev->private->state = DEV_STATE_DISCONNECTED_SENSE_ID;
 960         ccw_device_sense_id_start(cdev);
 961 }
 962
 963 void
 964 device_trigger_reprobe(struct subchannel *sch)
 965 {
 966         struct ccw_device *cdev;
 967         unsigned long flags;
 968
 969         if (!sch->dev.driver_data)
 970                 return;
 971         cdev = sch->dev.driver_data;
 972         spin_lock_irqsave(&sch->lock, flags);
 973         if (cdev->private->state != DEV_STATE_DISCONNECTED) {
 974                 spin_unlock_irqrestore(&sch->lock, flags);
 975                 return;
 976         }
 977         /* Update some values. */
 978         if (stsch(sch->irq, &sch->schib)) {
 979                 spin_unlock_irqrestore(&sch->lock, flags);
 980                 return;
 981         }
 982         /*
 983          * The pim, pam, pom values may not be accurate, but they are the best
 984          * we have before performing device selection :/
 985          */
 986         sch->lpm = sch->schib.pmcw.pim &
 987                 sch->schib.pmcw.pam &
 988                 sch->schib.pmcw.pom &
 989                 sch->opm;
 990         /* Re-set some bits in the pmcw that were lost. */
 991         sch->schib.pmcw.isc = 3;
 992         sch->schib.pmcw.csense = 1;
 993         sch->schib.pmcw.ena = 0;
 994         if ((sch->lpm & (sch->lpm - 1)) != 0)
 995                 sch->schib.pmcw.mp = 1;
 996         sch->schib.pmcw.intparm = (__u32)(unsigned long)sch;
 997         ccw_device_start_id(cdev, 0);
 998         spin_unlock_irqrestore(&sch->lock, flags);
 999 }
1000
1001 static void
1002 ccw_device_offline_irq(struct ccw_device *cdev, enum dev_event dev_event)
1003 {
1004         struct subchannel *sch;
1005
1006         sch = to_subchannel(cdev->dev.parent);
1007         /*
1008          * An interrupt in state offline means a previous disable was not
1009          * successful. Try again.
1010          */
1011         cio_disable_subchannel(sch);
1012 }
1013
1014 static void
1015 ccw_device_change_cmfstate(struct ccw_device *cdev, enum dev_event dev_event)
1016 {
1017         retry_set_schib(cdev);
1018         cdev->private->state = DEV_STATE_ONLINE;
1019         dev_fsm_event(cdev, dev_event);
1020 }
1021
1022
1023 static void
1024 ccw_device_quiesce_done(struct ccw_device *cdev, enum dev_event dev_event)
1025 {
1026         ccw_device_set_timeout(cdev, 0);
1027         if (dev_event == DEV_EVENT_NOTOPER)
1028                 cdev->private->state = DEV_STATE_NOT_OPER;
1029         else
1030                 cdev->private->state = DEV_STATE_OFFLINE;
1031         wake_up(&cdev->private->wait_q);
1032 }
1033
1034 static void
1035 ccw_device_quiesce_timeout(struct ccw_device *cdev, enum dev_event dev_event)
1036 {
1037         int ret;
1038
1039         ret = ccw_device_cancel_halt_clear(cdev);
1040         switch (ret) {
1041         case 0:
1042                 cdev->private->state = DEV_STATE_OFFLINE;
1043                 wake_up(&cdev->private->wait_q);
1044                 break;
1045         case -ENODEV:
1046                 cdev->private->state = DEV_STATE_NOT_OPER;
1047                 wake_up(&cdev->private->wait_q);
1048                 break;
1049         default:
1050                 ccw_device_set_timeout(cdev, HZ/10);
1051         }
1052 }
1053
1054 /*
1055  * No operation action. This is used e.g. to ignore a timeout event in
1056  * state offline.
1057  */
1058 static void
1059 ccw_device_nop(struct ccw_device *cdev, enum dev_event dev_event)
1060 {
1061 }
1062
1063 /*
1064  * Bug operation action.
1065  */
1066 static void
1067 ccw_device_bug(struct ccw_device *cdev, enum dev_event dev_event)
1068 {
1069         printk(KERN_EMERG "dev_jumptable[%i][%i] == NULL\n",
1070                cdev->private->state, dev_event);
1071         BUG();
1072 }
1073
1074 /*
1075  * device statemachine
1076  */
1077 fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
1078         [DEV_STATE_NOT_OPER] = {
1079                 [DEV_EVENT_NOTOPER]     = ccw_device_nop,
1080                 [DEV_EVENT_INTERRUPT]   = ccw_device_bug,
1081                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1082                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1083         },
1084         [DEV_STATE_SENSE_PGID] = {
1085                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1086                 [DEV_EVENT_INTERRUPT]   = ccw_device_sense_pgid_irq,
1087                 [DEV_EVENT_TIMEOUT]     = ccw_device_onoff_timeout,
1088                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1089         },
1090         [DEV_STATE_SENSE_ID] = {
1091                 [DEV_EVENT_NOTOPER]     = ccw_device_recog_notoper,
1092                 [DEV_EVENT_INTERRUPT]   = ccw_device_sense_id_irq,
1093                 [DEV_EVENT_TIMEOUT]     = ccw_device_recog_timeout,
1094                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1095         },
1096         [DEV_STATE_OFFLINE] = {
1097                 [DEV_EVENT_NOTOPER]     = ccw_device_offline_notoper,
1098                 [DEV_EVENT_INTERRUPT]   = ccw_device_offline_irq,
1099                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1100                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1101         },
1102         [DEV_STATE_VERIFY] = {
1103                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1104                 [DEV_EVENT_INTERRUPT]   = ccw_device_verify_irq,
1105                 [DEV_EVENT_TIMEOUT]     = ccw_device_onoff_timeout,
1106                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1107         },
1108         [DEV_STATE_ONLINE] = {
1109                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1110                 [DEV_EVENT_INTERRUPT]   = ccw_device_irq,
1111                 [DEV_EVENT_TIMEOUT]     = ccw_device_online_timeout,
1112                 [DEV_EVENT_VERIFY]      = ccw_device_online_verify,
1113         },
1114         [DEV_STATE_W4SENSE] = {
1115                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1116                 [DEV_EVENT_INTERRUPT]   = ccw_device_w4sense,
1117                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1118                 [DEV_EVENT_VERIFY]      = ccw_device_online_verify,
1119         },
1120         [DEV_STATE_DISBAND_PGID] = {
1121                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1122                 [DEV_EVENT_INTERRUPT]   = ccw_device_disband_irq,
1123                 [DEV_EVENT_TIMEOUT]     = ccw_device_onoff_timeout,
1124                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1125         },
1126         [DEV_STATE_BOXED] = {
1127                 [DEV_EVENT_NOTOPER]     = ccw_device_offline_notoper,
1128                 [DEV_EVENT_INTERRUPT]   = ccw_device_stlck_done,
1129                 [DEV_EVENT_TIMEOUT]     = ccw_device_stlck_done,
1130                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1131         },
1132         /* states to wait for i/o completion before doing something */
1133         [DEV_STATE_CLEAR_VERIFY] = {
1134                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1135                 [DEV_EVENT_INTERRUPT]   = ccw_device_clear_verify,
1136                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1137                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1138         },
1139         [DEV_STATE_TIMEOUT_KILL] = {
1140                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1141                 [DEV_EVENT_INTERRUPT]   = ccw_device_killing_irq,
1142                 [DEV_EVENT_TIMEOUT]     = ccw_device_killing_timeout,
1143                 [DEV_EVENT_VERIFY]      = ccw_device_nop, //FIXME
1144         },
1145         [DEV_STATE_WAIT4IO] = {
1146                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1147                 [DEV_EVENT_INTERRUPT]   = ccw_device_wait4io_irq,
1148                 [DEV_EVENT_TIMEOUT]     = ccw_device_wait4io_timeout,
1149                 [DEV_EVENT_VERIFY]      = ccw_device_wait4io_verify,
1150         },
1151         [DEV_STATE_QUIESCE] = {
1152                 [DEV_EVENT_NOTOPER]     = ccw_device_quiesce_done,
1153                 [DEV_EVENT_INTERRUPT]   = ccw_device_quiesce_done,
1154                 [DEV_EVENT_TIMEOUT]     = ccw_device_quiesce_timeout,
1155                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1156         },
1157         /* special states for devices gone not operational */
1158         [DEV_STATE_DISCONNECTED] = {
1159                 [DEV_EVENT_NOTOPER]     = ccw_device_nop,
1160                 [DEV_EVENT_INTERRUPT]   = ccw_device_start_id,
1161                 [DEV_EVENT_TIMEOUT]     = ccw_device_bug,
1162                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1163         },
1164         [DEV_STATE_DISCONNECTED_SENSE_ID] = {
1165                 [DEV_EVENT_NOTOPER]     = ccw_device_recog_notoper,
1166                 [DEV_EVENT_INTERRUPT]   = ccw_device_sense_id_irq,
1167                 [DEV_EVENT_TIMEOUT]     = ccw_device_recog_timeout,
1168                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1169         },
1170         [DEV_STATE_CMFCHANGE] = {
1171                 [DEV_EVENT_NOTOPER]     = ccw_device_change_cmfstate,
1172                 [DEV_EVENT_INTERRUPT]   = ccw_device_change_cmfstate,
1173                 [DEV_EVENT_TIMEOUT]     = ccw_device_change_cmfstate,
1174                 [DEV_EVENT_VERIFY]      = ccw_device_change_cmfstate,
1175         },
1176 };
1177
1178 /*
1179  * io_subchannel_irq is called for "real" interrupts or for status
1180  * pending conditions on msch.
1181  */
1182 void
1183 io_subchannel_irq (struct device *pdev)
1184 {
1185         struct ccw_device *cdev;
1186
1187         cdev = to_subchannel(pdev)->dev.driver_data;
1188
1189         CIO_TRACE_EVENT (3, "IRQ");
1190         CIO_TRACE_EVENT (3, pdev->bus_id);
1191
1192         dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1193 }
1194
1195 EXPORT_SYMBOL_GPL(ccw_device_set_timeout);