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                         cdev->private->state = DEV_STATE_OFFLINE;
 248                         ccw_device_online(cdev);
 249                         wake_up(&cdev->private->wait_q);
 250                         return;
 251                 }
 252                 /* Issue device info message. */
 253                 CIO_DEBUG(KERN_INFO, 2, "SenseID : device %04x reports: "
 254                           "CU  Type/Mod = %04X/%02X, Dev Type/Mod = "
 255                           "%04X/%02X\n", cdev->private->devno,
 256                           cdev->id.cu_type, cdev->id.cu_model,
 257                           cdev->id.dev_type, cdev->id.dev_model);
 258                 break;
 259         case DEV_STATE_BOXED:
 260                 CIO_DEBUG(KERN_WARNING, 2,
 261                           "SenseID : boxed device %04x on subchannel %04x\n",
 262                           cdev->private->devno, sch->irq);
 263                 break;
 264         }
 265         cdev->private->state = state;
 266         io_subchannel_recog_done(cdev);
 267         if (state != DEV_STATE_NOT_OPER)
 268                 wake_up(&cdev->private->wait_q);
 269 }
 270
 271 /*
 272  * Function called from device_id.c after sense id has completed.
 273  */
 274 void
 275 ccw_device_sense_id_done(struct ccw_device *cdev, int err)
 276 {
 277         switch (err) {
 278         case 0:
 279                 ccw_device_recog_done(cdev, DEV_STATE_OFFLINE);
 280                 break;
 281         case -ETIME:            /* Sense id stopped by timeout. */
 282                 ccw_device_recog_done(cdev, DEV_STATE_BOXED);
 283                 break;
 284         default:
 285                 ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
 286                 break;
 287         }
 288 }
 289
 290 static void
 291 ccw_device_oper_notify(void *data)
 292 {
 293         struct ccw_device *cdev;
 294         struct subchannel *sch;
 295         int ret;
 296
 297         cdev = (struct ccw_device *)data;
 298         sch = to_subchannel(cdev->dev.parent);
 299         ret = (sch->driver && sch->driver->notify) ?
 300                 sch->driver->notify(&sch->dev, CIO_OPER) : 0;
 301         if (!ret)
 302                 /* Driver doesn't want device back. */
 303                 ccw_device_do_unreg_rereg((void *)cdev);
 304         else
 305                 wake_up(&cdev->private->wait_q);
 306 }
 307
 308 /*
 309  * Finished with online/offline processing.
 310  */
 311 static void
 312 ccw_device_done(struct ccw_device *cdev, int state)
 313 {
 314         struct subchannel *sch;
 315
 316         sch = to_subchannel(cdev->dev.parent);
 317
 318         if (state != DEV_STATE_ONLINE)
 319                 cio_disable_subchannel(sch);
 320
 321         /* Reset device status. */
 322         memset(&cdev->private->irb, 0, sizeof(struct irb));
 323
 324         cdev->private->state = state;
 325
 326
 327         if (state == DEV_STATE_BOXED)
 328                 CIO_DEBUG(KERN_WARNING, 2,
 329                           "Boxed device %04x on subchannel %04x\n",
 330                           cdev->private->devno, sch->irq);
 331
 332         if (cdev->private->flags.donotify) {
 333                 cdev->private->flags.donotify = 0;
 334                 PREPARE_WORK(&cdev->private->kick_work, ccw_device_oper_notify,
 335                              (void *)cdev);
 336                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 337         }
 338         wake_up(&cdev->private->wait_q);
 339
 340         if (css_init_done && state != DEV_STATE_ONLINE)
 341                 put_device (&cdev->dev);
 342 }
 343
 344 /*
 345  * Function called from device_pgid.c after sense path ground has completed.
 346  */
 347 void
 348 ccw_device_sense_pgid_done(struct ccw_device *cdev, int err)
 349 {
 350         struct subchannel *sch;
 351
 352         sch = to_subchannel(cdev->dev.parent);
 353         switch (err) {
 354         case 0:
 355                 /* Start Path Group verification. */
 356                 sch->vpm = 0;   /* Start with no path groups set. */
 357                 cdev->private->state = DEV_STATE_VERIFY;
 358                 ccw_device_verify_start(cdev);
 359                 break;
 360         case -ETIME:            /* Sense path group id stopped by timeout. */
 361         case -EUSERS:           /* device is reserved for someone else. */
 362                 ccw_device_done(cdev, DEV_STATE_BOXED);
 363                 break;
 364         case -EOPNOTSUPP: /* path grouping not supported, just set online. */
 365                 cdev->private->options.pgroup = 0;
 366                 ccw_device_done(cdev, DEV_STATE_ONLINE);
 367                 break;
 368         default:
 369                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 370                 break;
 371         }
 372 }
 373
 374 /*
 375  * Start device recognition.
 376  */
 377 int
 378 ccw_device_recognition(struct ccw_device *cdev)
 379 {
 380         struct subchannel *sch;
 381         int ret;
 382
 383         if ((cdev->private->state != DEV_STATE_NOT_OPER) &&
 384             (cdev->private->state != DEV_STATE_BOXED))
 385                 return -EINVAL;
 386         sch = to_subchannel(cdev->dev.parent);
 387         ret = cio_enable_subchannel(sch, sch->schib.pmcw.isc);
 388         if (ret != 0)
 389                 /* Couldn't enable the subchannel for i/o. Sick device. */
 390                 return ret;
 391
 392         /* After 60s the device recognition is considered to have failed. */
 393         ccw_device_set_timeout(cdev, 60*HZ);
 394
 395         /*
 396          * We used to start here with a sense pgid to find out whether a device
 397          * is locked by someone else. Unfortunately, the sense pgid command
 398          * code has other meanings on devices predating the path grouping
 399          * algorithm, so we start with sense id and box the device after an
 400          * timeout (or if sense pgid during path verification detects the device
 401          * is locked, as may happen on newer devices).
 402          */
 403         cdev->private->flags.recog_done = 0;
 404         cdev->private->state = DEV_STATE_SENSE_ID;
 405         ccw_device_sense_id_start(cdev);
 406         return 0;
 407 }
 408
 409 /*
 410  * Handle timeout in device recognition.
 411  */
 412 static void
 413 ccw_device_recog_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 414 {
 415         int ret;
 416
 417         ret = ccw_device_cancel_halt_clear(cdev);
 418         switch (ret) {
 419         case 0:
 420                 ccw_device_recog_done(cdev, DEV_STATE_BOXED);
 421                 break;
 422         case -ENODEV:
 423                 ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
 424                 break;
 425         default:
 426                 ccw_device_set_timeout(cdev, 3*HZ);
 427         }
 428 }
 429
 430
 431 static void
 432 ccw_device_nopath_notify(void *data)
 433 {
 434         struct ccw_device *cdev;
 435         struct subchannel *sch;
 436         int ret;
 437
 438         cdev = (struct ccw_device *)data;
 439         sch = to_subchannel(cdev->dev.parent);
 440         /* Extra sanity. */
 441         if (sch->lpm)
 442                 return;
 443         ret = (sch->driver && sch->driver->notify) ?
 444                 sch->driver->notify(&sch->dev, CIO_NO_PATH) : 0;
 445         if (!ret) {
 446                 if (get_device(&sch->dev)) {
 447                         /* Driver doesn't want to keep device. */
 448                         cio_disable_subchannel(sch);
 449                         if (get_device(&cdev->dev)) {
 450                                 PREPARE_WORK(&cdev->private->kick_work,
 451                                              ccw_device_call_sch_unregister,
 452                                              (void *)cdev);
 453                                 queue_work(ccw_device_work,
 454                                            &cdev->private->kick_work);
 455                         }
 456                 }
 457         } else {
 458                 cio_disable_subchannel(sch);
 459                 ccw_device_set_timeout(cdev, 0);
 460                 cdev->private->state = DEV_STATE_DISCONNECTED;
 461                 wake_up(&cdev->private->wait_q);
 462         }
 463 }
 464
 465 void
 466 ccw_device_verify_done(struct ccw_device *cdev, int err)
 467 {
 468         cdev->private->flags.doverify = 0;
 469         switch (err) {
 470         case -EOPNOTSUPP: /* path grouping not supported, just set online. */
 471                 cdev->private->options.pgroup = 0;
 472         case 0:
 473                 ccw_device_done(cdev, DEV_STATE_ONLINE);
 474                 break;
 475         case -ETIME:
 476                 ccw_device_done(cdev, DEV_STATE_BOXED);
 477                 break;
 478         default:
 479                 PREPARE_WORK(&cdev->private->kick_work,
 480                              ccw_device_nopath_notify, (void *)cdev);
 481                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 482                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 483                 break;
 484         }
 485 }
 486
 487 /*
 488  * Get device online.
 489  */
 490 int
 491 ccw_device_online(struct ccw_device *cdev)
 492 {
 493         struct subchannel *sch;
 494         int ret;
 495
 496         if ((cdev->private->state != DEV_STATE_OFFLINE) &&
 497             (cdev->private->state != DEV_STATE_BOXED))
 498                 return -EINVAL;
 499         sch = to_subchannel(cdev->dev.parent);
 500         if (css_init_done && !get_device(&cdev->dev))
 501                 return -ENODEV;
 502         ret = cio_enable_subchannel(sch, sch->schib.pmcw.isc);
 503         if (ret != 0) {
 504                 /* Couldn't enable the subchannel for i/o. Sick device. */
 505                 if (ret == -ENODEV)
 506                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 507                 return ret;
 508         }
 509         /* Do we want to do path grouping? */
 510         if (!cdev->private->options.pgroup) {
 511                 /* No, set state online immediately. */
 512                 ccw_device_done(cdev, DEV_STATE_ONLINE);
 513                 return 0;
 514         }
 515         /* Do a SensePGID first. */
 516         cdev->private->state = DEV_STATE_SENSE_PGID;
 517         ccw_device_sense_pgid_start(cdev);
 518         return 0;
 519 }
 520
 521 void
 522 ccw_device_disband_done(struct ccw_device *cdev, int err)
 523 {
 524         switch (err) {
 525         case 0:
 526                 ccw_device_done(cdev, DEV_STATE_OFFLINE);
 527                 break;
 528         case -ETIME:
 529                 ccw_device_done(cdev, DEV_STATE_BOXED);
 530                 break;
 531         default:
 532                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 533                 break;
 534         }
 535 }
 536
 537 /*
 538  * Shutdown device.
 539  */
 540 int
 541 ccw_device_offline(struct ccw_device *cdev)
 542 {
 543         struct subchannel *sch;
 544
 545         sch = to_subchannel(cdev->dev.parent);
 546         if (cdev->private->state != DEV_STATE_ONLINE) {
 547                 if (sch->schib.scsw.actl != 0)
 548                         return -EBUSY;
 549                 return -EINVAL;
 550         }
 551         if (sch->schib.scsw.actl != 0)
 552                 return -EBUSY;
 553         /* Are we doing path grouping? */
 554         if (!cdev->private->options.pgroup) {
 555                 /* No, set state offline immediately. */
 556                 ccw_device_done(cdev, DEV_STATE_OFFLINE);
 557                 return 0;
 558         }
 559         /* Start Set Path Group commands. */
 560         cdev->private->state = DEV_STATE_DISBAND_PGID;
 561         ccw_device_disband_start(cdev);
 562         return 0;
 563 }
 564
 565 /*
 566  * Handle timeout in device online/offline process.
 567  */
 568 static void
 569 ccw_device_onoff_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 570 {
 571         int ret;
 572
 573         ret = ccw_device_cancel_halt_clear(cdev);
 574         switch (ret) {
 575         case 0:
 576                 ccw_device_done(cdev, DEV_STATE_BOXED);
 577                 break;
 578         case -ENODEV:
 579                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 580                 break;
 581         default:
 582                 ccw_device_set_timeout(cdev, 3*HZ);
 583         }
 584 }
 585
 586 /*
 587  * Handle not oper event in device recognition.
 588  */
 589 static void
 590 ccw_device_recog_notoper(struct ccw_device *cdev, enum dev_event dev_event)
 591 {
 592         ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
 593 }
 594
 595 /*
 596  * Handle not operational event while offline.
 597  */
 598 static void
 599 ccw_device_offline_notoper(struct ccw_device *cdev, enum dev_event dev_event)
 600 {
 601         struct subchannel *sch;
 602
 603         cdev->private->state = DEV_STATE_NOT_OPER;
 604         sch = to_subchannel(cdev->dev.parent);
 605         device_unregister(&sch->dev);
 606         sch->schib.pmcw.intparm = 0;
 607         cio_modify(sch);
 608         wake_up(&cdev->private->wait_q);
 609 }
 610
 611 /*
 612  * Handle not operational event while online.
 613  */
 614 static void
 615 ccw_device_online_notoper(struct ccw_device *cdev, enum dev_event dev_event)
 616 {
 617         struct subchannel *sch;
 618
 619         sch = to_subchannel(cdev->dev.parent);
 620         if (sch->driver->notify &&
 621             sch->driver->notify(&sch->dev, sch->lpm ? CIO_GONE : CIO_NO_PATH)) {
 622                         ccw_device_set_timeout(cdev, 0);
 623                         cdev->private->state = DEV_STATE_DISCONNECTED;
 624                         wake_up(&cdev->private->wait_q);
 625                         return;
 626         }
 627         cdev->private->state = DEV_STATE_NOT_OPER;
 628         cio_disable_subchannel(sch);
 629         if (sch->schib.scsw.actl != 0) {
 630                 // FIXME: not-oper indication to device driver ?
 631                 ccw_device_call_handler(cdev);
 632         }
 633         device_unregister(&sch->dev);
 634         sch->schib.pmcw.intparm = 0;
 635         cio_modify(sch);
 636         wake_up(&cdev->private->wait_q);
 637 }
 638
 639 /*
 640  * Handle path verification event.
 641  */
 642 static void
 643 ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
 644 {
 645         struct subchannel *sch;
 646
 647         if (!cdev->private->options.pgroup)
 648                 return;
 649         if (cdev->private->state == DEV_STATE_W4SENSE) {
 650                 cdev->private->flags.doverify = 1;
 651                 return;
 652         }
 653         sch = to_subchannel(cdev->dev.parent);
 654         if (sch->schib.scsw.actl != 0 ||
 655             (cdev->private->irb.scsw.stctl & SCSW_STCTL_STATUS_PEND)) {
 656                 /*
 657                  * No final status yet or final status not yet delivered
 658                  * to the device driver. Can't do path verfication now,
 659                  * delay until final status was delivered.
 660                  */
 661                 cdev->private->flags.doverify = 1;
 662                 return;
 663         }
 664         /* Device is idle, we can do the path verification. */
 665         cdev->private->state = DEV_STATE_VERIFY;
 666         ccw_device_verify_start(cdev);
 667 }
 668
 669 /*
 670  * Got an interrupt for a normal io (state online).
 671  */
 672 static void
 673 ccw_device_irq(struct ccw_device *cdev, enum dev_event dev_event)
 674 {
 675         struct irb *irb;
 676
 677         irb = (struct irb *) __LC_IRB;
 678         /* Check for unsolicited interrupt. */
 679         if ((irb->scsw.stctl ==
 680                         (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS))
 681             && (!irb->scsw.cc)) {
 682                 if ((irb->scsw.dstat & DEV_STAT_UNIT_CHECK) &&
 683                     !irb->esw.esw0.erw.cons) {
 684                         /* Unit check but no sense data. Need basic sense. */
 685                         if (ccw_device_do_sense(cdev, irb) != 0)
 686                                 goto call_handler_unsol;
 687                         memcpy(irb, &cdev->private->irb, sizeof(struct irb));
 688                         cdev->private->state = DEV_STATE_W4SENSE;
 689                         cdev->private->intparm = 0;
 690                         return;
 691                 }
 692 call_handler_unsol:
 693                 if (cdev->handler)
 694                         cdev->handler (cdev, 0, irb);
 695                 return;
 696         }
 697         /* Accumulate status and find out if a basic sense is needed. */
 698         ccw_device_accumulate_irb(cdev, irb);
 699         if (cdev->private->flags.dosense) {
 700                 if (ccw_device_do_sense(cdev, irb) == 0) {
 701                         cdev->private->state = DEV_STATE_W4SENSE;
 702                 }
 703                 return;
 704         }
 705         /* Call the handler. */
 706         if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
 707                 /* Start delayed path verification. */
 708                 ccw_device_online_verify(cdev, 0);
 709 }
 710
 711 /*
 712  * Got an timeout in online state.
 713  */
 714 static void
 715 ccw_device_online_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 716 {
 717         int ret;
 718
 719         ccw_device_set_timeout(cdev, 0);
 720         ret = ccw_device_cancel_halt_clear(cdev);
 721         if (ret == -EBUSY) {
 722                 ccw_device_set_timeout(cdev, 3*HZ);
 723                 cdev->private->state = DEV_STATE_TIMEOUT_KILL;
 724                 return;
 725         }
 726         if (ret == -ENODEV) {
 727                 struct subchannel *sch;
 728
 729                 sch = to_subchannel(cdev->dev.parent);
 730                 if (!sch->lpm) {
 731                         PREPARE_WORK(&cdev->private->kick_work,
 732                                      ccw_device_nopath_notify, (void *)cdev);
 733                         queue_work(ccw_device_notify_work,
 734                                    &cdev->private->kick_work);
 735                 } else
 736                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 737         } else if (cdev->handler)
 738                 cdev->handler(cdev, cdev->private->intparm,
 739                               ERR_PTR(-ETIMEDOUT));
 740 }
 741
 742 /*
 743  * Got an interrupt for a basic sense.
 744  */
 745 void
 746 ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
 747 {
 748         struct irb *irb;
 749
 750         irb = (struct irb *) __LC_IRB;
 751         /* Check for unsolicited interrupt. */
 752         if (irb->scsw.stctl ==
 753                         (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 754                 if (irb->scsw.cc == 1)
 755                         /* Basic sense hasn't started. Try again. */
 756                         ccw_device_do_sense(cdev, irb);
 757                 else {
 758                         printk("Huh? %s(%s): unsolicited interrupt...\n",
 759                                __FUNCTION__, cdev->dev.bus_id);
 760                         if (cdev->handler)
 761                                 cdev->handler (cdev, 0, irb);
 762                 }
 763                 return;
 764         }
 765         /* Add basic sense info to irb. */
 766         ccw_device_accumulate_basic_sense(cdev, irb);
 767         if (cdev->private->flags.dosense) {
 768                 /* Another basic sense is needed. */
 769                 ccw_device_do_sense(cdev, irb);
 770                 return;
 771         }
 772         cdev->private->state = DEV_STATE_ONLINE;
 773         /* Call the handler. */
 774         if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
 775                 /* Start delayed path verification. */
 776                 ccw_device_online_verify(cdev, 0);
 777 }
 778
 779 static void
 780 ccw_device_clear_verify(struct ccw_device *cdev, enum dev_event dev_event)
 781 {
 782         struct irb *irb;
 783
 784         irb = (struct irb *) __LC_IRB;
 785         /* Accumulate status. We don't do basic sense. */
 786         ccw_device_accumulate_irb(cdev, irb);
 787         /* Try to start delayed device verification. */
 788         ccw_device_online_verify(cdev, 0);
 789         /* Note: Don't call handler for cio initiated clear! */
 790 }
 791
 792 static void
 793 ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
 794 {
 795         struct subchannel *sch;
 796
 797         sch = to_subchannel(cdev->dev.parent);
 798         ccw_device_set_timeout(cdev, 0);
 799         /* OK, i/o is dead now. Call interrupt handler. */
 800         cdev->private->state = DEV_STATE_ONLINE;
 801         if (cdev->handler)
 802                 cdev->handler(cdev, cdev->private->intparm,
 803                               ERR_PTR(-ETIMEDOUT));
 804         if (!sch->lpm) {
 805                 PREPARE_WORK(&cdev->private->kick_work,
 806                              ccw_device_nopath_notify, (void *)cdev);
 807                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 808         } else if (cdev->private->flags.doverify)
 809                 /* Start delayed path verification. */
 810                 ccw_device_online_verify(cdev, 0);
 811 }
 812
 813 static void
 814 ccw_device_killing_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 815 {
 816         int ret;
 817
 818         ret = ccw_device_cancel_halt_clear(cdev);
 819         if (ret == -EBUSY) {
 820                 ccw_device_set_timeout(cdev, 3*HZ);
 821                 return;
 822         }
 823         if (ret == -ENODEV) {
 824                 struct subchannel *sch;
 825
 826                 sch = to_subchannel(cdev->dev.parent);
 827                 if (!sch->lpm) {
 828                         PREPARE_WORK(&cdev->private->kick_work,
 829                                      ccw_device_nopath_notify, (void *)cdev);
 830                         queue_work(ccw_device_notify_work,
 831                                    &cdev->private->kick_work);
 832                 } else
 833                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 834                 return;
 835         }
 836         //FIXME: Can we get here?
 837         cdev->private->state = DEV_STATE_ONLINE;
 838         if (cdev->handler)
 839                 cdev->handler(cdev, cdev->private->intparm,
 840                               ERR_PTR(-ETIMEDOUT));
 841 }
 842
 843 static void
 844 ccw_device_wait4io_irq(struct ccw_device *cdev, enum dev_event dev_event)
 845 {
 846         struct irb *irb;
 847         struct subchannel *sch;
 848
 849         irb = (struct irb *) __LC_IRB;
 850         /*
 851          * Accumulate status and find out if a basic sense is needed.
 852          * This is fine since we have already adapted the lpm.
 853          */
 854         ccw_device_accumulate_irb(cdev, irb);
 855         if (cdev->private->flags.dosense) {
 856                 if (ccw_device_do_sense(cdev, irb) == 0) {
 857                         cdev->private->state = DEV_STATE_W4SENSE;
 858                 }
 859                 return;
 860         }
 861
 862         /* Iff device is idle, reset timeout. */
 863         sch = to_subchannel(cdev->dev.parent);
 864         if (!stsch(sch->irq, &sch->schib))
 865                 if (sch->schib.scsw.actl == 0)
 866                         ccw_device_set_timeout(cdev, 0);
 867         /* Call the handler. */
 868         ccw_device_call_handler(cdev);
 869         if (!sch->lpm) {
 870                 PREPARE_WORK(&cdev->private->kick_work,
 871                              ccw_device_nopath_notify, (void *)cdev);
 872                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 873         } else if (cdev->private->flags.doverify)
 874                 ccw_device_online_verify(cdev, 0);
 875 }
 876
 877 static void
 878 ccw_device_wait4io_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 879 {
 880         int ret;
 881         struct subchannel *sch;
 882
 883         sch = to_subchannel(cdev->dev.parent);
 884         ccw_device_set_timeout(cdev, 0);
 885         ret = ccw_device_cancel_halt_clear(cdev);
 886         if (ret == -EBUSY) {
 887                 ccw_device_set_timeout(cdev, 3*HZ);
 888                 cdev->private->state = DEV_STATE_TIMEOUT_KILL;
 889                 return;
 890         }
 891         if (ret == -ENODEV) {
 892                 if (!sch->lpm) {
 893                         PREPARE_WORK(&cdev->private->kick_work,
 894                                      ccw_device_nopath_notify, (void *)cdev);
 895                         queue_work(ccw_device_notify_work,
 896                                    &cdev->private->kick_work);
 897                 } else
 898                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 899                 return;
 900         }
 901         if (cdev->handler)
 902                 cdev->handler(cdev, cdev->private->intparm,
 903                               ERR_PTR(-ETIMEDOUT));
 904         if (!sch->lpm) {
 905                 PREPARE_WORK(&cdev->private->kick_work,
 906                              ccw_device_nopath_notify, (void *)cdev);
 907                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 908         } else if (cdev->private->flags.doverify)
 909                 /* Start delayed path verification. */
 910                 ccw_device_online_verify(cdev, 0);
 911 }
 912
 913 static void
 914 ccw_device_wait4io_verify(struct ccw_device *cdev, enum dev_event dev_event)
 915 {
 916         /* When the I/O has terminated, we have to start verification. */
 917         if (cdev->private->options.pgroup)
 918                 cdev->private->flags.doverify = 1;
 919 }
 920
 921 static void
 922 ccw_device_stlck_done(struct ccw_device *cdev, enum dev_event dev_event)
 923 {
 924         struct irb *irb;
 925
 926         switch (dev_event) {
 927         case DEV_EVENT_INTERRUPT:
 928                 irb = (struct irb *) __LC_IRB;
 929                 /* Check for unsolicited interrupt. */
 930                 if ((irb->scsw.stctl ==
 931                      (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) &&
 932                     (!irb->scsw.cc))
 933                         /* FIXME: we should restart stlck here, but this
 934                          * is extremely unlikely ... */
 935                         goto out_wakeup;
 936
 937                 ccw_device_accumulate_irb(cdev, irb);
 938                 /* We don't care about basic sense etc. */
 939                 break;
 940         default: /* timeout */
 941                 break;
 942         }
 943 out_wakeup:
 944         wake_up(&cdev->private->wait_q);
 945 }
 946
 947 static void
 948 ccw_device_start_id(struct ccw_device *cdev, enum dev_event dev_event)
 949 {
 950         struct subchannel *sch;
 951
 952         sch = to_subchannel(cdev->dev.parent);
 953         if (cio_enable_subchannel(sch, sch->schib.pmcw.isc) != 0)
 954                 /* Couldn't enable the subchannel for i/o. Sick device. */
 955                 return;
 956
 957         /* After 60s the device recognition is considered to have failed. */
 958         ccw_device_set_timeout(cdev, 60*HZ);
 959
 960         cdev->private->state = DEV_STATE_DISCONNECTED_SENSE_ID;
 961         ccw_device_sense_id_start(cdev);
 962 }
 963
 964 void
 965 device_trigger_reprobe(struct subchannel *sch)
 966 {
 967         struct ccw_device *cdev;
 968         unsigned long flags;
 969
 970         if (!sch->dev.driver_data)
 971                 return;
 972         cdev = sch->dev.driver_data;
 973         spin_lock_irqsave(&sch->lock, flags);
 974         if (cdev->private->state != DEV_STATE_DISCONNECTED) {
 975                 spin_unlock_irqrestore(&sch->lock, flags);
 976                 return;
 977         }
 978         /* Update some values. */
 979         if (stsch(sch->irq, &sch->schib)) {
 980                 spin_unlock_irqrestore(&sch->lock, flags);
 981                 return;
 982         }
 983         /*
 984          * The pim, pam, pom values may not be accurate, but they are the best
 985          * we have before performing device selection :/
 986          */
 987         sch->lpm = sch->schib.pmcw.pim &
 988                 sch->schib.pmcw.pam &
 989                 sch->schib.pmcw.pom &
 990                 sch->opm;
 991         /* Re-set some bits in the pmcw that were lost. */
 992         sch->schib.pmcw.isc = 3;
 993         sch->schib.pmcw.csense = 1;
 994         sch->schib.pmcw.ena = 0;
 995         if ((sch->lpm & (sch->lpm - 1)) != 0)
 996                 sch->schib.pmcw.mp = 1;
 997         sch->schib.pmcw.intparm = (__u32)(unsigned long)sch;
 998         /* We should also udate ssd info, but this has to wait. */
 999         ccw_device_start_id(cdev, 0);
1000         spin_unlock_irqrestore(&sch->lock, flags);
1001 }
1002
1003 static void
1004 ccw_device_offline_irq(struct ccw_device *cdev, enum dev_event dev_event)
1005 {
1006         struct subchannel *sch;
1007
1008         sch = to_subchannel(cdev->dev.parent);
1009         /*
1010          * An interrupt in state offline means a previous disable was not
1011          * successful. Try again.
1012          */
1013         cio_disable_subchannel(sch);
1014 }
1015
1016 static void
1017 ccw_device_change_cmfstate(struct ccw_device *cdev, enum dev_event dev_event)
1018 {
1019         retry_set_schib(cdev);
1020         cdev->private->state = DEV_STATE_ONLINE;
1021         dev_fsm_event(cdev, dev_event);
1022 }
1023
1024
1025 static void
1026 ccw_device_quiesce_done(struct ccw_device *cdev, enum dev_event dev_event)
1027 {
1028         ccw_device_set_timeout(cdev, 0);
1029         if (dev_event == DEV_EVENT_NOTOPER)
1030                 cdev->private->state = DEV_STATE_NOT_OPER;
1031         else
1032                 cdev->private->state = DEV_STATE_OFFLINE;
1033         wake_up(&cdev->private->wait_q);
1034 }
1035
1036 static void
1037 ccw_device_quiesce_timeout(struct ccw_device *cdev, enum dev_event dev_event)
1038 {
1039         int ret;
1040
1041         ret = ccw_device_cancel_halt_clear(cdev);
1042         switch (ret) {
1043         case 0:
1044                 cdev->private->state = DEV_STATE_OFFLINE;
1045                 wake_up(&cdev->private->wait_q);
1046                 break;
1047         case -ENODEV:
1048                 cdev->private->state = DEV_STATE_NOT_OPER;
1049                 wake_up(&cdev->private->wait_q);
1050                 break;
1051         default:
1052                 ccw_device_set_timeout(cdev, HZ/10);
1053         }
1054 }
1055
1056 /*
1057  * No operation action. This is used e.g. to ignore a timeout event in
1058  * state offline.
1059  */
1060 static void
1061 ccw_device_nop(struct ccw_device *cdev, enum dev_event dev_event)
1062 {
1063 }
1064
1065 /*
1066  * Bug operation action.
1067  */
1068 static void
1069 ccw_device_bug(struct ccw_device *cdev, enum dev_event dev_event)
1070 {
1071         printk(KERN_EMERG "dev_jumptable[%i][%i] == NULL\n",
1072                cdev->private->state, dev_event);
1073         BUG();
1074 }
1075
1076 /*
1077  * device statemachine
1078  */
1079 fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
1080         [DEV_STATE_NOT_OPER] = {
1081                 [DEV_EVENT_NOTOPER]     = ccw_device_nop,
1082                 [DEV_EVENT_INTERRUPT]   = ccw_device_bug,
1083                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1084                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1085         },
1086         [DEV_STATE_SENSE_PGID] = {
1087                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1088                 [DEV_EVENT_INTERRUPT]   = ccw_device_sense_pgid_irq,
1089                 [DEV_EVENT_TIMEOUT]     = ccw_device_onoff_timeout,
1090                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1091         },
1092         [DEV_STATE_SENSE_ID] = {
1093                 [DEV_EVENT_NOTOPER]     = ccw_device_recog_notoper,
1094                 [DEV_EVENT_INTERRUPT]   = ccw_device_sense_id_irq,
1095                 [DEV_EVENT_TIMEOUT]     = ccw_device_recog_timeout,
1096                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1097         },
1098         [DEV_STATE_OFFLINE] = {
1099                 [DEV_EVENT_NOTOPER]     = ccw_device_offline_notoper,
1100                 [DEV_EVENT_INTERRUPT]   = ccw_device_offline_irq,
1101                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1102                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1103         },
1104         [DEV_STATE_VERIFY] = {
1105                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1106                 [DEV_EVENT_INTERRUPT]   = ccw_device_verify_irq,
1107                 [DEV_EVENT_TIMEOUT]     = ccw_device_onoff_timeout,
1108                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1109         },
1110         [DEV_STATE_ONLINE] = {
1111                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1112                 [DEV_EVENT_INTERRUPT]   = ccw_device_irq,
1113                 [DEV_EVENT_TIMEOUT]     = ccw_device_online_timeout,
1114                 [DEV_EVENT_VERIFY]      = ccw_device_online_verify,
1115         },
1116         [DEV_STATE_W4SENSE] = {
1117                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1118                 [DEV_EVENT_INTERRUPT]   = ccw_device_w4sense,
1119                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1120                 [DEV_EVENT_VERIFY]      = ccw_device_online_verify,
1121         },
1122         [DEV_STATE_DISBAND_PGID] = {
1123                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1124                 [DEV_EVENT_INTERRUPT]   = ccw_device_disband_irq,
1125                 [DEV_EVENT_TIMEOUT]     = ccw_device_onoff_timeout,
1126                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1127         },
1128         [DEV_STATE_BOXED] = {
1129                 [DEV_EVENT_NOTOPER]     = ccw_device_offline_notoper,
1130                 [DEV_EVENT_INTERRUPT]   = ccw_device_stlck_done,
1131                 [DEV_EVENT_TIMEOUT]     = ccw_device_stlck_done,
1132                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1133         },
1134         /* states to wait for i/o completion before doing something */
1135         [DEV_STATE_CLEAR_VERIFY] = {
1136                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1137                 [DEV_EVENT_INTERRUPT]   = ccw_device_clear_verify,
1138                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1139                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1140         },
1141         [DEV_STATE_TIMEOUT_KILL] = {
1142                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1143                 [DEV_EVENT_INTERRUPT]   = ccw_device_killing_irq,
1144                 [DEV_EVENT_TIMEOUT]     = ccw_device_killing_timeout,
1145                 [DEV_EVENT_VERIFY]      = ccw_device_nop, //FIXME
1146         },
1147         [DEV_STATE_WAIT4IO] = {
1148                 [DEV_EVENT_NOTOPER]     = ccw_device_online_notoper,
1149                 [DEV_EVENT_INTERRUPT]   = ccw_device_wait4io_irq,
1150                 [DEV_EVENT_TIMEOUT]     = ccw_device_wait4io_timeout,
1151                 [DEV_EVENT_VERIFY]      = ccw_device_wait4io_verify,
1152         },
1153         [DEV_STATE_QUIESCE] = {
1154                 [DEV_EVENT_NOTOPER]     = ccw_device_quiesce_done,
1155                 [DEV_EVENT_INTERRUPT]   = ccw_device_quiesce_done,
1156                 [DEV_EVENT_TIMEOUT]     = ccw_device_quiesce_timeout,
1157                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1158         },
1159         /* special states for devices gone not operational */
1160         [DEV_STATE_DISCONNECTED] = {
1161                 [DEV_EVENT_NOTOPER]     = ccw_device_nop,
1162                 [DEV_EVENT_INTERRUPT]   = ccw_device_start_id,
1163                 [DEV_EVENT_TIMEOUT]     = ccw_device_bug,
1164                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1165         },
1166         [DEV_STATE_DISCONNECTED_SENSE_ID] = {
1167                 [DEV_EVENT_NOTOPER]     = ccw_device_recog_notoper,
1168                 [DEV_EVENT_INTERRUPT]   = ccw_device_sense_id_irq,
1169                 [DEV_EVENT_TIMEOUT]     = ccw_device_recog_timeout,
1170                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1171         },
1172         [DEV_STATE_CMFCHANGE] = {
1173                 [DEV_EVENT_NOTOPER]     = ccw_device_change_cmfstate,
1174                 [DEV_EVENT_INTERRUPT]   = ccw_device_change_cmfstate,
1175                 [DEV_EVENT_TIMEOUT]     = ccw_device_change_cmfstate,
1176                 [DEV_EVENT_VERIFY]      = ccw_device_change_cmfstate,
1177         },
1178 };
1179
1180 /*
1181  * io_subchannel_irq is called for "real" interrupts or for status
1182  * pending conditions on msch.
1183  */
1184 void
1185 io_subchannel_irq (struct device *pdev)
1186 {
1187         struct ccw_device *cdev;
1188
1189         cdev = to_subchannel(pdev)->dev.driver_data;
1190
1191         CIO_TRACE_EVENT (3, "IRQ");
1192         CIO_TRACE_EVENT (3, pdev->bus_id);
1193
1194         dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1195 }
1196
1197 EXPORT_SYMBOL_GPL(ccw_device_set_timeout);