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