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.
 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                 PREPARE_WORK(&cdev->private->kick_work,
 162                              ccw_device_do_unreg_rereg, (void *)&cdev->dev);
 163                 queue_work(ccw_device_work, &cdev->private->kick_work);
 164                 return;
 165         }
 166         cdev->private->flags.donotify = 1;
 167         /* Get device online again. */
 168         ccw_device_online(cdev);
 169 }
 170
 171 /*
 172  * The machine won't give us any notification by machine check if a chpid has
 173  * been varied online on the SE so we have to find out by magic (i. e. driving
 174  * the channel subsystem to device selection and updating our path masks).
 175  */
 176 static inline void
 177 __recover_lost_chpids(struct subchannel *sch, int old_lpm)
 178 {
 179         int mask, i;
 180
 181         for (i = 0; i<8; i++) {
 182                 mask = 0x80 >> i;
 183                 if (!(sch->lpm & mask))
 184                         continue;
 185                 if (old_lpm & mask)
 186                         continue;
 187                 chpid_is_actually_online(sch->schib.pmcw.chpid[i]);
 188         }
 189 }
 190
 191 /*
 192  * Stop device recognition.
 193  */
 194 static void
 195 ccw_device_recog_done(struct ccw_device *cdev, int state)
 196 {
 197         struct subchannel *sch;
 198         int notify, old_lpm;
 199
 200         sch = to_subchannel(cdev->dev.parent);
 201
 202         ccw_device_set_timeout(cdev, 0);
 203         cio_disable_subchannel(sch);
 204         /*
 205          * Now that we tried recognition, we have performed device selection
 206          * through ssch() and the path information is up to date.
 207          */
 208         old_lpm = sch->lpm;
 209         stsch(sch->irq, &sch->schib);
 210         sch->lpm = sch->schib.pmcw.pim &
 211                 sch->schib.pmcw.pam &
 212                 sch->schib.pmcw.pom &
 213                 sch->opm;
 214         if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID)
 215                 /* Force reprobe on all chpids. */
 216                 old_lpm = 0;
 217         if (sch->lpm != old_lpm)
 218                 __recover_lost_chpids(sch, old_lpm);
 219         if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID) {
 220                 if (state == DEV_STATE_NOT_OPER) {
 221                         cdev->private->flags.recog_done = 1;
 222                         cdev->private->state = DEV_STATE_DISCONNECTED;
 223                         return;
 224                 }
 225                 /* Boxed devices don't need extra treatment. */
 226         }
 227         notify = 0;
 228         switch (state) {
 229         case DEV_STATE_NOT_OPER:
 230                 CIO_DEBUG(KERN_WARNING, 2,
 231                           "SenseID : unknown device %04x on subchannel %04x\n",
 232                           cdev->private->devno, sch->irq);
 233                 break;
 234         case DEV_STATE_OFFLINE:
 235                 if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID)
 236                         notify = 1;
 237                 else  /* fill out sense information */
 238                         cdev->id = (struct ccw_device_id) {
 239                                 .cu_type   = cdev->private->senseid.cu_type,
 240                                 .cu_model  = cdev->private->senseid.cu_model,
 241                                 .dev_type  = cdev->private->senseid.dev_type,
 242                                 .dev_model = cdev->private->senseid.dev_model,
 243                         };
 244                 /* Issue device info message. */
 245                 CIO_DEBUG(KERN_INFO, 2, "SenseID : device %04x reports: "
 246                           "CU  Type/Mod = %04X/%02X, Dev Type/Mod = "
 247                           "%04X/%02X\n", cdev->private->devno,
 248                           cdev->id.cu_type, cdev->id.cu_model,
 249                           cdev->id.dev_type, cdev->id.dev_model);
 250                 break;
 251         case DEV_STATE_BOXED:
 252                 CIO_DEBUG(KERN_WARNING, 2,
 253                           "SenseID : boxed device %04x on subchannel %04x\n",
 254                           cdev->private->devno, sch->irq);
 255                 break;
 256         }
 257         cdev->private->state = state;
 258         if (notify && state == DEV_STATE_OFFLINE)
 259                 ccw_device_handle_oper(cdev);
 260         else
 261                 io_subchannel_recog_done(cdev);
 262         if (state != DEV_STATE_NOT_OPER)
 263                 wake_up(&cdev->private->wait_q);
 264 }
 265
 266 /*
 267  * Function called from device_id.c after sense id has completed.
 268  */
 269 void
 270 ccw_device_sense_id_done(struct ccw_device *cdev, int err)
 271 {
 272         switch (err) {
 273         case 0:
 274                 ccw_device_recog_done(cdev, DEV_STATE_OFFLINE);
 275                 break;
 276         case -ETIME:            /* Sense id stopped by timeout. */
 277                 ccw_device_recog_done(cdev, DEV_STATE_BOXED);
 278                 break;
 279         default:
 280                 ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
 281                 break;
 282         }
 283 }
 284
 285 static void
 286 ccw_device_oper_notify(void *data)
 287 {
 288         struct ccw_device *cdev;
 289         struct subchannel *sch;
 290         int ret;
 291
 292         cdev = (struct ccw_device *)data;
 293         sch = to_subchannel(cdev->dev.parent);
 294         ret = (sch->driver && sch->driver->notify) ?
 295                 sch->driver->notify(&sch->dev, CIO_OPER) : 0;
 296         if (!ret)
 297                 /* Driver doesn't want device back. */
 298                 ccw_device_do_unreg_rereg((void *)&cdev->dev);
 299         else
 300                 wake_up(&cdev->private->wait_q);
 301 }
 302
 303 /*
 304  * Finished with online/offline processing.
 305  */
 306 static void
 307 ccw_device_done(struct ccw_device *cdev, int state)
 308 {
 309         struct subchannel *sch;
 310
 311         sch = to_subchannel(cdev->dev.parent);
 312
 313         if (state != DEV_STATE_ONLINE)
 314                 cio_disable_subchannel(sch);
 315
 316         /* Reset device status. */
 317         memset(&cdev->private->irb, 0, sizeof(struct irb));
 318
 319         cdev->private->state = state;
 320
 321
 322         if (state == DEV_STATE_BOXED)
 323                 CIO_DEBUG(KERN_WARNING, 2,
 324                           "Boxed device %04x on subchannel %04x\n",
 325                           cdev->private->devno, sch->irq);
 326
 327         if (cdev->private->flags.donotify) {
 328                 cdev->private->flags.donotify = 0;
 329                 PREPARE_WORK(&cdev->private->kick_work, ccw_device_oper_notify,
 330                              (void *)cdev);
 331                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 332         }
 333         wake_up(&cdev->private->wait_q);
 334
 335         if (css_init_done && state != DEV_STATE_ONLINE)
 336                 put_device (&cdev->dev);
 337 }
 338
 339 /*
 340  * Function called from device_pgid.c after sense path ground has completed.
 341  */
 342 void
 343 ccw_device_sense_pgid_done(struct ccw_device *cdev, int err)
 344 {
 345         struct subchannel *sch;
 346
 347         sch = to_subchannel(cdev->dev.parent);
 348         switch (err) {
 349         case 0:
 350                 /* Start Path Group verification. */
 351                 sch->vpm = 0;   /* Start with no path groups set. */
 352                 cdev->private->state = DEV_STATE_VERIFY;
 353                 ccw_device_verify_start(cdev);
 354                 break;
 355         case -ETIME:            /* Sense path group id stopped by timeout. */
 356         case -EUSERS:           /* device is reserved for someone else. */
 357                 ccw_device_done(cdev, DEV_STATE_BOXED);
 358                 break;
 359         case -EOPNOTSUPP: /* path grouping not supported, just set online. */
 360                 cdev->private->options.pgroup = 0;
 361                 ccw_device_done(cdev, DEV_STATE_ONLINE);
 362                 break;
 363         default:
 364                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 365                 break;
 366         }
 367 }
 368
 369 /*
 370  * Start device recognition.
 371  */
 372 int
 373 ccw_device_recognition(struct ccw_device *cdev)
 374 {
 375         struct subchannel *sch;
 376         int ret;
 377
 378         if ((cdev->private->state != DEV_STATE_NOT_OPER) &&
 379             (cdev->private->state != DEV_STATE_BOXED))
 380                 return -EINVAL;
 381         sch = to_subchannel(cdev->dev.parent);
 382         ret = cio_enable_subchannel(sch, sch->schib.pmcw.isc);
 383         if (ret != 0)
 384                 /* Couldn't enable the subchannel for i/o. Sick device. */
 385                 return ret;
 386
 387         /* After 60s the device recognition is considered to have failed. */
 388         ccw_device_set_timeout(cdev, 60*HZ);
 389
 390         /*
 391          * We used to start here with a sense pgid to find out whether a device
 392          * is locked by someone else. Unfortunately, the sense pgid command
 393          * code has other meanings on devices predating the path grouping
 394          * algorithm, so we start with sense id and box the device after an
 395          * timeout (or if sense pgid during path verification detects the device
 396          * is locked, as may happen on newer devices).
 397          */
 398         cdev->private->flags.recog_done = 0;
 399         cdev->private->state = DEV_STATE_SENSE_ID;
 400         ccw_device_sense_id_start(cdev);
 401         return 0;
 402 }
 403
 404 /*
 405  * Handle timeout in device recognition.
 406  */
 407 static void
 408 ccw_device_recog_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 409 {
 410         int ret;
 411
 412         ret = ccw_device_cancel_halt_clear(cdev);
 413         switch (ret) {
 414         case 0:
 415                 ccw_device_recog_done(cdev, DEV_STATE_BOXED);
 416                 break;
 417         case -ENODEV:
 418                 ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
 419                 break;
 420         default:
 421                 ccw_device_set_timeout(cdev, 3*HZ);
 422         }
 423 }
 424
 425
 426 static void
 427 ccw_device_nopath_notify(void *data)
 428 {
 429         struct ccw_device *cdev;
 430         struct subchannel *sch;
 431         int ret;
 432
 433         cdev = (struct ccw_device *)data;
 434         sch = to_subchannel(cdev->dev.parent);
 435         /* Extra sanity. */
 436         if (sch->lpm)
 437                 return;
 438         ret = (sch->driver && sch->driver->notify) ?
 439                 sch->driver->notify(&sch->dev, CIO_NO_PATH) : 0;
 440         if (!ret) {
 441                 if (get_device(&sch->dev)) {
 442                         /* Driver doesn't want to keep device. */
 443                         cio_disable_subchannel(sch);
 444                         if (get_device(&cdev->dev)) {
 445                                 PREPARE_WORK(&cdev->private->kick_work,
 446                                              ccw_device_call_sch_unregister,
 447                                              (void *)cdev);
 448                                 queue_work(ccw_device_work,
 449                                            &cdev->private->kick_work);
 450                         }
 451                 }
 452         } else {
 453                 cio_disable_subchannel(sch);
 454                 ccw_device_set_timeout(cdev, 0);
 455                 cdev->private->state = DEV_STATE_DISCONNECTED;
 456                 wake_up(&cdev->private->wait_q);
 457         }
 458 }
 459
 460 void
 461 device_call_nopath_notify(struct subchannel *sch)
 462 {
 463         struct ccw_device *cdev;
 464
 465         if (!sch->dev.driver_data)
 466                 return;
 467         cdev = sch->dev.driver_data;
 468         PREPARE_WORK(&cdev->private->kick_work,
 469                      ccw_device_nopath_notify, (void *)cdev);
 470         queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 471 }
 472
 473
 474 void
 475 ccw_device_verify_done(struct ccw_device *cdev, int err)
 476 {
 477         cdev->private->flags.doverify = 0;
 478         switch (err) {
 479         case 0:
 480                 ccw_device_done(cdev, DEV_STATE_ONLINE);
 481                 break;
 482         case -ETIME:
 483                 ccw_device_done(cdev, DEV_STATE_BOXED);
 484                 break;
 485         default:
 486                 PREPARE_WORK(&cdev->private->kick_work,
 487                              ccw_device_nopath_notify, (void *)cdev);
 488                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 489                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 490                 break;
 491         }
 492 }
 493
 494 /*
 495  * Get device online.
 496  */
 497 int
 498 ccw_device_online(struct ccw_device *cdev)
 499 {
 500         struct subchannel *sch;
 501         int ret;
 502
 503         if ((cdev->private->state != DEV_STATE_OFFLINE) &&
 504             (cdev->private->state != DEV_STATE_BOXED))
 505                 return -EINVAL;
 506         sch = to_subchannel(cdev->dev.parent);
 507         if (css_init_done && !get_device(&cdev->dev))
 508                 return -ENODEV;
 509         ret = cio_enable_subchannel(sch, sch->schib.pmcw.isc);
 510         if (ret != 0) {
 511                 /* Couldn't enable the subchannel for i/o. Sick device. */
 512                 if (ret == -ENODEV)
 513                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 514                 return ret;
 515         }
 516         /* Do we want to do path grouping? */
 517         if (!cdev->private->options.pgroup) {
 518                 /* No, set state online immediately. */
 519                 ccw_device_done(cdev, DEV_STATE_ONLINE);
 520                 return 0;
 521         }
 522         /* Do a SensePGID first. */
 523         cdev->private->state = DEV_STATE_SENSE_PGID;
 524         ccw_device_sense_pgid_start(cdev);
 525         return 0;
 526 }
 527
 528 void
 529 ccw_device_disband_done(struct ccw_device *cdev, int err)
 530 {
 531         switch (err) {
 532         case 0:
 533                 ccw_device_done(cdev, DEV_STATE_OFFLINE);
 534                 break;
 535         case -ETIME:
 536                 ccw_device_done(cdev, DEV_STATE_BOXED);
 537                 break;
 538         default:
 539                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 540                 break;
 541         }
 542 }
 543
 544 /*
 545  * Shutdown device.
 546  */
 547 int
 548 ccw_device_offline(struct ccw_device *cdev)
 549 {
 550         struct subchannel *sch;
 551
 552         sch = to_subchannel(cdev->dev.parent);
 553         if (cdev->private->state != DEV_STATE_ONLINE) {
 554                 if (sch->schib.scsw.actl != 0)
 555                         return -EBUSY;
 556                 return -EINVAL;
 557         }
 558         if (sch->schib.scsw.actl != 0)
 559                 return -EBUSY;
 560         /* Are we doing path grouping? */
 561         if (!cdev->private->options.pgroup) {
 562                 /* No, set state offline immediately. */
 563                 ccw_device_done(cdev, DEV_STATE_OFFLINE);
 564                 return 0;
 565         }
 566         /* Start Set Path Group commands. */
 567         cdev->private->state = DEV_STATE_DISBAND_PGID;
 568         ccw_device_disband_start(cdev);
 569         return 0;
 570 }
 571
 572 /*
 573  * Handle timeout in device online/offline process.
 574  */
 575 static void
 576 ccw_device_onoff_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 577 {
 578         int ret;
 579
 580         ret = ccw_device_cancel_halt_clear(cdev);
 581         switch (ret) {
 582         case 0:
 583                 ccw_device_done(cdev, DEV_STATE_BOXED);
 584                 break;
 585         case -ENODEV:
 586                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 587                 break;
 588         default:
 589                 ccw_device_set_timeout(cdev, 3*HZ);
 590         }
 591 }
 592
 593 /*
 594  * Handle not oper event in device recognition.
 595  */
 596 static void
 597 ccw_device_recog_notoper(struct ccw_device *cdev, enum dev_event dev_event)
 598 {
 599         ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
 600 }
 601
 602 /*
 603  * Handle not operational event while offline.
 604  */
 605 static void
 606 ccw_device_offline_notoper(struct ccw_device *cdev, enum dev_event dev_event)
 607 {
 608         struct subchannel *sch;
 609
 610         cdev->private->state = DEV_STATE_NOT_OPER;
 611         sch = to_subchannel(cdev->dev.parent);
 612         device_unregister(&sch->dev);
 613         sch->schib.pmcw.intparm = 0;
 614         cio_modify(sch);
 615         wake_up(&cdev->private->wait_q);
 616 }
 617
 618 /*
 619  * Handle not operational event while online.
 620  */
 621 static void
 622 ccw_device_online_notoper(struct ccw_device *cdev, enum dev_event dev_event)
 623 {
 624         struct subchannel *sch;
 625
 626         sch = to_subchannel(cdev->dev.parent);
 627         if (sch->driver->notify &&
 628             sch->driver->notify(&sch->dev, sch->lpm ? CIO_GONE : CIO_NO_PATH)) {
 629                         ccw_device_set_timeout(cdev, 0);
 630                         cdev->private->state = DEV_STATE_DISCONNECTED;
 631                         wake_up(&cdev->private->wait_q);
 632                         return;
 633         }
 634         cdev->private->state = DEV_STATE_NOT_OPER;
 635         cio_disable_subchannel(sch);
 636         if (sch->schib.scsw.actl != 0) {
 637                 // FIXME: not-oper indication to device driver ?
 638                 ccw_device_call_handler(cdev);
 639         }
 640         device_unregister(&sch->dev);
 641         sch->schib.pmcw.intparm = 0;
 642         cio_modify(sch);
 643         wake_up(&cdev->private->wait_q);
 644 }
 645
 646 /*
 647  * Handle path verification event.
 648  */
 649 static void
 650 ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
 651 {
 652         struct subchannel *sch;
 653
 654         if (!cdev->private->options.pgroup)
 655                 return;
 656         if (cdev->private->state == DEV_STATE_W4SENSE) {
 657                 cdev->private->flags.doverify = 1;
 658                 return;
 659         }
 660         sch = to_subchannel(cdev->dev.parent);
 661         if (sch->schib.scsw.actl != 0 ||
 662             (cdev->private->irb.scsw.stctl & SCSW_STCTL_STATUS_PEND)) {
 663                 /*
 664                  * No final status yet or final status not yet delivered
 665                  * to the device driver. Can't do path verfication now,
 666                  * delay until final status was delivered.
 667                  */
 668                 cdev->private->flags.doverify = 1;
 669                 return;
 670         }
 671         /* Device is idle, we can do the path verification. */
 672         cdev->private->state = DEV_STATE_VERIFY;
 673         ccw_device_verify_start(cdev);
 674 }
 675
 676 /*
 677  * Got an interrupt for a normal io (state online).
 678  */
 679 static void
 680 ccw_device_irq(struct ccw_device *cdev, enum dev_event dev_event)
 681 {
 682         struct irb *irb;
 683
 684         irb = (struct irb *) __LC_IRB;
 685         /* Check for unsolicited interrupt. */
 686         if (irb->scsw.stctl ==
 687                         (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 688                 if (cdev->handler)
 689                         cdev->handler (cdev, 0, irb);
 690                 return;
 691         }
 692         /* Accumulate status and find out if a basic sense is needed. */
 693         ccw_device_accumulate_irb(cdev, irb);
 694         if (cdev->private->flags.dosense) {
 695                 if (ccw_device_do_sense(cdev, irb) == 0) {
 696                         cdev->private->state = DEV_STATE_W4SENSE;
 697                 }
 698                 return;
 699         }
 700         /* Call the handler. */
 701         if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
 702                 /* Start delayed path verification. */
 703                 ccw_device_online_verify(cdev, 0);
 704 }
 705
 706 /*
 707  * Got an timeout in online state.
 708  */
 709 static void
 710 ccw_device_online_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 711 {
 712         int ret;
 713
 714         ccw_device_set_timeout(cdev, 0);
 715         ret = ccw_device_cancel_halt_clear(cdev);
 716         if (ret == -EBUSY) {
 717                 ccw_device_set_timeout(cdev, 3*HZ);
 718                 cdev->private->state = DEV_STATE_TIMEOUT_KILL;
 719                 return;
 720         }
 721         if (ret == -ENODEV) {
 722                 struct subchannel *sch;
 723
 724                 sch = to_subchannel(cdev->dev.parent);
 725                 if (!sch->lpm) {
 726                         PREPARE_WORK(&cdev->private->kick_work,
 727                                      ccw_device_nopath_notify, (void *)cdev);
 728                         queue_work(ccw_device_notify_work,
 729                                    &cdev->private->kick_work);
 730                 } else
 731                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 732         } else if (cdev->handler)
 733                 cdev->handler(cdev, cdev->private->intparm,
 734                               ERR_PTR(-ETIMEDOUT));
 735 }
 736
 737 /*
 738  * Got an interrupt for a basic sense.
 739  */
 740 void
 741 ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
 742 {
 743         struct irb *irb;
 744
 745         irb = (struct irb *) __LC_IRB;
 746         /* Check for unsolicited interrupt. */
 747         if (irb->scsw.stctl ==
 748                         (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 749                 if (cdev->handler)
 750                         cdev->handler (cdev, 0, irb);
 751                 if (irb->scsw.cc == 1)
 752                         /* Basic sense hasn't started. Try again. */
 753                         ccw_device_do_sense(cdev, irb);
 754                 return;
 755         }
 756         /* Add basic sense info to irb. */
 757         ccw_device_accumulate_basic_sense(cdev, irb);
 758         if (cdev->private->flags.dosense) {
 759                 /* Another basic sense is needed. */
 760                 ccw_device_do_sense(cdev, irb);
 761                 return;
 762         }
 763         cdev->private->state = DEV_STATE_ONLINE;
 764         /* Call the handler. */
 765         if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
 766                 /* Start delayed path verification. */
 767                 ccw_device_online_verify(cdev, 0);
 768 }
 769
 770 static void
 771 ccw_device_clear_verify(struct ccw_device *cdev, enum dev_event dev_event)
 772 {
 773         struct irb *irb;
 774
 775         irb = (struct irb *) __LC_IRB;
 776         /* Check for unsolicited interrupt. */
 777         if (irb->scsw.stctl ==
 778                         (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 779                 if (cdev->handler)
 780                         cdev->handler (cdev, 0, irb);
 781                 return;
 782         }
 783         /* Accumulate status. We don't do basic sense. */
 784         ccw_device_accumulate_irb(cdev, irb);
 785         /* Try to start delayed device verification. */
 786         ccw_device_online_verify(cdev, 0);
 787         /* Note: Don't call handler for cio initiated clear! */
 788 }
 789
 790 static void
 791 ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
 792 {
 793         struct subchannel *sch;
 794
 795         sch = to_subchannel(cdev->dev.parent);
 796         ccw_device_set_timeout(cdev, 0);
 797         /* OK, i/o is dead now. Call interrupt handler. */
 798         cdev->private->state = DEV_STATE_ONLINE;
 799         if (cdev->handler)
 800                 cdev->handler(cdev, cdev->private->intparm,
 801                               ERR_PTR(-ETIMEDOUT));
 802         if (!sch->lpm) {
 803                 PREPARE_WORK(&cdev->private->kick_work,
 804                              ccw_device_nopath_notify, (void *)cdev);
 805                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 806         } else if (cdev->private->flags.doverify)
 807                 /* Start delayed path verification. */
 808                 ccw_device_online_verify(cdev, 0);
 809 }
 810
 811 static void
 812 ccw_device_killing_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 813 {
 814         int ret;
 815
 816         ret = ccw_device_cancel_halt_clear(cdev);
 817         if (ret == -EBUSY) {
 818                 ccw_device_set_timeout(cdev, 3*HZ);
 819                 return;
 820         }
 821         if (ret == -ENODEV) {
 822                 struct subchannel *sch;
 823
 824                 sch = to_subchannel(cdev->dev.parent);
 825                 if (!sch->lpm) {
 826                         PREPARE_WORK(&cdev->private->kick_work,
 827                                      ccw_device_nopath_notify, (void *)cdev);
 828                         queue_work(ccw_device_notify_work,
 829                                    &cdev->private->kick_work);
 830                 } else
 831                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 832                 return;
 833         }
 834         //FIXME: Can we get here?
 835         cdev->private->state = DEV_STATE_ONLINE;
 836         if (cdev->handler)
 837                 cdev->handler(cdev, cdev->private->intparm,
 838                               ERR_PTR(-ETIMEDOUT));
 839 }
 840
 841 static void
 842 ccw_device_wait4io_irq(struct ccw_device *cdev, enum dev_event dev_event)
 843 {
 844         struct irb *irb;
 845         struct subchannel *sch;
 846
 847         irb = (struct irb *) __LC_IRB;
 848         /* Check for unsolicited interrupt. */
 849         if (irb->scsw.stctl ==
 850                         (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 851                 if (cdev->handler)
 852                         cdev->handler (cdev, 0, irb);
 853                 if (irb->scsw.cc == 1)
 854                         goto call_handler;
 855                 return;
 856         }
 857         /*
 858          * Accumulate status and find out if a basic sense is needed.
 859          * This is fine since we have already adapted the lpm.
 860          */
 861         ccw_device_accumulate_irb(cdev, irb);
 862         if (cdev->private->flags.dosense) {
 863                 if (ccw_device_do_sense(cdev, irb) == 0) {
 864                         cdev->private->state = DEV_STATE_W4SENSE;
 865                 }
 866                 return;
 867         }
 868 call_handler:
 869         /* Iff device is idle, reset timeout. */
 870         sch = to_subchannel(cdev->dev.parent);
 871         if (!stsch(sch->irq, &sch->schib))
 872                 if (sch->schib.scsw.actl == 0)
 873                         ccw_device_set_timeout(cdev, 0);
 874         /* Call the handler. */
 875         ccw_device_call_handler(cdev);
 876         if (!sch->lpm) {
 877                 PREPARE_WORK(&cdev->private->kick_work,
 878                              ccw_device_nopath_notify, (void *)cdev);
 879                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 880         } else if (cdev->private->flags.doverify)
 881                 ccw_device_online_verify(cdev, 0);
 882 }
 883
 884 static void
 885 ccw_device_wait4io_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 886 {
 887         int ret;
 888         struct subchannel *sch;
 889
 890         sch = to_subchannel(cdev->dev.parent);
 891         ccw_device_set_timeout(cdev, 0);
 892         ret = ccw_device_cancel_halt_clear(cdev);
 893         if (ret == -EBUSY) {
 894                 ccw_device_set_timeout(cdev, 3*HZ);
 895                 cdev->private->state = DEV_STATE_TIMEOUT_KILL;
 896                 return;
 897         }
 898         if (ret == -ENODEV) {
 899                 if (!sch->lpm) {
 900                         PREPARE_WORK(&cdev->private->kick_work,
 901                                      ccw_device_nopath_notify, (void *)cdev);
 902                         queue_work(ccw_device_notify_work,
 903                                    &cdev->private->kick_work);
 904                 } else
 905                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 906                 return;
 907         }
 908         if (cdev->handler)
 909                 cdev->handler(cdev, cdev->private->intparm,
 910                               ERR_PTR(-ETIMEDOUT));
 911         if (!sch->lpm) {
 912                 PREPARE_WORK(&cdev->private->kick_work,
 913                              ccw_device_nopath_notify, (void *)cdev);
 914                 queue_work(ccw_device_notify_work, &cdev->private->kick_work);
 915         } else if (cdev->private->flags.doverify)
 916                 /* Start delayed path verification. */
 917                 ccw_device_online_verify(cdev, 0);
 918 }
 919
 920 static void
 921 ccw_device_wait4io_verify(struct ccw_device *cdev, enum dev_event dev_event)
 922 {
 923         /* When the I/O has terminated, we have to start verification. */
 924         if (cdev->private->options.pgroup)
 925                 cdev->private->flags.doverify = 1;
 926 }
 927
 928 static void
 929 ccw_device_stlck_done(struct ccw_device *cdev, enum dev_event dev_event)
 930 {
 931         struct irb *irb;
 932
 933         switch (dev_event) {
 934         case DEV_EVENT_INTERRUPT:
 935                 irb = (struct irb *) __LC_IRB;
 936                 /* Check for unsolicited interrupt. */
 937                 if (irb->scsw.stctl ==
 938                     (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS))
 939                         /* FIXME: we should restart stlck here, but this
 940                          * is extremely unlikely ... */
 941                         goto out_wakeup;
 942
 943                 ccw_device_accumulate_irb(cdev, irb);
 944                 /* We don't care about basic sense etc. */
 945                 break;
 946         default: /* timeout */
 947                 break;
 948         }
 949 out_wakeup:
 950         wake_up(&cdev->private->wait_q);
 951 }
 952
 953 static void
 954 ccw_device_start_id(struct ccw_device *cdev, enum dev_event dev_event)
 955 {
 956         struct subchannel *sch;
 957
 958         sch = to_subchannel(cdev->dev.parent);
 959         if (cio_enable_subchannel(sch, sch->schib.pmcw.isc) != 0)
 960                 /* Couldn't enable the subchannel for i/o. Sick device. */
 961                 return;
 962
 963         /* After 60s the device recognition is considered to have failed. */
 964         ccw_device_set_timeout(cdev, 60*HZ);
 965
 966         cdev->private->state = DEV_STATE_DISCONNECTED_SENSE_ID;
 967         ccw_device_sense_id_start(cdev);
 968 }
 969
 970 void
 971 device_trigger_reprobe(struct subchannel *sch)
 972 {
 973         struct ccw_device *cdev;
 974         unsigned long flags;
 975
 976         if (!sch->dev.driver_data)
 977                 return;
 978         cdev = sch->dev.driver_data;
 979         spin_lock_irqsave(&sch->lock, flags);
 980         if (cdev->private->state != DEV_STATE_DISCONNECTED) {
 981                 spin_unlock_irqrestore(&sch->lock, flags);
 982                 return;
 983         }
 984         /* Update some values. */
 985         if (stsch(sch->irq, &sch->schib)) {
 986                 spin_unlock_irqrestore(&sch->lock, flags);
 987                 return;
 988         }
 989         /*
 990          * The pim, pam, pom values may not be accurate, but they are the best
 991          * we have before performing device selection :/
 992          */
 993         sch->lpm = sch->schib.pmcw.pim &
 994                 sch->schib.pmcw.pam &
 995                 sch->schib.pmcw.pom &
 996                 sch->opm;
 997         /* Re-set some bits in the pmcw that were lost. */
 998         sch->schib.pmcw.isc = 3;
 999         sch->schib.pmcw.csense = 1;
1000         sch->schib.pmcw.ena = 0;
1001         if ((sch->lpm & (sch->lpm - 1)) != 0)
1002                 sch->schib.pmcw.mp = 1;
1003         sch->schib.pmcw.intparm = (__u32)(unsigned long)sch;
1004         ccw_device_start_id(cdev, 0);
1005         spin_unlock_irqrestore(&sch->lock, flags);
1006 }
1007
1008 static void
1009 ccw_device_offline_irq(struct ccw_device *cdev, enum dev_event dev_event)
1010 {
1011         struct subchannel *sch;
1012
1013         sch = to_subchannel(cdev->dev.parent);
1014         /*
1015          * An interrupt in state offline means a previous disable was not
1016          * successful. Try again.
1017          */
1018         cio_disable_subchannel(sch);
1019 }
1020
1021 static void
1022 ccw_device_change_cmfstate(struct ccw_device *cdev, enum dev_event dev_event)
1023 {
1024         retry_set_schib(cdev);
1025         cdev->private->state = DEV_STATE_ONLINE;
1026         dev_fsm_event(cdev, dev_event);
1027 }
1028
1029
1030 static void
1031 ccw_device_quiesce_done(struct ccw_device *cdev, enum dev_event dev_event)
1032 {
1033         ccw_device_set_timeout(cdev, 0);
1034         if (dev_event == DEV_EVENT_NOTOPER)
1035                 cdev->private->state = DEV_STATE_NOT_OPER;
1036         else
1037                 cdev->private->state = DEV_STATE_OFFLINE;
1038         wake_up(&cdev->private->wait_q);
1039 }
1040
1041 static void
1042 ccw_device_quiesce_timeout(struct ccw_device *cdev, enum dev_event dev_event)
1043 {
1044         int ret;
1045
1046         ret = ccw_device_cancel_halt_clear(cdev);
1047         switch (ret) {
1048         case 0:
1049                 cdev->private->state = DEV_STATE_OFFLINE;
1050                 wake_up(&cdev->private->wait_q);
1051                 break;
1052         case -ENODEV:
1053                 cdev->private->state = DEV_STATE_NOT_OPER;
1054                 wake_up(&cdev->private->wait_q);
1055                 break;
1056         default:
1057                 ccw_device_set_timeout(cdev, HZ/10);
1058         }
1059 }
1060
1061 /*
1062  * No operation action. This is used e.g. to ignore a timeout event in
1063  * state offline.
1064  */
1065 static void
1066 ccw_device_nop(struct ccw_device *cdev, enum dev_event dev_event)
1067 {
1068 }
1069
1070 /*
1071  * Bug operation action.
1072  */
1073 static void
1074 ccw_device_bug(struct ccw_device *cdev, enum dev_event dev_event)
1075 {
1076         printk(KERN_EMERG "dev_jumptable[%i][%i] == NULL\n",
1077                cdev->private->state, dev_event);
1078         BUG();
1079 }
1080
1081 /*
1082  * device statemachine
1083  */
1084 fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
1085         [DEV_STATE_NOT_OPER] {
1086                 [DEV_EVENT_NOTOPER]     ccw_device_nop,
1087                 [DEV_EVENT_INTERRUPT]   ccw_device_bug,
1088                 [DEV_EVENT_TIMEOUT]     ccw_device_nop,
1089                 [DEV_EVENT_VERIFY]      ccw_device_nop,
1090         },
1091         [DEV_STATE_SENSE_PGID] {
1092                 [DEV_EVENT_NOTOPER]     ccw_device_online_notoper,
1093                 [DEV_EVENT_INTERRUPT]   ccw_device_sense_pgid_irq,
1094                 [DEV_EVENT_TIMEOUT]     ccw_device_onoff_timeout,
1095                 [DEV_EVENT_VERIFY]      ccw_device_nop,
1096         },
1097         [DEV_STATE_SENSE_ID] {
1098                 [DEV_EVENT_NOTOPER]     ccw_device_recog_notoper,
1099                 [DEV_EVENT_INTERRUPT]   ccw_device_sense_id_irq,
1100                 [DEV_EVENT_TIMEOUT]     ccw_device_recog_timeout,
1101                 [DEV_EVENT_VERIFY]      ccw_device_nop,
1102         },
1103         [DEV_STATE_OFFLINE] {
1104                 [DEV_EVENT_NOTOPER]     ccw_device_offline_notoper,
1105                 [DEV_EVENT_INTERRUPT]   ccw_device_offline_irq,
1106                 [DEV_EVENT_TIMEOUT]     ccw_device_nop,
1107                 [DEV_EVENT_VERIFY]      ccw_device_nop,
1108         },
1109         [DEV_STATE_VERIFY] {
1110                 [DEV_EVENT_NOTOPER]     ccw_device_online_notoper,
1111                 [DEV_EVENT_INTERRUPT]   ccw_device_verify_irq,
1112                 [DEV_EVENT_TIMEOUT]     ccw_device_onoff_timeout,
1113                 [DEV_EVENT_VERIFY]      ccw_device_nop,
1114         },
1115         [DEV_STATE_ONLINE] {
1116                 [DEV_EVENT_NOTOPER]     ccw_device_online_notoper,
1117                 [DEV_EVENT_INTERRUPT]   ccw_device_irq,
1118                 [DEV_EVENT_TIMEOUT]     ccw_device_online_timeout,
1119                 [DEV_EVENT_VERIFY]      ccw_device_online_verify,
1120         },
1121         [DEV_STATE_W4SENSE] {
1122                 [DEV_EVENT_NOTOPER]     ccw_device_online_notoper,
1123                 [DEV_EVENT_INTERRUPT]   ccw_device_w4sense,
1124                 [DEV_EVENT_TIMEOUT]     ccw_device_nop,
1125                 [DEV_EVENT_VERIFY]      ccw_device_online_verify,
1126         },
1127         [DEV_STATE_DISBAND_PGID] {
1128                 [DEV_EVENT_NOTOPER]     ccw_device_online_notoper,
1129                 [DEV_EVENT_INTERRUPT]   ccw_device_disband_irq,
1130                 [DEV_EVENT_TIMEOUT]     ccw_device_onoff_timeout,
1131                 [DEV_EVENT_VERIFY]      ccw_device_nop,
1132         },
1133         [DEV_STATE_BOXED] {
1134                 [DEV_EVENT_NOTOPER]     ccw_device_offline_notoper,
1135                 [DEV_EVENT_INTERRUPT]   ccw_device_stlck_done,
1136                 [DEV_EVENT_TIMEOUT]     ccw_device_stlck_done,
1137                 [DEV_EVENT_VERIFY]      ccw_device_nop,
1138         },
1139         /* states to wait for i/o completion before doing something */
1140         [DEV_STATE_CLEAR_VERIFY] {
1141                 [DEV_EVENT_NOTOPER]     ccw_device_online_notoper,
1142                 [DEV_EVENT_INTERRUPT]   ccw_device_clear_verify,
1143                 [DEV_EVENT_TIMEOUT]     ccw_device_nop,
1144                 [DEV_EVENT_VERIFY]      ccw_device_nop,
1145         },
1146         [DEV_STATE_TIMEOUT_KILL] {
1147                 [DEV_EVENT_NOTOPER]     ccw_device_online_notoper,
1148                 [DEV_EVENT_INTERRUPT]   ccw_device_killing_irq,
1149                 [DEV_EVENT_TIMEOUT]     ccw_device_killing_timeout,
1150                 [DEV_EVENT_VERIFY]      ccw_device_nop, //FIXME
1151         },
1152         [DEV_STATE_WAIT4IO] {
1153                 [DEV_EVENT_NOTOPER]     ccw_device_online_notoper,
1154                 [DEV_EVENT_INTERRUPT]   ccw_device_wait4io_irq,
1155                 [DEV_EVENT_TIMEOUT]     ccw_device_wait4io_timeout,
1156                 [DEV_EVENT_VERIFY]      ccw_device_wait4io_verify,
1157         },
1158         [DEV_STATE_QUIESCE] {
1159                 [DEV_EVENT_NOTOPER]     ccw_device_quiesce_done,
1160                 [DEV_EVENT_INTERRUPT]   ccw_device_quiesce_done,
1161                 [DEV_EVENT_TIMEOUT]     ccw_device_quiesce_timeout,
1162                 [DEV_EVENT_VERIFY]      ccw_device_nop,
1163         },
1164         /* special states for devices gone not operational */
1165         [DEV_STATE_DISCONNECTED] {
1166                 [DEV_EVENT_NOTOPER]     ccw_device_nop,
1167                 [DEV_EVENT_INTERRUPT]   ccw_device_start_id,
1168                 [DEV_EVENT_TIMEOUT]     ccw_device_bug,
1169                 [DEV_EVENT_VERIFY]      ccw_device_nop,
1170         },
1171         [DEV_STATE_DISCONNECTED_SENSE_ID] {
1172                 [DEV_EVENT_NOTOPER]     ccw_device_recog_notoper,
1173                 [DEV_EVENT_INTERRUPT]   ccw_device_sense_id_irq,
1174                 [DEV_EVENT_TIMEOUT]     ccw_device_recog_timeout,
1175                 [DEV_EVENT_VERIFY]      ccw_device_nop,
1176         },
1177         [DEV_STATE_CMFCHANGE] {
1178                 [DEV_EVENT_NOTOPER]     ccw_device_change_cmfstate,
1179                 [DEV_EVENT_INTERRUPT]   ccw_device_change_cmfstate,
1180                 [DEV_EVENT_TIMEOUT]     ccw_device_change_cmfstate,
1181                 [DEV_EVENT_VERIFY]      ccw_device_change_cmfstate,
1182         },
1183 };
1184
1185 /*
1186  * io_subchannel_irq is called for "real" interrupts or for status
1187  * pending conditions on msch.
1188  */
1189 void
1190 io_subchannel_irq (struct device *pdev)
1191 {
1192         struct ccw_device *cdev;
1193
1194         cdev = to_subchannel(pdev)->dev.driver_data;
1195
1196         CIO_TRACE_EVENT (3, "IRQ");
1197         CIO_TRACE_EVENT (3, pdev->bus_id);
1198
1199         dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1200 }
1201
1202 EXPORT_SYMBOL_GPL(ccw_device_set_timeout);