drivers/s390/cio/device_fsm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * finite state machine for device handling
   4  *
   5  *    Copyright IBM Corp. 2002, 2008
   6  *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
   7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/jiffies.h>
  13 #include <linux/string.h>
  14
  15 #include <asm/ccwdev.h>
  16 #include <asm/cio.h>
  17 #include <asm/chpid.h>
  18
  19 #include "cio.h"
  20 #include "cio_debug.h"
  21 #include "css.h"
  22 #include "device.h"
  23 #include "chsc.h"
  24 #include "ioasm.h"
  25 #include "chp.h"
  26
  27 static int timeout_log_enabled;
  28
  29 static int __init ccw_timeout_log_setup(char *unused)
  30 {
  31         timeout_log_enabled = 1;
  32         return 1;
  33 }
  34
  35 __setup("ccw_timeout_log", ccw_timeout_log_setup);
  36
  37 static void ccw_timeout_log(struct ccw_device *cdev)
  38 {
  39         struct schib schib;
  40         struct subchannel *sch;
  41         struct io_subchannel_private *private;
  42         union orb *orb;
  43         int cc;
  44
  45         sch = to_subchannel(cdev->dev.parent);
  46         private = to_io_private(sch);
  47         orb = &private->orb;
  48         cc = stsch(sch->schid, &schib);
  49
  50         printk(KERN_WARNING "cio: ccw device timeout occurred at %llx, "
  51                "device information:\n", get_tod_clock());
  52         printk(KERN_WARNING "cio: orb:\n");
  53         print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
  54                        orb, sizeof(*orb), 0);
  55         printk(KERN_WARNING "cio: ccw device bus id: %s\n",
  56                dev_name(&cdev->dev));
  57         printk(KERN_WARNING "cio: subchannel bus id: %s\n",
  58                dev_name(&sch->dev));
  59         printk(KERN_WARNING "cio: subchannel lpm: %02x, opm: %02x, "
  60                "vpm: %02x\n", sch->lpm, sch->opm, sch->vpm);
  61
  62         if (orb->tm.b) {
  63                 printk(KERN_WARNING "cio: orb indicates transport mode\n");
  64                 printk(KERN_WARNING "cio: last tcw:\n");
  65                 print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
  66                                (void *)(addr_t)orb->tm.tcw,
  67                                sizeof(struct tcw), 0);
  68         } else {
  69                 printk(KERN_WARNING "cio: orb indicates command mode\n");
  70                 if ((void *)(addr_t)orb->cmd.cpa == &private->sense_ccw ||
  71                     (void *)(addr_t)orb->cmd.cpa == cdev->private->iccws)
  72                         printk(KERN_WARNING "cio: last channel program "
  73                                "(intern):\n");
  74                 else
  75                         printk(KERN_WARNING "cio: last channel program:\n");
  76
  77                 print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
  78                                (void *)(addr_t)orb->cmd.cpa,
  79                                sizeof(struct ccw1), 0);
  80         }
  81         printk(KERN_WARNING "cio: ccw device state: %d\n",
  82                cdev->private->state);
  83         printk(KERN_WARNING "cio: store subchannel returned: cc=%d\n", cc);
  84         printk(KERN_WARNING "cio: schib:\n");
  85         print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
  86                        &schib, sizeof(schib), 0);
  87         printk(KERN_WARNING "cio: ccw device flags:\n");
  88         print_hex_dump(KERN_WARNING, "cio:  ", DUMP_PREFIX_NONE, 16, 1,
  89                        &cdev->private->flags, sizeof(cdev->private->flags), 0);
  90 }
  91
  92 /*
  93  * Timeout function. It just triggers a DEV_EVENT_TIMEOUT.
  94  */
  95 void
  96 ccw_device_timeout(struct timer_list *t)
  97 {
  98         struct ccw_device_private *priv = from_timer(priv, t, timer);
  99         struct ccw_device *cdev = priv->cdev;
 100
 101         spin_lock_irq(cdev->ccwlock);
 102         if (timeout_log_enabled)
 103                 ccw_timeout_log(cdev);
 104         dev_fsm_event(cdev, DEV_EVENT_TIMEOUT);
 105         spin_unlock_irq(cdev->ccwlock);
 106 }
 107
 108 /*
 109  * Set timeout
 110  */
 111 void
 112 ccw_device_set_timeout(struct ccw_device *cdev, int expires)
 113 {
 114         if (expires == 0) {
 115                 del_timer(&cdev->private->timer);
 116                 return;
 117         }
 118         if (timer_pending(&cdev->private->timer)) {
 119                 if (mod_timer(&cdev->private->timer, jiffies + expires))
 120                         return;
 121         }
 122         cdev->private->timer.expires = jiffies + expires;
 123         add_timer(&cdev->private->timer);
 124 }
 125
 126 int
 127 ccw_device_cancel_halt_clear(struct ccw_device *cdev)
 128 {
 129         struct subchannel *sch;
 130         int ret;
 131
 132         sch = to_subchannel(cdev->dev.parent);
 133         ret = cio_cancel_halt_clear(sch, &cdev->private->iretry);
 134
 135         if (ret == -EIO)
 136                 CIO_MSG_EVENT(0, "0.%x.%04x: could not stop I/O\n",
 137                               cdev->private->dev_id.ssid,
 138                               cdev->private->dev_id.devno);
 139
 140         return ret;
 141 }
 142
 143 void ccw_device_update_sense_data(struct ccw_device *cdev)
 144 {
 145         memset(&cdev->id, 0, sizeof(cdev->id));
 146         cdev->id.cu_type   = cdev->private->senseid.cu_type;
 147         cdev->id.cu_model  = cdev->private->senseid.cu_model;
 148         cdev->id.dev_type  = cdev->private->senseid.dev_type;
 149         cdev->id.dev_model = cdev->private->senseid.dev_model;
 150 }
 151
 152 int ccw_device_test_sense_data(struct ccw_device *cdev)
 153 {
 154         return cdev->id.cu_type == cdev->private->senseid.cu_type &&
 155                 cdev->id.cu_model == cdev->private->senseid.cu_model &&
 156                 cdev->id.dev_type == cdev->private->senseid.dev_type &&
 157                 cdev->id.dev_model == cdev->private->senseid.dev_model;
 158 }
 159
 160 /*
 161  * The machine won't give us any notification by machine check if a chpid has
 162  * been varied online on the SE so we have to find out by magic (i. e. driving
 163  * the channel subsystem to device selection and updating our path masks).
 164  */
 165 static void
 166 __recover_lost_chpids(struct subchannel *sch, int old_lpm)
 167 {
 168         int mask, i;
 169         struct chp_id chpid;
 170
 171         chp_id_init(&chpid);
 172         for (i = 0; i<8; i++) {
 173                 mask = 0x80 >> i;
 174                 if (!(sch->lpm & mask))
 175                         continue;
 176                 if (old_lpm & mask)
 177                         continue;
 178                 chpid.id = sch->schib.pmcw.chpid[i];
 179                 if (!chp_is_registered(chpid))
 180                         css_schedule_eval_all();
 181         }
 182 }
 183
 184 /*
 185  * Stop device recognition.
 186  */
 187 static void
 188 ccw_device_recog_done(struct ccw_device *cdev, int state)
 189 {
 190         struct subchannel *sch;
 191         int old_lpm;
 192
 193         sch = to_subchannel(cdev->dev.parent);
 194
 195         if (cio_disable_subchannel(sch))
 196                 state = DEV_STATE_NOT_OPER;
 197         /*
 198          * Now that we tried recognition, we have performed device selection
 199          * through ssch() and the path information is up to date.
 200          */
 201         old_lpm = sch->lpm;
 202
 203         /* Check since device may again have become not operational. */
 204         if (cio_update_schib(sch))
 205                 state = DEV_STATE_NOT_OPER;
 206         else
 207                 sch->lpm = sch->schib.pmcw.pam & sch->opm;
 208
 209         if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID)
 210                 /* Force reprobe on all chpids. */
 211                 old_lpm = 0;
 212         if (sch->lpm != old_lpm)
 213                 __recover_lost_chpids(sch, old_lpm);
 214         if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID &&
 215             (state == DEV_STATE_NOT_OPER || state == DEV_STATE_BOXED)) {
 216                 cdev->private->flags.recog_done = 1;
 217                 cdev->private->state = DEV_STATE_DISCONNECTED;
 218                 wake_up(&cdev->private->wait_q);
 219                 return;
 220         }
 221         if (cdev->private->flags.resuming) {
 222                 cdev->private->state = state;
 223                 cdev->private->flags.recog_done = 1;
 224                 wake_up(&cdev->private->wait_q);
 225                 return;
 226         }
 227         switch (state) {
 228         case DEV_STATE_NOT_OPER:
 229                 break;
 230         case DEV_STATE_OFFLINE:
 231                 if (!cdev->online) {
 232                         ccw_device_update_sense_data(cdev);
 233                         break;
 234                 }
 235                 cdev->private->state = DEV_STATE_OFFLINE;
 236                 cdev->private->flags.recog_done = 1;
 237                 if (ccw_device_test_sense_data(cdev)) {
 238                         cdev->private->flags.donotify = 1;
 239                         ccw_device_online(cdev);
 240                         wake_up(&cdev->private->wait_q);
 241                 } else {
 242                         ccw_device_update_sense_data(cdev);
 243                         ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
 244                 }
 245                 return;
 246         case DEV_STATE_BOXED:
 247                 if (cdev->id.cu_type != 0) { /* device was recognized before */
 248                         cdev->private->flags.recog_done = 1;
 249                         cdev->private->state = DEV_STATE_BOXED;
 250                         wake_up(&cdev->private->wait_q);
 251                         return;
 252                 }
 253                 break;
 254         }
 255         cdev->private->state = state;
 256         io_subchannel_recog_done(cdev);
 257         wake_up(&cdev->private->wait_q);
 258 }
 259
 260 /*
 261  * Function called from device_id.c after sense id has completed.
 262  */
 263 void
 264 ccw_device_sense_id_done(struct ccw_device *cdev, int err)
 265 {
 266         switch (err) {
 267         case 0:
 268                 ccw_device_recog_done(cdev, DEV_STATE_OFFLINE);
 269                 break;
 270         case -ETIME:            /* Sense id stopped by timeout. */
 271                 ccw_device_recog_done(cdev, DEV_STATE_BOXED);
 272                 break;
 273         default:
 274                 ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
 275                 break;
 276         }
 277 }
 278
 279 /**
 280   * ccw_device_notify() - inform the device's driver about an event
 281   * @cdev: device for which an event occurred
 282   * @event: event that occurred
 283   *
 284   * Returns:
 285   *   -%EINVAL if the device is offline or has no driver.
 286   *   -%EOPNOTSUPP if the device's driver has no notifier registered.
 287   *   %NOTIFY_OK if the driver wants to keep the device.
 288   *   %NOTIFY_BAD if the driver doesn't want to keep the device.
 289   */
 290 int ccw_device_notify(struct ccw_device *cdev, int event)
 291 {
 292         int ret = -EINVAL;
 293
 294         if (!cdev->drv)
 295                 goto out;
 296         if (!cdev->online)
 297                 goto out;
 298         CIO_MSG_EVENT(2, "notify called for 0.%x.%04x, event=%d\n",
 299                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
 300                       event);
 301         if (!cdev->drv->notify) {
 302                 ret = -EOPNOTSUPP;
 303                 goto out;
 304         }
 305         if (cdev->drv->notify(cdev, event))
 306                 ret = NOTIFY_OK;
 307         else
 308                 ret = NOTIFY_BAD;
 309 out:
 310         return ret;
 311 }
 312
 313 static void ccw_device_oper_notify(struct ccw_device *cdev)
 314 {
 315         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 316
 317         if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_OK) {
 318                 /* Reenable channel measurements, if needed. */
 319                 ccw_device_sched_todo(cdev, CDEV_TODO_ENABLE_CMF);
 320                 /* Save indication for new paths. */
 321                 cdev->private->path_new_mask = sch->vpm;
 322                 return;
 323         }
 324         /* Driver doesn't want device back. */
 325         ccw_device_set_notoper(cdev);
 326         ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
 327 }
 328
 329 /*
 330  * Finished with online/offline processing.
 331  */
 332 static void
 333 ccw_device_done(struct ccw_device *cdev, int state)
 334 {
 335         struct subchannel *sch;
 336
 337         sch = to_subchannel(cdev->dev.parent);
 338
 339         ccw_device_set_timeout(cdev, 0);
 340
 341         if (state != DEV_STATE_ONLINE)
 342                 cio_disable_subchannel(sch);
 343
 344         /* Reset device status. */
 345         memset(&cdev->private->irb, 0, sizeof(struct irb));
 346
 347         cdev->private->state = state;
 348
 349         switch (state) {
 350         case DEV_STATE_BOXED:
 351                 CIO_MSG_EVENT(0, "Boxed device %04x on subchannel %04x\n",
 352                               cdev->private->dev_id.devno, sch->schid.sch_no);
 353                 if (cdev->online &&
 354                     ccw_device_notify(cdev, CIO_BOXED) != NOTIFY_OK)
 355                         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 356                 cdev->private->flags.donotify = 0;
 357                 break;
 358         case DEV_STATE_NOT_OPER:
 359                 CIO_MSG_EVENT(0, "Device %04x gone on subchannel %04x\n",
 360                               cdev->private->dev_id.devno, sch->schid.sch_no);
 361                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
 362                         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 363                 else
 364                         ccw_device_set_disconnected(cdev);
 365                 cdev->private->flags.donotify = 0;
 366                 break;
 367         case DEV_STATE_DISCONNECTED:
 368                 CIO_MSG_EVENT(0, "Disconnected device %04x on subchannel "
 369                               "%04x\n", cdev->private->dev_id.devno,
 370                               sch->schid.sch_no);
 371                 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK) {
 372                         cdev->private->state = DEV_STATE_NOT_OPER;
 373                         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 374                 } else
 375                         ccw_device_set_disconnected(cdev);
 376                 cdev->private->flags.donotify = 0;
 377                 break;
 378         default:
 379                 break;
 380         }
 381
 382         if (cdev->private->flags.donotify) {
 383                 cdev->private->flags.donotify = 0;
 384                 ccw_device_oper_notify(cdev);
 385         }
 386         wake_up(&cdev->private->wait_q);
 387 }
 388
 389 /*
 390  * Start device recognition.
 391  */
 392 void ccw_device_recognition(struct ccw_device *cdev)
 393 {
 394         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 395
 396         /*
 397          * We used to start here with a sense pgid to find out whether a device
 398          * is locked by someone else. Unfortunately, the sense pgid command
 399          * code has other meanings on devices predating the path grouping
 400          * algorithm, so we start with sense id and box the device after an
 401          * timeout (or if sense pgid during path verification detects the device
 402          * is locked, as may happen on newer devices).
 403          */
 404         cdev->private->flags.recog_done = 0;
 405         cdev->private->state = DEV_STATE_SENSE_ID;
 406         if (cio_enable_subchannel(sch, (u32) (addr_t) sch)) {
 407                 ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
 408                 return;
 409         }
 410         ccw_device_sense_id_start(cdev);
 411 }
 412
 413 /*
 414  * Handle events for states that use the ccw request infrastructure.
 415  */
 416 static void ccw_device_request_event(struct ccw_device *cdev, enum dev_event e)
 417 {
 418         switch (e) {
 419         case DEV_EVENT_NOTOPER:
 420                 ccw_request_notoper(cdev);
 421                 break;
 422         case DEV_EVENT_INTERRUPT:
 423                 ccw_request_handler(cdev);
 424                 break;
 425         case DEV_EVENT_TIMEOUT:
 426                 ccw_request_timeout(cdev);
 427                 break;
 428         default:
 429                 break;
 430         }
 431 }
 432
 433 static void ccw_device_report_path_events(struct ccw_device *cdev)
 434 {
 435         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 436         int path_event[8];
 437         int chp, mask;
 438
 439         for (chp = 0, mask = 0x80; chp < 8; chp++, mask >>= 1) {
 440                 path_event[chp] = PE_NONE;
 441                 if (mask & cdev->private->path_gone_mask & ~(sch->vpm))
 442                         path_event[chp] |= PE_PATH_GONE;
 443                 if (mask & cdev->private->path_new_mask & sch->vpm)
 444                         path_event[chp] |= PE_PATH_AVAILABLE;
 445                 if (mask & cdev->private->pgid_reset_mask & sch->vpm)
 446                         path_event[chp] |= PE_PATHGROUP_ESTABLISHED;
 447         }
 448         if (cdev->online && cdev->drv->path_event)
 449                 cdev->drv->path_event(cdev, path_event);
 450 }
 451
 452 static void ccw_device_reset_path_events(struct ccw_device *cdev)
 453 {
 454         cdev->private->path_gone_mask = 0;
 455         cdev->private->path_new_mask = 0;
 456         cdev->private->pgid_reset_mask = 0;
 457 }
 458
 459 static void create_fake_irb(struct irb *irb, int type)
 460 {
 461         memset(irb, 0, sizeof(*irb));
 462         if (type == FAKE_CMD_IRB) {
 463                 struct cmd_scsw *scsw = &irb->scsw.cmd;
 464                 scsw->cc = 1;
 465                 scsw->fctl = SCSW_FCTL_START_FUNC;
 466                 scsw->actl = SCSW_ACTL_START_PEND;
 467                 scsw->stctl = SCSW_STCTL_STATUS_PEND;
 468         } else if (type == FAKE_TM_IRB) {
 469                 struct tm_scsw *scsw = &irb->scsw.tm;
 470                 scsw->x = 1;
 471                 scsw->cc = 1;
 472                 scsw->fctl = SCSW_FCTL_START_FUNC;
 473                 scsw->actl = SCSW_ACTL_START_PEND;
 474                 scsw->stctl = SCSW_STCTL_STATUS_PEND;
 475         }
 476 }
 477
 478 static void ccw_device_handle_broken_paths(struct ccw_device *cdev)
 479 {
 480         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 481         u8 broken_paths = (sch->schib.pmcw.pam & sch->opm) ^ sch->vpm;
 482
 483         if (broken_paths && (cdev->private->path_broken_mask != broken_paths))
 484                 ccw_device_schedule_recovery();
 485
 486         cdev->private->path_broken_mask = broken_paths;
 487 }
 488
 489 void ccw_device_verify_done(struct ccw_device *cdev, int err)
 490 {
 491         struct subchannel *sch;
 492
 493         sch = to_subchannel(cdev->dev.parent);
 494         /* Update schib - pom may have changed. */
 495         if (cio_update_schib(sch)) {
 496                 err = -ENODEV;
 497                 goto callback;
 498         }
 499         /* Update lpm with verified path mask. */
 500         sch->lpm = sch->vpm;
 501         /* Repeat path verification? */
 502         if (cdev->private->flags.doverify) {
 503                 ccw_device_verify_start(cdev);
 504                 return;
 505         }
 506 callback:
 507         switch (err) {
 508         case 0:
 509                 ccw_device_done(cdev, DEV_STATE_ONLINE);
 510                 /* Deliver fake irb to device driver, if needed. */
 511                 if (cdev->private->flags.fake_irb) {
 512                         create_fake_irb(&cdev->private->irb,
 513                                         cdev->private->flags.fake_irb);
 514                         cdev->private->flags.fake_irb = 0;
 515                         if (cdev->handler)
 516                                 cdev->handler(cdev, cdev->private->intparm,
 517                                               &cdev->private->irb);
 518                         memset(&cdev->private->irb, 0, sizeof(struct irb));
 519                 }
 520                 ccw_device_report_path_events(cdev);
 521                 ccw_device_handle_broken_paths(cdev);
 522                 break;
 523         case -ETIME:
 524         case -EUSERS:
 525                 /* Reset oper notify indication after verify error. */
 526                 cdev->private->flags.donotify = 0;
 527                 ccw_device_done(cdev, DEV_STATE_BOXED);
 528                 break;
 529         case -EACCES:
 530                 /* Reset oper notify indication after verify error. */
 531                 cdev->private->flags.donotify = 0;
 532                 ccw_device_done(cdev, DEV_STATE_DISCONNECTED);
 533                 break;
 534         default:
 535                 /* Reset oper notify indication after verify error. */
 536                 cdev->private->flags.donotify = 0;
 537                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 538                 break;
 539         }
 540         ccw_device_reset_path_events(cdev);
 541 }
 542
 543 /*
 544  * Get device online.
 545  */
 546 int
 547 ccw_device_online(struct ccw_device *cdev)
 548 {
 549         struct subchannel *sch;
 550         int ret;
 551
 552         if ((cdev->private->state != DEV_STATE_OFFLINE) &&
 553             (cdev->private->state != DEV_STATE_BOXED))
 554                 return -EINVAL;
 555         sch = to_subchannel(cdev->dev.parent);
 556         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
 557         if (ret != 0) {
 558                 /* Couldn't enable the subchannel for i/o. Sick device. */
 559                 if (ret == -ENODEV)
 560                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 561                 return ret;
 562         }
 563         /* Start initial path verification. */
 564         cdev->private->state = DEV_STATE_VERIFY;
 565         ccw_device_verify_start(cdev);
 566         return 0;
 567 }
 568
 569 void
 570 ccw_device_disband_done(struct ccw_device *cdev, int err)
 571 {
 572         switch (err) {
 573         case 0:
 574                 ccw_device_done(cdev, DEV_STATE_OFFLINE);
 575                 break;
 576         case -ETIME:
 577                 ccw_device_done(cdev, DEV_STATE_BOXED);
 578                 break;
 579         default:
 580                 cdev->private->flags.donotify = 0;
 581                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 582                 break;
 583         }
 584 }
 585
 586 /*
 587  * Shutdown device.
 588  */
 589 int
 590 ccw_device_offline(struct ccw_device *cdev)
 591 {
 592         struct subchannel *sch;
 593
 594         /* Allow ccw_device_offline while disconnected. */
 595         if (cdev->private->state == DEV_STATE_DISCONNECTED ||
 596             cdev->private->state == DEV_STATE_NOT_OPER) {
 597                 cdev->private->flags.donotify = 0;
 598                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 599                 return 0;
 600         }
 601         if (cdev->private->state == DEV_STATE_BOXED) {
 602                 ccw_device_done(cdev, DEV_STATE_BOXED);
 603                 return 0;
 604         }
 605         if (ccw_device_is_orphan(cdev)) {
 606                 ccw_device_done(cdev, DEV_STATE_OFFLINE);
 607                 return 0;
 608         }
 609         sch = to_subchannel(cdev->dev.parent);
 610         if (cio_update_schib(sch))
 611                 return -ENODEV;
 612         if (scsw_actl(&sch->schib.scsw) != 0)
 613                 return -EBUSY;
 614         if (cdev->private->state != DEV_STATE_ONLINE)
 615                 return -EINVAL;
 616         /* Are we doing path grouping? */
 617         if (!cdev->private->flags.pgroup) {
 618                 /* No, set state offline immediately. */
 619                 ccw_device_done(cdev, DEV_STATE_OFFLINE);
 620                 return 0;
 621         }
 622         /* Start Set Path Group commands. */
 623         cdev->private->state = DEV_STATE_DISBAND_PGID;
 624         ccw_device_disband_start(cdev);
 625         return 0;
 626 }
 627
 628 /*
 629  * Handle not operational event in non-special state.
 630  */
 631 static void ccw_device_generic_notoper(struct ccw_device *cdev,
 632                                        enum dev_event dev_event)
 633 {
 634         if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
 635                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 636         else
 637                 ccw_device_set_disconnected(cdev);
 638 }
 639
 640 /*
 641  * Handle path verification event in offline state.
 642  */
 643 static void ccw_device_offline_verify(struct ccw_device *cdev,
 644                                       enum dev_event dev_event)
 645 {
 646         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 647
 648         css_schedule_eval(sch->schid);
 649 }
 650
 651 /*
 652  * Handle path verification event.
 653  */
 654 static void
 655 ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
 656 {
 657         struct subchannel *sch;
 658
 659         if (cdev->private->state == DEV_STATE_W4SENSE) {
 660                 cdev->private->flags.doverify = 1;
 661                 return;
 662         }
 663         sch = to_subchannel(cdev->dev.parent);
 664         /*
 665          * Since we might not just be coming from an interrupt from the
 666          * subchannel we have to update the schib.
 667          */
 668         if (cio_update_schib(sch)) {
 669                 ccw_device_verify_done(cdev, -ENODEV);
 670                 return;
 671         }
 672
 673         if (scsw_actl(&sch->schib.scsw) != 0 ||
 674             (scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_STATUS_PEND) ||
 675             (scsw_stctl(&cdev->private->irb.scsw) & SCSW_STCTL_STATUS_PEND)) {
 676                 /*
 677                  * No final status yet or final status not yet delivered
 678                  * to the device driver. Can't do path verification now,
 679                  * delay until final status was delivered.
 680                  */
 681                 cdev->private->flags.doverify = 1;
 682                 return;
 683         }
 684         /* Device is idle, we can do the path verification. */
 685         cdev->private->state = DEV_STATE_VERIFY;
 686         ccw_device_verify_start(cdev);
 687 }
 688
 689 /*
 690  * Handle path verification event in boxed state.
 691  */
 692 static void ccw_device_boxed_verify(struct ccw_device *cdev,
 693                                     enum dev_event dev_event)
 694 {
 695         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 696
 697         if (cdev->online) {
 698                 if (cio_enable_subchannel(sch, (u32) (addr_t) sch))
 699                         ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 700                 else
 701                         ccw_device_online_verify(cdev, dev_event);
 702         } else
 703                 css_schedule_eval(sch->schid);
 704 }
 705
 706 /*
 707  * Pass interrupt to device driver.
 708  */
 709 static int ccw_device_call_handler(struct ccw_device *cdev)
 710 {
 711         unsigned int stctl;
 712         int ending_status;
 713
 714         /*
 715          * we allow for the device action handler if .
 716          *  - we received ending status
 717          *  - the action handler requested to see all interrupts
 718          *  - we received an intermediate status
 719          *  - fast notification was requested (primary status)
 720          *  - unsolicited interrupts
 721          */
 722         stctl = scsw_stctl(&cdev->private->irb.scsw);
 723         ending_status = (stctl & SCSW_STCTL_SEC_STATUS) ||
 724                 (stctl == (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)) ||
 725                 (stctl == SCSW_STCTL_STATUS_PEND);
 726         if (!ending_status &&
 727             !cdev->private->options.repall &&
 728             !(stctl & SCSW_STCTL_INTER_STATUS) &&
 729             !(cdev->private->options.fast &&
 730               (stctl & SCSW_STCTL_PRIM_STATUS)))
 731                 return 0;
 732
 733         if (ending_status)
 734                 ccw_device_set_timeout(cdev, 0);
 735
 736         if (cdev->handler)
 737                 cdev->handler(cdev, cdev->private->intparm,
 738                               &cdev->private->irb);
 739
 740         memset(&cdev->private->irb, 0, sizeof(struct irb));
 741         return 1;
 742 }
 743
 744 /*
 745  * Got an interrupt for a normal io (state online).
 746  */
 747 static void
 748 ccw_device_irq(struct ccw_device *cdev, enum dev_event dev_event)
 749 {
 750         struct irb *irb;
 751         int is_cmd;
 752
 753         irb = this_cpu_ptr(&cio_irb);
 754         is_cmd = !scsw_is_tm(&irb->scsw);
 755         /* Check for unsolicited interrupt. */
 756         if (!scsw_is_solicited(&irb->scsw)) {
 757                 if (is_cmd && (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) &&
 758                     !irb->esw.esw0.erw.cons) {
 759                         /* Unit check but no sense data. Need basic sense. */
 760                         if (ccw_device_do_sense(cdev, irb) != 0)
 761                                 goto call_handler_unsol;
 762                         memcpy(&cdev->private->irb, irb, sizeof(struct irb));
 763                         cdev->private->state = DEV_STATE_W4SENSE;
 764                         cdev->private->intparm = 0;
 765                         return;
 766                 }
 767 call_handler_unsol:
 768                 if (cdev->handler)
 769                         cdev->handler (cdev, 0, irb);
 770                 if (cdev->private->flags.doverify)
 771                         ccw_device_online_verify(cdev, 0);
 772                 return;
 773         }
 774         /* Accumulate status and find out if a basic sense is needed. */
 775         ccw_device_accumulate_irb(cdev, irb);
 776         if (is_cmd && cdev->private->flags.dosense) {
 777                 if (ccw_device_do_sense(cdev, irb) == 0) {
 778                         cdev->private->state = DEV_STATE_W4SENSE;
 779                 }
 780                 return;
 781         }
 782         /* Call the handler. */
 783         if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
 784                 /* Start delayed path verification. */
 785                 ccw_device_online_verify(cdev, 0);
 786 }
 787
 788 /*
 789  * Got an timeout in online state.
 790  */
 791 static void
 792 ccw_device_online_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 793 {
 794         int ret;
 795
 796         ccw_device_set_timeout(cdev, 0);
 797         cdev->private->iretry = 255;
 798         ret = ccw_device_cancel_halt_clear(cdev);
 799         if (ret == -EBUSY) {
 800                 ccw_device_set_timeout(cdev, 3*HZ);
 801                 cdev->private->state = DEV_STATE_TIMEOUT_KILL;
 802                 return;
 803         }
 804         if (ret)
 805                 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 806         else if (cdev->handler)
 807                 cdev->handler(cdev, cdev->private->intparm,
 808                               ERR_PTR(-ETIMEDOUT));
 809 }
 810
 811 /*
 812  * Got an interrupt for a basic sense.
 813  */
 814 static void
 815 ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
 816 {
 817         struct irb *irb;
 818
 819         irb = this_cpu_ptr(&cio_irb);
 820         /* Check for unsolicited interrupt. */
 821         if (scsw_stctl(&irb->scsw) ==
 822             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 823                 if (scsw_cc(&irb->scsw) == 1)
 824                         /* Basic sense hasn't started. Try again. */
 825                         ccw_device_do_sense(cdev, irb);
 826                 else {
 827                         CIO_MSG_EVENT(0, "0.%x.%04x: unsolicited "
 828                                       "interrupt during w4sense...\n",
 829                                       cdev->private->dev_id.ssid,
 830                                       cdev->private->dev_id.devno);
 831                         if (cdev->handler)
 832                                 cdev->handler (cdev, 0, irb);
 833                 }
 834                 return;
 835         }
 836         /*
 837          * Check if a halt or clear has been issued in the meanwhile. If yes,
 838          * only deliver the halt/clear interrupt to the device driver as if it
 839          * had killed the original request.
 840          */
 841         if (scsw_fctl(&irb->scsw) &
 842             (SCSW_FCTL_CLEAR_FUNC | SCSW_FCTL_HALT_FUNC)) {
 843                 cdev->private->flags.dosense = 0;
 844                 memset(&cdev->private->irb, 0, sizeof(struct irb));
 845                 ccw_device_accumulate_irb(cdev, irb);
 846                 goto call_handler;
 847         }
 848         /* Add basic sense info to irb. */
 849         ccw_device_accumulate_basic_sense(cdev, irb);
 850         if (cdev->private->flags.dosense) {
 851                 /* Another basic sense is needed. */
 852                 ccw_device_do_sense(cdev, irb);
 853                 return;
 854         }
 855 call_handler:
 856         cdev->private->state = DEV_STATE_ONLINE;
 857         /* In case sensing interfered with setting the device online */
 858         wake_up(&cdev->private->wait_q);
 859         /* Call the handler. */
 860         if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
 861                 /* Start delayed path verification. */
 862                 ccw_device_online_verify(cdev, 0);
 863 }
 864
 865 static void
 866 ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
 867 {
 868         ccw_device_set_timeout(cdev, 0);
 869         /* Start delayed path verification. */
 870         ccw_device_online_verify(cdev, 0);
 871         /* OK, i/o is dead now. Call interrupt handler. */
 872         if (cdev->handler)
 873                 cdev->handler(cdev, cdev->private->intparm,
 874                               ERR_PTR(-EIO));
 875 }
 876
 877 static void
 878 ccw_device_killing_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 879 {
 880         int ret;
 881
 882         ret = ccw_device_cancel_halt_clear(cdev);
 883         if (ret == -EBUSY) {
 884                 ccw_device_set_timeout(cdev, 3*HZ);
 885                 return;
 886         }
 887         /* Start delayed path verification. */
 888         ccw_device_online_verify(cdev, 0);
 889         if (cdev->handler)
 890                 cdev->handler(cdev, cdev->private->intparm,
 891                               ERR_PTR(-EIO));
 892 }
 893
 894 void ccw_device_kill_io(struct ccw_device *cdev)
 895 {
 896         int ret;
 897
 898         cdev->private->iretry = 255;
 899         ret = ccw_device_cancel_halt_clear(cdev);
 900         if (ret == -EBUSY) {
 901                 ccw_device_set_timeout(cdev, 3*HZ);
 902                 cdev->private->state = DEV_STATE_TIMEOUT_KILL;
 903                 return;
 904         }
 905         /* Start delayed path verification. */
 906         ccw_device_online_verify(cdev, 0);
 907         if (cdev->handler)
 908                 cdev->handler(cdev, cdev->private->intparm,
 909                               ERR_PTR(-EIO));
 910 }
 911
 912 static void
 913 ccw_device_delay_verify(struct ccw_device *cdev, enum dev_event dev_event)
 914 {
 915         /* Start verification after current task finished. */
 916         cdev->private->flags.doverify = 1;
 917 }
 918
 919 static void
 920 ccw_device_start_id(struct ccw_device *cdev, enum dev_event dev_event)
 921 {
 922         struct subchannel *sch;
 923
 924         sch = to_subchannel(cdev->dev.parent);
 925         if (cio_enable_subchannel(sch, (u32)(addr_t)sch) != 0)
 926                 /* Couldn't enable the subchannel for i/o. Sick device. */
 927                 return;
 928         cdev->private->state = DEV_STATE_DISCONNECTED_SENSE_ID;
 929         ccw_device_sense_id_start(cdev);
 930 }
 931
 932 void ccw_device_trigger_reprobe(struct ccw_device *cdev)
 933 {
 934         struct subchannel *sch;
 935
 936         if (cdev->private->state != DEV_STATE_DISCONNECTED)
 937                 return;
 938
 939         sch = to_subchannel(cdev->dev.parent);
 940         /* Update some values. */
 941         if (cio_update_schib(sch))
 942                 return;
 943         /*
 944          * The pim, pam, pom values may not be accurate, but they are the best
 945          * we have before performing device selection :/
 946          */
 947         sch->lpm = sch->schib.pmcw.pam & sch->opm;
 948         /*
 949          * Use the initial configuration since we can't be shure that the old
 950          * paths are valid.
 951          */
 952         io_subchannel_init_config(sch);
 953         if (cio_commit_config(sch))
 954                 return;
 955
 956         /* We should also udate ssd info, but this has to wait. */
 957         /* Check if this is another device which appeared on the same sch. */
 958         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno)
 959                 css_schedule_eval(sch->schid);
 960         else
 961                 ccw_device_start_id(cdev, 0);
 962 }
 963
 964 static void ccw_device_disabled_irq(struct ccw_device *cdev,
 965                                     enum dev_event dev_event)
 966 {
 967         struct subchannel *sch;
 968
 969         sch = to_subchannel(cdev->dev.parent);
 970         /*
 971          * An interrupt in a disabled state means a previous disable was not
 972          * successful - should not happen, but we try to disable again.
 973          */
 974         cio_disable_subchannel(sch);
 975 }
 976
 977 static void
 978 ccw_device_change_cmfstate(struct ccw_device *cdev, enum dev_event dev_event)
 979 {
 980         retry_set_schib(cdev);
 981         cdev->private->state = DEV_STATE_ONLINE;
 982         dev_fsm_event(cdev, dev_event);
 983 }
 984
 985 static void ccw_device_update_cmfblock(struct ccw_device *cdev,
 986                                        enum dev_event dev_event)
 987 {
 988         cmf_retry_copy_block(cdev);
 989         cdev->private->state = DEV_STATE_ONLINE;
 990         dev_fsm_event(cdev, dev_event);
 991 }
 992
 993 static void
 994 ccw_device_quiesce_done(struct ccw_device *cdev, enum dev_event dev_event)
 995 {
 996         ccw_device_set_timeout(cdev, 0);
 997         cdev->private->state = DEV_STATE_NOT_OPER;
 998         wake_up(&cdev->private->wait_q);
 999 }
1000
1001 static void
1002 ccw_device_quiesce_timeout(struct ccw_device *cdev, enum dev_event dev_event)
1003 {
1004         int ret;
1005
1006         ret = ccw_device_cancel_halt_clear(cdev);
1007         if (ret == -EBUSY) {
1008                 ccw_device_set_timeout(cdev, HZ/10);
1009         } else {
1010                 cdev->private->state = DEV_STATE_NOT_OPER;
1011                 wake_up(&cdev->private->wait_q);
1012         }
1013 }
1014
1015 /*
1016  * No operation action. This is used e.g. to ignore a timeout event in
1017  * state offline.
1018  */
1019 static void
1020 ccw_device_nop(struct ccw_device *cdev, enum dev_event dev_event)
1021 {
1022 }
1023
1024 /*
1025  * device statemachine
1026  */
1027 fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
1028         [DEV_STATE_NOT_OPER] = {
1029                 [DEV_EVENT_NOTOPER]     = ccw_device_nop,
1030                 [DEV_EVENT_INTERRUPT]   = ccw_device_disabled_irq,
1031                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1032                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1033         },
1034         [DEV_STATE_SENSE_ID] = {
1035                 [DEV_EVENT_NOTOPER]     = ccw_device_request_event,
1036                 [DEV_EVENT_INTERRUPT]   = ccw_device_request_event,
1037                 [DEV_EVENT_TIMEOUT]     = ccw_device_request_event,
1038                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1039         },
1040         [DEV_STATE_OFFLINE] = {
1041                 [DEV_EVENT_NOTOPER]     = ccw_device_generic_notoper,
1042                 [DEV_EVENT_INTERRUPT]   = ccw_device_disabled_irq,
1043                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1044                 [DEV_EVENT_VERIFY]      = ccw_device_offline_verify,
1045         },
1046         [DEV_STATE_VERIFY] = {
1047                 [DEV_EVENT_NOTOPER]     = ccw_device_request_event,
1048                 [DEV_EVENT_INTERRUPT]   = ccw_device_request_event,
1049                 [DEV_EVENT_TIMEOUT]     = ccw_device_request_event,
1050                 [DEV_EVENT_VERIFY]      = ccw_device_delay_verify,
1051         },
1052         [DEV_STATE_ONLINE] = {
1053                 [DEV_EVENT_NOTOPER]     = ccw_device_generic_notoper,
1054                 [DEV_EVENT_INTERRUPT]   = ccw_device_irq,
1055                 [DEV_EVENT_TIMEOUT]     = ccw_device_online_timeout,
1056                 [DEV_EVENT_VERIFY]      = ccw_device_online_verify,
1057         },
1058         [DEV_STATE_W4SENSE] = {
1059                 [DEV_EVENT_NOTOPER]     = ccw_device_generic_notoper,
1060                 [DEV_EVENT_INTERRUPT]   = ccw_device_w4sense,
1061                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1062                 [DEV_EVENT_VERIFY]      = ccw_device_online_verify,
1063         },
1064         [DEV_STATE_DISBAND_PGID] = {
1065                 [DEV_EVENT_NOTOPER]     = ccw_device_request_event,
1066                 [DEV_EVENT_INTERRUPT]   = ccw_device_request_event,
1067                 [DEV_EVENT_TIMEOUT]     = ccw_device_request_event,
1068                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1069         },
1070         [DEV_STATE_BOXED] = {
1071                 [DEV_EVENT_NOTOPER]     = ccw_device_generic_notoper,
1072                 [DEV_EVENT_INTERRUPT]   = ccw_device_nop,
1073                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1074                 [DEV_EVENT_VERIFY]      = ccw_device_boxed_verify,
1075         },
1076         /* states to wait for i/o completion before doing something */
1077         [DEV_STATE_TIMEOUT_KILL] = {
1078                 [DEV_EVENT_NOTOPER]     = ccw_device_generic_notoper,
1079                 [DEV_EVENT_INTERRUPT]   = ccw_device_killing_irq,
1080                 [DEV_EVENT_TIMEOUT]     = ccw_device_killing_timeout,
1081                 [DEV_EVENT_VERIFY]      = ccw_device_nop, //FIXME
1082         },
1083         [DEV_STATE_QUIESCE] = {
1084                 [DEV_EVENT_NOTOPER]     = ccw_device_quiesce_done,
1085                 [DEV_EVENT_INTERRUPT]   = ccw_device_quiesce_done,
1086                 [DEV_EVENT_TIMEOUT]     = ccw_device_quiesce_timeout,
1087                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1088         },
1089         /* special states for devices gone not operational */
1090         [DEV_STATE_DISCONNECTED] = {
1091                 [DEV_EVENT_NOTOPER]     = ccw_device_nop,
1092                 [DEV_EVENT_INTERRUPT]   = ccw_device_start_id,
1093                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1094                 [DEV_EVENT_VERIFY]      = ccw_device_start_id,
1095         },
1096         [DEV_STATE_DISCONNECTED_SENSE_ID] = {
1097                 [DEV_EVENT_NOTOPER]     = ccw_device_request_event,
1098                 [DEV_EVENT_INTERRUPT]   = ccw_device_request_event,
1099                 [DEV_EVENT_TIMEOUT]     = ccw_device_request_event,
1100                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1101         },
1102         [DEV_STATE_CMFCHANGE] = {
1103                 [DEV_EVENT_NOTOPER]     = ccw_device_change_cmfstate,
1104                 [DEV_EVENT_INTERRUPT]   = ccw_device_change_cmfstate,
1105                 [DEV_EVENT_TIMEOUT]     = ccw_device_change_cmfstate,
1106                 [DEV_EVENT_VERIFY]      = ccw_device_change_cmfstate,
1107         },
1108         [DEV_STATE_CMFUPDATE] = {
1109                 [DEV_EVENT_NOTOPER]     = ccw_device_update_cmfblock,
1110                 [DEV_EVENT_INTERRUPT]   = ccw_device_update_cmfblock,
1111                 [DEV_EVENT_TIMEOUT]     = ccw_device_update_cmfblock,
1112                 [DEV_EVENT_VERIFY]      = ccw_device_update_cmfblock,
1113         },
1114         [DEV_STATE_STEAL_LOCK] = {
1115                 [DEV_EVENT_NOTOPER]     = ccw_device_request_event,
1116                 [DEV_EVENT_INTERRUPT]   = ccw_device_request_event,
1117                 [DEV_EVENT_TIMEOUT]     = ccw_device_request_event,
1118                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1119         },
1120 };
1121
1122 EXPORT_SYMBOL_GPL(ccw_device_set_timeout);