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   1 /*
   2  * drivers/s390/cio/device_fsm.c
   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_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 static void
  96 ccw_device_timeout(unsigned long data)
  97 {
  98         struct ccw_device *cdev;
  99
 100         cdev = (struct ccw_device *) data;
 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.function = ccw_device_timeout;
 123         cdev->private->timer.data = (unsigned long) cdev;
 124         cdev->private->timer.expires = jiffies + expires;
 125         add_timer(&cdev->private->timer);
 126 }
 127
 128 /*
 129  * Cancel running i/o. This is called repeatedly since halt/clear are
 130  * asynchronous operations. We do one try with cio_cancel, two tries
 131  * with cio_halt, 255 tries with cio_clear. If everythings fails panic.
 132  * Returns 0 if device now idle, -ENODEV for device not operational and
 133  * -EBUSY if an interrupt is expected (either from halt/clear or from a
 134  * status pending).
 135  */
 136 int
 137 ccw_device_cancel_halt_clear(struct ccw_device *cdev)
 138 {
 139         struct subchannel *sch;
 140         int ret;
 141
 142         sch = to_subchannel(cdev->dev.parent);
 143         if (cio_update_schib(sch))
 144                 return -ENODEV;
 145         if (!sch->schib.pmcw.ena)
 146                 /* Not operational -> done. */
 147                 return 0;
 148         /* Stage 1: cancel io. */
 149         if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_HALT_PEND) &&
 150             !(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
 151                 if (!scsw_is_tm(&sch->schib.scsw)) {
 152                         ret = cio_cancel(sch);
 153                         if (ret != -EINVAL)
 154                                 return ret;
 155                 }
 156                 /* cancel io unsuccessful or not applicable (transport mode).
 157                  * Continue with asynchronous instructions. */
 158                 cdev->private->iretry = 3;      /* 3 halt retries. */
 159         }
 160         if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
 161                 /* Stage 2: halt io. */
 162                 if (cdev->private->iretry) {
 163                         cdev->private->iretry--;
 164                         ret = cio_halt(sch);
 165                         if (ret != -EBUSY)
 166                                 return (ret == 0) ? -EBUSY : ret;
 167                 }
 168                 /* halt io unsuccessful. */
 169                 cdev->private->iretry = 255;    /* 255 clear retries. */
 170         }
 171         /* Stage 3: clear io. */
 172         if (cdev->private->iretry) {
 173                 cdev->private->iretry--;
 174                 ret = cio_clear (sch);
 175                 return (ret == 0) ? -EBUSY : ret;
 176         }
 177         panic("Can't stop i/o on subchannel.\n");
 178 }
 179
 180 void ccw_device_update_sense_data(struct ccw_device *cdev)
 181 {
 182         memset(&cdev->id, 0, sizeof(cdev->id));
 183         cdev->id.cu_type   = cdev->private->senseid.cu_type;
 184         cdev->id.cu_model  = cdev->private->senseid.cu_model;
 185         cdev->id.dev_type  = cdev->private->senseid.dev_type;
 186         cdev->id.dev_model = cdev->private->senseid.dev_model;
 187 }
 188
 189 int ccw_device_test_sense_data(struct ccw_device *cdev)
 190 {
 191         return cdev->id.cu_type == cdev->private->senseid.cu_type &&
 192                 cdev->id.cu_model == cdev->private->senseid.cu_model &&
 193                 cdev->id.dev_type == cdev->private->senseid.dev_type &&
 194                 cdev->id.dev_model == cdev->private->senseid.dev_model;
 195 }
 196
 197 /*
 198  * The machine won't give us any notification by machine check if a chpid has
 199  * been varied online on the SE so we have to find out by magic (i. e. driving
 200  * the channel subsystem to device selection and updating our path masks).
 201  */
 202 static void
 203 __recover_lost_chpids(struct subchannel *sch, int old_lpm)
 204 {
 205         int mask, i;
 206         struct chp_id chpid;
 207
 208         chp_id_init(&chpid);
 209         for (i = 0; i<8; i++) {
 210                 mask = 0x80 >> i;
 211                 if (!(sch->lpm & mask))
 212                         continue;
 213                 if (old_lpm & mask)
 214                         continue;
 215                 chpid.id = sch->schib.pmcw.chpid[i];
 216                 if (!chp_is_registered(chpid))
 217                         css_schedule_eval_all();
 218         }
 219 }
 220
 221 /*
 222  * Stop device recognition.
 223  */
 224 static void
 225 ccw_device_recog_done(struct ccw_device *cdev, int state)
 226 {
 227         struct subchannel *sch;
 228         int old_lpm;
 229
 230         sch = to_subchannel(cdev->dev.parent);
 231
 232         cio_disable_subchannel(sch);
 233         /*
 234          * Now that we tried recognition, we have performed device selection
 235          * through ssch() and the path information is up to date.
 236          */
 237         old_lpm = sch->lpm;
 238
 239         /* Check since device may again have become not operational. */
 240         if (cio_update_schib(sch))
 241                 state = DEV_STATE_NOT_OPER;
 242         else
 243                 sch->lpm = sch->schib.pmcw.pam & sch->opm;
 244
 245         if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID)
 246                 /* Force reprobe on all chpids. */
 247                 old_lpm = 0;
 248         if (sch->lpm != old_lpm)
 249                 __recover_lost_chpids(sch, old_lpm);
 250         if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID &&
 251             (state == DEV_STATE_NOT_OPER || state == DEV_STATE_BOXED)) {
 252                 cdev->private->flags.recog_done = 1;
 253                 cdev->private->state = DEV_STATE_DISCONNECTED;
 254                 wake_up(&cdev->private->wait_q);
 255                 return;
 256         }
 257         if (cdev->private->flags.resuming) {
 258                 cdev->private->state = state;
 259                 cdev->private->flags.recog_done = 1;
 260                 wake_up(&cdev->private->wait_q);
 261                 return;
 262         }
 263         switch (state) {
 264         case DEV_STATE_NOT_OPER:
 265                 break;
 266         case DEV_STATE_OFFLINE:
 267                 if (!cdev->online) {
 268                         ccw_device_update_sense_data(cdev);
 269                         break;
 270                 }
 271                 cdev->private->state = DEV_STATE_OFFLINE;
 272                 cdev->private->flags.recog_done = 1;
 273                 if (ccw_device_test_sense_data(cdev)) {
 274                         cdev->private->flags.donotify = 1;
 275                         ccw_device_online(cdev);
 276                         wake_up(&cdev->private->wait_q);
 277                 } else {
 278                         ccw_device_update_sense_data(cdev);
 279                         ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
 280                 }
 281                 return;
 282         case DEV_STATE_BOXED:
 283                 if (cdev->id.cu_type != 0) { /* device was recognized before */
 284                         cdev->private->flags.recog_done = 1;
 285                         cdev->private->state = DEV_STATE_BOXED;
 286                         wake_up(&cdev->private->wait_q);
 287                         return;
 288                 }
 289                 break;
 290         }
 291         cdev->private->state = state;
 292         io_subchannel_recog_done(cdev);
 293         wake_up(&cdev->private->wait_q);
 294 }
 295
 296 /*
 297  * Function called from device_id.c after sense id has completed.
 298  */
 299 void
 300 ccw_device_sense_id_done(struct ccw_device *cdev, int err)
 301 {
 302         switch (err) {
 303         case 0:
 304                 ccw_device_recog_done(cdev, DEV_STATE_OFFLINE);
 305                 break;
 306         case -ETIME:            /* Sense id stopped by timeout. */
 307                 ccw_device_recog_done(cdev, DEV_STATE_BOXED);
 308                 break;
 309         default:
 310                 ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
 311                 break;
 312         }
 313 }
 314
 315 int ccw_device_notify(struct ccw_device *cdev, int event)
 316 {
 317         if (!cdev->drv)
 318                 return 0;
 319         if (!cdev->online)
 320                 return 0;
 321         CIO_MSG_EVENT(2, "notify called for 0.%x.%04x, event=%d\n",
 322                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
 323                       event);
 324         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
 325 }
 326
 327 static void ccw_device_oper_notify(struct ccw_device *cdev)
 328 {
 329         if (ccw_device_notify(cdev, CIO_OPER)) {
 330                 /* Reenable channel measurements, if needed. */
 331                 ccw_device_sched_todo(cdev, CDEV_TODO_ENABLE_CMF);
 332                 return;
 333         }
 334         /* Driver doesn't want device back. */
 335         ccw_device_set_notoper(cdev);
 336         ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
 337 }
 338
 339 /*
 340  * Finished with online/offline processing.
 341  */
 342 static void
 343 ccw_device_done(struct ccw_device *cdev, int state)
 344 {
 345         struct subchannel *sch;
 346
 347         sch = to_subchannel(cdev->dev.parent);
 348
 349         ccw_device_set_timeout(cdev, 0);
 350
 351         if (state != DEV_STATE_ONLINE)
 352                 cio_disable_subchannel(sch);
 353
 354         /* Reset device status. */
 355         memset(&cdev->private->irb, 0, sizeof(struct irb));
 356
 357         cdev->private->state = state;
 358
 359         switch (state) {
 360         case DEV_STATE_BOXED:
 361                 CIO_MSG_EVENT(0, "Boxed device %04x on subchannel %04x\n",
 362                               cdev->private->dev_id.devno, sch->schid.sch_no);
 363                 if (cdev->online && !ccw_device_notify(cdev, CIO_BOXED))
 364                         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 365                 cdev->private->flags.donotify = 0;
 366                 break;
 367         case DEV_STATE_NOT_OPER:
 368                 CIO_MSG_EVENT(0, "Device %04x gone on subchannel %04x\n",
 369                               cdev->private->dev_id.devno, sch->schid.sch_no);
 370                 if (!ccw_device_notify(cdev, CIO_GONE))
 371                         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 372                 else
 373                         ccw_device_set_disconnected(cdev);
 374                 cdev->private->flags.donotify = 0;
 375                 break;
 376         case DEV_STATE_DISCONNECTED:
 377                 CIO_MSG_EVENT(0, "Disconnected device %04x on subchannel "
 378                               "%04x\n", cdev->private->dev_id.devno,
 379                               sch->schid.sch_no);
 380                 if (!ccw_device_notify(cdev, CIO_NO_PATH))
 381                         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 382                 else
 383                         ccw_device_set_disconnected(cdev);
 384                 cdev->private->flags.donotify = 0;
 385                 break;
 386         default:
 387                 break;
 388         }
 389
 390         if (cdev->private->flags.donotify) {
 391                 cdev->private->flags.donotify = 0;
 392                 ccw_device_oper_notify(cdev);
 393         }
 394         wake_up(&cdev->private->wait_q);
 395 }
 396
 397 /*
 398  * Function called from device_pgid.c after sense path ground has completed.
 399  */
 400 void
 401 ccw_device_sense_pgid_done(struct ccw_device *cdev, int err)
 402 {
 403         struct subchannel *sch;
 404
 405         sch = to_subchannel(cdev->dev.parent);
 406         switch (err) {
 407         case -EOPNOTSUPP: /* path grouping not supported, use nop instead. */
 408         case 0: /* success */
 409         case -EACCES: /* partial success, some paths not operational */
 410                 break;
 411         case -ETIME:            /* Sense path group id stopped by timeout. */
 412         case -EUSERS:           /* device is reserved for someone else. */
 413                 ccw_device_done(cdev, DEV_STATE_BOXED);
 414                 return;
 415         default:
 416                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 417                 return;
 418         }
 419         /* Start Path Group verification. */
 420         cdev->private->state = DEV_STATE_VERIFY;
 421         ccw_device_verify_start(cdev);
 422 }
 423
 424 /*
 425  * Start device recognition.
 426  */
 427 void ccw_device_recognition(struct ccw_device *cdev)
 428 {
 429         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 430
 431         /*
 432          * We used to start here with a sense pgid to find out whether a device
 433          * is locked by someone else. Unfortunately, the sense pgid command
 434          * code has other meanings on devices predating the path grouping
 435          * algorithm, so we start with sense id and box the device after an
 436          * timeout (or if sense pgid during path verification detects the device
 437          * is locked, as may happen on newer devices).
 438          */
 439         cdev->private->flags.recog_done = 0;
 440         cdev->private->state = DEV_STATE_SENSE_ID;
 441         if (cio_enable_subchannel(sch, (u32) (addr_t) sch)) {
 442                 ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
 443                 return;
 444         }
 445         ccw_device_sense_id_start(cdev);
 446 }
 447
 448 /*
 449  * Handle events for states that use the ccw request infrastructure.
 450  */
 451 static void ccw_device_request_event(struct ccw_device *cdev, enum dev_event e)
 452 {
 453         switch (e) {
 454         case DEV_EVENT_NOTOPER:
 455                 ccw_request_notoper(cdev);
 456                 break;
 457         case DEV_EVENT_INTERRUPT:
 458                 ccw_request_handler(cdev);
 459                 break;
 460         case DEV_EVENT_TIMEOUT:
 461                 ccw_request_timeout(cdev);
 462                 break;
 463         default:
 464                 break;
 465         }
 466 }
 467
 468 void
 469 ccw_device_verify_done(struct ccw_device *cdev, int err)
 470 {
 471         struct subchannel *sch;
 472
 473         sch = to_subchannel(cdev->dev.parent);
 474         /* Update schib - pom may have changed. */
 475         if (cio_update_schib(sch)) {
 476                 err = -ENODEV;
 477                 goto callback;
 478         }
 479         /* Update lpm with verified path mask. */
 480         sch->lpm = sch->vpm;
 481         /* Repeat path verification? */
 482         if (cdev->private->flags.doverify) {
 483                 ccw_device_verify_start(cdev);
 484                 return;
 485         }
 486 callback:
 487         switch (err) {
 488         case 0:
 489                 ccw_device_done(cdev, DEV_STATE_ONLINE);
 490                 /* Deliver fake irb to device driver, if needed. */
 491                 if (cdev->private->flags.fake_irb) {
 492                         memset(&cdev->private->irb, 0, sizeof(struct irb));
 493                         cdev->private->irb.scsw.cmd.cc = 1;
 494                         cdev->private->irb.scsw.cmd.fctl = SCSW_FCTL_START_FUNC;
 495                         cdev->private->irb.scsw.cmd.actl = SCSW_ACTL_START_PEND;
 496                         cdev->private->irb.scsw.cmd.stctl =
 497                                 SCSW_STCTL_STATUS_PEND;
 498                         cdev->private->flags.fake_irb = 0;
 499                         if (cdev->handler)
 500                                 cdev->handler(cdev, cdev->private->intparm,
 501                                               &cdev->private->irb);
 502                         memset(&cdev->private->irb, 0, sizeof(struct irb));
 503                 }
 504                 break;
 505         case -ETIME:
 506                 /* Reset oper notify indication after verify error. */
 507                 cdev->private->flags.donotify = 0;
 508                 ccw_device_done(cdev, DEV_STATE_BOXED);
 509                 break;
 510         case -EACCES:
 511                 /* Reset oper notify indication after verify error. */
 512                 cdev->private->flags.donotify = 0;
 513                 ccw_device_done(cdev, DEV_STATE_DISCONNECTED);
 514                 break;
 515         default:
 516                 /* Reset oper notify indication after verify error. */
 517                 cdev->private->flags.donotify = 0;
 518                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 519                 break;
 520         }
 521 }
 522
 523 /*
 524  * Get device online.
 525  */
 526 int
 527 ccw_device_online(struct ccw_device *cdev)
 528 {
 529         struct subchannel *sch;
 530         int ret;
 531
 532         if ((cdev->private->state != DEV_STATE_OFFLINE) &&
 533             (cdev->private->state != DEV_STATE_BOXED))
 534                 return -EINVAL;
 535         sch = to_subchannel(cdev->dev.parent);
 536         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
 537         if (ret != 0) {
 538                 /* Couldn't enable the subchannel for i/o. Sick device. */
 539                 if (ret == -ENODEV)
 540                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 541                 return ret;
 542         }
 543         /* Do we want to do path grouping? */
 544         if (!cdev->private->options.pgroup) {
 545                 /* Start initial path verification. */
 546                 cdev->private->state = DEV_STATE_VERIFY;
 547                 ccw_device_verify_start(cdev);
 548                 return 0;
 549         }
 550         /* Do a SensePGID first. */
 551         cdev->private->state = DEV_STATE_SENSE_PGID;
 552         ccw_device_sense_pgid_start(cdev);
 553         return 0;
 554 }
 555
 556 void
 557 ccw_device_disband_done(struct ccw_device *cdev, int err)
 558 {
 559         switch (err) {
 560         case 0:
 561                 ccw_device_done(cdev, DEV_STATE_OFFLINE);
 562                 break;
 563         case -ETIME:
 564                 ccw_device_done(cdev, DEV_STATE_BOXED);
 565                 break;
 566         default:
 567                 cdev->private->flags.donotify = 0;
 568                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 569                 break;
 570         }
 571 }
 572
 573 /*
 574  * Shutdown device.
 575  */
 576 int
 577 ccw_device_offline(struct ccw_device *cdev)
 578 {
 579         struct subchannel *sch;
 580
 581         /* Allow ccw_device_offline while disconnected. */
 582         if (cdev->private->state == DEV_STATE_DISCONNECTED ||
 583             cdev->private->state == DEV_STATE_NOT_OPER) {
 584                 cdev->private->flags.donotify = 0;
 585                 ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 586                 return 0;
 587         }
 588         if (cdev->private->state == DEV_STATE_BOXED) {
 589                 ccw_device_done(cdev, DEV_STATE_BOXED);
 590                 return 0;
 591         }
 592         if (ccw_device_is_orphan(cdev)) {
 593                 ccw_device_done(cdev, DEV_STATE_OFFLINE);
 594                 return 0;
 595         }
 596         sch = to_subchannel(cdev->dev.parent);
 597         if (cio_update_schib(sch))
 598                 return -ENODEV;
 599         if (scsw_actl(&sch->schib.scsw) != 0)
 600                 return -EBUSY;
 601         if (cdev->private->state != DEV_STATE_ONLINE)
 602                 return -EINVAL;
 603         /* Are we doing path grouping? */
 604         if (!cdev->private->flags.pgroup) {
 605                 /* No, set state offline immediately. */
 606                 ccw_device_done(cdev, DEV_STATE_OFFLINE);
 607                 return 0;
 608         }
 609         /* Start Set Path Group commands. */
 610         cdev->private->state = DEV_STATE_DISBAND_PGID;
 611         ccw_device_disband_start(cdev);
 612         return 0;
 613 }
 614
 615 /*
 616  * Handle not operational event in non-special state.
 617  */
 618 static void ccw_device_generic_notoper(struct ccw_device *cdev,
 619                                        enum dev_event dev_event)
 620 {
 621         if (!ccw_device_notify(cdev, CIO_GONE))
 622                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 623         else
 624                 ccw_device_set_disconnected(cdev);
 625 }
 626
 627 /*
 628  * Handle path verification event in offline state.
 629  */
 630 static void ccw_device_offline_verify(struct ccw_device *cdev,
 631                                       enum dev_event dev_event)
 632 {
 633         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 634
 635         css_schedule_eval(sch->schid);
 636 }
 637
 638 /*
 639  * Handle path verification event.
 640  */
 641 static void
 642 ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
 643 {
 644         struct subchannel *sch;
 645
 646         if (cdev->private->state == DEV_STATE_W4SENSE) {
 647                 cdev->private->flags.doverify = 1;
 648                 return;
 649         }
 650         sch = to_subchannel(cdev->dev.parent);
 651         /*
 652          * Since we might not just be coming from an interrupt from the
 653          * subchannel we have to update the schib.
 654          */
 655         if (cio_update_schib(sch)) {
 656                 ccw_device_verify_done(cdev, -ENODEV);
 657                 return;
 658         }
 659
 660         if (scsw_actl(&sch->schib.scsw) != 0 ||
 661             (scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_STATUS_PEND) ||
 662             (scsw_stctl(&cdev->private->irb.scsw) & 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         int is_cmd;
 684
 685         irb = (struct irb *) __LC_IRB;
 686         is_cmd = !scsw_is_tm(&irb->scsw);
 687         /* Check for unsolicited interrupt. */
 688         if (!scsw_is_solicited(&irb->scsw)) {
 689                 if (is_cmd && (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) &&
 690                     !irb->esw.esw0.erw.cons) {
 691                         /* Unit check but no sense data. Need basic sense. */
 692                         if (ccw_device_do_sense(cdev, irb) != 0)
 693                                 goto call_handler_unsol;
 694                         memcpy(&cdev->private->irb, irb, sizeof(struct irb));
 695                         cdev->private->state = DEV_STATE_W4SENSE;
 696                         cdev->private->intparm = 0;
 697                         return;
 698                 }
 699 call_handler_unsol:
 700                 if (cdev->handler)
 701                         cdev->handler (cdev, 0, irb);
 702                 if (cdev->private->flags.doverify)
 703                         ccw_device_online_verify(cdev, 0);
 704                 return;
 705         }
 706         /* Accumulate status and find out if a basic sense is needed. */
 707         ccw_device_accumulate_irb(cdev, irb);
 708         if (is_cmd && cdev->private->flags.dosense) {
 709                 if (ccw_device_do_sense(cdev, irb) == 0) {
 710                         cdev->private->state = DEV_STATE_W4SENSE;
 711                 }
 712                 return;
 713         }
 714         /* Call the handler. */
 715         if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
 716                 /* Start delayed path verification. */
 717                 ccw_device_online_verify(cdev, 0);
 718 }
 719
 720 /*
 721  * Got an timeout in online state.
 722  */
 723 static void
 724 ccw_device_online_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 725 {
 726         int ret;
 727
 728         ccw_device_set_timeout(cdev, 0);
 729         ret = ccw_device_cancel_halt_clear(cdev);
 730         if (ret == -EBUSY) {
 731                 ccw_device_set_timeout(cdev, 3*HZ);
 732                 cdev->private->state = DEV_STATE_TIMEOUT_KILL;
 733                 return;
 734         }
 735         if (ret == -ENODEV)
 736                 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 737         else if (cdev->handler)
 738                 cdev->handler(cdev, cdev->private->intparm,
 739                               ERR_PTR(-ETIMEDOUT));
 740 }
 741
 742 /*
 743  * Got an interrupt for a basic sense.
 744  */
 745 static void
 746 ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
 747 {
 748         struct irb *irb;
 749
 750         irb = (struct irb *) __LC_IRB;
 751         /* Check for unsolicited interrupt. */
 752         if (scsw_stctl(&irb->scsw) ==
 753             (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
 754                 if (scsw_cc(&irb->scsw) == 1)
 755                         /* Basic sense hasn't started. Try again. */
 756                         ccw_device_do_sense(cdev, irb);
 757                 else {
 758                         CIO_MSG_EVENT(0, "0.%x.%04x: unsolicited "
 759                                       "interrupt during w4sense...\n",
 760                                       cdev->private->dev_id.ssid,
 761                                       cdev->private->dev_id.devno);
 762                         if (cdev->handler)
 763                                 cdev->handler (cdev, 0, irb);
 764                 }
 765                 return;
 766         }
 767         /*
 768          * Check if a halt or clear has been issued in the meanwhile. If yes,
 769          * only deliver the halt/clear interrupt to the device driver as if it
 770          * had killed the original request.
 771          */
 772         if (scsw_fctl(&irb->scsw) &
 773             (SCSW_FCTL_CLEAR_FUNC | SCSW_FCTL_HALT_FUNC)) {
 774                 cdev->private->flags.dosense = 0;
 775                 memset(&cdev->private->irb, 0, sizeof(struct irb));
 776                 ccw_device_accumulate_irb(cdev, irb);
 777                 goto call_handler;
 778         }
 779         /* Add basic sense info to irb. */
 780         ccw_device_accumulate_basic_sense(cdev, irb);
 781         if (cdev->private->flags.dosense) {
 782                 /* Another basic sense is needed. */
 783                 ccw_device_do_sense(cdev, irb);
 784                 return;
 785         }
 786 call_handler:
 787         cdev->private->state = DEV_STATE_ONLINE;
 788         /* In case sensing interfered with setting the device online */
 789         wake_up(&cdev->private->wait_q);
 790         /* Call the handler. */
 791         if (ccw_device_call_handler(cdev) && cdev->private->flags.doverify)
 792                 /* Start delayed path verification. */
 793                 ccw_device_online_verify(cdev, 0);
 794 }
 795
 796 static void
 797 ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
 798 {
 799         struct subchannel *sch;
 800
 801         sch = to_subchannel(cdev->dev.parent);
 802         ccw_device_set_timeout(cdev, 0);
 803         /* Start delayed path verification. */
 804         ccw_device_online_verify(cdev, 0);
 805         /* OK, i/o is dead now. Call interrupt handler. */
 806         if (cdev->handler)
 807                 cdev->handler(cdev, cdev->private->intparm,
 808                               ERR_PTR(-EIO));
 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         /* Start delayed path verification. */
 822         ccw_device_online_verify(cdev, 0);
 823         if (cdev->handler)
 824                 cdev->handler(cdev, cdev->private->intparm,
 825                               ERR_PTR(-EIO));
 826 }
 827
 828 void ccw_device_kill_io(struct ccw_device *cdev)
 829 {
 830         int ret;
 831
 832         ret = ccw_device_cancel_halt_clear(cdev);
 833         if (ret == -EBUSY) {
 834                 ccw_device_set_timeout(cdev, 3*HZ);
 835                 cdev->private->state = DEV_STATE_TIMEOUT_KILL;
 836                 return;
 837         }
 838         /* Start delayed path verification. */
 839         ccw_device_online_verify(cdev, 0);
 840         if (cdev->handler)
 841                 cdev->handler(cdev, cdev->private->intparm,
 842                               ERR_PTR(-EIO));
 843 }
 844
 845 static void
 846 ccw_device_delay_verify(struct ccw_device *cdev, enum dev_event dev_event)
 847 {
 848         /* Start verification after current task finished. */
 849         cdev->private->flags.doverify = 1;
 850 }
 851
 852 static void
 853 ccw_device_stlck_done(struct ccw_device *cdev, enum dev_event dev_event)
 854 {
 855         struct irb *irb;
 856
 857         switch (dev_event) {
 858         case DEV_EVENT_INTERRUPT:
 859                 irb = (struct irb *) __LC_IRB;
 860                 /* Check for unsolicited interrupt. */
 861                 if ((scsw_stctl(&irb->scsw) ==
 862                      (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) &&
 863                     (!scsw_cc(&irb->scsw)))
 864                         /* FIXME: we should restart stlck here, but this
 865                          * is extremely unlikely ... */
 866                         goto out_wakeup;
 867
 868                 ccw_device_accumulate_irb(cdev, irb);
 869                 /* We don't care about basic sense etc. */
 870                 break;
 871         default: /* timeout */
 872                 break;
 873         }
 874 out_wakeup:
 875         wake_up(&cdev->private->wait_q);
 876 }
 877
 878 static void
 879 ccw_device_start_id(struct ccw_device *cdev, enum dev_event dev_event)
 880 {
 881         struct subchannel *sch;
 882
 883         sch = to_subchannel(cdev->dev.parent);
 884         if (cio_enable_subchannel(sch, (u32)(addr_t)sch) != 0)
 885                 /* Couldn't enable the subchannel for i/o. Sick device. */
 886                 return;
 887         cdev->private->state = DEV_STATE_DISCONNECTED_SENSE_ID;
 888         ccw_device_sense_id_start(cdev);
 889 }
 890
 891 void ccw_device_trigger_reprobe(struct ccw_device *cdev)
 892 {
 893         struct subchannel *sch;
 894
 895         if (cdev->private->state != DEV_STATE_DISCONNECTED)
 896                 return;
 897
 898         sch = to_subchannel(cdev->dev.parent);
 899         /* Update some values. */
 900         if (cio_update_schib(sch))
 901                 return;
 902         /*
 903          * The pim, pam, pom values may not be accurate, but they are the best
 904          * we have before performing device selection :/
 905          */
 906         sch->lpm = sch->schib.pmcw.pam & sch->opm;
 907         /*
 908          * Use the initial configuration since we can't be shure that the old
 909          * paths are valid.
 910          */
 911         io_subchannel_init_config(sch);
 912         if (cio_commit_config(sch))
 913                 return;
 914
 915         /* We should also udate ssd info, but this has to wait. */
 916         /* Check if this is another device which appeared on the same sch. */
 917         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno)
 918                 css_schedule_eval(sch->schid);
 919         else
 920                 ccw_device_start_id(cdev, 0);
 921 }
 922
 923 static void ccw_device_disabled_irq(struct ccw_device *cdev,
 924                                     enum dev_event dev_event)
 925 {
 926         struct subchannel *sch;
 927
 928         sch = to_subchannel(cdev->dev.parent);
 929         /*
 930          * An interrupt in a disabled state means a previous disable was not
 931          * successful - should not happen, but we try to disable again.
 932          */
 933         cio_disable_subchannel(sch);
 934 }
 935
 936 static void
 937 ccw_device_change_cmfstate(struct ccw_device *cdev, enum dev_event dev_event)
 938 {
 939         retry_set_schib(cdev);
 940         cdev->private->state = DEV_STATE_ONLINE;
 941         dev_fsm_event(cdev, dev_event);
 942 }
 943
 944 static void ccw_device_update_cmfblock(struct ccw_device *cdev,
 945                                        enum dev_event dev_event)
 946 {
 947         cmf_retry_copy_block(cdev);
 948         cdev->private->state = DEV_STATE_ONLINE;
 949         dev_fsm_event(cdev, dev_event);
 950 }
 951
 952 static void
 953 ccw_device_quiesce_done(struct ccw_device *cdev, enum dev_event dev_event)
 954 {
 955         ccw_device_set_timeout(cdev, 0);
 956         if (dev_event == DEV_EVENT_NOTOPER)
 957                 cdev->private->state = DEV_STATE_NOT_OPER;
 958         else
 959                 cdev->private->state = DEV_STATE_OFFLINE;
 960         wake_up(&cdev->private->wait_q);
 961 }
 962
 963 static void
 964 ccw_device_quiesce_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 965 {
 966         int ret;
 967
 968         ret = ccw_device_cancel_halt_clear(cdev);
 969         switch (ret) {
 970         case 0:
 971                 cdev->private->state = DEV_STATE_OFFLINE;
 972                 wake_up(&cdev->private->wait_q);
 973                 break;
 974         case -ENODEV:
 975                 cdev->private->state = DEV_STATE_NOT_OPER;
 976                 wake_up(&cdev->private->wait_q);
 977                 break;
 978         default:
 979                 ccw_device_set_timeout(cdev, HZ/10);
 980         }
 981 }
 982
 983 /*
 984  * No operation action. This is used e.g. to ignore a timeout event in
 985  * state offline.
 986  */
 987 static void
 988 ccw_device_nop(struct ccw_device *cdev, enum dev_event dev_event)
 989 {
 990 }
 991
 992 /*
 993  * device statemachine
 994  */
 995 fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
 996         [DEV_STATE_NOT_OPER] = {
 997                 [DEV_EVENT_NOTOPER]     = ccw_device_nop,
 998                 [DEV_EVENT_INTERRUPT]   = ccw_device_disabled_irq,
 999                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1000                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1001         },
1002         [DEV_STATE_SENSE_PGID] = {
1003                 [DEV_EVENT_NOTOPER]     = ccw_device_request_event,
1004                 [DEV_EVENT_INTERRUPT]   = ccw_device_request_event,
1005                 [DEV_EVENT_TIMEOUT]     = ccw_device_request_event,
1006                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1007         },
1008         [DEV_STATE_SENSE_ID] = {
1009                 [DEV_EVENT_NOTOPER]     = ccw_device_request_event,
1010                 [DEV_EVENT_INTERRUPT]   = ccw_device_request_event,
1011                 [DEV_EVENT_TIMEOUT]     = ccw_device_request_event,
1012                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1013         },
1014         [DEV_STATE_OFFLINE] = {
1015                 [DEV_EVENT_NOTOPER]     = ccw_device_generic_notoper,
1016                 [DEV_EVENT_INTERRUPT]   = ccw_device_disabled_irq,
1017                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1018                 [DEV_EVENT_VERIFY]      = ccw_device_offline_verify,
1019         },
1020         [DEV_STATE_VERIFY] = {
1021                 [DEV_EVENT_NOTOPER]     = ccw_device_request_event,
1022                 [DEV_EVENT_INTERRUPT]   = ccw_device_request_event,
1023                 [DEV_EVENT_TIMEOUT]     = ccw_device_request_event,
1024                 [DEV_EVENT_VERIFY]      = ccw_device_delay_verify,
1025         },
1026         [DEV_STATE_ONLINE] = {
1027                 [DEV_EVENT_NOTOPER]     = ccw_device_generic_notoper,
1028                 [DEV_EVENT_INTERRUPT]   = ccw_device_irq,
1029                 [DEV_EVENT_TIMEOUT]     = ccw_device_online_timeout,
1030                 [DEV_EVENT_VERIFY]      = ccw_device_online_verify,
1031         },
1032         [DEV_STATE_W4SENSE] = {
1033                 [DEV_EVENT_NOTOPER]     = ccw_device_generic_notoper,
1034                 [DEV_EVENT_INTERRUPT]   = ccw_device_w4sense,
1035                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1036                 [DEV_EVENT_VERIFY]      = ccw_device_online_verify,
1037         },
1038         [DEV_STATE_DISBAND_PGID] = {
1039                 [DEV_EVENT_NOTOPER]     = ccw_device_request_event,
1040                 [DEV_EVENT_INTERRUPT]   = ccw_device_request_event,
1041                 [DEV_EVENT_TIMEOUT]     = ccw_device_request_event,
1042                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1043         },
1044         [DEV_STATE_BOXED] = {
1045                 [DEV_EVENT_NOTOPER]     = ccw_device_generic_notoper,
1046                 [DEV_EVENT_INTERRUPT]   = ccw_device_stlck_done,
1047                 [DEV_EVENT_TIMEOUT]     = ccw_device_stlck_done,
1048                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1049         },
1050         /* states to wait for i/o completion before doing something */
1051         [DEV_STATE_TIMEOUT_KILL] = {
1052                 [DEV_EVENT_NOTOPER]     = ccw_device_generic_notoper,
1053                 [DEV_EVENT_INTERRUPT]   = ccw_device_killing_irq,
1054                 [DEV_EVENT_TIMEOUT]     = ccw_device_killing_timeout,
1055                 [DEV_EVENT_VERIFY]      = ccw_device_nop, //FIXME
1056         },
1057         [DEV_STATE_QUIESCE] = {
1058                 [DEV_EVENT_NOTOPER]     = ccw_device_quiesce_done,
1059                 [DEV_EVENT_INTERRUPT]   = ccw_device_quiesce_done,
1060                 [DEV_EVENT_TIMEOUT]     = ccw_device_quiesce_timeout,
1061                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1062         },
1063         /* special states for devices gone not operational */
1064         [DEV_STATE_DISCONNECTED] = {
1065                 [DEV_EVENT_NOTOPER]     = ccw_device_nop,
1066                 [DEV_EVENT_INTERRUPT]   = ccw_device_start_id,
1067                 [DEV_EVENT_TIMEOUT]     = ccw_device_nop,
1068                 [DEV_EVENT_VERIFY]      = ccw_device_start_id,
1069         },
1070         [DEV_STATE_DISCONNECTED_SENSE_ID] = {
1071                 [DEV_EVENT_NOTOPER]     = ccw_device_request_event,
1072                 [DEV_EVENT_INTERRUPT]   = ccw_device_request_event,
1073                 [DEV_EVENT_TIMEOUT]     = ccw_device_request_event,
1074                 [DEV_EVENT_VERIFY]      = ccw_device_nop,
1075         },
1076         [DEV_STATE_CMFCHANGE] = {
1077                 [DEV_EVENT_NOTOPER]     = ccw_device_change_cmfstate,
1078                 [DEV_EVENT_INTERRUPT]   = ccw_device_change_cmfstate,
1079                 [DEV_EVENT_TIMEOUT]     = ccw_device_change_cmfstate,
1080                 [DEV_EVENT_VERIFY]      = ccw_device_change_cmfstate,
1081         },
1082         [DEV_STATE_CMFUPDATE] = {
1083                 [DEV_EVENT_NOTOPER]     = ccw_device_update_cmfblock,
1084                 [DEV_EVENT_INTERRUPT]   = ccw_device_update_cmfblock,
1085                 [DEV_EVENT_TIMEOUT]     = ccw_device_update_cmfblock,
1086                 [DEV_EVENT_VERIFY]      = ccw_device_update_cmfblock,
1087         },
1088 };
1089
1090 EXPORT_SYMBOL_GPL(ccw_device_set_timeout);