drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *
   5  *    Copyright IBM Corp. 2002,2008
   6  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   7  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   8  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   9  */
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/errno.h>
  14 #include <linux/err.h>
  15 #include <linux/slab.h>
  16 #include <linux/list.h>
  17 #include <linux/device.h>
  18 #include <linux/workqueue.h>
  19 #include <linux/timer.h>
  20
  21 #include <asm/ccwdev.h>
  22 #include <asm/cio.h>
  23 #include <asm/param.h>          /* HZ */
  24 #include <asm/cmb.h>
  25 #include <asm/isc.h>
  26
  27 #include "chp.h"
  28 #include "cio.h"
  29 #include "cio_debug.h"
  30 #include "css.h"
  31 #include "device.h"
  32 #include "ioasm.h"
  33 #include "io_sch.h"
  34 #include "blacklist.h"
  35
  36 static struct timer_list recovery_timer;
  37 static DEFINE_SPINLOCK(recovery_lock);
  38 static int recovery_phase;
  39 static const unsigned long recovery_delay[] = { 3, 30, 300 };
  40
  41 /******************* bus type handling ***********************/
  42
  43 /* The Linux driver model distinguishes between a bus type and
  44  * the bus itself. Of course we only have one channel
  45  * subsystem driver and one channel system per machine, but
  46  * we still use the abstraction. T.R. says it's a good idea. */
  47 static int
  48 ccw_bus_match (struct device * dev, struct device_driver * drv)
  49 {
  50         struct ccw_device *cdev = to_ccwdev(dev);
  51         struct ccw_driver *cdrv = to_ccwdrv(drv);
  52         const struct ccw_device_id *ids = cdrv->ids, *found;
  53
  54         if (!ids)
  55                 return 0;
  56
  57         found = ccw_device_id_match(ids, &cdev->id);
  58         if (!found)
  59                 return 0;
  60
  61         cdev->id.driver_info = found->driver_info;
  62
  63         return 1;
  64 }
  65
  66 /* Store modalias string delimited by prefix/suffix string into buffer with
  67  * specified size. Return length of resulting string (excluding trailing '\0')
  68  * even if string doesn't fit buffer (snprintf semantics). */
  69 static int snprint_alias(char *buf, size_t size,
  70                          struct ccw_device_id *id, const char *suffix)
  71 {
  72         int len;
  73
  74         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  75         if (len > size)
  76                 return len;
  77         buf += len;
  78         size -= len;
  79
  80         if (id->dev_type != 0)
  81                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  82                                 id->dev_model, suffix);
  83         else
  84                 len += snprintf(buf, size, "dtdm%s", suffix);
  85
  86         return len;
  87 }
  88
  89 /* Set up environment variables for ccw device uevent. Return 0 on success,
  90  * non-zero otherwise. */
  91 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
  92 {
  93         struct ccw_device *cdev = to_ccwdev(dev);
  94         struct ccw_device_id *id = &(cdev->id);
  95         int ret;
  96         char modalias_buf[30];
  97
  98         /* CU_TYPE= */
  99         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
 100         if (ret)
 101                 return ret;
 102
 103         /* CU_MODEL= */
 104         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 105         if (ret)
 106                 return ret;
 107
 108         /* The next two can be zero, that's ok for us */
 109         /* DEV_TYPE= */
 110         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 111         if (ret)
 112                 return ret;
 113
 114         /* DEV_MODEL= */
 115         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 116         if (ret)
 117                 return ret;
 118
 119         /* MODALIAS=  */
 120         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 121         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 122         return ret;
 123 }
 124
 125 struct bus_type ccw_bus_type;
 126
 127 static void io_subchannel_irq(struct subchannel *);
 128 static int io_subchannel_probe(struct subchannel *);
 129 static int io_subchannel_remove(struct subchannel *);
 130 static void io_subchannel_shutdown(struct subchannel *);
 131 static int io_subchannel_sch_event(struct subchannel *, int);
 132 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
 133                                    int);
 134
 135 static struct css_device_id io_subchannel_ids[] = {
 136         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 137         { /* end of list */ },
 138 };
 139 MODULE_DEVICE_TABLE(css, io_subchannel_ids);
 140
 141 static struct css_driver io_subchannel_driver = {
 142         .owner = THIS_MODULE,
 143         .subchannel_type = io_subchannel_ids,
 144         .name = "io_subchannel",
 145         .irq = io_subchannel_irq,
 146         .sch_event = io_subchannel_sch_event,
 147         .chp_event = io_subchannel_chp_event,
 148         .probe = io_subchannel_probe,
 149         .remove = io_subchannel_remove,
 150         .shutdown = io_subchannel_shutdown,
 151 };
 152
 153 struct workqueue_struct *ccw_device_work;
 154 wait_queue_head_t ccw_device_init_wq;
 155 atomic_t ccw_device_init_count;
 156
 157 static void recovery_func(unsigned long data);
 158
 159 static int __init
 160 init_ccw_bus_type (void)
 161 {
 162         int ret;
 163
 164         init_waitqueue_head(&ccw_device_init_wq);
 165         atomic_set(&ccw_device_init_count, 0);
 166         setup_timer(&recovery_timer, recovery_func, 0);
 167
 168         ccw_device_work = create_singlethread_workqueue("cio");
 169         if (!ccw_device_work)
 170                 return -ENOMEM; /* FIXME: better errno ? */
 171         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 172         if (!slow_path_wq) {
 173                 ret = -ENOMEM; /* FIXME: better errno ? */
 174                 goto out_err;
 175         }
 176         if ((ret = bus_register (&ccw_bus_type)))
 177                 goto out_err;
 178
 179         ret = css_driver_register(&io_subchannel_driver);
 180         if (ret)
 181                 goto out_err;
 182
 183         wait_event(ccw_device_init_wq,
 184                    atomic_read(&ccw_device_init_count) == 0);
 185         flush_workqueue(ccw_device_work);
 186         return 0;
 187 out_err:
 188         if (ccw_device_work)
 189                 destroy_workqueue(ccw_device_work);
 190         if (slow_path_wq)
 191                 destroy_workqueue(slow_path_wq);
 192         return ret;
 193 }
 194
 195 static void __exit
 196 cleanup_ccw_bus_type (void)
 197 {
 198         css_driver_unregister(&io_subchannel_driver);
 199         bus_unregister(&ccw_bus_type);
 200         destroy_workqueue(ccw_device_work);
 201 }
 202
 203 subsys_initcall(init_ccw_bus_type);
 204 module_exit(cleanup_ccw_bus_type);
 205
 206 /************************ device handling **************************/
 207
 208 /*
 209  * A ccw_device has some interfaces in sysfs in addition to the
 210  * standard ones.
 211  * The following entries are designed to export the information which
 212  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 213  * are obvious, so they don't have an entry :)
 214  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 215  */
 216 static ssize_t
 217 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 218 {
 219         struct subchannel *sch = to_subchannel(dev);
 220         struct chsc_ssd_info *ssd = &sch->ssd_info;
 221         ssize_t ret = 0;
 222         int chp;
 223         int mask;
 224
 225         for (chp = 0; chp < 8; chp++) {
 226                 mask = 0x80 >> chp;
 227                 if (ssd->path_mask & mask)
 228                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 229                 else
 230                         ret += sprintf(buf + ret, "00 ");
 231         }
 232         ret += sprintf (buf+ret, "\n");
 233         return min((ssize_t)PAGE_SIZE, ret);
 234 }
 235
 236 static ssize_t
 237 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 238 {
 239         struct subchannel *sch = to_subchannel(dev);
 240         struct pmcw *pmcw = &sch->schib.pmcw;
 241
 242         return sprintf (buf, "%02x %02x %02x\n",
 243                         pmcw->pim, pmcw->pam, pmcw->pom);
 244 }
 245
 246 static ssize_t
 247 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 248 {
 249         struct ccw_device *cdev = to_ccwdev(dev);
 250         struct ccw_device_id *id = &(cdev->id);
 251
 252         if (id->dev_type != 0)
 253                 return sprintf(buf, "%04x/%02x\n",
 254                                 id->dev_type, id->dev_model);
 255         else
 256                 return sprintf(buf, "n/a\n");
 257 }
 258
 259 static ssize_t
 260 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 261 {
 262         struct ccw_device *cdev = to_ccwdev(dev);
 263         struct ccw_device_id *id = &(cdev->id);
 264
 265         return sprintf(buf, "%04x/%02x\n",
 266                        id->cu_type, id->cu_model);
 267 }
 268
 269 static ssize_t
 270 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 271 {
 272         struct ccw_device *cdev = to_ccwdev(dev);
 273         struct ccw_device_id *id = &(cdev->id);
 274         int len;
 275
 276         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 277
 278         return len > PAGE_SIZE ? PAGE_SIZE : len;
 279 }
 280
 281 static ssize_t
 282 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 283 {
 284         struct ccw_device *cdev = to_ccwdev(dev);
 285
 286         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 287 }
 288
 289 int ccw_device_is_orphan(struct ccw_device *cdev)
 290 {
 291         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 292 }
 293
 294 static void ccw_device_unregister(struct ccw_device *cdev)
 295 {
 296         if (test_and_clear_bit(1, &cdev->private->registered))
 297                 device_del(&cdev->dev);
 298 }
 299
 300 static void ccw_device_remove_orphan_cb(struct work_struct *work)
 301 {
 302         struct ccw_device_private *priv;
 303         struct ccw_device *cdev;
 304
 305         priv = container_of(work, struct ccw_device_private, kick_work);
 306         cdev = priv->cdev;
 307         ccw_device_unregister(cdev);
 308         put_device(&cdev->dev);
 309         /* Release cdev reference for workqueue processing. */
 310         put_device(&cdev->dev);
 311 }
 312
 313 static void ccw_device_call_sch_unregister(struct work_struct *work);
 314
 315 static void
 316 ccw_device_remove_disconnected(struct ccw_device *cdev)
 317 {
 318         unsigned long flags;
 319
 320         /*
 321          * Forced offline in disconnected state means
 322          * 'throw away device'.
 323          */
 324         /* Get cdev reference for workqueue processing. */
 325         if (!get_device(&cdev->dev))
 326                 return;
 327         if (ccw_device_is_orphan(cdev)) {
 328                 /*
 329                  * Deregister ccw device.
 330                  * Unfortunately, we cannot do this directly from the
 331                  * attribute method.
 332                  */
 333                 spin_lock_irqsave(cdev->ccwlock, flags);
 334                 cdev->private->state = DEV_STATE_NOT_OPER;
 335                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 336                 PREPARE_WORK(&cdev->private->kick_work,
 337                                 ccw_device_remove_orphan_cb);
 338         } else
 339                 /* Deregister subchannel, which will kill the ccw device. */
 340                 PREPARE_WORK(&cdev->private->kick_work,
 341                                 ccw_device_call_sch_unregister);
 342         queue_work(slow_path_wq, &cdev->private->kick_work);
 343 }
 344
 345 /**
 346  * ccw_device_set_offline() - disable a ccw device for I/O
 347  * @cdev: target ccw device
 348  *
 349  * This function calls the driver's set_offline() function for @cdev, if
 350  * given, and then disables @cdev.
 351  * Returns:
 352  *   %0 on success and a negative error value on failure.
 353  * Context:
 354  *  enabled, ccw device lock not held
 355  */
 356 int ccw_device_set_offline(struct ccw_device *cdev)
 357 {
 358         int ret;
 359
 360         if (!cdev)
 361                 return -ENODEV;
 362         if (!cdev->online || !cdev->drv)
 363                 return -EINVAL;
 364
 365         if (cdev->drv->set_offline) {
 366                 ret = cdev->drv->set_offline(cdev);
 367                 if (ret != 0)
 368                         return ret;
 369         }
 370         cdev->online = 0;
 371         spin_lock_irq(cdev->ccwlock);
 372         ret = ccw_device_offline(cdev);
 373         if (ret == -ENODEV) {
 374                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 375                         cdev->private->state = DEV_STATE_OFFLINE;
 376                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 377                 }
 378                 spin_unlock_irq(cdev->ccwlock);
 379                 return ret;
 380         }
 381         spin_unlock_irq(cdev->ccwlock);
 382         if (ret == 0)
 383                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 384         else {
 385                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
 386                               "device 0.%x.%04x\n",
 387                               ret, cdev->private->dev_id.ssid,
 388                               cdev->private->dev_id.devno);
 389                 cdev->online = 1;
 390         }
 391         return ret;
 392 }
 393
 394 /**
 395  * ccw_device_set_online() - enable a ccw device for I/O
 396  * @cdev: target ccw device
 397  *
 398  * This function first enables @cdev and then calls the driver's set_online()
 399  * function for @cdev, if given. If set_online() returns an error, @cdev is
 400  * disabled again.
 401  * Returns:
 402  *   %0 on success and a negative error value on failure.
 403  * Context:
 404  *  enabled, ccw device lock not held
 405  */
 406 int ccw_device_set_online(struct ccw_device *cdev)
 407 {
 408         int ret;
 409
 410         if (!cdev)
 411                 return -ENODEV;
 412         if (cdev->online || !cdev->drv)
 413                 return -EINVAL;
 414
 415         spin_lock_irq(cdev->ccwlock);
 416         ret = ccw_device_online(cdev);
 417         spin_unlock_irq(cdev->ccwlock);
 418         if (ret == 0)
 419                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 420         else {
 421                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 422                               "device 0.%x.%04x\n",
 423                               ret, cdev->private->dev_id.ssid,
 424                               cdev->private->dev_id.devno);
 425                 return ret;
 426         }
 427         if (cdev->private->state != DEV_STATE_ONLINE)
 428                 return -ENODEV;
 429         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 430                 cdev->online = 1;
 431                 return 0;
 432         }
 433         spin_lock_irq(cdev->ccwlock);
 434         ret = ccw_device_offline(cdev);
 435         spin_unlock_irq(cdev->ccwlock);
 436         if (ret == 0)
 437                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 438         else
 439                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
 440                               "device 0.%x.%04x\n",
 441                               ret, cdev->private->dev_id.ssid,
 442                               cdev->private->dev_id.devno);
 443         return (ret == 0) ? -ENODEV : ret;
 444 }
 445
 446 static void online_store_handle_offline(struct ccw_device *cdev)
 447 {
 448         if (cdev->private->state == DEV_STATE_DISCONNECTED)
 449                 ccw_device_remove_disconnected(cdev);
 450         else if (cdev->drv && cdev->drv->set_offline)
 451                 ccw_device_set_offline(cdev);
 452 }
 453
 454 static int online_store_recog_and_online(struct ccw_device *cdev)
 455 {
 456         int ret;
 457
 458         /* Do device recognition, if needed. */
 459         if (cdev->id.cu_type == 0) {
 460                 ret = ccw_device_recognition(cdev);
 461                 if (ret) {
 462                         CIO_MSG_EVENT(0, "Couldn't start recognition "
 463                                       "for device 0.%x.%04x (ret=%d)\n",
 464                                       cdev->private->dev_id.ssid,
 465                                       cdev->private->dev_id.devno, ret);
 466                         return ret;
 467                 }
 468                 wait_event(cdev->private->wait_q,
 469                            cdev->private->flags.recog_done);
 470         }
 471         if (cdev->drv && cdev->drv->set_online)
 472                 ccw_device_set_online(cdev);
 473         return 0;
 474 }
 475 static int online_store_handle_online(struct ccw_device *cdev, int force)
 476 {
 477         int ret;
 478
 479         ret = online_store_recog_and_online(cdev);
 480         if (ret)
 481                 return ret;
 482         if (force && cdev->private->state == DEV_STATE_BOXED) {
 483                 ret = ccw_device_stlck(cdev);
 484                 if (ret)
 485                         return ret;
 486                 if (cdev->id.cu_type == 0)
 487                         cdev->private->state = DEV_STATE_NOT_OPER;
 488                 online_store_recog_and_online(cdev);
 489         }
 490         return 0;
 491 }
 492
 493 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 494                              const char *buf, size_t count)
 495 {
 496         struct ccw_device *cdev = to_ccwdev(dev);
 497         int force, ret;
 498         unsigned long i;
 499
 500         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 501                 return -EAGAIN;
 502
 503         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 504                 atomic_set(&cdev->private->onoff, 0);
 505                 return -EINVAL;
 506         }
 507         if (!strncmp(buf, "force\n", count)) {
 508                 force = 1;
 509                 i = 1;
 510                 ret = 0;
 511         } else {
 512                 force = 0;
 513                 ret = strict_strtoul(buf, 16, &i);
 514         }
 515         if (ret)
 516                 goto out;
 517         switch (i) {
 518         case 0:
 519                 online_store_handle_offline(cdev);
 520                 ret = count;
 521                 break;
 522         case 1:
 523                 ret = online_store_handle_online(cdev, force);
 524                 if (!ret)
 525                         ret = count;
 526                 break;
 527         default:
 528                 ret = -EINVAL;
 529         }
 530 out:
 531         if (cdev->drv)
 532                 module_put(cdev->drv->owner);
 533         atomic_set(&cdev->private->onoff, 0);
 534         return ret;
 535 }
 536
 537 static ssize_t
 538 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 539 {
 540         struct ccw_device *cdev = to_ccwdev(dev);
 541         struct subchannel *sch;
 542
 543         if (ccw_device_is_orphan(cdev))
 544                 return sprintf(buf, "no device\n");
 545         switch (cdev->private->state) {
 546         case DEV_STATE_BOXED:
 547                 return sprintf(buf, "boxed\n");
 548         case DEV_STATE_DISCONNECTED:
 549         case DEV_STATE_DISCONNECTED_SENSE_ID:
 550         case DEV_STATE_NOT_OPER:
 551                 sch = to_subchannel(dev->parent);
 552                 if (!sch->lpm)
 553                         return sprintf(buf, "no path\n");
 554                 else
 555                         return sprintf(buf, "no device\n");
 556         default:
 557                 /* All other states considered fine. */
 558                 return sprintf(buf, "good\n");
 559         }
 560 }
 561
 562 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 563 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 564 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 565 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 566 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 567 static DEVICE_ATTR(online, 0644, online_show, online_store);
 568 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 569
 570 static struct attribute *io_subchannel_attrs[] = {
 571         &dev_attr_chpids.attr,
 572         &dev_attr_pimpampom.attr,
 573         NULL,
 574 };
 575
 576 static struct attribute_group io_subchannel_attr_group = {
 577         .attrs = io_subchannel_attrs,
 578 };
 579
 580 static struct attribute * ccwdev_attrs[] = {
 581         &dev_attr_devtype.attr,
 582         &dev_attr_cutype.attr,
 583         &dev_attr_modalias.attr,
 584         &dev_attr_online.attr,
 585         &dev_attr_cmb_enable.attr,
 586         &dev_attr_availability.attr,
 587         NULL,
 588 };
 589
 590 static struct attribute_group ccwdev_attr_group = {
 591         .attrs = ccwdev_attrs,
 592 };
 593
 594 static struct attribute_group *ccwdev_attr_groups[] = {
 595         &ccwdev_attr_group,
 596         NULL,
 597 };
 598
 599 /* this is a simple abstraction for device_register that sets the
 600  * correct bus type and adds the bus specific files */
 601 static int ccw_device_register(struct ccw_device *cdev)
 602 {
 603         struct device *dev = &cdev->dev;
 604         int ret;
 605
 606         dev->bus = &ccw_bus_type;
 607
 608         if ((ret = device_add(dev)))
 609                 return ret;
 610
 611         set_bit(1, &cdev->private->registered);
 612         return ret;
 613 }
 614
 615 struct match_data {
 616         struct ccw_dev_id dev_id;
 617         struct ccw_device * sibling;
 618 };
 619
 620 static int
 621 match_devno(struct device * dev, void * data)
 622 {
 623         struct match_data * d = data;
 624         struct ccw_device * cdev;
 625
 626         cdev = to_ccwdev(dev);
 627         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 628             !ccw_device_is_orphan(cdev) &&
 629             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 630             (cdev != d->sibling))
 631                 return 1;
 632         return 0;
 633 }
 634
 635 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 636                                                      struct ccw_device *sibling)
 637 {
 638         struct device *dev;
 639         struct match_data data;
 640
 641         data.dev_id = *dev_id;
 642         data.sibling = sibling;
 643         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 644
 645         return dev ? to_ccwdev(dev) : NULL;
 646 }
 647
 648 static int match_orphan(struct device *dev, void *data)
 649 {
 650         struct ccw_dev_id *dev_id;
 651         struct ccw_device *cdev;
 652
 653         dev_id = data;
 654         cdev = to_ccwdev(dev);
 655         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 656 }
 657
 658 static struct ccw_device *
 659 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 660                               struct ccw_dev_id *dev_id)
 661 {
 662         struct device *dev;
 663
 664         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 665                                 match_orphan);
 666
 667         return dev ? to_ccwdev(dev) : NULL;
 668 }
 669
 670 static void
 671 ccw_device_add_changed(struct work_struct *work)
 672 {
 673         struct ccw_device_private *priv;
 674         struct ccw_device *cdev;
 675
 676         priv = container_of(work, struct ccw_device_private, kick_work);
 677         cdev = priv->cdev;
 678         if (device_add(&cdev->dev)) {
 679                 put_device(&cdev->dev);
 680                 return;
 681         }
 682         set_bit(1, &cdev->private->registered);
 683 }
 684
 685 void ccw_device_do_unreg_rereg(struct work_struct *work)
 686 {
 687         struct ccw_device_private *priv;
 688         struct ccw_device *cdev;
 689         struct subchannel *sch;
 690
 691         priv = container_of(work, struct ccw_device_private, kick_work);
 692         cdev = priv->cdev;
 693         sch = to_subchannel(cdev->dev.parent);
 694
 695         ccw_device_unregister(cdev);
 696         PREPARE_WORK(&cdev->private->kick_work,
 697                      ccw_device_add_changed);
 698         queue_work(ccw_device_work, &cdev->private->kick_work);
 699 }
 700
 701 static void
 702 ccw_device_release(struct device *dev)
 703 {
 704         struct ccw_device *cdev;
 705
 706         cdev = to_ccwdev(dev);
 707         kfree(cdev->private);
 708         kfree(cdev);
 709 }
 710
 711 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 712 {
 713         struct ccw_device *cdev;
 714
 715         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 716         if (cdev) {
 717                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 718                                         GFP_KERNEL | GFP_DMA);
 719                 if (cdev->private)
 720                         return cdev;
 721         }
 722         kfree(cdev);
 723         return ERR_PTR(-ENOMEM);
 724 }
 725
 726 static int io_subchannel_initialize_dev(struct subchannel *sch,
 727                                         struct ccw_device *cdev)
 728 {
 729         cdev->private->cdev = cdev;
 730         atomic_set(&cdev->private->onoff, 0);
 731         cdev->dev.parent = &sch->dev;
 732         cdev->dev.release = ccw_device_release;
 733         INIT_WORK(&cdev->private->kick_work, NULL);
 734         cdev->dev.groups = ccwdev_attr_groups;
 735         /* Do first half of device_register. */
 736         device_initialize(&cdev->dev);
 737         if (!get_device(&sch->dev)) {
 738                 if (cdev->dev.release)
 739                         cdev->dev.release(&cdev->dev);
 740                 return -ENODEV;
 741         }
 742         return 0;
 743 }
 744
 745 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 746 {
 747         struct ccw_device *cdev;
 748         int ret;
 749
 750         cdev = io_subchannel_allocate_dev(sch);
 751         if (!IS_ERR(cdev)) {
 752                 ret = io_subchannel_initialize_dev(sch, cdev);
 753                 if (ret) {
 754                         kfree(cdev);
 755                         cdev = ERR_PTR(ret);
 756                 }
 757         }
 758         return cdev;
 759 }
 760
 761 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 762
 763 static void sch_attach_device(struct subchannel *sch,
 764                               struct ccw_device *cdev)
 765 {
 766         css_update_ssd_info(sch);
 767         spin_lock_irq(sch->lock);
 768         sch_set_cdev(sch, cdev);
 769         cdev->private->schid = sch->schid;
 770         cdev->ccwlock = sch->lock;
 771         ccw_device_trigger_reprobe(cdev);
 772         spin_unlock_irq(sch->lock);
 773 }
 774
 775 static void sch_attach_disconnected_device(struct subchannel *sch,
 776                                            struct ccw_device *cdev)
 777 {
 778         struct subchannel *other_sch;
 779         int ret;
 780
 781         other_sch = to_subchannel(get_device(cdev->dev.parent));
 782         ret = device_move(&cdev->dev, &sch->dev);
 783         if (ret) {
 784                 CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed "
 785                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 786                               cdev->private->dev_id.devno, ret);
 787                 put_device(&other_sch->dev);
 788                 return;
 789         }
 790         sch_set_cdev(other_sch, NULL);
 791         /* No need to keep a subchannel without ccw device around. */
 792         css_sch_device_unregister(other_sch);
 793         put_device(&other_sch->dev);
 794         sch_attach_device(sch, cdev);
 795 }
 796
 797 static void sch_attach_orphaned_device(struct subchannel *sch,
 798                                        struct ccw_device *cdev)
 799 {
 800         int ret;
 801
 802         /* Try to move the ccw device to its new subchannel. */
 803         ret = device_move(&cdev->dev, &sch->dev);
 804         if (ret) {
 805                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 806                               "failed (ret=%d)!\n",
 807                               cdev->private->dev_id.ssid,
 808                               cdev->private->dev_id.devno, ret);
 809                 return;
 810         }
 811         sch_attach_device(sch, cdev);
 812 }
 813
 814 static void sch_create_and_recog_new_device(struct subchannel *sch)
 815 {
 816         struct ccw_device *cdev;
 817
 818         /* Need to allocate a new ccw device. */
 819         cdev = io_subchannel_create_ccwdev(sch);
 820         if (IS_ERR(cdev)) {
 821                 /* OK, we did everything we could... */
 822                 css_sch_device_unregister(sch);
 823                 return;
 824         }
 825         spin_lock_irq(sch->lock);
 826         sch_set_cdev(sch, cdev);
 827         spin_unlock_irq(sch->lock);
 828         /* Start recognition for the new ccw device. */
 829         if (io_subchannel_recog(cdev, sch)) {
 830                 spin_lock_irq(sch->lock);
 831                 sch_set_cdev(sch, NULL);
 832                 spin_unlock_irq(sch->lock);
 833                 if (cdev->dev.release)
 834                         cdev->dev.release(&cdev->dev);
 835                 css_sch_device_unregister(sch);
 836         }
 837 }
 838
 839
 840 void ccw_device_move_to_orphanage(struct work_struct *work)
 841 {
 842         struct ccw_device_private *priv;
 843         struct ccw_device *cdev;
 844         struct ccw_device *replacing_cdev;
 845         struct subchannel *sch;
 846         int ret;
 847         struct channel_subsystem *css;
 848         struct ccw_dev_id dev_id;
 849
 850         priv = container_of(work, struct ccw_device_private, kick_work);
 851         cdev = priv->cdev;
 852         sch = to_subchannel(cdev->dev.parent);
 853         css = to_css(sch->dev.parent);
 854         dev_id.devno = sch->schib.pmcw.dev;
 855         dev_id.ssid = sch->schid.ssid;
 856
 857         /*
 858          * Move the orphaned ccw device to the orphanage so the replacing
 859          * ccw device can take its place on the subchannel.
 860          */
 861         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
 862         if (ret) {
 863                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 864                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 865                               cdev->private->dev_id.devno, ret);
 866                 return;
 867         }
 868         cdev->ccwlock = css->pseudo_subchannel->lock;
 869         /*
 870          * Search for the replacing ccw device
 871          * - among the disconnected devices
 872          * - in the orphanage
 873          */
 874         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 875         if (replacing_cdev) {
 876                 sch_attach_disconnected_device(sch, replacing_cdev);
 877                 /* Release reference from get_disc_ccwdev_by_dev_id() */
 878                 put_device(&cdev->dev);
 879                 return;
 880         }
 881         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 882         if (replacing_cdev) {
 883                 sch_attach_orphaned_device(sch, replacing_cdev);
 884                 /* Release reference from get_orphaned_ccwdev_by_dev_id() */
 885                 put_device(&cdev->dev);
 886                 return;
 887         }
 888         sch_create_and_recog_new_device(sch);
 889 }
 890
 891 /*
 892  * Register recognized device.
 893  */
 894 static void
 895 io_subchannel_register(struct work_struct *work)
 896 {
 897         struct ccw_device_private *priv;
 898         struct ccw_device *cdev;
 899         struct subchannel *sch;
 900         int ret;
 901         unsigned long flags;
 902
 903         priv = container_of(work, struct ccw_device_private, kick_work);
 904         cdev = priv->cdev;
 905         sch = to_subchannel(cdev->dev.parent);
 906         css_update_ssd_info(sch);
 907         /*
 908          * io_subchannel_register() will also be called after device
 909          * recognition has been done for a boxed device (which will already
 910          * be registered). We need to reprobe since we may now have sense id
 911          * information.
 912          */
 913         if (klist_node_attached(&cdev->dev.knode_parent)) {
 914                 if (!cdev->drv) {
 915                         ret = device_reprobe(&cdev->dev);
 916                         if (ret)
 917                                 /* We can't do much here. */
 918                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 919                                               " %d for 0.%x.%04x\n", ret,
 920                                               cdev->private->dev_id.ssid,
 921                                               cdev->private->dev_id.devno);
 922                 }
 923                 goto out;
 924         }
 925         /*
 926          * Now we know this subchannel will stay, we can throw
 927          * our delayed uevent.
 928          */
 929         sch->dev.uevent_suppress = 0;
 930         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 931         /* make it known to the system */
 932         ret = ccw_device_register(cdev);
 933         if (ret) {
 934                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 935                               cdev->private->dev_id.ssid,
 936                               cdev->private->dev_id.devno, ret);
 937                 put_device(&cdev->dev);
 938                 spin_lock_irqsave(sch->lock, flags);
 939                 sch_set_cdev(sch, NULL);
 940                 spin_unlock_irqrestore(sch->lock, flags);
 941                 kfree (cdev->private);
 942                 kfree (cdev);
 943                 put_device(&sch->dev);
 944                 if (atomic_dec_and_test(&ccw_device_init_count))
 945                         wake_up(&ccw_device_init_wq);
 946                 return;
 947         }
 948         put_device(&cdev->dev);
 949 out:
 950         cdev->private->flags.recog_done = 1;
 951         put_device(&sch->dev);
 952         wake_up(&cdev->private->wait_q);
 953         if (atomic_dec_and_test(&ccw_device_init_count))
 954                 wake_up(&ccw_device_init_wq);
 955 }
 956
 957 static void ccw_device_call_sch_unregister(struct work_struct *work)
 958 {
 959         struct ccw_device_private *priv;
 960         struct ccw_device *cdev;
 961         struct subchannel *sch;
 962
 963         priv = container_of(work, struct ccw_device_private, kick_work);
 964         cdev = priv->cdev;
 965         /* Get subchannel reference for local processing. */
 966         if (!get_device(cdev->dev.parent))
 967                 return;
 968         sch = to_subchannel(cdev->dev.parent);
 969         css_sch_device_unregister(sch);
 970         /* Reset intparm to zeroes. */
 971         sch->schib.pmcw.intparm = 0;
 972         cio_modify(sch);
 973         /* Release cdev reference for workqueue processing.*/
 974         put_device(&cdev->dev);
 975         /* Release subchannel reference for local processing. */
 976         put_device(&sch->dev);
 977 }
 978
 979 /*
 980  * subchannel recognition done. Called from the state machine.
 981  */
 982 void
 983 io_subchannel_recog_done(struct ccw_device *cdev)
 984 {
 985         struct subchannel *sch;
 986
 987         if (css_init_done == 0) {
 988                 cdev->private->flags.recog_done = 1;
 989                 return;
 990         }
 991         switch (cdev->private->state) {
 992         case DEV_STATE_NOT_OPER:
 993                 cdev->private->flags.recog_done = 1;
 994                 /* Remove device found not operational. */
 995                 if (!get_device(&cdev->dev))
 996                         break;
 997                 sch = to_subchannel(cdev->dev.parent);
 998                 PREPARE_WORK(&cdev->private->kick_work,
 999                              ccw_device_call_sch_unregister);
1000                 queue_work(slow_path_wq, &cdev->private->kick_work);
1001                 /* Release subchannel reference for asynchronous recognition. */
1002                 put_device(&sch->dev);
1003                 if (atomic_dec_and_test(&ccw_device_init_count))
1004                         wake_up(&ccw_device_init_wq);
1005                 break;
1006         case DEV_STATE_BOXED:
1007                 /* Device did not respond in time. */
1008         case DEV_STATE_OFFLINE:
1009                 /*
1010                  * We can't register the device in interrupt context so
1011                  * we schedule a work item.
1012                  */
1013                 if (!get_device(&cdev->dev))
1014                         break;
1015                 PREPARE_WORK(&cdev->private->kick_work,
1016                              io_subchannel_register);
1017                 queue_work(slow_path_wq, &cdev->private->kick_work);
1018                 break;
1019         }
1020 }
1021
1022 static int
1023 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
1024 {
1025         int rc;
1026         struct ccw_device_private *priv;
1027
1028         sch_set_cdev(sch, cdev);
1029         cdev->ccwlock = sch->lock;
1030
1031         /* Init private data. */
1032         priv = cdev->private;
1033         priv->dev_id.devno = sch->schib.pmcw.dev;
1034         priv->dev_id.ssid = sch->schid.ssid;
1035         priv->schid = sch->schid;
1036         priv->state = DEV_STATE_NOT_OPER;
1037         INIT_LIST_HEAD(&priv->cmb_list);
1038         init_waitqueue_head(&priv->wait_q);
1039         init_timer(&priv->timer);
1040
1041         /* Set an initial name for the device. */
1042         if (cio_is_console(sch->schid))
1043                 cdev->dev.init_name = cio_get_console_cdev_name(sch);
1044         else
1045                 dev_set_name(&cdev->dev, "0.%x.%04x",
1046                              sch->schid.ssid, sch->schib.pmcw.dev);
1047
1048         /* Increase counter of devices currently in recognition. */
1049         atomic_inc(&ccw_device_init_count);
1050
1051         /* Start async. device sensing. */
1052         spin_lock_irq(sch->lock);
1053         rc = ccw_device_recognition(cdev);
1054         spin_unlock_irq(sch->lock);
1055         if (rc) {
1056                 if (atomic_dec_and_test(&ccw_device_init_count))
1057                         wake_up(&ccw_device_init_wq);
1058         }
1059         return rc;
1060 }
1061
1062 static void ccw_device_move_to_sch(struct work_struct *work)
1063 {
1064         struct ccw_device_private *priv;
1065         int rc;
1066         struct subchannel *sch;
1067         struct ccw_device *cdev;
1068         struct subchannel *former_parent;
1069
1070         priv = container_of(work, struct ccw_device_private, kick_work);
1071         sch = priv->sch;
1072         cdev = priv->cdev;
1073         former_parent = ccw_device_is_orphan(cdev) ?
1074                 NULL : to_subchannel(get_device(cdev->dev.parent));
1075         mutex_lock(&sch->reg_mutex);
1076         /* Try to move the ccw device to its new subchannel. */
1077         rc = device_move(&cdev->dev, &sch->dev);
1078         mutex_unlock(&sch->reg_mutex);
1079         if (rc) {
1080                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to subchannel "
1081                               "0.%x.%04x failed (ret=%d)!\n",
1082                               cdev->private->dev_id.ssid,
1083                               cdev->private->dev_id.devno, sch->schid.ssid,
1084                               sch->schid.sch_no, rc);
1085                 css_sch_device_unregister(sch);
1086                 goto out;
1087         }
1088         if (former_parent) {
1089                 spin_lock_irq(former_parent->lock);
1090                 sch_set_cdev(former_parent, NULL);
1091                 spin_unlock_irq(former_parent->lock);
1092                 css_sch_device_unregister(former_parent);
1093                 /* Reset intparm to zeroes. */
1094                 former_parent->schib.pmcw.intparm = 0;
1095                 cio_modify(former_parent);
1096         }
1097         sch_attach_device(sch, cdev);
1098 out:
1099         if (former_parent)
1100                 put_device(&former_parent->dev);
1101         put_device(&cdev->dev);
1102 }
1103
1104 static void io_subchannel_irq(struct subchannel *sch)
1105 {
1106         struct ccw_device *cdev;
1107
1108         cdev = sch_get_cdev(sch);
1109
1110         CIO_TRACE_EVENT(3, "IRQ");
1111         CIO_TRACE_EVENT(3, dev_name(&sch->dev));
1112         if (cdev)
1113                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1114 }
1115
1116 static void io_subchannel_init_fields(struct subchannel *sch)
1117 {
1118         if (cio_is_console(sch->schid))
1119                 sch->opm = 0xff;
1120         else
1121                 sch->opm = chp_get_sch_opm(sch);
1122         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1123         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1124
1125         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1126                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1127                       sch->schib.pmcw.dev, sch->schid.ssid,
1128                       sch->schid.sch_no, sch->schib.pmcw.pim,
1129                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1130         /* Initially set up some fields in the pmcw. */
1131         sch->schib.pmcw.ena = 0;
1132         sch->schib.pmcw.csense = 1;     /* concurrent sense */
1133         if ((sch->lpm & (sch->lpm - 1)) != 0)
1134                 sch->schib.pmcw.mp = 1; /* multipath mode */
1135         /* clean up possible residual cmf stuff */
1136         sch->schib.pmcw.mme = 0;
1137         sch->schib.pmcw.mbfc = 0;
1138         sch->schib.pmcw.mbi = 0;
1139         sch->schib.mba = 0;
1140 }
1141
1142 static int io_subchannel_probe(struct subchannel *sch)
1143 {
1144         struct ccw_device *cdev;
1145         int rc;
1146         unsigned long flags;
1147         struct ccw_dev_id dev_id;
1148
1149         cdev = sch_get_cdev(sch);
1150         if (cdev) {
1151                 rc = sysfs_create_group(&sch->dev.kobj,
1152                                         &io_subchannel_attr_group);
1153                 if (rc)
1154                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1155                                       "attributes for subchannel "
1156                                       "0.%x.%04x (rc=%d)\n",
1157                                       sch->schid.ssid, sch->schid.sch_no, rc);
1158                 /*
1159                  * This subchannel already has an associated ccw_device.
1160                  * Throw the delayed uevent for the subchannel, register
1161                  * the ccw_device and exit. This happens for all early
1162                  * devices, e.g. the console.
1163                  */
1164                 sch->dev.uevent_suppress = 0;
1165                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1166                 cdev->dev.groups = ccwdev_attr_groups;
1167                 device_initialize(&cdev->dev);
1168                 ccw_device_register(cdev);
1169                 /*
1170                  * Check if the device is already online. If it is
1171                  * the reference count needs to be corrected
1172                  * (see ccw_device_online and css_init_done for the
1173                  * ugly details).
1174                  */
1175                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1176                     cdev->private->state != DEV_STATE_OFFLINE &&
1177                     cdev->private->state != DEV_STATE_BOXED)
1178                         get_device(&cdev->dev);
1179                 return 0;
1180         }
1181         io_subchannel_init_fields(sch);
1182         /*
1183          * First check if a fitting device may be found amongst the
1184          * disconnected devices or in the orphanage.
1185          */
1186         dev_id.devno = sch->schib.pmcw.dev;
1187         dev_id.ssid = sch->schid.ssid;
1188         rc = sysfs_create_group(&sch->dev.kobj,
1189                                 &io_subchannel_attr_group);
1190         if (rc)
1191                 return rc;
1192         /* Allocate I/O subchannel private data. */
1193         sch->private = kzalloc(sizeof(struct io_subchannel_private),
1194                                GFP_KERNEL | GFP_DMA);
1195         if (!sch->private) {
1196                 rc = -ENOMEM;
1197                 goto out_err;
1198         }
1199         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1200         if (!cdev)
1201                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1202                                                      &dev_id);
1203         if (cdev) {
1204                 /*
1205                  * Schedule moving the device until when we have a registered
1206                  * subchannel to move to and succeed the probe. We can
1207                  * unregister later again, when the probe is through.
1208                  */
1209                 cdev->private->sch = sch;
1210                 PREPARE_WORK(&cdev->private->kick_work,
1211                              ccw_device_move_to_sch);
1212                 queue_work(slow_path_wq, &cdev->private->kick_work);
1213                 return 0;
1214         }
1215         cdev = io_subchannel_create_ccwdev(sch);
1216         if (IS_ERR(cdev)) {
1217                 rc = PTR_ERR(cdev);
1218                 goto out_err;
1219         }
1220         rc = io_subchannel_recog(cdev, sch);
1221         if (rc) {
1222                 spin_lock_irqsave(sch->lock, flags);
1223                 sch_set_cdev(sch, NULL);
1224                 spin_unlock_irqrestore(sch->lock, flags);
1225                 if (cdev->dev.release)
1226                         cdev->dev.release(&cdev->dev);
1227                 goto out_err;
1228         }
1229         return 0;
1230 out_err:
1231         kfree(sch->private);
1232         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1233         return rc;
1234 }
1235
1236 static int
1237 io_subchannel_remove (struct subchannel *sch)
1238 {
1239         struct ccw_device *cdev;
1240         unsigned long flags;
1241
1242         cdev = sch_get_cdev(sch);
1243         if (!cdev)
1244                 return 0;
1245         /* Set ccw device to not operational and drop reference. */
1246         spin_lock_irqsave(cdev->ccwlock, flags);
1247         sch_set_cdev(sch, NULL);
1248         cdev->private->state = DEV_STATE_NOT_OPER;
1249         spin_unlock_irqrestore(cdev->ccwlock, flags);
1250         ccw_device_unregister(cdev);
1251         put_device(&cdev->dev);
1252         kfree(sch->private);
1253         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1254         return 0;
1255 }
1256
1257 static int io_subchannel_notify(struct subchannel *sch, int event)
1258 {
1259         struct ccw_device *cdev;
1260
1261         cdev = sch_get_cdev(sch);
1262         if (!cdev)
1263                 return 0;
1264         return ccw_device_notify(cdev, event);
1265 }
1266
1267 static void io_subchannel_verify(struct subchannel *sch)
1268 {
1269         struct ccw_device *cdev;
1270
1271         cdev = sch_get_cdev(sch);
1272         if (cdev)
1273                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1274 }
1275
1276 static int check_for_io_on_path(struct subchannel *sch, int mask)
1277 {
1278         int cc;
1279
1280         cc = stsch(sch->schid, &sch->schib);
1281         if (cc)
1282                 return 0;
1283         if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
1284                 return 1;
1285         return 0;
1286 }
1287
1288 static void terminate_internal_io(struct subchannel *sch,
1289                                   struct ccw_device *cdev)
1290 {
1291         if (cio_clear(sch)) {
1292                 /* Recheck device in case clear failed. */
1293                 sch->lpm = 0;
1294                 if (cdev->online)
1295                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1296                 else
1297                         css_schedule_eval(sch->schid);
1298                 return;
1299         }
1300         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1301         /* Request retry of internal operation. */
1302         cdev->private->flags.intretry = 1;
1303         /* Call handler. */
1304         if (cdev->handler)
1305                 cdev->handler(cdev, cdev->private->intparm,
1306                               ERR_PTR(-EIO));
1307 }
1308
1309 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1310 {
1311         struct ccw_device *cdev;
1312
1313         cdev = sch_get_cdev(sch);
1314         if (!cdev)
1315                 return;
1316         if (check_for_io_on_path(sch, mask)) {
1317                 if (cdev->private->state == DEV_STATE_ONLINE)
1318                         ccw_device_kill_io(cdev);
1319                 else {
1320                         terminate_internal_io(sch, cdev);
1321                         /* Re-start path verification. */
1322                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1323                 }
1324         } else
1325                 /* trigger path verification. */
1326                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1327
1328 }
1329
1330 static int io_subchannel_chp_event(struct subchannel *sch,
1331                                    struct chp_link *link, int event)
1332 {
1333         int mask;
1334
1335         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1336         if (!mask)
1337                 return 0;
1338         switch (event) {
1339         case CHP_VARY_OFF:
1340                 sch->opm &= ~mask;
1341                 sch->lpm &= ~mask;
1342                 io_subchannel_terminate_path(sch, mask);
1343                 break;
1344         case CHP_VARY_ON:
1345                 sch->opm |= mask;
1346                 sch->lpm |= mask;
1347                 io_subchannel_verify(sch);
1348                 break;
1349         case CHP_OFFLINE:
1350                 if (stsch(sch->schid, &sch->schib))
1351                         return -ENXIO;
1352                 if (!css_sch_is_valid(&sch->schib))
1353                         return -ENODEV;
1354                 io_subchannel_terminate_path(sch, mask);
1355                 break;
1356         case CHP_ONLINE:
1357                 if (stsch(sch->schid, &sch->schib))
1358                         return -ENXIO;
1359                 sch->lpm |= mask & sch->opm;
1360                 io_subchannel_verify(sch);
1361                 break;
1362         }
1363         return 0;
1364 }
1365
1366 static void
1367 io_subchannel_shutdown(struct subchannel *sch)
1368 {
1369         struct ccw_device *cdev;
1370         int ret;
1371
1372         cdev = sch_get_cdev(sch);
1373
1374         if (cio_is_console(sch->schid))
1375                 return;
1376         if (!sch->schib.pmcw.ena)
1377                 /* Nothing to do. */
1378                 return;
1379         ret = cio_disable_subchannel(sch);
1380         if (ret != -EBUSY)
1381                 /* Subchannel is disabled, we're done. */
1382                 return;
1383         cdev->private->state = DEV_STATE_QUIESCE;
1384         if (cdev->handler)
1385                 cdev->handler(cdev, cdev->private->intparm,
1386                               ERR_PTR(-EIO));
1387         ret = ccw_device_cancel_halt_clear(cdev);
1388         if (ret == -EBUSY) {
1389                 ccw_device_set_timeout(cdev, HZ/10);
1390                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1391         }
1392         cio_disable_subchannel(sch);
1393 }
1394
1395 static int io_subchannel_get_status(struct subchannel *sch)
1396 {
1397         struct schib schib;
1398
1399         if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
1400                 return CIO_GONE;
1401         if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))
1402                 return CIO_REVALIDATE;
1403         if (!sch->lpm)
1404                 return CIO_NO_PATH;
1405         return CIO_OPER;
1406 }
1407
1408 static int device_is_disconnected(struct ccw_device *cdev)
1409 {
1410         if (!cdev)
1411                 return 0;
1412         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1413                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1414 }
1415
1416 static int recovery_check(struct device *dev, void *data)
1417 {
1418         struct ccw_device *cdev = to_ccwdev(dev);
1419         int *redo = data;
1420
1421         spin_lock_irq(cdev->ccwlock);
1422         switch (cdev->private->state) {
1423         case DEV_STATE_DISCONNECTED:
1424                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1425                               cdev->private->dev_id.ssid,
1426                               cdev->private->dev_id.devno);
1427                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1428                 *redo = 1;
1429                 break;
1430         case DEV_STATE_DISCONNECTED_SENSE_ID:
1431                 *redo = 1;
1432                 break;
1433         }
1434         spin_unlock_irq(cdev->ccwlock);
1435
1436         return 0;
1437 }
1438
1439 static void recovery_work_func(struct work_struct *unused)
1440 {
1441         int redo = 0;
1442
1443         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1444         if (redo) {
1445                 spin_lock_irq(&recovery_lock);
1446                 if (!timer_pending(&recovery_timer)) {
1447                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1448                                 recovery_phase++;
1449                         mod_timer(&recovery_timer, jiffies +
1450                                   recovery_delay[recovery_phase] * HZ);
1451                 }
1452                 spin_unlock_irq(&recovery_lock);
1453         } else
1454                 CIO_MSG_EVENT(4, "recovery: end\n");
1455 }
1456
1457 static DECLARE_WORK(recovery_work, recovery_work_func);
1458
1459 static void recovery_func(unsigned long data)
1460 {
1461         /*
1462          * We can't do our recovery in softirq context and it's not
1463          * performance critical, so we schedule it.
1464          */
1465         schedule_work(&recovery_work);
1466 }
1467
1468 static void ccw_device_schedule_recovery(void)
1469 {
1470         unsigned long flags;
1471
1472         CIO_MSG_EVENT(4, "recovery: schedule\n");
1473         spin_lock_irqsave(&recovery_lock, flags);
1474         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1475                 recovery_phase = 0;
1476                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1477         }
1478         spin_unlock_irqrestore(&recovery_lock, flags);
1479 }
1480
1481 static int purge_fn(struct device *dev, void *data)
1482 {
1483         struct ccw_device *cdev = to_ccwdev(dev);
1484         struct ccw_device_private *priv = cdev->private;
1485         int unreg;
1486
1487         spin_lock_irq(cdev->ccwlock);
1488         unreg = is_blacklisted(priv->dev_id.ssid, priv->dev_id.devno) &&
1489                 (priv->state == DEV_STATE_OFFLINE);
1490         spin_unlock_irq(cdev->ccwlock);
1491         if (!unreg)
1492                 goto out;
1493         if (!get_device(&cdev->dev))
1494                 goto out;
1495         CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", priv->dev_id.ssid,
1496                       priv->dev_id.devno);
1497         PREPARE_WORK(&cdev->private->kick_work, ccw_device_call_sch_unregister);
1498         queue_work(slow_path_wq, &cdev->private->kick_work);
1499
1500 out:
1501         /* Abort loop in case of pending signal. */
1502         if (signal_pending(current))
1503                 return -EINTR;
1504
1505         return 0;
1506 }
1507
1508 /**
1509  * ccw_purge_blacklisted - purge unused, blacklisted devices
1510  *
1511  * Unregister all ccw devices that are offline and on the blacklist.
1512  */
1513 int ccw_purge_blacklisted(void)
1514 {
1515         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1516         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1517         return 0;
1518 }
1519
1520 static void device_set_disconnected(struct ccw_device *cdev)
1521 {
1522         if (!cdev)
1523                 return;
1524         ccw_device_set_timeout(cdev, 0);
1525         cdev->private->flags.fake_irb = 0;
1526         cdev->private->state = DEV_STATE_DISCONNECTED;
1527         if (cdev->online)
1528                 ccw_device_schedule_recovery();
1529 }
1530
1531 void ccw_device_set_notoper(struct ccw_device *cdev)
1532 {
1533         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1534
1535         CIO_TRACE_EVENT(2, "notoper");
1536         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1537         ccw_device_set_timeout(cdev, 0);
1538         cio_disable_subchannel(sch);
1539         cdev->private->state = DEV_STATE_NOT_OPER;
1540 }
1541
1542 static int io_subchannel_sch_event(struct subchannel *sch, int slow)
1543 {
1544         int event, ret, disc;
1545         unsigned long flags;
1546         enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE, DISC } action;
1547         struct ccw_device *cdev;
1548
1549         spin_lock_irqsave(sch->lock, flags);
1550         cdev = sch_get_cdev(sch);
1551         disc = device_is_disconnected(cdev);
1552         if (disc && slow) {
1553                 /* Disconnected devices are evaluated directly only.*/
1554                 spin_unlock_irqrestore(sch->lock, flags);
1555                 return 0;
1556         }
1557         /* No interrupt after machine check - kill pending timers. */
1558         if (cdev)
1559                 ccw_device_set_timeout(cdev, 0);
1560         if (!disc && !slow) {
1561                 /* Non-disconnected devices are evaluated on the slow path. */
1562                 spin_unlock_irqrestore(sch->lock, flags);
1563                 return -EAGAIN;
1564         }
1565         event = io_subchannel_get_status(sch);
1566         CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",
1567                       sch->schid.ssid, sch->schid.sch_no, event,
1568                       disc ? "disconnected" : "normal",
1569                       slow ? "slow" : "fast");
1570         /* Analyze subchannel status. */
1571         action = NONE;
1572         switch (event) {
1573         case CIO_NO_PATH:
1574                 if (disc) {
1575                         /* Check if paths have become available. */
1576                         action = REPROBE;
1577                         break;
1578                 }
1579                 /* fall through */
1580         case CIO_GONE:
1581                 /* Ask driver what to do with device. */
1582                 if (io_subchannel_notify(sch, event))
1583                         action = DISC;
1584                 else
1585                         action = UNREGISTER;
1586                 break;
1587         case CIO_REVALIDATE:
1588                 /* Device will be removed, so no notify necessary. */
1589                 if (disc)
1590                         /* Reprobe because immediate unregister might block. */
1591                         action = REPROBE;
1592                 else
1593                         action = UNREGISTER_PROBE;
1594                 break;
1595         case CIO_OPER:
1596                 if (disc)
1597                         /* Get device operational again. */
1598                         action = REPROBE;
1599                 break;
1600         }
1601         /* Perform action. */
1602         ret = 0;
1603         switch (action) {
1604         case UNREGISTER:
1605         case UNREGISTER_PROBE:
1606                 ccw_device_set_notoper(cdev);
1607                 /* Unregister device (will use subchannel lock). */
1608                 spin_unlock_irqrestore(sch->lock, flags);
1609                 css_sch_device_unregister(sch);
1610                 spin_lock_irqsave(sch->lock, flags);
1611
1612                 /* Reset intparm to zeroes. */
1613                 sch->schib.pmcw.intparm = 0;
1614                 cio_modify(sch);
1615                 break;
1616         case REPROBE:
1617                 ccw_device_trigger_reprobe(cdev);
1618                 break;
1619         case DISC:
1620                 device_set_disconnected(cdev);
1621                 break;
1622         default:
1623                 break;
1624         }
1625         spin_unlock_irqrestore(sch->lock, flags);
1626         /* Probe if necessary. */
1627         if (action == UNREGISTER_PROBE)
1628                 ret = css_probe_device(sch->schid);
1629
1630         return ret;
1631 }
1632
1633 #ifdef CONFIG_CCW_CONSOLE
1634 static struct ccw_device console_cdev;
1635 static char console_cdev_name[10] = "0.x.xxxx";
1636 static struct ccw_device_private console_private;
1637 static int console_cdev_in_use;
1638
1639 static DEFINE_SPINLOCK(ccw_console_lock);
1640
1641 spinlock_t * cio_get_console_lock(void)
1642 {
1643         return &ccw_console_lock;
1644 }
1645
1646 static int ccw_device_console_enable(struct ccw_device *cdev,
1647                                      struct subchannel *sch)
1648 {
1649         int rc;
1650
1651         /* Attach subchannel private data. */
1652         sch->private = cio_get_console_priv();
1653         memset(sch->private, 0, sizeof(struct io_subchannel_private));
1654         io_subchannel_init_fields(sch);
1655         sch->driver = &io_subchannel_driver;
1656         /* Initialize the ccw_device structure. */
1657         cdev->dev.parent= &sch->dev;
1658         rc = io_subchannel_recog(cdev, sch);
1659         if (rc)
1660                 return rc;
1661
1662         /* Now wait for the async. recognition to come to an end. */
1663         spin_lock_irq(cdev->ccwlock);
1664         while (!dev_fsm_final_state(cdev))
1665                 wait_cons_dev();
1666         rc = -EIO;
1667         if (cdev->private->state != DEV_STATE_OFFLINE)
1668                 goto out_unlock;
1669         ccw_device_online(cdev);
1670         while (!dev_fsm_final_state(cdev))
1671                 wait_cons_dev();
1672         if (cdev->private->state != DEV_STATE_ONLINE)
1673                 goto out_unlock;
1674         rc = 0;
1675 out_unlock:
1676         spin_unlock_irq(cdev->ccwlock);
1677         return 0;
1678 }
1679
1680 struct ccw_device *
1681 ccw_device_probe_console(void)
1682 {
1683         struct subchannel *sch;
1684         int ret;
1685
1686         if (xchg(&console_cdev_in_use, 1) != 0)
1687                 return ERR_PTR(-EBUSY);
1688         sch = cio_probe_console();
1689         if (IS_ERR(sch)) {
1690                 console_cdev_in_use = 0;
1691                 return (void *) sch;
1692         }
1693         memset(&console_cdev, 0, sizeof(struct ccw_device));
1694         memset(&console_private, 0, sizeof(struct ccw_device_private));
1695         console_cdev.private = &console_private;
1696         console_private.cdev = &console_cdev;
1697         ret = ccw_device_console_enable(&console_cdev, sch);
1698         if (ret) {
1699                 cio_release_console();
1700                 console_cdev_in_use = 0;
1701                 return ERR_PTR(ret);
1702         }
1703         console_cdev.online = 1;
1704         return &console_cdev;
1705 }
1706
1707
1708 const char *cio_get_console_cdev_name(struct subchannel *sch)
1709 {
1710         snprintf(console_cdev_name, 10, "0.%x.%04x",
1711                  sch->schid.ssid, sch->schib.pmcw.dev);
1712         return (const char *)console_cdev_name;
1713 }
1714 #endif
1715
1716 /*
1717  * get ccw_device matching the busid, but only if owned by cdrv
1718  */
1719 static int
1720 __ccwdev_check_busid(struct device *dev, void *id)
1721 {
1722         char *bus_id;
1723
1724         bus_id = id;
1725
1726         return (strncmp(bus_id, dev_name(dev), BUS_ID_SIZE) == 0);
1727 }
1728
1729
1730 /**
1731  * get_ccwdev_by_busid() - obtain device from a bus id
1732  * @cdrv: driver the device is owned by
1733  * @bus_id: bus id of the device to be searched
1734  *
1735  * This function searches all devices owned by @cdrv for a device with a bus
1736  * id matching @bus_id.
1737  * Returns:
1738  *  If a match is found, its reference count of the found device is increased
1739  *  and it is returned; else %NULL is returned.
1740  */
1741 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1742                                        const char *bus_id)
1743 {
1744         struct device *dev;
1745         struct device_driver *drv;
1746
1747         drv = get_driver(&cdrv->driver);
1748         if (!drv)
1749                 return NULL;
1750
1751         dev = driver_find_device(drv, NULL, (void *)bus_id,
1752                                  __ccwdev_check_busid);
1753         put_driver(drv);
1754
1755         return dev ? to_ccwdev(dev) : NULL;
1756 }
1757
1758 /************************** device driver handling ************************/
1759
1760 /* This is the implementation of the ccw_driver class. The probe, remove
1761  * and release methods are initially very similar to the device_driver
1762  * implementations, with the difference that they have ccw_device
1763  * arguments.
1764  *
1765  * A ccw driver also contains the information that is needed for
1766  * device matching.
1767  */
1768 static int
1769 ccw_device_probe (struct device *dev)
1770 {
1771         struct ccw_device *cdev = to_ccwdev(dev);
1772         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1773         int ret;
1774
1775         cdev->drv = cdrv; /* to let the driver call _set_online */
1776
1777         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1778
1779         if (ret) {
1780                 cdev->drv = NULL;
1781                 return ret;
1782         }
1783
1784         return 0;
1785 }
1786
1787 static int
1788 ccw_device_remove (struct device *dev)
1789 {
1790         struct ccw_device *cdev = to_ccwdev(dev);
1791         struct ccw_driver *cdrv = cdev->drv;
1792         int ret;
1793
1794         if (cdrv->remove)
1795                 cdrv->remove(cdev);
1796         if (cdev->online) {
1797                 cdev->online = 0;
1798                 spin_lock_irq(cdev->ccwlock);
1799                 ret = ccw_device_offline(cdev);
1800                 spin_unlock_irq(cdev->ccwlock);
1801                 if (ret == 0)
1802                         wait_event(cdev->private->wait_q,
1803                                    dev_fsm_final_state(cdev));
1804                 else
1805                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1806                                       "device 0.%x.%04x\n",
1807                                       ret, cdev->private->dev_id.ssid,
1808                                       cdev->private->dev_id.devno);
1809         }
1810         ccw_device_set_timeout(cdev, 0);
1811         cdev->drv = NULL;
1812         return 0;
1813 }
1814
1815 static void ccw_device_shutdown(struct device *dev)
1816 {
1817         struct ccw_device *cdev;
1818
1819         cdev = to_ccwdev(dev);
1820         if (cdev->drv && cdev->drv->shutdown)
1821                 cdev->drv->shutdown(cdev);
1822         disable_cmf(cdev);
1823 }
1824
1825 struct bus_type ccw_bus_type = {
1826         .name   = "ccw",
1827         .match  = ccw_bus_match,
1828         .uevent = ccw_uevent,
1829         .probe  = ccw_device_probe,
1830         .remove = ccw_device_remove,
1831         .shutdown = ccw_device_shutdown,
1832 };
1833
1834 /**
1835  * ccw_driver_register() - register a ccw driver
1836  * @cdriver: driver to be registered
1837  *
1838  * This function is mainly a wrapper around driver_register().
1839  * Returns:
1840  *   %0 on success and a negative error value on failure.
1841  */
1842 int ccw_driver_register(struct ccw_driver *cdriver)
1843 {
1844         struct device_driver *drv = &cdriver->driver;
1845
1846         drv->bus = &ccw_bus_type;
1847         drv->name = cdriver->name;
1848         drv->owner = cdriver->owner;
1849
1850         return driver_register(drv);
1851 }
1852
1853 /**
1854  * ccw_driver_unregister() - deregister a ccw driver
1855  * @cdriver: driver to be deregistered
1856  *
1857  * This function is mainly a wrapper around driver_unregister().
1858  */
1859 void ccw_driver_unregister(struct ccw_driver *cdriver)
1860 {
1861         driver_unregister(&cdriver->driver);
1862 }
1863
1864 /* Helper func for qdio. */
1865 struct subchannel_id
1866 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1867 {
1868         struct subchannel *sch;
1869
1870         sch = to_subchannel(cdev->dev.parent);
1871         return sch->schid;
1872 }
1873
1874 MODULE_LICENSE("GPL");
1875 EXPORT_SYMBOL(ccw_device_set_online);
1876 EXPORT_SYMBOL(ccw_device_set_offline);
1877 EXPORT_SYMBOL(ccw_driver_register);
1878 EXPORT_SYMBOL(ccw_driver_unregister);
1879 EXPORT_SYMBOL(get_ccwdev_by_busid);
1880 EXPORT_SYMBOL(ccw_bus_type);
1881 EXPORT_SYMBOL(ccw_device_work);
1882 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);