drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *
   5  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
   6  *                       IBM Corporation
   7  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   8  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   9  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
  10  */
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/errno.h>
  15 #include <linux/err.h>
  16 #include <linux/slab.h>
  17 #include <linux/list.h>
  18 #include <linux/device.h>
  19 #include <linux/workqueue.h>
  20
  21 #include <asm/ccwdev.h>
  22 #include <asm/cio.h>
  23 #include <asm/param.h>          /* HZ */
  24
  25 #include "cio.h"
  26 #include "cio_debug.h"
  27 #include "css.h"
  28 #include "device.h"
  29 #include "ioasm.h"
  30
  31 /******************* bus type handling ***********************/
  32
  33 /* The Linux driver model distinguishes between a bus type and
  34  * the bus itself. Of course we only have one channel
  35  * subsystem driver and one channel system per machine, but
  36  * we still use the abstraction. T.R. says it's a good idea. */
  37 static int
  38 ccw_bus_match (struct device * dev, struct device_driver * drv)
  39 {
  40         struct ccw_device *cdev = to_ccwdev(dev);
  41         struct ccw_driver *cdrv = to_ccwdrv(drv);
  42         const struct ccw_device_id *ids = cdrv->ids, *found;
  43
  44         if (!ids)
  45                 return 0;
  46
  47         found = ccw_device_id_match(ids, &cdev->id);
  48         if (!found)
  49                 return 0;
  50
  51         cdev->id.driver_info = found->driver_info;
  52
  53         return 1;
  54 }
  55
  56 /* Store modalias string delimited by prefix/suffix string into buffer with
  57  * specified size. Return length of resulting string (excluding trailing '\0')
  58  * even if string doesn't fit buffer (snprintf semantics). */
  59 static int snprint_alias(char *buf, size_t size,
  60                          struct ccw_device_id *id, const char *suffix)
  61 {
  62         int len;
  63
  64         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  65         if (len > size)
  66                 return len;
  67         buf += len;
  68         size -= len;
  69
  70         if (id->dev_type != 0)
  71                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  72                                 id->dev_model, suffix);
  73         else
  74                 len += snprintf(buf, size, "dtdm%s", suffix);
  75
  76         return len;
  77 }
  78
  79 /* Set up environment variables for ccw device uevent. Return 0 on success,
  80  * non-zero otherwise. */
  81 static int ccw_uevent(struct device *dev, char **envp, int num_envp,
  82                       char *buffer, int buffer_size)
  83 {
  84         struct ccw_device *cdev = to_ccwdev(dev);
  85         struct ccw_device_id *id = &(cdev->id);
  86         int i = 0;
  87         int len = 0;
  88         int ret;
  89         char modalias_buf[30];
  90
  91         /* CU_TYPE= */
  92         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
  93                              "CU_TYPE=%04X", id->cu_type);
  94         if (ret)
  95                 return ret;
  96
  97         /* CU_MODEL= */
  98         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
  99                              "CU_MODEL=%02X", id->cu_model);
 100         if (ret)
 101                 return ret;
 102
 103         /* The next two can be zero, that's ok for us */
 104         /* DEV_TYPE= */
 105         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
 106                              "DEV_TYPE=%04X", id->dev_type);
 107         if (ret)
 108                 return ret;
 109
 110         /* DEV_MODEL= */
 111         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
 112                              "DEV_MODEL=%02X", id->dev_model);
 113         if (ret)
 114                 return ret;
 115
 116         /* MODALIAS=  */
 117         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 118         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
 119                              "MODALIAS=%s", modalias_buf);
 120         return ret;
 121 }
 122
 123 struct bus_type ccw_bus_type;
 124
 125 static int io_subchannel_probe (struct subchannel *);
 126 static int io_subchannel_remove (struct subchannel *);
 127 static int io_subchannel_notify(struct device *, int);
 128 static void io_subchannel_verify(struct device *);
 129 static void io_subchannel_ioterm(struct device *);
 130 static void io_subchannel_shutdown(struct subchannel *);
 131
 132 static struct css_driver io_subchannel_driver = {
 133         .subchannel_type = SUBCHANNEL_TYPE_IO,
 134         .drv = {
 135                 .name = "io_subchannel",
 136                 .bus  = &css_bus_type,
 137         },
 138         .irq = io_subchannel_irq,
 139         .notify = io_subchannel_notify,
 140         .verify = io_subchannel_verify,
 141         .termination = io_subchannel_ioterm,
 142         .probe = io_subchannel_probe,
 143         .remove = io_subchannel_remove,
 144         .shutdown = io_subchannel_shutdown,
 145 };
 146
 147 struct workqueue_struct *ccw_device_work;
 148 struct workqueue_struct *ccw_device_notify_work;
 149 wait_queue_head_t ccw_device_init_wq;
 150 atomic_t ccw_device_init_count;
 151
 152 static int __init
 153 init_ccw_bus_type (void)
 154 {
 155         int ret;
 156
 157         init_waitqueue_head(&ccw_device_init_wq);
 158         atomic_set(&ccw_device_init_count, 0);
 159
 160         ccw_device_work = create_singlethread_workqueue("cio");
 161         if (!ccw_device_work)
 162                 return -ENOMEM; /* FIXME: better errno ? */
 163         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
 164         if (!ccw_device_notify_work) {
 165                 ret = -ENOMEM; /* FIXME: better errno ? */
 166                 goto out_err;
 167         }
 168         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 169         if (!slow_path_wq) {
 170                 ret = -ENOMEM; /* FIXME: better errno ? */
 171                 goto out_err;
 172         }
 173         if ((ret = bus_register (&ccw_bus_type)))
 174                 goto out_err;
 175
 176         if ((ret = driver_register(&io_subchannel_driver.drv)))
 177                 goto out_err;
 178
 179         wait_event(ccw_device_init_wq,
 180                    atomic_read(&ccw_device_init_count) == 0);
 181         flush_workqueue(ccw_device_work);
 182         return 0;
 183 out_err:
 184         if (ccw_device_work)
 185                 destroy_workqueue(ccw_device_work);
 186         if (ccw_device_notify_work)
 187                 destroy_workqueue(ccw_device_notify_work);
 188         if (slow_path_wq)
 189                 destroy_workqueue(slow_path_wq);
 190         return ret;
 191 }
 192
 193 static void __exit
 194 cleanup_ccw_bus_type (void)
 195 {
 196         driver_unregister(&io_subchannel_driver.drv);
 197         bus_unregister(&ccw_bus_type);
 198         destroy_workqueue(ccw_device_notify_work);
 199         destroy_workqueue(ccw_device_work);
 200 }
 201
 202 subsys_initcall(init_ccw_bus_type);
 203 module_exit(cleanup_ccw_bus_type);
 204
 205 /************************ device handling **************************/
 206
 207 /*
 208  * A ccw_device has some interfaces in sysfs in addition to the
 209  * standard ones.
 210  * The following entries are designed to export the information which
 211  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 212  * are obvious, so they don't have an entry :)
 213  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 214  */
 215 static ssize_t
 216 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 217 {
 218         struct subchannel *sch = to_subchannel(dev);
 219         struct chsc_ssd_info *ssd = &sch->ssd_info;
 220         ssize_t ret = 0;
 221         int chp;
 222         int mask;
 223
 224         for (chp = 0; chp < 8; chp++) {
 225                 mask = 0x80 >> chp;
 226                 if (ssd->path_mask & mask)
 227                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 228                 else
 229                         ret += sprintf(buf + ret, "00 ");
 230         }
 231         ret += sprintf (buf+ret, "\n");
 232         return min((ssize_t)PAGE_SIZE, ret);
 233 }
 234
 235 static ssize_t
 236 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 237 {
 238         struct subchannel *sch = to_subchannel(dev);
 239         struct pmcw *pmcw = &sch->schib.pmcw;
 240
 241         return sprintf (buf, "%02x %02x %02x\n",
 242                         pmcw->pim, pmcw->pam, pmcw->pom);
 243 }
 244
 245 static ssize_t
 246 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 247 {
 248         struct ccw_device *cdev = to_ccwdev(dev);
 249         struct ccw_device_id *id = &(cdev->id);
 250
 251         if (id->dev_type != 0)
 252                 return sprintf(buf, "%04x/%02x\n",
 253                                 id->dev_type, id->dev_model);
 254         else
 255                 return sprintf(buf, "n/a\n");
 256 }
 257
 258 static ssize_t
 259 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 260 {
 261         struct ccw_device *cdev = to_ccwdev(dev);
 262         struct ccw_device_id *id = &(cdev->id);
 263
 264         return sprintf(buf, "%04x/%02x\n",
 265                        id->cu_type, id->cu_model);
 266 }
 267
 268 static ssize_t
 269 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 270 {
 271         struct ccw_device *cdev = to_ccwdev(dev);
 272         struct ccw_device_id *id = &(cdev->id);
 273         int len;
 274
 275         len = snprint_alias(buf, PAGE_SIZE, id, "\n") + 1;
 276
 277         return len > PAGE_SIZE ? PAGE_SIZE : len;
 278 }
 279
 280 static ssize_t
 281 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 282 {
 283         struct ccw_device *cdev = to_ccwdev(dev);
 284
 285         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 286 }
 287
 288 int ccw_device_is_orphan(struct ccw_device *cdev)
 289 {
 290         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 291 }
 292
 293 static void ccw_device_unregister(struct ccw_device *cdev)
 294 {
 295         if (test_and_clear_bit(1, &cdev->private->registered))
 296                 device_del(&cdev->dev);
 297 }
 298
 299 static void
 300 ccw_device_remove_disconnected(struct ccw_device *cdev)
 301 {
 302         struct subchannel *sch;
 303         unsigned long flags;
 304         /*
 305          * Forced offline in disconnected state means
 306          * 'throw away device'.
 307          */
 308         if (ccw_device_is_orphan(cdev)) {
 309                 /* Deregister ccw device. */
 310                 spin_lock_irqsave(cdev->ccwlock, flags);
 311                 cdev->private->state = DEV_STATE_NOT_OPER;
 312                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 313                 ccw_device_unregister(cdev);
 314                 put_device(&cdev->dev);
 315                 return ;
 316         }
 317         sch = to_subchannel(cdev->dev.parent);
 318         css_sch_device_unregister(sch);
 319         /* Reset intparm to zeroes. */
 320         sch->schib.pmcw.intparm = 0;
 321         cio_modify(sch);
 322         put_device(&sch->dev);
 323 }
 324
 325 int
 326 ccw_device_set_offline(struct ccw_device *cdev)
 327 {
 328         int ret;
 329
 330         if (!cdev)
 331                 return -ENODEV;
 332         if (!cdev->online || !cdev->drv)
 333                 return -EINVAL;
 334
 335         if (cdev->drv->set_offline) {
 336                 ret = cdev->drv->set_offline(cdev);
 337                 if (ret != 0)
 338                         return ret;
 339         }
 340         cdev->online = 0;
 341         spin_lock_irq(cdev->ccwlock);
 342         ret = ccw_device_offline(cdev);
 343         if (ret == -ENODEV) {
 344                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 345                         cdev->private->state = DEV_STATE_OFFLINE;
 346                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 347                 }
 348                 spin_unlock_irq(cdev->ccwlock);
 349                 return ret;
 350         }
 351         spin_unlock_irq(cdev->ccwlock);
 352         if (ret == 0)
 353                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 354         else {
 355                 pr_debug("ccw_device_offline returned %d, device %s\n",
 356                          ret, cdev->dev.bus_id);
 357                 cdev->online = 1;
 358         }
 359         return ret;
 360 }
 361
 362 int
 363 ccw_device_set_online(struct ccw_device *cdev)
 364 {
 365         int ret;
 366
 367         if (!cdev)
 368                 return -ENODEV;
 369         if (cdev->online || !cdev->drv)
 370                 return -EINVAL;
 371
 372         spin_lock_irq(cdev->ccwlock);
 373         ret = ccw_device_online(cdev);
 374         spin_unlock_irq(cdev->ccwlock);
 375         if (ret == 0)
 376                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 377         else {
 378                 pr_debug("ccw_device_online returned %d, device %s\n",
 379                          ret, cdev->dev.bus_id);
 380                 return ret;
 381         }
 382         if (cdev->private->state != DEV_STATE_ONLINE)
 383                 return -ENODEV;
 384         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 385                 cdev->online = 1;
 386                 return 0;
 387         }
 388         spin_lock_irq(cdev->ccwlock);
 389         ret = ccw_device_offline(cdev);
 390         spin_unlock_irq(cdev->ccwlock);
 391         if (ret == 0)
 392                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 393         else
 394                 pr_debug("ccw_device_offline returned %d, device %s\n",
 395                          ret, cdev->dev.bus_id);
 396         return (ret == 0) ? -ENODEV : ret;
 397 }
 398
 399 static void online_store_handle_offline(struct ccw_device *cdev)
 400 {
 401         if (cdev->private->state == DEV_STATE_DISCONNECTED)
 402                 ccw_device_remove_disconnected(cdev);
 403         else if (cdev->drv && cdev->drv->set_offline)
 404                 ccw_device_set_offline(cdev);
 405 }
 406
 407 static int online_store_recog_and_online(struct ccw_device *cdev)
 408 {
 409         int ret;
 410
 411         /* Do device recognition, if needed. */
 412         if (cdev->id.cu_type == 0) {
 413                 ret = ccw_device_recognition(cdev);
 414                 if (ret) {
 415                         printk(KERN_WARNING"Couldn't start recognition "
 416                                "for device %s (ret=%d)\n",
 417                                cdev->dev.bus_id, ret);
 418                         return ret;
 419                 }
 420                 wait_event(cdev->private->wait_q,
 421                            cdev->private->flags.recog_done);
 422         }
 423         if (cdev->drv && cdev->drv->set_online)
 424                 ccw_device_set_online(cdev);
 425         return 0;
 426 }
 427 static void online_store_handle_online(struct ccw_device *cdev, int force)
 428 {
 429         int ret;
 430
 431         ret = online_store_recog_and_online(cdev);
 432         if (ret)
 433                 return;
 434         if (force && cdev->private->state == DEV_STATE_BOXED) {
 435                 ret = ccw_device_stlck(cdev);
 436                 if (ret) {
 437                         printk(KERN_WARNING"ccw_device_stlck for device %s "
 438                                "returned %d!\n", cdev->dev.bus_id, ret);
 439                         return;
 440                 }
 441                 if (cdev->id.cu_type == 0)
 442                         cdev->private->state = DEV_STATE_NOT_OPER;
 443                 online_store_recog_and_online(cdev);
 444         }
 445
 446 }
 447
 448 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 449                              const char *buf, size_t count)
 450 {
 451         struct ccw_device *cdev = to_ccwdev(dev);
 452         int i, force;
 453         char *tmp;
 454
 455         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 456                 return -EAGAIN;
 457
 458         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 459                 atomic_set(&cdev->private->onoff, 0);
 460                 return -EINVAL;
 461         }
 462         if (!strncmp(buf, "force\n", count)) {
 463                 force = 1;
 464                 i = 1;
 465         } else {
 466                 force = 0;
 467                 i = simple_strtoul(buf, &tmp, 16);
 468         }
 469
 470         switch (i) {
 471         case 0:
 472                 online_store_handle_offline(cdev);
 473                 break;
 474         case 1:
 475                 online_store_handle_online(cdev, force);
 476                 break;
 477         default:
 478                 count = -EINVAL;
 479         }
 480         if (cdev->drv)
 481                 module_put(cdev->drv->owner);
 482         atomic_set(&cdev->private->onoff, 0);
 483         return count;
 484 }
 485
 486 static ssize_t
 487 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 488 {
 489         struct ccw_device *cdev = to_ccwdev(dev);
 490         struct subchannel *sch;
 491
 492         if (ccw_device_is_orphan(cdev))
 493                 return sprintf(buf, "no device\n");
 494         switch (cdev->private->state) {
 495         case DEV_STATE_BOXED:
 496                 return sprintf(buf, "boxed\n");
 497         case DEV_STATE_DISCONNECTED:
 498         case DEV_STATE_DISCONNECTED_SENSE_ID:
 499         case DEV_STATE_NOT_OPER:
 500                 sch = to_subchannel(dev->parent);
 501                 if (!sch->lpm)
 502                         return sprintf(buf, "no path\n");
 503                 else
 504                         return sprintf(buf, "no device\n");
 505         default:
 506                 /* All other states considered fine. */
 507                 return sprintf(buf, "good\n");
 508         }
 509 }
 510
 511 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 512 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 513 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 514 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 515 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 516 static DEVICE_ATTR(online, 0644, online_show, online_store);
 517 extern struct device_attribute dev_attr_cmb_enable;
 518 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 519
 520 static struct attribute * subch_attrs[] = {
 521         &dev_attr_chpids.attr,
 522         &dev_attr_pimpampom.attr,
 523         NULL,
 524 };
 525
 526 static struct attribute_group subch_attr_group = {
 527         .attrs = subch_attrs,
 528 };
 529
 530 struct attribute_group *subch_attr_groups[] = {
 531         &subch_attr_group,
 532         NULL,
 533 };
 534
 535 static struct attribute * ccwdev_attrs[] = {
 536         &dev_attr_devtype.attr,
 537         &dev_attr_cutype.attr,
 538         &dev_attr_modalias.attr,
 539         &dev_attr_online.attr,
 540         &dev_attr_cmb_enable.attr,
 541         &dev_attr_availability.attr,
 542         NULL,
 543 };
 544
 545 static struct attribute_group ccwdev_attr_group = {
 546         .attrs = ccwdev_attrs,
 547 };
 548
 549 static struct attribute_group *ccwdev_attr_groups[] = {
 550         &ccwdev_attr_group,
 551         NULL,
 552 };
 553
 554 /* this is a simple abstraction for device_register that sets the
 555  * correct bus type and adds the bus specific files */
 556 static int ccw_device_register(struct ccw_device *cdev)
 557 {
 558         struct device *dev = &cdev->dev;
 559         int ret;
 560
 561         dev->bus = &ccw_bus_type;
 562
 563         if ((ret = device_add(dev)))
 564                 return ret;
 565
 566         set_bit(1, &cdev->private->registered);
 567         return ret;
 568 }
 569
 570 struct match_data {
 571         struct ccw_dev_id dev_id;
 572         struct ccw_device * sibling;
 573 };
 574
 575 static int
 576 match_devno(struct device * dev, void * data)
 577 {
 578         struct match_data * d = data;
 579         struct ccw_device * cdev;
 580
 581         cdev = to_ccwdev(dev);
 582         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 583             !ccw_device_is_orphan(cdev) &&
 584             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 585             (cdev != d->sibling))
 586                 return 1;
 587         return 0;
 588 }
 589
 590 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 591                                                      struct ccw_device *sibling)
 592 {
 593         struct device *dev;
 594         struct match_data data;
 595
 596         data.dev_id = *dev_id;
 597         data.sibling = sibling;
 598         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 599
 600         return dev ? to_ccwdev(dev) : NULL;
 601 }
 602
 603 static int match_orphan(struct device *dev, void *data)
 604 {
 605         struct ccw_dev_id *dev_id;
 606         struct ccw_device *cdev;
 607
 608         dev_id = data;
 609         cdev = to_ccwdev(dev);
 610         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 611 }
 612
 613 static struct ccw_device *
 614 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 615                               struct ccw_dev_id *dev_id)
 616 {
 617         struct device *dev;
 618
 619         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 620                                 match_orphan);
 621
 622         return dev ? to_ccwdev(dev) : NULL;
 623 }
 624
 625 static void
 626 ccw_device_add_changed(struct work_struct *work)
 627 {
 628         struct ccw_device_private *priv;
 629         struct ccw_device *cdev;
 630
 631         priv = container_of(work, struct ccw_device_private, kick_work);
 632         cdev = priv->cdev;
 633         if (device_add(&cdev->dev)) {
 634                 put_device(&cdev->dev);
 635                 return;
 636         }
 637         set_bit(1, &cdev->private->registered);
 638 }
 639
 640 void ccw_device_do_unreg_rereg(struct work_struct *work)
 641 {
 642         struct ccw_device_private *priv;
 643         struct ccw_device *cdev;
 644         struct subchannel *sch;
 645
 646         priv = container_of(work, struct ccw_device_private, kick_work);
 647         cdev = priv->cdev;
 648         sch = to_subchannel(cdev->dev.parent);
 649
 650         ccw_device_unregister(cdev);
 651         PREPARE_WORK(&cdev->private->kick_work,
 652                      ccw_device_add_changed);
 653         queue_work(ccw_device_work, &cdev->private->kick_work);
 654 }
 655
 656 static void
 657 ccw_device_release(struct device *dev)
 658 {
 659         struct ccw_device *cdev;
 660
 661         cdev = to_ccwdev(dev);
 662         kfree(cdev->private);
 663         kfree(cdev);
 664 }
 665
 666 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 667 {
 668         struct ccw_device *cdev;
 669
 670         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 671         if (cdev) {
 672                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 673                                         GFP_KERNEL | GFP_DMA);
 674                 if (cdev->private)
 675                         return cdev;
 676         }
 677         kfree(cdev);
 678         return ERR_PTR(-ENOMEM);
 679 }
 680
 681 static int io_subchannel_initialize_dev(struct subchannel *sch,
 682                                         struct ccw_device *cdev)
 683 {
 684         cdev->private->cdev = cdev;
 685         atomic_set(&cdev->private->onoff, 0);
 686         cdev->dev.parent = &sch->dev;
 687         cdev->dev.release = ccw_device_release;
 688         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 689         cdev->dev.groups = ccwdev_attr_groups;
 690         /* Do first half of device_register. */
 691         device_initialize(&cdev->dev);
 692         if (!get_device(&sch->dev)) {
 693                 if (cdev->dev.release)
 694                         cdev->dev.release(&cdev->dev);
 695                 return -ENODEV;
 696         }
 697         return 0;
 698 }
 699
 700 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 701 {
 702         struct ccw_device *cdev;
 703         int ret;
 704
 705         cdev = io_subchannel_allocate_dev(sch);
 706         if (!IS_ERR(cdev)) {
 707                 ret = io_subchannel_initialize_dev(sch, cdev);
 708                 if (ret) {
 709                         kfree(cdev);
 710                         cdev = ERR_PTR(ret);
 711                 }
 712         }
 713         return cdev;
 714 }
 715
 716 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 717
 718 static void sch_attach_device(struct subchannel *sch,
 719                               struct ccw_device *cdev)
 720 {
 721         css_update_ssd_info(sch);
 722         spin_lock_irq(sch->lock);
 723         sch->dev.driver_data = cdev;
 724         cdev->private->schid = sch->schid;
 725         cdev->ccwlock = sch->lock;
 726         device_trigger_reprobe(sch);
 727         spin_unlock_irq(sch->lock);
 728 }
 729
 730 static void sch_attach_disconnected_device(struct subchannel *sch,
 731                                            struct ccw_device *cdev)
 732 {
 733         struct subchannel *other_sch;
 734         int ret;
 735
 736         other_sch = to_subchannel(get_device(cdev->dev.parent));
 737         ret = device_move(&cdev->dev, &sch->dev);
 738         if (ret) {
 739                 CIO_MSG_EVENT(2, "Moving disconnected device 0.%x.%04x failed "
 740                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 741                               cdev->private->dev_id.devno, ret);
 742                 put_device(&other_sch->dev);
 743                 return;
 744         }
 745         other_sch->dev.driver_data = NULL;
 746         /* No need to keep a subchannel without ccw device around. */
 747         css_sch_device_unregister(other_sch);
 748         put_device(&other_sch->dev);
 749         sch_attach_device(sch, cdev);
 750 }
 751
 752 static void sch_attach_orphaned_device(struct subchannel *sch,
 753                                        struct ccw_device *cdev)
 754 {
 755         int ret;
 756
 757         /* Try to move the ccw device to its new subchannel. */
 758         ret = device_move(&cdev->dev, &sch->dev);
 759         if (ret) {
 760                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 761                               "failed (ret=%d)!\n",
 762                               cdev->private->dev_id.ssid,
 763                               cdev->private->dev_id.devno, ret);
 764                 return;
 765         }
 766         sch_attach_device(sch, cdev);
 767 }
 768
 769 static void sch_create_and_recog_new_device(struct subchannel *sch)
 770 {
 771         struct ccw_device *cdev;
 772
 773         /* Need to allocate a new ccw device. */
 774         cdev = io_subchannel_create_ccwdev(sch);
 775         if (IS_ERR(cdev)) {
 776                 /* OK, we did everything we could... */
 777                 css_sch_device_unregister(sch);
 778                 return;
 779         }
 780         spin_lock_irq(sch->lock);
 781         sch->dev.driver_data = cdev;
 782         spin_unlock_irq(sch->lock);
 783         /* Start recognition for the new ccw device. */
 784         if (io_subchannel_recog(cdev, sch)) {
 785                 spin_lock_irq(sch->lock);
 786                 sch->dev.driver_data = NULL;
 787                 spin_unlock_irq(sch->lock);
 788                 if (cdev->dev.release)
 789                         cdev->dev.release(&cdev->dev);
 790                 css_sch_device_unregister(sch);
 791         }
 792 }
 793
 794
 795 void ccw_device_move_to_orphanage(struct work_struct *work)
 796 {
 797         struct ccw_device_private *priv;
 798         struct ccw_device *cdev;
 799         struct ccw_device *replacing_cdev;
 800         struct subchannel *sch;
 801         int ret;
 802         struct channel_subsystem *css;
 803         struct ccw_dev_id dev_id;
 804
 805         priv = container_of(work, struct ccw_device_private, kick_work);
 806         cdev = priv->cdev;
 807         sch = to_subchannel(cdev->dev.parent);
 808         css = to_css(sch->dev.parent);
 809         dev_id.devno = sch->schib.pmcw.dev;
 810         dev_id.ssid = sch->schid.ssid;
 811
 812         /*
 813          * Move the orphaned ccw device to the orphanage so the replacing
 814          * ccw device can take its place on the subchannel.
 815          */
 816         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
 817         if (ret) {
 818                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 819                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 820                               cdev->private->dev_id.devno, ret);
 821                 return;
 822         }
 823         cdev->ccwlock = css->pseudo_subchannel->lock;
 824         /*
 825          * Search for the replacing ccw device
 826          * - among the disconnected devices
 827          * - in the orphanage
 828          */
 829         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 830         if (replacing_cdev) {
 831                 sch_attach_disconnected_device(sch, replacing_cdev);
 832                 return;
 833         }
 834         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 835         if (replacing_cdev) {
 836                 sch_attach_orphaned_device(sch, replacing_cdev);
 837                 return;
 838         }
 839         sch_create_and_recog_new_device(sch);
 840 }
 841
 842 /*
 843  * Register recognized device.
 844  */
 845 static void
 846 io_subchannel_register(struct work_struct *work)
 847 {
 848         struct ccw_device_private *priv;
 849         struct ccw_device *cdev;
 850         struct subchannel *sch;
 851         int ret;
 852         unsigned long flags;
 853
 854         priv = container_of(work, struct ccw_device_private, kick_work);
 855         cdev = priv->cdev;
 856         sch = to_subchannel(cdev->dev.parent);
 857         css_update_ssd_info(sch);
 858         /*
 859          * io_subchannel_register() will also be called after device
 860          * recognition has been done for a boxed device (which will already
 861          * be registered). We need to reprobe since we may now have sense id
 862          * information.
 863          */
 864         if (klist_node_attached(&cdev->dev.knode_parent)) {
 865                 if (!cdev->drv) {
 866                         ret = device_reprobe(&cdev->dev);
 867                         if (ret)
 868                                 /* We can't do much here. */
 869                                 dev_info(&cdev->dev, "device_reprobe() returned"
 870                                          " %d\n", ret);
 871                 }
 872                 goto out;
 873         }
 874         /*
 875          * Now we know this subchannel will stay, we can throw
 876          * our delayed uevent.
 877          */
 878         sch->dev.uevent_suppress = 0;
 879         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 880         /* make it known to the system */
 881         ret = ccw_device_register(cdev);
 882         if (ret) {
 883                 printk (KERN_WARNING "%s: could not register %s\n",
 884                         __func__, cdev->dev.bus_id);
 885                 put_device(&cdev->dev);
 886                 spin_lock_irqsave(sch->lock, flags);
 887                 sch->dev.driver_data = NULL;
 888                 spin_unlock_irqrestore(sch->lock, flags);
 889                 kfree (cdev->private);
 890                 kfree (cdev);
 891                 put_device(&sch->dev);
 892                 if (atomic_dec_and_test(&ccw_device_init_count))
 893                         wake_up(&ccw_device_init_wq);
 894                 return;
 895         }
 896         put_device(&cdev->dev);
 897 out:
 898         cdev->private->flags.recog_done = 1;
 899         put_device(&sch->dev);
 900         wake_up(&cdev->private->wait_q);
 901         if (atomic_dec_and_test(&ccw_device_init_count))
 902                 wake_up(&ccw_device_init_wq);
 903 }
 904
 905 void
 906 ccw_device_call_sch_unregister(struct work_struct *work)
 907 {
 908         struct ccw_device_private *priv;
 909         struct ccw_device *cdev;
 910         struct subchannel *sch;
 911
 912         priv = container_of(work, struct ccw_device_private, kick_work);
 913         cdev = priv->cdev;
 914         sch = to_subchannel(cdev->dev.parent);
 915         css_sch_device_unregister(sch);
 916         /* Reset intparm to zeroes. */
 917         sch->schib.pmcw.intparm = 0;
 918         cio_modify(sch);
 919         put_device(&cdev->dev);
 920         put_device(&sch->dev);
 921 }
 922
 923 /*
 924  * subchannel recognition done. Called from the state machine.
 925  */
 926 void
 927 io_subchannel_recog_done(struct ccw_device *cdev)
 928 {
 929         struct subchannel *sch;
 930
 931         if (css_init_done == 0) {
 932                 cdev->private->flags.recog_done = 1;
 933                 return;
 934         }
 935         switch (cdev->private->state) {
 936         case DEV_STATE_NOT_OPER:
 937                 cdev->private->flags.recog_done = 1;
 938                 /* Remove device found not operational. */
 939                 if (!get_device(&cdev->dev))
 940                         break;
 941                 sch = to_subchannel(cdev->dev.parent);
 942                 PREPARE_WORK(&cdev->private->kick_work,
 943                              ccw_device_call_sch_unregister);
 944                 queue_work(slow_path_wq, &cdev->private->kick_work);
 945                 if (atomic_dec_and_test(&ccw_device_init_count))
 946                         wake_up(&ccw_device_init_wq);
 947                 break;
 948         case DEV_STATE_BOXED:
 949                 /* Device did not respond in time. */
 950         case DEV_STATE_OFFLINE:
 951                 /*
 952                  * We can't register the device in interrupt context so
 953                  * we schedule a work item.
 954                  */
 955                 if (!get_device(&cdev->dev))
 956                         break;
 957                 PREPARE_WORK(&cdev->private->kick_work,
 958                              io_subchannel_register);
 959                 queue_work(slow_path_wq, &cdev->private->kick_work);
 960                 break;
 961         }
 962 }
 963
 964 static int
 965 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 966 {
 967         int rc;
 968         struct ccw_device_private *priv;
 969
 970         sch->dev.driver_data = cdev;
 971         sch->driver = &io_subchannel_driver;
 972         cdev->ccwlock = sch->lock;
 973
 974         /* Init private data. */
 975         priv = cdev->private;
 976         priv->dev_id.devno = sch->schib.pmcw.dev;
 977         priv->dev_id.ssid = sch->schid.ssid;
 978         priv->schid = sch->schid;
 979         priv->state = DEV_STATE_NOT_OPER;
 980         INIT_LIST_HEAD(&priv->cmb_list);
 981         init_waitqueue_head(&priv->wait_q);
 982         init_timer(&priv->timer);
 983
 984         /* Set an initial name for the device. */
 985         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
 986                   sch->schid.ssid, sch->schib.pmcw.dev);
 987
 988         /* Increase counter of devices currently in recognition. */
 989         atomic_inc(&ccw_device_init_count);
 990
 991         /* Start async. device sensing. */
 992         spin_lock_irq(sch->lock);
 993         rc = ccw_device_recognition(cdev);
 994         spin_unlock_irq(sch->lock);
 995         if (rc) {
 996                 if (atomic_dec_and_test(&ccw_device_init_count))
 997                         wake_up(&ccw_device_init_wq);
 998         }
 999         return rc;
1000 }
1001
1002 static void ccw_device_move_to_sch(struct work_struct *work)
1003 {
1004         struct ccw_device_private *priv;
1005         int rc;
1006         struct subchannel *sch;
1007         struct ccw_device *cdev;
1008         struct subchannel *former_parent;
1009
1010         priv = container_of(work, struct ccw_device_private, kick_work);
1011         sch = priv->sch;
1012         cdev = priv->cdev;
1013         former_parent = ccw_device_is_orphan(cdev) ?
1014                 NULL : to_subchannel(get_device(cdev->dev.parent));
1015         mutex_lock(&sch->reg_mutex);
1016         /* Try to move the ccw device to its new subchannel. */
1017         rc = device_move(&cdev->dev, &sch->dev);
1018         mutex_unlock(&sch->reg_mutex);
1019         if (rc) {
1020                 CIO_MSG_EVENT(2, "Moving device 0.%x.%04x to subchannel "
1021                               "0.%x.%04x failed (ret=%d)!\n",
1022                               cdev->private->dev_id.ssid,
1023                               cdev->private->dev_id.devno, sch->schid.ssid,
1024                               sch->schid.sch_no, rc);
1025                 css_sch_device_unregister(sch);
1026                 goto out;
1027         }
1028         if (former_parent) {
1029                 spin_lock_irq(former_parent->lock);
1030                 former_parent->dev.driver_data = NULL;
1031                 spin_unlock_irq(former_parent->lock);
1032                 css_sch_device_unregister(former_parent);
1033                 /* Reset intparm to zeroes. */
1034                 former_parent->schib.pmcw.intparm = 0;
1035                 cio_modify(former_parent);
1036         }
1037         sch_attach_device(sch, cdev);
1038 out:
1039         if (former_parent)
1040                 put_device(&former_parent->dev);
1041         put_device(&cdev->dev);
1042 }
1043
1044 static int
1045 io_subchannel_probe (struct subchannel *sch)
1046 {
1047         struct ccw_device *cdev;
1048         int rc;
1049         unsigned long flags;
1050         struct ccw_dev_id dev_id;
1051
1052         if (sch->dev.driver_data) {
1053                 /*
1054                  * This subchannel already has an associated ccw_device.
1055                  * Register it and exit. This happens for all early
1056                  * device, e.g. the console.
1057                  */
1058                 cdev = sch->dev.driver_data;
1059                 device_initialize(&cdev->dev);
1060                 ccw_device_register(cdev);
1061                 /*
1062                  * Check if the device is already online. If it is
1063                  * the reference count needs to be corrected
1064                  * (see ccw_device_online and css_init_done for the
1065                  * ugly details).
1066                  */
1067                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1068                     cdev->private->state != DEV_STATE_OFFLINE &&
1069                     cdev->private->state != DEV_STATE_BOXED)
1070                         get_device(&cdev->dev);
1071                 return 0;
1072         }
1073         /*
1074          * First check if a fitting device may be found amongst the
1075          * disconnected devices or in the orphanage.
1076          */
1077         dev_id.devno = sch->schib.pmcw.dev;
1078         dev_id.ssid = sch->schid.ssid;
1079         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1080         if (!cdev)
1081                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1082                                                      &dev_id);
1083         if (cdev) {
1084                 /*
1085                  * Schedule moving the device until when we have a registered
1086                  * subchannel to move to and succeed the probe. We can
1087                  * unregister later again, when the probe is through.
1088                  */
1089                 cdev->private->sch = sch;
1090                 PREPARE_WORK(&cdev->private->kick_work,
1091                              ccw_device_move_to_sch);
1092                 queue_work(slow_path_wq, &cdev->private->kick_work);
1093                 return 0;
1094         }
1095         cdev = io_subchannel_create_ccwdev(sch);
1096         if (IS_ERR(cdev))
1097                 return PTR_ERR(cdev);
1098
1099         rc = io_subchannel_recog(cdev, sch);
1100         if (rc) {
1101                 spin_lock_irqsave(sch->lock, flags);
1102                 sch->dev.driver_data = NULL;
1103                 spin_unlock_irqrestore(sch->lock, flags);
1104                 if (cdev->dev.release)
1105                         cdev->dev.release(&cdev->dev);
1106         }
1107
1108         return rc;
1109 }
1110
1111 static int
1112 io_subchannel_remove (struct subchannel *sch)
1113 {
1114         struct ccw_device *cdev;
1115         unsigned long flags;
1116
1117         if (!sch->dev.driver_data)
1118                 return 0;
1119         cdev = sch->dev.driver_data;
1120         /* Set ccw device to not operational and drop reference. */
1121         spin_lock_irqsave(cdev->ccwlock, flags);
1122         sch->dev.driver_data = NULL;
1123         cdev->private->state = DEV_STATE_NOT_OPER;
1124         spin_unlock_irqrestore(cdev->ccwlock, flags);
1125         ccw_device_unregister(cdev);
1126         put_device(&cdev->dev);
1127         return 0;
1128 }
1129
1130 static int
1131 io_subchannel_notify(struct device *dev, int event)
1132 {
1133         struct ccw_device *cdev;
1134
1135         cdev = dev->driver_data;
1136         if (!cdev)
1137                 return 0;
1138         if (!cdev->drv)
1139                 return 0;
1140         if (!cdev->online)
1141                 return 0;
1142         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
1143 }
1144
1145 static void
1146 io_subchannel_verify(struct device *dev)
1147 {
1148         struct ccw_device *cdev;
1149
1150         cdev = dev->driver_data;
1151         if (cdev)
1152                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1153 }
1154
1155 static void
1156 io_subchannel_ioterm(struct device *dev)
1157 {
1158         struct ccw_device *cdev;
1159
1160         cdev = dev->driver_data;
1161         if (!cdev)
1162                 return;
1163         /* Internal I/O will be retried by the interrupt handler. */
1164         if (cdev->private->flags.intretry)
1165                 return;
1166         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1167         if (cdev->handler)
1168                 cdev->handler(cdev, cdev->private->intparm,
1169                               ERR_PTR(-EIO));
1170 }
1171
1172 static void
1173 io_subchannel_shutdown(struct subchannel *sch)
1174 {
1175         struct ccw_device *cdev;
1176         int ret;
1177
1178         cdev = sch->dev.driver_data;
1179
1180         if (cio_is_console(sch->schid))
1181                 return;
1182         if (!sch->schib.pmcw.ena)
1183                 /* Nothing to do. */
1184                 return;
1185         ret = cio_disable_subchannel(sch);
1186         if (ret != -EBUSY)
1187                 /* Subchannel is disabled, we're done. */
1188                 return;
1189         cdev->private->state = DEV_STATE_QUIESCE;
1190         if (cdev->handler)
1191                 cdev->handler(cdev, cdev->private->intparm,
1192                               ERR_PTR(-EIO));
1193         ret = ccw_device_cancel_halt_clear(cdev);
1194         if (ret == -EBUSY) {
1195                 ccw_device_set_timeout(cdev, HZ/10);
1196                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1197         }
1198         cio_disable_subchannel(sch);
1199 }
1200
1201 #ifdef CONFIG_CCW_CONSOLE
1202 static struct ccw_device console_cdev;
1203 static struct ccw_device_private console_private;
1204 static int console_cdev_in_use;
1205
1206 static DEFINE_SPINLOCK(ccw_console_lock);
1207
1208 spinlock_t * cio_get_console_lock(void)
1209 {
1210         return &ccw_console_lock;
1211 }
1212
1213 static int
1214 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
1215 {
1216         int rc;
1217
1218         /* Initialize the ccw_device structure. */
1219         cdev->dev.parent= &sch->dev;
1220         rc = io_subchannel_recog(cdev, sch);
1221         if (rc)
1222                 return rc;
1223
1224         /* Now wait for the async. recognition to come to an end. */
1225         spin_lock_irq(cdev->ccwlock);
1226         while (!dev_fsm_final_state(cdev))
1227                 wait_cons_dev();
1228         rc = -EIO;
1229         if (cdev->private->state != DEV_STATE_OFFLINE)
1230                 goto out_unlock;
1231         ccw_device_online(cdev);
1232         while (!dev_fsm_final_state(cdev))
1233                 wait_cons_dev();
1234         if (cdev->private->state != DEV_STATE_ONLINE)
1235                 goto out_unlock;
1236         rc = 0;
1237 out_unlock:
1238         spin_unlock_irq(cdev->ccwlock);
1239         return 0;
1240 }
1241
1242 struct ccw_device *
1243 ccw_device_probe_console(void)
1244 {
1245         struct subchannel *sch;
1246         int ret;
1247
1248         if (xchg(&console_cdev_in_use, 1) != 0)
1249                 return ERR_PTR(-EBUSY);
1250         sch = cio_probe_console();
1251         if (IS_ERR(sch)) {
1252                 console_cdev_in_use = 0;
1253                 return (void *) sch;
1254         }
1255         memset(&console_cdev, 0, sizeof(struct ccw_device));
1256         memset(&console_private, 0, sizeof(struct ccw_device_private));
1257         console_cdev.private = &console_private;
1258         console_private.cdev = &console_cdev;
1259         ret = ccw_device_console_enable(&console_cdev, sch);
1260         if (ret) {
1261                 cio_release_console();
1262                 console_cdev_in_use = 0;
1263                 return ERR_PTR(ret);
1264         }
1265         console_cdev.online = 1;
1266         return &console_cdev;
1267 }
1268 #endif
1269
1270 /*
1271  * get ccw_device matching the busid, but only if owned by cdrv
1272  */
1273 static int
1274 __ccwdev_check_busid(struct device *dev, void *id)
1275 {
1276         char *bus_id;
1277
1278         bus_id = id;
1279
1280         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1281 }
1282
1283
1284 struct ccw_device *
1285 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1286 {
1287         struct device *dev;
1288         struct device_driver *drv;
1289
1290         drv = get_driver(&cdrv->driver);
1291         if (!drv)
1292                 return NULL;
1293
1294         dev = driver_find_device(drv, NULL, (void *)bus_id,
1295                                  __ccwdev_check_busid);
1296         put_driver(drv);
1297
1298         return dev ? to_ccwdev(dev) : NULL;
1299 }
1300
1301 /************************** device driver handling ************************/
1302
1303 /* This is the implementation of the ccw_driver class. The probe, remove
1304  * and release methods are initially very similar to the device_driver
1305  * implementations, with the difference that they have ccw_device
1306  * arguments.
1307  *
1308  * A ccw driver also contains the information that is needed for
1309  * device matching.
1310  */
1311 static int
1312 ccw_device_probe (struct device *dev)
1313 {
1314         struct ccw_device *cdev = to_ccwdev(dev);
1315         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1316         int ret;
1317
1318         cdev->drv = cdrv; /* to let the driver call _set_online */
1319
1320         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1321
1322         if (ret) {
1323                 cdev->drv = NULL;
1324                 return ret;
1325         }
1326
1327         return 0;
1328 }
1329
1330 static int
1331 ccw_device_remove (struct device *dev)
1332 {
1333         struct ccw_device *cdev = to_ccwdev(dev);
1334         struct ccw_driver *cdrv = cdev->drv;
1335         int ret;
1336
1337         pr_debug("removing device %s\n", cdev->dev.bus_id);
1338         if (cdrv->remove)
1339                 cdrv->remove(cdev);
1340         if (cdev->online) {
1341                 cdev->online = 0;
1342                 spin_lock_irq(cdev->ccwlock);
1343                 ret = ccw_device_offline(cdev);
1344                 spin_unlock_irq(cdev->ccwlock);
1345                 if (ret == 0)
1346                         wait_event(cdev->private->wait_q,
1347                                    dev_fsm_final_state(cdev));
1348                 else
1349                         //FIXME: we can't fail!
1350                         pr_debug("ccw_device_offline returned %d, device %s\n",
1351                                  ret, cdev->dev.bus_id);
1352         }
1353         ccw_device_set_timeout(cdev, 0);
1354         cdev->drv = NULL;
1355         return 0;
1356 }
1357
1358 struct bus_type ccw_bus_type = {
1359         .name   = "ccw",
1360         .match  = ccw_bus_match,
1361         .uevent = ccw_uevent,
1362         .probe  = ccw_device_probe,
1363         .remove = ccw_device_remove,
1364 };
1365
1366 int
1367 ccw_driver_register (struct ccw_driver *cdriver)
1368 {
1369         struct device_driver *drv = &cdriver->driver;
1370
1371         drv->bus = &ccw_bus_type;
1372         drv->name = cdriver->name;
1373
1374         return driver_register(drv);
1375 }
1376
1377 void
1378 ccw_driver_unregister (struct ccw_driver *cdriver)
1379 {
1380         driver_unregister(&cdriver->driver);
1381 }
1382
1383 /* Helper func for qdio. */
1384 struct subchannel_id
1385 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1386 {
1387         struct subchannel *sch;
1388
1389         sch = to_subchannel(cdev->dev.parent);
1390         return sch->schid;
1391 }
1392
1393 MODULE_LICENSE("GPL");
1394 EXPORT_SYMBOL(ccw_device_set_online);
1395 EXPORT_SYMBOL(ccw_device_set_offline);
1396 EXPORT_SYMBOL(ccw_driver_register);
1397 EXPORT_SYMBOL(ccw_driver_unregister);
1398 EXPORT_SYMBOL(get_ccwdev_by_busid);
1399 EXPORT_SYMBOL(ccw_bus_type);
1400 EXPORT_SYMBOL(ccw_device_work);
1401 EXPORT_SYMBOL(ccw_device_notify_work);
1402 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);