err.no Git - linux-2.6/blob - 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 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 work_struct *work)
 294 {
 295         struct ccw_device_private *priv;
 296         struct ccw_device *cdev;
 297
 298         priv = container_of(work, struct ccw_device_private, kick_work);
 299         cdev = priv->cdev;
 300         if (test_and_clear_bit(1, &cdev->private->registered))
 301                 device_unregister(&cdev->dev);
 302         put_device(&cdev->dev);
 303 }
 304
 305 static void
 306 ccw_device_remove_disconnected(struct ccw_device *cdev)
 307 {
 308         struct subchannel *sch;
 309         unsigned long flags;
 310         /*
 311          * Forced offline in disconnected state means
 312          * 'throw away device'.
 313          */
 314         if (ccw_device_is_orphan(cdev)) {
 315                 /* Deregister ccw device. */
 316                 spin_lock_irqsave(cdev->ccwlock, flags);
 317                 cdev->private->state = DEV_STATE_NOT_OPER;
 318                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 319                 if (get_device(&cdev->dev)) {
 320                         PREPARE_WORK(&cdev->private->kick_work,
 321                                      ccw_device_unregister);
 322                         queue_work(ccw_device_work, &cdev->private->kick_work);
 323                 }
 324                 return ;
 325         }
 326         sch = to_subchannel(cdev->dev.parent);
 327         css_sch_device_unregister(sch);
 328         /* Reset intparm to zeroes. */
 329         sch->schib.pmcw.intparm = 0;
 330         cio_modify(sch);
 331         put_device(&sch->dev);
 332 }
 333
 334 int
 335 ccw_device_set_offline(struct ccw_device *cdev)
 336 {
 337         int ret;
 338
 339         if (!cdev)
 340                 return -ENODEV;
 341         if (!cdev->online || !cdev->drv)
 342                 return -EINVAL;
 343
 344         if (cdev->drv->set_offline) {
 345                 ret = cdev->drv->set_offline(cdev);
 346                 if (ret != 0)
 347                         return ret;
 348         }
 349         cdev->online = 0;
 350         spin_lock_irq(cdev->ccwlock);
 351         ret = ccw_device_offline(cdev);
 352         if (ret == -ENODEV) {
 353                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 354                         cdev->private->state = DEV_STATE_OFFLINE;
 355                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 356                 }
 357                 spin_unlock_irq(cdev->ccwlock);
 358                 return ret;
 359         }
 360         spin_unlock_irq(cdev->ccwlock);
 361         if (ret == 0)
 362                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 363         else {
 364                 pr_debug("ccw_device_offline returned %d, device %s\n",
 365                          ret, cdev->dev.bus_id);
 366                 cdev->online = 1;
 367         }
 368         return ret;
 369 }
 370
 371 int
 372 ccw_device_set_online(struct ccw_device *cdev)
 373 {
 374         int ret;
 375
 376         if (!cdev)
 377                 return -ENODEV;
 378         if (cdev->online || !cdev->drv)
 379                 return -EINVAL;
 380
 381         spin_lock_irq(cdev->ccwlock);
 382         ret = ccw_device_online(cdev);
 383         spin_unlock_irq(cdev->ccwlock);
 384         if (ret == 0)
 385                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 386         else {
 387                 pr_debug("ccw_device_online returned %d, device %s\n",
 388                          ret, cdev->dev.bus_id);
 389                 return ret;
 390         }
 391         if (cdev->private->state != DEV_STATE_ONLINE)
 392                 return -ENODEV;
 393         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 394                 cdev->online = 1;
 395                 return 0;
 396         }
 397         spin_lock_irq(cdev->ccwlock);
 398         ret = ccw_device_offline(cdev);
 399         spin_unlock_irq(cdev->ccwlock);
 400         if (ret == 0)
 401                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 402         else
 403                 pr_debug("ccw_device_offline returned %d, device %s\n",
 404                          ret, cdev->dev.bus_id);
 405         return (ret == 0) ? -ENODEV : ret;
 406 }
 407
 408 static void online_store_handle_offline(struct ccw_device *cdev)
 409 {
 410         if (cdev->private->state == DEV_STATE_DISCONNECTED)
 411                 ccw_device_remove_disconnected(cdev);
 412         else if (cdev->drv && cdev->drv->set_offline)
 413                 ccw_device_set_offline(cdev);
 414 }
 415
 416 static int online_store_recog_and_online(struct ccw_device *cdev)
 417 {
 418         int ret;
 419
 420         /* Do device recognition, if needed. */
 421         if (cdev->id.cu_type == 0) {
 422                 ret = ccw_device_recognition(cdev);
 423                 if (ret) {
 424                         printk(KERN_WARNING"Couldn't start recognition "
 425                                "for device %s (ret=%d)\n",
 426                                cdev->dev.bus_id, ret);
 427                         return ret;
 428                 }
 429                 wait_event(cdev->private->wait_q,
 430                            cdev->private->flags.recog_done);
 431         }
 432         if (cdev->drv && cdev->drv->set_online)
 433                 ccw_device_set_online(cdev);
 434         return 0;
 435 }
 436 static void online_store_handle_online(struct ccw_device *cdev, int force)
 437 {
 438         int ret;
 439
 440         ret = online_store_recog_and_online(cdev);
 441         if (ret)
 442                 return;
 443         if (force && cdev->private->state == DEV_STATE_BOXED) {
 444                 ret = ccw_device_stlck(cdev);
 445                 if (ret) {
 446                         printk(KERN_WARNING"ccw_device_stlck for device %s "
 447                                "returned %d!\n", cdev->dev.bus_id, ret);
 448                         return;
 449                 }
 450                 if (cdev->id.cu_type == 0)
 451                         cdev->private->state = DEV_STATE_NOT_OPER;
 452                 online_store_recog_and_online(cdev);
 453         }
 454
 455 }
 456
 457 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 458                              const char *buf, size_t count)
 459 {
 460         struct ccw_device *cdev = to_ccwdev(dev);
 461         int i, force;
 462         char *tmp;
 463
 464         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 465                 return -EAGAIN;
 466
 467         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 468                 atomic_set(&cdev->private->onoff, 0);
 469                 return -EINVAL;
 470         }
 471         if (!strncmp(buf, "force\n", count)) {
 472                 force = 1;
 473                 i = 1;
 474         } else {
 475                 force = 0;
 476                 i = simple_strtoul(buf, &tmp, 16);
 477         }
 478
 479         switch (i) {
 480         case 0:
 481                 online_store_handle_offline(cdev);
 482                 break;
 483         case 1:
 484                 online_store_handle_online(cdev, force);
 485                 break;
 486         default:
 487                 count = -EINVAL;
 488         }
 489         if (cdev->drv)
 490                 module_put(cdev->drv->owner);
 491         atomic_set(&cdev->private->onoff, 0);
 492         return count;
 493 }
 494
 495 static ssize_t
 496 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 497 {
 498         struct ccw_device *cdev = to_ccwdev(dev);
 499         struct subchannel *sch;
 500
 501         if (ccw_device_is_orphan(cdev))
 502                 return sprintf(buf, "no device\n");
 503         switch (cdev->private->state) {
 504         case DEV_STATE_BOXED:
 505                 return sprintf(buf, "boxed\n");
 506         case DEV_STATE_DISCONNECTED:
 507         case DEV_STATE_DISCONNECTED_SENSE_ID:
 508         case DEV_STATE_NOT_OPER:
 509                 sch = to_subchannel(dev->parent);
 510                 if (!sch->lpm)
 511                         return sprintf(buf, "no path\n");
 512                 else
 513                         return sprintf(buf, "no device\n");
 514         default:
 515                 /* All other states considered fine. */
 516                 return sprintf(buf, "good\n");
 517         }
 518 }
 519
 520 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 521 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 522 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 523 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 524 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 525 static DEVICE_ATTR(online, 0644, online_show, online_store);
 526 extern struct device_attribute dev_attr_cmb_enable;
 527 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 528
 529 static struct attribute * subch_attrs[] = {
 530         &dev_attr_chpids.attr,
 531         &dev_attr_pimpampom.attr,
 532         NULL,
 533 };
 534
 535 static struct attribute_group subch_attr_group = {
 536         .attrs = subch_attrs,
 537 };
 538
 539 struct attribute_group *subch_attr_groups[] = {
 540         &subch_attr_group,
 541         NULL,
 542 };
 543
 544 static struct attribute * ccwdev_attrs[] = {
 545         &dev_attr_devtype.attr,
 546         &dev_attr_cutype.attr,
 547         &dev_attr_modalias.attr,
 548         &dev_attr_online.attr,
 549         &dev_attr_cmb_enable.attr,
 550         &dev_attr_availability.attr,
 551         NULL,
 552 };
 553
 554 static struct attribute_group ccwdev_attr_group = {
 555         .attrs = ccwdev_attrs,
 556 };
 557
 558 static int
 559 device_add_files (struct device *dev)
 560 {
 561         return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
 562 }
 563
 564 static void
 565 device_remove_files(struct device *dev)
 566 {
 567         sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
 568 }
 569
 570 /* this is a simple abstraction for device_register that sets the
 571  * correct bus type and adds the bus specific files */
 572 static int ccw_device_register(struct ccw_device *cdev)
 573 {
 574         struct device *dev = &cdev->dev;
 575         int ret;
 576
 577         dev->bus = &ccw_bus_type;
 578
 579         if ((ret = device_add(dev)))
 580                 return ret;
 581
 582         set_bit(1, &cdev->private->registered);
 583         if ((ret = device_add_files(dev))) {
 584                 if (test_and_clear_bit(1, &cdev->private->registered))
 585                         device_del(dev);
 586         }
 587         return ret;
 588 }
 589
 590 struct match_data {
 591         struct ccw_dev_id dev_id;
 592         struct ccw_device * sibling;
 593 };
 594
 595 static int
 596 match_devno(struct device * dev, void * data)
 597 {
 598         struct match_data * d = data;
 599         struct ccw_device * cdev;
 600
 601         cdev = to_ccwdev(dev);
 602         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 603             !ccw_device_is_orphan(cdev) &&
 604             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 605             (cdev != d->sibling))
 606                 return 1;
 607         return 0;
 608 }
 609
 610 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 611                                                      struct ccw_device *sibling)
 612 {
 613         struct device *dev;
 614         struct match_data data;
 615
 616         data.dev_id = *dev_id;
 617         data.sibling = sibling;
 618         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 619
 620         return dev ? to_ccwdev(dev) : NULL;
 621 }
 622
 623 static int match_orphan(struct device *dev, void *data)
 624 {
 625         struct ccw_dev_id *dev_id;
 626         struct ccw_device *cdev;
 627
 628         dev_id = data;
 629         cdev = to_ccwdev(dev);
 630         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 631 }
 632
 633 static struct ccw_device *
 634 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 635                               struct ccw_dev_id *dev_id)
 636 {
 637         struct device *dev;
 638
 639         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 640                                 match_orphan);
 641
 642         return dev ? to_ccwdev(dev) : NULL;
 643 }
 644
 645 static void
 646 ccw_device_add_changed(struct work_struct *work)
 647 {
 648         struct ccw_device_private *priv;
 649         struct ccw_device *cdev;
 650
 651         priv = container_of(work, struct ccw_device_private, kick_work);
 652         cdev = priv->cdev;
 653         if (device_add(&cdev->dev)) {
 654                 put_device(&cdev->dev);
 655                 return;
 656         }
 657         set_bit(1, &cdev->private->registered);
 658         if (device_add_files(&cdev->dev)) {
 659                 if (test_and_clear_bit(1, &cdev->private->registered))
 660                         device_unregister(&cdev->dev);
 661         }
 662 }
 663
 664 void ccw_device_do_unreg_rereg(struct work_struct *work)
 665 {
 666         struct ccw_device_private *priv;
 667         struct ccw_device *cdev;
 668         struct subchannel *sch;
 669
 670         priv = container_of(work, struct ccw_device_private, kick_work);
 671         cdev = priv->cdev;
 672         sch = to_subchannel(cdev->dev.parent);
 673
 674         device_remove_files(&cdev->dev);
 675         if (test_and_clear_bit(1, &cdev->private->registered))
 676                 device_del(&cdev->dev);
 677         PREPARE_WORK(&cdev->private->kick_work,
 678                      ccw_device_add_changed);
 679         queue_work(ccw_device_work, &cdev->private->kick_work);
 680 }
 681
 682 static void
 683 ccw_device_release(struct device *dev)
 684 {
 685         struct ccw_device *cdev;
 686
 687         cdev = to_ccwdev(dev);
 688         kfree(cdev->private);
 689         kfree(cdev);
 690 }
 691
 692 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 693 {
 694         struct ccw_device *cdev;
 695
 696         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 697         if (cdev) {
 698                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 699                                         GFP_KERNEL | GFP_DMA);
 700                 if (cdev->private)
 701                         return cdev;
 702         }
 703         kfree(cdev);
 704         return ERR_PTR(-ENOMEM);
 705 }
 706
 707 static int io_subchannel_initialize_dev(struct subchannel *sch,
 708                                         struct ccw_device *cdev)
 709 {
 710         cdev->private->cdev = cdev;
 711         atomic_set(&cdev->private->onoff, 0);
 712         cdev->dev.parent = &sch->dev;
 713         cdev->dev.release = ccw_device_release;
 714         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 715         /* Do first half of device_register. */
 716         device_initialize(&cdev->dev);
 717         if (!get_device(&sch->dev)) {
 718                 if (cdev->dev.release)
 719                         cdev->dev.release(&cdev->dev);
 720                 return -ENODEV;
 721         }
 722         return 0;
 723 }
 724
 725 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 726 {
 727         struct ccw_device *cdev;
 728         int ret;
 729
 730         cdev = io_subchannel_allocate_dev(sch);
 731         if (!IS_ERR(cdev)) {
 732                 ret = io_subchannel_initialize_dev(sch, cdev);
 733                 if (ret) {
 734                         kfree(cdev);
 735                         cdev = ERR_PTR(ret);
 736                 }
 737         }
 738         return cdev;
 739 }
 740
 741 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 742
 743 static void sch_attach_device(struct subchannel *sch,
 744                               struct ccw_device *cdev)
 745 {
 746         css_update_ssd_info(sch);
 747         spin_lock_irq(sch->lock);
 748         sch->dev.driver_data = cdev;
 749         cdev->private->schid = sch->schid;
 750         cdev->ccwlock = sch->lock;
 751         device_trigger_reprobe(sch);
 752         spin_unlock_irq(sch->lock);
 753 }
 754
 755 static void sch_attach_disconnected_device(struct subchannel *sch,
 756                                            struct ccw_device *cdev)
 757 {
 758         struct subchannel *other_sch;
 759         int ret;
 760
 761         other_sch = to_subchannel(get_device(cdev->dev.parent));
 762         ret = device_move(&cdev->dev, &sch->dev);
 763         if (ret) {
 764                 CIO_MSG_EVENT(2, "Moving disconnected device 0.%x.%04x failed "
 765                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 766                               cdev->private->dev_id.devno, ret);
 767                 put_device(&other_sch->dev);
 768                 return;
 769         }
 770         other_sch->dev.driver_data = NULL;
 771         /* No need to keep a subchannel without ccw device around. */
 772         css_sch_device_unregister(other_sch);
 773         put_device(&other_sch->dev);
 774         sch_attach_device(sch, cdev);
 775 }
 776
 777 static void sch_attach_orphaned_device(struct subchannel *sch,
 778                                        struct ccw_device *cdev)
 779 {
 780         int ret;
 781
 782         /* Try to move the ccw device to its new subchannel. */
 783         ret = device_move(&cdev->dev, &sch->dev);
 784         if (ret) {
 785                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 786                               "failed (ret=%d)!\n",
 787                               cdev->private->dev_id.ssid,
 788                               cdev->private->dev_id.devno, ret);
 789                 return;
 790         }
 791         sch_attach_device(sch, cdev);
 792 }
 793
 794 static void sch_create_and_recog_new_device(struct subchannel *sch)
 795 {
 796         struct ccw_device *cdev;
 797
 798         /* Need to allocate a new ccw device. */
 799         cdev = io_subchannel_create_ccwdev(sch);
 800         if (IS_ERR(cdev)) {
 801                 /* OK, we did everything we could... */
 802                 css_sch_device_unregister(sch);
 803                 return;
 804         }
 805         spin_lock_irq(sch->lock);
 806         sch->dev.driver_data = cdev;
 807         spin_unlock_irq(sch->lock);
 808         /* Start recognition for the new ccw device. */
 809         if (io_subchannel_recog(cdev, sch)) {
 810                 spin_lock_irq(sch->lock);
 811                 sch->dev.driver_data = NULL;
 812                 spin_unlock_irq(sch->lock);
 813                 if (cdev->dev.release)
 814                         cdev->dev.release(&cdev->dev);
 815                 css_sch_device_unregister(sch);
 816         }
 817 }
 818
 819
 820 void ccw_device_move_to_orphanage(struct work_struct *work)
 821 {
 822         struct ccw_device_private *priv;
 823         struct ccw_device *cdev;
 824         struct ccw_device *replacing_cdev;
 825         struct subchannel *sch;
 826         int ret;
 827         struct channel_subsystem *css;
 828         struct ccw_dev_id dev_id;
 829
 830         priv = container_of(work, struct ccw_device_private, kick_work);
 831         cdev = priv->cdev;
 832         sch = to_subchannel(cdev->dev.parent);
 833         css = to_css(sch->dev.parent);
 834         dev_id.devno = sch->schib.pmcw.dev;
 835         dev_id.ssid = sch->schid.ssid;
 836
 837         /*
 838          * Move the orphaned ccw device to the orphanage so the replacing
 839          * ccw device can take its place on the subchannel.
 840          */
 841         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
 842         if (ret) {
 843                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 844                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 845                               cdev->private->dev_id.devno, ret);
 846                 return;
 847         }
 848         cdev->ccwlock = css->pseudo_subchannel->lock;
 849         /*
 850          * Search for the replacing ccw device
 851          * - among the disconnected devices
 852          * - in the orphanage
 853          */
 854         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 855         if (replacing_cdev) {
 856                 sch_attach_disconnected_device(sch, replacing_cdev);
 857                 return;
 858         }
 859         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 860         if (replacing_cdev) {
 861                 sch_attach_orphaned_device(sch, replacing_cdev);
 862                 return;
 863         }
 864         sch_create_and_recog_new_device(sch);
 865 }
 866
 867 /*
 868  * Register recognized device.
 869  */
 870 static void
 871 io_subchannel_register(struct work_struct *work)
 872 {
 873         struct ccw_device_private *priv;
 874         struct ccw_device *cdev;
 875         struct subchannel *sch;
 876         int ret;
 877         unsigned long flags;
 878
 879         priv = container_of(work, struct ccw_device_private, kick_work);
 880         cdev = priv->cdev;
 881         sch = to_subchannel(cdev->dev.parent);
 882         css_update_ssd_info(sch);
 883         /*
 884          * io_subchannel_register() will also be called after device
 885          * recognition has been done for a boxed device (which will already
 886          * be registered). We need to reprobe since we may now have sense id
 887          * information.
 888          */
 889         if (klist_node_attached(&cdev->dev.knode_parent)) {
 890                 if (!cdev->drv) {
 891                         ret = device_reprobe(&cdev->dev);
 892                         if (ret)
 893                                 /* We can't do much here. */
 894                                 dev_info(&cdev->dev, "device_reprobe() returned"
 895                                          " %d\n", ret);
 896                 }
 897                 goto out;
 898         }
 899         /* make it known to the system */
 900         ret = ccw_device_register(cdev);
 901         if (ret) {
 902                 printk (KERN_WARNING "%s: could not register %s\n",
 903                         __func__, cdev->dev.bus_id);
 904                 put_device(&cdev->dev);
 905                 spin_lock_irqsave(sch->lock, flags);
 906                 sch->dev.driver_data = NULL;
 907                 spin_unlock_irqrestore(sch->lock, flags);
 908                 kfree (cdev->private);
 909                 kfree (cdev);
 910                 put_device(&sch->dev);
 911                 if (atomic_dec_and_test(&ccw_device_init_count))
 912                         wake_up(&ccw_device_init_wq);
 913                 return;
 914         }
 915         put_device(&cdev->dev);
 916 out:
 917         cdev->private->flags.recog_done = 1;
 918         put_device(&sch->dev);
 919         wake_up(&cdev->private->wait_q);
 920         if (atomic_dec_and_test(&ccw_device_init_count))
 921                 wake_up(&ccw_device_init_wq);
 922 }
 923
 924 void
 925 ccw_device_call_sch_unregister(struct work_struct *work)
 926 {
 927         struct ccw_device_private *priv;
 928         struct ccw_device *cdev;
 929         struct subchannel *sch;
 930
 931         priv = container_of(work, struct ccw_device_private, kick_work);
 932         cdev = priv->cdev;
 933         sch = to_subchannel(cdev->dev.parent);
 934         css_sch_device_unregister(sch);
 935         /* Reset intparm to zeroes. */
 936         sch->schib.pmcw.intparm = 0;
 937         cio_modify(sch);
 938         put_device(&cdev->dev);
 939         put_device(&sch->dev);
 940 }
 941
 942 /*
 943  * subchannel recognition done. Called from the state machine.
 944  */
 945 void
 946 io_subchannel_recog_done(struct ccw_device *cdev)
 947 {
 948         struct subchannel *sch;
 949
 950         if (css_init_done == 0) {
 951                 cdev->private->flags.recog_done = 1;
 952                 return;
 953         }
 954         switch (cdev->private->state) {
 955         case DEV_STATE_NOT_OPER:
 956                 cdev->private->flags.recog_done = 1;
 957                 /* Remove device found not operational. */
 958                 if (!get_device(&cdev->dev))
 959                         break;
 960                 sch = to_subchannel(cdev->dev.parent);
 961                 PREPARE_WORK(&cdev->private->kick_work,
 962                              ccw_device_call_sch_unregister);
 963                 queue_work(slow_path_wq, &cdev->private->kick_work);
 964                 if (atomic_dec_and_test(&ccw_device_init_count))
 965                         wake_up(&ccw_device_init_wq);
 966                 break;
 967         case DEV_STATE_BOXED:
 968                 /* Device did not respond in time. */
 969         case DEV_STATE_OFFLINE:
 970                 /*
 971                  * We can't register the device in interrupt context so
 972                  * we schedule a work item.
 973                  */
 974                 if (!get_device(&cdev->dev))
 975                         break;
 976                 PREPARE_WORK(&cdev->private->kick_work,
 977                              io_subchannel_register);
 978                 queue_work(slow_path_wq, &cdev->private->kick_work);
 979                 break;
 980         }
 981 }
 982
 983 static int
 984 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 985 {
 986         int rc;
 987         struct ccw_device_private *priv;
 988
 989         sch->dev.driver_data = cdev;
 990         sch->driver = &io_subchannel_driver;
 991         cdev->ccwlock = sch->lock;
 992
 993         /* Init private data. */
 994         priv = cdev->private;
 995         priv->dev_id.devno = sch->schib.pmcw.dev;
 996         priv->dev_id.ssid = sch->schid.ssid;
 997         priv->schid = sch->schid;
 998         priv->state = DEV_STATE_NOT_OPER;
 999         INIT_LIST_HEAD(&priv->cmb_list);
1000         init_waitqueue_head(&priv->wait_q);
1001         init_timer(&priv->timer);
1002
1003         /* Set an initial name for the device. */
1004         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
1005                   sch->schid.ssid, sch->schib.pmcw.dev);
1006
1007         /* Increase counter of devices currently in recognition. */
1008         atomic_inc(&ccw_device_init_count);
1009
1010         /* Start async. device sensing. */
1011         spin_lock_irq(sch->lock);
1012         rc = ccw_device_recognition(cdev);
1013         spin_unlock_irq(sch->lock);
1014         if (rc) {
1015                 if (atomic_dec_and_test(&ccw_device_init_count))
1016                         wake_up(&ccw_device_init_wq);
1017         }
1018         return rc;
1019 }
1020
1021 static void ccw_device_move_to_sch(struct work_struct *work)
1022 {
1023         struct ccw_device_private *priv;
1024         int rc;
1025         struct subchannel *sch;
1026         struct ccw_device *cdev;
1027         struct subchannel *former_parent;
1028
1029         priv = container_of(work, struct ccw_device_private, kick_work);
1030         sch = priv->sch;
1031         cdev = priv->cdev;
1032         former_parent = ccw_device_is_orphan(cdev) ?
1033                 NULL : to_subchannel(get_device(cdev->dev.parent));
1034         mutex_lock(&sch->reg_mutex);
1035         /* Try to move the ccw device to its new subchannel. */
1036         rc = device_move(&cdev->dev, &sch->dev);
1037         mutex_unlock(&sch->reg_mutex);
1038         if (rc) {
1039                 CIO_MSG_EVENT(2, "Moving device 0.%x.%04x to subchannel "
1040                               "0.%x.%04x failed (ret=%d)!\n",
1041                               cdev->private->dev_id.ssid,
1042                               cdev->private->dev_id.devno, sch->schid.ssid,
1043                               sch->schid.sch_no, rc);
1044                 css_sch_device_unregister(sch);
1045                 goto out;
1046         }
1047         if (former_parent) {
1048                 spin_lock_irq(former_parent->lock);
1049                 former_parent->dev.driver_data = NULL;
1050                 spin_unlock_irq(former_parent->lock);
1051                 css_sch_device_unregister(former_parent);
1052                 /* Reset intparm to zeroes. */
1053                 former_parent->schib.pmcw.intparm = 0;
1054                 cio_modify(former_parent);
1055         }
1056         sch_attach_device(sch, cdev);
1057 out:
1058         if (former_parent)
1059                 put_device(&former_parent->dev);
1060         put_device(&cdev->dev);
1061 }
1062
1063 static int
1064 io_subchannel_probe (struct subchannel *sch)
1065 {
1066         struct ccw_device *cdev;
1067         int rc;
1068         unsigned long flags;
1069         struct ccw_dev_id dev_id;
1070
1071         if (sch->dev.driver_data) {
1072                 /*
1073                  * This subchannel already has an associated ccw_device.
1074                  * Register it and exit. This happens for all early
1075                  * device, e.g. the console.
1076                  */
1077                 cdev = sch->dev.driver_data;
1078                 device_initialize(&cdev->dev);
1079                 ccw_device_register(cdev);
1080                 /*
1081                  * Check if the device is already online. If it is
1082                  * the reference count needs to be corrected
1083                  * (see ccw_device_online and css_init_done for the
1084                  * ugly details).
1085                  */
1086                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1087                     cdev->private->state != DEV_STATE_OFFLINE &&
1088                     cdev->private->state != DEV_STATE_BOXED)
1089                         get_device(&cdev->dev);
1090                 return 0;
1091         }
1092         /*
1093          * First check if a fitting device may be found amongst the
1094          * disconnected devices or in the orphanage.
1095          */
1096         dev_id.devno = sch->schib.pmcw.dev;
1097         dev_id.ssid = sch->schid.ssid;
1098         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1099         if (!cdev)
1100                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1101                                                      &dev_id);
1102         if (cdev) {
1103                 /*
1104                  * Schedule moving the device until when we have a registered
1105                  * subchannel to move to and succeed the probe. We can
1106                  * unregister later again, when the probe is through.
1107                  */
1108                 cdev->private->sch = sch;
1109                 PREPARE_WORK(&cdev->private->kick_work,
1110                              ccw_device_move_to_sch);
1111                 queue_work(slow_path_wq, &cdev->private->kick_work);
1112                 return 0;
1113         }
1114         cdev = io_subchannel_create_ccwdev(sch);
1115         if (IS_ERR(cdev))
1116                 return PTR_ERR(cdev);
1117
1118         rc = io_subchannel_recog(cdev, sch);
1119         if (rc) {
1120                 spin_lock_irqsave(sch->lock, flags);
1121                 sch->dev.driver_data = NULL;
1122                 spin_unlock_irqrestore(sch->lock, flags);
1123                 if (cdev->dev.release)
1124                         cdev->dev.release(&cdev->dev);
1125         }
1126
1127         return rc;
1128 }
1129
1130 static int
1131 io_subchannel_remove (struct subchannel *sch)
1132 {
1133         struct ccw_device *cdev;
1134         unsigned long flags;
1135
1136         if (!sch->dev.driver_data)
1137                 return 0;
1138         cdev = sch->dev.driver_data;
1139         /* Set ccw device to not operational and drop reference. */
1140         spin_lock_irqsave(cdev->ccwlock, flags);
1141         sch->dev.driver_data = NULL;
1142         cdev->private->state = DEV_STATE_NOT_OPER;
1143         spin_unlock_irqrestore(cdev->ccwlock, flags);
1144         /*
1145          * Put unregistration on workqueue to avoid livelocks on the css bus
1146          * semaphore.
1147          */
1148         if (get_device(&cdev->dev)) {
1149                 PREPARE_WORK(&cdev->private->kick_work,
1150                              ccw_device_unregister);
1151                 queue_work(ccw_device_work, &cdev->private->kick_work);
1152         }
1153         return 0;
1154 }
1155
1156 static int
1157 io_subchannel_notify(struct device *dev, int event)
1158 {
1159         struct ccw_device *cdev;
1160
1161         cdev = dev->driver_data;
1162         if (!cdev)
1163                 return 0;
1164         if (!cdev->drv)
1165                 return 0;
1166         if (!cdev->online)
1167                 return 0;
1168         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
1169 }
1170
1171 static void
1172 io_subchannel_verify(struct device *dev)
1173 {
1174         struct ccw_device *cdev;
1175
1176         cdev = dev->driver_data;
1177         if (cdev)
1178                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1179 }
1180
1181 static void
1182 io_subchannel_ioterm(struct device *dev)
1183 {
1184         struct ccw_device *cdev;
1185
1186         cdev = dev->driver_data;
1187         if (!cdev)
1188                 return;
1189         /* Internal I/O will be retried by the interrupt handler. */
1190         if (cdev->private->flags.intretry)
1191                 return;
1192         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1193         if (cdev->handler)
1194                 cdev->handler(cdev, cdev->private->intparm,
1195                               ERR_PTR(-EIO));
1196 }
1197
1198 static void
1199 io_subchannel_shutdown(struct subchannel *sch)
1200 {
1201         struct ccw_device *cdev;
1202         int ret;
1203
1204         cdev = sch->dev.driver_data;
1205
1206         if (cio_is_console(sch->schid))
1207                 return;
1208         if (!sch->schib.pmcw.ena)
1209                 /* Nothing to do. */
1210                 return;
1211         ret = cio_disable_subchannel(sch);
1212         if (ret != -EBUSY)
1213                 /* Subchannel is disabled, we're done. */
1214                 return;
1215         cdev->private->state = DEV_STATE_QUIESCE;
1216         if (cdev->handler)
1217                 cdev->handler(cdev, cdev->private->intparm,
1218                               ERR_PTR(-EIO));
1219         ret = ccw_device_cancel_halt_clear(cdev);
1220         if (ret == -EBUSY) {
1221                 ccw_device_set_timeout(cdev, HZ/10);
1222                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1223         }
1224         cio_disable_subchannel(sch);
1225 }
1226
1227 #ifdef CONFIG_CCW_CONSOLE
1228 static struct ccw_device console_cdev;
1229 static struct ccw_device_private console_private;
1230 static int console_cdev_in_use;
1231
1232 static DEFINE_SPINLOCK(ccw_console_lock);
1233
1234 spinlock_t * cio_get_console_lock(void)
1235 {
1236         return &ccw_console_lock;
1237 }
1238
1239 static int
1240 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
1241 {
1242         int rc;
1243
1244         /* Initialize the ccw_device structure. */
1245         cdev->dev.parent= &sch->dev;
1246         rc = io_subchannel_recog(cdev, sch);
1247         if (rc)
1248                 return rc;
1249
1250         /* Now wait for the async. recognition to come to an end. */
1251         spin_lock_irq(cdev->ccwlock);
1252         while (!dev_fsm_final_state(cdev))
1253                 wait_cons_dev();
1254         rc = -EIO;
1255         if (cdev->private->state != DEV_STATE_OFFLINE)
1256                 goto out_unlock;
1257         ccw_device_online(cdev);
1258         while (!dev_fsm_final_state(cdev))
1259                 wait_cons_dev();
1260         if (cdev->private->state != DEV_STATE_ONLINE)
1261                 goto out_unlock;
1262         rc = 0;
1263 out_unlock:
1264         spin_unlock_irq(cdev->ccwlock);
1265         return 0;
1266 }
1267
1268 struct ccw_device *
1269 ccw_device_probe_console(void)
1270 {
1271         struct subchannel *sch;
1272         int ret;
1273
1274         if (xchg(&console_cdev_in_use, 1) != 0)
1275                 return ERR_PTR(-EBUSY);
1276         sch = cio_probe_console();
1277         if (IS_ERR(sch)) {
1278                 console_cdev_in_use = 0;
1279                 return (void *) sch;
1280         }
1281         memset(&console_cdev, 0, sizeof(struct ccw_device));
1282         memset(&console_private, 0, sizeof(struct ccw_device_private));
1283         console_cdev.private = &console_private;
1284         console_private.cdev = &console_cdev;
1285         ret = ccw_device_console_enable(&console_cdev, sch);
1286         if (ret) {
1287                 cio_release_console();
1288                 console_cdev_in_use = 0;
1289                 return ERR_PTR(ret);
1290         }
1291         console_cdev.online = 1;
1292         return &console_cdev;
1293 }
1294 #endif
1295
1296 /*
1297  * get ccw_device matching the busid, but only if owned by cdrv
1298  */
1299 static int
1300 __ccwdev_check_busid(struct device *dev, void *id)
1301 {
1302         char *bus_id;
1303
1304         bus_id = id;
1305
1306         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1307 }
1308
1309
1310 struct ccw_device *
1311 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1312 {
1313         struct device *dev;
1314         struct device_driver *drv;
1315
1316         drv = get_driver(&cdrv->driver);
1317         if (!drv)
1318                 return NULL;
1319
1320         dev = driver_find_device(drv, NULL, (void *)bus_id,
1321                                  __ccwdev_check_busid);
1322         put_driver(drv);
1323
1324         return dev ? to_ccwdev(dev) : NULL;
1325 }
1326
1327 /************************** device driver handling ************************/
1328
1329 /* This is the implementation of the ccw_driver class. The probe, remove
1330  * and release methods are initially very similar to the device_driver
1331  * implementations, with the difference that they have ccw_device
1332  * arguments.
1333  *
1334  * A ccw driver also contains the information that is needed for
1335  * device matching.
1336  */
1337 static int
1338 ccw_device_probe (struct device *dev)
1339 {
1340         struct ccw_device *cdev = to_ccwdev(dev);
1341         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1342         int ret;
1343
1344         cdev->drv = cdrv; /* to let the driver call _set_online */
1345
1346         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1347
1348         if (ret) {
1349                 cdev->drv = NULL;
1350                 return ret;
1351         }
1352
1353         return 0;
1354 }
1355
1356 static int
1357 ccw_device_remove (struct device *dev)
1358 {
1359         struct ccw_device *cdev = to_ccwdev(dev);
1360         struct ccw_driver *cdrv = cdev->drv;
1361         int ret;
1362
1363         pr_debug("removing device %s\n", cdev->dev.bus_id);
1364         if (cdrv->remove)
1365                 cdrv->remove(cdev);
1366         if (cdev->online) {
1367                 cdev->online = 0;
1368                 spin_lock_irq(cdev->ccwlock);
1369                 ret = ccw_device_offline(cdev);
1370                 spin_unlock_irq(cdev->ccwlock);
1371                 if (ret == 0)
1372                         wait_event(cdev->private->wait_q,
1373                                    dev_fsm_final_state(cdev));
1374                 else
1375                         //FIXME: we can't fail!
1376                         pr_debug("ccw_device_offline returned %d, device %s\n",
1377                                  ret, cdev->dev.bus_id);
1378         }
1379         ccw_device_set_timeout(cdev, 0);
1380         cdev->drv = NULL;
1381         return 0;
1382 }
1383
1384 struct bus_type ccw_bus_type = {
1385         .name   = "ccw",
1386         .match  = ccw_bus_match,
1387         .uevent = ccw_uevent,
1388         .probe  = ccw_device_probe,
1389         .remove = ccw_device_remove,
1390 };
1391
1392 int
1393 ccw_driver_register (struct ccw_driver *cdriver)
1394 {
1395         struct device_driver *drv = &cdriver->driver;
1396
1397         drv->bus = &ccw_bus_type;
1398         drv->name = cdriver->name;
1399
1400         return driver_register(drv);
1401 }
1402
1403 void
1404 ccw_driver_unregister (struct ccw_driver *cdriver)
1405 {
1406         driver_unregister(&cdriver->driver);
1407 }
1408
1409 /* Helper func for qdio. */
1410 struct subchannel_id
1411 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1412 {
1413         struct subchannel *sch;
1414
1415         sch = to_subchannel(cdev->dev.parent);
1416         return sch->schid;
1417 }
1418
1419 MODULE_LICENSE("GPL");
1420 EXPORT_SYMBOL(ccw_device_set_online);
1421 EXPORT_SYMBOL(ccw_device_set_offline);
1422 EXPORT_SYMBOL(ccw_driver_register);
1423 EXPORT_SYMBOL(ccw_driver_unregister);
1424 EXPORT_SYMBOL(get_ccwdev_by_busid);
1425 EXPORT_SYMBOL(ccw_bus_type);
1426 EXPORT_SYMBOL(ccw_device_work);
1427 EXPORT_SYMBOL(ccw_device_notify_work);
1428 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);