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   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 ccw_device_remove_orphan_cb(struct device *dev)
 300 {
 301         struct ccw_device *cdev = to_ccwdev(dev);
 302
 303         ccw_device_unregister(cdev);
 304         put_device(&cdev->dev);
 305 }
 306
 307 static void ccw_device_remove_sch_cb(struct device *dev)
 308 {
 309         struct subchannel *sch;
 310
 311         sch = to_subchannel(dev);
 312         css_sch_device_unregister(sch);
 313         /* Reset intparm to zeroes. */
 314         sch->schib.pmcw.intparm = 0;
 315         cio_modify(sch);
 316         put_device(&sch->dev);
 317 }
 318
 319 static void
 320 ccw_device_remove_disconnected(struct ccw_device *cdev)
 321 {
 322         unsigned long flags;
 323         int rc;
 324
 325         /*
 326          * Forced offline in disconnected state means
 327          * 'throw away device'.
 328          */
 329         if (ccw_device_is_orphan(cdev)) {
 330                 /*
 331                  * Deregister ccw device.
 332                  * Unfortunately, we cannot do this directly from the
 333                  * attribute method.
 334                  */
 335                 spin_lock_irqsave(cdev->ccwlock, flags);
 336                 cdev->private->state = DEV_STATE_NOT_OPER;
 337                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 338                 rc = device_schedule_callback(&cdev->dev,
 339                                               ccw_device_remove_orphan_cb);
 340                 if (rc)
 341                         dev_info(&cdev->dev, "Couldn't unregister orphan\n");
 342                 return;
 343         }
 344         /* Deregister subchannel, which will kill the ccw device. */
 345         rc = device_schedule_callback(cdev->dev.parent,
 346                                       ccw_device_remove_sch_cb);
 347         if (rc)
 348                 dev_info(&cdev->dev,
 349                          "Couldn't unregister disconnected device\n");
 350 }
 351
 352 int
 353 ccw_device_set_offline(struct ccw_device *cdev)
 354 {
 355         int ret;
 356
 357         if (!cdev)
 358                 return -ENODEV;
 359         if (!cdev->online || !cdev->drv)
 360                 return -EINVAL;
 361
 362         if (cdev->drv->set_offline) {
 363                 ret = cdev->drv->set_offline(cdev);
 364                 if (ret != 0)
 365                         return ret;
 366         }
 367         cdev->online = 0;
 368         spin_lock_irq(cdev->ccwlock);
 369         ret = ccw_device_offline(cdev);
 370         if (ret == -ENODEV) {
 371                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 372                         cdev->private->state = DEV_STATE_OFFLINE;
 373                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 374                 }
 375                 spin_unlock_irq(cdev->ccwlock);
 376                 return ret;
 377         }
 378         spin_unlock_irq(cdev->ccwlock);
 379         if (ret == 0)
 380                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 381         else {
 382                 pr_debug("ccw_device_offline returned %d, device %s\n",
 383                          ret, cdev->dev.bus_id);
 384                 cdev->online = 1;
 385         }
 386         return ret;
 387 }
 388
 389 int
 390 ccw_device_set_online(struct ccw_device *cdev)
 391 {
 392         int ret;
 393
 394         if (!cdev)
 395                 return -ENODEV;
 396         if (cdev->online || !cdev->drv)
 397                 return -EINVAL;
 398
 399         spin_lock_irq(cdev->ccwlock);
 400         ret = ccw_device_online(cdev);
 401         spin_unlock_irq(cdev->ccwlock);
 402         if (ret == 0)
 403                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 404         else {
 405                 pr_debug("ccw_device_online returned %d, device %s\n",
 406                          ret, cdev->dev.bus_id);
 407                 return ret;
 408         }
 409         if (cdev->private->state != DEV_STATE_ONLINE)
 410                 return -ENODEV;
 411         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 412                 cdev->online = 1;
 413                 return 0;
 414         }
 415         spin_lock_irq(cdev->ccwlock);
 416         ret = ccw_device_offline(cdev);
 417         spin_unlock_irq(cdev->ccwlock);
 418         if (ret == 0)
 419                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 420         else
 421                 pr_debug("ccw_device_offline returned %d, device %s\n",
 422                          ret, cdev->dev.bus_id);
 423         return (ret == 0) ? -ENODEV : ret;
 424 }
 425
 426 static void online_store_handle_offline(struct ccw_device *cdev)
 427 {
 428         if (cdev->private->state == DEV_STATE_DISCONNECTED)
 429                 ccw_device_remove_disconnected(cdev);
 430         else if (cdev->drv && cdev->drv->set_offline)
 431                 ccw_device_set_offline(cdev);
 432 }
 433
 434 static int online_store_recog_and_online(struct ccw_device *cdev)
 435 {
 436         int ret;
 437
 438         /* Do device recognition, if needed. */
 439         if (cdev->id.cu_type == 0) {
 440                 ret = ccw_device_recognition(cdev);
 441                 if (ret) {
 442                         printk(KERN_WARNING"Couldn't start recognition "
 443                                "for device %s (ret=%d)\n",
 444                                cdev->dev.bus_id, ret);
 445                         return ret;
 446                 }
 447                 wait_event(cdev->private->wait_q,
 448                            cdev->private->flags.recog_done);
 449         }
 450         if (cdev->drv && cdev->drv->set_online)
 451                 ccw_device_set_online(cdev);
 452         return 0;
 453 }
 454 static void online_store_handle_online(struct ccw_device *cdev, int force)
 455 {
 456         int ret;
 457
 458         ret = online_store_recog_and_online(cdev);
 459         if (ret)
 460                 return;
 461         if (force && cdev->private->state == DEV_STATE_BOXED) {
 462                 ret = ccw_device_stlck(cdev);
 463                 if (ret) {
 464                         printk(KERN_WARNING"ccw_device_stlck for device %s "
 465                                "returned %d!\n", cdev->dev.bus_id, ret);
 466                         return;
 467                 }
 468                 if (cdev->id.cu_type == 0)
 469                         cdev->private->state = DEV_STATE_NOT_OPER;
 470                 online_store_recog_and_online(cdev);
 471         }
 472
 473 }
 474
 475 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 476                              const char *buf, size_t count)
 477 {
 478         struct ccw_device *cdev = to_ccwdev(dev);
 479         int i, force;
 480         char *tmp;
 481
 482         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 483                 return -EAGAIN;
 484
 485         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 486                 atomic_set(&cdev->private->onoff, 0);
 487                 return -EINVAL;
 488         }
 489         if (!strncmp(buf, "force\n", count)) {
 490                 force = 1;
 491                 i = 1;
 492         } else {
 493                 force = 0;
 494                 i = simple_strtoul(buf, &tmp, 16);
 495         }
 496
 497         switch (i) {
 498         case 0:
 499                 online_store_handle_offline(cdev);
 500                 break;
 501         case 1:
 502                 online_store_handle_online(cdev, force);
 503                 break;
 504         default:
 505                 count = -EINVAL;
 506         }
 507         if (cdev->drv)
 508                 module_put(cdev->drv->owner);
 509         atomic_set(&cdev->private->onoff, 0);
 510         return count;
 511 }
 512
 513 static ssize_t
 514 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 515 {
 516         struct ccw_device *cdev = to_ccwdev(dev);
 517         struct subchannel *sch;
 518
 519         if (ccw_device_is_orphan(cdev))
 520                 return sprintf(buf, "no device\n");
 521         switch (cdev->private->state) {
 522         case DEV_STATE_BOXED:
 523                 return sprintf(buf, "boxed\n");
 524         case DEV_STATE_DISCONNECTED:
 525         case DEV_STATE_DISCONNECTED_SENSE_ID:
 526         case DEV_STATE_NOT_OPER:
 527                 sch = to_subchannel(dev->parent);
 528                 if (!sch->lpm)
 529                         return sprintf(buf, "no path\n");
 530                 else
 531                         return sprintf(buf, "no device\n");
 532         default:
 533                 /* All other states considered fine. */
 534                 return sprintf(buf, "good\n");
 535         }
 536 }
 537
 538 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 539 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 540 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 541 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 542 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 543 static DEVICE_ATTR(online, 0644, online_show, online_store);
 544 extern struct device_attribute dev_attr_cmb_enable;
 545 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 546
 547 static struct attribute * subch_attrs[] = {
 548         &dev_attr_chpids.attr,
 549         &dev_attr_pimpampom.attr,
 550         NULL,
 551 };
 552
 553 static struct attribute_group subch_attr_group = {
 554         .attrs = subch_attrs,
 555 };
 556
 557 struct attribute_group *subch_attr_groups[] = {
 558         &subch_attr_group,
 559         NULL,
 560 };
 561
 562 static struct attribute * ccwdev_attrs[] = {
 563         &dev_attr_devtype.attr,
 564         &dev_attr_cutype.attr,
 565         &dev_attr_modalias.attr,
 566         &dev_attr_online.attr,
 567         &dev_attr_cmb_enable.attr,
 568         &dev_attr_availability.attr,
 569         NULL,
 570 };
 571
 572 static struct attribute_group ccwdev_attr_group = {
 573         .attrs = ccwdev_attrs,
 574 };
 575
 576 static struct attribute_group *ccwdev_attr_groups[] = {
 577         &ccwdev_attr_group,
 578         NULL,
 579 };
 580
 581 /* this is a simple abstraction for device_register that sets the
 582  * correct bus type and adds the bus specific files */
 583 static int ccw_device_register(struct ccw_device *cdev)
 584 {
 585         struct device *dev = &cdev->dev;
 586         int ret;
 587
 588         dev->bus = &ccw_bus_type;
 589
 590         if ((ret = device_add(dev)))
 591                 return ret;
 592
 593         set_bit(1, &cdev->private->registered);
 594         return ret;
 595 }
 596
 597 struct match_data {
 598         struct ccw_dev_id dev_id;
 599         struct ccw_device * sibling;
 600 };
 601
 602 static int
 603 match_devno(struct device * dev, void * data)
 604 {
 605         struct match_data * d = data;
 606         struct ccw_device * cdev;
 607
 608         cdev = to_ccwdev(dev);
 609         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 610             !ccw_device_is_orphan(cdev) &&
 611             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 612             (cdev != d->sibling))
 613                 return 1;
 614         return 0;
 615 }
 616
 617 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 618                                                      struct ccw_device *sibling)
 619 {
 620         struct device *dev;
 621         struct match_data data;
 622
 623         data.dev_id = *dev_id;
 624         data.sibling = sibling;
 625         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 626
 627         return dev ? to_ccwdev(dev) : NULL;
 628 }
 629
 630 static int match_orphan(struct device *dev, void *data)
 631 {
 632         struct ccw_dev_id *dev_id;
 633         struct ccw_device *cdev;
 634
 635         dev_id = data;
 636         cdev = to_ccwdev(dev);
 637         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 638 }
 639
 640 static struct ccw_device *
 641 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 642                               struct ccw_dev_id *dev_id)
 643 {
 644         struct device *dev;
 645
 646         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 647                                 match_orphan);
 648
 649         return dev ? to_ccwdev(dev) : NULL;
 650 }
 651
 652 static void
 653 ccw_device_add_changed(struct work_struct *work)
 654 {
 655         struct ccw_device_private *priv;
 656         struct ccw_device *cdev;
 657
 658         priv = container_of(work, struct ccw_device_private, kick_work);
 659         cdev = priv->cdev;
 660         if (device_add(&cdev->dev)) {
 661                 put_device(&cdev->dev);
 662                 return;
 663         }
 664         set_bit(1, &cdev->private->registered);
 665 }
 666
 667 void ccw_device_do_unreg_rereg(struct work_struct *work)
 668 {
 669         struct ccw_device_private *priv;
 670         struct ccw_device *cdev;
 671         struct subchannel *sch;
 672
 673         priv = container_of(work, struct ccw_device_private, kick_work);
 674         cdev = priv->cdev;
 675         sch = to_subchannel(cdev->dev.parent);
 676
 677         ccw_device_unregister(cdev);
 678         PREPARE_WORK(&cdev->private->kick_work,
 679                      ccw_device_add_changed);
 680         queue_work(ccw_device_work, &cdev->private->kick_work);
 681 }
 682
 683 static void
 684 ccw_device_release(struct device *dev)
 685 {
 686         struct ccw_device *cdev;
 687
 688         cdev = to_ccwdev(dev);
 689         kfree(cdev->private);
 690         kfree(cdev);
 691 }
 692
 693 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 694 {
 695         struct ccw_device *cdev;
 696
 697         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 698         if (cdev) {
 699                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 700                                         GFP_KERNEL | GFP_DMA);
 701                 if (cdev->private)
 702                         return cdev;
 703         }
 704         kfree(cdev);
 705         return ERR_PTR(-ENOMEM);
 706 }
 707
 708 static int io_subchannel_initialize_dev(struct subchannel *sch,
 709                                         struct ccw_device *cdev)
 710 {
 711         cdev->private->cdev = cdev;
 712         atomic_set(&cdev->private->onoff, 0);
 713         cdev->dev.parent = &sch->dev;
 714         cdev->dev.release = ccw_device_release;
 715         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 716         cdev->dev.groups = ccwdev_attr_groups;
 717         /* Do first half of device_register. */
 718         device_initialize(&cdev->dev);
 719         if (!get_device(&sch->dev)) {
 720                 if (cdev->dev.release)
 721                         cdev->dev.release(&cdev->dev);
 722                 return -ENODEV;
 723         }
 724         return 0;
 725 }
 726
 727 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 728 {
 729         struct ccw_device *cdev;
 730         int ret;
 731
 732         cdev = io_subchannel_allocate_dev(sch);
 733         if (!IS_ERR(cdev)) {
 734                 ret = io_subchannel_initialize_dev(sch, cdev);
 735                 if (ret) {
 736                         kfree(cdev);
 737                         cdev = ERR_PTR(ret);
 738                 }
 739         }
 740         return cdev;
 741 }
 742
 743 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 744
 745 static void sch_attach_device(struct subchannel *sch,
 746                               struct ccw_device *cdev)
 747 {
 748         css_update_ssd_info(sch);
 749         spin_lock_irq(sch->lock);
 750         sch->dev.driver_data = cdev;
 751         cdev->private->schid = sch->schid;
 752         cdev->ccwlock = sch->lock;
 753         device_trigger_reprobe(sch);
 754         spin_unlock_irq(sch->lock);
 755 }
 756
 757 static void sch_attach_disconnected_device(struct subchannel *sch,
 758                                            struct ccw_device *cdev)
 759 {
 760         struct subchannel *other_sch;
 761         int ret;
 762
 763         other_sch = to_subchannel(get_device(cdev->dev.parent));
 764         ret = device_move(&cdev->dev, &sch->dev);
 765         if (ret) {
 766                 CIO_MSG_EVENT(2, "Moving disconnected device 0.%x.%04x failed "
 767                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 768                               cdev->private->dev_id.devno, ret);
 769                 put_device(&other_sch->dev);
 770                 return;
 771         }
 772         other_sch->dev.driver_data = NULL;
 773         /* No need to keep a subchannel without ccw device around. */
 774         css_sch_device_unregister(other_sch);
 775         put_device(&other_sch->dev);
 776         sch_attach_device(sch, cdev);
 777 }
 778
 779 static void sch_attach_orphaned_device(struct subchannel *sch,
 780                                        struct ccw_device *cdev)
 781 {
 782         int ret;
 783
 784         /* Try to move the ccw device to its new subchannel. */
 785         ret = device_move(&cdev->dev, &sch->dev);
 786         if (ret) {
 787                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 788                               "failed (ret=%d)!\n",
 789                               cdev->private->dev_id.ssid,
 790                               cdev->private->dev_id.devno, ret);
 791                 return;
 792         }
 793         sch_attach_device(sch, cdev);
 794 }
 795
 796 static void sch_create_and_recog_new_device(struct subchannel *sch)
 797 {
 798         struct ccw_device *cdev;
 799
 800         /* Need to allocate a new ccw device. */
 801         cdev = io_subchannel_create_ccwdev(sch);
 802         if (IS_ERR(cdev)) {
 803                 /* OK, we did everything we could... */
 804                 css_sch_device_unregister(sch);
 805                 return;
 806         }
 807         spin_lock_irq(sch->lock);
 808         sch->dev.driver_data = cdev;
 809         spin_unlock_irq(sch->lock);
 810         /* Start recognition for the new ccw device. */
 811         if (io_subchannel_recog(cdev, sch)) {
 812                 spin_lock_irq(sch->lock);
 813                 sch->dev.driver_data = NULL;
 814                 spin_unlock_irq(sch->lock);
 815                 if (cdev->dev.release)
 816                         cdev->dev.release(&cdev->dev);
 817                 css_sch_device_unregister(sch);
 818         }
 819 }
 820
 821
 822 void ccw_device_move_to_orphanage(struct work_struct *work)
 823 {
 824         struct ccw_device_private *priv;
 825         struct ccw_device *cdev;
 826         struct ccw_device *replacing_cdev;
 827         struct subchannel *sch;
 828         int ret;
 829         struct channel_subsystem *css;
 830         struct ccw_dev_id dev_id;
 831
 832         priv = container_of(work, struct ccw_device_private, kick_work);
 833         cdev = priv->cdev;
 834         sch = to_subchannel(cdev->dev.parent);
 835         css = to_css(sch->dev.parent);
 836         dev_id.devno = sch->schib.pmcw.dev;
 837         dev_id.ssid = sch->schid.ssid;
 838
 839         /*
 840          * Move the orphaned ccw device to the orphanage so the replacing
 841          * ccw device can take its place on the subchannel.
 842          */
 843         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
 844         if (ret) {
 845                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 846                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 847                               cdev->private->dev_id.devno, ret);
 848                 return;
 849         }
 850         cdev->ccwlock = css->pseudo_subchannel->lock;
 851         /*
 852          * Search for the replacing ccw device
 853          * - among the disconnected devices
 854          * - in the orphanage
 855          */
 856         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 857         if (replacing_cdev) {
 858                 sch_attach_disconnected_device(sch, replacing_cdev);
 859                 return;
 860         }
 861         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 862         if (replacing_cdev) {
 863                 sch_attach_orphaned_device(sch, replacing_cdev);
 864                 return;
 865         }
 866         sch_create_and_recog_new_device(sch);
 867 }
 868
 869 /*
 870  * Register recognized device.
 871  */
 872 static void
 873 io_subchannel_register(struct work_struct *work)
 874 {
 875         struct ccw_device_private *priv;
 876         struct ccw_device *cdev;
 877         struct subchannel *sch;
 878         int ret;
 879         unsigned long flags;
 880
 881         priv = container_of(work, struct ccw_device_private, kick_work);
 882         cdev = priv->cdev;
 883         sch = to_subchannel(cdev->dev.parent);
 884         css_update_ssd_info(sch);
 885         /*
 886          * io_subchannel_register() will also be called after device
 887          * recognition has been done for a boxed device (which will already
 888          * be registered). We need to reprobe since we may now have sense id
 889          * information.
 890          */
 891         if (klist_node_attached(&cdev->dev.knode_parent)) {
 892                 if (!cdev->drv) {
 893                         ret = device_reprobe(&cdev->dev);
 894                         if (ret)
 895                                 /* We can't do much here. */
 896                                 dev_info(&cdev->dev, "device_reprobe() returned"
 897                                          " %d\n", ret);
 898                 }
 899                 goto out;
 900         }
 901         /*
 902          * Now we know this subchannel will stay, we can throw
 903          * our delayed uevent.
 904          */
 905         sch->dev.uevent_suppress = 0;
 906         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 907         /* make it known to the system */
 908         ret = ccw_device_register(cdev);
 909         if (ret) {
 910                 printk (KERN_WARNING "%s: could not register %s\n",
 911                         __func__, cdev->dev.bus_id);
 912                 put_device(&cdev->dev);
 913                 spin_lock_irqsave(sch->lock, flags);
 914                 sch->dev.driver_data = NULL;
 915                 spin_unlock_irqrestore(sch->lock, flags);
 916                 kfree (cdev->private);
 917                 kfree (cdev);
 918                 put_device(&sch->dev);
 919                 if (atomic_dec_and_test(&ccw_device_init_count))
 920                         wake_up(&ccw_device_init_wq);
 921                 return;
 922         }
 923         put_device(&cdev->dev);
 924 out:
 925         cdev->private->flags.recog_done = 1;
 926         put_device(&sch->dev);
 927         wake_up(&cdev->private->wait_q);
 928         if (atomic_dec_and_test(&ccw_device_init_count))
 929                 wake_up(&ccw_device_init_wq);
 930 }
 931
 932 void
 933 ccw_device_call_sch_unregister(struct work_struct *work)
 934 {
 935         struct ccw_device_private *priv;
 936         struct ccw_device *cdev;
 937         struct subchannel *sch;
 938
 939         priv = container_of(work, struct ccw_device_private, kick_work);
 940         cdev = priv->cdev;
 941         sch = to_subchannel(cdev->dev.parent);
 942         css_sch_device_unregister(sch);
 943         /* Reset intparm to zeroes. */
 944         sch->schib.pmcw.intparm = 0;
 945         cio_modify(sch);
 946         put_device(&cdev->dev);
 947         put_device(&sch->dev);
 948 }
 949
 950 /*
 951  * subchannel recognition done. Called from the state machine.
 952  */
 953 void
 954 io_subchannel_recog_done(struct ccw_device *cdev)
 955 {
 956         struct subchannel *sch;
 957
 958         if (css_init_done == 0) {
 959                 cdev->private->flags.recog_done = 1;
 960                 return;
 961         }
 962         switch (cdev->private->state) {
 963         case DEV_STATE_NOT_OPER:
 964                 cdev->private->flags.recog_done = 1;
 965                 /* Remove device found not operational. */
 966                 if (!get_device(&cdev->dev))
 967                         break;
 968                 sch = to_subchannel(cdev->dev.parent);
 969                 PREPARE_WORK(&cdev->private->kick_work,
 970                              ccw_device_call_sch_unregister);
 971                 queue_work(slow_path_wq, &cdev->private->kick_work);
 972                 if (atomic_dec_and_test(&ccw_device_init_count))
 973                         wake_up(&ccw_device_init_wq);
 974                 break;
 975         case DEV_STATE_BOXED:
 976                 /* Device did not respond in time. */
 977         case DEV_STATE_OFFLINE:
 978                 /*
 979                  * We can't register the device in interrupt context so
 980                  * we schedule a work item.
 981                  */
 982                 if (!get_device(&cdev->dev))
 983                         break;
 984                 PREPARE_WORK(&cdev->private->kick_work,
 985                              io_subchannel_register);
 986                 queue_work(slow_path_wq, &cdev->private->kick_work);
 987                 break;
 988         }
 989 }
 990
 991 static int
 992 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 993 {
 994         int rc;
 995         struct ccw_device_private *priv;
 996
 997         sch->dev.driver_data = cdev;
 998         sch->driver = &io_subchannel_driver;
 999         cdev->ccwlock = sch->lock;
1000
1001         /* Init private data. */
1002         priv = cdev->private;
1003         priv->dev_id.devno = sch->schib.pmcw.dev;
1004         priv->dev_id.ssid = sch->schid.ssid;
1005         priv->schid = sch->schid;
1006         priv->state = DEV_STATE_NOT_OPER;
1007         INIT_LIST_HEAD(&priv->cmb_list);
1008         init_waitqueue_head(&priv->wait_q);
1009         init_timer(&priv->timer);
1010
1011         /* Set an initial name for the device. */
1012         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
1013                   sch->schid.ssid, sch->schib.pmcw.dev);
1014
1015         /* Increase counter of devices currently in recognition. */
1016         atomic_inc(&ccw_device_init_count);
1017
1018         /* Start async. device sensing. */
1019         spin_lock_irq(sch->lock);
1020         rc = ccw_device_recognition(cdev);
1021         spin_unlock_irq(sch->lock);
1022         if (rc) {
1023                 if (atomic_dec_and_test(&ccw_device_init_count))
1024                         wake_up(&ccw_device_init_wq);
1025         }
1026         return rc;
1027 }
1028
1029 static void ccw_device_move_to_sch(struct work_struct *work)
1030 {
1031         struct ccw_device_private *priv;
1032         int rc;
1033         struct subchannel *sch;
1034         struct ccw_device *cdev;
1035         struct subchannel *former_parent;
1036
1037         priv = container_of(work, struct ccw_device_private, kick_work);
1038         sch = priv->sch;
1039         cdev = priv->cdev;
1040         former_parent = ccw_device_is_orphan(cdev) ?
1041                 NULL : to_subchannel(get_device(cdev->dev.parent));
1042         mutex_lock(&sch->reg_mutex);
1043         /* Try to move the ccw device to its new subchannel. */
1044         rc = device_move(&cdev->dev, &sch->dev);
1045         mutex_unlock(&sch->reg_mutex);
1046         if (rc) {
1047                 CIO_MSG_EVENT(2, "Moving device 0.%x.%04x to subchannel "
1048                               "0.%x.%04x failed (ret=%d)!\n",
1049                               cdev->private->dev_id.ssid,
1050                               cdev->private->dev_id.devno, sch->schid.ssid,
1051                               sch->schid.sch_no, rc);
1052                 css_sch_device_unregister(sch);
1053                 goto out;
1054         }
1055         if (former_parent) {
1056                 spin_lock_irq(former_parent->lock);
1057                 former_parent->dev.driver_data = NULL;
1058                 spin_unlock_irq(former_parent->lock);
1059                 css_sch_device_unregister(former_parent);
1060                 /* Reset intparm to zeroes. */
1061                 former_parent->schib.pmcw.intparm = 0;
1062                 cio_modify(former_parent);
1063         }
1064         sch_attach_device(sch, cdev);
1065 out:
1066         if (former_parent)
1067                 put_device(&former_parent->dev);
1068         put_device(&cdev->dev);
1069 }
1070
1071 static int
1072 io_subchannel_probe (struct subchannel *sch)
1073 {
1074         struct ccw_device *cdev;
1075         int rc;
1076         unsigned long flags;
1077         struct ccw_dev_id dev_id;
1078
1079         if (sch->dev.driver_data) {
1080                 /*
1081                  * This subchannel already has an associated ccw_device.
1082                  * Register it and exit. This happens for all early
1083                  * device, e.g. the console.
1084                  */
1085                 cdev = sch->dev.driver_data;
1086                 device_initialize(&cdev->dev);
1087                 ccw_device_register(cdev);
1088                 /*
1089                  * Check if the device is already online. If it is
1090                  * the reference count needs to be corrected
1091                  * (see ccw_device_online and css_init_done for the
1092                  * ugly details).
1093                  */
1094                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1095                     cdev->private->state != DEV_STATE_OFFLINE &&
1096                     cdev->private->state != DEV_STATE_BOXED)
1097                         get_device(&cdev->dev);
1098                 return 0;
1099         }
1100         /*
1101          * First check if a fitting device may be found amongst the
1102          * disconnected devices or in the orphanage.
1103          */
1104         dev_id.devno = sch->schib.pmcw.dev;
1105         dev_id.ssid = sch->schid.ssid;
1106         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1107         if (!cdev)
1108                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1109                                                      &dev_id);
1110         if (cdev) {
1111                 /*
1112                  * Schedule moving the device until when we have a registered
1113                  * subchannel to move to and succeed the probe. We can
1114                  * unregister later again, when the probe is through.
1115                  */
1116                 cdev->private->sch = sch;
1117                 PREPARE_WORK(&cdev->private->kick_work,
1118                              ccw_device_move_to_sch);
1119                 queue_work(slow_path_wq, &cdev->private->kick_work);
1120                 return 0;
1121         }
1122         cdev = io_subchannel_create_ccwdev(sch);
1123         if (IS_ERR(cdev))
1124                 return PTR_ERR(cdev);
1125
1126         rc = io_subchannel_recog(cdev, sch);
1127         if (rc) {
1128                 spin_lock_irqsave(sch->lock, flags);
1129                 sch->dev.driver_data = NULL;
1130                 spin_unlock_irqrestore(sch->lock, flags);
1131                 if (cdev->dev.release)
1132                         cdev->dev.release(&cdev->dev);
1133         }
1134
1135         return rc;
1136 }
1137
1138 static int
1139 io_subchannel_remove (struct subchannel *sch)
1140 {
1141         struct ccw_device *cdev;
1142         unsigned long flags;
1143
1144         if (!sch->dev.driver_data)
1145                 return 0;
1146         cdev = sch->dev.driver_data;
1147         /* Set ccw device to not operational and drop reference. */
1148         spin_lock_irqsave(cdev->ccwlock, flags);
1149         sch->dev.driver_data = NULL;
1150         cdev->private->state = DEV_STATE_NOT_OPER;
1151         spin_unlock_irqrestore(cdev->ccwlock, flags);
1152         ccw_device_unregister(cdev);
1153         put_device(&cdev->dev);
1154         return 0;
1155 }
1156
1157 static int
1158 io_subchannel_notify(struct device *dev, int event)
1159 {
1160         struct ccw_device *cdev;
1161
1162         cdev = dev->driver_data;
1163         if (!cdev)
1164                 return 0;
1165         if (!cdev->drv)
1166                 return 0;
1167         if (!cdev->online)
1168                 return 0;
1169         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
1170 }
1171
1172 static void
1173 io_subchannel_verify(struct device *dev)
1174 {
1175         struct ccw_device *cdev;
1176
1177         cdev = dev->driver_data;
1178         if (cdev)
1179                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1180 }
1181
1182 static void
1183 io_subchannel_ioterm(struct device *dev)
1184 {
1185         struct ccw_device *cdev;
1186
1187         cdev = dev->driver_data;
1188         if (!cdev)
1189                 return;
1190         /* Internal I/O will be retried by the interrupt handler. */
1191         if (cdev->private->flags.intretry)
1192                 return;
1193         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1194         if (cdev->handler)
1195                 cdev->handler(cdev, cdev->private->intparm,
1196                               ERR_PTR(-EIO));
1197 }
1198
1199 static void
1200 io_subchannel_shutdown(struct subchannel *sch)
1201 {
1202         struct ccw_device *cdev;
1203         int ret;
1204
1205         cdev = sch->dev.driver_data;
1206
1207         if (cio_is_console(sch->schid))
1208                 return;
1209         if (!sch->schib.pmcw.ena)
1210                 /* Nothing to do. */
1211                 return;
1212         ret = cio_disable_subchannel(sch);
1213         if (ret != -EBUSY)
1214                 /* Subchannel is disabled, we're done. */
1215                 return;
1216         cdev->private->state = DEV_STATE_QUIESCE;
1217         if (cdev->handler)
1218                 cdev->handler(cdev, cdev->private->intparm,
1219                               ERR_PTR(-EIO));
1220         ret = ccw_device_cancel_halt_clear(cdev);
1221         if (ret == -EBUSY) {
1222                 ccw_device_set_timeout(cdev, HZ/10);
1223                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1224         }
1225         cio_disable_subchannel(sch);
1226 }
1227
1228 #ifdef CONFIG_CCW_CONSOLE
1229 static struct ccw_device console_cdev;
1230 static struct ccw_device_private console_private;
1231 static int console_cdev_in_use;
1232
1233 static DEFINE_SPINLOCK(ccw_console_lock);
1234
1235 spinlock_t * cio_get_console_lock(void)
1236 {
1237         return &ccw_console_lock;
1238 }
1239
1240 static int
1241 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
1242 {
1243         int rc;
1244
1245         /* Initialize the ccw_device structure. */
1246         cdev->dev.parent= &sch->dev;
1247         rc = io_subchannel_recog(cdev, sch);
1248         if (rc)
1249                 return rc;
1250
1251         /* Now wait for the async. recognition to come to an end. */
1252         spin_lock_irq(cdev->ccwlock);
1253         while (!dev_fsm_final_state(cdev))
1254                 wait_cons_dev();
1255         rc = -EIO;
1256         if (cdev->private->state != DEV_STATE_OFFLINE)
1257                 goto out_unlock;
1258         ccw_device_online(cdev);
1259         while (!dev_fsm_final_state(cdev))
1260                 wait_cons_dev();
1261         if (cdev->private->state != DEV_STATE_ONLINE)
1262                 goto out_unlock;
1263         rc = 0;
1264 out_unlock:
1265         spin_unlock_irq(cdev->ccwlock);
1266         return 0;
1267 }
1268
1269 struct ccw_device *
1270 ccw_device_probe_console(void)
1271 {
1272         struct subchannel *sch;
1273         int ret;
1274
1275         if (xchg(&console_cdev_in_use, 1) != 0)
1276                 return ERR_PTR(-EBUSY);
1277         sch = cio_probe_console();
1278         if (IS_ERR(sch)) {
1279                 console_cdev_in_use = 0;
1280                 return (void *) sch;
1281         }
1282         memset(&console_cdev, 0, sizeof(struct ccw_device));
1283         memset(&console_private, 0, sizeof(struct ccw_device_private));
1284         console_cdev.private = &console_private;
1285         console_private.cdev = &console_cdev;
1286         ret = ccw_device_console_enable(&console_cdev, sch);
1287         if (ret) {
1288                 cio_release_console();
1289                 console_cdev_in_use = 0;
1290                 return ERR_PTR(ret);
1291         }
1292         console_cdev.online = 1;
1293         return &console_cdev;
1294 }
1295 #endif
1296
1297 /*
1298  * get ccw_device matching the busid, but only if owned by cdrv
1299  */
1300 static int
1301 __ccwdev_check_busid(struct device *dev, void *id)
1302 {
1303         char *bus_id;
1304
1305         bus_id = id;
1306
1307         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1308 }
1309
1310
1311 struct ccw_device *
1312 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1313 {
1314         struct device *dev;
1315         struct device_driver *drv;
1316
1317         drv = get_driver(&cdrv->driver);
1318         if (!drv)
1319                 return NULL;
1320
1321         dev = driver_find_device(drv, NULL, (void *)bus_id,
1322                                  __ccwdev_check_busid);
1323         put_driver(drv);
1324
1325         return dev ? to_ccwdev(dev) : NULL;
1326 }
1327
1328 /************************** device driver handling ************************/
1329
1330 /* This is the implementation of the ccw_driver class. The probe, remove
1331  * and release methods are initially very similar to the device_driver
1332  * implementations, with the difference that they have ccw_device
1333  * arguments.
1334  *
1335  * A ccw driver also contains the information that is needed for
1336  * device matching.
1337  */
1338 static int
1339 ccw_device_probe (struct device *dev)
1340 {
1341         struct ccw_device *cdev = to_ccwdev(dev);
1342         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1343         int ret;
1344
1345         cdev->drv = cdrv; /* to let the driver call _set_online */
1346
1347         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1348
1349         if (ret) {
1350                 cdev->drv = NULL;
1351                 return ret;
1352         }
1353
1354         return 0;
1355 }
1356
1357 static int
1358 ccw_device_remove (struct device *dev)
1359 {
1360         struct ccw_device *cdev = to_ccwdev(dev);
1361         struct ccw_driver *cdrv = cdev->drv;
1362         int ret;
1363
1364         pr_debug("removing device %s\n", cdev->dev.bus_id);
1365         if (cdrv->remove)
1366                 cdrv->remove(cdev);
1367         if (cdev->online) {
1368                 cdev->online = 0;
1369                 spin_lock_irq(cdev->ccwlock);
1370                 ret = ccw_device_offline(cdev);
1371                 spin_unlock_irq(cdev->ccwlock);
1372                 if (ret == 0)
1373                         wait_event(cdev->private->wait_q,
1374                                    dev_fsm_final_state(cdev));
1375                 else
1376                         //FIXME: we can't fail!
1377                         pr_debug("ccw_device_offline returned %d, device %s\n",
1378                                  ret, cdev->dev.bus_id);
1379         }
1380         ccw_device_set_timeout(cdev, 0);
1381         cdev->drv = NULL;
1382         return 0;
1383 }
1384
1385 struct bus_type ccw_bus_type = {
1386         .name   = "ccw",
1387         .match  = ccw_bus_match,
1388         .uevent = ccw_uevent,
1389         .probe  = ccw_device_probe,
1390         .remove = ccw_device_remove,
1391 };
1392
1393 int
1394 ccw_driver_register (struct ccw_driver *cdriver)
1395 {
1396         struct device_driver *drv = &cdriver->driver;
1397
1398         drv->bus = &ccw_bus_type;
1399         drv->name = cdriver->name;
1400
1401         return driver_register(drv);
1402 }
1403
1404 void
1405 ccw_driver_unregister (struct ccw_driver *cdriver)
1406 {
1407         driver_unregister(&cdriver->driver);
1408 }
1409
1410 /* Helper func for qdio. */
1411 struct subchannel_id
1412 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1413 {
1414         struct subchannel *sch;
1415
1416         sch = to_subchannel(cdev->dev.parent);
1417         return sch->schid;
1418 }
1419
1420 MODULE_LICENSE("GPL");
1421 EXPORT_SYMBOL(ccw_device_set_online);
1422 EXPORT_SYMBOL(ccw_device_set_offline);
1423 EXPORT_SYMBOL(ccw_driver_register);
1424 EXPORT_SYMBOL(ccw_driver_unregister);
1425 EXPORT_SYMBOL(get_ccwdev_by_busid);
1426 EXPORT_SYMBOL(ccw_bus_type);
1427 EXPORT_SYMBOL(ccw_device_work);
1428 EXPORT_SYMBOL(ccw_device_notify_work);
1429 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);