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, const char *prefix,
  60                          struct ccw_device_id *id, const char *suffix)
  61 {
  62         int len;
  63
  64         len = snprintf(buf, size, "%sccw:t%04Xm%02X", prefix, id->cu_type,
  65                        id->cu_model);
  66         if (len > size)
  67                 return len;
  68         buf += len;
  69         size -= len;
  70
  71         if (id->dev_type != 0)
  72                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  73                                 id->dev_model, suffix);
  74         else
  75                 len += snprintf(buf, size, "dtdm%s", suffix);
  76
  77         return len;
  78 }
  79
  80 /* Set up environment variables for ccw device uevent. Return 0 on success,
  81  * non-zero otherwise. */
  82 static int ccw_uevent(struct device *dev, char **envp, int num_envp,
  83                       char *buffer, int buffer_size)
  84 {
  85         struct ccw_device *cdev = to_ccwdev(dev);
  86         struct ccw_device_id *id = &(cdev->id);
  87         int i = 0;
  88         int len;
  89
  90         /* CU_TYPE= */
  91         len = snprintf(buffer, buffer_size, "CU_TYPE=%04X", id->cu_type) + 1;
  92         if (len > buffer_size || i >= num_envp)
  93                 return -ENOMEM;
  94         envp[i++] = buffer;
  95         buffer += len;
  96         buffer_size -= len;
  97
  98         /* CU_MODEL= */
  99         len = snprintf(buffer, buffer_size, "CU_MODEL=%02X", id->cu_model) + 1;
 100         if (len > buffer_size || i >= num_envp)
 101                 return -ENOMEM;
 102         envp[i++] = buffer;
 103         buffer += len;
 104         buffer_size -= len;
 105
 106         /* The next two can be zero, that's ok for us */
 107         /* DEV_TYPE= */
 108         len = snprintf(buffer, buffer_size, "DEV_TYPE=%04X", id->dev_type) + 1;
 109         if (len > buffer_size || i >= num_envp)
 110                 return -ENOMEM;
 111         envp[i++] = buffer;
 112         buffer += len;
 113         buffer_size -= len;
 114
 115         /* DEV_MODEL= */
 116         len = snprintf(buffer, buffer_size, "DEV_MODEL=%02X",
 117                         (unsigned char) id->dev_model) + 1;
 118         if (len > buffer_size || i >= num_envp)
 119                 return -ENOMEM;
 120         envp[i++] = buffer;
 121         buffer += len;
 122         buffer_size -= len;
 123
 124         /* MODALIAS=  */
 125         len = snprint_alias(buffer, buffer_size, "MODALIAS=", id, "") + 1;
 126         if (len > buffer_size || i >= num_envp)
 127                 return -ENOMEM;
 128         envp[i++] = buffer;
 129         buffer += len;
 130         buffer_size -= len;
 131
 132         envp[i] = NULL;
 133
 134         return 0;
 135 }
 136
 137 struct bus_type ccw_bus_type;
 138
 139 static int io_subchannel_probe (struct subchannel *);
 140 static int io_subchannel_remove (struct subchannel *);
 141 void io_subchannel_irq (struct device *);
 142 static int io_subchannel_notify(struct device *, int);
 143 static void io_subchannel_verify(struct device *);
 144 static void io_subchannel_ioterm(struct device *);
 145 static void io_subchannel_shutdown(struct subchannel *);
 146
 147 struct css_driver io_subchannel_driver = {
 148         .subchannel_type = SUBCHANNEL_TYPE_IO,
 149         .drv = {
 150                 .name = "io_subchannel",
 151                 .bus  = &css_bus_type,
 152         },
 153         .irq = io_subchannel_irq,
 154         .notify = io_subchannel_notify,
 155         .verify = io_subchannel_verify,
 156         .termination = io_subchannel_ioterm,
 157         .probe = io_subchannel_probe,
 158         .remove = io_subchannel_remove,
 159         .shutdown = io_subchannel_shutdown,
 160 };
 161
 162 struct workqueue_struct *ccw_device_work;
 163 struct workqueue_struct *ccw_device_notify_work;
 164 wait_queue_head_t ccw_device_init_wq;
 165 atomic_t ccw_device_init_count;
 166
 167 static int __init
 168 init_ccw_bus_type (void)
 169 {
 170         int ret;
 171
 172         init_waitqueue_head(&ccw_device_init_wq);
 173         atomic_set(&ccw_device_init_count, 0);
 174
 175         ccw_device_work = create_singlethread_workqueue("cio");
 176         if (!ccw_device_work)
 177                 return -ENOMEM; /* FIXME: better errno ? */
 178         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
 179         if (!ccw_device_notify_work) {
 180                 ret = -ENOMEM; /* FIXME: better errno ? */
 181                 goto out_err;
 182         }
 183         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 184         if (!slow_path_wq) {
 185                 ret = -ENOMEM; /* FIXME: better errno ? */
 186                 goto out_err;
 187         }
 188         if ((ret = bus_register (&ccw_bus_type)))
 189                 goto out_err;
 190
 191         if ((ret = driver_register(&io_subchannel_driver.drv)))
 192                 goto out_err;
 193
 194         wait_event(ccw_device_init_wq,
 195                    atomic_read(&ccw_device_init_count) == 0);
 196         flush_workqueue(ccw_device_work);
 197         return 0;
 198 out_err:
 199         if (ccw_device_work)
 200                 destroy_workqueue(ccw_device_work);
 201         if (ccw_device_notify_work)
 202                 destroy_workqueue(ccw_device_notify_work);
 203         if (slow_path_wq)
 204                 destroy_workqueue(slow_path_wq);
 205         return ret;
 206 }
 207
 208 static void __exit
 209 cleanup_ccw_bus_type (void)
 210 {
 211         driver_unregister(&io_subchannel_driver.drv);
 212         bus_unregister(&ccw_bus_type);
 213         destroy_workqueue(ccw_device_notify_work);
 214         destroy_workqueue(ccw_device_work);
 215 }
 216
 217 subsys_initcall(init_ccw_bus_type);
 218 module_exit(cleanup_ccw_bus_type);
 219
 220 /************************ device handling **************************/
 221
 222 /*
 223  * A ccw_device has some interfaces in sysfs in addition to the
 224  * standard ones.
 225  * The following entries are designed to export the information which
 226  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 227  * are obvious, so they don't have an entry :)
 228  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 229  */
 230 static ssize_t
 231 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 232 {
 233         struct subchannel *sch = to_subchannel(dev);
 234         struct ssd_info *ssd = &sch->ssd_info;
 235         ssize_t ret = 0;
 236         int chp;
 237
 238         if (ssd)
 239                 for (chp = 0; chp < 8; chp++)
 240                         ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);
 241         else
 242                 ret += sprintf (buf, "n/a");
 243         ret += sprintf (buf+ret, "\n");
 244         return min((ssize_t)PAGE_SIZE, ret);
 245 }
 246
 247 static ssize_t
 248 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 249 {
 250         struct subchannel *sch = to_subchannel(dev);
 251         struct pmcw *pmcw = &sch->schib.pmcw;
 252
 253         return sprintf (buf, "%02x %02x %02x\n",
 254                         pmcw->pim, pmcw->pam, pmcw->pom);
 255 }
 256
 257 static ssize_t
 258 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 259 {
 260         struct ccw_device *cdev = to_ccwdev(dev);
 261         struct ccw_device_id *id = &(cdev->id);
 262
 263         if (id->dev_type != 0)
 264                 return sprintf(buf, "%04x/%02x\n",
 265                                 id->dev_type, id->dev_model);
 266         else
 267                 return sprintf(buf, "n/a\n");
 268 }
 269
 270 static ssize_t
 271 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 272 {
 273         struct ccw_device *cdev = to_ccwdev(dev);
 274         struct ccw_device_id *id = &(cdev->id);
 275
 276         return sprintf(buf, "%04x/%02x\n",
 277                        id->cu_type, id->cu_model);
 278 }
 279
 280 static ssize_t
 281 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 282 {
 283         struct ccw_device *cdev = to_ccwdev(dev);
 284         struct ccw_device_id *id = &(cdev->id);
 285         int len;
 286
 287         len = snprint_alias(buf, PAGE_SIZE, "", id, "\n") + 1;
 288
 289         return len > PAGE_SIZE ? PAGE_SIZE : len;
 290 }
 291
 292 static ssize_t
 293 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 294 {
 295         struct ccw_device *cdev = to_ccwdev(dev);
 296
 297         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 298 }
 299
 300 int ccw_device_is_orphan(struct ccw_device *cdev)
 301 {
 302         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 303 }
 304
 305 static void ccw_device_unregister(struct work_struct *work)
 306 {
 307         struct ccw_device_private *priv;
 308         struct ccw_device *cdev;
 309
 310         priv = container_of(work, struct ccw_device_private, kick_work);
 311         cdev = priv->cdev;
 312         if (test_and_clear_bit(1, &cdev->private->registered))
 313                 device_unregister(&cdev->dev);
 314         put_device(&cdev->dev);
 315 }
 316
 317 static void
 318 ccw_device_remove_disconnected(struct ccw_device *cdev)
 319 {
 320         struct subchannel *sch;
 321         unsigned long flags;
 322         /*
 323          * Forced offline in disconnected state means
 324          * 'throw away device'.
 325          */
 326         if (ccw_device_is_orphan(cdev)) {
 327                 /* Deregister ccw device. */
 328                 spin_lock_irqsave(cdev->ccwlock, flags);
 329                 cdev->private->state = DEV_STATE_NOT_OPER;
 330                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 331                 if (get_device(&cdev->dev)) {
 332                         PREPARE_WORK(&cdev->private->kick_work,
 333                                      ccw_device_unregister);
 334                         queue_work(ccw_device_work, &cdev->private->kick_work);
 335                 }
 336                 return ;
 337         }
 338         sch = to_subchannel(cdev->dev.parent);
 339         css_sch_device_unregister(sch);
 340         /* Reset intparm to zeroes. */
 341         sch->schib.pmcw.intparm = 0;
 342         cio_modify(sch);
 343         put_device(&sch->dev);
 344 }
 345
 346 int
 347 ccw_device_set_offline(struct ccw_device *cdev)
 348 {
 349         int ret;
 350
 351         if (!cdev)
 352                 return -ENODEV;
 353         if (!cdev->online || !cdev->drv)
 354                 return -EINVAL;
 355
 356         if (cdev->drv->set_offline) {
 357                 ret = cdev->drv->set_offline(cdev);
 358                 if (ret != 0)
 359                         return ret;
 360         }
 361         cdev->online = 0;
 362         spin_lock_irq(cdev->ccwlock);
 363         ret = ccw_device_offline(cdev);
 364         if (ret == -ENODEV) {
 365                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 366                         cdev->private->state = DEV_STATE_OFFLINE;
 367                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 368                 }
 369                 spin_unlock_irq(cdev->ccwlock);
 370                 return ret;
 371         }
 372         spin_unlock_irq(cdev->ccwlock);
 373         if (ret == 0)
 374                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 375         else {
 376                 pr_debug("ccw_device_offline returned %d, device %s\n",
 377                          ret, cdev->dev.bus_id);
 378                 cdev->online = 1;
 379         }
 380         return ret;
 381 }
 382
 383 int
 384 ccw_device_set_online(struct ccw_device *cdev)
 385 {
 386         int ret;
 387
 388         if (!cdev)
 389                 return -ENODEV;
 390         if (cdev->online || !cdev->drv)
 391                 return -EINVAL;
 392
 393         spin_lock_irq(cdev->ccwlock);
 394         ret = ccw_device_online(cdev);
 395         spin_unlock_irq(cdev->ccwlock);
 396         if (ret == 0)
 397                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 398         else {
 399                 pr_debug("ccw_device_online returned %d, device %s\n",
 400                          ret, cdev->dev.bus_id);
 401                 return ret;
 402         }
 403         if (cdev->private->state != DEV_STATE_ONLINE)
 404                 return -ENODEV;
 405         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 406                 cdev->online = 1;
 407                 return 0;
 408         }
 409         spin_lock_irq(cdev->ccwlock);
 410         ret = ccw_device_offline(cdev);
 411         spin_unlock_irq(cdev->ccwlock);
 412         if (ret == 0)
 413                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 414         else
 415                 pr_debug("ccw_device_offline returned %d, device %s\n",
 416                          ret, cdev->dev.bus_id);
 417         return (ret == 0) ? -ENODEV : ret;
 418 }
 419
 420 static ssize_t
 421 online_store (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 422 {
 423         struct ccw_device *cdev = to_ccwdev(dev);
 424         int i, force, ret;
 425         char *tmp;
 426
 427         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 428                 return -EAGAIN;
 429
 430         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 431                 atomic_set(&cdev->private->onoff, 0);
 432                 return -EINVAL;
 433         }
 434         if (!strncmp(buf, "force\n", count)) {
 435                 force = 1;
 436                 i = 1;
 437         } else {
 438                 force = 0;
 439                 i = simple_strtoul(buf, &tmp, 16);
 440         }
 441         if (i == 1) {
 442                 /* Do device recognition, if needed. */
 443                 if (cdev->id.cu_type == 0) {
 444                         ret = ccw_device_recognition(cdev);
 445                         if (ret) {
 446                                 printk(KERN_WARNING"Couldn't start recognition "
 447                                        "for device %s (ret=%d)\n",
 448                                        cdev->dev.bus_id, ret);
 449                                 goto out;
 450                         }
 451                         wait_event(cdev->private->wait_q,
 452                                    cdev->private->flags.recog_done);
 453                 }
 454                 if (cdev->drv && cdev->drv->set_online)
 455                         ccw_device_set_online(cdev);
 456         } else if (i == 0) {
 457                 if (cdev->private->state == DEV_STATE_DISCONNECTED)
 458                         ccw_device_remove_disconnected(cdev);
 459                 else if (cdev->drv && cdev->drv->set_offline)
 460                         ccw_device_set_offline(cdev);
 461         }
 462         if (force && cdev->private->state == DEV_STATE_BOXED) {
 463                 ret = ccw_device_stlck(cdev);
 464                 if (ret) {
 465                         printk(KERN_WARNING"ccw_device_stlck for device %s "
 466                                "returned %d!\n", cdev->dev.bus_id, ret);
 467                         goto out;
 468                 }
 469                 /* Do device recognition, if needed. */
 470                 if (cdev->id.cu_type == 0) {
 471                         cdev->private->state = DEV_STATE_NOT_OPER;
 472                         ret = ccw_device_recognition(cdev);
 473                         if (ret) {
 474                                 printk(KERN_WARNING"Couldn't start recognition "
 475                                        "for device %s (ret=%d)\n",
 476                                        cdev->dev.bus_id, ret);
 477                                 goto out;
 478                         }
 479                         wait_event(cdev->private->wait_q,
 480                                    cdev->private->flags.recog_done);
 481                 }
 482                 if (cdev->drv && cdev->drv->set_online)
 483                         ccw_device_set_online(cdev);
 484         }
 485         out:
 486         if (cdev->drv)
 487                 module_put(cdev->drv->owner);
 488         atomic_set(&cdev->private->onoff, 0);
 489         return count;
 490 }
 491
 492 static ssize_t
 493 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 494 {
 495         struct ccw_device *cdev = to_ccwdev(dev);
 496         struct subchannel *sch;
 497
 498         if (ccw_device_is_orphan(cdev))
 499                 return sprintf(buf, "no device\n");
 500         switch (cdev->private->state) {
 501         case DEV_STATE_BOXED:
 502                 return sprintf(buf, "boxed\n");
 503         case DEV_STATE_DISCONNECTED:
 504         case DEV_STATE_DISCONNECTED_SENSE_ID:
 505         case DEV_STATE_NOT_OPER:
 506                 sch = to_subchannel(dev->parent);
 507                 if (!sch->lpm)
 508                         return sprintf(buf, "no path\n");
 509                 else
 510                         return sprintf(buf, "no device\n");
 511         default:
 512                 /* All other states considered fine. */
 513                 return sprintf(buf, "good\n");
 514         }
 515 }
 516
 517 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 518 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 519 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 520 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 521 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 522 static DEVICE_ATTR(online, 0644, online_show, online_store);
 523 extern struct device_attribute dev_attr_cmb_enable;
 524 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 525
 526 static struct attribute * subch_attrs[] = {
 527         &dev_attr_chpids.attr,
 528         &dev_attr_pimpampom.attr,
 529         NULL,
 530 };
 531
 532 static struct attribute_group subch_attr_group = {
 533         .attrs = subch_attrs,
 534 };
 535
 536 struct attribute_group *subch_attr_groups[] = {
 537         &subch_attr_group,
 538         NULL,
 539 };
 540
 541 static struct attribute * ccwdev_attrs[] = {
 542         &dev_attr_devtype.attr,
 543         &dev_attr_cutype.attr,
 544         &dev_attr_modalias.attr,
 545         &dev_attr_online.attr,
 546         &dev_attr_cmb_enable.attr,
 547         &dev_attr_availability.attr,
 548         NULL,
 549 };
 550
 551 static struct attribute_group ccwdev_attr_group = {
 552         .attrs = ccwdev_attrs,
 553 };
 554
 555 static inline int
 556 device_add_files (struct device *dev)
 557 {
 558         return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
 559 }
 560
 561 static inline void
 562 device_remove_files(struct device *dev)
 563 {
 564         sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
 565 }
 566
 567 /* this is a simple abstraction for device_register that sets the
 568  * correct bus type and adds the bus specific files */
 569 static int ccw_device_register(struct ccw_device *cdev)
 570 {
 571         struct device *dev = &cdev->dev;
 572         int ret;
 573
 574         dev->bus = &ccw_bus_type;
 575
 576         if ((ret = device_add(dev)))
 577                 return ret;
 578
 579         set_bit(1, &cdev->private->registered);
 580         if ((ret = device_add_files(dev))) {
 581                 if (test_and_clear_bit(1, &cdev->private->registered))
 582                         device_del(dev);
 583         }
 584         return ret;
 585 }
 586
 587 struct match_data {
 588         struct ccw_dev_id dev_id;
 589         struct ccw_device * sibling;
 590 };
 591
 592 static int
 593 match_devno(struct device * dev, void * data)
 594 {
 595         struct match_data * d = data;
 596         struct ccw_device * cdev;
 597
 598         cdev = to_ccwdev(dev);
 599         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 600             !ccw_device_is_orphan(cdev) &&
 601             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 602             (cdev != d->sibling))
 603                 return 1;
 604         return 0;
 605 }
 606
 607 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 608                                                      struct ccw_device *sibling)
 609 {
 610         struct device *dev;
 611         struct match_data data;
 612
 613         data.dev_id = *dev_id;
 614         data.sibling = sibling;
 615         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 616
 617         return dev ? to_ccwdev(dev) : NULL;
 618 }
 619
 620 static int match_orphan(struct device *dev, void *data)
 621 {
 622         struct ccw_dev_id *dev_id;
 623         struct ccw_device *cdev;
 624
 625         dev_id = data;
 626         cdev = to_ccwdev(dev);
 627         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 628 }
 629
 630 static struct ccw_device *
 631 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 632                               struct ccw_dev_id *dev_id)
 633 {
 634         struct device *dev;
 635
 636         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 637                                 match_orphan);
 638
 639         return dev ? to_ccwdev(dev) : NULL;
 640 }
 641
 642 static void
 643 ccw_device_add_changed(struct work_struct *work)
 644 {
 645         struct ccw_device_private *priv;
 646         struct ccw_device *cdev;
 647
 648         priv = container_of(work, struct ccw_device_private, kick_work);
 649         cdev = priv->cdev;
 650         if (device_add(&cdev->dev)) {
 651                 put_device(&cdev->dev);
 652                 return;
 653         }
 654         set_bit(1, &cdev->private->registered);
 655         if (device_add_files(&cdev->dev)) {
 656                 if (test_and_clear_bit(1, &cdev->private->registered))
 657                         device_unregister(&cdev->dev);
 658         }
 659 }
 660
 661 void ccw_device_do_unreg_rereg(struct work_struct *work)
 662 {
 663         struct ccw_device_private *priv;
 664         struct ccw_device *cdev;
 665         struct subchannel *sch;
 666
 667         priv = container_of(work, struct ccw_device_private, kick_work);
 668         cdev = priv->cdev;
 669         sch = to_subchannel(cdev->dev.parent);
 670
 671         device_remove_files(&cdev->dev);
 672         if (test_and_clear_bit(1, &cdev->private->registered))
 673                 device_del(&cdev->dev);
 674         PREPARE_WORK(&cdev->private->kick_work,
 675                      ccw_device_add_changed);
 676         queue_work(ccw_device_work, &cdev->private->kick_work);
 677 }
 678
 679 static void
 680 ccw_device_release(struct device *dev)
 681 {
 682         struct ccw_device *cdev;
 683
 684         cdev = to_ccwdev(dev);
 685         kfree(cdev->private);
 686         kfree(cdev);
 687 }
 688
 689 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 690 {
 691         struct ccw_device *cdev;
 692
 693         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 694         if (cdev) {
 695                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 696                                         GFP_KERNEL | GFP_DMA);
 697                 if (cdev->private)
 698                         return cdev;
 699         }
 700         kfree(cdev);
 701         return ERR_PTR(-ENOMEM);
 702 }
 703
 704 static int io_subchannel_initialize_dev(struct subchannel *sch,
 705                                         struct ccw_device *cdev)
 706 {
 707         cdev->private->cdev = cdev;
 708         atomic_set(&cdev->private->onoff, 0);
 709         cdev->dev.parent = &sch->dev;
 710         cdev->dev.release = ccw_device_release;
 711         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 712         /* Do first half of device_register. */
 713         device_initialize(&cdev->dev);
 714         if (!get_device(&sch->dev)) {
 715                 if (cdev->dev.release)
 716                         cdev->dev.release(&cdev->dev);
 717                 return -ENODEV;
 718         }
 719         return 0;
 720 }
 721
 722 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 723 {
 724         struct ccw_device *cdev;
 725         int ret;
 726
 727         cdev = io_subchannel_allocate_dev(sch);
 728         if (!IS_ERR(cdev)) {
 729                 ret = io_subchannel_initialize_dev(sch, cdev);
 730                 if (ret) {
 731                         kfree(cdev);
 732                         cdev = ERR_PTR(ret);
 733                 }
 734         }
 735         return cdev;
 736 }
 737
 738 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 739
 740 static void sch_attach_device(struct subchannel *sch,
 741                               struct ccw_device *cdev)
 742 {
 743         spin_lock_irq(sch->lock);
 744         sch->dev.driver_data = cdev;
 745         cdev->private->schid = sch->schid;
 746         cdev->ccwlock = sch->lock;
 747         device_trigger_reprobe(sch);
 748         spin_unlock_irq(sch->lock);
 749 }
 750
 751 static void sch_attach_disconnected_device(struct subchannel *sch,
 752                                            struct ccw_device *cdev)
 753 {
 754         struct subchannel *other_sch;
 755         int ret;
 756
 757         other_sch = to_subchannel(get_device(cdev->dev.parent));
 758         ret = device_move(&cdev->dev, &sch->dev);
 759         if (ret) {
 760                 CIO_MSG_EVENT(2, "Moving disconnected device 0.%x.%04x failed "
 761                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 762                               cdev->private->dev_id.devno, ret);
 763                 put_device(&other_sch->dev);
 764                 return;
 765         }
 766         other_sch->dev.driver_data = NULL;
 767         /* No need to keep a subchannel without ccw device around. */
 768         css_sch_device_unregister(other_sch);
 769         put_device(&other_sch->dev);
 770         sch_attach_device(sch, cdev);
 771 }
 772
 773 static void sch_attach_orphaned_device(struct subchannel *sch,
 774                                        struct ccw_device *cdev)
 775 {
 776         int ret;
 777
 778         /* Try to move the ccw device to its new subchannel. */
 779         ret = device_move(&cdev->dev, &sch->dev);
 780         if (ret) {
 781                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 782                               "failed (ret=%d)!\n",
 783                               cdev->private->dev_id.ssid,
 784                               cdev->private->dev_id.devno, ret);
 785                 return;
 786         }
 787         sch_attach_device(sch, cdev);
 788 }
 789
 790 static void sch_create_and_recog_new_device(struct subchannel *sch)
 791 {
 792         struct ccw_device *cdev;
 793
 794         /* Need to allocate a new ccw device. */
 795         cdev = io_subchannel_create_ccwdev(sch);
 796         if (IS_ERR(cdev)) {
 797                 /* OK, we did everything we could... */
 798                 css_sch_device_unregister(sch);
 799                 return;
 800         }
 801         spin_lock_irq(sch->lock);
 802         sch->dev.driver_data = cdev;
 803         spin_unlock_irq(sch->lock);
 804         /* Start recognition for the new ccw device. */
 805         if (io_subchannel_recog(cdev, sch)) {
 806                 spin_lock_irq(sch->lock);
 807                 sch->dev.driver_data = NULL;
 808                 spin_unlock_irq(sch->lock);
 809                 if (cdev->dev.release)
 810                         cdev->dev.release(&cdev->dev);
 811                 css_sch_device_unregister(sch);
 812         }
 813 }
 814
 815
 816 void ccw_device_move_to_orphanage(struct work_struct *work)
 817 {
 818         struct ccw_device_private *priv;
 819         struct ccw_device *cdev;
 820         struct ccw_device *replacing_cdev;
 821         struct subchannel *sch;
 822         int ret;
 823         struct channel_subsystem *css;
 824         struct ccw_dev_id dev_id;
 825
 826         priv = container_of(work, struct ccw_device_private, kick_work);
 827         cdev = priv->cdev;
 828         sch = to_subchannel(cdev->dev.parent);
 829         css = to_css(sch->dev.parent);
 830         dev_id.devno = sch->schib.pmcw.dev;
 831         dev_id.ssid = sch->schid.ssid;
 832
 833         /*
 834          * Move the orphaned ccw device to the orphanage so the replacing
 835          * ccw device can take its place on the subchannel.
 836          */
 837         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
 838         if (ret) {
 839                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 840                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 841                               cdev->private->dev_id.devno, ret);
 842                 return;
 843         }
 844         cdev->ccwlock = css->pseudo_subchannel->lock;
 845         /*
 846          * Search for the replacing ccw device
 847          * - among the disconnected devices
 848          * - in the orphanage
 849          */
 850         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 851         if (replacing_cdev) {
 852                 sch_attach_disconnected_device(sch, replacing_cdev);
 853                 return;
 854         }
 855         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 856         if (replacing_cdev) {
 857                 sch_attach_orphaned_device(sch, replacing_cdev);
 858                 return;
 859         }
 860         sch_create_and_recog_new_device(sch);
 861 }
 862
 863 /*
 864  * Register recognized device.
 865  */
 866 static void
 867 io_subchannel_register(struct work_struct *work)
 868 {
 869         struct ccw_device_private *priv;
 870         struct ccw_device *cdev;
 871         struct subchannel *sch;
 872         int ret;
 873         unsigned long flags;
 874
 875         priv = container_of(work, struct ccw_device_private, kick_work);
 876         cdev = priv->cdev;
 877         sch = to_subchannel(cdev->dev.parent);
 878
 879         /*
 880          * io_subchannel_register() will also be called after device
 881          * recognition has been done for a boxed device (which will already
 882          * be registered). We need to reprobe since we may now have sense id
 883          * information.
 884          */
 885         if (klist_node_attached(&cdev->dev.knode_parent)) {
 886                 if (!cdev->drv) {
 887                         ret = device_reprobe(&cdev->dev);
 888                         if (ret)
 889                                 /* We can't do much here. */
 890                                 dev_info(&cdev->dev, "device_reprobe() returned"
 891                                          " %d\n", ret);
 892                 }
 893                 goto out;
 894         }
 895         /* make it known to the system */
 896         ret = ccw_device_register(cdev);
 897         if (ret) {
 898                 printk (KERN_WARNING "%s: could not register %s\n",
 899                         __func__, cdev->dev.bus_id);
 900                 put_device(&cdev->dev);
 901                 spin_lock_irqsave(sch->lock, flags);
 902                 sch->dev.driver_data = NULL;
 903                 spin_unlock_irqrestore(sch->lock, flags);
 904                 kfree (cdev->private);
 905                 kfree (cdev);
 906                 put_device(&sch->dev);
 907                 if (atomic_dec_and_test(&ccw_device_init_count))
 908                         wake_up(&ccw_device_init_wq);
 909                 return;
 910         }
 911         put_device(&cdev->dev);
 912 out:
 913         cdev->private->flags.recog_done = 1;
 914         put_device(&sch->dev);
 915         wake_up(&cdev->private->wait_q);
 916         if (atomic_dec_and_test(&ccw_device_init_count))
 917                 wake_up(&ccw_device_init_wq);
 918 }
 919
 920 void
 921 ccw_device_call_sch_unregister(struct work_struct *work)
 922 {
 923         struct ccw_device_private *priv;
 924         struct ccw_device *cdev;
 925         struct subchannel *sch;
 926
 927         priv = container_of(work, struct ccw_device_private, kick_work);
 928         cdev = priv->cdev;
 929         sch = to_subchannel(cdev->dev.parent);
 930         css_sch_device_unregister(sch);
 931         /* Reset intparm to zeroes. */
 932         sch->schib.pmcw.intparm = 0;
 933         cio_modify(sch);
 934         put_device(&cdev->dev);
 935         put_device(&sch->dev);
 936 }
 937
 938 /*
 939  * subchannel recognition done. Called from the state machine.
 940  */
 941 void
 942 io_subchannel_recog_done(struct ccw_device *cdev)
 943 {
 944         struct subchannel *sch;
 945
 946         if (css_init_done == 0) {
 947                 cdev->private->flags.recog_done = 1;
 948                 return;
 949         }
 950         switch (cdev->private->state) {
 951         case DEV_STATE_NOT_OPER:
 952                 cdev->private->flags.recog_done = 1;
 953                 /* Remove device found not operational. */
 954                 if (!get_device(&cdev->dev))
 955                         break;
 956                 sch = to_subchannel(cdev->dev.parent);
 957                 PREPARE_WORK(&cdev->private->kick_work,
 958                              ccw_device_call_sch_unregister);
 959                 queue_work(slow_path_wq, &cdev->private->kick_work);
 960                 if (atomic_dec_and_test(&ccw_device_init_count))
 961                         wake_up(&ccw_device_init_wq);
 962                 break;
 963         case DEV_STATE_BOXED:
 964                 /* Device did not respond in time. */
 965         case DEV_STATE_OFFLINE:
 966                 /*
 967                  * We can't register the device in interrupt context so
 968                  * we schedule a work item.
 969                  */
 970                 if (!get_device(&cdev->dev))
 971                         break;
 972                 PREPARE_WORK(&cdev->private->kick_work,
 973                              io_subchannel_register);
 974                 queue_work(slow_path_wq, &cdev->private->kick_work);
 975                 break;
 976         }
 977 }
 978
 979 static int
 980 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 981 {
 982         int rc;
 983         struct ccw_device_private *priv;
 984
 985         sch->dev.driver_data = cdev;
 986         sch->driver = &io_subchannel_driver;
 987         cdev->ccwlock = sch->lock;
 988
 989         /* Init private data. */
 990         priv = cdev->private;
 991         priv->dev_id.devno = sch->schib.pmcw.dev;
 992         priv->dev_id.ssid = sch->schid.ssid;
 993         priv->schid = sch->schid;
 994         priv->state = DEV_STATE_NOT_OPER;
 995         INIT_LIST_HEAD(&priv->cmb_list);
 996         init_waitqueue_head(&priv->wait_q);
 997         init_timer(&priv->timer);
 998
 999         /* Set an initial name for the device. */
1000         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
1001                   sch->schid.ssid, sch->schib.pmcw.dev);
1002
1003         /* Increase counter of devices currently in recognition. */
1004         atomic_inc(&ccw_device_init_count);
1005
1006         /* Start async. device sensing. */
1007         spin_lock_irq(sch->lock);
1008         rc = ccw_device_recognition(cdev);
1009         spin_unlock_irq(sch->lock);
1010         if (rc) {
1011                 if (atomic_dec_and_test(&ccw_device_init_count))
1012                         wake_up(&ccw_device_init_wq);
1013         }
1014         return rc;
1015 }
1016
1017 static void ccw_device_move_to_sch(struct work_struct *work)
1018 {
1019         struct ccw_device_private *priv;
1020         int rc;
1021         struct subchannel *sch;
1022         struct ccw_device *cdev;
1023         struct subchannel *former_parent;
1024
1025         priv = container_of(work, struct ccw_device_private, kick_work);
1026         sch = priv->sch;
1027         cdev = priv->cdev;
1028         former_parent = ccw_device_is_orphan(cdev) ?
1029                 NULL : to_subchannel(get_device(cdev->dev.parent));
1030         mutex_lock(&sch->reg_mutex);
1031         /* Try to move the ccw device to its new subchannel. */
1032         rc = device_move(&cdev->dev, &sch->dev);
1033         mutex_unlock(&sch->reg_mutex);
1034         if (rc) {
1035                 CIO_MSG_EVENT(2, "Moving device 0.%x.%04x to subchannel "
1036                               "0.%x.%04x failed (ret=%d)!\n",
1037                               cdev->private->dev_id.ssid,
1038                               cdev->private->dev_id.devno, sch->schid.ssid,
1039                               sch->schid.sch_no, rc);
1040                 css_sch_device_unregister(sch);
1041                 goto out;
1042         }
1043         if (former_parent) {
1044                 spin_lock_irq(former_parent->lock);
1045                 former_parent->dev.driver_data = NULL;
1046                 spin_unlock_irq(former_parent->lock);
1047                 css_sch_device_unregister(former_parent);
1048                 /* Reset intparm to zeroes. */
1049                 former_parent->schib.pmcw.intparm = 0;
1050                 cio_modify(former_parent);
1051         }
1052         sch_attach_device(sch, cdev);
1053 out:
1054         if (former_parent)
1055                 put_device(&former_parent->dev);
1056         put_device(&cdev->dev);
1057 }
1058
1059 static int
1060 io_subchannel_probe (struct subchannel *sch)
1061 {
1062         struct ccw_device *cdev;
1063         int rc;
1064         unsigned long flags;
1065         struct ccw_dev_id dev_id;
1066
1067         if (sch->dev.driver_data) {
1068                 /*
1069                  * This subchannel already has an associated ccw_device.
1070                  * Register it and exit. This happens for all early
1071                  * device, e.g. the console.
1072                  */
1073                 cdev = sch->dev.driver_data;
1074                 device_initialize(&cdev->dev);
1075                 ccw_device_register(cdev);
1076                 /*
1077                  * Check if the device is already online. If it is
1078                  * the reference count needs to be corrected
1079                  * (see ccw_device_online and css_init_done for the
1080                  * ugly details).
1081                  */
1082                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1083                     cdev->private->state != DEV_STATE_OFFLINE &&
1084                     cdev->private->state != DEV_STATE_BOXED)
1085                         get_device(&cdev->dev);
1086                 return 0;
1087         }
1088         /*
1089          * First check if a fitting device may be found amongst the
1090          * disconnected devices or in the orphanage.
1091          */
1092         dev_id.devno = sch->schib.pmcw.dev;
1093         dev_id.ssid = sch->schid.ssid;
1094         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1095         if (!cdev)
1096                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1097                                                      &dev_id);
1098         if (cdev) {
1099                 /*
1100                  * Schedule moving the device until when we have a registered
1101                  * subchannel to move to and succeed the probe. We can
1102                  * unregister later again, when the probe is through.
1103                  */
1104                 cdev->private->sch = sch;
1105                 PREPARE_WORK(&cdev->private->kick_work,
1106                              ccw_device_move_to_sch);
1107                 queue_work(slow_path_wq, &cdev->private->kick_work);
1108                 return 0;
1109         }
1110         cdev = io_subchannel_create_ccwdev(sch);
1111         if (IS_ERR(cdev))
1112                 return PTR_ERR(cdev);
1113
1114         rc = io_subchannel_recog(cdev, sch);
1115         if (rc) {
1116                 spin_lock_irqsave(sch->lock, flags);
1117                 sch->dev.driver_data = NULL;
1118                 spin_unlock_irqrestore(sch->lock, flags);
1119                 if (cdev->dev.release)
1120                         cdev->dev.release(&cdev->dev);
1121         }
1122
1123         return rc;
1124 }
1125
1126 static int
1127 io_subchannel_remove (struct subchannel *sch)
1128 {
1129         struct ccw_device *cdev;
1130         unsigned long flags;
1131
1132         if (!sch->dev.driver_data)
1133                 return 0;
1134         cdev = sch->dev.driver_data;
1135         /* Set ccw device to not operational and drop reference. */
1136         spin_lock_irqsave(cdev->ccwlock, flags);
1137         sch->dev.driver_data = NULL;
1138         cdev->private->state = DEV_STATE_NOT_OPER;
1139         spin_unlock_irqrestore(cdev->ccwlock, flags);
1140         /*
1141          * Put unregistration on workqueue to avoid livelocks on the css bus
1142          * semaphore.
1143          */
1144         if (get_device(&cdev->dev)) {
1145                 PREPARE_WORK(&cdev->private->kick_work,
1146                              ccw_device_unregister);
1147                 queue_work(ccw_device_work, &cdev->private->kick_work);
1148         }
1149         return 0;
1150 }
1151
1152 static int
1153 io_subchannel_notify(struct device *dev, int event)
1154 {
1155         struct ccw_device *cdev;
1156
1157         cdev = dev->driver_data;
1158         if (!cdev)
1159                 return 0;
1160         if (!cdev->drv)
1161                 return 0;
1162         if (!cdev->online)
1163                 return 0;
1164         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
1165 }
1166
1167 static void
1168 io_subchannel_verify(struct device *dev)
1169 {
1170         struct ccw_device *cdev;
1171
1172         cdev = dev->driver_data;
1173         if (cdev)
1174                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1175 }
1176
1177 static void
1178 io_subchannel_ioterm(struct device *dev)
1179 {
1180         struct ccw_device *cdev;
1181
1182         cdev = dev->driver_data;
1183         if (!cdev)
1184                 return;
1185         /* Internal I/O will be retried by the interrupt handler. */
1186         if (cdev->private->flags.intretry)
1187                 return;
1188         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1189         if (cdev->handler)
1190                 cdev->handler(cdev, cdev->private->intparm,
1191                               ERR_PTR(-EIO));
1192 }
1193
1194 static void
1195 io_subchannel_shutdown(struct subchannel *sch)
1196 {
1197         struct ccw_device *cdev;
1198         int ret;
1199
1200         cdev = sch->dev.driver_data;
1201
1202         if (cio_is_console(sch->schid))
1203                 return;
1204         if (!sch->schib.pmcw.ena)
1205                 /* Nothing to do. */
1206                 return;
1207         ret = cio_disable_subchannel(sch);
1208         if (ret != -EBUSY)
1209                 /* Subchannel is disabled, we're done. */
1210                 return;
1211         cdev->private->state = DEV_STATE_QUIESCE;
1212         if (cdev->handler)
1213                 cdev->handler(cdev, cdev->private->intparm,
1214                               ERR_PTR(-EIO));
1215         ret = ccw_device_cancel_halt_clear(cdev);
1216         if (ret == -EBUSY) {
1217                 ccw_device_set_timeout(cdev, HZ/10);
1218                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1219         }
1220         cio_disable_subchannel(sch);
1221 }
1222
1223 #ifdef CONFIG_CCW_CONSOLE
1224 static struct ccw_device console_cdev;
1225 static struct ccw_device_private console_private;
1226 static int console_cdev_in_use;
1227
1228 static DEFINE_SPINLOCK(ccw_console_lock);
1229
1230 spinlock_t * cio_get_console_lock(void)
1231 {
1232         return &ccw_console_lock;
1233 }
1234
1235 static int
1236 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
1237 {
1238         int rc;
1239
1240         /* Initialize the ccw_device structure. */
1241         cdev->dev.parent= &sch->dev;
1242         rc = io_subchannel_recog(cdev, sch);
1243         if (rc)
1244                 return rc;
1245
1246         /* Now wait for the async. recognition to come to an end. */
1247         spin_lock_irq(cdev->ccwlock);
1248         while (!dev_fsm_final_state(cdev))
1249                 wait_cons_dev();
1250         rc = -EIO;
1251         if (cdev->private->state != DEV_STATE_OFFLINE)
1252                 goto out_unlock;
1253         ccw_device_online(cdev);
1254         while (!dev_fsm_final_state(cdev))
1255                 wait_cons_dev();
1256         if (cdev->private->state != DEV_STATE_ONLINE)
1257                 goto out_unlock;
1258         rc = 0;
1259 out_unlock:
1260         spin_unlock_irq(cdev->ccwlock);
1261         return 0;
1262 }
1263
1264 struct ccw_device *
1265 ccw_device_probe_console(void)
1266 {
1267         struct subchannel *sch;
1268         int ret;
1269
1270         if (xchg(&console_cdev_in_use, 1) != 0)
1271                 return ERR_PTR(-EBUSY);
1272         sch = cio_probe_console();
1273         if (IS_ERR(sch)) {
1274                 console_cdev_in_use = 0;
1275                 return (void *) sch;
1276         }
1277         memset(&console_cdev, 0, sizeof(struct ccw_device));
1278         memset(&console_private, 0, sizeof(struct ccw_device_private));
1279         console_cdev.private = &console_private;
1280         console_private.cdev = &console_cdev;
1281         ret = ccw_device_console_enable(&console_cdev, sch);
1282         if (ret) {
1283                 cio_release_console();
1284                 console_cdev_in_use = 0;
1285                 return ERR_PTR(ret);
1286         }
1287         console_cdev.online = 1;
1288         return &console_cdev;
1289 }
1290 #endif
1291
1292 /*
1293  * get ccw_device matching the busid, but only if owned by cdrv
1294  */
1295 static int
1296 __ccwdev_check_busid(struct device *dev, void *id)
1297 {
1298         char *bus_id;
1299
1300         bus_id = id;
1301
1302         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1303 }
1304
1305
1306 struct ccw_device *
1307 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1308 {
1309         struct device *dev;
1310         struct device_driver *drv;
1311
1312         drv = get_driver(&cdrv->driver);
1313         if (!drv)
1314                 return NULL;
1315
1316         dev = driver_find_device(drv, NULL, (void *)bus_id,
1317                                  __ccwdev_check_busid);
1318         put_driver(drv);
1319
1320         return dev ? to_ccwdev(dev) : NULL;
1321 }
1322
1323 /************************** device driver handling ************************/
1324
1325 /* This is the implementation of the ccw_driver class. The probe, remove
1326  * and release methods are initially very similar to the device_driver
1327  * implementations, with the difference that they have ccw_device
1328  * arguments.
1329  *
1330  * A ccw driver also contains the information that is needed for
1331  * device matching.
1332  */
1333 static int
1334 ccw_device_probe (struct device *dev)
1335 {
1336         struct ccw_device *cdev = to_ccwdev(dev);
1337         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1338         int ret;
1339
1340         cdev->drv = cdrv; /* to let the driver call _set_online */
1341
1342         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1343
1344         if (ret) {
1345                 cdev->drv = NULL;
1346                 return ret;
1347         }
1348
1349         return 0;
1350 }
1351
1352 static int
1353 ccw_device_remove (struct device *dev)
1354 {
1355         struct ccw_device *cdev = to_ccwdev(dev);
1356         struct ccw_driver *cdrv = cdev->drv;
1357         int ret;
1358
1359         pr_debug("removing device %s\n", cdev->dev.bus_id);
1360         if (cdrv->remove)
1361                 cdrv->remove(cdev);
1362         if (cdev->online) {
1363                 cdev->online = 0;
1364                 spin_lock_irq(cdev->ccwlock);
1365                 ret = ccw_device_offline(cdev);
1366                 spin_unlock_irq(cdev->ccwlock);
1367                 if (ret == 0)
1368                         wait_event(cdev->private->wait_q,
1369                                    dev_fsm_final_state(cdev));
1370                 else
1371                         //FIXME: we can't fail!
1372                         pr_debug("ccw_device_offline returned %d, device %s\n",
1373                                  ret, cdev->dev.bus_id);
1374         }
1375         ccw_device_set_timeout(cdev, 0);
1376         cdev->drv = NULL;
1377         return 0;
1378 }
1379
1380 struct bus_type ccw_bus_type = {
1381         .name   = "ccw",
1382         .match  = ccw_bus_match,
1383         .uevent = ccw_uevent,
1384         .probe  = ccw_device_probe,
1385         .remove = ccw_device_remove,
1386 };
1387
1388 int
1389 ccw_driver_register (struct ccw_driver *cdriver)
1390 {
1391         struct device_driver *drv = &cdriver->driver;
1392
1393         drv->bus = &ccw_bus_type;
1394         drv->name = cdriver->name;
1395
1396         return driver_register(drv);
1397 }
1398
1399 void
1400 ccw_driver_unregister (struct ccw_driver *cdriver)
1401 {
1402         driver_unregister(&cdriver->driver);
1403 }
1404
1405 /* Helper func for qdio. */
1406 struct subchannel_id
1407 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1408 {
1409         struct subchannel *sch;
1410
1411         sch = to_subchannel(cdev->dev.parent);
1412         return sch->schid;
1413 }
1414
1415 MODULE_LICENSE("GPL");
1416 EXPORT_SYMBOL(ccw_device_set_online);
1417 EXPORT_SYMBOL(ccw_device_set_offline);
1418 EXPORT_SYMBOL(ccw_driver_register);
1419 EXPORT_SYMBOL(ccw_driver_unregister);
1420 EXPORT_SYMBOL(get_ccwdev_by_busid);
1421 EXPORT_SYMBOL(ccw_bus_type);
1422 EXPORT_SYMBOL(ccw_device_work);
1423 EXPORT_SYMBOL(ccw_device_notify_work);
1424 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);