drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *
   5  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
   6  *                       IBM Corporation
   7  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   8  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   9  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
  10  */
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/errno.h>
  15 #include <linux/err.h>
  16 #include <linux/slab.h>
  17 #include <linux/list.h>
  18 #include <linux/device.h>
  19 #include <linux/workqueue.h>
  20
  21 #include <asm/ccwdev.h>
  22 #include <asm/cio.h>
  23 #include <asm/param.h>          /* HZ */
  24
  25 #include "cio.h"
  26 #include "cio_debug.h"
  27 #include "css.h"
  28 #include "device.h"
  29 #include "ioasm.h"
  30
  31 /******************* bus type handling ***********************/
  32
  33 /* The Linux driver model distinguishes between a bus type and
  34  * the bus itself. Of course we only have one channel
  35  * subsystem driver and one channel system per machine, but
  36  * we still use the abstraction. T.R. says it's a good idea. */
  37 static int
  38 ccw_bus_match (struct device * dev, struct device_driver * drv)
  39 {
  40         struct ccw_device *cdev = to_ccwdev(dev);
  41         struct ccw_driver *cdrv = to_ccwdrv(drv);
  42         const struct ccw_device_id *ids = cdrv->ids, *found;
  43
  44         if (!ids)
  45                 return 0;
  46
  47         found = ccw_device_id_match(ids, &cdev->id);
  48         if (!found)
  49                 return 0;
  50
  51         cdev->id.driver_info = found->driver_info;
  52
  53         return 1;
  54 }
  55
  56 /* Store modalias string delimited by prefix/suffix string into buffer with
  57  * specified size. Return length of resulting string (excluding trailing '\0')
  58  * even if string doesn't fit buffer (snprintf semantics). */
  59 static int snprint_alias(char *buf, size_t size,
  60                          struct ccw_device_id *id, const char *suffix)
  61 {
  62         int len;
  63
  64         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  65         if (len > size)
  66                 return len;
  67         buf += len;
  68         size -= len;
  69
  70         if (id->dev_type != 0)
  71                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  72                                 id->dev_model, suffix);
  73         else
  74                 len += snprintf(buf, size, "dtdm%s", suffix);
  75
  76         return len;
  77 }
  78
  79 /* Set up environment variables for ccw device uevent. Return 0 on success,
  80  * non-zero otherwise. */
  81 static int ccw_uevent(struct device *dev, char **envp, int num_envp,
  82                       char *buffer, int buffer_size)
  83 {
  84         struct ccw_device *cdev = to_ccwdev(dev);
  85         struct ccw_device_id *id = &(cdev->id);
  86         int i = 0;
  87         int len = 0;
  88         int ret;
  89         char modalias_buf[30];
  90
  91         /* CU_TYPE= */
  92         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
  93                              "CU_TYPE=%04X", id->cu_type);
  94         if (ret)
  95                 return ret;
  96
  97         /* CU_MODEL= */
  98         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
  99                              "CU_MODEL=%02X", id->cu_model);
 100         if (ret)
 101                 return ret;
 102
 103         /* The next two can be zero, that's ok for us */
 104         /* DEV_TYPE= */
 105         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
 106                              "DEV_TYPE=%04X", id->dev_type);
 107         if (ret)
 108                 return ret;
 109
 110         /* DEV_MODEL= */
 111         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
 112                              "DEV_MODEL=%02X", id->dev_model);
 113         if (ret)
 114                 return ret;
 115
 116         /* MODALIAS=  */
 117         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 118         ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
 119                              "MODALIAS=%s", modalias_buf);
 120         if (ret)
 121                 return ret;
 122         envp[i] = NULL;
 123         return 0;
 124 }
 125
 126 struct bus_type ccw_bus_type;
 127
 128 static int io_subchannel_probe (struct subchannel *);
 129 static int io_subchannel_remove (struct subchannel *);
 130 static int io_subchannel_notify(struct device *, int);
 131 static void io_subchannel_verify(struct device *);
 132 static void io_subchannel_ioterm(struct device *);
 133 static void io_subchannel_shutdown(struct subchannel *);
 134
 135 static struct css_driver io_subchannel_driver = {
 136         .subchannel_type = SUBCHANNEL_TYPE_IO,
 137         .drv = {
 138                 .name = "io_subchannel",
 139                 .bus  = &css_bus_type,
 140         },
 141         .irq = io_subchannel_irq,
 142         .notify = io_subchannel_notify,
 143         .verify = io_subchannel_verify,
 144         .termination = io_subchannel_ioterm,
 145         .probe = io_subchannel_probe,
 146         .remove = io_subchannel_remove,
 147         .shutdown = io_subchannel_shutdown,
 148 };
 149
 150 struct workqueue_struct *ccw_device_work;
 151 struct workqueue_struct *ccw_device_notify_work;
 152 wait_queue_head_t ccw_device_init_wq;
 153 atomic_t ccw_device_init_count;
 154
 155 static int __init
 156 init_ccw_bus_type (void)
 157 {
 158         int ret;
 159
 160         init_waitqueue_head(&ccw_device_init_wq);
 161         atomic_set(&ccw_device_init_count, 0);
 162
 163         ccw_device_work = create_singlethread_workqueue("cio");
 164         if (!ccw_device_work)
 165                 return -ENOMEM; /* FIXME: better errno ? */
 166         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
 167         if (!ccw_device_notify_work) {
 168                 ret = -ENOMEM; /* FIXME: better errno ? */
 169                 goto out_err;
 170         }
 171         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 172         if (!slow_path_wq) {
 173                 ret = -ENOMEM; /* FIXME: better errno ? */
 174                 goto out_err;
 175         }
 176         if ((ret = bus_register (&ccw_bus_type)))
 177                 goto out_err;
 178
 179         if ((ret = driver_register(&io_subchannel_driver.drv)))
 180                 goto out_err;
 181
 182         wait_event(ccw_device_init_wq,
 183                    atomic_read(&ccw_device_init_count) == 0);
 184         flush_workqueue(ccw_device_work);
 185         return 0;
 186 out_err:
 187         if (ccw_device_work)
 188                 destroy_workqueue(ccw_device_work);
 189         if (ccw_device_notify_work)
 190                 destroy_workqueue(ccw_device_notify_work);
 191         if (slow_path_wq)
 192                 destroy_workqueue(slow_path_wq);
 193         return ret;
 194 }
 195
 196 static void __exit
 197 cleanup_ccw_bus_type (void)
 198 {
 199         driver_unregister(&io_subchannel_driver.drv);
 200         bus_unregister(&ccw_bus_type);
 201         destroy_workqueue(ccw_device_notify_work);
 202         destroy_workqueue(ccw_device_work);
 203 }
 204
 205 subsys_initcall(init_ccw_bus_type);
 206 module_exit(cleanup_ccw_bus_type);
 207
 208 /************************ device handling **************************/
 209
 210 /*
 211  * A ccw_device has some interfaces in sysfs in addition to the
 212  * standard ones.
 213  * The following entries are designed to export the information which
 214  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 215  * are obvious, so they don't have an entry :)
 216  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 217  */
 218 static ssize_t
 219 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 220 {
 221         struct subchannel *sch = to_subchannel(dev);
 222         struct chsc_ssd_info *ssd = &sch->ssd_info;
 223         ssize_t ret = 0;
 224         int chp;
 225         int mask;
 226
 227         for (chp = 0; chp < 8; chp++) {
 228                 mask = 0x80 >> chp;
 229                 if (ssd->path_mask & mask)
 230                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 231                 else
 232                         ret += sprintf(buf + ret, "00 ");
 233         }
 234         ret += sprintf (buf+ret, "\n");
 235         return min((ssize_t)PAGE_SIZE, ret);
 236 }
 237
 238 static ssize_t
 239 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 240 {
 241         struct subchannel *sch = to_subchannel(dev);
 242         struct pmcw *pmcw = &sch->schib.pmcw;
 243
 244         return sprintf (buf, "%02x %02x %02x\n",
 245                         pmcw->pim, pmcw->pam, pmcw->pom);
 246 }
 247
 248 static ssize_t
 249 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 250 {
 251         struct ccw_device *cdev = to_ccwdev(dev);
 252         struct ccw_device_id *id = &(cdev->id);
 253
 254         if (id->dev_type != 0)
 255                 return sprintf(buf, "%04x/%02x\n",
 256                                 id->dev_type, id->dev_model);
 257         else
 258                 return sprintf(buf, "n/a\n");
 259 }
 260
 261 static ssize_t
 262 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 263 {
 264         struct ccw_device *cdev = to_ccwdev(dev);
 265         struct ccw_device_id *id = &(cdev->id);
 266
 267         return sprintf(buf, "%04x/%02x\n",
 268                        id->cu_type, id->cu_model);
 269 }
 270
 271 static ssize_t
 272 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 273 {
 274         struct ccw_device *cdev = to_ccwdev(dev);
 275         struct ccw_device_id *id = &(cdev->id);
 276         int len;
 277
 278         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 279
 280         return len > PAGE_SIZE ? PAGE_SIZE : len;
 281 }
 282
 283 static ssize_t
 284 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 285 {
 286         struct ccw_device *cdev = to_ccwdev(dev);
 287
 288         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 289 }
 290
 291 int ccw_device_is_orphan(struct ccw_device *cdev)
 292 {
 293         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 294 }
 295
 296 static void ccw_device_unregister(struct ccw_device *cdev)
 297 {
 298         if (test_and_clear_bit(1, &cdev->private->registered))
 299                 device_del(&cdev->dev);
 300 }
 301
 302 static void ccw_device_remove_orphan_cb(struct device *dev)
 303 {
 304         struct ccw_device *cdev = to_ccwdev(dev);
 305
 306         ccw_device_unregister(cdev);
 307         put_device(&cdev->dev);
 308 }
 309
 310 static void ccw_device_remove_sch_cb(struct device *dev)
 311 {
 312         struct subchannel *sch;
 313
 314         sch = to_subchannel(dev);
 315         css_sch_device_unregister(sch);
 316         /* Reset intparm to zeroes. */
 317         sch->schib.pmcw.intparm = 0;
 318         cio_modify(sch);
 319         put_device(&sch->dev);
 320 }
 321
 322 static void
 323 ccw_device_remove_disconnected(struct ccw_device *cdev)
 324 {
 325         unsigned long flags;
 326         int rc;
 327
 328         /*
 329          * Forced offline in disconnected state means
 330          * 'throw away device'.
 331          */
 332         if (ccw_device_is_orphan(cdev)) {
 333                 /*
 334                  * Deregister ccw device.
 335                  * Unfortunately, we cannot do this directly from the
 336                  * attribute method.
 337                  */
 338                 spin_lock_irqsave(cdev->ccwlock, flags);
 339                 cdev->private->state = DEV_STATE_NOT_OPER;
 340                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 341                 rc = device_schedule_callback(&cdev->dev,
 342                                               ccw_device_remove_orphan_cb);
 343                 if (rc)
 344                         CIO_MSG_EVENT(2, "Couldn't unregister orphan "
 345                                       "0.%x.%04x\n",
 346                                       cdev->private->dev_id.ssid,
 347                                       cdev->private->dev_id.devno);
 348                 return;
 349         }
 350         /* Deregister subchannel, which will kill the ccw device. */
 351         rc = device_schedule_callback(cdev->dev.parent,
 352                                       ccw_device_remove_sch_cb);
 353         if (rc)
 354                 CIO_MSG_EVENT(2, "Couldn't unregister disconnected device "
 355                               "0.%x.%04x\n",
 356                               cdev->private->dev_id.ssid,
 357                               cdev->private->dev_id.devno);
 358 }
 359
 360 int
 361 ccw_device_set_offline(struct ccw_device *cdev)
 362 {
 363         int ret;
 364
 365         if (!cdev)
 366                 return -ENODEV;
 367         if (!cdev->online || !cdev->drv)
 368                 return -EINVAL;
 369
 370         if (cdev->drv->set_offline) {
 371                 ret = cdev->drv->set_offline(cdev);
 372                 if (ret != 0)
 373                         return ret;
 374         }
 375         cdev->online = 0;
 376         spin_lock_irq(cdev->ccwlock);
 377         ret = ccw_device_offline(cdev);
 378         if (ret == -ENODEV) {
 379                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 380                         cdev->private->state = DEV_STATE_OFFLINE;
 381                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 382                 }
 383                 spin_unlock_irq(cdev->ccwlock);
 384                 return ret;
 385         }
 386         spin_unlock_irq(cdev->ccwlock);
 387         if (ret == 0)
 388                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 389         else {
 390                 CIO_MSG_EVENT(2, "ccw_device_offline returned %d, "
 391                               "device 0.%x.%04x\n",
 392                               ret, cdev->private->dev_id.ssid,
 393                               cdev->private->dev_id.devno);
 394                 cdev->online = 1;
 395         }
 396         return ret;
 397 }
 398
 399 int
 400 ccw_device_set_online(struct ccw_device *cdev)
 401 {
 402         int ret;
 403
 404         if (!cdev)
 405                 return -ENODEV;
 406         if (cdev->online || !cdev->drv)
 407                 return -EINVAL;
 408
 409         spin_lock_irq(cdev->ccwlock);
 410         ret = ccw_device_online(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                 CIO_MSG_EVENT(2, "ccw_device_online returned %d, "
 416                               "device 0.%x.%04x\n",
 417                               ret, cdev->private->dev_id.ssid,
 418                               cdev->private->dev_id.devno);
 419                 return ret;
 420         }
 421         if (cdev->private->state != DEV_STATE_ONLINE)
 422                 return -ENODEV;
 423         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 424                 cdev->online = 1;
 425                 return 0;
 426         }
 427         spin_lock_irq(cdev->ccwlock);
 428         ret = ccw_device_offline(cdev);
 429         spin_unlock_irq(cdev->ccwlock);
 430         if (ret == 0)
 431                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 432         else
 433                 CIO_MSG_EVENT(2, "ccw_device_offline returned %d, "
 434                               "device 0.%x.%04x\n",
 435                               ret, cdev->private->dev_id.ssid,
 436                               cdev->private->dev_id.devno);
 437         return (ret == 0) ? -ENODEV : ret;
 438 }
 439
 440 static void online_store_handle_offline(struct ccw_device *cdev)
 441 {
 442         if (cdev->private->state == DEV_STATE_DISCONNECTED)
 443                 ccw_device_remove_disconnected(cdev);
 444         else if (cdev->drv && cdev->drv->set_offline)
 445                 ccw_device_set_offline(cdev);
 446 }
 447
 448 static int online_store_recog_and_online(struct ccw_device *cdev)
 449 {
 450         int ret;
 451
 452         /* Do device recognition, if needed. */
 453         if (cdev->id.cu_type == 0) {
 454                 ret = ccw_device_recognition(cdev);
 455                 if (ret) {
 456                         CIO_MSG_EVENT(0, "Couldn't start recognition "
 457                                       "for device 0.%x.%04x (ret=%d)\n",
 458                                       cdev->private->dev_id.ssid,
 459                                       cdev->private->dev_id.devno, ret);
 460                         return ret;
 461                 }
 462                 wait_event(cdev->private->wait_q,
 463                            cdev->private->flags.recog_done);
 464         }
 465         if (cdev->drv && cdev->drv->set_online)
 466                 ccw_device_set_online(cdev);
 467         return 0;
 468 }
 469 static void online_store_handle_online(struct ccw_device *cdev, int force)
 470 {
 471         int ret;
 472
 473         ret = online_store_recog_and_online(cdev);
 474         if (ret)
 475                 return;
 476         if (force && cdev->private->state == DEV_STATE_BOXED) {
 477                 ret = ccw_device_stlck(cdev);
 478                 if (ret) {
 479                         dev_warn(&cdev->dev,
 480                                  "ccw_device_stlck returned %d!\n", ret);
 481                         return;
 482                 }
 483                 if (cdev->id.cu_type == 0)
 484                         cdev->private->state = DEV_STATE_NOT_OPER;
 485                 online_store_recog_and_online(cdev);
 486         }
 487
 488 }
 489
 490 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 491                              const char *buf, size_t count)
 492 {
 493         struct ccw_device *cdev = to_ccwdev(dev);
 494         int i, force;
 495         char *tmp;
 496
 497         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 498                 return -EAGAIN;
 499
 500         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 501                 atomic_set(&cdev->private->onoff, 0);
 502                 return -EINVAL;
 503         }
 504         if (!strncmp(buf, "force\n", count)) {
 505                 force = 1;
 506                 i = 1;
 507         } else {
 508                 force = 0;
 509                 i = simple_strtoul(buf, &tmp, 16);
 510         }
 511
 512         switch (i) {
 513         case 0:
 514                 online_store_handle_offline(cdev);
 515                 break;
 516         case 1:
 517                 online_store_handle_online(cdev, force);
 518                 break;
 519         default:
 520                 count = -EINVAL;
 521         }
 522         if (cdev->drv)
 523                 module_put(cdev->drv->owner);
 524         atomic_set(&cdev->private->onoff, 0);
 525         return count;
 526 }
 527
 528 static ssize_t
 529 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 530 {
 531         struct ccw_device *cdev = to_ccwdev(dev);
 532         struct subchannel *sch;
 533
 534         if (ccw_device_is_orphan(cdev))
 535                 return sprintf(buf, "no device\n");
 536         switch (cdev->private->state) {
 537         case DEV_STATE_BOXED:
 538                 return sprintf(buf, "boxed\n");
 539         case DEV_STATE_DISCONNECTED:
 540         case DEV_STATE_DISCONNECTED_SENSE_ID:
 541         case DEV_STATE_NOT_OPER:
 542                 sch = to_subchannel(dev->parent);
 543                 if (!sch->lpm)
 544                         return sprintf(buf, "no path\n");
 545                 else
 546                         return sprintf(buf, "no device\n");
 547         default:
 548                 /* All other states considered fine. */
 549                 return sprintf(buf, "good\n");
 550         }
 551 }
 552
 553 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 554 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 555 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 556 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 557 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 558 static DEVICE_ATTR(online, 0644, online_show, online_store);
 559 extern struct device_attribute dev_attr_cmb_enable;
 560 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 561
 562 static struct attribute * subch_attrs[] = {
 563         &dev_attr_chpids.attr,
 564         &dev_attr_pimpampom.attr,
 565         NULL,
 566 };
 567
 568 static struct attribute_group subch_attr_group = {
 569         .attrs = subch_attrs,
 570 };
 571
 572 struct attribute_group *subch_attr_groups[] = {
 573         &subch_attr_group,
 574         NULL,
 575 };
 576
 577 static struct attribute * ccwdev_attrs[] = {
 578         &dev_attr_devtype.attr,
 579         &dev_attr_cutype.attr,
 580         &dev_attr_modalias.attr,
 581         &dev_attr_online.attr,
 582         &dev_attr_cmb_enable.attr,
 583         &dev_attr_availability.attr,
 584         NULL,
 585 };
 586
 587 static struct attribute_group ccwdev_attr_group = {
 588         .attrs = ccwdev_attrs,
 589 };
 590
 591 static struct attribute_group *ccwdev_attr_groups[] = {
 592         &ccwdev_attr_group,
 593         NULL,
 594 };
 595
 596 /* this is a simple abstraction for device_register that sets the
 597  * correct bus type and adds the bus specific files */
 598 static int ccw_device_register(struct ccw_device *cdev)
 599 {
 600         struct device *dev = &cdev->dev;
 601         int ret;
 602
 603         dev->bus = &ccw_bus_type;
 604
 605         if ((ret = device_add(dev)))
 606                 return ret;
 607
 608         set_bit(1, &cdev->private->registered);
 609         return ret;
 610 }
 611
 612 struct match_data {
 613         struct ccw_dev_id dev_id;
 614         struct ccw_device * sibling;
 615 };
 616
 617 static int
 618 match_devno(struct device * dev, void * data)
 619 {
 620         struct match_data * d = data;
 621         struct ccw_device * cdev;
 622
 623         cdev = to_ccwdev(dev);
 624         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 625             !ccw_device_is_orphan(cdev) &&
 626             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 627             (cdev != d->sibling))
 628                 return 1;
 629         return 0;
 630 }
 631
 632 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 633                                                      struct ccw_device *sibling)
 634 {
 635         struct device *dev;
 636         struct match_data data;
 637
 638         data.dev_id = *dev_id;
 639         data.sibling = sibling;
 640         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 641
 642         return dev ? to_ccwdev(dev) : NULL;
 643 }
 644
 645 static int match_orphan(struct device *dev, void *data)
 646 {
 647         struct ccw_dev_id *dev_id;
 648         struct ccw_device *cdev;
 649
 650         dev_id = data;
 651         cdev = to_ccwdev(dev);
 652         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 653 }
 654
 655 static struct ccw_device *
 656 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 657                               struct ccw_dev_id *dev_id)
 658 {
 659         struct device *dev;
 660
 661         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 662                                 match_orphan);
 663
 664         return dev ? to_ccwdev(dev) : NULL;
 665 }
 666
 667 static void
 668 ccw_device_add_changed(struct work_struct *work)
 669 {
 670         struct ccw_device_private *priv;
 671         struct ccw_device *cdev;
 672
 673         priv = container_of(work, struct ccw_device_private, kick_work);
 674         cdev = priv->cdev;
 675         if (device_add(&cdev->dev)) {
 676                 put_device(&cdev->dev);
 677                 return;
 678         }
 679         set_bit(1, &cdev->private->registered);
 680 }
 681
 682 void ccw_device_do_unreg_rereg(struct work_struct *work)
 683 {
 684         struct ccw_device_private *priv;
 685         struct ccw_device *cdev;
 686         struct subchannel *sch;
 687
 688         priv = container_of(work, struct ccw_device_private, kick_work);
 689         cdev = priv->cdev;
 690         sch = to_subchannel(cdev->dev.parent);
 691
 692         ccw_device_unregister(cdev);
 693         PREPARE_WORK(&cdev->private->kick_work,
 694                      ccw_device_add_changed);
 695         queue_work(ccw_device_work, &cdev->private->kick_work);
 696 }
 697
 698 static void
 699 ccw_device_release(struct device *dev)
 700 {
 701         struct ccw_device *cdev;
 702
 703         cdev = to_ccwdev(dev);
 704         kfree(cdev->private);
 705         kfree(cdev);
 706 }
 707
 708 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 709 {
 710         struct ccw_device *cdev;
 711
 712         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 713         if (cdev) {
 714                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 715                                         GFP_KERNEL | GFP_DMA);
 716                 if (cdev->private)
 717                         return cdev;
 718         }
 719         kfree(cdev);
 720         return ERR_PTR(-ENOMEM);
 721 }
 722
 723 static int io_subchannel_initialize_dev(struct subchannel *sch,
 724                                         struct ccw_device *cdev)
 725 {
 726         cdev->private->cdev = cdev;
 727         atomic_set(&cdev->private->onoff, 0);
 728         cdev->dev.parent = &sch->dev;
 729         cdev->dev.release = ccw_device_release;
 730         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
 731         cdev->dev.groups = ccwdev_attr_groups;
 732         /* Do first half of device_register. */
 733         device_initialize(&cdev->dev);
 734         if (!get_device(&sch->dev)) {
 735                 if (cdev->dev.release)
 736                         cdev->dev.release(&cdev->dev);
 737                 return -ENODEV;
 738         }
 739         return 0;
 740 }
 741
 742 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 743 {
 744         struct ccw_device *cdev;
 745         int ret;
 746
 747         cdev = io_subchannel_allocate_dev(sch);
 748         if (!IS_ERR(cdev)) {
 749                 ret = io_subchannel_initialize_dev(sch, cdev);
 750                 if (ret) {
 751                         kfree(cdev);
 752                         cdev = ERR_PTR(ret);
 753                 }
 754         }
 755         return cdev;
 756 }
 757
 758 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 759
 760 static void sch_attach_device(struct subchannel *sch,
 761                               struct ccw_device *cdev)
 762 {
 763         css_update_ssd_info(sch);
 764         spin_lock_irq(sch->lock);
 765         sch->dev.driver_data = cdev;
 766         cdev->private->schid = sch->schid;
 767         cdev->ccwlock = sch->lock;
 768         device_trigger_reprobe(sch);
 769         spin_unlock_irq(sch->lock);
 770 }
 771
 772 static void sch_attach_disconnected_device(struct subchannel *sch,
 773                                            struct ccw_device *cdev)
 774 {
 775         struct subchannel *other_sch;
 776         int ret;
 777
 778         other_sch = to_subchannel(get_device(cdev->dev.parent));
 779         ret = device_move(&cdev->dev, &sch->dev);
 780         if (ret) {
 781                 CIO_MSG_EVENT(2, "Moving disconnected device 0.%x.%04x failed "
 782                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 783                               cdev->private->dev_id.devno, ret);
 784                 put_device(&other_sch->dev);
 785                 return;
 786         }
 787         other_sch->dev.driver_data = NULL;
 788         /* No need to keep a subchannel without ccw device around. */
 789         css_sch_device_unregister(other_sch);
 790         put_device(&other_sch->dev);
 791         sch_attach_device(sch, cdev);
 792 }
 793
 794 static void sch_attach_orphaned_device(struct subchannel *sch,
 795                                        struct ccw_device *cdev)
 796 {
 797         int ret;
 798
 799         /* Try to move the ccw device to its new subchannel. */
 800         ret = device_move(&cdev->dev, &sch->dev);
 801         if (ret) {
 802                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 803                               "failed (ret=%d)!\n",
 804                               cdev->private->dev_id.ssid,
 805                               cdev->private->dev_id.devno, ret);
 806                 return;
 807         }
 808         sch_attach_device(sch, cdev);
 809 }
 810
 811 static void sch_create_and_recog_new_device(struct subchannel *sch)
 812 {
 813         struct ccw_device *cdev;
 814
 815         /* Need to allocate a new ccw device. */
 816         cdev = io_subchannel_create_ccwdev(sch);
 817         if (IS_ERR(cdev)) {
 818                 /* OK, we did everything we could... */
 819                 css_sch_device_unregister(sch);
 820                 return;
 821         }
 822         spin_lock_irq(sch->lock);
 823         sch->dev.driver_data = cdev;
 824         spin_unlock_irq(sch->lock);
 825         /* Start recognition for the new ccw device. */
 826         if (io_subchannel_recog(cdev, sch)) {
 827                 spin_lock_irq(sch->lock);
 828                 sch->dev.driver_data = NULL;
 829                 spin_unlock_irq(sch->lock);
 830                 if (cdev->dev.release)
 831                         cdev->dev.release(&cdev->dev);
 832                 css_sch_device_unregister(sch);
 833         }
 834 }
 835
 836
 837 void ccw_device_move_to_orphanage(struct work_struct *work)
 838 {
 839         struct ccw_device_private *priv;
 840         struct ccw_device *cdev;
 841         struct ccw_device *replacing_cdev;
 842         struct subchannel *sch;
 843         int ret;
 844         struct channel_subsystem *css;
 845         struct ccw_dev_id dev_id;
 846
 847         priv = container_of(work, struct ccw_device_private, kick_work);
 848         cdev = priv->cdev;
 849         sch = to_subchannel(cdev->dev.parent);
 850         css = to_css(sch->dev.parent);
 851         dev_id.devno = sch->schib.pmcw.dev;
 852         dev_id.ssid = sch->schid.ssid;
 853
 854         /*
 855          * Move the orphaned ccw device to the orphanage so the replacing
 856          * ccw device can take its place on the subchannel.
 857          */
 858         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
 859         if (ret) {
 860                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 861                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 862                               cdev->private->dev_id.devno, ret);
 863                 return;
 864         }
 865         cdev->ccwlock = css->pseudo_subchannel->lock;
 866         /*
 867          * Search for the replacing ccw device
 868          * - among the disconnected devices
 869          * - in the orphanage
 870          */
 871         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 872         if (replacing_cdev) {
 873                 sch_attach_disconnected_device(sch, replacing_cdev);
 874                 return;
 875         }
 876         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 877         if (replacing_cdev) {
 878                 sch_attach_orphaned_device(sch, replacing_cdev);
 879                 return;
 880         }
 881         sch_create_and_recog_new_device(sch);
 882 }
 883
 884 /*
 885  * Register recognized device.
 886  */
 887 static void
 888 io_subchannel_register(struct work_struct *work)
 889 {
 890         struct ccw_device_private *priv;
 891         struct ccw_device *cdev;
 892         struct subchannel *sch;
 893         int ret;
 894         unsigned long flags;
 895
 896         priv = container_of(work, struct ccw_device_private, kick_work);
 897         cdev = priv->cdev;
 898         sch = to_subchannel(cdev->dev.parent);
 899         css_update_ssd_info(sch);
 900         /*
 901          * io_subchannel_register() will also be called after device
 902          * recognition has been done for a boxed device (which will already
 903          * be registered). We need to reprobe since we may now have sense id
 904          * information.
 905          */
 906         if (klist_node_attached(&cdev->dev.knode_parent)) {
 907                 if (!cdev->drv) {
 908                         ret = device_reprobe(&cdev->dev);
 909                         if (ret)
 910                                 /* We can't do much here. */
 911                                 CIO_MSG_EVENT(2, "device_reprobe() returned"
 912                                               " %d for 0.%x.%04x\n", ret,
 913                                               cdev->private->dev_id.ssid,
 914                                               cdev->private->dev_id.devno);
 915                 }
 916                 goto out;
 917         }
 918         /*
 919          * Now we know this subchannel will stay, we can throw
 920          * our delayed uevent.
 921          */
 922         sch->dev.uevent_suppress = 0;
 923         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 924         /* make it known to the system */
 925         ret = ccw_device_register(cdev);
 926         if (ret) {
 927                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 928                               cdev->private->dev_id.ssid,
 929                               cdev->private->dev_id.devno, ret);
 930                 put_device(&cdev->dev);
 931                 spin_lock_irqsave(sch->lock, flags);
 932                 sch->dev.driver_data = NULL;
 933                 spin_unlock_irqrestore(sch->lock, flags);
 934                 kfree (cdev->private);
 935                 kfree (cdev);
 936                 put_device(&sch->dev);
 937                 if (atomic_dec_and_test(&ccw_device_init_count))
 938                         wake_up(&ccw_device_init_wq);
 939                 return;
 940         }
 941         put_device(&cdev->dev);
 942 out:
 943         cdev->private->flags.recog_done = 1;
 944         put_device(&sch->dev);
 945         wake_up(&cdev->private->wait_q);
 946         if (atomic_dec_and_test(&ccw_device_init_count))
 947                 wake_up(&ccw_device_init_wq);
 948 }
 949
 950 void
 951 ccw_device_call_sch_unregister(struct work_struct *work)
 952 {
 953         struct ccw_device_private *priv;
 954         struct ccw_device *cdev;
 955         struct subchannel *sch;
 956
 957         priv = container_of(work, struct ccw_device_private, kick_work);
 958         cdev = priv->cdev;
 959         sch = to_subchannel(cdev->dev.parent);
 960         css_sch_device_unregister(sch);
 961         /* Reset intparm to zeroes. */
 962         sch->schib.pmcw.intparm = 0;
 963         cio_modify(sch);
 964         put_device(&cdev->dev);
 965         put_device(&sch->dev);
 966 }
 967
 968 /*
 969  * subchannel recognition done. Called from the state machine.
 970  */
 971 void
 972 io_subchannel_recog_done(struct ccw_device *cdev)
 973 {
 974         struct subchannel *sch;
 975
 976         if (css_init_done == 0) {
 977                 cdev->private->flags.recog_done = 1;
 978                 return;
 979         }
 980         switch (cdev->private->state) {
 981         case DEV_STATE_NOT_OPER:
 982                 cdev->private->flags.recog_done = 1;
 983                 /* Remove device found not operational. */
 984                 if (!get_device(&cdev->dev))
 985                         break;
 986                 sch = to_subchannel(cdev->dev.parent);
 987                 PREPARE_WORK(&cdev->private->kick_work,
 988                              ccw_device_call_sch_unregister);
 989                 queue_work(slow_path_wq, &cdev->private->kick_work);
 990                 if (atomic_dec_and_test(&ccw_device_init_count))
 991                         wake_up(&ccw_device_init_wq);
 992                 break;
 993         case DEV_STATE_BOXED:
 994                 /* Device did not respond in time. */
 995         case DEV_STATE_OFFLINE:
 996                 /*
 997                  * We can't register the device in interrupt context so
 998                  * we schedule a work item.
 999                  */
1000                 if (!get_device(&cdev->dev))
1001                         break;
1002                 PREPARE_WORK(&cdev->private->kick_work,
1003                              io_subchannel_register);
1004                 queue_work(slow_path_wq, &cdev->private->kick_work);
1005                 break;
1006         }
1007 }
1008
1009 static int
1010 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
1011 {
1012         int rc;
1013         struct ccw_device_private *priv;
1014
1015         sch->dev.driver_data = cdev;
1016         sch->driver = &io_subchannel_driver;
1017         cdev->ccwlock = sch->lock;
1018
1019         /* Init private data. */
1020         priv = cdev->private;
1021         priv->dev_id.devno = sch->schib.pmcw.dev;
1022         priv->dev_id.ssid = sch->schid.ssid;
1023         priv->schid = sch->schid;
1024         priv->state = DEV_STATE_NOT_OPER;
1025         INIT_LIST_HEAD(&priv->cmb_list);
1026         init_waitqueue_head(&priv->wait_q);
1027         init_timer(&priv->timer);
1028
1029         /* Set an initial name for the device. */
1030         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
1031                   sch->schid.ssid, sch->schib.pmcw.dev);
1032
1033         /* Increase counter of devices currently in recognition. */
1034         atomic_inc(&ccw_device_init_count);
1035
1036         /* Start async. device sensing. */
1037         spin_lock_irq(sch->lock);
1038         rc = ccw_device_recognition(cdev);
1039         spin_unlock_irq(sch->lock);
1040         if (rc) {
1041                 if (atomic_dec_and_test(&ccw_device_init_count))
1042                         wake_up(&ccw_device_init_wq);
1043         }
1044         return rc;
1045 }
1046
1047 static void ccw_device_move_to_sch(struct work_struct *work)
1048 {
1049         struct ccw_device_private *priv;
1050         int rc;
1051         struct subchannel *sch;
1052         struct ccw_device *cdev;
1053         struct subchannel *former_parent;
1054
1055         priv = container_of(work, struct ccw_device_private, kick_work);
1056         sch = priv->sch;
1057         cdev = priv->cdev;
1058         former_parent = ccw_device_is_orphan(cdev) ?
1059                 NULL : to_subchannel(get_device(cdev->dev.parent));
1060         mutex_lock(&sch->reg_mutex);
1061         /* Try to move the ccw device to its new subchannel. */
1062         rc = device_move(&cdev->dev, &sch->dev);
1063         mutex_unlock(&sch->reg_mutex);
1064         if (rc) {
1065                 CIO_MSG_EVENT(2, "Moving device 0.%x.%04x to subchannel "
1066                               "0.%x.%04x failed (ret=%d)!\n",
1067                               cdev->private->dev_id.ssid,
1068                               cdev->private->dev_id.devno, sch->schid.ssid,
1069                               sch->schid.sch_no, rc);
1070                 css_sch_device_unregister(sch);
1071                 goto out;
1072         }
1073         if (former_parent) {
1074                 spin_lock_irq(former_parent->lock);
1075                 former_parent->dev.driver_data = NULL;
1076                 spin_unlock_irq(former_parent->lock);
1077                 css_sch_device_unregister(former_parent);
1078                 /* Reset intparm to zeroes. */
1079                 former_parent->schib.pmcw.intparm = 0;
1080                 cio_modify(former_parent);
1081         }
1082         sch_attach_device(sch, cdev);
1083 out:
1084         if (former_parent)
1085                 put_device(&former_parent->dev);
1086         put_device(&cdev->dev);
1087 }
1088
1089 static int
1090 io_subchannel_probe (struct subchannel *sch)
1091 {
1092         struct ccw_device *cdev;
1093         int rc;
1094         unsigned long flags;
1095         struct ccw_dev_id dev_id;
1096
1097         if (sch->dev.driver_data) {
1098                 /*
1099                  * This subchannel already has an associated ccw_device.
1100                  * Register it and exit. This happens for all early
1101                  * device, e.g. the console.
1102                  */
1103                 cdev = sch->dev.driver_data;
1104                 device_initialize(&cdev->dev);
1105                 ccw_device_register(cdev);
1106                 /*
1107                  * Check if the device is already online. If it is
1108                  * the reference count needs to be corrected
1109                  * (see ccw_device_online and css_init_done for the
1110                  * ugly details).
1111                  */
1112                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1113                     cdev->private->state != DEV_STATE_OFFLINE &&
1114                     cdev->private->state != DEV_STATE_BOXED)
1115                         get_device(&cdev->dev);
1116                 return 0;
1117         }
1118         /*
1119          * First check if a fitting device may be found amongst the
1120          * disconnected devices or in the orphanage.
1121          */
1122         dev_id.devno = sch->schib.pmcw.dev;
1123         dev_id.ssid = sch->schid.ssid;
1124         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1125         if (!cdev)
1126                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1127                                                      &dev_id);
1128         if (cdev) {
1129                 /*
1130                  * Schedule moving the device until when we have a registered
1131                  * subchannel to move to and succeed the probe. We can
1132                  * unregister later again, when the probe is through.
1133                  */
1134                 cdev->private->sch = sch;
1135                 PREPARE_WORK(&cdev->private->kick_work,
1136                              ccw_device_move_to_sch);
1137                 queue_work(slow_path_wq, &cdev->private->kick_work);
1138                 return 0;
1139         }
1140         cdev = io_subchannel_create_ccwdev(sch);
1141         if (IS_ERR(cdev))
1142                 return PTR_ERR(cdev);
1143
1144         rc = io_subchannel_recog(cdev, sch);
1145         if (rc) {
1146                 spin_lock_irqsave(sch->lock, flags);
1147                 sch->dev.driver_data = NULL;
1148                 spin_unlock_irqrestore(sch->lock, flags);
1149                 if (cdev->dev.release)
1150                         cdev->dev.release(&cdev->dev);
1151         }
1152
1153         return rc;
1154 }
1155
1156 static int
1157 io_subchannel_remove (struct subchannel *sch)
1158 {
1159         struct ccw_device *cdev;
1160         unsigned long flags;
1161
1162         if (!sch->dev.driver_data)
1163                 return 0;
1164         cdev = sch->dev.driver_data;
1165         /* Set ccw device to not operational and drop reference. */
1166         spin_lock_irqsave(cdev->ccwlock, flags);
1167         sch->dev.driver_data = NULL;
1168         cdev->private->state = DEV_STATE_NOT_OPER;
1169         spin_unlock_irqrestore(cdev->ccwlock, flags);
1170         ccw_device_unregister(cdev);
1171         put_device(&cdev->dev);
1172         return 0;
1173 }
1174
1175 static int
1176 io_subchannel_notify(struct device *dev, int event)
1177 {
1178         struct ccw_device *cdev;
1179
1180         cdev = dev->driver_data;
1181         if (!cdev)
1182                 return 0;
1183         if (!cdev->drv)
1184                 return 0;
1185         if (!cdev->online)
1186                 return 0;
1187         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
1188 }
1189
1190 static void
1191 io_subchannel_verify(struct device *dev)
1192 {
1193         struct ccw_device *cdev;
1194
1195         cdev = dev->driver_data;
1196         if (cdev)
1197                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1198 }
1199
1200 static void
1201 io_subchannel_ioterm(struct device *dev)
1202 {
1203         struct ccw_device *cdev;
1204
1205         cdev = dev->driver_data;
1206         if (!cdev)
1207                 return;
1208         /* Internal I/O will be retried by the interrupt handler. */
1209         if (cdev->private->flags.intretry)
1210                 return;
1211         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1212         if (cdev->handler)
1213                 cdev->handler(cdev, cdev->private->intparm,
1214                               ERR_PTR(-EIO));
1215 }
1216
1217 static void
1218 io_subchannel_shutdown(struct subchannel *sch)
1219 {
1220         struct ccw_device *cdev;
1221         int ret;
1222
1223         cdev = sch->dev.driver_data;
1224
1225         if (cio_is_console(sch->schid))
1226                 return;
1227         if (!sch->schib.pmcw.ena)
1228                 /* Nothing to do. */
1229                 return;
1230         ret = cio_disable_subchannel(sch);
1231         if (ret != -EBUSY)
1232                 /* Subchannel is disabled, we're done. */
1233                 return;
1234         cdev->private->state = DEV_STATE_QUIESCE;
1235         if (cdev->handler)
1236                 cdev->handler(cdev, cdev->private->intparm,
1237                               ERR_PTR(-EIO));
1238         ret = ccw_device_cancel_halt_clear(cdev);
1239         if (ret == -EBUSY) {
1240                 ccw_device_set_timeout(cdev, HZ/10);
1241                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1242         }
1243         cio_disable_subchannel(sch);
1244 }
1245
1246 #ifdef CONFIG_CCW_CONSOLE
1247 static struct ccw_device console_cdev;
1248 static struct ccw_device_private console_private;
1249 static int console_cdev_in_use;
1250
1251 static DEFINE_SPINLOCK(ccw_console_lock);
1252
1253 spinlock_t * cio_get_console_lock(void)
1254 {
1255         return &ccw_console_lock;
1256 }
1257
1258 static int
1259 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
1260 {
1261         int rc;
1262
1263         /* Initialize the ccw_device structure. */
1264         cdev->dev.parent= &sch->dev;
1265         rc = io_subchannel_recog(cdev, sch);
1266         if (rc)
1267                 return rc;
1268
1269         /* Now wait for the async. recognition to come to an end. */
1270         spin_lock_irq(cdev->ccwlock);
1271         while (!dev_fsm_final_state(cdev))
1272                 wait_cons_dev();
1273         rc = -EIO;
1274         if (cdev->private->state != DEV_STATE_OFFLINE)
1275                 goto out_unlock;
1276         ccw_device_online(cdev);
1277         while (!dev_fsm_final_state(cdev))
1278                 wait_cons_dev();
1279         if (cdev->private->state != DEV_STATE_ONLINE)
1280                 goto out_unlock;
1281         rc = 0;
1282 out_unlock:
1283         spin_unlock_irq(cdev->ccwlock);
1284         return 0;
1285 }
1286
1287 struct ccw_device *
1288 ccw_device_probe_console(void)
1289 {
1290         struct subchannel *sch;
1291         int ret;
1292
1293         if (xchg(&console_cdev_in_use, 1) != 0)
1294                 return ERR_PTR(-EBUSY);
1295         sch = cio_probe_console();
1296         if (IS_ERR(sch)) {
1297                 console_cdev_in_use = 0;
1298                 return (void *) sch;
1299         }
1300         memset(&console_cdev, 0, sizeof(struct ccw_device));
1301         memset(&console_private, 0, sizeof(struct ccw_device_private));
1302         console_cdev.private = &console_private;
1303         console_private.cdev = &console_cdev;
1304         ret = ccw_device_console_enable(&console_cdev, sch);
1305         if (ret) {
1306                 cio_release_console();
1307                 console_cdev_in_use = 0;
1308                 return ERR_PTR(ret);
1309         }
1310         console_cdev.online = 1;
1311         return &console_cdev;
1312 }
1313 #endif
1314
1315 /*
1316  * get ccw_device matching the busid, but only if owned by cdrv
1317  */
1318 static int
1319 __ccwdev_check_busid(struct device *dev, void *id)
1320 {
1321         char *bus_id;
1322
1323         bus_id = id;
1324
1325         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1326 }
1327
1328
1329 struct ccw_device *
1330 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1331 {
1332         struct device *dev;
1333         struct device_driver *drv;
1334
1335         drv = get_driver(&cdrv->driver);
1336         if (!drv)
1337                 return NULL;
1338
1339         dev = driver_find_device(drv, NULL, (void *)bus_id,
1340                                  __ccwdev_check_busid);
1341         put_driver(drv);
1342
1343         return dev ? to_ccwdev(dev) : NULL;
1344 }
1345
1346 /************************** device driver handling ************************/
1347
1348 /* This is the implementation of the ccw_driver class. The probe, remove
1349  * and release methods are initially very similar to the device_driver
1350  * implementations, with the difference that they have ccw_device
1351  * arguments.
1352  *
1353  * A ccw driver also contains the information that is needed for
1354  * device matching.
1355  */
1356 static int
1357 ccw_device_probe (struct device *dev)
1358 {
1359         struct ccw_device *cdev = to_ccwdev(dev);
1360         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1361         int ret;
1362
1363         cdev->drv = cdrv; /* to let the driver call _set_online */
1364
1365         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1366
1367         if (ret) {
1368                 cdev->drv = NULL;
1369                 return ret;
1370         }
1371
1372         return 0;
1373 }
1374
1375 static int
1376 ccw_device_remove (struct device *dev)
1377 {
1378         struct ccw_device *cdev = to_ccwdev(dev);
1379         struct ccw_driver *cdrv = cdev->drv;
1380         int ret;
1381
1382         if (cdrv->remove)
1383                 cdrv->remove(cdev);
1384         if (cdev->online) {
1385                 cdev->online = 0;
1386                 spin_lock_irq(cdev->ccwlock);
1387                 ret = ccw_device_offline(cdev);
1388                 spin_unlock_irq(cdev->ccwlock);
1389                 if (ret == 0)
1390                         wait_event(cdev->private->wait_q,
1391                                    dev_fsm_final_state(cdev));
1392                 else
1393                         //FIXME: we can't fail!
1394                         CIO_MSG_EVENT(2, "ccw_device_offline returned %d, "
1395                                       "device 0.%x.%04x\n",
1396                                       ret, cdev->private->dev_id.ssid,
1397                                       cdev->private->dev_id.devno);
1398         }
1399         ccw_device_set_timeout(cdev, 0);
1400         cdev->drv = NULL;
1401         return 0;
1402 }
1403
1404 struct bus_type ccw_bus_type = {
1405         .name   = "ccw",
1406         .match  = ccw_bus_match,
1407         .uevent = ccw_uevent,
1408         .probe  = ccw_device_probe,
1409         .remove = ccw_device_remove,
1410 };
1411
1412 int
1413 ccw_driver_register (struct ccw_driver *cdriver)
1414 {
1415         struct device_driver *drv = &cdriver->driver;
1416
1417         drv->bus = &ccw_bus_type;
1418         drv->name = cdriver->name;
1419
1420         return driver_register(drv);
1421 }
1422
1423 void
1424 ccw_driver_unregister (struct ccw_driver *cdriver)
1425 {
1426         driver_unregister(&cdriver->driver);
1427 }
1428
1429 /* Helper func for qdio. */
1430 struct subchannel_id
1431 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1432 {
1433         struct subchannel *sch;
1434
1435         sch = to_subchannel(cdev->dev.parent);
1436         return sch->schid;
1437 }
1438
1439 MODULE_LICENSE("GPL");
1440 EXPORT_SYMBOL(ccw_device_set_online);
1441 EXPORT_SYMBOL(ccw_device_set_offline);
1442 EXPORT_SYMBOL(ccw_driver_register);
1443 EXPORT_SYMBOL(ccw_driver_unregister);
1444 EXPORT_SYMBOL(get_ccwdev_by_busid);
1445 EXPORT_SYMBOL(ccw_bus_type);
1446 EXPORT_SYMBOL(ccw_device_work);
1447 EXPORT_SYMBOL(ccw_device_notify_work);
1448 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);